PVC Heat stabilizer is a kind of chemical additive used for preventing or or reducing thermal decomposition or cross-link in polymer processing and extending the durability of polymers. In general, PVC heat Stabilizers can be classified into salt based, fatty-acid soap based, organic tin compounds and composite stabilizer.
1. Salt Based Stabilizer
Salt based stabilizer are those inorganic and organic acid lead salts combined with “base”. This type of stabilizer is characterized by excellent heat stability, weatherability, electric insulation relatively low cost, low transparency and some certain toxicity. The recommended dosage ranges from 0.5%~5.0%.
2. Fatty-acid Heat Stabilizer
This type of heat stabilizer is chemical compounds made up of fatty-acid radicals and metal ions, also called metallic soap stabilizer. Its properties are related to acid radicals and metal ions. Recommended dosage is 0.1%~3.0%.
3. Organo-tin Heat Stabilizer
This type of stabilizer together may form a ligand with unstable chlorine atom in polyvinyl chloride. And carboxylic esterbase of organic tin in ligand won’t replace the unstable chlorine atom. This type of heat stabilizer is characterized by high heat stability, good transparency and heat resistance. The shortcoming of this type of stabilizer is relatively high cost.
4. Compound Heat Stabilizer
This type of heat stabilizer is chemical compound in liquid type based on salt based or metallic soap or solid type based on organic tin. Metal salt stabilizers include Ca-Mg-Zn, Ba-Ca-Zn, Ca-Zn, Ba-Zn and Ba-Cr stabilizer. Generally used organic acid include organic fatty acid, naphthenic acid, oleic acid, benzoic acid and salicylic acid, etc.
5. Organic Compound Heat Stabilizer
Few of this type of heat stabilizer can be used as main stabilizer (mainly organic chemical compound containing nitrogen). In addition, it also includes some other polyols and phosphite ester with high melting points.