光学ガラスの耐青ヤケ試験法

抄録

The staining resistivity of the optical glass is not only related to the forming rate of the stained layer but also dependent on the visibility of the stained layer formed. Therefore. it should be determined by measuring the time needed to form the stained layer which gives a certain value of the visibility. We established the new measuring method based on such a consideration. In the previous measuring method for chemical durability, most of dense flint glasses were known to have relatively high staining resistivity. However, in spite of the relatively slow rate of formation of the stained layer, the visibility of the layer is considerably high due to the big difference in refractive indices between the formed layer and the bulk glass. Accordingly, it takes considerably short time to form the visible stained layer. In the new measuring method, most of dense flint glasses are considered to be the glass having poor staining resistivity. This corresponds well to the results obtained in manufacturing process.