Dark gray colored glass

Abstract

A dark gray colored glass comprising 100 parts by weight of a soda lime silicate glass as a matrix component and coloring components consisting essentially of from 0.8 to 1.5 parts by weight of total iron calculated as Fe 2 O 3 , from 0.1 to 0.3 part by weight of FeO, from 0 to 1.0 part by weight of TiO 2 , from 0.0005 to 0.015 part by weight of Se, from 0.02 to 0.05 part be weight of CoO and from 0.002 to 0.05 part by weight of Cr 2 O 3 .

What is claimed is:  
     
       1. A dark gray colored glass comprising 100 parts by weight of a soda lime silicate glass as a matrix component and coloring components consisting essentially of from 0.8 to 1 parts by weight of total iron calculated as Fe 2 O 3 , from 0.1 to 0.3 part by weight of FeO, from 0 to 1.0 part by weight of TiO 2 , from 0.0005 to 0.15 part by weight of Se, from 0.021 to 0.05 part by weight of CoO and from 0.002 to 0.05 part by weight of Cr 2 O 3  wherein the glass with a thickness of from 3 to 5 mm has an excitation purity of at most 7%, as measured by using illuminant C 
       and wherein the glass with a thickness of 5 mm has a visible light transmittance of at most 20% and a solar radiation transmittance of at most 20% as measured using illuminant A.  
     
     
       2. The dark gray colored glass according to  claim 1 , wherein a proportion of ferrous iron calculated as Fe 2 O 3  in the total iron calculated as Fe 2 O 3  is from 10 to 30%. 
     
     
       3. The dark gray colored glass according to  claim 1 , wherein the glass with a thickness of 5 mm has an ultraviolet ray transmittance of at most 10%. 
     
     
       4. The dark gray colored glass according to  claim 1 , wherein the glass with a thickness of from 3 to 5 mm has a dominant wavelength of from 490 to 580 nm, as measured by using illuminant C. 
     
     
       5. The dary gray colored glass according to  claim 1 , wherein the soda lime silicate glass comprises from 65 to 75 wt % of SiO 2 , from 0.1 to 5 wt % of Al 2 O 3 , from 10 to 18 wt % of Na 2 O+K 2 O, from 5 to 15 wt % of CaO and from 1 to 6 wt % of MgO. 
     
     
       6. A glass sheet which is made of the dark gray colored glass according to  claim 1 , and which has a thickness of from 2.6 to 6 mm. 
     
     
       7. The dark gray colored glass according to  claim 1 , wherein the amount of Cr 2 O 3  is from 0.002 to 0.015 part by weight. 
     
     
       8. The dark gray colored glass according to  claim 1 , wherein said glass does not contain NiO. 
     
     
       9. The dark gray colored glass according to  claim 1 , wherein said glass does not contain NiS. 
     
     
       10. A dark gray colored glass comprising  100  parts by weight of a soda lime silicate glass as a matrix component and coloring components consisting essentially of from  1 . 0  to  1 . 35  parts by weight of total iron calculated as Fe 2   O   3   , from  0 . 1  to  0 . 3  part by weight of FeO, from  0  to  1 . 0  part by weight of TiO   2   , from  0 . 0005  to  0 . 015  part by weight of Se, from  0 . 021  to  0 . 05  part by weight of CoO and from  0 . 002  to  0 . 05  part by weight of Cr   2   O   3    wherein the glass with a thickness of from  3  to  5  mm has an excitation purity of at most  7   % , as measured by using illuminant C    
         and wherein the glass with a thickness of  5  mm has a visible light transmittance of at most  20   %  as measured using illuminant A, and a solar radiation transmittance of at most  20   % .   
     
     
       11. The dark gray colored glass according to  claim 10 , wherein a proportion of ferrous iron calculated as Fe 2   O   3    in the total iron calculated as Fe   2   O   3    is from  10  to  30   % .   
     
     
       12. The dark gray colored glass according to  claim 10 , wherein the glass with a thickness of  5  mm has an ultraviolet ray transmittance of at most  10 % .   
     
     
       13. The dark gray colored glass according to  claim 10 , wherein the glass with a thickness of from  3  to  5  mm has a dominant wavelength of from  490  to  580  nm, as measured by using illuminant C. 
     
     
       14. The dark gray colored glass according to  claim 10 , wherein the soda lime silicate glass comprises from  65  to  75  wt %  of SiO   2   , from  0 . 1  to  5  wt  %  of Al   2   O   3   , from  10  to  18  wt  %  of Na   2    O+K   2   O, from  5  to  15  wt  %  of CaO and from  1  to  6  wt  %  of MgO.   
     
     
       15. A glass sheet which is made of the dark gray colored glass according to  claim 10 , and which has a thickness of from  2 . 6  to  6  mm. 
     
     
       16. The dark gray colored glass according to  claim 10 , wherein the amount of Cr 2   O   3    is from  0 . 002  to  0 . 015  part by weight.   
     
     
       17. The dark gray colored glass according to  claim 10 , wherein said glass does not contain NiO. 
     
     
       18. The dark gray colored glass according to  claim 10 , wherein said glass does not contain NiS.