Water-dispersible silicone resins

摘要

A process for preparing an aqueous dispersion of a silicone resin is disclosed by reacting a mixture containing an alkylalkoxysilane and a cationic alkoxysilane to form a self dispersing silicone resin and subsequently combining the silicone resin with water to form the dispersion. The resulting dispersions are useful for forming coatings on various substrates that are essentially free of co-surfactants or volatile organic solvents.

主权项

1. A process for preparing an aqueous dispersion of a silicone resin comprising:
I) reacting a mixture containing:
a) 80 to 99.9% by weight of an alkylalkoxysilane of the formula
R1aSi(OR2)4-a b) 0.1 to 20% by weight of a cationic alkoxysilane of the formula
R3bR4Si(OR5)3-b where:R1 is an alkyl group containing 1 to 30 carbon atoms,R2 and R5 are independently selected from the group consisting of hydrogen, alkyl groups containing 1 to 4 carbon atoms, CH3C(O)—, CH3CH2C(O)—, HOCH2CH2—, CH3OCH2CH2—, and C2H5OCH2CH2—,R3 is an alkyl group containing 1 to 4 carbons,R4 is a monovalent hydrocarbon having at least one quaternary ammonium group substituent,a is 1 or 2,b is 0, 1 or 2,under an inert atmosphere at reflux temperature, and then subsequently to a temperature ranging from 120-140° C. to form a reaction product comprising a silicone resin; and II) combining 5 to 95 wt % of the reaction product of step I) with 5 to 95 wt % of water to form an aqueous dispersion,wherein the aqueous dispersion does not contain further surfactants and co-surfactants.