Lead salt stabilizers are inexpensive and have good the […]
Lead salt stabilizers are inexpensive and have good thermal stability. They have been widely used, but the powder of lead salt is small, and the dust caused by the powder of lead salt is the main cause of lead poisoning in the body. In the early 1970s, a new type of composite lead salt heat stabilizer was developed based on traditional heat stabilizers such as three salts, two salts and hard salts. The composite additive adopts the symbiotic reaction technology to mix the three salt, the two salt and the metal soap in the reaction system with the initial ecological grain size and various lubricants to ensure the sufficient dispersion of the heat stabilizer in the PVC system. At the same time, due to co-melting with the lubricant to form granules, poisoning caused by lead dust is also avoided. The composite lead salt stabilizer contains the heat stabilizer component and lubricant component required for processing and is referred to as a full package heat stabilizer. It has the following advantages:
(1). The various components of the composite heat stabilizer are sufficiently uniformly mixed in the production process thereof, and the dispersion uniformity when mixed with the resin is greatly improved.
(2). When the formula is mixed, the number of times of measurement is simplified, and the probability of measuring errors and the loss caused thereby are reduced.
(3). Convenient supply and storage of excipients is conducive to the management of production quality.
(4). Provides the possibility of dust-free production and improves production conditions.
In short, the composite heat stabilizer is conducive to scale production, providing a new direction for the development of lead salt heat stabilizer. An important indicator of the composite lead salt stabilizer is the lead content. The lead content of the composite lead salt stabilizer currently produced is from 20% to 60%; the amount of the PVC plastic door and window profile is 3.5 to 6 parts. Table 2-1-2 shows the grades and amounts of composite lead salt stabilizers used in the production of some PVC profiles.