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Efficiency Cure Accelerator/Mercapto-Type Silane Combination: Improved Rolling Resistance without Wet Traction Loss through Competitive Inhibition
W. Michael York and Russell Cody
Momentive Performance Materials
Abstract
European legislation requires that a label containing the rolling resistance, wet grip, and noise ratings be attached to a passenger car or light truck tire at the point of sale. The new labels spotlight the importance of improving rolling resistance without losing wet traction, which is no easy feat. Mercapto-type silanes can produce improved hysteresis and reinforcement in passenger car tire tread compounds. However, significantly reduced scorch safety and processability tend to deter their usage. This research was concerned with substantially improving rolling resistance in a passenger car tread compound using a virtually ethanol-free mercapto-type silane. The principle of competitive inhibition was utilized to design a cure package that works well with a mercaptan that has a unique molecular structure that maintains good scorch safety, decreases Mooney viscosity, reduces hysteresis, and improves reinforcement. These performance attributes are achieved simultaneously with dynamic properties representative of equivalent or improved wet traction.