Silicone polyether stabilized silicone latex solvent thickening

• US 5,939,478 A
• Filed: 11/13/1997
• Issued: 08/17/1999
• Est. Priority Date: 07/21/1997
• Status: Expired due to Fees

• Current Assignee: Dow, Inc.
• Original Assignee: Dow, Inc.
• Inventors: O'Neil, Virginia Kay, Cobb, Vicky Sue, Beck, James Anderson, Cuthbert, Cassie Emelia, Joffre, Eric Jude, Wrolson, Burt Michael
• Primary Examiner(s): SERGENT, RABON A
• Application Number:
  US08/969,888
• Time in Patent Office: 642 Days
• Field of Search: 524/186, 524/188, 524/270, 524/284, 524/354, 524/356, 524/366, 524/376, 524/377, 524/379, 524/386, 524/462, 524/464, 524/714, 524/755, 524/761, 524/766, 524/765, 524/770 , 524/773, 524/792, 524/794, 524/265, 524/266, 524/588, 524/730, 524/731, 524/837, 524/838, 524/858, 524/860, 524/863, 524/864, 524/861, 424/78.08, 424/59, 424/61, 424/63, 424/64, 424/65, 424/70.1, 424/70.6, 424/70.7, 424/70.12, 424/70.122, 8/94.16
• US Class Current: 524/266
• CPC Class Codes: A61K 8/042 Gels
• CPC Class Codes: A61K 8/894 modified by a polyoxyalkylene group, e.g. cetyl dimethicone copolyol
• CPC Class Codes: A61K 8/895 containing silicon bound to unsaturated aliphatic groups, e.g. vinyl dimethicone
• CPC Class Codes: A61Q 19/00 Preparations for care of the skin
• CPC Class Codes: C08J 2383/04 Polysiloxanes
• CPC Class Codes: C08J 3/03 in aqueous media
• CPC Class Codes: C08J 3/09 in organic liquids

Abstract

The viscosity of a solvent is modified by thickening the solvent with a silicone latex. A silicone latex having a plurality of crosslinked polysiloxane particles is first prepared by mixing the siloxane polymer, a surfactant, and water; emulsifying the mixture to a gel phase; diluting the emulsion with water; adding a cure package (i.e., a catalyst, a crosslinker, or both, or a self catalytic crosslinker); and then without removing the water from the latex and after the particles of siloxane polymer in the latex have been cured, mixing the latex and solvent to thicken the solvent, forming viscous liquids, gels, and pastes. Water in the latex thickened solvent composition can be stabilized by adding a silicone polyether during mixing of the latex and the solvent. These stabilized latex thickened solvent compositions have beneficial properties such as clarity, shelf stability, and ease of preparation; and therefore have wide areas of application, especially as additives in antiperspirants, deodorants, and other personal care applications.

Claims

1. A method of modifying the viscosity of a solvent, the method comprising (I) adding a silicone latex containing water and a plurality of cured crosslinked polysiloxane particles to a solvent after the particles have been cured and without removing the water from the latex;

(II) mixing the latex containing the water and the cured particles, and the solvent together to thicken the solvent; and

(III) stabilizing water in the latex thickened solvent by adding a silicone polyether during step (II);

the latex prepared by a method comprising;

(A) mixing (i) 100 weight parts of a siloxane polymer having a viscosity of greater than 5,000 mPa.s but less than 500,000 mPa.s at 25°

C., (ii) 0.5-10 weight parts of a surfactant, and (iii) 0.5-25 weight parts of water, (B) emulsifying the mixture into a gel phase having a siloxane polymer content of at least 80% by weight;

(C) diluting the emulsion with further water to a siloxane polymer content of at least 75% by weight, (D) adding 0.00001-20 weight parts catalyst either before or after the emulsification, or before or after the dilution;

(E) adding 0.1-20 weight parts crosslinker either before or after the emulsification, or before or after the dilution;

(F) or in place of adding (D) and (E), adding 1-5 weight parts self catalytic crosslinker either before or after the emulsification, or before or after the dilution;

the silicone polyether having the formula MD_10-1,000 D'"'"'_1-100 M where M represents monofunctional unit R₃ SiO_1/2, D represents difunctional unit R₂ SiO_2/2, and D'"'"' represents difunctional unit RR'"'"'SiO_2/2, in which R is an alkyl group containing 1-6 carbon atoms or an aryl group, and R'"'"' is oxyalkylene unit EO_10-100 PO_0-100 in which EO represents --(CH₂ CH₂ O)-- and PO represents --(CH₂ CH(CH₃)O)--, respectively.

2. A method according to claim 1 in which the latex has a solids content of siloxane polymer of at least 90 percent by weight.

3. A method according to claim 1 in which the siloxane polymer has the formula X_3-n R_n --YO--(R¹₂ SiO)_z --Y--R_n X_3-n where n is 0, 1, 2 or 3;

z is an integer from 500-5,000;

X is hydrogen, a vinyl group, or a hydroxyl group Y is a silicon atom, the group .tbd.Si--(CH₂)_m --SiR¹₂ --, or the group .tbd.Si--(CH₂)_m --SiR¹₂ OSiR¹₂ (CH₂)m--SiR¹₂ --, where m is 1-8;

R is selected from the group consisting of aliphatic alkyl, aminoalkyl, polyaminoalkyl, epoxyalkyl, alkenyl, and an aromatic group; and

R¹ is selected from the group consisting of X, aliphatic alkyl, alkenyl, and an aromatic group.

4. A method according to claim 3 in which the siloxane polymer has at least two vinyl groups per molecule bonded to a silicon atom, the crosslinker having an average of at least two silicon-bonded hydrogen atoms and being a silicon hydride crosslinker present in an amount sufficient to provide at least one hydrogen atom for each vinyl group in the siloxane polymer, and the catalyst is a noble metal catalyst.

5. A method according to claim 1 in which the self catalyzing crosslinker has at least one catalytic leaving group selected from the group consisting of acetoxy, amide, acetamide, aminoxy, and oxime.

6. A method according to claim 5 in which the self catalyzing crosslinker is a compound of the formula ##STR3## where R is the same or a different alkyl group of 1-8 carbon atoms;

a is zero or a positive integer, and b is greater than two.

7. A method according to claim 1 in which the surfactant is selected from the group consisting of nonionic surfactants, cationic surfactants, anionic surfactants, amphoteric surfactants, and mixtures thereof.

8. A method according to claim 1 in which the solvent is selected from the group consisting of aromatic hydrocarbons, aliphatic hydrocarbons, alcohols, aldehydes, ketones, amines, esters, ethers, glycols, glycol ethers, alkyl halides, aromatic halides, petroleum hydrocarbons, lubricating oils, fatty oils, and mixtures thereof.

9. A latex thickened solvent composition prepared according to the method described in claim 1.

10. A personal care product containing the latex thickened solvent composition of claim 9 selected from the group consisting of antiperspirants, deodorants, skin creams, skin care lotions, moisturizers, acne removers, wrinkle removers, facial cleansers, bath oils, perfumes, colognes, sachets, sunscreens, pre-shave lotions, after-shave lotions, shaving soaps, shaving lathers, hair shampoos, hair conditioners, hair sprays, mousses, permanents, depilatories, cuticle coats, make-ups, color cosmetics, foundations, blushes, lipsticks, eyeliners, mascaras, oil removers, cosmetic removers, delivery systems for oil and water soluble substances, and powders.

11. A method of treating hair or skin comprising applying to the hair or skin a composition containing the latex thickened solvent composition of claim 9.