摘要 |
The novel, optically clear, isotropic moulding for optical purposes which is free from orientation birefringence comprises a mixture of polyphenylene ethers, vinylaromatic polymers and, as additives, traces of novel diphenoquinone and/or diphenohydroquinone derivatives. In addition, the novel moulding may contain, as further additives, novel ammonium salts of sulphuric acid monoesters of diphenohydroquinones. The novel moulding has a yellowness index (YI) of from 40 to 90. It can be produced simply by injection moulding. The novel moulding, in the form of a circular, perforated disc, is highly suitable for use as a dimensionally stable substrate for audio compact discs (CD), audio-visual compact discs (CDV), laser-optical data discs and magnetooptical data discs, and data carriers of this type which contain this novel dimensionally stable substrate have particularly advantageous applicational properties. |