Zinc stearate is a zinc soap that repels water. It is insoluble in polar solvents such as alcohol and ether but soluble in aromatic hydrocarbons (e.g., benzene and chlorinated hydrocarbons) when heated. It is the most powerful mold release agent among all metal soaps. It contains no electrolyte and has a hydrophobic effect.
Zinc Stearate improves the early colour when used in PVC and additionally gives good lubricating action. When incorporated in PVC, Zinc Stearate is not used alone but principally combined with Calcium stabilizer. Care should be taken not to use too high a dosage of Zinc Stearate, although the early colour improves, the heat stability may decrease. The addition of an epoxy plasticiser will also assist in improving the heat stability.
Zinc Stearate also finds uses in:
- Polystyrene and A.B.S. as lubricant and / or dispersant.
- The paint industry as a matting agent / grinding agent.
- The rubber industry as an anti blocking agent.