Nickel ion-free blue glass composition

Abstract

A blue glass composition is disclosed. This blue glass composition is based on a standard formulation for soda/lime silica glass, except that neither the basic glass composition nor the coloring components therefor contains nickel. The blue glass color is developed by using coloring components consisting essentially of 0.3-0.6% Fe 2 O 3 , 0.004-0.008% .[.Co 3 O 4 .]. .Iadd.Co, .Iaddend.and is a neutral blue having a dominant wavelength of 482 nm±1 nm, color purity of 13%±1% and transmission (T) equal to at least 54%±1% using Illuminant C (corrected to 0.25 inch glass thickness).

We claim: 
     
       1. A blue glass composition having no nickel ion contained therein and having a dominant wavelength of 482 mm±1 nm, color purity of 13%±1% and light transmission (T) equal to 54%±1% using Illuminant C corrected to 0.25 inch glass thickness, and consisting essentially of the following base components in percent by weight: 68-75% SiO 2 , 0-5% Al 2  Ohd 3, 5-15% CaO, 0-10% MgO, 10-18% Na 2  O, 0-5% K 2  O, where CaO+MgO is 6-15% and Na 2  O+K 2  O is 10-20%, together with coloring components of 0.42% Fe 2  O 3 , 0.005% 1∫Co 3  O 4  .]. .Iadd.Co.Iaddend., and 0.003% Se.