| 摘要 |
PROBLEM TO BE SOLVED: To provide a resol type phenol resin composition for a wet friction material capable of providing a wet friction material high in porosity, excellent in oil penetrability to a fiber substrate and excellent in durability without reducing mechanical strength of the friction material.SOLUTION: There is provided a resol type phenol resin composition used for a wet friction material, having weight average molecular weight of 100 to 500 and constituted with containing a constitutional unit having no substituent with 2 to 10 carbon atoms on an aromatic ring having a phenolic hydroxyl group and a constitutional unit having a substituent with 2 to 10 carbon atoms on the aromatic ring having the phenolic hydroxyl group. There is provided a wet friction material by impregnating a fiber substrate with the resol type phenol resin composition.SELECTED DRAWING: None |
