JP2003191365A - Image display sheet, sheet base material with adhesive layer, protecting film in which image can be formed and method for manufacturing image display sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image display sheet with such advantages that a protecting film and a sheet base material can be bonded together at a comparatively lower temperature without inflicting thermal damage to the sheet base material, a manufacturing process can be easily simplified, and further the entire thickness of the image display sheet can be made as thin as possible. <P>SOLUTION: The image display sheet is formed of a light-transmitting protecting film with both face and back; a sheet base material bonded to the protecting film and formed of a toner applied to the back of the protecting film and a visually recognizable image through the protecting film, and a face arranged opposite to the back of the protecting film with a back facing opposite to the face; and an adhesive layer which bonds the protecting film in which an image is formed and the sheet base material together. In this sheet, the adhesive layer has a pressure-sensitive adhesive layer which tightly adheres to the back of the protecting film in which an image is formed and the face of the sheet base material. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light-transmitting protective film, an image formed from a toner applied to the back surface of the protective film and visible through the protective film, and an image facing the back surface of the protective film. The present invention relates to an improvement of an image display sheet provided with a sheet base material that is arranged and adhered to the protective film. In the image display sheet of the present invention, an adhesive layer for adhering the protective film on which the image is formed and the sheet base material to each other has a feeling of being in close contact with both the back surface of the protective film on which the image is formed and the surface of the sheet base material. It has a pressure-bonding layer.

[0002]

2. Description of the Related Art An image display including a light-transmissive protective film and a sheet base material which is arranged so as to face the back surface of the protective film and is adhered to the protective film, and which includes an image visually recognizable through the protective film. The seat is, for example,
An image is formed on the surface of the sheet base material using toner printing,
After that, the printed surface is covered with a protective film to be manufactured. However, this method is not suitable when it is difficult to form an image on the surface of the sheet base material. For example, when the surface of the sheet base material has a coating layer made of a cured resin having low adhesion to toner, it is difficult to form an image on the surface of the sheet base material. The melting point of the coating layer made of cured resin is higher than the thermal transfer temperature of the toner,
Alternatively, it does not melt and is less likely to be softened in the toner transfer step.

Further, in order to enhance the appearance and design of the completed image display sheet, the surface of the sheet is subjected to a designing process such as embossing, and a wallpaper or the like having a relatively large surface irregularity (roughness) is used as a sheet base material. Even if it is present, it is difficult to form an image on the surface of the sheet base material. This is because when the toner is transferred to such a design processed sheet base material, the toner can only adhere to the convex portions of the surface under normal transfer conditions. Further, when the transfer temperature and the transfer pressure are increased in order to improve the fluidity of the toner and bring the toner into close contact with the concave portion of the surface, the unevenness on the surface of the sheet base material is deformed, and the design is impaired.

On the other hand, there is also known a method in which a toner is applied to the back surface of a protective film, an image visible through the protection film is formed from the toner, and a sheet substrate is adhered to the back surface of the protective film. According to this method, even when it is difficult to form an image on the surface of the sheet base material, an image display sheet including an image visible through the protective film can be easily manufactured.

The protective film capable of forming an image on the back side is
For example, it is disclosed in JP-A-63-173693.
This publication discloses an intermediate transfer consisting of a temporary carrier (carrier film) and an image-receiving layer which is detachable from the temporary carrier using a material capable of dyeing a heat transfer dye on one surface thereof. A medium is disclosed. This image receiving layer functions as a constituent material of a protective film capable of forming an image on the back surface. The image receiving layer is usually formed of a thermoplastic resin such as polyester resin or acrylic resin. In addition, the mechanical properties (scratch resistance, etc.) of the protective film may be relatively low by itself. Therefore, in the disclosure of this publication, a protective layer made of a relatively hard resin such as a cured acrylic resin is laminated on the image receiving layer, and this laminated body is used as a protective film including an imageable image receiving layer.

The method of using this intermediate transfer medium (method of decorating an article) is disclosed as follows. That is, an image is formed by a thermal transfer method using a thermal transfer sheet having a heat transferable dye layer in the image receiving layer and a thermal head, and then the protective film on which the image is formed is thermocompression-bonded to a transferred article via a fusion sheet. After that, the temporary carrier is removed. By using this intermediate transfer medium and the sheet-shaped substrate as the transferred article, an image display sheet formed on the back surface of the protective film and containing an image visually recognizable through the protective film can be manufactured.

Japanese Unexamined Patent Publication No. 2001-113890 discloses a thermal transfer film having a multilayer structure in which a clear coat layer, an ink layer, and a polyester adhesive layer are sequentially laminated on a polyester carrier film. A release agent layer is disposed on the surface of the carrier film that contacts the clear coat layer. This clear coat layer functions as a protective film capable of forming an image on the back surface.

The method of using this thermal transfer film is disclosed as follows. That is, in a transfer method for performing a predetermined printing on a transfer object having a three-dimensional shape with a thermal transfer film, the transfer film is arranged so as to be at a predetermined position of the transfer target, and the transfer target is transferred while heating the thermal transfer film. It is pressure-bonded to the object, and the clear coat layer with the ink layer is heat-bonded to the transfer target through the polyester adhesive layer,
It then includes removing the carrier film.
Therefore, by using this thermal transfer film and the sheet-shaped substrate as the transferred material, an image display sheet including an image formed on the back surface of the protective film and visually recognizable through the protective film can be manufactured. It should be noted that this publication does not disclose a resin for forming a clear coat layer, nor does it disclose that toner printing (toner thermal transfer) is possible on such a clear coat layer. .

US Pat. No. 5,681,631 (International Application Publication No. WO95 / 18720) discloses the following image transferable image overlay composite.
Is disclosed. The overlay composite disclosed herein comprises a premask layer (temporary carrier) and a protective layer (protective film), which is capable of receiving thermal transfer toner and functions as a backside imageable protective film. . The protective layer is usually formed of a thermoplastic resin. As the thermoplastic resin, for example, an acrylic copolymer or a homopolymer, which is a polymer of a monomer containing methyl methacrylate, ethyl methacrylate, or the like, polyurethane, or vinyl chloride-vinyl acetate (vinyl chloride acetate) copolymer is disclosed.

In this publication, one example of the method of using the overlay composite is disclosed as follows. That is, an image is printed on the outermost surface (back side) of the protective layer of the image overlay composite, the imaged protective layer is bonded to the toner receptor, and the premask layer is stripped and removed from the protective layer. Thereby, it is formed on the back surface of the protective layer,
A laminate can be produced that contains the image visible through the protective layer. The toner receiver is, for example, a laminated film having a toner-receptive flexible film and a pressure-sensitive adhesive layer. In order to bond the image-bearing protective layer to the toner receptor, pressure-bonding is usually performed while heating to soften the toner receptor. By adhering the laminate containing the image produced in this manner to the sheet-shaped substrate via the pressure-sensitive adhesive layer, an image display sheet containing an image visible through the protective layer can be produced.

It is also possible to adhere the protective film with an image to an adherend via a solvent activated adhesive. However, when forming an image display sheet, a solvent coating step and a drying step for shortening the time until the solvent is dried and the adhesion is completed are necessary, and it is difficult to simplify the manufacturing process. . Also, a sheet base material that is not resistant to organic solvents cannot be used. Examples using such solvent-active adhesives are disclosed in, for example, JP-A-58-84791, JP-A-58-84792, and JP-A-58-84793.

On the other hand, recently, manufacturers and users of image display sheets have demanded a protective film capable of forming an image and having a good antifouling property on the surface. However, none of the above publications teaches improvement of the antifouling property of the front surface (the surface facing the back surface on which an image is formed) of the image-formable protective film.

[0013]

As described above, it has been relatively advantageous that the adhesive layer for adhering to the protective film contains a thermocompression-bonding adhesive (thermosensitive adhesive) which does not require solvent activity. Therefore, a protective film with an image (a protective film with a visible image formed on the back surface through the protective film)
And the sheet base material were bonded by thermocompression bonding using a heat-sensitive adhesive. Further, on the back surface of the protective film on which the image is formed, the lumps of toner are convex to form irregularities. When the protective film with an image and the adhesive layer are bonded together, the adhesive layer must be deformed (flowed) so as to follow such irregularities, and the protective film and the adhesive layer must be in close contact with each other. This is because the poor adhesion between the protective film and the adhesive layer results in the inclusion of bubbles, and the bubbles visible to the observer impair the appearance and visibility of the image. Therefore, it was relatively advantageous to perform the thermocompression bonding operation in order to enhance the unevenness followability (fluidity) of the adhesive layer.

However, if a thermocompression bonding operation is performed when the protective film and the sheet base material are bonded together, the sheet base material is thermally affected. Therefore, in the manufacturing method including the thermocompression bonding operation, a base material that is easily damaged by heat cannot be used. For example, in order to enhance the appearance and design of the image display sheet,
When a wallpaper on the surface of which a designing process such as embossing is applied is used as a sheet base material and a protective film is adhered by thermocompression bonding to the sheet base material, irregularities on the surface of the sheet base material are deformed and the design property is impaired. Further, a sheet base material containing a material that is discolored by heating cannot be used as a constituent material of an image display sheet manufactured by such a method.

On the other hand, as disclosed in the above-mentioned US Pat. No. 5,681,631, if a laminated film having a flexible film and a pressure-sensitive adhesive layer is used as an adhesive layer, the sheet base material itself is heated. The protective film and the sheet base material can be adhered to each other without the need. That is, the protective film on which an image is formed and the above-mentioned laminated film adhesive layer are subjected to thermocompression bonding to prepare a protective film with an adhesive layer, and then the protective film with an adhesive layer and the sheet base material are thermally applied to the sheet base material. Relatively low temperature (usually room temperature, 20-30
C.) to bond them together to bond the protective film and the sheet substrate.

However, in this way, it is difficult to simplify the manufacturing process by the method of attaching the adhesive layer to the protective film after image formation and then adhering the protective film and the sheet base material. That is, in such a method, the step of forming an image on the protective film (image forming step) and the final step of adhering the sheet base material to the protective film with image to complete the image display sheet are incorporated in one line. For this purpose, a step of heating and pressure-bonding the adhesive layer to the protective film to fix the adhesive layer is required between the image forming step and the final step. However, this requires incorporating three steps into one line, and the manufacturing process could not be simplified as it is. Furthermore, when the above-mentioned laminated film adhesive layer is used, it is difficult to reduce the thickness of the entire image display sheet as much as possible, because the adhesive layer includes an extra layer such as a flexible film.

Therefore, an object of the present invention is that the protective film and the sheet base material can be adhered to each other at a relatively low temperature which does not cause thermal damage to the sheet base material, the manufacturing process can be easily simplified, and the image display sheet can be easily manufactured. An object of the present invention is to provide an image display sheet in which it is easy to reduce the total thickness as much as possible. Another object of the present invention is to provide a sheet substrate with an adhesive layer and a protective film, which can be suitably used for producing the image display sheet as described above. Still another object of the present invention is to provide a method for producing the above image display sheet.

[0018]

In order to solve the above problems, the present invention comprises (a) a light-transmitting protective film having a front surface and a back surface, and (b) a toner applied to the back surface of the protective film. A sheet substrate that is formed and is visible through the protective film, (c) a sheet substrate that has a front surface that faces the back surface of the protective film, and a back surface that faces the front surface, and that is adhered to the protective film. Wood and
(D) In an image display sheet comprising a protective film on which the image is formed and an adhesive layer that adheres the sheet base material to each other, the adhesive layer includes a back surface of the protective film on which the image is formed. An image display sheet having a pressure-sensitive adhesive layer in close contact with both the surface of the sheet base material; a sheet base material used in the production of the image display sheet of the present invention, wherein the back surface of the protective film is A sheet substrate having an adhesive layer, the sheet substrate having a front surface disposed toward the front surface and a back surface facing the front surface, and the adhesive layer being fixed to the front surface; used for manufacturing the image display sheet of the present invention. Which is a protective film comprising a fluorine-containing polymer and a non-fluorine-containing polymer, the thermoplastic resin having a back surface arranged toward the surface of the sheet substrate, and a surface facing the back surface. An image-forming protective film comprising a film, the back surface of which is capable of receiving a toner to be thermally transferred; and a method for producing the image display sheet of the present invention, comprising: (i) facing the back surface of the protective film. A sheet base material with an adhesive layer, in which the adhesive layer is fixed to the surface to be arranged, is prepared, and (ii) separately, the toner is applied to the back surface of the protective film to form the image, and the protective film with the image is formed. (Iii) above (i)
The sheet base material with an adhesive layer prepared in 1. and the protective film with an image prepared in (ii) are overlapped, and they are pressure-contacted so as not to give thermal damage to the sheet base material, and the adhesive layer is interposed. And a step of adhering the protective film and the sheet base material together.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION [Function] In the image display sheet of the present invention, the protective film on which the image is formed and the adhesive layer for adhering the sheet base material to each other are formed on the back surface of the protective film on which the image is formed and the sheet. It has a pressure-sensitive adhesive layer in close contact with both the surface of the substrate. Therefore, the protective film and the sheet base material can be bonded to each other at room temperature (usually 20 to 30 ° C.) without heating the sheet base material itself.

The pressure-sensitive adhesive layer is a self-adhesive polymer (self-adher
An adhesive layer containing an ent polymer) does not require a heating operation for enhancing the irregularity followability (fluidity) of the adhesive layer. Therefore, in order to prevent air bubbles from being caught between the adhesive film and the back surface of the protective film on which the lumps of toner are convex and form irregularities, it is sufficient to press at room temperature. Further, the protective film and the sheet base material can be bonded to each other without heating the sheet base material itself. That is, it is not necessary to heat the three members, that is, the protective film, the adhesive layer, and the sheet base material, by pressure bonding.

When manufacturing the image display sheet of the present invention, it is easy to simplify the manufacturing process. That is, a step of forming an image on the protective film (image forming step),
The final step of adhering the sheet base material to the protective film with an image to complete the image display sheet can be incorporated into one process line without including the operation of heating the sheet base material. For example, an adhesive layer-attached sheet base material having an adhesive layer fixed on its surface is prepared and used.
The pressure-sensitive adhesive layer can be fixed in close contact with the sheet base material without heating. Therefore, the step of laminating the adhesive layer on the protective film is not required between the image forming step and the final step, the manufacturing process can be easily simplified, and the sheet base material is not thermally damaged. Further, it is not necessary to dispose a thermocompression bonding layer such as a flexible film between the image forming surface of the protective film and the adhesive layer in order to enhance the adhesion between the protective film and the sheet base material. Therefore, it is easy to reduce the thickness of the entire image display sheet as much as possible.

The pressure sensitive adhesive layer preferably contains a crosslinked tacky polymer. When it contains a crosslinked tacky polymer, compared to the case where it is not crosslinked, even if the image display sheet formed by adhering the protective film and the sheet base material to each other is rolled and stored, The adhesive is not squeezed out from the side part (side part) of the roll, and it is possible to effectively prevent the overlapping image display sheets from sticking to each other. Therefore, the roll of the image display sheet after storage can be easily unwound. The adhesive layer is
Unless the thickness of the entire image display sheet becomes unnecessarily large and the effect of the present invention is not impaired, the image display sheet may have two pressure-sensitive adhesive layers, and the first pressure-sensitive adhesive layer adhered to the protective film and the sheet. It may also have a second pressure-sensitive adhesive layer that adheres to the substrate.

(Image Display Sheet) A preferred example of the image display sheet of the present invention will be described with reference to FIG. In the illustrated image display sheet (100), the light-transmitting protective film (1) is composed of a single layer thermoplastic resin film.
The protective film has a front surface (11) and a back surface (12), and the back surface (12) receives the toner (2). The toner (2) forms a visible image through the protective film (1). In the illustrated example, the surface (11) is covered with the liner (5), but the image display sheet (10)
0) When used, the liner (5) is peeled and removed. That is, the surface of the protective film (1
1) is the outermost surface that contacts the outside. Therefore, the scratch resistance and antifouling property of this protective film surface (11) are
It is preferable to be increased as much as possible.

The sheet base material (4) has a front surface (41) arranged to face the back surface (12) of the protective film, and a back surface (42) facing the front surface (41), and has an adhesive layer (3). )) To the protective film (1).
The adhesive layer (3) is a pressure-sensitive adhesive layer containing a tacky polymer. Examples of such a pressure-sensitive adhesive layer include a pressure-sensitive adhesive film in the form of a single layer film containing an adhesive polymer, a first pressure-sensitive adhesive layer that adheres to a protective film, and a sheet substrate. A double-sided adhesive sheet having a second pressure-sensitive adhesive layer is preferably used.

In the illustrated example, the surface of the sheet substrate (41)
In order to enhance the appearance design of the completed image display sheet (100), design processing is performed to form irregularities. As described above, when the sheet base material (4) and the protective film (1) are bonded together, they are pressure-bonded without heating. Further, before fixing the protective film (1), when the adhesive layer (3) is fixed to the sheet base material (4), it is pressure-bonded without heating. Therefore, the adhesive layer (3) is in close contact with the surface of the sheet base material (41) without impairing the design of the surface of the sheet base material (41). In the illustrated example, the transparency of the adhesive layer (3) is increased so that the observer can improve the design irregularity of the sheet base material surface (41) through the protective film (1) and the adhesive layer (3). Can be seen.

The back surface of the protective film on which the image is formed (1
The toner (2) is convex on the surface 2) to form irregularities. Since the adhesive layer (3) has pressure-sensitive adhesiveness, it is deformed (flows) so as to follow the irregularities without being heated, and the back surface (12) of the protective film and the adhesive layer (3) are in close contact with each other.

The liner (5) usually comprises a support and a release layer (not shown) in contact with the protective film surface (11). The support is usually a polymer sheet or polymer film. As the polymer of the support, for example, polyester, polyvinyl chloride, ionomer,
Synthetic polymers such as acrylic polymers, polyolefins and polyurethanes can be used.

The release layer is preferably formed from a coating film of a release agent composition containing a silicone polymer. The silicone-based polymer is usually a modified silicone. The modified silicone is a polydimethylsiloxane in which most of the side chain methyl groups bonded to the main chain (—Si—O: siloxane skeleton) are left as they are and some of the methyl groups are replaced with organic groups other than methyl groups. It is a polymer of structure. As such an organic group, an alkyl group having 2 or more carbon atoms,
Examples thereof include a phenyl group, an aralkyl group and a fluorinated alkyl group. In addition, a reactive functional group (for example, a mercapto group, etc.)
May be included. Incidentally, the release layer, as an additive, for example, a heat stabilizer, an ultraviolet absorber, an antistatic agent,
Antioxidants, dyes, pigments and the like can also be added.
Examples of commercially available products of such a liner include a PET film (trademark) Tetron film with a release layer manufactured by Teijin Ltd. and a PP film (trademark) with a release layer manufactured by Toray Co., Ltd.
Telefan BO etc. can be mentioned.

(Image-Formable Protective Film) The image-formable protective film usually comprises a thermoplastic resin film formed of a thermoplastic resin. The thermoplastic resin is selected so that it has high adhesion to the toner for image formation and that the toner can be thermally transferred to the back surface of the protective film.

For example, the complex dynamic viscosity of the thermoplastic resin film measured with a viscoelastic spectrometer at 25 ° C. is usually 0.5 to 3 poises, preferably 1 to 3 poises.
It is 2.5 poise. If the complex dynamic viscosity is too small, the adhesion with the toner may be reduced, or the thermal transfer of the toner may be difficult. On the other hand, if the dynamic viscosity is too large, the mechanical strength of the protective film is lowered, and especially when the protective film is composed of a single layer of the thermoplastic resin film, the scratch resistance of the protective film may be lowered.

The Vicat softening point of the thermoplastic resin film is usually 30 to 95 ° C, preferably 40 to 93 ° C.
If the Vicat softening point is too high, the adhesion with the toner may be reduced, or thermal transfer of the toner may be difficult. On the other hand, when the Vicat softening point is too low, the mechanical strength of the protective film is lowered, and especially when the protective film is composed of a thermoplastic resin film single layer, the scratch resistance of the protective film may be lowered. The Vicat softening point is a softening temperature measured by a method conforming to the test method described in Japanese Industrial Standard JIS-K7206, and a predetermined load is applied to a needle-shaped indenter standing upright on a test piece (thermoplastic resin film). Is the temperature when the temperature of the test piece is raised at a constant rate while the indenter penetrates the test piece by 1 mm.

The melting point of the thermoplastic resin film measured by a differential scanning calorimeter (DSC) is usually 80 to 123 ° C.
It is preferably 90 to 121 ° C. If the melting point is too high, the adhesion with the toner may be reduced, or the thermal transfer of the toner may be difficult. On the other hand, when the melting point is too low, the mechanical strength of the protective film is lowered, and especially when the protective film is composed of a thermoplastic resin film single layer, the scratch resistance of the protective film may be lowered. The melting point is a value determined as follows. First, a film having a thickness of 1 to 2 mm is prepared as a sample. This sample is subjected to DSC,
Temperature rise from -120 to 120 ° C (first scan)
Then, the temperature is cooled from 120 to −120 ° C. (second scan), and the melting point is obtained from the endothermic peak corresponding to the first-order transition point during the second scan. The glass transition point of the thermoplastic resin film is not particularly limited, but usually 0 to
It is 100 ° C.

The protective film may be a laminate comprising a support positioned on the outer surface of the protective film in the state of being incorporated in the image display sheet and a thermoplastic resin film, but preferably, It is a single-layer film consisting only of a thermoplastic resin film. In the case of such a single-layer film, it is easier to reduce the thickness of the entire image display sheet as much as possible.

As the thermoplastic resin film, a film made of a resin such as polyester resin, acrylic resin, vinyl chloride resin, vinyl acetate resin or polyurethane resin can be preferably used. The polyester resin is preferably a random copolymer of polyethylene terephthalate and polyethylene sebacate, or a resin composition containing the copolymer. The acrylic resin is preferably a polyalkyl (meth) acrylate alone or a resin composition containing a polyalkyl (meth) acrylate. The resin used by being mixed with the polyalkyl (meth) acrylate is, for example, a vinyl acetate-based polymer.

The protective film which is composed of a single-layered thermoplastic resin film and which can be imaged on the back side is preferably
It is formed from a polymer blend comprising a fluorinated polymer and a non-fluorinated polymer. The fluoropolymer acts so as to enhance the antifouling property of the protective film. However, toner adhesion is low, and toner transfer (image formation) tends to be difficult. The non-fluorine-based polymer acts to supplement such weak points of the fluorine-based polymer and effectively enhance the toner adhesion of the protective film.

As the fluorine-based polymer, for example, polyvinylidene fluoride, polyhexafluoropropylene, polytetrafluoroethylene, polytrifluorochloroethylene, etc. can be used. As the non-fluorine-based polymer, for example, polyester, acrylic polymer, polyvinyl chloride, polyvinyl acetate, polyurethane and the like can be used.
The acrylic polymer preferably contains polymethylmethacrylate.

In order to improve the antifouling property and the toner adhesion property in a balanced manner, the weight ratio (N: P) of the non-fluorine type polymer (N) and the fluorine type polymer (P) is usually 1
0:90 to 45:55, preferably 15:85 to 4
The range is 0:60. The polymer blend as described above is preferably a polymer blend containing a methylmethacrylate-based polymer as a non-fluorine-based polymer and a vinylidene fluoride-based polymer as a fluorine-based polymer. Methyl methacrylate polymer has the function of effectively increasing the toner adhesion of the protective film,
The vinylidene fluoride polymer has a function of effectively enhancing the antifouling property of the protective film.

Here, the "methyl methacrylate polymer" is a polymer obtained by polymerizing a monomer containing methyl methacrylate as a main component. Such a monomer is preferably methyl methacrylate in an amount of 60% by weight or more,
Particularly preferably, the content is 90% by weight or more. The content of methyl methacrylate in the monomer is 60% by weight.
If the amount is less than the above, the compatibility between the methyl methacrylate-based polymer and the vinylidene fluoride-based polymer may decrease, the transparency may decrease, and the adhesion of the toner may deteriorate. The above-mentioned monomers include, in addition to methyl methacrylate, methacrylates such as ethyl methacrylate, propyl methacrylate and butyl methacrylate, acrylates such as methyl acrylate, ethyl acrylate, propyl acrylate and butyl acrylate, vinylidene fluoride, hexafluoropropylene, tetrafluoroethylene, and trifluoroethylene. It may contain one or more copolymerizable monomers such as fluoromonomers such as fluorochloroethylene.

The methyl methacrylate polymer is a trunk polymer formed by polymerizing methyl methacrylate,
A graft copolymer obtained by grafting a branch polymer obtained by polymerizing the above-mentioned copolymerizable monomer may be used.

On the other hand, the "vinylidene fluoride polymer" is a polymer obtained by polymerizing a monomer containing vinylidene fluoride as a main component. The monomer is preferably vinylidene fluoride in an amount of 60% by weight or more, particularly preferably 9% by weight.
It is contained in a proportion of 0% by weight or more. When the content of vinylidene fluoride in the monomer is less than 60% by weight, the compatibility between the methylmethacrylate-based polymer and the vinylidenefluoride-based polymer may be lowered, and the transparency may be lowered. Antifouling property may decrease. The monomer is, in addition to vinylidene fluoride, hexafluoropropylene, tetrafluoroethylene, a fluorine-based monomer such as trifluorochloroethylene, methyl methacrylate, ethyl methacrylate, propyl methacrylate, methacrylate such as butyl methacrylate, methyl acrylate, ethyl acrylate, It may contain one or more copolymerizable monomers such as acrylates such as propyl acrylate, butyl acrylate and the like.

The vinylidene fluoride-based polymer may be a graft copolymer in which a trunk polymer formed by polymerizing vinylidene fluoride is grafted with a branch polymer formed by polymerizing the copolymerizable monomer. .

In order to balance and improve the antifouling property and toner adhesion, the weight ratio (A: F) of the methyl methacrylate polymer (A) and the vinylidene fluoride polymer (F) is usually 10. : 90 to 45:55, preferably 15:85 to 40:60. In such a case, the protective film may contain a polymer other than the methyl methacrylate-based polymer and the vinylidene fluoride-based polymer. In that case, the total content of the methyl methacrylate-based polymer and the vinylidene fluoride-based polymer contained in the protective film is preferably 80% by weight or more, particularly preferably 90% by weight, based on the entire polymer contained in the protective film. That is all.

Even if a vinylidene fluoride-based polymer is replaced with a fluorine-based polymer blend of a first fluorine-based polymer composed of polyvinylidene fluoride and a second fluorine-based polymer other than polyvinylidene fluoride, the same effect can be obtained. Is obtained. Polyhexafluoropropylene, polytetrafluoroethylene, or polytrifluorochloroethylene is useful as the second fluorine-based polymer.
In this case, the methyl methacrylate polymer (A),
Weight ratio with fluoropolymer blend (B) (A: B)
Is usually in the range of 10:90 to 45:55, preferably 1
The range is 5:85 to 40:60. Also in this case,
The protective film may contain a polymer other than the methyl methacrylate-based polymer and the fluorine-based polymer. In that case, the total content of the methyl methacrylate-based polymer and the fluorine-based polymer contained in the protective film is preferably 80% by weight or more, particularly preferably 90% by weight or more, based on the entire polymer contained in the protective film. Is.

The protective film composed of a monolayer film can be formed by a usual film forming method. For example, it can be formed by applying a coating material containing the above resin on the release surface of the liner and solidifying it. A usual coater, for example, a bar coater, a knife coater, a roll coater, a die coater or the like can be used for the coating device. The solidification operation is a drying operation in the case of a paint containing a volatile solvent, or an operation of cooling the molten resin. Further, it can be formed by a melt extrusion molding method.

The protective film containing the support and the thermoplastic resin film can be formed by bringing the above-mentioned image-formable protective film into close contact with the support made of another resin film. As the resin film serving as a support, a film formed from a polymer blend containing the above-mentioned fluorine-containing polymer and a non-fluorine-containing polymer, or a polymer film containing one or more of the above-mentioned fluorine-containing polymer can be used. .

The total thickness of the protective film is usually 1 to 30.
μm. Further, as described above, it is preferable to use a protective film composed of a single layer film in order to reduce the thickness of the entire image display sheet as much as possible. In such a case, the thickness of the monolayer protective film is preferably 10 μm or less.
The thickness of the single-layer protective film is preferably 1 μm or more. If the thickness is too thin, the mechanical strength of the protective film may decrease, and the toner transfer performance of the toner receiving layer may decrease, which may make image formation difficult. Particularly preferably, the thickness of the monolayer protective film is 1.5 to 8 μm.

The protective film has a light transmitting property as a whole. The light transmittance is usually 60% or more, preferably 70% or more, and particularly preferably 80% or more. The "light transmittance" in this specification means the total light transmittance measured using the light of 550 nm using the spectrophotometer or the color meter also equipped with the function of a photometer.

The scratch resistance of the surface of the protective film is preferably evaluated, for example, according to Japanese Industrial Standard JIS K 5400, using the pencil hardness measured with a load of 100 g as an index. The pencil hardness of the surface of the protective film measured by this method is usually H or higher, preferably 2H or higher. Also,
The antifouling property of the surface of the protective film is based on JIS
It is preferable to evaluate the contamination recovery rate as an index, which is measured by a method according to A5712. The contamination recovery rate of the protective film surface measured by this method is usually 70%.
Or more, preferably 80% or more, particularly preferably 90% or more. For example, when the protective film is a single layer film containing a fluorine-based polymer and a non-fluorine-based polymer, the stain recovery rate can easily be 90% or more.

Here, the above-mentioned contamination recovery rate test will be explained.
Reveal First, as a test subject, a plane size of 3 cm x 3 cm
Prepare a protective film cut into a rectangular shape. This subject
After cleaning the surface with a cloth soaked in 5% soap water,
Reflectance of the period Y₀To measure. Next, on the surface of the subject,
1 g of the dirt component described below is rubbed in to adhere.
Let it sit for 30 minutes and then use a dry, unused cloth to test
After rubbing the body surface 10 times to wipe off the dirt components on the surface,
Diffuse reflectance Y after wiping operation (after contamination recovery) ₁Measure
To do. The stain component is white petrolatum (according to the Japanese Pharmacopoeia)
And carbon black are mixed in a mass ratio of 10: 1.
Form. Two hundred diffuse reflectances measured in this way
Split ratio (Y = Y₁/ Y₀X100) and calculate
Pollution recovery rate with value (Y) (Clean Recovery = CR)
And

(Sheet Substrate) The sheet substrate used in the present invention can be formed from paper, non-woven fabric, woven fabric or polymer film. The polymer film can be formed using a composition containing a polymer such as acrylic resin, polyester, epoxy resin, polyurethane, polyvinyl chloride, polyamide, or polyolefin. The sheet base material may include a pigment or a dye and may be colored. Further, a design may be printed on the surface of the sheet base material as long as the effect of the present invention is not impaired. Further, the surface of the sheet base material may be subjected to flameproofing treatment or antistatic treatment unless the effects of the present invention are impaired.

When the image display sheet of the present invention is used as a wallpaper containing an image, the surface of the sheet base material is preferably subjected to a designing process such as embossing as described above.
As the design processing, for example, irregular irregularities having a relatively large surface roughness are formed on the surface to give a non-glossy appearance, or a predetermined pattern is formed in accordance with the design or pattern included in the image of the protective film. By forming irregularities in the shape, it is possible to give a realistic appearance and a three-dimensional effect. More specifically, for example, wood tone, grain tone, stone tone, Japanese paper tone, cloth tone, hairline,
A three-dimensional pattern having a suede-like design can be provided.

The roughness of the surface of the sheet substrate that has been subjected to the design treatment is not particularly limited, but usually, it is measured by a surface roughness measuring device.
Ra measured under the condition that the measurement length is 0.4 mm is 3 to 25.
It is 0 μm or more. If Ra is too small, it may be difficult to provide the design appearance such as the three-dimensional appearance as described above. On the other hand, if Ra is too large, the adhesion with the adhesive layer may be difficult. From such a viewpoint, Ra of the surface of the sheet base material after processing is preferably 3.5 to 200 μm, and particularly preferably 4 to 150 μm. The thickness of the sheet base material is usually 10 to 1,000 μm, preferably 20 to 7 μm.
It is 00 μm.

(Adhesive Layer) The pressure-sensitive adhesive layer of the adhesive layer can be formed from, for example, a coating film of an adhesive containing a tacky polymer. A preferred adhesive contains a tacky polymer and a crosslinking agent that crosslinks the tacky polymer. The components and physical properties of the adhesive are plastically deformed following the completion of adhesion of the protective film and the sheet base material, followed by the unevenness of the toner on the back surface of the protective film, and the design unevenness formed on the surface of the sheet base material, and the protective film and It is selected so as to adhere to the sheet base material.

In the present specification, the tacky polymer is a polymer which exhibits tackiness at room temperature (about 25 ° C.). As the adhesive polymer, acrylic polymer, polyurethane, polyolefin, polyester and the like can be used. One example of the synthesis of the tacky polymer will be described by taking an acrylic polymer as an example. First, as the first monomer,
A polar (meth) acrylic monomer such as an acrylic unsaturated acid (eg, acrylic acid, methacrylic acid, itaconic acid, maleic acid, etc.) or acrylonitrile is prepared. This first
A monomer and an acrylic monomer as the second monomer are mixed to prepare a monomer mixture. As the second monomer, an alkyl acrylate, for example, isooctyl acrylate, butyl acrylate, 2-methylbutyl acrylate, 2-ethylhexyl acrylate, isononyl acrylate or the like can be used. The thus-prepared monomer mixture is polymerized by a usual polymerization method such as solution polymerization, emulsion polymerization or bulk polymerization to synthesize an adhesive polymer having a predetermined molecular weight.

When a cross-linking agent is used to cross-link the adhesive polymer, the addition amount of the cross-linking agent depends on the kind of the cross-linking agent, but is usually 0.0 per 100 parts by weight of the adhesive polymer.
It is 2 to 2 parts by mass, preferably 0.03 to 1 part by mass. The crosslinking agent is an isocyanate compound, a melamine compound, a poly (meth) acrylate compound, an epoxy compound, an amide compound, a bisamide compound (isophthaloylbis (2-
A bisaziridine derivative) of a dibasic acid such as methylaziridine) can be used.

The glass transition point (Tg) of the pressure-sensitive adhesive layer is preferably -50 to 0 ° C, particularly preferably -45 to -5 ° C. If the Tg of the pressure-sensitive adhesive layer is too high, the adhesion with the protective film and the sheet base material may be decreased. On the contrary, if the Tg is too low, when the image display sheet is rolled and stored, The adhesive seeps out from the end surface of the roll,
It may not be possible to prevent the image display sheets that overlap each other from sticking together. In this specification, the Tg of the pressure-sensitive adhesive layer is a value obtained by using DSC as follows. First, an adhesive layer having a thickness of 1 to 2 mm is prepared as a sample.
This sample is subjected to DSC, the temperature is raised from -120 to 120 ° C (first scan), and then 120 to -1.
After cooling to 20 ° C. (second scan), Tg is determined from the endothermic peak corresponding to the second-order transition point during the second scan.

Further, it is preferable to control the elastic modulus of the pressure sensitive adhesive layer within a predetermined range. For example, the dynamic elastic modulus of the adhesive layer at 65 ° C. is preferably 2 × 10 ^{4 to} 7 × 10 ⁵ dyne /
cm ² ( ^{2 to} 70 kPa), particularly preferably 3 × 10 ^{4 to} 6
× 10 ⁵ dyne / cm ² (3 to 60 kPa). If the elastic modulus at such a relatively high temperature is sufficiently high, even if the rolled image display sheet is stored at room temperature (20 to 30 ° C.) for a relatively long period of time (for example, several months), the stains of the adhesive may be observed. It can be effectively prevented. On the other hand, if the elastic modulus measured in this way is too high, the elastic modulus at room temperature becomes unnecessarily high, and the adhesion to the protective film and the sheet base material may deteriorate.

The total thickness of the adhesive layer is preferably 20 to 20.
It is 0 μm, particularly preferably 30 to 100 μm. Also,
The pressure-sensitive adhesive layer may contain additives such as a tackifier, a tacky polymer microsphere, a crystalline polymer, an inorganic powder and an ultraviolet absorber as long as the effect of the present invention is not impaired.

(Image formation) An image is formed by transferring toner to the back surface of the protective film using a usual printing method such as an electrostatic printing method. In the electrostatic printing method, an image is directly printed on the back surface of the protective film, and a transfer method in which the image is temporarily printed on the temporary carrier and then the image is transferred to the protective film. There is. In the latter transfer method, an image is formed on a temporary carrier called transfer medium, and the image is heated on the back surface of the protective film,
Transfer by pressure to complete the protective film with image. The toner forming an image contains a binder resin and a pigment dispersed in the binder resin. The binder resin is formed, for example, of one type selected from the group consisting of vinyl chloride-acetate-based copolymers, acrylic resins and polyester resins, or a mixture containing two or more types. For details of such an electrostatic printing method, for example,
JP-A-4-216562, JP-A-11-513818
It is disclosed in Japanese Patent Publication No.

(Method for Producing Image Display Sheet) The image display sheet of the present invention is preferably a sheet substrate with an adhesive layer,
Laminating the protective film with an image, pressing them so as not to give thermal damage to the sheet base material, and adhering the protective film and the sheet base material via the adhesive layer. Manufactured by the method. In this manufacturing method, first, an adhesive layer is fixed to the surface of a sheet base material that is arranged so as to face the back surface of the protective film, and a sheet base material with an adhesive layer is prepared. On the other hand, toner is applied to the back surface of the protective film to form a printed image to prepare a protective film with an image. Normal,
Prepare a sheet base material with an adhesive layer, in a line with an image forming step, take in a step of adhering a protective film and a sheet base material, after forming an image on the protective film,
The protective film with image and the sheet base material are pressure-bonded to each other to complete the image display sheet.

The adhesive layer is prepared as an adhesive layer with a liner, for example, by forming a coating film of an adhesive containing an adhesive polymer on the release surface of the liner. This liner-attached adhesive layer is pressure-bonded to the surface of the sheet base material, and then the liner is removed to form a sheet base material with an adhesive layer. Alternatively, the double-sided adhesive sheet having two pressure-sensitive adhesive layers and the sheet base material may be pressure-bonded to each other to form a sheet base material with an adhesive layer. Further, if necessary, the second adhesive layer may be fixed to the back surface of the sheet base material to be used as an image display sheet with an adhesive layer. The second adhesive layer is used to fix the image display sheet to the surface of an object such as a building, a vehicle, a machine or the like.

In a production line using a protective film composed of a monolayer film, a protective film roll formed by winding a protective film whose surface is coated with a liner is usually wound, and an adhesive surface is coated with a liner. A sheet base material roll formed by winding a sheet base material with an adhesive layer in a roll shape is used. While unwinding these rolls, image formation and adhesion of the protective film and the sheet base material are performed, and the completed image display sheet is wound into a roll to form an image display sheet roll. The liner coated with the protective film may be peeled off or removed from the protective film before winding the completed image display sheet into a roll,
The image display sheet may be wound into a roll without being removed while being covered with the liner.

[0063]

(Example) Using a 3M electrostatic printing system, Scotchprint (trademark) 9512, a transfer medium 8601J manufactured by 3M is formed with a dedicated toner to form a digital image for transfer. did. This transfer medium with an image was wound into a roll to prepare a media roll.

Next, the media roll produced above was attached to the media roll unwinding shaft of Orca (trademark) III, a laminator manufactured by 3M, and the transfer film roll unwinding shaft was covered with a protective film surface-coated with a liner. For the completion of the image display sheet, a sheet base material with an adhesive layer provided with a vinyl chloride sheet and a pressure-sensitive adhesive layer fixed to the surface is attached to the unwinding roll of the overlaminate film roll. Prepared

The protective film was formed from a polymer blend containing 35% by weight of polymethylmethacrylate and 65% by weight of a fluoropolymer, and had a thickness of 3 μm.
It was a single layer thermoplastic resin film of m. The fluoropolymer was a mixture of polyvinylidene fluoride and polytrifluorochloroethylene. The complex dynamic viscosity of the protective film is 2 poise, the Vicat softening point is 45 ° C., D
The glass transition point measured by SC was 71 ° C.

The thickness of the vinyl chloride sheet of the sheet base material was 50 μm, and the thickness of the pressure-sensitive adhesive layer was 30 μm.
The pressure-sensitive adhesive layer is prepared by adding 0.15 parts by mass (nonvolatile content ratio) of a bisamide compound as a crosslinking agent to a solution containing 100 parts by mass of an acrylic tacky polymer to prepare an adhesive solution. Was coated on a liner having a silicone release surface and dried to form an adhesive coating film, and the coating film was transferred by pressure contact with the vinyl chloride sheet surface.

The acrylic adhesive polymer was 90 parts by weight of 2-methylbutyl acrylate and 10 parts of acrylic acid.
It was an acrylic copolymer obtained by polymerizing a monomer mixture containing parts by mass. The above-mentioned cross-linking agent reacted with a carboxyl group derived from acrylic acid to cross-link the adhesive polymer. The dynamic shear modulus at 65 ° C. of the pressure-sensitive adhesive layer was 4.2 × 10 ⁵ dyne / cm ² (42
kPa). The dynamic shear modulus is determined by using a dynamic analyzer RDAII manufactured by Rheometrics,
Measured in share mode by dynamic viscoelasticity measurement method,
It was read from the viscoelastic spectrum in the range of 25 to 125 ° C. The share frequency was 1 rad / sec.

Subsequent to the above preparation, the laminator was operated under the following conditions to prepare a polyvinyl chloride sheet with an image in which the surface of the protective film was covered with a liner, which was wound into a roll and An example image display sheet roll was obtained. * Image transfer conditions: -Upper roll temperature = 130 ° C-Lower roll temperature = 50 ° C-Web transport speed = 70 cm / min-Pressure = Approximately 480 kPa (70 psi) * Pressure bonding condition between protective film and sheet substrate; = 25 ° C-Pressure = about 480 kPa (70 psi) -Web transport speed = 70 cm / min

The roll of the image display sheet was stored at about 25 ° C. for 2 months. No exudation of the adhesive in the adhesive layer was observed, and the roll after storage could be easily unwound and the desired length was obtained. I was able to remove the image display sheet.

In the image display sheet from which the liner covering the protective film was removed after taking out in this manner, the image observed through the protective film was clear. Also,
The pencil hardness and stain recovery rate of the protective film surface evaluated by the above-mentioned method were 9H and 96%, respectively. That is, it was confirmed that the image display sheet of this example had a scratch resistance and an antifouling property at a level sufficient for use as an advertising banner (image display sheet for hanging a ceiling).

(Example 2) An image display sheet of this example was obtained in the same manner as in Example 1 except that the following sheet substrate with an adhesive layer was used. The sheet base material used in this example is a wallpaper made of polyolefin of Sangetsu Co., Ltd., product number RE252.
And a double-sided adhesive sheet fixed to the surface of the wallpaper having irregularities in terms of design. The thickness of the wallpaper was 290 μm. Also, the double-sided adhesive sheet is 3
It was an acrylic pressure-sensitive double-sided pressure-sensitive adhesive sheet manufactured by M company. The double-sided adhesive sheet had two pressure-sensitive adhesive layers containing a crosslinked acrylic tacky polymer. Also,
The light transmittance of this double-sided adhesive sheet was 90%.

A roll of the image display sheet was stored at about 25 ° C. for 2 months in the same manner as in Example 1. The roll after storage could be easily unwound, and an image display sheet of a desired length was obtained. I was able to take it out. In the image display sheet that was taken out from the roll and the liner was removed, the image observed through the protective film was clear. Furthermore, the unevenness of the wallpaper surface was hardly deformed, and the designability was not impaired. It was confirmed that the image display sheet of this example had a design property, a scratch resistance, and an antifouling property at a level sufficient for use as a wallpaper.

(Comparative Example 1) An image was directly transferred by heat onto a sheet substrate (wallpaper) surface having no adhesive layer, and after the image transfer, a protective film having no image was adhered to the surface of the sheet substrate through the adhesive layer. An image display sheet of this example was obtained in the same manner as in Example 2 except for the above. The image on the image display sheet of this example was unclear. In addition, the unevenness of the wallpaper surface is
The image was deformed by the image transfer operation (operation involving heating and pressurization), and the original design of the wallpaper was significantly impaired.

[Brief description of drawings]

FIG. 1 is a sectional view of a preferred example of an image display sheet of the present invention.

[Explanation of symbols]

100: image display sheet; 1: protective film, 11: front surface, 12: back surface; 2: toner; 3: adhesive layer; 4: sheet base material, 41: front surface, 42: back surface; 5: liner

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4F100 AK01A AK01C AK17A AK18                       AK19 AK25 AL05A AL05C                       AR00C AT00B BA03 BA07                       BA10A BA10B CB05 EJ05C                       EK06 GB90 JB16A JL13                       JL13C JN01A

Claims (7)

[Claims] 1. A light-transmitting protective film having a front surface and a back surface; (b) an image formed from the toner applied to the back surface of the protective film and visible through the protective film; (c) A sheet substrate having a front surface arranged to face the back surface of the protective film and a back surface facing the front surface, and bonded to the protective film; (d) the protective film on which the image is formed; In an image display sheet comprising an adhesive layer that adheres a sheet base material to each other, the adhesive layer is a pressure-sensitive material that is in close contact with both the back surface of the protective film on which the image is formed and the surface of the sheet base material. An image display sheet having an adhesive layer. 2. The image display sheet according to claim 1, wherein the pressure-sensitive adhesive layer contains a crosslinked tacky polymer. 3. The image display sheet according to claim 1, wherein the protective film is made of a thermoplastic resin film, and the transferred toner is received on the back surface thereof. 4. The image display sheet according to claim 3, wherein the thermoplastic resin film contains a fluoropolymer and a non-fluorine polymer. 5. A sheet base material used for producing the image display sheet according to claim 1, comprising a front surface arranged toward the back surface of the protective film, and a back surface facing the front surface. A sheet base material with an adhesive layer, the adhesive layer being fixed to the surface thereof. 6. A protective film used for producing the image display sheet according to claim 1, comprising a fluorine-based polymer and a non-fluorine-based polymer, and arranged toward the surface of the sheet base material. An imageable protective film comprising a thermoplastic resin film having a back surface and a surface facing the back surface, the back surface capable of receiving the toner to be thermally transferred. 7. The method for manufacturing an image display sheet according to claim 1, wherein (i) the adhesive layer is fixed to the front surface of the protective film, the adhesive layer being fixed to the front surface. A base material is prepared, and (ii) separately, the toner is applied to the back surface of the protective film to form the image to prepare a protective film with an image, and (iii) a sheet with an adhesive layer prepared in (i) above. The base material and the protective film with an image prepared in (ii) are superposed, they are pressure-contacted so as not to give thermal damage to the sheet base material, and the protective film and the sheet are interposed via the adhesive layer. A method of manufacturing, comprising the step of adhering to a base material.