Radiative cooling device

A radiative cooling device comprising:

• an infrared radiative layer having a radiative surface for radiating infrared light;
• and
• a light reflective layer on a side of the infrared radiative layer, which is opposite to the radiative surface, and
• wherein:
• the infrared radiative layer is a resin material layer that has a thickness adjusted so that the resin material layer emits heat radiation energy greater than absorbed solar energy in a wavelength range from 8 μm to 14 μm, wherein the thickness of the resin material layer is adjusted so that the resin material layer has:
• light absorption properties that allow for a wavelength average absorptivity of 13% or less in a wavelength range from 0.4 μm to 0.5 μm, a wavelength average absorptivity of 4% or less in a wavelength range from 0.5 μm to 0.8 μm, a wavelength average absorptivity of 1% or less in a wavelength range from 0.8 μm to 1.5 μm, and a wavelength average absorptivity of 40% or less in a wavelength range from 1.5 μm to 2.5 μm;
• and
• heat radiation properties that allow for a wavelength average emissivity of 40% or more in the wavelength range from 8 μm to 14 μm,
• the resin material layer comprises a vinyl chloride-based resin as a resin material in which a plasticizer is mixed, and
• the plasticizer is at least one compound selected from the group consisting of phthalic acid esters, aliphatic dibasic acid esters, and phosphoric acid esters.

A radiative cooling device comprising:

• an infrared radiative layer having a radiative surface for radiating infrared light;
• and
• a light reflective layer on a side of the infrared radiative layer, which is opposite to the radiative surface, and
• wherein:
• the infrared radiative layer is a resin material layer that has a thickness adjusted so that the resin material layer emits heat radiation energy greater than absorbed solar energy in a wavelength range from 8 μm to 14 μm,
• the resin material layer comprises a vinyl chloride-based resin as a resin material in which a plasticizer is mixed, and
• the plasticizer is at least one compound selected from the group consisting of phthalic acid esters, aliphatic dibasic acid esters, and phosphoric acid esters;
• and
• the light reflective layer has a reflectance of 90% or more in a wavelength range from 0.4 μm to 0.5 μm and a reflectance of 96% or more with respect to light having a wavelength longer than 0.5 μm.