AQUEOUS COMPOSITE RESIN AND EXTERIOR COATING AGENT COMPRISING THE SAME

To provide an aqueous composite resin having good weather resistance and excellent in adhesiveness, followability and wet friction resistance with respect to various base materials such as a nonpolar plastic base material even in an outdoor use mode.SOLUTION: An aqueous composite resin (F) is provided, which obtained by polymerizing an ethylenically unsaturated monomer (E) comprising an ethylenically unsaturated monomer (e-1) having a structure of a piperidylmethacrylate derivative and/or an ethylenically unsaturated monomer (e-2) of a methacrylate derivative having a phenolic structure to which a benzotriazole ring is connected, using a urethane resin (C-2) containing a mercapto group at both ends as a chain transfer agent prepared by allowing a compound (D) having a mercapto group to react with a urethane prepolymer (C-1) prepared by the reaction of a polyol (A) and a polyisocyanate (B).SELECTED DRAWING: None 【課題】耐候性が良好であり、屋外での使用形態でも非極性プラスチック基材をはじめとする各種基材への密着性、追従性、耐水摩擦性に優れる水性複合樹脂の提供。【解決手段】ポリオール（Ａ）とポリイソシアネート（Ｂ）とを反応させてなるウレタンプレポリマー（Ｃ−１）に、メルカプト基を有する化合物（Ｄ）を反応させてなる両末端メルカプト基含有ウレタン樹脂（Ｃ−２）を連鎖移動剤として、ピペリジルメタクリレート誘導体の構造を有するエチレン性不飽和単量体（ｅ−１）及び／又はベンゾトリアゾール環が連結したフェノール構造を有するメタクリレート誘導体のエチレン性不飽和単量体（ｅ−２）を含むエチレン性不飽和単量体（Ｅ）を重合してなる水性複合樹脂（Ｆ）。【選択図】なし