Hydrotalcite acid acceptor for polyolefin

Abstract

The invention discloses a hydrotalcite acid acceptor for polyolefin. The hydrotalcite has a structural formula [Mga(1-x) <2+>Ca(1-a)(1-x)<2+>Alx<3+>(OH)2]<x+>(A<n->)x / n.yH2O, wherein A<n-> is an interlayer negative ion, n is the charge number of the interlayer negative ion and is equal to 1-7; x is the ratio of the amount of substance of Al<3+> to (Ca<2+>+ Al<3+>) and has a value range of equal to or greater than 0.2 and less than or equal to 0.33; a is the ratio of the amount of substance of Mg<2+> to (Mg<2+>+ Ca<2+>) and has a value range of equal to or greater than 0 and less than or equal to 1; and y is the number of water of crystallization and has a value range of equal to or greater than 0 and less than or equal to 2. By adopting hydrotalcite as a clean polyolefin talc acid acceptor, chlorine ions can be effectively absorbed and fixed by virtue of the layered structure and the porous structure of hydrotalcite and by virtue of intercalation modification of the organic acid negative ion, the dispersity of hydrotalcite in the resin can be increased; by adjusting and controlling the laminate structure and interlayer negative ion, the different application requirements can be met and meanwhile, hydrotalcite is hardly precipitated in the resin, the corrosion of metal stearate acid acceptor residues to a production device is eliminated and the acid acceptor is low in toxicity and environment friendly and is in line with the requirements of the current environment-friendly production.

Description

Technical field: [0001] The invention belongs to the field of polyolefin additives, in particular to a hydrotalcite acid absorbing agent for polyolefin. Background technique [0002] Ziegler-Natta catalysts and free radical initiators used in polyolefin synthesis can reduce side reactions and better obtain products with less branched chains, but because Ziegler-Natta catalysts mostly deposit titanium chloride on CaCl 2 Crystal or SiO 2 On the carrier, this will cause a small amount of chlorine-containing compounds to remain in the product. In addition, other additives (mainly bromine-containing flame retardants) will also leave other acidic impurities in the production process. These residues will make products made of polymers in the long-term Discoloration and damage will also occur during the use of stainless steel. At the same time, chloride ions are also common corrosive ions, which can easily cause corrosion of stainless steel and cause harm to production equipment an...

AI Technical Summary

Problems solved by technology

[0002] Ziegler-Natta catalysts and free radical initiators used in polyolefin synthesis can reduce side reactions and better obtain products with less branched chains, but because Ziegler-Natta catalysts mostly deposit titanium chloride on CaCl 2 Crystal or SiO 2 On the carrier, this will cause a small amount of chlorine-containing compounds to remain in the product. In addition, other additives (mainly bromine-containing flame retardants) will also leave other acidic impurities in the production process. These residues will make products made of polymers in the long-term Discoloration and damage will also occur during the use process. At the same time, chloride ions are common corrosive ions, which can easily cause corrosion of stainless steel and cause harm to production equipment and pipelines.

The demoulding ability of commonly used metal stearate acid absorbing agents will cause a small amount of calcium stearate to remain on the inner wall of the processing equipment. Calcium stearate will generate stearic acid vapor under heated conditions, resulting in corrosion