Laminated glass, and method for producing same

1. A laminated glass comprising a first glass substrate, a first adhesive layer, a heat reflective film, a second adhesive layer and a second glass substrate, laminated in this order,

wherein the heat reflective film comprises a resin film having a thermal shrinkage in a direction that a thermal shrinkage becomes maximum, of 0.5% or more and 3% or less and a thermal shrinkage in a direction orthogonal to the direction of 0.1% or more and 2% or less, and a heat reflective coating formed on the resin film;

the first adhesive layer and the second adhesive layer comprise a polyvinyl butyral film having a thermal shrinkage in a direction that a thermal shrinkage becomes maximum, of 0.5% or more and 3% or less and a thermal shrinkage in a direction orthogonal to the direction of −2.5% or more and −0.5% or less; and

the direction that a thermal shrinkage becomes maximum, of the resin film and the direction that a thermal shrinkage becomes maximum, of the polyvinyl butyral film are orthogonal to each other;

provided that the thermal shrinkage of the resin film is a thermal shrinkage when the resin film is maintained at 150° C. for 30 minutes, and the thermal shrinkage of the polyvinyl butyral film is a thermal shrinkage when the polyvinyl butyral film is maintained at 60° C. for 30 minutes.

2. The laminated glass according to claim 1 , wherein the resin film has a thickness of 5 μm or more and 200 μm or less.

3. The laminated glass according to claim 1 , wherein the resin film comprises polyethylene terephthalate.

4. The laminated glass according to claim 1 , wherein the polyvinyl butyral film has a thickness of 50 μm or more and 1,000 μm or less.

5. A method for manufacturing a laminated glass, the method comprising:

an intermediate production step of overlaying first and second polyvinyl butyral films on both surfaces of a heat reflective film, followed by heating and pressuring, thereby obtaining an intermediate; and

a pressing step of overlaying first and second glass substrates on both surfaces of the intermediate, followed by heating and pressuring, thereby obtaining a laminated glass,

wherein the heat reflective film comprises a resin film having a thermal shrinkage in a direction that a thermal shrinkage becomes maximum, of 0.5% or more and 3% or less and a thermal shrinkage in a direction orthogonal to the direction of 0.1% or more and 2% or less, and a heat reflective coating formed on the resin film;

the first and second polyvinyl butyral films have a thermal shrinkage in a direction that a thermal shrinkage becomes maximum, of 0.5% or more and 3% or less and a thermal shrinkage in a direction orthogonal to the direction of −2.5% or more and −0.5% or less; and

in the intermediate production step, the heat reflective film and the first and second polyvinyl butyral films are overlaid such that the direction that a thermal shrinkage becomes maximum, of the resin film and the direction that a thermal shrinkage becomes maximum, of the first and second polyvinyl butyral films are orthogonal to each other;

provided that the thermal shrinkage of the resin film is a thermal shrinkage when the resin film is maintained at 150° C. for 30 minutes, and the thermal shrinkage of the polyvinyl butyral film is a thermal shrinkage when the polyvinyl butyral film is maintained at 60° C. for 30 minutes.

6. The method for manufacturing a laminated glass according to claim 5 , wherein the heating and pressuring in the intermediate production step are conducted under conditions of temperature: 40 to 80° C. and pressure: 0.1 to 1.0 MPa.

7. The method for manufacturing a laminated glass according to claim 5 , wherein the heating and pressuring in the pressing step are conducted under conditions of temperature: 120 to 150° C. and pressure: 0.98 to 1.47 MPa.

8. The method for manufacturing a laminated glass according to claim 5 , wherein in the pressing step, the heating and pressuring are conducted after preliminary pressing of heating to 70 to 120° C. while deaerating so as to achieve pressure: 1 to 100 kPa.

9. A method for manufacturing a laminated glass, the method comprising:

a lamination step of overlaying a first glass substrate, a first polyvinyl butyral film, a heat reflective film, a second polyvinyl butyral film and a second glass substrate in this order to obtain an unpressed laminated glass; and

a pressing step of heating and pressuring the unpressed laminated glass to obtain a laminated glass;

wherein the heat reflective film comprises a resin film having a thermal shrinkage in a direction that a thermal shrinkage becomes maximum, of 0.5% or more and 3% or less and a thermal shrinkage in a direction orthogonal to the direction of 0.1% or more and 2% or less, and a heat reflective coating formed on the resin film;

the first and second polyvinyl butyral films have a thermal shrinkage in a direction that a thermal shrinkage becomes maximum, of 0.5% or more and 3% or less and a thermal shrinkage in a direction orthogonal to the direction of −2.5% or more and −0.5% or less; and

in the lamination step, the heat reflective film and the first and second polyvinyl butyral films are overlaid such that the direction that a thermal shrinkage becomes maximum, of the resin film and the direction that a thermal shrinkage becomes maximum, of the first and second polyvinyl butyral films are orthogonal to each other;

provided that the thermal shrinkage of the resin film is a thermal shrinkage when the resin film is maintained at 150° C. for 30 minutes, and the thermal shrinkage of the polyvinyl butyral film is a thermal shrinkage when the polyvinyl butyral film is maintained at 60° C. for 30 minutes.

10. The method for manufacturing a laminated glass according to claim 9 , wherein the heating and pressuring in the pressing step are conducted under conditions of temperature: 120 to 150° C. and pressure: 0.98 to 1.47 MPa.

11. The method for manufacturing a laminated glass according to claim 9 , wherein in the pressing step, the heating and pressuring are conducted after preliminary pressing of heating to 70 to 120° C. while deaerating so as to achieve pressure: 1 to 100 kPa.