Title of Invention	A method for making surface functionalised bicomponent fibre
Abstract	The invention relates to producing polyester fibres, with high and durable wicking properties and good retention of tensile properties. Many approaches like modifying the cross section of the fibre, modification of fibre surface and chemically modifying the polymer prior to spinning have been patented as approaches for achieving moisture management properties in polyester fibres. Chemical approaches are known to give high and durable wicking, while surface treatment are known to give enhanced wicking without loss of other bulk properties. In the present invention, high and durable wicking polyester fibres have benn prepared by a novel approach of surface funtionalisation of polyester fibres, wherein benefits of chemical modification and surface modifications can be effectively combined. In the present invention, a hydrophilic masterbatch was gravimetrically fed to the main polymer stream during melt spinning to obtain fibres having good and durable moisture management properties. Addition of the masterbatch was also restricted to sheath in a bicomponent sheath/core spinning system to get the effect. In addition, the work has shown that by reducing the sheath component (restricting addition closer to surface), while keeping the masterbatch addition on sheath same, improved wicking could be achieved. Alternately, under reduced sheath component, similar transport levels could be achieved with a lower percentage of materbatch addition on sheath.

Title of Invention

A method for making surface functionalised bicomponent fibre

Abstract

The invention relates to producing polyester fibres, with high and durable wicking properties and good retention of tensile properties. Many approaches like modifying the cross section of the fibre, modification of fibre surface and chemically modifying the polymer prior to spinning have been patented as approaches for achieving moisture management properties in polyester fibres. Chemical approaches are known to give high and durable wicking, while surface treatment are known to give enhanced wicking without loss of other bulk properties. In the present invention, high and durable wicking polyester fibres have benn prepared by a novel approach of surface funtionalisation of polyester fibres, wherein benefits of chemical modification and surface modifications can be effectively combined. In the present invention, a hydrophilic masterbatch was gravimetrically fed to the main polymer stream during melt spinning to obtain fibres having good and durable moisture management properties. Addition of the masterbatch was also restricted to sheath in a bicomponent sheath/core spinning system to get the effect. In addition, the work has shown that by reducing the sheath component (restricting addition closer to surface), while keeping the masterbatch addition on sheath same, improved wicking could be achieved. Alternately, under reduced sheath component, similar transport levels could be achieved with a lower percentage of materbatch addition on sheath.

Full Text	FORM 2 THE PATENTS ACT, 1970 (39 of 1970) As amended by the Patents (Amendment) Act, 2005 & The Patents Rules, 2003 As amended by the Patents (Amendment) Rules, 2005 PROVISIONAL SPECIFICATION (See section 10 and rule 13) TITLE OF THE INVENTION MODIFIED SURFACE FUNCTIONALIZED POLYESTER FIBRES, FILAMENT YARNS OR FABRICS AND PROCESS FOR PRODUCING THE SAME APPLICANTS Name: Reliance Industries Limited Address : Reliance Technology Center, B-4 MIDC Industrial Area, Patalganga 410220, Dist Raigad, Maharashtra, India Nationality: Indian company incorporated under the Companies Act 1956 INVENTORS Name : Nadkarni Vikas Madhusudan Address : A18 Garden Estate, Off DP Road, Aundh.Pune —411007, Maharashtra, India Nationality: Indian Name: Gurudatt Krishnamurthy Address : No. 12, Dattatreya road, Basavanagudi, Bangalore 560 004. Karnataka India Nationality: Indian Name : Mukhopadhyay Anjan Kumar Address : B-203, Neel Orchid, Plot No.41, Sector 10, Khanda Colony, New Panvel (West), Navi Mumbai 410206 Maharashtra India Nationality: Indian Name : Kashetwar Abhijit Vasantrao Address : Gandhinagar, Ami. Dist - Yavatmal - 445103 (M.S.) Maharashtra India Nationality: Indian PREAMBLE TO THE DESCRIPTION The following specification particularly describes the nature of this invention and the manner in which it is to be performed : FIELD OF THE INVENTION The invention relates to modified surface functionalized polyester fibres, filament yarns or fabrics having high and durable wicking characteristics. The present invention also relates to method for producing the above modified surface functionalized polyester fibres or filament yams or fabrics which have high and durable wicking characteristics. BACKGROUND OF THE INVENTION Fabrics made from polyester fibres are popular for their easy care and durable properties. However they are predominantly used in blend with fibres like cotton, viscose and wool, mainly due to their lack of comfort properties. One of the major aspects of comfort is sweat management to keep a favourable microclimate next to skin. The attribute, which is desired in a fibre for good sweat management is wicking. Wicking is the spontaneous flow of liquid driven by capillary and wetting forces. Polyesters due to their hydrophobic nature inherently lack in wicking. The unmodified polyester fibres do not show high wicking. It is known in the art to improve wicking of polyester fabrics / fibres by various ways. One of the various ways is to apply finish treatments on fabrics to improve wicking (US patent 2005 101209). However these treatments at best are semi durable. Another way is to apply topical coating on the polyester fabric to improve wicking. However, the coating gets reduced and finally completely washed off after repeated washing and hence not durable. Yet another way known in the art is to modify the 2 polyester fibre either physically (by using fine deniers or by creating surface roughness or by modifying cross section of fibres (US patent 97 992045, WO 9836027)) or chemically (US patent 2002 6623853). The physical modifications are easier to achieve, but found to be ineffective in the absence of finish treatment. Further wicking property is not durable after repeated washing. Chemical modifications give the most effective and durable results, but have limitations in terms of reduced productivity due to temperature limitations of polymerisation and adverse effect on other properties like fibre tenacity (strength). Further the chemical modification is a very expensive method as it involves bulk treatment. Yet another known method to improve wicking is by modifying only the surface of the polyester by alkali treatment (J.Dave, R.Kumar & H.C.Srivastava, Studies on modification of polyester fibres I- Alkaline hydrolysis, J. Appl. Poly. Sci., 33, 455-477 (1987)), enzyme treatment (US patent 2002 6436696) and plasma treatments (Leroux, F.; Perwuelz, A.; Campagne, C; Behary, N. Journal of Adhesion Science and Technology, 20 (9), 939-957 (2006)). Surface treatments result in enhanced wicking, while retaining the other properties of the fibres like tenacity. However surface treatments have their set of drawbacks. Alkali treatment suffers from loss of wicking after wet processing like dyeing. Enzyme and plasma treatments are not yet commercially established and in any case their usage would be restricted to application on fabrics. In view of the above prior art, the art desires a polyester fibre or filament or textile with improved wicking property based on surface functionalization but at the 3 same time retaining the physical properties of the polyester, durability and having efficacy of a chemically modified fibre or filament or fabric. The present invention provides the solution to the aforesaid prior art needs. OBJECTS OF THE INVENTION An object of the present invention is to provide modified surface functionalized polyester fibres /filaments that possess high wicking characteristics. Another object of the present invention is to provide modified surface functionalized polyester fibres /filaments having high wicking characteristic which is durable. Yet another object of the present invention is to provide modified surface functionalized polyester fibres /filaments having high wicking characteristic and durable yet retaining other physical properties to a greater extent. Yet another object of the present invention is to provide modified surface functionalized polyester fibres /filaments having high wicking characteristic and durable yet retaining other physical properties to a greater extent without need of any additional surface treatment like finish treatment. Yet another object of the present invention is to provide modified surface functionalized polyester fibres /filaments having high wicking characteristic and 4 durable, yet retaining other physical properties to a greater extent without need of any additional surface treatment like finish treatment thereby making the product efficient and cost-effective. Yet another object of the present invention is to provide a method for producing the above modified surface functionalized polyester fibres /filaments having high wicking characteristic and durability yet retaining other physical properties to a greater extent without need of any additional surface treatment like finish treatment. Yet another object of the present invention is to provide a method for producing the above modified surface functionalized polyester fibres /filaments having high wicking characteristic and durable yet retaining other physical properties to a greater extent without need of any additional surface treatment like finish treatment thereby making the process cost-effective. Yet another object of the present invention is to provide fabric prepared from modified surface functionalized polyester fibres /filaments having high wicking characteristic and durable, yet retaining other physical properties to a greater extent without need of any additional surface treatment like finish treatment thereby making the product efficient and cost-effective. 5 DETAILED DESCRIPTION: According to the invention, there is provided modified surface functionalized polyester fibres or filaments having high wicking characteristics comprising at least two polyester polymer components compounded in bi-component sheath-core geometry; the sheath polyester polymer component is chemically modified by using polyester which comprises hydrophilic additive in the form of master batch and size of the sheath polyester is reduced to upto 5 %. The sheath polymer is chemically modified by incorporating a master batch containing a hydrophilic additive. Typically additive used in the present invention are disclosed in WO 2006/008256. The master batch comprising 5 to 50% of hydrophilic additive is used to prepare the modified surface functionalized polyester of the invention. According to the present invention, there is also provided a method for producing the above modified surface functionalized polyester fibres or filaments having high wicking characteristic, the method comprising a) extruding at least two polyester polymer components at temperature in the range of 275 to 300 °C; b) melt spinning the extrudate at temperature in the range of 275 to 300°C to obtain bi-component fibres or filaments having sheath-core geometry; c) gravimetrically feeding a polyester polymer component comprising a hydrophilic additive in the form of a master batch into the stream of sheath 6 polymer either during the extrusion but at any stage before the melt spinning; and d) reducing size of the sheath polyester polymer component to upto a minimum of 5 % by controlling the relative extrusion thruput of sheath and core polymers. The above method is either a batch process or a continuous process. In the batch process the sheath and core polyester polymer components are added in the form of chips for extrusion, the master batch comprising hydrophilic additive is gravimetrically fed at any time during the extrusion, while in the continuous process, the sheath and core polyester polymer components are fed to spin beam from a continuous polymerization plant, the master batch comprising hydrophilic additive is gravimetrically added by a transfer line injection (extruder with 3 dimensional mixer) at any time into the melt flow manifold of the sheath polymer before melt spinning. The polyester polymer component used as a sheath component or core component is selected from polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polylactic acid, co-polyesters or combinations thereof in order to achieve additional functionality such as easy dyeability, cationic dyeability, flame retardance etc. Additives used for obtaining other specific attributes include those imparting hydrophobicity, fire retardancy, anti-static, anti soiling, inherent colour, adhesion, etc can also be added while preparing the master batch of polyester comprising hydrophilic additive. The sheath component is reduced to a minimum of 5% by adjusting the relative extrusion thruput of sheath and core polymers. As 7 example, the concentration of hydrophilic additive in the reduced sheath could be in the range of 0.625 % to 10%. The above method is either single stage process or two-stage process. The single stage process comprising : extruding at least two polyester polymer components at temperatures of 275 to 300°C, melt spinning the extrudate to produce filament yam having bi-component sheath-core geometry; gravimetrically feeding a polyester comprising at least one hydrophilic additive in the form of a master batch into the stream of the sheath polymer either during the extrusion but at any stage before melt spinning; quenching the filament yams at temperatures of 14 to 25°C; spinning the yam at speed in the range of 1000 to 2500 m/min; passing the yam over a pair of heated draw rollers between 60 to 180 °C; drawing the yarn to levels of 1.5 to 3.5; winding the filaments on bobbins between 3300 to 5000 m/min to obtain fully drawn yams (FDY). The two-stage method comprising : extruding at least two polyester polymer components at temperatures of 275 to 300°C, melt spinning the extrudate at temperature in the range of 275 to 300°C to produce filament yam having bi-component sheath-core geometry; gravimetrically feeding a polyester comprising at least one hydrophilic additive in the form of a master batch into the stream of the sheath polymer either during the extrusion but at any stage before melt spinning; quenching the filament yams at temperatures of 14 to 25°C; spinning the yam at speed in the range of 2500 to 8 4500 m/min; passing the yam over a pair of cold rollers; winding the filaments on bobbins between 2500 to 4500 m/min to obtain partially oriented yams (POY). According to the present invention there is also provided a method for producing the above modified surface functionalized polyester staple fibres having high wicking characteristic, the method comprising a) extruding at least two polyester polymer components at temperature in the range of 275 to 300°C; b) melt spinning the extrudate at temperature in the range of 275 to 300°C to produce filament yam having bi-component sheath-core geometry; c) gravimetrically feeding a polyester comprising at least one hydrophilic additive in the form of a master batch into the stream of the sheath polymer either during the extrusion but at any stage before melt spinning; d) winding the spun tow at winding speed between 1000 to 2500 m/min to produce low oriented yam (LOY) in tow form; e) drawing the spun tow at temperature of 20 to 80° C and at a drawing ratio of 2.0 to 4.0; f) annealing the drawn tow using steam heated rollers; and g) crimping, drying and cutting the tows into staple fibres of desired length. The entire process of drawing to cutting takes place in a continuous line at speeds of 50 m/min to 400 m/min. The cross-section of the filament yarn or fibre is either circular or non-circular. 9 The fibres or filaments prepared from the modified surface functionalized polyester according to the invention have wicking height of 2.0 cms to more than 7.0 cms. (Evaluated in knit hose form of 90 gsm by vertical wicking test at 30 minutes). On 20 washes under harsh conditions the loss of wicking was observed is very minimal in the range of 5% to 15%. Thus the wicking characteristic of the fibres or filaments of the invention is durable at the same time retaining the tenacity of 80 to 100 %. Further reduction in sheath component to 15, 10 or 5% can also be carried out under specific process condition. The filament yams of the present invention can be further twisted or texturised. According to the invention there is provided a fabric having high and durable wicking characteristic while retaining the tensile properties prepared from the modified surface functionalized polyester fibres or filaments of the present invention by weaving or knitting method. According to the invention, the modified surface functionalized polyester fibres / filaments can be spun into blended yarns by mixing with other kinds of natural and/or synthetic fibres to produce fibre or filament having high and durable wicking characteristics while retaining physical properties like tenacity. 10 According to the invention, the modified surface functionalized polyester fibre / filament having high wicking characteristic and durability without sacrificing physical properties such as tensile strength, by restricting the chemically modified sheath polymer closest to the surface, by process control. Increase in wicking height is observed at lower level of additive content on the sheath polyester polymer component, when the size of the sheath component is reduced. This implies dependence of wicking/moisture transport on availability of active sites at the surface. With reducing sheath component, the ratio of available surface active sites for imparting desired functionality, to fibre volume would increase resulting in enhancement in wicking. Sheath-core configuration of the bicomponent melt spinning reduces the cost of the process as well as the product as it reduces the quantity of expensive additives by incorporating the same to sheath component only and not in bulk. Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms. Example 1 : Core component, polyethylene terephthalate and sheath component, polyethylene terephthalate was extruded in the ratio of 25 : 75, 50 : 50 and 75 : 25 at temperatures of 285 to 290°C and further melt spun to produce filament yarn having bi-component sheath-core geometry. The filament yam was quenched at temperatures of 20 to 22°C. The yam was spun at speed in the range of 1200 to 1400 m/min and further passed over a pair of heated draw rollers having temperature between 80 to 150°C. The yam was drawn to level of 11 2.4 to 2.9 and the filaments were wound on bobbins between 3500 to 4500 m/min to obtain fully drawn yam (FDY). The yam was further knitted to hose fabric. The fabric was tested for wicking height after 5 wash cycles and the results obtained are depicted in the Figure 1. Example 2: Core component, polyethylene terephthalate and sheath component, polyethylene terephthalate was extruded in the ratio of 25 : 75, 50 : 50 and 75 : 25 at temperatures of 285 to 290°C and further melt spun to produce filament yam having bi-component sheath-core geometry. 5 % of the master batch of polyethylene terephthalate comprising 25% of hydrophilic additive was gravimetrically added in sheath polyethylene terephthalate during the extrusion to obtain 1.25% additive content on the sheath. The filament yam was quenched at temperatures of 20 to 22° C. The yam was spun at speed in the range of 1200 to 1400 m/min and further passed over a pair of heated draw roller having temperature between 80 to 150 °C. The yam was drawn to level of 2.4 to 2.9 and the filaments were wound on bobbins between 3500 to 4500 m/min to obtain fully drawn yams (FDY). The yam was further knitted to hose fabric. The fabric was tested for wicking height after 5 wash cycles and the results obtained are depicted in the Figure 1. Example 3: Core component, polyethylene terephthalate and sheath component, polyethylene terephthalate was extruded in the ratio of 25 : 75, 50 : 50 and 75 : 25 at temperatures of 285 to 290°C and further melt spun to produce filament 12 yam having bi-component sheath-core geometry. 10% of the master batch of polyethylene terephthalate comprising 25% of hydrophilic additive was gravimetrically added in sheath polyethylene terephthalate during the extrusion to obtain 2.50 % additive content on the sheath. The filament yam was quenched at temperatures of 20 to 22°C. The yam was spun at speed in the range of 1200 to 1400 m/min and further passed over a pair of heated draw rollers having temperature between 80 to 150 °C. The yam was drawn to level of 2.4 to 2.9 and the filaments were wound on bobbins between 3500 to 4500 m/min to obtain fully drawn yam (FDY). The yam was further knitted to hose fabric. The fabric was tested for wicking height after 5 wash cycles and the results obtained are depicted in the Figure 1. Example 4: Core component, polyethylene terephthalate and sheath component, polyethylene terephthalate was extruded in the ratio of 25 : 75, 50 : 50 and 75 : 25 at temperatures of 285 to 290°C and further melt spun to produce filament yam having bi-component sheath-core geometry. 15% of the master batch of polyethylene terephthalate comprising 25% of hydrophilic additive was gravimetrically added in sheath polyethylene terephthalate during the extrusion to obtain 3.75% additive content on the sheath. The filament yam was quenched at temperatures of 20 to 22°C. The yam was spun at speed in the range of 1200 to 1400 m/min and further passed over a pair of heated draw roller having temperature between 80 to 150 °C. The yam was drawn to levels of 2.4 to 2.9 and the filaments were wound on bobbins between 3500 to 4500 m/min to obtain fully drawn yam (FDY). The yarn Was further knitted to hose fabric. The 13 fabric was tested for wicking height after 5 wash cycles and the results obtained are depicted in the Figure 1. Example 5 : Core component, polyethylene terephthalate and sheath component, polyethylene terephthalate was extruded in the ratio of 25 : 75, 50 : 50 and 75 : 25 at temperatures of 285 to 295°C and further melt spunto produce filament yam having bi-component sheath-core geometry. 20% of the master batch of polyethylene terephthalate comprising 25% of hydrophilic additive was gravimetrically added in sheath polyethylene terephthalate during the extrusion to obtain 5.0% additive content on the sheath. The filament yams was quenched at temperatures of 20 to 22°C. The yam was spun at speed in the range of 1200 to 1400 m/min and further passed over a pair of heated draw roller having temperature between 80 to 150 °C. The yarn was drawn to levels of 2.4 to 2.9 and the filaments were wound on bobbins between 3500 to 4500 m/min to obtain fully drawn yam (FDY). The yam was further knitted to hose fabric. The fabric was tested for wicking height after 5 wash cycles and the results obtained are depicted in the Figure 1. Wicking heights of knit hoses made from filament yarns of the present invention, after 5 wash cycles are depicted in the Figure 1. Figure 1 illustrates trend in wicking height in cms. (referred as 1) to sheath component (referred as 2), for various masterbatch component on sheath, 0% (referred as 3), 5%(referred as 4), 10%(referred as 5), 15%(referred as 14 6) and 20%(referred as 7). Wicking height was measured by Vertical wicking test based on DIN 53924. Washing of samples was carried out using AATCC method 135 at 40°C. The wicking height value is 5.2 for knit hose made with 20% mastebatch addition on sheath with 50% sheath component. On reducing the sheath component to 25% a wicking height of 7.65 is shown, at the same level of masterbatch addition on the sheath. With reducing the sheath size, the increase in wicking height for a given level of additive content in sheath is observed. Alternately, similar wicking heights are observed at lower level of additive content on sheath, when the sheath size is reduced. By this novel approach of reducing sheath component, enhanced surface functionlisation of polyester fibre/filament is being achieved. This implies dependence of wicking/moisture transport on availability of active sites at the surface. Wicking heights of knit hoses made from filament yarns according to the examples 1 to 5, after different wash cycles are shown in Table I for the specific sample prepared in 50/50 bi-component configuration. Table I Wicking heights of knit hose samples for sample in 50/50 Sheath core configuration at different wash cycles Masterbatchaddition onsheath(% wt.) After 5 Washes After 10 Washes After 20 Washes 0 0.2 - 5 0.8 0.7 0.8 10 2.4 2.2 2.1 15 3.0 3.1 2.9 15 20 5.2 4.8 4.2 Washing of samples was carried out using AATCC method 135 at 40*0. Loss of wicking height with number of washes is minimal and within acceptable limit in the art. Tenacity and retention of tenacity is also checked on the filament yams prepared according to the Examples 1 to 5. Tenacity and retention of tenacity vis-a-vis an unmodified polyester filament yam is compared in Table II for the filament yarns of the present invention. Table II Retention of tensile properties of polyester filament yarns (FDY - 75/36 Denier) Masterbatchaddition onsheath%wt Monocomponentwith masterbatchincorporation onwhole of fibre BICO ConfigurationS/C50/50 BICO ConfigurationS/C25/75 Tenacity (gpd) Retentionin tenacity% Tenacity (gpd) Retentionin tenacity% Tenacity (gpd) Retentionin tenacity% 5.0 - - 4.22 94.2 - - 10.0 4.26 95.1 4.32 96.3 15.0 3.99 89.1 4.01 89.6 4.39 98.0 20.0 3.69 82.4 3.90 87.1 4.15 92.7 Retention with respect to unmodified FDY sample having 4.48 gpd tenacity. Test carried out on Statimat 4 Tensile tester. 16 Retention of tenacity for 20% master addition on sheath with 50/50 configuration is 87.1 %, which improves to 92.7%, when the configuration is changed to 25775 at the same masterbatch addition on sheath. Retention of tenacity with respect to the unmodified polyester fibre/filament is better at a given masterbatch addition on sheath as the sheath size is reduced. Dated this the 23rd day of February 2007 17

Full Text

FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
As amended by the Patents (Amendment) Act, 2005
&
The Patents Rules, 2003
As amended by the Patents (Amendment) Rules, 2005
PROVISIONAL SPECIFICATION
(See section 10 and rule 13)
TITLE OF THE INVENTION
MODIFIED SURFACE FUNCTIONALIZED POLYESTER FIBRES, FILAMENT YARNS
OR FABRICS AND PROCESS FOR PRODUCING THE SAME
APPLICANTS
Name: Reliance Industries Limited
Address : Reliance Technology Center, B-4 MIDC Industrial Area, Patalganga 410220,
Dist Raigad, Maharashtra, India
Nationality: Indian company incorporated under the Companies Act 1956
INVENTORS
Name : Nadkarni Vikas Madhusudan
Address : A18 Garden Estate, Off DP Road, Aundh.Pune —411007, Maharashtra, India
Nationality: Indian
Name: Gurudatt Krishnamurthy
Address : No. 12, Dattatreya road, Basavanagudi, Bangalore 560 004.
Karnataka India
Nationality: Indian
Name : Mukhopadhyay Anjan Kumar
Address : B-203, Neel Orchid,
Plot No.41, Sector 10, Khanda Colony,
New Panvel (West), Navi Mumbai 410206
Maharashtra India
Nationality: Indian
Name : Kashetwar Abhijit Vasantrao
Address : Gandhinagar, Ami. Dist - Yavatmal - 445103 (M.S.)
Maharashtra India
Nationality: Indian
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the nature of this invention and the manner in which it is to be performed :

FIELD OF THE INVENTION
The invention relates to modified surface functionalized polyester fibres, filament yarns or fabrics having high and durable wicking characteristics.
The present invention also relates to method for producing the above modified surface functionalized polyester fibres or filament yams or fabrics which have high and durable wicking characteristics.
BACKGROUND OF THE INVENTION
Fabrics made from polyester fibres are popular for their easy care and durable properties. However they are predominantly used in blend with fibres like cotton, viscose and wool, mainly due to their lack of comfort properties. One of the major aspects of comfort is sweat management to keep a favourable microclimate next to skin. The attribute, which is desired in a fibre for good sweat management is wicking. Wicking is the spontaneous flow of liquid driven by capillary and wetting forces. Polyesters due to their hydrophobic nature inherently lack in wicking.
The unmodified polyester fibres do not show high wicking. It is known in the art to improve wicking of polyester fabrics / fibres by various ways. One of the various ways is to apply finish treatments on fabrics to improve wicking (US patent 2005 101209). However these treatments at best are semi durable. Another way is to apply topical coating on the polyester fabric to improve wicking. However, the coating gets reduced and finally completely washed off after repeated washing
and hence not durable. Yet another way known in the art is to modify the
2

polyester fibre either physically (by using fine deniers or by creating surface roughness or by modifying cross section of fibres (US patent 97 992045, WO 9836027)) or chemically (US patent 2002 6623853). The physical modifications are easier to achieve, but found to be ineffective in the absence of finish treatment. Further wicking property is not durable after repeated washing. Chemical modifications give the most effective and durable results, but have limitations in terms of reduced productivity due to temperature limitations of polymerisation and adverse effect on other properties like fibre tenacity (strength). Further the chemical modification is a very expensive method as it involves bulk treatment.
Yet another known method to improve wicking is by modifying only the surface of the polyester by alkali treatment (J.Dave, R.Kumar & H.C.Srivastava, Studies on modification of polyester fibres I- Alkaline hydrolysis, J. Appl. Poly. Sci., 33, 455-477 (1987)), enzyme treatment (US patent 2002 6436696) and plasma treatments (Leroux, F.; Perwuelz, A.; Campagne, C; Behary, N. Journal of Adhesion Science and Technology, 20 (9), 939-957 (2006)). Surface treatments result in enhanced wicking, while retaining the other properties of the fibres like tenacity. However surface treatments have their set of drawbacks. Alkali treatment suffers from loss of wicking after wet processing like dyeing. Enzyme and plasma treatments are not yet commercially established and in any case their usage would be restricted to application on fabrics.
In view of the above prior art, the art desires a polyester fibre or filament or textile
with improved wicking property based on surface functionalization but at the
3

same time retaining the physical properties of the polyester, durability and having efficacy of a chemically modified fibre or filament or fabric.
The present invention provides the solution to the aforesaid prior art needs.
OBJECTS OF THE INVENTION
An object of the present invention is to provide modified surface functionalized polyester fibres /filaments that possess high wicking characteristics.
Another object of the present invention is to provide modified surface functionalized polyester fibres /filaments having high wicking characteristic which is durable.
Yet another object of the present invention is to provide modified surface functionalized polyester fibres /filaments having high wicking characteristic and durable yet retaining other physical properties to a greater extent.
Yet another object of the present invention is to provide modified surface functionalized polyester fibres /filaments having high wicking characteristic and durable yet retaining other physical properties to a greater extent without need of any additional surface treatment like finish treatment.
Yet another object of the present invention is to provide modified surface
functionalized polyester fibres /filaments having high wicking characteristic and
4

durable, yet retaining other physical properties to a greater extent without need of any additional surface treatment like finish treatment thereby making the product efficient and cost-effective.
Yet another object of the present invention is to provide a method for producing the above modified surface functionalized polyester fibres /filaments having high wicking characteristic and durability yet retaining other physical properties to a greater extent without need of any additional surface treatment like finish treatment.
Yet another object of the present invention is to provide a method for producing the above modified surface functionalized polyester fibres /filaments having high wicking characteristic and durable yet retaining other physical properties to a greater extent without need of any additional surface treatment like finish treatment thereby making the process cost-effective.
Yet another object of the present invention is to provide fabric prepared from modified surface functionalized polyester fibres /filaments having high wicking characteristic and durable, yet retaining other physical properties to a greater extent without need of any additional surface treatment like finish treatment thereby making the product efficient and cost-effective.
5

DETAILED DESCRIPTION:
According to the invention, there is provided modified surface functionalized polyester fibres or filaments having high wicking characteristics comprising at least two polyester polymer components compounded in bi-component sheath-core geometry; the sheath polyester polymer component is chemically modified by using polyester which comprises hydrophilic additive in the form of master batch and size of the sheath polyester is reduced to upto 5 %.
The sheath polymer is chemically modified by incorporating a master batch containing a hydrophilic additive. Typically additive used in the present invention are disclosed in WO 2006/008256. The master batch comprising 5 to 50% of hydrophilic additive is used to prepare the modified surface functionalized polyester of the invention.
According to the present invention, there is also provided a method for producing the above modified surface functionalized polyester fibres or filaments having high wicking characteristic, the method comprising
a) extruding at least two polyester polymer components at temperature in the range of 275 to 300 °C;
b) melt spinning the extrudate at temperature in the range of 275 to 300°C to obtain bi-component fibres or filaments having sheath-core geometry;
c) gravimetrically feeding a polyester polymer component comprising a hydrophilic additive in the form of a master batch into the stream of sheath
6

polymer either during the extrusion but at any stage before the melt spinning; and
d) reducing size of the sheath polyester polymer component to upto a minimum of 5 % by controlling the relative extrusion thruput of sheath and core polymers.
The above method is either a batch process or a continuous process. In the batch process the sheath and core polyester polymer components are added in the form of chips for extrusion, the master batch comprising hydrophilic additive is gravimetrically fed at any time during the extrusion, while in the continuous process, the sheath and core polyester polymer components are fed to spin beam from a continuous polymerization plant, the master batch comprising hydrophilic additive is gravimetrically added by a transfer line injection (extruder with 3 dimensional mixer) at any time into the melt flow manifold of the sheath polymer before melt spinning. The polyester polymer component used as a sheath component or core component is selected from polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polylactic acid, co-polyesters or combinations thereof in order to achieve additional functionality such as easy dyeability, cationic dyeability, flame retardance etc. Additives used for obtaining other specific attributes include those imparting hydrophobicity, fire retardancy, anti-static, anti soiling, inherent colour, adhesion, etc can also be added while preparing the master batch of polyester comprising hydrophilic additive. The sheath component is reduced to a minimum of 5% by adjusting the relative extrusion thruput of sheath and core polymers. As
7

example, the concentration of hydrophilic additive in the reduced sheath could be in the range of 0.625 % to 10%.
The above method is either single stage process or two-stage process. The single stage process comprising :
extruding at least two polyester polymer components at temperatures of 275 to 300°C, melt spinning the extrudate to produce filament yam having bi-component sheath-core geometry; gravimetrically feeding a polyester comprising at least one hydrophilic additive in the form of a master batch into the stream of the sheath polymer either during the extrusion but at any stage before melt spinning; quenching the filament yams at temperatures of 14 to 25°C; spinning the yam at speed in the range of 1000 to 2500 m/min; passing the yam over a pair of heated draw rollers between 60 to 180 °C; drawing the yarn to levels of 1.5 to 3.5; winding the filaments on bobbins between 3300 to 5000 m/min to obtain fully drawn yams (FDY).
The two-stage method comprising :
extruding at least two polyester polymer components at temperatures of 275 to 300°C, melt spinning the extrudate at temperature in the range of 275 to 300°C to produce filament yam having bi-component sheath-core geometry; gravimetrically feeding a polyester comprising at least one hydrophilic additive in the form of a master batch into the stream of the sheath polymer either during the extrusion but at any stage before melt spinning; quenching the filament yams at temperatures of 14 to 25°C; spinning the yam at speed in the range of 2500 to
8

4500 m/min; passing the yam over a pair of cold rollers; winding the filaments on bobbins between 2500 to 4500 m/min to obtain partially oriented yams (POY).
According to the present invention there is also provided a method for producing the above modified surface functionalized polyester staple fibres having high wicking characteristic, the method comprising
a) extruding at least two polyester polymer components at temperature in the range of 275 to 300°C;
b) melt spinning the extrudate at temperature in the range of 275 to 300°C to produce filament yam having bi-component sheath-core geometry;
c) gravimetrically feeding a polyester comprising at least one hydrophilic additive in the form of a master batch into the stream of the sheath polymer either during the extrusion but at any stage before melt spinning;
d) winding the spun tow at winding speed between 1000 to 2500 m/min to produce
low oriented yam (LOY) in tow form;
e) drawing the spun tow at temperature of 20 to 80° C and at a drawing ratio of 2.0 to 4.0;
f) annealing the drawn tow using steam heated rollers; and
g) crimping, drying and cutting the tows into staple fibres of desired length.
The entire process of drawing to cutting takes place in a continuous line at speeds of 50 m/min to 400 m/min.
The cross-section of the filament yarn or fibre is either circular or non-circular.
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The fibres or filaments prepared from the modified surface functionalized polyester according to the invention have wicking height of 2.0 cms to more than 7.0 cms. (Evaluated in knit hose form of 90 gsm by vertical wicking test at 30 minutes). On 20 washes under harsh conditions the loss of wicking was observed is very minimal in the range of 5% to 15%. Thus the wicking characteristic of the fibres or filaments of the invention is durable at the same time retaining the tenacity of 80 to 100 %.
Further reduction in sheath component to 15, 10 or 5% can also be carried out under specific process condition.
The filament yams of the present invention can be further twisted or texturised.
According to the invention there is provided a fabric having high and durable wicking characteristic while retaining the tensile properties prepared from the modified surface functionalized polyester fibres or filaments of the present invention by weaving or knitting method.
According to the invention, the modified surface functionalized polyester fibres / filaments can be spun into blended yarns by mixing with other kinds of natural and/or synthetic fibres to produce fibre or filament having high and durable wicking characteristics while retaining physical properties like tenacity.
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According to the invention, the modified surface functionalized polyester fibre / filament having high wicking characteristic and durability without sacrificing physical properties such as tensile strength, by restricting the chemically modified sheath polymer closest to the surface, by process control. Increase in wicking height is observed at lower level of additive content on the sheath polyester polymer component, when the size of the sheath component is reduced. This implies dependence of wicking/moisture transport on availability of active sites at the surface. With reducing sheath component, the ratio of available surface active sites for imparting desired functionality, to fibre volume would increase resulting in enhancement in wicking. Sheath-core configuration of the bicomponent melt spinning reduces the cost of the process as well as the product as it reduces the quantity of expensive additives by incorporating the same to sheath component only and not in bulk.
Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms.
Example 1 :
Core component, polyethylene terephthalate and sheath component, polyethylene terephthalate was extruded in the ratio of 25 : 75, 50 : 50 and 75 : 25 at temperatures of 285 to 290°C and further melt spun to produce filament yarn having bi-component sheath-core geometry. The filament yam was quenched at temperatures of 20 to 22°C. The yam was spun at speed in the range of 1200 to 1400 m/min and further passed over a pair of heated draw rollers having temperature between 80 to 150°C. The yam was drawn to level of
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2.4 to 2.9 and the filaments were wound on bobbins between 3500 to 4500 m/min to obtain fully drawn yam (FDY). The yam was further knitted to hose fabric. The fabric was tested for wicking height after 5 wash cycles and the results obtained are depicted in the Figure 1.
Example 2:
Core component, polyethylene terephthalate and sheath component, polyethylene terephthalate was extruded in the ratio of 25 : 75, 50 : 50 and 75 : 25 at temperatures of 285 to 290°C and further melt spun to produce filament yam having bi-component sheath-core geometry. 5 % of the master batch of polyethylene terephthalate comprising 25% of hydrophilic additive was gravimetrically added in sheath polyethylene terephthalate during the extrusion to obtain 1.25% additive content on the sheath. The filament yam was quenched at temperatures of 20 to 22° C. The yam was spun at speed in the range of 1200 to 1400 m/min and further passed over a pair of heated draw roller having temperature between 80 to 150 °C. The yam was drawn to level of 2.4 to 2.9 and the filaments were wound on bobbins between 3500 to 4500 m/min to obtain fully drawn yams (FDY). The yam was further knitted to hose fabric. The fabric was tested for wicking height after 5 wash cycles and the results obtained are depicted in the Figure 1.
Example 3:
Core component, polyethylene terephthalate and sheath component, polyethylene terephthalate was extruded in the ratio of 25 : 75, 50 : 50 and 75 :
25 at temperatures of 285 to 290°C and further melt spun to produce filament
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yam having bi-component sheath-core geometry. 10% of the master batch of polyethylene terephthalate comprising 25% of hydrophilic additive was gravimetrically added in sheath polyethylene terephthalate during the extrusion to obtain 2.50 % additive content on the sheath. The filament yam was quenched at temperatures of 20 to 22°C. The yam was spun at speed in the range of 1200 to 1400 m/min and further passed over a pair of heated draw rollers having temperature between 80 to 150 °C. The yam was drawn to level of 2.4 to 2.9 and the filaments were wound on bobbins between 3500 to 4500 m/min to obtain fully drawn yam (FDY). The yam was further knitted to hose fabric. The fabric was tested for wicking height after 5 wash cycles and the results obtained are depicted in the Figure 1.
Example 4:
Core component, polyethylene terephthalate and sheath component,
polyethylene terephthalate was extruded in the ratio of 25 : 75, 50 : 50 and 75 :
25 at temperatures of 285 to 290°C and further melt spun to produce filament
yam having bi-component sheath-core geometry. 15% of the master batch of
polyethylene terephthalate comprising 25% of hydrophilic additive was
gravimetrically added in sheath polyethylene terephthalate during the extrusion
to obtain 3.75% additive content on the sheath. The filament yam was quenched
at temperatures of 20 to 22°C. The yam was spun at speed in the range of 1200
to 1400 m/min and further passed over a pair of heated draw roller having
temperature between 80 to 150 °C. The yam was drawn to levels of 2.4 to 2.9
and the filaments were wound on bobbins between 3500 to 4500 m/min to
obtain fully drawn yam (FDY). The yarn Was further knitted to hose fabric. The
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fabric was tested for wicking height after 5 wash cycles and the results obtained are depicted in the Figure 1.
Example 5 :
Core component, polyethylene terephthalate and sheath component, polyethylene terephthalate was extruded in the ratio of 25 : 75, 50 : 50 and 75 : 25 at temperatures of 285 to 295°C and further melt spunto produce filament yam having bi-component sheath-core geometry. 20% of the master batch of polyethylene terephthalate comprising 25% of hydrophilic additive was gravimetrically added in sheath polyethylene terephthalate during the extrusion to obtain 5.0% additive content on the sheath. The filament yams was quenched
at temperatures of 20 to 22°C. The yam was spun at speed in the range of 1200 to 1400 m/min and further passed over a pair of heated draw roller having temperature between 80 to 150 °C. The yarn was drawn to levels of 2.4 to 2.9 and the filaments were wound on bobbins between 3500 to 4500 m/min to obtain fully drawn yam (FDY). The yam was further knitted to hose fabric. The fabric was tested for wicking height after 5 wash cycles and the results obtained are depicted in the Figure 1.
Wicking heights of knit hoses made from filament yarns of the present invention, after 5 wash cycles are depicted in the Figure 1. Figure 1 illustrates trend in wicking height in cms. (referred as 1) to sheath component (referred as 2), for various masterbatch component on sheath, 0% (referred as 3), 5%(referred as 4), 10%(referred as 5), 15%(referred as
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6) and 20%(referred as 7). Wicking height was measured by Vertical wicking test based on DIN 53924. Washing of samples was carried out using AATCC method 135 at 40°C. The wicking height value is 5.2 for knit hose made with 20% mastebatch addition on sheath with 50% sheath component. On reducing the sheath component to 25% a wicking height of 7.65 is shown, at the same level of masterbatch addition on the sheath. With reducing the sheath size, the increase in wicking height for a given level of additive content in sheath is observed. Alternately, similar wicking heights are observed at lower level of additive content on sheath, when the sheath size is reduced. By this novel approach of reducing sheath component, enhanced surface functionlisation of polyester fibre/filament is being achieved. This implies dependence of wicking/moisture transport on availability of active sites at the surface.
Wicking heights of knit hoses made from filament yarns according to the
examples 1 to 5, after different wash cycles are shown in Table I for the specific
sample prepared in 50/50 bi-component configuration.
Table I
Wicking heights of knit hose samples for sample in 50/50 Sheath core configuration at different wash cycles

Masterbatchaddition onsheath(% wt.) After 5 Washes After 10 Washes After 20 Washes
0 0.2 -
5 0.8 0.7 0.8
10 2.4 2.2 2.1
15 3.0 3.1 2.9
15

20

5.2

4.8

4.2

Washing of samples was carried out using AATCC method 135 at 40*0.
Loss of wicking height with number of washes is minimal and within acceptable limit in the art.
Tenacity and retention of tenacity is also checked on the filament yams prepared according to the Examples 1 to 5. Tenacity and retention of tenacity vis-a-vis an unmodified polyester filament yam is compared in Table II for the filament yarns of the present invention.
Table II
Retention of tensile properties of polyester filament yarns (FDY - 75/36
Denier)

Masterbatchaddition onsheath%wt Monocomponentwith masterbatchincorporation onwhole of fibre BICO ConfigurationS/C50/50 BICO ConfigurationS/C25/75
Tenacity (gpd) Retentionin tenacity% Tenacity (gpd) Retentionin tenacity% Tenacity (gpd) Retentionin tenacity%
5.0 - - 4.22 94.2 - -
10.0 4.26 95.1 4.32 96.3
15.0 3.99 89.1 4.01 89.6 4.39 98.0
20.0 3.69 82.4 3.90 87.1 4.15 92.7
Retention with respect to unmodified FDY sample having 4.48 gpd tenacity. Test carried out on Statimat 4 Tensile tester.
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Retention of tenacity for 20% master addition on sheath with 50/50 configuration is 87.1 %, which improves to 92.7%, when the configuration is changed to 25775 at the same masterbatch addition on sheath. Retention of tenacity with respect to the unmodified polyester fibre/filament is better at a given masterbatch addition on sheath as the sheath size is reduced.
Dated this the 23rd day of February 2007

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Patent Number

278159

Indian Patent Application Number

397/MUM/2007

PG Journal Number

52/2016

Publication Date

16-Dec-2016

Grant Date

15-Dec-2016

Date of Filing

01-Mar-2007

Name of Patentee

RELIANCE INDUSTRIES LTD

Applicant Address

RELIANCE TECHNOLOGY CENTRE, B-4 MIDC INDUSTRIAL AREA, PATALGANGA, 410 220 DIST RAIGAD,

Inventors:

#	Inventor's Name	Inventor's Address
1	NADKARNI VIKAS MADHUSUDAN	A18 GARDEN ESTATE, OFF D P ROAD, AUNDH, PUNE 411007
2	GURUDATT KRISHNAMURTHY	NO.12, DATTATREYA ROAD, BASAVANAGUDI, BANGALORE 560004
3	MUKHOPADHYAY ANJAN KUMAR	B-203, NEEL ORCHID, PLOT NO 41, SECTOR 10 KHANDA COLONY, NEW PANVEL (WEST), NAVI MUMBAI 410206
4	KASHETWAR ABHIJIT VASANTRAO	GANDHINAGAR, ARNI, DIST-YAVATMAL 445103

PCT International Classification Number

A04193/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA