Powdered Fast Curing Novolac Phenolic Resin for Brake Linings
Novolak Phenolic resin (two-step) is produced by condensing a molal excess of phenol with formaldehyde to complete the reaction in the presence of an acid catalyst. This produces a thermoplastic resin. To cure this resin, a hardening agent is used, HMTA (or hexa). Hexa is made from ammonia and formaldehyde.Under heat and pressure, it yields ammonia and formaldehyde as methylene groups to cure the resin, hence the term “two-step,” because of the two formaldehyde additions. A novolak phenolic resin has an infinite shelf life under normal storage conditions.
Novolac Phenolic resin effortlessly penetrates and adheres to the structure of many organic and inorganic fillers and reinforcements, which makes it an ideal candidate for various end uses. A brief thermal exposure to complete the cross-linking or "thermoset" process results in attainment of final properties. The unique ability of phenolic resin to "wet out" and to cross-link throughout the fillers and reinforcements provides the means to engineer the desired mechanical, thermal, and chemically resistant properties.
Novolac Phenolic resin is the choice for composite friction materials: the pads, blocks, linings, discs and adhesives used in brake & clutch systems that create retarding or holding forces with application against a moving part. The inherently heat resistant phenolic resin carbonizes and chars at extreme service temperatures, it does not melt and smear like other polymer matrices. This property results in restored friction properties when the material cools and "recovers" from hard braking. Formulas for phenolic composite friction materials are combinations of friction and wear-controlling agents, reinforcing fibers and inert fillers blended with un-cured phenolic resin in an amount necessary to bond the other ingredients in place with sufficient strength and resiliency when finished. Judicious selection of the types and amounts of raw materials used allows for the optimization of performance with cost and consistency
Curing time @150°C
the package is paper-plastics bag in 25KGS each one
The storage life of this product is several months in a cool and dry place in original closed bags