Abstract: Process for the preparation of aqueous solutions of hydrolysed styrene/acrylonitrile copolymers, the carboxyl groups of which are entirely or partly present as NH.sub.4 and/or alkali metal salt, characterized in that(a) 40-90% by weight of acrylonitrile,(b) 10-60% by weight of styrene and0-20% by weight of further monomer which can be hydrolysed by alkaliare subjected to suspension or emulsion polymerization, the aqueous dispersion or emulsion is subsequently hydrolysed at 90.degree.-220.degree. C. in the presence of alkali metals and/or alkaline earth metals, and, if appropriate, the copolymer solution is treated with hydrogen peroxide wherein a part of the styrene may be replaced by a further monomer which cannot be hydrolysed by alkali.

Abstract: Water swellable substances based on crosslinked polyacrylonitrile hydrolysates, preferably in granulate form useful for improving water retention in sandy soils and plant substrates.

Abstract: Coupled tubular casings are obtained by placing a coupling piece, preferably a multilayered foil, on the inside of and overlapping two adjacent ends of tubular casings to be coupled and whose adjacent edges make an angle of 10.degree. to 80.degree. with the envisaged axis of the tubular casing, and sealing it.

Abstract: A process for the production of water-soluble hydrolyzed polyacrylonitrile polymers, wherein the acrylonitrile is polymerized in the presence of 1-8% by weight of hydrolyzed polyacrylonitrile and hydrolyzed without intermediate isolation from the reaction mixture.

Abstract: Aqueous polymer mixture, process for its preparation and its use as substrate anchoring, blocking resistant one-coat sealing lacquer on sheet products.An aqueous polymer mixture containing at least two polymeric components A and B, A being present in form of an aqueous dispersion and consisting of micronuclear shell structures comprising as nuclear portion a copolymer of methyl acrylate, ethyl acrylate, acrylic acid, methacrylic acid -n-butyl ester and/or methyl methacrylate and vinylidene halide and as shell portion a copolymer of methyl acrylate, ethyl acrylate, ethyl methacrylate ethyl hexyl acrylate, n-butyl (meth)acrylate and/or itacaconic acid and vinylidene halide; and B being present in form of an aqueous alkaline solution and consists of a (co)polymer of unsaturated carboxylic acid amide -N-methylol derivatives and optionally unsaturated carboxylic acids and/or amides of said acids.