Wet friction material
The purpose of the present invention is to provide a wet friction material which has a high coefficient of friction, has reduced overall thickness change, and excellent heat resistance (resistance to heat spots). In order to accomplish the purpose, the present invention provides a wet friction material prepared by impregnating a base material including a fibrous substance with a thermosetting resin, and then thermally curing it, wherein the aspect ratio of the fibrous substance is 10 or higher, and the fibrous substance is contained in the base material in an amount of 60 to 75 weight %.
1. A wet friction material prepared by impregnating a base material comprising a fibrous substance with a thermosetting resin, and then thermally curing same, wherein the aspect ratio of the fibrous substance is 10 or higher, and the fibrous substance is contained in the base material in an amount of 60 to 75 weight %, provided that the fibrous substance comprises at least 3 weight % of fibrous carbon selected from the group consisting of carbon nanotubes, carbon nanofibers, vapor-deposited carbon fibers, and mixtures thereof in the base material.
2. The wet friction material according to claim 1 , wherein the fibrous substance is selected from the group consisting of cellulose, metal fibers, ceramic fibers, aramid fibers, fibrous carbon, and a mixture thereof.
3. The wet friction material according to claim 2 , wherein the fibrous substance is fibrous carbon.