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:
Feb. 21, 1989
Filed:
Jun. 05, 1987
Applicant:
Inventor:
Nicolas Hardy, Jemeppe-sur-Sambre, BE;
Assignee:
Solvay & Cie (Societe Anonyme), Brussels, BE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C08L / ;
U.S. Cl.
CPC ...
528249 ; 528250 ; 528497 ; 528498 ; 528501 ; 525 54 ; 525472 ;
Abstract
Polyacetal obtained by the polymerization of trioxane, for example, suspended in an organic solvent, in the presence of a comonomer (for example, ethylene oxide), is stabilized by hydrolysis in the heated state under pressure and then, after hydrolysis, the reaction mixture is depressurized to atmospheric pressure in order to release an aqueous phase containing the polymer and a vapor phase which contains formaldehyde and trioxane. According to the invention, the latter is recycled directly into the formaldehyde trimerization stage under reduced pressure.