Title of Invention | SURFACE-ACTIVE MATERIAL AND ITS APPLICATION |
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Abstract | Surface-active material, characterised in that it comprises fibres which have been modified so as to impart 5 surface-active properties onto said fibres and giving it a contact angle between 60° and 120°, wherein the fibres have an aspect ratio of more than 10 to 1,000. |
Full Text | F7879/V FORM - 2 THE PATENTS ACT, 1970 (39 of 1970) & The Patents Rules, 2003 COMPLETE SPECIFICATION (See Section 10 and Rule 13) SURFACE-ACTIVE MATERIAL AND ITS APPLICATION HINDUSTAN UNILEVER LIMITED, a company incorporated under the Indian Companies Act, 1913 and having its registered office at Hindustan Lever House, 165/166, Backbay Reclamation, Mumbai -400 020, Maharashtra, India The following specification particularly describes the invention and the manner in which it is to be performed WO 2007/068344 PCT/EP2006/011382 1 SURFACE-ACTIVE MATERIAL AND ITS APPLICATION FIELD OF THE INVENTION 5 The invention relates to a new surface-active material and its applications in the area of foam and emulsion formation and stabilisation, coatings, encapsulation and drug delivery. More in particular, it relates to a surface-active material that comprises surface-active fibres and to a method for preparing 10 said surface-active material, as well as to products comprising said surface-active material. BACKGROUND TO THE INVENTION 15 A surface-active agent or surfactant is a substance that lowers the surface tension of the medium in which it is dissolved, and/or the interfacial tension with other phases. Accordingly, it is positively adsorbed at the liquid/vapour and/or at other interfaces. 20 Surface-active agents are widely used industry, for instance in foods, cleaning compositions and personal care products. In foods, they are used to achieve emulsions of oily and water-phases, such as in fat spreads or mayonnaise. In laundry 25 cleaning applications, they are used to solubilise dirt and keep it is solution, so that it can be effectively removed from the fabric. For cleaning applications, the surface-active compounds may be 30 chosen from anionic, cationic, nonionic, amphoteric and zwitterionic surfactants. Many suitable surface-active compounds are available and are fully described in the literature, for example, in "Surface-Active Agents and Detergents", Volumes I and II, by Schwartz, Perry and Berch. WO 2007/068344 PCT/EP2006/011382 2 The most commonly used detergent-active compounds are soaps and synthetic non-soap anionic and nonionic compounds. Examples of anionic surfactants include alkylbenzene sulphonates, particularly linear alkylbenzene sulphonates 5 having an alkyl chain length of C3-C15; primary and secondary alkylsulphates, particularly C3-C15 primary alkyl sulphates; alkyl ether sulphates; olefin sulphonates; alkyl xylene sulphonates; dialkyl sulpho-succinates; and fatty acid ester sulphonates. Sodium salts are generally preferred. 10 Examples of nonionic surfactants include the primary and secondary alcohol ethoxylates, especially the C3-C2o aliphatic alcohols ethoxylated with an average of from 1 to 20 moles of ethylene oxide per mole of alcohol, and more especially the 15 C10-C15 primary and secondary aliphatic alcohols ethoxylated with an average of from 1 to 10, preferably 3 to 7 moles of ethylene oxide per mole of alcohol. Non-ethoxylated nonionic surfactants include alkylpolyglycosides, glycerol monoethers, and polyhydroxy-amides (glucamide) . 20 The choice of the surface-active material (surfactant), and the amount present, will depend on the intended use of the detergent composition. For fabric washing compositions, different surfactant systems may be chosen, as is well known 25 to the skilled formulator, than for handwashing products or mechanical dishwashing products. In foods, surface-active materials are commonly used to prepare emulsions. Edible emulsions are used as a base for 30 many types of food products. Mayonnaise compositions, for example, comprise edible oil-in-water emulsions that typically contain between SO to 3 5% by weight oil, and egg yolk, salt, vinegar and water. Mayonnaise compositions are enjoyed by many consumers, and particularly, on sandwiches, in dips, with fish WO 2007/068344 PCT/EP2006/011382 3 and other food applications. The oil present in the edible emulsions used in such food products is generally present as droplets dispersed in the water phase. In addition to droplet size and the amount of droplets dispersed, the close packing 5 of the oil droplets results in the characteristic rheological behaviour of the emulsions used to make the desired food product, such as mayonnaise or margarine. The surface-active agents that are most commonly used in food 10 applications comprise low molecular weight emulsifiers that are primarily based on fatty acid derivatives. Examples include: lecithin's, monoglycerides (saturated and unsaturated), polysorbate esters (Tweens), sorbitan esters (Spans), polyglycerol esters, propylene glycol monostearate, 15 sodium and calcium stearoyl lactylates, sucrose esters, organic acid (lactic, acetic, tartaric, succinic) esters of monoglycerides. Proteins and other surface-active biopolymers can also be used for this purpose. Typical examples of food proteins include mil}: proteins (caseins and whey proteins), 20 soy protein, egg protein, lupin protein, pea protein, wheat protein. Examples of other surface-active biopolymers include gum Arabic, modified surface active pectin and OSA, modified starch. 5 Recently, the interest in the study of solid particles as emulsifiers of dispersed systems has been re-awakened. Much o this activity has been stimulated by the research of Binks an co-workers (Binks, B. P. Curr. Opin. Colloid Interface Sci. 2002, 7, 21), though the principles of such stabilisation wer 0 observed at least 100 years ago (Pamsden, W. Proc. R. Soc. London 1903, 72, 156). The advantage of particle stabilisatio. is that it is almost impossible to displace an adsorbed particle once adsorbed to an interface. This gives particle stabilised emulsions and foams excellent stability, especially WO 2007/068344 PCT/EP2006/011382 4 with respect to ripening mechanisms such as disproportionation. Whilst the use of particles to stabilise o/w, w/o and duplex 5 emulsions and foams has been amply demonstrated in recant years, much less research has been carried out on non-spherical structures with respect to the stabilisation of interfaces. Furthermore, it has recently been demonstrated by Alargova et. al. (Langmuir, 2004, 20, 10371), that epo>:y rods 10 can be used to provide interfacial stabilisation to emulsions and foams. Notwithstanding the fact that many surface-active materials are known and available, there is a continuous need for new 15 alternative or improved surface-active materials, especially environmentally friendly surface-active materials having good biodegradability properties. It is therefore an object of the present invention to provide such surface-active materials. It is a further object to provide surface-active materials that 20 are useful in the stabilisation of emulsions and foams. Surprisingly, it has now been found that one or more of the above-mentioned objects can be achieved by the surface-active material according to the invention, which is characterised in 2 5 that it comprises fibres which have been modified so as to impart surface-active properties onto said fibres and giving it a contact angle between 60° and 120°. The present inventors have found that the shape and size are 30 of critical importance for the colloidal stability of foams and emulsions. Rod like (fibril) shapes are much more efficient then spherical particles. Another key factor for good foam and emulsion stabilisation is particle contact angle at oil/water or air/water interface, which must be as close to WO 2007/068344 PCT/EP2006/011382 5 90° as possible. The rod-like structures must therefore be amphiphathic in design (o/w and w/o stabilisation depends on the relative balance between hydrophobicity and hydrophilicity). Rod- and fibre-like structures such as microcrystalline cellulose (MCC) and natural plant fibres have been used in ■food systems. Such structures often find application as bulk structuring agents, providing a contribution to the rheology of a formulation, without showing a tendency to adsorb at interfaces or exhibiting surface-active properties. SUMMARY OF THE INVENTION According to a first aspect, the invention provides a surface-active material that which is characterised in that it comprises fibres which have been modified so as to impart surface-active properties onto said fibres and giving it a contact angle between 60° and 120°, wherein the fibres have an aspect ratio of more than 10 to 1,000. According to a second aspect, there is provided a process for preparing such a surface-active material. According to a third aspect, there is provided a product comprising said surface-active material for the purpose of foam and emulsion formation and stabilisation, coatings, encapsulation and drug delivery. The fourth aspect involves the application of said surface-active material in home and personal care, foods, oilfield, agriculture, textile, construction, emulsion polymerisation, leather, plastic, pulp, paper and pharma. WO 2007/068344 PCT/EP2006/011382 6 DETAILED DESCRIPTION OF THE INVENTION In its first aspect, the invention relates to a surface-active material comprising natural fibres that have been modified. By the word "fibre", we mean any structure, especially an 5 insoluble, particulate structure, wherein the ratio between the length and the diameter ranges from 10 to infinite. Here, the diameter means the largest distance of the cross-section. The materials of the "fibre" substance can be organic, inorganic, polymeric and macromolecular. The fibre topology 10 might be liner or branched (star-like). The aspect ration in this case is defined as aspect ratio of the longest branch. The fibres used in the present invention have a length of 0.1 to 100 micrometer, preferably from 1 to 50 micrometer. Their 15 diameter is in the range of 0.01 to 10 micrometer. The aspect ratio (length / diameter) is generally more than 10, preferably more than 20 up to 1,000. The fibres may be of organic or inorganic origin. In 20 particular, organic, natural fibres made of a crystalline, insoluble form of carbohydrates, such as microcrystalline cellulose, can be used. Such fibres have the advantage that they are very biodegradable, which is favourable for the environment. Very often organic fibres are also food-grade. 25 One example of a suitable source is the microcrystalline cellulose obtainable from Acetobacter. Other examples are citrus fibres, onion fibres, silk, stearic acid, polyhydroxybutyrate-valerate, PVP (polyvinyl pyrrolidone), PCL (polycaprolactone), their derivatives and copolymers, and 30 other polymers that car. be spun with diameter ranging from 0.01 to 30 micrometers. Examples of inorganic fibres are CaC02, CaSO4, 3nO, TiO2, Mg0, MgSO4, Mg(OH)2, Hg2B205, aluminium borate, potassium titanate, WO 2007/068344 PCT/EP2006/011382 7 barium titanate, hydroxyapatite, attapulgite, but other inorganic crystals with fibre-like morphology could also be used. 5 The fibres that are used in the present invention are not used as such, but in modified form. As a consequence of the modification, the contact angle is modified such that is in the range of between 60° and 120°, preferably between 70° and 110°, more preferably between 80° and 100°. Ey contact angle 10 we mean the three-phase contact angle at the fibre/air/water interface or the fibre/oil/water interface, depending on the type product in which the surface-active material of the present invention is used. For foams this will be the fibre/air/water contact angle, for emulsions, the 15 fibre/oil/water contact angle. The contact angle can be measured using the gel-trapping technique as described by technique as described by Paunov (Langmuir, 2003, 19, 7970-7976) or alternatively by using 20 commercial contact angle measurement apparatus such as the Dataphysics OCA20. The modification of the fibres can be achieved by chemical or physical means. The chemical modification involves 25 esterification or etherification, by means of hydrophobic groups, such like stearate and ethoxy groups, using well-known techniques. The physical modification includes coating of the fibres with hydrophobic materials, for example ethylcellulose or hydroxypropyl-celluloss. One can also use waxes, such as 30 shellac, carnauba or bees wax. Fat and fatty acids such as stearic acid may also be used. The coating can be done using colloidal precipittaion using solvent or temperature change, for instance. The physical modification may also involve WO 2007/068344 PCT/EP2006/011382 8 "decoration" of rod like materials using hydrophobic nano-particles, for instance silica. According to the invention, one can use the process of 5 controlled esterification of Microcrystalline cellulose (Antova et. al, Carbohyd. Polym., 2004, 57 (2), 131) as possible route for controlled hydrophobicity modification and therefore obtaining particles with surface-active properties. Eased on this principle, it will be understood that the 10 skilled person can easily find other routes to modify the hydrophobicity of other types of fibres of organic or inorganic origin. According to another aspect of the present invention, there is 15 provided a surface-active material, obtainable by modification of fibres so as to impart surface-active properties onto said fibres and giving it a contact angle between 60° and 120°, wherein the fibres have an aspect ratio of more than 10 to 1,000. 20 Possible applications for the surface-active materials of the present invention are in the area of foam and emulsion formation and stabilisation, for instance as foam stabilisers for ice cream, as emulsion stabilisers for mayonnaise or 25 margarine, as foam formation agent and stabiliser for home and personal care products such as toothpaste, and as flotation agent, for instance in the mining industry. They may also be used for coatings, encapsulation and drug delivery. 30 The industries where these surface-active materials of the present invention could be applied include home and personal care, foods, oil industry, agriculture, textile, construction, polymer industry (emulsion polymerisation), leather, plastic, pulp, paper and pharma. WO 2007/068344 PCT/EP2006/011382 9 The invention will now be further illustrated by .means of the following non-limiting examples. 5 Example 1 In a 50-ml beaker, 0.05g ethyl cellulose (EC, Aldrich product, viscosity: lOcps) was added, into 20 ml of acetone. Then under ultrasonication (Branson Ultrasonics Corporation, 5510E-DTH) and magnetic stirring {IKA, RCT basic), the ethyl cellulose 10 gradually dissolved to form a homogenous solution. Next 0.2g of Microcrystalline cellulose (MCC, rod-like, Diameter: ~20nm, Length: several to tens of microns) was added into the system and ultrasonication was applied for 10 minutes to induce the homogenous dispersion of the MCC. As a non-solvent of ethyl 15 cellulose, 10 ml of water was dropped into the above system to induce coacervation of ethyl cellulose, during which the coacervated ethyl cellulose particles were attached to MCC fibers. Subsequently, the acetone was completely removed by stirring or under reduced pressure at an elevated temperature. 20 The obtained MCC/ethyl cellulose water dispersion was used to investigate the foamability and foam stability. The foams were prepared at room temperature by hand-shaking for a period of 4 0s. The foams stabilized by this material are stable at ambient conditions for more than two weeks. 25 Example 2 4.0 g of rod-like CaCO; (provided by Qinghai Haixing Science and Technology Development Co., Ltd, China, Diameter: -2 microns, Length: -50 microns) was dispersed into 40 ml acetone 30 solution containing 0.20 g of ethyl cellulose (EC, Aldrich product, viscosity: lOcps). Ultrasonication (Branson Ultrasonics Corporation, 5510E-DTH) was used for 10 minutes to induce the homogenous dispersion of the CaCC3. Then 160ml of water was quickly poured into, the dispersion to make the ethyl WO 2007/068344 PCT/EP2006/011382 10 cellulose deposit fast on the surface of CaC03 particles. After magnetic stirring (IKA, RCT basic) for 2 minutes, the dispersion was filtrated, and the filter cake was immediately dried in vacuum oven at 80'C. Finally CaC03/ethyl cellulose 5 composite was obtained. Then the powder was put into water to investigate foamability and foam stability. The foams were prepared at room temperatura by hand-shaking for a period of 4Us. The foams stabilized by these materials are stable for more then one month. The initial volume of the foam linearly 10 increased with the amount of material added. It is interesting to note that initial Eoam volume of the foams stabilized by these materials passee trough a maximum at a ratio of EC:CaC03 of about 1:20 (which was chosen in this example). 15 Example 3 4.0 g of rod-like ZnO (tetrapod-like, provided by Chengdu Advanced Technologies and Crystal-Wide Co., Ltd, China, Diameter: 2 microns, Length: several tens of micron) was dispersed into 40 ml of acetone solution containing 0.20 g of 20 ethyl cellulose (EC, Aldrich product, viscosity: lOcps). Ultrasonication (Branson ultrasonics Corporation, 5510E-DTH) was used for 10 minutes to induce the homogenous dispersion of the ZnO. Then 160ml of water was quickly poured into the dispersion to make ethyl cellulose deposit fast on the surface 25 of ZnO particles. After magnetic stirring (IKA, RCT basic) for 2 minutes, the dispersion was filtrated, and the filter cake was immediately dried in vacuum oven at 80"C. Finally, a ZnO/ ethyl cellulose composite was obtained. Then the powder was put into water to investigate foamability and foam stability. 30 The foams were preparerd at room temperature by hand-shaking for a period of 40s. The foams stabilized by this material are stable at ambient conditions for more than two weeks. WO 2007/068344 PCT/EP2006/011382 11 CLAIMS 1. Surface-active material, characterised in that it comprises fibres which have been modified so as to impart 5 surface-active properties onto said fibres and giving it a contact angle between 60° and 120°, wherein the fibres have an aspect ratio of more than 10 to 1,000. 2. Surface-active material according to claim 1, having a 10 contact angle between 70° and 110°, preferably between 80° and 100°. 3. Surface-active material according to any one of the preceding claims, wherein the fibres have a length of 0.1 to 15 100 micrometer, preferably from 1 to 10 micrometer. 4. Surface-active material according to any one of the preceding claims, wherein the fibres are organic fibres. 20 5. Surface-active material according to claim 4, wherein the fibres are cellulose fibres, for example citrus fibres. 6. Surface-active material according to claim 5, wherein the fibres are microcrystalline cellulose. 25 7. Surface-active material according to claim 6, wherein the fibres are microcrystalline cellulose obtainable from Acetobacter. 30 3. Surface-active material according to any one of claims 1-3, wherein the fibres are inorganic. 9. Surface-active material according to claim 3, wherein the fibres are selected from the group consisting of CaC03, CaSO4, WO 2007/068344 PCT/EP2006/0113S2 12 ZnO, Ti02, MgO, MgS04/ Mg(OH)2, Mg2B2O5, aluminium borate, potassium titanate, barium titanate, hydroxyapatite, attapulgite, and other crystals with fibre-like morphology. 5 10. Surface-active material, obtainable by modification of fibres so as to impart surface-active properties onto said fibres, and giving it a contact angle between 60° and 120°, wherein the fibres have an aspect ratio of more than 10 to 1,000. 10 11. Process for the preparation of a surface-active material according to any one of the preceding claims, comprising the steps of selecting a fibre material and modifying it using physical and/or chemical means so as to impart surface-active 15 properties onto said fibres and giving it a contact angle between 60° and 120°, preferably between 70° and 110°, more preferably between 30° and 100°, wherein the fibres have an aspect ratio of more than 10 to 1,000. 20 12. Food product comprising the surface-active material according to any one of claims 1-10, wherein the food product is selected from aerated products such as foams, mousses, ice cream, or non-aerated products such as fat-spreads or dressings. 25 13. Food product according to claim 12, in the form of a liquid product selected from the group consisting of sauces, soups and drinks. 30 1-]. Process for the preparation of a stabilised food product according to claims 12-13, comprising the step of adding the surface-active material according to claims 1 to 10 to a food product. WO 2007/068344 PCT/EP2006/011382 13 15. Use of the surface-active material according to claims 1-10 for foam and emulsion formation and stabilisation, coatings, encapsulation and drug delivery. 5 16. Use according to claim 15, in the following industries: home and personal care, foods, oilfield, agriculture, textile, construction, emulsion polymerisation, leather, plastic, pulp, paper and pharma. Dated this 28th day of May 2008 HINDUSTAN UNILEVER LIMITED (S. Venkatramani) Senior Patents Manager |
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1063-MUMNP-2008-ANNEXURE TO FORM 3(16-4-2012).pdf
1063-MUMNP-2008-AU DOCUMENT(16-4-2012).pdf
1063-MUMNP-2008-CLAIMS(AMENDED)-(16-4-2012).pdf
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1063-MUMNP-2008-CLAIMS(GRANTED).pdf
1063-MUMNP-2008-CLAIMS(MARKED COPY)-(16-4-2012).pdf
1063-MUMNP-2008-CORRESPONDENCE(25-8-2009).pdf
1063-mumnp-2008-correspondence(28-5-2008).pdf
1063-MUMNP-2008-CORRESPONDENCE(29-1-2013).pdf
1063-MUMNP-2008-CORRESPONDENCE(3-12-2012).pdf
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1063-MUMNP-2008-EP DOCUMENT(16-4-2012).pdf
1063-MUMNP-2008-FORM 13(8-2-2012).pdf
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1063-MUMNP-2008-REPLY TO EXAMINATION REPORT(16-4-2012).pdf
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Patent Number | 255424 | |||||||||||||||||||||||||||
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Indian Patent Application Number | 1063/MUMNP/2008 | |||||||||||||||||||||||||||
PG Journal Number | 08/2013 | |||||||||||||||||||||||||||
Publication Date | 22-Feb-2013 | |||||||||||||||||||||||||||
Grant Date | 20-Feb-2013 | |||||||||||||||||||||||||||
Date of Filing | 28-May-2008 | |||||||||||||||||||||||||||
Name of Patentee | HINDUSTAN UNILEVER LIMITED | |||||||||||||||||||||||||||
Applicant Address | UNILEVER HOUSE, B.D. SAWANT MARG, CHAKALA, ANDHERI EAST, MUMBAI 400 099, MAHARASHTRA, INDIA. | |||||||||||||||||||||||||||
Inventors:
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PCT International Classification Number | C11D1/00 | |||||||||||||||||||||||||||
PCT International Application Number | PCT/EP2006/011382 | |||||||||||||||||||||||||||
PCT International Filing date | 2006-11-22 | |||||||||||||||||||||||||||
PCT Conventions:
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