Friction materials containing tin oxides

Abstract

A friction material matrix, comprising: at least one tin oxide-containing material having a Mohs hardness level of about 6.5; and at least one binder system, the binder system physically or chemically binding the at least one tin oxide-containing material; wherein the friction material matrix is made without asbestos and the at least one tin oxide-containing material is present in an amount in the range of about 0.3 to about 20 weight percent, based on the total weight of the friction material matrix.

Description

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation of U.S. patent application Ser. No. 09 / 962,067, filed Sep. 25, 2001, now U.S. Pat. No. 7,179,850, issued Feb. 20, 2007 the contents of which are incorporated herein by reference thereto.FIELD OF THE INVENTION [0002] The present invention relates generally to friction materials, and more particularly to friction materials containing tin oxides. BACKGROUND OF THE INVENTION [0003] Friction materials serve in a variety of ways to control the deceleration of a variety of vehicles and machines such as, but not limited to automobiles. In an automotive vehicle, one of the purposes of the friction members is to physically stop the vehicle. These units, including disk brake pads and rotors and brake shoes and drums, convert physical movement into frictional heat. Every wheel contains either a disk or brake drum assembly. [0004] Friction members for brakes are typically made from materials that will produce frict...

AI Technical Summary

Benefits of technology

[0009] In accordance with a third embodiment of the present invention, an automotive braking element is provided, comprising: (1) at least one tin oxide-containing material; and (2) at least one binder system, the binder system physically or chemically binding the at least one tin oxide-containing material so as to form a friction material matrix; wherein the at least one tin oxide-containing material is present in an amount in the range of about 0.3 to about 20 weight percent, based on the total weight of the friction material matrix; wherein the at least one tin oxide-containing material improves the performance behavior of a friction couple at an interface between the friction material matrix and the automotive braking element.

Problems solved by technology

Because asbestos has been alleged to be the cause of certain health problems and is no longer environmentally acceptable, most modern brake pads and drum linings are made without asbestos.

However, the wear mechanisms governing the wear life of friction materials under low-duty conditions are significantly different from the factors governing heavy-duty conditions.

Unfortunately, conventional friction material compositions are somewhat unsatisfactory with respect to the performance behavior of the friction couple, especially during low-duty conditions.

This can lead to sub-par performance of the braking system, as well as objectionable noises when braking, both of which lead to consumer dissatisfaction.