KURZ-FLINT OPTICAL GLASS Russian patent published in 2013 - IPC C03C3/66 

FIELD: chemistry.

SUBSTANCE: invention relates to production of special flint type optical glass for making glass pairs in a high-aperture double-lens apochromatic object glass. The kurz-flint type optical glass contains SiO₂, B₂O₃, Al₂O₃, K₂O, Na₂O, ZnO, CaO, ZrO₂, Ta₂O₅, GeO₂ and As₂O₃ with the following ratio of components (in wt %): SiO₂ 12.5-30.3; B₂O₃ 37-49.2; Al₂O₃ 4-6; K₂O 1-5; Na₂O 1.4-4; ZnO 2.5-3.9; CaO 2-4; ZrO₂ 1.9-6; Ta₂O₅ 7.5-14.2; GeO₂ 4-6; As₂O₃ 0.1-1. The glass has melting temperature of 1450-1470°C and group A-II chemical resistance.

EFFECT: optical glass with low relative partial dispersion values.

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