Patent GB-833459-A (GB)
Title: Amphoteric polyelectrolytes and process for the production thereof
IPC: C08F2/00
Filed: 1956-09-07
Abstract: Polyampholytes may be prepared by heating alkali-soluble polymers containing carboxyl groups with (1) N,N-dialkylformamide com-plexes of monohydric aliphatic aminoalcohols, or (2) hydrazines of the form <FORM:0833459/IV (a)/1> where R1 and R2 are alkyl, aryl, aralkyl or alkaryl groups and R3 is hydrogen or an alkyl aryl, aralkyl or alkaryl group.  Preferred aminoalcohols are those having the structure <FORM:0833459/IV (a)/2> where R1 and R2 are alkyl or aryl groups and R3 is an alkylene group.  The carboxylic polymers may be prepared by homopolymerizing or interpolymerizing ethylenically unsaturated acids, e.g. acrylic acid, methacrylic acid, sorbic acid, crotonic acid, itaconic acid, maleic acid and maleic anhydride, or by hydrolysing polymers containing nitrile, amide or ester groups, e.g. homopolymers and interpolymers of acrylic esters, acrylamide and acrylonitrile.  Specified comonomers are butadiene, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate, vinyl methyl ether, vinyl isobutyl ether, ethylene, isobutylene, amylene, styrene, a -methylstyrene, ortho - chlorostyrene, parachlorostyrene, 2,5-dichlorostyrene, 2,4-dichlorostyrene, para - ethylstyrene, divinylbenzene, vinylnaphthalene, methyl, ethyl, butyl and allyl acrylates, methacrylates and ethacrylates, vinyl chloride, vinyl bromide and vinylidene chloride, optionally when maleic acid or anhydride is used together with half esters thereof, e.g. methyl acid maleate.  Specified aminoalcohols are monoethanolamine, monoisopropanolamine, N - methylethanolamine, N,N - dimethylethanolamine and N-(b -hydroxyethyl)-N1-methyl-1,4-piperazine, and specified N,N-dialkylformamides are N,N-dimethylformamide, N,N-diethylformamide and N-methyl-N-ethylformamide.  Specified hydrazines are N,N-di methylhydrazine, N,N-diethylhydrazine, N,N-dibutylhydrazine, N-methyl-N-hexylhydrazine, N,N-di-(2-ethylhexyl)-hydrazine, N-methyl-N-phenylhydrazine, N,N-diphenylhydrazine and N-methyl-N-propylhydrazine.  Reaction with the polymer may be effected in an inert, waterimmiscible liquid, e.g. benzene, toluene and xylene.  The properties of the polyampholytes may be modified by partially pre-esterifying the polymer or the carboxyl-containing monomer from which it is prepared with an aliphatic, heterocyclic or aromatic alcohol.  The polyampholytes are flocculating agents, and may be used in beer and soft drink manufacturing processes, sugar refining, sewage treatment, as soil conditioners and as additives to oil-well drilling muds.  Examples describe the reaction of the N,N-dimethylformamide complex of N,N-dimethylethanolamine with (I and VI) isobutylene-maleic anhydride interpolymers, (II and III) isobutylene-maleic anhydride-methyl acid maleate terpolymers, (IV) vinyl acetate-maleic anhydride-methyl acid maleate terpolymer, (V) methylvinyl ether-maleic anhydride interpolymer, (VII) polyacrylic acid, (VIII) vinyl acetatemethacrylic acid copolymer and (IX) butadienemethacrylic acid copolymer; N,N-dimethylhydrazine with (X) ethylene-maleic anhydride interpolymer, (XIII) isobutylene-maleic anhydride, (XIV and XV) styrene-maleic anhydride-methyl acid maleate terpolymers, (XVI) vinyl acetate-maleic anhydride-methyl acid maleate terpolymer, (XVII) vinyl methyl ethermaleic anhydride interpolymer, (XVIII) polyacrylic acid, (XIX) vinyl acetate-methacrylic acid copolymer and (XX) butadiene-methacrylic acid copolymer; and ethylene-maleic anhydride interpolymers with (XI) N,N-diethylhydrazine and (XII) N-phenyl-N-methylhydrazine.