摘要:
Stable water-in-oil emulsions of a hydrolyzed polymer of an N-vinylamide of the formula ##STR1## where R and R.sup.1 are each H or C.sub.1 -C.sub.6 -alkyl, are prepared by polymerizing a compound of the formula I, alone or as a mixture with other monoethylenically unsaturated monomers, in the form of a water-in-oil emulsion to give a water-in-oil polymer emulsion, and then hydrolyzing the polymer, hydrolysis of the polymer in the form of the water-in-oil polymer emulsion being carried out in the presence of an acid or base, and additives in the form of antioxidants, reducing agents or aldehyde acceptors being added for stabilization.
摘要:
Paper, board and cardboard are produced from paper stocks containing foreign substances by drainage in the presence of a polymer which contains, as typical polymerized constituents, units of the formulae ##STR1## where R.sup.1 and R.sup.2 are each H, C.sub.1 -C.sub.3 -alkyl, and which have K values of not less than 130, the polymers containing less than 10 mol % of units of the formula II.
摘要:
Paper, board and cardboard are produced by draining a paper stock, containing undesirable substances, in the presence of hydrolyzed homo- and/or copolymers of N-vinylformamide having a degree of hydrolysis of not less than 60% and a cationic retention aid. According to the invention, faster drainage and improved retention are obtained compared with the use of known fixing agents.
摘要:
Copolymers which are obtained by copolymerization ofa) from 5 to 99 mol % of N-vinylcarboxamides,b) from 95 to 1 mol % of monoethylenically unsaturated carboxylic acids and/or the alkali metal, alkaline earth metal, ammonium or amine salts thereof, and if required,c) up to 30 mol % of other monoethylenically unsaturated compounds, and if required,d) up to 2 mol % of crosslinking agents,and subsequent partial or complete elimination of the acyl groups from the N-vinylcarboxamides polymerized in the copolymer, with formation of amino or ammonium groups, are used as additives to paper stock for increasing the drainage rate and the retention in papermaking, and the dry and wet strength of the paper.
摘要:
Graft polymers are obtainable by free radical polymerization of(A) monomers or monomer mixtures of(a) from 10 to 100% by weight of open-chain N-vinylcarboxamides(b) from 0 to 90% by weight of other, carboxyl-free monoethylenically unsaturated monomers which are copolymerizable with the monomers (a) and(c) from 0 to 5% by weight of monomers containing two or more ethylenically unsaturated, non-conjugated double bonds in the molecule, in the presence of(B) natural substances containing saccharide structures, such as mono-, oligo- and polysaccharides,in a weight ratio (A):(B) of from 95:5 to 20:80 and, if required, subsequent hydrolysis of the amido groups of the polymerized monomers (a) of the graft polymer with formation of amino groups, and said polymers are used as dry and wet strength agents for paper, board and cardboard.
摘要:
Graft polymers are obtainable by free radical polymerization of(A) monomers or monomer mixtures of(a) from 10 to 100% by weight of open-chain N-vinylcarboxamides(b) from 0 to 90% by weight of other, carboxyl-free monoethylenically unsaturated monomers which are copolymerizable with the monomers (a) and(c) from 0 to 5% by weight of monomers containing two or more ethylenically unsaturated, non-conjugated double bonds in the molecule,in the presence of(B) natural substances containing saccharide structures, such as mono-, oligo- and polysaccharides,in a weight ratio (A):(B) of from 95:5 to 20:80 and, if required, subsequent hydrolysis of the amido groups of the polymerized monomers (a) of the graft polymer with formation of amino groups, and said polymers are used as dry and wet strength agents for paper, board and cardboard.
摘要:
Graft polymers are obtainable by free radical polymerization of(A) monomers or monomer mixtures of(a) from 10 to 100% by weight of open-chain N-vinylcarboxamides(b) from 0 to 90% by weight of other, carboxyl-free moneothylenically unsaturated monomers which are copolymerizable with the monomers (a) and(c) from 0 to 5% by weight of monomers containing two or more ethylenically unsaturated, non-conjugated double bonds in the molecule, in the presence of(B) natural substances containing saccharide structures, such as mono-, oligo- and polysaccharides,in a weight ratio (A):(B) of from 95:5 to 20:80 and, if required, subsequent hydrolysis of the amido groups of the polymerized monomers (a) of the graft polymer with formation of amino groups, and said polymers are used as dry and wet strength agents for paper, board and cardboard.
摘要:
In a cationic modification process for starch, starch is reacted with polymers that contain amino and/or ammonium groups in an aqueous medium at temperatures from 115.degree. C. to 180.degree. C. under an increased pressure and in the absence of oxidizers, polymerization initiators and alkali. The reaction is conducted so that maximum 10% by weight starch has its molar weight reduced. Also disclosed is the use of the thus obtained reaction products as dry strength agents for paper.
摘要:
Paper, board and cardboard are produced by draining a pulp slurry in the presence of high molecular weight, water-soluble polymers of N-vinylamides as drainage aids, retention agents and flocculants. These polymers are particularly effective in a pulp slurry which has a high content of interfering substances and other phenolic compounds.
摘要:
A process for removing anionic compounds from water which is recycled in manufacturing processes, and from waste water, by adding (1) water-soluble products obtained by reacting an alkylating agent, having an aromatic substituent, with a cationic polyelectrolyte and (2) mineral adsorbents and/or a magnesium salt, aluminum salt or iron salt, with formation and flocculation of water-insoluble reaction products.