521 / | HD | SYNTHETIC RESINS OR NATURAL RUBBERS -- PART OF THE CLASS 520 SERIES |
* | SYNTHETIC RESINS (Class 520, Subclass 1) {3} | |
25 | DF | .~> ION-EXCHANGE POLYMER OR PROCESS OF PREPARING {7} |
40 | DF | .~> PROCESS OF TREATING SCRAP OR WASTE PRODUCT CONTAINING SOLID ORGANIC POLYMER TO RECOVER A SOLID POLYMER THEREFROM {5} |
50 | DF | .~> CELLULAR PRODUCTS OR PROCESSES OF PREPARING A CELLULAR PRODUCT, E.G., FOAMS, PORES, CHANNELS, ETC. {27} |