JP6730101B2 - Graphic sheet and building structure - Google Patents

Description

The present disclosure relates to a graphic sheet and a building structure, and more particularly to a graphic sheet suitable for interior use and a building structure including the same.

A graphic sheet having an adhesive layer provided on a film base material having a printing layer is used for interior applications such as inner walls of stores, movie theaters, public facilities, and the like.

For example, a graphic sheet used as an advertising poster in a movie theater often has a relatively large area, for example, an A1 size (594 mm×841 mm) or more. The graphic sheet used for the purpose of temporary advertisement is replaced after a predetermined advertisement period has elapsed.

Patent Document 1 (Japanese Patent Laid-Open No. 2003-076308) discloses "a so-called backing advertisement poster sheet in which a printed image is viewed from the front side by being stuck on the back surface of a transparent window glass, a transparent window glass of a car, a transparent plastic plate or the like". The micro sucker sheet used as is described.

Patent Document 2 (Japanese Patent Laid-Open No. 2013-114137) is suitable for "advertising posters attached to transparent adherends such as glass and plastic films, and advertisement stickers that can be attached to the inside of the glass of railways and cars. Applied to” a foam with a printed layer.

JP, 2003-076308, A JP, 2013-114137, A

Conventionally, as a large graphic sheet that is attached to the inner wall material such as gypsum board and wallpaper, the adhesive force that can maintain sufficient adhesiveness to the base material such as the inner wall material so that the graphic sheet does not peel off. A pressure-sensitive adhesive sheet provided with was used. On the other hand, unlike window glass, plastic film, etc. where peeling or damage of the base material is unlikely to occur, when existing graphic sheets pasted on gypsum board or wallpaper such as polyvinyl chloride sheet can be replaced, existing When peeling off the graphic sheet, the base material, such as gypsum board, is often peeled off together, and it was necessary to replace the base material such as the base material, gypsum board. Even when a graphic sheet is attached to a wall or a window on which a wallpaper or a poster is already attached, it is necessary to remove the wallpaper. For this reason, most of the work of replacing the graphic sheet is used for the repair work of the base material that is the base, and in many cases, the work of a skilled contractor was required.

However, most of graphic sheets used in stores, movie theaters, etc. for advertising purposes need to be replaced in a short period of time, and it is necessary to perform replacement work frequently.

The present disclosure, even when applied on a relatively brittle base material such as gypsum board, wallpaper, posters, etc., it is possible to replace without damaging the base material that is the base, even if you are not a person skilled in construction, It is an object to provide a graphic sheet that can be easily peeled off.

According to an embodiment of the present disclosure, a graphic sheet that can be peeled off from a base material, the base film layer having a first surface and a second surface facing the first surface, and the base film. An adhesive layer disposed on the second surface of the layer, the initial adhesive force of the adhesive layer to the substrate is 0.5 N/25 mm or more at 20° C., and the normal adhesive force is 8 N/25 mm at 20° C. The following graphic sheets are provided.

According to another embodiment of the present disclosure, there is provided a building structure including a base material and the graphic sheet arranged on the surface of the base material.

The graphic sheet of the present disclosure can be replaced without damaging the base material, which is a base, even when it is applied on a relatively fragile base material such as gypsum board, wallpaper, poster, etc. However, it can be easily removed from the substrate without causing adhesive residue and substrate destruction. Therefore, the graphic sheet of the present disclosure can be advantageously used as a graphic sheet for temporary advertisement, particularly as a graphic sheet for large-area advertisement, for interior use of stores, movie theaters, public facilities, and the like.

However, the above description should not be construed as disclosing all embodiments of the present invention and all advantages associated with the present invention.

1 is a schematic cross-sectional view of a graphic sheet according to an embodiment of the present disclosure. It is a schematic sectional drawing of the graphic sheet of another embodiment of this indication. It is a schematic sectional drawing of the graphic sheet of another embodiment of this indication.

Hereinafter, the present invention will be described in more detail with reference to the drawings for the purpose of illustrating representative embodiments of the present invention, but the present invention is not limited to these embodiments.

In the present disclosure, “sheet” also includes an article called “film”.

In the present disclosure, “(meth)acrylic” means acrylic or methacrylic, and “(meth)acrylate” means acrylate or methacrylate.

In the present disclosure, “transparent” means that in the visible light region (400 nm to 800 nm), the graphic sheet or its constituent elements has an average light transmittance of about 60% or more, preferably about 80% or more, more preferably about 90%. It means having a region that is at least %. The entire graphic sheet may be transparent, or a part or a plurality of parts may be transparent.

A graphic sheet according to an embodiment of the present disclosure is a graphic sheet that can be attached to and removed from a base material, and includes a base film layer having a first surface and a second surface facing the first surface, and the base. An adhesive layer disposed on the second side of the film layer.

The initial adhesive force of the adhesive layer to the substrate is 0.5 N/25 mm or more at 20° C., and the normal adhesive force is 8 N/25 mm or less at 20° C. By having such initial and normal adhesive strength, it is possible to fix the graphic sheet on the base material with sufficient adhesive strength at the time of sticking, while on the other hand, adhesive residue and breakage of the base material even after sticking for a certain period of time. The graphic sheet can be easily removed from the base material without causing The adhesive strength is such that a graphic sheet cut into a length of 150 mm and a width of 25 mm is attached to a target base material in an environment of 20° C. in accordance with JIS Z 0237, and a tensile tester is used to measure a temperature of 20° C. and a speed of 300 mm. It is a value when 90 degree peeling is performed at /min. The initial adhesive force means the adhesive force 20 minutes after the attachment, and the normal adhesive force means the adhesive force 24 hours after the attachment.

In some embodiments, the initial adhesion to the substrate at 20° C. is 0.5 N/25 mm or greater, 1 N/25 mm or greater, or 2 N/25 mm or greater. When the initial adhesive force is within the above range, the graphic sheet can be adhered and fixed with sufficient holding force without being peeled off from the base material at the time of attachment.

In some embodiments, the normal adhesion to the substrate at 20° C. is 8 N/25 mm or less, 6 N/25 mm or less, or 4 N/25 mm or less. When the normal adhesive strength is within the above range, for example, even on a wall to which a gypsum board, a polyvinyl chloride sheet or the like is attached as a base material, only the graphic sheet can be peeled off without damaging the base material. In the case of the gypsum board treated with the primer, the graphic sheet alone or the graphic sheet and the primer layer attached to the graphic sheet can be peeled off, so that the gypsum board itself is not damaged.

When the base material is a gypsum board with a primer treatment, the initial adhesive strength of the adhesive layer may be 0.5 N/25 mm or more at 20° C., and the normal adhesive strength may be 7 N/25 mm or less at 20° C. When the substrate is a polyvinyl chloride sheet, the initial adhesive force of the adhesive layer may be 0.5 N/25 mm or more at 20° C., and the normal adhesive force may be 5 N/25 mm or less at 20° C.

In one embodiment, the adhesive layer has a textured microstructured surface, and the microstructured surface of the adhesive layer has passages or openings to expel air into or out of the adhesive layer. In this embodiment, the air sandwiched between the surface of the adhesive layer and the surface of the substrate when the graphic sheet is attached to the substrate is discharged to the outside through these passages or openings or absorbed by the adhesive layer, The inclusion of observable bubbles at the interface between the substrate and the substrate is suppressed or prevented. With this structure, bubbles remaining between the base material and the graphic sheet can be easily removed at the time of attachment, so that even an unskilled person can obtain a graphic sheet with a good appearance without causing defective appearance due to remaining bubbles. The attachment work can be easily performed.

FIG. 1 shows a schematic cross-sectional view of a graphic sheet 10 according to an embodiment of the present disclosure. The graphic sheet 10 is disposed on a base film layer 12 having a first surface (an upper surface in FIG. 1) and a second surface (a lower surface in FIG. 1) facing the first surface, and a second surface of the base film layer 12. And an adhesive layer 14. As shown in FIG. 1, the base film layer 12 and the adhesive layer 14 may be in direct contact with each other, or may be adhered via a bonding layer. The base film layer 12 may have a surface treatment such as a primer treatment or a corona treatment on the contact surface with the adhesive layer 14. In FIG. 1, a liner 16 is arranged on the adhesive layer 14 (lower surface in FIG. 1) as an optional component.

As the base film layer, various resins such as acrylic resin containing polymethylmethacrylate (PMMA), polyurethane (PU), polyvinyl chloride (PVC), polycarbonate (PC), polyethylene (PE), polypropylene (PP), etc. Polyolefin, polyester such as polyethylene terephthalate (PET), polyethylene naphthalate, fluororesin, ethylene-vinyl acetate copolymer (EVA), ethylene-acrylic acid copolymer, ethylene-ethyl acrylate copolymer, ethylene-vinyl acetate A film containing a copolymer, a copolymer such as acrylonitrile-butadiene rubber (NBR), acrylonitrile-butadiene-styrene copolymer (ABS), or a mixture thereof can be used.

From the viewpoint of strength, impact resistance, etc., a film containing polyurethane, polyvinyl chloride, polyethylene terephthalate, acrylonitrile-butadiene-styrene copolymer or polycarbonate as the base film layer can be advantageously used. The base film layer can also function as a receptor layer for printing ink and/or as a protective layer that protects the substrate surface from external punctures, impacts, and the like. When the base film layer functions as a receptor layer for printing ink, it is advantageous in terms of printability and solvent resistance (eg alcohol resistance) that the base film layer is a film containing polyvinyl chloride or polyurethane. .. The film layer containing polyvinyl chloride is also advantageous in making the graphic sheet flame-retardant.

The thickness of the base film layer may vary, but from the viewpoint of strength and handleability of the graphic sheet, it is generally about 10 μm or more, about 20 μm or more, or about 50 μm or more, about 500 μm or less, about 200 μm or less, or about 100 μm. It can be: The thickness of the base film layer when the base film layer is not flat means the thickness of the thinnest portion of the base film layer. For example, the base film layer may be embossed. The embossing depth can be about 1 μm or more, about 2 μm or more, or about 5 μm or more, about 50 μm or less, about 20 μm or less, or about 10 μm or less, generally in the range of less than the thickness of the base film layer.

The base film layer may be transparent or opaque, and may be colored. In one embodiment, the base film layer is colored white. This embodiment is advantageous in terms of sharpness, color development and the like of the image produced by the printing layer which is directly or indirectly arranged on the base film layer.

In one embodiment, the base film layer is solid. This embodiment is advantageous in terms of aesthetics of the graphic sheet since there are no discontinuities in the base film material such as vent holes on the surface of the base film.

The adhesive layer shown in FIG. 1 has, as an optional component, a textured microstructured surface. The shapes and dimensions of the passages and openings on the microstructured surface of the adhesive layer, and the internal structure of the adhesive layer may be any as long as they can suppress or prevent the inclusion of air bubbles at the interface between the graphic sheet and the substrate.

For example, in the embodiment shown in FIG. 1, the microstructured surface 17 of the adhesive layer 16 has groove-shaped communication passages 18 extending to the outer edge of the adhesive layer. The air sandwiched between the adhesive layer 14 and the surface of the substrate at the time of attaching the graphic sheet reaches the outer edge of the adhesive layer through the communication passage 18, and is discharged to the outside from there.

The communication path extending to the outer edge of the adhesive layer is formed by forming the microstructured surface of the adhesive layer from a convex portion including the adhesive surface and a concave portion (groove portion) surrounding the convex portion. You can An example of a method of forming such a microstructured surface on the adhesive layer will be described below, but the method is not limited thereto.

A liner having a release surface having a predetermined uneven structure is prepared. An adhesive for forming the adhesive layer of the graphic sheet is applied to the release surface of the liner, and dried and/or irradiated with radiation if necessary to form the adhesive layer. Thereby, the uneven structure (negative structure) of the liner is transferred to the surface of the adhesive layer in contact with the liner (this becomes the adhesive surface of the graphic sheet), and the fine structure having a predetermined uneven structure (positive structure) in the adhesive layer. To form an activated surface. The microstructured surface is pre-designed such that when the convex portion of the adhesive layer contacts the substrate, the concave portion of the adhesive layer forms a groove-shaped communication path.

The communication path is arranged so as to prevent air bubbles from remaining when the graphic sheet is bonded to the substrate. For example, regular shaped grooves may be arranged on the microstructured surface in a regular pattern to form a regular pattern of communicating channels, or irregular shaped grooves may be disposed to form an irregular pattern of communicating channels. Good. When a plurality of communication passages are formed so as to be arranged substantially parallel to each other, the distance between the communication passages is generally about 10 μm or more, about 20 μm or more, or about 50 μm or more, about 2 mm or less, about 1 mm or less, or about 500 μm. It can be:

The width of the communication passage (maximum width when viewed from the direction perpendicular to the bonding surface) is generally about 5 μm or more, about 10 μm or more, or about 20 μm or more, about 100 μm or less, about 80 μm or less, or about 50 μm or less. You can

The depth of the communication passage (the distance from the adhesion surface to the bottom of the communication passage when measured in a direction perpendicular to the adhesion surface) is generally about 5 μm or more, about 10 μm or more, or about 20 μm or more, about 100 μm or less, about 80 μm. Or less, or about 50 μm or less. In one embodiment, the bottom of the communication passage also has an adhesive surface, ie the adhesive layer is not divided by the communication passage.

The shape of the communication passage is not particularly limited as long as the effect of the present invention is not impaired. For example, when the graphic sheet is adhered to the base material, the shape of the communication path is such that the cross section of the communication path in the direction perpendicular to the bonding surface is triangular, substantially rectangular (including trapezoidal), substantially semicircular, substantially semielliptical, etc. Can be selected to be

Various types of adhesives such as acrylic, polyolefin, polyurethane, polyester, rubber, etc., solvent type, emulsion type, pressure sensitive type, heat sensitive type, heat curable type or UV curable type are used to form the adhesive layer. A mold adhesive can be used. In one embodiment, the adhesive layer comprises an acrylic adhesive, a polyurethane adhesive, or a rubber adhesive.

Advantageously, the adhesive layer comprises an acrylic adhesive. The adhesive layer containing the acrylic adhesive can impart excellent durability and discoloration resistance to the graphic sheet. Since the acrylic adhesive is easily modified, the adhesive property can be adjusted according to the type and surface condition of the material of the substrate, such as surface roughness and the presence or absence of primer treatment. Acrylic adhesives include tacky acrylic polymers. In some embodiments, the acrylic adhesive is methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, isoamyl (meth)acrylate, 2-methylbutyl (meth)acrylate, n-hexyl. (Meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, etc. Alkyl (meth)acrylate; Phenoxyalkyl (meth)acrylate such as phenoxyethyl (meth)acrylate; Alkoxyalkyl (meth)acrylate such as methoxypropyl (meth)acrylate and 2-methoxybutyl (meth)acrylate; Glycidyl (meth)acrylate Cyclic ether-containing (meth)acrylates such as tetrahydrofurfuryl (meth)acrylate; hydroxyl group-containing monomers such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; A monomer composition containing a carboxyl group-containing monomer such as (meth)acrylic acid, crotonic acid, itaconic acid, fumaric acid, citraconic acid and maleic acid; and one or more monomers selected from the group consisting of (meth)acrylamide It includes a tacky acrylic polymer that is a polymer.

Alkyl (meth)acrylate constitutes the main component of the tacky acrylic polymer. In some embodiments, the amount of alkyl (meth)acrylate is about 50 parts by weight or more, about 70 parts by weight or more, or about 80 parts by weight or more, based on 100 parts by weight of the polymerizable component of the monomer composition. It is about 99.5 parts by mass or less, about 99 parts by mass or less, or about 98 parts by mass or less. The “polymerizable component” in the present disclosure means a component that can be polymerized by radical polymerization described below. When "polymerizable component" is used in relation to parts by weight, it means the total weight of these components.

The hydroxyl group-containing monomer, the carboxyl group-containing monomer, and the (meth)acrylamide are polar monomers having a functional group having a relatively high polarity in the molecule. Polar monomers are known to impart high cohesive strength to tacky acrylic polymers and/or enhance the interaction of tacky acrylic polymers with the substrate surface. In the present disclosure, the amount of the polar monomer compounded is small compared to general adhesive applications, in order to realize the easy removal property while imparting the necessary adhesive force to the adhesive layer. In some embodiments, the amount of polar monomer is about 0.1 parts by weight or more, about 0.5 parts by weight or more, or about 1 part by weight or more, based on 100 parts by weight of the polymerizable component of the monomer composition. , About 10 parts by mass or less, about 5 parts by mass or less, or about 3 parts by mass or less. In one embodiment, the monomer composition does not include a carboxyl group-containing monomer. In another embodiment the polar monomer comprises (meth)acrylamide, especially acrylamide. In these embodiments, while ensuring the cohesive force required for the adhesive layer, the interaction between the adhesive acrylic polymer and the surface of the substrate can be reduced to improve the ease of removal of the adhesive layer.

The monomer composition may contain a (meth)acrylate having a UV-crosslinkable site. By polymerizing a monomer composition containing a (meth)acrylate having a UV-crosslinkable site, a UV-crosslinkable tacky acrylic polymer can be obtained. As a (meth)acrylate having a UV-crosslinkable site, activated by UV irradiation to form crosslinks with other parts in the polymer molecule or to form crosslinks with other polymer molecules. (Meth)acrylate having a site capable of For example, as the UV-crosslinkable site, it is possible to use a structure that can be excited by UV irradiation to withdraw a hydrogen radical from another part in the polymer molecule or from another polymer molecule. Examples thereof include a benzophenone structure, a benzyl structure, an o-benzoylbenzoate structure, a thioxanthone structure, a 3-ketocoumarin structure, a 2-ethylanthraquinone structure, and a camphorquinone structure.

Among the above structures, the benzophenone structure is advantageous in terms of transparency and reactivity. Examples of the (meth)acrylate having such a benzophenone structure include 4-acryloyloxybenzophenone, 4-acryloyloxyethoxybenzophenone, 4-acryloyloxy-4′-methoxybenzophenone and 4-acryloyloxyethoxy-4′-methoxybenzophenone. , 4-acryloyloxy-4'-bromobenzophenone, 4-acryloyloxyethoxy-4'-bromobenzophenone, 4-methacryloyloxybenzophenone, 4-methacryloyloxyethoxybenzophenone, 4-methacryloyloxy-4'-methoxybenzophenone, 4- Examples thereof include methacryloyloxyethoxy-4′-methoxybenzophenone, 4-methacryloyloxy-4′-bromobenzophenone and 4-methacryloyloxyethoxy-4′-bromobenzophenone. The (meth)acrylate having a UV-crosslinkable moiety may be used alone or in combination of two or more.

In some embodiments, the amount of the (meth)acrylate having a UV-crosslinkable site is about 0.05 parts by weight or more and about 0.1 parts by weight based on 100 parts by weight of the polymerizable component of the monomer composition. Or more, or about 0.2 parts by mass or more, about 5 parts by mass or less, about 3 parts by mass or less, or about 2 parts by mass or less.

The tacky acrylic polymer can be obtained by polymerizing the above-mentioned monomer composition using a usual radical polymerization method such as solution polymerization, suspension polymerization, emulsion polymerization, or bulk polymerization. As a polymerization initiator, benzoyl peroxide, lauroyl peroxide, organic peroxides such as bis(4-tert-butylcyclohexyl)peroxydicarbonate, 2,2′-azobisisobutyronitrile, 2,2′-azobis( 2-methylbutyronitrile), dimethyl-2,2-azobis(2-methylpropionate), 4,4'-azobis(4-cyanovalerianic acid), 2,2'-azobis(2-methylpropionic acid) ) Azo-based polymerization initiators such as dimethyl and azobis(2,4-dimethylvaleronitrile) (AVN) can be used. The amount of the polymerization initiator used is generally about 0.01 parts by mass or more, or about 0.05 parts by mass or more, about 5 parts by mass or less, or about 3 parts by mass, based on 100 parts by mass of the polymerizable component of the monomer composition. It can be equal to or less than a part.

In some embodiments, the tacky acrylic polymer has a weight average molecular weight of about 200,000 or more, or about 400,000 or more, about 1 million or less, or about 700,000 or less. The weight average molecular weight of the tacky acrylic polymer is determined by standard GPC (gel permeation chromatography) using standard polystyrene.

The tacky acrylic polymer may be crosslinked with a crosslinking agent. As a crosslinking agent, an isocyanate compound, a melamine compound, a poly(meth)acrylate compound, an epoxy compound, an amide compound, a bisamide compound, for example, a bisaziridine of a dibasic acid such as 1,1′-isophthaloyl-bis(2-methylaziridine) Derivatives and the like can be used. It is preferable to use an isocyanate compound, especially hexamethylene diisocyanate, as the crosslinking agent. The addition amount of the cross-linking agent depends on the type of the cross-linking agent, but is generally about 0.1 parts by mass or more, or about 0.5 parts by mass or more and about 10 parts by mass or less with respect to 100 parts by mass of the acrylic adhesive. , Or about 5 parts by mass or less. By adjusting the cross-linking agent within this range and increasing the cross-linking density, it is possible to maintain a more stable adhesive force even after attachment.

When the adhesive acrylic polymer has a UV-crosslinkable site, the adhesive acrylic polymer may be crosslinked via the UV-crosslinkable site. Since the tacky polymer cross-linked through the UV cross-linking site is cross-linked at a relatively high density, it is possible to obtain a harder adhesive layer having excellent removability. This cross-linking can be performed by irradiating an acrylic adhesive containing a tacky acrylic polymer with ultraviolet rays. Ultraviolet rays may be irradiated after forming an adhesive layer using an acrylic adhesive.

（Ｔｇ_１：成分１のホモポリマーのガラス転移温度
Ｔｇ_２：成分２のホモポリマーのガラス転移温度
・・・
Ｔｇ_ｎ：成分ｎのホモポリマーのガラス転移温度
Ｘ_１：重合の際に添加した成分１のモノマーの質量分率
Ｘ_２：重合の際に添加した成分２のモノマーの質量分率
・・・
Ｘ_ｎ：重合の際に添加した成分ｎのモノマーの質量分率
Ｘ_１＋Ｘ_２＋・・・＋Ｘ_ｎ＝１） The glass transition temperature (Tg) of the tacky acrylic polymer can be, for example, about -60°C or higher, or about -50°C or higher, about 25°C or lower, about 0°C or lower, or about -10°C or lower. .. By setting the glass transition temperature of the tacky acrylic polymer within the above range, the adhesive force of the adhesive layer can be adjusted to provide both the adhesive force and the easy-removability required for the adhesive layer. The glass transition temperature (Tg) of the tacky acrylic polymer is the following FOX formula (Fox, TG, Bull. Am. Phys. Soc.) assuming that the tacky acrylic polymer is copolymerized from n kinds of monomers. , 1 (1956), p. 123).

(Tg ₁ : glass transition temperature of homopolymer of component 1 Tg ₂ : glass transition temperature of homopolymer of component 2...
Tg _n : glass transition temperature of homopolymer of component n X ₁ : mass fraction of monomer of component 1 added during polymerization X ₂ : mass fraction of monomer of component 2 added during polymerization...
X _n : Mass fraction of monomer of component n added during polymerization X ₁ +X ₂ +...+X _n =1)

The acrylic adhesive may contain additives such as a tackifier, elastic microspheres, adhesive polymer microspheres, crystalline polymer, inorganic powder, and ultraviolet absorber as long as the effects of the present invention are not impaired.

In another embodiment, the adhesive layer can be formed of an open cell foam to provide an adhesive layer with openings formed in the microstructured surface. For example, in the embodiment shown in Figure 2, the adhesive layer 24 is formed of open cell foam, with the cells forming openings in the microstructured surface or cavities within the adhesive layer. In FIG. 2, the microstructured surface 27 of the adhesive layer 24 has a plurality of openings 28, the adhesive layer including therein cavities 29 in communication with the openings. The air sandwiched between the adhesive layer 24 and the surface of the substrate at the time of attaching the graphic sheet is held inside the cavity 29 through the opening 28, or when the cavity 29 communicates with the outer edge of the adhesive layer. It is discharged from there. In this way, observable air bubbles are suppressed or prevented from being mixed in the interface between the graphic sheet and the base material. When the open-cell foam is used as the adhesive layer, the tackiness can be adjusted by adjusting the size and number density of the cells, the density of the adhesive layer, the thickness, the resin composition, the production conditions and the like.

The average diameter of the cells of the open cell foam can generally be about 1 μm or more, about 5 μm or more, or about 10 μm or more, about 300 μm or less, about 250 μm or less, or about 200 μm or less. By setting the average diameter of the bubbles in the above range, the air sandwiched between the surface of the adhesive layer and the surface of the substrate when the graphic sheet is attached to the substrate can be retained in these bubbles, and also from the outside. It is possible to suppress a decrease in adhesive strength due to intrusion of water or the like. Further, by setting the average diameter of the bubbles in the above range, when the base film layer is printed as a receptor layer of the printing ink using a solvent ink, the solvent that has permeated the base film layer penetrates into the open cell foam. By doing so, it is possible to suppress a decrease in adhesive strength.

The average diameter of the openings in the microstructured surface of the open cell foam can generally be about 1 μm or more, about 5 μm or more, or about 10 μm or more, about 300 μm or less, about 250 μm or less, or about 200 μm or less. By setting the average diameter of the openings in the above range, the air sandwiched between the adhesive layer surface and the substrate surface when the graphic sheet is attached to the substrate can be quickly moved to the cavity inside the adhesive layer.

The area of the openings in the microstructured surface of the open cell foam is generally about 1% or more, about 5% or more, or about 10% or more, about 30% or less, about 25% or less, or It can be about 20% or less. By setting the area of the opening in the above range, the air sandwiched between the adhesive layer surface and the substrate surface when the graphic sheet is attached to the substrate is quickly moved to the cavity inside the adhesive layer, and the adhesive force is sufficient. The graphic sheet can be fixed on the substrate with.

The cell content of the open-cell foam is generally about 2% by volume or more, about 5% by volume or more, or about 10% by volume or more, about 30% by volume or less, about 25% by volume or less, based on the volume of the open-cell foam. Alternatively, it can be about 20% by volume or less. By setting the cell content within the above range, it is possible to impart the necessary adhesive strength and strength to the open cell foam.

The density of the open cell foam is generally about 0.2 g/cm ³ or more, about 0.3 g/cm ³ or more, or about 0.5 g/cm ³ or more, about 1.5 g/cm ³ or less, about 0.9 g/ It can be less than or equal to cm ³ , or less than or equal to about 0.7 g/cm ³ . By setting the density within the above range, the adhesive strength and strength required for the open-cell foam can be imparted.

The hardness of the open-cell foam is not particularly limited, but it is desirable that the open-cell foam has such flexibility that cracks and the like do not occur due to the deformation that occurs in the graphic sheet when it is peeled off from the substrate.

The open cell foam may have an open cell structure having a plurality of spherical cells and through holes between adjacent spherical cells. The average diameter of the spherical cells may be about 5 μm or more and about 300 μm or less, and the average diameter of the through holes may be about 0.1 μm or more and less than about 5 μm. In some embodiments, the average diameter of the spherical cells is about 8 μm or greater, or about 10 μm or greater, about 100 μm or less, or about 20 μm or less. In some embodiments, the average diameter of the through holes is about 0.5 μm or greater, or about 1 μm or greater, about 4 μm or less, or about 3 μm or less.

The open-cell foam can be formed by foaming a composition containing a thermoplastic resin, a thermosetting resin, or an ultraviolet curable resin. The foaming of the composition includes a chemical foaming method in which a gas is generated in the composition by utilizing a chemical reaction, a mechanical foaming method in which a gas such as air or nitrogen is mechanically mixed into the composition, and a low boiling point solvent in the composition. A solvent vaporization method of vaporizing the composition, a solvent removal method of forming a void by removing the solvent contained in the composition by extraction, etc., a composition in a supercritical state such as carbon dioxide which is a gas at room temperature and atmospheric pressure. A method such as a supercritical method in which the pressure is returned to atmospheric pressure after impregnation can be used. Polyolefins such as polyurethane, polystyrene, polyethylene and polypropylene, acrylic resins, polyvinyl chloride, silicone and the like can be used as the thermoplastic resin and the thermosetting resin. In one embodiment, the open-cell foam is a UV-cured product obtained by foaming a composition containing a UV-curable resin.

The open-cell foam may be an open-cell acrylic foam containing an acrylic resin. Acrylic foam can impart excellent durability and discoloration resistance to a graphic sheet. Since the acrylic resin is easily modified, the adhesive properties of the foam can be adjusted according to the type and surface condition of the material of the substrate, such as surface roughness and the presence or absence of primer treatment. An example of a method for forming an acrylic foam will be described below, but the method is not limited to this.

The acrylic foam can be formed by stirring and mixing a foam-forming gas with an acrylic foam precursor composition to generate bubbles in the composition, and then performing a polymerization reaction to cure the foam. In one embodiment, the acrylic foam precursor is a non-aqueous composition. In this embodiment, it is not necessary to introduce into the polymer a polar group (for example, a carboxyl group) necessary for dispersing the polymer in water as in the polymerization reaction using the emulsion composition. It is possible to obtain an adhesive layer having an adhesive force necessary for fixing the adhesive layer on top and excellent in easy removability. In another embodiment, the acrylic foam precursor is a UV curable composition. Since the acrylic foam obtained by using the ultraviolet curable composition is relatively hard, it is possible to obtain an adhesive layer having excellent removability.

The acrylic foam precursor composition includes a partial polymer obtained by polymerizing a monomer composition containing a (meth)acrylate to such a viscosity that the precursor composition can contain stable cells. As the (meth)acrylate, generally, an alkyl(meth)acrylate having an alkyl group having 12 or less carbon atoms, for example, n-propyl(meth)acrylate, n-butyl(meth)acrylate, n-amyl(meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth) Acrylate or the like can be used as a main component. As the other monomer capable of polymerizing with the alkyl (meth)acrylate, a carboxyl group-containing monomer such as (meth)acrylic acid and itaconic acid, a hydroxyl group-containing monomer such as hydroxyalkyl (meth)acrylate, and a polar monomer such as (meth)acrylamide Can be used. These polar monomers are used in an amount that provides the acrylic foam with the required adhesive force and easily removable property. In some embodiments, the amount of polar monomer is about 0.1 parts by weight or more, about 0.5 parts by weight or more, or about 1 part by weight or more, based on 100 parts by weight of the polymerizable component of the monomer composition. , About 10 parts by mass or less, about 5 parts by mass or less, or about 3 parts by mass or less. In one embodiment, the monomer composition does not include a carboxyl group-containing monomer. In this embodiment, the interaction between the acrylic foam and the surface of the substrate can be reduced to improve the easy-removability of the adhesive layer.

Partial polymerization of the monomer composition can be performed by radiation polymerization using ultraviolet light or the like in the presence of a photopolymerization initiator. As the photopolymerization initiator, benzoin alkyl ether, benzophenone, benzyl methyl ketal, hydroxycyclohexyl phenyl ketone, 1,1-dichloroacetophenone, 2-chlorothioxanthone and the like can be used. The photopolymerization initiator is generally used in an amount of about 0.01 parts by mass or more and about 5 parts by mass or less based on 100 parts by mass of the polymerizable component of the monomer composition. Partial polymerization can also be carried out by thermal polymerization using a thermal polymerization initiator.

An acrylic foam precursor composition can be obtained by further adding other components to the partial polymer, if necessary. The acrylic foam precursor composition has a suitable viscosity to form stable cells in the precursor composition when stirred and mixed with a cell-forming gas. In some embodiments, the precursor composition has a viscosity of about 500 mPa·s or more, about 1000 mPa·s or more, or about 2000 mPa·s or more, about 100, at operating temperature (eg, 25° C.) in a stir mixer. 000 mPa·s or less, about 80,000 mPa·s or less, or about 50,000 mPa·s or less. By setting the viscosity within the above range, bubbles can be formed with a sufficient amount of bubbles without giving an excessive load to the stirring and mixing apparatus.

The acrylic foam precursor composition may include a polyfunctional (meth)acrylate such as 1,6-hexanediol diacrylate as a cross-linking agent. A photoinitiator for further polymerizing and curing the foam may be added to the acrylic foam precursor composition. The photopolymerization initiator and its amount are the same as in the case of the above partial polymerization.

The acrylic foam precursor composition may include a surfactant. By adding the surfactant, it is possible to keep the bubbles stable and reduce the density of the obtained foam. A silicone-based surfactant or a fluorine-based surfactant can be used as the surfactant. The amount of the surfactant compounded can be generally about 1 part by mass or more and about 5 parts by mass or less based on 100 parts by mass of the acrylic foam precursor composition.

The acrylic foam precursor composition may contain a filler for the purpose of enhancing mechanical properties of the foam after curing, improving processability, or lowering the unit cost of the product. Fillers include reinforcing threads, woven and non-woven fabrics, glass beads, polymer hollow microspheres, polymer beads, pigments and the like.

As a method for producing an acrylic foam, a foaming agent is foamed in a pre-cured acrylic foam precursor composition, and then a chemical foaming method by curing the foaming agent, or an acrylic foam precursor before curing. A mechanical foaming method can be used in which a gas for forming bubbles is dispersed and mixed into the composition, and the composition is cured. For example, when the mechanical foaming method is used, a gas that is inert to the precursor composition when mixed with the acrylic foam precursor composition is used as the gas for forming cells. An inert gas such as argon or nitrogen can be used as the bubble-forming gas, and it is advantageous to use nitrogen gas because it is inexpensive. The amount of the gas used for forming bubbles is generally about 5% by volume or more, or about 10% by volume or more, about 30% by volume or less, or about 20% by volume or less based on the volume of the acrylic foam precursor composition. You can

In the mechanical foaming method, the acrylic foam can be produced, for example, by using a stirring and mixing device using a vibration principle. By using such a stirring and mixing apparatus, it is possible to obtain finely and uniformly dispersed bubbles without causing a temperature rise of the composition. An agitating and mixing apparatus using the vibration principle includes a casing provided with a flow passage through which a fluid flows, and an agitating blade disposed inside the casing and vibrating in the axial direction of the casing. There is. The acrylic foam precursor composition is pumped using a pump, while the bubble-forming gas is introduced into the casing by pumping using a compressor or by the pressure of a gas cylinder, and after stirring and mixing in the apparatus, the foam-containing gas contains bubbles. The precursor composition is discharged from the outlet. In the casing, due to the reciprocating vibration of the stirring body, the fluid collides with the blade and is stirred and mixed.

An acrylic foam can be formed by applying an acrylic foam precursor composition containing bubbles formed by a stirring and mixing device onto a base film layer or another liner and curing the composition by a polymerization reaction. The polymerization reaction can be performed by irradiation with radiation such as ultraviolet rays. Since air tends to inhibit UV polymerization, it is advantageous to carry out the polymerization in an atmosphere of an inert gas such as nitrogen or carbon dioxide. A polymer film such as a polyethylene terephthalate (PET) film can be used as the liner. If the base film layer or liner is an ultraviolet-transparent transparent film, ultraviolet irradiation can be performed from the side of the base film layer or liner as well, so that a more uniform acrylic foam can be obtained. The acrylic foam formed on the liner can be transferred to the base film layer after providing the bonding layer on the acrylic foam or on the base film layer.

In yet another embodiment, the adhesive layer may be formed of a woven or non-woven fabric to obtain an adhesive layer having a microstructured surface composed of a plurality of fibers contained in the woven or non-woven fabric. For example, in the embodiment shown in FIG. 3, the adhesive layer 34 is formed of a non-woven fabric and the voids between the fibers contained in the non-woven fabric define openings in the microstructured surface or cavities within the adhesive layer. The air sandwiched between the adhesive layer 34 and the surface of the base material at the time of attaching the graphic sheet is held inside the void through the opening, or if the void is connected to the outer edge of the adhesive layer, the air is external Is discharged to. In this way, observable air bubbles are suppressed or prevented from being mixed in the interface between the graphic sheet and the base material.

The average fiber diameter of the fibers can generally be about 0.5 μm or more, about 1 μm or more, or about 3 μm or more, about 100 μm or less, about 50 μm or less, or about 25 μm or less. By setting the average fiber diameter within the above range, an adhesive layer having sufficient strength can be formed.

The basis weight (mass per 1 m ² ) of woven and non-woven fabrics is generally about 1 g/m ² or more, about 5 g/m ² or more, or about 10 g/m ² or more, about 500 g/m ² or less, about 300 g/m. ² or less, or about 200 g / ^{m 2} or less. By setting the grammage within the above range, while absorbing sufficient strength and dimensional stability to the adhesive layer, the air sandwiched between the adhesive layer and the substrate surface is absorbed into the adhesive layer or discharged to the outside. can do.

The woven fabric and the non-woven fabric forming the adhesive layer are made of a material exhibiting adhesiveness. In some embodiments, the woven and non-woven fabrics are acrylic woven and non-woven fabrics that include acrylic polymer fibers. These woven and non-woven fabrics can be integrated with the base film layer via a bonding layer.

The glass transition temperature (Tg) of the acrylic polymer fiber can be, for example, about -60°C or higher, or about -50°C or higher, about 25°C or lower, about 0°C or lower, or about -10°C or lower. By setting the glass transition temperature of the acrylic polymer fiber within the above range, it is possible to impart both necessary adhesive strength and easy removability to the woven and non-woven fabrics. The glass transition temperature of the acrylic polymer fiber can be obtained from the FOX equation, as in the case of the tacky acrylic polymer described above.

The acrylic woven fabric can be formed by intersecting warp yarns (warp) with weft yarns (filling) using a loom. The weave of the acrylic woven fabric can be generally selected from plain weave, twill weave, thick twill weave, or satin weave. The acrylic polymer fibers used to make the acrylic woven fabrics are commonly available in the form of continuous tows called rovings (aggregates of one or more strands of untwisted acrylic polymer fibers) or yarns. The woven structure of the acrylic woven cloth imparts high dimensional stability to the adhesive layer, and consequently contributes to the dimensional stability of the graphic sheet. Since the acrylic woven fabric is excellent in strength and dimensional stability, it is advantageous to use a plain weave.

Acrylic non-woven fabrics include, for example, a process of pouring molten acrylic polymer from a plurality of orifices to form filaments, a process of thinning the filaments into fibers, and collecting the fibers as a non-woven web on a spindle to produce acrylic non-woven fabrics. Can be produced by a melt blown method. In one embodiment, the nonwoven web may be compressed by calendering, heating, or pressing. In another embodiment, a binder may be added to the acrylic non-woven fabric. In these embodiments, the dimensional stability of the acrylic non-woven fabric can be enhanced.

The thickness of the adhesive layer can generally be about 0.5 μm or more, about 1 μm or more, or about 5 μm or more, about 500 μm or less, about 400 μm or less, or about 300 μm or less. The thickness of the adhesive layer means the thickness of the thinnest part of the adhesive layer.

The area of the adhesive surface of the adhesive layer (the area where the adhesive layer contacts the substrate and contributes to adhesion) has an area of about 1% or more, about 5% or more, or about 10% or more and less than 100% of the area of the adhesive layer, It can be about 99% or less, about 95% or less, or about 90% or less.

In one embodiment, the adhesive layer has substantially the same shape and area as the base film layer, or the same shape and area as viewed from the direction along the thickness of the graphic sheet. That is, the adhesive layer extends substantially over the entire surface of the base film layer, or extends over the entire surface. In some embodiments, the area of the adhesive layer is about 3% or more, about 5% or more, or about 10% or more, 100% or less, about 95% or less, or about 90% or less of the area of the base film layer. is there.

The adhesive layer may be colored. In one embodiment, the adhesive layer is colored white. This embodiment is advantageous in terms of image sharpness, color development, etc. when the print layer is provided on the graphic sheet.

As shown in FIGS. 1 to 3, the graphic sheet may have liners 16, 26 and 36 on the surface of the adhesive layer opposite to the base film layer. Examples of the liner include paper such as kraft paper; polymers such as polyethylene, polypropylene, polyester, and cellulose acetate; paper coated with such a polymer. These liners may have a surface that has been release-treated with silicone, fluorocarbon, or the like. The liner thickness can generally be about 5 μm or more, about 15 μm or more or about 25 μm or more, about 300 μm or less, about 200 μm or less or about 150 μm or less.

If the microstructured surface of the adhesive layer has communicating passages extending to the outer edge of the adhesive layer, the liner may have a relief structure on its release surface that corresponds to the microstructured surface of the adhesive layer. In this embodiment, the liner may be the same as or different from that used in forming the microstructured surface of the adhesive layer.

On the base film layer, other layers, for example, a printing layer, a decorative layer such as a metal layer, a surface protective layer, a clear layer, and a receptor layer for printing ink may be laminated. These layers may be joined by a joining layer. The decoration layer may be arranged so as to correspond to the entire surface of the graphic sheet, or may be arranged so as to correspond to a part or a plurality of parts.

The print layer can be used to give the graphic sheet a decorative property or a design property by a picture, a pattern, or the like. A printing layer can be formed on the base film layer or the receptor layer by printing with a colorant such as toner or ink. The printing layer can also be formed on the surface protective layer or between the base film layer and the adhesive layer. The print layer can be formed by using a printing technique such as gravure printing, electrostatic printing, screen printing, inkjet printing, offset printing, or the like. Solvent-based ink or UV curable ink can be used as the printing ink. The thickness of the print layer can vary, and generally can be about 1 μm or more, or about 2 μm or more, about 10 μm or less, or about 5 μm or less when using solvent-based inks. When UV curable ink is used, it can be about 1 μm or more, or about 5 μm or more, about 50 μm or less, or about 30 μm or less.

The metal layer can be formed by depositing a metal such as indium, tin, or chromium on the base film layer or another layer by vapor deposition, sputtering, or the like. A pattern or a pattern can be formed by using a metal mask or the like at the time of vapor deposition or sputtering. The thickness of the metal layer can vary and generally can be about 5 nm or more, about 10 nm or more, or about 20 nm or more, about 10 μm or less, about 5 μm or less, or about 2 μm or less.

Various resin films can be used as the surface protective layer. The surface protective layer preferably has flexibility and/or stretchability. Examples of the resin constituting the surface protective layer include polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyurethane, acrylic resin, resin containing at least one of polyolefins, or a combination thereof. The surface protective layer is preferably transparent at least to visible light. The thickness of the surface protection layer can vary and generally can be about 40 μm or more, about 50 μm or more, or about 60 μm or more, about 200 μm or less, about 150 μm or less, or about 100 μm or less.

The clear layer can be formed by coating the composition for forming a clear layer on the base film layer, the printing layer or another layer. As the composition for forming a clear layer, a composition containing an isocyanate-reactive resin (for example, a compound containing a hydroxyl group) and an isocyanate-based crosslinking agent can be used. As the isocyanate-reactive resin, for example, the following resins having an isocyanate-reactive functional group such as a hydroxyl group: fluorine resin, phthalate polyester (PET, PEN, etc.), acrylic resin, petroleum-resistant resin, etc. Can be used. As the isocyanate-based crosslinking agent, for example, isophorone diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, aromatic isocyanate such as xylylene diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, aliphatic such as hexamethylene diisocyanate Isocyanates, multimers of tolylene diisocyanate, Coronate L, polyisocyanates such as polymethylene polyisocyanate, and the like, and combinations thereof. Regarding the ratio of the isocyanate group of the isocyanate-based cross-linking agent and the isocyanate-reactive functional group of the isocyanate-reactive resin, the value of isocyanate group/isocyanate-reactive functional group is about 0.3 or more, about 0.5 or more, or about 0. It can be 7 or more, about 1.2 or less, about 1.1 or less, or about 1.05 or less. The thickness of the clear layer can be about 1 μm or more, about 2 μm or more, or about 5 μm or more, about 50 μm or less, about 30 μm or less, or about 20 μm or less.

Various resin films can be used as the receptor layer. The resin constituting the receptor layer is not particularly limited, but acrylic polymers, polyolefins, polyvinyl acetals, phenoxy resins and the like can be used. The glass transition temperature of the resin forming the receptor layer can be generally about 0° C. or higher and about 100° C. or lower. By setting the glass transition temperature within the above range, a clear image can be obtained by toner transfer or ink printing without impairing the flexibility of the entire graphic sheet. The thickness of the receptor layer can generally be about 2 μm or more, about 5 μm or more, or about 10 μm or more, about 50 μm or less, about 40 μm or less, or about 30 μm or less.

The bonding layer for connecting the layers forming the graphic sheet is generally an acrylic type, a polyolefin type, a polyurethane type, a polyester type, a rubber type, etc., and is of a solvent type, an emulsion type, a pressure sensitive type, a heat sensitive type, a thermosetting type or an ultraviolet curing type. Including adhesive. The thickness of the bonding layer can generally be about 1 μm or more, about 2 μm or more, or about 5 μm or more, about 50 μm or less, about 40 μm or less, or about 30 μm or less.

The total thickness of the graphic sheet can generally be about 50 μm or more, about 55 μm or more, or about 60 μm or more, about 200 μm or less, about 150 μm or less, or about 100 μm or less. The total thickness of the graphic sheet does not include the thickness of the liner.

Area of the graphic sheet is generally from about 50 cm ² or more, about 77cm ² or more, or about 623cm ² or more, about 300 meters ² or less, may be about 200 meters ² or less, or about 100 m ² or less.

The graphic sheet can be adhered to the surface of various substrates. In one embodiment, the graphic sheet is used as a surface-adhering graphic sheet, that is, a graphic sheet on which an image or the like is visually recognized by an observer when viewed from the first surface side of the base film layer when adhered to a base material. Suitable as a base material such as gypsum board, wallpaper such as polyvinyl chloride sheet, or poster, which is relatively easy to peel off from the surface to which these base materials are attached, such as wall surface, and is fragile. It can be applied to any base material. For example, it can be applied to glass, painted plate, flooring material and the like. The substrate may be part of a building structure, such as a wall, window, floor, ceiling, pillar, etc.

The following examples illustrate specific embodiments of the present disclosure, but the present invention is not limited thereto. All parts and percentages are by weight unless otherwise stated.

<Adhesive strength>
A test piece cut into a length of 150 mm and a width of 25 mm is used. The test piece is attached to a base material in an environment of 20°C. The sticking method is based on JIS Z 0237. The test piece attached to the base material is aged in a thermostatic chamber at a temperature of 20° C. for 20 minutes or for 24 hours, or in an oven at 65° C. for 7 days. After curing, a tensile tester (Tensilon universal tester, model number: RTC-1210A, A&D Co., Ltd., Toshima-ku, Tokyo, Japan) was used to peel at 90° at a temperature of 20°C and a speed of 300 mm/min. To do. The average value of the values obtained by measuring twice is taken as the adhesive strength.

<Air release>
A test piece cut into a length of 150 mm and a width of 70 mm is used. The test piece is attached to a base material using a squeegee in an environment of 20°C. If air can be slid on the base material and air bubbles are not observed at the interface between the test piece and the base material, the air bleeding property is set to “good”, and the air cannot be slid on the base material and the air bubbles between the test piece and the base material cannot be slid. When observed at the interface, the air bleeding property is defined as “poor”.

<Removability>
A test piece cut into a length of 150 mm and a width of 25 mm is used. The test piece is attached to a base material in an environment of 20°C. The sticking method is based on JIS Z 0237. The test piece attached to the base material is cured in an oven at 65° C. for 7 days. After curing, a tensile tester (Tensilon universal tester, model number: RTC-1210A, A&D Co., Ltd., Toshima-ku, Tokyo, Japan) was used to peel at 90° at a temperature of 20°C and a speed of 300 mm/min. Removability is evaluated by the ratio of the adhesive residue at the time of peeling. When there is adhesive residue on the surface of the base material, the area ratio of the adhesive residue is shown as a percentage (%), and when there is no adhesive residue, it is defined as 0%.

<Adhesion stability>
A test piece cut into a length of 50 mm and a width of 50 mm is used. The test piece is attached to a base material in an environment of 20°C. The test piece attached to the base material is aged in an oven at 65° C. for 24 hours. After curing, if the appearance of the sheet does not float or the edge changes such as turning over, the dimensional stability is defined as "good", and if the sheet floats or the appearance changes such as turning over from the edge, the dimensional stability is determined. "Bad"

<Example 1>
98 parts by mass of 2-ethylhexyl acrylate (2EHA), 2 parts by mass of acrylamide (AcM), and 0.5 parts by mass of 4-acryloyloxyethoxybenzophenone (AEBP) which is a crosslinkable monomer were mixed to prepare an acrylic adhesive. .. The acrylic adhesive and methyl ethyl ketone (MEK) were mixed at a ratio of 3:1 (mass ratio). The obtained mixed solution was applied using a notch bar to a liner having a release surface having a concavo-convex structure composed of a grid pattern having a height of about 25 μm and a width of about 15 μm and a side of about 200 μm. A polyvinyl chloride (PVC) film with a PET liner having a thickness of 70 μm was laminated thereon, and the adhesive layer was transferred onto the PVC film. The PVC film having the adhesive layer was put in an oven at 65° C. for 1 minute, and then the adhesive layer was irradiated with UVC at an irradiation dose of 27 mJ/m ² to cure the adhesive layer and form an adhesive layer having a thickness of 25 μm. .. Finally, a flat release paper was laminated on the adhesive layer to obtain the graphic sheet of Example 1.

<Example 2-1>
A PVC film with a thickness of 70 μm using an acrylic adhesive on an acrylic foam sheet having an open cell structure (PureCell (registered trademark), density 500 kg/m ³ , thickness 60 μm, Inoac Corporation (Nagoya City, Aichi Prefecture, Japan)). Were laminated to obtain a graphic sheet of Example 2-1. This acrylic foam sheet has an open cell structure having a plurality of spherical cells and through holes between adjacent spherical cells.

<Example 2-2>
A PVC film with a thickness of 70 μm using an acrylic adhesive on an open-celled acrylic foam sheet (PureCell (registered trademark), density 530 kg/m ³ , thickness 70 μm, Inoac Corporation (Nagoya City, Aichi Prefecture, Japan)). Were laminated to obtain a graphic sheet of Example 2-2. Similar to Example 2-1, the acrylic foam sheet has an open cell structure having a plurality of spherical cells and through holes between adjacent spherical cells.

<Example 2-3>
A PVC film with a thickness of 70 μm using an acrylic adhesive on an open-celled acrylic foam sheet (PureCell (registered trademark), density 550 kg/m ³ , thickness 100 μm, Inoac Corporation (Nagoya City, Aichi Prefecture, Japan)). Were laminated to obtain a graphic sheet of Example 2-3. Similar to Example 2-1, the acrylic foam sheet has an open cell structure having a plurality of spherical cells and through holes between adjacent spherical cells.

<Example 2-4>
A PVC film having a thickness of 70 μm using an acrylic adhesive on an acrylic foam sheet having an open cell structure (PureCell (registered trademark), density 500 kg/m ³ , thickness 200 μm, Inoac Corporation (Nagoya City, Aichi Prefecture, Japan)). Were laminated to obtain a graphic sheet of Example 2-4. Similar to Example 2-1, the acrylic foam sheet has an open cell structure having a plurality of spherical cells and through holes between adjacent spherical cells.

<Example 3>
A fiber having a fiber diameter of 20 μm was formed by a melt blown method using an acrylic resin (Clarity LA2140, Kuraray Trading Co., Ltd. (Osaka City, Osaka, Japan)), and the fiber was exfoliated at a basis weight of 47 g/m ² . It was sprayed on a PET film to form an adhesive layer containing an acrylic non-woven fabric. A 70 μm thick PVC film was laminated on the adhesive layer to obtain a graphic sheet of Example 3.

<Comparative Example 1>
An existing marking film product, 3M (registered trademark) Scotchcal (registered trademark) graphic film IJ1220NF (3M Japan Co., Ltd. (Shinagawa-ku, Tokyo)) was used as the graphic sheet of Comparative Example 1. This product is a PVC film having an acrylic pressure-sensitive adhesive layer on the back surface, and no groove is formed on the surface of the pressure-sensitive adhesive layer.

<Comparative example 2>
An existing marking film product, 3M (registered trademark) Scotchcal (registered trademark) graphic film SP4283C (3M Japan Co., Ltd. (Shinagawa-ku, Tokyo, Japan)) was used as the graphic sheet of Comparative Example 2. This product is a PVC film having an acrylic pressure-sensitive adhesive layer on the back surface, and grooves similar to those in Example 1 are formed on the pressure-sensitive adhesive layer surface.

Primer DP-900N3 (3M Japan Co., Ltd. (Shinagawa-ku, Tokyo))
Gypsum board GB-R (Yoshino Gypsum Co., Ltd. (Chiyoda-ku, Tokyo, Japan)) treated with a film and a wallpaper film (3M (registered trademark) Dynock (registered trademark) film ME- whose surface layer is a polyvinyl chloride sheet. 1174 (3M Japan Co., Ltd. (Shinagawa-ku, Tokyo)) was prepared as a base material, and the graphic sheets of Examples 1, 2-1 to 2-4, and 3 and Comparative Examples 1 and 2 were applied. The evaluation results of are shown in Tables 1 and 2, respectively.

It will be apparent to those skilled in the art that the above embodiments and examples can be variously modified without departing from the basic principle of the present invention. It will also be apparent to those skilled in the art that various improvements and modifications of the present invention can be implemented without departing from the spirit and scope of the present invention. The present disclosure includes the following aspects 1 to 11.
[Aspect 1]
A graphic sheet that can be peeled off from a base material,
A base film layer having a first surface and a second surface facing the first surface;
An adhesive layer disposed on the second surface of the base film layer;
Including
A graphic sheet, wherein the initial adhesive strength of the adhesive layer to the substrate is 0.5 N/25 mm or more at 20° C., and the normal adhesive strength is 8 N/25 mm or less at 20° C.
[Aspect 2]
The graphic sheet according to aspect 1, wherein the adhesive layer has a microstructured surface having irregularities, and the microstructured surface of the adhesive layer has passages or openings for discharging air to the outside or taking in the adhesive layer.
[Aspect 3]
The graphic sheet according to aspect 2, wherein the adhesive layer includes an acrylic adhesive, and the microstructured surface of the adhesive layer has a communication path extending to an outer edge of the adhesive layer.
[Aspect 4]
The graphic sheet according to aspect 2, wherein the adhesive layer comprises an open cell acrylic foam.
[Aspect 5]
The graphic sheet according to aspect 4, wherein the open-cell acrylic foam has an open-cell structure having a plurality of spherical cells and a through hole between adjacent spherical cells.
[Aspect 6]
The graphic sheet according to aspect 2, wherein the adhesive layer includes an acrylic woven fabric or an acrylic nonwoven fabric.
[Aspect 7]
The graphic sheet according to any one of aspects 1 to 6, wherein the base material is a gypsum board or a polyvinyl chloride sheet.
[Aspect 8]
Aspect 1 wherein the base material is a gypsum board that has been subjected to a primer treatment, and the adhesive layer has an initial adhesive force of 0.5 N/25 mm or more at 20°C and a normal adhesive force of 7 N/25 mm or less at 20°C. The graphic sheet according to any one of to 6.
[Aspect 9]
Aspects 1 to 6, wherein the base material is a polyvinyl chloride sheet, the initial adhesive force of the adhesive layer is 0.5 N/25 mm or more at 20° C., and the normal adhesive force is 5 N/25 mm or less at 20° C. Graphic sheet according to any one of.
[Aspect 10]
A building structure comprising a base material and the graphic sheet according to any one of aspects 1 to 9 arranged on a surface of the base material.
[Aspect 11]
11. The building structure according to aspect 10, wherein the base material is a gypsum board or a polyvinyl chloride sheet.

10, 20, 30 Graphic sheet 12, 22, 32 Base film layer 14, 24, 34 Adhesive layer 16, 26, 36 Liner 17, 27, 37 Microstructured surface 18 Communication path 28 Opening 29 Cavity

Claims (11)

A graphic sheet that can be peeled off from a base material,
A base film layer having a first surface and a second surface facing the first surface;
An adhesive layer disposed on the second surface of the base film layer,
The initial adhesion to the gypsum board or polyvinyl chloride sheet of the adhesive layer has a 0.5 N / 25 mm or higher at 20 ° C., ordinary state adhesive strength Ri 8N / 25 mm der less at 20 ° C., the initial adhesive strength, long A graphic sheet cut into a size of 150 mm and a width of 25 mm is attached to the gypsum board or the polyvinyl chloride sheet in an environment of 20° C. according to JIS Z 0237, and 20 minutes after the attachment, the temperature is 20° C. It is a value when 90 degrees peeling is performed at a speed of 300 mm/min, and the normal adhesive strength is a graphic sheet cut into a length of 150 mm and a width of 25 mm on the gypsum board or the polyvinyl chloride sheet at 20° C. paste in conformity with JIS Z 0237 under, after 24 hours from the paste, the temperature 20 ° C., Ru value der when performing 90 degree peel at a rate of 300 mm / min, the graphic sheet. The graphic sheet according to claim 1, wherein the adhesive layer has a microstructured surface having irregularities, and the microstructured surface of the adhesive layer has passages or openings for discharging air to the outside or taking in the adhesive layer. .. The graphic sheet according to claim 2, wherein the adhesive layer includes an acrylic adhesive, and a microstructured surface of the adhesive layer has a communication path extending to an outer edge of the adhesive layer. The adhesive layer is observed containing an open cell acrylic foam, the adhesive layer has a microstructured surface, the microstructured surface of the adhesive layer has an opening for taking air into the adhesive layer, according to claim 1 Graphic sheet. The graphic sheet according to claim 4, wherein the open-cell acrylic foam has an open-cell structure having a plurality of spherical cells and through holes between adjacent spherical cells. The adhesive layer is observed containing acrylic woven or acrylic nonwoven, the adhesive layer has a configured microstructured surface from a plurality of fibers, said micro-structured surface of the adhesive layer air to the adhesive layer The graphic sheet according to claim 1 , wherein the graphic sheet has an opening . The graphic sheet according to claim 1, wherein the base material is a gypsum board or a polyvinyl chloride sheet. The substrate is a primer-treated gypsum board, the initial adhesive strength of the adhesive layer is 0.5 N/25 mm or more at 20° C., and the normal adhesive strength is 7 N/25 mm or less at 20° C. The graphic sheet according to any one of 1 to 6. The base material is a polyvinyl chloride sheet, the initial adhesive force of the adhesive layer is 0.5 N/25 mm or more at 20° C., and the normal adhesive force is 5 N/25 mm or less at 20° C. 6. The graphic sheet according to any one of 6 above. A building structure comprising a base material and the graphic sheet according to any one of claims 1 to 9 arranged on a surface of the base material. The building structure according to claim 10, wherein the base material is a gypsum board or a polyvinyl chloride sheet.

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