Abstract

The skid resistance of tires can be improved with tread compounds which have high hysteresis losses. Chlorobutyl rubber is a chlorinated isobutylene‐isoprene copolymer of interest in tread compounds because of its high damping (low resilience) characteristics. The traction of tread stocks containing blends of Chlorobutyl and SBR has been evaluated in laboratory and tire tests. In the laboratory, traction performance is estimated using the Portable Skid Resistance Tester as well as the classical rebound tests. Typical results are summarized. The influence of compounding parameters, namely, composition of the polymer blend and carbon black loading, on the skid properties of the tread compound is also discussed. Tire traction performance is determined with an automated vehicle designed to measure both peak and sliding skid resistance. Overall, significant improvements in traction performance have been found for radial tires with Chlorobutyl‐containing tire treads; the level of improvement is directly proportional to the Chlorobutyl content of the polymer blend. Some loss in treadwear appears unavoidable, however.