Indian Patents. 256674:ACRYLIC THERMOREGULATORY FIBER AND A METHOD OF MAKING THEREOF

Title of Invention	ACRYLIC THERMOREGULATORY FIBER AND A METHOD OF MAKING THEREOF
Abstract	An acrylic fiber having thermoregulatory activity and a method of making thereof is disclosed. Micro-reservoirs are formed in the fibers in which the thermoregulatory constituents are embedded.

Full Text	FORM - 2 THE PATENTS ACT, 1970 (39 OF 1970) AND THE PATENTS RULES, 2003 COMPLETE SPECIFICATION (See section 10; rule 13) ACRYLIC THERMOREGULATORY FIBER AND A METHOD OF . MAKING THEREOF ADITYA BIRLA SCIENCE & TECHNOLOGY CO. LTD. an Indian Company of Aditya Birla Center, 2nd floor, C Wing, S. K. Ahire Marg, Mumbai 400 025, Maharashtra, India THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED. Field of the invention The present invention relates to textile fibers. Background of the invention Introduction The term "fiber" or "textile fiber" means a substance which is capable of being spun into a yarn or made into a fabric by bonding or by interlacing in a variety of methods including weaving, knitting, braiding, felting, twisting, or webbing, and which is the basic structural element of textile products. Fibers are classified on the basis of their length such as short fibers or staple fiber and long fibers or filament fiber. The fibers can also be classified on the basis of their origin such as natural fibers and man-made fibers. The term natural fibers means any fiber that exists as such in the natural state e.g. vegetable fibers or wood fibers. The other type of fibers is obtained from chemical substances. These are called man made fibers. They are, polyester, nylon, acrylic (cashmilon) and the like. For centuries, mankind has relied upon various plants and animals to provide raw materials for fabrics and clothing. In recent times, the industrialization and scientific advancement has provided several improved materials having far superior properties, particularly suitable for clothing. Acrylic fibers are synthetic fibers containing at least 85% of acrylonitrile monomer. The acrylic fibers are prepared from a polymer Polyacrylonitrile which is obtained by free radical polymerisation with an average molecular weight of 100,000. Typical properties of acrylic fibers include resistance to moths, oils, and 2 chemicals. Furthermore, they are also resistant to deterioration from sunlight exposure. The process steps involved in the preparation of Acrylic fibers are as follows: The Polyacrylonitrile is dissolved in solvents like N,N-dimethylformamide or aqueous sodium thiocyanate. Then it is metered through a multi-hole spinnerette and the resultant filaments are coagulated in an aqueous solution of the same solvent. The resultant filaments are washed, stretched, dried and crimped to obtain final acrylic fibers. Acrylic fibers are typically produced in a range of deniers from 1 to 15. Acrylic is lightweight, soft, and warm, with a wool-like feel. It dyes very well and has excellent colorfastness. It is resilient, retains its shape, and resists shrinkage and wrinkles. Acrylic fibers are commonly used in sweaters, hand-knitting yarns, rugs, awnings, boat covers, and beanies; the fiber is also used as a precursor for carbon fiber. From the spun or filament yarn, fabric is formed by knitting or weaving operations. Knitted fabrics can be made by using hooked needles to interlock one or more sets of yarns through a set of loops. The loops may be either loosely or closely constructed, depending on the purpose of the fabric. Knitted fabrics can be used for hosiery, underwear, sweaters, slacks, suits, coats, rugs and other home furnishings. Knitting is performed using either weft or warp processes. Some typical preparations that are involved in the weaving operations are warping, slashing or sizing. Sizing agents are added to the yarn by solution or pad/dry techniques. Differences in raw materials, processing chemicals, fiber diameter, post treatments and blend ratios can be manipulated to produce a fiber having customized properties suitable for desired application. It is often desired that the 3 acrylic fabrics possess typical properties such as thermal stability, ability to retain perfumes, antibacterial properties and the like. These properties are essential in several industrial as well as household applications. There has been a considerable interest in developing such materials. In order to impart various desirable properties to the fabric as mentioned above to the fabric, several additives are added. Such additives include antimicrobial agents, deodorizing agents, antistatic agents, perfumes. Besides such specific additives, generic additives for improving overall quality of the fabric, such as sizing agents, additives for increasing yarn softness and pliability are also added. Prior Art WO2008030648 discloses a temperature regulating, polymer containing fabric and a suspension formulation used in preparation of such fibers. The suspension comprises a solvent and plurality of microcapsules containing phase-change material. The suspension is used for incorporating the microcapsules in the fabric. The microcapsules comprise a shell composed of acrylic acid and their derivatives and a core which is composed of a phase change material having a latent heat in a range between 80 J/g and 400 J/gm and a transition temperature in the range of 20°C-50°C. Earlier known processes of incorporating such additives, as reported in the above mentioned patents/applications, mainly involved conventional methods like spraying, encapsulating, solvent spinning the additives on the fabric. However, these methods suffer from several disadvantages which include non-uniform and improper adhesion of additives onto the fiber material, fading, waning and gradual washing out of the additives over a period of time and which further affects the feel and texture of the fabric. 4 There is thus felt a need for a process of incorporating additives to fabric which overcomes these shortcomings. Objects of the Invention It is an object of this invention to provide thermoregulatory acrylic products, wherein at least one thermoregulatory constituent is incorporated into the body of the fiber. Another object of this invention is to provide a process of incorporating thermoregulatory constituents into acrylic fibers which ensures uniform distribution of the thermoregulatory constituent throughout the fiber length. Yet another object of this invention is to provide thermoregulatory acrylic fibers wherein the thermoregulatory constituents are retained in the acrylic product over a prolonged period of time. Yet another object of this invention is to provide a process of incorporating thermoregulatory constituents to acrylic fibers which does not affect the feel and texture of the fabric. Still another object of this invention is to provide a process of incorporating thermoregulatory constituents to acrylic fibers such that inherent properties of the acrylic fibers such as fiber strength, linear density, tenacity, heat resistance, dyeability and drying properties are not altered. 5 Definitions: As used in the present specification, the following words and phrases are generally intended to have the meanings as set forth below, except to the extent that the context in which they are used indicates otherwise. "Phase-change agent" means a substance having the ability to releases or absorbs heat whenever it undergoes change in its physical state. Enthalpy means heat content or total heat, including both sensible and latent heat. "Latent heat" means the heat energy needed to change the state of a substance (ie: from a solid to a liquid) but not it's temperature. "Flash point" means the temperature at which a substance gives off a sufficient amount of vapors to form an ignitable mixture with air, "Non-aqueous phase" means a melted mixture in liquid state which is water insoluble. "Aqueous phase" means substance dissolved in water. "Acrylic polymer" means regular acrylic and modacrylic polymers, containing atleast 35% acrylonitrile as a monomer for modacrylic and 85% for regular acrylic polymer. The other comonomers can be methylacrylate, ethyl vinyl ether, vinyl bromide, vinyl chloride, vinyledene chloride, vinyl acetate, vinyl sulfonic acid, itaconic acid, and/or methylmethacrylate and sulfonated monomers such as sodium styrene sulfonate, sodium methallyl sulfonate, sodium sulfophenyl methallyl ether. 6 "Acrylic Polymer dope" means an intermediate material in the manufacture of acrylic products that is used for preparation of fibers. "Preform mass" means an intermediate material suitable for making fibers. Summary of the Invention In accordance with this invention there is provided a thermoregulatory acrylic formulation meant for manufacture of acrylic products comprising: ■ at least one non-water-soluble thermoregulatory constituent having a melting point lying in a predetermined range of temperature said constituent being in the range of about 0.01 to 7% of the mass of the formulation, ■ at least one water soluble nonionic surfactant having HLB value in the range of 9 to 40,said surfactant being in the range of 0.001 to 35 % of the mass of the formulation, ■ acrylic polymer in the range of about 1 to 15% of the mass of the formulation, ■ a solvent for polyacrylonitrile in the range of 20 to 60% of the mass of the formulation; and ■ water in the range of about 5 % to 60 % of the mass of the formulation. Typically, the thermoregulatory constituent is at least one selected from a group consisting of nonadecane, eicosane, heptadecane, octadecane, decyl alcohol, lauryl alcohol and myristyl alcohol. Typically, the surfactant is at least one non-ionic surfactant selected from a group of non-ionic surfactants consisting of alkyl phenol ethoxylates and aliphatic alcohol ethoxylates. 7 Typically, the alkyl phenol ethoxylates is at least one selected from a group consisting of Surfonic N-95(Poly (oxy-1, 2-ethanediyl), alpha- (nonyl phenyl)-omega-hydroxyl-glycol ether) ( nonylphenol 9.5-mole ethoxylate) , Surfonic N-120(nonylphenol 12-mole ethoxylate) , Surfonic N-150 (nonylphenol 15-mole ethoxylate), Surfonic N-200 (nonylphenol 20-mole ethoxylate) , Surfonic N-300( nonylphenol 30-mole ethoxylate) , Surfonic N-400 nonylphenpl 40-mole ethoxylate, Surfonic LF-7 (Alkyl polyoxyalkylene ether) , Surfonic LF-17 (ethoxylated and propoxylated linear primary 12-14 carbon number alcohol). In accordance with one preferred embodiment of the invention, the HLB value of the surfactant is 17.5. Typically, the solvent for polyacrylonitrile is at least one selected from a group consisting of sodium thiocyanate , dimethyl formamide, dimethyl acetamide, dimethyl sulfoxide, ethylene carbonate, aqueous zinc chloride and aqueous nitric acid. The polymer percentages in the acrylic dope will vary depending on the solvent. For dimethyl formamide, acrylic polymer concentration is as high as 28-32%; for dimethyl acetamide, it is as high as 22-27%; for dimethyl sulfoxide, it is as high as 20-25%; for ethylene carbonate, it is as high as 15-18%o, for aqueous nitric acid, it is as high as 8-12% and for zinc chloride, it is as high as 8-12%). For Sodium thiocyanate as a solvent, acrylic polymer concentration is as high as 10-15%. In accordance with one aspect of the invention, the thermoregulatory constituent, the solvent and the surfactant are processed to form micro-reservoirs which are embedded into the body of the formulation. 8 Typically, the average mean size of the micro-reservoir is in the range of 5 nm to 2000 nm. The invention also extends to a thermoregulatory acrylic fiber, yarn and fabric manufactured from the formulation in accordance with this invention. In accordance with this invention there is also provided a process for preparation of a thermoregulatory acrylic formulation meant for manufacture of acrylic products comprising the following steps: • selecting a non-water-soluble thermoregulatory constituent having a melting point lying in a predetermined range and heating said constituent upto 95 C to form a non-aqueous phase ; • dissolving and stirring a surfactant, optionally with a co-surfactant, a solvent for polyacrylonitrile in water to obtain an aqueous phase; • heating the aqueous phase; • mixing the aqueous phase with the non-aqueous phase in liquid state to form an admixture, and homogenizing to obtain a micro-emulsion; • mixing the micro-emulsion with an acrylic polymer solution in a solvent and water and further homogenizing and dispersing the micro-emulsion to obtain a preform mass wherein the thermoregulatory constituent is in the form of evenly dispersed micro-reservoirs. Brief Description of the accompanying Drawings: The invention will be described in detail with reference to the accompanying drawings. .9 In the accompanying drawing, Figure 1 illustrates the block diagram showing the method steps involved in the process in accordance with this invention. Figure 2 illustrates the cross-sectional view of thermoregulatory acrylic fibers prepared in accordance with this invention which shows uniform distribution of micro-reservoirs of thermoregulatory constituents entrapped across the length of the fibers. Detailed Description: Acrylic fibers were the first viable manufactured fibers. The reason behind the most widespread use of these fibers lies in their versatility. Furthermore, these fibers also have peculiar ability to blend easily with many fibers which makes them the fibers of choice. Though fibers and fabrics made from them have many desirable' properties, oftentimes, consumers expect performance characteristics beyond those for which fibers were designed. In order to meet with these increasing expectations, various thermoregulatory constituents are incorporated in the acrylic fibers. There has been a considerable interest in developing such materials. One of the additional desirable properties of acrylic fibers which has enormous demand is "thermoregulatory activity". Thermoregulatory constituents improve the thermal insulation of the acrylic fibers during changes in environmental temperature conditions. Thermoregulatory constituents are phase change materials which improve the thermal performance of 10 clothing by absorbing or releasing heat when subjected to heating" or cooling during a phase change. Thermoregulatory acrylic product abates the transient effect on a human body's heat loss when the person wearing such fabric is exposed to temperature swings resulting from change in environmental conditions. At least one thermoregulatory constituents is selected a group consisting of nonadecane, eicosane, heptadecane, octadecane, hexadecane, pentadecane decyl alcohol, lauryl alcohol and myristyl alcohol. Thermoregulatory ability of the thermoregulatory constituents is governed by several factors which include melting point, quantity of the thermoregulatory constituent in the fabric, different combinations and proportions in which the thermoregulatory constituents are blended together, type of the polymer used in the fabric, thickness of the fabric, distribution of the thermoregulatory constituent in the fabric, and the process used for incorporating the thermoregulatory constituent in the fabric. Physicochemical characteristics of the thermoregulatory constituents that used, are provided herein below: Nonadecane:(Molecular formula: C19H40 , CAS No: 629-92-5 EC No: 211-116-8 ) Appearance: white crystalline solid Melting point: 32-34 C Boiling point: 330 C Flashpoint: 168 C Eicosane (Molecular formula: C2oH42 CAS No: 112-95-8 11 EINECS No: 204-018-1 Appearance: colourless crystals or wax-like solid Melting point: 36.7 C Boiling point: 342.7 C Heptadecane (n-heptadecane )Molecular formula: C17H36 CAS No: 629-78-7 EC No: 211-108-4 Appearance: colourless liquid or white solid Melting point: 21 C Boiling point: 302 C Flash point: 148 C (closed cup) Octadecane Molecular formula: C18H38, CAS No: 593-45-3 EINECS No: 209-790-3 Appearance: white crystals or powder Melting point: 28-30 C Boiling point: 317 C Flashpoint: 165 C Myristyl alcohol: (Molecular formula: C14H30O)CASNo: 112-72-1, 27196-00-5 EC No: 204-000-3, 248-318-0 Appearance: white crystalline semi-solid Melting point37 - 39 C Boiling point: 277 - 288 C Flashpoint: 145 C Hexadecane Molecular formula: C16H34 CAS No: 544-76-3 Melting point: 18 °C, Boiling point: 287 °C Flashpoint: 135 °C 12 Pentadecane Molecular formula: Ci5H32 Molecular weight: 212.42 CAS No: 629-62-9 EC No: 211-098-1 Appearance: colourless liquid Melting point: 9.9 °C Boiling point: 268 - 270 °C Flashpoint: 132°C Name : decyl alcohol Molecular formula: C10H22O CAS No: ff2-Jtf-f EINECS No: 203-956-9 Appearance: colourless liquid Melting point: 7 C Boiling point: 233 C Flash point: 82 C Autoignition temperature: 287 C Name : Lauryl alcohol Molecular formula: Ci2H260 Molecular weight: 186.2 CAS No: [112-53-8] Appearance: Colorless solid Melting point:: 24 °C 13 " Boiling point:: 259 °C Flashpoint: 127 °C Specific thermoformable properties of the fabric with respect to the desired temperature zones are adjusted by careful blend of the thermoregulatory constituents in specific proportions. The thermoregulatory constituent is selected such that it has a melting point that falls within the range of temperature in which thermal regulation is desired to be achieved. Thus, if thermal regulation is desired in the range of 21 -30 °C, then the melting point of the thermoregulatory constituent must fall within this range. Again if the fabric is to be used in climatic regions, where regulation is desired below 20 °C, then the thermoregulatory constituent having melting point below 20 °C is used. The thermoregulatory acrylic fabric acts as a transient thermal barrier "by protecting the wearer ol this, fabric from the effects of cold or hot environments. When such thermoregulatory acrylic fabric is subjected to heating from the sun or a hot environment, it will absorb transient heat as it changes phase from solid to liquid, and it will prevent the temperature of the fabric from rising by keeping it constant at the tfielting point temperature of the thermoregulatory constituent. Once thermoregulatory constituent has completely melted, its transient effect will cease and the temperature of the fabric will rise. In a similar manner, when a thermoregulatory fabric is subjected to a cold environment where the temperature is below its crystallization point, it will interrupt the cooling effect of the fabric Structure by changing phase from liquid to solid, and the temperature of fabric will be kept constant at the crystallization point. Once all the thermoregulatory constituents have crystallized, the fabric temperature will drop, and the thermoregulatory constituents will have no effect on the fabric's thermal performance. 14 Thus, the thermal performance of a thermoregulatory constituent is a function of phase change temperature, the amount of thermoregulatory constituent and the amount of energy it absorbs or releases during a phase change. In accordance with this invention there is provided a thermoregulatory acrylic formulation meant for manufacture of acrylic products comprising : ■ at least one non-water-soluble thermoregulatory constituent having a melting point lying in a predetermined range of temperature said constituent being in the range of about 0.01 to 7% of the mass of the formulation , ■ at least one water soluble nonionic surfactant having HLB value in the range of 9 to 40,said surfactant being in the range of 0.001 to 3 % of the mass of the formulation, ■ acrylic polymer in the range of about 1 to 15% of the mass of the formulation, ■ a solvent for polyacrylonitrile in the range of 20 to 60% of the mass of the formulation; and ■ water in the range of about 5 % to 60 % of the mass of the formulation. In accordance with the invention, one or more thermoregulatory constituent is selected from a group consisting of nonadecane, eicosane, heptadecane, octadecane, hexadecane, pentadecane decyl alcohol, lauryl alcohol and myristyl alcohol. The thermoregulatory constituent imparts thermoregulation property to the fibers and ultimately to the fabric or garments made from these fibers. 15 Preferably, paraffin wax either alone or in combination with stearyl alcohol is used as the non-aqueous solvent. In accordance with this invention only water soluble non-ionic siirfactant/co- surfactant selected from a group consisting of alkyl phenoxy ethoxylated non-ionic surfactants and ethoxylated alkyl alcohol surfactants, Polyethylene-block-Poly propylene glycol-block-polyethylene glycol and Ethylenediamine tetrakis(propylene oxide-block-ethylene oxide) tetrol is used. Typically, the alkyl phenoxy ethoxylated non-ionic surfactant is at least one selected from a group consisting of Polyoxyethylene(8) isooctylphenyl ether, Nonylphenol polyethylene glycol ether, Polyoxyethylene(9) nonylphenyl ether, Polyoxyethylene(lO) isooctylphenyl ether, Polyoxyethylene(12) nonylphenyl ether, Polyoxyethylene(12) isooctylphenyl ether, Polyoxyethylene(40) nonylphenyl ether, Polyoxyethylene(40) isooctylphenyl ether, Polyoxyethylene(lOO) nonylphenyl ether, Polyoxyethylene( 150) dinonylphenyl ether, Surfonic N-95(Poly (oxy-1, 2- ethanediyl), alpha- (nonyl phenyl)-omega-hydroxyl-glycol ether) ( nonylphenol 9.5-mole ethoxylate) , Surfonic N-95(Poly (oxy-1, 2-ethanediyl), alpha- (nonyl phenyl)-omega-hydroxyl-glycol ether) ( nonylphenol 9.5-mole ethoxylate) , Surfonic N-120(nonylphenol 12-mole ethoxylate) , Surfonic N-150 (nonylphenol 15-mole ethoxylate), Surfonic N-200 (nonylphenol 20-mole ethoxylate) , Surfonic N-300( nonylphenol 30-mole ethoxylate) , Surfonic N-400 nonylphenol 40-mole ethoxylate, Surfonic LF-7 (Alkyl polyoxyalkylene ether) , Surfonic LF-17 (ethoxylated and propoxylated linear primary 12-14 carbon number alcohol), Igepal CO-630 (nonylphenoxy poly(ethyleneoxy)ethanol,branched), Surfonic DNP-40 (dinonylphenol ethoxylate glycol ether). 16 Typically, the solvent for polyacrylonitrile is at least one selected from a group consisting of sodium thiocyanate , dimethyl formamide, dimethyl acetamide, dimethyl sulfoxide, ethylene carbonate, aqueous zinc chloride and aqueous nitric acid. The polymer percentages in the acrylic dope will vary depending on the solvent. For dimethyl formamide, acrylic polymer concentration soluble in polymer dope is as high as 28-32%; for dimethyl acetamide, it is as high as 22-27%; for dimethyl sulfoxide, it is as high as 20-25%; for ethylene carbonate, it is as high as 15-18%, for aqueous nitric acid, it is as high as 8-12% and for zinc chloride, it is as high as 8-12%). For Sodium thiocyanate as a solvent, acrylic polymer concentration is as high as 10-15%. The non-ionic surfactant is selected such that the lipophilic portion of the non-ionic surfactant is compatible with the thermoregulatory constituent and the surfactant forms oil in water niicroemulsion. Surfactants with HLB values within the range of 9 to 40 are used. Preferably, non-ionic surfactants with HLB values more than 13 are used. In accordance with one preferred embodiment of the invention, the HLB value of the surfactant is between 16 and 40. In accordance with one aspect of the invention, the thermoregulatory constituent, the solvent and the surfactant are processed to form micro-reservoirs which are embedded into the body of the formulation. The thermoregulatory acrylic product contains uniformly dispersed micro-reservoirs throughout the body of the fibers. The micro-reservoirs are discrete, nano-sized structures without any definite geometrical shape. 17 Typically, the average mean size of the micro-resefvoir is in the range of 5 nm to 2000 nm. The invention also extends to a thermoregulatory acrylic fiber, yarn and fabric manufactured from a formulation in accordance with this invention. In accordance with this invention there is also provided a process for preparation of a thermoregulatory acrylic formulation meant for manufacture of acrylic products comprising the following steps: • selecting a non-water-soluble thermoregulatory constituent having a melting point lying in a predetermined range and heating said constituent upto 95 C to form a non-aqueous phase ; • dissolving and stirring a surfactant, optionally with a co-surfactant, a solvent for polyacrylonitrile in water to obtain an aqueous phase; • heating the aqueous phase; • mixing the aqueous phase with the non-aqueous phase in liquid state to form an admixture, and homogenizing to obtain a micro-emulsion; • mixing the micro-emulsion with an acrylic polymer solution in a solvent and water and further homogenizing and dispersing the micro-emulsion to obtain a preform mass wherein the thermoregulatory constituent is in the form of evenly dispersed micro-reservoirs. Typically, the pH of the aqueous phase is in the range of 7 to 13. Typically, the amount of non-aqueous phase in the micro-emulsion is in the range of 0.1 to 40% of the mass of the micro-emulsion. 18 Typically, the amount of surfactant in the micro-emulsion is in the range of 0.1 to 20% of the mass of the micro-emulsion. Typically, the proportion of thermoregulatory constituent in the acrylic product is in the range of 0.01 to 30% with respect to the mass of the acrylic product. Before arriving at the optimum concentration of the surfactant to be used, cloud point of the aqueous phase is determined. Furthermore, alkalinity of the aqueous phase matches with that of the acrylic polymer dope thereby avoiding any drastic change in the alkalinity during the emulsification and homogenization step. Typically, the melted non-aqueous phase containing thermoregulatory constituent in a non-aqueous solvent along with aqueous phase containing surfactants is emulsified using high speed mixers such as Ultraturrex or a mechanical emulsifier; a colloid mill; a high pressure homogenizer and an ultrasonic emulsifier to form a microemulsion. The micro-emulsion may contain further additional thermoregulatory constituents, if desired. It is important that the non-aqueous phase is maintained in liquid state throughout the mixing process. The aqueous phase therefore is typically heated upto a particular temperature to ensure that the temperature of the resulting emulsion is above the melting point of the thermoregulatory constituent. If this does not happen, the resulting emulsion will break down. Typically, the proportion of thermoregulatory constituent in the acrylic product is in the range of 0.01 to 30% with respect to the mass of the acrylic product. 19 The active ingredients are released from the micro-reservoir into the acrylic matrix. The structure of micro-reservoir, acrylic and surrounding conditions determine the release rate of the thermoregulatory constituent. The molecules of the volatile thermoregulatory constituents migrate from micro-reservoirs to the surrounding primarily by diffusion. The thermoregulatory constituent is released from the matrix in a controlled release manner. Preform mass is spun to fiber in a bath containing 12.5% of Sodium thiocyanate solution. The temperature of the bath is maintained at -2.5°C. Thereafter, the fiber is cold stretched, gel treated at pH 2.8 at 45°C, then hot stretch at 90°C. The void in the fibers is removed by treating the fiber at 125°C. Fiber is then relaxed and annealed at 120 C and then taken up for post-treatment. The acrylic fibers can be further subjected to post treatment to make fabric which typically involves: o Convert to Yarn in blend or pure o Convert to Warp Beam o Sizing o Fabric Manufacturing- Weaving /Knitting o Dyeing o Finishing Alternatively, the filaments so obtained are further blended using standard equipment. The blended fibers are laid in to a web using standard equipment followed by Consolidation of the web to obtain Non-woven Acrylic Fabric. The acrylic product made from the formulation in accordance with this invention contains uniformly dispersed micro-reservoirs throughout the mass which is shown in Fig. 2. 20 The thermoregulatory acrylic fibers contain the entrapped thermoregulatory constituent in releasable form. Microscopic examination of the micro-reservoirs in the acrylic fibers is shown in Fig 2. Thermoregulatory fabric improves the comfort of people irrespective of the fluctuations in the temperature of their surroundings on either side. Besides this, thermoregulatory fabric also improves the comfort of people as their body goes through a very active state (high metabolic production) to an inactive state on an intermittent basis in a cold environment. This feature is of particular relevance for outdoor sportsmen. The resultant acrylic fabric containing thermoregulatory constituent are tested. Linear Density (Denier) of the acrylic Fibers is determined by using standard ASTM Test Method (D 1577). The denier of the standard acrylic fiber (acrylic fiber without any thermoregulatory constituents) and thermoregulatory enriched acrylic fiber remains the same. Thus addition of thermoregulatory constituents does not change the linear density of the acrylic fibers. Tensile strength and Young's modulus of acrylic fiber sample is tested on an Instron tensile testing machine as per the ASTM CI557-03 procedure at ambient temperature. Visual appearance of the thermoregulatory enriched fiber is evaluated by methods as prescribed in AATCC 124. As far as parameters like % Loss in Dry Tenacity and % loss in dry elongation are concerned, these remain the same in the thermoregulatory enriched acrylic fiber and the standard fiber. Incorporation of thermoregulatory constituent in accordance with this invention does not affect the visual appearance of the fiber. 21 Feel of the fiber: The thermoregulatory enriched acrylic fiber as prepared in accordance with this invention offers the same feel effect as is observed in case of plain acrylic fiber without any thermoregulatory constituent (Also referred as standard). Another important concern in textile industry is dye-ability of the fabric, which is tested by comparing the dyeability of the thermoregulatory constituent enriched fabric and the standard acrylic fabric. Dyeability of the thermoregulatory enriched acrylic fibers as prepared in accordance with this invention remains the same as that of the standard acrylic fiber. The invention will now be described with the help of the following non-limiting examples. Examples Example 1 Example 1A- Preparation of micro emulsion Myristyl alcohol (200gm) and hexadecane (50 gm) were heated upto 50°C. Surfonic N-400 nonylphenol 40-mole ethoxylate (surfactant) ( 28 gm ) was dissolved and stirred in water 525 ml and Sodium thiocyanate (250 gm) to obtain (803 gm) of aqueous phase. The aqueous phase (803 gm) was heated temperature of the molten non-aqueous phase (250 gm) and both the phases were homogenized in a high speed mixer (Ultraturrex) to obtain a micro-emulsion (1053 gm). Example 1 B- Preparation of fiber 22 (1053 gm) of micro-emulsion as prepared in Example 1A was mixed at 50 C with acrylic Polymer Dope containing 5000gm of acrylic polymer and 16670 gm of sodium thiocyanate and 20000 ml of water were added to obtained preform mass. Preform mass was spun in a bath containing 12.5% of Sodium thiocyanate solution. The temperature of the bath was maintained at -2.5°C. Thereafter, the fiber was cold stretched, gel treated at pH 2.8 at 45°C, then hot stretch at 90°C. The void in the fibers was removed by treating the fiber at 125°C. Fiber is then relaxed and annealed at 120°C and then taken up for post-treatments and was spun into fiber. The acrylic fiber thus obtained contained micro-reservoirs having the entrapped releasable thermoregulatory constituents. Although the micro reservoirs did not have any specific shape or size, they were found to be uniformly distributed throughout the body of the fiber. Example 2 Example 2A- Preparation of micro emulsion Nonadecane (200gm) and hexadecane (50 gm) were heated upto 50°C. Surfonic N- 400 nonylphenol 40-mole ethoxylate (surfactant) ( 28 gm ) was dissolved and stirred in water 525 ml and sodium thiocyanate (250 gm) to obtain (803 gm) of aqueous phase. The aqueous phase (803 gm) was heated temperature of the molten non-aqueous phase (250 gm) and both the phases were homogenized in a high speed mixer (Ultraturrex) to obtain a micro-emulsion (1053 gm). 23 Example 2 B- Preparation of fiber (1053 gm) of micro-emulsion as prepared in Example 2A was mixed at 50°C with acrylic Polymer Dope containing 5000gm of acrylic polymer and 16670 gm of sodium thiocyanate and 20000 ml of water were added to obtained preform mass and was spun into fiber as described in example 1. Example 3 Example 3 A Pentadecane (200gm) and Myristyl alcohol (50 gm) were heated -upto 40°C. Surfonic N-400 nonylphenol 40-mole ethoxylate (surfactant) ( 28 gm ) was dissolved and stirred in water 525 ml and sodium thiocyanate (250 gm) to obtain (803 gm) of aqueous phase. The aqueous phase (803 gm) was heated temperature of the molten non-aqueous phase (250 gm) and both the phases were homogenized in a high speed mixer (Ultraturrex) to obtain a micro-emulsion (1053 gm). Example 3 B- Preparation of fiber (1053 gm) of micro-emulsion as prepared in Example 3A was mixed at 50°C with acrylic Polymer Dope containing (5000gm) of acrylic polymer and (16670 gm) of sodium thiocyanate and 20000 ml of water were added to obtained preform mass and was spun into fiber as described in example 1. Example 4 Example 4 A Preparation of thermoregulatory formulation Nonadecane (200gm) and octadecane (50 gm) were heated upto 45°C. Surfonic N- 400 nonylphenol 40-mole ethoxylate (surfactant) ( 28 gm ) was dissolved and 24 stirred in water 525 ml and sodium thiocyanate (250 gm) to obtain (803 gm) of aqueous phase. The aqueous phase (803 gm) was heated temperature of the molten non-aqueous phase (250 gm) and both the phases were homogenized in a high speed mixer (Ultraturrex) to obtain a micro-emulsion (1053 gm). Example 4 B Preparation of fiber (1053 gm) of micro-emulsion as prepared in Example 4A was mixed at 50°C with acrylic Polymer Dope containing (5000gm) of acrylic polymer and (16670 gm) of sodium thiocyanate and 20000 ml of water were added to obtained preform mass and was spun into fiber as described in example 1. Example 5 Example 5 A Preparation of thermoregulatory formulation Icosane (1 lOgm) and hexadecane (140 gm) were heated upto 45°C. Surfonic N-400 nonylphenol 40-mole ethoxylate (surfactant) ( 28 gm ) was dissolved and stirred in water 525 ml and sodium thiocyanate (250 gm) to obtain (803 gm) of aqueous phase. The aqueous phase (803 gm) was heated temperature of the molten non-aqueous phase (250 gm) and both the phases were homogenized in a high speed mixer (Ultraturrex) to obtain a micro-emulsion (1053 gm). Example 5 B- Preparation of fiber (1053 gm) of micro-emulsion as prepared in Example 5A was mixed at 50°C with acrylic Polymer Dope containing 1086 gm of acrylic polymer and 3620 gm of 25 sodium thiocyanate and 4340 ml of water were added to obtained preform mass and was spun into fiber as described in example 1. Example 6 Example 6 A Preparation of thermoregulatory formulation Nonadecane (HOgm) and hexadecane (140 gm) were heated upto 45°C. Surfonic N-400 nonylphenol 40-mole ethoxylate (surfactant) ( 28 gm ) was dissolved and stirred in water 525 ml and sodium thiocyanate (250 gm) to obtain (803 gm) of aqueous phase. The aqueous phase (803 gm) was heated temperature of the molten non-aqueous phase (250 gm) and both the phases were homogenized in a high speed mixer (Ultraturrex) to obtain a micro-emulsion (1053 gm). Example 6 B- Preparation of fiber (1053 gm) of micro-emulsion as prepared in Example 6A was mixed at 50°C with acrylic Polymer Dope containing (5000gm) of acrylic polymer and (16670 gm) of sodium thiocyanate and 20000 ml of water were added to obtained preform mass and was spun into fiber as described in example 1. Example 7 Example 7 A Preparation of thermoregulatory formulation Eicosane (lOOgm) and hexadecane (150 gm) were heated upto 45°C. Surfonic N- 400 nonylphenol 40-mole ethoxylate (surfactant) ( 28 gm ) was dissolved and stirred in water 525 ml and sodium thiocyanate (250 gm) to obtain (803 gm) of aqueous phase. 26 The aqueous phase (803 gm) was heated temperature of the molten non-aqueous phase (250 gm) and both the phases were homogenized in a high speed mixer (Ultraturrex) to obtain a micro-emulsion (1053 gm). Example 7 B- Preparation of fiber (1053 gm) of micro-emulsion as prepared in Example 7A was mixed at 50 C with acrylic Polymer Dope containing (5000gm) of acrylic polymer and (16670 gm) of sodium thiocyanate and 20000 ml of water were added to obtained preform mass and was spun into fiber as described in example 1. Example 8 Example 8 A Preparation of thermoregulatory formulation Heptadecane (lOOgm) and hexadecane (150 gm) were heated upto 45°C. Surfonic N-400 nonylphenol 40-mole ethoxylate (surfactant) ( 28 gm ) was dissolved and stirred in water 525 ml and sodium thiocyanate (250 gm) to obtain (803 gm) of aqueous phase. The aqueous phase (803 gm) was heated temperature of the molten non-aqueous phase (250 gm) and both the phases were homogenized in a high speed mixer (Ultraturrex) to obtain a micro-emulsion (1053 gm). Example 8 B- Preparation of fiber (1053 gm) of micro-emulsion as prepared in Example 8 A was mixed at 50°C with acrylic Polymer Dope containing (5000gm) of acrylic polymer and (16670 gm) of sodium thiocyanate and 20000 ml of water were added to obtained preform mass and was spun into fiber as described in example 1. 27" Example 9 Example 9A- Preparation of micro emulsion Preparation of thermoregulatory formulation Nonadecane (250 gm) was heated upto 40°C. Surfonic N-400 nonylphenol 40-mole ethoxylate (surfactant) ( 28 gm ) was dissolved and stirred in water 525 ml and sodium thiocyanate (250 gm) to obtain (803 gm) of aqueous phase. The aqueous phase (803 gm) was heated temperature of the molten non-aqueous phase (250 gm) and both the phases were homogenized in a high speed mixer (Ultraturrex) to obtain a micro-emulsion (1053 gm). Example 9 B- Preparation of fiber (1053 gm) of micro-emulsion as prepared in Example 9A was mixed at 50°C with acrylic Polymer Dope containing 5000 gm of acrylic polymer and 16670 gm of sodium thiocyanate and 20000 ml of water were added to obtained preform mass and was spun into fiber as described in example 1. Example 10 Example 10 A- Preparation of micro emulsion Myristyl alcohol (I50gm ) pentadecane (100 gm) were heated upto 40°C. Surfonic N-400 nonylphenol 40-mole ethoxylate (surfactant) ( 28 gm ) was dissolved and stirred in water 525 ml and sodium thiocyanate (250 gm) to obtain (803 gm) of aqueous phase. The aqueous phase (803 gm) was heated temperature of the molten non-aqueous phase (250 gm) and both the phases were homogenized in a high speed mixer (Ultraturrex) to obtain a micro-emulsion (1053 gm). Example 10 B- Preparation of fiber 28 (1053 gm) of micro-emulsion as prepared in Example 10A was mixed at 50°C with acrylic Polymer Dope containing 5000 gm of acrylic polymer and 16670 gm of sodium thiocyanate and 20000 ml of water were added to obtained 5000 gm preform mass and was spun into fiber as described in example 1. Testing procedures: The thermoregulatory acrylic products as prepared in the above examples (1 to 10) were tested by using following test procedures: 1) Linear Density (Denier) of the acrylicFibers was determined by using standard ASTM Test Method (D 1577). The denier of the standard acrylicfiber (without any thermoregulatory constituents) and thermoregulatory acrylic fibers as prepared in accordance with example IB was found to be uniform(1.5 denier) irrespective of the type and quantity of the thermoregulatory constituent. 2) Tensile strength and Young's modulus of acrylic fiber samples were tested on an Instron tensile testing machine as per the ASTM CI557-03 procedure at ambient temperature. 3) Emulsion stability: The stability of micro-emulsions as prepared in the above examples, was evaluated by keeping the same under observation in measuring cylinders for 3 days. During this period no phase separation was observed. 4) Feel of the fabric: The acrylic fabrics as prepared in the above examples and standard fabric (acrylic fabric without thermoregulatory constituents), were randomly given to twenty subjects and they were asked to evaluate the texture and feel of the fiber. The test fiber material was interchanged several times amongst the human subjects. Collective results as submitted by the human subjects confirmed that nobody could distinguish between the 29 thermoregulatory acrylic fabrics prepared in accordance with the Examples provided above and the standard fabric. 5) Dyeability: The thermoregulatory acrylic fabrics as prepared in the above examples and the standard fabric as described above were dyed uniformly with reactive dyes. No noticeable difference as to the Dyeability of the two respective acrylic fabrics, with and without thermoregulatory constituent was reported. 6) Visual appearance of the thermoregulatory acrylic fiber was evaluated by methods as prescribed in AATCC 124. As far as parameters like % Loss in Dry Tenacity and % loss in dry elongation are concerned, these remained the same ( and the standard fiber 7) Determination of enthalpy of the fabric specimen: the thermoregulatory properties of the specimen fabrics/fibers as prepared in examples 1 to 20 were evaluated by measuring respective enthalpies of the specimen. The enthalpies were measured using DSC (Differential scanning calorimetry) technique. The recorded enthalpies of the fiber and fabric obtained in examples 1 to 20 are provided in the Table 1. 30 Table 1 Specimen No. Enthalpy J/g Fiber Enthalpy J/g Fabric 1 5.5 45.4 2 6.4 6.38 3 5.6 5.63 4 6.02 5.98 5 37 36.3 6 7.6 7.58 7 8.4 8.41 8 7.2 7.19 9 7.6 7.6 10 5.2 5.24 8. Thermoregulatory Testing: Free flowing robes made to fit the physique of twenty human volunteers, selected at random between ages 16 to 56, were made from undyed thermoregulatory acrylic fabric prepared in accordance with this invention. Simultaneously, identical robes with same design were also made from undyed standard fabric (Acrylic fabric without any thermo regulatory constituents). A temperature monitored room was selected where the temperature could be precisely controlled. The human volunteers were made to randomly wear either a standard robe (robe made from standard fabric) or a robe made from the fabric of 31 this invention. But they were not informed about the type of the robe that was being worn. The temperature in the room was set at 21°C. The twenty human volunteers were requested to wear the robes and assemble in the room and be there in the room for a period of 30 min. After 30 minutes, all the volunteers were asked to step out into the outside non-air-conditioned environment, where the temperature was 28°C and they were asked to observe and note the time when they felt warm in the area covered by the robes. Thereafter, all the volunteers switched their robes, ie: The volunteer given a robe of standard fabric, was allotted a robe made from the fabric of this invention and vise-a-versa. They were again asked to go back into the room and remain there for 30 min. and again step out into the external environment and again observe and note the time when they started feeling warm. The volunteers were then asked to give an evaluation of the time required to feel the warmth in both the instances. The results of the experiment were as follows. Sixteen volunteers opined that they felt warm in the standard fabric, at least on an average of 90 sec. quicker than the fabric of this invention. Three volunteers could not sense significant difference in time and one volunteer recorded an earlier feeling of warmth in case of the fabric of this invention. In case of direct comparison between the robes, 18 volunteers opined that they felt cooler and more comfortable wearing a ward-robe made from the fabric of this invention. Two volunteers expressed no significant difference between the two. There was no volunteer who provided any reverse finding. Similar test was conducted in which the volunteers were made to go from a hotter external environment at 30 C to an air-conditioned environment maintained at 21°C. 18 of the volunteers expressed that they felt warmer and more comfortable in 32 the robe made from the fabric of this invention and the reported response time for feeling cold was on an average 3 min. "longer. Two of the volunteers could not discern any significant difference between the two robes. It is thus concluded that the fabric made in accordance with this invention exhibits thermoregulatory effect in either situation, ie when there is a rise in temperature and when there is a fall in the temperature. While considerable emphasis has been placed herein on the specific steps of the preferred embodiment, it will be appreciated that many alterations can be made and that many modifications can be made in the preferred embodiment without departing from the principles of the invention. These and other changes in the preferred embodiment as well as other embodiments of the invention will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation. 33 We Claim: 1. A thermoregulatory acrylic formulation meant for manufacture of acrylic products comprising : ■ at least one non-water-soluble thermoregulatory constituent having a melting point lying in a predetermined range of temperature said constituent being in the range of about 0.01 to 7% of the mass of the formulation , ■ at least one water soluble nonionic surfactant having HLB value in the range of 9 to 40,said surfactant being in the range of 0.001 to 3 % of the mass of the formulation, ■ acrylic polymer in the range of about 1 to 15% of the mass of the formulation, ■ a solvent for polyacrylonitrile in the range of 20 to 60% of the -mass of the formulation; and ■ water in the range of about 5 % to 60 % of the mass of the formulation. 2. A formulation as claimed in claim 8, wherein the thermoregulatory constituent is at least one selected from a group consisting of nonadecane, eicosane, heptadecane, octadecane, hexadecane, pentadecane decyl alcohol, lauryl alcohol and myristyl alcohol. 3. A formulation as claimed in claim 1, wherein the surfactant is at least one non-ionic surfactant selected from a group of alkyl phenoxy ethoxylated non-ionic surfactants and ethoxylated alkyl alcohol surfactants, Poiyethylene-block-Poly 34 propylene glycol-block-polyethylene glycol and Ethylenediamine tetrakis(propylene oxide-block-ethylene oxide) tetrol. 4. A formulation as claimed in claim 4, wherein the alkyl phenol ethoxylates is at least one selected from a group consisting of Polyoxyethylene(8) isooctylphenyl ether, Nonylphenol polyethylene glycol ether, Polyoxyethylene(9) nonylpheny 1 ether, Polyoxyethylene( 10) isooctylphenyl ether, Polyoxyethylene(12) nonylphenyl ether, Polyoxyethylene(12) isooctylphenyl ether, Polyoxyethylene(40) nonylphenyl ether, Polyoxyethylene(40) isooctylphenyl ether, Polyoxyethylene(lOO) nonylphenyl ether, Polyoxyethylene(150) dinonylphenyl ether, Surfonic N-95(Poly (oxy-1, 2-ethanediyl), alpha- (nonyl phenyl)-omega-hydroxyl-glycol ether) ( nonylphenol 9.5-mole ethoxylate) , Surfonic N-95(Poly (oxy-1, 2-ethanediyl), alpha- (nonyl phenyl)-omega-hydroxyl-glycol ether) (nonylphenol 9.5-mole ethoxylate) , Surfonic N-120(nonylphenol 12-mole ethoxylate) , Surfonic N- 150 (nonylphenol 15-mole ethoxylate), Surfonic N-200 (nonylphenol 20-mole ethoxylate) , Surfonic N-300( nonylphenol 30-mole ethoxylate) , Surfonic N- 400 nonylphenol 40-mole ethoxylate, Surfonic LF-7 (Alkyl polyoxyalkylene ether) , Surfonic LF-17 (ethoxylated and propoxylated linear primary 12-14 carbon number alcohol). 5. A formulation as claimed in claim 1, wherein the preferred HLB value of the surfactant is between 16 and 40. 6. A formulation as claimed in claim 1, wherein the solvent for polyacrylonitrile is at least one selected from a group consisting of sodium thiocyanate , 35 dimethyl formamide, dimethyl acetamide, dimethyl sulfoxide, ethylene carbonate, aqueous zinc chloride and aqueous nitric acid. 7. A formulation as claimed in claim 1, wherein the average mean size of the micro-reservoir is in the range of 5 nm to 2000 nm. 8. A thermoregulatory acrylic fiber manufactured from a formulation as claimed in claim 1. 9. A thermoregulatory acrylic yarn manufactured from a formulation as claimed in claim 1. 10.A thermoregulatory acrylic fabric manufactured from a formulation as claimed in claim 1. 1 l.A process of preparation of a thermoregulatory acrylic formulation meant for manufacture of acrylic products comprising the following steps : • selecting a non-water-soluble thermoregulatory constituent having a melting point lying in a predetermined range and heating said constituent upto 95°C to form a non-aqueous phase ; • dissolving and stirring a surfactant, optionally with a co-surfactant, a solvent for acrylic polymer in water to obtain an aqueous phase; • heating the aqueous phase; • mixing the aqueous phase with the non-aqueous phase in liquid state to form an admixture, and homogenizing to obtain a micro-emulsion; 36 mixing the micro-emulsion with an acrylic polymer solution in a solvent and water and further homogenizing and dispersing the micro-emulsion to obtain a preform mass wherein the thermoregulatory constituent is in the form of evenly dispersed micro-reservoirs. ,rd Dated this 3rd day of July, 2008 Mohan Dewan of R. K. Dewan and Co. Applicants' Patent Attorney 37

Full Text

FORM - 2
THE PATENTS ACT, 1970
(39 OF 1970)
AND
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION (See section 10; rule 13)
ACRYLIC THERMOREGULATORY FIBER AND A METHOD OF .
MAKING THEREOF

ADITYA BIRLA SCIENCE & TECHNOLOGY CO. LTD.
an Indian Company of Aditya Birla Center, 2nd floor, C Wing, S. K. Ahire Marg, Mumbai 400 025,
Maharashtra, India

THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.

Field of the invention
The present invention relates to textile fibers.
Background of the invention Introduction
The term "fiber" or "textile fiber" means a substance which is capable of being spun into a yarn or made into a fabric by bonding or by interlacing in a variety of methods including weaving, knitting, braiding, felting, twisting, or webbing, and which is the basic structural element of textile products.
Fibers are classified on the basis of their length such as short fibers or staple fiber and long fibers or filament fiber. The fibers can also be classified on the basis of their origin such as natural fibers and man-made fibers. The term natural fibers means any fiber that exists as such in the natural state e.g. vegetable fibers or wood fibers. The other type of fibers is obtained from chemical substances. These are called man made fibers. They are, polyester, nylon, acrylic (cashmilon) and the like.
For centuries, mankind has relied upon various plants and animals to provide raw materials for fabrics and clothing. In recent times, the industrialization and scientific advancement has provided several improved materials having far superior properties, particularly suitable for clothing.
Acrylic fibers are synthetic fibers containing at least 85% of acrylonitrile monomer. The acrylic fibers are prepared from a polymer Polyacrylonitrile which is obtained by free radical polymerisation with an average molecular weight of 100,000. Typical properties of acrylic fibers include resistance to moths, oils, and
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chemicals. Furthermore, they are also resistant to deterioration from sunlight exposure.
The process steps involved in the preparation of Acrylic fibers are as follows: The Polyacrylonitrile is dissolved in solvents like N,N-dimethylformamide or aqueous sodium thiocyanate. Then it is metered through a multi-hole spinnerette and the resultant filaments are coagulated in an aqueous solution of the same solvent. The resultant filaments are washed, stretched, dried and crimped to obtain final acrylic fibers. Acrylic fibers are typically produced in a range of deniers from 1 to 15.
Acrylic is lightweight, soft, and warm, with a wool-like feel. It dyes very well and has excellent colorfastness. It is resilient, retains its shape, and resists shrinkage and wrinkles. Acrylic fibers are commonly used in sweaters, hand-knitting yarns, rugs, awnings, boat covers, and beanies; the fiber is also used as a precursor for carbon fiber.
From the spun or filament yarn, fabric is formed by knitting or weaving operations. Knitted fabrics can be made by using hooked needles to interlock one or more sets of yarns through a set of loops. The loops may be either loosely or closely constructed, depending on the purpose of the fabric. Knitted fabrics can be used for hosiery, underwear, sweaters, slacks, suits, coats, rugs and other home furnishings. Knitting is performed using either weft or warp processes.
Some typical preparations that are involved in the weaving operations are warping, slashing or sizing. Sizing agents are added to the yarn by solution or pad/dry techniques. Differences in raw materials, processing chemicals, fiber diameter, post treatments and blend ratios can be manipulated to produce a fiber having customized properties suitable for desired application. It is often desired that the
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acrylic fabrics possess typical properties such as thermal stability, ability to retain perfumes, antibacterial properties and the like. These properties are essential in several industrial as well as household applications. There has been a considerable interest in developing such materials. In order to impart various desirable properties to the fabric as mentioned above to the fabric, several additives are added. Such additives include antimicrobial agents, deodorizing agents, antistatic agents, perfumes. Besides such specific additives, generic additives for improving overall quality of the fabric, such as sizing agents, additives for increasing yarn softness and pliability are also added.
Prior Art
WO2008030648 discloses a temperature regulating, polymer containing fabric and a suspension formulation used in preparation of such fibers. The suspension comprises a solvent and plurality of microcapsules containing phase-change material. The suspension is used for incorporating the microcapsules in the fabric. The microcapsules comprise a shell composed of acrylic acid and their derivatives and a core which is composed of a phase change material having a latent heat in a range between 80 J/g and 400 J/gm and a transition temperature in the range of 20°C-50°C.
Earlier known processes of incorporating such additives, as reported in the above mentioned patents/applications, mainly involved conventional methods like spraying, encapsulating, solvent spinning the additives on the fabric. However, these methods suffer from several disadvantages which include non-uniform and improper adhesion of additives onto the fiber material, fading, waning and gradual washing out of the additives over a period of time and which further affects the feel and texture of the fabric.
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There is thus felt a need for a process of incorporating additives to fabric which overcomes these shortcomings.
Objects of the Invention
It is an object of this invention to provide thermoregulatory acrylic products, wherein at least one thermoregulatory constituent is incorporated into the body of the fiber.
Another object of this invention is to provide a process of incorporating thermoregulatory constituents into acrylic fibers which ensures uniform distribution of the thermoregulatory constituent throughout the fiber length.
Yet another object of this invention is to provide thermoregulatory acrylic fibers wherein the thermoregulatory constituents are retained in the acrylic product over a prolonged period of time.
Yet another object of this invention is to provide a process of incorporating thermoregulatory constituents to acrylic fibers which does not affect the feel and texture of the fabric.
Still another object of this invention is to provide a process of incorporating thermoregulatory constituents to acrylic fibers such that inherent properties of the acrylic fibers such as fiber strength, linear density, tenacity, heat resistance, dyeability and drying properties are not altered.
5

Definitions:
As used in the present specification, the following words and phrases are generally
intended to have the meanings as set forth below, except to the extent that the context in which they are used indicates otherwise.
"Phase-change agent" means a substance having the ability to releases or absorbs heat whenever it undergoes change in its physical state.
Enthalpy means heat content or total heat, including both sensible and latent heat.
"Latent heat" means the heat energy needed to change the state of a substance (ie: from a solid to a liquid) but not it's temperature.
"Flash point" means the temperature at which a substance gives off a sufficient amount of vapors to form an ignitable mixture with air,
"Non-aqueous phase" means a melted mixture in liquid state which is water insoluble.
"Aqueous phase" means substance dissolved in water.
"Acrylic polymer" means regular acrylic and modacrylic polymers, containing atleast 35% acrylonitrile as a monomer for modacrylic and 85% for regular acrylic polymer. The other comonomers can be methylacrylate, ethyl vinyl ether, vinyl bromide, vinyl chloride, vinyledene chloride, vinyl acetate, vinyl sulfonic acid, itaconic acid, and/or methylmethacrylate and sulfonated monomers such as sodium styrene sulfonate, sodium methallyl sulfonate, sodium sulfophenyl methallyl ether.
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"Acrylic Polymer dope" means an intermediate material in the manufacture of
acrylic products that is used for preparation of fibers.
"Preform mass" means an intermediate material suitable for making fibers.
Summary of the Invention
In accordance with this invention there is provided a thermoregulatory acrylic formulation meant for manufacture of acrylic products comprising:
■ at least one non-water-soluble thermoregulatory constituent having a melting point lying in a predetermined range of temperature said constituent being in the range of about 0.01 to 7% of the mass of the formulation,
■ at least one water soluble nonionic surfactant having HLB value in the range of 9 to 40,said surfactant being in the range of 0.001 to 35 % of the mass of the formulation,
■ acrylic polymer in the range of about 1 to 15% of the mass of the formulation,
■ a solvent for polyacrylonitrile in the range of 20 to 60% of the mass of the formulation; and
■ water in the range of about 5 % to 60 % of the mass of the formulation.
Typically, the thermoregulatory constituent is at least one selected from a group consisting of nonadecane, eicosane, heptadecane, octadecane, decyl alcohol, lauryl alcohol and myristyl alcohol.
Typically, the surfactant is at least one non-ionic surfactant selected from a group of non-ionic surfactants consisting of alkyl phenol ethoxylates and aliphatic alcohol ethoxylates.
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Typically, the alkyl phenol ethoxylates is at least one selected from a group consisting of Surfonic N-95(Poly (oxy-1, 2-ethanediyl), alpha- (nonyl phenyl)-omega-hydroxyl-glycol ether) ( nonylphenol 9.5-mole ethoxylate) , Surfonic N-120(nonylphenol 12-mole ethoxylate) , Surfonic N-150 (nonylphenol 15-mole ethoxylate), Surfonic N-200 (nonylphenol 20-mole ethoxylate) , Surfonic N-300( nonylphenol 30-mole ethoxylate) , Surfonic N-400 nonylphenpl 40-mole ethoxylate, Surfonic LF-7 (Alkyl polyoxyalkylene ether) , Surfonic LF-17 (ethoxylated and propoxylated linear primary 12-14 carbon number alcohol).
In accordance with one preferred embodiment of the invention, the HLB value of
the surfactant is 17.5.
Typically, the solvent for polyacrylonitrile is at least one selected from a group consisting of sodium thiocyanate , dimethyl formamide, dimethyl acetamide, dimethyl sulfoxide, ethylene carbonate, aqueous zinc chloride and aqueous nitric acid. The polymer percentages in the acrylic dope will vary depending on the solvent. For dimethyl formamide, acrylic polymer concentration is as high as 28-32%; for dimethyl acetamide, it is as high as 22-27%; for dimethyl sulfoxide, it is as high as 20-25%; for ethylene carbonate, it is as high as 15-18%o, for aqueous nitric acid, it is as high as 8-12% and for zinc chloride, it is as high as 8-12%). For Sodium thiocyanate as a solvent, acrylic polymer concentration is as high as 10-15%.
In accordance with one aspect of the invention, the thermoregulatory constituent, the solvent and the surfactant are processed to form micro-reservoirs which are embedded into the body of the formulation.
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Typically, the average mean size of the micro-reservoir is in the range of 5 nm to 2000 nm.
The invention also extends to a thermoregulatory acrylic fiber, yarn and fabric manufactured from the formulation in accordance with this invention.
In accordance with this invention there is also provided a process for preparation of a thermoregulatory acrylic formulation meant for manufacture of acrylic products comprising the following steps:
• selecting a non-water-soluble thermoregulatory constituent having a melting point lying in a predetermined range and heating said constituent upto 95 C to form a non-aqueous phase ;
• dissolving and stirring a surfactant, optionally with a co-surfactant, a solvent for polyacrylonitrile in water to obtain an aqueous phase;
• heating the aqueous phase;
• mixing the aqueous phase with the non-aqueous phase in liquid state to form an admixture, and homogenizing to obtain a micro-emulsion;
• mixing the micro-emulsion with an acrylic polymer solution in a solvent and water and further homogenizing and dispersing the micro-emulsion to obtain a preform mass wherein the thermoregulatory constituent is in the form of evenly dispersed micro-reservoirs.
Brief Description of the accompanying Drawings:
The invention will be described in detail with reference to the accompanying drawings.
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In the accompanying drawing, Figure 1 illustrates the block diagram showing the method steps involved in the process in accordance with this invention.
Figure 2 illustrates the cross-sectional view of thermoregulatory acrylic fibers prepared in accordance with this invention which shows uniform distribution of micro-reservoirs of thermoregulatory constituents entrapped across the length of the fibers.
Detailed Description:
Acrylic fibers were the first viable manufactured fibers. The reason behind the most widespread use of these fibers lies in their versatility. Furthermore, these fibers also have peculiar ability to blend easily with many fibers which makes them the fibers of choice.
Though fibers and fabrics made from them have many desirable' properties, oftentimes, consumers expect performance characteristics beyond those for which fibers were designed. In order to meet with these increasing expectations, various thermoregulatory constituents are incorporated in the acrylic fibers. There has been a considerable interest in developing such materials.
One of the additional desirable properties of acrylic fibers which has enormous demand is "thermoregulatory activity".
Thermoregulatory constituents improve the thermal insulation of the acrylic fibers during changes in environmental temperature conditions. Thermoregulatory constituents are phase change materials which improve the thermal performance of
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clothing by absorbing or releasing heat when subjected to heating" or cooling during a phase change.
Thermoregulatory acrylic product abates the transient effect on a human body's heat loss when the person wearing such fabric is exposed to temperature swings resulting from change in environmental conditions.
At least one thermoregulatory constituents is selected a group consisting of nonadecane, eicosane, heptadecane, octadecane, hexadecane, pentadecane decyl alcohol, lauryl alcohol and myristyl alcohol.
Thermoregulatory ability of the thermoregulatory constituents is governed by several factors which include melting point, quantity of the thermoregulatory constituent in the fabric, different combinations and proportions in which the thermoregulatory constituents are blended together, type of the polymer used in the fabric, thickness of the fabric, distribution of the thermoregulatory constituent in the fabric, and the process used for incorporating the thermoregulatory constituent in the fabric.
Physicochemical characteristics of the thermoregulatory constituents that used, are provided herein below:
Nonadecane:(Molecular formula: C19H40 , CAS No: 629-92-5 EC No: 211-116-8 ) Appearance: white crystalline solid Melting point: 32-34 C Boiling point: 330 C Flashpoint: 168 C
Eicosane (Molecular formula: C2oH42 CAS No: 112-95-8
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EINECS No: 204-018-1 Appearance: colourless crystals or wax-like solid Melting point: 36.7 C Boiling point: 342.7 C
Heptadecane (n-heptadecane )Molecular formula: C17H36
CAS No: 629-78-7 EC No: 211-108-4 Appearance: colourless liquid or white solid
Melting point: 21 C
Boiling point: 302 C
Flash point: 148 C (closed cup)
Octadecane Molecular formula: C18H38, CAS No: 593-45-3 EINECS No: 209-790-3 Appearance: white crystals or powder Melting point: 28-30 C Boiling point: 317 C Flashpoint: 165 C
Myristyl alcohol: (Molecular formula: C14H30O)CASNo: 112-72-1, 27196-00-5 EC No: 204-000-3, 248-318-0 Appearance: white crystalline semi-solid Melting point37 - 39 C Boiling point: 277 - 288 C Flashpoint: 145 C
Hexadecane
Molecular formula: C16H34
CAS No: 544-76-3 Melting point: 18 °C, Boiling point: 287 °C Flashpoint: 135 °C
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Pentadecane
Molecular formula: Ci5H32 Molecular weight: 212.42 CAS No: 629-62-9 EC No: 211-098-1 Appearance: colourless liquid Melting point: 9.9 °C Boiling point: 268 - 270 °C Flashpoint: 132°C
Name : decyl alcohol Molecular formula: C10H22O CAS No: ff2-Jtf-f EINECS No: 203-956-9 Appearance: colourless liquid Melting point: 7 C Boiling point: 233 C Flash point: 82 C Autoignition temperature: 287 C
Name : Lauryl alcohol Molecular formula: Ci2H260 Molecular weight: 186.2 CAS No: [112-53-8] Appearance: Colorless solid Melting point:: 24 °C

13 "

Boiling point:: 259 °C Flashpoint: 127 °C
Specific thermoformable properties of the fabric with respect to the desired temperature zones are adjusted by careful blend of the thermoregulatory constituents in specific proportions. The thermoregulatory constituent is selected such that it has a melting point that falls within the range of temperature in which thermal regulation is desired to be achieved. Thus, if thermal regulation is desired in the range of 21 -30 °C, then the melting point of the thermoregulatory constituent must fall within this range. Again if the fabric is to be used in climatic regions, where regulation is desired below 20 °C, then the thermoregulatory constituent having melting point below 20 °C is used. The thermoregulatory acrylic fabric acts as a transient thermal barrier "by protecting the wearer ol this, fabric from the effects of cold or hot environments. When such thermoregulatory acrylic fabric is subjected to heating from the sun or a hot environment, it will absorb transient heat as it changes phase from solid to liquid, and it will prevent the temperature of the fabric from rising by keeping it constant at the tfielting point temperature of the thermoregulatory constituent. Once thermoregulatory constituent has completely melted, its transient effect will cease and the temperature of the fabric will rise. In a similar manner, when a thermoregulatory fabric is subjected to a cold environment where the temperature is below its crystallization point, it will interrupt the cooling effect of the fabric Structure by changing phase from liquid to solid, and the temperature of fabric will be kept constant at the crystallization point. Once all the thermoregulatory constituents have crystallized, the fabric temperature will drop, and the thermoregulatory constituents will have no effect on the fabric's thermal performance.
14

Thus, the thermal performance of a thermoregulatory constituent is a function of phase change temperature, the amount of thermoregulatory constituent and the amount of energy it absorbs or releases during a phase change.
In accordance with this invention there is provided a thermoregulatory acrylic formulation meant for manufacture of acrylic products comprising :
■ at least one non-water-soluble thermoregulatory constituent having a melting point lying in a predetermined range of temperature said constituent being in the range of about 0.01 to 7% of the mass of the formulation ,
■ at least one water soluble nonionic surfactant having HLB value in the range of 9 to 40,said surfactant being in the range of 0.001 to 3 % of the mass of the formulation,
■ acrylic polymer in the range of about 1 to 15% of the mass of the formulation,
■ a solvent for polyacrylonitrile in the range of 20 to 60% of the mass of the formulation; and
■ water in the range of about 5 % to 60 % of the mass of the formulation.
In accordance with the invention, one or more thermoregulatory constituent is selected from a group consisting of nonadecane, eicosane, heptadecane, octadecane, hexadecane, pentadecane decyl alcohol, lauryl alcohol and myristyl alcohol.
The thermoregulatory constituent imparts thermoregulation property to the fibers and ultimately to the fabric or garments made from these fibers.
15

Preferably, paraffin wax either alone or in combination with stearyl alcohol is used as the non-aqueous solvent.
In accordance with this invention only water soluble non-ionic siirfactant/co-
surfactant selected from a group consisting of alkyl phenoxy ethoxylated non-ionic
surfactants and ethoxylated alkyl alcohol surfactants, Polyethylene-block-Poly
propylene glycol-block-polyethylene glycol and Ethylenediamine
tetrakis(propylene oxide-block-ethylene oxide) tetrol is used. Typically, the alkyl
phenoxy ethoxylated non-ionic surfactant is at least one selected from a group
consisting of Polyoxyethylene(8) isooctylphenyl ether, Nonylphenol polyethylene
glycol ether, Polyoxyethylene(9) nonylphenyl ether, Polyoxyethylene(lO)
isooctylphenyl ether, Polyoxyethylene(12) nonylphenyl ether, Polyoxyethylene(12)
isooctylphenyl ether, Polyoxyethylene(40) nonylphenyl ether, Polyoxyethylene(40)
isooctylphenyl ether, Polyoxyethylene(lOO) nonylphenyl ether,
Polyoxyethylene( 150) dinonylphenyl ether, Surfonic N-95(Poly (oxy-1, 2-
ethanediyl), alpha- (nonyl phenyl)-omega-hydroxyl-glycol ether) ( nonylphenol
9.5-mole ethoxylate) , Surfonic N-95(Poly (oxy-1, 2-ethanediyl), alpha- (nonyl
phenyl)-omega-hydroxyl-glycol ether) ( nonylphenol 9.5-mole ethoxylate) ,
Surfonic N-120(nonylphenol 12-mole ethoxylate) , Surfonic N-150 (nonylphenol
15-mole ethoxylate), Surfonic N-200 (nonylphenol 20-mole ethoxylate) , Surfonic
N-300( nonylphenol 30-mole ethoxylate) , Surfonic N-400 nonylphenol 40-mole
ethoxylate, Surfonic LF-7 (Alkyl polyoxyalkylene ether) , Surfonic LF-17
(ethoxylated and propoxylated linear primary 12-14 carbon number alcohol),
Igepal CO-630 (nonylphenoxy poly(ethyleneoxy)ethanol,branched), Surfonic
DNP-40 (dinonylphenol ethoxylate glycol ether).
16

Typically, the solvent for polyacrylonitrile is at least one selected from a group consisting of sodium thiocyanate , dimethyl formamide, dimethyl acetamide, dimethyl sulfoxide, ethylene carbonate, aqueous zinc chloride and aqueous nitric acid. The polymer percentages in the acrylic dope will vary depending on the solvent. For dimethyl formamide, acrylic polymer concentration soluble in polymer dope is as high as 28-32%; for dimethyl acetamide, it is as high as 22-27%; for dimethyl sulfoxide, it is as high as 20-25%; for ethylene carbonate, it is as high as 15-18%, for aqueous nitric acid, it is as high as 8-12% and for zinc chloride, it is as high as 8-12%). For Sodium thiocyanate as a solvent, acrylic polymer concentration is as high as 10-15%.
The non-ionic surfactant is selected such that the lipophilic portion of the non-ionic surfactant is compatible with the thermoregulatory constituent and the surfactant forms oil in water niicroemulsion. Surfactants with HLB values within the range of 9 to 40 are used. Preferably, non-ionic surfactants with HLB values more than 13 are used.
In accordance with one preferred embodiment of the invention, the HLB value of the surfactant is between 16 and 40.
In accordance with one aspect of the invention, the thermoregulatory constituent, the solvent and the surfactant are processed to form micro-reservoirs which are embedded into the body of the formulation. The thermoregulatory acrylic product contains uniformly dispersed micro-reservoirs throughout the body of the fibers. The micro-reservoirs are discrete, nano-sized structures without any definite geometrical shape.
17

Typically, the average mean size of the micro-resefvoir is in the range of 5 nm to 2000 nm.
The invention also extends to a thermoregulatory acrylic fiber, yarn and fabric manufactured from a formulation in accordance with this invention.
In accordance with this invention there is also provided a process for preparation of a thermoregulatory acrylic formulation meant for manufacture of acrylic products comprising the following steps:
• selecting a non-water-soluble thermoregulatory constituent having a melting point lying in a predetermined range and heating said constituent upto 95 C to form a non-aqueous phase ;
• dissolving and stirring a surfactant, optionally with a co-surfactant, a solvent for polyacrylonitrile in water to obtain an aqueous phase;
• heating the aqueous phase;
• mixing the aqueous phase with the non-aqueous phase in liquid state to form an admixture, and homogenizing to obtain a micro-emulsion;
• mixing the micro-emulsion with an acrylic polymer solution in a solvent and water and further homogenizing and dispersing the micro-emulsion to obtain a preform mass wherein the thermoregulatory constituent is in the form of evenly dispersed micro-reservoirs.
Typically, the pH of the aqueous phase is in the range of 7 to 13.
Typically, the amount of non-aqueous phase in the micro-emulsion is in the range of 0.1 to 40% of the mass of the micro-emulsion.
18

Typically, the amount of surfactant in the micro-emulsion is in the range of 0.1 to 20% of the mass of the micro-emulsion.
Typically, the proportion of thermoregulatory constituent in the acrylic product is in the range of 0.01 to 30% with respect to the mass of the acrylic product.
Before arriving at the optimum concentration of the surfactant to be used, cloud point of the aqueous phase is determined. Furthermore, alkalinity of the aqueous phase matches with that of the acrylic polymer dope thereby avoiding any drastic change in the alkalinity during the emulsification and homogenization step.
Typically, the melted non-aqueous phase containing thermoregulatory constituent in a non-aqueous solvent along with aqueous phase containing surfactants is emulsified using high speed mixers such as Ultraturrex or a mechanical emulsifier; a colloid mill; a high pressure homogenizer and an ultrasonic emulsifier to form a microemulsion. The micro-emulsion may contain further additional thermoregulatory constituents, if desired.
It is important that the non-aqueous phase is maintained in liquid state throughout the mixing process. The aqueous phase therefore is typically heated upto a particular temperature to ensure that the temperature of the resulting emulsion is above the melting point of the thermoregulatory constituent. If this does not happen, the resulting emulsion will break down.
Typically, the proportion of thermoregulatory constituent in the acrylic product is in the range of 0.01 to 30% with respect to the mass of the acrylic product.
19

The active ingredients are released from the micro-reservoir into the acrylic matrix. The structure of micro-reservoir, acrylic and surrounding conditions determine the release rate of the thermoregulatory constituent. The molecules of the volatile thermoregulatory constituents migrate from micro-reservoirs to the surrounding primarily by diffusion. The thermoregulatory constituent is released from the matrix in a controlled release manner.
Preform mass is spun to fiber in a bath containing 12.5% of Sodium thiocyanate solution. The temperature of the bath is maintained at -2.5°C. Thereafter, the fiber is cold stretched, gel treated at pH 2.8 at 45°C, then hot stretch at 90°C. The void in the fibers is removed by treating the fiber at 125°C. Fiber is then relaxed and annealed at 120 C and then taken up for post-treatment.
The acrylic fibers can be further subjected to post treatment to make fabric which
typically involves:
o Convert to Yarn in blend or pure
o Convert to Warp Beam
o Sizing
o Fabric Manufacturing- Weaving /Knitting
o Dyeing
o Finishing
Alternatively, the filaments so obtained are further blended using standard equipment. The blended fibers are laid in to a web using standard equipment followed by Consolidation of the web to obtain Non-woven Acrylic Fabric.
The acrylic product made from the formulation in accordance with this invention contains uniformly dispersed micro-reservoirs throughout the mass which is shown in Fig. 2.
20

The thermoregulatory acrylic fibers contain the entrapped thermoregulatory constituent in releasable form. Microscopic examination of the micro-reservoirs in the acrylic fibers is shown in Fig 2.
Thermoregulatory fabric improves the comfort of people irrespective of the fluctuations in the temperature of their surroundings on either side. Besides this, thermoregulatory fabric also improves the comfort of people as their body goes through a very active state (high metabolic production) to an inactive state on an intermittent basis in a cold environment. This feature is of particular relevance for outdoor sportsmen.
The resultant acrylic fabric containing thermoregulatory constituent are tested. Linear Density (Denier) of the acrylic Fibers is determined by using standard ASTM Test Method (D 1577). The denier of the standard acrylic fiber (acrylic fiber without any thermoregulatory constituents) and thermoregulatory enriched acrylic fiber remains the same. Thus addition of thermoregulatory constituents does not change the linear density of the acrylic fibers.
Tensile strength and Young's modulus of acrylic fiber sample is tested on an Instron tensile testing machine as per the ASTM CI557-03 procedure at ambient temperature.
Visual appearance of the thermoregulatory enriched fiber is evaluated by methods as prescribed in AATCC 124. As far as parameters like % Loss in Dry Tenacity and % loss in dry elongation are concerned, these remain the same in the thermoregulatory enriched acrylic fiber and the standard fiber. Incorporation of thermoregulatory constituent in accordance with this invention does not affect the visual appearance of the fiber.
21

Feel of the fiber: The thermoregulatory enriched acrylic fiber as prepared in accordance with this invention offers the same feel effect as is observed in case of plain acrylic fiber without any thermoregulatory constituent (Also referred as standard).
Another important concern in textile industry is dye-ability of the fabric, which is tested by comparing the dyeability of the thermoregulatory constituent enriched fabric and the standard acrylic fabric. Dyeability of the thermoregulatory enriched acrylic fibers as prepared in accordance with this invention remains the same as that of the standard acrylic fiber.
The invention will now be described with the help of the following non-limiting examples.
Examples Example 1
Example 1A- Preparation of micro emulsion
Myristyl alcohol (200gm) and hexadecane (50 gm) were heated upto 50°C.
Surfonic N-400 nonylphenol 40-mole ethoxylate (surfactant) ( 28 gm ) was
dissolved and stirred in water 525 ml and Sodium thiocyanate (250 gm) to
obtain (803 gm) of aqueous phase.
The aqueous phase (803 gm) was heated temperature of the molten non-aqueous
phase (250 gm) and both the phases were homogenized in a high speed mixer
(Ultraturrex) to obtain a micro-emulsion (1053 gm).
Example 1 B- Preparation of fiber
22

(1053 gm) of micro-emulsion as prepared in Example 1A was mixed at 50 C with acrylic Polymer Dope containing 5000gm of acrylic polymer and 16670 gm of sodium thiocyanate and 20000 ml of water were added to obtained preform mass. Preform mass was spun in a bath containing 12.5% of Sodium thiocyanate solution. The temperature of the bath was maintained at -2.5°C. Thereafter, the fiber was cold stretched, gel treated at pH 2.8 at 45°C, then hot stretch at 90°C. The void in the fibers was removed by treating the fiber at 125°C. Fiber is then relaxed and annealed at 120°C and then taken up for post-treatments and was spun into fiber.
The acrylic fiber thus obtained contained micro-reservoirs having the entrapped releasable thermoregulatory constituents. Although the micro reservoirs did not have any specific shape or size, they were found to be uniformly distributed throughout the body of the fiber.
Example 2
Example 2A- Preparation of micro emulsion
Nonadecane (200gm) and hexadecane (50 gm) were heated upto 50°C. Surfonic N-
400 nonylphenol 40-mole ethoxylate (surfactant) ( 28 gm ) was dissolved and
stirred in water 525 ml and sodium thiocyanate (250 gm) to obtain (803 gm) of
aqueous phase.
The aqueous phase (803 gm) was heated temperature of the molten non-aqueous
phase (250 gm) and both the phases were homogenized in a high speed mixer
(Ultraturrex) to obtain a micro-emulsion (1053 gm).
23

Example 2 B- Preparation of fiber
(1053 gm) of micro-emulsion as prepared in Example 2A was mixed at 50°C with acrylic Polymer Dope containing 5000gm of acrylic polymer and 16670 gm of sodium thiocyanate and 20000 ml of water were added to obtained preform mass and was spun into fiber as described in example 1.
Example 3
Example 3 A
Pentadecane (200gm) and Myristyl alcohol (50 gm) were heated -upto 40°C.
Surfonic N-400 nonylphenol 40-mole ethoxylate (surfactant) ( 28 gm ) was
dissolved and stirred in water 525 ml and sodium thiocyanate (250 gm) to obtain
(803 gm) of aqueous phase.
The aqueous phase (803 gm) was heated temperature of the molten non-aqueous
phase (250 gm) and both the phases were homogenized in a high speed mixer
(Ultraturrex) to obtain a micro-emulsion (1053 gm).
Example 3 B- Preparation of fiber
(1053 gm) of micro-emulsion as prepared in Example 3A was mixed at 50°C with acrylic Polymer Dope containing (5000gm) of acrylic polymer and (16670 gm) of sodium thiocyanate and 20000 ml of water were added to obtained preform mass and was spun into fiber as described in example 1.
Example 4
Example 4 A
Preparation of thermoregulatory formulation
Nonadecane (200gm) and octadecane (50 gm) were heated upto 45°C. Surfonic N-
400 nonylphenol 40-mole ethoxylate (surfactant) ( 28 gm ) was dissolved and
24

stirred in water 525 ml and sodium thiocyanate (250 gm) to obtain (803 gm) of aqueous phase.
The aqueous phase (803 gm) was heated temperature of the molten non-aqueous phase (250 gm) and both the phases were homogenized in a high speed mixer (Ultraturrex) to obtain a micro-emulsion (1053 gm).
Example 4 B
Preparation of fiber
(1053 gm) of micro-emulsion as prepared in Example 4A was mixed at 50°C with
acrylic Polymer Dope containing (5000gm) of acrylic polymer and (16670 gm) of
sodium thiocyanate and 20000 ml of water were added to obtained preform mass
and was spun into fiber as described in example 1.
Example 5
Example 5 A
Preparation of thermoregulatory formulation
Icosane (1 lOgm) and hexadecane (140 gm) were heated upto 45°C. Surfonic N-400
nonylphenol 40-mole ethoxylate (surfactant) ( 28 gm ) was dissolved and stirred
in water 525 ml and sodium thiocyanate (250 gm) to obtain (803 gm) of aqueous
phase.
The aqueous phase (803 gm) was heated temperature of the molten non-aqueous
phase (250 gm) and both the phases were homogenized in a high speed mixer
(Ultraturrex) to obtain a micro-emulsion (1053 gm).
Example 5 B- Preparation of fiber
(1053 gm) of micro-emulsion as prepared in Example 5A was mixed at 50°C with
acrylic Polymer Dope containing 1086 gm of acrylic polymer and 3620 gm of
25

sodium thiocyanate and 4340 ml of water were added to obtained preform mass and was spun into fiber as described in example 1.
Example 6
Example 6 A
Preparation of thermoregulatory formulation
Nonadecane (HOgm) and hexadecane (140 gm) were heated upto 45°C. Surfonic
N-400 nonylphenol 40-mole ethoxylate (surfactant) ( 28 gm ) was dissolved and
stirred in water 525 ml and sodium thiocyanate (250 gm) to obtain (803 gm) of
aqueous phase.
The aqueous phase (803 gm) was heated temperature of the molten non-aqueous
phase (250 gm) and both the phases were homogenized in a high speed mixer
(Ultraturrex) to obtain a micro-emulsion (1053 gm).
Example 6 B- Preparation of fiber
(1053 gm) of micro-emulsion as prepared in Example 6A was mixed at 50°C with acrylic Polymer Dope containing (5000gm) of acrylic polymer and (16670 gm) of sodium thiocyanate and 20000 ml of water were added to obtained preform mass and was spun into fiber as described in example 1.
Example 7
Example 7 A
Preparation of thermoregulatory formulation
Eicosane (lOOgm) and hexadecane (150 gm) were heated upto 45°C. Surfonic N-
400 nonylphenol 40-mole ethoxylate (surfactant) ( 28 gm ) was dissolved and
stirred in water 525 ml and sodium thiocyanate (250 gm) to obtain (803 gm) of
aqueous phase.
26

The aqueous phase (803 gm) was heated temperature of the molten non-aqueous phase (250 gm) and both the phases were homogenized in a high speed mixer (Ultraturrex) to obtain a micro-emulsion (1053 gm).
Example 7 B- Preparation of fiber
(1053 gm) of micro-emulsion as prepared in Example 7A was mixed at 50 C with acrylic Polymer Dope containing (5000gm) of acrylic polymer and (16670 gm) of sodium thiocyanate and 20000 ml of water were added to obtained preform mass and was spun into fiber as described in example 1.
Example 8
Example 8 A
Preparation of thermoregulatory formulation
Heptadecane (lOOgm) and hexadecane (150 gm) were heated upto 45°C. Surfonic
N-400 nonylphenol 40-mole ethoxylate (surfactant) ( 28 gm ) was dissolved and
stirred in water 525 ml and sodium thiocyanate (250 gm) to obtain (803 gm) of
aqueous phase.
The aqueous phase (803 gm) was heated temperature of the molten non-aqueous
phase (250 gm) and both the phases were homogenized in a high speed mixer
(Ultraturrex) to obtain a micro-emulsion (1053 gm).
Example 8 B- Preparation of fiber
(1053 gm) of micro-emulsion as prepared in Example 8 A was mixed at 50°C with acrylic Polymer Dope containing (5000gm) of acrylic polymer and (16670 gm) of sodium thiocyanate and 20000 ml of water were added to obtained preform mass and was spun into fiber as described in example 1.
27"

Example 9
Example 9A- Preparation of micro emulsion Preparation of thermoregulatory formulation
Nonadecane (250 gm) was heated upto 40°C. Surfonic N-400 nonylphenol 40-mole ethoxylate (surfactant) ( 28 gm ) was dissolved and stirred in water 525 ml and sodium thiocyanate (250 gm) to obtain (803 gm) of aqueous phase. The aqueous phase (803 gm) was heated temperature of the molten non-aqueous phase (250 gm) and both the phases were homogenized in a high speed mixer (Ultraturrex) to obtain a micro-emulsion (1053 gm).
Example 9 B- Preparation of fiber
(1053 gm) of micro-emulsion as prepared in Example 9A was mixed at 50°C with acrylic Polymer Dope containing 5000 gm of acrylic polymer and 16670 gm of sodium thiocyanate and 20000 ml of water were added to obtained preform mass and was spun into fiber as described in example 1.
Example 10
Example 10 A- Preparation of micro emulsion
Myristyl alcohol (I50gm ) pentadecane (100 gm) were heated upto 40°C. Surfonic
N-400 nonylphenol 40-mole ethoxylate (surfactant) ( 28 gm ) was dissolved and
stirred in water 525 ml and sodium thiocyanate (250 gm) to obtain (803 gm) of
aqueous phase.
The aqueous phase (803 gm) was heated temperature of the molten non-aqueous
phase (250 gm) and both the phases were homogenized in a high speed mixer
(Ultraturrex) to obtain a micro-emulsion (1053 gm).
Example 10 B- Preparation of fiber
28

(1053 gm) of micro-emulsion as prepared in Example 10A was mixed at 50°C with acrylic Polymer Dope containing 5000 gm of acrylic polymer and 16670 gm of sodium thiocyanate and 20000 ml of water were added to obtained 5000 gm preform mass and was spun into fiber as described in example 1.
Testing procedures:
The thermoregulatory acrylic products as prepared in the above examples (1 to 10) were tested by using following test procedures:
1) Linear Density (Denier) of the acrylicFibers was determined by using standard
ASTM Test Method (D 1577).
The denier of the standard acrylicfiber (without any thermoregulatory constituents) and thermoregulatory acrylic fibers as prepared in accordance with example IB was found to be uniform(1.5 denier) irrespective of the type and quantity of the thermoregulatory constituent.
2) Tensile strength and Young's modulus of acrylic fiber samples were tested on an Instron tensile testing machine as per the ASTM CI557-03 procedure at ambient temperature.
3) Emulsion stability: The stability of micro-emulsions as prepared in the above examples, was evaluated by keeping the same under observation in measuring cylinders for 3 days. During this period no phase separation was observed.
4) Feel of the fabric: The acrylic fabrics as prepared in the above examples and standard fabric (acrylic fabric without thermoregulatory constituents), were randomly given to twenty subjects and they were asked to evaluate the texture and feel of the fiber. The test fiber material was interchanged several times amongst the human subjects. Collective results as submitted by the human subjects confirmed that nobody could distinguish between the
29

thermoregulatory acrylic fabrics prepared in accordance with the Examples provided above and the standard fabric.
5) Dyeability: The thermoregulatory acrylic fabrics as prepared in the above
examples and the standard fabric as described above were dyed uniformly
with reactive dyes. No noticeable difference as to the Dyeability of the two
respective acrylic fabrics, with and without thermoregulatory constituent was
reported.
6) Visual appearance of the thermoregulatory acrylic fiber was evaluated by
methods as prescribed in AATCC 124. As far as parameters like % Loss in Dry
Tenacity and % loss in dry elongation are concerned, these remained the same
( and the standard fiber
7) Determination of enthalpy of the fabric specimen: the thermoregulatory properties of the specimen fabrics/fibers as prepared in examples 1 to 20 were evaluated by measuring respective enthalpies of the specimen. The enthalpies were measured using DSC (Differential scanning calorimetry) technique. The recorded enthalpies of the fiber and fabric obtained in examples 1 to 20 are provided in the Table 1.
30

Table 1

Specimen No. Enthalpy J/g Fiber Enthalpy J/g Fabric
1 5.5 45.4
2 6.4 6.38
3 5.6 5.63
4 6.02 5.98
5 37 36.3
6 7.6 7.58
7 8.4 8.41
8 7.2 7.19
9 7.6 7.6
10 5.2 5.24
8. Thermoregulatory Testing:
Free flowing robes made to fit the physique of twenty human volunteers, selected at random between ages 16 to 56, were made from undyed thermoregulatory acrylic fabric prepared in accordance with this invention. Simultaneously, identical robes with same design were also made from undyed standard fabric (Acrylic fabric without any thermo regulatory constituents).
A temperature monitored room was selected where the temperature could be precisely controlled. The human volunteers were made to randomly wear either a standard robe (robe made from standard fabric) or a robe made from the fabric of
31

this invention. But they were not informed about the type of the robe that was being worn. The temperature in the room was set at 21°C. The twenty human volunteers were requested to wear the robes and assemble in the room and be there in the room for a period of 30 min. After 30 minutes, all the volunteers were asked to step out into the outside non-air-conditioned environment, where the temperature was 28°C and they were asked to observe and note the time when they felt warm in the area covered by the robes.
Thereafter, all the volunteers switched their robes, ie: The volunteer given a robe of standard fabric, was allotted a robe made from the fabric of this invention and vise-a-versa. They were again asked to go back into the room and remain there for 30 min. and again step out into the external environment and again observe and note the time when they started feeling warm. The volunteers were then asked to give an evaluation of the time required to feel the warmth in both the instances. The results of the experiment were as follows.
Sixteen volunteers opined that they felt warm in the standard fabric, at least on an average of 90 sec. quicker than the fabric of this invention.
Three volunteers could not sense significant difference in time and one volunteer recorded an earlier feeling of warmth in case of the fabric of this invention.
In case of direct comparison between the robes, 18 volunteers opined that they felt cooler and more comfortable wearing a ward-robe made from the fabric of this invention.
Two volunteers expressed no significant difference between the two. There was no volunteer who provided any reverse finding.
Similar test was conducted in which the volunteers were made to go from a hotter external environment at 30 C to an air-conditioned environment maintained at 21°C. 18 of the volunteers expressed that they felt warmer and more comfortable in
32

the robe made from the fabric of this invention and the reported response time for feeling cold was on an average 3 min. "longer. Two of the volunteers could not discern any significant difference between the two robes.
It is thus concluded that the fabric made in accordance with this invention exhibits thermoregulatory effect in either situation, ie when there is a rise in temperature and when there is a fall in the temperature.
While considerable emphasis has been placed herein on the specific steps of the preferred embodiment, it will be appreciated that many alterations can be made and that many modifications can be made in the preferred embodiment without departing from the principles of the invention. These and other changes in the preferred embodiment as well as other embodiments of the invention will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.
33

We Claim:
1. A thermoregulatory acrylic formulation meant for manufacture of acrylic
products comprising :
■ at least one non-water-soluble thermoregulatory constituent having a
melting point lying in a predetermined range of temperature said constituent
being in the range of about 0.01 to 7% of the mass of the formulation ,
■ at least one water soluble nonionic surfactant having HLB value in the range of 9 to 40,said surfactant being in the range of 0.001 to 3 % of the mass of the formulation,
■ acrylic polymer in the range of about 1 to 15% of the mass of the formulation,
■ a solvent for polyacrylonitrile in the range of 20 to 60% of the -mass of the formulation; and
■ water in the range of about 5 % to 60 % of the mass of the formulation.

2. A formulation as claimed in claim 8, wherein the thermoregulatory constituent is at least one selected from a group consisting of nonadecane, eicosane, heptadecane, octadecane, hexadecane, pentadecane decyl alcohol, lauryl alcohol and myristyl alcohol.
3. A formulation as claimed in claim 1, wherein the surfactant is at least one non-ionic surfactant selected from a group of alkyl phenoxy ethoxylated non-ionic surfactants and ethoxylated alkyl alcohol surfactants, Poiyethylene-block-Poly
34

propylene glycol-block-polyethylene glycol and Ethylenediamine tetrakis(propylene oxide-block-ethylene oxide) tetrol.
4. A formulation as claimed in claim 4, wherein the alkyl phenol ethoxylates is
at least one selected from a group consisting of Polyoxyethylene(8)
isooctylphenyl ether, Nonylphenol polyethylene glycol ether,
Polyoxyethylene(9) nonylpheny 1 ether, Polyoxyethylene( 10) isooctylphenyl
ether, Polyoxyethylene(12) nonylphenyl ether, Polyoxyethylene(12)
isooctylphenyl ether, Polyoxyethylene(40) nonylphenyl ether,
Polyoxyethylene(40) isooctylphenyl ether, Polyoxyethylene(lOO) nonylphenyl
ether, Polyoxyethylene(150) dinonylphenyl ether, Surfonic N-95(Poly (oxy-1,
2-ethanediyl), alpha- (nonyl phenyl)-omega-hydroxyl-glycol ether) (
nonylphenol 9.5-mole ethoxylate) , Surfonic N-95(Poly (oxy-1, 2-ethanediyl),
alpha- (nonyl phenyl)-omega-hydroxyl-glycol ether) (nonylphenol 9.5-mole
ethoxylate) , Surfonic N-120(nonylphenol 12-mole ethoxylate) , Surfonic N-
150 (nonylphenol 15-mole ethoxylate), Surfonic N-200 (nonylphenol 20-mole
ethoxylate) , Surfonic N-300( nonylphenol 30-mole ethoxylate) , Surfonic N-
400 nonylphenol 40-mole ethoxylate, Surfonic LF-7 (Alkyl polyoxyalkylene
ether) , Surfonic LF-17 (ethoxylated and propoxylated linear primary 12-14
carbon number alcohol).
5. A formulation as claimed in claim 1, wherein the preferred HLB value of the surfactant is between 16 and 40.
6. A formulation as claimed in claim 1, wherein the solvent for polyacrylonitrile is at least one selected from a group consisting of sodium thiocyanate ,
35

dimethyl formamide, dimethyl acetamide, dimethyl sulfoxide, ethylene carbonate, aqueous zinc chloride and aqueous nitric acid.
7. A formulation as claimed in claim 1, wherein the average mean size of the micro-reservoir is in the range of 5 nm to 2000 nm.
8. A thermoregulatory acrylic fiber manufactured from a formulation as claimed in claim 1.
9. A thermoregulatory acrylic yarn manufactured from a formulation as claimed in claim 1.
10.A thermoregulatory acrylic fabric manufactured from a formulation as claimed in claim 1.
1 l.A process of preparation of a thermoregulatory acrylic formulation meant for manufacture of acrylic products comprising the following steps :
• selecting a non-water-soluble thermoregulatory constituent having a melting
point lying in a predetermined range and heating said constituent upto 95°C
to form a non-aqueous phase ;
• dissolving and stirring a surfactant, optionally with a co-surfactant, a
solvent for acrylic polymer in water to obtain an aqueous phase;
• heating the aqueous phase;
• mixing the aqueous phase with the non-aqueous phase in liquid state to form an admixture, and homogenizing to obtain a micro-emulsion;
36

mixing the micro-emulsion with an acrylic polymer solution in a solvent and water and further homogenizing and dispersing the micro-emulsion to obtain a preform mass wherein the thermoregulatory constituent is in the form of evenly dispersed micro-reservoirs.

,rd
Dated this 3rd day of July, 2008

Mohan Dewan of R. K. Dewan and Co.
Applicants' Patent Attorney

37

Documents:

1393-MUM-2008-ABSTRACT.doc

1393-MUM-2008-ABSTRACT.pdf

1393-MUM-2008-ANNEXURE TO FORM 3(26-9-2012).pdf

1393-MUM-2008-CLAIMS(AMENDED)-(26-9-2012).pdf

1393-MUM-2008-CLAIMS.doc

1393-MUM-2008-CLAIMS.pdf

1393-MUM-2008-CORRESPONDENCE(13-04-2010).pdf

1393-mum-2008-correspondence(18-7-2008).pdf

1393-MUM-2008-CORRESPONDENCE(24-7-2009).pdf

1393-MUM-2008-CORRESPONDENCE(28-6-2013).pdf

1393-MUM-2008-CORRESPONDENCE.pdf

1393-MUM-2008-DESCRIPTION(COMPLETE).doc

1393-MUM-2008-DESCRIPTION(COMPLETE).pdf

1393-MUM-2008-DRAWING.pdf

1393-MUM-2008-EP DOCUMENT(26-9-2012).pdf

1393-mum-2008-form 1(18-7-2008).pdf

1393-MUM-2008-FORM 1(28-6-2013).pdf

1393-MUM-2008-FORM 1(MARKED COPY)-(28-6-2013).pdf

1393-MUM-2008-FORM 1.pdf

1393-MUM-2008-FORM 18(24-7-2009).pdf

1393-MUM-2008-FORM 2(TITLE PAGE).pdf

1393-MUM-2008-FORM 2.doc

1393-MUM-2008-FORM 2.pdf

1393-MUM-2008-FORM 26(26-9-2012).pdf

1393-MUM-2008-FORM 3(13-04-2010).pdf

1393-mum-2008-form 3(13-4-2010).pdf

1393-mum-2008-form 3(3-7-2008).pdf

1393-MUM-2008-FORM 3.pdf

1393-MUM-2008-MARKED COPY(26-9-2012).pdf

1393-MUM-2008-PETITION UNDER RULE-137(28-6-2013).pdf

1393-MUM-2008-REPLY TO EXAMINATION REPORT(26-9-2012).pdf

1393-MUM-2008-SPECIFICATION(AMENDED)-(26-9-2012).pdf

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Patent Number

256674

Indian Patent Application Number

1393/MUM/2008

PG Journal Number

29/2013

Publication Date

19-Jul-2013

Grant Date

15-Jul-2013

Date of Filing

03-Jul-2008

Name of Patentee

ADITYA BIRLA SCIENCE & TECHNOLOGY CO. LTD.

Applicant Address

ADITYA BIRLA CENTRE, 2ND FLOOR, C WING, S.K. AHIRE MARG, MUMBAI,

Inventors:

#	Inventor's Name	Inventor's Address
1	LODHA PREETI	ADITYA BIRLA CENTRE, 2ND FLOOR, C WING, S.K. AHIRE MARG, MUMBAI-400 025,
2	KAPOOR BIR	ADITYA BIRLA CENTRE, 2ND FLOOR, C WING, S.K. AHIRE MARG, MUMBAI-400 025,
3	MAHAJAN TUSHAR	ADITYA BIRLA CENTRE, 2ND FLOOR, C WING, S.K. AHIRE MARG, MUMBAI-400 025,
4	LODHA PREETI	ADITYA BIRLA CENTRE, 2ND FLOOR, C WING, S.K. AHIRE MARG, MUMBAI-400 025,
5	KAPOOR BIR	ADITYA BIRLA CENTRE, 2ND FLOOR, C WING, S.K. AHIRE MARG, MUMBAI-400 025,
6	MAHAJAN TUSHAR	ADITYA BIRLA CENTRE, 2ND FLOOR, C WING, S.K. AHIRE MARG, MUMBAI-400 025,

PCT International Classification Number

A41B11/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	1259/MUM/2007	2007-07-03	India