AQUEOUS RESIN COMPOSITION AND PRODUCTION METHOD THEREOF, AND COATING MATERIAL AND COATED ARTICLE

PROBLEM TO BE SOLVED: To provide an aqueous resin composition capable of obtaining a coating film having excellent adhesiveness to a hardly adhesive substrate such as metals and rust-prevention performance.SOLUTION: An aqueous resin composition contains a polymer P1 that contains (i) 45 mass% to 55 mass% of a constituent unit derived from alkyl (meth)acrylate a1 in which an alkyl group bound with a (meth)acryloyloxy group is an alkyl group having 4 to 22 carbons, (ii) 0.1 mass% to 5 mass% of a constituent unit derived from a radical polymerizable monomer a2 having a phosphate group, (iii) 2 mass% to 15 mass% of a constituent unit derived from a radical monomer a3 having a carbonyl group (where, alkyl(meth)acrylate and monomer a2 are excluded), and (iv) 25 mass% to 45 mass% of a constituent unit derived from a radical polymerizable monomer a4 other than the monomers a1, a2 and a3.SELECTED DRAWING: None 【課題】金属等の難密着性の基材に対する密着性及び防錆性に優れた塗膜を得ることができる水性樹脂組成物を提供する。【解決手段】（ｉ）（メタ）アクリロイルオキシ基と結合したアルキル基が炭素数４から２２のアルキル基であるアルキル（メタ）アクリレートａ１由来の構成単位を４５質量％以上５５質量%以下、（ｉｉ）リン酸基を有するラジカル重合性単量体ａ２由来の構成単位を０．１質量％以上５質量％以下、（ｉｉｉ）カルボニル基を有するラジカル性単量体ａ３（ただし、アルキル（メタ）アクリレート及び単量体ａ２を除く）由来の構成単位を２質量％以上１５質量％以下、及び（ｉｖ）前記単量体ａ１、ａ２及びａ３以外のラジカル重合性単量体ａ４由来の構成単位を２５質量％以上４５質量％以下、含有する重合体Ｐ１を含む水性樹脂組成物。【選択図】 なし