Rubber laminate

Abstract

A rubber laminate which is obtained by integrally bonding, by vulcanization, an unvulcanized carboxyl group-containing acrylic rubber layer and an unvulcanized polyol-crosslinkable fluorine rubber layer. The unvulcanized carboxyl group-containing acrylic rubber layer contains: an aromatic polyvalent amine; 1,8-diazabicyclo[5.4.0]undecene-7, 1,5-diazabicyclo[4.3.0]nonene-5, or a salt of 1,8-diazabicyclo[5.4.0]undecene-7 or 1,5-diazabicyclo[4.3.0]nonene-5; and a guanidine compound. The guanidine compound is used in an amount of 3-8 parts by weight, preferably 4-6 parts by weight per 100 parts by weight of the unvulcanized carboxyl group-containing acrylic rubber. The unvulcanized acrylic rubber layer of this rubber laminate has excellent scorching stability and bondability.

Description

technical field [0001] The present invention relates to a rubber laminate. More specifically, it relates to a fluororubber / acrylate rubber laminate. Background technique [0002] For fuel hoses, rubber laminates in which the inner layer is made of fluororubber and the outer layer is made of epichlorohydrin-based rubber are first used (Patent Documents 1 and 2). However, the heat resistance of the rubber laminate is insufficient in a high-temperature environment close to an engine, and a fluororubber / acrylate rubber laminate excellent in heat resistance is required for such an application (Patent Document 3). [0003] In the rubber laminate and hose described in Patent Document 3, although the unvulcanized epoxy group-containing acrylate rubber layer and the unvulcanized fluororubber layer mixed with a silica-based filler are subjected to peroxide co-crosslinking, However, when an epoxy group-containing acrylate rubber was used, a laminate was formed, and a problem of poor ...

AI Technical Summary

Problems solved by technology

However, the heat resistance of the rubber laminate is insufficient in a high-temperature environment close to an engine, and a fluororubber / acrylate rubber laminate excellent in heat resistance is required for such an application (Patent Document 3)

[0003] In the rubber laminate and hose described in Patent Document 3, although the unvulcanized epoxy group-containing acrylate rubber layer and the unvulcanized fluororubber layer mixed with a silica-based filler are subjected to peroxide co-crosslinking, However, when using epoxy-containing acrylate rubber, it was found that the heat resistance or compression set resistance was poor.

[0004] Due to the high cost of fluororubber, it is seldom used alone as a hose material, and is often used as a laminated hose with other rubber materials. The above-mentioned patent document 3 is one example, but it has been found that fluororubber and Problems with generally poor vulcanized adhesion to other rubber materials

[0005] It is known to add 1,8-diazabicyclo[5.4.0]undecene-7 salt [DBU salt] or 1,5 -Diazabicyclo[4.3.0]nonene-5 salt [DBN salt] (Patent Document 4), when adding DBU salt or DBN salt to carboxyl group-containing acrylate rubber, it was found that scorch (t5) changed short question

In the case of molded products obtained by extrusion molding such as hoses, if the scorch value is shortened, the problem of burning of the rubber compound during extrusion (生地ヤケ) occurs, and the problem of an increase in the defective rate has been found.

[0006] In addition, Patent Document 5 describes that when vulcanizing an unvulcanized rubber layer mainly composed of fluororubber and an unvulcanized rubber layer not containing fluororubber, at least one of the layers is mixed with hydrochloride of DBU or DBN, Rubber laminates of sulfonate or phenate and oxides, hydroxides or carbonates of Group II to IV metals, as the rubber used in the unvulcanized rubber layer not containing fluororubber, acrylate rubber or The acrylate copolymer obtained by copolymerizing α,β-ethylenically unsaturated carboxylic acid can be used in various hoses, but the same problem as in Patent Document 4 was found in this case as well.

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