Outdoor heat shielding sheet

Abstract

To provide an outdoor heat shielding sheet capable of inhibiting an influence of radiant heat due to solar radiation.SOLUTION: An outdoor heat shielding sheet having an inner side and an outer side includes: a first rubber layer located on the inner side; a second rubber layer located on the outer side; and a reinforcing fabric laminatedly disposed between the first rubber layer and the second rubber layer. Different kinds of rubber are used in the first rubber layer and the second rubber layer. The second rubber layer or both of the first rubber layer and the second rubber layer contain an infrared reflection agent in a blending amount of 5-30 wt.%.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to an outdoor heat-insulating sheet.

Background Art

[0002] For example, a technique related to a protective sheet that protects the human body from toxic gases, liquids, etc. is disclosed in Japanese Patent No. 5784812 (Patent Document 1). Such a protective sheet is required to have good gas penetration resistance and liquid-proof protection on the material surface, and techniques related to the surface treatment of the material are disclosed in, for example, Japanese Patent Application Laid-Open No. 2003-2903 (Patent Document 2) and Japanese Patent Application Laid-Open No. 2010-24279 (Patent Document 3).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] Since the protective clothing using the protective sheet covers the whole body, when used outdoors, due to the influence of radiant heat from solar radiation, the inside of the protective clothing becomes hot. Therefore, it is difficult to wear the protective clothing for a long time, and as a result, the work efficiency of the work performed while wearing the protective clothing decreases.

[0005] Not limited to the protective sheet, when working outdoors, it is important to consider the influence of radiant heat from solar radiation.

[0006] In the present disclosure, it is an object to solve the above problems and provide an outdoor heat-insulating sheet capable of suppressing the influence of radiant heat caused by solar radiation.

Means for Solving the Problems

[0007] [1] The outdoor heat-insulating sheet of the present disclosure is an outdoor heat-insulating sheet having an inner side and an outer side, including a first rubber layer located on the inner side, a second rubber layer located on the outer side, and a reinforcing cloth laminated and disposed between the first rubber layer and the second rubber layer. Different types of rubber are used for the first rubber layer and the second rubber layer, and the second rubber layer contains an infrared reflecting agent in an amount of 5 wt% or more and 30 wt% or less based on the solid content excluding the infrared reflecting agent in the total solid content of the second rubber layer. Outdoor heat-insulating sheet.

[0008] [2]: The first rubber layer contains an infrared reflecting agent in an amount of 5 wt% or more and 30 wt% or less based on the solid content excluding the infrared reflecting agent in the total solid content of the first rubber layer. The outdoor heat-insulating sheet according to [1].

[0009] [3]: One of the first rubber layer and the second rubber layer is made of acrylonitrile-butadiene rubber, and the other is made of chlorobutyl rubber. The outdoor heat-insulating sheet according to [1] or [2].

[0010] [4]: The acrylonitrile-butadiene rubber has an acrylonitrile content of 36 wt% or more. The outdoor heat-insulating sheet according to [3].

[0011] [5]: The infrared reflecting agent is in a particulate form, and its average particle diameter is 600 nm or more and 1500 nm or less. The outdoor heat-insulating sheet according to any one of [1] to [4].

[0012] [6]: The infrared reflecting agent is a pigment containing one or more metal elements of titanium, manganese, calcium, iron, bismuth, chromium, nickel. The outdoor heat-insulating sheet according to any one of [1] to [5].

[0013] [7]: The reinforcing fabric is a woven fabric, knitted fabric, or non-woven fabric, and is the outdoor heat-insulating sheet according to any one of [1] to [6].

[0014] [8]: The outdoor heat-insulating sheet is used for any one of outdoor tools, awning materials, tent materials, tarps, umbrellas, wrapping materials, bodies of automobiles, building materials, clothing, sports, and outdoor supplies, and is the outdoor heat-insulating sheet according to any one item of [1] to [7].

Advantages of the Invention

[0015] According to the present disclosure, it is possible to provide an outdoor heat-insulating sheet capable of suppressing the influence of radiant heat due to solar radiation.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Modes for Carrying Out the Invention

[0017] Outdoor heat-insulating sheets and protective clothing according to each embodiment based on the present disclosure will be described below with reference to the drawings. In the embodiments described below, when referring to the number, amount, etc., unless otherwise specified, the scope of the present invention is not necessarily limited to the number, amount, etc. The same parts and corresponding parts are given the same reference numerals, and repeated descriptions may not be repeated. It is initially planned to use the configurations in the embodiments in appropriate combinations. For ease of understanding, the film thickness and layer thickness shown in the figures are different from the actual ratios.

[0018] In the specification, "outer side" means the side exposed to liquids, etc. when the outdoor heat-insulating sheet is in use, and "inner side" means the side not exposed to liquids, etc. when the outdoor heat-insulating sheet is in use.

[0019] [Embodiment 1: Outdoor heat-insulating sheets 1A-1 to 1A-4] With reference to FIG. 1, the outdoor heat-insulating sheets 1A-1 to 1A-4 of the present embodiment will be described. FIG. 1 is a cross-sectional structure diagram of the outdoor heat-insulating sheets 1A-1 to 1A-4.

[0020] The outdoor heat-insulating sheets 1A-1 to 1A-4 of the present embodiment include an inner side and an outer side, a first rubber layer 11 located on the inner side, a second rubber layer 13 located on the outer side, and a reinforcing cloth 12 laminated between the first rubber layer 11 and the second rubber layer 13.

[0021] Different rubbers are used for the first rubber layer 11 and the second rubber layer 13. In the present embodiment, acrylonitrile-butadiene rubber (NBR) is used for the first rubber layer 11, and chlorobutyl rubber is used for the second rubber layer 13. A nylon fabric with a yarn thickness of 70 decitex is used for the reinforcing cloth 12. The yarn thickness is not limited to this thickness. Also, the material is not limited to nylon. For example, polyester, cotton, etc. can also be used. Also, in addition to woven fabrics, knits, thin fabrics, non-woven fabrics, etc. can also be used.

[0022] The thickness of the first rubber layer 11 is about 0.08 mm to about 0.2 mm, the thickness of the second rubber layer 13 is about 0.08 mm to about 0.2 mm, and the thickness when a woven base fabric is used for the reinforcing fabric 12 is about 0.1 mm. When a knitted fabric is used for the reinforcing fabric 12, the thickness of the reinforcing fabric 12 is about 0.2 mm to about 0.3 mm.

[0023] Acrylonitrile-butadiene rubber (NBR) is one of the synthetic rubbers and is a copolymer of acrylonitrile and 1,3-butadiene. Depending on the acrylonitrile content, it is classified into 24 wt% or less (low nitrile), 25 - 30 wt% (medium nitrile), 31 - 35 wt% (medium-high nitrile), 36 - 42 wt% (high nitrile), and 43 wt% or more (extremely high nitrile). The acrylonitrile-butadiene rubber (NBR) of the present embodiment is preferably high nitrile or more, more preferably extremely high nitrile. In the outdoor heat-insulating sheets 1A-1 to 1A-4 of the present embodiment, acrylonitrile-butadiene rubber (NBR) classified as extremely high nitrile is used.

[0024] The second rubber layer 13 contains an infrared reflecting agent. The infrared reflecting agent means a material capable of reflecting light in the near-infrared region (780 nm to 2500 nm) contained in natural light. For example, as the infrared reflecting agent, a pigment containing one or more metal elements such as titanium, manganese, calcium, iron, bismuth, chromium, nickel, etc. can be used. In the present embodiment, the content of the infrared reflecting agent contained in the second rubber layer 13 is about 5 wt% to 30 wt%, preferably 15 - 20 wt%, based on the solid content (100 wt%) excluding the infrared reflecting agent in the total solid content of the second rubber layer 13. When an additive is contained in the first rubber layer 11, this additive falls into the solid content excluding the infrared reflecting agent.

[0025] (Manufacturing method of the outdoor heat-insulating sheets 1A-1 to 1A-4) The manufacturing method of chlorobutyl rubber or acrylonitrile butadiene rubber (NBR) used for the first rubber layer 11 and the second rubber layer 13 will be described. First, by blending additives (vulcanizing agent, accelerator, reinforcing material, softening agent, pigment, etc.) and infrared reflection into the raw rubber, raw rubber mixed with an infrared reflecting agent can be obtained. This raw rubber is kneaded, stretched, and sheeted.

[0026] Next, a chlorobutyl rubber sheet mixed with an infrared reflecting agent is laminated on one side of the fabric (step 1), and then an NBR rubber sheet is also laminated on the opposite side of the fabric (step 2). Then, heat vulcanization is performed on this laminated sheet (step 3). The order of step 1 and step 2 may be reversed.

[0027] As described above, outdoor heat insulation sheets 1A-1 to 1A-4 having a three-layer structure of the first rubber layer 11, the reinforcing fabric 12, and the second rubber layer 13 are obtained.

[0028] The infrared reflecting agent is blended at 5 wt% to 30 wt%, preferably 15 to 20 wt%, based on the solid content (raw rubber + additives) (100 wt%) excluding the infrared reflecting agent in the total solid content of the first rubber layer 11. For example, an infrared reflecting agent composed of metal elements such as titanium, manganese, and calcium (「SG-101」manufactured by Ishihara Sangyo Co., Ltd.) can be used. In this embodiment, outdoor heat insulation sheets 1A-1 to 1A-4 were produced using chlorobutyl rubber sheets in which the infrared reflecting agent was blended at 5, 15, 20, and 30 wt% respectively based on the solid content (raw rubber + additives) (100 wt%) excluding the infrared reflecting agent.

[0029] [Embodiment 2: Outdoor heat insulation sheet 1B] Referring to FIG. 2, the outdoor heat insulation sheet 1B of this embodiment will be described. FIG. 2 is a cross-sectional structure diagram of the outdoor heat insulation sheet 1B.

[0030] The process of obtaining the three-layer structure of the outdoor heat-insulating sheet 1B of this embodiment, namely the first rubber layer 14, the reinforcing cloth 15, and the second rubber layer 16, is the same as that of the outdoor heat-insulating sheets 1A-1 to 1A-4 of Embodiment 1, but the types of rubber are reversed. That is, chlorobutyl rubber is used for the first rubber layer 14, and acrylonitrile-butadiene rubber (NBR rubber) containing an infrared reflective agent is used for the second rubber layer 16. The infrared reflective agent is blended at 15 wt% based on the solid content (100 wt%) excluding the infrared reflective agent in the total solid content of the second rubber layer 16.

[0031] Chlorobutyl rubber is used for the first rubber layer 14, and acrylonitrile-butadiene rubber (NBR) is used for the second rubber layer 16. A nylon fabric with a yarn thickness of 70 decitex is used for the reinforcing cloth 15. The yarn thickness is not limited to this value. Also, the material is not limited to nylon. For example, polyester, cotton, etc. can also be used. In addition to fabrics, knits, thin fabrics, non-woven fabrics, etc. can also be used.

[0032] The thickness of the first rubber layer 14 is about 0.08 mm to 0.2 mm, the thickness of the second rubber layer 16 is about 0.08 mm to 0.2 mm, and the thickness when a fabric base cloth is used for the reinforcing cloth 15 is about 0.1 mm. When a knitted fabric is used for the reinforcing cloth 15, the thickness of the reinforcing cloth 15 is about 0.2 mm to 0.3 mm. In this embodiment, the thickness of the first rubber layer, the thickness of the second rubber layer, the material and thickness of the reinforcing cloth are the same as those in Embodiment 1.

[0033] (Manufacturing method of the outdoor heat-insulating sheet 1B) As the manufacturing method of the outdoor heat-insulating sheet 1B, similar to the outdoor heat-insulating sheets 1A-1 to 1A-4 of Embodiment 1, an NBR rubber sheet mixed with an infrared reflective agent is laminated on one side of the fabric (Step 1), and then a chlorobutyl rubber sheet is laminated on the opposite side of the fabric (Step 2). Then, heat vulcanization is performed on this laminated sheet (Step 3). The order of Step 1 and Step 2 may be reversed.

[0034] As described above, an outdoor heat-insulating sheet 1B having a three-layer structure of a first rubber layer 14, a reinforcing cloth 15, and a second rubber layer 16 is obtained.

[0035] [Embodiment 3: Outdoor heat-insulating sheet 1C] Referring to FIG. 3, the outdoor heat-insulating sheet 1C of the present embodiment will be described. FIG. 3 is a cross-sectional structure diagram of the outdoor heat-insulating sheet 1C.

[0036] (Outdoor heat-insulating sheet 1C) The process until the outdoor heat-insulating sheet 1C obtains a three-layer structure of a first rubber layer 17, a reinforcing cloth 18, and a second rubber layer 19 is the same as that of the outdoor heat-insulating sheets 1A-1 to 1A-4 of Embodiment 1. However, an infrared reflecting agent is added to both the first rubber layer 17 and the second rubber layer 19 at 15 wt% based on the solid content excluding the infrared reflecting agent in the total solid content of each layer.

[0037] Chlorobutyl rubber is used for the first rubber layer 17, and acrylonitrile-butadiene rubber (NBR) is used for the second rubber layer 19. A nylon fabric with a yarn thickness of 70 decitex is used for the reinforcing cloth 18. The yarn thickness is not limited to this thickness. Also, the material is not limited to nylon. For example, polyester, cotton, etc. can also be used. Also, in addition to fabrics, knits, thin fabrics, non-woven fabrics, etc. can also be used.

[0038] The thickness of the first rubber layer 17 is about 0.08 mm to 0.2 mm, the thickness of the second rubber layer 19 is about 0.08 mm to 0.2 mm, and the thickness when a fabric base fabric is used for the reinforcing cloth 18 is about 0.1 mm. When a knit fabric is used for the reinforcing cloth 18, the thickness of the reinforcing cloth 15 is about 0.2 mm to 0.3 mm. In the present embodiment, the thickness of the first rubber layer, the thickness of the second rubber layer, the material and thickness of the reinforcing cloth are the same as those in Embodiment 1.

[0039] (Manufacturing method of outdoor heat-insulating sheet 1C) Similar to the outdoor heat-insulating sheet 1A of Embodiment 1, an NBR rubber sheet mixed with an infrared reflective agent is laminated on one side of the reinforcing fabric 18 (Step 1), and then, a chlorobutyl rubber sheet mixed with an infrared reflective agent is laminated on the opposite side of the reinforcing fabric 18 (Step 2). Thereafter, heat vulcanization is performed on this laminated sheet (Step 3). The order of Step 1 and Step 2 may be reversed.

[0040] As described above, an outdoor heat-insulating sheet 1C having a three-layer structure of the first rubber layer 17, the reinforcing fabric 18, and the second rubber layer 19 is obtained.

[0041] [Embodiment 4: Outdoor heat-insulating sheet 1D] With reference to FIG. 4, the outdoor heat-insulating sheet 1D of the present embodiment will be described. FIG. 4 is a cross-sectional structural view of the outdoor heat-insulating sheet 1D.

[0042] (Outdoor heat-insulating sheet 1D) The three-layer structure of the outdoor heat-insulating sheet 1D, which includes the first rubber layer 21, the reinforcing fabric 22, and the second rubber layer 23, is the same as that of the outdoor heat-insulating sheets 1A-1 to 1A-4 of Embodiment 1. However, in addition to the three-layer structure, a fabric 20 is laminated on the innermost layer.

[0043] Chlorobutyl rubber is used for the first rubber layer 21, and acrylonitrile butadiene rubber (NBR) is used for the second rubber layer 23. A nylon fabric with a yarn thickness of 70 decitex is used for the reinforcing fabric 22. The yarn thickness is not limited to this thickness. Also, the material is not limited to nylon. For example, polyester, cotton, etc. can also be used. In addition to woven fabrics, knits, thin fabrics, non-woven fabrics, etc. can also be used.

[0044] The thickness of the first rubber layer 21 is about 0.08 mm to about 0.2 mm, the thickness of the second rubber layer 23 is about 0.08 mm to about 0.2 mm, and the thickness when a woven base fabric is used for the reinforcing fabric 22 is about 0.1 mm. When a knitted fabric is used for the reinforcing fabric 22, the thickness of the reinforcing fabric 22 is about 0.2 mm to about 0.3 mm. In this embodiment, the thickness of the first rubber layer, the thickness of the second rubber layer, the material and thickness of the reinforcing fabric are the same as those in Embodiment 1.

[0045] (Method for manufacturing the outdoor heat-insulating sheet 1D) A chlorobutyl rubber sheet mixed with an infrared reflecting agent is laminated on one side of the reinforcing fabric 22 (Step 1), and then an NBR rubber sheet is also laminated on the opposite side of the reinforcing fabric 22 (Step 2). Then, the fabric 20 is laminated on the NBR rubber sheet (Step 3). Heat vulcanization is performed on this laminated sheet (Step 4). The order of Step 1 and Step 2 may be reversed.

[0046] As described above, an outdoor heat-insulating sheet 1D having a four-layer structure of the fabric 20, the first rubber layer 21, the reinforcing fabric 22, and the second rubber layer 23 is obtained.

[0047] [Comparative Example 1: Outdoor heat-insulating sheet 2] With reference to FIG. 5, the outdoor heat-insulating sheet 2 of Comparative Example 1 will be described. FIG. 5 is a cross-sectional structural view of the outdoor heat-insulating sheet 2.

[0048] (Outdoor heat-insulating sheet 2) The outdoor heat-insulating sheet 2 of Comparative Example 1 has a three-layer structure of the first rubber layer 24, the reinforcing fabric 25, and the second rubber layer 26. In the outdoor heat-insulating sheet 2, a chlorobutyl rubber in which an infrared reflecting agent is blended at 15 wt% with respect to the solid content (100 wt%) excluding the infrared reflecting agent in the total solid content of the second rubber layer 26 is used for the second rubber layer 26. A chlorobutyl rubber without an infrared reflecting agent blended is used for the first rubber layer 24.

[0049] Chlorobutyl rubber is used for the first rubber layer 24 and the second rubber layer 26. In Comparative Example 1, the thickness of the first rubber layer, the thickness of the second rubber layer, the material and thickness of the reinforcing fabric are the same as those in Embodiment 1.

[0050] (Manufacturing Method of Outdoor Heat-Insulating Sheet 2) A chlorobutyl rubber sheet is laminated on one side of the reinforcing fabric 25 (Step 1), and then a chlorobutyl rubber sheet containing an infrared reflective agent is laminated on the opposite side of the reinforcing fabric 25 (Step 2). Thereafter, heat vulcanization is performed on this laminated sheet (Step 3).

[0051] Thus, an outdoor heat-insulating sheet 2 having a three-layer structure of a first rubber layer 24, a reinforcing fabric 25, and a second rubber layer 26 is obtained.

[0052] [Comparative Example 2: Outdoor Heat-Insulating Sheet 3] Referring to FIG. 6, the outdoor heat-insulating sheet 3 of Comparative Example 2 will be described. FIG. 6 is a cross-sectional structure diagram of the outdoor heat-insulating sheet 23.

[0053] (Outdoor Heat-Insulating Sheet 3) The outdoor heat-insulating sheet 3 of Comparative Example 2 has a three-layer structure of a first rubber layer 27, a reinforcing fabric 28, and a second rubber layer 29. In the outdoor heat-insulating sheet 3, carbon black is used in the second rubber layer 29 in an amount of 1.5 wt% based on the solid content (100 wt%) excluding the carbon black in the total solid content of the second rubber layer 29.

[0054] Chlorobutyl rubber is used for the first rubber layer 27, and acrylonitrile-butadiene rubber (NBR) is used for the second rubber layer 29. In Comparative Example 2, the thickness of the first rubber layer, the thickness of the second rubber layer, the material and thickness of the reinforcing fabric were made the same as those in Embodiment 1.

[0055] (Manufacturing Method of Outdoor Heat-Insulating Sheet 2) A chlorobutyl rubber sheet containing carbon black is laminated on one side of the reinforcing fabric 28 (Step 1), and then an acrylonitrile-butadiene (NBR) rubber sheet is laminated on the opposite side of the reinforcing fabric 28 (Step 2). Thereafter, heat vulcanization is performed on this laminated sheet (Step 3).

[0056] As described above, an outdoor heat-insulating sheet 3 having a three-layer structure of a first rubber layer 27, a reinforcing fabric 28, and a second rubber layer 29 is obtained.

[0057] [Comparative Example 3: Outdoor heat-insulating sheet 4] Referring to FIG. 7, the outdoor heat-insulating sheet 4 of Comparative Example 3 will be described. FIG. 7 is a cross-sectional structure diagram of the outdoor heat-insulating sheet 4.

[0058] (Outdoor heat-insulating sheet 4) The outdoor heat-insulating sheet 4 of Comparative Example 3 has a three-layer structure of a first rubber layer 30, a reinforcing fabric 31, and a second rubber layer 32. In the outdoor heat-insulating sheet 4, an infrared reflecting agent was blended in the second rubber layer 32 at 1 wt% with respect to the solid content (100 wt%) excluding the infrared reflecting agent in the total solid content of the second rubber layer 32.

[0059] Acrylonitrile-butadiene rubber (NBR) is used for the first rubber layer 30, and chlorobutyl rubber is used for the second rubber layer 32. In Comparative Example 3, the thickness of the first rubber layer, the thickness of the second rubber layer, the material and thickness of the reinforcing fabric were the same as those in Embodiment 1.

[0060] (Manufacturing method of outdoor heat-insulating sheet 4) A chlorobutyl rubber sheet containing 1 wt% of an infrared reflecting agent was laminated on one side of the reinforcing fabric 31 (Step 1), and then an acrylonitrile-butadiene (NBR) rubber sheet was laminated on the opposite side of the reinforcing fabric 31 (Step 2). Thereafter, the laminated sheet was heated and vulcanized (Step 3).

[0061] As described above, an outdoor heat-insulating sheet 4 having a three-layer structure of a first rubber layer 30, a reinforcing fabric 31, and a second rubber layer 32 is obtained.

[0062] [Evaluation method] Next, referring to FIGS. 9 and 10, the evaluation method of the outdoor heat-insulating sheet will be described. FIG. 9 is a schematic diagram of the surface temperature measurement method, and FIG. 10 is a schematic diagram of the "water repellency (static contact angle)" evaluation.

[0063] For the evaluation of solar radiation influence (surface temperature), a test apparatus prepared with reference to JIS L 1951 (Test for heat insulation property of fabrics) was used. The surface temperature of the fabric was determined by reading with a FLIR thermal camera. In the test apparatus shown in Fig. 9, the ambient temperature was set to 20°C to 25°C, and a reflector lamp 120 (Iwaki Electric PRS-500W) was used as the light source. The output of the reflector lamp 120 is 500W. A 5-mm-thick spacer 124 and an outdoor heat-insulating sheet sample 121 were placed on the test bench 121, and the distance between the outdoor heat-insulating sheet sample 121 and the reflector lamp was adjusted to 40 cm. Regarding the surface temperature of the fabric, 15 minutes after light irradiation, for the outdoor heat-insulating sheet sample 121, the surface temperature was measured at a position where the angle between the test bench 122 - the center of the outdoor heat-insulating sheet sample 121 - the thermal camera 123 was 45 degrees and the distance between the outdoor heat-insulating sheet sample 121 and the thermal camera 123 was 60 cm. As the judgment criteria, when the surface temperature 15 minutes after light irradiation is 53°C or less, it is marked as "◎", when it exceeds 53°C and is less than 60°C, it is marked as "〇", and when it is 60°C or more, it is marked as "△".

[0064] For the evaluation of solar radiation influence (solar reflectance), a spectrophotometer (manufactured by Shimadzu Corporation, UV-VIS-NIR spectrophotometer SolidSpec-3700) was used. The spectral reflectance in the range of 300 - 2500 nm was measured, and the determination was made in the near-ultraviolet / visible light region (300 - 780 nm) and the near-infrared region (780 - 2500 nm) based on JIS K 5602:2008 (Solar reflectance of coating films). The judgment criteria were that when the solar reflectance in the near-ultraviolet / visible light region is less than 15%, it is marked as "〇", and when it is 15% or more, it is marked as "×". Also, when the solar reflectance in the near-infrared region is 40% or more, it is marked as 〇, and when it is less than 40%, it is marked as "×".

[0065] The evaluation of "water repellency (static contact angle)" is, as shown in Fig. 10, to evaluate the adhesion state of the droplet W1 to a horizontal surface. The larger the angle θ formed between the tangent to the surface of the droplet W1 and the horizontal plane, the smaller the amount of adhesion of the droplet W1 to the horizontal surface, and the droplet W1 maintains a shape close to a sphere, and it can be evaluated as a droplet W1 with good water repellency. If θ is 150 degrees or more, the droplet W1 bounces around on the horizontal surface and is in a state where it is easy to slide.

[0066] The air permeability was evaluated in accordance with JIS L1096 (Air Permeability Test). JIS L1096 (Air Permeability Test) is a test for evaluating the airtightness by examining the amount of air passing through the gaps in the fabric structure. The same applies to the following outdoor heat-insulating sheets.

[0067] [Evaluation Results] Next, with reference to FIG. 8, the evaluation results will be described.

[0068] (Outdoor heat-insulating sheet 2A) The outdoor heat-insulating sheet 2A includes a rubber layer on the outside and a fabric layer on the inside. The thickness of the rubber layer is about 20 μm to several millimeters, specifically about 0.1 mm to 0.3 mm. The types of rubber used for the rubber layer include nitrile rubber (NBR), epichlorohydrin rubber (CO, ECO), chlorinated butyl rubber (CIIR), butyl rubber (IIR), brominated butyl rubber (BrIIR), fluororubber, chloroprene rubber (CR), chlorosulfonated polyethylene rubber (CSM), urethane rubber, etc.

[0069] An infrared reflector is kneaded into the rubber layer. The infrared reflector means a material capable of reflecting light in the near-infrared region (780 nm to 2500 nm) contained in natural light. For example, metal oxides (Fe2O3, Mn3O4, Cr2O3, CoO, CuO), etc. are used as the infrared reflector. The content of the infrared reflector contained in the rubber layer is about 0.5% to 20%.

[0070] The thickness of the fabric layer is 0.45 mm. Specifically, a nylon fabric with a yarn thickness of 70 decitex is used. The yarn thickness is not limited to this thickness. Also, the material is not limited to nylon. For example, polyester, cotton, etc. can also be used. Also, in addition to fabrics, knits, thin fabrics, non-woven fabrics, etc. can also be used.

[0071] On the outermost layer of this outdoor heat-insulating sheet 2A, water-repellent treatment is performed on the outside with a fluorine treatment agent. Regarding the fluorine film, the solid content adhesion amount of the fluoropolymer is 0.01 g / m 2 ~10.5 g / m 2 , preferably 0.05 g / m 2 ~5 g / m 2 , more preferably 0.1 g / m 2 ~2 g / m 2 and it is diluted with water to adjust the concentration so as to be within this range.

[0072] As the fluorine-based water and oil repellent, for example, it is advisable to use the water and oil repellent treatment agent disclosed in Japanese Patent No. 5784812. As an example of a specific fluorine-based water and oil repellent treatment agent, a repeating unit derived from α-chloroacrylate (A) having a fluoroalkyl group represented by the following formula (1), and a repeating unit derived from a non-fluorine monomer (B) having no fluoroalkyl group and having a hydrocarbon group with 6 or more carbon atoms may be used.

[0073] CH2=C(-Cl)-C(=O)-X-Y-Rf ··· Formula (1) [In the formula, X is -O- or -NH-, Y is a direct bond or a divalent organic group, and Rf is a fluoroalkyl group having 1 to 20 carbon atoms.] The method of fixing the fluorine-based water and oil repellent to the rubber layer can be carried out, for example, as follows. A fluorine-based water and oil repellent with an apparent concentration of 7% is dropped onto the surface of the rubber layer or the fabric layer at 20 cc / m 2 . Then, using a spatula, the fluorine-based water and oil repellent is uniformly spread on the surface of the rubber layer. Then, heat treatment (for example, 170 degrees, 5 minutes) is performed to complete the fluorine film (solid content adhesion amount 0.7 g / m 2 ). The evaluation of the water repellency of the outdoor heat-insulating sheet 2A will be described later.

[0074] The manufacturing method of the outdoor heat-insulating sheet 2A is the same as the method according to the above-described Embodiments 1 to 4, so duplicate explanations will not be repeated.

[0075] The heat insulation sheet 2A having the above structure has a rubber layer with a water repellent function and an infrared reflection function. The heat insulation rate was "50% (◎)" and "surface temperature 56°C (○)". The "solar reflectance" was 36% in the "entire wavelength range (300 nm to 2500 nm)", 13% in the "near ultraviolet and visible light range (300 nm to 780 nm)", and 51% in the "near infrared range (780 nm to 2500 nm)". The "water repellency (static contact angle)" was ">120° (○)". The air permeability was "none".

[0076] (Outdoor heat insulation sheet 2B) The outdoor heat insulation sheet 2B has a structure in which the outer and inner sides of the above outdoor heat insulation sheet 2A are swapped. The outdoor heat insulation sheet 2B having the above structure has a fabric layer with a water repellent function and a rubber layer with an infrared reflection function. The heat insulation rate was "52% (◎)" and "surface temperature 53°C (◎)". The "solar reflectance" was 44% in the "entire wavelength range (300 nm to 2500 nm)", 14% in the "near ultraviolet and visible light range (300 nm to 780 nm)", and 63% in the "near infrared range (780 nm to 2500 nm)". The "water repellency (static contact angle)" was ">120° (○)". The air permeability was "none".

[0077] (Outdoor heat insulation sheet 2C) The outdoor heat insulation sheet 2C has a structure consisting only of the fabric layer of the above outdoor heat insulation sheet 2A. This fabric layer has a water repellent function and an infrared reflection function. The heat insulation rate was "46% (○)" and "surface temperature 59°C (○)". The "solar reflectance" was 34% in the "entire wavelength range (300 nm to 2500 nm)", 15% in the "near ultraviolet and visible light range (300 nm to 780 nm)", and 47% in the "near infrared range (780 nm to 2500 nm)". The "water repellency (static contact angle)" was ">120° (○)". The air permeability was "yes (50 cm 3 / cm 2 ·s or more)".

[0078] The method for fixing an infrared reflecting agent and a fluorine-based water and oil repellent agent to a fabric layer may be carried out, for example, as follows. A fluorine-based water and oil repellent agent with an apparent concentration of 7% is dropped onto the surface of the fabric layer at 20 cc / m2. Then, using a spatula, the fluorine-based water and oil repellent agent is uniformly spread on the surface of the fabric layer. Then, heat treatment (for example, 170 degrees, 5 minutes) is performed to complete a fluorine film on the fiber surface (solid content adhesion amount 0.7 g / m 2 ).

[0079] (Comparative Example A) Comparative Example A of the outdoor heat-insulating sheet is the same as the configuration of the above-described outdoor heat-insulating sheet 2A, but the infrared reflecting agent is not kneaded into the rubber layer. The heat-insulating rate was "35% (△)" and "surface temperature 68 °C (△)". The "solar reflectance" was 6% in the "entire wavelength range (300 nm to 2500 nm)", 6.6% in the "near ultraviolet / visible light range (300 nm to 780 nm)", and 5.7% in the "near infrared range (780 nm to 2500 nm)", and the values were low in any wavelength range. The "water repellency (static contact angle)" was "<90° (△)". The air permeability was "none".

[0080] [Specific application examples of outdoor heat-insulating sheets] Next, specific application examples of the above-described heat-insulating sheet will be described.

[0081] When the above-described outdoor heat-insulating sheet is used for outdoor tools (awning materials, tent materials, tarps) and umbrellas, it is possible to prevent wetting and soiling and take measures against solar radiation (using an infrared reflecting material in combination).

[0082] When the above-described outdoor heat-insulating sheet is used for wrapping materials (bodies of automobiles, etc., building materials, etc.), it is possible to prevent wetting and soiling and take measures against solar radiation (using an infrared reflecting material in combination).

[0083] When the above-described outdoor heat-insulating sheet is used for the bodies of automobiles, etc., building materials, etc., it is possible to prevent wetting and soiling and take measures against solar radiation (using an infrared reflecting material in combination).

[0084] When the above-mentioned outdoor heat-insulating sheet is used for clothing and sports / outdoor goods, it is possible to prevent wetting and soiling and take measures against solar radiation (used in combination with an infrared reflecting material).

[0085] The embodiments disclosed this time should be considered as illustrative in all respects and not restrictive. The scope of the present invention is shown not by the above description but by the claims, and it is intended that all modifications within the meaning and scope equivalent to the claims are included.

Explanation of Signs

[0086] 1A-1 to 1A-4, 1B, 1C, 1D, 2, 3, 4 Outdoor heat-insulating sheet, 11, 14, 17, 21, 24, 27, 30 First rubber layer, 13, 16, 19, 23, 26, 29, 32 Second rubber layer, 12, 15, 18, 22, 25, 28, 31 Reinforcing cloth, 20 Fabric.

Claims

**Claim 1** An outdoor heat-insulating sheet having an inner side and an outer side, comprising a first rubber layer located on the inner side, a second rubber layer located on the outer side, and a reinforcing cloth laminated between the first rubber layer and the second rubber layer, wherein different types of rubber are used for the first rubber layer and the second rubber layer, and the second rubber layer contains an infrared reflective agent in an amount of 5 wt% or more and 30 wt% or less based on the solid content of the second rubber layer excluding the infrared reflective agent, an outdoor heat-insulating sheet. **Claim 2** The outdoor heat-insulating sheet according to claim 1, wherein the outdoor heat-insulating sheet is used for any one of outdoor tools, awning materials, tent materials, tarps, umbrellas, wrapping materials, bodies of automobiles, building materials, clothing, sports, and outdoor supplies. the outdoor heat-insulating sheet according to claim 1.

Images