| 摘要 |
PROBLEM TO BE SOLVED: To obtain an aqueous composition which is excellent in curability by an active energy ray and gives a cured film excellent in hardness and resistances to solvents and water by dispersing or dissolving a copolymer formed from an imide (meth)acrylate having a specific chemical structure and a monomer having an ethylenically unsaturated group and an acidic group or a salt of the copolymer in an aqueous medium. SOLUTION: The copolymer is formed from a monomer having an ethylenically unsaturated group and a cyclic imide group of the formula and a monomer having an ethylenically unsaturated group and an acidic group, and is excellent in curability by activation energy ray. In the formula, R1 and R2 are each independently 4C or lower alkyl or one of them is H and the other is 4C or lower alkyl provided they may combine with each other to form a carbocycle. Preferably, the copolymer has an acid value of 20-400 mgKOH/g. Preferably, the copolymer (salt) in an amount of 20-95 pts.wt. is compounded with 80-5 pts.wt. compound having at least two (meth)acryloyl groups in order to improve the curability of the objective aqueous composition and the hardness of a cured film obtained therefrom.
|
