Under-layer for a brake pad of a brake disc rotor
View Patent ↗Technologies are generally described for a composition for an under-layer of a brake pad of a brake disc rotor. The composition may include a fiber pack, a powdered rubber, at least one binder, and at least one filler, wherein the fiber pack includes aramid fibers up to about 3 wt %.
1 . A composition for an under-layer of a brake pad, the composition comprising:
a fiber pack comprising acrylic fibers in an amount of about 1 wt % to about 4 wt %, aramid fibers in an amount of about 0.5 wt % to less than 1 wt %, and inorganic mineral fibers in an amount of about 1 wt % to less than 3 wt %;
a powdered rubber;
at least one binder; and
at least one filler, wherein the fiber pack, the powdered rubber, the at least one filler and the at least one binder are dry-mixed.
2 . The composition of claim 1 , wherein the acrylic fibers comprise acrylic poly acrylonitrile pulp (PAN), the aramid fibers comprise poly(p-phenylene terephthalamide) fibers (PPTA), and the inorganic mineral fibers comprise natural stonewool fibers.
3 . The composition of claim 1 , wherein the powdered rubber comprises from about 5 wt % to about 25 wt % of the composition, is compounded with an inorganic filler, and includes one or more of nitrile rubber (NBR), ethylene propylene rubber (EPM), ethylene propylene diene monomer rubber (EPDM), and styrene-butadiene rubber (SBR).
4 . The composition of claim 1 , wherein the powdered rubber has an average diameter in a range from about 0.3 mm to about 0.7 mm.
5 . The composition of claim 1 , wherein the at least one binder comprises a mixture of phenol-formaldehyde resins (PF Novolak) and Hexmethylene Tetramine (HMT).
6 . The composition of claim 1 , wherein the at least one filler comprises barium sulfate.
7 . The composition of claim 1 , further comprising an organic pigment phthalocyanine.
8 . The composition of claim 1 , further comprising steel fibers with an aspect ratio from about 20 to about 100.
9 . The composition of claim 1 , wherein when formed into the under-layer for the brake pad, the composition has a shear strength in a range of about 35 kN to about 60 kN after being exposed at a temperature of about 300° C. for 1 h.
10 . The composition of claim 1 , wherein when formed into the under-layer for the brake pad, the composition has a specific shear strength in a range of about 300 N/cm 2 to about 600 N/cm 2 at about room temperature.
11 . The composition of claim 1 , wherein when formed into the under-layer for the brake pad, the composition has a compressibility in a range of about 0.08 mm to about 0.12 mm at about room temperature with a pressure of 100 bar.
12 . The composition of claim 1 , wherein when formed into the under-layer for the brake pad, the composition has a compressibility in a range of about 0.13 mm to about 0.15 mm at a temperature of about 400° C. with a pressure of 100 bar.