Abstract: Paste-forming vinyl chloride polymers are prepared using an emulsifier system of:(a) an alkali metal or ammonium salt of a fatty acid, alkylsulfonic acid, alkylarylsulfonic acid or a sulfosuccinic acid ester in quantities of 0.2 to 3.0 by weight with respect to the quantity of monomers,(b) a straight chain or branched C.sub.12 -C.sub.20 alkanol in quantities of 50 to 200% by weight with respect to the amount of surface active agent (a) used,(c) water and optionally,(d) a monomer-soluble catalyst. The emulsifier system is homogenized by means of homogenizing apparatus, and, subsequently is mixed with the monomer. Polymerization ensues. Pastes based on this polymer exhibit low viscosities, a near Newtonian flow behavior and good storage stability.

Abstract: Paste-forming polymers of vinyl chloride are produced by discontinuous emulsion polymerization, adding to the polymerization charge, in a batchwise or continuous fashion, an emulsifier system comprising(a) alkyl sulfonates, alkylaryl sulfonates, or sulfosuccinates in amounts of 0.2-3% by weight, based on the amount of monomer, and(b) 50-200% by weight, based on the amount of surface active agent employed, of a C.sub.14 -C.sub.20 -alkyl alcohol.the PVC powders obtained yield pastes exhibiting low viscosities in both the low and high shear ranges.

Abstract: In a process for the thermal after-treatment of paste-forming homo- or copolymers of vinyl chloride, obtained by aqueous emulsion polymerization, followed by spray-drying to produce a spray-dried powder, an improvement is provided wherein 20 to 60 percent by weight of the spray-dried powder is warmed for 1 second to 30 minutes to a treating temperature of 75.degree.-110.degree. C., and then is recombined with the non heat-treated, 80-40 percent by weight portion of the powder.

Abstract: In a process for removing monomeric impurities from an aqueous dispersion of homopolymers or copolymers of vinyl chloride having a surface tension below 60 dyn/cm. by treatment with steam while avoiding foam formation by a rapid lowering of the pressure at high flow velocities, the improvement which comprises:(a) continuously mixing said dispersion in a flow pipe with steam at a steam pressure of 800-4660 millibars for an average residence time of about 0.01-5 seconds;(b) continuously passing the resultant admixture from said flow pipe at a velocity of at least 30 meters per second directly to a degasification vessel having a pressure of 133-660 millibars; and(c) continuously recovering a polymer product containing less than 20 p.p.m. residual monomer impurities therefrom.

Abstract: Improved PVC polymers are prepared by an emulsion polymerization process using an emulsifier mixture comprising:(a) 70-30% by weight of an alkyl sulfate of the formula R--OSO.sub.3 Me wherein R is alkyl of 10-18 carbon atoms and Me is Na or K; and(b) correspondingly 30-70% by weight of at least one member selected from the group consisting of(i) 0-65% by weight of an alkyl ether sulfate of the formula R--(OCH.sub.2 --CH.sub.2).sub.n --OSO.sub.3 Me wherein n is an integer of 1-5 inclusive and R and Me have the above-indicated values, and(ii) 0-60% by weight of a sodium alkyl sulfonate wherein the alkyl chain is of 10-20 carbon atoms.

Abstract: The rheological properties of plastisols of powdered polymerizates produced by polymerizing vinyl chloride or a mixture of vinyl chloride and a copolymerizable monomer in an aqueous emulsion in the presence of a water-soluble catalyst and an alkali salt of a fatty acid as the polymerization emulsifier and spray drying the resultant polymerizate, are improved by treating the powdered polymerizate with water in a weight ratio of from 1:2 to 1:15 and then drying.

Abstract: An improved process for the production of emulsifier-containing vinyl chloride polymers suitable for hard processing, the particle diameter of 90% of which is more than 63 .mu., by polymerization of vinyl chloride and optionally monomers copolymerizable therewith in an aqueous emulsion in the presence of water-soluble catalysts and alkali salts of carboxylic acids as emulsifiers at pH 9.5-11.5 and spray-drying the thus-obtained latex, is characterized by conducting the polymerization in a dispersion containing at least 45% by weight of monomers with sodium or potassium salts of fatty acids of 8-18 carbon atoms as emulsifiers to a conversion of at least 80%, and, during the spray-drying step, reducing the pH to 6.0-8.0.

Abstract: In a process for the production of polyvinyl chloride based powders suitable for plastisol preparation, wherein such powders are obtained by:Polymerization in aqueous emulsion in the presence of water-soluble catalyst or by polymerization in microsuspension in the presence of oil-soluble catalysts;Addition of an additive material; andSpray-drying;An improvement comprises spray-drying at least one such additive in the liquid phase concurrently with the dispersion.This improvement enables production of powders containing the additives homogenously distributed therein, even when the additives are immiscible in the dispersion or cause the dispersion to coagulate if added thereto.

Abstract: Aqueous dispersions of homo- and co-polymers of vinyl chloride are freed of residual monomer in a continuous manner by mixing the dispersion with steam in a first flow pipe maintained at reduced pressure; degasifying the mixture to a first degasification vessel maintained at a lower pressure; again mixing the degassed mixture with steam in a second flow pipe, also maintained at reduced pressure and having fluid flow diverting means therein; and then again degasifying the mixture in a second degasification vessel maintained at a lower pressure than the second flow pipe.

Abstract: An improved process for the aqueous emulsion polymerization of vinyl chloride to be spray-dried and thus form paste-yielding polymers wherein the polymerization is conducted in an emulsion containing at least 45% by weight of monomers together with an emulsifying amount of alkali metal fatty acid salts of 8-18 carbon atoms at a pH of 9.5-11.5, and wherein the pH is reduced to a value between 6 and 7.5 prior to spray-drying or to a value between 4 and 7.5 during the spray-drying step.

Abstract: The rheological properties of paste-formable, powdered polymerizates produced by polymerizing vinyl chloride or a mixture of vinyl chloride and a copolymerizable monomer in an aqueous emulsion in the presence of a water-soluble catalyst and an alkali metal salt of a fatty acid as the polymerization emulsifier and spray drying the resultant polymerizate, are improved by treating the powdered polymerizate with a gas which forms an acid in an aqueous solution.

Abstract: A process and apparatus for the withdrawal of samples from a reaction vessel under pressure containing a solid-liquid dispersion, emulsion, or suspension sensitive to mechanical stress, wherein a portion of the liquid consists of a liquefied gas present in the emulsion, dispersion, or suspension in a dissolved or emulsified form, as for example, the withdrawal of samples during the manufacture of polyvinyl chloride in accordance with the suspension or emulsion method. A syringe and cannula combination are filled with an inert protective fluid with the cannula being passed through a valve arrangement in the reaction vessel to eject the protective fluid thereinto and to replace the ejected fluid with a sample from the reaction vessel. The sample-containing syringe is sealed before withdrawal of the cannula of the combination from the reaction vessel, which is again sealed by the valve arrangement.

Abstract: A process for removing residual monomer from an emulsifier-containing aqueous dispersion of a solid vinyl chloride polymer having a surface tension of less than 60 dyne/cm., which comprises continuously admixing the polymer dispersion with steam in a fluid flow pipe under a pressure of 150-600 torr at a flow velocity of 1-20 m./sec., and passing said admixture at an exit velocity of 30-100 m./sec. horizontally into and along the walls of a degasification tank having a pressure 30-200 torr lower than the pressure in said flow pipe to evaporate residual monomer.

Abstract: The method for preparing synthetic powders based upon polyvinyl chloride or vinyl chloride copolymers by spray drying the polymer dispersions is improved by using single material nozzles with atomizing pressures of about 550 to 1000 bars where a bar is a C.G.S. unit of pressure equal to 750 mm of Hg.

Abstract: The method of preparing synthetic powders containing emulsifiers having good paste qualities by spray-drying polymer dispersions through a two-fluid atomizer having a spray ratio of about 1.6 to 5.0 kg. of spray air for each kg. of dispersion is improved. The polymer dipersions are prepared by emulsifying vinyl chloride monomer or a mixture of vinyl chloride monomer and unsaturated polymerizable compounds and polymerizing the monomers to produce polymers and copolymers of vinyl chloride. The improvement in paste qualities of the powders is achieved by introducing the spray dried powder into an air jet having a velocity from about 330 to 550 meters per second and having a weight ratio of gas to solids ranging from 1:10 to 5:1.