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:
Jan. 12, 1993
Filed:
Oct. 23, 1991
Noritoshi Ishida, Fukuoka, JP;
Zunzi Tashima, Ohmuta, JP;
Mitsunori Shimamatsu, Fukuoka, JP;
Kazunari Nitta, Ohmuta, JP;
Takashi Nagou, Yokohama, JP;
Mitsui Toatsu Chemicals Inc., Tokyo, JP;
Abstract
A fractionation process of a methylene bridged polyphenylene polyisocyanate mixture obtained by phosgenating condensation product of aniline and formaldehyde is disclosed. In order to apply the above mixture to a variety of uses, the process separates the mixture into fractions by giving primary attention to the content of 4,4'-and 2,4'-isomer of diphenylmethane diisocyanate and at the same time reduces the content of impurities having acidity and hydrolyzable chlorine.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile