To obtain the subject coating composition which can form coating films capable of being easily removed with an alkali agent, when stained, and has excellent film-forming property and excellent adhesivity by adding a copolymer comprising a specific (meth)acrylic acid ester, a specific dimethyl polysiloxane and the like as essential coating film components.
A coating composition whose coating films can be removed with an alkali agent contains as an essential coating film component a copolymer (whose acid value is preferably 100-500) which comprises (A) a polymerizable unsaturated carboxylic acid such as (meth) acrylic acid preferably in an amount of 15-70 wt.%, (B) a (meth)acrylic acid 1-8C alkyl ester preferably in an amount of 10-50 wt.%, and (C) a dimethylpolysiloxane of formula I or II [R1 is H or methyl; R2 is a 1-6C alkylene or an alkyleneoxy; R3 is a 1-6C alkyl, hydroxyl group or the like; (a) is 5-300; A is O or imino; (b) is 0-6; (c) is 5-300] preferably in an amount of 10-70 wt.%. The coating film of the coating composition is preferably reacted and removed with an alkali agent at pH 8 or higher.
NISHIDA HIDEO
WAKAO HIDEKI
ARIMOTO KUNIO
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