Glass fiber friction facing

Claim 1

A disc-shaped friction facing having an inner diameter and an outer diameter, said facing comprising a tape impregnated with a heat-curable cement system and disposed in an undulating annular 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 rovings of substantially continuous glass filaments having been impregnated with a pre-coat composition and then impregnated with a heat-curable cement system, each impregnation having been accomplished by passing said rovings through aqueous dispersions of the respective pre-coat composition and cement system, said dispersions containing from about 0.25 to about 1.25 percent, by weight of solids, of a surfactant or dispersant, and the surfaces of said filaments prior to said impregnations having been treated with an anchoring agent capable of providing a strong bond between said filament surfaces and said pre-coat composition, said pre-coat compositions comprising from about 40 to about 50 percent of a vulcanizable carboxy nitrile rubber, from about 40 to about 50 percent of a watersoluble, low molecular weight, one-step phenol formaldehyde resin and from about 16 to about 20 percent furnace black having a particle size in the range of about 65 to about 85 mμ, said percentages being by weight based on the combined weight of said pre-coat constituents, and said cement system comprising from about 6 to about 12 percent of said vulcanizable rubber, from about 12 to about 16 percent of said phenol formaldehyde resin, and about 72 to 82 percent particulate friction modifiers, said percentages being by weight, based on the combined weight of said constituents forming said cement system.

Claim 11

The method of forming an annular friction facing for a clutch or the like comprising the steps of: (A) impregnating plurality of rovings formed of substantially continuous glass filaments with a pre-coat composition comprising about 40 to about 50 percent of a vulcanizable carboxy nitrile rubber, about 40 to about 50 percent of a water soluble, low molecular weight, one-step thermosetting phenol formaldehyde resin, and about 10 to about 20 percent of furnace black having a particle size in the range of about 65 to about 85 mμ, said percentages being by weight, based on the combined weight of said components, by passing said rovings through a low solids aqueous dispersion of said pre-coat composition containing from about 0.25 to about 1.25 percent, based on weight of pre-coat solids, of a surfactant or dispersant, the surfaces of said filaments of said rovings having been treated with an anchoring agent capable of providing a strong bond between said filaments and said pre-caot composition; (B) drying said pre-coat impregnated rovings to a moisture content in the range of about 2 to about 4 percent, by weight of said coated rovings; (C) further impregnating said pre-coat impregnated rovings with a heat-curable cement system comprising from about 6 to about 12 percent of a vulcanizable carboxy nitrile rubber, from about 12 to about 16 percent of a water-soluble, low molecular weight one-step, thermosetting phenol formaldehyde resin, and from about 72 to about 82 percent of particulate friction modifiers, said percentages being by weight, based on the combined weight of said components of said cement system, by passing said rovings through a high solids aqueous dispersion of said cement system containing from about 0.25 to about 1.25 percent, based on weight of cement system solids, of a surfactant or dispersant; (D) drying said rovings impregnated with said heat-curable cement system to a moisture content of about 2 to about 4 percent, by weight of said impregnated rovings; (E) combining a plurality of said impregnated rovings to form a tape; (F) winding said tape in undulating fashion to form a disc-shaped friction facing preform; and (G) subjecting said preform to heat and pressure to densify said preform and cure said cement.

Claim 12

The method of forming an annular friction facing for a clutch or the like comprising the steps of: (A) impregnating plurality of rovings formed of substantially continuous glass filaments with a pre-coat composition comprising about 40 to about 50 percent of a vulcanizable carboxy nitrile rubber, about 40 to about 50 percent of a water soluble, low molecular weight, one-step thermosetting phenol formaldehyde resin, and about 10 to about 20 percent of furnace black having a particle size in the range of about 65 to about 85 mμ, said percentages being by weight, based on the combined weight of said components, by passing said rovings through a low solids aqueous dispersion of said pre-coat composition containing from about 0.25 to about 1.25 percent, based on weight of pre-coat solids, of a surfactant or dispersant, the surfaces of said filaments of said rovings having been treated with an anchoring agent capable of providing a strong bond between said filaments and said pre-caot composition; (B) drying said pre-coat impregnated rovings to a moisture content in the range of about 2 to about 4 percent, by weight of said coated rovings; (C) further impregnating said pre-coat impregnated rovings with a heat-curable cement system comprising from about 6 to about 12 percent of a vulcanizable carboxy nitrile rubber, from about 12 to about 16 percent of a water-soluble, low molecular weight one-step, thermosetting phenol formaldehyde resin, and from about 72 to about 82 percent of particulate friction modifiers, said percentages being by weight, based on the combined weight of said components of said cement system, by passing said rovings through a high solids aqueous dispersion of said cement system containing from about 0.25 to about 1.25 percent, based on weight of cement system solids, of a surfactant or dispersant; (D) drying said rovings impregnated with said heat-curable cement system to a moisture content of about 2 to about 4 percent, by weight of said impregnated rovings; (E) combining a plurality of said impregnated rovings to form a tape; (F) winding said tape in undulating fashion to form a disc-shaped friction facing preform; and (G) subjecting said preform to heat and pressure to densify said preform and cure said cement.