| Number | Date | Country | Kind |
|---|---|---|---|
| 1-343287 | Dec 1989 | JPX | |
| 2-120678 | May 1990 | JPX |
| Number | Date | Country |
|---|---|---|
| 0287079 | Oct 1988 | EPX |
| 2186256 | Jan 1974 | FRX |
| Entry |
|---|
| Derwent Japandes Patent Reports, vol. 13, No. 63 (C-568)[3411], Feb. 13, 1989; JP-A-63 258 463 (Kurniori) *abstract* . |