Abstract: The invention provides a novel oil thickener that can impart a thickening effect for oils used in cosmetics, and a novel oil-soluble copolymer that can be used as the thickener. The cosmetic oil thickener of the invention is an oil-soluble copolymer having a monomer unit composed of a hydrophilic monomer, a monomer unit composed of an easily-crystallizing hydrophobic monomer, and a monomer unit composed of a poorly-crystallizing hydrophobic monomer.

Abstract: The invention provides a novel oil thickener that can impart a thickening effect for oils used in cosmetics, and a novel oil-soluble copolymer that can be used as the thickener. The cosmetic oil thickener of the invention is an oil-soluble copolymer having a monomer unit composed of a hydrophilic monomer, a monomer unit composed of an easily-crystallizing hydrophobic monomer, and a monomer unit composed of a poorly-crystallizing hydrophobic monomer.

Abstract: Copolymers derived from hydrophobic monomers of formula (1), and hydrophilic monomers of formulas (2) and (3), are provided The copolymers are useful as gelling agents for oils used in cosmetics and cosmetic emulsions.

Abstract: The present invention provides a copolymer used as oily gelling agent with which a stable oily gelled composition can be prepared. The copolymer of the present invention is characterized by comprising a hydrophobic monomer represented by the following general formula (1) and a hydrophilic monomer represented by the following general formula (2) and/or the following general formula (3). (In formula (1), R1 is a straight-chain or branched-chain alkyl group having 16 to 22 carbon atoms. R2 is a hydrogen atom or a methyl group.) (In formula (2), R3 is a hydrogen atom, a glyceryl group, a straight-chain or branched-chain hydroxyalkyl group having 1 to 4 carbon atoms, or a polypropylene glycol group represented by —(C3H6O)nH (here, n is an integer of 2 to 10). R4 is a hydrogen atom or a methyl group.