Interlayer for laminated glass and laminated glass

Abstract

The present invention provides an interlayer film for laminated glass, that exhibits an excellent sound-insulating performance for solid-borne sound in an environment at or below 0° C. Another object is to provide laminated glass that is obtained using this interlayer film for laminated glass. The present invention is an interlayer film for laminated glass, that has a sound-insulating layer for which a temperature T1, which is the temperature that gives the maximum value of tan δ at a frequency of 1 Hz, is in the range from −30° C. to 0° C.

1 . An interlayer film for laminated glass,
 comprising a sound-insulating layer for which a temperature T1, which is a temperature that gives a maximum value of tan δ at a frequency of 1 Hz, is in a range from −30° C. to 0° C.   
     
     
         2 . The interlayer film for laminated glass according to  claim 1 ,
 wherein the sound-insulating layer contains 71 parts by weight or more of plasticizer with respect to 100 parts by weight of polyvinyl acetal resin that has 3 or 4 carbons in an acetal group.   
     
     
         3 . The interlayer film for laminated glass according to  claim 2 ,
 wherein the plasticizer content is 160 parts by weight or less with respect to 100 parts by weight of the polyvinyl acetal resin that has 3 or 4 carbons in the acetal group.   
     
     
         4 . The interlayer film for laminated glass according to  claim 2 ,
 wherein the polyvinyl acetal resin that has 3 or 4 carbons in the acetal group has an average degree of polymerization of 2600 or more.   
     
     
         5 . The interlayer film for laminated glass according to  claim 2 ,
 wherein a quantity of the hydroxyl group in the polyvinyl acetal resin that has 3 or 4 carbons in the acetal group is 21.5 mol % or less.   
     
     
         6 . The interlayer film for laminated glass according to  claim 2 ,
 wherein a quantity of the acetyl group in the polyvinyl acetal resin that has 3 or 4 carbons in the acetal group is 15 mol % or more.   
     
     
         7 . The interlayer film for laminated glass according to  claim 1 ,
 wherein the sound-insulating layer contains 50 parts by weight or more of plasticizer with respect to 100 parts by weight of polyvinyl acetal resin that has 5 or more carbons in the acetal group.   
     
     
         8 . The interlayer film for laminated glass according to  claim 7 ,
 wherein the plasticizer content is 80 parts by weight or less with respect to 100 parts by weight of the polyvinyl acetal resin that has 5 or more carbons in the acetal group.   
     
     
         9 . The interlayer film for laminated glass according to  claim 7 ,
 wherein the polyvinyl acetal resin that has 5 or more carbons in the acetal group has an average degree of polymerization of 2600 or more.   
     
     
         10 . The interlayer film for laminated glass according to  claim 7 ,
 wherein the quantity of the hydroxyl group in the polyvinyl acetal resin that has 5 or more carbons in the acetal group is 39 mol % or less.   
     
     
         11 . The interlayer film for laminated glass according to  claim 7 ,
 wherein the quantity of the acetyl group in the polyvinyl acetal resin that has 5 or more carbons in the acetal group is 5 mol % or more.   
     
     
         12 . The interlayer film for laminated glass according to  claim 1 ,
 wherein the sound-insulating layer is interposed between two protective layers, and the temperature T2, which is the temperature that gives the maximum value of tan δ for the protective layer at a frequency of 1 Hz, is greater than T1.   
     
     
         13 . The interlayer film for laminated glass according to  claim 8 ,
 wherein the temperature T2, which is the temperature that gives the maximum value of tan δ for the protective layer at a frequency of 1 Hz, is in the range from 0° C. to 40° C.   
     
     
         14 . The interlayer film for laminated glass according to  claim 8 ,
 wherein the protective layer contains 25 to 50 parts by weight of plasticizer with respect to 100 parts by weight of a polyvinyl acetal resin in which the acetal group has 3 or 4 carbons, the degree of acetalation is 60 to 75 mol %, and the quantity of acetyl group is 10 mol % or less.   
     
     
         15 . A laminated glass,
 which comprises the interlayer film for laminated glass according to  claim 1 , interposed between two transparent sheets.   
     
     
         16 . A method of producing an interlayer film for laminated glass having a sound-insulating layer for which a temperature T1, which is a temperature that gives a maximum value of tan δ at a frequency of 1 Hz, is in a range from −30° C. to 0° C., which is interposed between two protective layers, and the temperature T2, which is the temperature that gives the maximum value of tan δ for the protective layer at a frequency of 1 Hz, is greater than T1, comprising
 a step of preparing a resin composition for forming the sound-insulating layer and a resin composition for forming the protective layer individually, and 
 a step of co-extruding these resin compositions into a single body. 
 
     
     
         17 . A method of producing an interlayer film for laminated glass having a sound-insulating layer for which a temperature T1, which is a temperature that gives a maximum value of tan δ at a frequency of 1 Hz, is in a range from −30° C. to 0° C., which is interposed between two protective layers, and the temperature T2, which is the temperature that gives the maximum value of tan δ for the protective layer at a frequency of 1 Hz, is greater than T1, comprising
 a step of preparing a resin composition for forming the sound-insulating layer and a resin composition for forming the protective layer individually, and 
 a step of converting these resin compositions into a sheet by extrusion or press molding, and 
 a step of laminating and conversing them into a single body.