<Methyltetrahydrophthalic anhydride>
Tetrahydrophthalic anhydride (C9H10O3) epoxy resin curing agent performance characteristics: high purity, light color: can be directly prepared or prepared in various colors of epoxy resin curing agent products. Low viscosity: good processability in casting and potting. A large amount of filler can be added during casting to make the cured product excellent in performance. Stable performance: long pot life, low freezing point, long-term storage at room temperature. Low volatility: low toxicity, low heat loss, toxicity is only one forty times lower than amine curing agents. Can obtain high-quality cured products, cured products not only have higher mechanical strength, but also have good electrical properties and heat and corrosion resistance. It has good transparency, weather resistance, and potting and casting stability. It is especially suitable for white potting casting materials. It is an ideal curing agent to replace B-570 imported by Dainippon Ink Chemical Company. During storage and transportation, avoid light, seal, and moisture. If it is improperly stored, precipitation will occur after absorbing moisture, and it only needs to be heated to 140 ° C to restore the original state without affecting the original performance.
Tetrahydrophthalic anhydride is an intermediate for the production of dumpling-resistant, corrosion-resistant and highly decorative polyester resins. This resin can be used to produce modern paints. Tetrahydrophthalic anhydride can also be used as a fungicide ketotan and insecticide Pyrethrum Tetrahydrophthalic anhydride is a white crystal with no odor. Melting point is 04 ° C at 5 ° C. Density is 1.601 / at 130_, density is 1.2 /, solubility at 25 "(mole fraction): benzene one 0.0729. Ethyl acetate-.5 Ether-.0266,?-. 09478, -0.0033,22—0.089,32—0.018. Hydrolysis in hot water to produce tetrahydrophthalic acid, the critical allowable concentration in the air of the production site is .6 / tetrahydrophthalic anhydride is a flammable substance. At the lower concentration limit (2.5 /), the dusty air mixture will explode. Its flash point is 35-163 ℃, the ignition point is 65 ℃, and the auto-ignition point is 48 ℃. In 928, 0 was first produced from -1, and maleic anhydride was used to polycondensate with butadiene. In recent years, this method has been used to prepare the product not only in the laboratory but also in industrial production. The reaction is in the solvent 0 (such as (Benzene), and the temperature is about 0 ° C. Recently, some patents have been reported on the use of pressure, solvent, and temperature increase methods to increase yield and speed up the reaction. For example, The Japanese patent proposes to use a solvent, the reaction temperature is 70 ° C and to prepare tetrahydrophthalic anhydride in the presence of a inhibitor [(0)].
A new method for producing liquid methyltetrahydrophthalic anhydride is achieved by using solid methyltetrahydrophthalic anhydride or crude methyltetrahydrophthalic anhydride formed by the reaction of mixed carbon five with maleic anhydride as a raw material, in an acid isomerization catalyst In the presence of acetic acid, the isomerization reaction is performed at 130 to 160 ° C for 1 to 5 hours, and an equivalent amount of a weakly basic compound such as an acidic catalyst is added. The reaction is continued for 15 to 30 minutes, and then distilled under reduced pressure to obtain liquid methyltetrahydrogen. Phthalic anhydride. The liquid methyl tetrahydrophthalic anhydride produced by this method has indicators such as freezing point, stability, viscosity, and chromaticity, which have reached the level of similar foreign products.
Tetrahydrophthalic anhydride is a widely used chemical raw material. It is used as a curing agent for epoxy resins, plasticizers for atomic ash resins, adhesives, paints, modifiers for unsaturated polyesters, agents for the fiber industry, and pesticides. Insecticide, wetting agent, polyester resin, etc.
