Borosilicate glass is obtained by replacing some of the alkali metal oxide in the ordinary glass with boron oxide. The high boron low silicon borosilicate glass with no alkali metal oxide. Coronal glass and barium - coronal glass belong to an alkali borosilicate glass system. Recoronal glass belongs to the alkali free borosilicate glass system. The content of B2O5 is gradually increased in borosilicate glass, and this phenomenon is called the anomalous phenomenon of boron. It has good chemical stability, so it has been widely used in chemical industry.