Cationic hydrogels based on hydroxyalkyl acrylates and methacrylates

Claim 1

The cationic, polymeric hydrogel produced by the process which comprises simultaneously polymerizing and cross-linking a mixture consisting essentially of the following monomers; a. about 40 to about 95 weight percent, based on the total weight of monomers of an acrylic monomer selected from the group consisting of glyceryl monoacrylates and monomethacrylates and acrylic monomers having the formula: ##STR13## wherein: R and R' each represents hydrogen or lower alkyl of 1 to about 6 carbon atoms; n represents an integer of from 1 to about 50; b. about 50 to about 0.05 weight percent, based on the total weight of monomers, of a monoethylenically unsaturated cationic monomer, capable of copolymerizing with (a), and which is a quaternary ammonium compound having the formula: ##STR14## wherein: R represents hydrogen, methyl or aryl; R 1 represents hydrogen or alkyl of 1 to about 18 carbons; A and A 1 , each of which may be the same or different, each represents an alkylene group of from about 2 to about 8 carbons or an arylene group; R 2 , r 3 and R 4 , each of which may be the same or different, each represents alkyl, aryl or alkaryl or the R 2 and R 3 on the same nitrogen atom, taken together represent a divalent aliphatic group of 4 to 5 atoms which jointly with the amino nitrogen forms a 5 or 6 membered heterocyclic amino group; X and Y, each of which may be the same or different, each represents an anion forming the anion portion of a quanternary ammonium group; and n represents an integer, including 0, of from 0 to about 10; and m represents an integer, including 0, of from 0 to about 5; c. about 0.2 to about 12 weight percent, based on the total weight of monomers, of a polymerizable cross-linking agent capable of copolymerizing with (a) and (b); and having the formula: ##STR15## wherein R represents a member of the group consisting of hydrogen and alkyl of from 1 to about 4 carbon atoms; A represents alkylene of from 2 to about 10 carbons or a polyglycol ether group of the formula: ##STR16## in which R' represents a member of the group consisting of hydrogen and alkyl of 1 to 2 carbon atoms; and n represents an integer of from 1 to about 20; and (d) from 0 to about 50 weight percent, based on the total weight of monomers, of other monoethylenically unsaturated monomers capable of copolymerizing with (a), (b) and (c) and selected from the group consisting of: acrylamides, methacrylamides, alkyl acrylates, alkyl methacrylates, N-vinyl lactams, N-vinyl succinimide, N-vinyl diglycoylimide, N-vinyl glutarimide, N-vinyl-3-morpholinone, N-vinyl-5-methyl-3-morpholinone and N-vinyl imidazole; provided that (a) ≧ (d) and (a) + (d) = about 40 to about 95 weight percent, and when an N-vinyl lactam, N-vinyl succinimide, N-vinyl diglycoylimide, N-vinyl glutarimide, N-vinyl-3-morpholinone, N-vinyl-5-methyl-3-morpholinone or N-vinyl imidazole is used it is present in an amount of less than 20 weight percent; in the presence of a free radical polymerization catalyst in an amount of from about 0.05 to about 4 weight percent, based on the total weight of monomers; and at a temperature of from about 20° to about 125° C.