JP2002264265A - Film for printing and tacky sheet for printing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film for printing which is capable of following up the shrinking of ink and especially shows outstanding adhesive properties with an UV ink. SOLUTION: This film for printing has an elastic material layer with a degree of elongation of a rupture point being set at 150% or higher, formed on a base material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing film and a pressure-sensitive adhesive sheet used for printing,
The present invention relates to a printing film and a pressure-sensitive adhesive sheet having excellent adhesion to printing ink.

[0002]

2. Description of the Related Art Plastic films have been used as printing films used for various types of printing. Generally, when the material of the printing film is a plastic film, an ink receiving layer is provided on the surface of the printing film in order to improve the adhesion to the ink.
In recent years, the demand for flexographic printing has been increasing in the Japanese printing industry. In the United States and Europe, water-based ink is the mainstream of flexographic printing ink, but UV ink is the mainstream in Japan. However, flexographic printing has a larger amount of ink than normal offset printing or the like, and thus has a large effect on a printing sheet or the like due to curing shrinkage of the ink. When flexographic printing is performed using a UV ink, there is a problem that the ink drops due to curing shrinkage of the ink. Accordingly, there has been a demand for a printing film and a pressure-sensitive adhesive sheet that can follow the shrinkage of the UV ink even when performing flexographic printing using the UV ink and have excellent adhesion to the UV ink.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and an object of the present invention is to provide a UV light source.
An object of the present invention is to provide a printing film and a pressure-sensitive adhesive sheet that can follow the curing shrinkage of the ink and have excellent adhesion to an ink such as a UV ink.

[0004]

The printing film of the present invention is characterized in that a substrate is provided with an elastic layer having an elongation at break of 150% or more. Here, the elastic layer may include at least one of a group consisting of a polyester-based resin, a polyolefin-based resin, and a urethane-based resin. Further, an intermediate layer can be provided between the base material and the elastic layer. Further, the elastic layer and the top coat layer can be sequentially provided on the base material. The pressure-sensitive adhesive sheet for printing of the present invention, on the surface on the side opposite to the surface on which the elastic layer of the substrate in any one of the printing films is formed,
An adhesive layer is provided.

According to the present invention, the adhesion between the UV ink and the printing sheet is enhanced by providing an elastic layer to alleviate the stress caused by the curing shrinkage of the UV ink.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The printing film of the present invention has a substrate on which an elastic layer having an elongation at break of 150% or more is provided.
By providing such an elastic layer, it is possible to reduce the influence on the printing film due to the curing shrinkage of the UV ink. That is, by adopting the configuration of the present invention,
The stress generated by the curing shrinkage of the ink is alleviated, so that the printing is prevented from falling off from the printing film, and the adhesion to the UV ink can be improved.

As the substrate for the printing film of the present invention, known materials such as plastic film and synthetic paper can be used. For example, polyethylene terephthalate (PET), polypropylene, polyethylene, nylon, polyurethane, polycarbonate, acrylic, polyamide, polyester amide, polyether, polyimide, polyamide imide, polystyrene, poly-p-phenylene sulfide, polyether ester, polyvinyl chloride, Examples thereof include films of poly (meth) acrylate and the like, and synthetic papers made of polyolefin and polyester. A film having good adhesion to the elastic layer may be selected from these films and synthetic papers. For example, when the resin of the elastic layer is a polyurethane resin, the base material is particularly preferably a polypropylene film. In addition, when an adhesive layer is provided and used as an adhesive label, polyethylene terephthalate, polypropylene film, or the like can be preferably used from the viewpoint of flexibility of the film. In the present invention, the thickness of the substrate is not particularly limited, but is preferably, for example, in the range of 25 to 300 μm.

In the present invention, the elongation at break is 150
% Or more of the elastic layer is not particularly limited as long as the resin has an elongation at break of 150% or more. For example, a polyester resin, a polyolefin resin, a polyurethane resin,
Acrylic resins, epoxy resins, hydrocarbon resins, vinyl resins, acetal resins, styrene resins, rubber resins, and copolymers and mixtures thereof, among others, among which, adhesion to the substrate Polyester-based resins, polyolefin-based resins, and polyurethane-based resins having high properties and high durability at high temperature and high humidity are preferably used. If the above resin is used and if the elongation at break can be ensured to be 150% or more, another resin, a crosslinking agent, a dye or the like may be added. In addition, a UV curable resin can be selected in addition to these resins. In the present invention, the thickness of the elastic layer is not particularly limited, for example,
It is preferably in the range of 0.01 to 20 μm, and more preferably in the range of 0.1 to 10 μm.

In the present invention, the elastic layer may be formed so as to be in direct contact with the substrate. However, in order to improve the adhesion between the elastic layer and the substrate, the elastic layer may be formed between the elastic layer and the substrate. It is preferable to provide an intermediate layer or the like on the surface. The resin used for the intermediate layer is not particularly limited. For example, when the substrate is a polypropylene or polyester film, it is preferable to use a layer made of a polyester resin. The thickness of the intermediate layer is not particularly limited, but is preferably in the range of 0.01 to 5 μm.

In the present invention, printing may be performed directly on the surface of the elastic layer. Alternatively, a top coat layer may be provided as an outermost layer on the elastic layer, and printing may be performed on this surface. As the top coat layer, in order to improve the adhesiveness with the ink, for example, an acrylic resin, a styrene-acrylic copolymer resin, a polyester-based resin, and a urethane-based resin having good adhesion to a normal UV ink for letter press are used. Although it can be used, it is not particularly limited to these. The thickness of the top coat layer is not particularly limited, but is preferably in the range of 0.01 to 5 μm.

In the present invention, a printing film can be obtained by forming an elastic layer on one or both sides of a substrate. As a method for producing such a printing film, a usual method can be used without particular limitation, for example, forming an elastic layer on a substrate by a gravure roll method, an air knife method, a wire bar coating method, or the like. can do. Further, the printing film of the present invention,
An intermediate layer and / or a top coat layer may be further provided if necessary. The same method can be applied to the case where an intermediate layer and a top coat layer are provided.

The printing film of the present invention can be provided with a pressure-sensitive adhesive layer on one surface to form a printing pressure-sensitive adhesive sheet.
The pressure-sensitive adhesive layer is provided on the surface of the substrate opposite to the surface on which the elastic layer is provided. As the pressure-sensitive adhesive used for the pressure-sensitive adhesive layer, a known pressure-sensitive adhesive such as an acrylic pressure-sensitive adhesive, an epoxy-based pressure-sensitive adhesive, a rubber-based pressure-sensitive adhesive, or a silicone-based pressure-sensitive adhesive can be used. The pressure-sensitive adhesive layer may be provided by directly applying a pressure-sensitive adhesive layer coating solution to the surface of the substrate opposite to the surface having the elastic layer, or may be provided on the surface on which the release treatment of the release material has been performed. A pressure-sensitive adhesive layer with a release material may be formed by forming a pressure-sensitive adhesive layer and bonding the pressure-sensitive adhesive layer to a surface of the substrate opposite to the surface on which the elastic layer is formed. The method for forming the pressure-sensitive adhesive layer is not particularly limited, and an ordinary method can be used. For example, the pressure-sensitive adhesive layer can be formed by a gravure roll method, a roll knife method, or the like. In the present invention, the thickness of the pressure-sensitive adhesive layer is not particularly limited,
Usually, it is in the range of 5 to 100 μm, especially 10 to 50 μm.
It is preferably within the range of μm.

Usually, a release material is temporarily adhered to the surface of the pressure-sensitive adhesive layer in order to protect the pressure-sensitive adhesive layer until use. As the release material, known materials can be used. For example, release paper or a release film that has been subjected to release treatment with a release agent such as a silicone-based or polyethylene-based release agent can be used.

The printing film and the pressure-sensitive adhesive sheet of the present invention are suitably used for flexographic printing using a UV ink. The printing film of the present invention can be used not only for flexographic printing using UV ink, but also for various printing films, for example, offset printing using ordinary ink.

[0015]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. The numerical values and evaluations used in the following examples were measured for elongation at break, substrate adhesion, ink adhesion, and ink adhesion after acceleration as follows.

Test Method: (1) Elongation at Break A film having a thickness of 45 μm was prepared using a resin constituting the elastic layer, and cut into a size of about 15 mm × 80 mm. Using this film, the elongation at break was measured at a chuck interval of 50 mm based on JIS K7127. (2) Substrate adhesion (interlayer adhesion of printing film) JIS K-5400 using a printing film
Based on the cross-cut tape method described in 5.2, the cut gap 1
In mm (the number of squares is 100), evaluation was made as to whether or not the adhesion between the layers of the printing film was good. In particular,
A cut was made from the substrate side, and the adhesion between the substrate and all the other layers in the printing film was evaluated. The evaluation was performed based on the above-mentioned test method in six stages of 0, 2, 4, 6, 8, and 10 points. The higher the score, the better the adhesion. in this case,
In the case of a printing film in which two or more layers are formed on a base material, whether or not these two or more layers have good adhesion to each other is also an object to be evaluated. (3) Printing test UV ink (trade name: Flexo White 5) was added to the printing film.
00, manufactured by T & K TOKA Co., Ltd.), and subjected to flexographic printing with a flexographic printing machine (trade name: MA-2200, manufactured by Mercandie, printing speed 20 M / min).
UV irradiation (metal halide lamp 3 kw) is performed to obtain a printed image. The cell of the anilox roller of the flexographic printing machine is a turtle shell type # 200, and the cell capacity is 16 cm ³ / m ^2.
It is. Ink Adhesion Using a printing film on which a printed image is formed, JIS
Based on the cross-cut tape method of K-5400 8.5.2., The adhesion between the ink and the printing film is evaluated at a gap of cuts of 1 mm (the number of squares is 100). Ink Adhesion After Acceleration The printing film on which the printed image was formed was heated at room temperature 40 ° C.
After leaving for 7 days in an environment with a humidity of 80%, the temperature is returned to normal temperature.
This was conditioned at room temperature for one day, and the same evaluation as the above-mentioned ink adhesion was performed.

Example 1 A polyethylene terephthalate film (PET film) having a thickness of 50 μm as a substrate (trade name: Lumirror PET)
50 T-60, manufactured by Toray Industries, Inc.), 15 parts of a polyester-based resin (trade name: Byron 296, manufactured by Toyobo Co., Ltd.) and a polyester-based resin (trade name: Byron) 300 parts, manufactured by Toyobo Co., Ltd., 5 parts of an isocyanate cross-linking agent (trade name: Coronate HL, manufactured by Nippon Polyurethane Industry Co., Ltd.), 40 parts of toluene and 40 parts of methyl ethyl ketone were applied by a wire bar coating method. After drying, a film for printing was produced. The thickness of the elastic layer after drying was 2 μm, and the drying condition was 100 ° C. for 1 minute.

Example 2 A 50 μm thick polypropylene film (P
P film) (Product name: ALFAN PP50 SY20)
2. On one side of Oji Paper Co., Ltd., 15 parts of polyolefin resin (trade name: Surfren E-2000, manufactured by Mitsubishi Chemical Corporation), 55 parts of toluene and 30 parts of methyl ethyl ketone as a coating solution for the elastic layer. Was applied by a wire bar coating method and dried to prepare a printing film. The thickness of the elastic layer after drying was 4 μm, and the drying condition was 70 ° C. for 3 minutes.

Example 3 A 50 μm thick polypropylene film (P
P film) (Product name: ALFAN PP50 SY20)
2, Oji Paper Co., Ltd.)
UV-curable urethane acrylate resin as cloth liquid
(Product name: Unidex RC20-024, Dainippon Inn
Apply a coating liquid consisting of
Apply by coating method and cure by UV irradiation
To prepare a printing film. Thickness of elastic layer after drying
The thickness is 4 μm, and 250 mJ / cm ²UV irradiation under the conditions
Fired.

Example 4 A 50 μm thick polypropylene film (P
P film) (Product name: ALFAN PP50 SY20)
2. On one side of Oji Paper Co., Ltd., a polyester resin (trade name: Byron 20) was used as a coating solution for the intermediate layer.
Co., Ltd., 20 parts, manufactured by Toyobo Co., Ltd.), a coating liquid consisting of 40 parts of toluene and 40 parts of methyl ethyl ketone was applied by a wire bar coating method and dried. Then, a polyester resin (trade name:
15 parts of Byron 296, manufactured by Toyobo Co., Ltd., 5 parts of polyester resin (trade name: Byron 300, manufactured by Toyobo Co., Ltd.), 2 parts of isocyanate crosslinking agent (trade name: Coronate HL, manufactured by Nippon Polyurethane Industry Co., Ltd.), toluene A coating solution composed of 40 parts and 40 parts of methyl ethyl ketone was applied to the surface of the intermediate layer by a wire bar coating method, and dried to prepare a printing film. The thickness of the intermediate layer after drying was 1 μm, the thickness of the elastic layer after drying was 2 μm, and the drying conditions were each 70 ° C. for 3 minutes.

Example 5 As a substrate, a 50 μm thick polypropylene film (P
P film) (Product name: ALFAN PP50 SY20)
2. On one surface of Oji Paper Co., Ltd., a polyurethane resin (trade name: NB300) was used as a coating solution for the elastic layer.
(A) 10 parts of a medium, manufactured by Dainichi Seika Co., Ltd., 1 part of an isocyanate crosslinking agent (trade name: Lamic B hardener, manufactured by Dainichi Seika Co., Ltd.), 40 parts of toluene, and 40 parts of methyl ethyl ketone were coated with a wire bar. It was applied by a coating method and dried. Next, as a coating liquid for the top coat layer, 20 parts of a polyester resin (trade name: Byron 200, manufactured by Toyobo Co., Ltd.) and toluene 4
A coating liquid consisting of 0 parts and 40 parts of methyl ethyl ketone was applied to the surface of the elastic layer by a wire bar coating method, and dried to prepare a printing film. The thickness of the elastic layer after drying was 1 μm, the thickness of the top coat layer after drying was 2 μm, and the drying conditions were each 70 ° C. for 3 minutes. Separately, a 38 μm thick polyester film (trade name: Lumirror # 38 T type, manufactured by Toray Industries, Inc.) is coated with a silicone resin (trade name: SYL OFF7198, manufactured by Dow Corning Silicone Co., Ltd.) to a dry film thickness of 2 μm. , And dried to prepare a release material having a release layer formed thereon. An acrylic pressure-sensitive adhesive (trade name: BPS3233D, manufactured by Toyo Ink Co., Ltd.) was applied on the release layer of the release material by a roll knife method so as to have a dry film thickness of 30 μm, and dried at 100 ° C. for 1 minute. A release material having a uniform pressure-sensitive adhesive layer was produced. Next, on the other surface of the substrate on which the top coat layer and the elastic layer were formed, a pressure-sensitive adhesive layer of a release material was superposed to produce a pressure-sensitive adhesive label.

Comparative Example 1 A 50 μm thick polypropylene film (P
P film) (Product name: ALFAN PP50 SY20)
2. On one surface of Oji Paper Co., Ltd., a polyester resin (trade name: Byron 2) was used as a coating solution for the elastic layer.
00, manufactured by Toyobo Co., Ltd.) 10 parts, polyester resin (trade name: Byron 290, manufactured by Toyobo Co., Ltd.) 15
, A coating solution consisting of 45 parts of toluene and 45 parts of methyl ethyl ketone was applied by a wire bar coating method and dried to prepare a printing film. The thickness of the elastic layer after drying was 2 μm, and the drying condition was 70 ° C. for 3 minutes.

Comparative Example 2 A polyester resin (trade name) was coated on one surface of a 50 μm thick PET film (trade name: Lumirror PET50 T-60, manufactured by Toray Industries, Inc.) as a substrate. : Byron 200, manufactured by Toyobo Co., Ltd.) 35
Of a polyester resin (trade name: Byron 290, manufactured by Toyobo Co., Ltd.), 40 parts of toluene, and 40 parts of methyl ethyl ketone were applied by a wire bar coating method and dried to prepare a printing film. . The thickness of the elastic layer after drying was 2 μm, and the drying condition was 100 ° C. for 1 minute.

Comparative Example 3 A polyethylene terephthalate film (PET film) having a thickness of 50 μm as a substrate (trade name: Lumirror PET)
50 T-60, manufactured by Toray Industries, Inc.), as a coating solution for a top coat layer, from 20 parts of a polyester resin (trade name: Byron 200, manufactured by Toyobo Co., Ltd.), 40 parts of toluene, and 40 parts of methyl ethyl ketone. The resulting coating solution was applied by a wire bar coating method and dried to prepare a printing film. The thickness of the top coat layer after drying was 2 μm, and the drying conditions were 70 ° C. for 3 minutes.

The printing films and the like obtained in Examples 1 to 5 and Comparative Examples 1 to 3 were evaluated for substrate adhesion, ink adhesion, ink adhesion after acceleration, and the like. Table 1 shows the results.

[0026]

[Table 1]

As is clear from Table 1, the printing film of the present invention has the following properties: substrate adhesion, UV ink adhesion,
It was found that excellent results were obtained in all of the V ink adhesion. Further, it was found that a pressure-sensitive adhesive sheet for printing having excellent adhesion to UV ink and adhesion to a substrate was obtained using the printing film of the present invention.

[0028]

As described above, the use of the printing film of the present invention makes it possible to alleviate the stress caused by the curing shrinkage of the ink, and to improve the adhesion to the UV ink for flexographic printing and the adhesion to the substrate. Excellent in printability and did not cause dropout of printing.

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Claims (5)

[Claims] 1. A printing film, wherein an elastic layer having an elongation at break of 150% or more is provided on at least one surface of a substrate. 2. The printing film according to claim 1, wherein the elastic layer contains at least one of a group consisting of a polyester resin, a polyolefin resin and a polyurethane resin. 3. The printing film according to claim 1, wherein an intermediate layer is provided between the base material and the elastic layer. 4. The printing film according to claim 1, wherein the elastic layer and the top coat layer are sequentially provided on the base material. 5. The printing film according to claim 1, wherein an adhesive layer is provided on a surface of the substrate opposite to the surface on which the elastic layer is formed. Characteristic adhesive sheet for printing.