Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – At least one aryl ring which is part of a fused or bridged...
Patent
1986-08-13
1988-08-09
Bleutge, John C.
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
At least one aryl ring which is part of a fused or bridged...
524445, 524517, 525194, 525195, 525207, C08J 324, C08K 322
Patent
active
047628774
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to compositions based on a polyolefin elastomer, a process for their manufacture and articles produced by converting the said compositions.
Polyolefin elastomers, especially random ethylene/propylene/diene polymers, are rubbers which are very widely employed in industry. In order to convert them using extrusion and moulding techniques, it is necessary to have available compositions of very high hardness. Such compositions must nevertheless retain an elastomeric behaviour and not assume that of a thermoplastic. Consequently, the compositions must not only be crosslinkable but must also have good processability, that is to say be capable of being converted using rubber conversion methods and on machines used in this field; in particular, it is essential that the conversion temperature does not exceed 110.degree. C. after crosslinking agents have been incorporated.
The addition of conventional reinforcing agents, such as carbon black, clay or silica, to the polyolefin elastomers does not per se make it possible to attain a hardness which is satisfactory in this respect.
Furthermore, it is known to add styrene resins (French Patent No. 1,337,598) or phenolic agents (German Patent No. 2,324,987) to polyolefin elastomers in order to increase their hardness. However, such compositions are not wholly satisfactory, since their elastic recovery after deformation at 20.degree. C. is not very good and, above all, since they are characterized by a very high dimensional instability in use.
French Patent No. 1,491,940 discloses a mixture intended for the manufacture of golf balls, comprising from 5 to 95% by weight of a synthetic rubber chosen from polybutadiene, polychloroprene, polyisoprene, acrylonitrile/butadiene/styrene polymers, styrene/butadiene/styrene block copolymers and ethylene/propylene copolymers and from 95 to 5% by weight of a copolymer of an olefin and an unsaturated carboxylic acid. U.S. Pat. No. 3,454,676 also discloses a mixture consisting of 20 to 80% by weight of an ethylene/propylene/1,4-hexadiene elastomer and of 80 to 20% by weight of an ethylene-based ionic copolymer containing from 1 to 25% on a molar basis of repeat units derived from an ethylenically .alpha.,.beta.-unsaturated mono- or dicarboxylic acid, in which at least 30% of the acid groups are neutralized with metal ions. In the absence of a filler such as carbon black and in the absence of a vulcanizing agent such as sulphur, this last mixture has a relatively mediocre break strength of between 22 and 100 kg/cm.sup.2.
An aim of the present invention is therefore to provide compositions based on an unsaturated polyolefin elastomer which, while having a Shore A hardness of at least 80, have an excellent dimensional stability in use, good adhesion to metals such as steel and a satisfactory degree of Zwick rebound.
The compositions forming the first subject of the present invention comprise at least one unsaturated polyolefin elastomer, at least one vulcanizing agent and at least one vulcanization activator for the said elastomer, and are characterized in that they additionally comprise at least one terpolymer (A) containing repeat units derived from ethylene, repeat units derived from maleic anhydride and repeat units derived from at least one ester of acrylic or methacrylic acid.
Within the meaning of the present invention, an unsaturated polyolefin elastomer is preferably understood to mean a terpolymer (B) of ethylene with at least one .alpha.-olefin containing from 3 to 6 carbon atoms and at least one diene. Ethylene/propylene terpolymers are more especially preferred, the diene being chosen from conjugated or unconjugated linear or cyclic dienes such as, for example, butadiene, isoprene, 1,3-pentadiene, 1,4-pentadiene, 1,4-hexadiene, 1,5-hexadiene, 1,9-decadiene, 5-methylene-2-norbornene, 5-vinyl-2-norbornene, 2-alkyl-2,5-norbornadienes, 5-(5-hexenyl)-2-norbornene, 1,5-cyclooctadiene, bicyclo[2.2.2]octa-2,5-diene, cyclopentadiene, 4,7,8,9-tetrahydroindene and isopropylidenetetrahydroindene. Such elastomer
REFERENCES:
patent: 3451962 (1969-06-01), Auler et al.
patent: 3454676 (1969-07-01), Busse
patent: 3557028 (1971-01-01), Turk
patent: 3821134 (1974-06-01), Son et al.
patent: 3852354 (1974-12-01), Usamoto et al.
patent: 3873494 (1975-03-01), Lewis
patent: 3968065 (1976-07-01), Morris et al.
patent: 4431775 (1984-02-01), Maeda et al.
Bleutge John C.
Sellers II Robert E. L.
Societe Chimique Des Charbonnages S.A.
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