GLAZE Russian patent published in 2008 - IPC C03C8/12 

FIELD: chemistry.

SUBSTANCE: present invention concerns silicate technology and fritted glaze compositions that can be efficiently applied in facing tile production. The glaze contains SiO₂, Al₂O₃, B₂O₃, CaO, MgO, ZnO, Na₂O, K₂O, ZrO₂, Fe₂O₃, CuO and TiO₂ in the following component ratio, in mass %: SiO₂ - 55.0-61.0; Al₂O₃ - 6.0-8.0; B₂O₃ - 10.0-12.0; CaO - 2.0-6.0; MgO - 6.0-8.0; ZnO - 2.0-3.0; Na₂O - 1.0-2.0; K₂O - 1.0-2.0; ZrO₂ - 4.0-6.0; Fe₂O₃ - 0.2-0.4; CuO - 0.6-0.8; TiO₂ - 1.0-2.0.

EFFECT: improved frost resistance of glaze.

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