2. High borosilicate glass is a kind of glass with sodium oxide (Na2O), boron oxide (B2O3) and silicon dioxide (SIO2) as its basic components. The contents of boron and silicon in this kind of glass are relatively high, that is, boron: 12.5~ 13.5% and silicon: 78~80%, so this kind of glass is called high borosilicate glass, which is safe and stable, has no toxic and side effects, and its thermal expansion coefficient is very low, only about one third of that of ordinary glass, so it can withstand sudden temperature difference, for example. It is a good glass cup material commonly used in life.