JPH11123787A - Sheet for forming transfer type protective film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet for forming a transfer type protective film suitable for an object to be protected made of a soft material by scarcely forming a wrinkle or the like even by adhering a protective layer and then bending a surface to be protected. SOLUTION: In the sheet for forming a transfer type protective film comprising a separator layer 1, an adhesive layer 2, a protective layer 3 and an applicator layer 4 sequentially laminated in this order in such a manner that the layers 1 and 2 and the layers 3 and 4 are laminated releasably therebetween, the layer 3 has a thickness of 2 to 20 μm, and a resin layer exhibiting an elongation of 150 to 400% is used as the layer 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a protective film forming sheet for forming a protective film layer for protecting the surface of various display materials, printed materials, photographs, and the like. The present invention relates to a transfer-type sheet for forming a protective film, which does not impair the texture of the surface and does not cause wrinkles in the protective film even when the object to be protected is bent and used or stored.

[0002]

2. Description of the Related Art Original plates, advertisements,
2. Description of the Related Art A surface protective film is used for the purpose of preventing stains and scratches on the surface of a display, a photograph or the like formed by various printing methods or the like for a sign.

Conventionally, as such a protective film, a transparent plastic film provided with an adhesive layer so as to be adhered to an object to be protected has been used. However, since a relatively thick film is used for such a protective film, if it is attached to the surface of the object to be protected, the texture of the surface becomes that of the protective film, and the texture of the object to be protected is lost.

On the other hand, in order to eliminate the above-mentioned drawbacks by making the protective layer extremely thin, a separator layer, an adhesive layer, a protective layer, and an applicator layer are laminated in this order, and the separation between the separator layer and the adhesive layer is performed. Transfer type protective film forming sheets which are laminated so as to be peelable between the protective layer and the applicator layer have been developed.

According to such a transfer-type protective film forming sheet, the separator layer is peeled off, the adhesive layer is stuck on the object to be protected, and then the applicator layer is peeled off. Is obtained. Since the protective layer is handled in one piece with the applicator, a much thinner protective layer can be used,
The above objective has been achieved.

However, even if the protective layer is made very thin, if the object to be protected is bent and used or stored after application of the protective layer, wrinkles may occur in the protective layer. Such a protective layer is made of a soft material. Was unsuitable for a surface protection target consisting of

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to form a wrinkle or the like even when the surface of the object to be protected is bent after the protective layer is attached, and to be suitable for an object to be protected made of a flexible material. An object of the present invention is to provide such a transfer-type sheet for forming a protective film.

[0008]

As a result of the study by the present inventors, in the above-mentioned transfer type protective film forming sheet, the protective layer is made to have a specific thickness, and the protective layer has a certain elongation. It has been found that by forming the protective film from the material, it is possible to obtain a protective film in which wrinkles and the like are not easily formed even when the surface to be protected is bent after the application as described above.

Accordingly, the present invention provides a separator layer, an adhesive layer, a protective layer and an applicator layer which are laminated in this order, so that the separator layer and the adhesive layer and the protective layer and the applicator layer can be peeled off. A laminated transfer-type protective film forming sheet, wherein the protective layer has a thickness of 2 to 20.
A sheet for forming a transfer-type protective film, which is a resin layer having a thickness of μm and exhibiting an elongation of 150 to 400%.

In the transfer protective film forming sheet of the present invention, the protective layer is preferably one or more resins selected from polyurethane resins, vinylidene chloride resins, polyamide resins, polyester resins, acrylic resins, and mixtures thereof, or It comprises one or more resins selected from polyvinyl chloride resins, vinyl chloride / vinyl acetate copolymers, cellulose ester derivatives, cellulose ether derivatives and mixtures thereof, and a plasticizer and / or rubber material.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The sheet for forming a protective film of the present invention will be specifically described below.

The sheet for forming a protective film of the present invention has a separator layer 1, an adhesive layer 2,
The protective layer 3 and the applicator layer 4 are laminated in this order.

The applicator layer 1 is made of a general transparent or opaque film such as polyester, polyethylene terephthalate, polycarbonate, polyethylene, polypropylene, triacetyl cellulose, polyvinyl chloride, acrylic resin, polystyrene, polyamide, polyimide, vinylidene chloride. A synthetic resin film such as a vinyl chloride copolymer, paper, or a composite film of paper and the resin film can be used.

Further, if necessary, in order to improve the releasability from the protective layer, the surface on which the protective layer is to be applied may be subjected to a release treatment. For example, the above-mentioned film coated with polyethylene wax or a silicone release agent can be used.

When the applicator layer is thin, a coating such as a backing treatment for preventing curling may be applied to the surface of the applicator layer opposite to the side on which the protective layer is provided.

The thickness of the applicator layer 1 is not particularly limited, and can be appropriately selected in consideration of the material and its flexibility so as to obtain good workability at the time of sticking, for example, about 4 to 250 μm. Is preferably used.

For the pressure-sensitive adhesive layer 2, a known transparent pressure-sensitive adhesive such as an acrylic or rubber-based adhesive can be used. Since the sheet of the present invention is intended to form a protective film for protecting images and the like, it is desirable that the pressure-sensitive adhesive is also transparent and has high weather resistance itself. As such a pressure-sensitive adhesive, a urethane crosslinkable or epoxy crosslinkable high molecular weight acrylic pressure-sensitive adhesive is suitable.

The acrylic monomers used for the acrylic pressure-sensitive adhesive include methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, isobutyl acrylate,
-Methylbutyl acrylate, 2-ethylbutyl acrylate, 3-methylbutyl acrylate, 1,3-dimethylbutyl acrylate, pentyl acrylate, 3-
Pentyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, heptyl acrylate, 2
-Heptyl acrylate, octyl acrylate, 2-
Alkyl ester monomers such as octyl acrylate and nonyl acrylate; alkoxy such as 2-ethoxyethyl ethyl acrylate, 3-ethoxypropyl acrylate, 2-ethoxybutyl acrylate, 3-methoxybutyl acrylate, 2-ethoxyethyl acrylate, and 3-methoxypropyl acrylate Alkyl ester monomers; polyvinyl methyl ether, etc., and have a glass transition temperature of −3 ° C. to − when formed into a homopolymer.
It is preferable to use mainly an acrylate monomer having a temperature range of 75 ° C.

The thickness of the adhesive layer 2 is generally 2 to 30 μm,
Preferably it is in the range of about 2 to 10 μm.

If necessary, an antifoaming agent, a leveling agent, a UV absorber, a light stabilizer, a pigment and the like may be added to the adhesive layer 2.

The adhesive strength of the pressure-sensitive adhesive layer is expressed by a cohesive force defined as a force required for peeling the pressure-sensitive adhesive layer by cohesive failure, preferably 300 to 2000 g / inch, more preferably 500 to 1500 g / inch. Of the order.
If the value is greater than 2000 g / inch, air bubbles are easily entrapped during lamination, and the quality of the obtained image is reduced. If the value is less than 300 g / inch, the adhesive migrates during storage of the protective coating material. It may be eluted from the protective coating material.

Incidentally, the cohesive force of the pressure-sensitive adhesive layer in the present invention means that the two films coated with the pressure-sensitive adhesive are coated with a linear pressure of 2 kg / 30 c.
m using a rubber roller, heating and laminating as necessary. The resulting laminated film is 180 ° C. at a peeling rate of 3 cm / sec at room temperature using a tensile tester.
Peeling at an angle of ° means the force required to cause cohesive failure of the adhesive layer and to peel it. A non-peelable film is used as the film used for measuring the cohesive force.

The protective layer 3 is a layer to be a protective film and has an elongation of 150 to 400%, preferably 200 to 350%.
% Of the resin material. If the elongation value is less than 150%, it is insufficient to achieve the object of the present invention, and
If it exceeds 00%, it becomes difficult to produce a sheet for forming a protective film.

The elongation percentage of the protective layer according to the present invention is determined by measuring the elongation of the protective layer as a separate film according to JIS C23.
18 Refers to the elongation measured by the test method of 6.3.3. That is, using a constant-speed tension-type tensile tester, a width of 15 m
m, a film test piece of about 200 mm in length is attached to the grip with the grip of the testing machine being about 100 mm apart, pulled at a speed of about 200 mm in 1 minute, and measured by measuring the elongation when cut. is there.

As such a resin, it is possible to use a resin which originally exhibits a good elongation, a resin whose elongation is increased by adding and mixing a plasticizer and / or a rubber material, and the like.

Resins that exhibit good elongation by nature include polyurethane resins, vinylidene chloride resins, polyamide resins,
Examples thereof include polyester resins, acrylic resins, and mixtures thereof. With respect to these resins, a film having the above-mentioned elongation can be obtained by appropriately selecting the molecular weight depending on the resin.

The resin serving as the base of the resin whose elongation is increased by mixing a plasticizer and / or a rubber material includes polyvinyl chloride resin, vinyl chloride / vinyl acetate copolymer, methylcellulose, ethylcellulose, methylethylcellulose, and the like. Cellulose derivatives such as hydroxypropylcellulose, acetylcellulose, cellulose propionate, cellulose butyrate, and nitrocellulose, and mixtures thereof can be preferably used.

As the plasticizer added to the resin as described above, a usual plasticizer can be used, and examples thereof include dioctyl phthalate, diisodecyl phthalate, and trioctyl phosphate. These can be used alone or as a mixture. The amount of the plasticizer varies depending on the type of the resin and the plasticizer.
The amount is 2 parts by weight or more, preferably 3 parts by weight or more, more preferably 5 parts by weight or more with respect to 0 parts by weight, and the upper limit is about 60 parts by weight. If the amount is less than 2 parts by weight, sufficient elongation cannot be obtained, and if the amount exceeds 60 parts by weight, the effect of increasing the elongation reaches a plateau, which is not preferable in terms of cost. For 100 parts by weight of the resin, it is preferable to add a plasticizer of 20 parts by weight or more when the resin is polyvinyl chloride resin, 5 parts by weight or more when the cellulose derivative is used, and 3 parts by weight or more when the acrylic resin is used. .

As the rubber material added to the resin as described above, ordinary natural rubber and synthetic rubber can be used, but nitrile rubber, natural rubber, cyclized rubber and the like can be preferably used. The amount of the rubber material varies depending on the type of resin, the molecular weight, the type of rubber, and the like.
It is about 40% by weight. If it is less than 10% by weight, a sufficient increase in elongation cannot be obtained, and if it exceeds 50% by weight, the effect of increasing the elongation is hardly improved, so that it is not preferable from the viewpoint of cost.

In the peeling of the protective layer and the applicator layer, if the peeling is once stopped and the peeling is started again, a linear trace (stop pattern) is easily generated at the place where the peeling was stopped and restarted, which is not preferable. Such a stop pattern can be reduced by adding a cellulose ether derivative to the composition of the protective layer as described above. The addition amount of the cellulose ether derivative for preventing the stop pattern is generally 1 to 5% by weight, preferably 2 to 4% by weight based on the whole resin. If it is less than 1%, the effect of preventing the stop pattern cannot be obtained, and if it exceeds 5%, the effect is hardly improved, and the cost increases, which is not preferable.

If necessary, additives such as an antifoaming agent, a leveling agent, a UV absorber, a light stabilizer, and a pigment may be added to the resin or the resin composition of the protective layer as described above. For example, natural wax, synthetic wax such as polyolefin, lubricating agent such as silicone may be added in an amount of 0.1 to 3.0 parts by weight based on the total amount to improve lubricity, or the applicator layer may be peeled off when forming a surface protective film. In consideration of the properties, a fluorine-based surfactant, a release agent such as silicone may be used in an amount of 0.01 to
It can be added in the range of 5.0 parts by weight. From the viewpoint of image protection, it is particularly preferable to include a UV absorber, a light stabilizer and the like, and a hindered amine-based light stabilizer (for example, TINUVIN manufactured by Nippon Ciba Geigy) can be particularly preferably used.

Although the thickness of the protective layer 3 is preferably as thin as possible, it is not less than about 2 μm from the viewpoint of manufacturing, and is not more than 20 μm in order to achieve the above-mentioned object of the present invention.
More preferably, those having a range of 2 to 10 μm are used.

As the separator layer 4, a transparent or opaque film similar to the applicator layer 1, for example, polyester, polyethylene terephthalate, polycarbonate, polyethylene, polypropylene, triacetyl cellulose, polyvinyl chloride, acrylic, polystyrene, polyamide, polyimide, chloride A synthetic resin film such as vinylidene-vinyl chloride copolymer, paper, or a composite film of paper and the resin film can be used.

The thickness of the separator layer 4 is also not particularly limited, and can be appropriately selected in consideration of the material and the flexibility obtained thereby so as to obtain good workability at the time of sticking or the like. Those having a thickness of 250 μm are preferably used.

In the transfer type protective film forming sheet of the present invention comprising the above layers, the transfer layer is laminated so that the separator layer and the adhesive layer and the protective layer and the applicator layer can be separated. The protective layer is formed by peeling off the separator layer and sticking the adhesive layer on the object to be protected, and then peeling off the applicator layer. Therefore,
In order to be able to perform such an operation, the adhesive force between the protective layer and the applicator layer must be larger than the adhesive force between the separator layer and the adhesive layer.

In the transfer type protective film forming sheet of the present invention, the adhesive force between the separator layer and the adhesive layer is 18
In the 0 ° peel test, it is preferably 10 to 120 g / inch, particularly preferably 20 to 80 g / inch in terms of work when forming a protective film using the transfer-type protective film forming sheet of the present invention.

The adhesive strength between the protective layer and the applicator layer was also 20 to 300 g in a 180 ° peel test.
/ Inch, particularly preferably 30 to 200 g / inch. If the peeling force is greater than 300 g / inch, cohesive failure tends to occur on the surface of the protective layer, so that the solid resin layer may lose its surface gloss or peel off from the image surface.

Then, the adhesive strength between the protective layer and the applicator layer is 1 more than the adhesive strength between the separator layer and the adhesive layer.
Desirably, it is larger than 0 g / inch, especially about 30 g / inch or more. This difference in adhesion is 10
If it is smaller than g / inch, the applicator layer may peel off when the separator layer is peeled off from the adhesive layer.

The above-mentioned adhesive strength was measured by using a tensile tester at an angle of 180 ° at room temperature at 3 ° C.
It is determined as the force required to peel the layer at a peel speed of m / sec.

The adhesive strength between the layers can be easily adjusted by changing the kind, composition, etc. of the resin constituting each layer. For example, as the most effective method for adjusting the cohesive force of the adhesive layer, a methacrylate monomer, vinyl acetate, styrene, acrylonitrile, acrylamide, or methacrylamide can be used as a copolymer component.

As another method for adjusting the cohesive force of the adhesive layer, crosslinking can be performed using N-methylolacrylamide, N-methylolmethacrylate, diacetoneacrylamide, or butoxymethylacrylamide. Further, a hydroxyl group-containing monomer may be copolymerized and crosslinked with a polyvalent isocyanate compound.
Examples of such hydroxyl group-containing monomers include 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, hydroxybutyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, hydroxybutyl methacrylate, and acrylic acid esters of polyhydric alcohols. And methacrylic acid esters of polyhydric alcohols, ethyl carbitol acrylate, methyl triglycol acrylate, 2-hydroxyethyl acryloyl phosphate, propoxyethyl acrylate, dimethylaminoethyl methacrylate and the like. As polyvalent isocyanate compounds, tolylene diisocyanate, hexamethylene diisocyanate,
Diphenylmethane diisocyanate, isophorone diisocyanate, xylylene diisocyanate, bis (isocyanatomethyl) cyclohexane, dicyclohexylmethane diisocyanate, lysine diisocyanate, trimethylhexamethylene diisocyanate and tolylene diisocyanate, hexamethylene diisocyanate Nart adduct, urethane modified, allophanate modified,
A buret modified product, an isocyanurate modified product, a urethane prepolymer (an oligomer compound having an isocyanate group at both ends) and the like are used.

The cohesive force of the pressure-sensitive adhesive layer can be adjusted by introducing a carboxyl group into the acrylic resin and crosslinking with an epoxy resin.

The adjustment of the adhesive strength of the applicator layer to the protective layer can be performed, for example, by subjecting the surface to which the applicator layer is attached to mat treatment, corona treatment, flame treatment, or the like.

In the sheet for forming a protective film of the present invention, a release agent such as silicone is added to the protective layer in order to improve the lubricity of the protective layer or the releasability from the applicator layer. In this case, an intermediate layer may be provided between the adhesive layer 2 and the protective layer 3 in order to prevent the release agent from migrating to the adhesive layer.

The intermediate layer is mainly composed of a polyester resin,
An acrylic resin or the like can be used alone or as a mixture, and a surfactant for lowering the surface tension of the coating solution or a conductive agent for imparting antistatic properties can be added as necessary. be able to.

The protective film forming sheet of the present invention having the above-mentioned structure is prepared by applying a coating liquid obtained by dispersing or dissolving a resin for a protective layer of an applicator layer in a solvent together with various additives as required by a bar coating method. It is preferably manufactured by applying and drying by a known coating method such as a spray coating method or a roll coating method, then applying and drying an adhesive layer, and finally attaching a separator. The method for producing the sheet for forming a protective film is not limited to this.

[0047]

The present invention will be described in more detail with reference to the following examples.

Example 1 A coating solution for a protective layer having the following composition was applied to a polyethylene terephthalate film (X45, manufactured by Toray Industries, Ltd.) having a thickness of about 26 μm by bar coating, and a protective layer having a thickness of about 10 μm after drying was applied. A layer was formed.

Composition of coating solution for protective layer 10 parts by weight of vinyl chloride / vinyl acetate copolymer resin (VYHD, manufactured by Union Carbide) 0.5 part by weight of ethyl cellulose resin (Ethocel STD4, manufactured by Nissin Kasei) Nitrile rubber 5 parts by weight (1432J, manufactured by Zeon Corporation) ・ UV absorber 1 part by weight (TINUVIVN, manufactured by Nippon Ciba Geigy) ・ Silicone 0.1 part by weight (Paintad 54, manufactured by Dow Corning Asia) ・ Methyl ethyl ketone 40 Parts by weight ・ 40 parts by weight of toluene

Further, the thickness after drying is 8 μm on the protective layer.
m, an acrylic pressure-sensitive adhesive layer coating solution prepared by dissolving in isopropyl alcohol / n-butanol (S
K Dyne 1604S, manufactured by Soken Chemical Co., Ltd.) is applied by bar coating, dried to form an adhesive layer, and has a thickness of 25 μm.
m, a separator sheet (MRB: manufactured by Diafoil Hoechst) was laminated to obtain a transfer-type protective film forming sheet of the present invention.

The separator sheet of the sheet for forming a protective film of the present invention is peeled off, and the exposed pressure-sensitive adhesive layer is adhered to the image formed on the ink jet printing paper by ink jet printing.
Was peeled off to form a surface protective film having a thickness of about 18 μm, comprising an adhesive layer and a protective layer on the image.

The above-mentioned surface protective film hardly impairs the texture of the original display material, and the protective layer is wrinkled even if the printed material on which the protective layer is adhered is rolled to a diameter of about 2.5 cm and bent. Not at all.

Example 2 A coating solution for a protective layer having the following composition was applied by bar coating on a polyethylene terephthalate film (T60, manufactured by Toray Industries, Ltd.) having a thickness of about 50 μm, and the protective layer having a thickness of about 8 μm after drying was applied. A layer was formed.

Composition of coating solution for protective layer: 50 parts by weight of vinylidene chloride copolymer (DO-819, manufactured by Kureha Chemical Industry Co., Ltd., solid content: 50% by weight) 0.2 parts by weight of silicone (BYK348, BYK Chemie)・ 25 parts by weight of water ・ 25 parts by weight of meta-modified alcohol

Further, an adhesive layer was provided on the protective layer in the same manner as in Example 1, and a separator sheet was laminated to obtain a transfer-type protective film forming sheet of the present invention.

The separator sheet of the protective film-forming sheet of the present invention is peeled off, and the exposed pressure-sensitive adhesive layer is adhered to the image formed on the ink-jet printing paper by ink-jet printing.
Was peeled off to form a surface protective film having a thickness of about 16 μm, comprising an adhesive layer and a protective layer on the image.

The surface protective film described above hardly impairs the texture of the original display material, and the protective layer does not wrinkle at all even if the printed material on which the protective layer is adhered is rolled to a diameter of about 2.5 cm and bent. Was.

Example 3 A coating solution for a protective layer having the following composition was applied by bar coating on a polyethylene terephthalate film (Tamapoly GF105, manufactured by Tama Polyethylene) having a thickness of about 40 μm, and the thickness after drying was about 10 μm.
m of protective layers were formed.

Composition of coating solution for protective layer: 30 parts by weight of acrylic resin (Acridic A-195, solid content: 40% by weight, manufactured by Dainippon Ink Co., Ltd.) 0.7 parts by weight of dioctyl phthalate UV absorber 0.5 Parts by weight (TINUVIVN, manufactured by Nippon Ciba Geigy) ・ silicone 0.02 parts by weight (Paintad M, manufactured by Dow Corning) ・ methyl ethyl ketone 30 parts by weight ・ toluene 30 parts by weight ・ anone 10 parts by weight

Further, an adhesive layer was provided on the protective layer in the same manner as in Example 1, and a separator sheet was laminated to obtain a transfer-type protective film forming sheet of the present invention.

After the separator sheet of the protective film-forming sheet of the present invention was peeled off and the exposed pressure-sensitive adhesive layer was adhered to the image formed on the ink jet printing paper by ink jet printing, the applicator film (Tamapoly GF105) was applied. By peeling off, a surface protective film consisting of an adhesive layer and a protective layer and having a thickness of about 18 μm was formed on the image.

The surface protective film described above hardly impairs the texture of the original display material, and the protective layer does not wrinkle at all even if the printed material on which the protective layer is adhered is rolled to a diameter of about 2.5 cm and bent. Was.

[0063]

According to the transfer type protective film forming sheet of the present invention, a surface protective layer which does not impair the texture of the display object on various display objects and which does not easily generate wrinkles even when the display object is bent is provided. The transfer-type protective film forming sheet of the present invention, which can be formed, is particularly suitable for protecting the surface of a display or the like which is bent and used or stored.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing one embodiment of a sheet for forming a transfer-type surface protective film of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Separator layer 2 ... Adhesive layer 3 ... Protective layer 4 ... Applicator layer

Claims (3)

[Claims] 1. A separator layer, an adhesive layer, a protective layer, and an applicator layer are laminated in this order, and are laminated so that the separator layer and the adhesive layer and the protective layer and the applicator layer can be peeled off. A protective layer having a thickness of 2 to 20 μm and a resin layer exhibiting an elongation of 150 to 400%. . 2. The transfer type protective film according to claim 1, wherein the protective layer is made of at least one resin selected from polyurethane resins, vinylidene chloride resins, polyamide resins, polyester resins, acrylic resins and mixtures thereof. Sheet. 3. The method according to claim 1, wherein the protective layer comprises one or more resins selected from a polyvinyl chloride resin, a vinyl chloride / vinyl acetate copolymer, a cellulose ester derivative, a cellulose ether derivative and a mixture thereof, and a plasticizer and / or a rubber material. The transfer type protective film forming sheet according to claim 1, comprising: