Since the homo-anhydride has a special structure, it can be used to make many products with superior heat resistance, electrical insulation and chemical resistance. The current use continues to expand, and its main uses are as follows.

1.1 Heat resistant polymer

The largest use of the anhydride is used as a raw material for polyimide. The polyimide obtained by reacting an average anhydride with an aromatic diamine compound such as p-diaminodiphenyl ether has the characteristics of being insoluble and infusible, and has excellent chemical resistance and wear resistance compared with other plastics. Sexual and radioactive, the main use in the industry is to make a film for use as a heat-resistant insulating gasket or wrapping material for Class H or Class C motors and cables, or as a flexible circuit board substrate; Electrical materials used in atomic reactors and space, and jet engine tubing materials that operate at 200 to 232 °C. The reaction of the phthalic anhydride with the aromatic tetraamine gives polybenzimidazole pyrrolidone (pyridinium), which is the most studied type of ladder polymer, its radiation resistance, oxidation resistance and hydrolysis resistance under acidic conditions. Stronger than polyimide, but poor in alkali resistance, currently used mainly in space technology.

1.2 Plasticizer

Tetraphthalic acid tetrabutyl acrylate (TBPM) and tetramethylene tetracarboxylate (TOPM) prepared by the reaction of the phthalic anhydride and the corresponding alcohol have good electrical insulation and heat resistance and can be used for the production of heat-resistant high pressure. Cable, heat-resistant polyvinyl chloride high-grade artificial leather, especially medical plastic products; tetrakis(2-ethylhexyl) ester of pyromellitic acid obtained by esterification of phthalic anhydride with 2-ethylhexanol, is polyvinyl chloride heat-resistant A plasticizer that can be used to produce heat-resistant cables of 102 to 120 ° C to produce special durable heat-resistant plastic products, polyvinyl chloride products for medicine and food.

1.3 epoxy resin curing agent

The use of an epoxy resin for casting and laminating to manufacture motor materials, particularly for the manufacture of leakage-proof motor materials, uses an acid anhydride as a curing agent. Using the anhydride as a curing agent, it can not only be made into a large casting with good insulation performance, but also has a heat resistance of 200 to 250 ° C. With a curing agent for the epoxy resin adhesive, it can be quickly bonded to obtain an impact resistance. Instantaneous adhesive.

1.4 other applications

The stepwise esterification reaction of the homo-anhydride and the higher alcohol can produce a "green" surfactant or emulsifier with biodegradability; the homo-anhydride and the higher fatty alcohol esterification reaction can be controlled by controlling the ratio of the alcohol to the anhydride. A surfactant having excellent properties is obtained. In addition, the anhydride is also used as a water treatment agent, a metal corrosion inhibitor, an additive for leather tanning agents, a low temperature performance improver for diesel, an electrophotographic color tone improver, and a high temperature resistant lubricant, dye, alkyd resin and polyester resin. Modification, etc.