Abstract: A (meth)acrylate-based block copolymer including a polymer block and a (meth)acrylate-based polymer block, wherein: the (meth)acrylate-based block copolymer contains 5 to 30% by mass of the polymeric block and 70 to 95% by mass of the (meth)acrylate-based polymer block with respect to 100% by mass of the (meth)acrylate-based block copolymer; the polymer block has a monomer unit derived from a monomer; when the monomer is polymerized alone, a polymer with a glass transition temperature of 80° C. or higher can be obtained; and a tensile strength at break measured in accordance with JIS K 6251 of a film obtained by immersion-molding a (meth)acrylate-based block copolymer latex containing the (meth)acrylate-based block copolymer and heat-treating at 130° C. for 30 minutes is 14 MPa or more.

Abstract: A zinc-nickel alloy plating solution in an aqueous solution comprising, as represented in terms of ions, 4-30 g/liter of zinc and 0.05-4 g/liter of nickel, together with 50-220 g/liter of an alkali hydroxide, 4-110 g/liter of a complexing agent, 0.1-10 g/liter of a primary brightener, 0.01-0.2 g/liter of a booster brightener and preferably, further, 0.01-0.05 g/liter of a tertiary brightener. The primary brightener is at least one selected from the reaction products of amines such as ethylenediamine or its methyl-substituted derivatives, propylenediamine or its methyl-substituted derivatives, diethylenetriamine or its methyl-substituted derivatives, and the like with epihalohydrin. The booster brightener is at least one selected from aromatic aldehydes such as anisaldehyde, vanillin, heliotropin, veratraldehyde, and the like. The tertiary brightener is at least one selected from tellurium oxide, tellurous acid or its salts, or telluric acid or its salt.