Terephthalic Toray process

Esterification ofTerephthalicAcid. Esterification of terephthaUc acid is also used to produce dimethyl terephthalate commercially, although the amount made by this process has declined. Imperial Chemical Industries, Eastman Kodak, Amoco, Toray, Mitsubishi, and Mitsui Petrochemical have all developed processes. Esterification (qv) generally uses a large excess of methanol in a Hquid process at 250—300°C. The reaction proceeds rapidly without a catalyst, but metal catalysts such as zinc, molybdenum, antimony, and tin can be used. Conversion to dimethyl terephthalate is limited by equiHbrium, but yields of 96% have been reported (75,76). 

Toray (2) process for making terephthalic acid by oxidizing p-xylene, using a cobalt catalyst promoted by paraldehyde. 

Most of the companies already producing diethylene glycol terephthalate polymers have launched into the applications of polyester film to video and data processing, Hoechst through its Kalle subsidiary, ICI, Rhone-Poulenc, Du Pont, Japan s Toray, Teijin, and Toyobo, the latter in association with Rhone-Poulenc in Nippon Magphane. 

Other processes for manufacturing dimethyl tercphthalate pass through the intermediate of fixe terephthalic acid Amoco, Du Pont, Eastman Kodak, ICl (Imperial Chemical Industries). Mitsubishi, Mitsui, Petrochemicals. Toray, etc) which is esterified around 250 to 300°C in the presence of catalysts based on antimony, tin, molybdenum, zroc, etc, with molar yields of 96 per cent and complete conversion, provided that water is removed as soon as it is formed. 

PET with 2 phr of poly[bis (4-methoxy phenyl)terephthalate] Processability and excellent mechanical properties Toray Industries, Inc. 1980... 

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