Patent ID: 7935772

Claim:
A water-based resin composition comprising a copolymer (A) which is obtained by carrying out emulsion polymerization of unsaturated monomers comprising: 0.5 to 50 parts by mass of at least one ethylenically unsaturated monomer (a), represented by the following general formula (I), having a piperidyl group in a molecule and 50 to 99.5 parts by mass of at least one ethylenically unsaturated monomer (b), wherein ethylenically unsaturated monomer (b) does not substantially contain an ethylenically unsaturated monomer having a functional group represented by the following formula (II), (III), or (IV) in a molecule, with the total of the ethylenically unsaturated monomers (a) and (b) being 100 parts by mass, in the presence of 0.1 to 10 parts by mass of an emulsifier, wherein R 1 represents a hydrogen atom or an alkyl group having 1 to 2 carbon atoms, X represents an oxygen atom or an imino group, Y represents a hydrogen atom or an alkyl or alkoxyl group having 1 to 20 carbon atoms, and Z represents a hydrogen atom or a cyano group —COOH (II) —SO 3 H (III) —PO 3 H (IV).