| Number | Date | Country | Kind |
|---|---|---|---|
| 197 09 798 | Mar 1997 | DEX |
| Number | Name | Date | Kind |
|---|---|---|---|
| 3357983 | Weener et al. | Dec 1967 | |
| 3554776 | Gerson et al. | Jan 1971 | |
| 4262851 | Graser et al. | Apr 1981 | |
| 4599408 | Spietschka et al. | Jul 1986 | |
| 4709029 | Spietschka et al. | Nov 1987 | |
| 4762569 | Miki et al. | Aug 1988 | |
| 5154770 | Spietschka et al. | Oct 1992 | |
| 5753030 | Flatt et al. | May 1998 |
| Number | Date | Country |
|---|---|---|
| 0035299 | Sep 1981 | EPX |
| 0321919 | Jun 1989 | EPX |
| 1067157 | Oct 1959 | DEX |
| 3017185 | Nov 1981 | DEX |
| 296300 | Nov 1991 | DEX |
| Entry |
|---|
| Chemical Abstracts, 55:2136c, abstract of Great Britain Patent Specification No. 835,459 (May 1960). |