GB801300A - Improved reinforced rubber articles - Google Patents

Abstract

A rubber article reinforced with cord is prepared by dipping relaxed cord in a dilute adhesive to wet it throughout, then partially drying it, immersing the partially dried cord in a second dip comprising the adhesive and an agent for preserving the adhesive bond, drying the cord to set the solids of the second dip on the cord surface, embedding the treated cord in rubber, and vulcanizing the assembly under heat and pressure. The cord may consist of cotton, rayon, nylon, or a linear polyester resin. The adhesive preferably comprises a phenolaldehyde resin in combination with synthetic or natural rubber latex, and may also contain casein, gelatin, wheat protein, dried blood, a wetting agent, another synthetic resin, carbon black, artificial dispersion of rubber, and/or a water-soluble adhesive. The agent for preserving the adhesive bond may comprise urea, thiourea, ethylene thiourea, an amine, e.g. disalicylal propylene diamine, a mixture of N,N1-aryl disubstituted p-phenylene diamines, N,N1 - diphenyl - p - phenylene diamine, 2-mercaptobenzimidazole, o,o1 - dihydroxy benzninilide, buiret, dithiobuiret, aniline-formaldehyde, reaction product, or the reaction product of acrylonitrile and tetraethylene pentamine, or of guiacol, morpholine, and formaldehyde, or a blend of these agents. In an example, rayon tyre cord is dipped into a diluted mixture of resorcinol, formaldehyde, sodium hydroxide, and butadiene styrene latex. The dipped cords are partially dried for 3 minutes at 72 DEG F. and then immersed in a second dip containing urea in addition to the ingredients of the first dip. The cord is then dried at 300 DEG F. for 5 minutes to set the adhesive and embedded in a vulcanizable composition of natural rubber, and the assembly is vulcanized.