| Number | Date | Country | Kind |
|---|---|---|---|
| 3409233 | Mar 1984 | DEX |
| Number | Name | Date | Kind |
|---|---|---|---|
| 1734293 | Hellweg | Nov 1929 | |
| 1802602 | Hellweg | Apr 1931 | |
| 2525997 | Beier | Oct 1950 | |
| 3295305 | Nimtz | Jan 1967 | |
| 3400528 | Nimtz et al. | Sep 1968 | |
| 3423922 | Smith | Jan 1969 | |
| 3474756 | Van Dijk | Oct 1969 | |
| 3848565 | Schweppe | Nov 1974 | |
| 3864901 | Beymes et al. | Feb 1975 | |
| 4311114 | Lees et al. | Jan 1982 | |
| 4334404 | Franzen | Jun 1982 | |
| 4380891 | Wehrmeister | Apr 1983 |
| Entry |
|---|
| "Chemiefasern/Textillindustrie," 27/79 (1977), 1018-1021. |