Toyoda Gosei Co., Ltd.

Kiyomitsu Terashima

Masayoshi Ichikawa

Masatoshi Sugimoto

Atsushi Suzuki

Hidenori Hayashi

Hiroji Enyo

Hidekazu Kurimoto

Hidenobu Honda

Fumio Ikeda

Eitaro Okuya

Rikizou Nakata

Ryuichi Horiba

Yasushi Nakahara

Shinichiro Iwanaga

A sulfur curing system EPDM composition in which one or more types of vulcanization accelerators selected from thiazole type and sulfenamide type accelerators and one or more types of vulcanization accelerators selected from dithiocarbamate type and thiuram type accelerators are combined together so as to be compounded into the EPDM composition as a vulcanization accelerator, and an automotive brake system rubber component made of the EPDM composition.

EPDM composition and automotive brake system rubber component

An ethylene propylene rubber blend containing an ethylene-.alpha.-olefin-diene copolymer as the rubber component of the blend. The ethylene-.alpha.-olefin-diene copolymer has a propylene content of about 43% to about 51% by weight, an iodine value of about 33 to about 39, a Mooney viscosity (ML.sub.1+4 100.degree. C.) of about 34 to about 44, and a molecular weight distribution (M.sub.W /M.sub.N) of about 5 or less. The ethylene propylene rubber blend can be used, for example, for formulating articles such as hoses, and in particular brake hoses. At least an inner tube provided inside the hose is preferably formed of the ethylene propylene rubber blend. The ethylene propylene rubber blends have a modulus of elasticity not significantly dependent upon temperature and are excellent in compression set and processability.

Ethylene propylene rubber blend and hose formulated from the same

A reinforced rubber hose having a layer of ethylene-propylene rubber outside or inside a fiber-reinforcing layer. The two layers are firmly bonded to each other by an extruded adhesive layer of butyl rubber which exhibits a high bond strength after vulcanization. This obviates the necessity of treating (usually by dipping) the fibrous reinforcement with an adhesive before its braiding or knitting.

Reinforced rubber hose

An ethylene-propylene rubber composition vulcanizable with sulfur in which the rubber component totally or mainly composed of EPDM is incorporated with a zinc oxide, a carbon black, and other ingredients. The EPDM has an iodine value of 20 to 35 and an active zinc oxide is incorporated therein as the zinc oxide in an amount of 1 to 10 PHR. Even with a sulfur vulcanization system, this ethylene-propylene rubber composition is permitted to have compression set resistance equivalent to that of conventional SBR and is improved in heat resistance as well.

Ethylene-propylene rubber compositions

A sealing part formed a peroxide vulcanizate of a rubber compound having as a polymer component an EPDM mixture of 50 to 90 parts by weight of an EPDM having a Mooney viscosity (ML.sub.1+4 100.degree. C.) of 35 to 55, and 50 to 10 parts by weight of a low-Mooney EPDM (a sub-polymer) having a Mooney viscosity (ML.sub.1+4 100.degree. C.) of 5 to 25. The sealing part of the present invention has a high resistance to low-temperature compression permanent strain and is excellent in the kneadability of a rubber compound for producing the sealing part.

Sealing part for hydraulic cylinder

A high-pressure rubber hose has a reinforcing layer embedded therein, has at least an outer layer thereof formed of the vulcanization product of an ethylene-propylene-diene copolymer rubber (hereinafter referred to as 'EPDM' for short), and is adapted to be used as fastened by staking to a sleeved joint. The high-pressure rubber hose requires that the ethylene/.alpha.-olefin ratio (by weight) in the EPDM should fall in the range of 45/55 to 58/42 and that the Mooney viscosity of polymer (ML.sub.1+4 100.degree. C.) of the EPDM should fall in the range of 120 to 250. This high-pressure rubber hose manifests dynamic resistance to ozone and mechanical properties such as tensile strength to advantage without any sacrifice of the compression permanent set necessary for the sake of the sealing property.

High-pressure rubber hose

A rubber laminate of a fluororubber layer and an NBR layer firmly bonded through vulcanization is provided. The fluororubber layer is made of a fluororubber compound containing a peroxide vulcanizing agent, polyol vulcanizing agent, or polyamine vulcanizing agent. In the case where the fluororubber compound contains a peroxide vulcanizing agent, it further contains a metal oxide. The NBR layer is made of a functional NBR having a specific functional group which is determined according to the vulcanizing agent contained in the fluororubber compound. In the case where the fluororubber compound contains a peroxide vulcanizing agent or polyol vulcanizing agent, the NBR compound further contains a metal oxide. The two layers are firmly bonded through vulcanization. This rubber laminate is used for automotive fuel hoses and fuel pump diaphragms.

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Nagoya, Japan

Kiyomitsu Terashima