Low barium high refractive index glass micropearl

Abstract

A high-refractivity low-Ba glass micro-bead is a TiO2-ZrO2-SiO2 system and is proportionally prepared from TiO2, ZrO2, SiO2, Al2O3, B2O3, ZnO and BaO. The content of its free Ba is less than 1000 mg / kg.

Description

technical field [0001] The invention relates to the technical field of glass microsphere manufacture, in particular to the manufacture of retroreflective low-barium high-refractive-index glass microspheres. Background technique [0002] As microbead glass for retroreflection, because it is expected to have higher reflective intensity, high refractive index oxides such as lead oxide, titanium oxide, and barium oxide are usually used to make the refractive index of bead glass reach 1.9 or more. German patent DD258133, British patent GB1130284, and U.S. patent USP3293051 all use a large amount of lead oxide, but because lead-containing products pollute the environment and endanger people's health in the process of manufacture and use, such lead-containing microbeads have been banned in various countries manufacture and use. U.S. Patent USP3419403, Chinese Patent CN86106629, and Chinese Patent CN99114956 all use TiO 2 -BaO system, a large amount of barium oxide with a low refr...

AI Technical Summary

Problems solved by technology

German patent DD258133, British patent GB1130284, and U.S. patent USP3293051 all use a large amount of lead oxide, but because lead-containing products pollute the environment and endanger people's health in the process of manufacture and use, such lead-containing microbeads have been banned in various countries manufacture and use

U.S. Patent USP3419403, Chinese Patent CN86106629, and Chinese Patent CN99114956 all use TiO 2 -BaO system, a large amount of barium oxide with a low refractive index exists, which is not conducive to increasing the refractive index, so a large amount of bismuth oxide, antimony oxide or lanthanum oxide, niobium oxide, and tungsten oxide have to be introduced to increase the refractive index. These precious raw materials are introduced to make the glass Increased cost and affects the stability and anti-devitrification performance of the glass

More importantly, according to European Standard EN71 Part 3, the content of "free barium" in microbead materials shall not exceed 1000mg / Kg, and the presence of a large amount of barium oxide makes the "free barium" of microbeads made of these glass The content seriously exceeds the standard, which limits the scope of use of microbeads. Although the content of "free barium" can reach the standard after complex treatment of microbeads, this kind of treatment is cumbersome and complicated, time-consuming and laborious, which not only increases the cost, but also has "three wastes" emissions, pollute the environment