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:
Mar. 13, 1979
Filed:
Nov. 26, 1974
Dieter Dieterich, Leverkusen, DE;
Peter Markusch, Cologne, DE;
Bayer Aktiengesellschaft, Leverkusen, DE;
Abstract
Aromatic polyisocyanates containing sulphonic acid or sulphonate groups which are substantially free from crystalline product and a method for making them are provided wherein a mixture of aromatic polyisocyanates having an isocyanato content of from about 10% to about 42% by weight is sulphonated, the improvement which comprises mixing and reacting liquid aromatic polyisocyanates having a viscosity of from about 8 cP to about 49 cP at 25.degree. C. and containing at least 40% by weight of phosgenation products of an aniline-phosgenation condensate and at least about 20% by weight of 2,6-tolylene diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate or a mixture thereof, based on the weight of said liquid aromatic polyisocyanates with a sulphonating agent in an amount equivalent to from about 0.1% to about 40% by weight sulphur trioxide, based on the weight of said liquid aromatic polyisocyanates.