Reinforcing resins see wide application in rubber formulating, especially in automobile tires. They improve surface hardness, increase static and lower strain dynamic modulus.
Traditional commercially available reinforcing resins are based on phenol-formalde-hyde novolacs, some being modified with cashew or tall oils. This study explores the structure-property relationship of resins where, in contrast to the above mentioned resins, the plasticizing alkylphenol moiety is embedded inside the P/F framework.
Our recent efforts to develop advancements and a new generation of reinforcing resins resulted in an unmodified reinforcing resin based on copolymerized alkylphenol and phenol. These resins are still in the research and development stage, but are made in pilot quantities. During rubber mixing, these unique resins actually reduce the mixing viscosity and power draw, while providing good disper- sion of carbon black fillers. This comes with equivalent or better properties in the final cured rubber article.