# US 5,707,905 A · Fibrous base material for a friction lining material comprising less fibrillated aramid fibers and synthetic graphite > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,707,905 A - Document ID: US5707905A - Status: Granted - Kind: A - Application number: 08/789,063 - Filed: 1997-01-28 - Granted: 1998-01-13 - Earliest claimed: 1993-08-04 - Assignees: Borg-Warner Automotive, Inc. - Inventors: Robert C. Lam; Marc A. Yesnik - Web page: https://patentgrep.com/patent/US5707905A ## CPC - B05D 3/02: by baking {(B05D3/04 takes precedence)} - B32B 5/16: characterised by features of a layer formed of particles, e.g. chips, powder {or granules (layer formed of natural mineral particles B32B19/00; layer being formed of wood fibres, chips or particles B32B21/02)} - C08L 61/06: of aldehydes with phenols - F16D 69/026: {containing fibres} - F16D 2200/0082: Production methods therefor - Y10T 442/2344: Coating or impregnation is anti-slip or friction-increasing other than specified as an abrasive - Y10T 442/699: Including particulate material other than strand or fiber material - B05D: PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL (conveying articles or workpieces through baths of liquid B65G, e.g. B65G49/02) - B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) - F16D: COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract The present invention relates to a fibrous base material comprising less fibrillated aramid fibers, synthetic graphite and at least one filler material, and a non-asbestos friction material produced therefrom. In certain embodiments, the fibrous base material is impregnated with a phenolic or phenolic-base resin material, including, for example, a mixture of a phenolic resin and a silicone resin. ## Claims ### Claim 1 A fibrous base material for use in a non-asbestos friction material comprising a plurality of less fibrillated aramid fibers having a freeness of at least about 530 on the Canadian Standard Freeness (CSF) index; synthetic graphite; and, at least one filler material. ### Claim 2 (depends on 1) The fibrous base material of claim 1, wherein the less fibrillated aramid fiber and synthetic graphite are present in amounts sufficient to provide high heat resistance and substantially uniform coefficient of friction to the friction material. ### Claim 3 (depends on 1) The fibrous base material of claim 1, wherein the less fibrillated aramid fibers have a freeness about 580-640 on the Canadian Standard Freeness index. ### Claim 4 (depends on 1) The fibrous base material of claim 1, wherein the synthetic graphite is made by graphitization at temperatures of about 2800.degree.-3,000.degree. C. and has a size ranging from about 20 to about 50 microns in diameter. ### Claim 5 (depends on 1) The fibrous base material of claim 1, wherein the less fibrillated aramid fibers have average fiber lengths in the range of 0.5 mm to 6 mm. ### Claim 6 (depends on 1) The fibrous base material of claim 1, wherein the filler comprises diatomaceous earth. ### Claim 7 (depends on 1) The fibrous base material of claim 1, wherein the fibrous base material defines pores ranging in mean average size from about 2.0 to about 15 microns in diameter. ### Claim 8 (depends on 1) The friction member of claim 1, wherein the friction material has readily available air voids of at least about 50%. ### Claim 9 (depends on 1) The fibrous base material of claim 1 comprising about 10 to about 50%, by weight, less fibrillated aramid fiber; about 10 to about 35, by weight, synthetic graphite; and about 20 to about 45%, by weight, filler material. ### Claim 10 (depends on 1) The fibrous base material of claim 1 comprising in percent, by weight, about 20 to about 30% less fibrilated aramid fibers, about 10 to about 35% synthetic graphite, about 20 to about 30% filler, and about 0 to about 40% cotton fibers. ### Claim 11 (depends on 10) The friction material of claim 10, wherein the fibrous base material comprises about 20% to about 40% cotton fibers. ### Claim 12 (depends on 1) A non-asbestos friction material comprising the fibrous base material of claim 1 impregnated with a phenolic resin or a modified phenolic resin. ### Claim 13 (depends on 12) The friction material of claim 12, wherein the friction material comprises approximately 40 to about 60% resin, by weight. ### Claim 14 (depends on 1) A non-asbestos friction material comprising the fibrous base material of claim 1 impregnated with a mixture of a phenolic resin and a silicone resin wherein the amount of silicone resin in the mixture ranges from approximately 5 to approximately 80%, by weight, based on the weight of the mixture, the friction material exhibiting high heat resistance and substantially uniform coefficient of friction. ### Claim 15 (depends on 14) The friction material of claim 14, wherein the phenolic resin is present in a solvent material and the silicone resin is present in a solvent material which is compatible with the solvent material of the phenolic resin. ### Claim 16 (depends on 14) The friction material of claim 14, wherein the amount of silicone resin present in the silicone-phenolic resin mixture ranges from about 20 to about 25%, by weight, based on the weight of the mixture. ### Claim 17 (depends on 14) The friction material of claim 14, wherein the amount of silicone resin present in the silicone phenolic resin mixture ranges from about 15 to about 25%, by weight, based on the weight of the mixture. ### Claim 18 (depends on 12) The friction material of claim 12, wherein the modified phenolic resin comprises an epoxy phenolic resin. ### Claim 19 (depends on 18) The friction material of claim 18, wherein the amount of epoxy resin present in the epoxy phenolic resin ranges from about 5 to about 25%, by weight, based on the weight of the epoxy phenolic resin. ### Claim 20 (depends on 18) The friction material of claim 18, wherein the amount of epoxy resin present in the epoxy phenolic resin ranges from about 10 to about 15%, by weight, based on the weight of the epoxy phenolic resin. ### Claim 21 A process for producing a non-asbestos friction material comprising mixing less fibrillated aramid fibers having a freeness of at least about 530 on the Canadian Standard Freeness (CSF) index with synthetic graphite and at least one filler to form a fibrous base material, impregnating the fibrous base material with a phenolic resin or modified phenolic resin, and thereafter curing the impregnated fibrous base material at a predetermined temperature for a predetermined period of time. ### Claim 22 (depends on 1) A process for producing a non-asbestos friction material comprising mixing a phenolic resin with a silicone resin, impregnating the fibrous base material of claim 1 with the silicone-phenolic resin mixture, and thereafter heating the impregnated fibrous base material to cure the phenolic resin and the silicone resin.