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:
Sep. 15, 1981
Filed:
Oct. 26, 1979
Masayuki Oba, Yokohama, JP;
Motoo Kawamata, Yokohama, JP;
Hikotada Tsuboi, Yokohama, JP;
Nobuhito Koga, Yokohama, JP;
Mitsui Toatsu Chemicals, Incorporated, Tokyo, JP;
Abstract
N-(hydroxyphenyl) maleimides of the general formula ##STR1## where R' stands for H, CH.sub.3, C.sub.2 H.sub.5, F, Cl, Br or I and n is an integer of 1-5 are produced by treating the corresponding maleamic acid or by treating the ester of said N-(hydroxyphenyl) maleimide at a temperature of 0.degree.-150.degree. C. in the presence of at least one dehydrating agent selected for the group consisting of oxides and oxyacids of sulfur or phosphorus and alkali metal and alkaline earth metal salts of the said oxyacids. The corresponding maleamic acid can be obtained by reacting an aminophenol having one or more hydroxyl groups on its phenyl nucleus with maleic anhydride. The esters of the N-(hydroxyphenyl maleimide) can be obtained by reacting said aminophenol and said maleic anhydride in the presence of a conventional acid anhydride dehydrating agent and a conventional imide-forming cyclization catalyst.