PROBLEM TO BE SOLVED: To provide a base agent for a hair cosmetic capable of imparting good hair styling properties to a hair cosmetic and maintaining re-styling properties of the styled hair over a long period of time and a hair cosmetic containing this base agent for a hair cosmetic.SOLUTION: A base agent for a hair cosmetic comprises a polymer of an ethylenically unsaturated monomer component. The polymer has a structure comprising at least either or both of a skeleton represented by the formula (Ia) and a skeleton represented by the formula (Ib), and a skeleton represented by the formula (II).COPYRIGHT: (C)2014,JPO&INPIT【課題】毛髪化粧料に良好なヘアスタイリング性を付与すると共に整髪された毛髪の再整髪性を長時間に亘り維持することができる毛髪化粧料用基剤、並びにこの毛髪化粧料用基剤を含有する毛髪化粧料を提供する。【解決手段】毛髪化粧料用基剤は、エチレン性不飽和単量体成分の重合体を含む。前記重合体は、少なくとも式(Ia)で示される骨格及び式(Ib)で示される骨格のいずれか一方又は両方と、式(II)で示される骨格とを含む構造を有している。【選択図】なし
