Controlled Friction Additives for Brake Pads and Clutches

The elimination of asbestos in brake and clutch compositions, as well as the use of smaller brake pads for down-sized and compact cars, has produced new requirements for friction lining materials. The emerging semi-metallic compositions generally need some friction modifiers to reduce squeal and wear and to produce friction characteristics that are less dependent on temperature.

In Europe MoS₂ has been utilized as a friction modifier for harder brake pad compositions for many years, but provided only limited improvements. Research on solid friction control additives at Dow Corning has produced new technology by which friction and wear properties can be tailored to specific requirements of the friction lining industry. This material has been evaluated in a number of brake and clutch compositions at a level of from one to six weight percent. The additive was found to provide one or more of the requirements of new brake design, such as reduced noise level, less disc wear and less change of friction with temp.