Winter Tire Rubber Composition for Ice Grip and Low Rolling Resistance

The patent applies parameter changes by carefully controlling the glass transition temperatures of the rubber components. It uses a first polybutadiene rubber with Tg of -80°C to -105°C and a second polybutadiene rubber with Tg of -20°C to -40°C, along with polyisoprene and plasticizers having specific Tg ranges. This precise parameter control allows the rubber composition to maintain optimal elasticity and grip on ice while minimizing energy loss through reduced rolling resistance.

The patent employs composite materials by combining multiple rubber types in specific proportions: 35-60 phr first polybutadiene rubber, 5-30 phr second polybutadiene rubber, and 10-60 phr polyisoprene. This composite approach creates a synergistic effect where each component contributes different properties, achieving both superior ice grip and acceptable rolling resistance that cannot be obtained with single rubber types.

The patent uses parameter changes by selecting rubber components with complementary glass transition temperatures. The first polybutadiene rubber (Tg: -80°C to -105°C) provides low-temperature flexibility for ice grip, while the second polybutadiene rubber (Tg: -20°C to -40°C) and polyisoprene maintain elasticity across broader temperature ranges, ensuring acceptable performance on snow, wet, and dry surfaces.

The patent applies local quality by assigning different functional roles to different rubber components based on their properties. The low-Tg first polybutadiene rubber specifically targets ice contact performance, while the higher-Tg second polybutadiene rubber and polyisoprene provide general-purpose handling characteristics, creating a composition with spatially differentiated functional properties.