| 摘要 |
Butyl rubber treated before vulcanisation by heating with not more than 3% by weight of a p-nitroso-secondary aniline having an aliphatic or aromatic substituent attached to the amino nitrogen atom has improved vulcanisation properties. The butyl rubbers comprise elastomeric copolymers of isobutylene and not more than 15% by weight of di-olefine hydrocarbons. The nitroso-anilines may contain additional nuclear substituents such as alkyl, alkoxy, acyloxy and aralkoxy groups and halogen atoms, and the aliphatic substituent attached to the amino nitrogen atom may be an alkyl or alkenyl group or alkyl or alkenyl groups substituted with groups such as alkoxy, hydroxy, carbolkoxy, or carbamido or halogen atoms and the aromatic substituent may be phenyl. Compounds specified p are methyl-N(p-nitrosophenyl) B-alanate, 3-chloro- and 3-ethoxy N-ethyl p-nitrosoaniline, N-sec butyl, N-amyl, N-hexyl, N-heptyl, N-octyl, N-decyl, N-dodecyl, and N-cyclohexyl p-nitrosoaniline, N-(p-nitrosophenyl) glycine amide, 3-(p-nitrosoanilino) proprionamide and 2-(p-nitrosoanilino) ethanol. Fillers, e.g. carbon black and silica may be present during at least part of the heat treatment and dynamic or static conditions of heating, preferably at about 149 DEG C. may be employed. In an example butyl rubber was mixed with the nitrosoaniline compound for 10 minutes at 150 DEG C., carbon black added and the mixing continued for a further 10 minutes at 150 DEG C. The modified rubber was compounded with zinc oxide, tetramethyl thiuram disulphide, 221 dithiobis (benzothiazole) and sulphur, and vulcanised at 144 DEG C. for 45 minutes to yield a product which showed improved modulus of elasticity, resilience, and resistance to flow. U.S.A. Specification 2,046,356 is referred to.ALSO:The invention comprises p-nitrosophenylamino acyl esters having the general formula ON-C6H4NH-R-CO-OR1 in which R is an alkylene group, e.g. methylene dimethylene, or trimethylene, and R1 is an alkyl group, such as methyl N-(p-nitrosophenyl)-b -alanate, which may be prepared from the corresponding anilino nitrile by nitrosation and simultaneous hydrolysis and esterification of the nitrile group. In an example, anilinopropionitrile is added with stirring to a cooled solution of hydrogen chloride in methanol, sodium nitrite added the mixture cooled, brought to a pH of 8, and methyl - N - (p - nitroso - phenyl) beta alanate mp. 108-9 obtained after recrystallization. Alternatively the product may be obtained by the N-nitrosation and rearrangement of methyl-N-phenyl beta alanate. The compounds are used in the prevulcanization treatment of butyl rubber. U.S.A. Specification 2,046,356 is referred to. |
