Abstract: A process for the suspension polymerization of vinyl chloride, in the presence of a redox catalyst system consisting of a peroxyester or diacyl peroxide and isoascorbic acid.

Abstract: A laminated, cylindrical, metal screen or molding element for vacuum perforation of plastic film or sheets, comprising two or more relatively thin cylindrical metal screens, each having a predetermined inside and outside diameter and each having a plurality of openings or holes therein of a predetermined size and geometrical shape, and said relatively thin screens stacked and bonded together, diametrically one inside the other thereby providing a screen of a desired thickness and a desired hole geometry wherein the holes in the screen have substantially straight walls perpendicular to the surface of the screen.A method of producing a relatively thick cylindrical metal screen for vacuum perforation of plastic film or sheets wherein the holes or openings in the screen have substantially straight walls perpendicular to the surface of the screen, comprising stacking and bonding together two or more matched relatively thin metal screens diametrically one inside the other.

Abstract: Tackifying agents for rubber comprising at least one chemically or physically treated guayule resin fraction are disclosed. Physical treatments include vacuum deoiling, steam stripping deoiling, hexane deoiling, while chemical treatments include formaldehyde reaction, phenol/formaldehyde reaction, urea formaldehyde reaction, acid reaction and sulphur reaction. Untreated guayule resin fractions can also be used. Vulcanized and unvulcanized rubber compositions containing guayule resin derived tackifying agents as well as articles made therefrom are also disclosed.

Abstract: Latices of vinyl acetate polymers comprising particles having an average diameter between 0.05 and 1 .mu.m and being present in the latex at a concentration of between 10 and 70% by weight. The polymers have a glass transition temperature between -20.degree. and 50.degree. C. The latices also contain a protective colloid comprising a water-soluble polymer (a) containing at least one monomer selected from the group consisting of N-methylolacrylamide and N-methylolmethacrylamide and a water-soluble polymer (b) of ethylene glycol, the polymer (b) having a molecular weight between 1,000 and 50,000.The latices are prepared by polymerization in aqueous emulsion, in the presence of both an initiator and the above-reference protective colloid. The latices may be applied as binders in the manufacture of paints, glues, paper, textiles, floor coverings and mortar additives.

Abstract: A cis-1,4-polyisoprene rubber composition capable of giving a vulcanizate having improved strength, said composition comprising (1) a synthetic cis-1,4-polyisoprene rubber having epoxy groups, (2) a compound having at least two primary amino groups, and (3) a sulfur vulcanization system.

Abstract: Latices of particles of vinyl acetate/olefin copolymers. The particles have an average diameter between 0.05 and 1 .mu.M. The copolymers have a glass transition temperature between -30.degree. and 50.degree. C. The particles are present in the latices in a concentration between 10 and 70% by weight. The latices contain a protective colloid comprising a water-soluble polymer (a) containing at least one monomer selected from the group consisting of N-methylolacrylamide and N-methylolmethacrylamide and a water-soluble polymer (b) of ethylene glycol, wherein polymer (b) has a molecular weight of between 1,000 and 50,000.The latices are prepared by polymerization in aqueous emulsion, in the presence of an initiator and the above-described protective colloid.The latices may be applied as binders in the manufacture of paints, glues, paper, textiles, floor coverings and mortar additives.

Abstract: A process for producing vinyl chloride polymers and copolymers by suspension polymerization is carried out in the presence of small amounts of ethylene/vinyl acetate copolymers with a vinyl acetate content of 38% by weight to 55% by weight and with a viscosity number of 95-210 ml/g, the catalyst being added to the polymerization charge in dissolved form. The resultant polymers are suitable for lowering the viscosity of polyvinyl chloride plastisols.

Abstract: Process for the polymerization of vinyl chloride in aqueous suspension or microsuspension using an organo-soluble free-radical-yielding initiator wherein the initiator is progressively activated during polymerization by the progressive reduction of a non-initiator-activating water-soluble metal chelate complex to an initiator-activating form of the complex (which is otherwise substantially stable under the polymerization conditions) in which the metal is in a lower oxidation state, preferably a one- or two lower oxidation state.

Abstract: A process for producing a coagulated latex is disclosed which comprises spraying into a coagulating chamber a suspension liquid or a high polymer latex to disperse as droplets, simultaneously spraying a coagulant into the chamber in the form of gas or mist, introducing into the chamber super-heated steam to heat dispersed droplets of the suspension liquid or the high polymer latex and the coagulant, collecting coagulated particles in a film-like flow of water or an organic solvent flowing downward along side walls and the bottom of the chamber, and recovering the coagulated particles.

Abstract: The present invention provides a method for improving the environmental stress crack resistance of high impact poly(p-methylstyrene) by blending high impact poly(p-methylstyrene) with an additive copolymer having a higher environmental stress crack resistance. The invention further provides a shaped container resistant to fats.

Abstract: A novel polyvinylene chalcogenide of the formula: --CH.dbd.CH--L).sub.n wherein L is S or Se, is provided. This compound is prepared by reacting an ethylene dihalide of the formula: XHC.dbd.CHX' (X and X' are selected from F, Cl, Br and I) with an alkali metal chalcogenide or bichalcogenide.

Abstract: A process and catalyst system is disclosed herein for the preparation of (co)polymers having a 1,2-microstructure of between about 20 and about 65 percent. These (co)polymers are prepared in a hydrocarbon or non-polar solvent from a monomer system which contains at least one 1,3-diene monomer. The catalyst system which is employed in the production of the (co)polymer is a combination of an anionic initiator based on lithium and a phosphine oxide modifier which is substituted with three saturated heterocyclic rings, each hetero ring containing one nitrogen atom and either four, five or six carbon atoms.

Abstract: Acrylamide and related monomers are improved by incorporating therein an effective polymerization inhibitor in an amount greater than that which is inherently present in the monomer and a borane, i.e., sodium borohydride.

Abstract: A process is provided for the coagulation of rubber polymers from aqueous emulsions thereof wherein the coagulation is undertaken in the presence of an additive selected from a polysaccharide material and from a vegetable derived proteinaceous material. The polymers so coagulated are readily dried and may be used for the manufacture of products well known for the specific polymers.

Abstract: Novel organic polymers have a chain carrying active groups, a hydroxyl, alkoxy, halogen, thiol or sulphide group or a second active group being attached as a substituent to a carbon which is in the alpha position with respect to that carrying the first active group. The preparation of these polymers is advantageously effected using polymers carrying epoxide bridges, which are opened by the action of an active cosmetological or other active compound. These polymers are particularly suitable for the protection of the skin against solar radiation, as creams or gels for the skin and for the hair and/or as pigments.

Abstract: Polymers obtained by radical polymerization and containing(A) from 0.1 to 80 mole percent of polymerized units corresponding to the following formula ##STR1## in which R.sub.1 represents hydrogen or methyl,R.sub.2 represents alkyl, particularly primary or secondary alkyl containing from 1 to 4 carbon atoms, andR.sub.3 represents hydrogen or alkyl, particularly primary or secondary alkyl containing from 1 to 4 carbon atoms, and in which the sulphonic acid group may be present in the form of a salt, and(B) from 20 to 99.9 mole percent of polymerized units of one or more ethylenically unsaturated monomers, are particularly suitable for the production of filaments, fibres and films having a high absorption capacity for basic dyes.

Abstract: Physiologically unacceptable solvents are removed from polymers containing carboxyl or anhydride groups by a process in which the polymer is treated with aliphatic hydrocarbons at a temperature which is no lower than the lower limit of the softening range of the polymer.

Abstract: Compounds of formula I ##STR1## where R.sub.1 and R.sub.2 independently are alpha-branched alkyl of 3 to 8 carbon atoms, R.sub.3 is hydrogen, R.sub.4 is ethylene, 1,3-propylene or 1,4-butylene, and n is 2 or 4 are effective stabilizers for protecting elastomeric or acrylonitrile copolymer compositions or lubricating oil compositions against thermal oxidation and discoloration. 2-Mercaptoethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate is particularly useful.

Abstract: A method of preparing polyvinyl chloride via the suspension polymerization method which includes utilizing an effective amount of hydroxypropyl guar as the suspending agent.

Abstract: Apparatus and method for heat sealing a selected segment of a web of at least two layers of biaxially oriented plastic film. The web layers are pressed together and a selected segment of the pressed web is heated above the bonding temperature of the plastic while adjacent web segments are maintained below that temperature. The surfaces pressing thus the heated web segment has a relatively lower surface friction than the surfaces pressing the adjacent web segment, whereby the layers of the heated segment of the web are physically unrestrained against shrinking during heating and are allowed to shrink back to their pre-oriented molecular configuration while the adjacent segment is restrained against movement. A hermetic bead seal is thus formed between the web layers. A product heat sealed according to the novel method is also disclosed.