METHOD OF PRODUCING AQUEOUS DISPERSION OF POLYURETHANE SUITABLE FOR USE IN PERSONAL HYGIENE PRODUCTS, HAIR FIXER AND SUNTAN LOTION BASED ON SAID DISPERSION Russian patent published in 2013 - IPC C08G18/12 C08G18/32 C08G18/44 A61K8/04 A61K8/87 A61Q17/04 A61Q5/06 

FIELD: chemistry.

SUBSTANCE: method involves: (1) obtaining a prepolymer of formula: where R₁ is a divalent polycarbarbonate polyol radical, R₂ is an aliphatic or cycloaliphatic polyisocyanate radical, R₃ is a low-molecular weight diol radical, optionally substituted with ionic groups, n ranges from 1 to 5 and m ranges from 1 to 5; by reacting: (1a) at least one polycarbonate polyol, (1b) one or more aliphatic or cycloaliphatic polyisocyanates, and (1c) at least one low-molecular weight diol, optionally substituted with ionic groups; (2) reacting said prepolymer with at least one polyalkylene oxide with monohydroxyl functional groups with number-average molecular weight equal to less than about 3000; (3) elongating the chain of said prepolymer by reacting with (3a) at least one chain-elongating agent of formula: H₂N-R₄-NH₂, where R₄ is a an alkylene or alkylene oxide radical which is not substituted with ionic or potentially ionic groups, and in the presence of an organic solvent in order to form polyurethane; (4) dispersing the polyurethane in water; (5) removing the organic solvent to obtain an aqueous dispersion of polyurethane; where the polyalkylene oxide radical with monohydroxyl functional groups makes up between about 0.1 wt % to about 5 wt % per weight of polyurethane. Disclosed is a suntan lotion which contains said dispersion.

EFFECT: obtaining hair fixing compositions using said polyurethane dispersion, which demonstrate excellent adhesion to hair, reduce separation, provide improved moisture retention, higher lustre and a natural feel, as well as a suntan lotion having perfect water-repellence, is uniformly applied, gives a good feel and no clumping.

11 cl, 6 ex