PROBLEM TO BE SOLVED: To provide an antifouling agent for cosmetics capable of preventing or suppressing adhesion of cosmetic stain to a tooth surface, and to provide oral compositions.SOLUTION: An antifouling agent for cosmetics is made of a copolymer which has a weight average molecular weight of 10,000 to 5,000,000, and contains 10 to 90 mol% of a constitutional unit (A) based on 2-(meth)acryloyloxyethyl phosphorylcholine, and 90-10 mol% of at least one constitutional unit selected from the group consisting of a constitutional unit (B1) based on alkyl group-containing (meth)acrylic monomer, a constitutional unit (B2) based on quaternary ammonium group-containing (meth)acrylic monomer, and a constitutional unit (B3) based on (meth)acrylamide system monomer.SELECTED DRAWING: NoneCOPYRIGHT: (C)2017,JPO&INPIT【課題】化粧料汚れの歯面への付着を防止ないし抑制することが可能な化粧料汚れ付着防止剤および口腔用組成物を提供する。【解決手段】化粧料汚れ付着防止剤は、重量平均分子量10,000~5,000,000であり、2-(メタ)アクリロイルオキシエチルホスホリルコリンに基づく構成単位(A)10~90モル%と、アルキル基含有(メタ)アクリル系単量体に基づく構成単位(B1)、4級アンモニウム基含有(メタ)アクリル系単量体に基づく構成単位(B2)、および(メタ)アクリルアミド系単量体に基づく構成単位(B3)からなる群から選ばれる少なくとも1種の構成単位90~10モル%とを含有する共重合体からなる。【選択図】なし
