1,2,4-phthalic anhydride was first industrialized by Amoco company in 1962. With the large-scale ethylene plant, the resource of trimethylbenzene increased. As the raw material of plasticizer with excellent heat resistance and weather resistance, the consumption of 1,2,4-phthalic anhydride also increased. In the total consumption, more than 90% of this product is used in the production of PVC plasticizer trioctyl trimellitate. It can also be used as curing agent of epoxy resin, heat-resistant insulating laminate, heat-resistant varnish, stabilizer, dye, pigment, surfactant, film and polybasic acid for water-soluble coating.
Preparation of trioctyl trimellitate: trioctyl trimellitate (totm) produced by esterification of trimellitic anhydride and octanol has good heat resistance, low volatility, oil resistance and processability. It is widely used as PVC heat-resistant plasticizer, plasticizer of solvent resistant cross-linked vinyl chloride resin, main plasticizer of 90 ℃ and 105 ℃ grade heat-resistant cable formula, as well as 6 000 V Plasticizer for 10 000 v high voltage cable. In addition, it can also be used as impregnant and high temperature resistant insulating paint, and is widely used as coating materials for internal parts of electrical appliances, wires in automobiles, semiconductors, etc; It can be used as automobile cable, moisture proof and heat-resistant epoxy resin capsule component, anti fog polyethylene resin component and anhydrous dye component of fiber and thermoplastic; Used as car cushion, artificial leather, washing machine drainage hose, blinds, sealing materials and fillers.
Preparation of polyamide imide and polyester imide: polyamide imide can be prepared by the reaction of trimellitic anhydride and aromatic diamine, and polyester imide can be prepared by the reaction of trimellitic anhydride, hydroquinone and 4,4'diamine diphenyl ether. They have good heat resistance, electrical insulation resistance and mechanical properties, and also have good wear resistance at high temperature. They are mainly used for insulating materials of class F and H motors, such as enamelled wire paint, impregnating paint, silicon steel sheet paint and film, and can be used for a long time at 230 ~ 250 ℃. In addition, it can also be used to manufacture electrical components, valves, bearings, jet engine parts and other molded plastic parts.
Preparation of alkyd resin: trimellitic anhydride reacts with polyol and dicarboxylic acid to prepare alkyd resin coating with excellent performance. Thermoplastic alkyd resin is mainly used as primer for automobile, electrical appliances and mechanical products, as well as surface paint for kitchen and furniture, as well as industrial building materials and common paints. Room temperature curing resin is mainly used in industrial building materials and common paints.
Trimellitic anhydride can cure epoxy resin in a short time and make the cured epoxy resin have excellent physical and chemical properties. It is a cheap and practical curing agent. It can also be used in the production of polyester resin and powder coatings, widely used in home appliances, bicycles, steel doors, windows and other places with high decorative and anti-corrosion requirements. It can be used as heat-resistant insulating laminate, synthetic dye, heat-resistant varnish, stabilizer, fiber softener, pigment, water treatment agent, film and surfactant, etc.
