Absorbent compsn. used in packaging, soil improvement, cable jackets and hygiene prods. - contains water soluble or swellable polysaccharide deriv., water swellable synthetic polymer, soft matrix, crosslinker and antiblocking agent

摘要

A polymer compsn. contains (A) 70-99.99 wt.percent of a water-sol., or -swellable polymer based on polysaccharides and derivs., opt,. modifed by crosslinking, (B) 30-0.01 percent of a water-swellable synthetic (co)polymer based on (meth)acrylic acid, (meth)acrylonitrile, (metah)acrylamide, vinyl acetate, vinylpyrrolidone, vinylpyridine, maleic acid or anhydride, itaconic acid or anhydride, fumaric acid, vinyl-sulphonic acid and/or 2-acrylamido-2-methylpropane sulphonic acid, and the amides, N-alkyl or N,N'-dialkyl derivs. and esters contg. OH or amino gps. of these polymerisable acids, where 0.98 percent of the acid gps. have been neutralised and where the (co)polymers have been cross-linked by an at least bifunctional cpd., (c) 0.1-30, w.r.t. (A)+(B), of a matrix material with m.pt. or softening point below 180 deg.C, to prevent de-mixing and gel blocking, (D) 0.001-10 percent, w.r.t. (A)+(B), or an ionic or covalent grosslinker, and (E) 0.50 percent, w.r.t. (A)+(B), or an anti-blocking agent based on natural and/or synthetic fibres and/or materials with a large surface. The compsn. is prepd. by combining (A) and (B) in an aq. medium, drying and grinding, adding the other components, mixing to a uniform mixt. and heating, and opt., with addn. of the cross-linker after this heat treatment, fixing it in the matrix by a final heat treatment. USE/ADVANTAGE - The compsn. is used as fibres, films, powder or granulate for absorption of aq. solns. of dispersions and of body fluids, in technical prods., e.g. packing materials, in culture vessels, for soil improvement, as cable jackets, in hygienic prods., e.g. tampons and baby's napkins, and in animal hygiene prods. It is used in powder form or as a dispersion in hydrophobic media, opt. with dispersion stabilisers or in admixture with other substances. (Animal) hygiene prods., and technical prods. contg. the compsn. are claimed, as are slow release materials contg. active substances. The compsn. is based largely on renewable materials, is mainly biodegradable, and contains only small amts. of residual acrylic monomer. It has high and rapid absorption of water and aq. solns., shows no gel blocking or de-mixing, has high mechanical strength, and does not separate into single components on sieving or in a screw convey