Cosmetic oil thickener and oil-soluble copolymer

Patent metadata

Field	Value
Publication number	US-12296040-B2
Application number	US-202318217298-A
Country	US
Kind code	B2
Filing date	Jun 30, 2023
Priority date	May 23, 2018
Publication date	May 13, 2025
Grant date	May 13, 2025

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.

First claim

The invention claimed is:

1. A cosmetic containing an oil thickener, and at least one oil which is selected from the group consisting of a hydrocarbon oil, an ester oil, and a higher alcohol, wherein
the oil thickener 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,
the oil-soluble copolymer contains the monomer unit of the hydrophilic monomer in a range of 30 to 50 mol %, contains the monomer unit of the easily-crystallizing hydrophobic monomer in a range of 40 to 65 mol % and contains the monomer unit of the poorly-crystallizing hydrophobic monomer in a range of 5 to 15 mol %,
the hydrophilic monomer is at least one selected from among 2-hydroxyethyl (meth)acrylate, glyceryl (meth)acrylate, PPG-6 (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxy-2-methylpropyl (meth)acrylate, (meth)acrylic acid, N-(2-hydroxyethyl) (meth)acrylamide, N-isopropyl(meth)acrylamide, and 2-(meth)acrylamide-2-methylpropanesulfonic acid,
the easily-crystallizing hydrophobic monomer is at least one selected from among cetyl (meth)acrylate, stearyl (meth)acrylate and behenyl (meth)acrylate,
the poorly-crystallizing hydrophobic monomer is at least one selected from among hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate and isostearyl (meth)acrylate,
the molar ratio of the monomer unit of the easily-crystallizing hydrophobic monomer and the monomer unit of the poorly-crystallizing hydrophobic monomer in the oil-soluble copolymer is 5.5:1 to 8:1,
the amount of the oil thickener is 3 mass % or greater, in 100 mass % of a mixture of the oil thickener and the at least one oil,
the cosmetic exhibits a static viscosity of between 100 Pa-s and 20,000 Pa-s under conditions of a shear rate of 0.0001 s −1 and 25° C. atmosphere and
wherein the copolymer thickens the at least one oil without gelation.

2. The cosmetic according to claim 1 , wherein the weight-average molecular weight of the oil-soluble copolymer is 9000 to 80,000.

3. The cosmetic according to claim 1 , wherein the oil-soluble copolymer contains the monomer unit of the hydrophilic monomer in a range of 30 to 45 mol %, contains the monomer unit of the easily-crystallizing hydrophobic monomer in a range of 50 to 65 mol % and contains the monomer unit of the poorly-crystallizing hydrophobic monomer in a range of 5 to 15 mol %.

Assignees

• Shiseido Co Ltd

Inventors

• Uyama Makoto
• Miyazawa Kazuyuki
• Abe Mineo
• Furuta Takuya

Classifications

• C08F220/58

  containing oxygen in addition to the carbonamido oxygen {, e.g. N-methylolacrylamide, N-(meth)acryloylmorpholine} · CPC title

• C08F220/56

  Acrylamide; Methacrylamide · CPC title

• C08F220/20

  of polyhydric alcohols or phenols {, e.g. 2-hydroxyethyl (meth)acrylate or glycerol mono-(meth)acrylate} · CPC title

• C08F220/06

  Acrylic acid; Methacrylic acid; Metal salts or ammonium salts thereof · CPC title

• A61Q19/00

  Preparations for care of the skin · CPC title