Process for the preparation of stable polymer concentrates

Abstract

A process for the preparation of concentrates which comprise 5 to 80% by weight of a copolymer based on acryloyldimethyltauric acid or salts thereof, 20 to 95% by weight of one or more emulsifiers and/or a solvent or solvent mixture and 0 to 30% by weight of water is described. The concentrates can, for example, be used for the preparation of cosmetic, pharmaceutical and dermatological preparations.

1 . A process for the preparation of concentrates in liquid or liquid-disperse form comprising 
 I) 5 to 80% by weight of a copolymer which, in random distribution, formed, in an amount of 90 to 99.99% by weight, from monomers of the formula (1)    H 2 C═CHCONHC(CH 3 ) 2 CH 2 SO 3 X  (1)    in which x is a cation or a mixture of cations, and x consists of not more than 10 mol % of protons, and,    in an amount of 0.01 to 10% by weight, from monomers with at least two olefinic double bonds,    II) 20 to 95% by weight of one or more emulsifiers, a solvent, solvent mixture or mixtures thereof, and    III) 0 to 30% by weight of water,    wherein the concentrate is prepared by the process comprising the steps of:    a) free radically polymerizing the monomers of formula (1) in the presence of the monomers having at least two olefinic double bonds, in a polymerization medium which behaves largely inertly with regard to free-radical polymerization reactions and permits the formation of high molecular weights,    b) adding a higher-boiling solvent, solvent mixture, one or more emulsifiers or mixtures thereof to the mixture of polymer and polymerization medium, where the boiling point of the higher-boiling solvent or solvent mixture is at least 10° C. higher than that of the polymerization medium used for the polymerization and    c) removing the polymerization medium.    
     
     
         2 . The process as claimed in  claim 1 , wherein the counterion X in the formula (1) is a proton, a cation of an alkali metal, an equivalent of a cation of an alkaline earth metal or is an ammonium ion.  
     
     
         3 . The process as claimed in  claim 1 , wherein the monomers with at least two olefinic double bonds are selected from the group consisting of dipropyl glycol diallyl ether, polyglycol diallyl ether, triethylene glycol divinyl ether, hydroquinone diallyl ether, tetraallyloxyethane allyl or vinyl ethers of multifunctional alcohols, tetraethylene glycol diacrylate, triallylamine, trimethylolpropane diallyl ether, methylenebisacrylamide, divinylbenzene and trimethylolpropyl tri(meth)acrylate.  
     
     
         4 . The process as claimed in  claim 1 , wherein the polymerization medium is selected from the group consisting of water tertiary alcohols and hydrocarbons having 3 to 30 carbon atoms.  
     
     
         5 . The process as claimed in  claim 4 , wherein the polymerization medium is tert-butanol.  
     
     
         6 . A concentrate made by the process as claimed in  claim 1 .  
     
     
         7 . A cosmetic, pharmaceutical or dermatological preparation comprising a concentrate as claimed in  claim 6 .  
     
     
         8 . The process as claimed in  claim 1 , wherein the removing step further comprises removing the polymerization medium at pressure lower than atmospheric pressure.  
     
     
         9 . The process as claimed in  claim 1 , wherein the removing step further comprises removing the polymerization medium at a temperature greater than room temperature.  
     
     
         10 . The process as claimed in  claim 1 , wherein the adding step further comprises adding water to the mixture of polymer and polymerization medium.