Abstract: Rubber mixtures which can be easily processed and have good mechanical properties and are based on synthetic and/or natural grades of rubber, the usual additives also being used, contain a copolymer with a melt viscosity of not more than 150 Pa.s., measured at 180.degree. C., of(a) 20 to 100% by weight of at least one alkyl ester of .alpha.,.beta.-ethylenically unsaturated mono- and/or di-carboxylic acids which contains 1 to 12 carbon atoms in the alcohol radical,(b) 0 to 20% by weight of at least one amide of .alpha.,.beta.-ethylenically unsaturated mono- and/or di-carboxylic acids,(c) 0 to 15% by weight of at least one .alpha.,.beta.-ethylenically unsaturated mono- and/or di-carboxylic acid and(d) 0 to 50% by weight of at least one other .alpha.,.beta.-ethylenically unsaturated copolymerizable monomeric compound, the sum of the percentages in each case being 100. Rubber articles and motor vehicle tires with very good mechanical properties can be produced from these rubber mixtures.

Abstract: Rubber vulcanisates based on mixtures which contain at least 55% of active fillers and at least 10% of plasticizing oils, having Shore A hardnesses of below 65.degree. in which the active filler contains inorganic active fillers and 10 to 60% of phenolic resin systems consisting of novolaks and hardeners therefor, all these percentages being based on the weight of the rubber, the weight ratio of active inorganic fillers to the phenolic resin systems being from (9:1) to (1:9); the invention further relates to a process for producing such vulcanisates and rubber articles and tires produced from said vulcanisates.

Abstract: In a process for the preparation of reinforced vulcanisates by vulcanisation of compositions comprising natural rubber or synthetic diene rubber with novolak resins in the presence of from 0.5 to 120% by weight, based on the novolak resin, of a hardener of a reactive melamine resin obtained by reacting melamine with 0.5 to 6 mol of an aldehyde the improvement comprises that, instead of or together with the reactive melamine resins other aminoplast forming compounds containing hydroxy groups are used and the total amount of the aminoplast-forming compounds is also from 0.5 to 120% by weight, referred to novolak resin, a rubber article and vehicle tire prepared according to this process.

Abstract: A process for the preparation of reinforced vulcanizates which process comprises vulcanizing a mixture comprising rubber, a novolak and at least one reactive melamine resin obtained by reaction of one mol of melamine with 0.5 to 6 mols of aldehyde, said melamine resin being present in an amount of from 0.5 to 120% by weight, based on the weight of the novolak resin, and the phenolic component of said novolak resin being selected from the group consisting of phenol, polynuclear polyphenols, alkylphenols, a combination of alkylphenols with phenol, and a combination of at least one of said phenols with a further phenol selected from the group consisting of resorcinol, phenylphenol and polyalkylphenols. The invention also includes rubber articles prepared from a product of such a process.

Abstract: A rubber composition having an improved adhesion to steel cord comprising(a) a rubber vulcanizable with sulfur,(b) at least one reinforcing filler containing between 10 and 50% by weight of active silicic acid,(c) a vulcanization agent selected from the group consisting of sulfur and a sulfur donor,(d) at least one phenol resin derived from at least one mono- or polyhydric phenol and aldehyde, wherein at most 30% of the phenol component consists of a mono-nuclear polyhydric phenol,(e) a compound of a metal being capable of having various valencies and(f) a methylene donor and a rubber article prepared from said composition.