JP2016125060A - Self-adhesive sheet and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a repetitively detachably usable sheet having a thermochromic material.SOLUTION: A self-adhesive sheet has at least a self-adhesive porous foam layer obtained by foaming a composition containing an emulsion and a frother with a mechanical froth method, followed by curing. The emulsion contains one or more kinds of emulsions selected from among urethane emulsion, acryl emulsion, and ethylene-vinyl acetate copolymer resin emulsion. The sheet has a thermochromic material.SELECTED DRAWING: None

Description

  The present invention relates to a self-adhesive sheet and a method for producing the self-adhesive sheet.

  Conventionally, resin molded products (resin cups), posters, seals, and the like have been manufactured and sold as materials using a material whose color changes with temperature. Specific product examples include stickers used on automobile tires, temperature-sensitive resin cups that change color when poured with cold beer or hot coffee, and resin spoons that change color depending on cooking temperature. Exists.

JP 2008-056055 A

  Among these, as described in Patent Document 1, a sheet-like body (typically a seal) for use that is used by being attached to an adherend is temperature-sensitive discoloration on one surface (display surface) side. A material is provided, and an adhesive layer is provided on the other surface (back surface) side. The adhesive used here is not intended to be repeatedly desorbed, such as a pressure-sensitive adhesive (adhesive) or a hot-melt / thermosetting adhesive. There are also pressure-sensitive adhesives that can be used repeatedly, but the number of repetitions is limited. Then, this invention makes it a subject to provide the sheet | seat which has a temperature-sensitive color-change material which can be repeatedly used for desorption.

The present invention (1) is a sheet having at least a self-adhesive porous foam layer obtained by curing after foaming a composition containing an emulsion and a foaming agent by a mechanical floss method, The emulsion includes at least one emulsion selected from urethane emulsion, acrylic emulsion, and ethylene vinyl acetate copolymer resin emulsion, and the sheet has a temperature-sensitive color-changing material (the temperature-sensitive color-changing material in the sheet) Is a self-adhesive sheet. In the present invention (1), a product is defined by a manufacturing method. Here, the self-adhesive porous foam layer according to the present invention (1) uses an emulsion as a raw material, and is produced by curing after mechanical flossing. Thus, it is extremely difficult to specify which functional group of the resin constituting the emulsion how and how much it reacts even if it is analyzed using a conventional analytical means, and the structure or It is virtually impossible to express it comprehensively by its characteristics.
The present invention (2) is the self-adhesive sheet of the invention (1), wherein the emulsion contains an acrylic emulsion and an ethylene vinyl acetate copolymer emulsion.
The present invention (3) is a sheet having at least a self-adhesive porous foam layer containing one or more resins selected from urethane resins, acrylic resins and ethylene vinyl acetate copolymer resins,
The self-adhesive porous foam layer has a density of 150 to 300 kg / m ³ ;
The self-adhesive porous foam layer has a thickness of 0.5 to 2.0 mm;
The self-adhesive porous foam layer has an average cell diameter of 30 to 200 μm,
The delamination strength of the self-adhesive porous foam layer is 3.0 N / 12 mm or more,
25% compression load of the self-adhesive porous foam layer is 2.0 to 11.0 kPa,
The self-adhesive sheet is characterized in that the self-adhesive porous foam layer has an adhesive strength of 0.4 to 2.5 N / 24 mm.
This invention (4) is a self-adhesive sheet of the said invention (3) in which the said resin contains acrylic resin and ethylene vinyl acetate copolymer resin.
The present invention (5) is a method for producing a self-adhesive sheet having at least a self-adhesive porous foam layer,
Including a step of curing after foaming a composition containing an emulsion and a foaming agent by a mechanical floss method,
The emulsion includes at least one emulsion selected from urethane emulsion, acrylic emulsion, and ethylene vinyl acetate copolymer resin emulsion, and the sheet has a temperature-sensitive color-changing material (the temperature-sensitive color-changing material in the sheet) Exists)
This is a method for producing a self-adhesive sheet.
The present invention (6) is the process for producing a self-adhesive sheet according to the invention (5), wherein the emulsion contains an acrylic emulsion and an ethylene vinyl acetate copolymer emulsion.
In the present invention (7), the density of the self-adhesive porous foam layer is 150 to 300 kg / m ³ ,
The self-adhesive porous foam layer has a thickness of 0.5 to 2.0 mm;
The self-adhesive porous foam layer has an average cell diameter of 30 to 200 μm,
The delamination strength of the self-adhesive porous foam layer is 3.0 N / 12 mm or more,
25% compression load of the self-adhesive porous foam layer is 2.0 to 11.0 kPa,
It is a manufacturing method of the self-adhesive sheet of the said invention (5) or (6) whose adhesive strength of the said self-adhesive porous foam layer is 0.4-2.5N / 24mm.

Here, the following aspect is more preferable.
That is, this aspect (1)
A method for producing a self-adhesive sheet having at least a self-adhesive porous foam layer,
The manufacturing method includes a step of foaming an emulsion composition containing an emulsion, a crosslinking agent and a foaming agent using a mechanical floss method to form a foam, and curing the foam.
The emulsion contains an acrylic emulsion and an ethylene vinyl acetate copolymer emulsion,
In the emulsion composition, a weight ratio of the ethylene vinyl acetate copolymer emulsion (solid content) to the acrylic emulsion (solid content) (the ethylene vinyl acetate copolymer emulsion / the acrylic emulsion) is 0.05. ~ 1.7,
The weight ratio of the crosslinking agent to the acrylic emulsion (solid content) and the ethylene vinyl acetate copolymer emulsion (solid content) in the emulsion composition {the crosslinking agent / (the acrylic emulsion + the ethylene vinyl acetate copolymer). Polymer emulsion)} is 0.01 to 0.12, which is a method for producing a sheet.
This aspect (2)
The emulsion composition contains at least two ethylene vinyl acetate copolymer emulsions as the ethylene vinyl acetate copolymer emulsion,
The two kinds of ethylene vinyl acetate copolymer emulsions are the sheet manufacturing method according to the aspect (1), wherein the viscosity (mPa · s) and / or the glass transition temperature are different from each other.
This aspect (3)
Of the two types of ethylene vinyl acetate copolymer emulsions, one ethylene vinyl acetate copolymer emulsion has a viscosity of 2,000 to 4,000 mPa · s, and the other ethylene vinyl acetate copolymer emulsion has a viscosity of The sheet manufacturing method according to the aspect (2), wherein the viscosity is 500 to 1,500 mPa · s lower than the viscosity of the one ethylene vinyl acetate copolymer emulsion.
This aspect (4)
Of the two types of ethylene vinyl acetate copolymer emulsions, one ethylene vinyl acetate copolymer emulsion has a glass transition temperature of −30 ° C. to 30 ° C., and the other ethylene vinyl acetate copolymer emulsion has a glass transition temperature. Is a method for producing a sheet according to the aspect (2) or (3), which is lower by 5 ° C. or more than the glass transition temperature of the one ethylene vinyl acetate copolymer emulsion.
This aspect (5)
It is the manufacturing method of the sheet | seat as described in any one of said aspect (1)-(4) whose average particle diameter of the said ethylene vinyl acetate copolymer emulsion is 1.0 micrometer or less.
This aspect (6)
The method for producing a sheet according to any one of the above aspects (2) to (5), wherein a difference in average particle diameter between the two kinds of ethylene vinyl acetate copolymer emulsions is 0.1 to 0.5 μm. .
This aspect (7)
The glass transition temperature of the acrylic emulsion and the glass transition temperature of the ethylene vinyl acetate copolymer emulsion are both −10 ° C. or less, and the method for producing a sheet according to any one of the above aspects (1) to (6) It is.
This aspect (8)
The sheet according to the aspect (7), wherein the sheet further includes a first layer provided on one surface side of the porous foam layer.

Here, in the present invention, “self-adhesive” means that the adhesive adheres to the adherend when pressed because of the nature of the material without applying an adhesive (including providing an adhesive layer) or impregnation. However, when it peels, the property which can be peeled off from a junction part, without transferring to an adherend. In addition, the “semi-open cell structure” is a structure in which the pores (holes) between adjacent bubbles are small compared to the open cells, and unlike the closed cells, the bubbles have small pores and conforms to the JIS L 1096 A method. And a value measured with a Frazier type air permeability tester is 2 [ml / cm ² / s] or more and less than 80 [ml / cm ² / s].

  In the present invention, the “interlaminar peel 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 when the T-shaped peel is performed. Specifically, the strength can be measured by a test method described later.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the sheet | seat which has a temperature-sensitive color-change material which can be repeatedly used for desorption. Furthermore, according to this aspect, in addition to the effects of the present invention, a sheet that can maintain a sufficient adhesive force for an adherend such as surface-treated glass or uneven wallpaper for a long period of time and can be used repeatedly is provided. Can be provided. Moreover, the adhesive sheet which concerns on this aspect enabled the application to various applications.

It is a conceptual sectional view of a sheet which consists only of a porous foam layer concerning this form. It is a conceptual sectional view of a sheet which has a surface layer concerning this form. It is a conceptual sectional view of a sheet which has a surface layer and a functional layer concerning this form. It is a cross-sectional SEM photograph of the semi-open cell structure, open cell structure, and closed cell structure of the porous foam based on this form. It is a photograph of the member used for a sticking test. It is a photograph which shows the outline | summary of a sticking test. It is a schematic diagram of the cross section of the wallpaper used for the sticking test.

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

The sheet | seat which concerns on this form, and its manufacturing method are demonstrated in the following orders.
1 Sheet structure 2 Sheet manufacturing method 3 Sheet properties 4 Sheet usage

[Construction]
FIG. 1 is a conceptual cross-sectional view of a sheet 100 composed only of a porous foam layer. As will be described later, a function is imparted to the porous foam layer itself, and it can also serve as a functional layer. Here, the porous foam layer includes one or more resins selected from urethane resins, acrylic resins, and ethylene-vinyl acetate copolymer resins. A typical embodiment of the present invention has a single porous foam layer {that is, an embodiment in which a temperature-sensitive color-changing material is present in the porous foam layer (that is, a temperature-sensitive color-changing material is included in the raw material composition). A mode in which a porous foam layer is manufactured from the raw material composition) and a mode in which a temperature-sensitive color changing material is present on the surface of the porous foam layer (ie, after the porous foam layer is manufactured, for example, for printing) And a temperature-sensitive color-changing material is attached to the surface)}.

  However, one or more other layers may be laminated on the porous foam layer. In this case, a temperature-sensitive color changing material is preferably present in the outermost layer or on the surface. FIG. 2 is a conceptual cross-sectional view of a sheet 100 having a first layer (surface layer). As shown in FIG. 2, the sheet 100 according to this embodiment is a sheet-like laminate having a porous foam layer 110 and a first layer 120 on one surface of the porous foam layer 110. it can. FIG. 3 is a conceptual cross-sectional view of a sheet 100 further having a second layer 130 (surface layer) on the first layer. One or more layers between the porous foam layer and the first layer, between the first layer and the second layer, on the second layer (that is, opposite to the first layer). May be present.

  Next, each layer will be described. Here, as described above, since the typical embodiment is a sheet composed of only the porous foam layer, the porous foam layer will be described first. Next, in a sheet which is a laminate that is not a typical embodiment, the first layer (when the layer is a surface layer, for example, in the case of a two-layer structure, the layer can be a functional layer) and the second layer (the relevant layer In the case where the layer is a surface layer, for example, in the case of a three-layer structure, the layer can be a functional layer).

≪Porous foam layer≫
The porous foam layer 110 according to this embodiment has a self-adhesive nature as a material without applying or impregnating an adhesive, and functions as a layer that adheres to an adherend. 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 sucker effect. Since the porous foam layer 110 has high flexibility and stretchability, it can be applied with strong adhesive strength even to an adherend having unevenness on the surface such as surface-treated glass or wallpaper. However, it is good also as a structure which apply | coats an adhesive as needed. Here, in the present invention, “self-adhesive” means that the adhesive adheres to the adherend when pressed because of the nature of the material without applying an adhesive (including providing an adhesive layer) or impregnation. However, when it peels, the property which can be peeled off from a junction part, without transferring to an adherend. In addition, the “semi-open cell structure” is a structure in which the pores (holes) between adjacent bubbles are small compared to the open cells, and unlike the closed cells, the bubbles have small pores and conforms to the JIS L 1096 A method. And a value measured with a Frazier type air permeability tester is 2 [ml / cm ² / s] or more and less than 80 [ml / cm ² / s].

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

  Furthermore, 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 bonded portion, so that it can be used repeatedly. From this, when it is set as the structure which applies an adhesive, it is preferable that there are as few adhesive application parts as possible.

  When the adherend is made of glass, thermal cracking becomes a problem because the glass expands and contracts due to heat. In the sheet according to the present invention, since the porous foam layer 110 has high stretchability, it absorbs the stretch caused by the heat of the glass, so that thermal cracking hardly occurs.

  Here, the porous foam layer 110 according to this embodiment includes, for example, 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. An aqueous liquid medium (emulsion composition) containing an anionic surfactant as a foaming agent is foamed using a mechanical floss method to form a foam, and is produced by a step of curing the foam ( A specific method for producing the porous foam layer 110 will be described later). In the production of a sheet consisting of only the porous foam layer as a typical embodiment (particularly, a kneading type, in which a temperature-sensitive color-changing material is present in the porous foam layer), A temperature-sensitive color changing material is contained.

  The porous foam layer 110 according to this embodiment has both adhesive strength, material strength, and followability. Because of this property, smooth glass surfaces and SUS plates can of course be applied to surface-treated glass surfaces and wallpaper with uneven surfaces, and can be used repeatedly without material destruction. Become. In addition, from the material described below, the entire porous foam layer 110 exhibits adhesiveness and UV-cutting properties, and is excellent in light-shielding properties and UV-cutting properties. Moreover, by setting it as the structure which does not light-shield completely, if there is sunlight, light can be obtained indoors, without peeling the sheet | seat which concerns on this invention.

  Furthermore, according to the porous foam layer 110 which concerns on this form, heat insulation can be exhibited over the whole porous foam layer 110 from the below-mentioned material, and it can be excellent in heat insulation.

<Thickness>
The thickness of the porous foam layer 110 according to this embodiment can be appropriately designed according to the application and necessary properties, but is preferably 0.5 mm to 2.0 mm. More preferably, it is 1.0 mm to 2.0 mm. Within this range, it is preferable in that the followability to the uneven surface is further improved when a pressing load is applied.

<Density>
The following cell structure can be evaluated by measuring the density of the porous foam layer 110 according to the present embodiment. The higher the density, the smaller the average cell diameter. On the other hand, the lower the density, the more satisfactory the flexibility. Density can be measured by calculating the weight per unit volume. The density [kg / m ³ ] is preferably 150 to 300 [kg / m ³ ], and more preferably 200 to 250 [kg / m ³ ]. If it is 150 [kg / m ³ ] or more, the adhesive strength and delamination strength will be more sufficient. Moreover, if it is 300 [kg / m < ³ >] or less, since it has sufficient softness | flexibility, the followable | trackability to an uneven surface will increase, and the expansion / contraction of the adherend which has elasticity, such as glass, will be absorbed more. It is. The density was measured according to JIS K7222.

<Cell structure>
The porous foam layer 110 according to this embodiment has a semi-open cell structure. By setting it as such a structure, the adhesion degree can further be provided to the adhesiveness of the raw material which concerns on this invention by the suction cup effect. As a result, it does not have an adhesive layer, has self-adhesiveness, and is less likely to cause air accumulation and can be easily removed even if it occurs.

(Semi-open cell structure)
The semi-open cell structure is a structure in which pores (holes) between adjacent bubbles are smaller than open cells, and unlike the closed cells, the bubbles have small pores. By measuring the air permeability, it is possible to evaluate whether the structure is a semi-open cell structure. As described above, the air permeability measurement method is based on the JIS L 1096 A method, and 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 it has 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 20 to 50 [ml / cm ² / s]. More preferably. Moreover, the confirmation method of a semi-continuous cell structure can be confirmed also with the photograph of a cross section similarly to the calculation method of the following average cell diameter. FIG. 4 shows a cross-sectional SEM photograph. The center is an SEM photograph of a semi-open cell structure according to this embodiment.

  The semi-open cell structure is smaller than the open cell, and the pores (holes) between adjacent bubbles are small. Unlike the closed cell, the bubble has small pores, which is more flexible than the closed cell structure. Even when the material is brought into close contact with the adherend, an air escape path can be created, and the followability can be improved. On the contrary, when compared with a structure having only open cells, the surface in contact with the adherend becomes larger, a strong suction effect can be exhibited, and the adhesive strength is increased.

(Average cell diameter and cell diameter distribution)
The average cell diameter (average cross-sectional cell diameter) of the cells in the cross section of the porous foam layer 110 is preferably 30 to 200 μm, more preferably 50 to 150 μm, and still more preferably 70 to 100 μm. The reason is that if it is 200 μm or less, the surface in contact with the adherend becomes large. It is because the suction cup effect of a cell can be anticipated by being 30 micrometers or more. In addition, as a measuring method of an average cell diameter, the following method shall be followed.

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

(Bubble (cell) diameter distribution)
In the cross-sectional photograph, 70% or more of the bubbles are preferably 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, the material breakage at a large bubble portion is less likely to occur, and the delamination strength becomes stronger. Moreover, it is because the adhesive strength by a suction cup effect is obtained stably.

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

≪First layer ・ Second layer≫
As described above, the sheet according to this embodiment has the “first layer” or “first layer + second layer” on the porous foam (which may be provided with another layer). May be. The first layer and / or the second layer are, for example, (1) the role of maintaining the size and shape of the sheet when assuming the case of repeated desorption, (2) workability at the time of sticking (for example, , The role of improving the ease of air removal, etc. when there is an air pocket when affixed to the adherend, (3) the function itself (for example, a heat insulating layer or a water retaining layer, (For example, when the first layer is a surface layer). A well-known layer can be used for a 1st layer and a 2nd layer, It does not specifically limit. As described above, the temperature-sensitive color-changing material is preferably present in the outermost layer or on the surface (or the back surface when the outermost surface layer is a transparent material such as a transparent material).

  When providing the “first layer” or “first layer + second layer”, it is preferable that at least one layer has a lower expansion ratio than the expansion ratio of the porous foam layer as described above. . By setting it as such a structure, the sheet | seat which concerns on this invention can be affixed on a to-be-adhered body without wrinkles. In addition, regardless of the expansion / contraction rate of the surface layer, the porous foam layer absorbs the expansion / contraction caused by the heat of the adherend such as glass, so that thermal cracking does not occur even if it is applied indoors. In addition, although an expansion / contraction rate is mentioned later in detail, it measures based on JISK6251.

  The first layer and / or the second layer can have a single layer structure or a multilayer structure.

<Material>
The material (material) of the first layer and / or the second layer will be described in detail in the manufacturing method described later.

≪Functional layer≫
As described above, in the sheet according to the present embodiment, any one of the porous foam layer, the first layer, and the second layer, or a combination of these arbitrarily may be a functional layer. For example, in the case of FIG. 1, the porous foam layer itself is a functional layer, in the case of FIG. 2, the first layer (or porous foam layer) is a functional layer, and in the case of FIG. Two layers (or porous foam layer, first layer, porous foam layer + first layer, porous foam layer + second layer, first layer + second layer) are functional layers A certain aspect can be mentioned. Hereinafter, functional examples of the functional layer will be described. However, this example is only an example.

<Print layer>
For example, the printed layer is printed on the front surface / back surface (for example, when the layer is a transparent material such as a transparent layer), inside (for example, when the layer is transparent), or the whole (for example, a picture, a pattern, It is the layer which gave the character. In this case, (1) a layer that can be printed as a functional layer (for example, the second layer in FIG. 3) may be provided separately, or (2) the first layer (for example, the embodiment of FIG. 2 or FIG. 3). In which the first layer can be seen through) or the porous foam layer 110 (for example, the embodiment in FIG. 1, the embodiment in which the porous foam layer is seen through in FIG. 2, the embodiment in which the porous foam layer is seen through in FIG. ) It may be printed on itself. Here, when printing on the first layer or the second layer, examples of the material include a resin film and a paper material. The printing material may be a temperature-sensitive color changing 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 said mirror layer is obtained by vapor-depositing and laminating | stacking a vacuum evaporation plating layer, for example on a transparent resin layer, a film, and board (for example, 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 (partial transmission). An example of the method for producing the resin mirror layer is a method of generating a silver film by spraying aluminum particles on a PET resin film or the like (vacuum deposition plating). In addition, you may provide the function as said surface printing layer to the said resin mirror layer.

<Whiteboard>
As a functional layer, a layer having a function as a white board can be provided on the porous foam layer 110. Since the porous foam layer 110 is bonded and adhered to the adherend (for example, a glass window or wallpaper), the whiteboard can be attached to the adherend without using a magnet or a fixture.

[Production method]
The sheet 100 according to the present embodiment is a porous foam layer single layer (typical embodiment) or a laminate (one embodiment) formed by laminating a plurality of layers. Hereinafter, a method for producing a porous foam layer (a sheet according to the typical embodiment) will be described, and then a method of laminating a first layer or the like on the porous foam layer (a method for producing a sheet according to the embodiment). Will be explained. In the case where the sheet is a porous foam layer alone, the following “method for producing porous foam layer” is read as “sheet production method”, and when the sheet is a laminate, the following: “A manufacturing method of a porous foam layer” and “a manufacturing method of a laminate” are read as “a manufacturing method of a sheet”.

≪Method for producing porous foam layer≫
The method for producing the porous foam layer 110 according to the present embodiment includes 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. The emulsion composition preferably further contains a cross-linking agent. And in the said process, a porous foam layer is the said foam by bridge | crosslinking the resin which comprises the said emulsion by applying energy (via the said crosslinking agent, when a crosslinking agent exists) in the said process. Is obtained by curing. As a manufacturing method of the porous foam layer 110, a raw material, a composition (blending amount), and a process (specific preparation step) will be described in detail.

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

<Raw material>
The porous foam layer 110 according to the present embodiment includes an emulsion, a foaming agent (anionic surfactant) as a raw material, and water, a crosslinking agent and other additives as a dispersion medium (note that it is used in the foaming step). The foaming gas will be described in the foaming process). Further, as described above, in the case of the kneading type among the sheets composed only of the porous foam layer, a temperature-sensitive color changing material is used as one raw material. Therefore, the temperature-sensitive color changing material is also described in this item. However, as described above, even in the case of a sheet made of only a porous foam layer, in the case of a type in which a temperature-sensitive color-changing material is attached to the surface (for example, printing or coating), or in other layers, the temperature-sensitive color change is caused. In the case of a type containing or adhering a material, a temperature-sensitive color changing material is not necessary as a raw material for forming the porous foam layer.

(Type of emulsion)
One or more emulsions selected from urethane emulsion, acrylic emulsion and ethylene vinyl acetate copolymer resin emulsion are used as the emulsion raw material of the emulsion composition used when producing the porous foam layer 110 according to this embodiment. It is done. In particular, it is preferable to use at least an acrylic emulsion and an ethylene vinyl acetate copolymer resin emulsion. The acrylic emulsion is excellent in that it is excellent in adhesive strength, light weight, and heat insulation. And, by combining this acrylic emulsion and ethylene vinyl acetate copolymer resin emulsion, the delamination strength against high adhesive strength can be increased, so that material destruction is unlikely to occur and semi-continuous having self-adhesive strength It is understood that a foam having a cellular structure can be made. Further, by using a urethane emulsion, further material strength can be imparted, and this is particularly suitable when the adherend is an adhesive glass or the like. Moreover, the urethane resin foam obtained has excellent flexibility and low compressive residual strain.

  Other emulsions may be used as long as any one of the above three emulsions is used. Other emulsions include vinyl chloride emulsions and epoxy emulsions.

-Acrylic emulsion A method for producing an acrylic resin aqueous dispersion (acrylic emulsion) includes, for example, a (meth) acrylate monomer in the presence of a polymerization initiator, and if necessary, an emulsifier and a dispersion stabilizer. Can be obtained by copolymerizing a mixture of other polymerizable monomers copolymerizable with these monomers as necessary. Two or more acrylic emulsions may be used in combination.

  Examples of polymerizable monomers that can be used in the preparation of the acrylic emulsion include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) allylate, (meth ) Hexyl acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, octadecyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, nonyl (meth) acrylate, ( (Meth) acrylic acid such as dodecyl (meth) acrylate, stearyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate Ester monomers; acrylic acid, methacrylic acid, β-carboxyethyl ( Ta) acrylate, 2- (meth) acryloylpropionic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, itaconic acid half ester, maleic acid half ester, maleic anhydride, itaconic anhydride and other unsaturated groups having a carboxyl group Bond-containing monomers: Glycidyl group-containing polymerizable monomers such as glycidyl (meth) acrylate and allyl glycidyl ether; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, polyethylene glycol mono (meth) Hydroxyl group-containing polymerizable monomers such as acrylate and glycerol mono (meth) acrylate; ethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylo Examples thereof include propane propane tri (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, diallyl phthalate, divinylbenzene, and allyl (meth) acrylate.

  In addition, what is necessary is just to use a well-known emulsifier etc. when using an emulsifier at the time of preparation of acrylic emulsion.

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

  The ethylene vinyl acetate copolymer resin emulsion may be obtained by further copolymerizing 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 alkoxy group. Good.

  As the ethylene vinyl acetate copolymer resin emulsion, it is preferable to use at least two kinds of ethylene vinyl acetate copolymer resin emulsions described later. By adjusting the blending amount of each ethylene vinyl acetate copolymer resin emulsion, its flexibility and material strength can be adjusted, and the desired function of the present invention can be realized.

-Urethane emulsion Examples of the method for preparing an aqueous dispersion of urethane resin (urethane emulsion) include the following methods (I) to (III).
(I) An active hydrogen-containing compound, a compound having a hydrophilic group, and an organic solvent solution or an organic solvent dispersion of a urethane resin having a hydrophilic group obtained by reacting a polyisocyanate are neutralized as necessary. A method of obtaining a urethane resin emulsion by mixing an aqueous solution containing an agent.
(II) Whether 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 a polyisocyanate are mixed with an aqueous solution containing a neutralizing agent. Alternatively, a method of obtaining a urethane resin emulsion by adding a neutralizing agent to a prepolymer in advance, mixing water and dispersing in water, and then reacting with polyamine.
(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 a polyisocyanate are mixed with an aqueous solution containing a neutralizing agent and a polyamine. Or a method in which a neutralizing agent is added to the prepolymer in advance and then an aqueous solution containing 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-phenylene diisocyanate, p-phenylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 2,4 ′. -Diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 3,3'-dimethyl-4,4'-biphenylene diisocyanate, 3,3'-dimethoxy-4,4'-biphenylene diisocyanate, 3,3'-dichloro-4 , 4′-biphenylene diisocyanate, 1,5-naphthalene diisocyanate, 1,5-tetrahydronaphthalene diisocyanate, tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, Decamethylene diisocyanate, trimethylhexamethylene diisocyanate, 1,3-cyclohexylene diisocyanate, 1,4-cyclohexylene diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, hydrogenated xylylene diisocyanate, lysine diisocyanate, isophorone diisocyanate, 4,4 Examples include '-dicyclohexylmethane diisocyanate and 3,3'-dimethyl-4,4'-dicyclohexylmethane diisocyanate. Moreover, you may use together polyisocyanate more than trivalence in the range which does not impair the effect of invention.

  Examples of the compound having a hydrophilic group include polyester polyols, polyether polyols, polycarbonate polyols, polyacetal polyols, polyacrylate polyols, polyester amide polyols, polythioether polyols, polybutadiene-based polyolefin polyols, and the like. Two or more of these high molecular weight compounds may be used in combination. Known polyester polyols may be used.

  In the above methods (I) to (III), an emulsifier may be further used as long as the effects of the invention are not impaired. Examples of such emulsifiers include nonionic emulsifiers such as polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl ether, polyoxyethylene styrenated phenyl ether, polyoxyethylene sorbitol tetraoleate; fatty acid salts such as sodium oleate, alkyl Anionic emulsifiers such as sulfate esters, alkylbenzene sulfonates, alkyl sulfosuccinates, naphthalene sulfonates, alkane sulfonate sodium salts, sodium alkyl diphenyl ether sulfonates; polyoxyethylene alkyl sulfates, polyoxyethylene alkylphenyl sulfates Nonionic anionic emulsifiers such as

(Physical properties of emulsion)
Among the emulsions used in the present invention, the physical properties of acrylic emulsions and ethylene vinyl acetate copolymer emulsions, which are preferred embodiments, will be described below.

・ Viscosity (mPa ・ s)
Viscosity is measured with a Brookfield viscometer (25 ° C.).

  The viscosity of the acrylic emulsion is preferably 5,000 to 20,000 mPa · s. More preferably, it is 8,000-15,000 mPa * s. This is because if the viscosity is 5,000 or more, the foam retention force at the time of molding is sufficient, finer cells can be molded, and the adhesive strength tends to become stronger. On the contrary, if the viscosity is 20,000 or less, the shearing force to the raw material can be reduced at the time of molding, so that a distortion-shaped cell can be prevented from being molded, so that more sufficient adhesive strength can be obtained.

  The two types of ethylene vinyl acetate copolymer emulsions used as the ethylene vinyl acetate copolymer resin emulsion preferably have different viscosities. The reason for this is presumed that the stirring efficiency between the ethylene vinyl acetate copolymer resin emulsions is remarkably increased by the difference in viscosity between the two types of ethylene vinyl acetate copolymer resin emulsions. It is considered that the increase in the stirring efficiency allows the vinyl acetate copolymer resin to be uniformly disposed, so that stronger adhesive strength and material strength can be exhibited.

  More specifically, the stirring efficiency is considered to be one of the important factors in the formation of bubbles during production by the mechanical floss method. The increase in stirring efficiency makes it possible to form bubbles that have entered the raw material more finely and uniformly. It is considered that the adhesion strength to the adherend is improved by increasing the adhesion area to the adherend. This is also presumed to influence the strong sucker effect brought about by the fine cells.

  Of the two types of ethylene vinyl acetate copolymer emulsions, the viscosity of one ethylene vinyl acetate copolymer emulsion is preferably 2,000 to 4,000 mPa · s, and preferably 2,000 to 3,000 mPa · s. It is more preferable that The viscosity of the other ethylene vinyl acetate copolymer emulsion is preferably 500 to 1,500 mPa · s lower than that of the one ethylene vinyl acetate copolymer emulsion, and preferably 800 to 1,300 mPa · s lower. More preferred. This is because the above-mentioned strong adhesive strength and material strength can be exhibited when the viscosity of the two types of ethylene vinyl acetate copolymer emulsions is within these ranges.

・ Glass transition temperature (Tg)
The glass transition temperature is a dynamic viscoelasticity device DMA (DII 6100 manufactured by SII Nanotechnology Co., Ltd.), and the temperature is increased from 25 ° C. to 200 ° C. at 2 ° C./min in a procedure based on JIS-K7198. The peak value of tan δ when measured in (1) is defined as the glass transition temperature.

  The two types of ethylene vinyl acetate copolymer emulsions used as the ethylene vinyl acetate copolymer resin emulsion preferably have different glass transition temperatures. Of these two types of ethylene vinyl acetate copolymer emulsions, the glass transition temperature of one ethylene vinyl acetate copolymer emulsion is preferably −30 ° C. to 30 ° C., and preferably −25 ° C. to 25 ° C. More preferred. The glass transition temperature of the other ethylene vinyl acetate copolymer emulsion is preferably 5 ° C. or more lower than the glass transition temperature of the one ethylene vinyl acetate copolymer emulsion, more preferably 5 to 70 ° C. .

  Moreover, it is preferable that the glass transition temperature of an acrylic emulsion and the glass transition temperature of an ethylene vinyl acetate copolymer emulsion are both -10 degrees C or less. This is because the acrylic resin and the ethylene vinyl acetate copolymer tend to increase in hardness or decrease in adhesiveness when used at low temperatures.

-Average particle diameter The average particle diameter was measured by a laser diffraction particle size distribution analyzer (LA-500 manufactured by Horiba, Ltd.), and the obtained median diameter (particle diameter corresponding to 50% of cumulative distribution, 50% (Particle diameter) is defined as the average particle diameter. In addition, the average particle diameter of two or more emulsions referred to in the present specification and claims is the weight ratio (compounding) of each emulsion (solid content) to the measured average particle diameter of each emulsion. The weight of one kind of emulsion / the sum of the weights of all kinds of emulsions) and then summing those values.

  The average particle size of the ethylene vinyl acetate copolymer emulsion is preferably 1.0 μm or less. When the average particle diameter of the ethylene vinyl acetate copolymer emulsion is 1.0 μm or less, it is expected that the stirring efficiency of the ethylene vinyl acetate copolymer emulsion and the acrylic emulsion is remarkably increased. By increasing the stirring efficiency, as described above, the acrylic resin and the ethylene-vinyl acetate copolymer resin are uniformly mixed and arranged uniformly, thereby exhibiting stronger adhesive strength and material strength. This is because it is considered possible. The lower limit of the average particle size of the ethylene vinyl acetate copolymer emulsion is not particularly limited, but is, for example, 0.01 μm.

  Moreover, it is preferable that the difference of the average particle diameter of said 2 types of ethylene vinyl acetate copolymer emulsion is 0.1-0.5 micrometer. This is because when the difference in average particle diameter is within the range, a larger bonding area is formed on the bonding surface.

-Other Regarding ethylene vinyl acetate copolymer emulsion, at least two parameters of viscosity, glass transition temperature and average particle diameter of one ethylene vinyl acetate copolymer emulsion (ie, viscosity and glass transition temperature, viscosity and average particle diameter, It is preferred that the glass transition temperature and the average particle size, as well as the viscosity, the average particle size and the glass transition temperature) are smaller than the other.

  For acrylic emulsions, those that are fillerless are preferred. The reason for this is presumed to be that the hardness can be reduced (providing flexibility) without filler, and the followability to the adherend is further improved.

(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. Examples of the water-soluble solvent include alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, ethyl carbitol, ethyl cellosolve, and butyl cellosolve, polar solvents such as N-methylpyrrolidone, and the like, one or more of these. A mixture of the above may be used.

(Foaming agent (anionic surfactant))
An anionic surfactant (foaming anionic surfactant) functions as a foaming agent for the emulsion composition.

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

  Here, the anionic surfactant used in this embodiment is preferably 10 or more, 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 determined by the Oda method. The method of obtaining HLB by the Oda method is “Introduction to New Surfactants”, pages 195 to 196, published by Sakai Shoten on March 20, 1957, “Synthetics and Applications of Surfactants” 492 It is described on page 502 and can be obtained by HLB = (inorganic / organic) × 10.

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

  Especially 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 is repelled, and the molecules of the anionic surfactant are kept at a certain distance from each other. In addition, since the electrically neutral double-sided surfactant enters between the molecules of the anionic surfactant, the bubbles can be further stabilized and the size of the bubbles can be reduced. For this reason, delamination strength can be improved. Therefore, it is preferable to use an anionic surfactant and an amphoteric surfactant in combination.

  The amphoteric surfactant that can be used in the present invention is not particularly limited, and amphoteric surfactants such as amino acid type, betaine type, and amine oxide type can be used. Betaine-type amphoteric surfactants are preferred because of the higher effects described above. Furthermore, the thing of C10-12 is preferable from the point of the penetration | invasion between the molecules of an anionic surfactant.

  Examples of amino acid type amphoteric surfactants include N-alkyl or alkenyl amino acids or salts thereof. In the N-alkyl or alkenyl amino acid, an alkyl group or an alkenyl group is bonded to a nitrogen atom, and one or two “—R—COOH” (wherein R represents a divalent hydrocarbon group, preferably An alkylene group, particularly preferably having 1 to 2 carbon atoms.). In a compound in which one “—R—COOH” is bonded, a hydrogen atom is further bonded to the nitrogen atom. One “—R—COOH” is called a mono form, and two are called a di form. As the amphoteric surfactant according to the present invention, any of these mono- and di-forms can be used. In the N-alkyl or alkenyl amino acid, the alkyl group and alkenyl group may be linear or branched. Specifically, examples of the amino acid type amphoteric surfactant include sodium lauryldiaminoethylglycine, sodium trimethylglycine, sodium cocoyl taurine, sodium cocoyl methyl taurine, sodium lauroyl glutamate, potassium lauroyl glutamate, lauroyl methyl-β-alanine and the like. It is done.

  Examples of betaine-type amphoteric surfactants include alkyl betaines, imidazolinium betaines, carbobetaines, amide carbobetaines, amide betaines, alkylamide betaines, sulfobetaines, amide sulfobetaines, phosphobetaines, and the like. Specifically, as a betaine type amphoteric surfactant, lauryl betaine, stearyl betaine, lauryl dimethylaminoacetic acid betaine, stearyl dimethylaminoacetic acid betaine, lauric acid amidopropyl dimethylaminoacetic acid betaine, isostearic acid amidoethyl dimethylaminoacetic acid betaine, Isostearic acid amidopropyl dimethylaminoacetic acid betaine, isostearic acid amidoethyl diethylaminoacetic acid betaine, isostearic acid amidopropyl diethylaminoacetic acid betaine, isostearic acid amidoethyl dimethylaminohydroxysulfobetaine, isostearic acid amidopropyl dimethylaminohydroxysulfobetaine, isostearic acid amidoethyl diethylamino Hydroxysulfobetaine, isostearamide Lopyldiethylaminohydroxysulfobetaine, N-lauryl-N, N-dimethylammonium-N-propylsulfobetaine, N-lauryl-N, N-dimethylammonium-N- (2-hydroxypropyl) sulfobetaine, N-lauryl- N, N-dimethyl-N- (2-hydroxy-1-sulfopropyl) ammonium sulfobetaine, lauryl hydroxysulfobetaine, dodecylaminomethyldimethylsulfopropylbetaine, octadecylaminomethyldimethylsulfopropylbetaine, 2-alkyl-N-carboxy Methyl-N-hydroxyethylimidazolinium betaine (2-lauryl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine 2-stearyl-N-carboxymethyl-N-hydroxy Betaine and the like), coconut oil fatty acid amidopropyl betaine, coconut oil fatty acid amide propyl hydroxy sultaine and the like.

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

  Among the amphoteric surfactants mentioned 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, alkylbetaines and imidazolinium betaines are used. Carbobetaine is particularly preferred. Examples of alkylbetaines that can be used in the present invention include stearyl betaine and lauryl betaine. Examples of imidazolinium betaines include 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine. .

(Crosslinking agent (curing agent))
By using a crosslinking agent (curing agent), the strength of the porous foam layer 110 according to this embodiment can be improved.

  Such a crosslinking agent is not particularly limited, and may be added in a necessary amount depending on the application. Examples of the crosslinking method using a crosslinking agent include physical crosslinking, ionic crosslinking, and chemical crosslinking, and the crosslinking method can be selected according to the type of the water-dispersible resin. As the crosslinking agent, a known crosslinking agent can be used, and an epoxy-based crosslinking agent, a melamine-based crosslinking agent, an isocyanate-based crosslinking agent, a carbodiimide-based crosslinking agent, a oxazoline-based crosslinking agent, etc. An appropriate amount can be used according to the type of group and the amount of functional group. In order to improve the adhesive strength, tack strength and delamination strength, an epoxy-based crosslinking agent and an isocyanate-based crosslinking agent are preferable. Isocyanate-based and epoxy-based crosslinking agents can prevent material destruction of the adherend and the porous foam by increasing the material strength. Of these, aliphatic isocyanates are more preferable. Two or more of these crosslinking agents may be used in combination.

(Temperature-sensitive discoloration material)
The temperature-sensitive color-changing material used in the present invention is not particularly limited, and if it is a substance that changes color depending on the temperature, a reversible temperature-sensitive color-changing component that returns to the original color when the temperature is lowered, even if the temperature is lowered. Any of irreversible temperature-sensitive color changing components that do not return to the original color may be used. Here, although depending on applications, it is desirable to use a macro-encapsulated material that can be used for a long period of time as a reversible temperature-sensitive color changing material in consideration of applications that require repeated use.

  Here, as the reversible temperature-sensitive color-changing component, for example, electron-accepting compounds (developers), electron-donating dyes that are colorless dyes that develop color by reacting with these compounds, and electron-accepting A temperature-sensitive color-changing material composed of a mixture of a compound and a desensitizing agent having a property of inhibiting the reaction between the compound and an electron-donating color-forming colorant at a temperature above or below a certain temperature. (Further, the material is microencapsulated). Examples of the electron-accepting compounds include a compound having a phenolic hydroxyl group (for example, bisphenol A) or a metal salt thereof, a metal salt of a carboxylic acid, or an acid acid ester (for example, propyl gallate) or a metal thereof. Examples include salts. Examples of electron-donating color-forming dyes include crystal violet lactone (blue), macalite green lactone (green), rhodamine B lactam (red), 3,6-dimethoxyfluorane (yellow), and 3-cyclohexyl. Examples include amino-6-chlorofluorane (orange), diethylaminobenzofluorane (peach), and 8-diethylamino-6-methyl-7-anilinofluorane (black). Further, examples of the desensitizer include alcohol and fatty acid.

Examples of irreversible temperature-sensitive color-changing materials include thermochromic organic dyes spiropyrans, ethylene derivatives substituted with condensed aromatic rings such as biantron and dixanthylene; metal complex crystals CoCl _2. (CH ₂ ) ₆ N _4. 10H ₂ O, PbCrO ₄ , Cu ₂ HgI ₄ , Ag ₂ HgI ₄ ; cholesteric liquid crystal (used by being encapsulated in a microcapsule); combination of electron-donating color-forming compound, electron-accepting compound and polar organic compound / electron Donating color-forming compounds Phenylmethane compounds (various fluoranes, phenylphthalides, etc.), various indolylphthalides, spiropyrans, leucooramines, acyl or aryl auramines, electron-accepting compounds having phenolic hydroxyl groups Compound, metal salt of compound having phenolic hydroxyl group, each Triazoles, carboxylic acids, metal salts of carboxylic acids, polar organic alcohols (oleyl alcohol, etc.), amides (acetoacetylanilide, etc.), esters (diphenylphthalate, etc.), primary amines of carboxylic acids that are poorly water-soluble Mention may be made of salts, ketones or ethers, and azomethines having at least one aromatic group as a linking group.

(Other additives)
As other additives, a water dispersible resin dispersing surfactant (emulsifier) or the like may be added.

-Water-dispersible resin-dispersing surfactant The water-dispersible resin-dispersing surfactant according to this embodiment is a surfactant for dispersing a water-dispersible resin (unlike an anionic surfactant, It may not have an effect as a foaming agent). Such a surfactant may be appropriately selected according to the water-dispersible resin to be selected.

<Composition>
(Blending amount and blending ratio of each raw material)
As a compounding quantity of water-dispersible resin (solid content) with respect to a liquid medium, 30-80 weight part is preferable with respect to 100 weight part of liquid media. By setting it as such a range, the effect that a stable foam can be shape | molded is acquired. In addition, below, the suitable compounding ratio about the combination of the acrylic emulsion which is a suitable emulsion, and an ethylene vinyl acetate copolymer emulsion is demonstrated. In the following description, the blending amounts and blending ratios are based on solids unless otherwise specified.

-Blending ratio in emulsion composition The blending ratio in the emulsion composition is the weight ratio of the ethylene vinyl acetate copolymer emulsion (solid content) to the acrylic emulsion (solid content) in the emulsion composition (copolymerization of ethylene vinyl acetate). Polymer emulsion / acrylic emulsion) is 0.05 to 1.70, preferably 0.10 to 0.90. More preferably, it is 0.20 to 0.75. This is because, within such a range, in terms of adhesive strength, hardness (flexibility), and material strength, the followability can be further increased with respect to the adherend, and the adhesive can be more strongly adhered. In addition, it is because sufficient material strength can be exhibited even in repeated use. In addition, the component which comprises the "solid content" of an emulsion said to this specification and a claim is a component remove | excluding the dispersion medium from the emulsion. Specifically, it contains a surfactant, a filler, and the like in addition to the resin.

  The acrylic emulsion is preferably contained in an amount exceeding 10 parts by weight and not more than 90 parts by weight based on the total amount of the emulsion (the total of the solid content and the non-solid content is 100 parts by weight). It is more preferably 20 parts by weight or more and 80 parts by weight or less, and further preferably 30 parts by weight or more and 75 parts by weight or less. Generally, the solid content of the emulsion is 30 to 80 parts by weight, preferably 40 to 70 parts by weight, and more preferably 50 to 60 parts by weight.

  Furthermore, it is preferable to contain 10 parts by weight or more and less than 90 parts by weight of an ethylene vinyl acetate copolymer resin emulsion based on the total amount of the emulsion (the total of the solid content and the non-solid content is 100 parts by weight). It is more preferably 20 parts by weight or more and 80 parts by weight or less, and further preferably 25 parts by weight or more and 75 parts by weight or less. This is because if it is 90 parts 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.

  Moreover, the total amount of the emulsion (the total of the solid content and the non-solid content is 100 parts by weight), and the acrylic emulsion and the ethylene vinyl acetate copolymer resin emulsion exceed 70 parts by weight in total. It is preferable to contain. It is more preferable to contain 80 parts by weight or more.

-Blending ratio in vinyl acetate copolymer emulsion In the present invention, it may be necessary to adjust the flexibility, adhesiveness and material strength in more detail depending on the application (application) and purpose. For example, in order to make it more suitable for a sticking test, when the two types of ethylene vinyl acetate copolymer resin emulsions described above are blended, the ethylene vinyl acetate copolymer resin emulsion 1 (solid content) is mixed with ethylene vinyl acetate copolymer. Weight ratio of polymer resin emulsion 1 (solid content) and ethylene vinyl acetate copolymer emulsion 2 {ethylene vinyl acetate copolymer resin emulsion 1 / (ethylene vinyl acetate copolymer resin emulsion 1 + ethylene vinyl acetate copolymer) The resin emulsion 2)} preferably contains 0.25 to 0.90, more preferably 0.30 to 0.85.

  Here, the ethylene vinyl acetate copolymer emulsion 1 is at least two parameters of the viscosity, glass transition temperature and average particle diameter of the ethylene vinyl acetate copolymer emulsion (that is, viscosity and glass transition temperature, viscosity and average particle diameter, Glass transition temperature and average particle size, and viscosity, average particle size and glass transition temperature) indicate that the ethylene vinyl acetate copolymer emulsion 2 is larger than the other, while the ethylene vinyl acetate copolymer emulsion 2 Is an ethylene vinyl acetate copolymer emulsion in which at least two parameters of the viscosity, glass transition temperature and average particle size of the ethylene vinyl acetate copolymer emulsion are lower than the other.

  As a blending amount of the urethane emulsion, 0 to 30 parts by weight of the urethane emulsion may be contained on the basis of the total amount of the emulsion (the total of the solid content and the non-solid content is 100 parts by weight). Further, it is preferably 20 parts by weight or less. This is because, within this range, the material strength can be increased, flexibility can be imparted, and the adhesive strength can satisfy desired properties.

  The blending amount of the anionic surfactant is preferably 1.0 to 10 parts by weight based on the total amount of the emulsion in the emulsion composition (the total of the solid content and the non-solid content is 100 parts by weight). 3 to 10 parts by weight is more preferable. By setting it as such a range, it is easy to make it suitable foaming, and the effect that a fine cell structure can be shape | molded is acquired.

  The blending amount of the amphoteric surfactant is preferably 0.5 to 10 parts by weight based on the total amount of the emulsion in the emulsion composition (the total of the solid content and the non-solid content is 100 parts by weight). 1 to 5 parts by weight is more preferable. By setting it as such a range, it is easy to make it suitable foaming, and the effect that a fine cell structure can be shape | molded is acquired.

-In the case of the blending amount (kneading type) of the temperature-sensitive color changing material, the total amount of the emulsion in the emulsion composition is used as a standard (the total of the solid content and the non-solid content is 100 parts by weight). 35 parts by weight (in terms of solid content, 0.5 to 17.5 parts by weight) is preferable, 1 to 20 parts by weight (in terms of solid content, 0.5 to 10 parts by weight) is more preferable, and 1 to 5 parts by weight (0.5 to 2.5 parts by weight in terms of solid content) is particularly preferable. By setting it as such a compounding quantity, the physical property in the sheet | seat obtained when a temperature-sensitive color-change material is not added can be ensured.

-Blending ratio of emulsion and crosslinking agent The blending amount of the crosslinking agent (curing agent) is the weight ratio of the crosslinking agent to the acrylic emulsion (solid content) and the ethylene vinyl acetate copolymer emulsion (solid content) in the emulsion composition. {The cross-linking agent / (the acrylic emulsion + the ethylene vinyl acetate copolymer emulsion)} is 0.01 to 0.12. It is preferable that it is 0.025-0.05. By setting it as such a range, since a foam with a small compression residual strain can be shape | molded and the followable | trackability to a to-be-adhered body can be improved more, the effect that adhesive strength improves is acquired.

-Blending ratio of ethylene vinyl acetate copolymer resin emulsion 2 and cross-linking agent Furthermore, when ethylene vinyl acetate copolymer resin emulsion 2 is blended as ethylene vinyl acetate copolymer resin emulsion, ethylene vinyl acetate copolymer resin The weight ratio of the crosslinking agent to the emulsion 2 (solid content) (crosslinking agent / ethylene vinyl acetate copolymer emulsion 2) is preferably 0.10 to 1.40, and preferably 0.20 to 1.0. Is more preferable. By being in such a range, since the followability to an adherend can be improved, the effect of improving the adhesive strength is more easily obtained.

<Manufacturing method>
The manufacturing method of the porous foam layer 110 according to the present embodiment includes a raw material preparation step and a foaming / curing step (foamed product obtained by foaming an emulsion composition containing at least an emulsion and a foaming agent using a mechanical froth method. And the step of curing the foam. The emulsion composition may further contain a crosslinking agent, and in the step, the foam may be cured by applying energy to crosslink the resin constituting the emulsion via the crosslinking agent. Hereinafter, each step will be described in detail.

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

(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 so that many bubbles are present in the emulsion composition (foamed 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 and the foaming gas with a mixing device such as a mixing head.

-Foaming gas The foaming gas mixed into the emulsion composition in the stirring / foaming step forms bubbles (cells) in the porous foam layer 110, and is obtained depending on the amount of the foaming gas mixed therein. The expansion 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 density of the desired porous foam and the volume of the raw material of the porous foam (for example, the inner volume of the mold into which the raw material of the porous foam is injected) It is only necessary to calculate the weight of the raw material of the porous foam and determine the amount of the foaming gas so that the desired volume is obtained at this weight. As the type of foaming gas, air is mainly used, but in addition, inert gases such as nitrogen, carbon dioxide, helium, and argon can also be used.

-Foaming method and foaming conditions As the foaming method used in the method for preparing the porous foam layer 110 according to the present invention, a mechanical floss (mechanical foaming) method is used. The mechanical flossing method is a method in which air in the atmosphere is mixed into 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, or the like can be used. According to this mechanical froth method, a porous foam having a density suitable for various applications can be obtained by adjusting the mixing ratio of the emulsion composition and air. Other foaming methods can be used in combination, but when a foaming method using a chemical foaming agent is used in combination, the ratio of closed cells increases, resulting in increased density and loss of flexibility of the porous foam. Therefore, it is not preferable.

  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 room temperature. Further, the stirring speed in the above mixing is preferably 200 rpm or more in order to make the bubbles fine (more preferably 500 rpm or more), and 2000 rpm or less is preferable (800 rpm or less is preferable) in order to smoothly discharge the foam from the foaming machine. More preferred).

-Foam formation The emulsion composition (foamed emulsion composition) foamed as described above is, for example, a sheet shape that matches the thickness of the desired porous foam by a known means such as a doctor knife or a doctor roll. Formed into a foam.

-Curing As a method for curing the foam, a known method can be used. Although the foam according to the present embodiment can be self-crosslinked, the foam may be cured by applying energy to crosslink the resin constituting the emulsion via a crosslinking agent. Although it does not specifically limit as a process of applying energy, For example, a heating process (thermal crosslinking) is mentioned.

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

  Further, in this heating step, the dispersion medium evaporates from the foamed emulsion composition, but the path when the vapor escapes communicates from the inside to the outside of the porous foam. Therefore, in the porous foam layer 110 according to the present embodiment, the path when the water vapor escapes remains as open cells, so that at least some of the bubbles existing in the porous foam become open cells. Here, when 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 the vapor in this step. In the case of continuous communication, open cells are formed in the obtained porous foam. That is, in the present invention, some of the bubbles in the porous foam are open cells, and the remaining bubbles are closed cells, resulting in a semi-open cell structure in which open cells and closed cells are mixed.

  When a crosslinking agent is added, in the heating process, the crosslinking (curing) reaction of the raw material proceeds and is completed. Specifically, the raw materials are cross-linked by the cross-linking agent described above to form a cured porous foam. The heating means in this case is not particularly limited as long as the raw material can be sufficiently heated and the raw material can be crosslinked (cured). For example, a tunnel heating furnace or the like can be used. Also, the heating temperature and the heating time may be any temperature and time that can crosslink (harden) the raw material. .

≪Method of forming first layer and second layer≫
Next, a method for forming the first layer (or + second layer) in an embodiment in which the sheet is a laminate will be described.

  The formation method of a 1st layer (or + 2nd layer) is not specifically limited, The general method of laminating | stacking another layer on a certain layer is employable. For example, a method of casting and curing the porous foam layer 110 on the first layer can be mentioned. Thus, by directly casting the porous foam layer 110 on another layer, the adhesion between the layers can be enhanced without using an adhesive or the like. In addition, the sheet-like layers may be laminated in a desired order, and may be laminated by appropriately adhering them with an adhesive or the like and integrating them. In addition, after forming the porous foam layer 110 first, a dispersion slurry containing the raw material of the first layer is applied on the porous foam layer 110 directly or via another layer, and the first layer 120 may be formed. The same applies to the second layer. In the case where the first layer is not necessary (that is, only the sheet = the porous foam layer), it may be produced by once forming the laminate and then peeling the surface layer after forming the porous foam layer 110. Good.

  In addition, although the formation method of the 1st layer and the 2nd layer was illustrated above, it can manufacture simply by the method of joining the following raw material to a porous foam layer by a well-known method. The material will be described below. For example, it is made of film, paper, synthetic paper, cloth, synthetic resin, or the like. These may be used alone or in combination. As the first layer and / or the second layer, for example, a film such as a polyester film, a polypropylene film, a polystyrene film, a vinyl chloride film, an olefin film, a polyimide film, synthetic paper, fine paper, coated paper, art paper, Examples thereof include paper such as cast coated paper, supercast paper, water-resistant paper, craft paper, recycled paper, impregnated paper, kent paper, and thermal paper, and cloth. From the manufacturing method described later, a sheet having low stretchability that does not allow the raw material to permeate is preferable.

  As a film material used for the first layer and / or the second layer, for example, a polyethylene film (PE film), a polyvinyl chloride film (PVC film), a polyvinylidene chloride film (PVDC film), a polyvinyl alcohol film (PVA) Film), 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), ethylene-methacrylic acid copolymer film (EMAA film), nylon film (NY film, polyamide (PA) film) , Cellophane, ionomer film (IO film), and the like. Various metals and magnetic materials can also be used as the film material used for the surface layer. 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 first layer and / or the second layer, high-quality paper, coated paper, foil paper, craft paper, recycled paper, synthetic paper, impregnated paper, Kent paper, thermal paper, various types of applications are possible. . These may be used alone or in combination. The paper material is not limited to the above example.

  Examples of the cloth material used for the first layer and / or the second layer may include cotton, gauze, double gauze, organza, and woven fabric. These may be used alone or in combination. The cloth and the material thereof are not limited to the above example.

  Synthetic resins used for the first layer and / or the second layer include phenol resin (PF), epoxy resin (EP), melamine resin (MF), urea resin (urea resin, UF), unsaturated polyester resin (UP), alkyd resin, polyurethane (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) Nylon), polyacetal (POM), polycarbonate (PC), modified polyphenylene ether (m-PPE, modified PPE, PPO), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), glass fiber reinforced polyethylene terephthalate (GF-) PET), cyclic polyolefin (COP), polyphenylene sulfide (PPS), polysulfone (PSF), polyethersulfone (PES), amorphous polyarylate (PAR), liquid crystal polymer (LCP), polyetheretherketone (PEEK) , Thermoplastic polyimide (PI), polyamideimide (PAI) and the like. These may be used alone or in combination. The synthetic resin is not limited to the above example.

As a 1st layer and / or a 2nd layer, sheets, such as a film and a nonwoven fabric, can be used as a base material as mentioned above. The basis weight of the nonwoven fabric is, for example, 5 to 100 g / m ² .

  Here, the sheet according to the present invention has a temperature-sensitive color-changing material. Here, as a method of supporting the temperature-sensitive color changing material, (1) a method of adding the temperature-sensitive color changing material to the raw material composition of the porous foam layer when the temperature-sensitive color changing material is contained in the porous foam layer; (2) When a temperature-sensitive color-changing material is supported on the surface of the porous foam layer, a method of attaching the temperature-sensitive color-changing material after the formation of the porous foam layer (for example, by applying as a solution or a dispersion liquid) (3) porous, applying a liquid to the porous foam layer and drying the solvent, or a known printing technique such as letterpress printing, silk screen printing, gravure printing, offset printing, on-demand printing, inkjet printing, etc.) When the temperature-sensitive color changing material is contained in a layer different from the porous foam layer (the temperature-sensitive color changing material may be present in the porous foam layer), the temperature-sensitive color changing material is contained in the raw material composition of the other layer. material (4) When the temperature-sensitive color changing material is supported on the surface of a layer different from the porous foam layer (the temperature-sensitive color changing material may be present in the porous foam layer), the other layer (For example, a method of applying a solution or dispersion to the porous foam layer and drying the solvent). The temperature-sensitive color changing material to be used may be one type or a plurality of types. When multiple types are used, it is possible to cause a color change in the temperature change region of each temperature-sensitive color changing material. Moreover, it is also possible to use together with the material (dye, pigment, etc.) which does not have temperature-sensitive discoloration.

[nature]
According to the sheet 100 according to the present embodiment, it is difficult to collect air, and even when it is possible, the air can be easily removed simply by pressing from above. Since this property is based on a semi-open cell structure, it can be evaluated by a breathability test.

  Moreover, it can stick with strong adhesive strength to glass. The glass includes not only those having a smooth surface but also surface-treated glass having irregularities on the surface such as ground glass, frosted glass, and template glass. This property can be evaluated by the adhesive strength.

  Furthermore, according to the sheet 100 according to the present embodiment, the porous foam layer has strong adhesiveness and flexibility, and therefore, for example, has a maximum unevenness of 0.7 mm, and sticks to a wallpaper or the like with a strong adhesiveness. be able to.

  Furthermore, when peeling off, it can be peeled off from the joint without applying the adhesive or being impregnated, so it can be peeled off from the bonded part without shifting to the adherend (no adhesive residue). Can do. Moreover, when peeled off, the material strength is high, so that it can be used repeatedly. The ability to be used repeatedly can be evaluated by delamination strength.

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

  The sheet 100 according to this embodiment has a light shielding property. The light shielding property can be evaluated by the solar transmittance and the ultraviolet absorption rate. Moreover, you may have heat insulation. Thermal insulation can be evaluated by thermal conductivity.

-Breathability Breathability is evaluated by a 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 20 [ml / cm ² / s] or more and less than 50 [ml / cm ² / s].

・ Adhesive strength (90 ° peel strength)
Adhesive strength (90 ° peel strength) conforms to JIS Z 0237, punched to 24 mm width x 150 mm, and foam (porous foam) with a single-sided adhesive tape on the surface (non-adhesive surface) to eliminate the effect of elongation Layer) is applied to a 30 mm wide × 200 mm wallpaper (model number LB-9721, manufactured by Sangetsu Co., Ltd.), reciprocated twice with a 2 kg roller, and left at room temperature for 24 hours. Then, it evaluates by measuring the test force which pulls up at a speed of 300 mm / min (90 degree peeling) using an autograph, and making it adhesive strength (90 degree peeling strength) (N / 24mm). The adhesive strength is preferably 0.4 to 2.5 N / 24 mm, more preferably 0.9 to 2.5 N / 24 mm, and still more preferably 1.1 to 2.5 N / 24 mm. . When the adhesive strength is less than 0.5 N / 24 mm, there is a problem that the adhesive strength is weak, and when it exceeds 2.5 N / 24 mm, there is a problem that material destruction is likely to occur. In addition, the adhesion / adhesion strength between the porous foam layer and other layers and between the other layers is higher than the adhesion / adhesion strength between the porous foam and the object (adhered body) in which the porous foam is used. preferable. This is because the porous foam layer 110 can be peeled off from the object surface without peeling off the other layers at the time of peeling, so that repeated use is possible.

・ Delamination strength (material strength)
The delamination strength (material strength) is evaluated by measuring the stress when the sample is peeled T-shaped. Specifically, a foam (porous foam layer) is punched out to a width of 12 mm × 150 mm, a double-sided tape (product number 5000NS, manufactured by Nitto Denko Corporation) is pasted on both sides of the foam, and a backing film (12 mm wide × 200 mm on both sides) PET film: manufactured by Toray Industries, Inc., product number S38) is pasted and reciprocated twice with a 2 kg roller, and left in an oven at 85 ° C. for 24 hours. Thereafter, the test force was measured by pulling the backing film at a rate of 1000 mm / min (T-peel peeling) using an autograph (model number AG-X, manufactured by Shimadzu Corporation) for 1 hour or longer at room temperature, and the delamination strength ( N / 12 mm). The delamination strength is preferably 3.0 N / 12 mm or more, more preferably 4.0 N / 12 mm or more, and still more preferably 7.0 N / 12 mm or more. When the delamination strength is less than 3.0 N / 12 mm, there is a problem that the film is broken when peeled and cannot be used repeatedly.

-Flexibility According to JIS K 6254, flexibility is evaluated at 25% compression load. Measure the stress when crushing a φ50 sample (porous foam layer) with a 100φ compression plate at a speed of 1.0 mm / min until reaching a thickness of 25% of the original thickness of the sample (sample Is measured by compressing the whole surface with a compression plate). The 25% compressive load is preferably 2.0 to 11.0 kPa, and more preferably 2.0 kPa or more and less than 7.0 kPa. This is because if the 25% compressive load is within the above range, the adherend will have more sufficient followability even if it has some irregularities.

-Light-shielding property Light-shielding property is evaluated by solar radiation transmittance (JIS R3106) and ultraviolet light absorption rate (ISO 9050). The solar transmittance is preferably less than 40%, and 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. When the ultraviolet absorption rate is less than 80%, the ultraviolet absorption rate is insufficient.

-Thermal insulation Thermal insulation depends on the material and thickness of the porous foam layer. What is necessary is just to change suitably according to the objective of use. Moreover, you may provide the layer for improving heat insulation. The heat insulating property can be evaluated by measuring the thermal conductivity in accordance with JIS A 1412-1. An example of the measuring instrument is a thermal conductivity measuring device (Auto Λ) HC-072 (manufactured by Eihiro Seiki Co., Ltd.).

-Sticking test The sticking test evaluates the adhesive strength and persistence of the porous foam layer. Specifically, the test is performed for the presence or absence of dropping after the porous foam layer is stuck. A composite of a foam and a flat steel plate (100 cm ² ) and a plate in which wallpaper is attached to a SUS plate are prepared. Then, as shown in FIG. 5A, a 6 kg weight is placed on the SUS plate, wallpaper, foam, and steel plate and allowed to stand for 30 seconds to adhere the foam to the wallpaper. After that, as shown in FIG. 5B, the wallpaper is set up vertically, the hook member is attached to the center of the steel plate, and the weight of 100g, 200g or 300g is hooked with the hook in the vertical direction and left for 24 hours, and then it is confirmed whether it has fallen or not. It can be evaluated by doing. By not falling, it has sufficient adhesive strength and its sustainability for the present invention.

・ Repeated pasting test The repeated pasting test evaluates whether the adhesive strength and sustainability can be maintained even after repeated use. After the above-mentioned sticking test is completed, it can be evaluated by confirming the presence or absence of dropping by a second sticking test. By not falling, it can be seen that the adhesive strength sufficient for the present invention and its sustainability can be maintained even in repeated application.

[Usage]
The sheet 100 according to the present embodiment has (1) a property that a color is changed by a temperature change, and (2) a property that can be repeatedly detached. This sheet is useful for applications requiring these properties. Applications of this sheet include, for example, a temperature management sheet that is affixed to a refrigerator, a toy sheet that can be affixed to a bathroom, a temperature management sheet that is affixed to equipment in a factory, and a temperature management sheet that can be affixed to a cup or tumbler. be able to. In addition to the above, in addition to the above-mentioned examples of applications that pay particular attention to the property (2), calendars, wallpaper (cross), dirt / scratch prevention covers, photo print media, advertising media (printing), warning plates , Panels (used at exhibitions, etc.), seasonal ornaments, toys, puzzles, stress relief goods, place mats, elbow pads, mouse pads, magnet replacements, thumbtack replacements, double-sided tape, sticky notes, Examples include slip prevention materials, packing materials, glass buffer materials (bottles, wine bottles, etc.), and grip buffer agents. Moreover, since it has light-shielding property, it can be widely used for the purpose of light-shielding a window glass etc. and preventing privacy infringement. Moreover, it can be widely used for purposes such as preventing glass scattering and preventing condensation.

  Furthermore, since it has a heat insulating property, it can be widely used in applications intended for heat insulation. In this case, as described above, the heat insulation can be improved.

  EXAMPLES Next, although an Example demonstrates this invention further more concretely, this invention is not limited at all by these examples.

[material]
≪Porous foam raw material≫
First, in this example, the following raw materials were used as raw materials for the porous foam.
<Water dispersible resin>
・ Acrylic emulsion 1:
Acrylic nitrile, alkyl acrylate ester, itaconic acid copolymer, pH 9, solid content 60%, viscosity 12,000 mPa · s, average particle size 0.2 μm, Tg-20 ° C.
・ Acrylic emulsion 2 (filler-less):
Ethyl acrylate, methyl methacrylate copolymer, pH 9, solid content 54%, viscosity 10,500 mPa · s, average particle size 0.2 μm, Tg-20 ° C.
・ Ethylene vinyl acetate copolymer resin emulsion 1:
Ethylene-vinyl acetate copolymer resin emulsion (trade name: S-410HQ, manufactured by Sumika Chemtex Co., Ltd.), pH 8.5, solid content 55%, viscosity 2,500 mPa · s, average particle size 0.9 μm, Tg-18 ° C.
・ Ethylene vinyl acetate copolymer resin emulsion 2:
Ethylene-vinyl acetate copolymer resin emulsion (trade name: S-950HQ, manufactured by Sumika Chemtex Co., Ltd.) pH 8.5, solid content 53%, viscosity 1,300 mPa · s, average particle size 0.6 μm, Tg-30 ° C.
・ Urethane emulsion 1 (polycarbonate):
pH 8.0, solid content 60%
<Foaming agent>
・ Anionic surfactant 1
Sodium alkylsulfosuccinate, pH 9.4, solid content 30%, HLB39.7
・ Anionic surfactant 2
Alkyl betaine, fatty acid alkaminolamide, 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
Hydrophobic HDI isocyanurate, 3.5 functional groups, 100% solids
<Temperature-sensitive discoloration material>
・ Temperature sensitive material 1:
Product name (Sakura TC color (color change: red ⇔ colorless type), color change temperature: 32 ° C
(Made by Sakura Crepas Co., Ltd.), solid content 50%

<Porous foam raw material 1>
Acrylic emulsion 1 and ethylene vinyl acetate copolymer resin emulsion 1 are used as main components, and the total amount of emulsion is 50:50 parts by weight based on the total amount of the emulsion (the total amount of solids and non-solids is 100 parts by weight). 3 parts by weight of anionic foaming agent 1, 3 parts by weight of anionic foaming agent 2, 1 part by weight of amphoteric foaming agent 3, and 2.0 parts by weight of a crosslinking agent The raw material 1 was obtained (corresponding to Example 1).
<Porous foam raw material 2-24>
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 1 (corresponding to Example 2-24).

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

[Sheet formation]
<< Preparation of Example 1 >>
An inert gas such as air or nitrogen gas is added to the porous foam raw material 1, foamed by a mechanical floss method (foaming conditions of 100 to 1000 rpm), cast on the base material 1, and then heat-treated (an oven or a drying furnace) ) To obtain a self-adhesive foamed sheet, and then printed on one surface of the sheet using the temperature-sensitive color-changing material 1 to obtain a sheet according to Example 1 (printing mold). In this example, printing was performed by silk screen printing.
<< Preparation of Example 2-24 >>
A sheet according to Example 2-15 was obtained in the same manner as in Example 1 except that the porous foam material used was prepared according to Table 1 (printing mold). However, for Examples 16-24, the temperature-sensitive color-changing material 1 was previously added to the porous foam material, and then a self-adhesive foam sheet was obtained (kneading type).

[Evaluation test]
Next, the sheet (Examples 1 to 24) was measured and evaluated. The results are shown in Table 1. As for discoloration, in any of the examples, the temperature of the constant temperature dryer was increased from 25 ° C. to 40 ° C. at a rate of 0.3 ° C./min, and the change in sheet color was confirmed. As the drying furnace, a constant temperature dryer manufactured by Yamato Scientific Co., Ltd. was used. In each example, it was confirmed that the color changed from red to white (the color of the base sheet prepared in the present invention) at 32 ° C.

-Appearance The surface of the foam was visually evaluated. The cell state was evaluated from a cross-sectional image of the foam by a scanning electron microscope. If the cell surface is uniform due to no foam breakage or cell coalescence on the foam surface, “○”, and if the cell surface is rough, the cell is rough, “△”. When it was very rough and when the cell was not formed (it did not foam), it evaluated as "x". Example 21 in which 35 parts by weight (17.5 parts by weight in terms of solids) of temperature-sensitive color-changing raw material was added based on the total amount of the emulsion (the total amount of solids and non-solids was 100 parts by weight) The foam of Example 24 showed some surface roughness, but the cells of the foams according to the other examples had uniform cells and no surface roughness.

-Bubble structure The foam structure was evaluated by measuring air permeability. If it is 2 [ml / cm < ² > / s] or more and 80 [ml / cm < ² > / s], it was set as the semi-open cell structure. Although not shown in the table, the foam according to the example formed a semi-open cell structure.

-Thickness Thickness was measured with a thickness gauge.

-Density Measured by calculating the weight per unit volume.

-Flexibility According to JIS K 6254, the flexibility was evaluated at 25% compression load. Measure the stress when crushing 25% of the thickness (75% of the original sample thickness) on a φ50 sample on a 100φ compression plate at a speed of 1.0 mm / min. At times, the entire surface of the sample is compressed by a compression plate). When the measured stress is 2.0 kPa or more and less than 3.0 kPa, “◎”, when 3.0 kPa or more and less than 7.0 kPa, “◯”, when 7.0 kPa or more and 11.0 kPa or less, “Δ”, 2 In the case of less than 0.0 kPa or more than 11.0 kPa, it was evaluated as “x”.

・ Adhesive strength (90 ° peel strength)
In accordance with JIS Z 0237, punched to 24 mm width x 150 mm, a foam with 30 mm width x 200 mm wallpaper (made by Sangetsu Co., Ltd.) with a single-sided adhesive tape on the surface (non-adhesive surface) to eliminate the influence of elongation. Attached to model No. LB-9721), reciprocated twice with a 2 kg roller, and left to stand at room temperature for 24 hours. Thereafter, the test force to pull up at a rate of 300 mm / min (90 ° peeling) is measured using an autograph, and the adhesive strength (90 ° peeling strength) (N / 24 mm) is obtained. When the adhesive strength (90 ° peel strength) is 1.1 N / 24 mm or more and 2.5 N / 24 mm or less, “◎”, and the adhesive strength (90 ° peel strength) is 0.9 N / 24 mm or more and less than 1.1 N / 24 mm. In the case “◯”, the adhesive strength (90 ° peel strength) is 0.4 N / 24 mm or more and less than 0.9 N / 24 mm, “Δ”, the adhesive strength (90 ° peel strength) is less than 0.4 N / 24 mm, or 2. When exceeding 5N / 24mm, it evaluated as "x".

・ Delamination strength (material strength)
In accordance with the test method described above, the foam was punched to 12 mm width × 150 mm, double-sided tape was pasted on both sides of the foam, a backing film (PET film) of 12 mm width × 200 mm was pasted on both sides, and reciprocated twice with a 2 kg roller for pressure bonding And left in a furnace at 85 ° C. for 24 hours. Thereafter, the test force was measured by allowing the backing film to stand at room temperature for 1 hour or longer and pulling the backing film at a rate of 1000 mm / min using an autograph (T-peeling) to obtain an interlayer peel strength (N / 12 mm). “◎” when the delamination strength is 7.0 N / 12 mm or more, “◯” when the delamination strength is 3.0 N / 12 mm or more and less than 7.0 N / 12 mm, and the delamination strength is less than 3.0 N / 12 mm The case was evaluated as “x”.

-Sticking test The sticking test was done by the test method mentioned above.
The equipment used in this study was:
-SUS board: Futaba Electronics Co., Ltd., model number SUS304
-Wallpaper: Sangetsu Co., Ltd., model number LB-9721
・ Hook: manufactured by Lek Co., Ltd., model number H-553
Steel plate: area 100cm ² , weight 80g, thickness 5.0mm

  As for the evaluation method, the pass / fail judgment was performed with ○ when there was no drop and × when there was a drop. In addition, when damage was seen in the adherend or the foam, it was marked as x.

If this sticking test is passed, the following conditions are established.
(1) 100 g load acceptance in the area ^{100cm 2 (100g / 100cm 2)} ⇒10kg / m 2
(2) at an area 100 cm ² 200 g load pass ^{(200g / 100cm 2) ⇒20kg /} m 2
(3) 300 g load acceptance in the area ^{100cm 2 (300g / 100cm 2)} ⇒30kg / m 2

  The maximum unevenness of the wallpaper (model number LB-9721, manufactured by Sangetsu Co., Ltd.) used for the sticking test is 0.7 mm (see the cross-sectional photograph in FIG. 6). The maximum value of 0.7 mm was taken using a scanning electron microscope (SEM, manufactured by Keyence Corporation, VHXD-500) to photograph a cross section of the wallpaper. Then, the unevenness depth was measured using image processing software Image-Pro PLUS (Media Cybernetics, 6.3 ver). More specifically, the SEM image was read, and then the uneven shape was read by image processing (the shape was recognized as it was). Next, “distance between two points” was selected as the measurement item. Next, for any 20 convex portions, the distance in the thickness direction of the bottom portion of the concave portion adjacent to the top portion of the convex portion was calculated, and the maximum distance was calculated.

-Repeated sticking test The repeated sticking test was done by the test method mentioned above. Although not shown in the table, it was found that the sheet according to the example in which the material destruction does not occur maintains the adhesive strength, the followability and the material strength even when repeatedly applied.

  As the evaluation method, a pass / fail judgment was made with “◯” when there was no drop and “×” when there was a drop. In addition, although it did not fall, it was set as "(triangle | delta)" when the adherend or the foam was damaged.

-Comprehensive determination Comprehensive determination was performed about the evaluation result (The result was shown in Table 1) of the said 25% compressive load, material strength, and adhesive strength. With respect to the results of the three types of evaluation items, the total was calculated with ◎ as 3 points, ○ as 2 points, Δ as 1 point, and x as 0 point. In this case, 8 points or more were designated as “AAA”, 7 points as “AA”, 6 points and 5 points as “A”, 4 points as “A ′”, and 3 points or less as “B”. These results are shown in Table 1.

  As shown in Table 1, in the examples, the evaluation is A ′ or higher in the comprehensive judgment based on the results of the adhesive strength, delamination strength, and 25% compressive load, and in the sticking test (100 g load), the result is ○. The object of the invention is achieved. In addition, it turned out that the sheet | seat which concerns on this invention can exhibit favorable adhesiveness also with respect to the glass surface and SUS board which are smooth surfaces.

  Moreover, the laminated sheet which provided the above-mentioned resin mirror layer as a functional layer so that it might become an outermost layer on the laminated sheet which provided the PET film in the sheet | seat of Example 8 was prepared. Similarly, a laminated sheet provided with a white board was prepared. When the laminated sheet was affixed to a SUS plate, a glass surface, surface-treated glass, and wallpaper, all adhered to each other with good adhesiveness, and could be used as a reflecting mirror or a white board, respectively. In addition, it was found that no drop occurred in the sticking test, and the laminated sheet could be used repeatedly without causing material destruction even during subsequent peeling.

100 Sheet 110 Porous foam layer 120 First layer 130 Second layer

Claims (7)

  A sheet having at least a self-adhesive porous foam layer obtained by foaming a composition containing an emulsion and a foaming agent by foaming by a mechanical floss method, and the emulsion is a urethane emulsion, an acrylic A self-adhesive sheet comprising at least one emulsion selected from an emulsion and an ethylene vinyl acetate copolymer resin emulsion, wherein the sheet has a temperature-sensitive color-changing material.   The self-adhesive sheet according to claim 1, wherein the emulsion contains an acrylic emulsion and an ethylene vinyl acetate copolymer emulsion. A sheet having at least a self-adhesive porous foam layer containing one or more resins selected from urethane resins, acrylic resins and ethylene vinyl acetate copolymer resins,
The self-adhesive porous foam layer has a density of 150 to 300 kg / m ³ ;
The self-adhesive porous foam layer has a thickness of 0.5 to 2.0 mm;
The self-adhesive porous foam layer has an average cell diameter of 30 to 200 μm,
The delamination strength of the self-adhesive porous foam layer is 3.0 N / 12 mm or more,
25% compression load of the self-adhesive porous foam layer is 2.0 to 11.0 kPa,
The self-adhesive sheet, wherein the self-adhesive porous foam layer has an adhesive strength of 0.4 to 2.5 N / 24 mm.   The self-adhesive sheet according to claim 3, wherein the resin contains an acrylic resin and an ethylene-vinyl acetate copolymer resin. A method for producing a self-adhesive sheet having at least a self-adhesive porous foam layer,
Including a step of curing after foaming a composition containing an emulsion and a foaming agent by a mechanical floss method,
The self-adhesive sheet, wherein the emulsion comprises one or more emulsions selected from urethane emulsions, acrylic emulsions, and ethylene vinyl acetate copolymer resin emulsions, and the sheet has a temperature-sensitive color changing material. Manufacturing method.   The method for producing a self-adhesive sheet according to claim 5, wherein the emulsion contains an acrylic emulsion and an ethylene vinyl acetate copolymer emulsion. The self-adhesive porous foam layer has a density of 150 to 300 kg / m ³ ;
The self-adhesive porous foam layer has a thickness of 0.5 to 2.0 mm;
The self-adhesive porous foam layer has an average cell diameter of 30 to 200 μm,
The delamination strength of the self-adhesive porous foam layer is 3.0 N / 12 mm or more,
25% compression load of the self-adhesive porous foam layer is 2.0 to 11.0 kPa,
The manufacturing method of the self-adhesive sheet of Claim 5 or 6 whose adhesive strength of the said self-adhesive porous foam layer is 0.4-2.5N / 24mm.