Rhein Chemie Rheinau Gmbh

Teroson Gmbh

Herbert Wagner

Wolfgang Fischer

Karl-Heinrich Schuhmacher

Winfried R Kohler

Aqueous external release agent for pneumatic tires which contains a fatty alcohol polyglycol ether and conductive carbon black, for establishing the electrical resistance of the tire.

Prevention of electrostatic charging of pneumatic tires

An external release agent is disclosed which contains:

External release agent

An aqueous outside release agent for the production of tires and other rubber articles is described, which contains 5 to 35% by wt. diatomaceous earth, 0.5 to 6% by wt. pyrogenic hydrophobic silica, 0.1 to 2% by wt. nonionic surfactant, 0.2 to 3% by wt. of a binder, 0.1 to 3% by wt. dye, 0 to 5% by wt. ethyl alcohol and the remainder water. Preferred binders are styrene-maleic acid or styrene-maleic anhydride copolymers and in particular ammonium salts thereof. Said outside release agent is used in processes for molding and vulcanizing tires and other rubber articles, it being sprayed onto the blank with the aid of air-atomizing guns before molding and vulcanization are carried out. A very good release effect is thereby achieved without vulcanization being impaired. As only very small quantities of outside release agent are needed, cleaning of the press mold and hence interruption of the production process are required very much less frequently than when conventional outside release agents are used.

Aqueous outside release agent comprising diatomaceous earth and

An environment-friendly aqueous slip and mold-release agent for the manufacture of tires and other rubber articles and a process for the molding and vulcanization of tires and other rubber articles are described. The aqueous slip and mold-release agent contains 0.5 to 6 wt. % polytetrafluoroethylene, 20 to 40 wt. % mineral fillers and at least 40 wt. % water. It is sprayed onto the inside of the tire blank prior to the molding and vulcanization, so that the water contained therein evaporates, accompanied by development of a slip and release agent film. Apart from the environment-friendliness and good release effect, the new slip and mold-release agent leads, despite the high water content, to a quick evaporation of the water and thus a rapid development, desired in industrial operations, of the slip and release agent film. The excellent effectiveness of the slip and mold-release agent according to the invention results in a substantial prolongation of the life of the heating membrane used for the molding and vulcanization.

Aqueous slip and mold-release agent and process for the molding and

Process for molding and vulcanizing tires and other rubber articles, in which in a press with the aid of a bladder negative shapes are pressed into the tire blank under high pressure and vulcanization is performed, the surface of the bladder having applied thereon a solvent which swells the surface, the swollen bladder being provided with a cross-linked, hardened, tightly adhering, elastic release agent film bonded to the bladder by chemical interactions before carrying out molding and vulcanization to prevent sticking of the molded and vulcanized tire to the bladder, the film comprising more than one thin coating each of which is produced by coating the bladder with an organic solvent solution comprising a mixture of a silicon release agent and a moisture or heat curable silicone rubber and curing the coated mixture through exposure to moisture or heat, and conducting at least 300 molding and vulcanizing cycles without recoating the bladder with the release agent film.

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Bad Schonborn, Germany

Herbert Wagner