Abstract: The invention concerns rubber compounds consisting of at least one double bond-containing rubber and additions of polybutadiene rubber particles having a glass transition temperature <−60° C. together with vulcanizates and rubber molding manufactured therefrom.

Abstract: Conjugated diolefins, optionally in combination with other unsaturated compounds which may be copolymerized with the diolefins, are polymerized by performing the polymerization of the diolefins in the presence of catalysts based on cobalt compounds, organoaluminum compounds and modifiers in the presence of aromatic vinyl compounds at temperatures of −30° C. to +80° C. By means of the process according to the invention, it is possible straightforwardly to produce solutions of polydiolefins, such as polybutadiene, having different 1,2 unit contents in aromatic vinyl compounds, which solutions may then, for example, be further processed to yield ABS or HIPS.

Abstract: The rubber mixtures according to the invention, containing uncrosslinked, double-bond-containing rubbers (A), crosslinked rubber particles (B) and multifunctional isocyanates (C), wherein the amount of component (B) in the mixture is from 1 to 150 parts by weight and the amount of multifunctional isocyanates (component C) is from 1 to 100 parts by weight, in each case based on 100 parts by weight (phr) of the rubber component (A), may be used in the production of rubber vulcanates and molded rubber bodies of any kind, the vulcanates produced therefrom having an advantageous combination of mechanical properties, such as tensile stress at 300% elongation, ultimate elongation, tear resistance and abrasion resistance.

Abstract: A rubber mixture containing at least one rubber component, at least one filler, and conventional additives that it contain at least one first gel as a filler, which is essentially comprised of a rubber, has a particle size of 3×10−9 to 1×10−6 m, and has a swelling index in toluene of 1 to 15, and at least the surface of this gel has acid or base groups, where these groups have not been produced by means of reaction with dithiophosphoric acid, and comprises: a) at least one second gel as an additional filler, which is essentially comprised of a rubber, has a particle size of 3×10−9 to 1×10−6 m, and has a swelling index in toluene of 1 to 15, which is in a position to undergo a neutralization reaction with the acid or base groups of the first gel and/or b) contains at least one substance as an additional additive, which is capable of undergoing a neutralization reaction with the acid or base groups of at least one gel.

Abstract: A rubber composition which contains a rubber mixture that can be vulcanized with a vulcanizing agent, which includes at least one rubber component, at least one filler having nucleophilic groups, gel particles comprising a rubber, having a particle size between about 3×10−9 and about 1×10−6 m and a swelling index in toluene of about 1 to about 15 and whose surface has electrophilic centers, and a substance acting as a coupling agent between the filler having nucleophilic groups and the additional filler, the substance acting as a coupling agent having the following structure: X—R1—Si—(R2)3, wherein X is a nucleophilic group, R1 is an alkyl group having up to about 6 carbon atoms or a phenyl group, and R2 may be the same as or different from each other and from R1 and is an alkyl or alkoxy group having up to 6 carbon atoms and at least one of R2 is an alkoxy group.

Abstract: The rubber mixtures containing modified rubber gels according to the invention prepared from at least one rubber gel modified with compounds containing sulphur and reactive towards C═C double bonds and at least one rubber containing double bonds are preferable suitable for the production of vulcanizates which have an unusually strong reinforcing action in rubber vulcanizates. The vulcanisates furthermore exhibit unusually low dynamic damping at relatively elevated temperatures. They are thus particularly suitable for the production of low rolling resistance motor vehicle tire treads.

Abstract: Highly branched polyisoolefines are produced according to the invention by the polymerization of isoolefines in a single-stage process, in solution, suspension or in the gas phase in the presence of bifunctional monomers which contain at least one group capable of cationic polymerization and at least one group which serves as an initiator for the cationic polymerization of isoolefines (inimer), at temperatures from +20 to -100.degree. C., optionally in the presence of inert, organic solvents, and in the presence of alkylalumoxanes (coinitiator).

Abstract: A rubber composition, which contains a rubber mixture that can be vulcanized with a vulcanizing agent, which includes at least one rubber component, at least one filler, gel particles comprising a rubber, having a particle size between about 3.times.10.sup.-9 and about 1.times.10.sup.-6 m and a swelling index in toluene of about 1 to about 15 and whose surface has electrophilic centers, and a substance which acts as a coupling agent between the gel particles and which has the structure A--R--A, wherein A is a nucleophilic group, and R is a saturated or unsaturated hydrocarbon group. The rubber composition has improved hysteresis behavior in the vulcanized state so that when this rubber composition is used in tires, the rolling resistance is reduced and the wet slippage behavior is improved in relation to the conventional rubber compositions. A method of formulating the rubber composition as well as a composition useful for tire treads and vehicle tires containing the composition are disclosed.

Abstract: Rubber mixtures prepared from at least one styrene/butadiene rubber gel and at least one rubber which contains double bonds and optionally further fillers and rubber auxiliary substances are in particular suitable for the preparation of vulcanizates having unusually high damping at temperatures of from -20 to +20.degree. C. as well as unusually low damping at temperatures of from 40 to 80.degree. C. The rubber mixtures may therefore be used, for example, to manufacture vehicle tires which grip in the wet and have low rolling resistance.

Abstract: This invention relates to an initiator system for the polymerization of isoolefins having 4 to 16 carbon atoms, optionally with monomers polymerizable with isoolefins, the system consisting of or one or more aromatic or heteroaromatic, polycyclic hydrocarbons and an aged, organic solution of vanadium tetrachloride, wherein the concentration of the vanadium tetrachloride is 0.01 mmol to 500 mmol per liter of solvent and the molar ratio of aged vanadium tetrachloride to polycyclic hydrocarbons is in the range from 100:1 to 1:100.It is possible by means of the initiator system according to the invention to produce polyisoolefins, in particular butyl rubbers, at relatively high temperatures with only a low gel content and of a sufficiently high molecular weight.

Abstract: Gel-free ethylene/vinyl acetate copolymers with a high content of copolymerized vinyl acetate and a high Mooney viscosity are produced by carrying out the polymerization in solution in the presence of 20 to 45% by weight tert.butanol, based on the reaction solution, at temperatures of 50.degree. to 80.degree. C. and under pressures of 300 to 450 bar using azo compounds in a cascade of stirred reactors with an average residence time of the reaction solution in the reactor cascade of 5 to 9 hours and a conversion of 50 to 70% by weight, based on the vinyl acetate used. The ethylene/vinyl acetate copolymers produced by the process according to the invention may be used for the production of vulcanizates having improved mechanical properties.

Abstract: Rhodium and ruthenium catalysts can be recovered from solutions of hydrogenated nitrile rubber by addition onto organosiloxane-based absorbers.

Abstract: Mixtures of A) polybutadiene gel and B) other rubbers containing C.dbd.C double bonds, the quantity of polybutadiene gel A), based on the sum of A)+B), being 1 to 70% by weight, show as vulcanizates a favorable combination of the properties hysteresis loss and abrasion resistance.

Abstract: Vulcanizable, mercaptan- and/or xanthogen-disulfide-regulated polychloroprene rubber are produced by emulsion polymerization of chloroprene and, based on polymerizable monomer used, 0 to 30 parts by weight ethylenically unsaturated, other monomers copolymerizable with chloroprene in an alkaline medium by a process in which(1) 0.1 to 10 parts by weight of a tricyclic diterpene carboxylic acid containing at least two conjugated C.dbd.C double bonds per molecule, based on the polymerizable monomer used, and optionally(2) 0.1 to 5 parts by weight, based on polymerizable monomer used, fatty acid estersare used for their production.The polychloroprene produced in accordance with the invention may be used for the production of vulcanized rubber articles. The polychloroprene rubbers produced by the process according to the invention have a minimal tendency to foul metal molds. The pollution of wastewaters by the process according to the invention is minimal.

Abstract: A solution polymerisation process carried out continuously in a cascade produces high molecular weight gel-free ethylene terpolymers having on the one hand high resistance to fuels, oils and organic solvents and on the other hand high flexibility even at low temperatures when narrow ranges are adhered to in respect of solvent content, pressure, temperature control and degree of conversion.

Abstract: Metal carboxylates which may be used for the polymerization of monomers suitable for Ziegler-Natta polymerization are prepared by reaction of the organic C.sub.2-20 carboxylic acids on which the carboxylates are based with ammonia and/or amines and/or tetraalkyl ammonium hydroxides and the corresponding metal nitrates in the presence of inert organic solvents at temperatures of 0.degree. to 150.degree. C.

Abstract: Rubber mixtures containing so-called "pre-crosslinked" polychloroprene give vulcanizates having an improved combination of low rolling resistance and low abrasion.

Abstract: In a method and an apparatus for singling cards such as check cards or identity cards, each card to be singled is moved beforehand into a singling groove, thereby passing out of the area of a stop holding the stack. The card thus presingled is thereupon taken completely off the stack using a suitable removing sucker. In this way, cards can be singled very reliably and gently.

Abstract: Ethylene/vinyl acetate solution polymers with increased strength and low gel content may be prepared by the copolymerization of small quantities of acryloyl or methacryloyl compounds.

Abstract: Ethylene/vinyl acetate high-pressure bulk polymers having reduced tackiness can be produced by copolymerization of small quantities of an acryloyl or methacryloyl compound.