Gasohol-resistant multilayer rubber tube - has layer of ternary fluoro-rubber with specific vulcanisation start time and layer of peroxide-vulcanised nitrile] rubber

摘要

The tube (I) comprises (A) a layer of fluororubber and (B) a layer of nitrile rubber. (A) consists of a vulcanised rubber mixt. contg. (A1) a ternary fluororubber and a vulcanisation system contg. (A2) an organic polyol system and (A3) a quat. ammonium salt, and has a vulcanisation trigger time (T10) which satisfies the following equation: T10 + (vulcanisation temp. - 170 deg. C) mins./10 deg. C = 4-7 mins. (B) consists of a vulcanised compsn. contg. (B1) a nitrile rubber contg.a functional gp. with a reactive H atom and (B2) an organic peroxide vulcanisation system. Pref. (A) contains 0.9-4.8 pts. wt. (A2) and 0.1-1.1 pts. wt. (A3) to 100 pts. wt. rubber (A1). (B) is a polyblend of (B1) with 5-30 wt.% PVC, contg. 1-5 pts. wt. (B2), and pref. also a cocrosslinker (B3) and 5-50 pts. wt. metal oxide (B4) (to 100 pts. wt. rubber). (I) also contains reinforcing agents, acid absorbers, plasticisers and processing aids. USE/ADVANTAGE - Used esp. for the prodn. of fuel lines for cars, partic. for use with petrol/alcohol mixts. (gasohol). Vulcanisation under the above conditions ensures good interlaminar strength which is unaffected by immersion in gasohol (contrast prior art fluororubber/nitrile rubber combinations).