Abstract: A polymer composition useful to produce a vulcanizate having improved compound scorch safety is described. The polymer composition includes three components. The first component is a polymer selected from the group comprising nitrile polymers and ethylene polymers. The second component is a salt of a strong base and a weak acid, the salt comprising a metal selected from Group I of the Periodic Table of Elements. The third component is a vulcanization system comprising an inorganic peroxide compound and a sulfur containing compound. The polymer compositions may further comprise optional ingredients such as one or more of: a polycarbodiimide and a filler. Vulcanizates produced from the polymer composition have a surprising and unexpected combination of properties.
Abstract: A vulcanizable dip-forming rubber latex composition comprising an unsaturated nitrile-conjugated diene copolymer rubber latex, a sulfur-containing vulcanizer, and a vulcanization accelerator comprising at least one compound selected from (i) dithiocarbamic acid compounds of the formula:
and (ii) zinc dithiocarbamate compounds of the formula:
wherein R1 and R2 are hydrocarbon groups having at least 6 carbon atoms which may be the same or different, and an optional thiazole compound. A rubber article dip-formed from the rubber latex composition has no crack occurrence, good surface luster and good vulcanization properties, and does not contain a nitrosamine, and therefore, is suitable for medical use.