JP2009061973A - Core material of panel for truck cargo compartment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a core material of a panel for a truck cargo compartment having light weight and sufficient shock resistance, the panel for the truck cargo compartment using the core material, and a door for the truck cargo compartment. <P>SOLUTION: This core material 1 includes at least a pair of base materials 2 formed by thermally fusing tips of projecting parts with each other of hollow projection body sheets in which hollow conically-shaped projecting parts having opened bottom sides are regularly and projectingly provided in abutting states in a thermoplastic resin sheet. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a core material for a truck cargo compartment panel that is excellent in light weight, water resistance, and heat retention and suitable for a truck cargo compartment wall or door.

In order to ensure rigidity while reducing weight, truck cargo compartment panels are made of plywood, aluminum or other honeycomb materials (metal cores), resin foam materials, etc., as core materials or bonded materials, with metal, FRP, In addition, a panel in which a plate material such as plastic is bonded as a surface plate is known.
However, when using plywood, it is generally flat and cannot be used for curved parts, etc. Also, it cannot be reduced to a plywood density of 0.7 to 1.9 g / cm ³ or less, and it has been used for many years. In addition, when used in a high humidity atmosphere, there are drawbacks such as a problem of moisture resistance.

On the other hand, in the case of using a honeycomb core (metal core) such as aluminum as the core material, the adhesive flows down to the lower surface plate side through the opening of the honeycomb core when the surface plates are bonded together, and partially On the other hand, there is a problem of balance of strength and weight, such as the fact that fillet (fillet) is not formed on the joint surface of the surface plate and the honeycomb core on the upper surface plate side, but the strength is insufficient on the upper surface plate side. .
In Patent Document 1, in order to solve the problem of this type of honeycomb core material, a restriction absorbing film material is disposed on the opening end face of the honeycomb core, and then a liquid thermosetting resin is adhered and impregnated on the fiber base material. , The composite fiber reinforced plastic layer is disposed on the opening end face of the honeycomb core through the regulation absorbing film material, and then the honeycomb core and the fiber reinforced plastic layer are bonded with the resin, and the whole Molded into a predetermined shape. However, the method described in Patent Document 1 is a case where the surface plate (surface plate) is a fiber-reinforced plastic layer and is difficult to apply to a metal plate or a plastic plate.

Patent Document 2 discloses a foam core composite plate used for trailer walls and doors.
However, in the foamed composite board described in Patent Document 2, the resin amount of the core material is reduced by up to 50% compared to the conventional composite board. Inadequate in terms.
As described above, the conventional core material for a truck cargo compartment panel has a problem that the foamed resin plate does not have sufficient lightness as a panel.

JP 2003-205559 A JP-T-2001-514115

  The present invention has been made in order to solve the problems in the core material of a conventional truck cargo compartment panel, and the object thereof is a core material of the truck cargo compartment panel that is lightweight and has sufficient impact resistance. Another object of the present invention is to provide a truck cargo compartment panel and a truck cargo compartment door using the core material.

As a result of diligent research to solve the above-described problems of the prior art, the present inventors have found that at least one set of base materials composed of two thermoplastic resin hollow projection sheets on the core of the truck cargo compartment panel. The base material used is one that is heat-sealed in a state in which the convex ends of the hollow projection sheet with the hollow frustum-shaped convex portions that are open on the bottom side are regularly projected. It has been found that the above problem can be solved by doing so.
That is, the present invention
(1) A core material for a truck cargo compartment panel, wherein the core material includes at least one set of base materials composed of two thermoplastic resin hollow projection sheets, and the base material is a hollow having an open bottom. A core material, characterized in that the frustum-shaped convex portion is heat-sealed in a state in which the convex portion tips of the hollow protrusion sheet are regularly projected,
(2) The core material according to (1), wherein two sets of the base materials are laminated,
(3) The core material according to (1) or (2), wherein a thermoplastic resin surface material is thermally fused to the bottom opening side of the hollow protrusion sheet of the base material,
(4) The hollow frustum-shaped convex part of the hollow projection sheet in the base material is a hollow frustoconical convex part having a lower bottom diameter of 5 to 7 mm, an upper bottom diameter of 1.5 to 4 mm, and a height of 3 to 6 mm. In the above (1) to (3), the center interval between adjacent frustoconical protrusions is 6 to 10 mm, the sheet thickness is 0.3 to 0.7 mm, and the taper angle of the frustoconical protrusions is 60 to 80 degrees. The core material according to any one of the above,
(5) The core according to any one of (1) to (4), wherein the plane compression strength is 300 to 5000 kN / m ² according to a plate compression test at a load speed of 10 mm / min in accordance with JIS Z 0403-1. Material,
(6) The core material according to any one of (1) to (5), wherein the base material is made of a polyolefin-based thermoplastic resin having a flexural modulus of 800 to 1400 MPa.
(7) A truck cargo compartment panel comprising a core plate according to any one of (1) to (6) laminated with a surface plate, and (8) a truck cargo according to (7) Truck freight compartment doors, using room panels,
Is to provide.

  The core material of the truck cargo compartment panel of the present invention is light in weight because it has a hollow frustum-like convex space, but on the opening side of the frustum there is a liner on the seat base, so It is easy to bond a sheet material or the like by heat fusion or an adhesive. Therefore, if a surface plate is laminated | stacked on this, the panel which has a light weight and rigidity is obtained, and it can utilize suitably as a truck cargo compartment or its door.

The core material of the truck cargo compartment panel according to the present invention includes at least one set of base materials composed of two thermoplastic resin hollow projection sheets, and the base material has a hollow frustum-shaped convex portion having an open bottom. Is characterized in that it is heat-sealed in a state where the projections of the hollow projection sheet regularly projected are in contact with each other.
The truck cargo compartment in the present invention is a floor panel based on a frame formed of a metal frame material on a truck body chassis, a box-like frame is arranged on the floor panel, and the panel is bonded to this. Box-shaped with doors on the rear or side, or a gate frame mounted on the floor panel, and the center of the front and rear portal frames are connected by a center beam, and the left and right side walls and ceiling of the cargo compartment It means a so-called wing-structured cargo compartment or the like that can be turned by flipping up the portion.
In the present invention, it is said that it includes at least one set of base materials that are heat-sealed in a state in which the projections of the hollow protrusion sheet are butted together, and this is generally the rigidity and heat insulation required for panel materials. This is because the thickness of the core material of the present invention can be changed by increasing / decreasing the number of sets of base materials in accordance with the demands for different panel thicknesses depending on the properties and applications.
More specifically, the core material of the truck cargo compartment panel of the present invention was heat-sealed in a state in which the hollow frustum-shaped convex portions regularly projected on the thermoplastic resin sheet faced each other. It is an intermediate of a hollow structure plate that can be manufactured by the method for manufacturing a hollow structure plate disclosed in the pamphlet of WO2003 / 080326 by the applicant and is commercially available under the trade name of Twin Cone.
In the present invention, the hollow frustum shape means a hollow frustum shape or a hollow frustum shape, and any of these may be used, but from the viewpoint of locking force by a screw, a hollow frustum shape is more preferable. .
Hereinafter, embodiments of a core material for a truck cargo compartment panel according to the present invention will be specifically described with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing an embodiment of a core material for a truck cargo compartment panel according to the present invention.

  The core material 1 of the truck cargo compartment panel shown in FIG. 1 has both surfaces of a base material 2 constituted by bonding the vertices of the convex portions of two hollow projection sheets 2a, 2b made of thermoplastic resin sheets together by fusion bonding. The surface materials 3a and 3b made of thermoplastic resin are bonded together.

The material of the hollow protrusion sheet is not particularly limited. For example, polyolefin resins such as low-density polyethylene, high-density polyethylene, linear low-density polyethylene, homopolypropylene, random polypropylene, block-type polypropylene, and their comonomers or copolymers of comonomers with other monomers, polyvinyl chloride , Chlorinated polyvinyl chloride, ABS, AAS, AES, polystyrene, polyethylene terephthalate, polycarbonate, polyamide, polyvinylidene fluoride, polyphenylene sulfide, polysulfone, polyether ketone and copolymers of these comonomers or comonomers with other monomers, etc. These may be used alone or in combination. As described above, various thermoplastic resins can be used, but considering the balance with characteristics such as cost, moldability, physical properties, low temperature resistance, heat resistance during transportation, polypropylene resin is preferable, When self-extinguishing properties are required, a polycarbonate resin is preferable.
In the case of a polypropylene-based resin, a core material using a polyolefin-based thermoplastic resin having a flexural modulus of 800 to 1400 MPa as a base material is preferable from the viewpoint of physical properties.
For the purpose of increasing the rigidity of the hollow projection sheet 2, a filler may be blended as an auxiliary material.
The auxiliary material is not particularly limited, but talc, calcium carbonate, and the like are preferable in consideration of the balance with cost, formability, handleability, and the like. Increasing the amount of filler added leads to high cost and specific gravity. Therefore, considering these balances, the amount added is about 5% by mass for talc and about 20% by mass for calcium carbonate based on the total weight. The following is preferable.
In addition to the filler, an antioxidant, an ultraviolet absorber, an antistatic agent, an antibacterial agent, a flame retardant, a light stabilizer, a lubricant and the like may be added as necessary.

The hollow projection sheet constituting the core material of the truck cargo compartment panel of the present invention will be described in more detail.
The hollow protrusion sheet 2a shown in FIG. 2 (a) has a hollow truncated cone shape in which a plurality of convex portions 13 are regularly provided on one surface of the hollow protrusion sheet base surface and the lower bottom side is open. In this embodiment, the protrusions 13 are provided in a row at predetermined intervals along the longitudinal direction of the main body portion 12 to form the protrusion rows 14, and the protrusion rows 14 are formed as hollow protrusions. A plurality of rows are provided at predetermined intervals in the width direction of the body sheet base surface 12. The shape of the convex portion may be a hollow truncated pyramid shape (not shown). In the following, description will be made by using a hollow frustoconical convex portion.

Each convex portion 13 has a hollow shape having a concave portion 15 opened on the other surface (lower surface) of the hollow projection sheet base surface 12, that is, the lower bottom side, on the inner surface side, and the outer peripheral surface extends from the tip to the root. Each convex part 13 is formed in the same shape and magnitude | size, and it is formed in the truncated cone shape of the taper surface where a diameter increases gradually.
Each recess 15 is formed in a conical space having a tapered surface whose inner surface gradually increases in diameter from the tip (deepest part) to the root (opening end). Each recess 15 is formed in the same shape and size.

The taper angle θ of each convex portion 13 and the taper angle θ [shown in FIG. 2 (b)] of each concave inner surface 15 is in the range of 46 to 80 °, more preferably in the range of 60 to 75 °. When the taper angle is less than 60 °, the pressure resistance as a core material is insufficient. Further, when the taper angle is set to 75 ° or more, there arises a manufacturing inconvenience that it is difficult to remove the molding pin.
Moreover, the lower bottom part diameter of each convex part 13 is 4-16 mm, the upper bottom part diameter is 1.5-4 mm, the pitch between the convex parts 14, 14 of each convex part row 4 is 6-10 mm, the adjacent convex part row 13, The pitch between 13 is 6 to 10 mm, and the height of the convex portion is 3 to 13 mm. When the pitch between the adjacent convex rows 14 and 14 and 13 and 13 is 6 mm or less, the weight of the hollow protrusion sheet increases and the cost is increased, or when the pitch is 10 mm or more, the pressure resistance tends to be insufficient. If the height of the convex portion is 3 to 13 mm, the hollow projection sheet of the core material has pressure resistance, and the rigidity of the panel can be secured.

  As for the thickness of the main-body part 12, 0.3-1 mm is preferable. If the thickness of the main body 12 is less than 0.3 mm, when the plurality of convex portions 13 are formed by molding with a molding machine, the convex portions 13 cannot obtain sufficient rigidity. The pressure resistance of the core material as a hollow protrusion sheet is insufficient.

  The core material of the truck cargo compartment panel of the present invention is formed by simultaneously molding the two hollow projection sheets 2a and 2b, heat-sealing the convex portion 13, and further heat-sealing the surface material if necessary. Although manufactured, the hollow protrusion sheet 2a, 2b may be combined with different dimensions and different materials. However, when flatness is required as the core material of the truck cargo compartment panel, if two hollow projection sheets of the same size or the same material are used, the neutral axis in the thickness direction is used. It is preferable because it becomes symmetrical and warping is less likely to occur.

From the viewpoint of securing the rigidity of the truck cargo compartment panel, the core material of the truck cargo compartment panel of the present invention has a plane compression strength of 300 according to a flat plate compression test at a load speed of 10 mm / min in accordance with JIS Z 0403-1. A sheet that is ˜3000 kN / m ² can be used.
When the plane compressive strength is in the range of 300 to 3000 kN / m ² , it has rigidity as a core material of a normal truck cargo compartment panel.

In order to use such a core material for a truck cargo compartment panel, it is particularly preferable to use an intermediate of a twin cone (manufactured by Ube Nitto Kasei Co., Ltd.) having the following specifications as the hollow projection sheet of the base material. it can.
Structure of the sheet on one side of the substrate (material) Polypropylene resin (projection shape) hollow frustum, (arrangement) houndstooth (tip diameter) φ2 mm, (base diameter) φ6 mm
(Lead center distance E) 8 mm, (projection peak height) 4 mm
(Sheet thickness) [Sheet part] 0.75 mm
[Thinnest part at or near the protrusion] 0.45 mm
(Ratio of the shortest distance between the base parts to the shortest distance between the tip parts) Distance C: Distance D = 3: 1
(Plane compression strength) Approx. 1700kN / m ²
(Weight) 750 g / m ²

Substrate structure (thickness) 10 mm
(Weight) 1500 g / m ²

On the other hand, the core material of the truck cargo compartment panel of the present invention can be a panel by using only the base material as a core material and laminating a surface plate on the core material, but the surface made of a thermoplastic resin on the bottom opening side. When the core material 1 is formed by heat-sealing the material, it is easy to apply the adhesive when laminating with the surface plate, and the adhesive does not hang down in the hollow portion. It is preferable in terms of ease and reduction of the amount of adhesive used.
That is, the surface material 3 made of a thermoplastic resin surface material to be bonded to both surfaces of the substrate 1 is preferably heat-sealed using a thermoplastic resin that is compatible with the substrate.
In general, a polyolefin resin is used for the hollow protrusion sheets 2a and 2b, and the same kind of polyolefin resin or adhesive polyolefin resin is used for the surface material 3.

  For the surface plate, trucks such as metals such as steel, stainless steel, aluminum, various thermoplastic resin plate materials, fiber reinforced thermosetting resin plate materials (FRP plates), fiber reinforced thermoplastic resin plate materials (FRTP plates), etc. The board material currently used as an outer board of a cargo compartment panel for a car is mentioned. In order to bond these plate material and core material, an adhesive or a method may be selected, and these may be laminated in combination.

In addition, when using the thermoplastic resin plate material for the surface plate 4, the thermoplastic resin plate material of the surface plate is supplied while extruding the thermoplastic resin surface material as the molten surface material on both surfaces of the base material. The method of pressure melting and bonding is preferable because the panel can be continuously formed.
Even in this case, it is preferable to use a resin having compatibility between the thermoplastic resin of the surface material 3 and the thermoplastic resin of the surface plate 4.
Further, a hot melt adhesive layer may be interposed on the adhesive surface for easy adhesion, and it may be used in combination with heat fusion, or may be bonded using an adhesive.
The thermoplastic resin surface plate 4 may be melt extruded into a continuous plate shape and laminated on both sides of the core material.
In the melt extrusion, for example, a thermoplastic resin as a surface plate material is formed as an upper layer, and a thermoplastic resin as a surface material is co-extruded as a lower layer. You may heat-seal with an opening side.

  The present invention also provides a truck cargo compartment door using the aforementioned truck cargo compartment panel. The truck cargo compartment door may be configured by inserting a panel into a door frame of a predetermined size, and can be reduced in weight as compared with a door made of a conventional composite panel.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention, this invention is not limited to these Examples at all.

Example 1
A masterbatch (Takehara Chemical Industry Co., Ltd.) with 90% by mass of polypropylene resin (made of prime polymer, E601, polypropylene block copolymer, MI = 0.5 g / 10 min, flexural modulus of 1300 Mpa) as thermoplastic resin and 70% by mass of talc. The main raw material was 10% by mass of a filler manufactured by Max 2070T) and dry blended.
The raw material is supplied to two melt extruders arranged in parallel, extruded from each T die in the form of a molten resin sheet having a width of 1360 mm and a thickness of 1.0 mm, and a pair of upper and lower members arranged rotatably in a vacuum chamber. A large number of hollow protrusions regularly arranged on the resin sheet in accordance with the pin shape protruding from the embossing roller by vacuum-adsorbing the molten resin sheet to each peripheral surface of the embossing roller and rotating the embossing roller A sheet-like material was obtained, and at the tangential position of both embossing rollers, the tip portion of the hollow protrusion sheet was heat-sealed and integrated to obtain a base material having a basis weight of 1000 g / m ² . In addition, the obtained base material has a base-cone protrusion in a hollow frustum shape, the protrusions are arranged in a staggered pattern, the tip of the hollow frustum is φ2 mm, the base diameter is φ6 mm, and the tip center distance Is 8 mm, the height of the truncated cone is 4 mm, the thickness of the sheet portion is 0.75 mm, the thinnest part at or near the protrusion is 0.45 mm, and the shortest distance between the bases with respect to the shortest distance between the protrusion tip parts is The ratio is 3: 1.
Further, on both the front and back surfaces of the base material, the same polypropylene polymer manufactured by Prime Polymer Co., Ltd. was extruded into a sheet shape, and a polypropylene resin sheet having a surface material thickness of 0.5 mm and a basis weight of 500 g / m 2 was obtained by heat-sealing. A core material for a truck cargo compartment panel having an overall thickness of 10 mm and a weight per unit area of 2000 g / m ² was obtained by bonding to the front and back surfaces of the base material.

Example 2
Two sets of 0.7 mm thick white PVC plates were prepared as two sets of the core material obtained in Example 1 and the surface plate 16, and laminated under pressure using a urethane-based adhesive, as shown in FIG. Thus, a truck cargo compartment panel 20 having two sets of core materials 1 and 1 ′ in the middle was obtained. The obtained panel has a total thickness of 20.3 mm and a basis weight of 4.2 kg / m ² (apparent density 0.21), compared with the conventional composite plywood panel (thickness 20 mm, apparent density 1.8). And achieved a significant weight reduction.
The panel thus obtained was subjected to an impact resistance test (falling ball impact test based on exterior decorative hardboard test). As a result, a dent having a diameter of 23 mm and a depth of 0.29 mm was generated as an average value in the four test pieces, but no cracks or peeling occurred on the surface of all the test pieces. It was confirmed that this had substantially the same impact resistance performance as compared with the test result of a conventional composite plywood panel (a dent having a diameter of 17 mm and a depth of 0.28 mm).
In addition, a wear resistance test (wear A test, flooring test based on Japanese Agricultural Standards) was conducted. As a result, an average weight loss of 0.050 g occurred in the three test pieces, but the surface material remained after 500 revolutions of Taber wear in all the test pieces, and the base material did not appear. It was. Compared with the test result (wear loss 0.047 g) of the conventional composite plywood panel, it was confirmed that this had almost the same wear resistance.

  The core material of the truck cargo compartment panel of the present invention is light in weight because it has a hollow frustum-like convex space, but on the opening side of the frustum there is a liner on the seat base, so It is easy to adhere sheet materials, etc. by heat fusion or adhesives, and if a surface plate is laminated on this, a lightweight, impact-resistant and wear-resistant panel can be obtained, which is suitable as a truck cargo compartment and its door Available to:

It is a fragmentary sectional view of the core material of the truck cargo compartment panel in the embodiment of the present invention. The structure of an example of the hollow protrusion sheet | seat which has a hollow truncated cone-shaped convex part which comprises a core material is shown, (a) Upper surface side perspective view, (b) The longitudinal cross-sectional view which shows the structure of a convex part, (c) Lower surface side It is a perspective view. It is a longitudinal cross-sectional explanatory drawing of the panel for truck cargo compartments of Example 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1 'Core material 2a, 2b Hollow protrusion sheet | seat 2 Base material 3a, 3b Surface material 12 Hollow protrusion sheet | seat base surface 13 The hollow frustum-shaped convex part (convex part) which the bottom bottom side opened
14 convex row 15 opening 16 surface plate (outer plate)
20 Truck cargo compartment panel

Claims (8)

  A core material for a truck cargo compartment panel, the core material including at least one set of base materials made of two thermoplastic resin hollow projection sheets, the base material having a hollow frustum shape having an open bottom side A core material, characterized in that it is heat-sealed in a state in which the protrusion tips of the hollow protrusion sheet with the protrusions regularly protruded.   The core material according to claim 1, wherein two sets of the base materials are laminated.   The core material according to claim 1 or 2, wherein a thermoplastic resin surface material is heat-sealed to the bottom opening side of the hollow projection sheet of the base material.   The hollow frustum-shaped convex part of the hollow protrusion sheet in the base material is a hollow frustoconical convex part, and has a bottom base diameter of 5 to 7 mm, a top base diameter of 1.5 to 4 mm, and a height of 3 to 6 mm. The core according to any one of claims 1 to 3, wherein the center interval of the frustoconical protrusions is 6 to 10 mm, the sheet thickness is 0.3 to 0.7 mm, and the taper angle of the frustoconical protrusions is 60 to 80 degrees. Wood. The core material according to any one of claims 1 to 4, which has a plane compressive strength of 300 to 5000 kN / m ² according to a flat plate compression test at a load speed of 10 mm / min in accordance with JIS Z 0403-1.   The core material according to any one of claims 1 to 5, wherein the base material is made of a polyolefin-based thermoplastic resin having a flexural modulus of 800 to 1400 MPa.   A truck cargo compartment panel comprising a core plate according to any one of claims 1 to 6 and a surface plate laminated thereon.   A truck cargo compartment door using the truck cargo compartment panel according to claim 7.

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