Phenolic resins for wet friction materials, phenolic resin compositions and wet friction materials

摘要

PROBLEM TO BE SOLVED: To provide a phenol resin for a wet friction material having excellent durability and a wet friction material using the same. SOLUTION: The phenol resin for a wet friction material of the present invention is derived from a structural unit A derived from a phenol compound having one phenolic hydroxyl group and a polyfunctional phenol compound having two phenolic hydroxyl groups in the molecular structure. It contains a resole-type phenolic resin having the structural unit B of. [Selection diagram] None