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:
Aug. 15, 1978
Filed:
Feb. 21, 1975
Rauma-Repola Oy, Rauma, FI;
Abstract
This invention relates to a three-dimensional, aromatic, sulfur-containing polymer based on lignin. The polymer is characterized in that it is amorphous, practically insoluble in water and conventional organic solvents; it contains thioether bonds and possibly sulfoxide and/or sulfone groups formed by oxidizing of thioether bonds, and possibly carbon-carbon bonds between aromatic rings and/or side chains and possibly other bonds typical to lignin, depending on reaction conditions. Its thermostability is at least 200.degree. C.; and it has been obtained from lignin which is dissolved or undissolved, chlorinated or unchlorinated, purified or containing other components of spent pulp liquor, by heating at about 160.degree.-350.degree. C., preferably in an atmosphere substantially of nitrogen and/or water vapor, for a time sufficient to form the polymer, with sulfur and/or inorganic or organic sulfur compounds so that degradation products of lignin, containing aromatic rings, or corresponding aromatic compounds, with an activating substituent have possibly been added.