(under subclass 426) Product in which a second layer contiguous with the quartz or glass layer contains boron in either its free or chemically combined state.
SEE OR SEARCH THIS CLASS, SUBCLASS:
366, for a rod*, strand* filament* or fiber* including boron or a compound thereof either as a coating or as the fiber*.
902, for a cross-reference art collection of high modulus filaments* or fibers* which may be of or include boron.
