Abstract
THE early development of the rubber industry was handicapped by two serious defects in rubber articles. They were not stable to temperature changes, and they deteriorated rapidly with age. Although the process of vulcanization corrected the first difficulty, rapid deterioration with age was common until the discovery of certain organic accelerators, such as p-aminodimethylaniline, the aldehydeamines, and mercaptobenzothiazole. Prior to these discoveries a number of materials had been patented for the purpose of improving the age-resisting properties of rubber, but many of them were of little merit and most of the others possessed some accelerating value, a fact which was not appreciated at the time. Typical of the more useful early patents for age-resisting materials are American patents by Murphy in 1870 (15), Moore in 1901 (14), and Martin in 1922 (12), and the German and English patents of the Ostwalds in 1908 and 1910 (19, 20). Murphy patented phenol, cresol, and cresylic acid, either added to the uncured stock or as dipping solutions for vulcanized articles for the purpose of improving their resistance to aging. Moore used reducing agents, including hydroquinone, pyrogallol, and p-aminophenol hydrochloride, to preserve the adhesive properties of rubber cements. Martin suggested aniline and other organic bases as a surface treatment for vulcanized articles. The Ostwalds also recognized the beneficial effects of aniline on rubber and stated that it could be added at any convenient stage of manufacture. (It is interesting to note that these inventors considered that addition of aniline to uncured stock or dipping the cured article in aniline were equivalent, and they, therefore, evidently did not recognize the accelerating effect of aniline.)
Investigations of Adhesive Properties of Polyamide Modified with Friction Reducing Agents
