Pyrex patentedIn 1919, Pyrex glass was issued a U.S. patent (No. 1,304,623). The inventors, Eugene C. Sullivan and William C. Taylor were company research chemists who assigned the patent to Corning Glass Works. Pyrex is the trademark for their sodium borosilicate glass. The original patent, filed on 24 Jun 1915, foresaw the applications including glass baking dishes and laboratory ware. The useful properties of this composition of glass were a low linear thermal expansivity, relatively high coefficient of thermal conductivity (internal heat transfer) and high stability (to resist chemical attack). The composition specified a high silica content of more than 70%. The patent included a discussion of the role of including in the composition certain porportions of alumina, boric acid, antimony and lithia.« |
