Acrylic copolymer which is water-soluble or moderately water-soluble and may be crosslinked; and its use

A copolymer which is water-soluble or moderately water-soluble and which may be crosslinked, comprising:

• (a) units of at least one monomer having ethylenic unsaturation and having at least one carboxylic acid group, which monomer is selected from the group consisting of monoacids, diacids, the anhydrides of carboxylic acids, and the hemiesters of diacids;
• (b) optionally, unit(s) of at least one monomer having ethylenic unsaturation and not having a carboxylic acid group selected from the group consisting of the esters, amides, and nitriles of (meth)acrylic acid, or selected from the group consisting of vinyl acetate, styrene, methylstyrene, diisobutylene, vinylpyrrolidone, and vinylcaprolactam;
• (c) units of at least one monomer having an oxyalkylated moiety, which monomer has ethylenic unsaturation and is terminated by a hydrophobic fatty chain, said monomer having formula I:
• ##STR3## where m and p represent numbers of oxyalkylene groups each .ltoreq.100;
• n represents the number of oxyethylene groups .ltoreq.100;
• q represents a number at least equal to 1 such that q(n+m+p).ltoreq.100;
• R.sub.1 represents hydrogen or a methyl group;
• R.sub.2 represents hydrogen or a methyl group;
• R' represents hydrophobic fatty hydrocarbon chain of at least 26 carbon atoms;
• and
• R represents an unsaturated polymerizable group selected from the group consisting of vinyl group containing moieties, methacryloyl, maleoyl, itaconoyl, crotonyl, an unsaturated urethane moiety, hemiester maleoyl, hemiester itaconoyl, CH.sub.2 .dbd.CHCH.sub.2 --O--, methacrylamido and substituted methacrylamido;
• and
• (d) optionally, unit(s) of at least one monomer having at least two sites of ethylenic unsaturation selected from the group consisting of ethylene glycol dimethacrylate, 2,2-dihydroxymethylbutanol triacrylate, allyl acrylate, methylenebis(meth)acrylamide, tetraallyloxyethane, triallyl cyanurate, and allyl ethers obtained from polyols.