Friction members formed from compositions containing aramid fibers and an aqueous heat-hardenable cement comprising a water soluble phenolic resin and a heat-curable elastomer
AssigneeRaybestos-Manhattan, Inc.
InventorStanley F. Covaleski
Life of this patent
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Abstract
A friction member of improved resistance to wear comprising aramid fibers impregnated with and bonded together by means of a heat-curable cement containing a vulcanizable, rubber which may be carboxylated, a water-soluble, one-step phenolic-type resin and friction modifiers.
Claims34
A disc-shaped clutch facing having an inner diameter and an outer diameter, said facing comprising a tape impregnated with an aqueous base heat-hardenable cement and disposed in spiral or undulating fashion and having been subjected to heat and pressure to compress said tape to form a disc-shaped facing and to cure said cement, said tape comprising a plurality of strands of aramid fibers having a decomposition temperature of at least about 850.degree. F. coated with a heat-hardenable cement comprising a water-soluble, one-step thermosetting phenolic resin, a heat-curable elastomer selected from the group consisting of carboxylated neoprene rubber, carboxy nitrile rubber and carboxy butadiene styrene rubber, and particulate friction modifier, said friction facing comprising from about 40 to about 95 percent of heat-hardenable cement, said percentages being by weight based on the total weight of fibers and cement solids in said facings.
A friction member of improved resistance to wear comprising from about 5 to about 60 percent of aramid fibers having a decomposition temperature of at least about 850.degree. F. bonded together with from about 40 to about 95 percent of heat-hardenable cement comprising a water-soluble, one-step thermosetting phenolic resin, and a heat-curable elastomer selected from the group consisting of carboxylated neoprene rubber, carboxy nitrile rubber and carboxy butadiene styrene rubber, and particulate friction modifier, said percentages being by weight based on the combined weight of fibers and cement, said cement having been applied to said fibers in the form of an aqueous suspension and said member having been subjected to heat and pressure to consolidate said fibers and to cure said cement.
A composition for use in forming a friction member of improved resistance to wear comprising a mixture of from about 5 to about 60 percent of aramid fibers having a decomposition temperature of at least about 850.degree. F. coated with from about 40 to about 95 percent of an aqueous base heat-hardenable cement comprising a water soluble, one-step thermosetting phenolic resin, and a heat-curable elastomer selected from the group consisting of carboxylated neoprene rubber, carboxy nitrile rubber and carboxy butadiene styrene rubber, and particulate friction modifiers, said percentages being by weight based on the combined weight of fibers and cement solids.
The method of forming an annular facing for a clutch or the like comprising the steps of:
- (A) impregnating a plurality of yarns comprising aramid filaments having a decomposition temperature above about 850.degree. F. with a heat-curable system comprising from about 5 to about 40 percent of a vulcanizable rubber selected from the group consisting of carboxylated neoprene rubber, carboxy nitrile rubber and carboxy butadiene styrene rubber, from about 5 to about 40 percent of a water-soluble, low molecular weight one-step, thermosetting phenolic resin, and from about 20 to about 80 percent of particulate friction modifier, said percentages being by weight, based on the combined weight of said components of said cement system, by passing said yarns through a high solids aqueous dispersion of said cement system containing from about 0.01 to about 5 percent, based on weight of cement system solids, of a surfactant or dispersant,
- (B) drying said yarns impregnated with said heat-curable cement system,
- (C) winding said yarns in spiral or undulating fashion to form a disc-shaped clutch facing preform, and
- (D) subjecting said preform to heat and pressure to densify said preform and cure said cement.
Dependencies are inferred from the claim text.