JP2003118051A - Plastic foamed composite - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that a foamed material has excellent heat insulating properties but absorbs water upon the contact with water to be lowered in its heat insulating properties and, if pressure is applied to the foamed material, the foamed material is deformed to become thin and increased in its density to be lowered in heat insulating properties. SOLUTION: A plastic box absorbing no moisture is demarcated by reinforcing members combined so as to become parallel and right-angled to side surfaces and respective chambers surrounded by the reinforcing members are closely filled with the foamed material and a lid is welded to the box to form the composite. This composite does not generate the lowering of heat insulating properties due to water absorption and, since the foamed material is prevented from becoming thin by compression and not increased in density, it is extremely good as a heat insulating material and can be used over a long period of time. Further, this composite is preferable as a cushioning material, a shock absorber, a floating material or the like.

Description

Detailed Description of the Invention

Plastic foams are widely used in large quantities over a wide range because they are excellent in heat insulating properties and cushioning properties, lightweight and inexpensive. On the other hand, the foamed body has such characteristics, but it has a drawback that it absorbs moisture to lower the heat insulating property, has low strength and is easily deformed. The present invention has a minimum thickness of 1.5 mm with a thickness of 3 mm or more.
A low density plastic foam is placed in the above polyolefin box-like body to prevent moisture absorption and improve strength. Also, a combination of reinforcing plates in parallel and right angles may be put in a box and a foam may be put in each chamber surrounded by the reinforcing plate for use, and this composite has excellent strength.
It has been used for many years as a heat insulating material, shock absorbing material, cushioning material, levitating material, etc. [Technical Field of the Invention]

Heat insulating materials, heat insulating containers, shock absorbing materials, cushioning materials, levitation materials [prior art]

[0003] The heat storage air-conditioning technology is capable of using cheap nighttime electric power, and therefore its applications are expanding year by year. This technology creates a large amount of ice water at night and stores it for use during daytime cooling. This pool of ice water uses foamed plastic on the bottom, walls, and ceiling to insulate it and to prevent it from absorbing moisture on it. Since this pool will be used for a long period of time, water will reach the foamed plastic through the waterproof sheet, and the foamed plastic will absorb water and the heat insulation will deteriorate.
Further, even if the overlapping portions and corners of the waterproof sheet are not completely waterproof even if they are adhered, water also invades from here and absorbs the foamed plastic. Foamed plastics that are thirty times foamed are used as the best insulation. This foam is a polyhedral cell, and the thickness of the cell membrane is several microns, and the center of each surface is particularly thin, so that water is thought to pass through the membrane.

This pool usually has a depth of about 3 m, and the foam attached near the bottom of the pool is subject to a water pressure of 0.3 atm. Since a foam is usually made of a thin film of thermoplastic resin and air bubbles, cold flow occurs even if a slight pressure continues for a long time, and the thickness of the foam deforms and becomes thin. And this decrease in thickness leads to an increase in the density of the foam, which reduces the heat insulation.

In the case of a heat-insulating container, for example, a polystyrene container is molded and covered with polystyrene foam before use. Polystyrene foam is a good insulator and easily
There is no problem in using this as a heat insulating material, since a molded body of 0 times can be obtained. However, if the plastic foam is used as it is, it absorbs moisture in the air and the heat insulating property deteriorates. Since this decrease is remarkable in a high humidity place and in a condition where it is exposed to rain, use of the foam as it is should be avoided. Further, since the bubbles of the plastic foam are stretched, the weather resistance is poor, and it deteriorates when exposed to ultraviolet rays, and the foam itself cannot withstand sufficient use. And stainless steel containers are heavy and expensive. [Problems to be Solved by the Invention]

The present invention prevents the plastic foam from absorbing water and is not subjected to pressure, and prevents deterioration of heat insulation.
It is also used for many years by putting it in a box so that it will not be directly irradiated with ultraviolet rays. The method of using this foamed plastic was conceived as a heat insulating material, but since such a molded body is lightweight, inexpensive, strong and elastic, it can also be used as a cushioning material, shock absorbing material, levitation material, etc. , Can be widely put to practical use. [Embodiment of the Invention]

The present invention is completely impermeable to water 3
A low-density closed-cell plastic foam with low thermal conductivity is placed and sealed in a polyolefin box having a thickness of at least mm and a minimum thickness of at least 1.5 mm. Polyolefin is a polymer that does not absorb moisture, and if this polymer is made into a box with a thickness of 3 mm or more and a minimum thickness of 1.5 mm or more, water will not enter even if it is placed in water for many years. Moreover, this polymer is easy to melt-bond the lid and the box and is easy to reuse after use. Therefore, even if this heat insulating material is used for decades, it does not absorb moisture to lower the heat insulating property. The box of the present invention is provided with a reinforcing plate assembled parallel to the side surface and at a right angle, and a foam is put in a space surrounded by the reinforcing body so that the reinforcing body receives pressure. Therefore, the foam does not become thin and the density does not increase, so that the heat insulating property does not decrease. And it can be used even if the water depth is deeper than 3 m. Further, the foam of the present invention is used in a box and is not deteriorated by ultraviolet rays. Next, examples of the present invention will be described. [Example 1]

A cross-sectional view of a heat insulating material using the reinforcing body of the present invention is shown in FIG. (1) of FIG. 1 is a high-density polyethylene box having a thickness of 3 mm and a minimum thickness of 1.5 mm, which is impermeable to water. Inner method is 1000 × 1000 × 50mm
Is. (2) is a lid, and after putting the contents with the same thickness and the same material as in (1), put it on the box-like body and weld it to prevent water from entering. (3) is a foam of uniform fine cells of crosslinked polyethylene, having a density of 0.03 g / cm ³ and a thickness of 50 mm.
Then, make a slightly larger product and compress it to make no gap. This foam is uniform fine bubbles, has excellent heat insulation properties, does not deform over time, and does not deteriorate due to moisture absorption. (4) is a reinforcing plate which is a foam plate three times as thick as polypropylene, which has heat insulating properties and strength.
330x330x50m combined by making a 25x5mm incision at 330 and 660mm points of m length
Make 9 chambers of m. Since the reinforcing body is used in parallel with the sides at right angles, it is in contact with the upper and lower plates without a gap and makes a right angle, so it is strong and has the same height as the thickness of the foam, so the foam deforms even if pressure is applied to the box. Do not let The combined parts, edges, and top and bottom of the reinforcement are bonded to the box. This heat insulating plate is attached to the bottom, wall, and ceiling of the pool with an adhesive, and the upper part is pressed down with an iron plate or the like when necessary. Put plastic foam between the boxes to prevent water from passing.
The foam in this heat insulating plate does not absorb water, and it does not deform and become thin and its density does not increase, so there is no deterioration in heat insulating property and once used it can be used for many years. It is possible. [Example 2]

An example of the heat insulating container of the present invention is shown in FIG.
(5) in FIG. 2 is a plastic outer box made of LL polyethylene, which has good weather resistance by using carbon black, an ultraviolet absorber, an antioxidant and the like. Thickness is 10 mm
And the minimum thickness is 5 mm. (6) is an inner box with the same material and thickness as (5), and the inner method is 1700 x 1700 x 17
The internal volume is 4.9 M ³ at 00 mm. The plate on the side surface of the inner box is inclined by 3% so that the molded product can be easily removed from the mold during molding, and r is set at each corner. The upper part is bent at a right angle and becomes long, and after the heat insulating material is put in, the tip is joined to the outer box. (8) is a foam having a density of 0.03 g / cm ³ and a thickness of 50 mm. The reinforcing body (7) has a height of 50 mm and a width of 10 mm, and is a polypropylene triple foam. These have the same structure as the inside except the box in Fig. 1 and 1700 x
The area of 1700 mm is divided into 16 parts, and a reinforcing body is also attached to the surrounding area to make it strong and put between the inner and outer boxes. (9) It is a metal fitting to prevent the container from swelling and deforming due to water pressure. And there should be a reinforcing plate at the metal fittings. The bottom plate of the outer box is provided with 30 × 10 mm convex portions (10) in the shape of a cross, and the reinforcing body of the heat insulating material on the bottom rides on this so that the bottom surface does not come into direct contact with the ground. Since the heat insulating material on the bottom surface is under pressure, an area of 1700 x 1700 mm is 25
It is divided into parts. When water is put into this heat-insulating container, the outer box, the inner box and the heat insulating material are united by the pressure, and the molded product is excellent in durability because it is pressed by the clasps. And since the foam does not absorb moisture, the thickness does not decrease, the density does not increase due to pressure, and it does not deteriorate due to ultraviolet rays, so it can be used for many years as a heat-insulating container for energy saving. Is. This heat-insulating container is lightweight, can be placed anywhere, has good heat insulation, weather resistance and impact resistance.

The box of the present invention may have a thickness of 3 mm or more of water-impermeable polyolefin and a minimum thickness of 1.5 mm or more, and may be reinforced with glass fiber or the like. Preferred are crosslinked LDPE, LLDPE or HDPE. Further, in order to improve the heat insulating property, a foam may be used, but the expansion ratio of this foam is 4 times or less for spherical cells. And because it is a polyolefin, it is easy to reuse. The box and lid are joined by fusion or adhesive,
In the melt-bonding, the entire surface can be melted, or a joint such as a soldering iron can be used to compress the joint to form a recess, and then the melted resin can be filled or water-expandable rubber can be wound. The foam of the present invention is a plastic foam and has a foaming ratio of 15 times or more, preferably 30 from the viewpoint of heat insulation.
It is double. In the present invention, it is preferable that the cells are uniform and fine closed cells, and it is preferable that the cells do not have a thick material at the ridges and vertices of the cells and have a uniform thickness. From these points, a cross-linked polyethylene foam is particularly preferable. The reinforcing body of the present invention may be a plate-shaped material that is lightweight, has strength, and does not absorb moisture. Preferred is a plastic foam having a spherical shape and having an elasticity of 1.5 to 5 times, and a polypropylene foam is particularly preferred from the viewpoint of strength. The reinforcing body is used by making a notch in the plate and combining them in parallel at right angles. When making a 50 mm heat insulating plate, use a reinforcing body with a height of 50 mm, but this plate has a length of 25 m.
Make a notch with the width of m and the thickness of the reinforcement body, and combine them vertically at the top and bottom. The thickness of the reinforcement is usually 5 to 30 mm. The combination of the reinforcements is strong because all the reinforcements have the same height and receive the pressure evenly throughout. The metal fitting of the present invention is an iron plate having a thickness of 2 to 5 mm.
The width is 10 to 50 mm and it is fixed by screwing. This clasp is attached to the place where there is a reinforcement to make the composite strong.
It is also possible to make an open box-like body with an iron angle instead of the squeezing metal fittings and put a heat insulating box in it.

It is preferable that the box, the reinforcing member and the foam are adhered to be integrated with each other, but in the present invention, they are naturally integrated with each other by hydraulic pressure, and therefore they may not be adhered. In the present invention, since the side surface of the box has a taper, a small gap is formed between the outer box and the inner box at the top and bottom. Fill the gaps with foam so that there are no gaps. In the present invention, when the pool is shallow and the water pressure is low, a reinforcing body is not used, and a polystyrene foam having high compressive strength is used. It is sufficient to put the foam in a box when the water pressure is low. A plastic foam sheet can be attached to the surface of the heat insulating plate or the heat insulating container of the present invention for use. Although the foamed sheet absorbs moisture in water and its heat insulating property is deteriorated, the heat insulating property is still left, so that the heat insulating property is improved. Preferred are closed cell foams having a thickness of 5 to 20 mm. The composite of the present invention comprises a skin, a foam and a reinforcement, and is a good heat insulating material. In addition, this composite is lightweight, inexpensive, has excellent durability, and has cushioning and shock absorbing properties, so it can be used without foam plastic for applications other than heat insulating materials. It can be used as an absorber. At this time, it is preferable that the reinforcing body is well adhered to the box. [The invention's effect]

As described above, the plate-shaped heat insulating material and the heat insulating container of the present invention use the foam having the highest heat insulating property, and do not absorb the water or deform it to reduce the thickness and increase the density. Since it is used, it has good heat insulation properties, is lightweight, inexpensive, easy to install, and can be used for an extremely long period of time, and is the best as a heat insulating material for heat storage air conditioning. This composite and the composite consisting only of the box and the reinforcing body have good cushioning properties, shock absorbing properties and impact resistance, and are also used as cushioning materials, shock absorbing materials, levitation materials and the like.

[Brief description of drawings]

FIG. 1 is a sectional view of a heat insulating plate of the present invention.

FIG. 2 is a sectional view of the heat insulation tank of the present invention.

[Explanation of symbols]

(1) Box-shaped body (2) Lid (3) Foam (4) Reinforcement (5) Outer box (6) Inner box (7) Reinforcement (8) Foam (9) Clamp (10) Projection on the bottom

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 3E067 BA05A BB15A BB16A BB17A                       BB25A BC06A BC07A CA18                       EA35 EE38 FC01 GA14                 4F100 AK01C AK01D AK01E AK03A                       AK03B AK05 AK07 BA03                       BA10A BA10B BA10D BA10E                       DD32 DH00C DJ01C DJ01D                       DJ01E GB16 JA15C JB20                       JD15 JJ02 JK10 JK11 JL03                       YY00A YY00B

Claims (5)

[Claims] 1. A polyolefin box-shaped body having an average thickness of 3 m.
A foamed composite in which a low-density plastic foam is put in a material having a minimum thickness of 1.5 mm or more and a lid is adhered. 2. A combination of plate-shaped reinforcing members arranged parallel to each other on the side surface of the box of claim 1 is placed, and a low-density foam is put in each chamber surrounded by the reinforcing member and the upper and lower plates, A foam composite with a lid attached. 3. A combination of two boxes of similar-shaped polyolefins having different sizes, a reinforcing member combined in parallel and at right angles between the parallel portions on the side and bottom surfaces, and low density in each chamber surrounded by the reinforcing member. A heat-insulated container in which two boxes are joined together by putting the one containing the foam. 4. A composite body according to claim 1, claim 2 or claim 3,
A foam composite in which a plastic foam sheet is attached to the surface of a heat insulating container. 5. A composite body comprising the box-shaped body according to claim 1 and a plate-shaped reinforcing body combined in parallel with each other on its side surface, and a lid joined thereto.