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. 24, 1999
Filed:
Sep. 25, 1997
Claudia Beyer, Bickenbach, DE;
Horst Pennewiss, Darmstadt, DE;
Roehm GmbH Chemische Fabrik, Darmstadt, DE;
Abstract
The invention relates to a method for making oligomers, including homo-oligomers and cooligomers, by the free radical polymerization of at least one monomer component B) having a greater tendency to polymerize and 0-90 wt. %, calculated on the oligomers, of a monomer component A) having a lesser tendency to polymerize, at an elevated temperature and in the presence of a polymerization initiator in a conventional polymerization vessel, by adding monomer component B) to monomer component A), or to a solution of monomer component A), or merely to a solvent, so that the mol ratio of B) to A), if A) is present, passes through values of 0 to about 0.2 during the initial phase of the polymerization and takes the value 0.2 to 20 during the terminal phase of the polymerization, the reaction temperature being in a region in which a homopolymer of the monomer component B) is already significantly depolymerized, and the initiator, which has a half-life time at the reaction temperature from 1 minute to about 5 hours, being added throughout the duration of the polymerization in an amount from 0.1 to 10 percent of the total weight of the monomers.