JP2008023741A - Corrugated cardboard and pallet for transportation using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide corrugated cardboard which is light in weight, can be produced by a simple process, prevents a load from falling down even in a humid environment, has durability, is biodegraded with the passage of time when dumped under the ground, is environment-friendly, and is excellent in dumping properties and a pallet for transportation using the corrugated cardboard. <P>SOLUTION: A sheet in which at least both surfaces are water resistant and formed from a biodegradable resin is used as a core sheet constituting the corrugated cardboard. The corrugated cardboard is used as a main structural material used in the ceiling plate, bottom plate, beam bridge, legs, etc., of the pallet for transportation. Preferably, a harmful insect repellent is added into the structural material of the corrugated cardboard or sprayed on the corrugated card or the surface of the pallet for transportation. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a corrugated cardboard and a transport pallet using the same, and more particularly to a corrugated cardboard having excellent water resistance and disposal properties and a transport pallet using the same.

  Conventionally, as a pallet for transportation, a wooden pallet in which a wooden board is nailed to a wooden square material with a nail is widely used because of easy availability and production. However, wooden pallets are not welcome because of their heavy weight and the tendency of bacteria and insects to propagate due to the characteristics of the materials. There are characteristics. As an alternative, an inexpensive plastic, particularly a recycled plastic, is used, and a lightweight and high-strength plastic pallet has been proposed by devising a molding structure. However, the pallet for transportation is originally transported with goods to be transported such as goods, but after unloading the goods, it is possible to take it home if it is a short distance, but in the case of a long distance, especially to take home from abroad, It is too costly and procedural. For this reason, the pallet for transportation is left at the site where the package is transported. In this case, the pallet for transportation is reused as needed, but the excess is discarded.

However, since plastic pallets are generally excellent in durability, they are extremely troublesome objects for disposal. From such a point of view, a pallet for transportation using corrugated cardboard as a material that can be incinerated and easily corroded if buried in the ground has been proposed. In this case, the cardboard is made of paper and the structure includes a hollow part, so it is lightweight and easy to handle. There has been proposed a pallet for transport that is improved in strength by combining the contrivance and the orientation and structure of the corrugated board surface during assembly as a pallet for transport (Patent Documents 1, 2, and 3).

By the way, corrugated cardboard generally refers to a composite sheet that is reinforced by attaching a liner sheet via an adhesive to the wave ridge of a core sheet that is bent into a corrugated shape. Single-sided cardboard with a liner sheet attached to only one side of the core sheet, double-sided cardboard with liner sheets attached to both sides of the corrugated core sheet, and [Liner sheet / corrugated core sheet / Multilayer double-sided corrugated cardboard having a plurality of sheet layers such as liner sheet / corrugated core sheet / liner sheet] is generally used. Corrugated cardboard has a remarkable direction of strength. The thickness direction seen from the liner sheet surface side is easy to be crushed by pressure. Of the directions perpendicular to the thickness direction (horizontal direction), the wave of the core sheet The ridge direction (hereinafter referred to as the longitudinal direction) has a relatively large resistance to pressure. Of the horizontal direction, the direction perpendicular to the longitudinal direction is easy to bend due to the force. It is easy to form into a three-dimensional structure such as a cylindrical shape or a rectangular tube shape.

The transport pallet using the cardboard as described above has no particular problem when the package is loaded in a normal dry state or for a relatively short period of time. If loading continues in an environment, the corrugated cardboard may lose its shape due to moisture absorption, and in extreme cases, the piles of stacked luggage may collapse. As a method for solving such problems of poor water resistance or poor moisture resistance, for example, a pallet for transport using corn starch paste using water-resistant paper and adhering a modified ketone resin as a water resistance-imparting additive for their adhesion (Refer patent document 4) and the conveyance pallet (refer patent document 5) using the corrugated board which pinched | interposed the water-resistant plastic film and improved water resistance is proposed. Since the transport pallet proposed in Patent Document 4 uses water-resistant paper, when the landfill is disposed of after disposal, the residue finally causes the remaining ground to be contaminated. In addition, the transport pallet described in Patent Document 5 is a non-corrosive plastic film used for improving water resistance as in the case of the transport pallet described in Patent Document 4 above. Causes soil contamination without semi-permanent decomposition.

Japanese Patent Laid-Open No. 11-348888 JP 09-309532 A JP 09-193934 A JP 2003-191357 A Japanese Patent Laid-Open No. 06-315997

In view of the above problems, the present invention provides a transport pallet that is lightweight, water-resistant, has a pest repellent effect, and has excellent disposal properties that do not pollute the environment even if buried in the ground after disposal. provide.

The first gist of the present invention resides in a corrugated cardboard characterized in that at least both surfaces thereof are made of a water-resistant and biodegradable resin as a core sheet constituting the corrugated cardboard. And the 2nd summary of this invention exists in the pallet for conveyance characterized by using the cardboard as described in any one of Claim 1 to 4 as main structural material.

Since the corrugated cardboard of the present invention is composed of a sheet composed of a water-resistant and biodegradable resin on at least both surfaces of the core sheet constituting the corrugated board, even if it is stored for a long time in a humid environment, There is virtually no moisture absorption, and even after disposal, the plastic resin and paper material part decomposes over time even if buried in the ground. Yes. Therefore, the transport pallet made using this corrugated cardboard is lightweight and moisture-resistant, so it will not lose its shape even if it is stored for a long time in a humid environment with the load loaded. Mountains with many layers of piles will not collapse, have excellent safety, stably hold the cargo to be transported, and if it becomes unnecessary and is buried in the ground and disposed of, Because it is disassembled and returned to the soil, it is an environmentally friendly pallet for transportation. In addition, when pest repellent is included in the material constituting the cardboard or the surface layer of the cardboard, the pest will not settle or propagate when used as cardboard or as a pallet for transportation. I can do it.

The corrugated cardboard of the present invention is configured by attaching a liner sheet via an adhesive to a wave ridge portion of a specific core sheet bent into a corrugated shape.

The above core sheet is composed of at least both surfaces made of water-resistant and biodegradable resin. Such a core sheet may be a resin sheet made of a water-resistant and biodegradable resin over the entire thickness, or a film made of a water-resistant and biodegradable resin on both surfaces of the base material. It may be formed by coating with a coating layer. The thickness of the core sheet is appropriately determined according to the use application of the corrugated cardboard, but is usually about 100 μm to 3 mm.
In the present invention, the terms sheet and film are mixed. Although the two are not essentially different, the sheet is mainly used when it has a thickness or waist that can be used as a structure by itself, and the film is thin and other substrates are used. Used in the case of being used by being laminated on materials. However, in the case of a citation from a cited document, it is displayed as described in the cited document.

The resin film manufactured with a water-resistant and biodegradable resin over the entire thickness is not particularly limited as long as it is water-resistant and biodegradable. A melt-extruded film of a biodegradable aliphatic polyester described in Japanese Patent No. 3333, a biodegradable plastic film described in Japanese Patent Laid-Open No. 7-195646, and a bio-degradable plastic film described in Japanese Patent Laid-Open No. 7-62220 A film obtained by using a biodegradable resin composition obtained by mixing 20 to 80 parts by weight of degradable plastics and 80 to 20 parts by weight of a crosslinked polyalkylene oxide, described in JP-A-8-73722 A multilayer film made of a biodegradable plastic, a film obtained by using a biodegradable resin composition described in JP-A-6-299077, The film and laminate having biodegradability described in JP-A-7-188432, a film obtained using the biodegradable polymer composition described in JP-A-8-193168, JP-A-11- The film etc. which are obtained using the modified starch composition for biodegradable plastic article manufacture described in 335401 gazette can be mentioned.

In addition, as both the surfaces of the core sheet are coated with a resin layer made of a water-resistant and biodegradable resin, a film made of a water-resistant and biodegradable resin is formed on both surfaces of the base sheet. A laminate or a water-resistant and biodegradable resin solution is applied to both sides of a base sheet and dried. Such substrate sheet, but may be a known paper material, for example, the strength and stiffness of strength, typically 50 to 500 g / ^{m 2,} practical basis weight 100 to 400 / m ² is A preferred example is paper called kraft paper or a derivative thereof. These may be single gloss bleached crafts or double bleached crafts.

As a film used for the above-mentioned coating, a film having a small thickness, for example, 1 to 500 μm, practically 5 to 100 μm, is used among the above-mentioned water-resistant and biodegradable resin films. I can do it. As a method for laminating such a thin film on the surface of the base sheet, a known method can be applied. However, as a laminating adhesive, a water-resistant and biodegradable resin as a main ingredient is preferable.

As the water-resistant and biodegradable resin for coating that is applied to the surface of the base sheet and dried, the resin constituting the resin film produced with the water-resistant and biodegradable resin or a composition thereof is used. In addition, for example, 3-hydroxybutyrate-3-hydroxyvalerate copolymer, 3-hydroxyalkanoate copolymer polyester, 3-hydroxybutyrate-4-hydroxybutyrate copolymer 3-hydroxybutyrate-3-hydroxyvalerate-5-hydroxyvalerate copolymer. Specific examples of these products include biodegradable plastics (trade name, Bionore; manufactured by Showa Polymer Co., Ltd.). Examples of biodegradable microbial polysaccharides include dextran, xanthan gum, pullulan, curdlan, cellulose, and hyaluronic acid.

As the liner sheet, a known liner sheet can be used, but preferably, at least one surface, more preferably, both surfaces are coated with a water-resistant and biodegradable resin. If both sides are coated and the printed surface or information display property (hereinafter simply abbreviated as printability) of the coated surface is insufficient, a printed label can be attached or printed Can be further applied or laminated to improve display properties.

The corrugated cardboard of the present invention has a core sheet made of the above water-resistant and biodegradable plastic film, a core sheet coated with a resin film made of a thin water-resistant and biodegradable resin, or the surface is water-resistant. And it can manufacture by folding the sheet | seat for cores with which biodegradable resin was apply | coated to a wave shape, and sticking the sheet | seat for liners via the adhesive agent on the wave | root ridge part of the sheet | seat for cores. A known corrugated board manufacturing method can be applied to the manufacturing method. At this time, the corrugated pitch and the wave height of the core sheet disposed in a corrugated manner can be appropriately determined according to the target characteristics. For example, the pitch is 5 to 20 mm, and the wave height is The length is about 1 to 10 mm.

Further, the adhesive used for bonding the ridge portion of the core sheet and the liner sheet is not particularly limited, but the adhesive is also preferably biodegradable, water-resistant and biodegradable resin. It is more preferable to use a material containing as a main component. Examples of such biodegradable adhesives include those obtained by adding a tackifier to a polymer elastic material that gives cohesion as a main component. Examples of the polymer elastic material that gives the cohesive force include natural rubber and resin produced by microorganisms, and these natural materials have biodegradability because they have impurities and unsaturated bonds in the material. Examples of the tackifier include natural polymers such as rosin and terpene, and biodegradation is promoted by an enzyme produced by a microorganism.

When a natural rubber adhesive is used, the elastomeric property may be reinforced by vulcanization, but this vulcanization is preferably vulcanized to such an extent that biodegradability is not impaired. The natural rubber-based pressure-sensitive adhesive may contain a plasticizer, but it is preferable to use a plasticizer having a low molecular weight as much as possible in order to maintain biodegradability.

The structure of the corrugated cardboard obtained as described above can be a known structure such as single-sided cardboard, single-sided cardboard, two-layer double-sided cardboard, and three-layer double-sided cardboard so as to have the required strength and thickness. In the case of multilayer cardboard, the pitch and wave height of each layer are arbitrary, and may be the same or all different. If necessary, a plurality of cardboards obtained as described above can be joined and used.

The conveyance pallet of the present invention is manufactured using the above-mentioned cardboard. As the structure of such a transport pallet, for example, (1) transport of a basic shape that can be said to be a so-called stepping plate in which two or three rectangular bar-shaped girder bridges in which thin corrugated cardboards are laminated on the bottom surface of a flat corrugated cardboard is attached. (2) a paper pallet (Japanese Patent Laid-Open No. 6-171649) fixed with a paper tube made of corrugated cardboard between an upper top plate and a lower bottom plate, and (3) a lower corrugated cardboard A predetermined number of paper tubes of a predetermined height are fixed at predetermined positions so that the upper board corrugated board and the lower board corrugated board are held in parallel with a certain interval between the upper board cardboard and the upper board cardboard and the lower board cardboard. It is a reinforcing pallet in which an auxiliary material having a width close to the predetermined height is inserted into a space formed between board cardboards and fixed with needles or nails from above and below (Japanese Patent Laid-Open No. 7-17543), (4) Flat made of cardboard sheet A corrugated cardboard structure is formed by a V-shaped continuous corrugated digit portion disposed on the lower surface of the deck board portion, and each top of the corrugated digit portion is connected to the deck board portion. Corrugated cardboard pallet constructed by contacting the lower surface (Japanese Patent Laid-Open No. 8-133287), (5) a bottom plate, a leg mounted on the bottom plate and fixed to the bottom plate by an adhesive, and on the leg In the transporting pallet made of corrugated cardboard made of a top plate fixed to the leg by a mounting adhesive, the top plate is composed of at least three layers of plates that are foldably connected to each other, and the connecting portion of the plates A pallet for transportation (Japanese Patent Laid-Open No. 9-221134) having a narrow plate portion for bending, and (6) a top deck and a bottom deck of rectangular paperboard having a required width facing each other, Equally spaced It consists of a girder that is bonded and supported on both the upper and lower sides, and a top deck, a bottom deck, and a U-shaped pad that is backed by the upper and both sides of the space formed between the girder. Is a cylinder-shaped sleeve body formed by bending a corrugated paperboard at a right angle to its longitudinal line to form a rectangular cross section of a predetermined length, and the corrugated paperboard is folded in a bellows shape with its vertical line up and down. And a U-shaped pad is a corrugated pallet (Japanese Patent Laid-Open No. 9-309532) constructed by bending corrugated paperboard at right angles to its longitudinal eye. Gazette), (7) A plurality of paper tube storages having a bottom wall and left and right vertical walls raised from the left and right by folding a series of sheet materials such as interleaving paper and corrugated paper into a mountain and a valley. And the left vertical wall and right of the adjacent paper tube storage unit A continuous section connecting between the vertical walls is formed, and each paper tube storage portion stores a square paper tube with its axial direction substantially horizontal, and the left vertical position of the paper tube storage portion located at the left end of the pallet. From each of the wall and the right vertical wall of the paper tube storage section located at the right end of the pallet, a lateral support wall is extended upward, and these papers are placed on the paper tubes stored in each paper tube storage section. Examples thereof include a transfer pallet (Japanese Patent Laid-Open No. 11-11480) in which a top paper tube is arranged in a direction crossing the tube.

As described above, as the leg member for connecting the girders provided under the top plate and the top plate and the bottom plate, the cardboard of the present invention is cut to a predetermined width so as to have a required thickness. It can be obtained by joining and laminating a plurality of sheets, and the cardboard of the present invention, if necessary, on one side as a leg member for joining the girders provided under the top board or the top board and the bottom board. It is also possible to use a prismatic or round bar shape that is peeled off from the liner sheet and wound into a cylindrical shape.

The above-mentioned corrugated cardboard and the parts of the transport pallets that use it that do not use water-resistant and biodegradable resin are usually made of a sheet of paper material, and microorganisms and insects are generally easy to breed. In order to suppress the growth of these microorganisms and insects, it is necessary to disinfect or disinfect these paper materials, resins, adhesives, etc. However, it is preferable to use environmentally friendly chemicals in order to avoid environmental pollution after disposal. Such environmentally friendly agents are not disinfectants or insecticides that kill microorganisms and insects, but components that prevent microorganisms and insects from approaching the above cardboard and transport pallets, which may be the result, but suppress growth. Preference is given to the use of ingredients, for example, pest repellents. As such an unpleasant pest repellent, a commercial product “trade name, Salutchu” (released by Oji Tsusho Co., Ltd.) composed of 100% natural plant extract is exemplified. Since such a drug has a finite lifetime, additional use by spraying the drug or the like is preferable whenever the use period is long.

The present invention relates to a corrugated cardboard in which at least both surfaces of the corrugated cardboard are made of a water-resistant and biodegradable resin, and the corrugated cardboard is a main constituent material. As the surface of the core sheet for corrugated cardboard is water-resistant and composed of a biodegradable material as a whole including the liner sheet, it is used as corrugated cardboard. The transport pallet used as the main component material is lightweight, has a simple manufacturing process, and is not crushed over time due to the load of the load loaded on it even under high humidity conditions, When it is no longer needed, it is biodegraded by being buried in the ground, so it can be safely disposed of without polluting the environment. Therefore, the industrial utilization effect is great.

Claims (5)

A corrugated cardboard, wherein a sheet comprising at least both surfaces made of a water-resistant and biodegradable resin is used as a core sheet constituting the corrugated cardboard.
The corrugated board according to claim 1, wherein the core sheet is a resin sheet made of a water-resistant and biodegradable resin over the entire thickness.
The corrugated cardboard according to claim 1, wherein the core sheet is formed by coating both surfaces of a base material with a water-resistant and biodegradable resin.
4. The corrugated cardboard according to any one of claims 1 to 3, wherein the corrugated cardboard material or the surface layer of the corrugated cardboard contains a pest repellent.
A cardboard according to any one of claims 1 to 4 is used as a main structural material.