Packing method and contents

Abstract

To achieve a packing method capable of suppressing temperature rise in a black foam.SOLUTION: In a packing method, a black foam (1A) is packed by using a packing material (2) including a black resin packaging sheet (3). The packing method includes a covering step of covering an outer periphery of the black foam (1A) with the packing material (2) in a state where air is filled in between the black foam (1A) and the packing material (2) to provide a gap therein.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to a packaging method and a packaged product. [Background technology]

[0002] Bead foam molded products (foams) are used in a wide range of applications, such as packaging materials, building materials, and vehicle components, because they offer excellent cushioning and lightweight properties, and their shapes can be designed to suit various applications. For example, bead foam molded products are manufactured by pre-foaming foamable resin particles in a molding plant to create pre-foamed particles, and then molding these pre-foamed particles in a mold. Because they can be foamed into various shapes depending on the mold used for in-mold molding, bead foam molded products are widely used in a variety of shapes, from block shapes to box shapes.

[0003] Black foamed bead products containing carbon materials such as graphite (hereinafter sometimes referred to as black foams) have superior thermal insulation performance compared to general foamed bead products, and therefore, demand for them as residential insulation materials has been increasing in recent years.

[0004] Such packaging technology for black foam is disclosed, for example, in Patent Document 1 or 2. Patent Document 1 discloses a package in which an insulating panel containing carbon particles is packaged with a packaging sheet. The packaging sheet is configured so that the insulating panel can block all or part of the radiant heat. The packaging sheet is, for example, a white or blue sheet obtained by compounding a white or blue pigment into a transparent synthetic resin base material. The packaging sheet also has a plurality of ventilation holes.

[0005] Furthermore, Patent Document 2 discloses a packaging method in which a carbon-containing foamed molded body, which is a black foam, is packaged in white paper. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2018-95293 [Patent Document 2] Japanese Patent Publication No. 2019-202786 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, the technologies described in Patent Documents 1 and 2 have room for improvement in terms of suppressing the temperature rise of black foams.

[0008] One aspect of the present invention aims to provide a packaging method and packaging body that can suppress the temperature rise of a black foam when packaging the black foam. [Means for solving the problem]

[0009] One aspect of the present invention includes the following configuration.

[0010] <1> A packaging method for packaging a black foam using packaging material, wherein the packaging material includes a black resin packaging sheet, and the packaging method includes a covering step of covering the outer periphery of the black foam with the packaging material while air is introduced between the black foam and the packaging material to create a gap.

[0011] <2> The covering step includes a packaging material manufacturing step of forming the black resin packaging sheet into a bag shape by enclosing air, and a packaging step of containing the black foam in the packaging material. <1> Packing instructions as described.

[0012] <3> The bag-shaped black resin packaging sheet has gaps inside which the black foam can move. <2> Packing instructions as described.

[0013] <4> The gap between the packaging material and the black foam is 1 mm or more. <1> ~ <3> The packing method is as described in one of the following.

[0014] <5> The surface temperature of the black foam is less than 90°C. <1> ~ <4> The packing method is as described in one of the following.

[0015] <6>The thickness of the black resin packaging sheet is 7 μm to 30 μm, and it is the packaging method according to any one of <1> to <5>.

[0016] <7>The black resin packaging sheet contains 2.0 to 15.0 parts by weight of carbon black with respect to 100 parts by weight of the polyolefin resin, and it is the packaging method according to any one of <1> to <6>.

[0017] <8>The black resin packaging sheet is composed of a tubular or bag-shaped film and has at least one opening through which the black foam can pass, and it is the packaging method according to any one of <1> to <7>.

[0018] <9>The thermal conductivity of the black foam is 0.032 W / m·K or less, and it is the packaging method according to any one of <1> to <8>.

[0019] <10>The density of the black foam is 5 kg / m 3 ~25 kg / m 3 and it is the packaging method according to any one of <1> to <9>.

[0020] <11>It includes a black foam and a packaging material for packaging the black foam. The packaging material includes a black resin packaging sheet, and the black foam is covered with the black resin packaging sheet with a gap provided between the black resin packaging sheet and the outer periphery of the black foam.

Advantages of the Invention

[0021] According to one aspect of the present invention, when packaging a black foam, the temperature rise of the black foam can be suppressed.

Brief Description of the Drawings

[0022] [Figure 1] 101 and 102 are diagrams schematically showing an example of the covering process in the packaging method according to an embodiment of the present invention. [Figure 2]The schematic configuration of a package according to one embodiment of the present invention is shown, where 201 is a perspective view and 202 is a cross-sectional view. [Modes for carrying out the invention]

[0023] One embodiment of the present invention is described below, but the present invention is not limited thereto. The present invention is not limited to the configurations described below, and various modifications are possible within the scope of the claims. Furthermore, embodiments or examples obtained by combining the technical means disclosed in different embodiments or examples are also included in the technical scope of the present invention. Moreover, new technical features can be formed by combining the technical means disclosed in each embodiment. All academic and patent documents mentioned herein are incorporated as references herein. Furthermore, unless otherwise specified herein, "A to B" representing a numerical range means "A or greater (including A and greater than A) and B or less (including B and less than B)." Furthermore, each drawing is shown for clarity when referred to in conjunction with the following description and is not necessarily drawn to a fixed scale.

[0024] [1. Outline of one embodiment of the present invention] As mentioned above, black foams have superior thermal insulation performance compared to general bead foam molded products, and in recent years, demand for them as residential insulation materials has been increasing. The carbon material contained in black foams absorbs electromagnetic waves (radiant heat). Therefore, when transporting or temporarily storing such black foams at the construction site, the material temperature rises due to exposure to sunlight. As a result, black foams may develop quality defects such as deformation or melting due to tertiary foaming.

[0025] The packaging technologies described in Patent Documents 1 and 2 can prevent deformation of black foam due to sunlight irradiation. However, the packaging technologies described in Patent Documents 1 and 2 use materials that block radiant heat as packaging material, and do not consider the case where black foam is packaged with packaging material that includes a black packaging sheet that can absorb sunlight. Therefore, the packaging technologies described in Patent Documents 1 and 2 have room for improvement in suppressing the temperature rise of black foam when black foam is packaged with packaging material that includes a black packaging sheet.

[0026] Therefore, the inventors diligently conducted research with the aim of realizing a packaging method and packaging body that can suppress the temperature rise of black foam when packaging black foam using packaging materials including black packaging sheets, and as a result, completed the present invention.

[0027] One embodiment of the present invention will be described in detail below.

[0028] [2. Packaging Method] A packaging method according to one embodiment of the present invention (hereinafter sometimes referred to as "this packaging method") is a packaging method for packaging a black foam using a packaging material. The packaging material includes a black resin packaging sheet. This packaging method includes a covering step of covering the outer periphery of the black foam with the packaging material while air is introduced between the black foam and the packaging material to create a gap.

[0029] According to the above configuration, in the covering step, air is introduced between the black foam and the packaging material to create a gap, and the outer periphery of the black foam is covered with the packaging material. The packaging material also includes a black resin packaging sheet. The black resin packaging sheet is the main body of the packaging material. Therefore, since air is interposed between the black foam and the black resin packaging sheet, heat absorbed by the black resin packaging sheet is less likely to be transferred to the black foam. Consequently, according to the above configuration, the temperature rise of the black foam can be suppressed. Furthermore, warping, deformation, or dimensional changes of the black foam due to this temperature rise can be prevented. Moreover, according to the above configuration, even without opening vents in the white or blue packaging sheet as in the technology described in Patent Document 1, the temperature rise of the black foam can be suppressed by interposing air between the black foam and the black resin packaging sheet. Therefore, according to the above configuration, compared to the technology described in Patent Document 1, the cost can be reduced by not requiring the processing cost of vents. Furthermore, since the black resin packaging sheet does not have ventilation holes, the packaging method according to one embodiment of the present invention reduces the risk of dust entering the packaged goods compared to the technology described in Patent Document 1, and as a result, reduces the risk of the black foam becoming contaminated.

[0030] Here, in the covering step, the black foam does not need to be covered by the packaging material with a gap between its entire outer circumference and the packaging material. It is sufficient for the black foam to be covered by the packaging material with a gap between at least a portion of its outer circumference and the packaging material. For example, the covering state of the black foam by the packaging material may be such that both the top and side surfaces of the outer circumference of the black foam have a gap with the packaging material, while the bottom surface is in contact with the packaging material. Furthermore, it is preferable that the contact points between the black foam and the packaging material are not fixed but changeable. If the contact points between the black foam and the packaging material are fixed, the temperature of the black foam will rise locally at those contact points. To avoid such temperature rises, it is preferable that the black foam is movable within the packaging material.

[0031] Furthermore, the method of covering the black foam with the packaging material in the covering step is not particularly limited, as long as air is ultimately interposed between the black foam and the packaging material, creating a gap. The covering method does not necessarily have to include a step of actively introducing air into the packaging material, for example, with a pump.

[0032] One example of the covering method may include the following steps: preparing a packaging material having an opening and being larger than the dimensions of the black foam; placing the black foam into the prepared packaging material through the opening; and adjusting the position of the black foam within the packaging material so that air is interposed between the black foam and the packaging material, creating a gap. Another example of the covering method may include the following steps: preparing a packaging material having an opening and being larger than the dimensions of the black foam; placing the black foam into the prepared packaging material through the opening; and introducing air into the packaging material using a pump or the like so that a gap is created between the black foam and the packaging material. Yet another example of the covering method may include the following steps: preparing a packaging material having an opening and being larger than the dimensions of the black foam; and covering the black foam from above while drawing in air through the opening of the prepared packaging material.

[0033] (Coating process) Figures 101 and 102 of Figure 1 schematically show an example of the covering process in this packaging method. In this packaging method, the covering process includes the packaging material preparation process shown in Figure 101 and the containment process shown in Figure 102. In the packaging material preparation process, a black resin packaging sheet 3 is formed into a bag shape by enclosing air to create a packaging material 2. In the containment process, a black foam 1A is contained in the packaging material 2.

[0034] Here, the black foam 1A is a laminate formed by stacking multiple black foam plates 1. However, the black foam 1A may also consist of a single black foam plate 1. Furthermore, the black foam 1A is not limited to a plate shape and can adopt any shape.

[0035] The form of the black resin packaging sheet 3 used in the packaging material manufacturing process is not particularly limited, as long as it can be made into a bag shape. In the configuration shown in Figure 1, 101, the black resin packaging sheet 3 is made of a bag-shaped film and has one opening 3a through which the black foam 1A can pass. Alternatively, the black resin packaging sheet 3 may be made of a tubular film and have two openings 3a through which the black foam 1A can pass. In this case, the black resin packaging sheet 3 can be made into a bag shape by closing one of the two openings 3a of the tubular film, for example, by welding. Furthermore, the black resin packaging sheet 3 is not limited to having one or two openings 3a, but only needs to have at least one opening 3a. That is, when the black resin packaging sheet 3 is made of a bag-shaped film, the black resin packaging sheet 3 has a configuration having two or more openings 3a. Also, when the black resin packaging sheet 3 is made of a tubular film, the black resin packaging sheet 3 has a configuration having three or more openings 3a. If a black resin packaging sheet 3 made of a tubular film has three or more openings 3a, it can be formed into a bag shape having two or more openings 3a by closing at least one of these openings 3a. Thus, if the black resin packaging sheet 3 is made of a tubular or bag-shaped film and has at least one opening 3a for containing the black foam 1A, the black resin packaging sheet 3 can be easily made into a bag shape.

[0036] Furthermore, the "bag-shaped film" is not particularly limited as long as it is a black resin packaging sheet 3 capable of covering the entire outer periphery of the black foam 1A. For example, the black resin packaging sheet 3 may be made of a box-shaped film. Alternatively, the black resin packaging sheet 3 may consist of a single film of a predetermined size, and the film may be configured to wrap the black foam 1A like a furoshiki (traditional Japanese wrapping cloth).

[0037] In the packaging material manufacturing process, the black resin packaging sheet 3 is formed into a bag shape by enclosing air. Here, "enclosing air" means, as shown in Figure 1, 101, if the black resin packaging sheet 3 is made of a bag-shaped film, air is introduced through the opening 3a. By introducing air through the opening 3a, the black resin packaging sheet 3 is formed into a bag shape to the extent that it can accommodate the black foam 1A. If the black resin packaging sheet 3 is made of a tubular film, "enclosing air" means closing one of the two openings 3a and then introducing air through the other opening 3a. Furthermore, in the packaging material manufacturing process, it is sufficient to form the black resin packaging sheet 3 into a bag shape at least until the opening 3a is large enough to accommodate the black foam 1A.

[0038] Furthermore, the method of introducing air into the packaging material during the manufacturing process, that is, the method of introducing air through the opening 3a, is not particularly limited. This method may involve introducing air into the black resin packaging sheet 3 through the opening 3a using a pump or the like. Alternatively, this method may involve introducing air into the black resin packaging sheet 3 by moving the black resin packaging sheet 3 while the opening 3a is widened.

[0039] As shown in Figure 1, 102, in the containment step, the black foam 1A is contained in the packaging material 2. In this containment step, the black foam 1A is contained through the opening 3a of the bag-shaped black resin packaging sheet 3. When the black foam 1A is contained, the bag-shaped black resin packaging sheet 3 has a gap inside which the black foam 1A can move. In this way, since the black foam 1A can move within the bag-shaped black resin packaging sheet 3, air is interposed between the black foam 1A and the black resin packaging sheet 3.

[0040] The method for containing the black foam 1A in the packaging material 2 is not particularly limited, as long as air is ultimately interposed between the black foam 1A and the packaging material 2, creating a gap. This method can be set, for example, according to the dimensions of the black foam 1A. If the dimensions of the black foam 1A are relatively small, as shown in 102 of Figure 1, the black foam 1A may be contained by moving it and inserting it through the opening 3a while a bag-shaped black resin packaging sheet 3 is set up with the opening 3a facing upwards. Alternatively, if the dimensions of the black foam 1A are relatively large, the black foam 1A may be contained by covering the black foam 1A, which is placed on the ground or elsewhere, with the bag-shaped black resin packaging sheet 3 so that it passes through the opening 3a.

[0041] In this packaging method, the black foam 1A is placed in the packaging material 2 after the packaging material manufacturing process and the placement process. This packaging method may optionally include a closing process for closing the opening 3a of the bag-shaped black resin packaging sheet 3 in which the black foam 1A is placed. In this closing process, for example, the opening 3a is closed by fastening the end 3b of the bag-shaped black resin packaging sheet 3 on the opening 3a side in a drawstring manner. Note that the method of closing the opening 3a (fastening method) is not limited to a drawstring fastening, and known fastening methods can be used. For example, such closing methods include fastening by making a knot at the end 3b, or fastening by welding the opening 3a or the end 3b.

[0042] Furthermore, in this packaging method, the order of the packaging material manufacturing process and the storage process is not limited to the order shown in 101 and 102 of Figure 1. In this packaging method, the storage process may be performed after the packaging material manufacturing process, or the packaging material manufacturing process may be performed after the storage process.

[0043] For example, if the black resin packaging sheet 3 is made of a tubular film, it is possible to perform the packaging material manufacturing process after the storage process. That is, first, in the storage process, the opening 3a of the tubular black resin packaging sheet 3 is opened and the black foam 1A is placed inside the tubular black resin packaging sheet 3. Then, in the packaging material manufacturing process, the black resin packaging sheet 3 containing the black foam 1A is made into a bag shape by closing one of the two openings 3a, for example, by welding. Then, air is introduced through the other opening 3a.

[0044] (Packaging) Figure 2 shows a schematic configuration of a package 10 according to one embodiment of the present invention, where 201 in Figure 2 is a perspective view and 202 in Figure 2 is a cross-sectional view. The package 10 can be obtained, for example, by the packaging method shown in 101 and 102 of Figure 1.

[0045] As shown in Figures 201 and 202, the package 10 comprises a black foam 1A and a packaging material 2 for packaging the black foam 1A. The packaging material 2 includes a black resin packaging sheet 3. The black foam 1A is covered by the black resin packaging sheet 3, with a gap between the black resin packaging sheet 3 and the outer periphery of the black foam 1A. The black foam 1A is a laminate of black foam plates 1.

[0046] The black resin packaging sheet 3 contained in the packaging material 2 is in the shape of a bag with an opening 3a. The black foam 1A is contained within the bag-shaped black resin packaging sheet 3 through the opening 3a. The end 3b of the black resin packaging sheet 3 on the opening 3a side is fastened in a drawstring manner. This closes the opening 3a.

[0047] Thus, the packaging 10 comprises a black foam 1A and a closed, bag-shaped black resin packaging sheet 3. In this packaging 10, the black resin packaging sheet 3 covers the black foam 1A with a gap D between them. Therefore, since air is interposed in the gap D between the black foam 1A and the black resin packaging sheet 3, the heat absorbed by the black resin packaging sheet 3 is less likely to be transferred to the black foam 1A. Consequently, the packaging 10 can suppress the temperature rise of the black foam 1A. Furthermore, it can prevent warping, deformation, or dimensional changes of the black foam 1A that occur due to this temperature rise.

[0048] In the packaged product 10 or this packaging method, the dimensions of the gap D between the packaging material 2 (black resin packaging sheet 3) and the black foam 1A are not particularly limited, as long as the heat absorbed by the black resin packaging sheet 3 is not transferred to the black foam 1A. The gap D between the packaging material 2 and the black foam 1A is preferably 1 mm or more, more preferably 5 mm or more, and even more preferably 10 mm or more.

[0049] Furthermore, in the packaged product 10 or this packaging method, the surface temperature of the black foam 1A is preferably less than 90°C, more preferably 85°C or lower, and even more preferably 80°C or lower. Maintaining the surface temperature of the black foam 1A within the above numerical range prevents warping, deformation, or dimensional changes of the black foam 1A.

[0050] The following describes in detail each of the materials constituting the packaging 10 according to one embodiment of the present invention.

[0051] (Black foam 1A, Black foam plate 1) The black foam 1A (black foam plate 1) used in one embodiment of the present invention is not particularly limited as long as it is a black bead foam molded article containing a carbon material such as graphite. Preferably, the black foam 1A is a black resin foam molded article having a lightness index L* of less than 65, and is a bead foam molded article obtained by pre-foaming and molding foamable thermoplastic resin particles, or a bead foam molded article obtained by foam molding thermoplastic resin foam particles. The black foam 1A may consist of one black foam plate 1 having a lightness index L* of less than 65, or it may be composed of two or more black foam plates 1 having a lightness index L* of less than 65 laminated together.

[0052] The thermoplastic resin constituting the foamed thermoplastic resin particles or thermoplastic foamed particles is not particularly limited, but examples include styrene-based resins such as polystyrene (PS), styrene-acrylonitrile copolymer (AS), styrene-(meth)acrylic acid copolymer (heat-resistant PS), styrene-(meth)acrylic acid ester copolymer, styrene-butadiene copolymer (HIPS), N-phenylmaleimide-styrene-maleic anhydride three-dimensional copolymer, and alloys thereof with AS (IP); vinyl-based resins such as polymethyl methacrylate, polyacrylonitrile-based resin, and polyvinyl chloride-based resin; and polyolefin-based resins such as polypropylene, polyethylene, ethylene-propylene copolymer, ethylene-propylene-butene three-dimensional copolymer, and cycloolefin-based (co)polymers. Examples include polyolefin resins with rheological control by introducing branched or crosslinked structures; polyamide resins such as nylon 6, nylon 66, nylon 11, nylon 12, and MXD nylon; aromatic polyester resins such as polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; aliphatic polyester resins such as polylactic acid; and engineering plastics such as polycarbonate resin, polyphenylene ether resin (PPE), modified polyphenylene ether resin (modified PPE), polyoxymethylene resin, polyphenylene sulfide resin, polyphenylene sulfide resin, aromatic polyether resin, and polyether ether ketone resin. These may be used individually or mixed in combination of two or more. Among these thermoplastic resins, polystyrene resins are preferred because they are relatively inexpensive, can be molded using low-pressure steam without special methods, and provide high cushioning and heat insulation effects. In other words, in one embodiment of the present invention, the black foam 1A is preferably a foam made of polystyrene foam resin.

[0053] In one embodiment of the present invention, the method for making a bead foam molded body made of thermoplastic resin a black color is not particularly limited, and examples include a method of incorporating carbon into the foamed thermoplastic resin particles or thermoplastic foam particles constituting the bead foam molded body, or a method of incorporating a black pigment. Among these, the method of incorporating carbon into the foamed thermoplastic resin particles or thermoplastic foam particles is preferred because it can impart excellent heat insulation properties to the black foam 1A. In other words, it is preferable that the black foam 1A used in one embodiment of the present invention contains carbon.

[0054] The carbon content of the black foam 1A used in one embodiment of the present invention is not particularly limited, but from the viewpoint of improving heat insulation, it is preferable that the carbon content be 2% by weight or more in 100% by weight black foam 1A, and 25% by weight or less in order to obtain good foaming moldability.

[0055] The carbon contained in black foam 1A can include graphite, graphene, activated carbon, coke, and carbon black. Among these, graphite or carbon black is preferred, with graphite being more preferred, due to its excellent balance of cost and thermal insulation improvement effect.

[0056] In one embodiment of the present invention, the black foam 1A has a lightness index L* of less than 65, preferably less than 60, more preferably less than 55, and even more preferably less than 50. Foams with a lightness index L* of less than 65 are black or gray in color. Therefore, when the black foam 1A is packaged using conventional packaging methods, it may heat up due to absorption of sunlight, causing it to melt or deform. On the other hand, when the black foam 1A is packaged using this packaging method, the heating of the black foam 1A can be suppressed, so even black foam 1A with a lightness index L* of less than 65 can be packaged and stored stably.

[0057] In this specification, the lightness index L* refers to the value of the lightness index L* in the CIE1976 L*a*b* color space. For example, the lightness index L* value for white is 100, and the lightness index L* value for black is 0. The lightness index L* in the CIE1976 L*a*b* color space can be measured, for example, using a spectrophotometer (such as the Konica Minolta CM-2500d), with a xenon lamp as the light source and a measurement diameter of φ8 mm.

[0058] In one embodiment of the present invention, the shape of the black foam 1A is not particularly limited and can be rectangular, triangular or hexagonal, circular, or the like. The black foam 1A may also be embedded within a wooden panel such as a load-bearing wall panel. The shape of the black foam 1A can be appropriately set according to the desired application.

[0059] In one embodiment of the present invention, it is preferable that the foaming ratio of the black foam 1A is 40 times or more. If the foaming ratio of the black foam 1A is 40 times or more, the foam can be provided at a relatively low cost, which is economically advantageous.

[0060] Furthermore, in one embodiment of the present invention, the thermal conductivity of the black foam 1A is preferably 0.032 W / m·K or less, and more preferably 0.030 W / m·K or less. Having the thermal conductivity of the black foam 1A within this range provides the effect of exhibiting high thermal insulation performance. The thermal conductivity can be measured by a known method, for example, by the method described in Japanese Patent Application Publication No. 2019-65073.

[0061] Furthermore, in one embodiment of the present invention, the density of the black foam 1A is 5 kg / m³ 3 ~25kg / m 3 Preferably, it is 8 kg / m 3 ~20kg / m 3It is more preferable that the density of the black foam 1A is within this numerical range, which has the effect of producing a lightweight foam at a relatively low cost. The density is a value that can be measured by a known method, and specifically can be measured according to the method of JIS K7222 (2005 edition).

[0062] (Black resin packaging sheet 3) The black resin packaging sheet 3 according to one embodiment of the present invention is made of a black synthetic resin composition.

[0063] In one embodiment of the present invention, the synthetic resin constituting the black resin packaging sheet 3 is not particularly limited, and examples include polyolefin resins, acrylic resins, polyvinyl chloride resins, etc. Among these synthetic resins, polyolefin resins are preferred from the viewpoint of cost and versatility, and polyethylene resins are particularly preferred.

[0064] In this specification, a black synthetic resin composition is preferably a synthetic resin composition that exhibits a dark color having a solar absorptive rate of 90% or more in the wavelength range of 380 to 720 nm. The wavelength range of 380 to 720 nm is referred to as the visible light range, which is light that humans can perceive with the naked eye, and a high absorption rate of light in the visible light range results in a dark color such as black or gray.

[0065] In this specification, the solar absorptance in the wavelength range of 380 to 720 nm can be measured by the following methods (1) to (5): (1) Prepare a black resin packaging sheet as a test specimen, and using a self-recording spectrophotometer, set the reflectance of a white alumina substrate to 100% and measure the reflectance (spectral reflectance) at each wavelength in the wavelength range of 380 to 720 nm at 1 nm intervals; (2) Using Appendix 3 of JIS A5759, calculate the value obtained by multiplying the spectral reflectance at each wavelength measured in (1) by the corresponding weighting coefficient at each wavelength, and calculate the solar reflectance as the sum of these values ​​(spectral solar reflectance test method); (3) Using a self-recording spectrophotometer, set the transmittance without the test specimen to 100% and measure the transmittance (spectral transmittance) at each wavelength; (4) JIS Using Appendix Table 3 of A5759, calculate the values ​​obtained by multiplying the spectral transmittance at each wavelength measured in (3) by the weighting coefficient at each wavelength, and calculate the solar transmittance as the sum of these values; (5) Furthermore, from the obtained solar reflectance and solar transmittance values, calculate the solar absorptance using the following formula (1): (Solar absorptivity) = 100% - (Solar reflectance) - (Solar transmittance) ... (1).

[0066] In one embodiment of the present invention, the method for making the black resin packaging sheet 3 black is not particularly limited, but one method is to blend a pigment into the synthetic resin constituting the black resin packaging sheet 3. By blending a black pigment such as carbon black or aniline black as the pigment, the black resin packaging sheet 3 can be made black, that is, the solar radiation absorptivity of the black resin packaging sheet 3 in the wavelength range of 380 nm to 720 nm can be made 90% or more. As the black pigment, carbon black is particularly preferred from the viewpoint of cost and ease of handling.

[0067] The pigment (black pigment) content in the synthetic resin is influenced by the film thickness and the desired light-shielding performance, and therefore cannot be determined definitively. However, it is preferably 2.0 to 15.0 parts by weight per 100 parts by weight of synthetic resin. In particular, the lower limit is preferably 3.0 parts by weight or more, and more preferably 4.0 parts by weight or more. The upper limit is preferably 12.0 parts by weight or less, and more preferably 10.0 parts by weight or less. If the pigment content is 2.0 parts by weight or more, the total light transmittance is low and the decrease in solar absorptive rate is suppressed, so even when exposed to sunlight, excessive temperature rise of the foam can be suppressed. Furthermore, if the pigment content is 15.0 parts by weight or less, it does not affect the scratch resistance and flexibility of the synthetic resin, so there is no risk of deterioration of moldability due to a decrease in strength and elongation of the black resin packaging sheet 3, and furthermore, there is no risk of increased cost or deterioration of lightness due to an increase in specific gravity. In a more preferred embodiment, the black resin packaging sheet 3 contains 2.0 to 15.0 parts by weight of carbon black per 100 parts by weight of polyolefin resin.

[0068] The thickness of the black resin packaging sheet 3 used in one embodiment of the present invention is preferably 7 μm to 30 μm, more preferably 10 μm to 25 μm, and even more preferably 12 μm to 22 μm. If the thickness of the black resin packaging sheet 3 is within the above numerical range, the temperature rise of the black foam 1A can be suppressed, the strength as a packaging material can be ensured, and the risk of damage to the packaging material during transport to the construction site or in a temporary storage state can be reduced. [Examples]

[0069] Examples, comparative examples, and reference examples are given below, but the present invention is not limited thereto.

[0070] 〔material〕 The materials used in the examples, comparative examples, and reference examples are shown below.

[0071] (Black foam) A black foam molded body made of carbon-containing bead styrene resin was used as the black foam material. Specifically, a graphite-containing bead foam molded body with a foaming ratio of 80 times and dimensions of 400 mm in length, 400 mm in width, and 50 mm in thickness was prepared according to the method described in Example 1 of Japanese Patent Application Publication No. 2019-65073. The thermal conductivity was 0.031 W / mK. A sample for irradiation testing, measuring 100 × 100 × 50 (t) mm with skin on the top and bottom surfaces (100 × 100 mm), was cut from the above bead foam molded body.

[0072] (Resin packaging sheet) Black resin packaging sheet I: Manufactured by Household Japan Co., Ltd. Thickness: 7 μm, Resin: High-density polyethylene (HDPE), Carbon black content: 4 wt%. Black resin packaging sheet II: Manufactured by Household Japan Co., Ltd. Thickness: 12 μm, Resin: High-density polyethylene, Carbon black content: 4 wt%. Black resin packaging sheet III: Manufactured by Household Japan Co., Ltd. Thickness: 22 μm, Resin: High-density polyethylene, Carbon black content: 4 wt%. Black resin packaging sheet IV: Manufactured by Sanwa Film Co., Ltd. Thickness: 30 μm, Resin: High-density polyethylene, Carbon black content: 5 wt%. White translucent resin packaging sheet I: Manufactured by Sekisui Film Co., Ltd. Thickness: 20 μm, Resin: High-density polyethylene.

[0073] [Irradiation Test] The equipment used in the irradiation tests conducted in the examples and comparative examples, and the illuminance adjustment methods before the tests, are as follows.

[0074] <Equipment used> Artificial sunlight irradiation device: Simple light irradiation device manufactured by Iwasaki Electric Co., Ltd. (MCLS15B16-KNK01) Sunshine meter: Hideko Seiki Pyranometer MS-602 Thermometer: Thermocouple type thermometer.

[0075] <Measurement Conditions> The irradiation test was carried out in a space with a temperature of 23°C and a humidity of 50%.

[0076] <Illuminance Adjustment Method> The power of the artificial sunlight irradiator was turned on to light the lamp. After 1 hour, the sunshine recorder was installed so that the upper surface of the sunshine recorder was at a position 600 mm below the lower surface of the lamp installed at the upper part inside the chamber, and the illuminance after 1 minute was measured. After the measurement was completed, the sunshine recorder was taken out from the device. If the illuminance was not 1000 W / m 2 it was adjusted by the dimming machine. Then, 30 minutes after the adjustment, the sunshine recorder was installed so that the upper surface of the sunshine recorder was at a position 600 mm below the lower surface of the lamp installed at the upper part inside the chamber, and the illuminance after 1 minute was measured. The above operation was repeated until it reached 1000 ± 50 W / m 2 At the height position of the upper surface of the black foam sample, the distance between the lamp of the irradiation device and the upper surface of the sample was adjusted so that the illuminance became 1000 W / m 2

[0077] 〔Evaluation Method〕 The evaluation of the surface state of the black foam after the irradiation test is shown below.

[0078] <s (Surface Melting State) After the irradiation test, the black foam was visually inspected, and the surface melting state of the black foam was evaluated according to the following criteria; None (Good): No abnormality was found in the beads constituting the black foam<s Melting (Bad): Melting of the beads constituting the black foam was observed Partial Melting (Bad): Partial melting of the beads constituting the black foam was observed.

[0079] (Swelling of Foaming Particles on the Surface of Black Foam) After the irradiation test, the black foam was visually inspected, and the swelling of the foaming particles on the surface of the black foam was evaluated according to the following criteria; None (Good): No abnormality was found in the beads constituting the black foam Yes (Bad): Swelling of the beads constituting the black foam was observed.​

[0080] [Example 1] A thermocouple thermometer was set 10 mm below the top surface (100 x 100 mm skin surface) of a 100 x 100 x 50 (t) mm black foam sample. The temperature at this measurement point is called the surface temperature. The black foam sample and thermocouple thermometer were fixed in place to prevent movement of the temperature sensing junction.

[0081] Furthermore, a wooden frame with a packaging sheet was created by attaching a 7μm thick black resin packaging sheet I to the opening of a wooden frame with external dimensions of 300mm x 300mm and internal dimensions of 280mm x 280mm. The wooden frame with the packaging sheet was then set up so that the surface of the black resin packaging sheet was positioned 20mm above the top surface of the sample on which the thermocouple thermometer was installed. Here, the gap between the top surface of the sample and the black resin packaging sheet is defined as the "minimum distance between the packaging material and the foam."

[0082] A thermocouple thermometer was attached to the top surface of the sample, positioned 600 mm below the bottom surface of the lamp located in the upper part of the artificial sunlight irradiation chamber. The surface temperature of the sample was measured 60 minutes after placement. After 60 minutes of irradiation, the sample was removed, and the surface condition of the black foam sample was evaluated. The results are shown in Table 1.

[0083] [Example 2] Except for changing to a 12 μm thick black resin packaging sheet II, the irradiation test was performed in the same manner as in Example 1, and the physical properties of the black foam sample were measured and evaluated. The results are shown in Table 1.

[0084] [Example 3] Except for changing to a 22 μm thick black resin packaging sheet III, the irradiation test was performed in the same manner as in Example 1, and the physical properties of the black foam sample were measured and evaluated. The results are shown in Table 1.

[0085] [Example 4] Except for changing to a 30 μm thick black resin packaging sheet IV, the irradiation test was performed in the same manner as in Example 1, and the physical properties of the black foam sample were measured and evaluated. The results are shown in Table 1.

[0086] [Example 5] Except for changing the minimum distance between the packaging material and the foam to 5 mm and using a 22 μm thick black resin packaging sheet III, the irradiation test was performed in the same manner as in Example 1, and the physical properties of the black foam sample were measured and evaluated. The results are shown in Table 1.

[0087] [Comparative Example 1] Except for not using a black resin packaging sheet, the irradiation test was performed in the same manner as in Example 1, and the physical properties of the black foam sample were measured and evaluated. The results are shown in Table 2.

[0088] [Comparative Example 2] Except for the black resin packaging sheet being replaced with a 20 μm thick white translucent resin packaging sheet III, the irradiation test was performed in the same manner as in Example 1, and the physical properties of the black foam samples were measured and evaluated. The results are shown in Table 2.

[0089] [Comparative Example 3] A thermocouple thermometer was set 10 mm below the top surface (100 x 100 mm skin surface) of a 100 x 100 x 50 (t) mm black foam sample. The temperature at this measurement point is called the surface temperature. The thermocouple thermometer was fixed in place so that the temperature sensing junction position would not move. The black foam sample and the thermocouple thermometer were fixed in place so that the temperature sensing junction position would not move.

[0090] Then, a 22 μm thick black resin packaging sheet III was tightly packed over the entire sample on which the thermocouple thermometer was installed. In Comparative Example 3, the "minimum distance between the packaging material and the foam" was 0 mm.

[0091] A thermocouple thermometer was attached to the top surface of the sample, positioned 600 mm below the bottom surface of the lamp located in the upper part of the artificial sunlight irradiation chamber. The surface temperature of the sample was measured 60 minutes after placement. After 60 minutes of irradiation, the sample was removed, and the surface condition of the black foam sample was evaluated. The results are shown in Table 2.

[0092] [Table 1]

[0093] [Table 2]

[0094] As shown in Table 1, in Examples 1-5, where there was a gap between the black foam and the packaging material, the surface temperature of the black foam could be reduced, and the surface condition of the black foam was also good. On the other hand, as can be seen from Comparative Examples 1-3 in Table 2, when no packaging material was used, when packaging material without a black resin packaging sheet was used, or when there was no gap between the black foam and the packaging material, the surface temperature of the black foam could not be reduced. [Industrial applicability]

[0095] According to one embodiment of the present invention, a method for packaging black foam can be provided that can suppress the temperature rise of the black foam. The black foam can be suitably used for applications such as residential insulation. [Explanation of symbols]

[0096] 1. Black foam plate (black foam material) 1A Black foam 2 Packaging materials 3. Black resin packaging sheets 3a opening 10. Packaging

Claims

1. A packaging method for packaging a black foam using packaging materials, The aforementioned packaging material includes a black resin packaging sheet. The process includes a covering step in which air is introduced between the black foam and the packaging material to create a gap, and the outer periphery of the black foam is covered with the packaging material, The coating process is as follows: A packaging material manufacturing process in which the black resin packaging sheet is formed into a bag shape by enclosing air, and the packaging material is manufactured, A packing step of packing the black foam into the packing material such that air is interposed between the black foam and the black resin packing sheet, A packaging method comprising a closing step of closing the opening of a bag-shaped black resin packaging sheet containing a black foam so as to maintain a state in which air is interposed between the black foam and the black resin packaging sheet.

2. The packaging method according to claim 1, wherein the black resin packaging sheet is not provided with ventilation holes.

3. The packaging method according to claim 1, wherein the bag-shaped black resin packaging sheet has gaps inside which the black foam can move.

4. The packaging method according to claim 1, wherein the gap between the packaging material and the black foam is 1 mm or more.

5. The packaging method according to claim 1, wherein the thickness of the black resin packaging sheet is 7 μm to 30 μm.

6. The packaging method according to claim 1, wherein the black resin packaging sheet comprises 2.0 to 15.0 parts by weight of carbon black per 100 parts by weight of polyolefin resin.

7. The packaging method according to claim 1, wherein the black resin packaging sheet is composed of a tubular or bag-shaped film and has at least one opening through which the black foam can pass.

8. The packaging method according to claim 1, wherein the thermal conductivity of the black foam is 0.032 W / m·K or less.

9. The density of the black foam is 5 kg / m³. ３ ~25 kg / m ３ The packaging method according to claim 1.

10. The packaging method according to claim 1, wherein the black resin packaging sheet is made of a synthetic resin composition.

11. The packaging method according to claim 1, wherein in the coating step, air is introduced into the packaging material using a pump so that a gap is created between the black foam and the packaging material.

12. Black foam and The package includes a packaging material for packaging the aforementioned black foam, The packaging material includes a bag-shaped black resin packaging sheet having an opening. The black resin packaging sheet covers the black foam, with a gap provided between the black resin packaging sheet and the outer periphery of the black foam. The opening of the aforementioned black resin packaging sheet is closed. A package in which air is interposed between the black foam and the black resin packaging sheet.

13. The packaged product according to claim 12, wherein the black resin packaging sheet is not provided with ventilation holes.

14. The packaging according to claim 12, wherein the black resin packaging sheet is made of a synthetic resin composition.

15. The surface temperature of the black foam is less than 90°C. Here, the surface temperature is the temperature at a position 10 mm below the top surface of the black foam, as measured under the following measurement conditions, for the packaging according to claim 12; Measurement conditions: In a space with a temperature of 23°C and a humidity of 50%, the lamp was positioned so that the illuminance at the height of the top surface of the black foam sample was 1000 W / m². The lamp was positioned 600 mm below the bottom surface and a thermocouple thermometer was set 10 mm below the top surface of the black foam sample. The surface temperature of the black foam sample was measured 60 minutes after setup.

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