| Number | Name | Date | Kind |
|---|---|---|---|
| 3823131 | Stingl | Jul 1974 |
| Number | Date | Country |
|---|---|---|
| 2006261 | Aug 1971 | DEX |
| 2628470 | Jan 1977 | DEX |
| 48-15228 | Dec 1973 | JPX |
| 1322704 | Jul 1973 | GBX |
| 1445726 | Aug 1976 | GBX |
| Entry |
|---|
| Colour Index, vol. 4, 1971, p. 4228, C.I. 26200. |
| Crompton et al., "Derwent-Netherlands Patents", No. 08569x/05 (1974). |
| ICI, "Derwent-Belgian Patents", No. 22489w/14, (1975). |