Friction material

Patent metadata

Field	Value
Publication number	US-12460691-B2
Application number	US-202217693933-A
Country	US
Kind code	B2
Filing date	Mar 14, 2022
Priority date	Aug 7, 2012
Publication date	Nov 4, 2025
Grant date	Nov 4, 2025

Abstract

An asbestos-free organic friction material, in particular for producing brake pads and shoes for vehicles made up of a composition or mixture having a fibrous base, a filler, an organic binder and optional metal oxides. The composition is completely free of copper and copper compounds or alloys and includes in the fibrous base, together with inorganic and/or organic fibers, from 1% to 10% by volume, calculated relative to the total volume of the composition, of stainless steel fibers. The friction material further includes between 1% and 25% by volume of a system of fibrous oxides consisting of potassium hexatitanate and zirconia.

First claim

The invention claimed is:

1 . A non-asbestos organic (NAO) friction material comprising:
a fibrous base comprising: inorganic fibers; organic fibers; and between 1 and 10% by volume of stainless steel fibers, based on the total volume of the non-asbestos organic friction material; a filler selected from the group consisting of: calcium silicate, rock wool, calcium carbonate, barium sulfate, calcium hydroxide, calcium fluoride, slaked lime, talc, mica, and vermiculite and combinations thereof; optional metal oxides, wherein the only optional metal oxides in the non-asbestos organic friction material are selected from the group consisting of magnesium oxide, molybdenum trioxide, iron oxide and combinations thereof; an organic binder, and between 1 and 25% by volume of a system of fibrous oxides consisting of: i) potassium hexatitanate, and ii) zirconia, wherein a ratio between the percentage content by volume of the zirconia and potassium hexatitanate in the system of fibrous oxides is between 1:1.3 and 1:2, and wherein a ratio between the percentage content by volume of stainless steel fibers to the sum total of the zirconia and potassium hexatitanate in the system of fibrous oxides is between 1:7 and 1:8, wherein the stainless steel fibers in the fibrous base have a total fiber length between 0.5 and 1.5 mm and a fiber diameter of between 40 and 150 microns and wherein the non-asbestos organic friction material is free from copper, copper compounds or copper alloys.

2 . The non-asbestos organic friction material according to claim 1 , further comprising from 0% to 10% by volume of solid lubricants, based on the total volume of the non-asbestos organic friction material.

3 . The non-asbestos organic friction material according to claim 1 , further comprising between 2% and 15% by volume of the total composition of the non-asbestos organic friction material of at least one of graphite or coke.

4 . The non-asbestos organic friction material according to claim 1 , wherein the fibrous base has a total fiber length between 0.5 and 1.5 mm and a fiber diameter of between 40 and 150 microns.

5 . The non-asbestos organic friction material according to claim 1 , comprising a composition based on the total volume of the non-asbestos organic friction material, as follows:
1-10% by volume organic fibers; 1-20% by volume inorganic fibers; 5-30% by volume resin; 1-15% by volume carbon materials; 0-10% by volume other metals; 0-15% by volume inorganic sulfurs; 0-30% by volume inorganic salts; 1-30% by volume inorganic oxides; 1-20% by volume silicates; 1-25% by volume titanates; and 1-10% by volume stainless steel.

6 . The non-asbestos organic friction material according to claim 1 , wherein the binder is a phenolic resin and from 2 to 30% by volume relative to the total volume of the non-asbestos organic friction material.

7 . The non-asbestos organic friction material according to claim 1 , further comprising zinc fibers in a total quantity of between 1 and 10% by volume.

8 . The non-asbestos organic friction material according to claim 7 , wherein the zinc fibers have a total length of between 0.2 and 1.5 mm and a total diameter of between 50 and 250 microns.

9 . The non-asbestos organic friction material according to claim 1 , wherein the filler comprises between 2-40% by volume based on the total composition of the non-asbestos organic friction material.

10 . The non-asbestos organic friction material according to claim 1 , wherein the friction material is used for producing brake pads or brake shoes for vehicles or for other equipment including clutch disks.

Assignees

• Itt Italia Srl

Inventors

• Trombotto Flavio

Classifications

• F16D2200/0065

  Inorganic, e.g. non-asbestos mineral fibres · CPC title

• F16D2200/0073

  having lubricating properties · CPC title

• F16D2200/0069

  being characterised by their size · CPC title

• F16D2200/006

  containing fibres or particles · CPC title

• F16D69/026 Primary

  containing fibres · CPC title