Interlayer for laminated glass and laminated glass

Abstract

The present invention provides an interlayer for laminated glass which comprises at least one layer composed of an opaque ethylene-vinyl acetate copolymer resin composition or opaque polyvinyl acetal resin composition, and also provides the laminated glass using such interlayers. The interlayer for laminated glass and the laminated glass according to the present invention can offer excellent privacy protection.

1 - 16 . (canceled) 
     
     
         17 . An interlayer for laminated glass, which comprises at least two kinds of layers of (A) an opaque and sound-insulating polyvinyl acetal resin layer containing fine-particle inorganic powder and 45 parts by weight or more of a plasticizer per 100 parts by weight of a polyvinyl acetal resin, and (B) a transparent polyvinyl acetal resin layer, the layers being laminated together,
 wherein the amount of the plasticizer in (A) the opaque and sound-insulating polyvinyl acetal resin layer is larger than the amount of the plasticizer in (B) the transparent polyvinyl acetal resin layer, and   wherein (A) the opaque and the sound-insulating polyvinyl acetal resin layer has a different viscoelastic property than (B) the transparent polyvinyl acetal resin layer.   
     
     
         18 . The interlayer for laminated glass according to  claim 17 , wherein the fine-particle inorganic powder is calcium carbonate or silica. 
     
     
         19 . The inter layer for laminated glass according to  claim 17 , wherein the amount of the particle inorganic powder is in the range of 0.3 to 30 parts by weight, per 100 parts by weight of the polyvinyl acetal resin. 
     
     
         20 . The inter layer for laminated glass according to  claim 17 , wherein (B) the transparent polyvinyl acetal resin layer comprises polyvinyl acetal resin (b) with a vinyl acetate content (residual acetyl groups) of not more than 14 mol % produced by acetalization of a polyvinyl alcohol with an aldehyde having 3 to 4 carbon atoms and a plasticizer. 
     
     
         21 . The inter layer for laminated glass according to  claim 17 , wherein at least either one of (A) the opaque and sound-insulating polyvinyl acetal resin layer and (B) the transparent polyvinyl acetal resin layer contains heat-ray shielding fine particles. 
     
     
         22 . A laminated glass comprising at least two transparent glass sheets, wherein the interlayer for laminated glass according to  claim 17  is bonded between at least two glass sheets. 
     
     
         23 . The inter layer for laminated glass according to  claim 18 , wherein the amount of the particle inorganic powder is in the range of 0.3 to 30 parts by weight, per 100 parts by weight of the polyvinyl acetal resin. 
     
     
         24 . The inter layer for laminated glass according to  claim 18 , wherein (B) the transparent polyvinyl acetal resin layer comprises polyvinyl acetal resin (b) with a vinyl acetate content (residual acetyl groups) of not more than 14 mol % produced by acetalization of a polyvinyl alcohol with an aldehyde having 3 to 4 carbon atoms and a plasticizer. 
     
     
         25 . The inter layer for laminated glass according to  claim 18 , wherein at least either one of (A) the opaque and sound-insulating polyvinyl acetal resin layer and (B) the transparent polyvinyl acetal resin layer contains heat-ray shielding fine particles. 
     
     
         26 . A laminated glass comprising at least two transparent glass sheets, wherein the interlayer for laminated glass according to  claim 21  is bonded between at least two glass sheets. 
     
     
         27 . A laminated glass comprising at least two transparent glass sheets, wherein the interlayer for laminated glass according to  claim 25  is bonded between at least two glass sheets.