Leadless low-melting point glasses with very high refractive index and method for making same

Abstract

The invention relates to a leadless low-melting-point bismuthate glass and a corresponding preparation method. The glass consists of Bi2O3 (20 to 75), B2O3 (10 to 50), BaO (0 to 20), Ga2O3 (0 to 20), La2O3 (0 to 10), Sb2O3 (0 to 5), SiO2 (0 to 15), TiO2 (0 to 5), ZrO2 (0 to 5), Nb>O5 (0 to 5), Ta2O5 (0 to 5) and CeO2 (0 to 1). The glass of the invention is provided with glass transition temperature T<g> which is less than or equal to 395.8 DEG C, and a thermal stability parameter Delta T which is greater than or equal to 88 DEG C, and the refractive index n<d> which is up to 2.182; and the highest transmittance can reach 80 percent in a wave range between 400nm and 1600nm. The glass is suitable to be adopted as material with low fusion-point and high refractive index.

Description

technical field [0001] The invention relates to glass, in particular to a lead-free low melting point high refractive index glass and a preparation method thereof. Background technique [0002] In optical design and optical communication, optical glass with a refractive index between 1.9 and 2.2 is of great significance to simplify the optical system and improve the imaging quality. The development of ultra-high refractive index optical glass is very urgent for the further miniaturization of mobile phones and digital cameras and the advancement of optical communication technology. However, traditional high-refractive-index optical glass contains a large amount of arsenic and lead, and its refractive index is only between 1.8 and 1.85, which not only has a gap in technical indicators, but also hinders environmental protection. [0003] Optical glass used in optical communication and digital cameras, such as aspheric glass lenses, ball lenses, prisms, etc., usually requires a...

AI Technical Summary

Problems solved by technology

However, the preparation conditions of chalcogenide glass are complicated, the chemical stability of the glass is poor, and the transmittance in the visible light range is low, which cannot fully meet the requirements of lens optical glass.

In Chinese patent CN 1583626A, a Bi 2 o 3 -PbO glass, although this glass has good infrared transmission performance, it has a high glass transition temperature, which is not conducive to the preparation of pressed optical glass

Although lead oxide can improve the crystallization performance of glass and increase the refractive index, due to the large amount of volatilization of lead in the melting process, it will cause serious environmental pollution and cause serious harm to the operator's body.

Chinese patent CN 1930098A introduces a lead-free low-melting glass, which has a relatively low softening point (500°C to 630°C), but the glass has a relatively low refractive index and is not suitable for molding with a high refractive index lens glass

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