Gas-Free Phenolic Resin for Friction Materials 2006-01-3186
Phenolic resins have been widely used as a binder for friction materials such as disk pads and brake linings. Requirements for disk pads are flexibility, heat resistance, low wear and so on.
To solve the above requirements, we have developed various modified resins. At the same time, reduction of manufacturing cost is also required to maintain price competitiveness.
The way to reduce manufacturing costs is to cut down the molding cycles and post-baking time, as well as use raw materials with a low price. To increase the molding temperature is one of the effective methods for reducing molding cycle, because the reactivity of phenolic resin increases. However, it is much more difficult to determine the gas release time because large amounts of gas evolve in a very short period of time. The phenol-hexamine curing system is limited in its ability to reduce the molding cycle.
In this study we developed a gas-free resin system. This curing reaction system does not create any gasses, such as ammonia: therefore, it is possible to increase the molding temperature.
As a result we succeeded in reducing the molding cycle of disk pads using a gas-free resin and found that the physical properties of the disk pad and its friction properties are equal to that of conventional system.
In addition, the amount of exhaust gases, such as ammonia, was drastically decreased during molding. This resin is also effective for improving the working environment.