An acidic catalyst and a molar excess of phenol to formaldehyde are conditions used to make novolac resins.The final novolac resin is unable to react further without the addition of a cross-linkinThe most common phenolic resin cross-linking agent is hexamethylenetetramine, also known as hexa, hexamine, or HMTA. Ground and blended with the resin.
Application
Novolac Phenolic Resin Powder 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.
Specification:
Properties | Value | Test standard |
Curing time @150°C | 30-50s | GB/T24411-2009 |
Flow Distance@125°C | 30-40mm | GB/T24411-2009 |
Free-phenol | 2.0-2.5% | GB/T30773-2014 |
hexa content | 8-10% | ZJHM-QESP-01-2015 |
Water content | 0.5-2.0% | GB/T2683-2008 |
Screening 200mesh/0.074mm | 99% | GB/T24411-2009 |
Packing&Storage
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 . Fast Curing Novolac Phenolic Resin Powder for Friction Materials