(under subclass 301.16) Compositions which include a synthetic resin.
SEE OR SEARCH CLASS
520, Synthetic Resins or Natural Rubbers, the Class Definition for a discussion of "synthetic resin."
523, Synthetic Resins or Natural Rubbers,
136, for a composition containing a synthetic resin or natural rubber which is resistant to, yet does not absorb, radioactive materials or cathode rays or to processes of preparing said composition.