METHOD FOR PRODUCING A LITHIUM SILICATE GLASS BLANK AND LITHIUM SILICATE GLASS-CERAMIC BLANK Russian patent published in 2018 - IPC C03C3/97 C03C3/87 C03C10/12 A61K6/02 

FIELD: technological processes.

SUBSTANCE: invention relates to a method for producing a lithium silicate glass preform which can be used as a dental material. To obtain a preform of a composition comprising (wt%) 46–72 SiO₂, 10–25 Li₂O and at least 8 wt%, preferably 9 to 20 wt%, of a stabiliser selected from ZrO₂, HfO₂ or mixtures thereof, raw material in powder form with grain size d₅₀=0.3–1.5 mcm is melted at a temperature T_AU = 1,450–1,600 °C in a reservoir. Melt is kept in the reservoir for a time t_H at least 1 hour, poured into containers, wherein the temperature during pouring from the reservoir is 150–350 °C below the melting point. Containers are filled and the melt is formed therein with a cooling rate of 5 to 100 K/s to a temperature of 600–650 °C.

EFFECT: exclusion of the operation of re-melting the preform in the absence of homogeneity defects, which shortens the process of obtaining products.

15 cl, 4 ex