Gate plate for truck, and truck

Abstract

To provide a gate plate for a truck with excellent heat insulation performance.SOLUTION: A gate plate (20) for a truck comprises a gate plate body (10) and a latent heat storage material (5), and the latent heat storage material (5) is disposed on at least one surface (10a) of the gate plate body (10).SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a tailgate for a truck, and to a truck. [Background technology]

[0002] 2. Description of the Related Art Freight vehicles such as trucks are provided with a loading platform, and a tailgate is rotatably attached to the floor frame of the loading platform by means of a tailgate hinge.

[0003] From the standpoint of imparting insulating properties to the panel that constitutes the gate board body, Patent Document 1, for example, discloses a gate board having a gate board body made of an insulating sandwich panel in which insulating material is foamed and filled between a pair of aluminum plates. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Utility Model Application Publication No. 1-83681 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when transportation requires maintaining a lower temperature, such as the transportation of fresh food, the gate plate described in Patent Document 1 has room for improvement in terms of heat insulating performance.

[0006] An object of one aspect of the present invention is to provide a tailgate for a truck, and a truck, having excellent thermal insulation performance. [Means for solving the problem]

[0007] In order to solve the above problems, one aspect of the present invention is as follows.

[0008] [1] A tailgate for trucks, comprising a tailgate body and a latent heat storage material, the latent heat storage material being disposed on at least one surface of the tailgate body.

[0009] [2] The tailgate for trucks according to [1], wherein the phase change peak temperature of the latent heat storage material is 5°C to 35°C.

[0010] [3] The latent heat storage material is in sheet form, the tailgate for a truck according to [1] or [2].

[0011] [4] A tailgate for trucks according to any one of [1] to [3], wherein the tailgate body comprises an aluminum hollow material and a foam filled in the hollow material.

[0012] [5] The tailgate for trucks according to [4], wherein the foam is made by foaming pre-expanded thermoplastic resin particles.

[0013] [6] A tailgate for trucks according to any one of [1] to [5], wherein the latent heat storage material is adhered to one surface of the tailgate body by a foam double-sided tape.

[0014] [7] A truck comprising a storage shed having a tailgate for a truck of any one of [1] to [6], the tailgate body and the latent heat storage material being arranged in this order from the outside of the storage shed toward the inside of the storage shed.

[0015] [8] The truck of [7], wherein the storage facility comprises a ceiling component and a side wall upper component arranged above the gate plate and constituting a side wall together with the gate plate, and the latent heat storage material is arranged on the inside surface of at least one of the ceiling component and the side wall upper component. Effect of the Invention

[0016] According to one aspect of the present invention, a tailgate for a truck can be provided with excellent heat insulating performance. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is an exploded perspective view showing a schematic configuration of a tailgate for a truck according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a perspective view showing a schematic configuration of a tailgate body, which is the main body of the tailgate for a truck according to the embodiment of the present invention. [Diagram 3] 1 is a cross-sectional view showing a schematic configuration of a tailgate for a truck according to an embodiment of the present invention. [Figure 4] 1 is a cross-sectional view showing a schematic configuration of a storage facility provided in a truck according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] An embodiment of the present invention will be described below, but the present invention is not limited thereto. The present invention is not limited to each configuration described below, and various modifications are possible within the scope of the claims. In addition, 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. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment. All academic documents and patent documents described in this specification are incorporated herein by reference. Furthermore, unless otherwise specified in this specification, "A to B" representing a numerical range is intended to mean "A or more (including A and greater than A) and B or less (including B and smaller than B)". Furthermore, each drawing is shown for easy understanding when referred to in conjunction with the following description, and is not necessarily drawn to a constant scale.

[0019] Fig. 1 is an exploded perspective view showing a schematic configuration of a gate plate 20 for trucks according to this embodiment. Fig. 2 is a perspective view showing a schematic configuration of a gate plate body 10, which is the main body of the gate plate 20 for trucks according to this embodiment. Fig. 3 is a cross-sectional view showing a schematic configuration of the gate plate 20 for trucks according to this embodiment. In Fig. 3, the rod member 4 is omitted for the sake of simplicity.

[0020] As shown in Fig. 2, the gate plate body 10 is a strip-shaped plate member, and includes an aluminum hollow material 1 and a foam 2. The foam 2 is filled in the hollow material 1. Here, the longitudinal direction of the strip-shaped gate plate body 10 is the X direction, the thickness direction is the Y direction, and the short side direction is the Z direction. When attached to a truck, the gate plate body 10 is attached so that the Z direction is the up-down direction.

[0021] The hollow material 1 is a strip-shaped bottomless cylinder having a hollow portion therein that is filled with a foam 2. In addition, the hollow material 1 has openings 1a-1a on two side surfaces that face each other in the X direction. In addition, the hollow material 1 has rail portions 1b-1b on two side surfaces that face each other in the Z direction. The rail portions 1b are recessed grooves that extend in the X direction.

[0022] The foam 2 has a configuration in which a plurality of heat-expanded expanded particles 2a are fused to each other. The foam 2 is obtained by expanding pre-expanded thermoplastic resin particles 2a'. More specifically, the expanded particles 2a are obtained by heat-expanding the pre-expanded thermoplastic resin particles 2a' within the hollow shape 1. When manufacturing the gate board main body 10, the pre-expanded thermoplastic resin particles 2a' are filled into the hollow shape 1 through the opening 1a. Then, the pre-expanded thermoplastic resin particles 2a' are heat-expanded within the hollow shape 1 to become the foam 2. The foam 2 has an average filling rate of 40% or more and less than 90%, and a fusion rate of 1% to 70%.

[0023] As shown in Figs. 1 and 3, the gate plate 20 includes a gate plate main body 10, end posts 3, a rod member 4, and a latent heat storage material 5. The rod member 4 is a long rod-shaped member having a diameter equal to or smaller than the width of the groove constituting the rail portion 1b. The length of the rod member 4 is equal to or greater than the dimension of the gate plate main body 10 in the X direction. In the gate plate 20, the rod members 4 are disposed on both sides of the gate plate main body 10 in the Z direction. The rail portion 1b has a structure that can be attached to the rod member 4. By attaching the rail portion 1b to the rod member 4, the gate plate main body 10 is free from distortion in the X direction.

[0024] The end post 3 has a U-shaped cross section cut along an XY plane parallel to the X and Y directions (hereinafter, may be referred to as a U-shaped cross section). The end post 3 is a blocking member that blocks the opening 1a of the hollow shape member 1, and is fitted into the opening 1a. Although not shown, the end post 3 has a groove extending in the vertical direction at the corner of the inner surface of the U-shaped cross section. A sealant is attached to this groove. The size of the groove is determined according to the size of the hollow shape member 1. Here, examples of the sealant include solid packing and a paste-like material that can maintain flexibility. By attaching the sealant to the groove in this way, it is possible to prevent rainwater from entering between the hollow shape member 1 and the end post 3. The end post 3 is not limited to the above configuration, and may be any material that can block the opening 1a of the hollow shape member 1. In the gate board 20, the end posts 3 are attached to the openings 1a and 1a formed on the two side surfaces of the hollow shape member 1 in the X direction in the gate board body 10, respectively.

[0025] 3, the latent heat storage material 5 is disposed on one surface 10a of the gate plate body 10. More specifically, the latent heat storage material 5 is disposed on one surface 10a of the gate plate body 10 having surfaces 10a and 10b in the Y direction.

[0026] The latent heat storage material 5 contains a cold storage component in addition to the heat storage component itself. That is, the latent heat storage material 5 contains at least one of a heat storage component and a cold storage component.

[0027] The latent heat storage material composition constituting the heat storage component or cold storage component can absorb thermal energy during phase transition from a solidified state to a molten state, thereby maintaining, for example, the room temperature at a desired temperature below the ambient temperature even in a high-temperature environment (for example, in summer). Furthermore, the latent heat storage material composition can release thermal energy during phase transition from a molten state to a solidified state, thereby maintaining, for example, the room temperature at a desired temperature above the ambient temperature even in a low-temperature environment (for example, in winter). In other words, the latent heat storage material composition can maintain, for example, the room temperature at a desired temperature in both high-temperature and low-temperature environments.

[0028] The latent heat storage material composition used in this embodiment is not particularly limited, and for example, compositions disclosed in International Publication No. 2014 / 125878, International Publication No. 2019 / 151074, International Publication No. 2016 / 068256, International Publication No. 2019 / 172260, International Publication No. 2018 / 180506, etc. can be used.

[0029] Here, according to the gate plate 20 of this embodiment, the latent heat storage material 5 is arranged on one surface 10a of the gate plate body 10. When the gate plate 20 is attached to the truck storage shed, the surface 10a on which the latent heat storage material 5 is arranged is attached to the storage shed. In other words, the gate plate 20 of this embodiment is attached to the truck storage shed, and includes the gate plate body 10 and the latent heat storage material 5, and the latent heat storage material 5 is arranged on the surface 1a of the gate plate body 10 on the inner side of the storage shed. Since the latent heat storage material 5 is arranged in this way, the temperature inside the truck storage shed can be maintained at a desired temperature by the action of the latent heat storage material 5. Therefore, according to this embodiment, the effect of making the gate plate 20 for trucks excellent in thermal insulation performance is achieved.

[0030] In consideration of the above-mentioned effects, the latent heat storage material 5 may be disposed on at least one surface 10a of the gate plate body 10. Even if the latent heat storage material 5 is disposed on both surfaces 10a and 10b of the gate plate body 10, the above-mentioned effects can be obtained.

[0031] In particular, transportation such as transportation of fresh foods requires that the temperature be kept at a lower level. For this reason, the temperature inside the truck storage is lowered by an air conditioner installed in the storage or by cooling down before departure. In this state, the truck travels outdoors in direct sunlight to transport the luggage. Here, in the truck storage, the parts other than the gate plate (ceiling, etc.) are configured by filling a foam into an aluminum hollow member, while the gate plate part is generally made of aluminum. Therefore, while the luggage is being transported as described above, the parts other than the gate plate in the truck storage are kept cool, but the gate plate part is not insulated. For this reason, the truck storage has a problem that the outdoor heat is transferred to the inside of the storage through the aluminum gate plate part as a thermal bridge, causing the inside of the storage to heat up.

[0032] Increasing the capacity and size of the cooling equipment inside the warehouse will waste air conditioning and kinetic energy, which will directly lead to a decrease in fuel efficiency. Furthermore, there is also the issue of it taking up space inside the warehouse that is originally intended for loading the transported items.

[0033] According to this embodiment, the temperature inside the truck storage facility can be maintained at a desired temperature by the action of the latent heat storage material 5, thereby improving the insulation performance of the gate plate 20, and there is no need to increase the capacity and size of the air conditioner inside the storage facility. This effect also contributes to the achievement of, for example, Goal 7 of the Sustainable Development Goals (SDGs) advocated by the United Nations, "Ensure access to affordable, reliable, sustainable and modern energy for all."

[0034] Furthermore, according to the gate plate 20 of this embodiment, the gate plate body 10 includes an aluminum hollow material 1 and a foam 2 filled in the hollow material 1. This also makes the gate plate body 10 insulated, so that the insulating performance of the gate plate 20 for trucks is further improved. Note that, in the gate plate 20 of this embodiment, the gate plate body 10 is not limited to a configuration including a hollow material 1 and a foam 2.

[0035] As shown in FIG. 1 and FIG. 3, an adhesive layer 6 for disposing the latent heat storage material 5 is provided on the surface 10a of the gate plate body 10. This prevents the latent heat storage material 5 from moving relative to the gate plate body 10. The adhesive layer 6 may be made of a material capable of bonding the gate plate body 10 and the latent heat storage material 5. The adhesive layer 6 is preferably a foamed double-sided tape. That is, the latent heat storage material 5 is preferably bonded to one surface 10a of the gate plate body 10 by the foamed double-sided tape. The foamed double-sided tape uses a foam such as polyethylene as a base material, and has a high retention force for the latent heat storage material 5 and is difficult to peel off from the gate plate body 10. The foamed double-sided tape may be a conventionally known one as long as it has the retention force for the latent heat storage material 5 relative to the gate plate body 10.

[0036] [Latent heat storage material 5] The latent heat storage material 5 may be in any form as long as it contains a latent heat storage material composition that constitutes a heat storage component or a cold storage component. The latent heat storage material 5 may be a latent heat storage material composition sealed in a rectangular plastic container or the like.

[0037] In this case, the material of the container in which the latent heat storage material composition is filled is not particularly limited, and examples thereof include polyethylene, polypropylene, polyethylene terephthalate, polystyrene, polyvinyl chloride, nylon, and polyester. As the material of the container in which the heat storage component or cold storage component is filled, one of these exemplified materials may be used alone, or two or more of these exemplified materials may be used in combination to improve heat resistance and barrier properties. When two or more types are used in combination, the container may have a multi-layer structure made of different materials.

[0038] The latent heat storage material 5 is preferably in a sheet form. This allows the interior space for loading the transported object to be increased, and the gate plate body 10 can be protected from the luggage. The sheet-shaped latent heat storage material 5 is not particularly limited. Examples of the sheet-shaped latent heat storage material 5 include (1) a heat storage sheet A in which a latent heat storage material is dispersed in a resin matrix, (2) a heat storage sheet B in which one or two intermediate bodies in which microcapsules containing a latent heat storage material composition in a resin are supported by a fiber structure are laminated by a heat press, and (3) a heat storage sheet C in which a resin containing a latent heat storage material composition that has undergone a phase change at a specific temperature is made into a sheet form.

[0039] In the heat storage sheet A, the resin constituting the resin matrix may be vinyl chloride resin or the like. In addition, in the heat storage sheet A, a microencapsulated latent heat storage material containing a latent heat storage material composition in an organic microcapsule is used as the latent heat storage material. As the heat storage sheet A, for example, the heat storage sheet disclosed in International Publication No. 2015 / 098739 may be mentioned. In addition, as the heat storage sheet B, for example, the heat storage sheet disclosed in JP-A-2016-142056 may be mentioned.

[0040] The resin constituting the heat storage sheet C is, for example, a resin C1 in which a gelled inorganic latent heat storage material composition that does not separate into solid and liquid when heated to a melting temperature +25°C is dispersed in a reaction-curing liquid resin. Furthermore, when using the resin, it is preferable that the inorganic latent heat storage material composition contains calcium chloride hexahydrate, a melting point regulator, a supercooling inhibitor, and a gelling agent. Furthermore, it is preferable that the reaction-curing liquid resin is at least one selected from the group consisting of silicone-based resins, acrylic-based resins, polyisobutylene-based resins, urethane-based resins, and epoxy-based resins. Furthermore, it is preferable that the heat storage sheet C has a surface layer provided on the surface of the resin so as to be in contact with the resin at the interface between the outside air and the resin containing the latent heat storage material composition. As a result, the heat storage sheet C has low moisture absorption and excellent moisture resistance. Therefore, the heat storage sheet C has the advantage that the reduction in the heat storage effect as a latent heat storage material caused by the moisture absorption of the inorganic latent heat storage material composition is suppressed. Such resin C1 is disclosed, for example, in WO 2019 / 221006 and WO 2020 / 203749.

[0041] In addition, the resin constituting the heat storage sheet C is not limited to the resin C1. For example, the resin may be a resin C2 in which a specific functional group (such as an ester-based side chain) is introduced into a polyolefin-based resin. In the resin C2, the crystallization temperature of the resin C2 is controlled by the functional group introduced into the polyolefin-based resin, and a phase change from a crystalline state to a non-crystalline state or from a non-crystalline state to a crystalline state is caused at a specific temperature. Such a resin C2 is disclosed, for example, in International Publication No. 2018 / 021467. In addition, the heat storage sheet C made of the resin C2 is commercially available as a Passermo (registered trademark) sheet.

[0042] Among the heat storage sheets A to C, the latent heat storage material 5 is preferably the heat storage sheet C. The gate plate 20 is a portion that is easily subjected to impact force when loading and unloading luggage. From the viewpoint of preventing the latent heat storage material composition from leaking due to such impact force, the heat storage sheet C is preferably used as the latent heat storage material 5 because it is configured by forming a resin containing a latent heat storage material composition that has undergone a phase change at a specific temperature into a sheet shape as described above. Furthermore, since the heat storage sheet C has slipperiness, it is possible to prevent the gate plate body 10 from being scratched by friction with luggage. In the heat storage sheets A and B, a microencapsulated latent heat storage material is used as the latent heat storage material, so that when an impact force or the like is applied, the microcapsules may break and the filled latent heat storage material composition may leak out, and measures against this are required.

[0043] In addition, for example, in consideration of the solar radiation heat in summer and the thermal resistance value of the gate plate body 10, the phase change peak temperature of the latent heat storage material 5 is preferably 5°C to 35°C, and more preferably 25°C to 35°C. Here, the phase change peak temperature is intended to be the peak top temperature of the phase change peak in the DSC curve obtained when DSC measurement is performed. The phase change peak temperature includes the "freezing peak temperature" and the "melting peak temperature", and is preferably the "melting peak temperature".

[0044] The melting peak temperature or the freezing peak temperature of the latent heat storage material 5 is preferably a value measured by, for example, the following measurement method. That is, it is preferable to perform measurement using a differential scanning calorimeter (DSC) on the latent heat storage material composition constituting the latent heat storage material 5, and measure the change in the calorific value of the composition with a temperature increase or decrease, and to set the temperature at which a peak of the calorific value appears as the melting peak temperature or the freezing peak temperature, respectively. Specifically, the temperature of the peak in the melting behavior or the freezing behavior of the DSC curve measured by DSC is set as the melting peak temperature or the freezing peak temperature, respectively, and when there are multiple peaks, it is preferable to select the temperature of the peak having the largest peak area as the melting peak temperature or the freezing peak temperature. Here, the DSC curve measured by a differential scanning calorimeter (DSC) in this embodiment refers to a chart or spectrum obtained when DSC measurement is performed on the latent heat storage material composition at a heating rate of, for example, 2°C / min.

[0045] [Foam 2 (hereinafter, sometimes simply referred to as foam or secondary foamed molded product)] The foam 2 filled in the hollow portion of the hollow profile 1 is composed of a plurality of foamed particles 2a made of a thermoplastic resin fused to one another. The foamed particles 2a are formed by secondary expansion (heat foaming) of pre-expanded thermoplastic resin particles 2a'.

[0046] The pre-expanded thermoplastic resin particles 2a' used in the secondary expansion are obtained by heating expandable thermoplastic resin particles, which are thermoplastic resin particles impregnated with a foaming agent, at about 80°C to 105°C using water vapor (hereinafter, this operation may be referred to as "pre-expanding"). The average particle size of the pre-expanded thermoplastic resin particles 2a' is preferably 0.5 mm to 1.4 mm. If the average particle size is within this range, the filling property of the pre-expanded thermoplastic resin particles 2a' into the hollow shape 1 is good, and the pre-expanded thermoplastic resin particles 2a' are highly uniformly expandable by heating. As a result, the fusion property between the expanded particles 2a expanded by heating is good.

[0047] Here, in order to obtain good fusion between the expanded particles 2a, the pre-expanded thermoplastic resin particles 2a' are filled in the hollow portion of the hollow profile 1 and then heated and expanded, and the following (i) and (ii) are required: (i) It is necessary to heat and expand the particles at a relatively low heating temperature using a relatively simple drying furnace or heating furnace such as a dryer or oven, and (ii) It is necessary to prepare expandable thermoplastic resin particles suitable for maintaining the usage period (bead life) of the pre-expanded thermoplastic resin particles 2a'.

[0048] Therefore, the thermoplastic resin pre-expanded particles 2a' are not particularly limited as long as they satisfy the requirements of (i) and (ii), but the base resin constituting the thermoplastic resin pre-expanded particles 2a' (which can also be said to be the base resin constituting the expandable thermoplastic resin particles) preferably has a glass transition temperature (Tg) of 85° C. to 100° C., more preferably 90° C. to 100° C. Furthermore, the base resin is preferably a polystyrene-based resin.

[0049] When the glass transition temperature of the base resin exceeds 100°C, the equipment required for heating becomes large-scale, and heating using a simple heating furnace or drying furnace tends to be insufficient to heat and expand the thermoplastic resin pre-expanded particles 2a' within the hollow shape 1. On the other hand, in order to ensure heat resistance as a member constituting the bed of a truck or other freight vehicle, the glass transition temperature is preferably 85°C or higher.

[0050] The glass transition temperature of the base resin constituting the thermoplastic resin pre-expanded particles 2a' can be determined by the following method. Specifically, 1.0 g of a sample of the thermoplastic resin pre-expanded particles 2a' is placed in a 150-mesh wire mesh bag. Next, about 200 ml of xylene is placed in a 200 ml round flask, and the sample placed in the wire mesh bag is placed in a Soxhlet extraction tube. The sample is heated for 8 hours with a mantle heater to perform Soxhlet extraction.

[0051] Next, the extracted xylene solution is dropped into 600 ml of acetone, followed by decantation and evaporation to dryness under reduced pressure to obtain a thermoplastic resin (e.g., styrene-based resin) as an acetone-soluble portion. Heat flux differential scanning calorimetry is performed on 2 to 4 mg of the obtained thermoplastic resin based on JIS K7121 (1987). The midpoint glass transition temperature of the DSC curve obtained under the condition of a heating rate of 10°C / min can be taken as the glass transition temperature (Tg). As a measuring device, a 2010-type DSC measuring device manufactured by TA Instruments can be used.

[0052] The base resin constituting the thermoplastic resin pre-expanded particles 2a' is preferably a polystyrene resin made of an acrylic acid ester copolymer. The polystyrene resin is a copolymer of a styrene monomer and an acrylic acid ester monomer. That is, the base resin constituting the thermoplastic resin pre-expanded particles 2a' contains, as constituent units, a constituent unit derived from a styrene monomer and a constituent unit derived from an acrylic acid ester monomer.

[0053] Examples of the styrene monomer include styrene, α-methylstyrene, paramethylstyrene, t-butylstyrene, chlorostyrene, etc. These styrene monomers may be used alone or in combination of two or more.

[0054] Examples of the acrylic acid ester monomer include alkyl acrylates such as methyl acrylate and butyl acrylate. These acrylic acid ester monomers may be used alone or in combination of two or more. Among these, butyl acrylate is preferred because it is easily copolymerized with styrene monomers and has good moldability.

[0055] In addition, the base resin constituting the thermoplastic resin pre-expanded particles 2a' preferably contains 90% to 99% by weight of structural units derived from styrene monomers and 1% to 10% by weight of structural units derived from acrylic acid ester monomers (the total amount of structural units derived from styrene monomers and structural units derived from acrylic acid ester monomers is taken as 100% by weight). More preferably, the structural units derived from styrene monomers are 94% to 96% by weight, and the structural units derived from acrylic acid ester monomers are 4% to 6% by weight.

[0056] If the content of the acrylic ester monomer in the base resin exceeds 10% by weight, the foam 2 is more likely to shrink, particularly when highly expanded, and the appearance of the foam 2 tends to deteriorate. If the content of the acrylic ester monomer is less than 1% by weight, expansion at low temperatures tends to become difficult (the heating temperature required to obtain expanded beads 2a with the desired expansion ratio and the molding temperature required to obtain a foam 2 with excellent fusibility tend to increase).

[0057] The total amount of the solvent and plasticizer contained in the expandable thermoplastic resin particles before pre-expanding into the pre-expanded thermoplastic resin particles 2a' is less than 0.1 parts by weight per 100 parts by weight of the base resin. Note that the solvent referred to here is one having a boiling point of 50°C or higher, in order to distinguish it from the foaming agent.

[0058] Examples of the solvent include aliphatic hydrocarbons having 6 or more carbon atoms, such as hexane and heptane, and alicyclic hydrocarbons having 6 or more carbon atoms, such as cyclohexane and cyclooctane. Examples of the plasticizer include diisobutyl adipate, dioctyl adipate, dibutyl sebacate, glycerin tristearate, glycerin tricaprylate, coconut oil, palm oil, rapeseed oil, etc. These solvents and plasticizers soften the resin by their plasticizing effect when heated, and further vaporize and expand, thereby maintaining the internal pressure required for foam molding.

[0059] As for the solvents and plasticizers that do not vaporize during pre-foaming and heating, they either reduce the strength of the foam 2 or soften the resin, causing shrinkage, so it is preferable to limit their usage to 0.1% by weight or less.

[0060] The amount of unreacted monomer components contained in the expandable thermoplastic resin particles is less than 0.3% by weight. The unreacted monomer components tend to volatilize from the secondary foamed molded product (foamed product 2) obtained by expanding the pre-expanded thermoplastic resin particles 2a' in the hollow shape 1. In particular, when the amount of unreacted monomer components is 0.3% by weight or more, it is not preferable for use as automobile or building components. The amount of unreacted monomer components can be controlled by a combination of the amount of initiator used when polymerizing the thermoplastic resin particles and the polymerization temperature.

[0061] The expandable thermoplastic resin particles contain a foaming agent. The foaming agent is not particularly limited, but may be, for example, aliphatic hydrocarbons such as propane, butane, and pentane, alicyclic hydrocarbons such as cyclobutane and cyclopentane, and halogenated hydrocarbons such as methyl chloride, dichlorodifluoromethane, and dichlorotetrafluoroethane. These foaming agents may be used alone or in combination of two or more. Among these foaming agents, butane is essential because of its good foaming power.

[0062] In addition, when the blowing agent is butane, the blowing agent is preferably a butane composition containing normal butane and isobutane. When the total amount of the butane components in the butane composition is 100% by weight, the ratio of isobutane is preferably 35% by weight to 70% by weight, more preferably 40% by weight to 60% by weight. If the ratio of isobutane is less than 35% by weight, the normal butane dissipates during storage, reducing the total amount of the butane components, which tends to shorten the usage period of the blowing agent. If the ratio of isobutane is more than 70% by weight, it becomes difficult to fill the gaps between the particles of the secondary foamed molded product, which tends to impair the surface beauty.

[0063] The content of the butane composition foaming agent is preferably 3.0% by weight to 8.0% by weight, and more preferably 4.0% by weight to 6.0% by weight, when the expandable thermoplastic resin particles are taken as 100% by weight. If the foaming agent content is less than 3% by weight, the pre-expansion time tends to be longer and the fusion rate during secondary foam molding tends to be lower, which increases the production cost and is economically disadvantageous. If the foaming agent content exceeds 8% by weight, the secondary foam molded product tends to shrink and the appearance of the secondary foam molded product (foam 2) tends to be impaired.

[0064] The weight-average molecular weight Mw of the expandable thermoplastic resin particles is preferably 220,000 or more and 310,000 or less, more preferably 220,000 or more and 280,000 or less. If the weight-average molecular weight Mw is less than 220,000, not only will the strength of the secondary foamed molded product decrease, but the surface of the molded product will tend to melt easily, impairing the appearance. If the weight-average molecular weight Mw exceeds 310,000, the expandability of the expandable thermoplastic resin particles will decrease, and moldability will tend to deteriorate (the heating temperature required to obtain the expanded beads 2a with the desired expansion ratio, and the molding temperature required to obtain the foamed product 2 with excellent fusion adhesion will tend to increase).

[0065] The weight average molecular weight Mw can be controlled by a combination of the amount of initiator used and the polymerization temperature when polymerizing the thermoplastic resin particles. For example, the weight average molecular weight Mw can be reduced by increasing the amount of initiator used and / or increasing the polymerization temperature.

[0066] Here, when the expandable thermoplastic resin particles are expandable polystyrene-based resin particles, the weight average molecular weight Mw is a value measured under the following conditions using a gel permeation chromatograph (hereinafter sometimes abbreviated as "GPC").

[0067] 0.02g of the obtained expandable polystyrene resin particles was dissolved in 20ml of tetrahydrofuran (hereinafter sometimes abbreviated as "THF"), and then gel permeation chromatography (GPC) was used to perform GPC measurement under the following conditions to obtain a GPC measurement chart, weight average molecular weight (Mw) and number average molecular weight (Mn). The obtained values ​​are relative values ​​converted into polystyrene. Measurement equipment: Tosoh Corporation, high-speed GPC equipment HLC-8220 Columns used: Tosoh Corporation, SuperHZM-H x 2, SuperH-RC x 2 Column temperature: 40°C, mobile phase: THF (tetrahydrofuran) Flow rate: 0.35ml / min, injection volume: 10μl Detector: RI.

[0068] In addition, the expandable thermoplastic resin particles preferably have an average chord length of cells on a cut surface of a foam obtained from the expandable thermoplastic resin particles of 70 μm to 120 μm, more preferably 80 μm to 110 μm. If the average chord length is less than 70 μm, the membrane thickness of the cells constituting the foam tends to be thin, and internal fusion and surface properties tend to be reduced. If the average chord length exceeds 120 μm, the fracture displacement of the fracture strength (for example, bending strength of JIS A9511 and bottom split strength of box-shaped molded body) tends to be short, resulting in a brittle molded body.

[0069] The average chord length of the cells in the cross section of the foam can be controlled by the amount of nucleating agent: more nucleating agent will decrease the average chord length, and less nucleating agent will increase the average chord length.

[0070] Examples of the nucleating agent include methyl methacrylate copolymers, polyethylene wax, talc, fatty acid bisamides, ethylene-vinyl acetate copolymer resins, etc. Specific examples of fatty acid bisamides include methylene bisstearyl amide, ethylene bisstearyl amide, hexamethylene bispalmitic acid amide, ethylene bisoleic acid amide, etc.

[0071] In addition, the method for producing expandable thermoplastic resin particles can be a conventionally known method, and examples of the method include a method of impregnating a blowing agent into thermoplastic resin particles obtained by suspension polymerization in an aqueous medium, a method of impregnating a blowing agent into thermoplastic resin pellets produced by bulk polymerization or the like in an aqueous medium, and a method of melt-kneading a thermoplastic resin and a blowing agent using an extruder, and extruding the molten resin in an unfoamed state to form pellets.

[0072] When polymerizing the thermoplastic resin particles, additives that can be added include external additives, flame retardants, flame retardant auxiliaries, and the like, within the range that does not impair the effects of this embodiment.

[0073] As the flame retardant and flame retardant auxiliary, known and commonly used ones can be used.

[0074] Specific examples of the flame retardant include halogenated aliphatic hydrocarbon compounds such as hexabromocyclododecane, tetrabromobutane, and hexabromocyclohexane; brominated phenols such as tetrabromobisphenol A, tetrabromobisphenol F, and 2,4,6-tribromophenol; tetrabromobisphenol A-bis(2,3-dibromopropyl ether), tetrabromobisphenol A-bis(2,3-dibromo-2-methylpropyl ether), tetrabromobisphenol A-dibromopropyl ether, ... Examples of the flame retardant include glycidyl ether, brominated phenol derivatives such as 2,2-bis[4'(2",3"-dibromoalkoxy)-3',5'-dibromophenyl]-propane, brominated styrene-butadiene block copolymers, brominated random styrene-butadiene copolymers, and brominated styrene-butadiene graft copolymers, and other brominated butadiene-vinyl aromatic hydrocarbon copolymers (for example, EMERALD3000 manufactured by Chemtura and those disclosed in JP-T-2009-516019). These flame retardants may be used alone or in combination of two or more.

[0075] Specific examples of the flame retardant auxiliary include initiators such as cumene hydroperoxide, dicumyl peroxide, t-butyl hydroperoxide, and 2,3-dimethyl-2,3-diphenylbutane.

[0076] As the external additives and auxiliary substances, known and commonly used substances can be used.

[0077] Specific examples of the above-mentioned external additives and attachments include fatty acid triglycerides such as lauric acid triglyceride, stearic acid triglyceride, and linoleic acid triglyceride, fatty acid diglycerides such as lauric acid diglyceride, stearic acid diglyceride, and linoleic acid diglyceride, fatty acid monoglycerides such as lauric acid monoglyceride, stearic acid monoglyceride, and linoleic acid monoglyceride, fatty acid metal salts such as zinc stearate, calcium stearate, magnesium stearate, aluminum stearate, zinc laurate, and calcium laurate, and nonionic surfactants such as polyoxyethylene cetyl ether, polyoxyethylene oleyl ether, polyoxyethylene stearyl ether, polyoxyethylene laurate, polyoxyethylene palmitate, polyoxyethylene stearate, and polyoxyethylene oleate. These external additives and attachments may be used alone or in combination of two or more. In addition, these external additives and adhesives may be added to the aqueous composition containing the thermoplastic resin particles when the foaming agent is impregnated into the thermoplastic resin particles, or may be added to the particles after the aqueous composition is dehydrated or dried to coat them. The method of adding and coating the external additives and adhesives to the particles is not particularly limited, but is preferably a method of adding the external additives and adhesives after drying, and coating them by mixing and stirring.

[0078] As the thermoplastic resin pre-expanded particles 2a', polystyrene resin pre-expanded particles in particular are easily charged, and therefore there is a risk of ignition due to static electricity. In addition, when the polystyrene resin pre-expanded particles are filled into the hollow shape 1, the polystyrene resin pre-expanded particles stick to filling equipment and the like due to static electricity, which deteriorates handling (productivity). For this reason, it is desirable to apply an antistatic agent to the surface of the obtained expandable polystyrene resin particles so that the antistatic agent is present on the surface of the polystyrene resin pre-expanded particles.

[0079] Examples of the antistatic agent include commonly used 1-amino-2-hydroxy compounds such as N-hydroxyethyl-N-(2-hydroxyalkyl)amine, N,N-bis(hydroxyethyl)dodecylamine, and N,N-bis(hydroxyethyl)tetradecylamine, glycerin, fatty acid monoglycerides, polyoxyethylene alkyl ethers, and polyoxyethylene fatty acid esters. These may be used alone or in combination of two or more kinds.

[0080] Among these, N-hydroxyethyl-N-(2-hydroxyalkyl)amine is the most preferable as an antistatic agent because it has the best antistatic performance. In particular, when magnesium stearate is added, polystyrene resin pre-expanded particles tend to become charged, so the use of N-hydroxyethyl-N-(2-hydroxyalkyl)amine makes it possible to prevent charging.

[0081] A preferred method for applying the antistatic agent is to stir the expandable polystyrene resin particles together with the antistatic agent in a stirrer, such as a Nauta mixer, a super mixer, a universal mixer, a tumbler mixer, or a Loedige mixer.

[0082] In addition, in order to further improve the flowability of the expandable thermoplastic resin particles, a flow promoter can be added to the expandable thermoplastic resin particles. As a method for adding the flow promoter, it is preferable to stir the expandable thermoplastic resin particles together with the flow promoter and the antistatic agent in a stirrer. In addition, as the stirrer, a Nauta mixer, a super mixer, a universal mixer, a tumbler mixer, a Redige mixer, etc. can be used.

[0083] The flow promoter is not particularly limited, but zinc stearate can be used. The amount of zinc stearate added to the expandable thermoplastic resin particles is preferably 0.5 to 1.2 parts by weight per 100 parts by weight of the expandable thermoplastic resin particles. If the amount of zinc stearate added is less than 0.5 parts by weight, the flowability of the expandable thermoplastic resin particles is insufficient, and the expandable thermoplastic resin particles are likely to bond together during the secondary expansion operation. If the amount of zinc stearate added exceeds 1.2 parts by weight, the amount of zinc stearate remaining on the expandable thermoplastic resin particles exceeds 1.0 part by weight. Therefore, the zinc stearate is likely to peel off from the expandable thermoplastic resin particles during air transportation, which causes blockage of the pipe.

[0084] As other glidants, metal salts of fatty acids such as magnesium stearate, calcium stearate, aluminum stearate, zinc laurate, calcium laurate, etc. may be used in combination with zinc stearate.

[0085] (Pre-foamed) The pre-expanded thermoplastic resin particles 2a' used in this production method are obtained by pre-expanding expandable thermoplastic resin particles. The obtained pre-expanded thermoplastic resin particles 2a' are filled into a hollow shape 1 and heated and expanded in a heating furnace, a dryer, or the like, to become a foam 2 as a secondary foam.

[0086] The pre-expanding method for the expandable thermoplastic resin particles can be a conventional method, for example, using a cylindrical pre-expanding device and heating with steam or the like to cause expansion.

[0087] The foaming temperature (temperature inside the can) during pre-expansion is appropriately adjusted by the blown steam pressure and the amount of air, but is usually about 101 to 105° C. In the production of the pre-expanded thermoplastic resin particles used in the present production method, pre-expansion is possible even if the foaming temperature during pre-expansion is a temperature of 100° C. or less, for example, a low temperature of about 97 to 100° C.

[0088] As a method for heating and foaming the thermoplastic resin pre-expanded particles 2a' within the hollow profile 1, a conventional method such as the so-called in-mold foaming method can be used, in which the thermoplastic resin pre-expanded particles 2a' are filled into the hollow profile 1, and the foam 2 is obtained by blowing in steam or the like and heating it.

[0089] For example, the foam 2 is obtained by the following procedure. First, the hollow portion of the hollow shape material 1 is filled with thermoplastic resin pre-expanded particles 2a' (filling step). Then, using a heating device such as an oven or a drying furnace, hot air is blown into the hollow shape material 1 filled with the thermoplastic resin pre-expanded particles 2a' to heat and expand the thermoplastic resin pre-expanded particles 2a' (secondary expansion) (expanding step). Through these steps, the thermal insulating foam 2 formed by filling the hollow portion of the hollow shape material 1 can be obtained.

[0090] The pre-expanded thermoplastic resin particles 2a' can be expanded even at a low processing temperature (heating temperature for secondary expansion) in the expansion step of 100° C. to 130° C. Therefore, according to this production method, a heat insulating foam for gate boards can be obtained in a more energy-saving and simple manner.

[0091] 〔track〕 The truck according to the present embodiment will be described. The truck according to the present embodiment is equipped with a storage shed equipped with the above-mentioned truck tailgate 20. Fig. 4 is a cross-sectional view showing a schematic configuration of the storage shed 30 provided in the truck according to the present embodiment.

[0092] As shown in Fig. 4, in the storage cabinet 30, the gate board 20 is configured such that the gate board body 10 and the latent heat storage material 5 are arranged in this order from the outside to the inside of the storage cabinet 30. In other words, the gate board 20 is configured such that the latent heat storage material 5 is arranged on the inside of the storage cabinet with respect to the gate board body 10. The latent heat storage material 5 is bonded to the gate board body 10 via an adhesive layer 6. This makes it possible to maintain the temperature inside the storage cabinet 30 at a desired temperature.

[0093] The storage 30 also includes a ceiling component 31, a gate plate 20, and a sidewall upper component 32. The ceiling component 31 is a component that constitutes the ceiling of the storage 30. The gate plate 20 constitutes the lower part of the sidewall of the storage 30. The sidewall upper component 32 constitutes the upper part of the sidewall of the storage 30. That is, the sidewall upper component 32 is disposed above the gate plate 20, and constitutes the sidewall of the storage 30 together with the gate plate 20. In the storage 30, a latent heat storage material 5 is disposed on the interior surfaces of both the ceiling component 31 and the sidewall upper component 32. The latent heat storage material 5 is bonded to the interior surfaces of both the ceiling component 31 and the sidewall upper component 32 via an adhesive layer 6. This makes it possible to maintain the temperature inside the storage 30 at a desired temperature even more. In addition, the latent heat storage material 5 only needs to be arranged on the inside surface of at least one of the ceiling component 31 and the side wall upper component 32, and may be arranged on only one surface of the ceiling component 31 and the side wall upper component 32.

[0094] The ceiling constituent part 31 and the side wall upper constituent part 32 are configured to be filled with foam 2A. Since the foam 2A is filled in this way, the insulation performance of the ceiling constituent part 31 and the side wall upper constituent part 32 is excellent. The configuration of the ceiling constituent part 31 or the side wall upper constituent part 32 is appropriately set according to the insulation performance required in the storage room, and is not limited to the configuration filled with the foam 2A. The ceiling constituent part 31 or the side wall upper constituent part 32 may not have the foam 2A. The foam 2A is preferably an extruded foam board, and among such extruded foam boards, a polystyrene resin extruded foam board is particularly preferable. In addition, the foam 2A filled in the side wall upper constituent part 32 may be, in addition to the above extruded foam board, a foam made of expandable thermoplastic resin particles. The expandable thermoplastic resin particles used for the foam 2A are preferably the same expandable thermoplastic resin particles as those of the gate board 20, that is, the thermoplastic resin pre-expanded particles 2a'.

[0095] The storage shed 30 of the truck according to the present embodiment is preferably a so-called wing body. In general, the rear wall of such a wing body has a door structure that opens to the left and right. The left and right side walls have lower portions that are gate plates 20, and the gate plates 20 are opened outward around a pivot shaft that extends from the lower end in the front-rear direction and can be deployed to hang down. Furthermore, the side wall upper portion constituent parts 32 that constitute the upper parts of each of the left and right side walls are wing parts that are continuous with the ceiling constituent part 31. The wing body has wing parts for each of the left and right side walls. These two wing parts open upward around a pivot shaft that extends in the front-rear direction through the center of the width direction of the ceiling constituent part 31 and are raised like bird wings, so that the storage shed 30 can be opened to both the left and right sides.

[0096] From the viewpoint of maintaining the temperature inside the storage compartment 30, it is more preferable that the latent heat storage material 5 is also disposed on the side walls of the storage compartment 30 in the front and rear directions. [Explanation of symbols]

[0097] 1 Hollow profile 2. Foam 2a Foam particles 2a' Thermoplastic resin pre-expanded particles 5 Latent heat storage material 6 Adhesive layer (double-sided foam tape) 10. Gate board body 30 Storage 31 Ceiling components 32 Upper side wall component

Claims

1. The gate board itself, A latent heat storage material, The latent heat storage material is disposed on at least one surface of the gate body of the gate for trucks.

2. The truck tailgate according to claim 1, wherein the phase change peak temperature of the latent heat storage material is 5°C to 35°C.

3. The truck gate plate according to claim 1 , wherein the latent heat storage material is in a sheet form.

4. The gate plate body is Aluminum hollow profile, The tailgate for a truck according to claim 1 , further comprising a foam filled in the hollow member.

5. The truck tailgate according to claim 4, wherein the foam is made by foaming pre-expanded thermoplastic resin particles.

6. 2. The gate plate for trucks according to claim 1, wherein the latent heat storage material is adhered to one surface of the gate plate body by a foam double-sided tape.

7. A storage facility having a side panel for a truck according to any one of claims 1 to 6, The truck has the gate plate body and the latent heat storage material arranged in this order from the outside to the inside of the storage shed.

8. The storage facility includes: A ceiling component, a side wall upper portion constituting portion disposed above the gate plate and constituting a side wall together with the gate plate; The truck according to claim 7 , wherein the latent heat storage material is disposed on an inner surface of at least one of the ceiling component and the side wall upper component.

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