JP4573671B2 - Heat ray shielding sheet - Google Patents

Description

  The present invention, when used in a sheet-like structure such as a tent or tarp, can effectively suppress an increase in temperature due to sunlight of an object placed inside the structure, and the surface of the sheet It is related with the heat ray shielding sheet which can prevent deterioration of the sheet | seat accompanying the temperature rise.

Conventionally, a material used for a tent or the like is called tarpaulin and generally has a structure in which both surfaces of a fiber base material such as a polyester knitted fabric or a woven fabric are covered with polyvinyl chloride or rubber.
Tarpaulins with such a configuration are never good in terms of heat-shielding properties, especially in tent warehouses that are used semi-permanently. This product is not comfortable for workers.
Furthermore, the temperature rise in the tent is also a big problem for military tents used in emergency situations and temporary tents used in disasters.

Conventionally, the same tarpaulin or a canvas impregnated with resin has been used as a truck hood. However, as in the case of the above tent, the temperature rise in the truck bed is large during the midsummer day. It is a problem and there are restrictions on the luggage to be carried.

  By the way, the technique regarding the sheet | seat which has the heat-shielding property (henceforth "heat-shielding property") has been studied for a long time, for example, in Unexamined-Japanese-Patent No. 8-81567 (patent document 1), plastic resin is made from aluminum. In a sheet having a heat shielding property by containing a specific amount of powder, Japanese Patent Application Laid-Open No. 2002-12679 (Patent Document 2), two or more pigments having a heat shielding property are mixed in a thermoplastic resin film. A heat-shielding color film to be molded, Japanese Patent Application Laid-Open No. 2000-71858 (Patent Document 3), a sheet in which a plastic layer and a metal-deposited polyester film are laminated is known.

  However, the sheet described in Patent Document 1 is dazzling because of a layer containing a large amount of aluminum on the surface, and the sheet surface is not suitable for printing or the like. Furthermore, it is difficult for the sheet having such a configuration to increase the solar reflectance to 75% or more and to reduce the solar absorption rate to 10% or less.

  In the film described in Patent Document 2, not only is it necessary to use an expensive pigment having excellent heat shielding performance, but also a general inexpensive white titanium oxide pigment has excellent reflection performance compared to such an expensive pigment. There is also. Moreover, although the film can keep the surface temperature low, the film as a whole has a large amount of light transmission, and therefore directly heats an object placed inside the structure using the film. The temperature of this object tends to increase.

  Although the sheet described in Patent Document 3 does not receive sunlight directly inside, the metal-deposited polyester film absorbs light and the sheet itself is heated to a high temperature, so indirect heating due to heat propagation is considered, Furthermore, there is a concern about deterioration of the sheet itself.

As another method for imparting heat shielding properties to the sheet, a method of applying a paint having a heat shielding effect to the surface of the sheet is also conceivable, but the paint itself is more expensive than a general paint, After creating a structure such as a tent, it is necessary to apply paint so that a certain level of performance can be achieved. For example, it is necessary to apply paint many times to make it thicker. There is a problem that it takes time and effort.
JP-A-8-81567 JP 2002-12679 A JP 2000-71858 A

  The present invention solves various problems in the above-described heat-insulating sheets that have been used or proposed so far, and is a sheet having high reflection performance, which reflects most of sunlight. It is an object of the present invention to provide a sheet that exhibits excellent heat ray shielding properties by absorbing light that cannot be reflected by the absorption layer.

In order to solve the above-mentioned problems, the present inventors have conducted various studies.
(Α) A laminated structure of a “reflection layer” that reflects light of a specific wavelength and an “absorption layer” that absorbs light having a wavelength that contributes to heat generation, which is transmitted through the reflection layer. By reflecting sunlight through the outermost “reflective layer” and effectively absorbing transmitted light that cannot be reflected by the “absorbing layer”, the temperature rise due to sunlight inside the sheet-like structure such as a tent is increased. In addition to preventing, the inventors have found that excessive heating of the heat ray shielding sheet itself can be suppressed.

Next, as a result of further examination under this knowledge,
(Β) By setting the specific heat capacity of the “absorbing layer” to be larger than that of the “reflecting layer”, the solar energy absorbed by the “absorbing layer” is contained in the “absorbing layer”, and the sheet-like structure of the energy It has been found that the escape to the inside of the body, the temperature rise inside the structure due to this result can be effectively suppressed,
(Γ) Such a laminated sheet has a specific solar reflectance and solar absorptivity with respect to light of a specific wavelength, so that heat storage of the sheet itself and heat generation of the sheet surface can be more effectively prevented. The headline and the present invention were completed.

That is, the present invention is a sheet having a structure in which at least two layers of a reflection layer and an absorption layer are laminated, and the reflection layer is disposed on the outermost layer that directly receives sunlight, and the absorption layer is disposed on the inner side of the reflection layer. The layer has a solar reflectance at a wavelength of 350 to 1600 nm calculated based on the provisions of JIS-A5759 of 75% or more and a solar absorptance of 10% or less, and the absorptive layer has a solar absorptivity at a wavelength of 800 to 1600 nm. 60% or more, and as a whole sheet, the solar reflectance at a wavelength of 350-2100 nm calculated based on the provisions of JIS-A5759 is 75% or more, the solar reflectance at a wavelength of 800-1600 nm is 80% or more, and a wavelength of 350- The gist of the heat ray shielding sheet is that the solar radiation absorption rate at 2100 nm is 10% or more, and the specific heat capacity of the absorbing layer is 10% or more larger than the specific heat capacity of the reflective layer.
In this case, (1) reflection layer has a thickness of 0.1 to 1 mm, relative to 100 parts by weight of polyvinyl chloride resin, glass beads, hollow glass balloons, at least one selected from the microcapsules 5 ~ 20 parts by weight, preferably 3-30 parts by weight of a titanium oxide white pigment, and ( 2 ) the absorption layer has a thickness of 25-500 μm, a polyvinyl chloride resin, an acrylic type At least one selected from a resin, a polyester-based resin, a polyolefin-based resin, and a urethane-based resin may be included.

The heat ray shielding sheet according to the present invention has a structure in which at least a reflective layer and an absorption layer are laminated, and the solar reflectance calculated from the standard of JIS-A5759 is 75% or more, and the wavelength is 800 to 1600 nm. The solar reflectance is 80% or more, and the solar absorptance at a wavelength of 350 to 2100 nm is 10% or more.
If the solar reflectance at a wavelength of 350 to 2100 nm, particularly 800 to 1600 nm is too low, heat storage of the sheet cannot be avoided sufficiently, so the reflectance is preferably not less than the above reflectance, and preferably not less than 85%. On the other hand, when the solar radiation absorptivity at a wavelength of 350 to 2100 nm is too low, the temperature inside the sheet-like structure rises excessively, so that it is not less than the above absorptivity, preferably not less than 15%.

  In addition, it is preferable that the solar radiation transmittance calculated based on prescription | regulation of JIS-A5759 with a wavelength of 350-2100 nm is 7% or less at this time. If the solar radiation transmittance of the heat ray shielding sheet is too high, the temperature inside the sheet-like structure also rises, so the above transmittance is preferable, and more preferably 0%.

Further, the absorbent layer than the reflective layer, it is important that the specific heat capacity is greater, in the absorption layer, by the structure of storing more heat, heat from solar energy to the internal sheet-like structures Is prevented as much as possible, and temperature rise inside the structure is suppressed.
The heat capacity is a value obtained by measuring each of the reflective layer and the absorption layer with a DSC (differential scanning calorimeter), and the specific heat capacity is the amount of heat required to raise the temperature of each layer by 1 ° C. It is a value converted per hit.
In this invention, 47 degreeC is employ | adopted as a representative value of the temperature of the sheet | seat heated with sunlight, and the specific heat capacity of an absorption layer and a reflection layer is calculated | required by making the heat capacity in this temperature into a representative value, and the specific heat capacity of an absorption layer is calculated. And 10% or more of that of the reflective layer (ie, if the specific heat capacity of the reflective layer is Ha and the specific heat capacity of the absorption layer is Hb, then Hb ≧ 1.1 Ha).
If the specific heat capacity of the absorption layer is about the same as or smaller than that of the reflective layer (the specific heat capacity of the reflective layer cannot be increased due to the property of reflecting light), the heat absorbed by the absorption layer However, it does not stay inside the absorption layer but escapes to the inside of the sheet-like structure, leading to an increase in temperature inside the structure.
However, since the heat capacity to be retained in the absorption layer is saturated even if it is too large, the upper limit may be increased by about 50% of the specific heat capacity of the reflective layer (that is, Hb ≧ 1.5 Ha as the upper limit). It is practical.

  When used as a sheet-like structure such as a tent, it reaches the inside of the structure by absorbing the reflective layer as the outermost layer that receives sunlight directly, and absorbing sunlight that cannot be reflected by the reflective layer. In order to reduce the influence of sunlight, it is reasonable to place an absorption layer in the innermost layer. If the absorbing layer is located on the outermost layer, the sheet itself generates heat, and even if the reflecting layer is located on the innermost layer, the characteristics of the reflecting layer cannot be fully utilized.

Furthermore, in the heat ray shielding sheet of the present invention, the reflective layer has a solar reflectance of 75% or more and a solar absorptivity of 10% or less calculated at a wavelength of 350 to 1600 nm calculated on the basis of JIS-A5759. is, solar radiation absorption at a wavelength of 800~1600nm is Ru der 60% or more.
The solar reflectance is less than 75% reflective layer, reflection is insufficient for hardly avoid heat storage sheet, is 75% or more, good preferable is 85% or more.
The solar absorptance of less than 60% of the absorbent layer is not completely sufficient to take the light transmitted through the reflective layer by the absorption layer, since results in heating the surface of an object, of 60% or more, 80% or more favorable preferable.

By having such a solar reflectance and solar absorptivity for the reflective layer and the absorbing layer, higher shielding performance is exhibited, and excessive heat generation of the sheet itself (front surface / back surface) is further prevented. Is possible.
This is because the reflectance of the entire heat ray shielding sheet is controlled by the reflective layer, and the shielding effect is ensured to some extent by this reflective action, and light that has passed through the reflective layer and contributes to heat generation is absorbed by the absorbing layer. This is because excellent heat ray shielding performance can be expressed by efficiently absorbing the water.

  Therefore, within the ranges of the specific heat capacity, solar reflectance, and solar absorptance as described above, the thickness of the reflective layer and the absorbing layer (thickness and layer ratio of each layer), composition (mixing ratio), color, etc. can be determined. Good.

In the heat ray shielding sheet of this invention, it is preferable that a reflection layer has a thickness of 0.1-1 mm, and an absorption layer has a thickness of 25-500 micrometers.
If the thickness of the reflective layer is too thin, it will be difficult to ensure a sufficient solar reflectance, and if it is too thick, not only will this action be saturated, but also the weight will increase and handling will be reduced. A more preferable thickness is 0.2 to 0.8 mm.
On the other hand, if the thickness of the absorbing layer is too thin, it is difficult to obtain a desired solar radiation absorption rate. If it is too thick, not only will this action be saturated, but also the weight will be increased and handling will be reduced. A more preferable thickness is 25 to 500 μm.

In the heat ray shielding sheet having a structure in which at least two layers of the reflection layer and the absorption layer are laminated according to the present invention, the thickness ratio between the reflection layer and the absorption layer is not particularly limited, but the thermal conductivity, flexibility, and formability are not limited. From such a viewpoint, the reflective layer: absorbing layer is preferably in the range of 4: 1 to 1: 2, more preferably the reflective layer is slightly thicker than 1: 1.
If the reflective layer is too thin with respect to the thickness of the absorbing layer, it is difficult to obtain the desired solar reflectance in the reflective layer, as in the case where the thickness of the reflective layer is too thin. As in the case where the thickness of the reflective layer is too thick, the action of the reflective layer is saturated, resulting in a useless increase in thickness.

  Further, the reflective layer in the present invention comprises 5 to 20 parts by weight of at least one selected from glass beads, hollow glass balloons, and microcapsules with respect to 100 parts by weight of the polyvinyl chloride resin, and 3 to 3% of the titanium oxide white pigment. It preferably contains 30 parts by weight.

As the above-mentioned polyvinyl chloride resin, a homopolymer of a polyvinyl chloride monomer, a copolymer of a polyvinyl chloride monomer and a monomer copolymerizable with a polyvinyl chloride monomer such as a vinyl acetate monomer or an acrylonitrile monomer is used. it can.
These polyvinyl chloride resins can be used by emulsion polymerization method (emulsion polymerization method), micro suspension polymerization method, soap-free emulsion polymerization method, suspension polymerization method (suspension polymerization method), among others, fillers It is preferable to use an emulsion polymerization method in which a paste plastisol can be formed by mixing with a plasticizer.

In the reflective layer mainly composed of polyvinyl chloride resin, a filler, a pigment, or the like may be blended so that the solar reflectance at a wavelength of 350 to 1600 nm is 75% or more and the solar absorption is 10% or less. it can.
Examples of the filler include glass beads, hollow glass balloons, and microcapsules. Examples of the pigment include titanium oxide-based white pigments.

Commercially available glass beads, hollow glass balloons, and microcapsules that are fillers can be used as they are, but any of those having a particle size of about 1 to 150 μm is preferably used.
If the particle size is too large, the workability at the time of preparing the composition or molding into a sheet deteriorates, and if it is too small, it becomes difficult to obtain a desired shielding effect by adding a filler. A more preferable particle size is 5 to 100 μm, and a more preferable particle size is 8 to 80 μm.

In the case of glass beads and hollow glass balloons, the glass composition, specific gravity (hollow ratio), etc. are not particularly limited, and various coupling treatments etc. may be optionally performed in order to enhance adhesion with the vinyl chloride resin component. it can.
In the case of microcapsules, the shell composition is not particularly limited, and a heat expansion type or an already expansion type can be used, and a hollow type or a solid (bead) type can also be used.

  These fillers such as beads are preferably transparent, translucent, white or milky white in order to further improve heat reflectivity.

The amount of at least one selected from these fillers, particularly glass beads, hollow glass balloons, and microcapsules in the reflective layer is preferably 5 to 20 parts by weight, more preferably 100 parts by weight of the polyvinyl chloride resin. 10 to 15 parts by weight.
If the amount is too small, a sufficient shielding effect cannot be obtained. If the amount is too large, it tends to be difficult to form the sheet.

Moreover, as a titanium oxide type white pigment which is a pigment, although both a rutile type and an anatase type can be used, a general rutile type is used preferably.
The titanium oxide-based white pigment can be arbitrarily blended in a toner state dispersed in a plasticizer or the like in advance.

The amount of the white pigment added to the reflective layer is preferably 3 to 30 parts by weight, more preferably 10 to 20 parts by weight, based on 100 parts by weight of the polyvinyl chloride resin.
If the amount is too small, the reflection effect may be small. If the amount is too large, the increase in the reflection effect is not recognized so much that the problem tends to arise in the formability of the sheet.

  As a compounding composition for the reflective layer of the heat ray shielding sheet according to the present invention, in addition to the filler and the pigment, the composition of the present invention can be plasticized within a range that does not impair the characteristics of the present invention (such as shielding properties and molding processability). Additives such as UV absorbers, antioxidants, thickeners and thickeners to improve processability, such as additives, stabilizers, hindered amine compounds, benzotriazole compounds, benzothiazole compounds It can be added as appropriate.

As the plasticizer, compounds used in ordinary polyvinyl chloride resins can be used. Specifically, di-2-ethylhexyl phthalate (DEHP), diisononyl phthalate (DINP), diisodecyl phthalate (DIDP), dibutyl phthalate (DBP), diphthaldecyl phthalate (DUP), phthalate ester represented by butylbenzyl phthalate (BBP), trimellitic ester represented by trioctyl trimellitate (TOTM), dioctyl adipate (DOA) ), Dioctyl sebacate (DOS), fatty acid ester typified by dioctyl azelate (DOZ) and the like, and polyester typified by polypropylene adipate and the like can be used.
The addition amount of the plasticizer is not particularly limited, but is 25 to 150 parts by weight, preferably 60 to 100 parts by weight with respect to 100 parts by weight of the polyvinyl chloride resin. If the amount of plasticizer added is too small, the viscosity of the paste becomes high, making it difficult to laminate, making it difficult to obtain a good sheet, and if it is too large, the sheet itself becomes too soft, softening during use, and heat resistance. May worsen sex.

  As stabilizers, compounds used in ordinary polyvinyl chloride resins can be used. Specifically, metal stabilizers such as Ba-Zn, Ca-Zn, and zinc oxide are widely used. Can do.

The composition for the reflective layer as described above can be prepared by weighing each component and mixing them uniformly with a mixing stirrer such as a dissolver mixer.
Furthermore, if necessary, filtration for removing undispersed matter and degassing under reduced pressure for removing bubbles can be optionally performed.

  The composition thus obtained may be processed into a sheet by a known means such as extrusion molding, calendar molding, press molding, or a paste plastisol mainly composed of a polyvinyl chloride resin is used as a base material. (Paper or film having releasability) may be coated and heated and solidified to form a sheet.

  Furthermore, the absorption layer in the present invention preferably contains at least one selected from polyvinyl chloride resin, acrylic resin, polyester resin, polyolefin resin, and urethane resin.

  As the polyvinyl chloride resin constituting the absorption layer, a homopolymer of a vinyl chloride monomer and a copolymer of a monomer that can be copolymerized with a vinyl chloride monomer can be used as in the case of the reflective layer. These polyvinyl chloride resins May be obtained by any polymerization method, and among them, the emulsion polymerization method is preferably used as in the case of the reflective layer.

  Moreover, as said acrylic resin, polyester-type resin, polyolefin-type resin, and urethane type resin, the normal thing normally used for the sheet-like material can each be used conveniently.

In order to efficiently achieve the purpose of absorbing light transmitted from the reflective layer, various dark pigments and dyes are added to the absorption layer containing at least one selected from the above resins as a main component. can do.
Specific examples include yellow lead, ultramarine blue, titanium yellow, carbon black, and aluminum powder. Among these, carbon black black pigments are particularly preferably used.
The amount of the pigment to be added is not particularly limited, but is 3 to 20 parts by weight, preferably 5 to 10 parts by weight with respect to 100 parts by weight of the resin component. If the addition amount of the pigment is too small, the light absorption effect may be small, and if it is too large, the increase in the absorption effect is not recognized so much that the cost increases.

  Furthermore, you may form an absorption layer by vapor-depositing or sputtering a metal thin film on the surface of a heat ray shielding sheet.

  In addition to the above pigments and dyes, the composition for the absorbing layer is added in the reflective layer as necessary, as long as it does not impair the properties of the present invention (such as light-shielding properties and molding processability). Various additives such as similar plasticizers, stabilizers, fillers, ultraviolet absorbers, antioxidants, thickeners and thickeners can be appropriately added.

  The composition for the absorption layer can be prepared by mixing homogeneously with a mixing stirrer such as a dissolver mixer as in the case of the reflective layer, and if necessary, filtered for the purpose of removing undispersed material. In addition, degassing under reduced pressure can be arbitrarily performed for the purpose of removing bubbles.

  The composition thus obtained may be processed into a sheet by known means such as extrusion, calendering, press molding, etc., as in the case of the reflective layer, or at least one selected from the above resins The paste plastisol as a main component may be coated on a base material (paper or film having releasability) and solidified by heating to form a sheet.

The heat ray shielding sheet according to the present invention has a structure in which at least two layers of a reflection layer and an absorption layer are laminated.
Various methods can be selected as the lamination method. First, the reflective layer can be formed into a sheet by extrusion or the like, and the absorbent layer can be laminated on one surface. In addition, it is possible to arbitrarily form the absorption layer first and then laminate the reflection layer on one surface thereof.
In addition, when using polyvinyl chloride resin paste plastisol for both the reflective layer and the absorption layer, the reflective layer (or absorption layer) is coated to a predetermined thickness on a paper or film having releasability and solidified by heating. Then, on this reflective layer (or absorbent layer), the absorbent layer (or reflective layer) is coated to a predetermined thickness by an appropriate method, heated and solidified, and then peeled off from the release paper or film as described above. A layer stack can also be formed. This method is particularly excellent in that fillers such as hollow glass balloons are not destroyed during molding.
Furthermore, when an acrylic resin or urethane resin is used for the absorption layer, only the reflective layer is coated on a paper or film having releasability, and after heating and solidifying, it is peeled off to create a reflective layer sheet. It is also possible to stack the absorption layer on the reflection layer by a laminator or the like in a separate process.

  Further, in the heat ray shielding sheet of the present invention, a fiber base material such as a knitted fabric, a woven fabric, or a non-woven fabric is provided between the reflective layer and the absorbent layer or on the absorbent layer side of the laminated reflective layer and the absorbent layer. A reinforcing layer may be provided.

This reinforcing layer may be laminated with an adhesive or the like on the absorbent layer side of the laminate of the reflective layer and the absorbent layer, or the reflective layer and the absorbent layer may be laminated on both sides of the reinforcing layer sequentially or simultaneously. is there. At this time, each layer can be heated to the softening point or higher to be heat-sealed. Alternatively, the fibrous base material can be impregnated with the resin composition of each layer and then solidified to form a layer.
By providing such a reinforcing layer, the tear strength and tensile strength of the sheet itself are increased, and durability during use and dimensional stability during construction are improved.

  Further, in order to make the reinforcing layer also serve as the absorbing layer, the fibrous base material itself that is the reinforcing layer may be dyed in ultramarine or black, and the solar radiation absorption rate at a wavelength of 800 to 1600 nm may be 60% or more. Is possible.

In the heat ray shielding sheet of the present invention, an antifouling layer or a surface protective layer may be provided on the surface of the reflective layer.
The antifouling layer is, for example, an acrylic resin-based, vinyl chloride resin-based, cellulose resin-based, fluororesin-based, polyamide resin-based, urethane resin-based, epoxy resin-based, or silicone resin-based paint; acrylic resin-based, polyester Water-based paints such as resin-based, urethane-resin-based, and epoxy-resin-based antifouling paints such as acrylic resin-based, acrylic-modified urethane resin-based, acrylic-modified epoxy resin-based, mercapto derivative-based, and epoxy resin-based UV-curable paints It can form by coating etc.
The surface protective layer can be provided with various hard coat layers, surface slipping layers, and the like.

  The total thickness of the heat ray shielding sheet according to the present invention as described above is appropriately adjusted depending on the application, but is generally about 0.2 to 0.7 mm.

The heat ray shielding sheet of the present invention includes (1) a “reflective layer” that reflects light of a specific wavelength, and an “absorptive layer” that absorbs transmitted light that cannot be reflected by the reflective layer, particularly light having a wavelength that contributes to heat generation. And (2) the “absorbing layer” has a higher specific heat capacity than the “reflective layer”, and (3) such a laminated structure (sheet) is light of a specific wavelength. By having specific solar reflectance and solar absorption rate for
When used for a sheet-like structure such as a tent or a truck hood, the temperature rise due to sunlight of an object placed inside the sheet structure can be effectively suppressed, and further accompanying the temperature rise of the sheet surface Deterioration due to long-term use can also be reduced.

Examples 1-4, Comparative Examples 1-5
The paste-like plastisol for the reflective layer prepared so as to have the thermal conductivity, the solar reflectance and the solar absorptivity shown in Table 1 were coated on the release paper by the knife coating method so as to have the thickness shown in Table 1. And heated at 140 ° C. for 2 minutes.
Next, the paste-like plastisol for the absorption layer prepared so as to have the solar absorptance shown in Table 1 was coated on the reflective layer after the heating so as to have the thickness shown in Table 1, and 3 ° C. at 195 ° C. Heating was performed for a minute.
Then, it was cooled and the release paper was peeled off to prepare a two-layer laminated sheet.

The specific heat capacity was measured by DSC (differential scanning calorimeter) for each layer, and the heat capacity at 47 ° C. was used as a representative value in the present invention as described above.
The solar reflectance was measured using a self-recording spectrophotometer (trade name “V-570” manufactured by JASCO Corporation), with a standard white plate (fluororesin porous body) as 100% reflectance, and a wavelength of 350-2100 nm. The spectral reflectance was measured in the range, and the solar reflectance was derived using Appendix 3 of JIS-A5759.
The solar absorptance was calculated by measuring the solar transmittance in the same manner as in the case of the solar reflectance, and subtracting the solar reflectance and the solar transmittance from 100%.
Table 1 shows the thickness, specific heat capacity, solar reflectance, solar radiation absorption rate and solar radiation transmittance of the obtained laminated sheet.

In Table 1,
Solar reflectance ¹ : Solar reflectance calculated based on JIS-A5759 with a wavelength of 350 to 1600 nm.
Solar reflectance ² : Solar reflectance as defined by JIS-A5759 with a wavelength of 350-2100 nm.
Solar reflectance ³ : Solar reflectance calculated based on JIS-A5759 with a wavelength of 800 to 1600 nm.
Solar absorptance ¹ : Solar reflectance calculated based on JIS-A5759 having a wavelength of 350 to 1600 nm.
Solar radiation absorptivity ² : Solar radiation reflectance calculated based on JIS-A5759 having a wavelength of 800 to 1600 nm.
Solar absorptance ³ : Solar absorptance defined by JIS-A5759 with a wavelength of 350-2100 nm.
Solar radiation transmittance ¹ : Solar radiation transmittance defined by JIS-A5759 with a wavelength of 350-2100 nm.

[Shielding performance test method]
Laminated sheets obtained in each of the examples and comparative examples on the upper surface of a box surrounded by a polystyrene foam having a thickness of 30 mm as shown in FIG. 1 except for the upper surface having a height of 150 mm, a width of 220 mm, and a length of 310 mm. After irradiating a 200 W incandescent lamp from a height of 300 mm above the sample (sheet) for 40 minutes, the temperature of A) sample surface, B) back surface, C) inside the box, and D) blackboard placed at the bottom Each was measured with a thermocouple.
Table 2 shows the measurement results.

About Examples 1-4, the temperature of the surface of a sheet | seat and the back surface were all suppressed to 45 degrees C or less, and the temperature inside a sheet | seat was suppressed within 32 degrees C, and the outstanding shielding effect was shown.
About Comparative Examples 1-5, it turned out that a shielding effect is clearly inferior compared with Examples 1-4.

  In addition, in order to obtain the specific heat capacity, the solar reflectance, and the solar absorptivity in Table 1, the composition of the reflective layer and the absorbing layer was as shown in Table 3. At this time, each compound was uniformly mixed with a dissolver mixer, and a paste-like plastisol was prepared for each layer.

The numbers in Table 3 indicate parts by weight.
(Raw material)
Vinyl chloride resin ¹ (emulsion polymerization polyvinyl chloride): Shin-Daiichi PVC Co., Ltd. Trade name “PQHPN”
Vinyl chloride resin ² (emulsion polymerization polyvinyl chloride): manufactured by Kaneka Chemical Co., Ltd., trade name “PSH-23”
Filler ¹ (Hollow glass balloon << particle system 63μm >>): Asahi Glass Co., Ltd., trade name "Cell Star Z27"
Filler ² (Ceramic balloon << particle system 100μm >>): Taiheiyo Cement Co., Ltd., trade name “E-SPHERES”
Pigment ¹ (Titanium oxide white pigment): Product name “JR-600A” manufactured by Teika
Pigment ² (Carbon Black): Tokai Carbon Co., Ltd. Product name “SEAST S”
Pigment ³ (green pigment): manufactured by Special Colorant Industries Co., Ltd. “KT-1800”
Plasticizer (isononyl phthalate): Sekisui Chemical Co., Ltd. trade name “DINP”
Stabilizer: Product name “AC183” manufactured by Asahi Denka Kogyo Co., Ltd.

  When the heat ray shielding sheet of the present invention is used for a sheet-like structure such as a tent, the internal temperature rise due to sunlight is suppressed, and further, the temperature rise of the sheet surface is also suppressed, so that deterioration due to long-term use is reduced. Therefore, it can be suitably used as a military tent, a temporary tent at the time of a disaster, a tent warehouse that is used semipermanently for a long period of time, a truck hood, etc. It is effective when used in tropical or desert climates where there is strong weather.

It is the schematic which shows the apparatus for evaluating shielding performance.

Explanation of symbols

1 Heat ray shielding sheet 2 Box made of expanded polystyrene 3 Blackboard 4 Incandescent lamp

Claims (3)

A sheet having a structure in which at least two layers of a reflection layer and an absorption layer are laminated,
A reflection layer is arranged on the outermost layer that receives sunlight directly, and an absorption layer is arranged inside the reflection layer.
The reflective layer has a solar reflectance of 75% or more and a solar absorptivity of 10% or less calculated at a wavelength of 350 to 1600 nm calculated based on the provisions of JIS-A5759.
The absorption layer has a solar absorptance of 60% or more at a wavelength of 800 to 1600 nm,
As a whole sheet, the solar reflectance at a wavelength of 350-2100 nm calculated based on the provisions of JIS-A5759 is 75% or more, the solar reflectance at a wavelength of 800-1600 nm is 80% or more, and the solar reflectance at a wavelength of 350-2100 nm is The heat ray shielding sheet, which is 10% or more and has a specific heat capacity of the absorbing layer which is 10% or more larger than a specific heat capacity of the reflective layer. The reflective layer has a thickness of 0.1 to 1 mm, and 5 to 20 parts by weight of at least one selected from glass beads, hollow glass balloons, and microcapsules with respect to 100 parts by weight of the polyvinyl chloride resin, titanium oxide The heat ray shielding sheet according to claim 1 , comprising 3 to 30 parts by weight of a white pigment. According absorbing layer, which has a thickness of 25 to 500 [mu] m, the poly vinyl chloride resin, characterized by comprising the acrylic resin, a polyester resin, a polyolefin resin, at least one selected from urethane resin Item 3. The heat ray shielding sheet according to Item 1 or 2 .