JPH06344459A - Manufacture of fold metal plate and continuous bubble body - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a metal folded plate that has excellent water retention and heat insulating properties and can withstand long-term use, and a method for producing an open-cell body in which an adhesive sheet can be laminated simultaneously with foaming. To do. [Structure] A low-density polyethylene foam body 1 having a thickness of 5 mm and composed of open cells is laminated on a metal plate 3 via an adhesive sheet 2. The polyethylene foam 1 has a large number of small holes 11 penetrating the front and back surfaces thereof and small holes 12 not penetrating to the back surface thereof. The diameter of the small holes 11, 12 is about 0.3-
It is 0.8 mm, and the density of small holes is about 1 hole / cm ² . The adhesive sheet 2 is an impermeable sheet made of ethylene-vinyl acetate resin and has a thickness of 0.07 mm. The adhesive sheet 2 is adhered to the foam 1 and the metal plate 3 by heat fusion so that the foam 1 and the metal plate 3 are insulated from each other with respect to water and air. This laminated body is made into a metal folded plate by bending.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-insulating metal folded plate and a method for producing open cells.

[0002]

2. Description of the Related Art A heat-insulating fold plate made by folding a heat-insulating steel plate in which a heat insulating material containing synthetic resin foam or glass fiber is laminated on a coated steel plate, etc. is not only heat-insulating but also sound-proof and dew-proof. It is widely used because of its excellent quality. Conventionally, many synthetic resin foams used for this are made of polyethylene resin, and have closed cells.

A heat-insulating folded plate is also known in which a foam sheet having small holes penetrating the front and back of a foam made of closed cells is attached to a metal plate (Japanese Patent Laid-Open No. 61-123).
30 publication). Further, as a technique for producing an open-cell body using a polyolefin resin, Japanese Patent Laid-Open No. 56-146732
In the publication, a foamable composition made of an ethylene polymer is heated to a decomposition rate of a foaming agent of 60% or less, and further heated to a high temperature to decompose the remaining foaming agent into a closed cell foam, which is A method of compressing and breaking the closed cells to form an open cell body is disclosed, and Japanese Patent Publication No. 5-5254 discloses an ethylene-based resin which does not require a step of breaking bubbles by pressurization by a one-step heating method. An open cell foam composition is disclosed.

[0004]

When a foam made of closed cells, such as the conventional heat-insulating folded plate, is used, when the foam is bonded to a metal plate by heating and pressing, the pressure of the pressure-bonding roll is used to form the foam. The closed cells are destroyed, and the thickness hardly recovers while being compressed. Therefore, the thickness of the foam has been recovered by previously providing a large number of small holes penetrating the front and back of the foam. When the small holes are formed on the front and back of the foam in this way, there is a problem that after being bonded to the metal plate, water enters through the small holes and corrodes the metal plate.

Further, when a heat insulating folded plate using a foam made of closed cells is used for a roof of a warehouse, for example, since the outer side is metal, it is easy to cool even if the heat insulating material is attached,
In winter, the temperature difference from the outside air causes dew condensation on the indoor side, that is, the surface of the foam. The water condensed on this surface is not absorbed by the foam and gradually grows and drops. There is a problem that the dropped water wets the cargo such as a cardboard box and reduces the commercial value.

Further, when a polyurethane foam, which is an open-cell body, is adhered as a heat insulating material, there is a problem that it absorbs water but is hydrolyzed and does not last long.

The present invention solves the above-mentioned problems of the prior art, has excellent water retention and heat insulating properties, and has a folded metal plate capable of withstanding long-term use, and continuous cells capable of laminating an adhesive sheet at the same time as foaming. It is an object to provide a method for manufacturing a body.

[0008]

A metal folded plate of the present invention has a structure in which a foam made of a thermoplastic resin is laminated on one side of a metal plate,
In the folded metal plate, the foam is an open-cell body, and the foam is adhered to the metal plate via an adhesive sheet.

According to a second aspect of the present invention, in the method for producing an open-cell body, an unfoamed or incompletely-foamed foamable sheet obtained by temporarily adhering an adhesive sheet to one surface is heat-foamed to form an open-cell foam. In addition to forming a body, the adhesive sheet is fused and laminated on the foam by heat used for foaming.

In the method for producing an open-cell body according to the third aspect of the present invention, an unfoamed or incompletely-foamed foamable sheet obtained by temporarily adhering an adhesive sheet to one surface is heat-foamed to form a foamed open-cell body. In addition to forming a body, the adhesive sheet is fusion-laminated on the foam by heat used for foaming, and a large number of small holes are provided on one surface of the foam.

According to a fourth aspect of the present invention, in the method for producing an open-cell body, an unfoamed or incompletely-foamed foamable sheet obtained by temporarily adhering an adhesive sheet to one surface is heat-foamed to form foamed open-cell bodies. In addition to forming a body, the adhesive sheet is fusion-laminated on the foam by heat used for foaming, and the skin layer of the foam is removed.

As the foam in the present invention, a polyolefin resin, vinyl chloride resin, rubber or the like can be used, but a polyolefin resin is preferable from the viewpoints of light weight and processability. The polyolefin-based resin is a polymer or copolymer of olefin-based hydrocarbon, for example,
Low-density polyethylene, linear low-density polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-styrene copolymer, propylene-styrene copolymer Examples thereof include one kind or a mixture of two or more kinds such as a polymer, a propylene-styrene-ethylene-butadiene copolymer, and a vinyl chloride-ethylene copolymer. Among them, those mainly composed of low-density polyethylene are rich in flexibility and are preferable in terms of practicality.

The above-mentioned foam is preferable because it is cross-linked but has fine and uniform cells, good cushioning property and excellent strength, and is not mixed with a cross-linking agent such as a foaming agent or an organic peroxide. After the foamed resin composition is molded into a sheet and then crosslinked (chemically crosslinked), the unfoamed resin composition mixed with the foaming agent without adding the crosslinking agent is irradiated with ionizing radiation to be crosslinked. Foamed (radiation crosslinked)
But it's okay.

The expansion ratio of the foam is preferably in the range of 5 to 50 times, preferably 15 to 25 times. If the expansion ratio is lower than 5 times, the flexibility and cushioning property will be deteriorated, and if the expansion ratio is higher than 50 times, the strength will be poor and it will be easily broken. The thickness of the foam is easily in the range of 1 to 30 mm, preferably 3 to 10 mm.
mm.

The foam is an open cell. In order to form an open-cell body, for example, a method of passing an ethylene-based resin open-cell type foam composition described in JP-B-5-5254 through a heating furnace at a temperature at which a foaming agent does not decompose, As described in JP-A-56-146732, a foamable composition made of an ethylene polymer is heated to a decomposition rate of a foaming agent of 60% or less, and further heated to a high temperature to decompose the remaining foaming agent to produce closed cells. There is a method of forming a foam, and then compressing the foam to break the closed cells into an open-cell body.

The adhesive sheet is for adhering a foam and a metal folded plate, and includes polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, polyester, polyamide, and the like. Examples of the heat-fusion resin include a mixture of the above.

A method of laminating the adhesive sheet on a foam is, for example, by feeding an unfoamed or incompletely foamed resin sheet made of a foamable resin composition as described in the above-mentioned prior art while feeding the resin sheet surface. It is preferable that the above-mentioned adhesive sheet is superposed and adhered or temporarily adhered by a pressure bonding roll, and this is sent to a heating furnace to foam the resin sheet in the heating furnace, and at the same time, the adhesive sheet is melt-bonded to the surface of the foam.

When the adhesive sheet is laminated on the foamed material by the above method, the adhesive sheet is melted and adhered to the foamed material by the heat used for foaming simultaneously with the foaming of the unfoamed or incompletely foamed sheet, which is efficient. No equipment is required for bonding. Further, since the foam is an open-cell body, when it is bonded to the adhesive sheet, no bubbles remain between the adhesive sheet and the foam, and the foam is completely bonded.

As another method, an extrusion laminating method of melt-extruding the above heat-sealing resin on the surface of a foam or a metal plate, or once molding the above heat-sealing resin into a sheet, which is then formed into a foam or a metal plate. There is a method of heating and adhering to the surface of. In the case where the adhesive sheet is laminated on the surface of the foam, the adhesive sheet or the metal plate is heated and melted at a temperature higher than the melting temperature of the adhesive sheet to bond the foam and the metal plate.
When the adhesive sheet is provided on the surface of the metal plate, the adhesive sheet is heated and melted at a temperature equal to or higher than its melting temperature to bond the foamed body.

Since the foam adhered to the metal plate is an open-cell body, water droplets condensed on the surface of the foam are absorbed inside the foam, do not drip, and evaporate when the temperature rises. When the surface of the foam laminated on the metal plate has a skin layer formed during foam molding, if many small holes are formed from the surface of the skin layer to the foam, condensed water generated on the surface of the foam Is absorbed linearly in the thickness direction of the foam in the small hole portion and is absorbed in the plane direction inside the foam, so that the condensed water is easily absorbed. The diameter of the small hole is 0.1
1.2 mm, preferably 0.3-0.8 mm,
A hole interval of 2 to 100 mm is preferable because the dew condensation water is absorbed quickly.

If only the skin layer of the foam is removed by slicing or the like instead of forming the small holes, the open cells are exposed and the condensed water is easily absorbed. Since the thickness of the skin layer is about 0.01 to 0.1 mm, open cells are exposed by slicing with this thickness. To slice
For example, it is carried out by a method in which a foam layer is fed in a plane direction and a blade is applied to the skin layer to scrape it off.

If small holes are formed in the foam and the skin layer is removed by slicing or the like, open cells are exposed on the entire surface of the foam, and since there are small holes, the dew condensation water is absorbed. Is more preferable because it becomes faster.

[0023]

According to the metal folded plate of claim 1, since the foam adhered to the metal plate is an open cell, water droplets condensed on the surface of the foam are absorbed inside the foam and do not drip.
It evaporates when the temperature rises. Even if a large amount of condensed water is absorbed by the foam, the foam is laminated on the metal plate via the adhesive sheet, so the metal plate does not come into contact with water and corrosion can be avoided.

According to the method for producing an open-cell body according to claim 2, an unfoamed or incompletely foamable sheet can be foamed, and at the same time, an adhesive sheet can be adhesively laminated on the surface of the foamed body. Open cells have water absorption,
Water is blocked by the adhesive sheet.

According to the method for producing an open-cell body according to claim 3, since a large number of small pores are formed in the foam body from the surface of the skin layer, the condensed water generated on the surface of the foam body is foamed at the small pore portions. While being absorbed linearly in the thickness direction of the body, it is also absorbed in the plane direction, so that the dew condensation water is absorbed faster. It is preferable that the large number of small holes do not penetrate the adhesive sheet,
Of these, even if there are small holes that penetrate the adhesive sheet,
When the adhesive sheet is heat-sealed to the metal plate, the small holes are closed at the same time.

Further, according to the method for producing an open-cell body according to claim 4, since only the skin layer of the foam is removed by slicing or the like, the open-cells are exposed on the entire surface and the condensed water is easily absorbed. .

[0027]

EXAMPLES Examples of the present invention will be described below.

(Embodiment 1) FIG. 1 is a sectional view showing an embodiment of a metal folded plate of the present invention. 1 is 5m thick consisting of open cells
m low density polyethylene foam laminated on the metal plate 3 with the adhesive sheet 2 interposed therebetween. The foam 1 is formed with a large number of small holes 11 penetrating the front and back sides and small holes 12 not penetrating to the back side. The small holes 11, 12 have a diameter of about 0.
It is 3 to 0.8 mm, and the density of small holes is about 1 hole / cm ² . The adhesive sheet 2 is an impermeable sheet made of ethylene-vinyl acetate resin and has a thickness of 0.07 mm. The adhesive sheet 2 is adhered to the foam 1 and the metal plate 3 by heat fusion so that the foam 1 and the metal plate 3 are insulated from each other with respect to water and air. This laminated body is made into a metal folded plate by bending.

(Embodiment 2) FIG. 2 is an explanatory view for explaining an embodiment of the method for producing an open-cell body according to the present invention. While feeding the foamable sheet 4 made of low-density polyethylene, an adhesive sheet 2 made of ethylene-vinyl acetate resin having a thickness of 0.7 mm was superposed on the surface and temporarily adhered by pressure-bonding rolls 5 and 150-300. The foamable sheet 4 is sent to a heating furnace 6 having a temperature distribution of ℃ for 5 minutes to foam to form continuous cells, and at the same time, the heat of the heating furnace 6 causes the adhesive sheet 2 to adhere to the surface of the foam 1. The open cell body 9 was obtained by adhesion by heat fusion. The thickness of this open-cell body 9 was 5 mm, and the expansion ratio was about 25 times. Further, a skin layer 13 having a thickness of 10 μm was formed on the surface of the foam body 1 on the side opposite to the adhesive sheet 2.

(Embodiment 3) FIG. 3 is an explanatory view for explaining an embodiment of the method for producing an open-cell body according to the present invention. In the same manner as in Example 2, the adhesive sheet 2 was laminated on the surface of the foamed body 1 composed of open cells. After cooling the foam, the adhesive sheet is passed from the skin layer 13 of the foam 1 to a depth of 1 to 4 mm by passing it between the perforation roll 7 having a large number of needles 71 planted on the surface and the perforation receiving roll 72. The small holes 12 that did not reach 2 were formed to obtain the open-cell body 91.

A test piece obtained by cutting the open-cell body 91 into a size of 10 × 10 cm was immersed in water at room temperature for 20 minutes in a vat, taken out, placed on a flat surface on a stainless plate, and impregnated with ethanol. The surface of the test piece was lightly wiped with gauze, allowed to stand for 20 minutes, and the difference between the weight of the test piece and the weight before immersion in water was measured. As a result, it was increased by 350 g / m ² .

(Embodiment 4) FIG. 4 is an explanatory view for explaining an embodiment of the method for producing an open-cell body according to the present invention. In the same manner as in Example 2, the adhesive sheet 2 was laminated on the surface of the foam 1 composed of open cells, and while being supported by the slice blade receiving roll 81 from above the foam, it was formed on the foam surface by the slice blade 8. The skin layer 13 was sliced and removed to obtain an open cell body 92.

The difference between the open cell body 92 and the weight before immersion in water was measured in the same manner as in Example 3, and as a result, it was 500 g / m.
² had increased.

(Comparative Example) A polyethylene foam consisting of closed cells from which the skin layer was removed was immersed in water in the same manner as in Example 1 and the change in weight was measured and found to be 150 g / m ² .

[0035]

EFFECTS OF THE INVENTION The metal folded plate of the present invention has the above-mentioned structure. Since water droplets condensed on the surface of the foam are absorbed inside the foam and do not drip, it does not damage the cargo such as a warehouse by wetting it. The water absorbed by the foam evaporates when the temperature rises, and regains heat insulation. Even if the dew condensation water is absorbed by the foam, since the foam is laminated on the metal plate via the adhesive sheet, the metal plate does not come into contact with water and corrosion can be avoided.

According to the method for producing an open-cell body of the present invention as defined in claim 2, the expandable sheet can be foamed, and at the same time, the adhesive sheet can be adhered and laminated on the foam surface. It has water absorbency, and the adhesive sheet prevents the metal plate from coming into contact with water and avoiding corrosion.

According to the method for producing an open-cell body of the present invention as set forth in claim 3, due to the large number of small holes formed in the foam, the water absorption of the dew condensation water generated on the surface of the foam is excellent and the metal plate is not corroded. An open cell body can be obtained.

According to the method for producing an open-cell body of the present invention as defined in claim 4, since the open-cells are exposed on the entire surface of the foam, the water-absorbing property of the condensed water is further excellent and the metal plate is not corroded. You can get the body.

[0039]

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a folded metal plate of the present invention.

FIG. 2 is an explanatory view showing an embodiment of a method for manufacturing a folded metal plate of the present invention.

FIG. 3 is an explanatory view showing another embodiment of the method for producing a folded metal plate of the present invention.

FIG. 4 is an explanatory view showing still another embodiment of the method for producing a folded metal plate of the present invention.

[Explanation of symbols]

 1: Foamed body 2: Adhesive sheet 3: Metal plate 4: Foamable sheet 5: Crimping roll 6: Heating furnace 7: Drilling roll 8: Slice blade 9,91, 92: Open cell body 11, 12: Small hole 13: Skin layer

Claims (4)

[Claims] 1. A metal folding plate in which a foam made of a thermoplastic resin is laminated on one surface of a metal plate and is bent, and the foam is an open-cell body, and the foam is an adhesive sheet. A metal folding plate characterized by being bonded to a metal plate through. 2. An unfoamed or incompletely foamable sheet obtained by temporarily adhering an adhesive sheet to one surface of the foamed sheet is heat-foamed to form a foamed body composed of continuous cells, and the adhesiveness is improved by the heat used for foaming. A method for producing an open-cell body, comprising fusing and laminating a sheet to the foam. 3. An unfoamed or incompletely foamable sheet obtained by temporarily adhering an adhesive sheet to one surface of the foamed sheet is heated and foamed into a foamed body composed of continuous cells, and the adhesiveness is improved by the heat used for foaming. A method for producing an open-cell body, comprising fusing and laminating a sheet on the foam, and providing a large number of small holes on one surface of the foam. 4. An unfoamed or incompletely foamable sheet obtained by temporarily adhering an adhesive sheet to one surface of the foamed sheet is heated and foamed to form a foamed body composed of continuous cells, and the adhesiveness is improved by the heat used for foaming. A method for producing an open-cell body, comprising fusing and laminating a sheet to the foam, and removing the skin layer of the foam.