Organic binders in friction materials - phenolic resins
Phenolic resin is a binder mainly used in friction materials containing organic binders. It is a kind of polymer made from phenolic compounds and aldehyde compounds as raw materials and acid or alkali as catalysts through polymer polycondensation reaction. Among them, the phenolic resin formed by the polycondensation of phenol and formaldehyde is the most important.
What are the specific requirements for resins in friction materials:
1. Good heat resistance, good thermal decomposition temperature and low thermal weight loss.
2. The fineness of the powdery resin should be high, generally 100-200 mesh, which is beneficial to the uniformity of the dispersion of the mixture and reduces the amount of resin in the formula.
3. Low free phenol content.
4. The suitable curing speed is 40-60s and the flow distance is 40-80mm.
The resins in friction materials are classified into thermoplastic and thermosetting phenolic resins according to the type of catalyst.
