JPH0911377A - Laminate - Google Patents

Abstract

PURPOSE: To provide a laminate excellent in handling properties, capable of being simply packed even in a narrow space and effectively usable in various fields as a seal material, a heat insulating material or a cushion material. CONSTITUTION: A laminate consists of a foam layer composed of a sheet like closed-cell resin foam having delayed shape recovery properties and a resin sheet material with bending rigidity of 1g.cm or more and a coating layer 2 is provided to at least one surface of the foam layer 1.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a laminate.

[0002]

2. Description of the Related Art For example, open-cell type synthetic resin foams such as synthetic rubber foams disclosed in Japanese Patent Laid-Open Nos. 50-37863 and 62-189236,
Polystyrene foam disclosed in JP-A-6-336245, polypropylene resin foam disclosed in JP-B-6-43512, JP-B-6-435
Various closed-cell type synthetic resin foams such as the polyethylene resin foams disclosed in JP-A No. 13 are superior to conventional ones in functions such as heat insulation and cushioning.
It is used as a heat insulating material, cushioning material, sealing material, etc. in various fields such as houses, construction, civil engineering, vehicles, home appliances, stationery, miscellaneous goods, and clothing.

[0003]

However, the conventional closed-cell type synthetic resin foam may have the following problems in some cases. If you try to fill it into a tight space,
If it is forcibly pushed, the foam will be broken and fall apart, and will no longer serve as a filler, resulting in very poor workability.

[0004] When it is molded into chips and filled in a container such as a box to protect the contents in the box, it is difficult to completely fill the box without any gaps at the beginning. Refilling of the body occurs, creating gaps that cannot adequately protect the contents of the box, causing damage or breakage of the contents. By using the injection foaming method (Nikkan Kogyo Shimbun, 1974, Plastic Foam Handbook P.200) in which liquid is injected into the hollow portion of the panel and then foamed, the foam can be filled without problems even in a narrow space. Since it is a liquid, there is a problem in handleability, and there is also a problem that it is difficult to form a foam other than a gap continuous with the injection port.

On the other hand, JP-A-50-37863 and 6
In the case of the open-cell type foam disclosed in Japanese Unexamined Patent Publication No. 2-189236, since asphalt or the like is filled in the open-cells, the asphalt or the like bleeds on the surface when it is compressed to fill a gap or the like. Therefore, the workability is poor.

[0006]

In view of such circumstances, the present invention has excellent handleability, can be easily filled even in a narrow space, and has various properties such as a sealing material, a heat insulating material and a cushioning material. The object is to provide a laminate that can be effectively used in the field.

[0007]

In order to achieve such an object, a laminate according to the present invention comprises a foam layer made of a sheet-shaped closed cell resin foam having a delayed shape recovery property and a bent layer. A resin sheet material having a rigidity of 1 g · cm or more is provided, and a covering layer for covering at least one surface of the foam layer is provided.

In the above structure, the closed-cell resin foam having a delayed shape recovery property is defined as follows. The gas permeability coefficient of carbon dioxide gas or liquefied gas is larger than that of air, and the gas at room temperature or the gas that liquefies at room temperature is used as the foaming gas. The elastic recovery force gradually recovers the original thickness while balancing the internal and external pressures of the bubbles.

When a gas other than the foaming gas is used as the foaming gas and a compressive strain is applied in the elastic region, the internal pressure of the closed cells constituting the foam rises, and immediately after removing the external force, The foam instantly recovers its original shape, but if the strain is maintained for a predetermined time or longer, the gas permeability of the resin causes the gas in the bubbles to gradually escape from the bubble film, and the internal pressure and the external pressure balance, Even if the external force is removed, instantaneous shape recovery does not occur, and if the strain is within the elastic region of the resin, when compression is released, the elastic recovery force of the resin balances the internal and external pressure of the bubbles and gradually increases the original thickness. Those that have the property of recovering to.

A gas other than the bubbling gas was used as a bubbling gas, and the bubbling was performed under a reduced pressure so that the gas pressure in the bubbling was kept below atmospheric pressure, cooled and fixed, and then taken out into the atmosphere. At this time, the foam is once compressed by atmospheric pressure and gradually recovers its original thickness while balancing the internal and external pressures of the bubbles by the elastic recovery force of the resin.

The closed cell rate of the closed cell resin foam is determined by the amount of recovery required for the compressed foam itself, and it can be used if it is approximately 5% or more, but a particularly preferable range is 60% to 60%. It is 100%. The resin constituting the closed-cell resin foam is not particularly limited, but those having a compression set (based on JISK6767) of 20% or less, particularly 10% or less are preferable because of excellent shape recoverability.

Examples of such resins include the following thermoplastic resins and thermosetting resins. [Thermoplastic resin] Polyolefin, polypropylene, ethylene-propylene copolymer, ethylene-propylene-diene copolymer, olefin resin such as ethylene-pinyl acetate copolymer, polymethyl acrylate, polymethylmethacrylate, ethylene-ethyl Acrylic resin such as acrylate copolymer, butadiene-styrene, acrylonitrile-styrene, styrene, styrene-butadiene-
Styrene, styrene-isobrene-styrene, styrene-styrene resin such as acrylic acid, acrylonitrile-
Polyvinyl chloride resins such as polyvinyl chloride and polyvinyl chloride-ethylene; vinyl fluoride resins such as polyvinyl fluoride and polyvinylidene fluoride; amide resins such as 6-nylon, 6.6-nylon and 12-nylon; polyethylene Saturated ester resins such as terephthalate and polybutylene terephthalate, polycarbonate, polyphenylene oxide, polyacetal, polyphenylene sulfide,
Silicone resin, thermoplastic urethane resin, polyetheretherketone, polyetherimide, various elastomers and cross-linked products of these.

[Thermosetting Resin] A cured product of epoxy resin, phenol resin, melamine resin, urethane resin, imide resin, urea resin, silicone resin, unsaturated polyester resin, and the like. These resins may be used alone or in combination of two or more.

Among the above-mentioned resins, olefin resins, styrene resins, amide resins, acrylic copolymers, soft polyurethanes, soft vinyl chloride resins, polyacetals, silicone resins and various elastomers are particularly excellent in shape recovery. Is especially mentioned. Known foaming methods, including those described in the Plastic Foam Handbook, may be used, and any method may be used.

The resin sheet material is not particularly limited, but one having gas permeability is preferable, and in consideration of the shape of the foam layer (foam accumulation, surface area, bubble diameter, bubble film thickness). Since the compression recovery time of the laminate changes, various selections are made according to the application of the laminate.
In order to impart a sufficient recovery function to the laminate, those having a gas permeability of 7 × 10 ⁻¹⁷ cm ³ / atm · sec · cm ² or more are particularly preferable. Examples of the material of such a resin sheet include the following thermoplastic resins or thermosetting resins.

[Thermoplastic resin] Olefin resin such as polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-propylene-diene copolymer, ethylene-pinyl acetate copolymer, polymethyl acrylate,
Acrylic resin such as polymethylmethacrylate, styrene-resin such as butadiene-styrene, acrylonitrile-styrene, styrene, styrene-acrylic acid, vinyl chloride-based resin such as acrylonitrile-polyvinyl chloride, polyvinyl chloride-ethylene, etc. Vinyl fluoride, polyvinylidene fluoride, and other vinyl fluoride resins, 6-nylon, 6,6-nylon, 12-nylon, and other amide resins, polyethylene terephthalate, polybutylene terephthalate, and other saturated ester resins, polycarbonate,
Polyphenylene oxide, polyacetal, polyphenylene sulfide, polyether ether ketone, polyether imide and cross-linked products thereof.

[Thermosetting Resin] A cured product of epoxy resin, phenol resin, melamine resin, urethane resin, imide resin, urea resin, silicone resin, unsaturated polyester resin, and the like.

Examples of the method for laminating the foam layer and the coating layer include a method performed immediately after the foam is manufactured and a method performed after the foam is contracted. The former method is
It is used when laminating the foam layer and the coating layer by heat fusion, and the latter method is often used when laminating by adhesion with an adhesive, but lamination by heat fusion is preferable.

The heat fusion is carried out by, for example, superposing a foam body serving as a foam layer and a resin sheet serving as a coating layer, and applying a pressure in a state where both or at least one of the interfaces is heated by high frequency heating or the like. Obtainable. Further, the heat fusion temperature is preferably equal to or lower than the softening point of the foam when the foam is fused in the contracted state, but may be equal to or higher than the melting point in the non-contracted state immediately after the production. Further, a filler, a reinforcing fiber, a colorant, an ultraviolet absorber, an antioxidant, a flame retardant and the like may be mixed in the foam and the resin sheet as needed.

Examples of the filler include calcium carbonate, talc, clay, magnesium oxide, zinc oxide, carbon black, silicon dioxide, titanium oxide, glass powder and glass beads. As a reinforcing fiber,
For example, glass fiber, single layer fiber, etc. may be mentioned. Examples of the coloring agent include pigments such as titanium oxide.

The antioxidant is not particularly limited as long as it is generally used, and examples thereof include tetrakis [methylene (3,5-di-t-butyl-4-hydroxyhydrocinnamate)] methane and thiodiene. Examples thereof include dilauryl propionate and 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane. As the flame retardant, hexabromophenyl ether,
Examples thereof include one kind or a mixture of two or more kinds of bromine flame retardants such as decabromodiphenyl ether, phosphoric acid flame retardants such as ammonium polyphosphate, trimethyl phosphate and triethyl phosphate, melamine derivatives and inorganic flame retardants.

[0022]

According to the above structure, the foam layer is compressed by natural contraction, atmospheric pressure or mechanical pressure, but at least one surface of the foam layer has a bending rigidity of 1 g · cm or more. Since the coating layer made of is laminated, it is compressed only in the thickness direction. Moreover, since the coating layer is laminated, the shrinking / recovering direction is limited to one direction, and wrinkles and the like that occur during shrinking are suppressed, and the surface of the foamed body after recovery is kept smooth.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to embodiments. (Example 1) Low-density polyethylene (LD
PE, ZC30 manufactured by Mitsubishi Petrochemical Co., Ltd., foamed with carbon dioxide gas (foaming ratio 20 times, 500 × 500 mm, thickness 10 m)
m, closed cell rate 85%) polypropylene sheet (Mitsubishi Kasei Co., Ltd., Mitsubishi Polypro 4300J, 52) forming a coating layer
0 × 520 mm, thickness 0.5 mm, gas permeation coefficient (CO
₂ ) 3.45 × 10 ⁻¹⁴ cm ³ / atm · sec · cm ² , bending rigidity 18 g · cm) are fused on both sides, and the covering layer 2 is integrally formed on both sides of the foam layer 1 as shown in FIG. The provided laminated body 3 was molded. After 7 hours, the layered product 3 was 3/1 by gas permeation.
Although it naturally contracted to a thickness of 0, wrinkles and bending were not observed in the laminate 3. After that, when left for 45 days in the atmosphere, the thickness of the laminated body 3 recovered to approximately 8 mm, but wrinkles and bending were not observed in the laminated body 3 after the recovery.

(Example 2) Low density polyethylene (LDPE, ZC manufactured by Mitsubishi Petrochemical Co., Ltd.) containing azidocarbamide (ADCA, uniform SOL manufactured by Otsuka Chemical Co., Ltd.) as a foaming agent.
30) is a sheet-like foamed body (foaming ratio 30 times, 400
× 400 mm, thickness 10 mm, closed cell ratio 83%), a low-density polyethylene sheet (Mitsubishi Petrochemical Co., Ltd. Ultzex 1520L, 420 × 420 mm) as a coating layer.
Thickness 0.5 mm, gas permeability coefficient (N ₂ ) 3.65 × 10
^-15 cm ³ / atm sec cm ² and bending rigidity 15 g cm) were fused on both sides to obtain a laminate.

This laminate was compressed to 1/10 using a pressing machine, held for 4 days, and then taken out to find that the thickness of the laminate was 4 mm. No wrinkles or folds were observed in the compressed laminate at this time. afterwards,
When left in the atmosphere for 30 days, the thickness of the laminated body recovered to approximately 8 mm, but no wrinkles or bending was observed in the laminated body after the recovery.

Example 3 Polyurethane-vinyl chloride copolymer resin (DOMINASK-90 manufactured by Nippon Polyurethane Industry Co., Ltd.) containing azidocarbamide (ADCA, Uniform SOL manufactured by Otsuka Chemical Co., Ltd.) as a foaming agent for forming a foam layer.
0A) was molded into a sheet and heated and foamed under reduced pressure (0.3 atm) (foaming ratio 20 times, 500 × 50).
0 mm, thickness 30 mm, closed cell ratio 50%, under the same pressure, low density polyethylene sheet (Ultzex 1520L, Mitsubishi Petrochemical Co., Ltd., 500 × 500) to be a coating layer.
mm, thickness 1.0 mm, gas permeability coefficient (N ₂ ) 7.3 ×
10 ^-15 cm ³ / atm ・ sec ・ cm ² , bending rigidity 1.2 kg
・ Cm) was fused on one side and taken out at atmospheric pressure. The laminate contracted to 10 mm due to the pressure difference, but wrinkles and bending were not recognized on the sheet surface. After that, when left in the atmosphere for 30 days, the laminated body had a thickness of about 25 mm.
However, no wrinkles or bending was observed in the laminated body after the recovery.

(Comparative Example 1) When nothing was laminated on the surface of the foam used in Example 2, the thickness naturally contracted to 3 mm in 30 minutes, but it contracted three-dimensionally, and the foam surface wrinkled. The desired foam was not obtained because of twisting. In addition, the size at the time of contraction is about 350 x 350 mm, 3
The dimensions at the time of recovery after 0 days are approximately 470 x 470 mm, thickness 8
It became mm. Even at this point, some wrinkles remained on the surface of the foam.

The laminate according to the present invention is not limited to the above embodiment. For example, in the above embodiment, the coating layer was gas permeable, but when the coating layer is provided on one side, or the coating layer on one side, the resin sheet having no gas permeability should be fused. It doesn't matter.

[0029]

EFFECTS OF THE INVENTION Since the laminate according to the present invention shrinks like a sheet during construction without wrinkles or folds as described above, it can be easily constructed even in a narrow gap and has excellent workability. Since it is taken in by the air bubbles and expands,
The gap will be filled tightly. Therefore, it is excellent in airtightness, heat insulation, and sealability, and is effective in various fields such as pipe insulation, building insulation, cushioning material for packaging, cushioning material for interiors such as vehicles, sealing material for buildings, joint material, etc. Applicable.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a laminated body according to the present invention.

[Explanation of symbols]

 1 Foam layer 2 Cover layer 3 Laminate

Claims (1)

[Claims] 1. A foam layer made of a sheet-shaped closed-cell resin foam having a delayed shape recovery property and a flexural rigidity of 1 g.
A laminate comprising a resin sheet material of cm or more, and a coating layer that covers at least one surface of the foam layer.