- 专利标题: Colored photochromic glasses and method
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申请号: US650846申请日: 1984-09-17
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公开(公告)号: US4537612A公开(公告)日: 1985-08-27
- 发明人: Nicholas F. Borrelli , George B. Hares , Dennis W. Smith , Brent M. Wedding
- 申请人: Nicholas F. Borrelli , George B. Hares , Dennis W. Smith , Brent M. Wedding
- 申请人地址: NY Corning
- 专利权人: Corning Glass Works
- 当前专利权人: Corning Glass Works
- 当前专利权人地址: NY Corning
- 主分类号: C03C4/06
- IPC分类号: C03C4/06 ; C03C21/00 ; C03C23/00 ; C03C3/26
摘要:
This invention is directed to a method for modifying the coloration produced in a silver halide-containing photochromic glass when heat treating the glass at a temperature not exceeding 450.degree. C. under reducing conditions. The method comprises subjecting such a glass having a base composition which contains at least 1% by weight Li.sub.2 O, at least 2% by weight Na.sub.2 O, and at least 6% by weight Li.sub.2 O+Na.sub.2 O+K.sub.2 O to an ion exchange reaction, wherein lithium ions, and potassium ions, when the latter are present in the composition, in the glass surface are exchanged with sodium ions from an external source, prior to the reduction heat treatment.