JP2001010629A - container - Google Patents

Abstract

(57) [Problem] To provide a container excellent in lightweight and airtightness in addition to the features of a conventional thermoplastic resin container. SOLUTION: The wall member of the container made of a thermoplastic resin is provided with a window for the purpose of weight reduction, and the container is provided with a thin portion made of a sheet having a thickness of 0.5 mm or less at the window opening.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a container having light weight and a function of preventing liquid leakage, and a container used for transporting or storing articles having excellent heat insulation.

[0002]

2. Description of the Related Art At present, containers, pallets and the like for improving the efficiency of transportation of articles are widely used, especially paper, wooden, metal, thermoplastic resin and the like as small-sized transport or storage containers. Various containers are used. Among containers made of these materials, thermoplastic resin containers are becoming mainstream from the viewpoints of moldability, durability, and lightness. However, depending on the type of the stored items, the specific gravity is often low due to the low specific gravity or the bulkiness.In transporting and storing such items, the weight of the container is often heavier than the weight of the stored item. In addition, further weight reduction has been desired after securing. Therefore, for these purposes, lightweight containers have been proposed and distributed in the market by making the container wall members into a colander or lattice shape, but the injection molding pressure is considerable when making such fine-grained molded products. They need to be high, which not only requires extra energy but also hinders productivity. Furthermore, this shape is unsuitable as a container for articles that require heat insulation, dust proofing or liquid leakage preventing function, hermeticity such as waterproofing, and the like, and its improvement has been demanded.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and provides a container which is excellent in lightness and airtightness in addition to the features of a conventional thermoplastic resin container. The purpose is to do.

[0004]

According to the present invention, a wall surface member of a container made of a thermoplastic resin is provided with a window for the purpose of weight reduction, and a thin-walled member made of a sheet having a thickness of 0.5 mm or less is provided in the window-opened portion. The above objectives have been achieved by developing a container with parts. That is, the present invention
[1] A wall member of a container made of a thermoplastic resin has a window, and a thickness of 0.5 m is provided inside the window.
m, a container provided with a thin portion made of a sheet of m or less,

[2] The container according to the above [1], wherein the sheet of the thin portion is tightly integrated with the wall member, [3] Affixed to the window-opening portion during injection molding in the manufacture of the container. [1] The container according to [1] or [2] above, wherein the sheet to be adhered to the window-opening portion is a thermoplastic resin at least at the surface layer. Any one of the above-mentioned [1] to [4], wherein the container according to any one of [1] to [3], and [5] a heat insulating material is laminated on the entire inner surface of the wall member in which the sheet to be adhered to the window opening portion is tightly integrated. The above-mentioned problem has been solved by developing a heat insulating container described in Crab.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The contents of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an overall view showing an example of the container of the present invention. Typical examples of the thermoplastic resin used for the wall member 1 include polyethylene and polypropylene. However, the thermoplastic resin is not particularly limited as long as it can be molded in general and satisfies required characteristics as a product. May be single or a mixture. In addition, additives such as antioxidants, heat stabilizers and light stabilizers, fillers (eg, mica, talc, glass, organic fibers, carbon), flame retardants, coloring which are generally used in the synthetic resin field. You may add a pigment etc. and use it as a composite material.

The method for producing the container is not particularly limited. For example, the container can be produced by injection molding, hollow molding, sheet molding or the like used in the production of conventional containers. The wall member 1 of the container according to the present invention is provided with a window for the purpose of weight reduction as far as required strength is allowed. The shape of the window can be freely selected, but usually a rectangular shape with rounded corners is preferable in consideration of the flow of the resin. The size at that time depends on the area of the wall member, but if the size is 500 mm x 700 mm or less, it is usually about 2 to 30 pieces. However, the shape of the stored articles (with or without sharp points), hardness, etc. According to about 10 pieces
It is preferable to keep it at about 0 cm ² or less.

The porosity of the windowed portion 2 is determined by the shape of the stored article (the presence or absence of a pointed portion), the apparent specific gravity, the type of the resin material of the container, the amount of the reinforcing filler such as glass fiber, the wall member, and the like. It is affected by many factors, such as the thickness of the container, the size of the container, and the presence or absence of reinforcing ribs, and cannot be quantified.
%, Particularly preferably 40 to 70%. If it is less than 20%, the contribution to weight reduction is small, and if it exceeds 80%, the strength becomes insufficient, which is not preferable. In consideration of stacking, etc. as a container, in order to maintain the strength and shape of the container, it is necessary to provide a pillar portion 3 rather than one large window, that is, a plurality of small windows. preferable.

The window-opening portion 2 of the wall surface member 1 in the container of the present invention has a thickness of about 500 μm or less, depending on the size of the window, for the purpose of providing a sealing property and a function of preventing liquid leakage. And depending on the apparent specific gravity,
There is provided a thin part 4 made of a sheet thicker than a micron, preferably thicker than 200 microns. Thin part 4
May be a thin and integrally formed wall member 1 (this is also referred to as a "sheet" in the present invention), and a bag-shaped sheet molded article having the same shape as the container is adhered to the inner surface of the container. Or a sheet separate from the container with the sheet adhered to the inner surface of the windowed portion 2 of the container. These sheets are all integrated with the wall member 1, and the sheet and the wall member 1 are tightly integrated by an adhesive, a pressure-sensitive adhesive, heat welding, integral molding or the like.

The method of integrating the sheet with the wall member 1 may be any method, and is not particularly limited. For example, after the sheet is inserted in a mold in advance, the wall member 1 is formed by injection molding. Examples include a so-called insert injection molding method for molding, and a bonding method using a so-called dry laminating adhesive in which an adhesive is applied to the wall member 1 of a preformed container and then the sheets are bonded and laminated. The sheet of the thin portion 4 is not particularly limited, but preferably has a large tear strength and is transparent, and when performing the above-mentioned heat welding or integral molding, at least the surface layer on the close contact side is preferably a thermoplastic resin. preferable. As the material resin of the sheet, considering the recyclability at the time of disposal, the same resin as the container, for example, a container in which a sheet made of a biaxially stretched polypropylene sheet or the like is adhered to a polypropylene container is suitable. The sheet can be obtained by inflation molding, T-die molding, lamination molding, etc., which are commonly used in molding of synthetic resins.

When the container of the present invention is required to have a heat retaining performance or a cold retaining property, for example, as shown in FIG. 2, a heat insulating material 5 is incorporated inside the wall member 1 in which the sheet of the thin portion 4 is integrated. . The heat insulating material 5 may be simply inserted and fixed, but may be tightly integrated with the inner surface of the wall member by an adhesive, a pressure-sensitive adhesive, heat welding, integral molding or the like. The type of the heat insulating material 5 is not particularly limited, and examples thereof include foams, paper, and wood made of a thermoplastic resin. A foam made of a thermoplastic resin that is the same material as the wall surface member is preferable. Since the thickness of the heat insulating material is determined by the heat insulating property required of the container, a fixed value cannot be shown, but is generally 5 to 40 m.
A material having a thickness of about m is used.

When a thermoplastic resin foam board is used as a heat insulating material, the thickness of the foam board is usually 0.05 to 0.05 mm in order to increase the surface strength of the foam board (the strength of the surface serving as the inner surface of the container).
A surface coating of a non-foaming layer or a very low foaming layer of 0.5 mm is provided, and the surface in contact with the inner layer and the container is formed from a foam layer which is foamed ten times or more and which is usually used for a heat insulating container. Is preferred. The total thickness should be at least 1 as in the case of a normal insulated container due to the need for insulation.
It is preferable to set it to 0 mm or more. The method for producing the foam board may be any method and is not limited. For example, the thickness is 10 to 20 times larger than the required thickness.
To obtain a foam board with a surface strength that can be used repeatedly, by creating a board with a required foaming degree of mm thick and applying heat from hot air or a hot plate to this surface to form a required surface layer Can be. Alternatively, a surface layer may be formed by spraying a solvent of a thermoplastic resin.

[0013] Further, a lid for the container of the present invention, which is required for a structure requiring a structure capable of closing the inside of the container, is required. It is preferable to provide a thin portion made of a sheet in this portion. When a heat insulating material is incorporated in the container, it is preferable to similarly integrate the heat insulating material into the lid member.

[0014]

The container of the present invention has a function of preventing liquid leakage and is excellent in lightness, and is a container for transporting and storing articles having a low specific gravity or bulk and a small apparent specific gravity. It is useful for storing and transporting articles and the like that easily leak. In addition, by using a lid member and incorporating a heat insulating material on the inner surface of the container, the container can be used as a container for keeping heat or a container for keeping cold, and can be used as a container for transporting stored articles requiring heat insulation.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a container of the present invention.

FIG. 2 is a perspective view of a container in which a heat insulating material is disposed inside the container shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wall member 2 Window part 3 Pillar part 4 Thin part 5 Heat insulation material

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Junji Yotsuyanagi 3-2 Chidori-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Showa Denko KK Research Institute Chidori- indoor F-term (reference) 3E033 AA09 BA13 BA15 BA16 BB04 BB05 BB08 CA08 DA08 DD01 DE04 FA02 3E061 AA02 AB16 AD07 BB12 DB01 DB06 3E067 BA05A BB14A BC06A CA18 EE18

Claims (5)

[Claims] 1. A container characterized in that a wall member of a container made of a thermoplastic resin has a window, and a thin portion made of a sheet having a thickness of 0.5 mm or less is provided inside the window. 2. The container according to claim 1, wherein the sheet of the thin portion is tightly integrated with the wall member. 3. The container according to claim 1, wherein a sheet to be stuck to the window-opening portion is insert-molded and tightly integrated at the time of injection molding for producing the container. 4. The method according to claim 1, wherein at least the surface layer of the sheet to be attached to the window-opening portion is a thermoplastic resin.
A container according to any one of the preceding claims. 5. A heat insulating material is laminated on the entire inner surface of a wall member in which a sheet to be adhered to a window-opening portion is tightly integrated.
The heat-insulating container according to any one of Items 4 to 4.