JP2001260549A - Protective film of printing surface - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a protective film of a printing surface which is excellent in properties of sticking to the printing surface and also in re-releasability and properties of sticking on the occasion of re-sticking. SOLUTION: The protective film 1 of the printing surface has an adhesive layer 3 on one surface of a transparent plastic film 2. The adhesive layer 3 has an adhesively of 0.24-1.6 N/10 mm to SUS304 and a layer thickness of 6.0 μm or more. The layer 3 is preferably constituted of a polyurethane or acrylic adhesive. A release sheet 4 is laminated ordinarily on the surface of the adhesive layer 3. A hard coat layer 5 is provided preferably on the other surface of the plastic film 2 and it contributes to improving the resistance to scuffing. The hard coat layer 5 preferably contains an ultraviolet absorber and contributes to preventing change and fading of color of an image.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing surface protection film, and more particularly, to an ink jet printer,
The present invention relates to a print surface protection film for protecting an image printed on paper by a sublimation printer, a thermal transfer printer, or the like. The printed surface protection film of the present invention is used by attaching it to a printed surface of paper or the like as a base material. The term “printed image” is used for a concept that includes not only images but also characters and the like.

[0002]

2. Description of the Related Art In recent years, the spread of ink jet printers, sublimation printers, and thermal transfer printers has been remarkable.
Images input from a digital still camera or the like can be easily enjoyed by printing on a printing substrate such as paper with these printers even at home.

[0003] However, these printed materials are susceptible to damages such as dirt and missing images due to adhesion of water and the like in a storage environment after printing and rubbing. In addition, dye-based inks used in many inkjet printers are
Discoloration due to ultraviolet rays easily occurs together with bleeding due to moisture. For these reasons, it is difficult to maintain a clear image during printing for a long period of time.

Therefore, a protective sheet having a transparent plastic film provided with an adhesive layer has been commercialized for the purpose of protecting a printed image. Some products have a UV shielding effect by mixing a plastic film with an ultraviolet absorber.

[0005] At present, image protective films on the market use an adhesive generally called a strong adhesive type as an adhesive layer. Therefore, when sticking to a print to be protected, uniform sticking cannot be achieved unless great care is taken. In addition, when peeling from a printed material, for example, when the pasting has failed, damage to the printed material is unavoidable, and it is very difficult to re-paste due to paper fibers and the like transferred to the adhesive layer.

[0006] Japanese Patent Application Laid-Open No. 9-67550 discloses a printed surface protection sheet of a type in which a support is removed after pasting to a printed matter to be protected. According to the publication, it is considered that the adhesive layer of the protective sheet has good adhesiveness to the printing surface, but no consideration is given to the removability after application.

Furthermore, plastic films such as polyethylene terephthalate, which are usually used as a base material of an image protection film, are easily scratched by rubbing and their transparency is impaired, so that there is a high possibility of deteriorating the appearance of printed matter. .

[0008]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned disadvantages of the prior art, to provide excellent adhesion to a printing surface, and to improve removability and adhesion during reattachment. It is to provide an excellent printed surface protection film. Another object of the present invention is to provide a printed surface protective film further provided with a hard coat layer and having excellent surface hardness and scratch resistance.

As a result of intensive studies, the present inventor has found that an adhesive layer having a specific adhesive strength and a specific film thickness has both sufficient sticking property to a printing surface and removability, so that the adhesive layer can be re-attached to the printing surface. It has been found that a printed surface protective film having a sticking property can be obtained, and the present invention has been completed.

[0010]

That is, the present invention relates to a printed surface protective film having an adhesive layer on one side of a transparent plastic film, wherein the adhesive layer has an adhesive strength of 0.24 to SUS304. 1.6N / 10m
m, and the thickness of the pressure-sensitive adhesive layer is 6.0 μm or more. The layer thickness of the adhesive layer,
Preferably it is 7.0 μm to 100 μm. The term “film” is a concept including both a sheet and a film. Transparent means that visible light is transmitted. Regarding the degree of transparency, the required level differs depending on the application. In the present invention, those having scattering which is generally called translucent are also included. The pressure-sensitive adhesive layer mainly includes, for example, a pressure-sensitive adhesive selected from the group consisting of a polyurethane-based pressure-sensitive adhesive and an acrylic-based pressure-sensitive adhesive.

In the present invention, a release sheet is generally laminated on the surface of the adhesive layer to protect the adhesive layer until use.

In the present invention, it is preferable that a hard coat layer is provided on the other surface of the transparent plastic film (the surface on which the adhesive layer is not provided) in order to improve abrasion resistance. Further, in order to prevent discoloration of the image, the hard coat layer preferably contains an ultraviolet absorbent.

The printed surface protection film of the present invention is suitable for protecting an image printed on paper, and is suitable for protecting an image printed on paper by an ink jet printer, a sublimation type printer or a thermal transfer type printer. It is. Paper includes regular paper, inkjet printer paper,
Various materials such as glassine paper and polyethylene laminated paper are included.

[0014]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view showing the basic layer configuration of the printed surface protection film of the present invention. Printing surface protection film
(1) Adhesive layer on one side of transparent plastic film (2)
(3). FIG. 2 is a cross-sectional view illustrating a preferred layer configuration example of the printed surface protection film of the present invention. The printing surface protective film (1) has an adhesive layer (3) on one side of the transparent plastic film (2), and is applied to the surface of the adhesive layer (3) to protect the adhesive layer (3) until use. A release sheet (4) is laminated, and a hard coat layer (5) is provided on the other surface of the plastic film (2) for improving scratch resistance.

The type of the transparent plastic film (2) is not limited as long as it is transparent so that the printed surface can be recognized. For example, a polyester film such as polyethylene terephthalate, a polyarylate film, an acrylic film, a polycarbonate film, a polyvinyl chloride film, a polyethylene film, or the like can be used. From the viewpoints of transparency, flexibility and cost, polyester films, polyvinyl chloride films, polyethylene films and the like are preferred.

The thickness of the transparent plastic film (2) is
Although not limited, it is generally about 10 to 250 μm, preferably about 15 to 150 μm.

An adhesive layer (3) is formed on one side of the transparent plastic film (2). The adhesive strength of the adhesive layer is 0.24 to 1.6 N / 10 with respect to stainless steel SUS304.
mm, and the thickness of the adhesive layer is 6.0 μm or more.

In the present invention, in order to accurately display the adhesive strength, the adhesive strength is defined by the adhesive strength to SUS304. By setting the adhesive strength of the adhesive layer in such a range, removability at the time of attaching the printing surface protection film to a printing surface such as paper is ensured. That is, even when a failure such as misalignment occurs when attaching the printing surface protection film to the printing surface, the protection film can be smoothly peeled off from the printing surface without damaging the printing surface. And
The peeled protective film can be attached again to the printing surface. The sticking property during re-sticking is also good.

When the adhesive strength is less than 0.24 N / 10 mm, even if the thickness of the adhesive layer is 6.0 μm or more, the adhesive strength (sticking property) to the printing surface cannot be sufficiently obtained, and exceeds 1.6 N / 10 mm. Thus, when peeled from the printing surface, the possibility of damaging the printing surface increases. Adhesive strength must be SUS30 in order to achieve both adhesion to the printing surface and removability from the printing surface.
It is necessary to be 0.24 to 1.6 N / 10 mm for 4.

In the present invention, by setting the thickness of the pressure-sensitive adhesive layer having the above-mentioned range of adhesive strength to 6.0 μm or more, a sufficient adhesive force to a printing surface such as paper can be obtained. If the thickness of the pressure-sensitive adhesive layer is less than 6.0 μm, sufficient adhesion to the printing surface cannot be obtained. The thickness of the pressure-sensitive adhesive layer is preferably 7.0 μm or more, and the upper limit is not particularly limited. However, considering the purpose of a printed surface protection film, it is usually 100 μm or less, and preferably 30 μm or less.

The thickness t ₃ of the adhesive layer can be measured, for example, as follows. Two printed surface protective film (1), those of the pressure-sensitive adhesive layer (3) is laminated so that the inside, the film (1) two thickness 2t ₁ measured using a digital micrometer. Subsequently, the adhesive layer from the film (1) to (3) was removed using a suitable solvent, to measure the film thickness t ₂ of the resulting plastic film (2). t
₃ = (2t ₁ -2t ₂ ) / 2

The pressure-sensitive adhesive layer can be formed using a pressure-sensitive adhesive material that satisfies the above range of pressure-sensitive adhesive, for example, a pressure-sensitive adhesive such as a polyurethane-based pressure-sensitive adhesive or an acrylic-based pressure-sensitive adhesive.
Further, a polyester-based adhesive or a polyamide-based adhesive may be used. Preferably, a cross-linking agent is added to these pressure-sensitive adhesives, and the pressure-sensitive adhesive is cured by heating. In the present invention, it is important that the adhesive strength of the adhesive layer satisfies the above range, and the type of the adhesive is not limited as long as this range is satisfied.

The polyurethane-based pressure-sensitive adhesive is produced by a polyaddition reaction between a polyol such as a polyether polyol or a polyester polyol and a diisocyanate.
Usually, it is preferable to synthesize a prepolymer having a terminal isocyanate group and add a cross-linking agent such as triol or diamine to the prepolymer to make it three-dimensional. As a diisocyanate,
For example, 2,4-tolylene diisocyanate (TDI), diphenylmethane-4,4'-diisocyanate (MDI), naphthalene-1,5-diisocyanate (NDI) and the like can be mentioned. Any one-part, two-part, or one-shot multi-component polyurethane adhesives based on the prepolymer method may be used. The polyurethane-based pressure-sensitive adhesive can be used without any particular limitation as long as the pressure-sensitive adhesive satisfies the above range of adhesive strength.

The acrylic pressure-sensitive adhesive is mainly composed of an acrylic polymer and can be used without any particular limitation as long as it satisfies the above range of adhesive strength. Generally, an acrylic pressure-sensitive adhesive is produced by subjecting a monomer composition mainly composed of an acrylate-based monomer such as an alkyl (meth) acrylate to solution polymerization in an organic solvent or emulsion polymerization in an aqueous system. The alkyl (meth) acrylate is not particularly limited, and may be an ester having an alkyl group having 1 to 12 carbon atoms, for example,
N-butyl (meth) acrylate, 2 (meth) acrylate
-Ethylhexyl, isooctyl (meth) acrylate,
And isononyl (meth) acrylate. The monomer composition often contains another monomer copolymerizable with the acrylate monomer. Examples of the other monomer include, but are not limited to, (meth) acrylic acid, (meth) acrylamide, (meth) acrylonitrile, hydroxyethyl (meth) acrylate, carboxyethyl (meth) acrylate, N-vinylpyrrolidone, and the like. No.

Various polyisocyanates can be used as the crosslinking agent. For example, a cross-linking agent obtained by modifying at least one of tolylene diisocyanate, hexamethylene diisocyanate, methylene diisocyanate, and the like with a compound having a plurality of hydroxyl groups such as trimethylolpropane, or three molecules of a diisocyanate compound are bonded. It is preferable to use an isocyanurate type crosslinking agent.

In the present invention, polyurethane-based pressure-sensitive adhesives and acrylic-based pressure-sensitive adhesives are preferred because they easily satisfy the above-mentioned range of adhesive strength. Fine adjustment of the adhesive strength can be performed by changing the type and amount of the crosslinking agent to be added, and by changing the heating temperature and the heating time after the application of the adhesive layer. In this case, the adhesive strength decreases as the amount of the crosslinking agent increases. In addition, the higher the heating temperature and the longer the heating time, the lower the adhesive strength. A small amount of a tackifier such as a petroleum resin, a terpene resin, a coumarone resin, a rosin resin, or a phenol resin may be used.

The adhesive layer (3) is formed by applying a liquid obtained by mixing an adhesive, a cross-linking agent, a solvent, and, if necessary, an additive onto one surface of the transparent plastic film (2) by a known coating method, for example, The coating can be performed by a method such as a gravure cylinder, a reverse coater, a roll coater such as a Meyer bar, or a slit die coater so as to have a desired film thickness, followed by drying.

In the present invention, a release sheet (4) is often laminated on the surface of the adhesive layer to protect the adhesive layer (3) until use. In other words, when storing the protective film (1) or aligning it with the printing surface before use, the adhesive layer (3)
It is preferable to protect the surface of the adhesive layer (3) in order to prevent the surface from sticking to other objects or dust. Also, an adhesive layer (3) is first formed on a release sheet (4), and then the transparent plastic film (2) is applied to the adhesive layer.
(3) may be laminated together with the release sheet (4).

As the release sheet (4), various known release sheets can be used. For example, paper having a silicone coating, polyethylene terephthalate film,
A polyethylene film, a polypropylene film, or the like can be used. The thickness of the release sheet (4) is, for example,
It is about 30 to 300 μm.

In the present invention, instead of using a release sheet to protect the adhesive layer (3), it is also possible to protect the adhesive layer (3) by using the protective film (1) as a roll. That is, when the protective film (1) is a wound body, the other surface of the plastic film (2) (the surface on which the adhesive layer is not provided) or the surface of the hard coat layer (5) described below is a release sheet. The adhesive layer (3) is protected. Or plastic film (2) and adhesive layer (3)
Protective film consisting of (1) or plastic film
When the protective film (1) composed of (2), the adhesive layer (3) and the hard coat layer (5) is laminated in multiple layers, the other surface of the plastic film (2) or the surface of the hard coat layer (5) Plays a role of a release sheet, so that the adhesive layer (3) is protected.

In the present invention, the plastic film
It is preferable that a hard coat layer (5) is provided on the other surface of (2). A plastic film such as polyethylene terephthalate has a lower surface hardness than glass and is easily scratched on the film surface. Scratching impairs its transparency and the appearance of the printed matter. Therefore, it is preferable to form a hard coat layer (5) for improving scratch resistance.

The hard coat layer (5) can be formed by applying a liquid obtained by dissolving a hard coat agent in a solvent, if necessary, drying and curing the other surface of the plastic film (2). . The hard coating agent is not particularly limited, and various known hard coating agents can be used. For example, silicone, acrylic,
A melamine-based thermosetting hard coat agent can be used. Among them, silicone-based hard coat agents are excellent in that high hardness can be obtained.

Also, radically polymerizable hard coating agents such as unsaturated polyester resin type and acrylic type, epoxy type,
An ultraviolet-curable hard coat agent such as a vinyl ether-based cationic polymerizable hard coat agent may be used. The UV-curable hard coat agent is preferable from the viewpoint of productivity such as curing reactivity. Among these, an acrylic radical polymerizable hard coat agent is desirable in consideration of curing reactivity and surface hardness.

The application of the hard coat agent may be performed by a known method such as a gravure cylinder, a reverse coater, a roll coater such as a Meyer bar, or a slit die coater. After application, it is dried in an appropriate temperature range and then cured. In the case of a thermosetting hard coat agent, give appropriate heat,
For example, in the case of a silicone hard coat agent, 60 to 1
Heat to about 20 ° C. for 1 minute to 48 hours to cure.
In the case of an ultraviolet-curable hard coat agent, ultraviolet irradiation is performed to cure. Ultraviolet irradiation is performed using a lamp such as a xenon lamp, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, a carbon arc lamp, and a tungsten lamp.
Irradiation of about mJ / cm ² is preferable. Hard coat layer (5)
Has a thickness of, for example, about 0.5 to 20 μm, and preferably about 2 to 5 μm.

The hard coat layer (5) contains an ultraviolet absorbent.
It is preferably contained. UV absorber
Thus, discoloration of the printed image is prevented. UV absorber
It is preferable to use various known ultraviolet absorbers. example
For example, salicylic acid UV absorber, benzophenone UV
Ray absorber, benzotriazole UV absorber, cyano
Acrylic UV absorbers and the like can be mentioned. these
The amount used may be determined as appropriate, for example, a hard coat
0.01 to 20 mg / m2 per unit area of layer (5) ^TwoAbout
Degrees.

The hard coat layer (5) may further contain, if necessary, various known additives such as a light stabilizer such as a hindered amine light stabilizer, an antioxidant, an antistatic agent and a flame retardant. You may not. UV absorbers and various additives
What is necessary is just to add and apply in a hard-coat agent. These additives are used in the plastic film (2) or in the adhesive layer.
(3) It is also possible to include them in.

To use the printed surface protective film (1) of the present invention, first, the release sheet (4) is peeled off, or the protective film (1) is pulled out from the roll to expose the adhesive layer (3). . Then, the surface of the adhesive layer (3) is attached to the printing surface to be protected. Since the adhesive strength of the adhesive layer (3) is set in a specific range, even if the application fails, the protective film (1) can be smoothly peeled off from the printing surface, causing damage to the printing surface. I will not give. The peeled protective film (1) can be pasted again on the printing surface. In the used state after pasting, the sticking property between the protective film (1) and the printing surface is sufficient.

[0038]

EXAMPLES The present invention will be described more specifically with reference to the following examples, but the present invention is not limited to these examples. Example 1 Printed surface protection film having a layer structure shown in FIG.
Created (1). First, on one side of a 50 μm-thick polyethylene terephthalate film (2), 100 parts by weight of a silicone-based thermosetting hard coat agent (Frescellar N: manufactured by Matsushita Electric Works, Ltd.) and a benzotriazole-based ultraviolet absorber ( A hard coat agent mixed with 2 parts by weight of Sumisorb 200 (manufactured by Sumitomo Chemical Co., Ltd.) was applied so that the film thickness after curing was 5 μm, and was cured by heating at 70 ° C. for 24 hours. Thus, a hard coat layer (5) was formed.

Next, an adhesive solution having the following composition was applied to the other surface of the polyethylene terephthalate film (2) by a reverse method so that the film thickness after drying was 12.0 μm.
After drying at 120 ° C. for 1 minute, an adhesive layer (3) was formed.

(Adhesive Solution) Urethane-based (polyether polyol) adhesive Vainsol U-250 [manufactured by Ongaku Yushi Kogyo Co., Ltd., solid content concentration 60 wt%, solvent: MEK / toluene = 1/1 (wt ratio)] 100 parts by weight TDI-based cross-linking agent B-45 2.5 parts by weight [manufactured by Yushi Co., Ltd., solid content: 45 wt%, solvent: ethyl acetate] Methyl ethyl ketone (MEK) 50 parts by weight Toluene 50 parts by weight The components were added and mixed to obtain an adhesive solution.

Paper having a silicone coating on one side (thickness 1
20 μm), and the silicone coated surface was laminated on the adhesive layer (3) surface so as to be in contact with the adhesive layer (3) surface to obtain a release sheet (4). Thus, a protective film (1) was obtained.

(Adhesion Test) The peeling sheet (4) of the protective film (1) sample was peeled off to expose the adhesive layer (3). The adhesive strength of the adhesive layer (3) to SUS304 was measured according to JIS Z
It was measured by the 90 ° peeling method described in “0237 (Testing method for pressure-sensitive adhesive tape / pressure-sensitive adhesive sheet)”.

(Printed Product Adhesion Test: Adhesion and Removability) Plain paper (XEROX copy paper), Konica gloss film (PHOT)
A sticking test was performed on three types of paper: OJET FILM (Glosey Film): manufactured by Konica) and Fuji Photo Glossy Paper (Super Photo Grade: manufactured by Fuji Photo Film). These three types of papers were adhered to a test plate (SUS304) with a double-sided tape, and a protective film test piece with the adhesive layer (3) exposed was adhered to each paper surface in accordance with JIS Z0237. The sticking property at this time was evaluated. After sticking, the film was peeled off by 90 ° with a finger, and the peeled surface was observed. The removability at this time was evaluated.

(Pasteability) ：: sufficiently adhered, no practical problem. Δ: Adhered, but air bubbles indicating that the paper surface and the adhesive layer (3) were not adhered in some places were observed, and the adhesive strength was weak. ×: When the attached test plate is made vertical, the protective film test piece peels off.

(Removability) ：: Peeled smoothly and the paper was not damaged when peeled.
Also, no paper adheres to the adhesive surface. Δ: Peeling did not occur smoothly, and the paper was damaged during peeling.
Also, paper is partially adhered to the adhesive surface. ×: No peeling. If it is forcibly peeled off, the paper will adhere to almost the entire surface of the adhesive surface.

[Examples 2 to 4, Comparative Examples 1 to 3] The amount of the cross-linking agent in the pressure-sensitive adhesive solution and the thickness of the pressure-sensitive adhesive applied were varied as shown in Table 1, and the film had the film thickness and adhesive strength shown in Table 1. A protective film was prepared in the same manner as in Example 1 except that an adhesive layer was formed. A sticking test was performed in the same manner as in Example 1 to evaluate sticking properties and removability. [Example 5] (Pressure-sensitive adhesive solution) 100 parts by weight of acrylic pressure-sensitive adhesive AS-409 (manufactured by Yatsusha Yushi Kogyo Co., Ltd., solid content concentration: 42 wt%) Isocyanate-based cross-linking agent B-45 5 parts by weight (Hitachi Yushi Yushi Kogyo) Methyl ethyl ketone (MEK) 50 parts by weight Toluene 50 parts by weight Each component was added to an adhesive and mixed to obtain an adhesive solution. Using this adhesive solution, a protective film was prepared in the same manner as in Example 1 except that an adhesive layer having the film thickness and adhesive strength shown in Table 1 was formed. A sticking test was performed in the same manner as in Example 1 to evaluate sticking properties and removability. [Examples 6 to 7, Comparative Examples 4 to 10] The amount of the cross-linking agent in the pressure-sensitive adhesive solution and the pressure-sensitive adhesive coating thickness were changed as shown in Table 1, and the pressure-sensitive adhesive layer having the film thickness and pressure-sensitive adhesive strength shown in Table 1 A protective film was prepared in the same manner as in Example 5 except that the protective film was formed. A sticking test was performed in the same manner as in Example 1 to evaluate sticking properties and removability.

[0047]

[Table 1]

As shown in Table 1, the protective films of Examples 1 to 7 have a specific range of adhesive strength and an appropriate adhesive layer thickness. The peelability was also excellent. And in Examples 1-7, when the protective film after re-peeling was again stuck on each of the three types of paper, sufficient sticking properties were obtained. Comparative Example 1,
In No. 3, since the adhesive strength was low and the thickness of the adhesive layer was small, the sticking property was insufficient. In Comparative Example 2, although the thickness of the adhesive layer was 9 μm, the adhesive strength was weak, and the adhesiveness was insufficient. In Comparative Examples 4 to 6, the adhesive strength itself was within an appropriate range, but the adhesive layer thickness was small, so that the adhesiveness was insufficient depending on the type of paper. In Comparative Examples 7 to 10, since the adhesive strength was too large, the removability was poor depending on the type of paper. That is, plain paper was damaged by the re-peeling, and a piece of paper adhered to the adhesive surface of the protective film. The re-peeled protective film could not be adhered to the paper again.

(Abrasion Resistance Test) The protective film of Example 1 was subjected to a wear test at a load of 250 g and a load of 500 g at 100 rpm using a wear tester MODEL503 manufactured by Taba. The haze value before and after the abrasion test was measured with a haze meter TC-H3DPK manufactured by Tokyo Denshoku Technical Center, and the change in haze value (ΔH:%) was determined. For comparison, the same abrasion test was performed on the same polyethylene terephthalate film as used in Example 1 to determine a change in haze value (ΔH). Table 2 shows the results. As shown in Table 2, the protective film of Example 1 was excellent in abrasion resistance because the hard coat layer was formed.

[0050]

[Table 2]

(Ultraviolet Absorbing Ability) The transmittance (%) at each wavelength of the protective film of Example 1 (from which the release sheet was peeled off) was measured using a spectrophotometer MPS-2000 manufactured by Shimadzu Corporation. For comparison, the same measurement was performed on the same polyethylene terephthalate film used in Example 1. Table 3 shows the results. Table 3
Thus, in the protective film of Example 1, since the hard coat layer contained the ultraviolet absorber, the ultraviolet transmittance was significantly reduced. This prevents discoloration of the printed image.

[0052]

[Table 3]

[0053]

According to the present invention, the adhesive layer having a specific adhesive strength and a specific film thickness has both sufficient sticking property to a printing surface and removability, and is suitable for re-attaching to a printing surface. There is provided a printed surface protective film which also has a sticking property. Further, the protective film provided with the hard coat layer is excellent in surface hardness and scratch resistance. Further, the protective film containing an ultraviolet absorbent in the hard coat layer has an effect of remarkably reducing ultraviolet transmission and suppressing discoloration of a printed image due to ultraviolet light. The printing surface protection film of the present invention is suitable for protecting an image printed on paper, and is particularly suitable for protecting an image printed on paper by an inkjet printer, a sublimation type printer, a thermal transfer type printer, and the like. is there.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a layer configuration of a printed surface protection film of the present invention.

FIG. 2 is a cross-sectional view illustrating a preferred layer configuration example of the printed surface protection film of the present invention.

[Explanation of symbols]

 (1) Printing surface protection film (2) Transparent plastic film (3) Adhesive layer (4) Release sheet (5) Hard coat layer

Claims (10)

[Claims] 1. A printed surface protective film having an adhesive layer on one side of a transparent plastic film, wherein the adhesive layer has an adhesive strength of 0.24 to stainless steel SUS304.
A printed surface protection film having a thickness of 1.6 N / 10 mm and a thickness of the pressure-sensitive adhesive layer of 6.0 μm or more. 2. The adhesive layer has a thickness of 7.0 μm to 100 μm.
The printed surface protection film according to claim 1, which has a thickness of μm. 3. The printed surface protection film according to claim 1, wherein the pressure-sensitive adhesive layer is mainly composed of a pressure-sensitive adhesive selected from the group consisting of a polyurethane-based pressure-sensitive adhesive and an acrylic-based pressure-sensitive adhesive. 4. The printed surface protection film according to claim 1, wherein a release sheet is laminated on the surface of the adhesive layer. 5. The printed surface protection film according to claim 1, wherein a hard coat layer is provided on the other surface of the transparent plastic film. 6. The printed surface protection film according to claim 5, wherein the hard coat layer contains an ultraviolet absorber. 7. A method for protecting an image printed on paper,
The printed surface protection film according to any one of claims 1 to 6. 8. The method according to claim 1, wherein an image printed on paper by an ink jet printer, a sublimation printer or a thermal transfer printer is protected.
Printed surface protection film according to the item. 9. The printed surface protective film according to claim 1, which has removability from the printed surface. 10. The printed surface protective film according to claim 1, which has a sticking property when pasted again on a printed surface.