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:
Jul. 14, 1992
Filed:
Feb. 01, 1990
Karl-Heinz Feuerherd, Hettenleidelheim, DE;
Carola Hedtmann-Rein, Hirschberg, DE;
Ludger Leber, Dannstadt-Schauernheim, DE;
BASF Aktiengesellschaft, Ludwigshafen, DE;
Abstract
A novel, optically transparent, isotropic molding for optical purposes which is free of orientation birefringence consists of a mixture of polyphenylene ethers, vinylaromatic polymers and additives. The novel molding contains traces of novel diphenoquinone and/or diphenohydroquinone derivatives as additives and may also contain novel ammonium salts of sulfuric acid half esters of diphenohydroquinones as further additives. The novel molding has a yellowness index (YI) of from 40 to 90. It can be produced in a simple manner by injection molding processes. The novel molding in the form of a circular disk having a central hole is very useful as a dimensionally stable substrate of audio compact disks (CD), audiovisual compact disks (CDV), laser-optical computer disks and magneto-optical computer disks, and data media of this type which contain these novel dimensionally stable substrates have particularly advantageous performance characteristics.