Compound stabilizers can be divided into the following types:
1. Liquid barium-zinc composite stabilizers are generally light yellow to yellow-brown oily liquids, with a bai specific gravity of 1.0-1.1 at room temperature, good heat resistance, and no sulfide pollution. Combined use with epoxy plasticizers can improve the stabilization effect. It has an activating effect on foaming agents.
2. Liquid calcium-zinc compound stabilizer – The main components of the non-toxic liquid calcium-zinc stabilizer are calcium stearate, calcium ricinoleate, zinc stearate, zinc ricinoleate, epoxy soybean oil, ultraviolet absorber, etc. Liquid calcium and zinc stabilizers generally use fatty calcium salts and zinc salts that are more soluble in organic solvents and have fewer carbons. Due to different components and different properties, it is generally light yellow to yellow clear oily liquid with a specific gravity of 1.0-1.05 at room temperature. It is a non-toxic stabilizer for PVC, mainly used as a stabilizer for food packaging films and foam artificial leather for utensils.
3. Liquid barium-cadmium and liquid barium-cadmium-zinc composite stabilizers. This type of composite stabilizer is mainly used in the processing of soft PVC products. The basic components include:
(1) Barium salt-can be barium alkylphenate, barium 2-ethylhexanoate, barium laurate (for powder composite), benzoic acid and substituted barium benzoate, barium neodecanoate, etc. Barium salt accounts for 6-7% in the composite, that is, the ratio of barium salt to cadmium salt is about 2:1-32 (in terms of metal, weight percentage, the same below).
(2) Cadmium salt-can be 2-ethylhexanoate, cadmium laurate, cadmium oleate, phenyl acid and substituted cadmium benzoate, cadmium naphthenate, cadmium neodecanoate, etc. Cadmium salt accounts for about 3-4% in the composite.
(3) Zinc salt-can be zinc 2-ethylhexanoate, zinc laurate (for powder composite), zinc naphthenate, zinc neodecanoate, benzoic acid and zinc substituted benzoate, etc. Zinc salt accounts for 0.5-1% in the composite.
(4) Phosphite-can be triphenyl phosphite, diphenyl monooctyl phosphite, diphenyl monodecyl phosphite, tris (nonylphenyl) phosphite, etc. Phosphite occupies about 15-20% (weight) in the complex and is used as a chelating agent.
(5) Others-including a small amount of 2,6-di-tert-butyl-p-cresol, bisphenol A, nonylphenol and other phenolic antioxidants and UV absorbers, as well as liquid paraffin, white oil, diesel, spindle oil, etc. Mineral oil is used as a solvent, and a small amount of defoamers such as higher alcohols are also required.
Liquid barium-cadmium-zinc composite stabilizers have different properties due to their different compositions. But generally it is a light yellow to yellow clear liquid with a specific gravity of 0.95-1.02 at room temperature, a viscosity of less than 100 centipoise, and a freezing point of about -15°C. Liquid barium cadmium is similar to liquid barium cadmium zinc, both of which have excellent thermal and light stability, small initial coloration, good transparency and color stability. Their stabilizing effect is stronger than that of solid composite soaps, so the amount can be reduced, generally 2-3 parts, no dust poisoning, and completely dissolved in general plasticizers, with good dispersibility, and low precipitation tendency. Among them, the initial coloring of liquid barium cadmium zinc is smaller than that of liquid barium cadmium.
4. Lead salt composite stabilizer has good thermal stability and has been widely used. However, the powder of lead salt is small, and the dust in the ingredients and mixing will cause lead poisoning. For this reason, scientific and technical personnel have developed a new type The composite lead salt heat stabilizer. This composite additive uses symbiotic reaction technology to mix the tri-salt, di-salt and metal soap in the reaction system with nascent grain size and various lubricants to ensure the full dispersion of the heat stabilizer in the PVC system At the same time, because it melts with the lubricant to form a granular shape, it also avoids the poisoning caused by lead dust. The composite lead salt stabilizer contains the heat stabilizer components and lubricant components required for processing, and is called a full package heat stabilizer.
It has the following advantages:
(1) The various components of the composite heat stabilizer can be fully mixed during the production process, which greatly improves the uniformity of mixing and dispersion with the resin.
(2) When the formula is mixed, the number of measurement is simplified, and the probability of measurement error and the loss caused by it are reduced.
(3) The supply and storage of auxiliary materials are simplified, which is beneficial to production and quality management.
(4) It provides the possibility of dust-free production of products and improves production conditions.