Patent ID: 8647539

Claim:
A process for producing a near infrared cut filter glass, the process comprising: mixing a glass material and an oxidant for oxidizing Sb, thereby obtaining a raw material mixture; and melting the raw material mixture, thereby obtaining the near infrared cut filter glass, wherein: the glass material comprises, by mass based on a total amount of the raw material mixture: P 2 O 5 : from 30 to 55%, AlF 3 : from 5 to 15%, at least one alkaline earth metal fluoride selected from the group consisting of MgF 2 , CaF 2 , SrF 2 and BaF 2 : from 1 to 50% in terms of a total amount of MgF 2 +CaF 2 +SrF 2 +BaF 2 , ZnF 2 : from 0 to 20%, at least one alkaline metal fluoride selected from the group consisting of LiF, NaF and KF: from 1 to 16% in terms of a total amount of LiF+NaF+KF, CuO: from 5 to 14%, and Sb 2 O 3 : from 0.1 to 3%; up to 70% of fluorides based on a total amount of the fluorides in the glass material are optionally substituted by oxides; the oxidant for oxidizing Sb is in an amount of from 0.1 to 5% by mass based on the total amount of the raw material mixture; and the oxidant for oxidizing Sb comprises at least one compound selected from the group consisting of a nitrate compound, a sulfate compound, a peroxide, a perchlorate and chloric acid.