JP6900972B2 - Sheet-shaped adhesive layer, laminate and method of manufacturing them - Google Patents

Description

The present invention relates to a decorative sheet.

Conventionally, there is known a decorative sheet which uses a plastic sheet as a base material, gives a color or a pattern to the plastic sheet, and imparts a mirror surface property to the surface.
These decorative sheets are used by being attached to various materials such as interior and exterior of buildings, building materials, furniture, and home appliances. The mirror surface of the surface can give a design that creates a feeling of cleanliness, luxury, and the like.
As a decorative sheet having such a mirror surface property, a decorative sheet using a polyester film has been proposed (for example, Patent Document 1).

When attaching a decorative sheet to a material, an adhesive (also called an adhesive) is applied to the surface of the decorative sheet side, the material side, or both sides of the material during the pasting process, and the decorative sheet is attached to the material. This is done, or the adhesive layer formed on the back surface of the decorative sheet in advance is used for pasting.
In addition, if it is expected that the decorative sheet once pasted will be peeled off, the position to be pasted will be changed and adjusted, and then pasted again, or another decorative sheet will be reattached to the peeled mark, it will be adhered. It is also possible to use an adhesive material (also called an adhesive) that is relatively easy to peel off instead of the material. However, in reality, it is unexpectedly difficult to reuse a decorative sheet in the form of laminating using a conventional adhesive material, such as re-peeling and re-pasting. For example, wrinkles occur during pasting. If the sticking fails, the peeled decorative sheet may be deformed or torn, so it is necessary to dispose of it, or when trying to re-stick to the material, it is necessary to clean the adhesive material remaining on the surface of the material. For this reason, it was difficult to attach the decorative sheet because special equipment was required and a skilled craftsman was required. In particular, in recent years, there has been a shortage of craftsmen, and inexperienced people and amateurs have frequently failed to apply the decorative sheet in the work of attaching the decorative sheet.
Therefore, in order to make the decorative sheet easier to use, it has been desired to improve the so-called reworkability, which allows the decorative sheet to be peeled off and reattached as it is when the application fails or is replaced.

On the other hand, Patent Document 2 discloses a technique relating to a micro suction cup film composed of an adhesive layer having a large number of minute suction cup groups on the surface of an adherend. Since the micro-sucker film of Patent Document 2 can be reversibly attached and detached from the adherend, if a decorative sheet having an adhesive layer made of this micro-sucker film can be realized, a makeup having reworkability can be realized. It is considered possible to use a sheet. However, although the composition disclosed in Patent Document 2 is capable of forming a micro suction cup film even at a temperature of about room temperature, it achieves a sufficient balance between an adsorption force and a peeling force on an adherend, and is sufficient. It was difficult to stably produce an adhesive layer having reworkability, and the above composition could not be applied to a decorative sheet for use.

JP-A-2007-204966 JP-A-2017-36404

An object of the present invention is to provide a decorative sheet having reworkability.

The present invention solves the above problems by the following solutions. In addition, in order to facilitate understanding, the description will be given with reference numerals corresponding to the embodiments of the present invention, but the present invention is not limited thereto.

The first invention is a surface layer (12) formed on the outermost surface and including a layer formed of at least a polyester resin, and laminated on the back surface side of the surface layer (12), and has a plurality of concave shapes on both sides (a plurality of concave shapes (12). The adhesive layer (13) including the adhesive layer (13) and the concave shape (13a) are uniformly formed on both surfaces of the adhesive layer (13) and open to the surface on the surface layer (12) side. The average value of the diameters of the openings of the concave shape (13a) is set to Dave 1, and the average value of the diameters of the openings of the concave shape (13a) that opens on the side opposite to the surface layer (12) is defined as Dave 1. when the D ave 2, | a / D ave 2 ≦ 0.5 decorative sheet satisfying the relationship (1,1B, 1C) | D ave 1 -D ave 2.

The second invention is characterized in that, in the decorative sheet (1,1B, 1C) according to the first invention, the layer thickness t of the adhesive layer (13) is in the range of 20 μm ≦ t ≦ 40 μm. Cosmetic sheets (1,1B, 1C) to be used.

The third invention states that, in the decorative sheet (1C) according to the first invention or the second invention, the surface layer (12) is composed of only a layer formed of a polyester resin. It is a characteristic decorative sheet (1C).

The fourth invention is the decorative sheet (1,1B) according to the first invention or the second invention, wherein the surface layer (12) is a layer (121) formed of a polyester resin and the polyester. The decorative sheet (1,1B, 1C) is provided with a surface protective layer (122) formed on the surface side of the layer (121) formed of the based resin.

The fifth invention is arranged between the surface layer (12) and the adhesive layer (13) in the decorative sheet (1) according to any one of the first to fourth inventions, and at least. The decorative sheet (1) is characterized by further having a decorative layer (11) including a pattern.

According to the sixth invention, in the decorative sheet (1,1B, 1C) according to any one of the first to fifth inventions, the outermost surface of the surface layer (12) is formed as a mirror surface. It is a decorative sheet (1,1B, 1C) characterized by that.

The seventh invention is the decorative sheet (1,1B, 1C) according to any one of the first to sixth inventions, wherein the adhesive layer (13) is a liquid resin composition containing bubbles. The decorative sheet (1,1B, 1C) is obtained by curing the above-mentioned, and is characterized in that a plurality of the concave shapes (13a) based on the air bubbles are formed on both sides.

The eighth invention is the decorative sheet (1,1B, 1C) according to any one of the first to seventh inventions, wherein the adhesive layer (13) has a density of 0.1 g / cm ³ or more. , 0.7 g / cm ³ or less, which is a decorative sheet (1,1B, 1C).

A ninth aspect of the present invention is the decorative sheet (1,1B, 1C) according to any one of the first to eighth inventions, wherein the adhesive layer (13) has a peelable base sheet on the back surface side. It is a decorative sheet (1,1B, 1C) characterized in that (15) is laminated.

The tenth invention is characterized in that the decorative sheet (1,1B, 1C) according to any one of the first to ninth inventions is configured in a rolled form. Decorative sheets (1,1B, 1C).

According to the present invention, it is possible to provide a decorative sheet having reworkability.

It is sectional drawing which shows 1st Embodiment of the decorative sheet by this invention. It is sectional drawing which shows the form at the time of use of a decorative sheet 1 in more detail sequentially. It is a perspective view which shows the form in which the decorative sheet 1 is wound in the form of a roll 1R. It is a figure which shows the manufacturing apparatus of the decorative sheet 1. It is a figure explaining the manufacturing method of the decorative sheet 1. It is an enlarged photograph of the adhesive layer 13 of the decorative sheet 1 of the embodiment when viewed from the back surface side (adhesive surface side). FIG. 5 is an enlarged view of a portion of the decorative sheet 1 of the embodiment near the back surface side (adhesive surface side) of the adhesive layer 13 in a cross section in a direction orthogonal to the sheet surface. It is a figure which shows the peeling force of an Example and a comparative example. It is a figure which shows the observation result of the sample 1. It is a figure which shows the observation result of the sample 2. It is a figure which shows the observation result of the sample 3. It is a figure which shows the observation result of the sample 4. It is sectional drawing which shows the 2nd Embodiment of a decorative sheet. It is sectional drawing which shows the 3rd Embodiment of a decorative sheet.

Hereinafter, the best mode for carrying out the present invention will be described with reference to drawings and the like.

(First Embodiment)
FIG. 1 is a cross-sectional view showing a first embodiment of a decorative sheet according to the present invention.
In addition, except for FIGS. 6, 7, and 9 to 13 of the live-action film, each of the figures shown below is a diagram schematically shown, and the size and shape of each part are for easy understanding. Is exaggerated as appropriate.
Further, in the following description, specific numerical values, shapes, materials and the like will be described, but these can be changed as appropriate.
In this specification, terms such as board, sheet, and film are used, but as a general usage, these are used in the order of thickness, board, sheet, and film. It is used in the same way in the book. However, in the present invention, since there is no technical meaning in such proper use, these words can be appropriately replaced and used, and even if they are appropriately replaced, the words of each claim and the specification of the present application are used. Can be interpreted in the same way.
Further, when the decorative sheet is used, the side that becomes the front side (the side of the layer 121 formed of the polyester resin and the upper side in FIG. 1) is called the front side, and the opposite side (the adhesive layer 13 side and the upper side). The lower side in FIG. 1) is referred to as the back side.

In the following description, first, as an example of the decorative sheet, as shown in FIG. 1, the decorative layer 1 and the surface layer 12 including the layer 121 formed of the polyester resin are laminated and bonded to each other. Will be explained. Hereinafter, the "layer 121 formed of the polyester resin" is also abbreviated as the "polyester resin layer 121" for the sake of simplicity. Further, as will be described later, for example, the decorative sheet may be provided with only the polyester resin layer 121 without the decorative layer 11, or the polyester resin layer 121 may not be provided with the surface protective layer 122. ..

In the embodiment illustrated in FIG. 1, the decorative sheet 1 includes a decorative layer 11, a surface layer 12, an adhesive layer 13, an adhesive layer 14, and a peelable base sheet 15.

(Decorative layer 11)
The decorative layer 11 includes a base material layer 111 and a printing layer 112.
(Base material layer 111)
The base material layer 111 is a base material layer made of a thermoplastic resin. Examples of the thermoplastic resin forming the base material layer include low-density polyethylene (including linear low-density polyethylene), medium-density polyethylene (PP), high-density polyethylene, ethylene-α-olefin copolymer, polypropylene, polymethylpentene, and the like. Polypropylene, ethylene-propylene copolymer, propylene-butene copolymer, olefin-based thermoplastic elastomer, ionomer, or a mixture thereof, and the like; polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, vinyl chloride-vinyl acetate copolymer weight Vinyl-based products such as coalescing, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, or mixtures thereof; polyethylene terephthalate, polyvinyl terephthalate (PET), polyethylene naphthalate-isophthalate copolymer, polyester-based thermal Polyester resins such as thermoplastic elastomers; methyl poly (meth) acrylate resins, ethyl poly (meth) acrylates, butyl poly (meth) acrylates, methyl (meth) acrylate-butyl acrylate copolymers, etc. Acrylic resin; polyamide represented by nylon 6 or nylon 66; cellulose-based resin such as cellulose triacetate and cellophane; polystyrene; or polyimide and the like can be mentioned. In the specification of the present invention, (meth) acrylic acid means acrylic acid or methacrylic acid. Further, (meth) acrylate means acrylate or methacrylate.
Of these, polyolefins and polyester resins can be used alone or as a mixture, but polyolefins and polyester resins are preferable, and among them, toxic chlorine-based gas is used when the decorative sheet after production is incinerated and disposed of. Polyolefins are more preferable, and polyethylene or polypropylene is preferable among the polyolefins from the viewpoint of not occurring and cost.

Further, the base material layer 111 is preferably formed of colored polyolefin. By using colored polyolefin, the stability of the color tone of the pattern layer formed on the surface of the decorative sheet can be ensured, and when the surface hue of the adherend substrate to which the decorative sheet is attached varies. It is possible to satisfactorily conceal the hue of the uneven surface.
The colorant used for such a purpose may be appropriately selected depending on the intended use. For example, the base material layer 111 can be colored transparent or colored opaque. Generally, it is necessary to conceal the surface of the adherend, so it is preferable to make it colored and opaque. Coloring agents include carbon black (black), iron black, titanium white, antimony white, yellow lead, titanium yellow, petals, cadmium red, ultramarine, cobalt blue and other inorganic pigments, quinacridone red, isoindolinone yellow, nickel. -Azo complex, organic pigments such as phthalocyanine blue or dyes, metal pigments consisting of scaly foil pieces such as aluminum and brass, titanium dioxide-coated mica, pearl gloss pigments consisting of scaly foil pieces such as basic lead carbonate. Etc. are used.

Further, if necessary, an inorganic filler may be added, and examples thereof include powders of calcium carbonate, barium sulfate, clay, talc, silica (silicon dioxide), alumina (aluminum oxide) and the like. The amount of the colorant added is usually about 1 to 80 parts by mass with respect to 100 parts by mass of the resin material forming the above-mentioned base material layer 111.

In the present invention, in order to improve the adhesion of the resin film used for the base material layer 111 to the layer provided on the resin film, if desired, one side or both sides of the resin film may be subjected to physics such as an oxidation method or an unevenness method. Physical or chemical surface treatments can be applied.
Examples of the oxidation method include a corona discharge treatment, a chromium oxidation treatment, a flame treatment, a hot air treatment, an ozone / ultraviolet treatment method, and the like, and examples of the unevenness method include a sandblast method and a solvent treatment method. These surface treatments are appropriately selected depending on the type of the base material, but in general, the corona discharge treatment method is preferably used from the viewpoints of effectiveness, operability, and the like.
Further, the base material may be subjected to a treatment such as forming a primer layer for the purpose of strengthening the interlayer adhesion between the base material and each layer.

Even if the base material layer 111 contains various other additives such as a filler, a foaming agent, a flame retardant, a lubricant, an antioxidant, an ultraviolet absorber, and a light stabilizer, if necessary. Good.

The thickness of the base material layer 111 is not particularly limited, but when a sheet made of the resin (plastic) as described above is used, the thickness is usually preferably 10 to 300 μm, more preferably 30 to 100 μm. , More preferably in the range of 50 to 85 μm. When the thickness of the base material layer 111 is within the above range, the surface of the decorative sheet of the present invention is not cracked during processing, and excellent processing characteristics can be obtained.

The printing layer 112 gives a design to the decorative sheet of the present invention, and may be a solid printing layer, a pattern printing layer, or a combination of a solid printing layer and a pattern printing layer. It may be. The solid printing layer is provided for the purpose of concealing the background of the base material layer 111, and is usually formed as a completely solid colored layer without a pattern. On the other hand, the pattern printing layer is composed of wood grain pattern, stone grain pattern, cloth grain pattern, leather squeezing pattern, surface pattern of natural leather, geometric figure, abstract pattern, etc., depending on figures, characters, symbols, colors, combinations thereof, etc. It has a pattern or color and is formed as a flat, uneven, or convex layer on a solid print layer. The pattern printing layer may also act as a solid printing layer, and the printing layer 112 may be composed of only the solid printing layer or only the pattern printing layer.

As the ink composition used for forming the print layer 112, a binder mixed with a colorant such as a pigment or a dye, an extender pigment, a solvent, a stabilizer, a plasticizer, a catalyst, a curing agent or the like is used. The binder is not particularly limited, and for example, polyurethane resin, vinyl acetate resin, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-acrylic copolymer, chlorinated polyethylene, chlorinated polypropylene. Any one of the based, acrylic resin, polyester resin, polyamide resin, butyral resin, polystyrene resin, nitrocellulose resin, cellulose acetate resin, etc. can be used alone or in combination of two or more. Is used. Among them, from the viewpoint of the effect of the present invention, it is preferable to use one kind of polyurethane resin, vinyl acetate resin, acrylic resin, polyester resin, cellulose resin, polyamide resin, etc. alone or a mixture of two or more kinds. preferable.
The colorant is not particularly limited, and for example, inorganic pigments such as carbon black (black), iron black, titanium white, antimony white, chrome yellow, titanium yellow, valve handle, cadmium red, ultramarine blue, cobalt blue, and quinacridone red. Organic pigments or dyes such as isoindolinone yellow, nickel-azo complex, phthalocyanine blue, metal pigments consisting of scaly foil pieces such as aluminum, nickel, chromium, gold, silver, copper, tin and brass, titanium dioxide coated mica, Examples thereof include pearl pigments made of scaly foil pieces such as basic lead carbonate.

(Print layer 112)
The print layer 112 can generally be formed by a well-known printing method such as gravure printing, offset printing, silk screen printing, transfer printing from a transfer sheet, and plateless printing such as ink jet printing. The pattern of the pattern printing layer is formed by multicolor printing with ordinary yellow, red, blue, and black process colors, and multicolor printing with special colors performed by preparing plates of the individual colors that make up the pattern. Is also formed by.
The thickness of the print layer 112 is usually about 1 to 20 μm, preferably 1 to 10 μm.

Further, the print layer 112 may be formed of a metal thin film. The metal thin film uses a metal such as aluminum, nickel, chromium, gold, silver, copper, tin, brass, and stainless steel, and is formed by a method such as vacuum deposition or sputtering. These may be used in combination. The metal thin film can be provided on the entire surface of the base material layer 111 or can be partially provided in a pattern.

(Adhesive layer 14)
The adhesive layer 14 is a layer provided between the printing layer 112 and the polyester-based resin layer 121 described later, and the adhesive layer 14 is formed by an adhesive coating agent composed of a resin composition, a solvent, and other additives. Will be done.
Examples of the resin composition include polyester resin, acrylic resin, epoxy resin, urethane resin, rubber resin and the like. Of these, polyester resin is preferably used. By adopting a polyester resin as the resin composition, the adhesive strength between the base material layer 111 and the polyester-based resin layer 121 is improved, and the decorative sheet of the present invention can be made thinner. As the polyester resin preferably used as the resin composition, those obtained by reacting at least one of each of a polyvalent carboxylic acid and an alcohol component are preferably mentioned.

Examples of polyvalent carboxylic acids include aliphatic dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, and dodecanedicarboxylic acid; unsaturated aliphatic acids such as fumaric acid, maleic acid, itaconic acid, hexahydrophthalic acid, and tetrahydrophthalic acid. Alicyclic dicarboxylic acids; aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid; aromatic oxycarboxylic acids such as oxybenzoic acid and hydroxyethoxybenzoic acid; unsaturated hydroxycarboxylic acids such as linoleic acid, etc. Be done.

Alcohol components include ethylene glycol, propylene glycol, propanediol, butanediol, pentanediol, hexanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, cyclohexanedimethanol, spiroglycol, phenylene glycol and its ethylene oxide adduct, and bisphenol. Examples thereof include ethylene oxide adduct and propylene oxide adduct of A, triol and tetraol such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, trimethylolethane, trimethylolpropane, glycerin and pentaerythritol.

Further, it is preferable to use a curing agent for the resin composition. Examples of the curing agent include isocyanate-based curing agents such as aliphatic polyisocyanate, alicyclic polyisocyanate and aromatic aliphatic polyisocyanate, hexamethoxymethyl melamine, hexamethoxymethylol melamine, pentamethoxymethylol melamine, trimethyl melamine and tris. Preferable examples include a melamine-based curing agent such as methoxymethyl melamine, an epoxy-based curing agent, a silane coupling agent, and a zirco-aluminum coupling agent. By using these curing agents, stronger adhesive strength can be obtained. From the viewpoint of obtaining stronger adhesive strength, an isocyanate-based curing agent and a melamine-based curing agent are preferable, and an isocyanate-based curing agent is more preferable.
The amount of the curing agent used is preferably 1 to 30 parts by mass, more preferably 1 to 20 parts by mass with respect to 100 parts by mass of the polyester resin.

The glass transition point (Tg) of the polyester resin is preferably in the range of -20 to 100 ° C, more preferably -10 to 90 ° C. Here, the glass transition point (Tg) is a value measured by a differential scanning calorimetry (DSC).
The elastic modulus is preferably in the range of −0.8 to 4 MPa, more preferably 1 to 3 MPa. Here, the elastic modulus is a value obtained by measuring the stress when an elongation of 100% or more is applied in accordance with JIS K6732.

The solvent used for the adhesive coating agent forming the adhesive layer 14 is not particularly limited, and for example, toluene, xylene, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether and the like are used. Examples thereof include water-insoluble organic solvents, water-soluble organic solvents such as methanol, ethanol, isopropyl alcohol and normal propyl alcohol, water, and mixed solvents thereof. As the adhesive coating agent, it is also possible to use a solvent-free type adhesive coating agent that does not use a solvent. Solvent-free type adhesive coating agents are environmentally friendly and are preferably used.

When a solvent is used, the adhesive coating agent forming the adhesive layer 14 contains a resin composition and, if necessary, other additives in the solvent, and is dissolved, dispersed, and mixed by a known method. Prepared.

The adhesive layer 14 is formed by applying the above-mentioned adhesive coating agent on the printing layer 112, drying and curing the adhesive layer 14. As the coating method, various known methods such as roll coating, gravure coating, air knife coating, comma coating and the like are used, and gravure coating and comma coating are preferably used from the viewpoint of productivity.
The adhesive layer 14 is coated so that the coating amount after drying is 0.1 to 20 g / m ² , preferably about 1 to 10 g / m ^2.

(Surface layer 12)
The surface layer 12 includes a polyester resin layer 121 and a surface protection layer 122. The surface protection layer 122 is not essential.
(Polyester resin layer 121)
The polyester-based resin layer 121 is a layer laminated on the adhesive layer 14 from the viewpoints of protecting the printed layer 112 from scratches and the like, improving the surface strength of the decorative sheet, and imparting a coating feeling. The polyester resin forming the polyester-based resin layer 121 is also advantageous in terms of the environment in that the organic gas generated when the decorative sheet after production is incinerated and disposed of is highly safe.

The polyester resin forming the polyester resin layer 121 includes aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid as acid components, and ethylene glycol, diethylene glycol, butanediol, and 1,4 cyclohexane as alcohol components. A copolymer obtained by an esterification reaction with an aliphatic diol such as diethanol or hexanediol is preferable. Specific polyester resins used in the present invention include, for example, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, ethylene glycol-terephthalic acid-isophthalic acid copolymer, terephthalic acid-ethylene glycol-1,4 cyclohexanedimethanol. Examples thereof include copolymers and various polyester-based thermoplastic elastomers.

The polyester resin forming the polyester-based resin layer 121 may be colored or colorless and transparent, but is preferably transparent from the viewpoint of design. When coloring, it is preferable that the color is transparent, and the colorant described in the base material layer 111 can be used.
The polyester resin forming the polyester resin layer 121 may be unstretched or stretched, but is biaxially stretched from the viewpoint of improving surface physical properties such as dimensional stability, strength, crystallinity, and solvent resistance. Is preferred. Further, since the mirror surface property is important in the present invention, a biaxially stretched product crystallized by stretching orientation is preferable from the viewpoint of imparting excellent mirror surface property to the decorative sheet.

The transparency (haze) of the polyester resin forming the polyester-based resin layer 121 is preferably 0 to 5%, more preferably 0 to 3%. Here, the haze is a value measured according to JIS K7105. When the haze of the polyester resin is within the above range, excellent designability can be obtained.
The heat shrinkage rate of the polyester resin forming the polyester resin layer 121 is preferably 0 to 5%, more preferably 0 to 3%. Here, the heat shrinkage rate is a value measured according to JIS C2318. When the heat shrinkage rate is within the above range, excellent surface physical characteristics can be obtained.

Known additives such as fillers, ultraviolet absorbers, light stabilizers, matting agents, antioxidants, and antiblocking agents are added to the polyester resin forming the polyester resin layer 121, if necessary. ..

The polyester resin layer 121 is formed by laminating a polyester resin film formed in advance on the adhesive layer 14 by various laminating methods such as dry lamination and thermal lamination, or by any other known method. Of these, a method in which a resin film is formed in advance and dry lamination is preferable. Further, in order to improve the adhesiveness, in addition to the formation of the easy-adhesion layer described later, a corona treatment or the like can be performed.

The thickness of the polyester-based resin layer 121 is arbitrary, but is preferably 50 to 100 μm, and more preferably 60 to 80 μm. When the thickness of the polyester-based resin layer 121 is within the above range, the decorative sheet of the present invention can be thinned, so that excellent processing characteristics can be obtained and cracks or the like do not occur on the sheet surface during processing. , A decorative board having an excellent appearance can be obtained.
The total thickness of the base material layer 111 and the polyester resin layer 121 is preferably 100 to 180 μm, more preferably 110 to 160 μm, and even more preferably 120 to 140 μm. When the total thickness of the base material layer 111 and the polyester resin layer 121 is within the above range, excellent processing characteristics can be obtained, and cracks and the like do not occur on the sheet surface during processing, resulting in an excellent appearance. It is possible to obtain a decorative board to have.

Further, the surface of the polyester resin layer 121 can be shaped by embossing. By forming the embossed pattern, the design of the decorative sheet can be improved. The embossed pattern is not particularly limited as long as it is a pattern suitable for the purpose of the decorative sheet. For example, wood grain conduit groove, wood grain annual ring unevenness, floating annual ring unevenness, wood surface unevenness, sand grain, satin finish, hairline, perforated groove, stone surface unevenness such as granite cleavage surface, texture surface texture, skin squeezing, letters, geometry. Patterns such as academic patterns can be mentioned. Further, when the surface is to be sharpened, the smoothness can be further improved by applying pressure using a mirror surface roll.

(Surface protection layer 122)
The surface protective layer 122 is a layer provided to impart surface properties such as abrasion resistance, scratch resistance, stain resistance, and chemical resistance to the decorative sheet of the present invention as well as excellent mirror surface properties.
The surface protective layer 122 needs to have a coating film elongation rate of 10 to 30%, preferably 10 to 25%. If the coating film elongation is less than 10%, the processing characteristics are deteriorated, and if it is more than 30%, the surface characteristics are deteriorated. Here, the coating film elongation rate is obtained by gravure-printing an ionizing radiation-curable resin on a polypropylene resin sheet (thickness: 60 μm) so that the thickness after drying is 5 μm, and irradiating with an electron beam (thickness). Pressurized voltage: 175 kV, irradiation dose: 30 kGy) The elongation rate was measured in accordance with JIL K7113-1995 for the sheet formed by cross-linking and curing (using No. 2 test piece, test temperature; 23 ° C., Test speed: 50 mm / min ± 10%). When the surface protective layer 122 has a predetermined elongation rate, it is possible to impart excellent processing characteristics to the decorative sheet of the present invention.

The surface protective layer 122 is an appropriate material from conventionally known surface coating films according to the desired surface appearance (gloss, haze, color tone, etc.) and surface physical characteristics (scratch resistance, stain resistance, weather resistance, etc.). And the film thickness may be selected.
A typical material of the surface protective layer 122 is an ionizing radiation curable resin composition or a layer formed by cross-linking and curing a thermosetting resin composition. Specifically, it can be appropriately selected and used from the polymerizable monomers and polymerizable oligomers conventionally used as ionizing and radiation curable resins.

As the polymerizable monomer, a (meth) acrylate-based monomer having a radically polymerizable unsaturated group in the molecule is preferable, and a polyfunctional (meth) acrylate monomer is particularly preferable. The polyfunctional (meth) acrylate monomer is a (meth) acrylate monomer having two or more ionizing radiation curable functional groups in the molecule and having at least a (meth) acryloyl group as the functional group, for example. , Ethylene glycol di (meth) acrylate, bisphenol A tetraethoxydiacrylate, bisphenol A tetrapropoxydiacrylate, bifunctional (meth) acrylate such as 1,6-hexanediol diacrylate; trimethylpropantri (meth) acrylate, penta Elythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, isocyanuric acid-modified tri (meth) acrylate And the like, trifunctional (meth) acrylate and the like can be mentioned.
From the viewpoint of improving processing characteristics and scratch resistance, the number of functional groups of the polyfunctional (meth) acrylate monomer is preferably 2 or more and 8 or less, more preferably 2 or more and 6 or less, further preferably 2 or more and 4 or less, and 2 or more. 3 or less is even more preferable. These polyfunctional (meth) acrylate monomers may be used alone or in combination of two or more. Further, one or more of these polyfunctional (meth) acrylate monomers and one or more (meth) acrylate oligomers described later may be used in combination.

Examples of the polymerizable oligomer include a (meth) acrylate oligomer having two or more ionizing radiation curable functional groups in the molecule and having at least a (meth) acryloyl group as the functional group. For example, urethane (meth) acrylate oligomer, epoxy (meth) acrylate oligomer, polyester (meth) acrylate oligomer, polyether (meth) acrylate oligomer, polycarbonate (meth) acrylate oligomer, acrylic (meth) acrylate oligomer and the like can be mentioned.
Further, as the polymerizable oligomer, a polybutadiene (meth) acrylate-based oligomer having a (meth) acrylate group on the side chain of the polybutadiene oligomer and a silicone (meth) acrylate-based oligomer having a polysiloxane bond on the main chain are also used. In molecules such as aminoplast resin (meth) acrylate-based oligomers modified from aminoplast resins having many reactive groups in small molecules, novolak type epoxy resins, bisphenol type epoxy resins, aliphatic vinyl ethers, aromatic vinyl ethers, etc. There are oligomers and the like having cationically polymerizable functional groups.

These polymerizable oligomers may be used alone or in combination of two or more. Urethane (meth) acrylate oligomer, epoxy (meth) acrylate oligomer, polyester (meth) acrylate oligomer, polyether (meth) acrylate oligomer, polycarbonate (meth) acrylate oligomer from the viewpoint of improving processing properties, scratch resistance and weather resistance. , Acrylate (meth) acrylate oligomers are preferable, urethane (meth) acrylate oligomers and polycarbonate (meth) acrylate oligomers are more preferable, and urethane (meth) acrylate oligomers are even more preferable.
The number of functional groups of these polymerizable oligomers is preferably 2 or more and 8 or less, more preferably 6 or less, still more preferably 4 or less, from the viewpoint of improving processing characteristics, scratch resistance and weather resistance. 3 or less is even more preferable.
The weight average molecular weight of these polymerizable oligomers is preferably 2,500 or more and 7,500 or less, and more preferably 3,000 or more and 7,000 or less, from the viewpoint of improving processing characteristics, scratch resistance and weather resistance. , 3,500 or more and 6,000 or less are more preferable. Here, the weight average molecular weight is an average molecular weight measured by GPC analysis and converted with standard polystyrene.

A monofunctional (meth) acrylate can be used in combination with the ionizing radiation curable resin composition for the purpose of reducing the viscosity of the ionizing radiation curable resin composition. These monofunctional (meth) acrylates may be used alone or in combination of two or more.
When the ionizing radiation curable composition is ultraviolet or visible light curable, the composition preferably contains additives such as a photopolymerization initiator and a photopolymerization accelerator.
Examples of the photopolymerization initiator include one or more selected from acetophenone, benzophenone, α-hydroxyalkylphenone, Michler ketone, benzoin, benzyl dimethyl ketal, benzoyl benzoate, α-acyl oxime ester, thioxanthones and the like.
Further, the photopolymerization accelerator can reduce the polymerization inhibition by air at the time of curing and accelerate the curing rate. For example, from p-dimethylaminobenzoic acid isoamyl ester, p-dimethylaminobenzoic acid ethyl ester and the like. One or more selected species can be mentioned.
As the ionizing radiation, electromagnetic waves such as ultraviolet rays, visible rays and X-rays, or charged particle beams such as electron beams, α rays and various ion rays can be used, but ultraviolet rays or electron beams are usually used.

The thermocurable resin composition includes a two-component curable ureta resin, an epoxy resin, a melamine resin, a phenol resin, an unsaturated polyester resin, a melamine resin, and a fluororesin, which use a polyol compound as a main component and an isocyanate compound as a curing agent (crosslinking agent). Examples thereof include resin and silicon resin.
The film thickness of the surface protective layer 122 can be in the range of about 1 to 100 μm.

(Adhesive layer 13)
The adhesive layer 13 is laminated on the surface of the decorative layer 11 opposite to the polyester resin layer 121 (the lower surface in FIG. 1, which is also referred to as the back surface side of the decorative layer 11). It is a layer having adhesiveness to an adherend such as a wall surface. The adhesive layer 13 has a plurality of concave shapes 13a opened on both sides thereof, that is, on the side in contact with the decorative layer 11 and the side in contact with the peelable base sheet 15. Further, the adhesive layer 13 has elasticity, and since the plurality of concave shapes 13a each act as a fine suction cup, it is possible to exert an adhesive force (adhesive force) on various adherends (adhesive force). See FIG. 2 (c)).

The adhesive layer 13 is formed by, for example, a production method described later using a liquid resin composition (acrylic emulsion) disclosed in Patent Document 2 (Japanese Unexamined Patent Publication No. 2017-36404). The resin composition used for the adhesive layer 13 contains, for example, 2-ethylhexyl polyacrylate as a main component, and sulfur, bicine: N, N-Bis (2-hydroxyethyl) glycine, N.I. N. -A substance containing dimethyloctadecamine or the like can be used.

The layer thickness of the adhesive layer 13 is preferably 1 μm or more and 500 μm or less. If it is less than the lower limit of the layer thickness range, it becomes difficult to form the concave shape, or the size of the concave shape becomes too small, and the adhesive (adsorption) property deteriorates. On the other hand, if the upper limit of the layer thickness range is exceeded, the flexibility of the decorative sheet is lowered and the workability is deteriorated.
Further, in order to evenly provide the concave shape 13a on both surfaces of the adhesive layer 13, it is desirable that the layer thickness t of the adhesive layer 13 is in the range of 20 μm ≦ t ≦ 40 μm. This point will be described later.

The size (diameter) and density of the concave shape 13a of the adhesive layer 13 can be adjusted by changing various conditions in the manufacturing process described later. For example, the adhesive layer 13 can use the density of the adhesive layer 13 as an index indicating the degree to which the concave shape 13a is included. The density of the adhesive layer 13 is not particularly limited, but can be, for example, 0.1 g / cm ³ or more and 0.7 g / cm ³ or less. The size (diameter) of the concave shape 13a is not particularly limited, but may be, for example, 1 μm or more and 300 μm or less. When the concave shape 13a can be regarded as a sphere, the diameter of the concave shape 13a is set to the size of the concave shape 13a. If the concave shape 13a cannot be regarded as a sphere, the diameter of the sphere having the same volume as the concave shape 13a is set to the size of the concave shape 13a.

(Removable base material sheet 15)
The peelable base material sheet 15 is laminated on the side opposite to the decorative layer 11 of the adhesive layer 13 (in FIG. 1, it is the lower surface, which is also referred to as the back surface side of the adhesive layer 13). .. The peelable base material sheet 15 is provided in consideration of handleability until the decorative sheet 1 is used, and the decorative sheet 1 is attached to the surface of the adherend when the decorative sheet 1 is used, that is, the decorative sheet 1 is attached to the surface of the adherend. It is peeled off at the time. As the peelable base material sheet 15, various forms such as a conventionally known release film, separate paper, separate film, release film, and release paper can be appropriately used. For example, high-quality paper, coated paper, impregnated paper, plastic film, or the like having a release layer formed on one side or both sides may be used. The release layer is not particularly limited as long as it is a material having releasability, but for example, silicone resin, organic resin modified silicone resin, fluororesin, aminoalkyd resin, melamine resin, acrylic resin, polyester resin and the like. Can be mentioned. As these resins, any of emulsion type, solvent type and solvent-free type can be used. When a release film provided with a release layer is used, for example, a silicone release type PET (polyethylene terephthalate) film, an untreated PET film, a PP film, a silicone release type paper, or the like can be used.

The thickness of the peelable base sheet 15 is preferably, for example, 10 μm or more and 100 μm or less, and more preferably 20 μm or more and 60 μm or less. If it is less than the lower limit of the above layer thickness range, there is no stiffness and it becomes difficult to peel off. Further, if the upper limit value of the layer thickness range is exceeded, the stiffness is too strong and the workability at the time of sticking is lowered.
Further, as the peelable base sheet 15, a commercially available one may be used. For example, a polyester film having a thickness of 38 μm in which one side is easily peeled with a silicone-based release agent (Mitsui Chemicals Tohcello Co., Ltd.) Manufactured, trade name: SP-PET-01) and the like.
In this embodiment, the form including the peelable base sheet 15 is illustrated, but the peelable base sheet 15 may be omitted depending on the usage mode.

If necessary, a primer layer may be provided between the layers in order to improve the bonding force between the layers. As the primer layer, when the decorative layer 11 is a polyolefin, polyester resin, vinyl chloride resin or the like, a two-component curable urethane resin composed of a polyol and an isocyanate and using isocyanate as a curing agent, or vinyl chloride using isocyanate as a curing agent. -Vinyl acetate copolymer resin or the like can be used.

FIG. 2 is a cross-sectional view showing in more detail the form of the decorative sheet 1 when used.
As shown in FIG. 2A, the above-mentioned decorative sheet 1 includes a peelable base sheet 15. When the decorative sheet 1 is attached to the adherend 50, the peelable base sheet 15 is peeled off (FIG. 2B). Then, by attaching the exposed adhesive layer 13 to the adherend 50 and applying an appropriate pressure to the surface thereof, a large number of concave shapes 13a existing on the exposed surface of the adhesive layer are elastically deformed, thereby causing a conventional micro suction cup. It will be adsorbed (adhesive) to the adherend 50 by the same action as in (FIG. 2 (c)).
That is, due to the elastic deformation around the concave shape 13a, a force that tries to return from the deformed state to the original shape acts on the concave shape 13a. Due to this force, the closed space in the concave shape 13a becomes a negative pressure, and an adsorption action on the adherend 50 occurs. Although the suction force of the concave shape 13a alone is weak, the necessary suction force can be secured as a whole because a large number of concave shapes 13a are formed. Further, when the adhesive layer 13 is manufactured, the adhesive force (adhesive force) of the adhesive layer 13 can be adjusted by adjusting the amount including the concave shape 13a as a parameter, for example, the density.

FIG. 3 is a perspective view showing a form in which the decorative sheet 1 is wound in the form of a roll 1R.
The decorative sheet 1 of the present embodiment can be manufactured and distributed in the form of a roll 1R as shown in FIG. 3, for example. In such a form, a required predetermined amount of the decorative sheet 1 is unwound from the roll 1R as shown in FIG. 3 according to the adherend to be attached, and then cut into a required size and shape. Can be used. In addition, it is possible to prevent the product from being bent during distribution. The decorative sheet 1 is not limited to the form wound in the form of the roll 1R, but may be in the form of a single leaf.
As shown in FIG. 3, such a roll 1R normally winds the decorative sheet 1 around a winding shaft 1S such as a paper tube, but a form in which only the decorative sheet 1 is wound without the winding shaft 1S is also possible. The decorative sheet 1 constituting the roll 1R may be configured to include the peelable base sheet 15 or may not include the peelable base sheet 15, but the decorative sheet 1 at the time of unwinding may be included. In order to ensure smooth unwinding of the sheet 1 and to prevent changes in the phase appearance of the folds and the like due to the interaction between the surface of the surface layer 12 and the adhesive layer 13, the decorative sheet 1 in the form of including the peelable base sheet 15 It is preferable to wind up to form a low 1R form.

Next, a method for manufacturing the decorative sheet 1 will be described.
FIG. 4 is a diagram showing a manufacturing apparatus for the decorative sheet 1.
FIG. 5 is a diagram illustrating a method for manufacturing the decorative sheet 1.

In order to produce the decorative sheet 1, first, the composition of the acrylic emulsion disclosed in Patent Document 2 for forming the adhesive layer 13 is put into a stirrer, and nitrogen gas is mixed in the composition. Stirring is performed to include bubbles in the composition to prepare a bubble-containing composition 130 (P1: whipping step in the figure).

Next, the bubble-containing composition 130 is coated on the peelable base material sheet 15 to form the liquid coating layer 130CL of the bubble-containing composition 130 (P2 in the figure: coating step). In the coating step, for example, a comma coater can be used, but other known coating methods may be used.

After the liquid coating layer 130CL of the bubble-containing composition is coated on the peelable base material sheet 15, the liquid coating layer 130CL is dried while heating to form the adhesive layer 13 as the solidification coating layer 130CS of the bubble-containing composition. (P3 in the figure: drying step). In the drying step, for example, a drying furnace having a temperature of about 60 ° C. to 140 ° C. can be used. As the drying time, for example, about 30 seconds to 10 minutes can be exemplified. Further, in the drying step, drying may be promoted while blowing air to the bubble-containing composition 130. By performing the drying step, openings having the same or substantially the same average diameter on both the exposed surface side (upper side in FIG. 5) and the peelable base sheet 15 side of the solidified coating layer 130CS of the bubble-containing composition 130. The concave shape 13a having the above shape is formed, and the adhesive layer 13 is formed. In the concave shape 13a, among the bubbles contained in the bubble-containing composition 130, the bubbles near the exposed surface side are ruptured and a part of the bubble shape remains on the exposed surface side of the solidification coating layer 130CS. On the other hand, the air bubbles gathered at the interface between the solidified coating layer 130CS and the peelable base sheet 15 and its vicinity are solidified by the solidification of the bubble-containing composition, and the interface shape with the bubbles in the solidified composition is fixed. Is formed by. Here, if the bubbles burst in a state where the bubble-containing composition 130 is insufficiently cured, the concave shape 13a is unlikely to remain. On the other hand, if the bubble-containing composition 130 is cured before the bubbles burst, the concave shape 13a may not be formed. Therefore, it is desirable that the drying step is performed under the condition that the foam is broken while the bubble-containing composition 130 is cured to some extent. Therefore, the temperature and the amount of air blown in the drying step have a great influence on the state of the concave shape 13a.

After the adhesive layer 13 is formed by the drying step, the decorative layer 11 and the surface layer 12 prepared separately are joined to the adhesive layer 13 (P4: laminating step in the figure). In this laminating step, since laminating is performed by the adsorption force (adhesive force) of the concave shape 13a of the adhesive layer 13, heating is not required, and joining is possible with only a slight pressing force. Therefore, the decorative layer 11 and the surface layer 12 are not damaged.

When the laminating step is completed, the decorative sheet 1 is completed.
As described above, in the production of the decorative sheet 1 of the present embodiment, the decorative sheet 1 can be efficiently produced without damaging the decorative layer 11 and the surface layer 12 by heat when the adhesive layer 13 is formed. The decorative sheet may then be rolled up or cut to a required size.

Next, an example in which the decorative sheet 1 of the present embodiment is actually produced will be shown, and the results of comparison with the comparative example will be described.
In the decorative sheet 1 of the example, a biaxially stretched PET film having releasability is used for the peelable base sheet 15, and a bubble-containing composition which has been whipped using a comma coater having a clearance of 200 μm on the biaxially stretched PET film. 130 was applied. This was dried in a drying path at 100 ° C. for 1 minute to form an adhesive layer 13, and the decorative layer 11 and the surface layer 12 were laminated to obtain a decorative sheet 1. The density of the adhesive layer 13 in this case was 0.58 g / cm3, and the thickness was 50 μm.
FIG. 6 is an enlarged photograph of the adhesive layer 13 of the decorative sheet 1 of the embodiment as viewed from the back surface side (adhesive surface side).
FIG. 7 is an enlarged view of the portion near the back surface side (adhesive surface side) of the adhesive layer 13 of the decorative sheet 1 of the embodiment in a cross section in a direction orthogonal to the sheet surface.
As shown in FIGS. 6 and 7, it can be confirmed that a large number of concave shapes 13a are formed on the adhesive layer 13.
In the present specification, the sheet surface means a surface of each sheet that is in the plane direction of the sheet when viewed as a whole. In FIG. 1, the front surface or the back surface of the decorative layer 11, or any surface parallel to these surfaces corresponds to the sheet surface.

As Comparative Example 1, a decorative sheet prepared in the same manner as in the above-mentioned Example was prepared except that the whipping step was not performed. The density of the adhesive layer after preparation was 0.87 g / cm3, and the thickness was 100 μm.
As Comparative Example 2, a decorative sheet (referred to as acrylic adhesive A type) in which an adhesive layer was prepared by applying an acrylic resin manufactured by Soken Chemical Co., Ltd .: SK2094 without a whipping step was prepared.
As Comparative Example 3, a decorative sheet (referred to as acrylic adhesive B type) having an adhesive layer formed by coating with SK1502C manufactured by Soken Chemical Co., Ltd., which is an acrylic resin, without a whipping step was prepared.

The above four types of decorative sheets were prepared and their peeling power was compared.
FIG. 8 is a diagram showing peeling force of Examples and Comparative Examples.
The peeling force in FIG. 8 is the result of measuring the peeling force at that time by performing 180 ° peeling at a tensile speed of 300 mm / min using a tensile tester. The peeling force was measured immediately after pasting (0.5 hours) and 1000 hours after pasting.

In the examples, it can be seen that the peeling force can be relatively small both immediately after the sticking and after 1000 hours have passed. With such a peeling force, it does not peel off naturally, and it can be easily peeled off by applying force to peel it off. Moreover, since the adsorption is performed by the concave shape 13a, the adhesive layer 13 does not remain on the surface of the test adherend as if it were the adherend 50 after peeling, and the adhesive strength (peeling force) of the adhesive layer 13 itself. However, there was virtually no change and it was possible to re-paste.
In Comparative Example 1, small pieces can be peeled off with a relatively small peeling force, but in the case of a large size, a certain amount of force is required for peeling. Further, after the peeling, the adhesive layer remained on the surface of the adherend, and it was impossible to completely reattach.
In Comparative Example 2, in the case of a large size, a certain amount of force is required for peeling, and it is possible to peel off immediately after pasting, but after 1000 hours, the peeling force increases significantly. It was in a state where it was difficult to peel it off by hand, or the decorative layer 11 and the surface layer 12 might be damaged if it was forcibly peeled off.
In Comparative Example 3, the peeling force was too large immediately after pasting, and it was difficult to peel it by hand, or if it was forcibly peeled off, the decorative layer 11 and the surface layer 12 might be damaged. ..
Further, both Comparative Example 2 and Comparative Example 3 are suitable for reattachment because a part of the adhesive material remains on the test adherend or the adhesive strength is lowered after the peeling. There wasn't.

(Verification experiment on the concave shape 13a of the adhesive layer 13)
As described above, in the present invention, the concave shape 13a of the adhesive layer 13 has a great influence on the adhesive force. If the concave shape 13a is not evenly provided on both surfaces of the adhesive layer 13, the adhesive force (adhesive force) of one surface of the adhesive layer may decrease or increase as compared with the other surface. Further, since the concave shape 13a is evenly provided on both surfaces of the adhesive layer 13, the physical properties of the adhesive layer 13 become homogeneous, and the decorative layer 11 and the peelable base material sheet, or the decorative layer 11 and the adherend. It is also preferable in terms of exhibiting sufficient adhesive strength to both of the above and removability with the adherend.

In order to evenly provide the concave shape 13a on both surfaces of the adhesive layer 13, it is important to control the coating amount (layer thickness t) of the adhesive layer 13. In this regard, Patent Document 2 (Japanese Unexamined Patent Publication No. 2017-36404) does not consider anything, and it is sufficient that a micro suction cup is simply formed. In Patent Document 2, in FIG. 2 (FIG. 2 of Patent Document 2), which is a cross-sectional photograph of Example 1 formed with a WET thickness of 800 μm, a portion shown as a surface having a micro suction cup has a fine suction cup structure. However, in the part shown as the surface peeled off from the glass substrate, a structure that seems to be a huge bubble that is incomparable to the fine suction cup structure can be confirmed. That is, in the configuration of Patent Document 2, a micro suction cup (corresponding to the concave shape 13a in the present embodiment) is formed on one surface of the adhesive layer, but a micro suction cup (concave shape 13a) is formed on the other surface. Is not roughly formed.

This point was also verified by the applicant.
As a verification experiment, samples of four types of adhesive layers were prepared, and the concave shapes 13a on both sides were observed by SEM. The samples are the following four types.
Sample 1: Adhesive layer thickness t = 25 μm
Sample 2: Adhesive layer thickness t = 30 μm
Sample 3: Adhesive layer thickness t = 35 μm
Sample 4: Adhesive layer thickness t≈2000 μm
The layer thickness of the sample is the layer thickness after drying. Further, for Samples 1 to 3, the glass surface was coated with the foam-containing composition after the foaming treatment using a coater, and the drying treatment was carried out using a drying oven at 100 degrees. Sample 4 was drip-coated on a glass surface and naturally dried at room temperature (room temperature 20 ° C.). The reason why the drying conditions of Sample 4 were changed is to verify the description in Patent Document 2 that drying at room temperature is sufficient. In each sample, the density of the adhesive layer after the foaming treatment was 0.4 g / cm ³ .

FIG. 9 is a diagram showing the observation results of Sample 1.
FIG. 10 is a diagram showing the observation results of Sample 2.
FIG. 11 is a diagram showing the observation results of the sample 3.
FIG. 12 is a diagram showing the observation results of the sample 4.
As shown in FIGS. 9 to 11, it was confirmed that the fine concave shape 13a was uniformly formed on both sides of the samples 1 to 3 in which the layer thickness t of the adhesive layer was controlled and the heat-dried samples 1 to 3 were dried. ..
On the other hand, in the sample 4 having a large film thickness and dried at room temperature shown in FIG. 12, an extreme difference in the size of the concave shape 13a was observed between the dried surface and the glass side surface, which was the same as in FIG. 2 of Patent Document 2. The result was obtained.
Therefore, in order to evenly provide the concave shape 13a on both surfaces of the adhesive layer 13, it can be determined that the layer thickness t of the adhesive layer 13 is preferably in the range of 20 μm ≦ t ≦ 40 μm.

Here, regarding the state in which the concave shape 13a is evenly provided on both surfaces of the adhesive layer 13, it is desirable to satisfy the following relationships in more detail.
The average value of the diameters of the openings of the concave 13a that opens on the surface on the decorative layer 11 side is set to ^Dave _1, and each opening of the concave 13a that opens on the peelable base sheet side (opposite to the decorative layer). When the average value of the diameter of the part is ^Dave ₂ ,
| D ^ave _1- D ^ave ₂ | / D ^ave ₂ ≤ 0.5
It is desirable to satisfy the relationship of.
Also,
| D ^ave _1- D ^ave ₂ | / D ^ave ₂ ≤ 0.25
It is even more desirable to satisfy the relationship.
By satisfying these relationships, it is possible to reduce the difference in adhesive strength between both sides of the adhesive layer, and it is sufficient for both the decorative layer 11 and the peelable base material sheet or the decorative layer 11 and the adherend. It is possible to satisfactorily exhibit a good adhesive force and removability with an adherend.

By reducing the difference in adhesive strength between both sides of the adhesive layer in this way, the convenience of the decorative sheet 1 can be significantly improved. That is, since there is no difference in the adhesive strength on both sides of the adhesive layer, it becomes easy to adjust the necessary adhesive strength according to the specific usage pattern of the decorative sheet 1. For example, when the adhesive force between the adherend to which the decorative sheet 1 is attached and the adhesive layer is strong, when the decorative sheet 1 is peeled off, it is peeled off at the interface between the decorative layer 11 and the adhesive layer 13, so-called "glue". There is a risk of producing "remaining". In such a case, it is possible to easily adjust the balance of the adhesive force by performing a primer treatment on the adherend side in advance to weaken the adhesive force.

Since it is practically impossible to obtain the average value of the diameters of all the openings as the average value of the diameters of the openings, here, the openings having a large diameter within the observation range of 1500 μm × 1100 μm. The diameters of the three openings were measured in order from the beginning, and the average value was used.

Here, when the openings of the samples of FIGS. 10 to 13 were measured and | D ^ave ₁ − D ^ave ₂ | / D ^ave ₂ was obtained, sample 1: 0.04 and sample 2: 0.06 were obtained. , Sample 3: 0.12, Sample 4: 0.69.
As a method of obtaining the average value of the diameters of each opening, the above-mentioned method is an example, and it is desirable to appropriately optimize it according to the actual form of the adhesive layer 13. For example, a peculiar opening such as an opening having an extremely large diameter or an opening having a distorted opening shape may be excluded from the calculation of the average value. Also, instead of using three samples in order from the opening with the largest diameter, up to three openings in order from the opening with the largest diameter can be excluded, and the openings of subsequent sizes can be used as a sample for calculating the average value. Good. Further, the number of samples N may be increased to more than three to improve the accuracy.
Regarding the determination of the number of samples N when calculating the average value, the standard deviation σ ( ^Dave ₁ (N)) ^{of the average values Dave} ₁ (N) and ^Dave _{2 (N) in the number of samples N and} it may be determined as the minimum number of samples to be Han斷When thoroughly Convergence with increasing _{^{σ (D ave 2 (N)}} ) is N. In the usual case, it is about 3 ≦ N ≦ 100, preferably about 10 ≦ N ≦ 30.

As described above, the decorative sheet 1 of the present embodiment has a plurality of concave shapes based on air bubbles formed on both surfaces of the adhesive layer 13. Therefore, the adhesive layer 13 can be provided as a decorative sheet without heating the polyester resin layer 121, and the polyester resin layer 121 can be easily manufactured without damaging the polyester resin layer 121.
Further, since the adhesive force of the adhesive layer 13 is due to the adsorption force of the concave shape 13a, the reworkability is high, and even if the sticking fails, it is easy to re-tension, and it is easy to use.
Further, since the concave shape 13a has a fine size and is provided in large numbers, the adhesive force (adhesive force) can be exhibited even if the surface of the adherend has some irregularities.
Furthermore, since a phenomenon such as adhesive residue does not occur on the surface of the adherend after the decorative sheet 1 is peeled off, it does not need to be cleaned and can be reattached as it is, which improves workability. It is good.
Further, since the decorative sheet 1 of the present embodiment can form the adhesive layer 13 without heating, various forms of the decorative layer 11 and the surface layer including the heat-sensitive decorative layer 11 and the surface layer are used. It is possible to construct a decorative sheet.
(Use)
The decorative sheet 1 of this embodiment and each of the other embodiments is attached to the entire surface of the surface of various materials or the surface of a part of the area to decorate the surface of the wall, floor, ceiling, etc. of the building. It can be used for various purposes such as furniture such as cupboards and desks, doors, sliding doors, surrounding edges, fittings and building members such as waist walls, housings for home appliances, and interior materials for vehicles such as automobiles.
Further, the material, that is, the adherend of the decorative sheet 1, is made of various materials such as wood, resin, metal, ceramics, glass, sentment, calcium silicate, and has various shapes and forms such as a flat plate, a hollow, or a solid columnar body. Can be used.

(Second Embodiment)
FIG. 13 is a cross-sectional view showing a second embodiment of the decorative sheet.
The second embodiment and the third embodiment described later have the same configuration as the first embodiment except that some layer configurations are omitted. Therefore, the same reference numerals are given to the parts that perform the same functions as those of the first embodiment described above, and duplicate description will be omitted as appropriate.
The decorative sheet 1B of the second embodiment is a form in which the decorative layer 11 and the adhesive layer 14 are omitted from the decorative sheet 1 of the first embodiment. In the case of such a form, for example, the polyester resin layer 121 may be colored.

(Third Embodiment)
FIG. 14 is a cross-sectional view showing a third embodiment of the decorative sheet.
The decorative sheet 1C of the third embodiment is a form in which the surface protective layer 122 is further omitted from the decorative sheet 1 of the second embodiment. In the case of such a form, for example, if the surface of the polyester resin layer 121 is smoothed, it is possible to provide the mirror surface property of the surface without the surface protective layer 122.

Not limited to the embodiments described above, various modifications and changes are possible, and these are also within the scope of the present invention.
Although each embodiment and modified form can be used in combination as appropriate, detailed description thereof will be omitted. Moreover, the present invention is not limited to each of the embodiments described above.

1, 1B, 1C Decorative sheet 1R Roll 1S Winding shaft 11 Decorative layer 12 Surface layer 13 Adhesive layer 13a Concave shape 14 Adhesive layer 15 Detachable base sheet 50 Adhesive body 111 Base layer 112 Printing layer 121 Polyester resin layer 122 Surface protection layer 130 Bubble-containing composition 130CL Liquid coating layer 130CS Solidification coating layer

Claims (10)

A sheet-like adhesive layer having a first surface and a second surface.
The adhesive layer has a first concave shape having an opening on the first surface and a second concave shape having an opening on the second surface.
The average value of the diameters of the openings of the first concave shape is D. ^ave ₁ The average value of the diameters of the openings of the second concave shape is D. ^ave ₂ When
｜ D ^ave ₁ -D ^ave ₂ ｜ / D ^ave ₂ ≤0.5
Satisfy the relationship,
Sheet-like adhesive layer. The thickness of the adhesive layer is 20 μm or more and 40 μm or less.
The sheet-like adhesive layer according to claim 1. Average value D of the diameter of the opening of the first concave shape ^ave ₁ And the average value D of the diameter of the opening of the second concave shape ^ave ₂ Is 1 μm or more and 300 μm or less.
The sheet-like adhesive layer according to claim 1 or 2. The density of the adhesive layer is 0.1 g / cm ³ Above, 0.7 g / cm ³ Is below
The sheet-like adhesive layer according to any one of claims 1 to 3. ｜ D ^ave ₁ -D ^ave ₂ ｜ / D ^ave ₂ ≤0.25
Satisfy the relationship,
The sheet-like adhesive layer according to any one of claims 1 to 4. The adhesive layer has an acrylic resin.
The sheet-like adhesive layer according to any one of claims 1 to 5. A step of adding air bubbles to the resin composition by stirring the liquid resin composition for forming the adhesive layer, and
The process of applying the resin composition and
The step of forming the adhesive layer by drying the resin composition and
To prepare
The method for producing a sheet-like adhesive layer according to any one of claims 1 to 6. In the step of applying the resin composition, the resin composition is applied to a peelable base material sheet.
The method for producing a sheet-like adhesive layer according to claim 7. A laminated body in which the sheet-shaped adhesive layer according to any one of claims 1 to 6 is laminated. A step of adding air bubbles to the resin composition by stirring the liquid resin composition for forming the adhesive layer, and
The step of applying the resin composition to the peelable base material sheet and
The step of forming the adhesive layer by drying the resin composition and
A step of contacting and laminating the surface side of the adhesive layer opposite to the surface on which the peelable base material sheet exists in contact with another layer.
To prepare
The method for producing a laminate according to claim 9.

Images