Abstract: A catalyst comprising (a) copper or a copper compound; (b) vanadium or a vanadium compound; (c) zirconium, aluminum, nickel, iron, manganese, lanthanum, chromium, zinc, lead, or cerium, or a compound thereof; and optionally, (d) platinum, rhodium, or palladium, or a compound thereof is carried on a porous ceramic body to assist in purifying exhaust gases from Diesel engines.

Abstract: In a method of producing silicon carbide by heating starting materials comprising siliceous material and carbonaceous material in a non-oxidizing atmosphere, those ingredients contained in gases evolved upon heating and solidified at a low temperature into impurities for silicon carbide are eliminated from the atmosphere during heating.

Abstract: A process for decomposing vulcanized rubber which comprises swelling 100 parts by weight of vulcanized rubber with 10-3000 parts by weight of an organic solution, and adding and mixing 0.1-20 parts by weight of an organic hydroperoxide (a) and of 0.001-1 mole equivalent per said (a) of at least one member (b) selected from the group consisting of copper salts, cobalt salts, and strongly alkaline compounds.

Abstract: Vulcanized rubber is decomposed by treating 100 parts by weight of vulcanized rubber with a solution containing 1-30 parts by weight of a diacyl peroxide having decomposition temperature of 90.degree. C. or below and at least one member capable of swelling vulcanized rubber selected from the group consisting of solvents and radical-polymerizable monomers.

Abstract: Tire filling material having high resilience produced by curing a mixture of(a) a polyoxypropylene polyol having an OH equivalent molecular weight of 900-1,800 and a functionality of 2-4,(b) a polyisocyanate, and(c) a plasticizerin the presence of a catalyst where the equivalent ratio (NCO/OH) of isocyanate groups in component (b) to hydroxyl groups in component (a) is from 0.8-2.0 and the amount of component (c) is 10-200 parts by weight per 100 parts by weight of component (a).

Abstract: Scrap vulcanized rubber is reclaimed by mixing with a reclaiming agent selected from (a) 1,8-diazabicyclo-[5,4,0]-undecene-7, (DBU) (b) phenol salts of DBU, (c) carboxylic acid salts of DBU, (d) thiuramsulfide compounds, (e) aromatic disulfides, and (f) benzene sulfinic acid compounds or benzene sulfonyl hydrazides, provided that (e) aromatic disulfides are not used alone.Aliphatic or alicyclic amines may be used together with a compound selected from compounds (a)-(f) to enhance the reclaiming effect.

Abstract: A soft polyurethane elastomer containing isocyanurate ring prepared by reacting polyoxypropylene polyol having an OH equivalent molecular weight of about 500-3,000, and a functionality of about 2-5, and polyisocyanate compound in the presence of tertiary amine catalyst, and if desired further combined with organic tin catalyst. This process is advantageous in facilitation of material control during curing reaction, low exothermicity and high thermal stability of the resulting polymer. Further the properties of the polymer are improved by using ethyleneoxide addition polyoxypropylene polyol instead of the above polymer and a specific tertiary amine as a catalyst. The elastomer thus prepared is significantly suitable for tire filling material.

Abstract: A polyurethane composition having high tear strength has been produced by mixing homogeneously 20 to 50 parts by weight of finely divided acidic silica particles, 100 parts by weight of isocyanate-terminated prepolymer and appropriate parts of curative, and curing the mixture in a manner well known in the prior art, where the ratio (l/d) of average chain distance (l) between adjacent crosslinking points of the cured polyurethane chains to average size (d) of finely divided silica particles is in the range of from 2.5 to 20.

Abstract: Polydiene polyurethanes having high tear strength are obtained by using polydiene glycols, prepared with use of lithium-based catalyst, having a number average molecular weight of 1,000 to 5,000 and functionality of 1.8 - 2.1, diisocyanates and chain-extending agents, and by controlling chemical cross-link density being 4 .times. 10.sup.-5 mole/cc and less. When the chemical cross-link density is within the above range, elongation and tensile strength in addition to tear strength of the polyurethane are improved significantly. Furthermore, when 10 - 50 parts by weight of the specified carbon black are added to 100 parts by weight of the mixture of the prepolymer, the chain-extending agent and the additive prior to curing the prepolymer, these mechanical properties of the polyurethane are improved further.

Abstract: Polyether urethane elastomer composition having improved mechanical properties has been prepared by using polyfunctional isocyanate, curing agent and polyether having active hydrogen terminal groups, wherein the weight average molecular weight of said polyether is within the range of 1,000 to less than 4,500 and the molecular weight distribution curve of said polyether has at least two peaks, at least one of which is located in the higher molecular weight region and at least another one of which is located in the lower molecular weight region than the rheological critical molecular weight of said polyether and wherein the equivalent ratio (d) of active hydrogen of a curing agent to the isocyanate group of said polyfunctional isocyanate is in the range of 0.9<d<1.2.