Transparent heat-shielding/heat-insulating member having transparent screen function

1. A transparent heat-shielding/heat-insulating member having a transparent screen function,

wherein the transparent heat-shielding/heat-insulating member having a transparent screen function comprises, with respect to a transparent base substrate, at least:

(1) an infrared reflective layer and an optical adjustment protective layer in this order from the transparent base substrate side; and

(2) a light diffusing layer on a surface of the transparent base substrate that is opposite to the surface on which the infrared reflective layer is formed or between the transparent base substrate and the infrared reflective layer,

(3) the infrared reflective layer includes a metal layer and at least one selected from a metal oxide layer and a metal nitride layer,

(4) the optical adjustment protective layer includes at least a high refractive index layer and a low refractive index layer in this order from the infrared reflective layer side, and has a total thickness of 250 nm to 980 nm,

(5) the light diffusing layer contains a transparent resin and light diffusing particles, and

the transparent heat-shielding/heat-insulating member having a transparent screen function has (6) a visible light reflectance measured in accordance with JIS R3106-1998 of 12% or more and 30% or less, (7) a haze value measured in accordance with JIS K7136-2000 of 5% or more and 35% or less, (8) a shading coefficient measured in accordance with JIS A5759-2008 of 0.69 or less, and (9) a normal emissivity measured in accordance with JIS R3106-2008 of 0.22 or less.

2. The transparent heat-shielding/heat-insulating member having a transparent screen function according to claim 1 ,

wherein the optical adjustment protective layer includes a high refractive index layer and a low refractive index layer in this order from the infrared reflective layer side,

the high refractive index layer has a refractive index at a wavelength of 550 nm of 1.65 to 1.95 and is set to have a thickness of 160 nm to 870 nm, and

the low refractive index layer has a refractive index at a wavelength of 550 nm of 1.30 to 1.45 and is set to have a thickness of 75 nm to 125 nm.

3. The transparent heat-shielding/heat-insulating member having a transparent screen function according to claim 1 ,

wherein the optical adjustment protective layer includes a medium refractive index layer, a high refractive index layer and a low refractive index layer in this order from the infrared reflective layer side,

the medium refractive index layer has a refractive index at a wavelength of 550 nm of 1.45 to 1.55 and is set to have a thickness of 80 nm to 200 nm,

the high refractive index layer has a refractive index at a wavelength of 550 nm of 1.65 to 1.95 and is set to have a thickness of 100 nm to 720 nm, and

the low refractive index layer has a refractive index at a wavelength of 550 nm of 1.30 to 1.45 and is set to have a thickness of 70 nm to 150 nm.

4. The transparent heat-shielding/heat-insulating member having a transparent screen function according to claim 3 , wherein the medium refractive index layer in the optical adjustment protective layer contains a modified polyolefin-based resin having an acidic group.

5. The transparent heat-shielding/heat-insulating member having a transparent screen function according to claim 1 ,

wherein, in a reflectance spectrum of the transparent heat-shielding/heat-insulating member having a transparent screen function measured in accordance with JIS R3106-1998,

provided that:

a point A is a point at a wavelength of 535 nm on a virtual line a that represents an average of a maximum reflectance and a minimum reflectance of the reflectance spectrum in a range of wavelengths from 500 nm to 570 nm;

a point B is a point at a wavelength of 700 nm on a virtual line b that represents an average of a maximum reflectance and a minimum reflectance of the reflectance spectrum in a range of wavelengths from 620 nm to 780 nm; and

a reference straight line AB is a straight line passing through the point A and the point B and extending in a range of wavelengths from 500 nm to 780 nm,

when reflectance values of the reflectance spectrum and reflectance values of the reference straight line AB are compared in the range of wavelengths from 500 nm to 570 nm, and provided that a maximum variation difference ΔA is an absolute value of a difference in the reflectance value between the reflectance spectrum and the reference straight line AB at a wavelength where the absolute value of the difference becomes maximum, the maximum variation difference ΔA expressed by percentage of reflectance is 7% or less, and

when reflectance values of the reflectance spectrum and reflectance values of the reference straight line AB are compared in the range of wavelengths from 620 nm to 780 nm, and provided that a maximum variation difference ΔB is an absolute value of a difference in the reflectance value between the reflectance spectrum and the reference straight line AB at a wavelength where the absolute value of the difference becomes maximum, the maximum variation difference ΔB expressed by percentage of reflectance is 9% or less.

6. The transparent heat-shielding/heat-insulating member having a transparent screen function according to claim 1 , wherein the transparent heat-shielding/heat-insulating member having a transparent screen function has a visible light transmittance measured in accordance with JIS A5759-2008 of 65% or more.

7. The transparent heat-shielding/heat-insulating member having a transparent screen function according to claim 1 , wherein the infrared reflective layer has a two-layer structure composed of a metal layer and a metal oxide layer or metal nitride layer that are stacked in this order on the transparent base substrate.

8. The transparent heat-shielding/heat-insulating member having a transparent screen function according to claim 1 , wherein the infrared reflective layer has a three-layer structure composed of a metal oxide layer or metal nitride layer, a metal layer, and a metal oxide layer or metal nitride layer that are stacked in this order on the transparent base substrate.