[EN] HARDNESS STABILIZATION BY MERCAPTOPYRIDINES<br/>[FR] STABILISATION DE LA DURETE AU MOYEN DE MERCAPTOPYRIDINES
申请人:FLEXSYS BV
公开号:WO2001016226A1
公开(公告)日:2001-03-08
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, R2, and R3¿ independently represent H or a C¿1?-C5 hydrocarbon group, optionally containing one or more oxygen, nitrogen or sulfur atoms, R?1 and R2¿, provided that R1 is in the 4-position, or R?2 and R3¿ 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 C¿1?-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.