Abstract: In a process for the production of pulverulent, tack-free, pourable, filler-containing elastomer particles by precipitating a stable, emulsified, homogeneous mixture of an aqueous elastomer emulsion and an aqueous dispersion of a solid filler for said elastomer in the presence of sodium silicate to form an aqueous suspension of the precipitated elastomer and the filler, the improvement which comprises:(a) precipitating the silicic acid in the aqueous suspension at a pH of 4.0 to 9.0, and then(b) mixing the thus-produced suspension of elastomer, filler and precipitated silicic acid with additional filler in the form of an emulsifier-free aqueous suspension.

Abstract: A process for the production of pure diglycolic acid by oxidation of diethylene glycol with nitric acid, comprises the steps of:A. cooling the reaction mixture formed during the oxidation to a temperature of -10.degree. to +25.degree. C. and separating a first quantity of thus-crystallized diglycolic acid;B. concentrating the first mother liquor at 5 - 530 millibars to a concentration of 35-45% by weight of HNO.sub.3 and cooling to a temperature of -10.degree. to +25.degree. C.;c. separating a further quantity of thus-crystallized diglycolic acid; andD. recycling the remaining second mother liquor to the reactor for oxidizing diethylene glycol with nitric acid.

Abstract: Homopolymers of butadiene having a vinyl content which varies substantially and decreasingly along the longitudinal axis of the macromolecule toward an end thereof are produced by conducting an organolithium-Lewis base catalyzed polymerization at a substantially constantly increasing polymerization temperature throughout the polymerization.

Abstract: Higher alkenes with a double bond in the 9-position, e.g. 9-tricosene and/or 9-heneicosene, are economically prepared by a metathesis reaction of suitable alkene starting materials.

Abstract: Acetone is produced by the catalytic, oxidative decarbonylation of isobutyraldehyde in the gaseous phase by contacting a gaseous mixture of 1-15% by volume of isobutyraldehyde, at least a stoichiometric amount and up to about 30% by volume of oxygen, and an inert diluent, with a copper oxide catalyst.

Abstract: A process for the manufacture of a pourable, pulverulent rubber-filler mixture containing plasticiser oil, by combining a filler containing plasticiser oil with an aqueous emulsion of a rubber solution, and precipitating and drying the mixture, wherein the plasticiser oil is adsorptively bound on the finely divided active filler in an amount of from 1 to 100 parts by weight, relative to 100 parts by weight of the filler, the premix thus obtained, which continues to be free-flowing and pulverulent, and consists of filler charged with plasticiser oil, is dispersed in water in the presence of an emulsifier, the resulting dispersion is intimately mixed with an aqueous emulsion of a synthetic rubber solution, this mixture is introduced into an aqueous precipitation bath which is at a temperature of from 40 to 95.degree.

Abstract: For facilitating the production of automotive tire treads of satisfactory abrasion and skid resistance, there is provided a composition consisting essentially of:A. a polybutadiene containing 25-50% of monomer units arranged in the 1,2-position; 10-40% of 1,4-cis-double bonds; 15-55% of 1,4-trans-double bonds; and an ML-4 value of 40-120;B. 5-100 parts by weight of a plasticizer oil; andC. 30-120 parts by weight of a carbon black.