| 摘要 |
The invention provides a chemical resistant composition comprising at least:- (a) 100 parts by weight of a hydrogenated (poly)butadiene block copolymer BDB or ÄB<1>EÜn<X,>wherein each of the blocks B and B<1> comprises a substantially linear, substantially pure polyethylene block, having a number average molecular weight (Mn) in the range of from 5,000 to 250,000; D and E are substantially linear elastomeric polymer blocks, being substantially free from olefinic unsaturation, and having a number of average molecular weight in the range of form 10,000 to 400,000, the weight distribution (Mw/Mn) of the blocks, B, BDB, B<1>E is <2, and wherein X is a coupling agent residue and n is an integer > 2; (b) from 20 to 100 parts by weight of a predominantly paraffinic and/or naphthenic extender oil; and (c) from 20 to 200 parts by weight of a homopolymer or copolymer of olefins having from 2 to 20 carbon atoms. The composition is are in particular to be used under the bonnet of automotives.
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