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:
May. 11, 1999
Filed:
Nov. 07, 1996
Rina Singh, Westerville, OH (US);
Laurence G Dammann, Powell, OH (US);
Ashland Inc., Columbus, OH (US);
Abstract
The invention relates to modified polymeric aromatic isocyanates having allophanate linkages prepared by (a) reacting a polymeric aromatic isocyanate with a monofunctional aliphatic alcohol to form an intermediate modified polymeric isocyanate; and (b) reacting the intermediate modified polymeric isocyanate at an elevated temperature in the presence of a divalent metal catalyst. The invention also relates to foundry binder systems which use these modified polyisocyanates. These modified polyisocyanates, along with a phenolic resole resin, are added to a foundry aggregate to form a foundry mix which is shaped and cured with a gaseous amine curing catalyst by the cold-box process.