| Number | Name | Date | Kind |
|---|---|---|---|
| 1390736 | Wadsworth | Sep 1921 | |
| 1485846 | Griffin | Mar 1924 | |
| 1699735 | Dabrohua et al. | Jan 1929 | |
| 1873178 | Bernstein | Aug 1932 | |
| 2160426 | Archer | May 1939 | |
| 2484096 | Kay | Oct 1949 | |
| 3143817 | Paulson | Aug 1964 | |
| 3200786 | Swezy et al. | Aug 1965 | |
| 3526200 | Doyle | Sep 1970 | |
| 4426800 | Brown | Jan 1984 | |
| 4490934 | Knapp | Jan 1985 | |
| 4507887 | Seely | Apr 1985 | |
| 4798356 | Alonso | Jan 1989 | |
| 4888894 | Brown | Dec 1989 | |
| 4980984 | Kulp et al. | Jan 1991 |
| Number | Date | Country |
|---|---|---|
| 9110986 | Jul 1991 | WOX |
| Entry |
|---|
| 1975-1976 Modern Plastics Encyclopedia, Plastic Properties Chart on p. 480. |