| Number | Date | Country | Kind |
|---|---|---|---|
| 44 19 533.8 | Jun 1994 | DEX |
| Number | Name | Date | Kind |
|---|---|---|---|
| 4017256 | Kogel et al. | Apr 1977 | |
| 4191532 | Gross et al. | Mar 1980 | |
| 4198204 | von der Eltz et al. | Apr 1980 | |
| 4849770 | Koike et al. | Jul 1989 | |
| 5356441 | Tokieda et al. | Oct 1994 |
| Entry |
|---|
| CA 102:158100 abstract of JP 59119346 Jul. 10, 1984; Daicel Chemical Industries Inc. |