Abstract: The invention pertains to a particle comprising a composition containing a matrix and a peroxide or azo radical initiator, wherein the particle is a fiber or fibrid selected from aramid, polyester, polyimide, cellulose, and glass. The invention further relates to particle-elastomers comprising said composition, and skim products, tires, tire treads, and belts comprising these particle-elastomers.

Abstract: The invention pertains to a particle comprising a composition containing a matrix and a peroxide or azo radical initiator, wherein the particle is a fiber or fibrid selected from aramid, polyester, polyamide, cellulose, and glass. The invention further relates to particle-elastomers comprising said composition, and skim products, tires, tire treads, and belts comprising these particle-elastomers.

Abstract: An aramid particle containing a peroxide radical initiator wherein the particle contains 3-40 wt % peroxide radical initiator based on the weight of the aramid particle. Also, disclosed is a particle-elastomer composition having 100 parts by weight of at least one natural or synthetic elastomer, such as rubber; 0.1 to 20 parts by weight of a peroxide or 0.1 to 25 parts by weight of sulfur, an amount of a sulfur donor providing the equivalent of 0.1 to 25 parts by weight of sulfur, or a mixture of sulfur and a sulfur donor to an equivalent total of 0.1 to 25 parts by weight of sulfur; and 0.1 to 20 parts by weight of the aramid particle.

Abstract: The invention pertains to a particle comprising a composition containing a matrix and a peroxide or azo radical initiator, wherein the particle is a fiber or fibrid selected from aramid, polyester, polyimide, cellulose, and glass. The invention further relates to particle-elastomers comprising said composition, and skim products, tires, tire treads, and belts comprising these particle-elastomers.

Abstract: The invention pertains to a composition comprising a particle and a matrix, wherein the particle is at least partially coated with a compound or a mixture of compounds a cured polysulfide polymer obtained from a polysulfide polymer having at least two epoxy end groups. Most preferred polysulfide polymers are: wherein n is independently 1-200 and R? is wherein m is 0 to 10, R3 is independently H or CH3, and the end indicated with the double asterisk is bonded to the epoxide group. The invention further relates to particle-elastomers comprising said composition, and skim products, tires, tire treads, and belts comprising these particle-elastomers.

Abstract: Process for cross-linking ethylene-?-olefin copolymers comprising the step of combining the copolymer with (a) an initiator capable of generating free radicals and (b) a sulfur-containing co-agent according to formula R—Y—Sx—Y—R. This process results in cross-linked copolymers with improved dynamic properties, tensile strength, delta torque, and/or modulus, without compromising on compression set or aging stability.

Abstract: The invention relates to a process to cross-link rubbers comprising the step of combining a rubber with an initiator capable of generating free radicals, a maleimide-type co-agent, and a sulfur donor, wherein said co-agent and said sulfur donor are two different chemicals.

Abstract: The invention pertains to a fiber comprising 0.5-30 wt. % based on the weight of the fiber of a composition comprising: a) a Bunte salt (A); b) a polysulfide compound (B) comprising the moiety {S]n— wherein n=2-6; and c) sulfur or a sulfur donor (C). Preferably the polysulfide compound has the formula: wherein n=2-6; R is independently selected from hydrogen, halogen, nitro, hydroxyl, C1-C12 alkyl or alkoxyl or aralkyl; The invention further relates to a vulcanization process for making a fiber-elastomer composition comprising the step of vulcanizing: (a) 100 parts by weight of at least one natural or synthetic rubber; (b) 0.1 to 25 parts by weight of an amount of sulfur and/or a sulfur donor, to provide the equivalent of 0.1 to 25 parts by weight of sulfur; and (c) 0.1 to 20 parts by weight of said fiber.

Abstract: The invention relates to a silica-filled, sulfur-vulcanizable rubber composition comprising an unsaturated rubber, 20 to 100 phr of a silica, 1.6 to 8 phr of a silica coupling agent, 0.05 to 5 phr of an antidegradant, 0.1 to 5 phr of a vulcanization accelerator, 0.1 to 10 phr of sulfur, and 0.5 to 5 phr of a quinone diimine, with the proviso that the antidegradant is not a quinone diimine. The invention also relates to a vulcanization process comprising mixing and heating said rubber composition and to rubber articles, such as pneumatic tires, comprising the rubber vulcanizate obtained by said process.

Abstract: A vulcanizable composition comprising a sulfur vulcanizable rubber, a sulfur vulcanizing agent, an accelerating agent selected from the group consisting of non-thiazole sulfenamide accelerators in an amount effective to not substantially inhibit vulcanization and an amount effective to improve the hardness stabilization of said rubber upon vulcanization of a hardness stabilization agent comprising a pyrimidine derivative. A method of improving the hardness stabilization of a composition comprising a sulfur vulcanizable rubber by adding to said composition the accelerators and pyrimidine derivative.

Abstract: The invention relates to a silica-filled, sulfur-vulcanizable rubber composition comprising an unsaturated rubber, 20 to 100 phr of a silica, 1.6 to 8 phr of a silica coupling agent, 0.05 to 5 phr of an antidegradant, 0.1 to 5 phr of a vulcanization accelerator, 0.1 to 10 phr of sulfur, and 0.5 to 5 phr of a quinone diimine, with the proviso that the antidegradant is not a quinone diimine. The invention also relates to a vulcanization process comprising mixing and heating said rubber composition and to rubber articles, such as pneumatic tires, comprising the rubber vulcanizate obtained by said process.

Abstract: A vulcanized rubber composition which comprises the vulcanization reaction product of 100 parts by weight of at least one natural or synthetic rubber; 0.1 to 25 parts by weight of sulfur and/or a sufficient amount of a sulfur donor to provide the equivalent of 0.1 to 25 parts by weight of sulfur; 10-100 parts by weight of at least one silica filler; 0.1 to 5 parts by weight of at least one anti-reversion coagent comprising at least two groups selected from citraconimide and/or itaconimide groups; and a sufficient amount of a least one cure-improving resin to significantly increase the delta torque of the rubber composition during the vulcanization process as compared to the delta torque of a similar rubber composition in the absence of the cure-improving resin, is disclosed. Also disclosed is a process for the vulcanization of this rubber composition, and articles of manufacture comprising the vulcanized rubber composition.

Abstract: A rubber composition which is the vulcanization reaction product of a rubber, sulfur or a sulfur donor, particular anti-reversion coagents, and an effective amount of zinc, complexed with at least one carboxylic acid group, is disclosed. The invention also relates to a sulfur-vulcanization process which is carried out in the presence of an anti-reversion coagent and the complexed zinc and the use of an anti-reversion coagent in combination with the complexed zinc in a process for the sulfur-vulcanization of rubber. The resulting sulfur-vulcanized rubbers have significantly improved physical properties.

Abstract: Novel metal salts of (poly)citraconimide and (poly)itaconimide carboxylic acids, and a vulcanizable rubber composition comprising these novel metal salts and which, upon vulcanization, exhibits improved dynamic properties, are disclosed. Also disclosed are a sulfur-vulcanization process carried out in the presence of these metal salts and the product of said vulcanization process. The novel metal salts are represented by the formulas I and II: ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 are independently selected from hydrogen, C.sub.1 -C.sub.18 alkyl groups, C.sub.3 -C.sub.18 cycloalkyl groups, C.sub.6 -C.sub.18 aryl groups, C.sub.7 -C.sub.30 aralkyl groups and C.sub.7 -C.sub.30 alkaryl groups and R.sub.2 and R.sub.3 may combine to form a ring when R.sub.1 is hydrogen; R.sub.4 is selected from divalent, trivalent or tetravalent linear or branched radical chosen from a C.sub.1 -C.sub.18 alkyl, C.sub.2 -C.sub.18 alkenyl, C.sub.2 -C.sub.18 alkynyl, C.sub.3 -C.sub.18 cycloalkyl, C.sub.3 -C.sub.

Abstract: A rubber composition which is the vulcanization reaction product of a rubber, particular anti-reversion coagents, and a sulfide resin, is disclosed. The invention also relates to a vulcanization process which is carried out in the presence of an anti-reversion coagent and a sulfide resin and the use of an anti-reversion coagent in combination with sulfide resin in a process for the vulcanization of rubber. The resulting vulcanized rubbers have significantly improved physical properties.

Abstract: Rubber compositions are provided having improved physical properties. More particularly, the present invention relates to sulfur-vulcanized rubber compositions which are vulcanized in the presence of certain bis-succinimide coagents, which possess anti-reversion and/or accelerating properties. The invention also relates to a sulfur-vulcanization process which is carried out in the presence of one or more bis-succinimide coagents, and to the use of bis-succinimide coagents in the sulfur-vulcanization of rubber. Finally, the invention relates to rubber products comprising rubber vulcanized with sulfur in the presence of one or more bis-succinimide coagents.