Thickening solvents with elastomeric silicone polyethers

Abstract

Low molecular weight siloxane fluids are thickened by silicone elastomers. The silicone elastomers are made by combining in one pot an .tbd.Si--H containing siloxane, a mono-alkenyl polyether, an alpha, omega-diene, and a low molecular weight siloxane fluid. An elastomer, i.e. gel, with polyether groups is produced. The elastomer can be swollen with the low molecular weight siloxane fluid under shear force, to provide a uniform silicone paste. The silicone paste has excellent spreadability upon rubbing, and possesses unique rheological properties in being thixotropic and shear thinning. The silicone paste can be easily emulsified with water to form a stable uniform emulsion, without using a surfactant to allow normally immiscible materials to become intimately mixed.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is related to a prior copending U.S. application Ser. No. 08/768,064, filed Dec. 16, 1996, now U.S. Pat. No. 5,811,487, entitled "Thickening Silicones With Elastomeric Silicone Polyethers". The prior application is assigned to the same assignee as the present application.

BACKGROUND OF THE INVENTION

This invention is directed to thickened low molecular weight siloxane fluids or solvents, in the form of silicone elastomers swollen into silicone gels and silicone pastes, which can be formed into silicone emulsions.

Cross-links are junctions of polymer strands in a three-dimensional network. They may be viewed as long-chain branches which are so numerous that a continuous insoluble network or gel is formed.

Increasingly, platinum catalyzed hydrosilylation reactions are being used to form networks. They typically involve reactions between a low molecular weight siloxane containing several .tbd.Si--H groups, and a high molecular weight siloxane containing several .tbd.Si--vinyl groups, or vice versa.

Attractive features of this mechanism are that (i) no by-products are formed, (ii) cross-linking sites and hence network architecture can be narrowly defined, and (iii) hydrosilylation will proceed even at room temperature to form the networks. In the mechanism, crosslinking involves addition of .tbd.SiH across double bonds, i.e., .tbd.SiH+CH.sub.2 .dbd.CH--R.fwdarw..tbd.SiCH.sub.2 CH.sub.2 --R; or crosslinking involves addition of .tbd.SiH across triple bonds, i.e., .tbd.SiH+HC.tbd.C--R.fwdarw..tbd.SiCH.dbd.CH--R.

I have utilized this mechanism, but by employing some unobvious and unique modifications of the mechanism, I have formulated a new range of products having new and unique properties and ranges of application. In particular, one unique aspect is that my silicone paste can be used to form an emulsion without the need of a surfactant. This can be of considerable value in the personal care arena where skin sensitivity due to the presence of certain surfactants can be an issue.

BRIEF SUMMARY OF THE INVENTION

My invention relates to a method of making a silicone elastomer by combining and reacting in one pot (A) an .tbd.Si--H containing polysiloxane; (B) a mono-alkenyl polyether; (C) an unsaturated hydrocarbon such as an alpha, omega-diene; (D) a solvent; and (E) a platinum catalyst, until a silicone elastomer is formed.

As another feature of my invention, additional solvent is added to the silicone elastomer, and the solvent and silicone elastomer are sheared until a silicone paste is formed.

As a further feature of my invention, water is added to the silicone paste, and the water and silicone paste are sheared until a silicone emulsion is formed. The silicone emulsion is formed free of the presence of a surfactant.

Silicone elastomers, silicone pastes, and silicone emulsions, prepared according to these methods, have particular value and utility in treating hair, skin, or underarm areas of the human body. In addition, the silicone elastomers, silicone pastes, and silicone emulsions, are capable of forming barrier films after evaporation of any solvent or volatile component.

These and other features of my invention will become apparent from a consideration of the detailed description.

DESCRIPTION OF THE INVENTION

The invention and steps carried out according to the process in the copending application Ser. No. 08/768,064, (hereafter referred to as the '064 application), now U.S. Pat. No. 5,811,487, are illustrated with reference to the procedure as shown below.

Step 1: Incorporation of the polyether

.tbd.SiH siloxane+mono-alkenyl polyether+platinum catalyst .fwdarw..tbd.SiH siloxane with polyether groups

Step 2: Gelation

.tbd.SiH siloxane with polyether groups+.tbd.SiH siloxane (optional)+alpha, omega-diene+low molecular weight siloxane fluid+platinum catalyst.fwdarw.gel (elastomer)

Step 3: Shearing and swelling

gel/elastomer+low molecular weight siloxane fluid.fwdarw.paste

Step 4: Emulsification

silicone paste+water+shear.fwdarw.silicone emulsion

In Step 1, the molar ratio of the polyether to the .tbd.SiH in the .tbd.SiH siloxane is between zero and one.

In Step 2, the weight ratio of the low molecular weight siloxane fluid to the weight of the .tbd.SiH siloxane with polyether groups and the alpha, omega-diene is from 1-98, but preferably is between 3-10. The molar ratio of .tbd.SiH in the .tbd.SiH siloxane with polyether groups to vinyl in the alpha, omega-diene is from 20:1 to 1:20, but preferably is 1:1. While Step 2 can include a mixture of various types of compounds, at least one .tbd.SiH containing siloxane must include a polyether group.

For example, one formulation found especially suitable for Step 2 is a mixture containing the following compounds:

Me.sub.3 SiO(Me.sub.2 SiO).sub.50 �MeQSiO!.sub.4 (MeHSiO).sub.5 SiMe.sub.3 HSiMe.sub.2 O(Me.sub.2 SiO).sub.10 SiHMe.sub.2 Me.sub.3 SiO(Me.sub.2 SiO).sub.8 (MeHSiO).sub.4 SiMe.sub.3 1,5-hexadiene, and decamethylcyclopentasiloxane. In these formulas, Me is methyl and Q is --CH.sub.2 CH.sub.2 CH.sub.2 (CH.sub.2 CH.sub.2 O).sub.10 H.

In Step 3, the silicone paste contains 80-98 percent by weight of the low molecular weight siloxane fluid or other fluid or solvent to be thickened.

In Step 4, the weight ratio of water to the silicone paste is 95:5 to 5:95.

In the present invention, however, I have eliminated separate Steps 1 and 2, so that all of the reactants (i.e., the .tbd.SiH containing siloxane(s), the mono-alkenyl polyether, the alpha, omega-diene, the low molecular weight siloxane or solvent, and the platinum catalyst), are all combined and reacted in one pot, so to speak.

The .tbd.Si--H containing polysiloxane is represented by compounds of the formula R.sub.3 SiO(R'.sub.2 SiO).sub.a (R"HSiO).sub.b SiR.sub.3 referred to as type A.sup.1, and compounds of the formula HR.sub.2 SiO(R'.sub.2 SiO).sub.c SiR.sub.2 H or compounds of the formula HR.sub.2 SiO(R'.sub.2 SiO).sub.a (R"HSiO).sub.b SiR.sub.2 H referred to as type A.sup.2. In the three formulas, R, R', and R", are alkyl groups with 1-6 carbon atoms; a is 0-250; b is 1-250; and c is 0-250. The molar ratio of compounds A.sup.2 :A.sup.1 is 0-20, preferably 0-5. In preferred embodiments, compounds of types A.sup.1 and A.sup.2 are used in the reaction, however, it is possible to successfully conduct the reaction using only compounds of type A.sup.1.

The .tbd.Si--H containing polysiloxane A.sup.1 can also comprise an alkylhydrogen cyclosiloxane or an alkylhydrogen-dialkyl cyclosiloxane copolymer, represented in general by the formula (R'.sub.2 SiO).sub.a (R"SiO).sub.b where R', R", a, and b, are as defined above. Preferably, a is 0-7; and b is 3-10. Some representative compounds are (OSiMeH).sub.4, (OSiMeH).sub.3 (OSiMeC.sub.6 H.sub.13), (OSiMeH).sub.2 (OSiMeC.sub.6 H.sub.13).sub.2, and (OSiMeH) (OSiMeC.sub.6 H.sub.13).sub.3, where Me is --CH.sub.3.

The most preferred unsaturated hydrocarbon is an alpha, omega-diene of the formula CH.sub.2 .dbd.CH(CH.sub.2).sub.x CH.dbd.CH.sub.2 where x is 1-20. Some representative examples of suitable alpha, omega-dienes for use herein are 1,4-pentadiene; 1,5-hexadiene; 1,6-heptadiene; 1,7-octadiene; 1,8-nonadiene; 1,9-decadiene; 1,11-dodecadiene; 1,13-tetradecadiene; and 1,19-eicosadiene.

However, other unsaturated hydrocarbons can be used such as alpha, omega-diynes of the formula CH.tbd.C(CH.sub.2).sub.x C.tbd.CH; or alpha, omega-ene-ynes of the formula CH.sub.2 .dbd.CH(CH.sub.2).sub.x C.tbd.CH where x is 1-20. Some representative examples of suitable alpha, omega-diynes for use herein are 1,3-butadiyne HC.tbd.C--C.tbd.CH and 1,5-hexadiyne (dipropargyl) HC.tbd.C--CH.sub.2 CH.sub.2 --C.tbd.CH. One representative example of a suitable alpha, omega-ene-yne for use herein is hexene-5-yne-1 CH.sub.2 .dbd.CHCH.sub.2 CH.sub.2 C.tbd.CH.

The reaction requires a catalyst to effect the reaction between the .tbd.SiH containing siloxanes, the mono-alkenyl polyether, and the alpha, omega-diene. Suitable catalysts are Group VIII transition metals, i.e., the noble metals. Such noble metal catalysts are described in U.S. Pat. No. 3,923,705, incorporated herein by reference, to show platinum catalysts. One preferred platinum catalyst is Karstedt's catalyst, which is described in Karstedt's U.S. Pat. Nos. 3,715,334 and 3,814,730, incorporated herein by reference. Karstedt's catalyst is a platinum divinyl tetramethyl disiloxane complex, typically containing about one weight percent of platinum, carried in a polydimethylsiloxane fluid or in a solvent such as toluene.

The particular catalyst used in the examples herein is 20 .mu.l, 40 .mu.l, or 200 .mu.l portions of Karstedt catalyst as 1-2 weight percent of platinum, carried in a two centistoke (mm.sup.2 /s) polydimethylsiloxane fluid, or in a volatile methyl siloxane such as decamethylcyclopentasiloxane. Another preferred platinum catalyst is a reaction product of chloroplatinic acid and an organosilicon compound containing terminal aliphatic unsaturation. It is described in U.S. Pat. No. 3,419,593, incorporated herein by reference. The noble metal catalysts are used in amounts from 0.00001-0.5 parts platinum per 100 weight parts of .tbd.SiH containing polysiloxane, preferably 0.00001-0.02 parts, most preferably 0.00001-0.002 parts.

The mono-alkenyl polyether is a compound of the formula CH.sub.2 .dbd.CH(CH.sub.2).sub.x O(CH.sub.2 CH.sub.2 O).sub.y (CH.sub.2 CH.sub.3 CHO).sub.z T, or a compound of the formula CH.sub.2 .dbd.CH--Q--O(CH.sub.2 CH.sub.2 O).sub.y (CH.sub.2 CH.sub.3 CHO).sub.z T. In the formulas, T represents an end group which can be hydrogen; a C1-C10 alkyl group such as methyl, ethyl, propyl, butyl, and decyl; an aryl group such as phenyl; or a C1-C20 acyl group such as acetyl, propionyl, butyryl, lauroyl, myristoyl, and stearoyl. Q is a divalent linking group containing unsaturation such as phenylene --C.sub.6 H.sub.4 --. The value of x is 1-6; y can be zero or have a value of 1-100; z can be zero or have a value of 1-100; with the proviso that y and z cannot both be zero.

Some representative examples of suitable mono-alkenyl polyethers are compounds with the formulas CH.sub.2 .dbd.CHCH.sub.2 O(CH.sub.2 CH.sub.2 O).sub.7 H, CH.sub.2 .dbd.CHCH.sub.2 O(CH.sub.2 CH.sub.2 O).sub.10 �CH(CH.sub.3)CH.sub.2 O).sub.4 H, and CH.sub.2 .dbd.CHCH.sub.2 O(CH.sub.2 CH.sub.2 O).sub.7 C(O)CH.sub.3.

The phrase low molecular weight silicone oil (D) includes compounds containing a silicon atom such as (i) low molecular weight linear and cyclic volatile methyl siloxanes, (ii) low molecular weight linear and cyclic volatile and non-volatile alkyl and aryl siloxanes, and (iii) low molecular weight functional linear and cyclic siloxanes. Most preferred, however, are low molecular weight linear and cyclic volatile methyl siloxanes (VMS).

VMS compounds correspond to the average unit formula (CH.sub.3).sub.a SiO.sub.(4-a)/2 in which a has an average value of two to three. The compounds contain siloxane units joined by .tbd.Si--O--Si.tbd. bonds. Representative units are monofunctional "M" units (CH.sub.3).sub.3 SiO.sub.1/2 and difunctional "D" units (CH.sub.3).sub.2 SiO.sub.2/2.

The presence of trifunctional "T" units CH.sub.3 SiO.sub.3/2 results in the formation of branched linear or cyclic volatile methyl siloxanes. The presence of tetrafunctional "Q" units SiO.sub.4/2 results in the formation of branched linear or cyclic volatile methyl siloxanes.

Linear VMS have the formula (CH.sub.3).sub.3 SiO{(CH.sub.3).sub.2 SiO}.sub.y Si(CH.sub.3).sub.3. The value of y is 0-5. Cyclic VMS have the formula {(CH.sub.3).sub.2 SiO}.sub.z. The value of z is 3-9. Preferably, these volatile methyl siloxane have boiling points less than about 250.degree. C. and viscosities of about 0.65 to about 5.0 centistokes (mm.sup.2 /s).

Representative linear volatile methyl siloxanes are hexamethyldisiloxane (MM) with a boiling point of 100.degree. C., viscosity of 0.65 mm.sup.2 /s, and formula Me.sub.3 SiOSiMe.sub.3 ; octamethyltrisiloxane (MDM) with a boiling point of 152.degree. C., viscosity of 1.04 mm.sup.2 /s, and formula Me.sub.3 SiOMe.sub.2 SiOSiMe.sub.3 ; decamethyltetrasiloxane (MD.sub.2 M) with a boiling point of 194.degree. C., viscosity of 1.53 mm.sup.2 /s, and formula Me.sub.3 SiO(Me.sub.2 SiO).sub.2 SiMe.sub.3 ; dodecamethylpentasiloxane (MD.sub.3 M) with a boiling point of 229.degree. C., viscosity of 2.06 mm.sup.2 /s, and formula Me.sub.3 SiO(Me.sub.2 SiO).sub.3 SiMe.sub.3 ; tetradecamethylhexasiloxane (MD.sub.4 M) with a boiling point of 245.degree. C., viscosity of 2.63 mm.sup.2 /s, and formula Me.sub.3 SiO(Me.sub.2 SiO).sub.4 SiMe.sub.3 ; and hexadecamethylheptasiloxane (MD.sub.5 M) with a boiling point of 270.degree. C., viscosity of 3.24 mm.sup.2 /s, and formula Me.sub.3 SiO(Me.sub.2 SiO).sub.5 SiMe.sub.3.

Representative cyclic volatile methyl siloxanes are hexamethylcyclotrisiloxane (D.sub.3) a solid with a boiling point of 134.degree. C. and formula {(Me.sub.2)SiO}.sub.3 ; octamethylcyclotetrasiloxane (D.sub.4) with a boiling point of 176.degree. C., viscosity of 2.3 mm.sup.2 /s, and formula {(Me.sub.2)SiO}.sub.4 ; decamethylcyclopentasiloxane (D.sub.5) with a boiling point of 210.degree. C., viscosity of 3.87 mm.sup.2 /s, and formula {(Me.sub.2)SiO}.sub.5 ; and dodecamethylcyclohexasiloxane (D.sub.6) with a boiling point of 245.degree. C., viscosity of 6.62 mm.sup.2 /s, and formula {(Me.sub.2)SiO}.sub.6.

Representative branched volatile methyl siloxanes are heptamethyl-3-{(trimethylsilyl)oxy}trisiloxane (M.sub.3 T) with a boiling point of 192.degree. C., viscosity of 1.57 mm.sup.2 /s, and formula C.sub.10 H.sub.30 O.sub.3 Si.sub.4 ; hexamethyl-3,3,bis {(trimethylsilyl)oxy} trisiloxane (M.sub.4 Q) with a boiling point of 222.degree. C., viscosity of 2.86 mm.sup.2 /s, and formula C.sub.12 H.sub.36 O.sub.4 Si.sub.5 ; and pentamethyl {(trimethylsilyl)oxy} cyclotrisiloxane (MD3) with the formula C.sub.8 H.sub.24 O.sub.4 Si.sub.4.

The process also includes using low molecular weight linear and cyclic volatile and non-volatile alkyl and aryl siloxanes represented respectively by formulas R.sub.3 SiO(R.sub.2 SiO).sub.y SiR.sub.3 and (R.sub.2 SiO).sub.z. R can be alkyl groups with 2-20 carbon atoms or aryl groups such as phenyl. The value of y is 0-80, preferably 5-20. The value of z is 3-9, preferably 4-6. These polysiloxanes have viscosities generally in the range of about 1-100 centistokes (mm.sup.2 /s). Polysiloxanes can also be used where y has a value sufficient to provide polymers with a viscosity in the range of about 100-1,000 centistokes (mm.sup.2 /sec). Typically, y can be about 80-375. Illustrative of such polysiloxanes are polydimethylsiloxane, polydiethylsiloxane, polymethylethylsiloxane, polymethylphenylsiloxane, and polydiphenylsiloxane.

Low molecular weight functional polysiloxanes can also be employed, and are represented by the formula R.sub.3 SiO(RQSiO).sub.y SiR.sub.3 where Q is a functional group. Examples of such functional polysiloxanes containing functional groups represented by Q are acrylamide functional siloxane fluids, acrylate functional siloxane fluids, amide functional siloxane fluids, amino functional siloxane fluids, carbinol functional siloxane fluids, carboxy functional siloxane fluids, chloroalkyl functional siloxane fluids, epoxy functional siloxane fluids, glycol functional siloxane fluids, ketal functional siloxane fluids, mercapto functional siloxane fluids, methyl ester functional siloxane fluids, perfluoro functional siloxane fluids, and silanol functional siloxanes.

My invention is not limited to swelling silicone elastomers with only low molecular weight polysiloxanes. Other types of solvents can swell the silicone elastomer. Thus, a single solvent or a mixture of solvents may be used.

By solvent is meant (i) organic compounds, (ii) compounds containing a silicon atom as enumerated above, (iii) mixtures of organic compounds, (iv) mixtures of compounds containing a silicon atom, or (v) mixtures of organic compounds and compounds containing a silicon atom; used on an industrial scale to dissolve, suspend, or change the physical properties of other materials.

In general, the organic compounds are aromatic hydrocarbons, aliphatic hydrocarbons, alcohols, aldehydes, ketones, amines, esters, ethers, glycols, glycol ethers, alkyl halides, or aromatic halides. Representative of some common organic solvents are alcohols such as methanol, ethanol, 1-propanol, cyclohexanol, benzyl alcohol, 2-octanol, ethylene glycol, propylene glycol, and glycerol; aliphatic hydrocarbons such as pentane, cyclohexane, heptane, VM&P solvent, and mineral spirits; alkyl halides such as chloroform, carbon tetrachloride, perchloroethylene, ethyl chloride, and chlorobenzene; aromatic hydrocarbons such as benzene, toluene, ethylbenzene, and xylene; esters such as ethyl acetate, isopropyl acetate, ethyl acetoacetate, amyl acetate, isobutyl isobutyrate, and benzyl acetate; ethers such as ethyl ether, n-butyl ether, tetrahydrofuran, and 1,4-dioxane; glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, diethylene glycol monobutyl ether, and propylene glycol monophenyl ether; ketones such as acetone, methyl ethyl ketone, cyclohexanone, diacetone alcohol, methyl amyl ketone, and diisobutyl ketone; petroleum hydrocarbons such as mineral oil, gasoline, naphtha, kerosene, gas oil, heavy oil, and crude oil; lubricating oils such as spindle oil and turbine oil; and fatty oils such as corn oil, soybean oil, olive oil, rape seed oil, cotton seed oil, sardine oil, herring oil, and whale oil.

Other miscellaneous organic solvents can also be used, such as acetonitrile, nitromethane, dimethylformamide, propylene oxide, trioctyl phosphate, butyrolactone, furfural, pine oil, turpentine, and m-creosol.

Further encompassed by the term solvent are volatile flavoring agents such as oil of wintergreen; peppermint oil; spearmint oil; menthol; vanilla; cinnamon oil; clove oil; bay oil; anise oil; eucalyptus oil; thyme oil; cedar leaf oil; oil of nutmeg; oil of sage; cassia oil; cocoa; licorice; high fructose corn syrup; citrus oils such as lemon, orange, lime, and grapefruit; fruit essences such as apple, pear, peach, grape, strawberry, raspberry, cherry, plum, pineapple, and apricot; and other useful flavoring agents including aldehydes and esters such as cinnamyl acetate, cinnamaldehyde, eugenyl formate, p-methylanisole, acetaldehyde, benzaldehyde, anisic aldehyde, citral, neral, decanal, vanillin, tolyl aldehyde, 2,6-dimethyloctanal, and 2-ethyl butyraldehyde.

In addition, the term solvent is intended to include volatile fragrances such as natural products and perfume oils. Some representative natural products and perfume oils are ambergris, benzoin, civet, clove, leaf oil, jasmine, mate', mimosa, musk, myrrh, orris, sandalwood oil, and vetivert oil; aroma chemicals such as amyl salicylate, amyl cinnamic aldehyde, benzyl acetate, citronellol, coumarin, geraniol, isobornyl acetate, ambrette, and terpinyl acetate; and the various classic family perfume oils such as the floral bouquet family, the oriental family, the chypre family, the woody family, the citrus family, the canoe family, the leather family, the spice family, and the herbal family.

The process is carried out by simply combining in one pot, as it were, the .tbd.SiH containing siloxane(s), the mono-alkenyl polyether, the alpha, omega-diene, the low molecular weight siloxane or solvent, and the platinum catalyst; and mixing these ingredients at room temperature until a gel, elastomer, paste, or emulsion, is formed. If desired, the gel, elastomer, paste, or emulsion, can be further diluted with an additional similar or dissimilar solvent(s), to form the final composition. A blend of hexane and tetrahydrofuran, a fragrance, an oil, or another low molecular weight siloxane, are examples of diluents that could be so employed. Higher temperatures to speed up the process can be used.

Additional amounts of low molecular weight siloxane or solvent are added to the gel, i.e., Step 3, and the resulting mixture is subjected to shear force to form the paste. In Step 4, shear force is again used, during or after water is added to the paste to form the emulsion. Any type of mixing and shearing equipment may be used to perform these steps such as a batch mixer, planetary mixer, single or multiple screw extruder, dynamic or static mixer, colloid mill, homogenizer, sonolator, or a combination thereof.

Typically, the process is carried out by using approximately a 1:1 molar ratio of the .tbd.SiH in the .tbd.Si--H containing siloxane and the vinyl in the alpha, omega-diene. It is expected that useful materials may also be prepared by carrying out the process with an excess of either the .tbd.Si--H containing siloxane or the alpha, omega-diene, but this would be considered a less efficient use of the materials. The remainder of the composition comprises the low molecular weight siloxane or solvent, in amounts generally within the range of about 65-98 percent by weight of the composition, but preferably about 80-98 percent by weight.

The following example is set forth for the purpose of illustrating the one pot method according to the present invention.

EXAMPLE 1

One Pot Method

15 g of an organopolysiloxane with the average structure Me.sub.3 SiO(Me.sub.2 Si0).sub.93 (MeHSiO).sub.6 SiMe.sub.3, 0.53 g of a polyether with the average structure CH.sub.2 .dbd.CHCH.sub.2 O(CH.sub.2 CH.sub.2 O).sub.7 C(O)CH.sub.3, 72 g decamethylcyclopentasiloxane, 0.48 g 1,5-hexadiene, and 40 .mu.l Karstedt catalyst (i.e., two weight percent platinum in decamethylcyclopentasiloxane), were placed in a reaction vessel. The solution was heated in a 60.degree. C. bath and vigorously stirred by a large magnetic stirring bar. Gelation occurred quickly, and the gel was heated in the 60.degree. C. bath for 5 hours. A slightly hazy gel resulted, and 70 g of the gel was sheared and swollen with 55 g of decamethylcyclopentasiloxane. A uniform paste was obtained having a viscosity at a shear rate of 0.01 s.sup.-1 of 1.17.times.10.sup.6 cP/mPa.cndot.s. Twenty grams of the uniform paste and 15 g of deionized water were mixed in a glass jar with a mechanical stirrer, forming a white emulsion paste having a viscosity at a shear rate of 0.01 s.sup.-1 of 5.29.times.10.sup.6 cP/mPa.cndot.s. No surfactant was required to make this emulsion.

The silicone elastomer, silicone gel, silicone paste, and silicone powder compositions of my invention have particular value in the personal care arena. Because of the unique volatility characteristics of the VMS component of these compositions, they can be used alone, or blended with other cosmetic fluids, to form a variety of over-the-counter (OTC) personal care products.

Thus, they are useful as carriers in antiperspirants and deodorants, since they leave a dry feel, and do not cool the skin upon evaporation. They are lubricious and will improve the properties of skin creams, skin care lotions, moisturizers, facial treatments such as acne or wrinkle removers, personal and facial cleansers, bath oils, perfumes, colognes, sachets, sunscreens, pre-shave and after-shave lotions, liquid soaps, shaving soaps, and shaving lathers. They can be used in hair shampoos, hair conditioners, hair sprays, mousses, permanents, depilatories, and cuticle coats, to enhance gloss and drying time, and provide conditioning benefits.

In cosmetics, they will function as leveling and spreading agents for pigments in make-ups, color cosmetics, foundations, blushes, lipsticks, lip balms, eyeliners, mascaras, oil removers, color cosmetic removers, and powders. They are useful as delivery systems for oil and water soluble substances such as vitamins. When incorporated into sticks, gels, lotions, aerosols, and roll-ons, the compositions impart a dry, silky-smooth, payout.

In addition, the compositions exhibit a variety of advantageous and beneficial properties such as clarity, shelf stability, and ease of preparation. Hence, they have wide application, but especially in antiperspirants, deodorants, in perfumes as a carrier, and for conditioning hair.

The silicone elastomers, gels, pastes, and powders, have uses beyond the personal care arena, including their use as a filler or insulation material for electrical cable, a soil or water barrier for in-ground stabilization, or as a replacement for epoxy materials used in coil-on-plug designs in the electronics industry.

They are also useful as carrier for crosslinked silicone rubber particles. In that application, (i) they allow ease of incorporation of the particles into such silicone or organic phases as sealants, paints, coatings, greases, adhesives, antifoams, and potting compounds; and (ii) they provide for modifying rheological, physical, or energy absorbing properties of such phases in either their neat or finished condition.

In addition, my silicone elastomers, gels, pastes, and powders, are capable of functioning as carriers for pharmaceuticals, biocides, herbicides, pesticides, and other biologically active substances; and can be used to incorporate water and water-soluble substances into hydrophobic systems. Examples of some water-soluble substances are salicylic acid, glycerol, enzymes, and glycolic acid.

Other variations may be made in compounds, compositions, and methods described herein, without departing from the essential features of my invention. The forms of invention are exemplary only, and not intended as limitations on their scope, as defined in the appended claims.

Claims

1. A method of making a silicone elastomer comprising simultaneously combining and reacting:

(A) an .tbd.Si--H containing polysiloxane of the formula R.sub.3 SiO(R'.sub.2 SiO).sub.a (R"HSiO).sub.b SiR.sub.3 or the formula (R'.sub.2 SiO).sub.a (R"HSiO).sub.b, and optionally an .tbd.Si--H containing polysiloxane of the formula HR.sub.2 SiO(R'.sub.2 SiO).sub.c SiR.sub.2 H or an .tbd.Si--H containing polysiloxane of the formula HR.sub.2 SiO(R'.sub.2 SiO).sub.a (R"HSiO).sub.b SiR.sub.2 H, where R, R', and R" are alkyl groups with 1-6 carbon atoms, a is 0-250, b is 1-250, and c is 0-250;

(B) a mono-alkenyl polyether of the formula CH.sub.2 .dbd.CH(CH.sub.2).sub.x O(CH.sub.2 CH.sub.2 O).sub.y (CH.sub.2 CH.sub.3 CHO).sub.z T, or the formula CH.sub.2 .dbd.CH--Q--O(CH.sub.2 CH.sub.2 O).sub.y (CH.sub.2 CH.sub.3 CHO).sub.z T, where T is hydrogen, a C.sub.1 -C.sub.10 alkyl group, an aryl group, or a C.sub.1 -C.sub.20 acyl group; Q is a divalent linking group containing unsaturation; x is 1-6, y is zero or 1-100; and z is zero or 1-100; provided y and z are both not zero;

(C) a platinum catalyst;

(D) an unsaturated hydrocarbon selected from the group consisting of alpha, omega-dienes of the formula CH.sub.2 .dbd.CH(CH.sub.2).sub.x CH.dbd.CH.sub.2, alpha, omega-diynes of the formula CH.tbd.C(CH.sub.2).sub.x C.tbd.CH, and alpha, omega-ene-ynes of the formula CH.sub.2 .dbd.CH(CH.sub.2).sub.x C.tbd.CH, where x is 1-20; and

(E) a solvent selected from the group consisting of (i) organic compounds, (ii) compounds containing a silicon atom, (iii) mixtures of organic compounds, (iv) mixtures of compounds containing a silicon atom, and (v) mixtures of organic compounds and compounds containing a silicon atom.

2. A method according to claim 1 including the further steps of adding additional amounts of solvent(s) to the silicone elastomer, and shearing the solvent(s) and silicone elastomer until a silicone paste is formed.

3. A method according to claim 2 including the further steps of adding water to the silicone paste, and shearing the water and silicone paste until a silicone emulsion is formed.

4. A method according to claim 3 in which the silicone emulsion is formed free of the presence of a surfactant.

5. A method according to claim 1 in which the solvent is a linear volatile methyl siloxane of the formula (CH.sub.3).sub.3 SiO{(CH.sub.3).sub.2 SiO}.sub.y Si(CH.sub.3).sub.3 where y is 0-5, or a cyclic volatile methyl siloxane of the formula {(CH.sub.3).sub.2 SiO}.sub.z where z is 3-8, the volatile methyl siloxane have a boiling point less than about 250.degree. C. and a viscosity of 0.65-5.0 centistokes (mm.sup.2 /s).

6. A silicone elastomer prepared according to the method defined in claim 1.

7. A silicone paste prepared according to the method defined in claim 2.

8. A silicone emulsion prepared according to the method defined in claim 3.

9. A method of treating hair, skin, or underarm comprising applying to the hair, skin, or underarm the silicone elastomer of claim 6.

10. A method of treating hair, skin, or underarm comprising applying to the hair, skin, or underarm the silicone paste of claim 7.

11. A method of treating hair, skin, or underarm comprising applying to the hair, skin, or underarm the silicone emulsion of claim 8.

12. A method of providing a barrier film to the surface of a substrate comprising applying to the substrate the silicone elastomer of claim 6, and allowing the solvent to evaporate.

13. A method of providing a barrier film to the surface of a substrate comprising applying to the substrate the silicone paste of claim 7, and allowing the solvent to evaporate.

14. A method of providing a barrier film to the surface of a substrate comprising applying to the substrate the silicone emulsion of claim 8, and allowing the solvent to evaporate.