Information signal recording disc
US4125654A · kind A · utility
7Cited by
10References
10Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 8, 1977 |
| Grant date | Nov 14, 1978 |
| Priority date | — |
| Expiry date | Jun 8, 1997 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31935
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A phonograph or video disc comprises at least one unsaturated nitrile copolymer and has therein an unsaturated nitrile content of from 40 to 90 percent by weight, and the disc exhibits a Clash-Berg flex temperature of from 50.degree. to 120.degree. C, an absorbed impact energy of at least 0.5kg.cm. when tested with a test specimen thereof of a 2-mm. thickness by a Dynstat impact test according to BS-1330-1946, and a Shore D hardness of from 75 to 95.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.