Glass composition and laminated glass

Abstract

A laminated glass having a low haze ratio and an excellent infrared rays shield performance and a glass composition suitable for use in a laminated glass and easy with respect to melting and molding works, which is a glass composition comprising 65 to 74% of SiO 2 , 0 to 5% of B 2 O 3 , 1.9 to 2.5% of Al 2 O 3 , 1.0 to 3.0% of MgO, 5 to 10% of CaO, 0 to 10% of SrO, 0 to 10% of BaO, 0 to 5% of Li 2 O, 13 to 17% of Na 2 O, 0.5 to 5% of K 2 O, 0 to 0.40% of TiO 2 and 0.3 to 2.0% of total iron oxide in terms of Fe 2 O 3 , on a weight basis, in which the sum of MgO, CaO, SrO and BaO is from 10 to 15% and the sum of Li 2 O, Na 2 O and K 2 O is from 14 to 20%, wherein the glass composition has a visible light transmittance of 80% or more as measured with the CIE Standard illuminant A and a total solar energy transmittance of not more than 62% at a thickness of 2.1 mm, and a laminated glass using a glass sheet made of that glass composition.

What is claimed is:  
     
         1 . A glass composition comprising: in % by weight, 65 to 74% of SiO 2 ; 
 0 to 5% of B 2 O 3 ;    1.9 to 2.5% of Al 2 O 3 ;    1.0 to 3.0% of MgO;    5 to 10% of CaO;    0 to 10% of SrO;    0 to 10% of BaO;    0 to 5% of Li 2 O;    13 to 17% of Na z O;    0.5 to 5% of K 2 O;    0 to 0.40% of TiO 2 ; and    0.3 to 2.0% of total iron oxide in terms of Fe 2 O 3  (T-Fe 2 O 3 ),    in which the sum of MgO, CaO, SrO and BaO is 10 to 15%, and the sum of Li 2 O, Na 2 O and K 2 O is 14 to 20%,    wherein, at a thickness of 2.1 mm, the glass composition has a visible light transmittance of 80% or more as measured with the CIE Standard illuminant A and a total solar energy transmittance of not more than 62%.    
     
     
         2 . The glass composition according to  claim 1 , wherein the content of SiO 2  is 65 to 71% by weight, the content of Al 2 O 3  is 2.0 to 2.4% by weight and the content of B 2 O 3  is 0 to 2% by weight.  
     
     
         3 . The glass composition according to  claim 1 , wherein the content of Na 2 O is 14 to 17% by weight, the sum of Li 2 O, Na 2 O and K 2 O is 14.5 to 19% by weight, the content of MgO is 1.0 to 2.0% by weight, and the sum of MgO, CaO, SrO and BaO is more than 10% by weight and less than 12% by weight.  
     
     
         4 . The glass composition according to  claim 1 , which has a melting point (a temperature at log η=2) of not higher than 1,400° C.  
     
     
         5 . The glass composition according to  claim 1 , which has a working point (a temperature at log η=4) of not higher than 1,010° C.  
     
     
         6 . The glass composition according to  claim 1 , wherein the content of T-Fe 2 O 3  is 0.55 to 1.3% by weight, the content of TiO 2  is 0.01 to 0.20% by weight, the content of CeO 2  is 0 to 2.0% by weight, and FeO in terms of Fe 2 O 3  accounts for 22 to 48% of the T-Fe 2 O 3 .  
     
     
         7 . A laminated glass comprising at least two glass sheets and at least one resin layer therebetween, wherein the at least two glass sheets includes at least one glass sheet comprising the glass composition according to  claim 1 , and the laminated glass has a visible light transmittance of 69% or more as measured with the CIE Standard illuminant A and a total solar energy transmittance of not more than 45%.  
     
     
         8 . The laminated glass according to  claim 7 , wherein the total solar energy transmittance is not more than 42%.  
     
     
         9 . The laminated glass according to  claim 7 , wherein the resin layer contains functional fine particles dispersed therein.