Resins for hairdressings

A process for producing a resin for hairdressing which comprises:

• copolymerizing, in a hydrophilic solvent, monomers of a monomer composition comprising:
• 25 to 45 percent by weight of a first monomer (1) represented by the formula ##STR7## 0to 50 percent by weight of a second monomer (2) represented by the formula ##STR8## 5to 65 percent by weight of a third monomer (3) represented by the formula ##STR9## 0to 20 percent by weight of a fourth monomer (4) which is a hydrophilic ethylenically unsaturated monomer, and 0 to 20 percent by weight of a fifth monomer (5) which is an ethylenically unsaturated monomer other than the monomers (1) through (4),
• the total content of the monomer (1) unit and the monomer (4) unit being 35 percent by weight at the least,
• in which formulas:
• R.sup.1 is a hydrogen atom or a methyl radical;
• R.sup.2 is an alkylene radical having 1 to 4 carbon atoms;
• each of R.sup.3 and R.sup.4 is a hydrogen atom or an alkyl radical having 1 to 4 carbon atoms;
• R.sup.5 is an alkyl or alkenyl radical having 1 to 3 carbon atoms;
• R.sup.6 is an alkyl or alkenyl radical having 4 to 24 carbon atoms or a cycloalkyl radical having 4 to 24 carbon atoms;
• and A is oxygen (O) or NH;
• causing the copolymer thus formed to react in the state of a solution in a hydrophilic solvent with sodium or potassium monochloroacetate;
• removing any precipitate formed as by-product;
• and,
• subjecting the copolymer solution thus obtained to an ion-exchange resin treatment thereby to remove ionic impurities.