 
                 Patent Grant
 Patent Grant
                     4555359
 4555359
                    | Number | Date | Country | Kind | 
|---|---|---|---|
| 3212326 | Apr 1982 | DEX | 
| Number | Name | Date | Kind | 
|---|---|---|---|
| 3681464 | Theimer | Aug 1972 | |
| 4162266 | Helmlinger et al. | Jul 1979 | |
| 4206089 | Willis et al. | Jun 1980 | |
| 4302363 | Bruns et al. | Nov 1981 | |
| 4304944 | Willis et al. | Dec 1981 | 
| Entry | 
|---|
| Chemical Abstracts, 88, 74232r, (1978). |