| 摘要 |
The invention relates to a sulfur vulcanization process comprising (a) a non-productive stage of mixing of a rubber composition comprising styrene-butadiene rubber, (b) a productive stage of mixing of a rubber composition further comprising sulfur and a vulcanization accelerator, and (c) vulcanization of said rubber composition and is characterized in that in the non-productive or productive stage of mixing there is added 0.1 to 1 phr of a hardness stabilizing coagent according to any one of formulae (I)-(IV) wherein R<1>, R<2>, and R<3> independently represent H or a C1-C5 hydrocarbon group, optionally containing one or more oxygen, nitrogen or sulfur atoms, R<1> and R<2>, provided that R<1> is in the 4-position, or R<2> and R<3> together with the carbon atoms to which they are attached may form a 5 or 6-membered ring, said ring optionally being substituted with a C1-C5 hydrocarbon group, said group optionally containing one or more oxygen, nitrogen or sulfur atoms, n is 1 to 4, M is selected from Na, Zn, Mg, AL, Fe and Te, and x is 1 to 4. The invention also relates to an article of manufacture, such as a pneumatic tyre, comprising the rubber vulcanizate obtained by said process. |
