Surfactant-free organopolysiloxane invert emulsions
Water-in-oil invert emulsions containing no surfactant are formed by simple mixing of water with organopolysiloxanes containing all of aralkyl, long chain alkyl, and hydrophilic groups. The surfactant-free water-in-oil invert emulsions have a wide variety of uses, for example in compositions for surface care, antifog coating compositions, cosmetic compositions, and hair care compositions.
1. An external-surfactant-free water-in-oil invert emulsion, comprising:
A) from 5 to 95 parts by weight of one or more self-emulsifying organopolysiloxanes of the formulae (i) and (ii):
(i) a liquid, branched organopolysiloxane of the formula
M a T b Q c
where a is at least 3, b is 0-4, and c is 0-2;
where M is a monovalent siloxy unit of the formula
R e R 1 f R 2 g R 3 h SiO (4−(e+f+g+h))/ 2
where e, f, g, and h are individually integers from 0 to 3 and the sum (e+f+g+h) equals 3;
R is a lower alkyl group or an aryl group,
R 1 is an aralkyl group
R 2 comprises an alkylene-bonded surfactant group selected from the group consisting of polyoxyalkylene polyethers, polyhydroxyl compounds, and saccharides,
R 3 is a long chain alkyl group;
where T is a trivalent siloxy unit of the formula
R e′ R 1 f′ R 2 g′ R 3 h′ SiO (4−(e′+f′+g′+h′))/ 2
where the sum (e′+f′+g′+h′) is 1;
where Q units are of the formula SiO 4/2 ,
and the liquid, branched organopolysiloxane contains at least one of each of R 1 , R 2 , and R 3 ;
(ii) a liquid organopolysiloxane comprising groups of the formula:
R′ 3 SiO, (R 1′ 2 SiO) w , (R 1′ JSiO) x , (R 1′ KSiO) y ,(R 1′ LSiO) z , and SiR′ 3
wherein
R′ is a group L or a C 1-30 hydrocarbon group, one R′ of the R 3 SiO— or —SiR′ 3 group is optionally a hydroxyl group, and one or more R′ of the R 3 SiO— or —SiR′ 3 group is/are optionally a C 1-8 alkoxy group;
R 1′ is hydrogen or a C 1-30 hydrocarbon group;
J is an aralkyl group;
K is a long chain C 8-45 alkyl group;
L is an Si—C bonded, oxygen-containing hydrophilic group having a molecular weight greater than 100 Daltons;
w is from 0 to 200;
x is from 1-100;
y is from 1 to 50; and
z is from 1 to 50, containing less than 5 mol percent, based on the total mols of w,x,y, and z, of R′SiO 3/2 groups and SiO 4/2 groups which form branching sites, wherein the refractive index of the liquid organopolysiloxane (ii) is at least 1.45, and
B) water.
2. The external-surfactant-free water-in-oil invert emulsion of claim 1 , wherein the self-emulsifying organopolysiloxanes is one of formula (i).
3. The external-surfactant-free water-in-oil invert emulsion of claim 1 , wherein the self-emulsifying organopolysiloxanes is one of formula (ii).
4. The external-surfactant-free water-in-oil emulsion of claim 1 , which has shear-thinning properties.
5. A composition for surface care application comprising an external-surfactant-free water-in-oil invert emulsion described in claim 1 , which provides good shine and shows good smudge resistance.
6. An antifog coating composition comprising an external-surfactant-free water-in-oil emulsion of claim 1 .
7. A cosmetic or hair care composition comprising an external-surfactant-free water-in-oil invert emulsion of claim 1 .
8. An external-surfactant-free water-in-oil invert emulsion of claim 1 , which has low cyclic silicone content.
9. An external-surfactant-free water-in-oil invert emulsion of claim 1 , which is prepared without application of high shear.
10. An external-surfactant-free water-in-oil invert emulsion described in claim 1 , which is prepared at room temperature without application of heat.
11. An external-surfactant-free water-in-oil invert emulsion described in claim 1 , which has an average particle size less than 100 nm.
12. A process for forming an external-surfactant-free water-in-oil invert emulsion of claim 1 , comprising adding an aqueous phase to at least one organopolysiloxane of formulae i) and ii) with stirring.