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:
Apr. 16, 1991
Filed:
Nov. 25, 1988
Frank R Hunter, Bellevue, WA (US);
Weyerhaeuser Company, Tacoma, WA (US);
Abstract
The invention is a method of making a cellulose based polymeric material and the products of the invention. A cellulosic substrate is impregnated with an essentially uncatalyzed polyfunctinal isocyanate and pressed at elevated temperature and pressure. The substrate may be a chemical or thermomechanical pulp or paper while the isocyanate is preferably diphenylmethane diisocyanate or its oligomers. Pressing conditions are preferably in the range of about 150.degree.-245.degree. C. at pressures in the range of about 2700-8300 kPa for times less than 2 minutes. Moisture content of the cellulosic substrate is not highly critical and may be as high as 7% without adverse effects. The product is especially useful as overlays and for forming strong, water resistant laminates which can be molded in either flat or three dimensional forms.