Stamicarbon B.v.

Dsm N.v.

Stamicarbon N.v.

Herman A Schepers

Wilhelmus A Debets

Bernard C Roest

Pieter Gijsman

Albertus Otto Dozeman

Rene H Seevens

The invention relates to a process for the preparation of a thermoplastic elastomer comprising preparing a blend of a rubber and a thermoplastic resin, in which the rubber is at least partially vulcanized by using a phenolic curative. The invention is that, to overcome problems with surface quality, an effective amount of a Lewis base is added after the desired degree of vulcanization of the rubber is obtained. The invention also relates to a process for the preparation of an UV-stable thermoplastic elastomer.

Process for the preparation of a thermoplastic elastomer

Impact resistant polyamide composition containing more than 45 wt. % polyamide and relatively minor amounts of an impact modifier. The impact modifier is an elastomer with groups that are reactive with respect to the polyamide. The impact modifier has an adverse effect on the high-temperature properties, which were already poor. According to the invention, compositions of polyamide, impact modifier and a copolymer of a vinylaromatic compound, in particular styrene, and maleic anhydride have improved high-temperature properties while maintaining good impact resistance.

Polyamide compositions

The invention relates to a graft copolymer obtainable by reacting a rubbery base polymer, which has been provided with hydroperoxide groups via photo-oxidation, with one or more radical-polymerizable graft monomers, the graft copolymer being based upon 90-20 parts of a rubbery base polymer containing at least 4 (four) hydroperoxide groups per rubber chain and 80-10 parts of one or more of the graft monomers.

Rubber-based graft copolymer

New polymer composition which has excellent thermal stability, good impact resistance and processability, containing the following compounds:

Thermoplastic polymer mixtures

A thermoplastic moulding compound based on a rubber-modified copolymer consisting of styrene and/or .alpha.-methylstyrene and maleic anhydride, wherein the moulding compound is composed of a mixture of:

Thermoplastic moulding compound

A process for preparing an impact resistant thermoplastic moulding compound based on a copolymer consisting of styrene and/or .alpha.-methylstyrene and maleic anhydride by mixing:

Process for preparing an impact-resistant thermoplastic moulding compound

Disclosed is an impact-resistant polymer composition based on a copolymer of an unsaturated nitrile, a substantially saturated rubber and a chlorinated polyethylene. To maintain high impact resistance while retaining good processing properties, the polymer composition comprises:

Polymer composition comprising nitrile copolymer, CPE and rubber

The invention relates to a polymer composition based on a copolymer of an unsaturated nitrile, a substantially saturated rubber, a chlorinated polyethylene, and a vinylchloride polymer. To improve the impact resistance and the flexural modulus, the polymer composition according to the invention comprises:

Polymer composition comprising ClPe, S/An, PVC, and rubber

An improved polymer composition having a combination of good flow behavior, UV stability, and very good impact resistance is described, essentially composed of

Polymer composition

A new elastomeric composition is described, having an improved combination of characteristics, which is composed of an intimate admixture of

Process for preparing a polymer mixture

Polyfunctional anionic initiators for the preparation of elastomeric block copolymers are prepared by reacting a monofunctional anionic initiator, such as secondary butyl lithium, with a monovinyl aromatic compound, such as styrene, or a conjugated diene, such as butadiene or isoprene or mixtures thereof to form a polyuric reaction product which in turn, is reacted with a polyvinyl aromatic compound, such as divinyl benzene. The cross-linked reaction product, prior to use, is reacted with styrene or another monovinyl aromatic compound. The resulting polyfunctional anionic initiators are useful in producing elastomeric block co-polymers of the A-B-(A)n type exhibiting good elastomeric properties.

Process for the preparation of thermoplastic elastomeric block copolymers

An improved process for preparing elastomeric block copolymers of the formula A-B-A, wherein A is a poly-alpha-methyl-styrene polymer block, and B is an elastomeric polymer block from a conjugated diene. Alpha-methyl-styrene is polymerized by means of a mono-functional anionic initiator and an activator with an initial monomer concentration in excess of 100 g of alpha-methyl styrene per liter of reaction mixture, at a temperature of between 0.degree. and 40.degree.C, the amount of said activator being present such that the molar ratio of activator/initiator ranges from about 0.1 and 35 for a polymerization time of no more than 120 minutes. Thereafter, a small amount of conjugated diene and/or styrene is added to the reaction mixture. Subsequently, a conjugated diene is added to the mixture and polymerized. A bi-block copolymer consisting of a poly-alpha-methyl-styrene block and a poly (conjugated diene) block is formed. Formation of the A-B-A block copolymer occurs through addition of a linking agent to this block copolymer of alpha-methyl-styrene and conjugated diene.

Process for preparing block copolymers containing alpha-methyl styrene

A method for preparing a block polymer A--B--C with alkyl lithium where the improvement is in the formation of block B. The method of forming block B which is a conjugated diene is carried out without the removal of contaminants.

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Stein, Netherlands

Herman A Schepers