Abstract: A natural rubber latex has been preserved and stabilized by at least one water-soluble carboxylic acid salt of the formula R--COO.sup.- M.sup.+, in which R is an alkyl or alkenyl radical having a branched carbon chain and M.sup.+ is a monovalent cation. A process for the preparation of the rubber latex mixture uses a water-soluble carboxylic acid salt for the preservation and stabilization of natural latex.

Abstract: A lubricant and release agent for rubber is made from a polyester of a polyethylene glycol or a mixture of polyethylene glycols with an average of 3 to 20 ethylene oxide units per molecule and a linear dicarboxylic acid or a mixture of linear dicarboxylic acids with an average of 4 to 10 carbon atoms. The use of such a lubricant and release agent for reducing the surface friction and stickiness in the case of rubber is also described.

Abstract: A vulcanization activator based upon zinc salts of organic carboxylic acids for rubber compounds, which may be vulcanized with sulfur, is disclosed. The vulcanization activator includes homogeneous mixed zinc salts of the following acids:(a) at least one carboxylic acid of the general formula R--COOH, in which R is an alkyl group having 5 to 17 carbon atoms, or a cycloalkyl group having 5 to 17 carbon atoms; and(b) an aromatic carboxylic acid,in which the molar ratio of component (a) and component (b) of the homogeneous zinc-mixed salt is preferably in the range of 1:19 to 19:1.A process for the preparation of the vulcanization activator of the invention is also disclosed.

Abstract: A colored or carbon-black-loaded rubber adhesive mixture that has a natural and/or synthetic rubber base, and that is intended for direct bonding to glass or metallic articles. The adhesive mixture contains: filler comprising 20 to 100 parts by weight relative to 100 parts by weight rubber, activator, plasticizer, vulcanizing agent, an adhesive system having a resorcinol/hexamethylenetetramine base, and an inorganic base.

Abstract: A lubricant for a tire and wheel assembly to reduce friction between the inner wall of a tire and the rim or other parts of the vehicle wheel. The lubricant comprises 50 to 70% by weight of polyethylene glycol and/or polyglycol ether, 49 to 27% by weight aluminum bronze, and 1 to 3% by weight of a wetting agent.