Bio-based and biodegradable elastomer for cosmetic and personal care

Abstract

To provide: a process for preparing a cross-linked polyurethane elastomer rubber composition; a gel composition comprising the cross-linked polyurethane elastomer rubber composition; and a process for preparing the gel composition; where the polyurethane elastomeric gel has good compatibility with cosmetic and natural oils and can be used as a gelling agent for these oils among other desirable cosmetic formulary roles.SOLUTION: A process for preparing a cross-linked polyurethane elastomer rubber composition comprises: reacting a polyisocyanate with a prepolymer having at least two free hydroxyl groups in the presence of a urethanation catalyst and a cosmetic emollient under conditions sufficient to form a cross-linked polyurethane rubber. Also provided is a gel composition comprising a mixture of the cross-linked polyurethane elastomer rubber composition in micronized form and at least one cosmetic emollient.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention includes compositions and processes / methods for preparing polyester-type and polyurethane-type materials for use in cosmetics. The compositions include an elastomer system based on at least 85% renewable bio-based materials that is inherently biodegradable. The compositions can be incorporated into gels and can form stable mixtures in medium-chain esters and low-polarity hydrocarbons. [Background technology]

[0002] Silicone elastomers are a broad class of three-dimensionally crosslinked dimethicone polymers that form three-dimensional polymeric structures, imparting beneficial texture and appearance to cosmetics. They are commonly incorporated into products to enhance consumer appeal by creating a pleasing sensory aesthetic profile while functioning as line fillers or soft-focus particles. Additionally, they can act as sebum absorbers and mattifying agents, defined as reducing excess oil on the skin surface and reducing shine. Furthermore, these crosslinked dimethicone polymers can deliver actives by acting as controlled-release polymers, reducing the oily texture of high-oil content formulas. To achieve sophisticated, everyday wear in skin care and cosmetics, silicone elastomers can be co-formulated with conventional ingredients, such as sunscreen actives and pigments. While silicone elastomers are completely safe ingredients, they are synthetic in origin and are recognized as not readily biodegradable, even if they are environmentally biodegradable.

[0003] Polyesters can be synthetic or naturally occurring and can range from hard thermoplastic solids to low-viscosity oils. According to Spiratex literature, thermoplastic polyester elastomers, or TPEs, combine the properties of high-performance elastomers and flexible polymers. These, sometimes referred to as thermoplastic rubbers, are high-strength materials known for their ability to withstand repeated flex cycles and their resistance to many chemicals and oils. Key parameters for characterizing elastomers are measurements of hardness and resilience. There are various methods for measuring hardness, or stiffness and resilience, or durometer hardness, as described by ASTM D-2240. The test method describes 12 types of rubber hardness measuring devices, known as durometers: Types A, B, C, D, DO, E, M, O, OO, OOO, OOO-S, and R. Appropriate scaling and adaptation based on material behavior is required. While elastomeric polymers have a wide range of hardnesses, the hardness of the present invention has been found to be consistent with gel-like materials. ASTM D2240 is an empirical test method that has been modified and adapted to be a procedure commonly used to evaluate soft gels, i.e., biopolymer gelatin composed of polypeptides. Briefly, the method is based on the compression and decompression force profiles of an indenter to a specified depth using a texture analyzer to evaluate both hardness and elasticity (resilience) of the present invention.

[0004] Silicone elastomers commonly used in cosmetics are finely divided particles (approximately 1-100 microns) of silicone rubber dispersed and semi-swollen in a carrier phase such as isododecane, cyclomethicone, or light silicone oil. Cosmetic silicone elastomers require extensive milling and dilution into the carrier phase to achieve the correct balance of cosmetically acceptable properties. In this highly processed form, if the refractive index is matched between the silicone elastomer and the carrier phase, the final mixture can have the appearance of a gel-like homogeneous system, only further revealing the presence of the elastomer in sensory testing. For example, if the carrier phase is volatile, the act of spreading the silicone elastomer mixture on the skin results in evaporation of the carrier phase on the skin and the release of finely divided "ball-bearing" particles of elastomer, which exhibit desirable texture and provide mattifying properties for sebum absorption on the skin. The state-of-the-art silicone elastomer dispersions used in cosmetics include nearly all premium leave-on skin care product formulations, resulting in textures and performance highly sought after by both formulators and consumers.

[0005] While the performance of dispersed silicone elastomers is unparalleled, there is a demand for alternatives to silicone elastomers because silicones are derived, in part, from non-renewable, petroleum-derived raw materials. Therefore, a primary goal is to create high-performance dispersed elastomers based primarily on renewable, bio-sourced raw materials. Second, while silicones can be chemically degraded over time in the environment, they are not inherently biodegradable through microbial action. Therefore, a second criterion is an inherently biodegradable elastomer dispersion. Third, the inherent properties of silicone elastomers exhibit functional compatibility with branched-chain hydrocarbons such as isododecane and good compatibility with silicone fluids. They are therefore inherently medium-polar, semi-hydrophobic, and as a result, will phase separate from more polar esters without the addition of other compatible ingredients or emulsifiers. Therefore, a further goal is to create a dispersion-gelled or thickened high-performance elastomer that meets the first two criteria but also offers compatibility with more polar cosmetic ingredients, such as esters and medium-chain triglycerides (MCTs), for formulation with ingredients not directly available in silicone elastomers. Fourth, a silicone gel replacement should have a comparable sensory aesthetic profile.

[0006] Alternative options for petroleum-based polymers are gaining importance in personal care industry applications. Biobased and biodegradable elastomeric polymers are an important class of materials for enhancing the texture attributes of cosmetic compositions. Elastomeric polymers swollen and dispersed in various cosmetic fluids can offer new formulation flexibility not realized with conventional elastomeric polymers, i.e., hydrogels, silicone gels, oil-based thickeners, etc. As a result, there is a need to develop new elastomeric polymers with enhanced texture attributes similar to those of silicone gels, hydrogels, oil-based thickeners, etc. The biobased and biodegradable gels represented by the present invention have good compatibility with cosmetic oils and natural oils and can be used as gelling agents for these oils.

[0007] Prior art related to the leave-on cosmetics industry includes numerous classifications of polyesters and polyurethanes that perform a variety of functions. Thousands of polyesters and polyurethanes are commercially listed in COSING (the EU's official cosmetic ingredients database). Many of these ingredients are conventional, fully synthetically produced, film-forming polymers that act as binders when combined with other solvents, including hairspray or water. They are often dispersed as lattices or dispersions in water, made from prepolymers crosslinked with diamino or triamino chain extenders to form carbamates. Amine-based building blocks are undesirable for cosmetic raw material development due to their prevalent high odor profile and their typical tendency to yellow the final product formulation. Another classification of urethanes is sold as solid, predominantly non-swelling, micronized powders based on synthetic raw materials from petroleum sources. For example, Grant Industries sells a product called Granpowder USQ, which contains 30-40% micronized, non-swelling urethane powder with the INCI designation HDI / trimethylolhexyllactone crosspolymer. It exhibits excellent feel and soft focus (optional) properties, but does not have elastic properties similar to silicone elastomers. It is a free-flowing powder with slightly elastic to non-elastic properties when dispersed in a medium polarity dispersion medium, such as MCT. Summary of the Invention [Problem to be solved by the invention]

[0008] In this regard, the present invention includes biobased and biodegradable swellable, elastomeric, non-ionic, non-aqueous materials using polyesters bonded between multifunctional, e.g., trifunctional, polyurethane crosslinkers in naturally occurring reaction solvents, also referred to herein as cosmetic emollients, using urethanization catalysts, e.g., bismuth catalysts. Preferred catalysts are generally considered to be non-toxic / safe alternatives to amine-based, organomercurial-based, or organotin-based urethane catalysts. This solvent category can include MCT.

[0009] The present invention also includes a method for preparing a gel, which comprises a grinding process of an MCT-based rubber elastomer, with a simultaneous or subsequent step of dilution with a solvent, which may be the same as or different from the reaction solvent. Renewably sourced volatile cosmetic alkanes are preferred to achieve the desired sensory aesthetic profile. [Means for solving the problem]

[0010] In one aspect of the present invention, (a) crosslinked polyurethane elastomer rubber; (b) cosmetic emollients, and (c) Urethane catalyst A crosslinked polyurethane elastomer rubber composition comprising: A crosslinked polyurethane elastomer rubber composition is provided in which a cosmetic emollient forms a solvent matrix that substantially surrounds the crosslinked polyurethane elastomer rubber. For purposes of the present invention, "substantially surrounds" is understood to mean that the solvent matrix is ​​in intimate contact with the surface of the rubber and covers a substantial portion of the rubber surface. The emollient does not necessarily completely surround the rubber.

[0011] In another aspect of the present invention, there is provided a method for preparing the crosslinked polyurethane elastomer rubber composition described herein, comprising reacting a prepolymer having at least two free hydroxyl groups with a polyisocyanate in the presence of a urethanization catalyst and a cosmetic emollient under conditions sufficient to form a crosslinked polyurethane rubber.

[0012] Further aspects of the present invention include gel compositions containing a mixture of the crosslinked polyurethane elastomer rubber composition described herein in ground form and at least one cosmetic emollient, and methods for making such gel compositions. The gel compositions are rubber dispersions refined through one or more grinding and dilution steps, each of which produces a desired equilibrium particle size range, resulting in a final product in the 1-100 micron range, preferably 1-60 microns. Further aspects of the present invention also include cosmetics, emulsions, lotions, creams, and other products containing the compositions and gels of the present invention.

[0013] The present invention results in a silicone-alternative elastomer gel that is at least 85% or even >98% biobased. This biobased elastomer has been tested to achieve "ultimate biodegradability / intrinsic biodegradability," a key set of performance attributes that are otherwise unidentified in the prior art. The primary invention is an elastomer that is not silicone-based, yet approaches high-value textures previously only achievable through silicone chemistry. The disclosed invention will be trademarked under Gransense™ and commercially available as a cosmetic ingredient from Grant Industries (Elmwood Park, New Jersey, USA). [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a biodegradation graph corresponding to Example 21. DETAILED DESCRIPTION OF THE INVENTION

[0015] In one aspect, the present invention relates to a polyurethane elastomer rubber composition comprising a bio-based polyol crosslinked with a bio-based isocyanate using a urethanization catalyst, such as a bismuth catalyst, in the presence of a cosmetic emollient. The isocyanate is a compound containing an isocyanate group (-NCO). They react with a compound containing an alcohol (hydroxyl) group to produce a polyurethane polymer. In a further aspect of the present invention, the crosslinked polyurethane elastomer rubber is milled in the presence of a bio-based emollient or a mixture of bio-based emollients and then incorporated into a gel. The polyurethane elastomer gel has good compatibility with cosmetic and natural oils and can be used as a gelling agent for these oils, among other desirable cosmetic formulation roles. The increased polarity of the polyurethane elastomer gel versus its silicone elastomer counterpart allows it to be incorporated into increasingly polar formulation media in which silicone elastomers are not compatible.

[0016] The crosslinked polyurethane elastomer rubber compositions of the present invention are preferably those in which the prepolymer, polyisocyanate, and cosmetic emollient are biobased and biodegradable. In some preferred embodiments of the present invention, the crosslinked polyurethane elastomer rubber compositions are comprised of greater than about 85%, preferably greater than about 95%, and in some alternative embodiments, greater than about 99% renewable biobased materials, or alternatively, plant-derived (non-petroleum-based) materials. In alternative embodiments, the rubber compositions can be produced using polyester prepolymers derived entirely from synthetic or petroleum-based sources rather than biobased sources. Similarly, in alternative embodiments, the emollient or mixture of emollients and / or isocyanate may be derived from synthetic or petroleum-based sources rather than biobased sources.

[0017] The grinding and dilution process converts the polyurethane rubber composition into an elastomeric gel that provides a smooth, non-sticky, non-oily, moisturizing skin feel with enhanced working time. The elastomeric gel of the present invention is an elegant addition to the cosmetic formulator's toolbox for creating stable cosmetic formulas with improved compatibility with more polar cosmetic emollients, actives, and additives typically incorporated into the oil phase of oil-based cosmetics.

[0018] In the present invention, a general method for preparing a polyurethane rubber composition and its subsequent conversion to a polyurethane elastomer gel follows these steps: First, using a urethanization catalyst, such as a bismuth catalyst, the bio-based prepolymer is reacted with a bio-based isocyanate in a reaction medium of a bio-based emollient or a mixture of bio-based emollients that acts as a solvent(s) to form an elastomeric polyurethane rubber composition at a suitable controlled temperature, such as from about 20° C. to about 100° C. Alternatively, the method may include forming the rubber composition at room temperature without agitation for about 24 hours.

[0019] As a result of the reaction conditions, the emollient forms a solvent matrix that substantially surrounds and / or swells the polyurethane rubber.

[0020] Second, the formed rubber is converted into a dispersion by high shear milling, whereby an optional additional charge of the same or a different bio-based emollient is added to the rubber composition before or after milling. The mixture is preferably milled into a polyurethane gel concentrate using suitable equipment known to those skilled in the art, such as a high shear disperser mixer. Milling reduces the particle size of the rubber composition, preferably to less than about 100 microns, more preferably to a range of about 1 to about 60 microns in cross-sectional diameter.

[0021] Third, the elastomer concentrate is further diluted to a viscosity suitable for cosmetic use with a second solvent, which can be a bio-based emollient with either volatile or non-volatile properties, depending on the intended use and desired skin feel characteristics of the finished elastomer gel. Thus, the gel can include a bio-based emollient or mixture of emollients that enhances aesthetic skin feel and / or cosmetic formulation compatibility.

[0022] In some embodiments, the rubber composition comprises a prepolymer in an amount of about 5 to about 25 weight percent. The prepolymer contains at least two hydroxyl groups. Preferably, the bio-based isocyanate is present in an amount of about 1 to about 20 weight percent, and optionally the isocyanate contains about 15 to about 38%, or about 15 to about 28%, of -NCO groups. The overall molar ratio of -NCO of the isocyanate to -OH of the polyol may be about 2:1 to about 1:2. The polyol may optionally have a hydroxyl number of 50 to 200 mg KOH / g, or 90 to 200 mg KOH / g.

[0023] The rubber composition may also include about 0.1 to about 2.5 weight percent of a catalyst.

[0024] Other preferred embodiments of the rubber of the present invention include having a hardness force of greater than 200 g, alternatively greater than 500 g and less than 4000 g, as measured by a texture analyzer before any grinding or dilution, and a resilience of 70% or greater, alternatively 90% or greater.

[0025] The rubbers of the present invention, in some embodiments, can be classified as ultimately biodegradable / intrinsically biodegradable according to OECD 301-B and can be made to contain as much as >97.0% biobased carbon according to ASTM D6866-18.

[0026] The formation of a grindable elastomeric gum that can be converted into a refined and stable gel for cosmetic use requires consideration of several physical parameters inherent in gum formation. The hardness of the polyurethane gum is an important factor in determining whether it can be easily processed into a gel. If the polyurethane gum is too hard, the gum granules will not swell properly or break down into a smooth gel upon treatment with an emollient. On the other hand, if the polyurethane gum is too soft, it will not be easily processed into a gel due to a lack of viscosity and swelling granules. Three important factors determine the hardness of a polyurethane gum: First, the ratio of polymer content to carrier fluid is important for synthesizing an optimal polyurethane elastomer. The total weight percent of bio-based emollient in the polyurethane elastomer should be in the range of 70-95%, or alternatively 70-90%. If too much carrier fluid is used, the density of the elastomer network will be too low to maintain viscosity. If too little carrier fluid is used, the polymer content will be too dense to disperse properly when milled. Second, the ratio of bio-based hydroxyl functionality of the bio-based prepolymer to NCO functionality of the polyisocyanate can be between 2:1 and 1:2, preferably 1:1. Third, the amount of catalyst used in the synthesis of the polyurethane rubber is another factor that determines its ability to be processed into a gel. If too much catalyst is used, the rubber will over-cure and be too hard to process into a gel. If too little catalyst is used, the rubber will not form. In practice, the amount of catalyst can be about 0.1 to 2.5 wt.%.

[0027] In many embodiments of the present invention, the gel compositions of the present invention may have a viscosity ranging from about 15,000 to about 1,000,000 cP, and in alternative embodiments, from about 40,000 to about 1,000,000 cP. The gels may optionally be classified as ultimately biodegradable / intrinsically biodegradable according to OECD 301-B and / or contain up to 97% bio-based carbon according to ASTM D6866-18. Optionally, a finishing agent containing an alcohol or, optionally, an amine may be added to the compositions of the present invention to quench unreacted isocyanate groups. The gels of the present invention may be non-Newtonian or thixotropic. The gels of the present invention may contain optional personal or healthcare actives, such as, but not limited to, vitamins, e.g., vitamin C and vitamin A, sunscreen, botanical extracts, and / or fragrances.

[0028] definition Thixotropic gel properties The preferred polyester and / or polyurethane linkages in elastomeric gels allow for the ability to form hydrogen bonds over time. This gel behavior allows for thixotropic properties. Thixotropic fluids exhibit non-Newtonian pseudoplastic behavior changes over time. Under static conditions, these types of gels (within the scope of the present invention) appear "pseudoplastic," but when a certain force (stirring, mixing, vibration, shear) is applied, they will begin to flow and their viscosity will decrease. If no force is applied, after a certain period of time, the gel will return to its initial steady state. Common examples of thixotropic fluids are yogurt and polyvinyl alcohol adhesive glue gels. Incorporating thixotropic gels into formulas offers many formulation advantages compared to traditional oils, waxes, gums, or powders. Examples include, but are not limited to, maintaining film thickness upon application to impart a soft, sophisticated feel, and improving the spreadability of cosmetics during application and use.

[0029] Thixotropic gels offer many benefits to formulators, such as their ability to act as suspending and thickening agents in sprays, and for memory-type applications in both skin and personal care. Additionally, thixotropic materials are considered process aids, providing enhanced stability and controlled spreadability in personal care products. Compared to silicone elastomers, shear-thinning behavior can enhance ease of mixing when incorporating other ingredients into a formula. Reduced viscosity requires less strain and faster incorporation of personal care actives in mixing and shear dispersion processing equipment, thereby reducing costs and saving time in production. Another benefit of thixotropic gels is that they stabilize formulas, minimizing phase separation and potentially stabilizing particle suspensions, i.e., pigments.

[0030] Ultimate Biodegradability - The level of degradation achieved when a test compound is completely utilized by microorganisms, resulting in the production of carbon dioxide, water, and inorganic salts, as well as new microbial cell material (biomass).

[0031] Inherently Biodegradable - A classification of chemicals for which there is clear evidence of biodegradation (initial or final) for any test of biodegradability.

[0032] Resilience - Able to embrace variety and change; flexible and adaptable.

[0033] Elastomer - A natural or synthetic polymer / polymeric material, e.g., rubber, that has elastic properties that allow it to return to shape when distorted by physical stress.

[0034] Polymer - A substance whose molecular structure consists primarily or entirely of many linked identical units, such as many synthetic organic materials used as plastics and resins; proteins, which comprise polypeptide molecules, are natural polymers made from various amino acid monomer units; nucleic acids are large natural polymers made from millions of nucleotide units.

[0035] Suitable polymers and prepolymers include, but are not limited to: Azelate polyol Butanediol / Adipic Acid Copolymer Butanediol / Azelaic Acid Copolymer Butanediol / Sebacic Acid Copolymer Capryloyl Glycerin / Sebacic Acid Copolymer Capryloyl Glycerin / Sebacic Acid Copolymer Capryloyl Glycerin / Sebacic Acid Copolymer Castor oil-derived polyhydroxystearic acid cellulose collagen Diheptyl succinate (and) Capryloyl glycerin / sebacic acid copolymer Dilinoleic Acid / Propanediol Copolymer Dimer Acid Diol lecithin Poly(polyol sebacate) Polybutylene succinate Polybutylene succinate Polycaprolactone polyester Polyethylene glycol Polyglycerol Polyglycolide Polyhydroxyalkanoates Polyhydroxybutyrate Polylactic acid and polylactide Polylactide-co-glycolide Polysaccharides Propanediol / adipic acid copolymer Propanediol / Azelaic Acid Copolymer Propanediol / Sebacic Acid Copolymer Propylene glycol / adipic acid copolymer Propylene Glycol / Azelaic Acid Copolymer Propylene glycol / sebacic acid copolymer Pullulan starch Trimethylpentanediol / adipic acid copolymer and mixtures thereof.

[0036] Preferred polyols for the synthesis of elastomeric rubbers are diol- or polyol-functional polyesters with effective molecular weights of 280-3,000 g / mol, or 500-3,000 g / mol. The polyols should have an acid value of <2 (mg KOH / g), a hydroxyl value of 50-200 or 90-200 (mg KOH / g), and a water content of <0.1 (KF, w / w%). A preferred prepolymer is dilinoleic acid / propanediol copolymer derived from 100% biobased sources, which has good compatibility with cosmetic oils. Preferably, the copolymer should be hydroxyl-terminated and have a low acid value, since hydroxyl groups react more readily with isocyanates than carboxylic acids. Castor oil, naturally containing a large number of hydroxyl groups, can also be used as a polyol in the synthesis of polyurethane rubbers. Additionally, there are many polyols available that can be used in the synthesis of polyurethane elastomer gels.

[0037] Suitable polyols include, but are not limited to: 1,2-ethanediol 1,2-Propanediol 1,3-propanediol Caprylyl glycol Castor oil corn oil Diethylene glycol ethylene glycol Ethylene oxide glycerol Heptanediol Hexanediol Hydrogenated or epoxidized vegetable oil Isomer butanediol Isosorbide linseed oil olive oil Other hydroxy-containing compounds Pentaerythritol Pentanediol Polytetramethylene Ether Glycol Propylene glycol Propylene oxide silanol sugar alcohols Triethylene Glycol Ether Glycol and mixtures thereof.

[0038] Suitable carboxylic acids include, but are not limited to, Azelaic acid Citric acid Dilinoleic acid dimer acid Itaconic acid Lactic acid Polylactic acid Sebacic acid Trilinoleic acid and mixtures thereof.

[0039] The emollient used in the synthesis of polyurethane rubber may be an ester, ether, alkane or a mixture thereof. The emollient used in the processing of this rubber into a gel may be an ester, ether, alkane or a mixture thereof. The emollient preferably has a viscosity of 1 to 65 (mPas) at 20°C. The spreading value (mm 2 / 10 minutes) is preferably 500 to 2500.

[0040] Suitable emollients or solvents include, but are not limited to: Butyl lactate butylene glycol C12-15 alkyl lactate C12-C15 alkyl benzoate C13-C15 alkanes C16-18 alkanes C18-C22 alkanes Caprylic / Capric Triglyceride Caprylic / Capric / Succinic Triglyceride Caprylyl (Caprylic / Capric Acid) Castor oil Cetyl ethylhexanoate Coco-Alkyl Caprylate / Caprate Cocoglycerides Decyl Oleate Dibutyl adipate Dicaprylyl Carbonate Dicaprylyl Ether Diheptyl succinate Dodecane Ethyl lactate Ethylhexyl isononanoate glycerin Glyceryl Trihexanoate Glyceryl Triheptanoate Glyceryl trioctanoate Hemisqualane Heptyl Undecylenate Isododecane Isononyl isononanoate Isopropyl myristate Isopropyl palmitate jojoba oil Myristyl myristate Neopentyl glycol diheptanoate Octyl Palmitate Oleyl erucate Olive Squalane Polybutene Propylene Carbonate Propylene glycol Propylene Glycol Dicaprylate / Dicaprate Shea butter ethyl ester Squalane Tridecane Triethylhexanoin Triheptanoin Undecane and mixtures thereof.

[0041] 1,5-Pentamethylene diisocyanate trimer was used as the preferred isocyanate for the synthesis of polyurethane elastomers. Derived from biobased raw materials, this isocyanate readily reacts with polyols in the presence of a polyurethane catalyst and an emollient to form polyurethane rubber. In addition, a large amount of difunctional isocyanates are available for widespread use in industry.

[0042] Suitable functional isocyanates include, but are not limited to: 1,1'-methylenebis(4-isocyanatocyclohexane) 1,3,3-trimethyl-1-(isocyanatomethyl)-5-isocyanatocyclohexane 1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 1,3,5-tris[(5-isocyanato-1,3,3-trimethylcyclohexyl)methyl] 1,3-bis(isocyanatomethyl)cyclohexane 1,3-Diazetidine-2,4-dione, 1,3-bis[4-[(2-isocyanatophenyl)methyl]phenyl] 1,3-Diazetidine-2,4-dione, 1,3-bis[4-[(4-isocyanatophenyl)methyl]phenyl] 1,3-phenylene diisocyanate 1,3-Propanediol, 2-ethyl-2-(hydroxymethyl)-, reaction product 5-isocyanato-1-(isocyanatomethyl)-1,3,3-trimethylcyclohexane 1,4-phenylene diisocyanate 1,5-Diisocyanato-2-methylpentane 1,5-Pentamethylene Diisocyanate 1,5-Pentamethylene Diisocyanate Dimer 1,5-Pentamethylene diisocyanate trimer 1,6-Hexamethylene Diisocyanate 1,8-Diisocyanato-2,4-dimethyloctane 2,2,4-trimethylhexane 1,6-diisocyanate 2,2'-Diisocyanatodiphenylmethane 2,4,4-trimethylhexane 1,6-diisocyanate 2,4,6-triisopropyl-m-phenylene diisocyanate 2,4'-methylenediphenyl diisocyanate 2,4-Toluene diisocyanate 2,4-Toluene diisocyanate trimer 2,4-Toluene diisocyanate dimer 2,5(6)-bis(isocyanatomethyl)bicyclo[2.2.1]heptane 2,6-Toluene diisocyanate 3,3'-Dimethoxy-4,4'-biphenylene diisocyanate 3,3'-Dimethyl-4,4'-biphenylene isocyanate 4,4',4''-Triisocyanatotriphenylmethane 4,4-MDI uretidinone 4,4'-methylenediphenyl diisocyanate 2,4-TDI 80%; 2,6-TDI 20%; a blend of isomers Benzene, 1-[(2,4-diisocyanatophenyl)methyl]- 3-isocyanato-2-methyl Bis(isocyanatomethyl)cyclohexane Diphenyloxide 4,4'-diisocyanate Diphenylmethane diisocyanate Hexamethylene diisocyanate biuret Hexamethylene diisocyanate dimer Hexamethylene Diisocyanate Isocyanurate Methyl 2,6-diisocyanate hexanoate Naphthalene, 1,5-diisocyanate Octahydro-4,7-methano-1H-indene dimethyl diisocyanate Polymethylene polyphenyl polyisocyanate Tris(4-isocyanatophenyl)thiophosphate and mixtures thereof.

[0043] Bismuth- or zinc-based polyurethane catalysts are preferred for the synthesis of polyurethane rubber due to their relatively low toxicity. However, organometallic and amine-based polyurethane catalysts can also be used. Bismuth-based catalysts are preferred for cosmetic applications due to their lower toxicity compared to amine-, mercury-, or tin-based catalysts.

[0044] Possible urethanization catalysts include, but are not limited to: lead compounds Mercury compounds (i.e., mercury salts, mercury hydroxide, mercury decanoate, bis(phenylmercury) dodecenyl succinate) and Stannous compounds (ie, stannous octoate, stannous chloride) are included.

[0045] Preferred urethanization catalysts with reduced toxicity compared to tin, mercury, and lead include, but are not limited to: Acidic Phosphate Complex aluminum Bis-(2-dimethylaminoethyl)-ether Bismuth Carboxylate Bismuth Ester Bismuth Citrate Bismuth Alkanoate Bismuth Neodecanoate Dimethylaminopropylamine DABCO (1,4-diazabicyclo[2.2.2]octane and DABCO derivatives) metal complexes Mixed Carboxylate N-methylimidazole N-Methylmorpholine tertiary amines triethylamine zinc acetate Zinc acetylacetonate Zinc complex Zinc esters and zinc alkanoates Zinc neodecanoate Zinc neodecanoate Zinc Octoate zinc oxalate zirconium and mixtures thereof.

[0046] Cosmetic powders can be combined with the elastomers of the present invention to enhance the performance of gels, altering their texture, absorbency, formula stability, and soft-focus characteristics desirable in finished cosmetics. Powders can be used to provide structural support, act as fillers, or alter the final appearance of the gel to have a more "mattified, soft-focus" appearance. Powders can be used to provide good slip and smoothness to the final product formulation, including, but not limited to, pressed powders, lotions, creams, hair gels, hair creams, mascaras, body creams, serums, lip care, and the like. Powders can also be used to adjust the viscosity of the final formula due to their inherent tendency to absorb a limited amount of liquid from the formula.

[0047] Suitable powders include, but are not limited to, (synthetic and natural) and blends thereof: Acrylates Copolymer alumina aluminum oxide Aluminum silicate Boron nitride Butter coating powder (wherein the butter may be, but is not limited to, shea, mango, cocoa, or almond, and the powder may be, but is not limited to, mica, talc, aluminum, cellulose, or polyhydroxyalkanoate) Calcium Starch Octenyl Succinate cellulose cellulose acetate Dimethicone / vinyl dimethicone crosspolymer Glass beads Kaolin clay Mica Natural waxes (such as, but not limited to, carnauba wax, beeswax, castor oil, etc.) nylon Polybutylene succinate polyester polyethylene Polyhydroxyalkanoates Polylactic acid Polymethylsilsesquioxane polypropylene Polytetrafluoroethylene Polyurethane powder (e.g., powder of a copolymer of hexamethylene diisocyanate and trimethylol hexyl lactone) Polyvinyl alcohol Polyvinyl Chloride Sericite silica starch Synthetic wax Paraffin wax talc Trimethoxysilicate Zeolite Zinc stearate Zinc oxide, and Titanium dioxide is one example.

[0048] When processing polyurethane elastomer gums into gels, a compatible emollient must be used to react with the newly formed polymer microparticles. Highly polar triglycerides, esters, and ethers can be used to swell the particles during the reaction and grinding process. Preferred emollients include plant-derived medium-chain triglycerides (MCTs), such as glyceryl trihexanoate, glyceryl triheptanoate, and glyceryl trioctanoate, or mixtures thereof. Once the elastomer gum is processed into a concentrated gel, a volatile emollient with a dry skin feel can be added to the gel until the desired viscosity is achieved. Triglycerides, esters, ethers, and alkanes can be used in this process.

[0049] The stability of polyurethane elastomer gels depends on the rubber synthesis and the emollient or mixture of emollients used in the resulting gel. If the polarity of the emollient or emollients is too low, the gel may initially form but will separate over time. Generally, triglycerides, esters, ethers, and alkanes can be used in various combinations. Preferably, plant-derived emollients are used, such as medium-chain triglycerides, C9-C12 alkanes and esters derived from short-chain fatty acids, and alcohols, such as caprylic / capric acid. In some embodiments, the emollient is considered a second solvent, and can be selected from, for example, triheptanoin, undecane, and tridecane. Alternatively, the second solvent is a naturally occurring alkane or a naturally occurring ester.

[0050] The gel composition can include a mixture of the crosslinked polyurethane elastomer composition described herein and a cosmetic emollient, preferably in finely divided form. For example, some gel compositions can include from about 5 to about 30% by weight or from about 5 to about 17% by weight of the finely divided crosslinked polyurethane elastomer rubber composition.

[0051] The gel composition may also include one or more cosmetically acceptable ingredients or emollients in an amount of from about 70 to about 95% by weight, or from about 83 to about 95% by weight. [Example]

[0052] In the following examples, bio-based and biodegradable cross-linked polyurethane elastomer gums and bio-based and biodegradable cross-linked polyurethane elastomer gels are described. The elastomer gums are processed into elastomer gels that can be further processed for optimal performance as cosmetic ingredients.

[0053] As explained in this specification, the formation of polyurethane rubber involves crosslinking a biosourced prepolymer containing at least two hydroxyl groups with a polyisocyanate in the presence of a catalyst and a sufficient amount of a biobased cosmetic emollient. The prepolymers selected as examples were a copolymer of C18-unsaturated fatty acid dimer and 1,3-propanediol (DAPD) with a hydroxyl number in the range of 60-80 mg KOH / g, and a biobased aliphatic polyisocyanate, pentylene diisocyanate trimer (PDT), containing an NCO content of approximately 20%. The bismuth catalyst was bismuth neodecanoate. The cosmetic emollient was a mixture of coco-caprylate / caprate and glyceryl triheptanoate.

[0054] [Example 1] Polyurethane rubber synthesis To an 8-ounce glass jar was added 11.25 g (12.5 wt%) of DAPD polyol, 3.15 g (3.5 wt%) of PDT, 18.81 g (20.9 wt%) of glyceryl triheptanoate, and 56.34 g (62.6 wt%) of coco-caprylate / caprate. The mixture was stirred with a propeller mixer for 10 minutes, and 0.45 g (0.5 wt%) of bismuth catalyst was added. After stirring the mixture for an additional 5 minutes, the stirring was stopped and the reactor was placed in an oil bath and heated to 60°C. The mixture was heated until a cured rubber formed, after which the reactor was removed from the heat. Typical gel times ranged from 5 minutes to 2 hours.

[0055] [Example 2] Synthesis of high density polyurethane rubber To an 8-ounce glass jar was added 17.05 g (18.9 wt%) of DAPD polyol, 4.77 g (5.3 wt%) of PDT, 16.9 g (18.78 wt%) of glyceryl triheptanoate, and 50.6 g (56.2 wt%) of coco-caprylate / caprate. The mixture was stirred with a propeller mixer for 10 minutes, and 0.68 g (0.76 wt%) of bismuth neodecanoate was added. After stirring the mixture for an additional 5 minutes, the stirring was stopped and the reactor was placed in an oil bath and heated to 60°C. The mixture was heated until a cured rubber formed, after which the reactor was removed from the heat. Typical gel times ranged from 5 minutes to 2 hours.

[0056] [Example 3] Synthesis of low-density polyurethane rubber To an 8-ounce glass jar was added 6.82 g (7.58 wt%) of DAPD polyol, 1.91 g (2.12 wt%) of PDT, 20.27 g (22.5 wt%) of glyceryl triheptanoate, and 60.73 g (67.5 wt%) of coco-caprylate / caprate. The mixture was stirred with a propeller mixer for 10 minutes, and 0.27 g (0.3 wt%) of bismuth neodecanoate was added. After stirring the mixture for an additional 5 minutes, the stirring was stopped and the reactor was placed in an oil bath and heated to 60°C. The mixture was heated until a cured rubber formed, after which the reactor was removed from the heat. Typical gel times ranged from 5 minutes to 2 hours.

[0057] [Example 4] Synthesis of polyurethane elastomers in glyceryl triheptanoate. To an 8 oz. glass jar was added 11.25 g (12.5 wt%) of DAPD polyol, 3.15 g (3.5 wt%) of PDT, and 75.15 g (83.5 wt%) of glyceryl triheptanoate. The mixture was stirred with a propeller mixer for 10 minutes, and 0.45 g (0.5 wt%) of bismuth neodecanoate was added. The mixture was stirred for an additional 5 minutes, after which the stirring was stopped and the reactor was placed in an oil bath and heated to 60°C. The mixture was heated until a cured rubber formed, and then the reactor was removed from the heat. Typical gel times ranged from 5 minutes to 2 hours.

[0058] [Example 5] Synthesis of polyurethane elastomers with coconut alkyl (caprylate / caprate). To an 8 oz. glass jar was added 11.25 g (12.5 wt%) of DAPD polyol, 3.15 g (3.5 wt%) of PDT, and 75.15 g (83.5 wt%) of coco-octanoate / caprate. The mixture was stirred with a propeller mixer for 10 minutes, and 0.45 g (0.5 wt%) of bismuth neodecanoate catalyst was added. The mixture was stirred for an additional 5 minutes, after which the stirring was stopped and the reactor was placed in an oil bath and heated to 60°C. The mixture was heated for 24 hours, during which time no elastomeric gel had formed.

[0059] [Table 1]

[0060] [Example 6] Method for preparing an elastomeric gel containing a volatile cosmetic emollient A mixing vessel is charged with 100 g of Example 1 rubber and 11.1 g of glyceryl triheptanoate. The mixture is milled using high-shear mixing to produce a viscous paste containing particles generally less than 100 microns. The mixture is further diluted with 12.3 g of glyceryl triheptanoate to form a soft, concentrated pre-elastomer using high-shear mixing, which is then dispersed using a high-shear mill to reduce the polyurethane particles to less than approximately 60 microns. The particle concentrate is further diluted with mixing by adding 18 g of a C9-C12 alkane (Vegelight 1214, Grant Industries, USA) to produce a smooth cosmetic elastomer with a slightly volatile texture profile and a viscosity of 102,440 cP (Brookfield DV-I+, spindle TD, 1.5 RPM). This elastomer gel is commercially available as part of the Gransense™ product line from Grant Industries (Elmwood Park, NJ, USA).

[0061] [Example 7] Method for preparing an elastomeric gel containing a non-volatile cosmetic emollient A mixing vessel is charged with 100 g of Example 1 rubber and 11.1 g of glyceryl triheptanoate. The mixture is milled as described in the previous example. The mixture is diluted with 12.3 g of glyceryl triheptanoate to form a soft, concentrated pre-elastomer through high-shear mixing, reducing the polyurethane particles to less than about 60 microns. The particle concentrate is further diluted with mixing by adding 30 g of glyceryl triheptanoate to produce a resilient cosmetic elastomer with a moisturizing skin feel and a viscosity of 416,667 cP (Brookfield DV-I+, spindle TE, 0.6 RPM). This elastomer gel is commercially available as part of the Gransense™ product line from Grant Industries (Elmwood Park, NJ, USA).

[0062] [Example 8] Method for preparing low viscosity elastomers containing non-volatile cosmetic emollients A mixing vessel is charged with 100 g of Example 1 rubber and 11.1 g of glyceryl triheptanoate. The mixture is milled as described in the previous example. The mixture is diluted with 12.3 g of glyceryl triheptanoate to form a soft, concentrated pre-elastomer through high-shear mixing, reducing the polyurethane particles to less than about 60 microns. The particle concentrate is further diluted with mixing by adding 58.4 g of glyceryl triheptanoate to produce a pourable cosmetic elastomer with a moisturizing, velvety skin feel and a viscosity of 37,500 cP (Brookfield DV-I+, spindle TC, 3.0 RPM). This elastomer gel is commercially available as part of the Gransense™ product line from Grant Industries (Elmwood Park, NJ, USA).

[0063] As explained in the present description, the formation of polyurethane rubber is not limited to the components provided in Examples 1-5. For Example 9, the prepolymer was a copolymer of C18 unsaturated fatty acid dimer and bio-sourced 1,4-butanediol (DABD) having a hydroxyl value in the range of 80-100 mg KOH / g. For Example 10, the cosmetic emollient was a mixture of isododecane and coco-caprylate / coco-caprate. For Example 11, the prepolymer selected was castor oil (CO). For Example 12, the catalyst selected was zinc neodecanoate. For Example 13, the polyisocyanate used was hexamethylene diisocyanate trimer (HDT). Rubbers were prepared from the reaction equivalents provided in Table 2 by following the protocols of Examples 1-5.

[0064] [Table 2]

[0065] [Example 14] Method for preparing elastomeric gels containing personal care actives A mixing vessel equipped with a side sweep was charged with 90 g of Example 6 and stirred at 120 RPM. To this was added 20 g of finely ground ascorbic acid in small portions over a period of 1 hour. The mixture was stirred until uniform, resulting in a viscous, opaque white paste.

[0066] [Example 15] SPF-50 sunscreen To prepare an SPF-50 sunscreen, the ingredients of Phase A, including the elastomer from Example 6, were combined in a main kettle using a homogenizer and mixed until homogeneous. Phase B was then added to the main kettle while mixing with a side-sweep stirring blade until homogeneous. SPF was measured in vitro based on the usage recommendations for zinc oxide and titanium dioxide products from Grant Industries.

[0067] [Table 3]

[0068] [Example 16] W / O emulsion cream The incorporation of the elastomers of the present invention allows for the stabilization of water-in-oil emulsion creams with viscosities ranging from 5,000 to 50,000 cPs. The presence of the elastomers of the present invention provides greater compatibility with the polar oil phase and natural polyglyceryl emulsifiers of this formula, while achieving the desired cushion / cloud-like feel typically only achieved with silicone elastomer formulations. There is market demand for higher natural content in cosmetic formulas, with formulators choosing naturally derived surfactants, emollients, and thickening aids. As demonstrated in this formulation, the elastomers of the present invention offer broader formulation possibilities in natural and bio-based formulation situations, again enabling the development of products with desirable texture and performance profiles.

[0069] To prepare a water-in-oil emulsion cream containing Gransense™ elastomer from Example 6, first combine the Phase A ingredients from Table 4 in a container and mix with a homogenizer at room temperature until a uniform consistency is achieved. In a side container, combine the Phase B ingredients. Add the Phase B ingredients to Phase A while homogenizing and mixing until homogenous.

[0070] [Table 4]

[0071] [Example 17] Cream to Powder Foundation The incorporation of the elastomer of the present invention allows for the stabilization of W / O emulsion creams with viscosities ranging from 500,000 to 1,000,000 cPs. The presence of the elastomer of the present invention from Example 6 enabled the use and stabilization of amino acid-treated inorganic pigments. Amino acid-treated pigments are used in conventional color cosmetics, but their stabilization generally requires high percentages and numerous combinations of various emulsifiers and humectants. The combination of the elastomer gel of the present invention from Example 6 with natural polyglyceryl and phospholipid-based emulsifiers in the presence of a polar oil phase enabled a stable W / O while achieving the cushion / cloud-like feel of known silicone elastomers.

[0072] To prepare a cream-to-powder foundation containing Gransense™ elastomer from Example 6, combine the ingredients from Phase A listed in Table 5 in a main container and mix with a homogenizer until homogenous. In a separate container, combine the Phase B ingredients and pulverize until the colors are completely blended and homogenous. Add Phase B to Phase A while homogenizing until homogenous. In a side container, combine the Phase C ingredients and mix with a homogenizer. Add Phase C to Phase AB while homogenizing until a homogenous foundation cream is obtained.

[0073] [Table 5]

[0074] [Example 18] Luminous Lipstick The elastomers of the present invention are ideal for lip care applications due to their good compatibility with common cosmetic waxes and pigments. When added to lip care formulations, the elastomers of the present invention provide moisturizing, cushiony feel, and improved compatibility between a wide variety of polar and non-polar ingredients.

[0075] To prepare the Luminous Lipstick containing Gransense™ Elastomer from Example 6, the ingredients from Table 6 were weighed into a main kettle equipped with a 3-prong blade. The container was heated to 90-95°C and mixed until homogeneous. The lipstick was poured into an applicator package at 75-80°C.

[0076] [Table 6]

[0077] [Example 19] Repairing Shampoo To prepare the repairing shampoo containing Gransense™ elastomer from Example 8, the ingredients from Table 7 were weighed into the main kettle and homogenized. Phase B was sprinkled into Phase A while mixing. Phase C was weighed into a side kettle and heated to the appropriate temperature where it was added to Phase AB and mixed for 10-15 minutes. Phase D was then added and mixed for 5-10 minutes. To complete, Phase E was added and mixed into the formula.

[0078] [Table 7]

[0079] [Example 20] anhydrous formulation The elastomeric gels of the present invention can be used in anhydrous cosmetic and personal care formulations where advantageous. To prepare an anhydrous formula containing Gransense™ elastomeric gel from Example 6, the ingredients from Table 8 were combined together by mixing until uniform. The anhydrous formulations described below can function as carriers for cosmetic active ingredients in other anhydrous formulations.

[0080] [Table 8]

[0081] Compatible with common personal care ingredients To demonstrate the unique compatibility of the polyurethane elastomers of the present invention with conventional personal care ingredients and emollients, the elastomer from Example 6 was mixed with selected personal care ingredients in ratios of 1:9, 1:1, and 9:1. When solids or waxes were used, the elastomer and wax were heated to the melting point of the wax, then combined and allowed to cool. The mixtures were evaluated and rated according to the footnotes in the table below. A commercially available silicone elastomer blend from Grant Industries was used as a reference. The results are shown below. Compared to conventional silicone elastomer gels, the polyurethane elastomer gels of the present invention can be dispersed in cosmetic esters and conventional cosmetic waxes. Interestingly, the polyurethane elastomer gels are more compatible with sunscreen actives than the silicone elastomers.

[0082] [Table 9]

[0083] Rubber hardness evaluation Gelled compositions prepared from elastomeric gums and rubbers can be characterized by their hardness or firmness. The Gelatin Manufacturers Institute of America uses a device, such as a "Texture Analyzer" (TA.XT Plus model, Stable Micro Systems Inc., Godalming, England), to quantify the hardness or firmness of materials with properties similar to those of the gum and gel compositions described in this invention. Using the texture analyzer, the surface of the gum or gel is compressed with a probe having a weight of 5.0 kg as a load cell at a predetermined speed of 1.0 mm / s to a programmed depth of 10 mm into the gum or gel, and then retracted at the same speed. The resistance force detected by the texture analyzer probe during compression of the gel or gum defines the "hardness" taught by Lin et al. (U.S. Pat. No. 8,222,363 B2). Hardness values ​​measured by the texture analyzer are recorded in grams (g) force and can be converted to Newtons (N) by dividing by 101.97.

[0084] In the present invention, rubber hardness, measured by a texture analyzer as the force in grams applied to the rubber when compressed, is a critical factor in the successful formation of an elastomeric gel from each elastomeric rubber precursor. By varying the concentrations of the polyurethane-forming components of the rubber composition (i.e., the prepolymer and polyisocyanate portions), rubbers of various hardnesses were formed. Additionally, the identity of the cosmetic emollient selected as the matrix influenced rubber hardness. A suitable hard gel was determined to have been formed when the required mixture of components was combined to form a gel having a minimum hardness of 200.0 g, preferably 500.0 g, to a maximum of 4000 g, as measured by texture analysis before grinding or diluting the formed rubber. If the rubber hardness was less than 200.0 g or greater than 4000 g, a suitable elastomeric rubber could not be produced by the above grinding procedure.

[0085] An additional parameter provided by the texture analyzer was the resilience of the rubber. Resilience was defined as the area of ​​the force curve after release of compression (force-time region 2-3) divided by the area of ​​the force curve during compression (force-time region 1-2) multiplied by 100%. A resilience value of 100% would represent an ideal elastic material. Through experimentation, it was determined that suitable polyurethane rubbers described in this invention require resilience values ​​of at least 70%, and preferably at least 90%.

[0086] [Example 21] Testing the Ultimate / Inherent Biodegradability of Gransense™ Elastomer Gel The elastomer gel of Example 6 was submitted to biodegradation testing by Situ Biosciences (Wheeling, IL) according to OECD 301 B: CO2 Evolution (Modified Sturm Test).

[0087] Samples were dispensed and the resulting data and graphs were analyzed by curve fitting to establish the plateau of biodegradation rate. Referring to Figure 1, the OECD 301B-Biodegradation graph shows test chamber carbon dioxide (CO2) measurements as percent theoretical maximum (ThCO2%). A curve fit was applied to calculate the predicted fit (solid curve). The shading below the curve fit indicates that the required amount of biodegradation was met, relative to the biodegradation requirements (ThCO2 10-60%) for determining biodegradability. See WO 2014 / 167518A, the contents of which are incorporated herein by reference.

[0088] In conclusion, the samples achieved the requirements for ultimate / intrinsic biodegradability by exceeding the 60% threshold before the end of the 28 day test time frame.

[0089] [Example 22] Testing the % Biobased Carbon Content of Gransense™ Elastomer Gel The elastomer gel of Example 6 was submitted for % biobased carbon analysis according to ASTM D6866-18 Method B using radiocarbon isotope analysis at Beta Analytic Inc. (Miami, FL). This is a naturally occurring isotope of carbon that is radioactive and decays to nothing approximately 45,000 years after the death of a plant or animal. The interpretation and application of the results is straightforward. A value of 100% biobased or biogenic carbon would indicate 100% of the carbon came from the by-products (biomass) of plants or animals living in their natural environment, while a value of 0% would mean that all of the carbon was derived from petrochemical, coal, and fossil sources. Values ​​between 0 and 100% would indicate a mixture. The higher the value, the higher the percentage of natural-source components in the material.

[0090] A sample was taken and the resulting data concluded that the sample contained 100% bio-based carbon content (as a fraction of total organic carbon).

Claims

1. (a) crosslinked polyurethane elastomer rubber; (b) cosmetic emollients, and (c) Urethane catalyst A crosslinked polyurethane elastomer rubber composition comprising: A crosslinked polyurethane elastomer rubber composition in which the cosmetic emollient forms a solvent matrix that substantially surrounds the crosslinked polyurethane elastomer rubber.

2. 2. The crosslinked polyurethane elastomer rubber composition according to claim 1, having a hardness force, measured by a texture analyzer, of greater than 200 g, preferably greater than 500 g, and less than 4000 g, before any grinding or dilution, and a resilience of 70% or greater, preferably 90% or greater.

3. 10. The crosslinked polyurethane elastomer rubber composition of claim 1, wherein the crosslinked polyurethane rubber is formed from a prepolymer having at least two free hydroxyl groups.

4. 10. The crosslinked polyurethane elastomer rubber composition of claim 1, wherein the solvent matrix comprises one or more cosmetic emollients.

5. 10. The crosslinked polyurethane elastomer rubber composition of claim 1, wherein the polyurethane elastomer rubber is formed from about 5 to about 25 weight percent of a prepolymer having at least two free hydroxyl groups.

6. 10. The crosslinked polyurethane elastomer rubber composition of claim 1, wherein the polyurethane elastomer rubber is formed from a prepolymer having from about 1 to about 20 weight percent isocyanate-functional molecules and OH groups.

7. 4. The crosslinked polyurethane elastomer rubber composition of claim 3, wherein the prepolymer is a polyester reaction product of a diol and a dimer acid.

8. 10. The crosslinked polyurethane rubber elastomer composition of claim 1, wherein the polyurethane elastomer rubber is formed with a polyisocyanate containing from about 15 to about 38 weight percent NCO, preferably from about 15 to about 28 weight percent NCO.

9. 2. The crosslinked polyurethane rubber elastomer composition of claim 1, wherein the amount of the urethanization catalyst is about 0.1 to about 2.5 wt. %.

10. 2. The crosslinked polyurethane elastomer rubber composition according to claim 1, wherein the urethanization catalyst is bismuth, zinc, or an amine catalyst.

11. 10. The crosslinked polyurethane elastomer rubber composition of claim 1, further comprising an alcohol- or amine-containing finishing agent in an amount sufficient to quench any unreacted isocyanate groups.

12. 7. The crosslinked polyurethane elastomer rubber composition according to claim 6, wherein the overall molar ratio of NCO groups of the polyisocyanate to OH groups of the prepolymer is from 2:1 to 1:

2.

13. 10. The crosslinked polyurethane elastomer rubber composition of claim 1, wherein the crosslinked polyurethane elastomer rubber is formed from a bio-based and biodegradable prepolymer.

14. 14. The crosslinked polyurethane elastomer rubber composition of claim 13, wherein the prepolymer, polyisocyanate, and cosmetic emollient are bio-based and biodegradable, and the crosslinked polyurethane elastomer rubber composition is comprised of greater than about 85%, preferably greater than about 95%, or greater than about 99% renewable bio-based raw materials.

15. 15. The crosslinked polyurethane elastomer rubber composition of claim 14, wherein the bio-based and biodegradable polyisocyanate is 1,5-pentamethylene diisocyanate trimer.

16. reacting a prepolymer having at least two free hydroxyl groups with a polyisocyanate in the presence of a urethanization catalyst and a cosmetic emollient under conditions sufficient to form a crosslinked polyurethane rubber. A method for preparing a crosslinked polyurethane elastomer rubber composition, comprising:

17. 17. The method of claim 16, wherein said conditions comprise reacting a prepolymer having at least two free hydroxyl groups, a urethanization catalyst, and a cosmetic emollient at a temperature of from about 20°C to about 100°C.

18. 17. The method of claim 16, wherein the urethanization catalyst is bismuth, zinc, or an amine catalyst.

19. 17. The method of claim 16, wherein the prepolymer, polyisocyanate, and cosmetic emollient are bio-based and biodegradable.

20. 20. The method of claim 19, wherein the crosslinked polyurethane elastomer rubber composition is comprised of greater than about 85%, preferably greater than about 95%, or greater than about 99% bio-based materials.

21. 10. A gel composition comprising a mixture of the crosslinked polyurethane elastomer rubber composition of claim 1 in micronized form and at least one cosmetic emollient.

22. 22. The gel composition of claim 21, wherein the amount of the micronized crosslinked polyurethane elastomer rubber composition is from about 30 to about 5% by weight.

23. 23. The gel composition of claim 22, wherein the amount of the micronized crosslinked polyurethane elastomer rubber composition is from about 5 to about 17% by weight.

24. 22. The gel composition of claim 21, wherein the amount of cosmetic emollient is from about 70 to about 95% by weight.

25. 23. The gel composition of claim 22, wherein the amount of cosmetic emollient is from about 83 to about 95% by weight.

26. 22. The gel composition of claim 21, further comprising a second solvent.

27. 27. The gel composition of claim 26, wherein the second solvent is selected from the group consisting of triheptanoin, undecane, tridecane, or the second solvent is a naturally occurring alkane or a naturally occurring ester.

28. 25. The gel composition of claim 24, optionally further comprising an active composition selected from the group consisting of vitamins, sunscreens, botanical extracts, fragrances, and mixtures thereof.

29. 22. The gel composition of claim 21, further comprising a member of the group consisting of fragrances, colorants, preservatives, active compositions, and mixtures thereof.

30. 22. The gel composition of claim 21, wherein the micronized crosslinked polyurethane elastomer rubber composition has a cross-sectional diameter of from about 1 to about 61 microns.

31. 22. The gel composition of claim 21, having a viscosity ranging from about 15,000 cP to about 1,000,000 cP, preferably from about 40,000 to about 1,000,000 cP.

32. 22. The gel composition of claim 21, wherein the gel is a non-Newtonian or thixotropic fluid.

33. a) micronizing the crosslinked polyurethane elastomer rubber composition of claim 1 in the presence of a cosmetic emollient, and optionally b) combining the mixture resulting from step a) with a second solvent. A method for preparing a gel composition, comprising:

34. 34. The method of claim 33, wherein the second solvent is selected from the group consisting of triheptanoin, undecane, tridecane, or the second solvent is a naturally occurring alkane or a naturally occurring ester.

Images