Abstract: A process for selectively hydrogenating ethylenically unsaturated double bonds in polymers P involves reacting the polymers P with hydrogen in the presence of at least one hydrogenation catalyst selected from the salts and complex compounds of rhodium and/or of ruthenium in an aqueous dispersion of the polymers P that comprises not more than 20% by volume of an organic solvent. This process can be used to give hydrogenated polymer dispersions and, from these dispersions, polymers. Also claimed are aqueous polymer dispersions comprising polymers P′, which include structural units I, II and III as in claim 10, with or without structural units IV and/or V as in claim 11.

Abstract: Improved compositions of the present invention are made from a rubber latex component (A) and an oil carrier component (B) having hygroscopic and vulcanizing agents. Upon intermixing of the components A and B, an elastomeric composition is formed that can undergo a rheological transformation from a flowable liquid to a solidified elastomeric solid. An improved linear slope between fluidity and temperature is achieved by using naphthenic oil in the oil carrier component (B) with an organic rheology modifier, such as a modified castor oil and/or a polyamide. Further exemplary compositions comprise an inorganic rheology modifier such as an activated clay.

Abstract: Process oil which satisfies requirements that a content of a polycyclic aromatic compound is less than 3% by weight, a content of an aromatic hydrocarbon is 18% by weight or more, a content of a polar compound is between 11 and 25% by weight, a kinematic viscosity at 100° C. is between 10 and 70 mm2/s, and a flash point is 210° C. or more.

Abstract: A method of treating natural rubber latex to reduce the antigenic protein content includes enzyme treatment of the natural rubber latex and utilizing a chemical stabilizer of the type similar to branched dodecyl benzene sulphonic acid alone or in combination with other stabilizers such as a sulfated fatty acid in combination with hydroxypropyl methylcellulose is disclosed. Also disclosed is a treatment of natural rubber latex with antioxidants either alone or together which ether serve to allow natural rubber latex products to be chlorinated without suffering debilitating aging effects. The first antioxidant is of the type 4,4-(6-T-butyl-M-cresol) or 4,4+-Butylidenebis (3-methyl-6-tert-butylphenol) while the second antioxidant is of the type of a polymeric hindered phenol or butylated reaction product of P-cresol and dicyclopentadiene.

Abstract: Various modified particles are described which can be used in polymerizations to attach one or more polymers onto modified particles. Also described are the resulting modified particles having attached monomer or polymer groups as well as methods of preparing such modified particles. The polymer groups on the modified particles can be terminated and these various modified particles with attached groups can be used in a variety of end uses.

Abstract: Resilient elastomeric mounts and in particular, natural rubber engine mounts, which maintain good mechanical and dynamic properties at temperatures in excess of 250° F., are provided. The natural rubber engine mounts of the present invention are thus ideal for use in underhood applications which require durability at high temperatures, i.e. from about 250° F. to about 280° F. The mounts generally comprise rubber produced by an efficient vulcanization (EV) system, which employs a curing system having a sulfur accelerator and sulfur donor. In a preferred composition, the accelerator is a sulfonamide and thiazole present at a level of about 1.2 phr to about 1.8 phr, and the sulfur donor is tetramethyl thuiram disulfide present at a level of about 0.1 phr to about 0.4 phr.

Abstract: A puncture sealing agent for sealing an inner surface of a tire comprises a deproteinized rubber latex that is formed by removing protein from a natural rubber latex. The puncture sealing agent includes nitrogen content at 0.1 wt. % or less of rubber solid content of the deproteinized rubber latex, and ammonia content at 0.5 wt. % or less of the rubber solid content.

Abstract: This invention relates to a technique for making a high quality natural rubber composition having a dirt content of less than 0.03 percent and a constant Mooney viscosity of 60 by blending up to 60 weight percent cup-lump rubber with natural rubber made by coagulating natural rubber latex.

Abstract: A process is disclosed, by which protein can be removed easily and efficiently from natural rubber latex so that deproteinized natural rubber latex can be produced with high productivity and low cost. Particularly, a process for the production of deproteinized natural rubber latex is disclosed, which comprises treating natural rubber latex with a proteolytic enzyme and a surfactant to decompose protein in natural rubber latex, washing the treated natural rubber latex in the presence of a salt. According to the process, deproteinized natural rubber latex useful as a counter-allergy material having stable qualities can be produced easily with high productivity and low cost.

Abstract: Disclosed are a deproteinizing agent comprising a proteolytic enzyme and one or more cationic surfactants selected from the group consisting of an alkylamine salt, an alkylamine derivative and quaternized compounds thereof; and a method of preparing a cationic deproteinized natural rubber latex, which comprises adding said deproteinizing agent to a field latex or an ammonia-treated latex thereby subjecting the latex to a deproteinization treatment and purifying the rubber particles in the latex.

Abstract: A process for producing a vulcanizable rubber composition containing silica and carbon black, comprises the step of intimately mixing at a temperature of from 130° to 180° C. at least a first cross-linkable unsaturated chain polymer with a first carbon black-based reinforcing filler, so as to obtain a first rubber composition capable of allowing a subsequent effective dispersion of a second silica-based reinforcing filler and of a second cross-linkable unsaturated chain polymer. The rubber composition thus obtained shows a homogeneous dispersion of the reinforcing fillers, in particular of the silica-based reinforcing filler, constant physical-mechanical characteristics, and improved drawability, and is particularly suitable for the manufacture of tire treads with low rolling resistance.

Abstract: A rubber composition which is superior in ozone resistance and is hard to be discolored brown and white which comprises 0.5 to 2.5 parts by weight of a wax containing a component with 45 or more carbon atoms and having an average number of carbon atoms of 28 to 38 and 3.0 to 7.0 parts by weight of antioxidant containing 30 to 100% by weight of N-(1-methylheptyl)-N′-phenyl-p-phenylenediamine per 100 parts by weight of a diene rubber component.

Abstract: This invention relates to mixtures of organosilane-polysulphanes of the general formula (RO)3Si(CH2)xS—Sz—S(CH2)xSi(OR)3  (I) in which R means alkyl, linear or branched, having 1-8 C atoms, in particular 1-3 C atoms x means an integer from 1-8 z means 0 to 6, wherein sum of the proportions of polysulphanes in which z=0 and z=1 amounts to ≧80% by weight, providing that the proportion of compounds in which z=0 remains below 80% and the proportion of organosilanepolysulphanes in which z means an integer from 2 to 6 does not exceed a proportion of 20 wt. % in the mixtures, and to the rubber compounds produced using these mixtures, in particular for tire treads.

Abstract: The rubber composition of the present invention comprises a rubber component which is a blend rubber of a copolymer rubber and other diene based rubbers or the copolymer rubber alone, the copolymer rubber having a glass transition temperature of −60° C.