Abstract: A clutch assembly for a motor vehicle drivetrain includes a rigid support and a wet friction material fixed to a surface of the rigid support. The wet friction material includes a base material including a matrix of fibers and filler particles embedded in the matrix of fibers; a binder embedded in the base material; and a colloidal silica coating applied onto an outer surface of the base material.

Abstract: A clutch assembly for a motor vehicle drivetrain includes a rigid support and a wet friction material fixed to a surface of the rigid support. The wet friction material includes a base material including a matrix of fibers and filler particles embedded in the matrix of fibers; and a binder embedded in the base material. The base material includes, by weight percent, 30-55% cellulose fibers and 10-50% calcined kaolin clay. The base material also includes at least one of 1-20% graphite having a mean particle size of 35 to 85 microns, 20-40% diatomaceous earth in combination with the binder being tung modified phenolic resin, 5-20% chopped aramid fibers, or 5-20% of novoloid fibers.

Abstract: A wet friction material includes a base including a matrix of fibers and filler particles embedded in the matrix of fibers; a binder embedded in an interior of the base; and a quaternary ammonium salt containing coating on an outer surface of the base. The quaternary ammonium salt containing coating can include a quaternary ammonium salt and a solution binder.

Abstract: A clutch assembly for a motor vehicle drivetrain includes a rigid support and a wet friction material fixed to a surface of the rigid support. The wet friction material includes a base material including a matrix of fibers and filler particles embedded in the matrix of fibers. The filler particles include calcined kaolin clay, and the base material includes, by percent weight, 5 to 60% of calcined kaolin clay. The wet friction material also includes a binder embedded in the base material. The binder is tung modified phenolic resin.

Abstract: A wet friction material includes a base including a matrix of fibers and filler particles embedded in the matrix of fibers; a binder embedded in an interior of the base; and a quaternary ammonium salt containing coating on an outer surface of the base.

Abstract: A method of making a wet friction material includes joining filler particles and fibers together and forming a base; coating an outer surface of the base with a quaternary ammonium salt containing solution; and drying the quaternary ammonium salt containing solution to form a quaternary ammonium salt containing coating on the outer surface of the base.

Abstract: A method of making a wet friction material includes coating a first outer surface of a cellulose layer with a friction coating; placing a matrix of fibers and filler particles on a second outer surface of the cellulose layer; and saturating the matrix of fibers and filler particles with a binder and curing the binder to join the matrix of fibers and filler particles together to form a wet friction material base layer and to join wet friction material base layer to the second outer surface of the cellulose layer.

Abstract: A method of making a wet friction material includes joining filler particles and fibers together and forming a base; coating an outer surface of the base with a quaternary ammonium salt containing solution; and drying the quaternary ammonium salt containing solution to form a quaternary ammonium salt containing coating on the outer surface of the base.