Blends of EPDM with highly unsaturated rubbers are co-cured with sulfur using as accelerators higher alkyl thiuram disulfides (e.g., tetralaurylthiuram disulfide) or benzothiazylsulfenamides (e.g., N-lauryl-benzothiazylsulfenamide).
This invention relates to a heat curing process and to heat activated compositions comprising (1) an ethylenically unsaturated compound containing at least two carbon-to-carbon double bonds and (2) a thiuram.
This invention relates to sulfido(disulfido)bis(N,N-substituted dithiocarbamato)W(VI) complexes, their preparation and use. More particularly, this invention relates to compounds of the formula WS(S.sub.2) (S.sub.2 CNR.sub.2).sub.2 which are mononuclear, seven-coordinate, neutral W(VI) complexes containing only seven sulfur atoms in the Mo coordination sphere. R is hydrogen, an alkyl, aryl, cycloalkyl group or mixture thereof. Preferably all of the R's are the same and are alkyl groups. These compounds are useful as catalysts or catalyst precursors for removing sulfur from sulfur containing hydrocarbons.
The compositions according to the invention comprise at least one unsaturated polyolefin elastomer, at least one vulcanizing agent and at least one vulcanization activator for the said elastomer, and in addition at least one terpolymer (A) comprising repeat units derived from ethylene, repeat units derived from maleic anhydride and repeat units derived from at least one ester of acrylic or methacrylic acid. For their manufacture, the unsaturated polyolefin elastomer, the vulcanizing agent, the vulcanization activator and the terpolymer are mixed at a temperature of between 70.degree. C. and 150.degree. C. for a sufficient time to produce homogenization of the mixture. Application to the production of articles such as seals, flexible connection pipings, belts, and the like.
A rubber composition is disclosed wherein the rubber composition contains at least (a) a rubber component; (b) a silica filler; and, (c) at least one thiuram disulfide accelerator, it being provided that diphenyl guanidine is substantially absent in the rubber composition. The compositions may also include suitable amounts of other ingredients such as carbon black, coupling agents, antiozonants, antioxidants, etc.
Rubber mixtures consisting of (1) 20 - 75 parts of a copolymer containing 60 - 80% by weight of ethylene, 20 - 40% by weight of an .alpha.-alkene, and 0 - 20% by weight of one or more polyenes and having, in the unvulcanized state, an elongation at rupture of over 800% and a tensile strength of between 10 and 100 kg/cm.sup.2 ; (2) 80 - 25 parts of at least one polymeric material which is a styrene-butadiene copolymer; polybutadiene or polyisoprene; and (3) a tackifier resin and optionally conventional fillers and additives, wherein the mixture of (1), (2) and (3) has an elongation at rupture of at least 800% and a tensile strength of between 1.3 and 50 kg/cm.sup.2.