Optical glass

Abstract

The invention provides optical glass which takes SiO2, B2O3, BaO and La2O3 as main components and contains no lead, thorium, cadmium, arsenic and fluorine. The refractive index (nd) of the optical glass is between 1.68-1.70, and the abbe number (vd) of the optical glass is 48-50. The optical glass has the characteristic of good crystallization property and is suitable for production. Through test according to a GB / T 17129 method, the water resistance (DW) of the optical glass is grade 1, and the acid resistance of the optical glass (DA) is grade 3 or above. The optical glass comprises the following components in percentage by weight: 21-25 percent of SiO2, 8-14 percent of B2O3, 12-18 percent of La2O3, 0.5-3 percent of ZrO2, 34-40 percent of BaO, 2-5 percent of TiO2, 2-5 percent of ZnO, 2-7 percent of CaO, 0-3 percent of Al2O3 and 0-1 percent of Sb2O3, and the total content of the components is above 95 percent, and the total content of glass components is 100 percent.

Description

technical field [0001] The invention relates to an optical glass, in particular to a silicate lanthanide optical glass with a refractive index (nd) between 1.68-1.70 and an Abbe number (vd) between 48-50. Background technique [0002] In recent years, optical glass with a refractive index (nd) between 1.68 and 1.70 and an Abbe number (vd) between 48 and 50 has been widely used in optical pickup lenses for CD, DVD and other optical disc systems. It is also widely used in photographic lenses. In order to make the glass have the above properties, the existing invention patents often contain more Nb 2 o 5 , ZnO, Li 2 O and other components, but too much of these components will lead to defects such as low glass viscosity, difficult molding, difficulty in obtaining high-quality streaks, and severe crystallization. [0003] The glass disclosed in the patent CN101389574A belongs to the same kind of glass as the present invention, but it contains Gd as an essential component and...

AI Technical Summary

Problems solved by technology

In order to make the glass have the above properties, the existing invention patents often contain more Nb 2 o 5 , ZnO, Li 2 O and other components, but too much of these components will lead to defects such as low glass viscosity, difficult molding, difficulty in obtaining high-quality streaks, and severe crystallization.

[0003] The glass disclosed in the patent CN101389574A belongs to the same kind of glass as the present invention, but it contains Gd as an essential component and is expensive, with a content of more than 15% 2 o 3 Composition and more than 2.5% of Li will corrode the smelting device and destroy the glass network structure, making the crystallization performance of the glass worse. 2 O component, this does not meet the purpose requirement of the present invention, in addition CN101389574A also contains more than 10% ZnO, too much ZnO will make glass devitrification resistance and chemical stability worse

[0004] The glass disclosed in patent CN1202033C belongs to the same kind of glass as the present invention, but it contains more than 6% ZnO, which is different from the protection scope of the present invention, and too much ZnO will make the glass devitrification resistance and chemical stability worse , at the same time, more ZnO will make the viscosity of the glass smaller, making the molding more difficult, and it is difficult to obtain a glass with higher uniformity

[0005] The glass disclosed in the patent CN101844866A belongs to the same kind of glass as the present invention, but it contains SnO as an essential component 2 Composition and less than 1% TiO 2 , which is different from the protection scope of the present invention, and SnO 2 The composition will affect the melting performance of the glass, and even produce infusibles, which will affect the uniformity and internal quality of the glass, and less TiO 2 will promote the introduction of more Nb 2 o 5 , which will deteriorate the crystallization performance of the glass

[0006] The glass disclosed in the patent CN101389576A belongs to the same kind of glass as the present invention, but it contains Gd as an essential component and is expensive, with a content of more than 10% 2 o 3 Composition and more than 1.5% of Li will corrode the smelting device and destroy the glass network structure, making the crystallization performance of the glass worse. 2 O component, which does not meet the requirements for the purpose of the present invention

[0007] The glass disclosed in the patent CN1967287A belongs to the same kind of glass as the present invention, but it contains Gd as an essential component and is expensive 2 o 3 Composition and more than 2% Li will corrode the smelting device and destroy the glass network structure, making the crystallization performance of the glass worse. 2 O component, this does not meet the purpose requirement of the present invention, in addition CN1967287A also contains more than 10% ZnO, too much ZnO will make glass devitrification resistance and chemical stability worse

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