JP2013147521A - Near-infrared light reflective material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a near-infrared light reflective material which includes foam having a cellular structure, the cellular structure being precisely controlled with a high bubble fraction, has a number of precisely-controlled minute surface openings, can develop extremely excellent reflective performance in a near-infrared region, and has excellent heat resistance and mechanical strength.SOLUTION: A near-infrared light reflective material includes foam having an interconnected cellular structure having through-holes between adjacent spherical bubbles. The foam includes a hydrophilic polyurethane polymer, the average pore diameter of the spherical bubbles is less than 20 μm, the average pore diameter of the through-holes is 5 μm or less, and the foam has surface openings having an average pore diameter of 20 μm or less on the surface. The reflective material has a total reflectivity of 60% or more in at least part of wavelengths in a wavelength region of 800-2,000 nm.

Description

  The present invention relates to a near-infrared light reflecting material.

  Conventionally, near-infrared light emitting devices are provided in, for example, illumination for night photography, infrared spotlights, infrared sensors, and the like. In order to improve the luminous efficiency of near infrared light emitted from the near infrared light emitting device, the near infrared light emitting device is provided with a reflective material, and the reflective material is required to have high near infrared light reflective performance.

  As a reflective material with high reflection performance, a diffuse reflector with a metal mirror surface deposited on the surface of a substrate such as metal, or a diffusion film containing pigment or fine particles that enhance light scattering Reflectors are known. However, the diffuse reflector formed with the metal mirror surface has a problem that the light scattering performance is low although the light reflecting performance is high. In addition, a diffuse reflector in which a film containing pigments and fine particles that enhance light scattering properties needs to increase the amount of pigments and fine particles added in order to suppress the leakage of light to the back side, There is a problem in that the loss due to light absorption cannot be ignored and the light reflection performance decreases as the amount of pigment or fine particles added increases.

  As a new diffuse reflector, a polyester foam containing fine bubbles has been reported (for example, Patent Document 1). This diffuse reflector utilizes the property that light is diffusely reflected by a large number of fine bubbles. However, the polyester foam reported in Patent Document 1 has a problem that the reflection performance in the near infrared region is insufficient. In addition, fine bubbles are arranged inside the polyester foam, and have an unfoamed skin layer near both surfaces. For this reason, there is a problem that fine bubbles do not exist in the vicinity of both surfaces, and sufficient diffuse reflection performance cannot be exhibited.

  Further, although LEDs are frequently used as the light source of the near-infrared light emitting device, the polyester foam reported in the cited document 1 has insufficient heat resistance and light resistance, and is damaged or damaged by heat generated from the LEDs. There is a problem that it is easy to deteriorate.

Japanese Patent Publication No. 9-1117

  An object of the present invention is a near-infrared light reflecting material including a foam having a bubble structure, wherein the bubble structure is precisely controlled, and has a large number of finely controlled surface openings. An object of the present invention is to provide a near-infrared light reflecting material that can exhibit very excellent reflection performance in the near-infrared region and has excellent heat resistance and light resistance.

  The near-infrared light reflecting material of the present invention includes a foam having an open cell structure having a through-hole between adjacent spherical bubbles, the foam includes a hydrophilic polyurethane-based polymer, and the average pore diameter of the spherical bubbles Is less than 20 μm, the average pore diameter of the through-holes is 5 μm or less, the surface of the foam has a surface opening with an average pore diameter of 20 μm or less, and at least part of wavelengths in the wavelength region of 800 nm to 2000 nm. The total reflectance is 60% or more.

  In a preferred embodiment, the near-infrared light reflecting material of the present invention has a total reflectance of 60% or more in a wavelength region of 800 nm to 1600 nm.

  In a preferred embodiment, the near-infrared light reflecting material of the present invention has a total reflectance of 60% or more in a wavelength region of 1800 nm to 2000 nm.

  In a preferred embodiment, the near-infrared light reflecting material of the present invention has a dimensional change rate of less than ± 5% when stored at 125 ° C. for 22 hours.

  According to another situation of this invention, the manufacturing method of a near-infrared-light reflective material is provided. The production method is a method for producing a near-infrared light reflecting material including a foam having an open-cell structure having through-holes between adjacent spherical bubbles, the continuous oil-phase component, the continuous oil-phase component and A step (I) for preparing a W / O emulsion containing a miscible aqueous phase component, a step (II) for shaping the obtained W / O emulsion, and a shaped W / O emulsion. It includes a step (III) of polymerizing and a step (IV) of dehydrating the obtained water-containing polymer, and the continuous oil phase component contains a hydrophilic polyurethane polymer, an ethylenically unsaturated monomer, and a crosslinking agent.

  In a preferred embodiment, the crosslinking agent has at least one selected from polyfunctional (meth) acrylates, polyfunctional (meth) acrylamides, and polymerization reactive oligomers having a weight average molecular weight of 800 or more, and a weight average molecular weight. 1 or more types chosen from polyfunctional (meth) acrylate and polyfunctional (meth) acrylamide which are 500 or less are included.

  In preferable embodiment, the said near-infrared-light reflective material is obtained by the said manufacturing method.

  According to the present invention, a near-infrared light reflecting material including a foam having a bubble structure, wherein the bubble structure is precisely controlled, the bubble ratio is high, and a large number of finely controlled fine surfaces. It is possible to provide a near-infrared light reflecting material that has an opening, can exhibit very excellent reflection performance in the near-infrared region, and has excellent heat resistance and mechanical strength.

It is a schematic sectional drawing which shows preferable embodiment of the near-infrared-light reflection material of this invention. It is a schematic sectional drawing which shows another preferable embodiment of the near-infrared-light reflecting material of this invention. It is a photograph figure of the cross-sectional SEM photograph of the near-infrared-light reflective material of this invention, Comprising: It is a photograph figure showing clearly the open-cell structure which has a through-hole between adjacent spherical bubbles. It is a photograph figure of the surface / cross-section SEM photograph which image | photographed the near-infrared-light reflective material produced in Example 1 from the diagonal. It is a chart figure which shows the measurement result of the total reflectance of the near-infrared-light reflection material in Example 1 and 2. It is a chart figure which shows the measurement result of the total reflectance of the near-infrared-light reflection material in Example 3. It is a chart figure which shows the measurement result of the total reflectance of the near-infrared-light reflective material in Example 4.

≪ << A. Near-infrared light reflector >>>>
The near-infrared light reflecting material of the present invention includes a foam containing a hydrophilic polyurethane-based polymer, and the foam has an open cell structure having through holes between adjacent spherical cells. As a typical structure, a near-infrared light reflecting material 100 (FIG. 1) made of the foam 10 and a near-infrared light reflecting material including a base material 20 (described later) between the foam 10a and the foam 10b. 100 (FIG. 2). In FIG. 1 and FIG. 2, the release film 30 is provided for protecting the surface of the near-infrared light reflecting material, but the release film may not be provided.

  In the present specification, the “spherical bubble” does not have to be a strict true spherical bubble, and may be, for example, a substantially spherical bubble having a partial strain or a bubble composed of a space having a large strain. .

  The average pore diameter of the spherical bubbles that the foam contained in the near-infrared light reflecting material of the present invention may have is less than 20 μm, preferably 15 μm or less, more preferably 10 μm or less. The lower limit value of the average pore diameter of the spherical bubbles of the foam contained in the near-infrared light reflecting material of the present invention is not particularly limited, for example, preferably 0.01 μm, more preferably 0.1 μm, Preferably it is 1 micrometer. The average pore diameter of the spherical bubbles of the foam contained in the near-infrared light reflecting material of the present invention is such that the average pore diameter of the spherical bubbles contained in the foam contained in the near-infrared light reflecting material of the present invention falls within the above range. Can be precisely controlled to be small, and a novel near-infrared light reflecting material excellent in flexibility and heat resistance can be provided.

  The foam contained in the near-infrared light reflecting material of the present invention has an open-cell structure having through holes between adjacent spherical bubbles. This open cell structure may be an open cell structure having through holes between most or all adjacent spherical cells, or may be a semi-independent semi-open cell structure having a relatively small number of through holes. . By using a foam having such an open cell structure, the near-infrared light reflecting material of the present invention can have a sufficient adhesive force. Since the near-infrared light reflecting material of the present invention has sufficient adhesive strength as described above, it can be attached without separately providing an adhesive layer or an adhesive layer.

  The through-hole which has between adjacent spherical bubbles influences the physical property of a near-infrared-light reflecting material. For example, the strength of the near-infrared light reflecting material tends to increase as the average hole diameter of the through holes decreases. FIG. 3 is a photographic view of a cross-sectional SEM photograph of the near-infrared light reflecting material of the present invention, and a photographic view clearly showing an open cell structure having through holes between adjacent spherical bubbles.

  The average pore diameter of the through holes between adjacent spherical bubbles is 5 μm or less, preferably 4 μm or less, more preferably 3 μm or less. The lower limit value of the average pore diameter of the through holes between adjacent spherical bubbles is not particularly limited, and is preferably 0.001 μm, and more preferably 0.01 μm, for example. When the average pore diameter of the through holes between adjacent spherical bubbles is within the above range, a novel near-infrared light reflecting material excellent in flexibility and heat resistance can be provided.

  The near-infrared light reflecting material of the present invention has a surface opening on the surface. The average pore diameter of the surface opening is 20 μm or less, preferably less than 20 μm, more preferably 15 μm or less, further preferably 10 μm or less, further preferably 5 μm or less, and particularly preferably 4 μm or less. And most preferably 3 μm or less. The lower limit of the average pore diameter of the surface opening is not particularly limited, and is preferably 0.001 μm, and more preferably 0.01 μm, for example. When the near-infrared light reflecting material of the present invention has a surface opening and the average pore diameter of the surface opening is within the above range, very excellent near-infrared light reflecting performance can be exhibited.

Density of the foam contained in the near-infrared light reflecting material of the present invention is preferably ^{0.15g / cm 3 ~0.6g / cm 3} , more preferably 0.15g ^/ cm 3 ~0.5g ^/ cm ^3, and more preferably from ^{0.15g / cm 3 ~0.45g / cm 3} , particularly preferably from ^{0.15g / cm 3 ~0.4g / cm 3} . After the density of the foam contained in the near-infrared light reflecting material of the present invention falls within the above range, the range of the density of the foam contained in the near-infrared light reflecting material of the present invention is widely controlled, A novel near-infrared light reflecting material excellent in flexibility and heat resistance can be provided.

  The foam contained in the near-infrared light reflecting material of the present invention has a cell ratio of preferably 30% or more, more preferably 40% or more, and further preferably 50% or more. In the near-infrared light reflecting material of the present invention, the bubble rate is within the above range, so that the near-infrared light reflecting material of the present invention can exhibit very excellent near-infrared light reflecting performance and has excellent flexibility. And excellent heat resistance.

  The foam contained in the near-infrared light reflecting material of the present invention contains a hydrophilic polyurethane polymer. Since the foam contained in the near-infrared light reflecting material of the present invention contains a hydrophilic polyurethane-based polymer, the bubble structure is precisely controlled, the bubble rate is high, and a large number of finely controlled fine particles. It is possible to provide a novel near-infrared light reflecting material that has a surface opening, can exhibit very excellent near-infrared light reflection performance, and has excellent flexibility and excellent heat resistance.

  The details of the foam contained in the near-infrared light reflecting material of the present invention and the details of the hydrophilic polyurethane polymer contained therein will be mentioned in the description of the production method described later.

  The near-infrared light reflecting material of the present invention has a total reflectance of 60% or more, preferably 70% or more, more preferably 80% or more, in at least some wavelengths in the wavelength region of 800 nm to 2000 nm. More preferably, it is 90% or more, and particularly preferably 95% or more.

  In the near-infrared light reflecting material of the present invention, the diffuse reflectance at at least a part of the wavelength region of 800 nm to 2000 nm is preferably 50% or more, more preferably 60% or more, and further preferably 70. % Or more, more preferably 80% or more, and particularly preferably 90% or more.

  In the near-infrared light reflecting material of the present invention, the total reflectance in the wavelength region of 800 nm to 1600 nm is preferably 60% or more, more preferably 70% or more, further preferably 80% or more, Preferably it is 90% or more, Most preferably, it is 95% or more.

  In the near-infrared light reflecting material of the present invention, the total reflectance in the wavelength region of 1800 nm to 2000 nm is preferably 60% or more, more preferably 70% or more, further preferably 80% or more, Preferably it is 90% or more, Most preferably, it is 95% or more.

  The near-infrared light reflecting material of the present invention has excellent light diffusion performance even in the visible light region.

  In the near-infrared light reflecting material of the present invention, the diffuse reflectance in the wavelength region of 400 nm to 600 nm is preferably 90% or more, more preferably 95% or more, and further preferably 98% or more. Preferably it is 99% or more, Most preferably, it is 99.5% or more.

  In the near-infrared light reflecting material of the present invention, the diffuse reflectance in the wavelength region of 400 nm to 800 nm is preferably 90% or more, more preferably 95% or more, and still more preferably 98% or more. Preferably it is 99% or more, Most preferably, it is 99.5% or more.

  In the near-infrared light reflecting material of the present invention, the dimensional change rate when stored at 125 ° C. for 22 hours is preferably less than ± 5%, more preferably ± 3% or less, and further preferably ± 1%. It is as follows. In the near-infrared light reflecting material of the present invention, when the dimensional change rate when stored at 125 ° C. for 22 hours is within the above range, the near-infrared light reflecting material of the present invention can have excellent heat resistance.

In the near-infrared light reflecting material of the present invention, the decrease in reflectance at a wavelength of 550 nm before and after irradiation with ultraviolet rays having an illuminance of 90 mW / cm ² for 100 hours is preferably 20% or less, more preferably 10% or less. Yes, more preferably 5% or less. When the decrease in reflectance before and after UV irradiation falls within the above range, the near-infrared light reflecting material of the present invention can have very excellent light resistance.

In the near-infrared light reflecting material of the present invention, the decrease in reflectance at a wavelength of 800 nm before and after irradiation with ultraviolet rays having an illuminance of 90 mW / cm ² for 100 hours is preferably 20% or less, more preferably 10% or less. Yes, more preferably 5% or less. When the decrease in reflectance before and after UV irradiation falls within the above range, the near-infrared light reflecting material of the present invention can have very excellent light resistance.

  The near-infrared light reflecting material of the present invention has a tensile strength change rate of preferably less than ± 20%, more preferably ± 18% or less when stored at 125 ° C. for 14 days. When the rate of change in tensile strength when stored at 125 ° C. for 14 days is within the above range, the near-infrared light reflecting material of the present invention can have very excellent heat resistance.

  The near-infrared light reflecting material of the present invention can take any appropriate shape. In the near-infrared light reflecting material of the present invention, the length, such as the thickness, the long side, and the short side, can take any appropriate value.

  The near-infrared light reflecting material of the present invention may contain any appropriate base material as long as the effects of the present invention are not impaired. As a form in which the base material is contained in the near-infrared light reflecting material of the present invention, for example, a form in which the base material is laminated on one surface of the near-infrared light reflecting material, the inside of the near-infrared light reflecting material The form with which the layer of the base material is provided in is mentioned. Examples of such a substrate include fiber woven fabric, fiber nonwoven fabric, fiber laminated fabric, fiber knitted fabric, inorganic fiber, resin sheet, and metal foil film sheet.

  As the fiber woven fabric, a woven fabric formed of any appropriate fiber can be adopted. Examples of such fibers include natural fibers such as plant fibers, animal fibers, and mineral fibers; artificial fibers such as regenerated fibers, synthetic fibers, semi-synthetic fibers, and artificial inorganic fibers. Examples of synthetic fibers include fibers obtained by melt spinning thermoplastic fibers. Further, the fiber woven fabric may be metallic processed by plating or sputtering.

  As a fiber nonwoven fabric, the nonwoven fabric formed from arbitrary appropriate fibers can be employ | adopted. Examples of such fibers include natural fibers such as plant fibers, animal fibers, and mineral fibers; artificial fibers such as regenerated fibers, synthetic fibers, semi-synthetic fibers, and artificial inorganic fibers. Examples of synthetic fibers include fibers obtained by melt spinning thermoplastic fibers. Moreover, the fiber nonwoven fabric may be metallic-processed by plating, sputtering, etc. More specifically, for example, a spunbond nonwoven fabric can be mentioned.

  As the fiber laminated fabric, a laminated fabric formed of any appropriate fiber can be adopted. Examples of such fibers include natural fibers such as plant fibers, animal fibers, and mineral fibers; artificial fibers such as regenerated fibers, synthetic fibers, semi-synthetic fibers, and artificial inorganic fibers. Examples of synthetic fibers include fibers obtained by melt spinning thermoplastic fibers. In addition, the fiber laminated fabric may be metallic processed by plating, sputtering, or the like. More specifically, for example, a polyester fiber laminated fabric can be mentioned.

  As a fiber knitted fabric, the knitted fabric formed from arbitrary appropriate fibers can be employ | adopted, for example. Examples of such fibers include natural fibers such as plant fibers, animal fibers, and mineral fibers; artificial fibers such as regenerated fibers, synthetic fibers, semi-synthetic fibers, and artificial inorganic fibers. Examples of synthetic fibers include fibers obtained by melt spinning thermoplastic fibers. Further, the fiber knitted fabric may be metallically processed by plating or sputtering.

  Any appropriate inorganic fiber can be adopted as the inorganic fiber. Specific examples of such inorganic fibers include glass fibers, metal fibers, and carbon fibers.

  As the resin sheet, a sheet formed of any appropriate resin can be adopted. An example of such a resin is a thermoplastic resin. The resin sheet may be metallic processed by plating or sputtering.

  As the metal foil film sheet, a sheet formed from any appropriate metal foil film can be adopted.

  When the near-infrared light reflecting material of the present invention has voids in the substrate, the same material as the near-infrared light reflecting material may be present in a part or all of the voids.

  Only 1 type may be used for a base material and it may use 2 or more types together.

≪≪B. Manufacturing method of near-infrared light reflecting material >>>>
The near-infrared light reflecting material of the present invention can be manufactured by any appropriate method. The near-infrared light reflecting material of the present invention can be preferably produced by shaping and polymerizing a W / O emulsion.

  As a manufacturing method of the near-infrared light reflection material of this invention, it can be used in order to obtain the near-infrared light reflection material of this invention, for example by supplying a continuous oil phase component and a water phase component to an emulsifier continuously. A “continuous method” is mentioned in which a W / O type emulsion is prepared, and then the obtained W / O type emulsion is polymerized to produce a water-containing polymer, followed by dehydration of the obtained water-containing polymer. It is done. As a method for producing the near-infrared light reflecting material of the present invention, for example, an appropriate amount of an aqueous phase component is charged into an emulsifier with respect to the continuous oil phase component, and the aqueous phase component is continuously supplied while stirring. By preparing a W / O emulsion that can be used to obtain the near-infrared light reflecting material of the present invention, the resulting W / O emulsion is polymerized to produce a hydrous polymer, and subsequently obtained. There is a “batch method” in which the obtained hydropolymer is dehydrated.

  The continuous polymerization method in which the W / O emulsion is continuously polymerized is a preferable method because the production efficiency is high and the effect of shortening the polymerization time and the shortening of the polymerization apparatus can be most effectively utilized.

More specifically, the near-infrared light reflecting material of the present invention is preferably,
Step (I) of preparing a W / O type emulsion that can be used to obtain the near-infrared light reflecting material of the present invention;
Step (II) of shaping the obtained W / O emulsion,
Polymerizing the shaped W / O emulsion (III);
Step (IV) of dehydrating the obtained hydrous polymer;
It can manufacture with the manufacturing method containing. Here, at least a part of the step (II) for shaping the obtained W / O emulsion and the step (III) for polymerizing the shaped W / O emulsion may be performed simultaneously.

<< B-1. Step for preparing W / O type emulsion (I) >>
The W / O type emulsion that can be used for obtaining the near-infrared light reflecting material of the present invention is a W / O type emulsion containing a continuous oil phase component and an aqueous phase component immiscible with the continuous oil phase component. More specifically, the W / O type emulsion is obtained by dispersing an aqueous phase component in a continuous oil phase component.

  The ratio of the water phase component to the continuous oil phase component in the W / O type emulsion that can be used to obtain the near-infrared light reflecting material of the present invention is arbitrarily appropriate as long as the W / O type emulsion can be formed. A ratio can be taken. The ratio of the water phase component to the continuous oil phase component in the W / O type emulsion that can be used for obtaining the near infrared light reflecting material of the present invention is the structure of the foam obtained by polymerization of the W / O type emulsion. Can be an important factor in determining mechanical, mechanical, and performance characteristics. Specifically, the ratio of the water phase component to the continuous oil phase component in the W / O type emulsion that can be used to obtain the near-infrared light reflecting material of the present invention is obtained by polymerization of the W / O type emulsion. It can be an important factor in determining the density of the foam to be formed, the bubble size, the bubble structure, the dimensions of the wall forming the porous structure, and the like.

  The ratio of the aqueous phase component in the W / O emulsion that can be used to obtain the near-infrared light reflecting material of the present invention is preferably 30% by weight, more preferably 40% by weight, as the lower limit. More preferably, it is 50% by weight, particularly preferably 55% by weight, and the upper limit is preferably 95% by weight, more preferably 90% by weight, still more preferably 85% by weight, particularly preferably. Is 80% by weight. If the ratio of the aqueous phase component in the W / O emulsion that can be used to obtain the near-infrared light reflecting material of the present invention is within the above range, the effects of the present invention can be sufficiently exhibited.

  The W / O emulsion that can be used to obtain the near-infrared light reflecting material of the present invention may contain any appropriate additive as long as the effects of the present invention are not impaired. Examples of such additives include tackifying resins; talc; calcium carbonate, magnesium carbonate, silicic acid and salts thereof, clay, mica powder, aluminum hydroxide, magnesium hydroxide, zinc white, bentonine, carbon black, Examples thereof include fillers such as silica, alumina, aluminum silicate, acetylene black, and aluminum powder; pigments; dyes; Only one kind of such an additive may be contained, or two or more kinds thereof may be contained.

  Any appropriate method can be adopted as a method for producing a W / O type emulsion that can be used for obtaining the near-infrared light reflecting material of the present invention. As a method for producing a W / O type emulsion that can be used for obtaining the near-infrared light reflecting material of the present invention, for example, a continuous oil phase component and an aqueous phase component are continuously supplied to an emulsifier. "Continuous method" for forming O-type emulsions, or W / O type by supplying an appropriate amount of water phase components to the emulsifier and continuously supplying the water phase components with stirring to the continuous oil phase components Examples include “batch method” for forming an emulsion.

  When producing a W / O type emulsion that can be used for obtaining the near-infrared light reflecting material of the present invention, as a shearing means for obtaining an emulsion state, for example, a rotor-stator mixer, a homogenizer, a microfluidizer, etc. Application of the high shear conditions used can be mentioned. In addition, as another shearing means for obtaining an emulsion state, for example, gentle mixing of continuous and dispersed phases by application of low shear conditions using a moving blade mixer or a pin mixer, low stirring conditions using a magnetic stir bar, etc. Can be mentioned.

  Examples of the apparatus for preparing the W / O emulsion by the “continuous method” include a static mixer, a rotor stator mixer, and a pin mixer. More intense agitation may be achieved by increasing the agitation speed or by using an apparatus designed to finely disperse the aqueous phase component in the W / O emulsion by a mixing method.

  Examples of the apparatus for preparing the W / O type emulsion by the “batch method” include manual mixing and shaking, a driven blade mixer, and three propeller mixing blades. Specifically, “TK Ajihomomica (trade name)” and “TK Combimix (trade name)” manufactured by Primix Co., Ltd. produce the target W / O emulsion under reduced pressure. This is possible, and the resulting W / O emulsion greatly reduces the incorporation of bubbles.

  Arbitrary appropriate methods can be employ | adopted as a method of preparing a continuous oil phase component. As a method for preparing the continuous oil phase component, typically, for example, a mixed syrup containing a hydrophilic polyurethane-based polymer and an ethylenically unsaturated monomer is prepared, and subsequently, a polymerization initiator, It is preferable to prepare a continuous oil phase component by blending a crosslinking agent and any other appropriate components.

  Any appropriate method can be adopted as a method of preparing the hydrophilic polyurethane-based polymer. A typical method for preparing a hydrophilic polyurethane-based polymer is, for example, by reacting polyoxyethylene polyoxypropylene glycol and a diisocyanate compound in the presence of a urethane reaction catalyst.

<B-1-1. Water phase component>
The aqueous phase component can be any aqueous fluid that is substantially immiscible with the continuous oil phase component. From the viewpoint of ease of handling and low cost, water such as ion-exchanged water is preferable.

  Any appropriate additive may be contained in the aqueous phase component as long as the effects of the present invention are not impaired. Examples of such additives include polymerization initiators and water-soluble salts. The water-soluble salt can be an effective additive for further stabilizing the W / O emulsion. Examples of such water-soluble salts include sodium carbonate, calcium carbonate, potassium carbonate, sodium phosphate, calcium phosphate, potassium phosphate, sodium chloride, potassium chloride and the like. Only one kind of such an additive may be contained, or two or more kinds thereof may be contained. The additive that can be contained in the aqueous phase component may be only one kind or two or more kinds.

<B-1-2. Continuous oil phase component>
The continuous oil phase component preferably contains a hydrophilic polyurethane polymer and an ethylenically unsaturated monomer. The content ratio of the hydrophilic polyurethane polymer and the ethylenically unsaturated monomer in the continuous oil phase component can take any appropriate content ratio as long as the effects of the present invention are not impaired.

  The hydrophilic polyurethane-based polymer depends on the polyoxyethylene ratio in the polyoxyethylene polyoxypropylene glycol unit constituting the hydrophilic polyurethane-based polymer or the amount of the aqueous phase component to be blended. The hydrophilic polyurethane polymer is in the range of 10 to 30 parts by weight with respect to 70 to 90 parts by weight of the ethylenically unsaturated monomer, and more preferably hydrophilic to 75 to 90 parts by weight of the ethylenically unsaturated monomer. The polyurethane polymer is in the range of 10 to 25 parts by weight. Further, for example, the hydrophilic polyurethane polymer is preferably in the range of 1 to 30 parts by weight, more preferably 1 to 25 parts by weight of the hydrophilic polyurethane polymer with respect to 100 parts by weight of the aqueous phase component. It is a range. If the content ratio of the hydrophilic polyurethane polymer is within the above range, the effects of the present invention can be sufficiently exhibited.

(B-1-2-1. Hydrophilic polyurethane polymer)
The hydrophilic polyurethane-based polymer preferably contains a polyoxyethylene polyoxypropylene unit derived from polyoxyethylene polyoxypropylene glycol, and 5 wt% to 25 wt% in the polyoxyethylene polyoxypropylene unit is polyoxyethylene. Ethylene.

  The content ratio of polyoxyethylene in the polyoxyethylene polyoxypropylene unit is preferably 5% by weight to 25% by weight as described above, and is more preferably 10% by weight as the lower limit, and the upper limit. More preferably, it is 25% by weight, and more preferably 20% by weight. The polyoxyethylene in the polyoxyethylene polyoxypropylene unit exhibits an effect of stably dispersing the aqueous phase component in the continuous oil phase component. When the content of polyoxyethylene in the polyoxyethylene polyoxypropylene unit is less than 5% by weight, it may be difficult to stably disperse the water phase component in the continuous oil phase component. If the polyoxyethylene content in the polyoxyethylene polyoxypropylene unit exceeds 25% by weight, there is a risk of phase inversion from a W / O type emulsion to an O / W type (oil-in-water type) emulsion as it approaches the HIPE condition. There is.

  A conventional hydrophilic polyurethane polymer can be obtained by reacting a diisocyanate compound with a hydrophobic long-chain diol, polyoxyethylene glycol and derivatives thereof, and a low molecular active hydrogen compound (chain extender). Since the number of polyoxyethylene groups contained in the hydrophilic polyurethane polymer obtained in 1) is uneven, the emulsion stability of such a W / O emulsion containing such a hydrophilic polyurethane polymer may be reduced. There is. On the other hand, the hydrophilic polyurethane-based polymer contained in the continuous oil phase component of the W / O type emulsion that can be used to obtain the near-infrared light reflecting material of the present invention has a characteristic structure as described above. When included in the continuous oil phase component of the W / O type emulsion, excellent emulsifying properties and excellent stationary storage stability can be expressed without positively adding an emulsifier or the like.

  The hydrophilic polyurethane-based polymer is preferably obtained by reacting polyoxyethylene polyoxypropylene glycol and a diisocyanate compound. In this case, the ratio between the polyoxyethylene polyoxypropylene glycol and the diisocyanate compound is NCO / OH (equivalent ratio), and the lower limit is preferably 1, more preferably 1.2, and still more preferably 1. .4, particularly preferably 1.6, and the upper limit is preferably 3, more preferably 2.5, and even more preferably 2. When NCO / OH (equivalent ratio) is less than 1, a gelled product may be easily formed when a hydrophilic polyurethane polymer is produced. When NCO / OH (equivalent ratio) exceeds 3, the residual diisocyanate compound increases, and the W / O emulsion that can be used to obtain the near-infrared light reflecting material of the present invention may become unstable. is there.

  Examples of the polyoxyethylene polyoxypropylene glycol include polyether polyols manufactured by ADEKA (Adeka (registered trademark) Pluronic L-31, L-61, L-71, L-101, L-121, L-42, L-62, L-72, L-122, 25R-1, 25R-2, 17R-2) and polyoxyethylene polyoxypropylene glycol (Pronon (registered trademark) 052, 102, 202) manufactured by NOF Corporation. Etc. As for polyoxyethylene polyoxypropylene glycol, only 1 type may be used and 2 or more types may be used together.

  Examples of the diisocyanate compound include aromatic, aliphatic, and alicyclic diisocyanates, dimers and trimers of these diisocyanates, polyphenylmethane polyisocyanate, and the like. Aromatic, aliphatic, and alicyclic diisocyanates include tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate. 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, butane-1,4-diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, cyclohexane-1,4 -Diisocyanate, dicyclohexylmethane-4,4-diisocyanate, 1,3-bis (isocyanatemethyl) cyclohexane, methyl Cyclohexane diisocyanate, m- tetramethylxylylene diisocyanate. Examples of the diisocyanate trimer include isocyanurate type, burette type, and allophanate type. Only 1 type may be used for a diisocyanate compound and it may use 2 or more types together.

  The diisocyanate compound may be selected as appropriate from the viewpoint of urethane reactivity with the polyol and the like, as well as the type and combination thereof. From the viewpoint of rapid urethane reactivity with polyol and suppression of reaction with water, it is preferable to use alicyclic diisocyanate.

  The weight average molecular weight of the hydrophilic polyurethane polymer is preferably 5000 as a lower limit, more preferably 7000, still more preferably 8000, particularly preferably 10,000, and preferably 50,000 as an upper limit. More preferably, it is 40000, more preferably 30000, and particularly preferably 20000.

  The hydrophilic polyurethane polymer may have an unsaturated double bond capable of radical polymerization at the terminal. By having an unsaturated double bond capable of radical polymerization at the terminal of the hydrophilic polyurethane-based polymer, the effects of the present invention can be further exhibited.

(B-1-2-2. Ethylenically unsaturated monomer)
As the ethylenically unsaturated monomer, any appropriate monomer can be adopted as long as it is a monomer having an ethylenically unsaturated double bond. Only one type of ethylenically unsaturated monomer may be used, or two or more types may be used.

  The ethylenically unsaturated monomer preferably comprises a (meth) acrylic ester. The content ratio of the (meth) acrylic acid ester in the ethylenically unsaturated monomer is preferably 80% by weight, more preferably 85% by weight as the lower limit, and preferably 100% by weight as the upper limit. More preferably, it is 98% by weight. Only one (meth) acrylic acid ester may be used, or two or more may be used.

  The (meth) acrylic acid ester is preferably an alkyl (meth) acrylate having an alkyl group having 1 to 20 carbon atoms (a concept including a cycloalkyl group, an alkyl (cycloalkyl) group, and a (cycloalkyl) alkyl group). It is. Preferably the carbon number of the said alkyl group is 4-18. In addition, (meth) acryl means acryl and / or methacryl, and (meth) acrylate means acrylate and / or methacrylate.

  Examples of the alkyl (meth) acrylate having an alkyl group having 1 to 20 carbon atoms include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, and s-butyl. (Meth) acrylate, t-butyl (meth) acrylate, isobutyl (meth) acrylate, n-pentyl (meth) acrylate, isopentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, isoamyl (meth) Acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, isode Ru (meth) acrylate, n-dodecyl (meth) acrylate, isomyristyl (meth) acrylate, n-tridecyl (meth) acrylate, n-tetradecyl (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate, pentadecyl (Meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, octadecyl (meth) acrylate, nonadecyl (meth) acrylate, eicosyl (meth) acrylate, isostearyl (meth) acrylate, isobornyl (meth) acrylate, etc. It is done. Among these, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and isobornyl (meth) acrylate are preferable. Only 1 type may be sufficient as the alkyl (meth) acrylate which has a C1-C20 alkyl group, and 2 or more types may be sufficient as it.

  The ethylenically unsaturated monomer preferably further comprises a polar monomer copolymerizable with the (meth) acrylic acid ester. By including the polar monomer, the effects of the present invention can be further exhibited. The content of the polar monomer in the ethylenically unsaturated monomer is preferably 0% by weight, more preferably 2% by weight as the lower limit, and preferably 20% by weight, more preferably as the upper limit. 15% by weight. Only one type of polar monomer may be used, or two or more types may be used.

  Examples of polar monomers include (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, ω-carboxy-polycaprolactone monoacrylate, phthalic acid monohydroxyethyl acrylate, itaconic acid, maleic acid, fumaric acid Carboxyl group-containing monomers such as acid and crotonic acid; acid anhydride monomers such as maleic anhydride and itaconic anhydride; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and (meth) acrylic acid 4-hydroxybutyl, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, (4-hydroxymethyl Shi Hydroxyl group-containing monomers such as cyclohexyl) methyl (meth) acrylate; amide group-containing monomers such as N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, and hydroxyethyl (meth) acrylamide; It is done.

(B-1-2-3. Polymerization initiator)
The continuous oil phase component preferably contains a polymerization initiator.

  Examples of the polymerization initiator include radical polymerization initiators and redox polymerization initiators. Examples of the radical polymerization initiator include a thermal polymerization initiator and a photopolymerization initiator.

  Examples of the thermal polymerization initiator include azo compounds, peroxides, peroxycarbonic acid, peroxycarboxylic acid, potassium persulfate, t-butylperoxyisobutyrate, and 2,2′-azobisisobutyronitrile. .

  Examples of the photopolymerization initiator include 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone (for example, Ciba Japan, trade name: Darocur-2959), α-hydroxy- α, α'-dimethylacetophenone (for example, Ciba Japan, trade name: Darocur-1173), methoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone (for example, Ciba Japan, trade name) Acetophenone photopolymerization initiators such as Irgacure-651) and 2-hydroxy-2-cyclohexylacetophenone (for example, Ciba Japan, trade name; Irgacure-184); Ketal photopolymerization initiator such as benzyldimethyl ketal Agents; Other halogenated ketones; Acylphosphine oxides (As an example, Ciba Japan Co., Ltd., trade name: Irgacure -819); and the like.

  The polymerization initiator may contain only 1 type and may contain 2 or more types.

  The content of the polymerization initiator is preferably 0.05% by weight, more preferably 0.1% by weight, more preferably 0.1%, and preferably 5.0% as a lower limit with respect to the entire continuous oil phase component. % By weight, more preferably 1.0% by weight. When the content of the polymerization initiator is less than 0.05% by weight based on the entire continuous oil phase component, the amount of unreacted monomer components increases, and the amount of residual monomers in the obtained near-infrared light reflecting material increases. There is a risk. When the content of the polymerization initiator exceeds 5.0% by weight with respect to the entire continuous oil phase component, the mechanical properties of the obtained near-infrared light reflecting material may be lowered.

  Note that the amount of radicals generated by the photopolymerization initiator varies depending on the type and intensity of light to be irradiated, the irradiation time, the amount of dissolved oxygen in the monomer and solvent mixture, and the like. And when there is much dissolved oxygen, the radical generation amount by a photoinitiator is suppressed, superposition | polymerization does not fully advance and an unreacted substance may increase. Therefore, it is preferable that an inert gas such as nitrogen is blown into the reaction system before the light irradiation, and oxygen is replaced with an inert gas or deaerated by a reduced pressure treatment.

(B-1-2-4. Crosslinking agent)
The continuous oil phase component preferably includes a cross-linking agent.

  Crosslinking agents are typically used to link polymer chains together to build a more three-dimensional molecular structure. The selection of the type and content of the cross-linking agent depends on the structural properties, mechanical properties, and fluid treatment properties desired for the resulting near infrared light reflector. The selection of the specific type and content of the cross-linking agent is important in achieving a desirable combination of structural properties, mechanical properties, and fluid treatment properties of the near infrared light reflector.

  In producing the near-infrared light reflecting material of the present invention, preferably, at least two kinds of crosslinking agents having different weight average molecular weights are used as the crosslinking agent.

  In producing the near-infrared light reflecting material of the present invention, more preferably, as a crosslinking agent, “polyfunctional (meth) acrylate having a weight average molecular weight of 800 or more, polyfunctional (meth) acrylamide, and polymerization reactivity”. “One or more selected from oligomers” and “one or more selected from polyfunctional (meth) acrylates and polyfunctional (meth) acrylamides having a weight average molecular weight of 500 or less” are used in combination. Here, the polyfunctional (meth) acrylate is specifically a polyfunctional (meth) acrylate having at least two ethylenically unsaturated groups in one molecule, and the polyfunctional (meth) acrylamide is Specifically, it is polyfunctional (meth) acrylamide having at least two ethylenically unsaturated groups in one molecule.

  Examples of the polyfunctional (meth) acrylate include diacrylates, triacrylates, tetraacrylates, dimethacrylates, trimethacrylates, and tetramethacrylates.

  Examples of the polyfunctional (meth) acrylamide include diacrylamides, triacrylamides, tetraacrylamides, dimethacrylamides, trimethacrylamides, tetramethacrylamides and the like.

  The polyfunctional (meth) acrylate can be derived from, for example, diols, triols, tetraols, bisphenol A and the like. Specifically, for example, 1,10-decanediol, 1,8-octanediol, 1,6 hexanediol, 1,4-butanediol, 1,3-butanediol, 1,4 butane-2-enediol , Ethylene glycol, diethylene glycol, trimethylolpropane, pentaerythritol, hydroquinone, catechol, resorcinol, triethylene glycol, polyethylene glycol, sorbitol, polypropylene glycol, polytetramethylene glycol, modified bisphenol A propylene oxide, and the like.

  The polyfunctional (meth) acrylamide can be derived from, for example, corresponding diamines, triamines, tetraamines and the like.

  Examples of the polymerization reactive oligomer include urethane (meth) acrylate, epoxy (meth) acrylate, copolyester (meth) acrylate, oligomer di (meth) acrylate and the like. Preferably, it is hydrophobic urethane (meth) acrylate.

  The weight average molecular weight of the polymerization reactive oligomer is preferably 1500 or more, more preferably 2000 or more. Although the upper limit of the weight average molecular weight of a polymerization reactive oligomer is not specifically limited, For example, Preferably it is 10,000 or less.

  As the cross-linking agent, “one or more selected from polyfunctional (meth) acrylates having a weight average molecular weight of 800 or more, polyfunctional (meth) acrylamides, and polymerization reactive oligomers” and “a weight average molecular weight of 500 or less. When using together with “one or more selected from functional (meth) acrylate and polyfunctional (meth) acrylamide” ”,“ polyfunctional (meth) acrylate having a weight average molecular weight of 800 or more, polyfunctional (meth) acrylamide, and polymerization ” The amount of “one or more selected from reactive oligomers” is preferably 40% by weight as a lower limit with respect to the total amount of the hydrophilic polyurethane polymer and the ethylenically unsaturated monomer in the continuous oil phase component. The upper limit is preferably 100% by weight, and more preferably 80% by weight. The amount of use of “one or more selected from a polyfunctional (meth) acrylate having a weight average molecular weight of 800 or more, a polyfunctional (meth) acrylamide, and a polymerization reactive oligomer” is a hydrophilic polyurethane-based heavy in the continuous oil phase component When the amount is less than 40% by weight with respect to the total amount of the coalesced and ethylenically unsaturated monomer, the cohesive force of the obtained near-infrared light reflecting material may be lowered, making it difficult to achieve both toughness and flexibility. There is a risk. The amount of use of “one or more selected from a polyfunctional (meth) acrylate having a weight average molecular weight of 800 or more, a polyfunctional (meth) acrylamide, and a polymerization reactive oligomer” is a hydrophilic polyurethane-based heavy in the continuous oil phase component When the amount exceeds 100% by weight with respect to the total amount of the coalesced and ethylenically unsaturated monomer, the emulsion stability of the W / O emulsion is lowered, and the desired near-infrared light reflecting material may not be obtained. .

  As the cross-linking agent, “one or more selected from polyfunctional (meth) acrylates having a weight average molecular weight of 800 or more, polyfunctional (meth) acrylamides, and polymerization reactive oligomers” and “a weight average molecular weight of 500 or less. When using together with “one or more selected from functional (meth) acrylate and polyfunctional (meth) acrylamide” ”,“ selected from polyfunctional (meth) acrylate and polyfunctional (meth) acrylamide having a weight average molecular weight of 500 or less ” The amount of “one or more” used is preferably 1% by weight, more preferably 5% as a lower limit with respect to the total amount of the hydrophilic polyurethane polymer and the ethylenically unsaturated monomer in the continuous oil phase component. The upper limit is preferably 30% by weight, and more preferably 20% by weight. Use amount of “one or more selected from polyfunctional (meth) acrylate having a weight average molecular weight of 500 or less and polyfunctional (meth) acrylamide” is a hydrophilic polyurethane polymer and ethylenic unsaturated in a continuous oil phase component When the amount is less than 1% by weight based on the total amount of monomers, the heat resistance is lowered, and the cell structure may be crushed by contraction in the step (IV) of dehydrating the water-containing polymer. Use amount of “one or more selected from polyfunctional (meth) acrylate having a weight average molecular weight of 500 or less and polyfunctional (meth) acrylamide” is a hydrophilic polyurethane polymer and ethylenic unsaturated in a continuous oil phase component When it exceeds 30 weight% with respect to the total amount of a monomer, the toughness of the near-infrared-light reflection material obtained may fall, and there exists a possibility of showing brittleness.

  The crosslinking agent may contain only 1 type and may contain 2 or more types.

(B-1-2-5. Other components in the continuous oil phase component)
The continuous oil phase component may contain any appropriate other component as long as the effects of the present invention are not impaired. Examples of such other components typically include a catalyst, an antioxidant, a light stabilizer, and an organic solvent. Such other components may be only one type or two or more types.

  Examples of the catalyst include a urethane reaction catalyst. Any appropriate catalyst can be adopted as the urethane reaction catalyst. Specific examples include dibutyltin dilaurate.

  Arbitrary appropriate content rates can be employ | adopted for the content rate of a catalyst according to the target catalytic reaction.

  The catalyst may contain only 1 type and may contain 2 or more types.

  Examples of the antioxidant include a phenol-based antioxidant, a thioether-based antioxidant, and a phosphorus-based antioxidant.

  Arbitrary appropriate content rates can be employ | adopted for the content rate of antioxidant in the range which does not impair the effect of this invention.

  Antioxidant may contain only 1 type and may contain 2 or more types.

  Any appropriate organic solvent can be adopted as the organic solvent as long as the effects of the present invention are not impaired.

  Arbitrary appropriate content rates can be employ | adopted for the content rate of an organic solvent in the range which does not impair the effect of this invention.

  The organic solvent may contain only 1 type and may contain 2 or more types.

  Any appropriate light stabilizer can be adopted as the light stabilizer as long as the effects of the present invention are not impaired.

  Arbitrary appropriate content rates can be employ | adopted for the content rate of a light stabilizer in the range which does not impair the effect of this invention.

  The light stabilizer may contain only 1 type and may contain 2 or more types.

<< B-2. Step of shaping W / O type emulsion (II) >>
In the step (II), any appropriate shaping method can be adopted as a method for shaping the W / O type emulsion. For example, there is a method in which a W / O emulsion is continuously supplied onto a traveling belt and shaped into a smooth sheet on the belt. Moreover, the method of apply | coating to one surface of a thermoplastic resin film, and shaping is mentioned.

  In the step (II), as a method of shaping the W / O type emulsion, when adopting a method of coating and shaping on one surface of a thermoplastic resin film, as a method of coating, for example, a roll coater, Examples include a method using a die coater, a knife coater, or the like.

<< B-3. Step of polymerizing shaped W / O emulsion (III) >>
In the step (III), any appropriate polymerization method can be adopted as a method for polymerizing the shaped W / O emulsion. For example, the belt surface of a belt conveyor is heated by a heating device, and a W / O type emulsion is continuously supplied onto a traveling belt and shaped into a smooth sheet on the belt by heating. A W / O emulsion is continuously supplied onto the running belt, with a method of polymerization and a structure in which the belt surface of the belt conveyor is heated by irradiation of active energy rays, and a smooth sheet is formed on the belt. The method of superposing | polymerizing by irradiation of an active energy ray is mentioned, shaping.

  In the case of polymerization by heating, the polymerization temperature (heating temperature) is preferably 23 ° C., more preferably 50 ° C., still more preferably 70 ° C., particularly preferably 80 ° C. as the lower limit. The upper limit is preferably 90 ° C, and is preferably 150 ° C, more preferably 130 ° C, and even more preferably 110 ° C. When the polymerization temperature is less than 23 ° C., the polymerization takes a long time, and industrial productivity may be reduced. When the polymerization temperature exceeds 150 ° C, the pore diameter of the obtained near-infrared light reflecting material may be nonuniform, and the strength of the near-infrared light reflecting material may be reduced. The polymerization temperature need not be constant. For example, the polymerization temperature may be varied in two stages or multiple stages during the polymerization.

  In the case of polymerization by irradiation with active energy rays, examples of the active energy rays include ultraviolet rays, visible rays, and electron beams. The active energy ray is preferably ultraviolet light or visible light, and more preferably visible to ultraviolet light having a wavelength of 200 nm to 800 nm. Since the W / O type emulsion has a strong tendency to scatter light, it is possible to penetrate the W / O type emulsion by using visible to ultraviolet light having a wavelength of 200 nm to 800 nm. Moreover, the photoinitiator which can be activated with a wavelength of 200 nm-800 nm is easy to obtain, and a light source is easy to obtain.

  The wavelength of the active energy ray is preferably 200 nm, more preferably 300 nm as the lower limit value, and preferably 800 nm, more preferably 450 nm as the upper limit value.

  As a typical apparatus used for irradiation of active energy rays, for example, an ultraviolet lamp capable of performing ultraviolet irradiation includes an apparatus having a spectral distribution in a wavelength region of 300 to 400 nm. , Black light (trade name manufactured by Toshiba Lighting & Technology), metal halide lamp, and the like.

  The illuminance at the time of irradiation with active energy rays can be set to any appropriate illuminance by adjusting the distance from the irradiation device to the irradiation object and the voltage. For example, by the method disclosed in Japanese Patent Application Laid-Open No. 2003-13015, the ultraviolet irradiation in each step is performed in a plurality of stages, thereby making it possible to precisely adjust the adhesive performance.

  In order to prevent the adverse effect of oxygen having an inhibitory action on the ultraviolet rays, for example, a W / O emulsion is applied to one surface of a substrate such as a thermoplastic resin film and then shaped under an inert gas atmosphere. UV rays such as polyethylene terephthalate coated with a release agent such as silicone after passing through a W / O emulsion on one surface of a substrate such as a thermoplastic resin film and shaping, but blocking oxygen It is preferable to carry out by covering the film.

  As the thermoplastic resin film, any appropriate thermoplastic resin film can be adopted as long as it can be formed by coating a W / O emulsion on one surface. Examples of the thermoplastic resin film include plastic films and sheets such as polyester, olefin resin, and polyvinyl chloride. Further, the film may be subjected to a peeling treatment on one side or both sides thereof.

  The inert gas atmosphere refers to an atmosphere in which oxygen in the light irradiation zone is replaced with an inert gas. Therefore, in the inert gas atmosphere, it is necessary that oxygen is not present as much as possible, and the oxygen concentration is preferably 5000 ppm or less.

<< B-4. Step of dehydrating the obtained water-containing polymer (IV) >>
In step (IV), the obtained water-containing polymer is dehydrated. In the water-containing polymer obtained in step (III), the aqueous phase component is present in a dispersed state. By removing the aqueous phase component by dehydration and drying, the foam contained in the near-infrared light reflecting material of the present invention is obtained. The obtained foam can be used as it is as a near-infrared light reflecting material of the present invention. Moreover, it can become the near-infrared light reflection material of this invention by combining with a base material so that it may mention later.

  Arbitrary appropriate drying methods can be employ | adopted as a dehydration method in process (IV). Examples of such a drying method include vacuum drying, freeze drying, press drying, microwave drying, drying in a heat oven, drying with infrared rays, or a combination of these techniques.

<< B-5. When the near-infrared light reflecting material of the present invention contains a base material >>
When the near-infrared light reflecting material of the present invention contains a substrate, as one preferred embodiment of the method for producing the near-infrared light reflecting material of the present invention, a W / O emulsion is applied to one surface of the substrate. W / O type emulsion by heating or irradiation with active energy rays in an inert gas atmosphere or in a state where oxygen is blocked by coating with a UV transparent film coated with a release agent such as silicone Is obtained as a water-containing polymer, and the obtained water-containing polymer is dehydrated to form a near-infrared light reflecting material having a substrate / foamed layer laminated structure.

  As another preferred embodiment of the method for producing a near-infrared light reflecting material of the present invention, 2 is obtained by applying a W / O emulsion to one surface of an ultraviolet transmissive film coated with a release agent such as silicone. A sheet is prepared, a substrate is laminated on the coated surface of one of the two W / O emulsion coated sheets, and another W / O emulsion is formed on the other surface of the laminated substrate. In a state where the coated surfaces of the coated sheets are laminated so as to match with each other, by heating or irradiating active energy rays, the W / O emulsion is polymerized to form a hydrous polymer, and the obtained hydrous polymer is dehydrated. The form which is set as the near-infrared light reflection material which has a laminated structure of a foam layer / base material / foam layer is mentioned.

  Examples of the method of coating the W / O type emulsion on one side of the base material or one surface of the ultraviolet ray transmissive film coated with a release agent such as silicone include a roll coater, a die coater, and a knife coater.

  Hereinafter, although the present invention is explained based on an example, the present invention is not limited to these. The normal temperature means 23 ° C.

(Molecular weight measurement)
The weight average molecular weight was determined by GPC (gel permeation chromatography).
Apparatus: “HLC-8020” manufactured by Tosoh Corporation
Column: “TSKgel GMH _HR- H (20)” manufactured by Tosoh Corporation
Solvent: Tetrahydrofuran Standard: Polystyrene

(Measurement of average pore diameter)
The obtained foam was cut in the thickness direction with a microtome cutter as a measurement sample. The cut surface of the sample for measurement was photographed with a scanning electron microscope (Hitachi, S-3400N) at 800 to 5000 times. Using the photographed image, measure the pore diameter of an arbitrary range of spherical bubbles, the diameter of a through-hole penetrating between the spherical bubbles of an arbitrary range, and the pore diameter of the surface opening of an arbitrary range. The average hole diameter, the average hole diameter of the through holes, and the average hole diameter of the surface openings were calculated.

(Reflectance)
Using a spectrophotometer “U-4100” (manufactured by Hitachi High-Tech Science Systems Co., Ltd.), in the reflectance measurement mode, under conditions of an incident angle of 0 °, a measurement wavelength region of 300 to 2000 nm, a sampling interval of 1 nm, and a scan speed of 300 nm / min. The spectral intensity of the total diffuse reflection component was measured as a relative value (%) to the reflected light of the barium sulfate white plate.

(Light resistance test)
Using a die plastic metal weather KU-R5N-W (manufactured by Daipura Wintes Co., Ltd.), ultraviolet rays having an illuminance of 90 mW / cm ² were continuously irradiated for 100 hours with a metal halide lamp under conditions of a temperature of 63 ° C. and a humidity of 50%.

(Dimensional change rate when stored at 125 ° C for 22 hours)
The heating dimensional change of the obtained near-infrared light reflecting material was measured based on the dimensional stability evaluation at high temperature of JIS-K-6767. That is, the obtained foam was cut into a size of 100 mm × 100 mm to obtain a test piece, which was stored in an oven at 125 ° C. for 22 hours, and then conformed to the dimensional stability evaluation at high temperature of JIS-K-6767. The dimensional change rate before and after the heat storage treatment was determined.

[Production Example 1]: Preparation of mixed syrup 1 In a reaction vessel equipped with a condenser, a thermometer, and a stirrer, 2-ethylhexyl acrylate as an ethylenically unsaturated monomer (manufactured by Toa Gosei Co., Ltd., hereinafter abbreviated as “2EHA”) 173.2 parts by weight of a monomer solution, 100 parts by weight of Adeka (registered trademark) Pluronic L-62 (molecular weight 2500, polyether polyol manufactured by ADEKA) as polyoxyethylene polyoxypropylene glycol, and urethane reaction catalyst Dibutyltin dilaurate (manufactured by Kishida Chemical Co., Ltd., hereinafter abbreviated as “DBTL”) was added in 0.014 part by weight. 12.4 parts by weight were added dropwise and reacted at 65 ° C. for 4 hours. In addition, the usage-amount of the polyisocyanate component and the polyol component was NCO / OH (equivalent ratio) = 1.6. Thereafter, 5.6 parts by weight of 2-hydroxyethyl acrylate (manufactured by Kishida Chemical Co., Ltd., hereinafter abbreviated as “HEA”) is added dropwise and reacted at 65 ° C. for 2 hours to have a hydrophilic polyurethane polymer having acryloyl groups at both ends. / Ethylenically unsaturated monomer mixed syrup was obtained. The weight average molecular weight of the obtained hydrophilic polyurethane polymer having acryloyl groups at both ends was 15,000. 27.3 parts by weight of 2EHA, n-butyl acrylate (manufactured by Toa Gosei Co., Ltd., hereinafter “100 parts by weight of hydrophilic polyurethane polymer having acryloyl groups at both ends / ethylenically unsaturated monomer mixed syrup”) 51.8 parts by weight of BA ”), 17.6 parts by weight of isobornyl acrylate (for example, Osaka Organic Chemical Industries, hereinafter referred to as“ IBXA ”), and acrylic acid (manufactured by Toagosei Co., Ltd.) as a polar monomer (Hereinafter abbreviated as “AA”) was added in an amount of 10.5 parts by weight to obtain a hydrophilic polyurethane polymer / ethylenically unsaturated monomer mixed syrup 1.

[Production Example 2]: Preparation of mixed syrup 2 In a reaction vessel equipped with a condenser, a thermometer, and a stirrer, 173.2 parts by weight of a monomer solution composed of 2EHA as an ethylenically unsaturated monomer, and polyoxyethylene polyoxy 100 parts by weight of Adeka (registered trademark) Pluronic L-62 (molecular weight 2500, manufactured by ADEKA, polyether polyol) as propylene glycol and 0.014 parts by weight of DBTL as a urethane reaction catalyst were added, and HXDI was stirred. 12.4 parts by weight were added dropwise and reacted at 65 ° C. for 4 hours. In addition, the usage-amount of the polyisocyanate component and the polyol component was NCO / OH (equivalent ratio) = 1.6. Then, 5.6 parts by weight of HEA was added dropwise and reacted at 65 ° C. for 2 hours to obtain a hydrophilic polyurethane polymer / ethylenically unsaturated monomer mixed syrup having acryloyl groups at both ends. The weight average molecular weight of the obtained hydrophilic polyurethane polymer having acryloyl groups at both ends was 15,000. 95.8 parts by weight of 2EHA, 92.5 parts by weight of BA, 31.3 parts by weight of IBXA, and 31.3 parts by weight of polar monomer based on 100 parts by weight of the obtained hydrophilic polyurethane polymer / ethylenically unsaturated monomer mixed syrup 18.8 parts by weight of AA was added to obtain a hydrophilic polyurethane polymer / ethylenically unsaturated monomer mixed syrup 2.

[Production Example 3]: Preparation of mixed syrup 3 In a reaction vessel equipped with a condenser, a thermometer, and a stirrer, 173.2 parts by weight of a monomer solution composed of 2EHA as an ethylenically unsaturated monomer, and polyoxyethylene polyoxy 100 parts by weight of Adeka (registered trademark) Pluronic L-62 (molecular weight 2500, manufactured by ADEKA, polyether polyol) as propylene glycol and 0.014 parts by weight of DBTL as a urethane reaction catalyst were added, and HXDI was stirred. 12.4 parts by weight were added dropwise and reacted at 65 ° C. for 4 hours. In addition, the usage-amount of the polyisocyanate component and the polyol component was NCO / OH (equivalent ratio) = 1.6. Then, 5.6 parts by weight of HEA was added dropwise and reacted at 65 ° C. for 2 hours to obtain a hydrophilic polyurethane polymer / ethylenically unsaturated monomer mixed syrup having acryloyl groups at both ends. The weight average molecular weight of the obtained hydrophilic polyurethane polymer having acryloyl groups at both ends was 15,000. 24.7 parts by weight of 2EHA, 41.9 parts by weight of BA, and 8.5 parts by weight of AA as a polar monomer are added to 100 parts by weight of the obtained hydrophilic polyurethane polymer / ethylenically unsaturated monomer mixed syrup. A hydrophilic polyurethane polymer / ethylenically unsaturated monomer mixed syrup 3 was obtained.

[Example 1]
To 100 parts by weight of the hydrophilic polyurethane polymer / ethylenically unsaturated monomer mixed syrup 1 obtained in Production Example 1, 1,6-hexanediol diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name “NK Ester A” -HD-N ") (molecular weight 226) 11.9 parts by weight, synthesized as a reactive oligomer from polytetramethylene glycol (hereinafter abbreviated as" PTMG ") and isophorone diisocyanate (hereinafter abbreviated as" IPDI "). 47.7 parts by weight of urethane acrylate having both ends of polyurethane treated with HEA and having ethylenically unsaturated groups at both ends (hereinafter abbreviated as “UA”) (molecular weight 3720) as a photoinitiator, 2,4,6-trimethylbenzoyl) phosphine oxide (BASF, trade name “Lucirin TPO”) 8 parts by weight, 0.95 parts by weight of a hindered phenol-based antioxidant (Ciba Japan, trade name “Irganox 1010”), 2.0 parts by weight of light stabilizer (BASF, trade name “TINUVIN123”) The parts were uniformly mixed to obtain a continuous oil phase component (hereinafter referred to as “oil phase”). On the other hand, 300 parts by weight of ion-exchanged water as an aqueous phase component (hereinafter referred to as “aqueous phase”) with respect to 100 parts by weight of the oil phase is continuously introduced into a stirring mixer that is an emulsifier charged with the oil phase at room temperature. A stable W / O emulsion (1) was prepared. The weight ratio of the water phase to the oil phase was 75/25.
The obtained W / O emulsion was stored at room temperature for 1 hour, and then applied onto a substrate that had been subjected to a release treatment so that the thickness after light irradiation was 0.3 mm, and was continuously molded. Further, a polyethylene terephthalate film having a thickness of 38 μm and subjected to a release treatment was placed thereon. This sheet was irradiated with ultraviolet light having a light illuminance of 5 mW / cm ² (measured with Topcon UVR-T1 having a peak sensitivity maximum wave of 350 nm) using black light (15 W / cm), and a highly water-containing crosslinked polymer having a thickness of 0.3 mm was obtained. Obtained. Next, the top film is peeled off, and the high water content cross-linked polymer is heated at 130 ° C. for 10 minutes to obtain a near-infrared light reflecting material (1) containing a foam having a thickness of about 0.3 mm. Obtained.
The results are shown in Table 1 and FIG.
Moreover, the photograph figure of the surface / cross-section SEM photograph which image | photographed the obtained near-infrared-light reflective material (1) from diagonally was shown in FIG.

[Example 2]
In Example 1, the obtained W / O emulsion was allowed to stand at room temperature for 1 hour, and then applied onto a release-treated substrate so that the thickness after light irradiation was 1 mm. A near-infrared light reflecting material (2) containing a foam having a thickness of about 1 mm was obtained by the same operation as in Example 1 except that the molding was performed.
The results are shown in Table 1 and FIG.

Example 3
To 100 parts by weight of the hydrophilic polyurethane polymer / ethylenically unsaturated monomer mixed syrup 1 obtained in Production Example 2, 10.0 parts by weight of 1,6-hexanediol diacrylate as a reactive oligomer, PTMG and 47.7 parts by weight of UA (molecular weight 3720) having ethylenically unsaturated groups at both ends, diphenyl (2,4,6-trimethylbenzoyl) phosphine treated with HEA at both ends of polyurethane synthesized from IPDI Finoxide (BASF, trade name "Lucirin TPO") 0.49 parts by weight, hindered phenolic antioxidant (Ciba Japan, trade name "Irganox 1010") 0.99 parts by weight, light stable 2.05 parts by weight of an agent (trade name “TINUVIN123”, manufactured by BASF Corporation) was uniformly mixed, and a continuous oil phase component (hereinafter referred to as “ Was referred to as a phase "). On the other hand, 186 parts by weight of ion-exchanged water as an aqueous phase component (hereinafter referred to as “aqueous phase”) with respect to 100 parts by weight of the oil phase is continuously placed in a stirring mixer which is an emulsifier charged with the oil phase at room temperature. Was added dropwise to prepare a stable W / O emulsion (2). The weight ratio of the water phase to the oil phase was 65/35.
About the obtained W / O type | mold emulsion, it carried out similarly to Example 1 and obtained the near-infrared-light reflection material (3) containing the foam about 0.3 mm thick.
The results are shown in Table 1 and FIG.

Example 4
To 100 parts by weight of the hydrophilic polyurethane polymer / ethylenically unsaturated monomer mixed syrup 3 obtained in Production Example 3, 20.0 parts by weight of 1,6-hexanediol diacrylate as a reactive oligomer, PTMG and 47.7 parts by weight of UA (molecular weight 3720) having ethylenically unsaturated groups at both ends, diphenyl (2,4,6-trimethylbenzoyl) phosphine treated with HEA at both ends of polyurethane synthesized from IPDI Finoxide (BASF, trade name "Lucirin TPO") 0.49 parts by weight, hindered phenolic antioxidant (Ciba Japan, trade name "Irganox 1010") 0.99 parts by weight, light stable 2.05 parts by weight of an agent (trade name “TINUVIN123”, manufactured by BASF Corporation) was uniformly mixed, and a continuous oil phase component (hereinafter referred to as “ Was referred to as a phase "). On the other hand, with respect to 100 parts by weight of the oil phase, 567 parts by weight of ion-exchanged water as an aqueous phase component (hereinafter referred to as “aqueous phase”) is continuously added in a stirring mixer which is an emulsifier charged with the oil phase at room temperature. Were added dropwise to prepare a stable W / O emulsion (3). The weight ratio of the water phase to the oil phase was 85/15.
About the obtained W / O type | mold emulsion, it carried out similarly to Example 1 and obtained the near-infrared-light reflection material (4) containing the foam about 0.4 mm thick.
The results are shown in Table 1 and FIG.

  In the charts of FIGS. 5 to 7, there is a region where the total reflectance exceeds 100%, which is due to the measurement apparatus being adjusted with the total reflectance of the barium sulfate powder being 100%. Presumed to be. However, when the barium sulfate powder that theoretically shows 100% total reflectivity is used as a comparative substance, the region where the measurement result of total reflectivity exceeds 100% is almost equal to or higher than that of barium sulfate powder. It is thought that it shows.

  The near-infrared light reflecting material of the present invention is useful as a reflecting material provided in a near-infrared light emitting device such as illumination for night photography, an infrared spotlight, and an infrared sensor.

100 Near-infrared light reflecting material 10 Foam 10a Foam 10b Foam 20 Base material 30 Release film

Claims (7)

Comprising a foam having an open cell structure with through-holes between adjacent spherical cells;
The foam comprises a hydrophilic polyurethane polymer;
The average pore size of the spherical bubbles is less than 20 μm,
The average pore diameter of the through holes is 5 μm or less,
The surface of the foam has a surface opening having an average pore diameter of 20 μm or less,
The total reflectance in at least some wavelengths in the wavelength region of 800 nm to 2000 nm is 60% or more,
Near-infrared light reflecting material.   The near-infrared-light reflective material of Claim 1 whose total reflectivity in a wavelength range of 800 nm-1600 nm is 60% or more.   The near-infrared light reflecting material according to claim 1 or 2, wherein the total reflectance in a wavelength region of 1800 nm to 2000 nm is 60% or more.   The near-infrared light reflecting material according to any one of claims 1 to 3, wherein a dimensional change rate when stored at 125 ° C for 22 hours is less than ± 5%. A method for producing a near-infrared light reflecting material including a foam having an open cell structure having a through-hole between adjacent spherical bubbles,
Step (I) for preparing a continuous oil phase component and a W / O emulsion containing an aqueous phase component immiscible with the continuous oil phase component, and a step (II) for shaping the obtained W / O emulsion And a step (III) of polymerizing the shaped W / O emulsion, and a step (IV) of dehydrating the obtained water-containing polymer,
The continuous oil phase component includes a hydrophilic polyurethane polymer, an ethylenically unsaturated monomer, and a crosslinking agent.
Manufacturing method of near-infrared light reflecting material.   The cross-linking agent is one or more selected from polyfunctional (meth) acrylates having a weight average molecular weight of 800 or more, polyfunctional (meth) acrylamides, and polymerization reactive oligomers, and polyfunctional having a weight average molecular weight of 500 or less. The manufacturing method of the near-infrared-light reflecting material of Claim 5 containing 1 or more types chosen from (meth) acrylate and polyfunctional (meth) acrylamide. A near-infrared light reflecting material obtained by the production method according to claim 5.