Isophthalic

See also Isophthalic acid.) pHTHALIC ACID AND OTHERBENZENEPOLYCARBOXYLIC ACIDS] (Vol 18)... 

Like terephthalic acid, isophthalic acid is used as a raw material in the production of polyesters. Much of the isophthaUc acid is used for unsaturated polyesters, whereas terephthaUc acid is used almost exclusively in saturated (thermoplastic) polyesters. However, a considerable amount of isophthaUc acid is used as a minor comonomer in saturated polyesters, where the principal diacid is terephthaUc acid. The production volume of isophthaUc acid is less than 2% that of terephthahc. IsophthaUc acid was formerly produced in technical or cmde grades and only a small amount was purified. Now, however, it is all purified to a standard similar to that of terephthahc acid. 

Table 24. Physical Constants and Properties of Isophthalic Acid...

Isophthahc acid is also used in formulations for adhesives, inks (qv), wire enamels, and dental materials (qv). Copper isophthalate [10027-31-3] is an ingredient in algicides and fungicides (98). 

Table 28. Properties of Isophthalic Esters and Isophthaloyl Chloride...

Some time earlier, Eastman-Kodak has been working on a novel polyester as an entry into the important polyester fiber market and had devised a new ahcychc diol, 1,4-cydohexanedimethanol [105-08-5] effectively made by exhaustive hydrogenation of dimethyl terephthalate. Reaction of the new diol with dimethyl terephthalate gave a crystalline polyester with a higher melting point than PET and it was introduced in the United States in 1954 as a new polyester fiber under the trade name Kodel (5). Much later the same polyester, now called PCT, and a cyclohexanedimethanol—terephthalate/isophthalate copolymer were introduced as mol ding resins and thermoforming materials (6). More recentiy stiU, copolymers of PET with CHDM units have been introduced for blow molded bottie resins (7). 

Table 3. Molar Component Ratio Used in Isophthalic Formulations ...

Fig. 7. Influence of copper naphthenate on exotherm temperature. Composition in pph isophthalic laminating resin is cobalt naphthenate (0.20), dimethylaniline (0.05), and copper naphthenate, A (0.00) B (0.01) C (0.015) orD (0.02).

Table 8. Strength Characteristics of Isophthalic Resin and Composite Derivatives...

Exploiting the relative basicity of the xylene isomers, commercial units employ superacids, typically HE—BF, as the acid complexing agent for the separation of / -xylene (feedstock for isophthalic acid) (15). Amoco produces high purity / -xylene at its Texas City facility using the HE—BF process (see Btx processing). Similar processes can be used for the separation of high purity mesitylene and isodurene from their and C q isomers, respectively. 

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