| 摘要 |
<p>A plate glass containing B2O3, having a total content of Li2O, Na2O and K2O of from 0 to 13 mol%, a content of BaO of from 0 to 0.8 mol% and a content of SiO2 of from 50 to 75 mol%, and having an average linear thermal expansion coefficient of from 75x10<-7> to 120x10<-7>/ DEG C in a range of from 50 to 350 DEG C, a strain point of at least 550 DEG C, a density of at most 2.65 g/cm<3> at 20 DEG C and an oxygen atom density of from 7.2x10<-2> to 9.0x10<-2> mol/cm<3> at 20 DEG C. <IMAGE></p> |
