US-12616644-B2 - Polyurethane gels

US12616644B2US 12616644 B2US12616644 B2US 12616644B2US-12616644-B2

Abstract

The present invention relates to gel compositions comprising a polyurethane elastomer. The polyurethane elastomer is formed from the reaction of a polyol, a polyisocyanate, and optionally a polyurethane reaction catalyst, optionally in the presence of a topically acceptable carrier fluid. In some embodiments, the gel composition comprises a personal active ingredient or a healthcare active ingredient, which may be incorporated into the gel composition via a pre-load method or a post-load method. Also provided herein are gel pastes and topical formulations comprising the polyurethane elastomers, and methods of making the same.

Inventors

Michael J. ISAACMAN
Anna K. CROOM
Ronald V. Lerum
John Gormley

Assignees

GRANT INDUSTRIES, INC.

Dates

Publication Date: 20260505
Application Date: 20200710

Claims (13)

1 . A gel composition comprising a polyurethane elastomer gel containing a reaction product of: (A) a polyisocyanate or a mixture of polyisocyanates comprising two or more isocyanate functional groups; (B) a polyol or mixture of polyols comprising two or more hydroxyl functional groups; (C) polyurethane reaction catalyst; and (D) topically acceptable carrier fluid acting as a solvent, the topically acceptable carrier fluid being selected from the group consisting of esters, triglycerides, hydrocarbons, oils, and combinations thereof, and the solvent being acceptable for cutaneous surfaces; wherein the reaction product has an elastomeric matrix with the topically acceptable carrier fluid entrapped in the elastomeric matrix; and wherein the composition is silicone-free.
2 . The gel composition of claim 1 , wherein the topically acceptable carrier fluid comprises diisooctyl succinate, heptyl undecylenate, neopentyl glycol diheptanoate, coco-caprylate/caprate, triheptanoin, caprylic/capric triglyceride, dodecane, tridecane, C13-15 alkane, squalene, squalene, isoamyl laurate, isopentyl laurate, caprylic/capric/myristic/stearic triglyceride, caprylic/capric/succinic triglyceride, isopropyl myristate, jojoba esters, tricaprylin, palm oil or combinations thereof.
3 . The gel composition of claim 1 , wherein a pharmaceutically active ingredient is dissolved in the topically acceptable carrier fluid.
4 . The gel composition of claim 1 , wherein the polyurethane reaction catalyst is a bismuth group containing catalyst.
5 . The gel composition of claim 1 , wherein greater than 50% of the carbon content of the topically acceptable carrier fluid is derived from one or more plant sources.
6 . The gel composition of claim 1 , wherein the polyol is a branched C 36 dicarboxylic acid/diol copolymer.
7 . The gel composition of claim 6 , wherein the branched C 36 dicarboxylic acid/diol copolymer is dilinoleic acid/propane diol copolymer or dilinoleic acid/dilinoleic diol copolymer.
8 . The gel composition of claim 1 , wherein the composition is in the form of a sunscreen, an oil-in-water emulsion, or a water-in-emulsion.
9 . A gel composition comprising a polyurethane elastomer gel containing a reaction product of: (A) castor oil, dilinoleic acid/propane diol copolymer, or dilinoleic acid/dilinoleic diol copolymer; (B) isophorone diisocyanate, pentamethylene diisocyanate trimer or hexamethylene diisocyanate trimer, wherein a molar ratio of isocyanate groups to hydroxyl groups is about 1:1 to about 1:2; (C) polyurethane reaction catalyst; and (D) topically acceptable carrier fluid acting as a solvent at a concentration of 60% (w/w) to 99.9% (w/w) of the gel composition, the topically acceptable carrier fluid being selected from the group consisting of esters, triglycerides, hydrocarbons, oils, and combinations thereof, and the solvent being acceptable for cutaneous surfaces; wherein a personal care or healthcare active ingredient is optionally incorporated into the polyurethane elastomer gel by dissolving the personal care or healthcare active ingredient in the topically acceptable carrier fluid during formation of the polyurethane elastomer gel, or by admixing the personal care or healthcare active ingredient with a formed polyurethane elastomer gel; wherein the reaction product has an elastomeric matrix with the topically acceptable carrier fluid entrapped in the elastomeric matrix; and wherein the composition is silicone-free.
10 . The gel composition of claim 9 , wherein the topically acceptable carrier fluid comprises diisooctyl succinate, heptyl undecylenate, neopentyl glycol diheptanoate, and coco-caprylate/caprate or combinations thereof.
11 . The gel composition of claim 9 , wherein a pharmaceutically active ingredient is dissolved in the topically acceptable carrier fluid.
12 . The gel composition of claim 9 , wherein the polyurethane reaction catalyst is a bismuth group containing catalyst.
13 . The gel composition of claim 9 , wherein greater than 50% of the carbon content of the topically acceptable carrier fluid is derived from one or more plant sources.

Description

FIELD OF THE INVENTION The present invention relates to gel compositions comprising a polyurethane elastomer. BACKGROUND OF THE INVENTION Elastomer gels consist of a cross-linked three-dimensional polymer network suspended in an emollient. Elastomer gels are capable of swelling in emollients and are useful as oil phase thickeners in cosmetic formulations. These elastomer gels have a ball bearing-like feel on skin and provide for enhanced aesthetics and feel. These desirable attributes cannot be achieved with traditional oil gels or linear polymers, making elastomer gels unique cosmetic application vehicles. Silicone elastomer gels are widely utilized ingredients in personal care products for their thickening and gelling efficiency, and unique silky and powdery sensory profile. When incorporated into formulations they provide a smooth, dry, and non-oily feel. Silicone elastomers are compatible with silicone-based fluids. Recently, concerns have been raised regarding the negative environmental impact of silicone-based ingredients in personal care products. Silicones are resistant to oxidative and chemical attack and are therefore not biodegradable. In addition, silicones are sourced from fossil fuels and are not considered to be a renewable resource. As consumers become increasingly educated with the environmental impact of cosmetics, the demand for biodegradable and renewably sourced ingredients that are silicone-free has rapidly increased. Silicone replacements derived from biomass have begun to enter the personal care market to meet these demands. However, these linear polymers and emollients do not provide the unique aesthetics that elastomer gels provide. Therefore, a need exists for a silicone-free elastomer gel that has a favorable environmental profile. The present invention consists of a polyurethane elastomer gel that is silicone-free and comprised of >99% bio-based materials. The polyurethane elastomer gel provides the aesthetic benefits of silicone-based elastomers while meeting a market demand for renewably sourced materials that are silicone-free. The invention further relates to a method for preparing the polyurethane elastomer gel. A bio-based polyol is reacted with a bio-based polyisocyanate using a polyurethane catalyst at elevated temperature in a reaction medium of bio-based emollient or a mixture of bio-based emollients to give a polyurethane elastomer rubber. A bio-based emollient is then added to the rubber, and the mixture is processed into a polyurethane elastomer gel. SUMMARY OF THE INVENTION In some embodiments, the invention provides a gel composition comprising a polyurethane elastomer requiring no purification and formed in a topically acceptable solvent from the reaction of: A) a polyol; B) a polyisocyanate; C) an optional polyurethane reaction catalyst; and D) a topically acceptable carrier fluid. In embodiments, a personal care or healthcare active ingredient (E) is incorporated into the polyurethane elastomer gel by dissolving it in the topically acceptable carrier fluid during the formation of the polyurethane elastomer gel (pre-load method) or admixing it with a formed polyurethane elastomer gel (post-load method). In further embodiments, the invention further provides a cross-linked polyurethane elastomer network with the following general structure: wherein: n is 2 to 10000000; A is an end group selected from a hydrogen, an isocyanate and a hydroxyl; R1 is a C1-C60 substituted or unsubstituted linear or branched aliphatic group, cycloaliphatic group, aryl group, heterocycloaliphatic group, or heteroaryl group, optionally comprising a heteroatom; R2 is a C1-C60 substituted or unsubstituted linear or branched aliphatic group, cycloaliphatic group, aryl group, heterocycloaliphatic group, or heteroaryl group, optionally comprising a heteroatom; and B is an end group selected from an isocyanate and a hydroxyl. In some embodiments, the invention provides a cross-linked polyurethane elastomer network according to the following general reaction scheme: where R is a polyol with two or more functional groups and where R1 is an isocyanate with three or more functional groups, and the emollient is topically acceptable. In further embodiments, the invention provides a cross-linked polyurethane elastomer network according to the following general reaction scheme: where R is a polyol with three or more functional groups and where R1 is an isocyanate with two or more functional groups, and the emollient is topically acceptable. In further embodiments, the invention provides a cross-linked polyurethane elastomer network according to the following general reaction scheme: where the emollient is topically acceptable. In still further embodiments, the invention provides a process for making a polyurethane elastomer gel comprising: Adding to a container a cosmetically acceptable emollient, polyol, and polyisocyanate; stirring the mixture at room temperature until a clear, homogeneous solution