LITHIUM-SILICATE GLASS CERAMICS Russian patent published in 2019 - IPC C03C10/04 C03C3/97 C03C10/12 

FIELD: medicine.

SUBSTANCE: invention relates to lithium-silicate glass-ceramic for dental purposes, which contains at least lithium disilicate as main crystalline phase and lithium aluminosilicate as an additional crystalline phase. Lithium-silicate glass-ceramic in the initial composition contains the following components, wt%: 54–62 SiO₂, 5–6 P₂O₅, 1.5–3.5 Al₂O₃, 13–16 Li₂O 0.6–1.8 K₂O, 8–11.5 ZrO₂, 0–6 B₂O₃, 0–1.9 Na₂O and colored pigments of up to 8. Method of producing lithium-silicate ceramics of the disclosed composition involves melting the initial components, loading the melt into containers with subsequent cooling and crystallisation of the molded parts. Crystallisation is carried out in two steps: at the first step, the parts are heated step-by-step to 700–850 °C with two intermediate exposures, at second step – to temperature of 720–760 °C with holding for preferably 1–5 minutes. Second stage of heat treatment ensures production of lithium aluminosilicate crystals.

EFFECT: obtaining glass-ceramic material of high strength when achieving improvement of color and elimination of blotchiness.

22 cl, 2 ex, 5 dwg