摘要:
A process for the preparation of polymaleic acid by polymerizing maleic anhydride in an aromatic hydrocarbon at from 60.degree. to 200.degree. C., using from 1 to 20% by weight, based on maleic anhydride, of peroxyesters derived from saturated or ethylenically unsaturated carboxylic acids, as the polymerization initiators and hydrolyzing the polymer, the polymaleic acid thus obtained and the use of the polymaleic acid as an agent for reducing scale formation and hard water deposits in systems through which water flows.
摘要:
Detergents which contain from 0.01 to 20% by weight of oxyalkylated, carbonyl-containing polymers can be prepared by reacting.(A) a polymer which contains, as copolymerized units, one or more monoethylenically unsaturated C.sub.3 -C.sub.6 -carboxylic acids with(B) ethylene oxide, propylene oxide, n-butylene oxide, isobutylene oxide or a mixture of these, in an aqueous medium at up to 150.degree. C.
摘要:
Linear, basic polymer powders which contain units of the formula ##STR1## and have a Fikentscher K value of from 10 to 200 are prepared by eliminating the formyl groups from N-vinylformamide polymer powders with a gaseous hydrogen halide in the presence of not more than 5% by weight, based on the polymer used, of water.
摘要:
Carboxyl-containing polymers which are water-soluble at least in the neutralized form are prepared by a method in which a monoethylenically unsaturated C.sub.3 -C.sub.5 -carboxylic acid is polymerized in the presence or absence of a carboxyl-free copolymerizable ethylenically unsaturated monomer in aqueous solution in the presence of polymerization initiator and of from 0.01 to 5% by weight, based on the monomers, of an inorganic acid of phosphorus in which the phosphorus has an oxidation state of from 1 to 4, its water-soluble salts, a water-soluble --PO(OH).sub.2 -containing compound and/or its water-soluble salts and, if required, a polymerization regulator. Virtually colorless or only slightly colored polymer solutions are obtained.
摘要:
Flocculants based on polymers of neutralized or quaternized di-C.sub.1 -C.sub.3 -alkylaminoneopentyl (meth)acrylates and copolymers thereof are used for clarifying waste water and for flocculating sludges.
摘要:
Water-soluble homopolymers and copolymers of di-C.sub.1 -C.sub.3 -alkylaminoneopentyl (meth)acrylates, the homopolymers and copolymers having a K value of from 150 to 300, are used as retention agents, drainage agents and flocculants in papermaking. Increased retention, drainage rate and flocculation are achieved in comparison with the conventional basic polyacrylates.
摘要:
A process for the preparation of high-viscosity polyvinylpyrrolidone, wherein an aqueous polyvinylpyrrolidone solution is subjected to a heat treatment in the presence of a water-insoluble peroxide and in the absence of oxygen, and thickeners containing the polyvinylpyrrolidone thus prepared.
摘要:
A process for the preparation of PVP-iodine having an iodine:iodide ratio of about 2:1 and a partition coefficient of 180-250, by reacting PVP with elementary iodine in the presence of formic acid, oxalic acid or an ammonium salt or amide of carbonic acid, formic acid or oxalic acid, in aqueous solution.
摘要:
Maleic anhydride copolymer powders are prepared by a process wherein a solution or dispersion of maleic anhydride in an alkyl vinyl ether and/or an alkene, containing from 3 to 25 moles of the alkyl vinyl ether and/or alkene per mole of maleic anhydride, is brought into contact with a powder bed under polymerization conditions, and is polymerized in the bed while the reaction mass is circulated and the powder state is maintained, and the heat generated during polymerization is removed by evaporating excess monomer which boils lower than maleic anhydride.
摘要:
A process for coating electrically conductive objects comprisingA. immersing said object as the anode of an electric current in an aqueous polyurethane dispersion prepared by(1) forming a polyurethane solution by reacting an organic polyisocyanate in the presence of an organic solvent with(a) an acrylic ester diol having a molecular weight of between 146 and 3,000;(b) an organic polyhydroxyl compound other than (a) having a molecular weight between 400 and 5,000 selected from the group consisting of polyester, polyols, polyether polyols, polycarbonates, polylactones, and mixtures thereof; and(c) a chain extender selected from the group consisting of diols, triols, diamines, aminoalcohols, having a molecular weight between 62 and 400, water, and mixtures thereof;(2) forming an anionic polyurethane addition product by reacting said polyurethane solution with a mercaptocarboxylic acid salt in the presence of a solvent;(3) adding water; and(4) removing the organic solvent, andB. passing an electric current between the anode and a cathode which is also dispersed in said dispersion, andC. irradiating said object with ultraviolet radiation or electron rays.The process can be used for coating metals such as iron, steel and aluminum.