Process for forming particles of microporous glass for tobacco smoke filters

Abstract

Abstract This invention relates to a process for forming small particles of microporous glass having interconnected pores suitable to filter tobacco smoke. It particularly relates to a method of melting a phase-separable, metal borosilicate glass composition, quenching the melted glass by contacting the molten glass with a quenching fluid to reduce rapidly the temperature below the strain point of the glass, thereby fracturing the glass into small fragments, phase separating the fragmented glass by treatment at elevated temperatures below the miscibility temperature of the glass for a sufficient period to form a silica-rich phase and a substantially continuous borate-rich phase, then cooling the phase-separated glass, and thereafter leaching the glass to remove a sufficient quantity of the boraterich phase to form microporous particles having interconnected pores.

Inventors

• 👤 Joseph J Hammel

Bibliographic Details