A wet running friction lining includes a plastic matrix, which contains at least one filler. The wet running friction lining contains bentonite as a filler.

A friction paper including filler, para-aramid pulp, and resin, characterised in that the para-aramid pulp includes 0.1 to 10 wt. % of polyvinyl pyrrolidone (PVP), the paper having a grammage in the range of 100 to 800 g/m2. It has been found that the use of a PVP-containing para-aramid pulp leads to improved friction performance as compared to the use of para-aramid pulp not containing PVP. Effects obtained include improved friction properties, improved strength properties, and improved filler retention.

A paper comprises from 60 to 99 weight percent of a aramid fibrous pulp and from 1 to 40 weight percent of a polyvinylpyrrolidone coating on the fiber surface, the coating being neither chemically nor electrostatically bound to the fibers. A friction paper composite comprising the paper and a resin coating is also described.

A phenol resin for a wet friction material of the invention contains a resol-type phenol resin having, in one molecule, a structural unit A which is derived from a phenol compound having one phenolic hydroxyl group and a structural unit B which is derived from a polyfunctional phenol compound having two phenolic hydroxyl groups.

The wet friction member 1 of the invention includes a core plate 2 formed in a flat ring shape, a friction part 3 arranged in a ring shape. The friction part 3 has segment pieces including rectangular shaped G.sub.1 to G.sub.4: G.sub.1 in which a lower right corner of rectangular piece is notched; G.sub.2 in which an upper left corner of rectangular piece is notched; G.sub.3 in which an upper right corner of rectangular piece is notched; G.sub.4 in which a lower left corner of rectangular piece is notched. The friction part 3 has arrangements T.sub.1 and T.sub.2: T.sub.1 in which G.sub.1 and G.sub.2 are arranged in a manner a right side of G.sub.1 and a left side of G.sub.2 face each other; T.sub.2 in which G.sub.3 and G.sub.4 are arranged in a manner a right side of the G.sub.3 and a left side of G.sub.4 face each other.

This invention relates to a paper friction material and a method of manufacturing the same, wherein the paper friction material is configured such that dispersibility and bondability are increased between a filler and a matrix. The paper friction material which is suitable for use in a vehicle, includes a friction base including pulp and a coating layer formed on the friction base using a mixture of latex and a functional material. The OH reactive group of the pulp and the aromatic ring of the latex are hydrogen-bonded so that the friction base and the coating layer are coupled with each other.

A number of variations may include a product including a single clutch pack having a plurality of clutch plates, and a first friction material on a first plate of the plurality of clutch plates, and a second friction material on a second plate of the plurality of plates, the first friction material being different than the second friction material, and constructed and arranged to provide a tailored combination of torque capacity and response time that would be produced by a clutch pack having solely the first friction material on plates thereof or the second friction material on plates thereof.

A friction material presents a friction generating surface and a bonding surface facing opposite said friction generating surface. The friction material includes structural fibers, friction particles, polyvinyl alcohol fibers, and a resin. A method of forming the friction material is also disclosed. The method comprises the steps of: combining the structural fibers, the friction particles, and the polyvinyl alcohol fibers having an average diameter of less than about 11 m, an average length of less than about 4 mm, an average denier of less than about 1, to form a substrate material; impregnating the substrate material with the resin; and curing the resin to form the friction material.

A present wet friction body includes a core plate, a plurality of friction parts disposed on a main surface thereof in a ring shape at intervals, a plurality of oil grooves defined by the corresponding friction parts. The friction parts include first to third friction parts in which forms of the pair of sidewalls are different each other. The first friction part includes a left sidewall inclining to the right and a right sidewall inclining to the left, with respect to an imaginary line segment, and an outer peripheral wall having a length less than a length of an inner peripheral wall. The second friction part includes a pair of sidewalls, both inclining to the right with respect to an imaginary line segment. The third friction part includes a pair of sidewalls, both inclining to the left with respect to an imaginary line segment.

A friction paper including filler, para-aramid pulp, and resin, characterised in that the para-aramid pulp includes 0.1 to 10 wt. % of polyvinyl pyrrolidone (PVP), the paper having a grammage in the range of 100 to 800 g/m2. It has been found that the use of a PVP-containing para-aramid pulp leads to improved friction performance as compared to the use of para-aramid pulp not containing PVP. Effects obtained include improved friction properties, improved strength properties, and improved filler retention.