Environment friendly heavy-lanthanide flint optical glass

Abstract

The invention provides environmental-friendly dense-lanthanum optical flint glass, comprising the following compositions in percentage by weight: 1 to 9 percent of SiO2, 15 to 30 percent of B2O3, 10 to 25 percent of La2O3, 10 to 30 percent of Nb2O5, 0 to 3 percent of Li2O, 0 to 6 percent of Na2O, 0 to 3 percent of K2O, 0 to 3 percent of MgO, 0 to 8 percent of CaO, 0 to 3 percent of SrO, 5 to 25 percent of BaO, 0 to 15 percent of TiO2, 0 to 10 percent of ZrO2, 0 to 3 percent of GeO2, 0 to 3 percent of WO3, 0 to 3 percent of P2O5, 0 to 3 percent of Gd2O3, 0 to 3 percent of Ta2O5, and 0 to 1 percent of Sb2O3. The optical flint glass has a refractive index between 1.81 and 1.90, an Abbe number between 25 and 33, and no PbO and As2O3, and has perfect optical property and excellent devitrification resistance.

Description

technical field [0001] The invention relates to lead-free, arsenic-free heavy lanthanum flint optical glass with high refractive index and high dispersion. Background technique [0002] In recent years, with the development of the optoelectronic industry, the requirements for miniaturization, light weight and high performance of optical components have been put forward. High refractive index glasses with a refractive index above 1.81 are suitable as optical components for manufacturing such miniaturized and lightweight optical components. glass material. Traditionally used optical glass with a high refractive index usually contains PbO to obtain ideal optical performance, but with the improvement of people's environmental awareness, more and more countries have proposed the environmental protection requirements of lead-free and arsenic-free optical materials . We know that the introduction of TiO in silicate-based or borate-based glasses 2 , Nb 2 o 5 , La 2 o 3 , Y 2...

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Problems solved by technology

[0003] U.S. Patent US4734389 describes an optical glass with a refractive index nd greater than 1.83 and an Abbe number Vd less than 25. Chinese patent CN1931755A describes an optical glass with a refractive index nd greater than 1.80 and an Abbe number Vd less than 30. In the above two glasses, TiO 2 Contents are 25-30% and 22-37%, respectively, in such a high TiO 2 When the content is low, the glass is easy to devitrify, the light absorption performance is poor, and the transmission performance shows a tendency to move to the long-wave side. TiO 2 Excessive content will also cause glass coloring, high softening temperature and high hardness of glass, which increases the difficulty of secondary molding and mechanical processing

[0004] U.S. Patent No. 5,288,669 describes an optical glass with a refractive index nd greater than 1.88 and an Abbe number Vd greater than 29. The disadvantage of this glass is that the viscosity of the glass is small, and the glass is easily devitrified. The viscosity of the glass near the liquidus temperature (about 1150 ° C) is only In the process of melting and forming, the glass is very easy to devitrify, and it is difficult to obtain transparent optical glass

[0005] Japanese Patent Laid-Open No. 63-265840 describes a SiO 2 -TiO 2 -Nb 2 o 5 It is an optical glass, which contains 0.5% PbO in its composition, which is not conducive to the requirements of environmental protection. In addition, it contains a relatively large amount of SiO 2 , the glass is difficult to melt and it is difficult to make optical glass with a refractive index greater than 1.82

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