Abstract: An azo polymerization initiator composition obtained by kneading an azo compound, a dispersing agent and a surface active agent at a temperature of 20.degree. C. or lower, while adjusting the water content of the composition to 0 to 50% by weight, has good storage stability for a long period of time and, at any time desired for polymerization, can give a uniform aqueous suspension of the azo compound for polymerization of unsaturated vinyl monomers with high polymerization initiator activity.

Abstract: A stable aqueous suspension containing an organic azo compound as polymerization initiator in fine particles, containing substantially no organic solvent and containing no foam which damages dispersing stability of the aqueous suspension and retards polymerization rate can be formed by dissolving an organic azo compound in an organic solvent, emulsifying the resulting solution by adding water and a dispersing agent A and a dispersing agent B thereto with stirring, and removing the organic solvent from the emulsified liquid preferably under reduced pressure.

Abstract: A process for producing a paste-blending vinyl chloride resin, which comprisesinitiating suspension polymerization of a vinyl chloride monomer or a mixture of it with a monomer copolymerizable therewith in an aqueous medium in the presence of a water-soluble protein as a suspending agent;adding a proteolytic enzyme to the polymerization system at any point in a time period running from the time when the polymerization conversion reaches 10% by weight to the time when the polymerization reaction is not yet complete; andthereafter continuing the suspension polymerization until the polymerization reaction is completed.

Abstract: A process for producing a blending vinyl chloride resin, which comprises subjecting a vinyl chloride monomer or a mixture of vinyl chloride and a monomer copolymerizable therewith to suspension polymerization in an aqueous medium using a water-soluble protein as a suspending agent, and treating the resulting polymer with a proteolytic enzyme.

Abstract: Polymerization method utilizing a three-phase system: water-in-oil-in-water or oil-in-water-in-oil comprising the steps (a) adding the monomer material to be polymerized into the innermost water or oil phase; (b) adding, with mechanical agitation, the product of Step a to the middle oil or water phase, said phase containing appropriate surfactant, whereby an emulsion is formed; (c) adding, with mechanical agitation, the emulsion product of Step b to the outermost water or oil phase, said phase containing appropriate surfactant, wherein polymerization proceeds in the innermost water or oil phase until complete.

Abstract: There is disclosed a process for the aqueous polymerization of acrylamide to produce polymers of high molecular weight utilizing mixtures of water and monomer, at least one of which can be contaminated with small amounts of polymerization inhibiting components. In the process of the invention, a minimum amount of a redox pair catalyst is utilized in order to obtain the desired high molecular weight polymer. The minimum amount of catalyst is automatically provided to the polymerization mixture by adding a first member of a redox pair to the polymerization mixture and intimately combining a second member of the redox pair catalyst with an organic polymer capable of forming a colloidal dispersion in an aqueous medium and adding this intimate mixture to the mixture of water, acrylamide monomer, and a first member of the redox pair catalyst.

Abstract: Vinyl halide polymers and copolymers are formed in the presence of a linear, branched chain or cyclic alkane, and the polymer is then heated to remove the alkane and unreacted vinyl halide therefrom. The polymers so formed have reduced amounts of vinyl halide therein and hence are less likely to contaminate the air with airborne vinyl halide.

Abstract: An improved method for the polymerization of vinyl chloride or a monomer mixture mainly composed of vinyl chloride in an aqueous polymerization medium is proposed in which a water-insoluble polymerization initiator, being solid at room temperature as dispersed in the aqueous medium and having a particle size distribution of 50 .mu.m or finer, is added to the polymerization mixture which is maintained at a temperature where the half-life period of the initiator is 120 minutes or longer or, alternatively, over a duration equal to or shorter than one-tenth of the half-life period of the initiator at the temperature of the polymerization mixture. By this method the polymerization can be homogeneously proceeded to produce vinyl chloride polymers having a uniform particle size distribution, excellent heat stability and much less fish-eyes when fabricated into sheets.

Abstract: A novel microporous resin which is useful in the treatment of hyperchloesterolemia. This resin is comprised of a cross-linked polystyrene matrix and is characterized by active moieties selected from among methylamino, methylammonium or a combination of methylamino and methylammonium groups. The porosity of this resin is capable of absorbing and retaining bile salts having an average diameter of 150-200 Angstrom units.

Abstract: Compounds which contain azo or peroxide linkages as well as the radical of an ultraviolet light stabilizing group are described. These compounds function as polymerization initiators which cause an ultraviolet light stabilization group to be chemically bound to the polymer.

Abstract: A method of suspension polymerizing in an aqueous medium vinyl chloride or a mixture of 50% or more vinyl chloride and remainder other monomers copolymerizable therewith in the presence of an oil soluble initiator, a suspension stabilizer and 0.005 to 50 ppm of nitrite, and 10 to 1000 ppm of water soluble metallic salt, the parts being based on the amount of aqueous medium.

Abstract: A process for suspension polymerization of vinyl chloride or a mixture of vinyl chloride and a monomer copolymerizable therewith in an aqueous medium in the presence of an oil-soluble polymerization catalyst is improved by the use of a suspending agent comprising a well known protective colloid and a saccharose alkyl ester.

Abstract: Vinyl chloride monomer, or a monomeric mixture comprising vinyl chloride as a main component and other monomers co-polymerizable therewith in an aqueous reaction medium, is polymerized in a polymerization vessel. All of the surfaces of the inside walls of the vessel and the agitator blades, the baffle plates and the like with which the vessel is equipped, are coated prior to the polymerization with at least one of a specific class of nitrogen-containing aromatic heterocyclic compounds. Not only is the deposition of polymer scale surprisingly reduced, but also the polymer thus obtained has good physical and chemical properties.