JP7068426B2 - Laminated sheet and manufacturing method of the laminated sheet - Google Patents

Description

The present invention relates to a laminated sheet and a method for manufacturing the laminated sheet.

Conventionally, in order to impart adhesiveness / adhesiveness to a foam, adhesive processing suitable for each application such as laminating an adhesive / adhesive layer, applying a hot melt adhesive, or impregnating an adhesive is performed. Often applied.

For example, Patent Document 1 proposes an adhesive sheet in which a foam sheet obtained by mechanically stirring an acrylic emulsion is used as a base material, and an adhesive is impregnated or laminated.

However, since the foam of open cells made of only an acrylic emulsion is vulnerable to splitting and easily causes material destruction, Patent Document 2 describes acrylic in which closed cells and open cells coexist using inorganic and organic foams. A foam sheet obtained by mechanically stirring a system emulsion has been proposed.

Further, Patent Document 3 proposes an adhesive sheet provided with an adhesive layer and a slit. In the case of products with adhesive, the slits are provided because air enters during construction and air pools are created, so it is common for professional craftsmen to install the windows. This is because it is possible to eliminate the air pool when it is attached to the like.

Japanese Unexamined Patent Publication No. 63-89585 Japanese Unexamined Patent Publication No. 4-45184 Japanese Unexamined Patent Publication No. 2012-126855

However, the conventional foam sheet has at least one of the following problems. First, since the conventional foam sheet is impregnated with an adhesive or provided with an adhesive layer to enhance the adhesive force, the foam sheet itself is a material when peeled from the adherend. There is a problem that it is not suitable for repeated use, such as causing breakage and reducing adhesive strength. In addition, there is a problem that it can be attached only to a smooth surface such as glass and cannot be attached to surface-treated glass, and in addition, it requires high technology when attaching a foam sheet to an adherend surface. There was a challenge. Further, although the adhesive sheet described in Patent Document 3 uses a synthetic resin film, it is attached indoors because the film does not stretch when the glass expands and contracts due to heat, so that the glass thermally cracks. There was a problem that it could not be done.

Therefore, the present invention has excellent workability, has adhesive strength, can be used repeatedly, and has a smooth adherend (for example, a glass surface, etc.) because air pools can be easily eliminated. It is an object of the present invention to provide a method for manufacturing a laminated sheet that can be attached to an adherend having irregularities or irregularities (for example, a surface-treated glass surface) and can follow expansion and contraction due to heat of the adherend. And.

As a result of diligent research to solve the above problems, the present inventors have obtained a specific porous foam layer obtained from an acrylic emulsion and an ethylene-vinyl acetate copolymer resin emulsion, and the porous foam having a stretch ratio. It has been found that a laminated sheet capable of achieving the above object can be obtained by using a method for manufacturing a laminated sheet having a low expansion / contraction rate layer lower than the expansion / contraction rate of the layer, and the present invention has been completed. ..

That is, the present invention (1) is
A method for producing a laminated sheet having a porous foam layer and a low expansion / contraction layer provided on one surface side of the porous foam layer and having a stretch ratio lower than that of the porous foam layer. ,
The production method comprises a step of foaming an emulsion composition containing an emulsion and a foaming agent using a mechanical floss method to form a foam, and curing the foam.
The emulsion composition comprises a mixture of an acrylic emulsion, an ethylene-vinyl acetate copolymer resin emulsion, and a urethane emulsion of 0% by weight or more and less than 30% by weight based on the total amount of the emulsion.
A method for producing a laminated sheet, wherein the porous foam layer has self-adhesiveness.
The present invention (2) is
The method for producing a laminated sheet according to the invention (1), wherein the porous foam layer has a semi-open cell structure.
The present invention (3) is
The emulsion composition is a mixture of an acrylic emulsion of more than 10% by weight and 90% by weight or less and an ethylene-vinyl acetate copolymer resin emulsion of 10% by weight or more and less than 90% by weight based on the total amount of the emulsion. The method for producing a laminated sheet according to the invention (1) or (2), which is characterized by the above.
The present invention (4) is
The emulsion composition further contains a cross-linking agent and
Any of the inventions (1) to (3), wherein in the step, the foam is cured by applying energy to crosslink the resin constituting the emulsion via the crosslinking agent. It is a method for manufacturing a laminated sheet according to 1.
The present invention (5)
The method for producing a laminated sheet according to any one of the inventions (1) to (4), wherein the laminated sheet has another layer on the low stretch ratio layer side of the porous foam layer.
The present invention (6) is
The laminated sheet according to any one of the inventions (1) to (5), wherein the low stretch ratio layer or the other layer is a layer having a function as a printing layer, a reflective layer, or a whiteboard. The method.
The present invention (7) is
The method for manufacturing a laminated sheet according to any one of the inventions (1) to (6), wherein the laminated sheet is for ceramics, metal, plastic, and glass, and surface-treated products thereof.
The present invention (8)
The method for manufacturing a laminated sheet according to any one of the inventions (1) to (7), wherein the laminated sheet is for glass and surface-treated glass and is for shading.
The present invention (9)
The method for manufacturing a laminated sheet according to any one of the inventions (1) to (8), wherein the laminated sheet has a heat insulating property.
The present invention (10)
Acrylic foam obtained using emulsion and
A laminated sheet composed of a surface layer formed by laminating a film or a non-woven fabric on the surface thereof.
The emulsion contains an acrylic emulsion and an ethylene-vinyl acetate copolymer resin emulsion.
The back surface of the acrylic foam has self-adhesiveness and is self-adhesive.
The surface layer is composed of a layer that does not have elasticity and can restrain the laminated sheet.
It is a laminated sheet.
The present invention (11)
The invention (10), wherein the emulsion contains 25 to 80% by weight of an acrylic emulsion and 20 to 75% by weight of an ethylene-vinyl acetate copolymer resin emulsion based on the total weight of the emulsion. It is a laminated sheet of.
The present invention (12)
The laminated sheet according to the invention (10) or (11), which has another layer on the surface layer side of the porous foam.
The present invention (13)
The laminated sheet according to any one of the inventions (10) to (12), wherein the surface layer or the other layer is a layer having a function as a printing layer, a reflective layer, or a whiteboard.

Here, in the present invention, "self-adhesiveness" means that the material adheres to the adherend when pressed due to the nature of the material without applying an adhesive (including providing an adhesive layer) or impregnating the material. However, when peeled off, it does not move to the adherend and can be peeled off from the joint. The "semi-open cell structure" is a structure in which the pores (holes) between adjacent bubbles are smaller than those of open cells, and unlike closed cells, the bubbles have small pores, and conforms to the JIS L 1096 A method. A structure in which the value measured using a Frazier type air permeability tester is 2 [ml / cm ² / s] or more and less than 80 [ml / cm ² / s].

Further, in the present invention, the "delamination strength" is one index of the material strength of the sheet according to the present invention, and refers to the stress at the time of tearing in the case of T-shaped peeling. Specifically, the strength can be measured by the test method described later.

According to the present invention, it is possible to easily eliminate air pools, so that it is excellent in workability, has adhesive strength, can be used repeatedly, and has a smooth adherend (for example, a glass surface). It is possible to provide a method for manufacturing a laminated sheet that can be attached to an adherend having irregularities (for example, a surface-treated glass surface) and can follow expansion and contraction due to heat of the adherend. Become. Further, the adhesive sheet according to the present invention can be applied to various applications (for example, a print medium, a mirror, a whiteboard) by satisfying the above-mentioned properties.

It is a conceptual sectional view of the laminated sheet which concerns on this embodiment. It is a conceptual cross-sectional view of the laminated sheet which has a functional layer which concerns on this embodiment. It is a cross-sectional SEM photograph of the semi-open cell structure, the open cell structure and the closed cell structure of the porous foam which concerns on this embodiment.

Hereinafter, preferred embodiments of the present invention will be described in detail, but these are merely examples, and the present invention is not limited to the following aspects.

The laminated sheet and the manufacturing method thereof according to this embodiment will be described in the following order.
1 Structure of laminated sheet 2 Manufacturing method of laminated sheet 3 Properties of laminated sheet 4 Applications of laminated sheet

[Construction]
FIG. 1 is a conceptual cross-sectional view of the laminated sheet 100. As shown in FIG. 1, the laminated sheet 100 according to the present embodiment is a sheet-like laminated body having a porous foam layer 110 and a surface layer 120 provided on one surface side of the porous foam layer 110. be. The laminated sheet 100 according to this embodiment may essentially include the porous foam layer 110 and the surface layer 120, and as shown in FIG. 2, other layers (for example, the functional layer 130). ) Can be further laminated, and the laminated structure can be changed as appropriate. The other layer (for example, the functional layer 130) may exist as one or more layers between the surface layer and the porous foam layer and / or at the position farthest from the porous foam layer. good. In this embodiment, the surface layer 120 is a low stretch ratio layer having a lower stretch ratio than the porous foam layer, but other layers (for example, the functional layer 130) may be a low stretch ratio layer.

Hereinafter, the porous foam layer 110 and the surface layer 120 will be described, and then the other layers will be described. In the present embodiment, in the laminated structure, the porous foam layer 110 that contacts the adherend on the side where the surface layer is provided is set as the "lower layer" side, and the surface layer 120 that does not contact the adherend is the "upper layer". "Side.

≪Porous foam layer≫
The porous foam layer 110 according to the present embodiment is a layer provided as a lower layer of the surface layer 120, and the properties of the material have self-adhesiveness without applying or impregnating an adhesive, and the adherend. Functions as a layer that adheres to. In addition, since the porous foam layer 110 in contact with the adherend has a semi-open cell structure, it adheres to the adherend due to the suction cup effect. Since the porous foam layer 110 has high elasticity, it can be attached with a strong adhesive strength even to an adherend having an uneven surface such as surface-treated glass. However, it may be configured to apply an adhesive if necessary.

Since the porous foam layer 110 has a semi-open cell structure, it is difficult for air to accumulate, and even if it is formed, air can be easily removed by simply pressing it from above.

Further, when peeling off, since the adhesive is not applied or impregnated, it does not move to the adherend and can be peeled off from the joint portion, so that it can be used repeatedly. For this reason, when the structure is such that the pressure-sensitive adhesive is applied, it is preferable that the number of coated portions of the pressure-sensitive adhesive is as small as possible.

When the adherend is glass or surface-treated glass, the glass or surface-treated glass expands and contracts due to heat, so that thermal cracking is particularly likely to occur. Since the porous foam layer 110 has high elasticity, the laminated sheet according to the present invention absorbs expansion and contraction due to heat of glass and the like, and thus has an effect that thermal cracking is less likely to occur regardless of the material of the surface layer. ..

Here, the porous foam layer 110 according to the present embodiment is an aqueous dispersion (emulsion) containing a water-dispersible resin as a dispersoid and water or a mixture of water and a water-soluble solvent as a dispersion medium, and a foaming agent. It is produced by a step of foaming an aqueous liquid medium (emulsion composition) containing an anionic surfactant as a foam using a mechanical floss method to form a foam and curing the foam (the porous). The specific manufacturing method of the quality foam layer 110 will be described later).

According to the porous foam layer 110 according to the present embodiment, from the material described later, the porous foam layer 110 exhibits light-shielding property and UV-cutting property, and is excellent in light-shielding property and UV-cutting property. Can be done. Further, by adopting a configuration that does not completely block light, light can be obtained indoors without peeling off the laminated sheet according to the present invention if there is sunlight.

Further, according to the porous foam layer 110 according to the present embodiment, it is possible to exhibit heat insulating properties over the entire porous foam layer 110 from the material described later, and to have excellent heat insulating properties.

<Thickness>
The thickness of the porous foam layer 110 according to the present embodiment can be appropriately designed according to the intended use and required properties, but is preferably 0.3 mm to 3.0 mm. The reason is that if it is less than 0.3 mm, sufficient light-shielding property and UV-cutting property cannot be obtained, and if it is thicker than 3.0 mm, the room becomes dark.

<Density>
The following cell structure can be evaluated by measuring the density of the porous foam layer 110 according to this embodiment. The higher the density, the smaller the average diameter of the cells tends to be, while the lower the density, the more the flexibility is satisfied. Density can be measured by calculating the weight per unit volume. The density [kg / m ³ ] is preferably 150 to 500 [kg / m ³ ], more preferably 160 to 400 [kg / m ³ ], and 170 to 350 [kg / m ³ ]. It is more preferable to have. When it is 150 [kg / m ³ ] or more, the desired light-shielding property and heat-insulating property are satisfied, and the adhesive strength and delamination strength are also sufficient. Further, if it is 500 [kg / m ³ ] or less, it has sufficient flexibility and absorbs the expansion and contraction of the glass.

<Cell structure>
The porous foam layer 110 according to this embodiment has a semi-open cell structure. With such a structure, the adhesiveness of the material according to the present invention can be further imparted by the suction cup effect. As a result, it has self-adhesiveness without having an adhesive layer, and air pools are unlikely to occur, and even if it does occur, it can be easily removed.

(Semi-open cell structure)
The semi-open cell structure has smaller pores (holes) between adjacent bubbles than open cells, and unlike closed bubbles, the bubbles have small pores. By measuring the air permeability, it is possible to evaluate whether or not the structure is a semi-open cell structure. As described above, the method for measuring the air permeability is based on the JIS L 1096 A method, and the air permeability is measured using a Frazier type air permeability tester. If the air permeability is 2 [ml / cm ² / s] or more and less than 80 [ml / cm ² / s], it can be said that the structure is a semi-open cell structure. The air permeability is preferably 5 to 70 [ml / cm ² / s], more preferably 10 to 60 [ml / cm ² / s], and more preferably 20 to 50 [ml / cm ² / s]. Is more preferable. Further, the method for confirming the semi-open cell structure can be confirmed by a photograph of a cross section in the same manner as the method for calculating the average cell diameter described below. FIG. 3 shows a cross-sectional SEM photograph. The center is an SEM photograph of the semi-open cell structure according to this embodiment.

The semi-open cell structure has smaller pores (holes) between adjacent bubbles than open bubbles, and unlike closed bubbles, it has small pores in the bubbles, and is more flexible than the structure with only closed bubbles. Even with a material, it is possible to create an escape route for air when it is in close contact with the adherend, and the followability is improved. On the contrary, when compared with the structure having only open cells, the surface in contact with the adherend becomes larger, a strong suction cup effect can be exhibited, and the adhesive strength becomes high.

(Average cell diameter and cell diameter distribution)
The average diameter (average cross-sectional cell diameter) of bubbles in the cross section of the porous foam layer 110 is preferably 200 μm or less, more preferably 150 μm or less, and particularly preferably 100 μm or less. The reason is that the finer the cell diameter, the larger the surface in contact with the adherend, and a stronger suction cup effect can be expected. The method for measuring the average cell diameter shall be as follows.

First, a photograph of a cross section of the porous foam layer 110 is taken using a scanning electron microscope (SEM, manufactured by Keyence Corporation, VHXD-500). Then, the diameter of each bubble (cell) is measured using the image processing software Image-Pro PLUS (6.3 ver manufactured by Media Cybernetics). More specifically, the contrast is adjusted in order to read the SEM image and recognize the bubbles (cells) by the contrast. Next, the shape of the foam (cell) is read by image processing (the shape is recognized as it is, not a perfect circle). Next, select "diameter (average)" as the measurement item. Next, the diameter passing through the center of gravity of the object is measured in increments of 2 degrees, and the diameter of each bubble (cell) is calculated as the average value.

(Distribution of bubble (cell) diameter)
Further, in the cross-sectional photograph, it is preferable that 70% or more of the bubbles are within ± 50 μm of the average diameter, more preferably within ± 30 μm, and particularly preferably within ± 20 μm. The reason is that when there is no variation, material breakage (material destruction) at the location of large bubbles is less likely to occur, and the delamination strength becomes stronger. Further, it is because the adhesive strength due to the suction cup effect can be stably obtained.

<Material>
The material of the porous foam layer 110 will be described in detail in the manufacturing method described later.

≪Surface layer≫
A known layer can be used as the surface layer (low stretch ratio layer), and the surface layer is not particularly limited. Since the surface layer is provided on one surface side of the porous foam layer, the porous foam layer having self-adhesiveness adheres to the adherend.

The expansion / contraction rate of the surface layer 120 is lower than the expansion / contraction rate of the porous foam layer. With such a configuration, the laminated sheet according to the present invention can be attached to the adherend without wrinkles. In addition, when affixed to an adherend that can expand and contract due to heat such as glass, the porous foam layer absorbs the expansion and contraction due to heat of glass and the like regardless of the expansion and contraction ratio of the surface layer, so that a space with a significantly different thermal environment can be created. Even if it is attached to a separating member (for example, window glass), thermal cracking does not occur. The expansion / contraction ratio will be described in detail later, but is measured in accordance with JIS K 6251.

The surface layer 120 can have a single-layer structure or a multi-layer structure. The surface layer 120 may also have a print layer on which a picture, a pattern, characters, or the like is printed.

<Material>
The material of the surface layer 120 will be described in detail in the manufacturing method described later.

≪Other layers (functional layers) ≫
As the laminated sheet 100 according to the present embodiment, in addition to the porous foam layer 110 and the surface layer 120, an appropriate layer can be provided depending on the purpose, for example, a layer for enhancing heat insulating properties and a layer for enhancing water retention. A layer or the like may be provided. When the expansion / contraction rate of these layers satisfies the above-mentioned properties and is provided on one surface side of the porous foam layer, it may also serve as a surface layer. Hereinafter, some layers that can be such functional layers will be illustrated and described.

<Print layer>
The printing layer is, for example, printing (for example, a picture, a pattern) on the front surface, the back surface (for example, when the layer is transparent), the inside (for example, the inner layer consisting of multiple layers when the layer is transparent), the whole, and the like. , Letters). In this case, (1) a layer that can be printed as a functional layer is separately provided, and (2) a surface layer (for example, when the functional layer can be seen through in the embodiment of FIG. 1 or FIG. 2), or the porous foam layer 110. (For example, the aspect in which the surface layer can be seen through in FIG. 1) itself may be used as the print layer. Here, when printing on the surface layer or the functional layer, examples of the material include a resin film and a paper material.

<Reflective layer>
The reflective layer is a layer that reflects light (for example, radio waves, infrared rays, visible light, ultraviolet rays, radiation, etc.), sound, and the like. For example, among the reflective layers, the mirror layer is a layer that totally or partially reflects visible light. The mirror layer can be obtained, for example, by depositing and laminating a vacuum vapor deposition plating layer on a transparent resin layer, film, or plate (for example, a resin mirror layer). The mirror layer functions as a mirror in the case of substantially total reflection and as a magic mirror in the case of partial reflection (partially transmitted). An example of a method for manufacturing a resin mirror layer is a method of forming a silver film by spraying aluminum particles (vacuum vapor deposition plating) onto, for example, a PET resin film. The resin mirror layer may be provided with the function as the surface printing layer.

<Whiteboard>
As the functional layer, a layer having a function as a whiteboard can be provided on the porous foam layer 110. Since the porous foam layer 110 is bonded to and adheres to the adherend (for example, a glass window or a metal plate), the whiteboard can be attached to the adherend without using a magnet, a fixture, or the like. A known whiteboard can be used.

[Production method]
The laminated sheet 100 according to this embodiment is a laminated body obtained by laminating a plurality of layers. The method for producing the porous foam layer 110 (lamination method) is not particularly limited, but a method of forming the surface layer 120 and then casting and curing the porous foam layer 110 on the surface layer is preferable. By casting the porous foam layer 110 directly on another layer in this way, the adhesion between the layers can be enhanced without using an adhesive or the like.

As a method for manufacturing the laminated sheet 100 (lamination method), in addition, each layer such as a sheet-shaped porous foam layer 110, a surface layer 120, and other layers is laminated in a desired order, and these are appropriately laminated with an adhesive or the like. It may be laminated by adhering, integrating, or the like.

Further, as a method for producing the porous foam layer 110 (lamination method), after the porous foam layer 110 is first formed, a dispersed slurry or the like including a surface layer is applied to the porous foam layer 110 directly or via another layer. It may be applied on top to form the surface layer 120, and the like.

Next, a specific manufacturing method of the porous foam layer 110 will be described in detail, and then a manufacturing method of the surface layer 120 will be described.

≪Manufacturing method of porous foam layer≫
The method for producing the porous foam layer 110 according to the present embodiment is a step of foaming an emulsion composition containing an emulsion and a foaming agent using a mechanical floss method to form a foam and curing the foam. including. It is preferable that the emulsion composition further contains a cross-linking agent, and in the step, energy is applied to cross-link the resin constituting the emulsion via the cross-linking agent to cure the foam. As a method for producing the porous foam layer 110, a raw material, a composition (blending amount), and a process (specific adjustment step) will be described in detail.

Further, in the method for producing the porous foam layer 110 according to the present embodiment, an amphoteric surfactant may be added in order to retain air bubbles. This is because the amphoteric tenside penetrates between the anionic surfactant as a foaming agent, which is called a booster effect.

<Raw materials>
The porous foam layer 110 according to this embodiment contains an emulsion, a foaming agent (anionic surfactant) as a raw material, water as a dispersion medium, a cross-linking agent, and other additives (note that it is used in the foaming step). The gas for foaming will be described in the foaming process).

(Emulsion)
The emulsion composition which is the raw material of the porous foam layer 110 according to this embodiment is an acrylic emulsion, an ethylene vinyl acetate copolymer resin emulsion, and a urethane emulsion of 0% by weight or more and less than 30% by weight based on the total amount of the emulsion. And are mixed. It is preferable to mix an acrylic emulsion of more than 10% by weight and 90% by weight or less and an ethylene-vinyl acetate copolymer resin emulsion of 10% by weight or more and less than 90% by weight, and further, the total of both emulsions is 70% by weight. It is preferable to mix them so as to exceed%. The porous foam layer obtained by using the emulsion may be referred to as acrylic foam.

An acrylic emulsion is used as the emulsion of the present invention because it is excellent in adhesive strength, light weight, and heat insulating property. Since the material strength of acrylic emasion alone is weak, an ethylene-vinyl acetate copolymer resin emulsion is added in order to improve the material strength and further increase the adhesive strength. By doing so, the material strength can be improved and the delamination strength against high adhesive strength can be increased, so that a foam having a semi-open cell structure having self-adhesive strength is produced, which is less likely to cause material destruction. It will be possible.

Examples of the emulsion contained therein include urethane emulsions, vinyl chloride emulsions, epoxy emulsions and the like. By using the urethane emulsion, the material strength can be further imparted, which is particularly suitable when the adherend is a sticky glass or the like. In addition, the obtained urethane resin foam has excellent flexibility and low compression residual strain.

-Acrylic emulsion As a method for producing an aqueous dispersion of acrylic resin (acrylic emulsion), a (meth) acrylic acid ester-based monomer is essential in the presence of a polymerization initiator, an emulsifier and a dispersion stabilizer as necessary. It can be obtained by using the above-mentioned polymerizable monomer component and, if necessary, copolymerizing a mixture of these monomers and other polymerizable monomers that can be copolymerized.

Examples of the polymerizable monomer that can be used for preparing the acrylic emulsion include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, and (meth). ) Hexyl acrylate, (meth) heptyl acrylate, octyl (meth) acrylate, octadecyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, nonyl (meth) acrylate, (meth) (Meta) acrylates such as dodecyl acrylate, stearyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate Ester-based monomers; acrylic acid, methacrylic acid, β-carboxyethyl (meth) acrylate, 2- (meth) acryloylpropionic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, itaconic acid half ester, maleic acid half Unsaturated bond-containing monomer having a carboxyl group such as ester, maleic anhydride, itaconic acid anhydride; glycidyl group-containing polymerizable monomer such as glycidyl (meth) acrylate and allylglycidyl ether; 2-hydroxyethyl (meth) Hydroxyl group-containing polymerizable monomers such as acrylate, 2-hydroxypropyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, and glycerol mono (meth) acrylate; ethylene glycol di (meth) acrylate, 1,6-hexanediol di. (Meta) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, diallyl phthalate, divinylbenzene, allyl (meth) acrylate Etc. can be exemplified.

When an emulsifier is used when preparing an acrylic emulsion, the above-mentioned emulsifier or the like may be used.

-Emulsion of ethylene vinyl acetate copolymer resin As a method for producing an ethylene vinyl acetate copolymer resin emulsion, for example, polyvinyl alcohol or the like is used as a protective colloid, and a cellulosic derivative such as hydroxyethyl cellulose or a surfactant is used as an emulsifying dispersant. However, it can be obtained by copolymerizing ethylene and a vinyl acetate monomer by an emulsion polymerization method.

The ethylene vinyl acetate copolymer resin emulsion may be further copolymerized with, for example, a vinyl monomer having a functional group such as a carboxyl group, an epoxy group, a sulfonic acid group, a hydroxyl group, a methylol group or an alkoxyic acid group. good.

-Urethane emulsion As a method for adjusting the aqueous dispersion (urethane emulsion) of the urethane resin, the following methods (I) to (III) can be exemplified.
(I) Neutralize with an organic solvent solution or organic solvent dispersion of a urethane resin having a hydrophilic group obtained by reacting an active hydrogen-containing compound, a compound having a hydrophilic group, and a polyisocyanate, if necessary. A method of obtaining a urethane resin emulsion by mixing an aqueous solution containing an agent.
(II) Whether to mix an active hydrogen-containing compound, a compound having a hydrophilic group, and a terminal isocyanate group-containing urethane prepolymer having a hydrophilic group obtained by reacting polyisocyanate with an aqueous solution containing a neutralizing agent. Alternatively, a method in which a neutralizing agent is added to a prepolymer in advance, water is mixed and dispersed in water, and then reacted with a polyamine to obtain a urethane resin emulsion.
(III) An active hydrogen-containing compound, a compound having a hydrophilic group, and a terminal isocyanate group-containing urethane prepolymer having a hydrophilic group obtained by reacting with a polyisocyanate are mixed with an aqueous solution containing a neutralizing agent and a polyamine. Or, after adding a neutralizing agent to the prepolymer in advance, an aqueous solution containing a polyamine is added and mixed to obtain a urethane resin emulsion.

Examples of the polyisocyanate used in the preparation of the urethane resin include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m-phenylenedi isocyanate, p-fuphenylenedi isocyanate, 4,4'-diphenylmethane diisocyanate, and 2,4. '-Diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 3,3'-dimethyl-4,4'-biphenylenediisocyanate, 3,3'-dimethoxy-4,4'-biphenylenediisocyanate, 3,3'-dichloro- 4,4'-biphenylenediocyanate, 1,5-naphthalenediocyanate, 1,5-tetrahydronaphthalenediocyanate, tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, dodecamethylene diisocyanate, trimethylhexamethylene diisocyanate, 1,3-cyclohexylene Diisocyanate, 1,4-cyclohexamethylene diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, hydrogenated xylylene diisocyanate, lysine diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 3,3'-dimethyl-4, Examples thereof include 4'-dicyclohexylmethane diisocyanate. Further, a polyisocyanate having a valence of 3 or more may be used in combination as long as the effect of the invention is not impaired.

Examples of the compound having a hydrophilic group include polyester polyols, polyether polyols, polycarbonate polyols, polyacetal polyols, polyacrylate polyols, polyesteramide polyols, polythioether polyols, and polyolefin polyols such as polybutadienes. Two or more of these high molecular weight compounds may be used in combination. As the polyester polyol, known ones may be used.

In the above methods (I) to (III), an emulsifier may be further used as long as the effect of the invention is not impaired. Examples of the emulsifier include nonionic emulsifiers such as polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl ether, polyoxyethylene styrene phenyl ether, and polyoxyethylene sorbitol tetraoleate; fatty acid salts such as sodium oleate, and alkyl. Anionic emulsifiers such as sulfate ester salt, alkylbenzene sulfonate, alkylsulfosuccinate, naphthalenesulfonate, alkanesulfonate sodium salt, alkyldiphenyl ether sulfonate sodium salt; polyoxyethylene alkyl sulfate, polyoxyethylene alkylphenyl sulfate And the like, nonionic anionic emulsifiers, etc. can be exemplified.

(Dispersion medium)
In this embodiment, the dispersion medium of the emulsion composition contains water as an essential component, but may be a mixture of water and a water-soluble solvent. The water-soluble solvent is, for example, alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, ethyl carbitol, ethyl cellosolve, butyl cellosolve, polar solvents such as N-methylpyrrolidone, and one or more of these. A mixture of the above may be used.

(Foaming agent (anionic surfactant))
The anionic surfactant (foaming anionic surfactant) functions as a foaming agent in the emulsion composition.

Specific examples of anionic surfactants include sodium laurate, sodium myristate, sodium stearate, ammonium stearate, sodium oleate, potassium oleate soap, potassium castor oil soap, potassium palm oil soap, and sodium lauroyl sarcosin. Mirithoyl sarcosin sodium, oleyl sarcosin sodium, cocoyl sarcosin sodium, palm oil alcohol sodium sulfate, polyoxyethylene lauryl ether sodium sulfate, alkyl sulfosuccinate sodium, lauryl sulfoacetate sodium, alkylbenzene sulfonate sodium, α-olefin sulfonate sodium, etc. Although mentioned above, sodium alkylsulfosuccinate is particularly preferable.

Here, the anionic surfactant used in the present embodiment preferably has an HLB of 10 or more, more preferably 20 or more, and more preferably 20 or more, in order to facilitate dispersion in the emulsion composition. The above is particularly preferable.

・ HLB
In the present invention, the HLB value means a hydrophilic-hydrophobic balance (HLB) value, and is obtained by the Oda method. The method of obtaining HLB by the Oda method is described in "Introduction to New Surfactants", pp. 195-196 and "Synthesis and Application of Surfactants" by Ryohei Oda, published by Maki Shoten on March 20, 1957. It is described on page 502 and can be determined by HLB = (inorganic / organic) × 10.

(Amphoteric surfactant)
In the porous foam layer 110 according to the present embodiment, bubbles are made fine and uniform by using an amphoteric surfactant in addition to the anionic surfactant.

In particular, when an anionic surfactant and an amphoteric surfactant are used in combination, the charge of the hydrophilic group between the molecules of the anionic surfactant repels each other, and the molecules of the anionic surfactant maintain a certain distance from each other. In addition, the electrically neutral double-sided activator penetrates between the molecules of the anionic surfactant, so that the bubbles can be further stabilized and the size of the bubbles can be reduced. Therefore, the delamination strength can be improved. Therefore, it is preferable to use an anionic surfactant and an amphoteric surfactant in combination.

The amphoteric tenside that can be used in the present invention is not particularly limited, and an amino acid type, betaine type, amine oxide type or the like can be used. Betaine-type amphoteric tenside agents are suitable because they have higher effects as described above. Further, from the viewpoint of easy entry of the anionic surfactant between the molecules, those of C10 to 12 are preferable.

Examples of the amino acid type amphoteric tenside agent include N-alkyl or alkenyl amino acids or salts thereof. The N-alkyl or alkenyl amino acid has an alkyl group or an alkenyl group bonded to a nitrogen atom, and further one or two "-R-COOH" (in the formula, R represents a divalent hydrocarbon group, preferably. It is an alkylene group, and particularly preferably has a structure in which a group represented by 1 to 2 carbon atoms is bonded. In the compound to which one "-R-COOH" is bonded, a hydrogen atom is further bonded to the nitrogen atom. One "-R-COOH" is called a mono body, and two things are called a di body. As the amphoteric tenside agent according to the present invention, either mono-form or di-form can be used. In N-alkyl or alkenyl amino acids, the alkyl group and the alkenyl group may be linear or branched chain. Specific examples of the amino acid type amphoteric tenside include sodium lauryldiaminoethylglycine, sodium trimethylglycine, sodium cocoyl taurine, sodium cocoyl methyl taurine, sodium lauroyl glutamate, potassium lauroyl glutamate, and lauroylmethyl-β-alanine. Be done.

Examples of the betaine-type amphoteric surfactant include alkyl betaine, imidazolinium betaine, carbobetaine, amide carbobetaine, amide betaine, alkylamide betaine, sulfobetaine, amide sulfobetaine, and phosphobetaine. Specifically, as betaine-type amphoteric surfactants, lauryl betaine, stearyl betaine, lauryldimethylaminoacetic acid betaine, stearyldimethylaminoacetic acid betaine, lauric acid amidopropyldimethylaminoacetic acid betaine, isostearate amidoethyldimethylaminoacetic acid betaine, Betaine amide propyldimethylaminoacetic acid isostearate, betaine amide ethyl isocyanateaminoacetate isostearate, betaine amide propyldiethylaminoacetate isostearate, amide ethyl isostearate dimethylaminohydroxysulfobetaine, propyldimethylaminohydroxysulfobetaine isostearate, ethyl diethylamino isostearate. Hydroxysulfobetaine, isostearate amidopropyldiethylaminohydroxysulfobetaine, N-lauryl-N, N-dimethylammonium-N-propylsulfobetaine, N-lauryl-N, N-dimethylammonium-N- (2-hydroxypropyl) sulfo Betaine, N-lauryl-N, N-dimethyl-N- (2-hydroxy-1-sulfopropyl) ammonium sulfobetaine, laurylhydroxysulfobetaine, dodecylaminomethyldimethylsulfopropyl betaine, octadecylaminomethyldimethylsulfopropyl betaine, 2 -Alkyl-N-carboxymethyl-N-hydroxyethyl imidazolinium betaine (2-lauryl-N-carboxymethyl-N-hydroxyethyl imidazolinium betaine 2-stearyl-N-carboxymethyl-N-hydroxyethyl imidazolinium) (Betaine, etc.), coconut oil fatty acid amide propyl betaine, coconut oil fatty acid amide propyl hydroxysultaine and the like.

Examples of the amine oxide type amphoteric surfactant include lauryldimethylamine-N-oxide, oleyldimethylamine-N-oxide and the like.

Among the amphoteric tensides described above, it is preferable to use a betaine type amphoteric surfactant in the method for producing the porous foam layer 110 according to the present invention, and among the betaine types, alkyl betaine and imidazolinium betaine. , Carbobetaine is particularly preferred. Examples of the alkyl betaine that can be used in the present invention include stearyl betaine and lauryl betaine, and examples of the imidazolinium betaine include 2-alkyl-N-carboxymethyl-N-hydroxyethyl imidazolinium betaine. ..

(Crosslinking agent (curing agent))
In the method for adjusting the porous foam layer 110 according to the present embodiment, the strength is improved by using a cross-linking agent (curing agent).

The cross-linking agent is not particularly limited, and a required amount may be added depending on the intended use. Examples of the cross-linking method using a cross-linking agent include physical cross-linking, ionic cross-linking, and chemical cross-linking, and the cross-linking method can be selected according to the type of the water-dispersible resin. As the cross-linking agent, a known cross-linking agent can be used, and the functionality contained in the resin compounding system using an epoxy-based cross-linking agent, a melamine-based cross-linking agent, an isocyanate-based cross-linking agent, a carbodiimide-based cross-linking agent, an oxazoline-based cross-linking agent, and the like. An appropriate amount can be used depending on the type of group and the amount of functional group. Epoxy-based cross-linking agents and isocyanate-based cross-linking agents are preferable in order to improve the adhesive strength, tack strength and delamination strength. Of these, aliphatic isocyanates are more preferable. Two or more of these cross-linking agents may be used in combination.

(Other additives)
As other additives, a surfactant (emulsifier) for dispersing a water-dispersible resin may be added.

-Surfactant for Dispersing Water Dispersible Resin The surfactant for dispersing water-dispersible resin according to this embodiment is a surfactant for dispersing the water-dispersible resin (unlike anionic surfactants). It does not have to have an effect as a foaming agent). Such a surfactant may be appropriately selected depending on the water-dispersible resin to be selected.

<Composition>
(Mixing amount and ratio of each raw material)
The blending amount of the water-dispersible resin (solid content) with respect to the liquid medium is preferably 30 to 80 parts by weight with respect to 100 parts by weight of the liquid medium. Within such a range, the effect that a stable foam can be molded can be obtained.

-Mixing ratio in emulsion composition Regarding the blending amount in the emulsion composition, it is preferable to contain an acrylic emulsion in an amount of more than 10% by weight and 90% by weight or less based on the total amount of the emulsion. It is more preferably 20% by weight or more and 80% by weight or less, and further preferably 30% by weight or more and 75% by weight or less.

Further, it is preferable to contain an ethylene-vinyl acetate copolymer resin emulsion of 10% by weight or more and less than 90% by weight based on the total amount of the emulsion. It is more preferably 20% by weight or more and 80% by weight or less, and further preferably 25% by weight or more and 75% by weight or less. This is because if the content is 90% by weight or more, it becomes difficult to produce a foam by the mechanical floss method, and the flexibility, adhesive strength and tack strength are lost.

Further, it is preferable that the acrylic emulsion and the ethylene-vinyl acetate copolymer resin emulsion are contained in an amount of more than 70% by weight in total based on the total amount of the emulsion. It is more preferable to contain 80% by weight or more or more.

As the blending amount of the urethane emulsion, the urethane emulsion may be contained in an amount of 0% by weight or more and less than 30% by weight based on the total amount of the emulsion. Further, it is preferably 20% by weight or less. This is because, within this range, the material strength can be increased, flexibility can be imparted, and the adhesive strength also satisfies the desired properties.

The amount of the anionic surfactant to be blended is preferably 1.0 to 10 parts by weight, more preferably 3 to 10 parts by weight, with the total amount of the emulsion being 100 parts by weight in the emulsion composition. Within such a range, it is easy to form an appropriate foam, and an effect that a fine cell structure can be formed can be obtained.

The amount of the amphoteric tenside agent to be blended is preferably 0.5 to 10 parts by weight, more preferably 1 to 5 parts by weight, with the total amount of the emulsion being 100 parts by weight in the emulsion composition. Within such a range, it is easy to form an appropriate foam, and an effect that a fine cell structure can be formed can be obtained.

The amount of the cross-linking agent (curing agent) to be blended is preferably 0.1 to 20 parts by weight, more preferably 1 to 10 parts by weight, with the total amount of the emulsion being 100 parts by weight in the emulsion composition. Within such a range, it is possible to obtain an effect that a foam having a small residual compression strain can be formed.

<Manufacturing method>
In the method for producing the porous foam layer 110 according to the present embodiment, a raw material preparation step and an emulsion composition containing an emulsion and a foaming agent are foamed by a mechanical floss method to form a foam, and the foaming is performed. Includes a step of hardening the body (foaming / hardening step). The emulsion composition may further contain a cross-linking agent, and the foam may be cured by applying energy in the step to cross-link the resin constituting the emulsion via the cross-linking agent. Hereinafter, each step will be described in detail.

(Raw material preparation process)
In the raw material preparation step, an emulsion composition which is a raw material mixture of the porous foam layer 110 is prepared by mixing each raw material as described above. The mixing method at this time is not particularly limited, but for example, mixing may be performed while stirring in a container such as a mixing tank in which each component is mixed.

(Foaming / curing process)
In the foaming / curing step, a predetermined foaming gas is added to the emulsion composition obtained in the raw material preparation step, and these are sufficiently mixed to allow a large number of bubbles to exist in the emulsion composition (foaming emulsion composition). ). This foaming / curing step is usually carried out by sufficiently mixing the raw material mixture of the liquid porous foam obtained in the raw material preparation step with the foaming gas by a mixing device such as a mixing head.

-Effervescent gas The effervescent gas mixed in the emulsion composition in the stirring and effervescent steps forms bubbles (cells) in the porous foam layer 110, and is obtained by the amount of the effervescent gas mixed in. The foaming ratio and density of the porous foam layer 110 are determined. In order to adjust the density of the porous foam, it is necessary from the desired density of the porous foam and the volume of the raw material of the porous foam (for example, the internal volume of the molding mold into which the raw material of the porous foam is injected). The weight of the raw material of the porous foam may be calculated, and the amount of the foaming gas may be determined so as to have a desired volume at this weight. Air is mainly used as the type of gas for foaming, but an inert gas such as nitrogen, carbon dioxide, helium, or argon can also be used.

Foaming method and foaming conditions As the foaming method used in the method for adjusting the porous foam layer 110 according to the present invention, a mechanical floss (mechanical flossing) method is used. The mechanical floss method is a method in which air in the atmosphere is mixed with the emulsion composition and foamed by stirring the emulsion composition with a stirring blade or the like. As the stirring device, a stirring device generally used in the mechanical floss method can be used without particular limitation, and for example, a homogenizer, a dissolver, a mechanical floss foaming machine and the like can be used. According to this mechanical floss method, by adjusting the mixing ratio of the emulsion composition and air, it is possible to obtain a porous foam having a density suitable for various uses. Although it is possible to use other foaming methods in combination, when the foaming method using a chemical foaming agent is used in combination, the proportion of closed cells increases, resulting in a higher density, and the flexibility and elasticity of the porous foam. May be unfavorable as the production method according to the present invention, such as loss of.

The mixing time of the emulsion composition and air is not particularly limited, but is usually 1 to 10 minutes, preferably 2 to 6 minutes. The mixing temperature is not particularly limited, but is usually normal temperature. Further, the stirring speed in the above mixing is preferably 200 rpm or more (more preferably 500 rpm or more) in order to make the bubbles finer, and preferably 2000 rpm or less (800 rpm or less is preferable) in order to smooth the discharge of the foam from the foaming machine. More preferred).

-Formation of foam The emulsion composition foamed as described above (foamed emulsion composition) is in the form of a sheet or the like according to a desired thickness of the porous foam by a known means such as a doctor knife or a doctor roll. Formed on the foam of.

-A known method can be used as a method for curing the cured foam. The foam according to this embodiment can be self-crosslinked, but the foam may be cured by applying energy to crosslink the resin constituting the emulsion via a crosslinking agent. The step of applying energy is not particularly limited, and examples thereof include a heating step (thermal cross-linking).

In the heating step, the dispersion medium in the molded foamed emulsion composition is evaporated. The drying method at this time is not particularly limited, but for example, hot air drying or the like may be used. Further, the drying temperature and the drying time are not particularly limited, but may be, for example, about 1 to 3 hours at about 80 ° C.

Further, in this heating step, the dispersion medium evaporates from the foamed emulsion composition, and the path through which the vapor escapes is communicated from the inside to the outside of the porous foam. Therefore, in the porous foam layer 110 according to the present embodiment, since the path through which the water vapor escapes remains as open cells, at least a part of the bubbles existing in the porous foam becomes open cells. Here, if the foaming gas mixed in the stirring / foaming step remains as it is, it becomes closed cells in the obtained porous foam, and the mixed foaming gas escapes steam in this step. When communicated with each other, open cells are formed in the obtained porous foam. That is, in the present invention, a structure is such that a part of the bubbles in the porous foam is an open cell and the remaining bubbles are closed cells, and the structure is a semi-open cell structure in which open cells and closed cells are mixed.

When a cross-linking agent is added, the heating step proceeds and completes the cross-linking (curing) reaction of the raw material. Specifically, the raw materials are crosslinked with each other by the above-mentioned cross-linking agent to form a cured porous foam. The heating means at this time is not particularly limited as long as the raw material can be sufficiently heated and the raw material can be crosslinked (cured), but for example, a tunnel type heating furnace or the like can be used. Further, the heating temperature and heating time may be any temperature and time as long as the raw material can be crosslinked (cured), and may be, for example, about 1 hour at 80 to 150 ° C. (particularly about 120 ° C.). ..

<< Preparation method of surface layer 120 >>
Next, a method for preparing the surface layer 120 will be described.

The surface layer 120 is provided on one surface of the porous foam layer, and the expansion / contraction rate is lower than the expansion / contraction rate of the porous foam layer. As long as it satisfies this property, it is not limited in any way, and includes, for example, a film, paper, synthetic paper, cloth, synthetic resin, and the like. These may be used alone or in combination. As the surface layer 120, for example, polyester film, polypropylene film, polystyrene film, vinyl chloride film, olefin film, polyimide film and other films, synthetic paper, high-quality paper, coated paper, art paper, cast coated paper, super cast paper, water resistant. Examples include paper, kraft paper, recycled paper, impregnated paper, Kent paper, heat-sensitive paper and other papers, and cloths. From the manufacturing method described later, a sheet having low elasticity that does not allow the raw material to permeate is preferable.

Examples of the film material used for the surface layer 120 include polyethylene film (PE film), polyvinyl chloride film (PVC film), polyvinylidene chloride film (PVDC film), polyvinyl alcohol film (PVA film), and polypropylene film (PP film). , Polyester film, Polycarbonate film (PC film), Polystyrene film (PS film), Polyacrylonitrile film (PAN film) Ethylene vinyl acetate copolymer film (EVA film), Ethylene-vinyl alcohol copolymer film (EVOH film), Examples thereof include ethylene-methacrylic acid copolymer film (EMAA film), nylon film (NY film, polyamide (PA) film), cellophane, ionomer film (IO film), and the like. As the film material used for the surface layer 120, various metals and magnetic materials can also be applied. These may be used alone or in combination. The film material is not limited to the above example.

As the paper material used for the surface layer 120, various types such as high-quality paper, coated paper, foil paper, kraft paper, recycled paper, synthetic paper, impregnated paper, Kent paper, and heat-sensitive paper can be applied. These may be used alone or in combination. The paper material is not limited to the above example.

The cloth material used for the surface layer 120 may include, for example, cotton, gauze, double gauze, organge, woven fabric and the like. These may be used alone or in combination. The cloth and its material are not limited to the above examples.

Examples of the synthetic resin used for the surface layer 120 include phenol resin (PF), epoxy resin (EP), melamine resin (MF), urea resin (ureia resin, UF), unsaturated polyester resin (UP), alkyd resin, and polyurethane (ulicide resin). PUR), thermosetting polyimide (PI) polyethylene (PE) (including high density polyethylene (HDPE), medium density polyethylene (MDPE), low density polyethylene (LDPE)), polypropylene (PP), polyvinyl chloride (PVC) , Polyvinylidene chloride, Polystyrene (PS), Polyvinyl acetate (PVAc), Teflon (registered trademark) (Polytetrafluoroethylene, PTFE), ABS resin (Acrylonitrile butadiene styrene resin), AS resin, Acrylic resin (PMMA), Polyamide (PA) (including nylon), polyacetal (POM), polycarbonate (PC), modified polyphenylene ether (m-PPE, modified PPE, PPO), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), glass fiber reinforced polyethylene. Telephthalate (GF-PET), Cyclic Polyolefin (COP), Polyphenylene Sulfide (PPS), Polysulfone (PSF), Polyether Sulfone (PES), Acrylic Polyarylate (PAR), Liquid Crystal Polymer (LCP), Polyether Ether Examples thereof include ketones (PEEK), thermoplastic polyimides (PI), polyamideimides (PAI) and the like. These may be used alone or in combination. The synthetic resin is not limited to the above example.

As the surface layer 120, as described above, a sheet such as a film or a non-woven fabric can be used as a base material. The basis weight of the non-woven fabric is, for example, 5 to 100 g / m ² .

[nature]
According to the laminated sheet 100 according to the present embodiment, it is difficult for air to accumulate, and even if it is formed, air can be easily evacuated by simply pressing it from above. This property can be evaluated by a breathability test because of the semi-open cell structure.

Further, it can be attached to an adherend having a smooth surface such as ceramics, metal, plastic, and glass with strong adhesive strength. Further, it can be similarly attached to surface-treated glass having irregularities on the surface such as frosted glass, frosted glass, and template glass with a strong adhesive force. This property can be evaluated by the adhesive strength.

Further, when peeling off, since the adhesive is not applied or impregnated, the adhesive can be peeled off from the joint without migrating to the adherend, so that the product can be used repeatedly. Moreover, since the material strength is high when peeled off, it can be used repeatedly. The ability to be used repeatedly can be evaluated by the delamination strength.

During use, as described above, the porous foam layer absorbs expansion and contraction due to heat of glass and the like, so that thermal cracking does not occur even if it is attached indoors.

Since the laminated sheet 100 according to this embodiment has a light-shielding property, it can be suitably used as a light-shielding sheet. The light-shielding property can be evaluated by the solar transmittance and the ultraviolet absorption rate. Further, it may have a heat insulating property. Insulation can be evaluated by thermal conductivity.

-Breathability Breathability is evaluated by the value measured using a Frazier type breathability tester in accordance with JIS L 1096 A method. If the air permeability is 2 [ml / cm ² / s] or more and less than 80 [ml / cm ² / s], it can be said that it has a semi-open cell structure. It is preferably 5 [ml / cm ² / s] or more and less than 70 [ml / cm ² / s], preferably 10 [ml / cm ² / s] or more and less than 60 [ml / cm ² / s]. More preferably, it is more than 20 [ml / cm ² / s] and more preferably less than 50 [ml / cm ² / s].

・ Adhesive strength (90 ° peel strength)
Adhesive strength (90 ° peel strength) is based on JIS Z 0237, punched to 24 mm width x 150 mm, and a foam with one-sided adhesive tape attached to the surface (non-adhesive surface) to eliminate the influence of elongation is 30 mm width x It is attached to 200 mm glass, reciprocated twice with a 2 kg roller, crimped, and left at room temperature for 24 hours. Then, the test force of pulling up at a speed of 300 mm / min (90 ° peeling) is measured using an autograph, and the adhesive strength (90 ° peeling strength) (N / 24 mm) is used for evaluation. The adhesive strength is preferably 1.0 N / 24 mm or more, and more preferably 1.5 N / 24 mm or more. When the adhesive strength is less than 1.0 N / 24 mm, there is a problem that the adhesive strength is weak.

・ Delamination strength (material strength)
Delamination strength was measured as an index showing the material strength of the porous foam of the present invention. Specifically, the delamination strength is as follows: the foam is punched to a width of 12 mm × 150 mm, double-sided tape is attached to both sides of the foam, and a backing film (PET film) having a width of 12 mm × 200 mm is attached to both sides thereof. It is reciprocated and crimped several times and left in a furnace at 85 ° C for 24 hours. Then, the backing film was pulled at a speed of 1000 mm / min using an autograph after being left at room temperature for 1 hour or more (T-shaped peeling), and the test force was measured and evaluated by determining the delamination strength (N / 12 mm). The delamination strength is preferably 2.0 N / 12 mm or more, and more preferably 4.0 N / 12 mm or more. If the delamination strength is less than 2.0 N / 12 mm, there is a problem that the delamination is broken at the time of delamination and cannot be used repeatedly.

-Flexibility According to JIS K 6254, flexibility is evaluated with a 25% compressive load. The stress when crushing a φ50 sample (porous foam layer) at a rate of 1.0 mm / min until it reaches 25% of the original thickness of the sample is measured. This 25% compressive load is preferably 0.02 MPa or less, and more preferably 0.01 MPa or less. This is because when the 25% compressive load is 0.02 MPa or less, the adherend has more sufficient followability even when it has some irregularities or has a large elasticity.

-In this form, in order to satisfy the good workability at the time of sticking, it is necessary that the elasticity of the low elasticity layer (surface layer) is lower than that of the porous foam layer. The expansion / contraction rate of the porous foam layer is evaluated in accordance with JIS K 6251. Specifically, the tensile strain generated in the test piece by the tensile stress, expressed as a ratio to the initial length, is measured. The measured tensile strain of the porous foam layer is preferably 100% or more, more preferably 300% or more. This is because if it is 100% or more, the expansion and contraction of the adherend can be sufficiently absorbed.

-Light-shielding property The light-shielding property is evaluated by the solar transmittance (JIS R 3106) and the ultraviolet absorption rate (ISO 9050). The solar transmittance is preferably less than 40%, more preferably less than 30%. When the solar transmittance is 40% or more, the light-shielding property is insufficient. The ultraviolet absorption rate is preferably 80% or more, and more preferably 90% or more. If the UV absorption rate is less than 80%, the UV absorption rate is insufficient.

-Heat insulation The heat insulation depends on the material and thickness of the porous foam layer. It may be changed as appropriate according to the purpose of use. Further, a layer for enhancing the heat insulating property may be provided. The heat insulating property conforms to JIS A 1412-1 and can be evaluated by measuring the thermal conductivity. Examples of the measuring device include a thermal conductivity measuring device (auto Λ) HC-072 (manufactured by Eiko Seiki Co., Ltd.).

[Use]
The laminated sheet 100 according to this embodiment can be applied to various uses due to its properties. Examples of such applications are calendars, wallpaper (cloth), stain / scratch prevention covers, photo printing media, advertising media (printing), warning boards, panels (used at exhibitions, etc.), and seasonal decorations. Goods, toys, puzzles, stress relief goods, luncheon mats, elbow pads, mouse pads, magnet substitutes, picture tack substitutes, double-sided tapes, sticky sticks, slip prevention materials, packing materials, glass cushioning materials (bottles, wines, bottles, etc.) ) And grip cushioning agents and the like. Further, since it has a light-shielding property, it can be widely used for the purpose of light-shielding window glass and the like and preventing privacy invasion. It can also be widely used for purposes such as preventing glass from scattering and dew condensation. Further, as a functional layer, a reflective layer can be provided to be used for a mirror, a magic mirror, or the like, and a layer having a function as a whiteboard can be provided to be used as a message board or the like. Further, it is suitable for adherends such as ceramics, metals, plastics, and glass, which may cause thermal expansion in an environment where temperature changes are repeated (for example, near windows, near PC equipment, in automobiles, in factories). Can be used for.

Further, since it has a heat insulating property, it can be widely used for the purpose of heat insulating. In this case, as described above, the configuration may be such that the heat insulating property is enhanced.

Next, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these examples.

[material]
≪Porous foam raw material≫
First, in this example and the comparative example, the following raw materials were used as raw materials for the porous foam.
<Water-dispersible resin>
・ Acrylic emulsion 1
Acrylonitrile, acrylic acid alkyl ester, itaconic acid copolymer, pH 9, solid content 60%
・ Acrylic emulsion 2
Ethyl acrylate, methyl methacrylate copolymer, pH 9, solid content 60%
-Ethylene-vinyl acetate copolymer resin emulsion Ethylene-vinyl acetate copolymer resin emulsion, pH 8.5, solid content 55%
<Foaming agent>
-Anionic surfactant 1
Sodium alkyl sulfosuccinate, pH 9.4, solid content 30%, HLB 39.7
-Anionic surfactant 2
Alkyl betaine, fatty acid alkaminoamide, diethanolamine, anionic surfactant mixed system pH 7, solid content 40%
・ Amphoteric foaming agent 3
Alkyl betaine, pH 10, solid content 40%
<Crosslinking agent>
・ Crosslinking agent 1
Epoxy compound, number of functional groups 6
・ Crosslinking agent 2
Hydrophobic HDI isocyanurate, number of functional groups 3.5

<Porous medium raw material 1>
Acrylic emulsion and ethylene vinyl acetate copolymer resin emulsion are used as the main ingredients, and 3 parts by weight of anionic foaming agent 1 and 3 parts by weight of anionic foaming agent 2 and 1 weight are used for 50:50 parts by weight each. A portion of the amphoteric foaming agent 3 and 2.5 parts by weight of the cross-linking agent were mixed to obtain a porous foam raw material 1 (corresponding to Example 1).
<Porous medium raw material 2-22>
A foam raw material was prepared in the same manner as the porous foam raw material 1 except that the raw materials were blended in the proportions shown in Tables 1 and 2 (corresponding to Examples 2-22).
<Porous medium raw material 23-31>
A foam raw material was prepared in the same manner as the porous foam raw material 1 except that the raw materials were blended in the proportions shown in Table 2 (corresponding to Comparative Examples 1-9).

≪Base material≫
The following materials were used as the base material for supporting the foam.
<Base material>
・ Base material 1
PET film that has been released (0.038 mm)

[Formation of laminated sheet]
<< Preparation of Example 1 >>
An inert gas such as air or nitrogen gas is added to the porous foam raw material 1, foamed by the mechanical floss method (foaming condition 100 to 1000 rpm), cast on the base material 1, and then heat-treated (oven or drying furnace). ), The laminated sheet according to Example 1 was obtained.
<< Preparation of Example 2-22 >>
A laminated sheet according to Example 2-22 was obtained in the same manner as in Example 1 except that the porous foam raw material used was changed to the porous foam raw material 2-22.
<< Comparative Example 1-9 >>
A laminated sheet (light-shielding foam with a front sheet) according to Comparative Example 1-9 was obtained in the same manner as in Example 1 except that the porous foam raw material used was changed to the porous foam raw material 23-31.

[Evaluation test]
Next, the laminated sheets (Examples 1 to 22 and Comparative Examples 1 to 9) were measured and evaluated. The results are shown in Tables 1 and 2.
-Appearance The surface of the foam was visually evaluated. The state of the cell was evaluated from a cross-sectional image of the foam by a scanning electron microscope. If the surface of the foam is not ruptured or roughened due to cell coalescence and the cell is uniform, "○", if the surface is slightly rough, and if the cell is rough, "△", the surface is rough and the cell is very rough. In the case, and when the cell was not formed (not foamed), it was evaluated as "x".
-Bubble structure The foam structure was evaluated by measuring the air permeability. If it is 2 [ml / cm ² / s] or more and 80 [ml / cm ² / s], a semi-open cell structure is used.
-Thickness The thickness was measured with a thickness gauge.
-Density Measured by calculating the weight per unit volume.
・ Flexibility (25% compression load)
Flexibility was evaluated at a 25% compressive load according to JIS K 6254. The stress when the φ50 sample is crushed at a speed of 1.0 mm / min until it reaches a thickness of 25% of the original thickness of the test piece is measured. When the measured stress was 0.01 MPa or less, it was evaluated as “◯”, when it was higher than 0.01 MPa and 0.02 MPa or less, it was evaluated as “Δ”, and when it was higher than 0.02 MPa, it was evaluated as “×”.
-Stretchability The elasticity was evaluated according to JIS K 6251. Specifically, the tensile strain generated in the test piece by the tensile stress, expressed as a ratio to the initial length, was measured. When the measured tensile strain was 300% or more, it was evaluated as "◯", when it was 100% or more and less than 300%, it was evaluated as "Δ", and when it was less than 100%, it was evaluated as "x".
・ Adhesive strength (90 ° peel strength)
In accordance with JIS Z 0237, punch out to a width of 24 mm x 150 mm, and attach a foam with a single-sided adhesive tape on the surface (the one that is not the adhesive surface) on the surface (the side that is not the adhesive surface) on a glass of 30 mm width x 200 mm, and use a 2 kg roller to 2 It is reciprocated and crimped and left at room temperature for 24 hours. Then, using an autograph, the test force of pulling up at a speed of 300 mm / min (90 ° peeling) is measured and used as the adhesive strength (90 ° peeling strength) (N / 24 mm). "○" when the adhesive strength (90 ° peel strength) is 1.5N / 24mm or more, "△" when the adhesive strength (90 ° peel strength) is 1.0N / 24mm or more and less than 1.5N / 24mm, adhesive When the strength (90 ° peel strength) was less than 1.0 N / 24 mm, it was evaluated as “x”.
・ Delamination strength (material strength)
Punch the foam to a width of 12 mm x 150 mm, attach double-sided tape to both sides of the foam, attach a backing film (PET film) of 12 mm width x 200 mm to both sides, and reciprocate twice with a 2 kg roller to crimp it into a furnace at 85 ° C. Leave for 24 hours. Then, the film was left at room temperature for 1 hour or more, and the backing film was pulled at a speed of 1000 mm / min using an autograph (T-shaped peeling), and the test force was measured to determine the delamination strength (N / 12 mm). “○” when the delamination strength is 4.0 N / 12 mm or more, “Δ” when the delamination strength is 2.0 N / 12 mm or more and less than 4.0 N / 12 mm, and the delamination strength is less than 2.0 N / 12 mm. In the case, it was evaluated as "x".
-Solar transmittance The solar transmittance was measured by an ultraviolet-visible spectrophotometer. When the solar transmittance was less than 30%, it was evaluated as "◯", when the solar transmittance was 30% or more and less than 40%, it was evaluated as "Δ", and when the solar transmittance was 40% or more, it was evaluated as "x".
-Ultraviolet absorption rate The ultraviolet transmittance was measured with an ultraviolet-visible spectrophotometer. When the ultraviolet absorption rate was 90% or more, it was evaluated as "◯", when the ultraviolet absorption rate was 80% or more and less than 90%, it was evaluated as "Δ", and when the ultraviolet absorption rate was less than 80%, it was evaluated as "x".

The heat insulating property was in accordance with JIS A 1412-1, and the thermal conductivity was measured using a thermal conductivity measuring device (Auto Λ) HC-072 (manufactured by Eiko Seiki Co., Ltd.). When Examples 13 and 22 were compared with the existing laminated sheet (manufactured by DuPont, Tyvek), the thermal conductivity of Examples 13 and 22 was lower. It was confirmed that the product has sufficient heat insulating properties.

As shown in Tables 1 and 2, the examples are Δ or ◯ in the evaluation items of the adhesive strength and the delamination strength, and the object of the present invention is achieved. It was found that good adhesive strength was exhibited for ceramics, metals, plastics, and glass, as well as these surface-treated products.

Further, a laminated sheet provided with a resin mirror layer as described above was prepared as another layer (functional layer) so as to be the outermost layer on the PET film of the laminated sheet of Example 3. Similarly, a laminated sheet provided with a whiteboard was prepared. When the laminated sheet was attached to the SUS plate and the glass surface, it was attached with good adhesiveness and could be used as a reflector or a whiteboard, respectively. It was also found that the laminated sheet does not cause material destruction even during subsequent peeling, and can be used repeatedly.

100 Laminated sheet 110 Porous foam layer 120 Surface layer 130 Functional layer

Claims (8)

Acrylic foam obtained using an emulsion composition containing an emulsion,
A laminated sheet provided on one surface side of the acrylic foam and having a low stretch ratio layer having a stretch ratio lower than that of the acrylic foam.
The emulsion contains an acrylic emulsion and an ethylene-vinyl acetate copolymer resin emulsion.
The adhesive strength (90 ° peel strength) of the acrylic foam is 1.0 N / 24 mm or more, and the acrylic foam has an adhesive strength of 1.0 N / 24 mm or more.
The other surface of the acrylic foam is a surface that directly adheres to the adherend .
A laminated sheet in which the acrylic foam has a semi-open cell structure . Acrylic foam obtained using an emulsion composition containing an emulsion,
A laminated sheet provided on one surface side of the acrylic foam and having a low stretch ratio layer having a stretch ratio lower than that of the acrylic foam.
The emulsion composition contains an acrylic emulsion and an ethylene-vinyl acetate copolymer resin emulsion.
The emulsion composition further contains a cross-linking agent and
The adhesive strength (90 ° peel strength) of the acrylic foam is 1.0 N / 24 mm or more, and the acrylic foam has an adhesive strength of 1.0 N / 24 mm or more.
A laminated sheet in which the acrylic foam has a semi-open cell structure . Acrylic foam obtained using an emulsion composition containing an emulsion,
A laminated sheet provided on one surface side of the acrylic foam and having a low stretch ratio layer having a stretch ratio lower than that of the acrylic foam.
The emulsion contains an acrylic emulsion and an ethylene-vinyl acetate copolymer resin emulsion.
The adhesive strength (90 ° peel strength) of the acrylic foam is 1.0 N / 24 mm or more, and the acrylic foam has an adhesive strength of 1.0 N / 24 mm or more.
The other surface of the acrylic foam is a surface that directly adheres to the adherend.
The breathability of the acrylic foam is 2 [ml / cm. ² / S] or more, 80 [ml / cm] ² Laminated sheet less than / s]. Acrylic foam obtained using an emulsion composition containing an emulsion,
A laminated sheet provided on one surface side of the acrylic foam and having a low stretch ratio layer having a stretch ratio lower than that of the acrylic foam.
The emulsion composition contains an acrylic emulsion and an ethylene-vinyl acetate copolymer resin emulsion.
The emulsion composition further contains a cross-linking agent and
The adhesive strength (90 ° peel strength) of the acrylic foam is 1.0 N / 24 mm or more, and the acrylic foam has an adhesive strength of 1.0 N / 24 mm or more.
The breathability of the acrylic foam is 2 [ml / cm. ² / S] or more, 80 [ml / cm] ² Laminated sheet less than / s]. The laminated sheet according to any one of claims 1 to 4 , wherein the acrylic foam has a tensile strain of 100% or more. The laminated sheet according to any one of claims 1 to 5 , wherein the acrylic foam has a 25% compressive load of 0.02 MPa or less. The laminated sheet according to any one of claims 1 to 6 , wherein the solar transmittance is less than 40%. The laminated sheet according to any one of claims 1 to 7 , wherein the ultraviolet absorption rate is 80% or more.

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