摘要:
A process for modifying superabsorbent polymers is disclosed. The surface of a polymer containing hydrolyzed polyacrylonitrile in the form of particulates, is modified by crosslinking in a water/alcohol reaction mixture and in the presence of silica. The resulting product features improved absorbency under load and lesser degree of gel blocking.
摘要:
Super-absorbent polymer in the form of pre-formed spherical particles obtainable by alkaline hydrolysis of aqueous emulsions of crosslinked and/or un-crosslinked homopolymers and/or copolymers of acrylonitrile in water/alcohol mixtures and the use of the polymer in hygiene products, as a water-storing material in agriculture and for the sheathing of electrical cables.
摘要:
Oil- and water-repellent papers are treated on the surface or in the pulp of the papers with fluorine-containing copolymers ofa) acrylates containing perfluoroalkyl groups, of the formulaCH.sub.2 .dbd.CR.sup.1 --COO--X--C.sub.n F.sub.2n+1 (I),b) monomers of the formulaCH.sub.2 .dbd.CR.sup.2 --COO--R.sup.3 (II),c) monomers of the formulaCH.sub.2 .dbd.CR.sup.4 --COO--(CH.sub.2 CH.sub.2 O).sub.m --R.sup.5 (III),d) monomers of the formulaCH.sub.2 .dbd.CR.sup.6 --COO--CH.sub.2 CH.sub.2 --N(R.sup.7,R.sup.8) (IVa)or, in salt-like form, of the formula[CH.sub.2 .dbd.CR.sup.6 --COO--CH.sub.2 CH.sub.2 --N(R.sup.7,R.sup.8,R.sup.9)].sup..sym. Y.sup..crclbar. (IVb)or, in N-oxidized form, of the formula ##STR1## and e) monomers of the formulaCH.sub.2 .dbd.CR.sup.10 CONHR.sup.11 (V)these substituents and indices in the formulae having the meaning given in the description and the copolymers comprising the monomers in amounts of a) =50 to 90% by weight, b) =1 to 35% by weight, c) =3 to 20% by weight, d) =1 to 20% by weight and e) =0 to 10% by weight. Such copolymers having a content of e) =0.5 to 10% by weight are new.
摘要:
Thermal dye sublimation transfer recording element for receiving sublimable basic dye-precursors, comprising a support having thereon a dye-developing layer containing a dye-developing copolymer having sulfonic acid side-groups that can react with the basic dye-precursor to produce a dye image, characterized in that said dye-developing vinyl copolymer comprises plasticizing comonomers, the weight percentage of plasticizing comonomers in the dye-developing vinyl copolymer being such that the glass transition temperature of the dye-developing vinyl copolymer is between 30.degree. C. and 90.degree. C.
摘要:
A process for the production of super-absorbent polymers with a swelling capacity in water-containing liquids of up to 1,000 g/g in which aqueous emulsions of particularly high molecular weight polymers of acrylonitrile are partly hydrolyzed by reaction with aqueous solutions of alkali metal and/or alkaline earth metal hydroxides, the polymers are precipitated in powder form by addition of water-miscible organic solvents, separated off, dried and then optionally heated for a short time. The super-absorbent polymers are used as water-storing materials, for example in sanitary articles, in agriculture or in the sheathing of electrical cables.
摘要:
Thermoreactive recording material contains, as developer, a mixture of an acidic-modified polymer of (meth)acrylonitrile and/or methacrylonitrile and a diphenol of the formula ##STR1## in which Y is, for example, a single bond, an alkylene or alkylidene radical, gives, on thermal printing, a dye which has a reduced tendency to sublime.
摘要:
A process for the production of highly elastic elastane fibers (spandex fibers) based on segmented polyurethane (urea) elastomers having high elasticity and, at the same time, high strength values, balanced elastic properties and excellent thermal and hydrothermal behavior, wherein relatively high molecular weight, carbonate-linked, block-like polyester of polyester etherdiols having molecular weight of 3,300 to 7,000 are reacted with macrodiols with diisocyanates in a molecular ratio of 1:2.5 to 1:4.5 to obtain NCO prepolymers which have NCO contents of 2.10 to 4.0% NCO, then the NCO prepolymer is chain-extended with (cyclo)-aliphatic diamines to fom polyurethane (urea) elastomers.
摘要:
A thermoreactive recording material contains a dyestuff precursor and an acid-modified polymer of acrylonitrile or methacrylonitrile and a 4-hydroxybenzoic acid ester as acceptor.
摘要:
The invention relates to a homopolymer or copolymer of acrylonitrile which comprises from 0 to 30% by weight, incorporated by polymerization, of comonomer units which are free from ionic groups, said polymers having a K-value of from 50 to 100, a dye absorption capacity for cationic dyes of at least 0.5% by weight, a conductivity, measured in dimethylformamide solution, of at least 10.mu. Siemens, and from 0.2 to 1.5% by weight of sulphur fixed to said polymer as well as to a process for the production thereof.