摘要 |
<p>PROCESS FOR MAKING BELTED TIRES FREE OF UNDERTREAD CEMENTS A process is disclosed for economical mass production of radial and bias/belted tires which eliminates undertread cements and solves chronic factory tack problems by providing a synthetic rubber-based undertread compound containing predominant amounts of cis-polybutadiene and having unique tack retention properties. The building tack is optimized by use of a special mixture of a p-t-alkylphenol-formaldehyde tackifying resin, a trimethyl-dihydroquinoline polymer, and a N,N'-disubstituted-p-phenylenedi-amine. The process utilizes standard factory equipment with simple modifications and requires new formulations and special prodecures during mixing and processing to minimize the amount of zinc oleate, to convert virtually all of the fatty acids to zinc salts, principally stearates, and to minimize diffusion and migration of zinc stearate in a direction toward the undertread surface. High velocity jets of air are directed upwardly between adjacent shrink rolls, and water sprays are directed upwardly through openings in the conveyor belts as the dual-layer tread strip moves from the extruder to the cooling tank.</p> |