The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 21, 1979
Filed:
Oct. 25, 1977
Shigeo Yoshinaka, Niigata, JP;
Masaharu Doya, Niigata, JP;
Seiji Uchiyama, Niigata, JP;
Sadao Nozaki, Niigata, JP;
Mitsubishi Gas Chemical Company, Inc., Tokyo, JP;
Abstract
A batchwise or continuous process for producing isophthaloyl dichloride or terephthaloyl dichloride having a high purity which comprises, in combination, (1) a first step of producing .alpha.,.alpha.,.alpha.,.alpha.',.alpha.',.alpha.'-hexachloroxylene by reacting meta- or para-xylene with chlorine under the irradiation of ultraviolet-containing rays, the reaction being carried out in the presence of, as a solvent, .alpha.,.alpha.,.alpha.,.alpha.',.alpha.',.alpha.'-hexachloroxylene added at the outset of the reaction; (2) a second step of producing isophthaloyl dichloride or terephthaloyl dichloride by reacting the .alpha.,.alpha.,.alpha.,.alpha.',.alpha.',.alpha.'-hexachloroxylene obtained in the first step with isophthalic acid or terephthalic acid; and (3) a third step of purifying the isophthaloyl dichloride or terephthaloyl dichloride obtained in the second step by dissolving the isophthaloyl dichloride or terephthaloyl dichloride in 0.3 to 6 parts by weight; per part by weight of the phthaloyl dichloride, of C.sub.6 -C.sub.10 aliphatic hydrocarbon solvent, and cooling the solution to a temperature of the specified range thereby to recrystallize the phthaloyl dichloride.