| 摘要 |
<p>A copolymer comprising copolymerization of a monomer component mixture (m) that includes: (m-1) a macromonomer having (i) a backbone that comprises a polymer chain having a number average molecular weight of 1,000 to 10,000 and polymerising a monomer component (I) that contains 5-100 mass% of a C4-C24 alkyl-containing polymerisable unsaturated monomer (a), and (ii) a polymerisable unsaturated group; and (m-2) a polymerisable unsaturated monomer containing a hydrophilic group; wherein the copolymer is a graft polymer having a main chain and a side chain, component (m-2) contains at least one kind of hydrophilic group selected from acrylic acid and methacrylic acid, and wherein content of component (m-1) is 1-40 mass%, and component (m-2) is 5-75 mass% based on the total of monomer component (m). Component (m-2) can optionally be a non-ionic polymerisable unsaturated monomer containing at least one kind of hydrophilic group selected from N-substituted (meth)acrylamide having a polyoxyalkylene chain, and N-vinyl-2-pyrrolidone, and wherein content of component (m-1) is 1-29 mass%, and content of component (m-2) is 20-99 mass% based on the total of monomer component (m). The proviso is that a graft copolymer consisting of (A) a main chain containing an N-substituted (meth) acrylamide in a monomer component and having a lower critical solution temperature in water of 40oC or higher; and (B) a hydrophobic side chain is excluded. Also disclosed is an aqueous coating composition containing the copolymer and a method for forming a multilayer coating film containing the copolymer.</p> |
