Abstract: Novel catalyst systems for metathesis reactions, in particular for the metathesis of nitrile rubber, which contain a specific salt additive in addition to the metathesis catalyst are provided.

Abstract: A novel process produces a novel hydrogenated nitrile rubber (B) which features a very narrow molecular weight distribution and a correspondingly low value for the polydispersity index. The preparation process encompasses the treatment of a hydrogenated nitrile rubber (A) with ultrasound, whereupon the resultant hydrogenated nitrile rubber (B) has a lower weight-average molecular weight (Mw) than the hydrogenated nitrile rubber (A). The resultant hydrogenated nitrile rubber (B) has excellent suitability for the production of mouldings via processing by extrusion processes or by injection-moulding processes.

Abstract: The present invention relates to a method for the hydrogenation of unsaturated polymers containing double bonds, the unsaturated polymers present in latex form being hydrogenated in the presence of a metal-containing colloid.

Abstract: The present invention provides a novel process for preparing hydrogenated nitrile rubbers comprising subjecting nitrile rubbers in a spinning disk reactor to hydrogenation. The present process is less demanding with regard to its reaction conditions, like e.g. the hydrogen pressure to be applied, compared to known processes and significantly reduces the cost of the hydrogenation process and in particular the equipment cost.

Abstract: An improved process for the metathetic degradation of nitrile rubber using catalyst systems comprising the catalyst and also a phosphane or diphosphane is provided.

Abstract: The present invention relates to thermoplastic vulcanizates (TPVs) based on low Mooney, optionally hydrogenated nitrile butadiene rubber and polyamides. The present invention also relates to TPVs based on low Mooney, optionally, hydrogenated nitrile terpolymers and polyamides. TPVs prepared according to the present invention have improved morphology, smaller rubber particle size, and improved processability compared to TPVs containing non-low Mooney, optionally hydrogenated nitrile butadiene rubber.

Abstract: Novel crosslinkable compositions based on elastomers, at least one of which has carboxyl and/or carboxylate groups, are provided, these crosslinkable compositions containing special unsaturated organic salts of metal ions and a crosslinking system which acts as a free radical donor. Crosslinked elastomers which have excellent physical properties are obtainable therefrom. The novel crosslinkable compositions have a wide range of uses.

Abstract: The present invention relates to adhesive polymer composites containing at least one nitrile rubber polymer having a Mooney viscosity (ML 1+4 @ 100° C.) below 30, optionally at least one filler and optionally at least one cross-linking agent, a process for preparing the polymer composite wherein at least one nitrile rubber polymer having a Mooney viscosity (ML 1+4 @ 100° C.) below 30, optionally at least one filler and optionally at least one cross-linking agent are mixed and a self-supporting shaped article containing the compound optionally layered on or interposed between one or more supporting means. The present invention also relates to a tape containing the adhesive polymer composite optionally layered on or interposed between one or more supporting means. Further, the present invention relates to a sealant composition containing the adhesive polymer composite.

Abstract: The present invention relates to a process for the production of hydrogenated nitrile rubber polymers having lower molecular weights and narrower molecular weight distributions than those known in the art in the characterized that the process is carried out in the presence of hydrogen and optionally at least one co-(olefin).

Abstract: Nitrile rubber polymers, optionally hydrogenated, having lower molecular weight and narrower molecular weight distribution than those known in the art, are prepared by metathesis of nitrile butadiene rubber, optionally followed by hydrogenation. The process comprises the steps of a) reacting a nitrile rubber in the presence of at least one compound which is a ruthenium or osmium based indenylidene complex and optionally b) hydrogenating the resulting lower molecular weight nitrile rubber using standard techniques known in the art. The optionally hydrogenated nitrile rubber, with lower molecular weight and narrower molecular weight distribution has very good heat resistance, excellent ozone and chemical resistance and excellent oil resistance. It is used in automotive, oil, electrical, mechanical engineering and shipbuilding industries.

Abstract: The present invention relates to hydrogenated carboxylated nitrile-butadiene rubber (HXNBR), which contain molecularly dispersed triphenylphosphine, and which is useful as a cross-linking agent for elastomers, plastics and/or adhesive systems. The present invention also relates to products which are obtainable from the HXNBR having molecularly dispersed triphenylphosphine and elastomer, plastics and/or adhesive systems, a composition containing a HXNBR having molecularly dispersed triphenylphosphine and further non-molecularly dispersed activators, a process for the preparation of the composition as well as the use of HXNBR having molecularly dispersed triphenylphosphine, as an elasticizing agent for elastomer, plastics and/or adhesive systems.

Abstract: A novel process for the degradation of nitrile rubber by metathesis using ruthenium- or osmium-based catalysts which have both a substituted or unsubstituted imidazolidine ligand and a carbene ligand bearing a phosphonium radical is provided.

Abstract: The present invention relates to a continuous process for producing polymers at conversions ranging from 50% to 95% having a Mooney viscosity of at least 25 Mooney-units and a gel content of less than 15 wt. % containing repeating units derived from at least one isoolefin monomer, more than 4.1 mol % of repeating units derived from at least one multiolefin monomer and optionally further copolymerizable monomers in the presence of AlCl3 and a suitable proton source (e.g. water) or cationogen and at least one multiolefin cross-linking agent wherein the process is conducted in the absence of transition metal compounds and organic nitro compounds.

Abstract: The present invention relates to a composition containing a hydrogenated nitrile-butadiene rubber (HNBR), a peroxide crosslinking system and a resorcinol-formaldehyde resin, to a process for the preparation of the composition, to the use of the composition as an adhesion promoter, and also to a multilayer product containing the composition according to the present invention.

Abstract: The present invention relates to a process for the hydrogenation of the carbon-carbon double bonds in diene based polymer latex.

Abstract: The present invention relates to a process for the production of hydrogenated nitrile rubber polymers having lower molecular weights and narrower molecular weight distributions than those known in the art in the absence of a co-(olefin).

Abstract: A continuous process for the production of an elastomer-modified thermoplastic is disclosed. The process entails (i) obtaining graft elastomer (D) having residual moisture content of 1 to 50 wt. %, particularly 5 to 50 wt. %, particularly preferably 10 to 40 wt. %, (ii) introducing (D) and thermoplastic resin (B) through an inlet to a reactor operating under conditions calculated to melt (D) and (B) and to remove organic volatile components C) to produce a molten blend, the reactor being equipped with a plurality of kneading bars, that convey a portion of the molten blend towards the reactor inlet.

Abstract: A process is provided for the hydrogenation of carbon-carbon double bonds in polymers by treatment of the polymers with hydrogen in the presence of rhodium-based catalysts and in the complete absence of organic solvent.

Abstract: The present invention relates to a peroxide curable rubber compound comprising at least one elastomeric polymer comprising repeating units derived from at least one C4 to C7 isomonoolefin monomer, at least one C4 to C14 multiolefin monomer and at least one m- or p-alkylstyrene monomer.

Abstract: The present invention relates to a multistage process including at least two steps for making a heat and oil resistant preroxide-cured thermoplastic vulcanizates (TPV) based on hydrogenated carboxiated nitrile butadiene rubber (HXNBR) and at least one polyamide. TPV's according to the present invention have improved properties and morphology over known TPV's prepared in single-stage processes.