Glass and glass product

Abstract

A glass having a high coefficient of thermal expansion and excellent thermal shock resistance is prepared from the following raw materials in mole percentage: SiO2: 55-80%; B2O3: 0-10%; Al2O3: 0-10%;ZnO: 2-20%; MgO: 0-15%; Li2O+Na2O+K2O: not more than 30%. The glass obtained by the invention has higher thermal expansion coefficient and excellent thermal shock resistance through reasonable proportion of components. The glass of the invention is suitable for chemical strengthening, and the glass product obtained after chemical strengthening has larger surface stress and deeper stress layer depth.

Description

technical field [0001] The present invention relates to a kind of glass, especially relates to a kind of glass and glass products with relatively large coefficient of thermal expansion and excellent thermal shock resistance. Background technique [0002] In recent years, aspheric spectacle lenses with a refractive index greater than 1.70 and multifocal aspheric resin spectacle lenses have been widely used in the field of myopia correction. [0003] The current mainstream method of producing resin lenses is to inject molten resin into the upper and lower molds designed according to the curvature of the spectacle lens, and separate the upper and lower molds after the resin cools down to obtain resin spectacle lenses that meet the requirements. The key to determining the quality and yield of resin lenses is the material and design of the injection mold. [0004] Glass precision molding molds usually use silicon carbide or tungsten carbide, but the coefficient of thermal expa...

AI Technical Summary

Problems solved by technology

[0005] Not all glasses can be used as resin molds. Glass with a large expansion coefficient is beneficial to improve the surface quality of resin lenses. However, in the prior art, glass with a large expansion coefficient often has low thermal shock resistance. In the process, especially in the cooling process, the glass mold will be subject to strong thermal shock. If the thermal shock resistance is poor, the glass mold will burst. Therefore, the resin lens mold glass needs to have excellent thermal shock resistance.

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