Oil-in-water silicone emulsion composition

1. An oil-in-water silicone emulsion composition comprising

(A) 100 mass parts of a polyorganosiloxane that contains in each molecule at least two silicon-bonded hydroxyl or hydrolyzable groups,

(B) 0.1 to 200 mass parts of a colloidal silica,

(C) 1 to 100 mass parts of an ionic emulsifying agent,

(D) 0.1 to 50 mass parts of a polyoxyethylene-polyoxypropylene copolymer nonionic emulsifying agent, wherein the component (D) polyoxyethylene-polyoxypropylene copolymer nonionic emulsifying agent is a compound represented by the following general formula (1) or general formula (2):

HO(CH 2 CH 2 O) a (CH(CH 3 )CH 2 O) b (CH 2 CH 2 O) c H  (1)

HO(CH(CH 3 )CH 2 O) d (CH 2 CH 2 O) e (CH(CH 3 )CH 2 O) f H  (2)

wherein a, b, c, d, e, and f in general formulas (1) and (2) are the average number of moles of addition of ethylene oxide or propylene oxide and are each independently a number from 1 to 350, and

(E) 10 to 200 mass parts water.

2. The oil-in-water silicone emulsion composition according to claim 1 , wherein the total content of siloxane oligomers comprising 4 to 5 siloxane units is not more than 2 mass %.

3. The oil-in-water silicone emulsion composition according to claim 2 , wherein the component (A) polyorganosiloxane is a diorganopolysiloxane endblocked at both molecular chain terminals by the hydroxyl group.

4. The oil-in-water silicone emulsion composition according to claim 3 , wherein the viscosity of component (A) at 25° C. is from 50 mPa·s to 2,000,000 mPa·s.

5. The oil-in-water silicone emulsion composition according to claim 1 , wherein the component (A) polyorganosiloxane is a diorganopolysiloxane endblocked at both molecular chain terminals by a hydroxyl group.

6. The oil-in-water silicone emulsion composition according to claim 5 , wherein the viscosity of component (A) at 25° C. is from 50 mPa·s to 2,000,000 mPa·s.

7. The oil-in-water silicone emulsion composition according to claim 1 , further comprising, as a component (F), 0.1 to 50 mass parts of an alkoxysilane or alkoxyalkoxysilane represented by R a SiX 4-a wherein R is an unsubstituted monovalent hydrocarbyl group or a substituted monovalent hydrocarbyl group, X is an alkoxy group or an alkoxyalkoxy group, and a is 0, 1, or 2, or a partial hydrolysis and condensation product of the alkoxysilane or alkoxyalkoxysilane.

8. The oil-in-water silicone emulsion composition according to claim 1 , further comprising an amine as a component (G).

9. The oil-in-water silicone emulsion composition according to claim 1 , wherein the average particle size of the emulsion particles is not more than 300 nm.

10. A method of producing the oil-in-water silicone emulsion composition according to claim 1 , the method comprising the steps of:

carrying out emulsification and dispersion on the (A) polyorganosiloxane that contains in each molecule at least two silicon-bonded hydroxyl or hydrolyzable groups, the (C) ionic emulsifying agent, the (D) polyoxyethylene-polyoxypropylene copolymer nonionic emulsifying agent, and a portion of the (E) water; and

incorporating the (B) colloidal silica and the remainder of the (E) water in the emulsion provided by the preceding step.

11. A method of treating a surface of a substrate, the method comprising carrying out a surface treatment on the surface of the substrate with the oil-in-water silicone emulsion composition according to claim 1 .