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. 10, 1995
Filed:
Oct. 15, 1993
Neste OY, Porvoo, FI;
Abstract
The present invention relates to a production method of lactic acid-based polyurethanes. In the first phase of the product ion, the monomeric lactic acid is polymerized into an oligomer, the molecular weight thereof being about 500 to 10,000. Next, the oligomer thus obtained is copolymerized with an isocyanate reacting with the free hydroxyl and carboxyl groups thereof into polyurethane with a high molecular weight. To make the oligomer react with diol prior to the copolymerization is unnecessary according to the invention. The lactic acid used need not be absolutely pure, and by modifying the process, various biodegradable end products can be obtained therefrom, which according to the invention are appropriate for the material of disposable packages, agricultural film or planting pots, or as a coating of fertilizer granules.