Preparation of aqueous resin for coating - by mixing a composite resin comprising polysiloxane and polymer segments with polysiloxane

摘要

A process for producing an aqueous resin is by mixing between a composite resin (C) comprising a polysiloxane segment (A) with 1 or more silicon (Si) atoms selected from the groups of a Si atom having at least 1 organic group with a total of not less than 3C atoms and a hydrolysable group and/or at least 1 hydroxyl group bonded together, a Si atom with 2 methyl and/or ethyl groups and 1 hydrolysable or hydroxyl group bonded together, and a Si atom with 1 or more triorganosiloxy groups and at least 1 hydrolysable and/or hydroxyl groups bonded together, and a polymer segment (B) having at least 1 hydrophilic group chosen from the group consisting of anionic, cationic and nonionic groups, and a polysiloxane (D) having a hydrolysable group bonded to a Si atom and/or a hydroxyl group linked to a Si atom and containing an essential structural of formula (I), optionally condensing and dissolving the mixture in an aqueous medium.(I) -O-SiR1(-O-)-O- (I) R1 = methyl or ethyl. Also claimed are the following: (i) an aqueous curable resin composition containing the above aqueous resin as the essential component; (ii) a similar composition containing the aqueous resin and a compound (E) having functional groups that can react with those in the resin; and (iii) a method for forming coating by application of the aqueous paint to a substrate, or to a substrate already coated with an undercoat, before curing.