EP-4741731-A1 - COMPOSITE COOLING MATERIAL

EP4741731A1EP 4741731 A1EP4741731 A1EP 4741731A1EP-4741731-A1

Abstract

Provided is a composite cooling material with improved ease of use. The composite cooling material includes a magnetic material layer E including a magnetic material and a cooling layer CP provided on an outer surface of the magnetic material layer E, and has a first optical characteristic of having a solar reflectance of 80% or more.

Inventors

OSUGI, RYOSUKE
SUEMITSU, MASAHIRO
OOHASHI, KENJI

Assignees

Osaka Gas Co., Ltd.

Dates

Publication Date: 20260513
Application Date: 20240624

Claims (13)

A composite cooling material comprising: a magnetic material layer including a magnetic material; and a cooling layer provided on an outer surface of the magnetic material layer, wherein the cooling layer has a first optical characteristic of having a solar reflectance of 80% or more.
The composite cooling material according to claim 1, wherein the cooling layer includes: 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 the cooling layer has a second optical characteristic of having an average emissivity of 80% or more, the average emissivity being a wavelength average emissivity of infrared light in a wavelength range of 8 µm or more and 14 µm or less, the infrared radiative layer is a resin material layer including a vinyl chloride resin or a vinylidene chloride resin and having 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 light reflective layer includes silver or a silver alloy, and the cooling layer and the magnetic material layer are joined by a joining layer including any one or two or more of a vinyl chloride resin, a vinylidene chloride resin, a polyolefin resin, a polyester resin, an acrylic resin, a urethane resin, a silicone resin, and a rubber resin.
The composite cooling material according to claim 1 or 2, wherein the joining layer includes at least one of a vinyl chloride resin and a polyolefin resin.
The composite cooling material according to claim 1 or 2, wherein the magnetic material layer includes at least ferrite and a binder resin and has a thickness of 0.2 mm or more and 2.0 mm or less.
The composite cooling material according to claim 1 or 2, wherein the cooling layer includes an infrared radiative layer having a radiative surface for radiating infrared light, and the infrared radiative layer includes a plurality of particulate light reflecting portions that reflect light.
The composite cooling material according to claim 5, wherein the light reflecting portions have a particle size of 1 nm or more and 300 µm or less.
The composite cooling material according to claim 6, wherein the light reflecting portions are porous.
The composite cooling material according to claim 6, wherein the light reflecting portions include at least one of an inorganic filler and an organic filler, the inorganic filler includes at least one type of particles selected from glass microbeads, ceramic microbeads, silicon oxide particles, silicon carbide particles, silicon nitride particles, barium sulfate particles, and calcium carbonate particles, and the organic filler includes at least one type of polymer having a functional group selected from C-O, C-Cl, C-F, C-N, C-Si, and Si-O.
The composite cooling material according to claim 1 or 2, wherein the cooling layer includes an inorganic filler, and the inorganic filler includes at least one type of particles selected from glass microbeads, ceramic microbeads, silicon oxide particles, silicon carbide particles, silicon nitride particles, barium sulfate particles, and calcium carbonate particles.
The composite cooling material according to claim 2, 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.
The composite cooling material according to claim 2, wherein 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.
The composite cooling material according to claim 2, wherein the light reflective layer has a thickness of 50 nm or more.
The composite cooling material according to claim 2, wherein the light reflective layer has a layered structure including silver or a silver alloy close to the resin material layer and aluminum or an aluminum alloy apart from the resin material layer.

Description

Technical Field The present disclosure relates to a composite cooling material that has a function of cooling a back surface of the material. Background Art Radiative cooling is known as a function of cooling a back surface of a material. Radiative cooling is a phenomenon in which the temperature of a substance decreases as a result of the substance radiating electromagnetic waves such as infrared rays to the surrounding environment. By using this phenomenon, it is possible to configure a composite cooling material (composite cooling device) that cools a cooling target without consuming energy such as electricity, for example. As a conventional example of a composite cooling material (composite cooling device), there is a composite cooling material including: 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 (see Patent Document 1, for example). That is, the composite cooling material (composite cooling device) can cool a cooling target even under solar radiation during the day because the infrared radiative layer emits a large heat radiation energy in a wavelength range from 8 µm to 14 µm and the light reflective layer reflects light (ultraviolet light, visible light, infrared light) that has passed through the infrared radiative layer, and causes the light to be radiated from the radiative surface, thus avoiding a situation in which the cooling target is heated. In addition to light that has passed through the infrared radiative layer, light radiated from the infrared radiative layer toward the light reflective layer is also reflected by the light reflective layer toward the infrared radiative layer, but in the following description, the light reflective layer is described as being provided for the purpose of reflecting light (ultraviolet light, visible light, infrared light) that has passed through the infrared radiative layer. Prior Art Document Patent Document Patent Document 1: JP 2018-526599A Disclosure of the Invention Problem to be Solved by the Invention As an application example of a composite cooling material, there are cases where it is desired to use the composite cooling material by pasting (attaching) the material to an outer surface of a plate-shaped metal member (e.g., made of metal such as iron or an iron alloy, or a steel plate), such as an outer surface of an automobile or an outer surface of a container, with an adhesive agent or a pressure-sensitive adhesive agent. In such cases, a layer that is the closest to the back surface of the composite cooling material, e.g., a separation-side protective layer is used to join the composite cooling material to an attachment target. That is, the separation-side protective layer is pasted to an outer surface of a plate-shaped metal member with an adhesive agent or a pressure-sensitive adhesive agent. However, if the separation-side protective layer is made of an acrylic resin, the separation-side protective layer cannot be appropriately pasted to the plate-shaped metal member with an adhesive agent. Accordingly, conventional composite cooling materials are not easy to use in some cases, and improvement is desired. The present disclosure was made in view of the above problem, and has an object of providing a composite cooling material that has improved ease of use. Means for Solving Problem A composite cooling material according to an embodiment of the present disclosure is characterized by including: a magnetic material layer including a magnetic material; anda cooling layer provided on an outer surface of the magnetic material layer,wherein the cooling layer has a first optical characteristic of having a solar reflectance of 80% or more. According to this configuration, the cooling layer has the first optical characteristic of having a solar reflectance of 80% or more, and therefore, the composite cooling material can favorably exhibit a predetermined solar reflection function. Moreover, the composite cooling material according to this configuration includes, on its back surface side opposite to an outer surface of the cooling layer, the magnetic material layer that can be attached to a plate-shaped metal member, which is an attachment target, with magnetic force, and accordingly, the composite cooling material can be attached to the attachment target. That is, if a plate-shaped metal member to which the magnetic material layer can be attached with magnetic force generated in the magnetic material layer is appropriately selected as the attachment target, the composite cooling material can be favorably attached to the plate-shaped member. In short, with the characteristic configuration of the composite cooling material, it is possible to improve ease of use of the composite cooling material. The composite cooling material is further characterized in that the cooling layer includes: an infrared radia