Abstract: A method for removing polymer scales adhering to the inner surface of a polymerization vessel, which comprises polymerizing vinyl chloride monomer in an aqueous medium, discharging the resulting vinyl chloride polymer together with the aqueous medium from the polymerization vessel, thereafter placing in the vessel both a reaction product resulting from the reaction of an amine and acrylic acid or its derivative and an organic liquid which can dissolve or swell the polyvinyl polymer, and washing the inner surface of the vessel with the organic liquid solution of the reaction product.

Abstract: The low temperature properties (i.e., the stability of the emulsion upon repeated freeze-thaw cycles and/or the fluidity of the emulsion at low temperatures such as -20.degree. C.) of a self-inverting water-in-oil emulsion of a water-soluble polymer are improved by incorporating an N,N-dialkyl amide in the emulsion.

Abstract: Polymers containing organotin compounds having advantageous use as paint binders obtained by reacting a cyclized rubber with organotin compounds of the formula R.sub.3 --Sn--O--Z wherein R represents a hydrocarbon group from 1 to 15 carbon atoms and Z is a phenolate group derived from a phenolic compound having from 6 to 15 carbon atoms. In marine applications paints incorporating such polymers remain un-fouled after extended use and are self-polishing. Such polymers are obtained by reacting cyclized rubber and an organotin compound at an elevated temperature in an inert solvent.

Abstract: A hydrophilic polymer shaped article adapted for use as a soft contact lens is treated to provide at least on the surfaces thereof a modified, less hydrophilic polymeric structure inhibiting penetration by proteins and other substances in the eye environment, whereby development of clouding and discoloration of the lens material during use is significantly retarded.

Abstract: A color deepening agent comprises (a) an aqueous resin composition obtained by polymerizing a monomer having a polymerizable unsaturated bond, in the presence of a polyurethane emulsion having a thermosetting reactivity, the refractive index of a dry film of said aqueous resin composition being lower than 1.50, and (b) at least one compound selected from the group consisting of silicon compounds and fluorine compounds.

Abstract: A color deepening agent comprises an aqueous resin composition obtained by polymerizing a monomer having a polymerizable unsaturated bond, in the presence of a polyurethane emulsion having a thermosetting reactivity, the refractive index of a dry film of said aqueous resin composition being lower than 1.50.

Abstract: In a process for preparing a vinyl chloride resin by polymerizing vinyl chloride alone or with up to 20% by weight of other polymerizable unsaturated monomers, in an aqueous suspension, in the presence of a monomer-soluble free radical catalyst and a suspension stabilizer which is partially hydrolyzed polyvinyl acetate or cellulose ether, there is an improvement wherein the polymerization is conducted in the presence of 0.02-0.3% by weight, based on the amount of monomer to be polymerized, of a cosuspension stabilizer which is a copolymer of 2-n-propyl-.DELTA..sup.2 -oxazoline, 2-isopropyl-.DELTA..sup.2 -oxazoline or both and 2-methyl-.DELTA..sup.2 oxazoline, 2-ethyl-.DELTA..sup.2 -oxazoline or both, the copolymer having a viscosity number of 35-70 (ml/g), measured at 25.degree. C. in an isopropanol/water mixture (50 vol-% of isopropanol), in a concentration of 0.5% (weight/volume of the solution).

Abstract: A process is described for making sterically stabilized non-aqueous dispersions of polymer microparticles, in which (1) monomers including at least one crosslinking monomer are polymerized in an aqueous medium at a temperature at least 10.degree. higher than the glass transition temperature of the polymer to be formed, in the presence of a block or graft copolymer stabilizing agent containing in the molecule, as the component solvated by the aqueous medium, a polymer chain derived from a polyethylene glycol of molecular weight at least 1000, under conditions such that there is at no time present a separate monomer phase and (2) the microparticles thus obtained are transferred into a non-aqueous medium which is capable of dissolving the polyethylene glycol in question, when the latter is in the non-hydrated state, to the extent of at least 10% by weight at room temperature.

Abstract: The present invention relates to the treatment of leather and more particularly to a novel non-rewet dry cleanable leather, and the treatment method by which it is produced. The water-resistance property of a leather which has been treated with a polymeric phosphate ester syntan is significantly improved by subsequently subjecting such a treated leather to a non-aqueous solvent extraction procedure.