JP3279734B2 - Flexographic printing plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a flexographic printing plate, and more particularly to a structure of a compressible flexographic printing plate excellent in plate making and printing characteristics.

[0002]

2. Description of the Related Art Heretofore, as a printing plate used for flexographic printing, a flexographic printing plate using a photocurable resin having low hardness has been used. However, since this flexographic printing plate did not have sufficient elasticity, when printing was performed using a printing machine with low accuracy, the obtained printed matter was distorted, or the image became uneven in thickness. For example, there is a problem that high quality printed matter cannot be obtained.

In order to solve this problem, the back surface of the flexographic printing plate (the surface on which a relief image is not formed,
Hereafter, a method has been used in which an elastic foam tape is disposed on the “back side” via an adhesive to impart elasticity to the flexographic printing plate. However, in this method, there is a problem that the foam tape is easily stretched, and it is not possible to always give uniform elasticity to the flexographic printing plate. Further, there is a problem that the adhesive strength of the foam tape is weak, and the flexographic printing plate is easily peeled or shifted from the foam tape during printing.
For this reason, high-precision printing could not be performed.

Further, when the foam tape is peeled off from the back surface of the flexographic printing plate, the adhesive tends to remain on the back surface of the flexographic printing plate, making it difficult to handle. To solve this problem, Japanese Patent Application Laid-Open Nos. Sho 57-210341, Sho 61-84289, and Sho 62-2
As disclosed in JP-A-29127, an elastic foam layer is provided on a support having excellent dimensional stability via a first adhesive layer, and a second adhesive layer is provided on the elastic foam layer. There has been proposed a compressible flexographic printing plate in which a photocurable resin layer is provided via an adhesive layer.

[0005] In this compressible flexographic printing plate, an elastic foam layer is previously bonded to the back surface of the photocurable resin layer via an adhesive layer. In comparison, the photocurable resin layer is prevented from peeling or shifting from the elastic foam layer during printing, and high-precision printing can be performed. In addition, since the support supports the elastic foam layer, there is an advantage that the dimensions of the elastic foam layer can be prevented from changing.

However, in the conventional compressible flexographic printing plate disclosed in the above publication, the constituent materials of the elastic foam layer and the photocurable resin layer are different, or the plasticity contained in the photocurable resin layer is different. Since low molecular substances such as an agent migrate to the vicinity of the interface with the elastic foam layer, the adhesive force between the photocurable resin layer and the elastic foam layer decreases, and there is still a problem that both are easily peeled off during plate making or printing. there were.

Therefore, as disclosed in JP-A-2-56554, a polyurethane layer is provided between the photocurable resin layer and the second adhesive layer disclosed in the above-mentioned publication. Thus, there is a conventional example in which the photocurable resin layer and the elastic foam layer are prevented from peeling off.

[0008]

However, the compressible flexographic printing plate disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 2-56554 has improved image distortion of the obtained printed matter and unevenness in image thickness. On the other hand, in printing high-precision images, the reproducibility of the printing plate itself, which reproduces fine and complicated original contents with high accuracy, is inferior, and it is not possible to obtain high-precision, high-quality printed matter. There was a problem.

In particular, when a fine and complicated image such as a screen object such as a photograph is used as a printing plate to be transferred to a printing substrate, image exposure is performed so as to form a required extreme highlight point at the time of plate making. When the number is increased, the reproducibility of the dark part is reduced, and the outline of the image cannot be balanced, for example, the white line is filled. For this reason, it has not been possible to obtain a high-quality printed matter that requires very fine and complicated image reproduction with high precision, and the fact is that it has not yet been adapted to this field.

The inventors of the present invention have investigated the factors that cause this problem, and found that the deterioration in image reproducibility of the printing plate itself is due to the fact that the light incident on the photo-curable resin layer is hardened by the elastic foam layer and the support. And the reflected light is reentered into the photocurable resin layer again, that is, it is caused by a so-called halation phenomenon. That is, since the elastic foam layer used for the flexographic printing plate has fine bubbles, light passing through the photocurable resin layer is likely to be irregularly reflected by the elastic foam layer, and the non-image portion of the photocurable resin layer It was considered that a UV image was reversed up to a region (a region that should not be exposed) and this portion was cured, so that a relief image having high precision reproducibility could not be obtained. This phenomenon is more remarkable when a large amount of light is required, such as forming a fine and high-precision relief image. Crushing and dirt are inevitable.

SUMMARY OF THE INVENTION An object of the present invention is to solve such a conventional problem, and it is possible to reproduce fine and complicated original contents with high precision, and to obtain a printed matter of higher precision and quality. It is an object of the present invention to provide a flexographic printing plate capable of obtaining the following.

[0012]

In order to achieve the above object, according to the first aspect of the present invention, a photocurable resin layer, an antihalation layer, an elastic foam layer, and a support are laminated in this order. The ultraviolet reflectance of the prevention layer is 1
It is intended to provide a flexographic printing plate characterized by being 0% or less.

The invention according to claim 2 is the invention according to claim 1.
The present invention also provides a flexographic printing plate in which the laminate comprising the antihalation layer, the elastic foam layer and the support according to the above has an ultraviolet transmittance of 1% or more. According to a third aspect of the present invention, there is provided a flexographic printing method in which an adhesive layer is interposed between at least one of the photocurable resin layer and the antihalation layer according to the first aspect, or between the antihalation layer and the elastic foam layer. The board is provided.

Further, the invention according to claim 4 is the same as the invention according to claim 3.
The present invention also provides a flexographic printing plate wherein the laminate comprising the antihalation layer, the adhesive layer, the elastic foam layer, and the support has an ultraviolet transmittance of 1% or more. According to the fifth aspect of the present invention, a photocurable resin layer, a photocurable resin layer containing an antihalation agent, an elastic foam layer, and a support are sequentially laminated, and the antihalation agent is contained. An object of the present invention is to provide a flexographic printing plate, characterized in that the ultraviolet reflectance of the photocured resin layer obtained is 10% or less.

Further, according to the invention of claim 6, the laminated body comprising the photocurable resin layer, the elastic foam layer and the support containing the antihalation agent according to claim 5 has an ultraviolet transmittance of 1%. The present invention provides a flexographic printing plate as described above. According to the seventh aspect of the present invention,
An object of the present invention is to provide a flexographic printing plate having an adhesive layer interposed between a photocurable resin layer containing the antihalation agent according to claim 5 and an elastic foam layer.

According to the eighth aspect of the present invention, there is provided a laminate comprising a photocurable resin layer, an adhesive layer, an elastic foam layer and a support containing the antihalation agent according to the seventh aspect of the present invention. A flexographic printing plate having a ratio of 1% or more is provided.

[0017]

According to the present invention, the antihalation layer having an ultraviolet reflectance of 10% or less is provided between the photocurable resin layer and the elastic foam layer. The light that enters and exposes the photocurable resin layer is
The anti-halation layer is prevented from reentering the photocurable resin layer again.

That is, most of the ultraviolet rays that have passed through the photocurable resin layer and have reached the antihalation layer are absorbed here and then reach the elastic foam layer and the support. In addition, the ultraviolet rays that reach the elastic foam layer and the support, and are reflected there, enter the antihalation layer again and are absorbed there, and then the remaining ultraviolet rays enter the photocurable resin layer. For this reason, the ultraviolet rays reflected by the elastic foam layer and the support are greatly suppressed from entering the photocurable resin layer again.

Here, the ultraviolet reflectance is such that the ultraviolet light that has passed through the antihalation layer and reached the elastic foam layer or the support is reflected here and reenters the antihalation layer to prevent the antihalation again. It also contains ultraviolet light emitted from the surface of the layer. Here, if the reflectance of the ultraviolet ray entering the photocurable resin layer is 10% or less, the ultraviolet ray entered backward contributes to the photochemical reaction of the photocurable resin layer,
There is no adverse effect on the formed relief image.

On the other hand, if the reflectance of the ultraviolet ray entering the photocurable resin layer exceeds 10%, the photocurable resin layer is re-exposed to the photocurable resin layer due to the ultraviolet ray which enters the photocurable resin layer, causing a photochemical reaction, and should not be photocured. Reproduction accuracy of the formed relief image is reduced, for example, the region (region serving as a non-image portion) is hardened. Therefore, the ultraviolet reflectance of the antihalation layer is set to 10
% Or less.

As the antihalation layer, a layer having excellent properties of adhesion to the photocurable resin layer and adhesion to the elastic foam layer, that is, an antihalation layer having an adhesive function may be used. preferable. Therefore, the antihalation layer may contain any substance having an adhesive function, such as a polymer or a copolymer. When using an antihalation layer having this adhesive function, it is necessary to provide an adhesive layer between the photocurable resin and the antihalation layer, between the antihalation layer and the elastic foam layer, or both. Because there is no
The manufacturing process is simplified.

The antihalation layer may be provided by directly applying the composition constituting the antihalation layer onto the elastic foam layer, or by applying the composition once onto a transfer paper or the like in advance and then transferring the composition onto the elastic foam layer. -Arranged by a desired method such as pasting. According to the second aspect of the present invention, the laminated body comprising the antihalation layer, the elastic foam layer and the support according to the first aspect has an ultraviolet transmittance of 1% or more. Back exposure. For this reason, further excellent relief image forming properties can be obtained.

Here, the laminate has an ultraviolet transmittance of 1%.
When the amount is less than the above range, it is not possible to reach the photocurable resin layer with an amount of ultraviolet light capable of obtaining excellent relief image formability when back exposure is performed. Therefore, the antihalation layer,
The ultraviolet transmittance of the laminate comprising the elastic foam layer and the support was limited to 1% or more.

According to the third aspect of the present invention, by interposing an adhesive layer, in addition to the above-mentioned functions, adhesion to the photocurable resin layer and adhesion to the elastic foam layer (adhesion) Even if the anti-halation layer is inferior, the adhesive strength between the adjacent layers is improved due to the excellent adhesiveness of the adhesive layer. Therefore, it is possible to use an antihalation layer having poor adhesion to the photocurable resin layer and adhesion to the elastic foam layer.

According to the fourth aspect of the present invention, the laminated body comprising the antihalation layer, the adhesive layer, the elastic foam layer and the support according to the third aspect has an ultraviolet transmittance of 1%.
As described above, an effective back exposure can be performed similarly to the flexographic printing plate according to the second aspect. For this reason, further excellent relief image forming properties can be obtained. The performance of the antihalation layer can be defined, for example, by an ultraviolet spectrophotometer using an integrating sphere. The ultraviolet reflectance of the antihalation layer can be determined, for example, by referring to "Spectrophotometer UV2100S (trade name); manufactured by Shimadzu Corporation"
S-260 (trade name; manufactured by Shimadzu Corporation), with the reflectance of the magnesium sulfate plate being 100%, 360 nm,
It is determined by the average value of each reflectance measured at three points of 370 nm and 380 nm. The ultraviolet reflectance limited in the present invention is limited based on the result obtained by the above method using the above-mentioned apparatus.

The antihalation layer has a thickness of 360-38.
It is particularly desirable that the reflectivity of ultraviolet light having a wavelength region of 0 nm is 10% or less. Examples of the substance that effectively absorbs ultraviolet rays in the wavelength range of 360 to 380 nm include organic solvent-soluble dyes such as "Eizen Spiron Yellow 3RH (trade name); manufactured by Hodogaya Chemical" and "Eizen Spiron Yellow RHS- Liq (trade name); made by Hodogaya Chemical "," Eizen Spiron Red BEH (trade name); made by Hodogaya Chemical "," Eizen Spiron Red G
EH Special (trade name; manufactured by Hodogaya Chemical Co., Ltd.), "Variazole Yellow MYE (trade name); manufactured by Orient Chemical Co., Ltd."
edH (trade name); manufactured by Mitsubishi Chemical Corporation, "Diaresin BlueJ (trade name); manufactured by Mitsubishi Chemical Corporation", "Diaresin YellowF (trade name); manufactured by Mitsubishi Chemical Corporation", and the like.
However, the material is not limited to this as long as it meets practical needs such as compatibility with the photocurable resin layer and the adhesive layer.

The photosensitive resin composition which is a component of the photocurable resin layer may have either physical properties of liquid or solid, but the resin properties after photocuring can be used as a flexographic printing plate. Use things. And 360-3
It is preferable to have a photosensitive wavelength region in the ultraviolet region of 80 nm. Examples of such a photosensitive resin composition include, for example, JP-A-55-48744 and JP-A-63-086.
No. 88555, JP-B-51-37320, JP-B-51-43374, JP-B-53-37762.
And Japanese Patent Publication No. 59-22219.

As the adhesive layer, for example, a polymer or copolymer containing at least one selected from the group consisting of polyurethane, acrylic resin, vinyl chloride, vinylidene chloride and vinyl acetate, or polybutadiene, polyisoprene, styrene isoprene copolymer,
It is preferable to use a polymer containing at least one selected from the group consisting of styrene-butadiene-styrene copolymers, but it is preferable to have adhesion to the photocurable resin layer, adhesion to the elastic foam layer, or a low-molecular substance from the photocurable resin layer. The material is not limited to this, as long as the material satisfies practical necessity such as transferability of the film and ultraviolet transmittance that does not hinder back exposure during plate making.

The adhesive layer may be composed of a plurality of layers made of a polymer or a copolymer selected from the above group. Examples of the elastic foam material include polyolefins having continuous and / or single fine cells, polyurethane, ethylene propylene rubber, etc., having a density of 0.1 to 0.6.
g / cm ³ , and a Shore A hardness of 10 to 65 degrees are preferable, but an ultraviolet transmittance that does not hinder the backside exposure at the time of plate making and an elastic property that does not hinder the actual printing characteristics There is no particular limitation as long as the conditions are satisfied.
Such an elastic foam layer is described in, for example,
7-210341, JP-A-59-212298, JP-A-61-84289, JP-A-62-2
No. 29127 and the like.

Examples of the support include films and sheets of polyester and the like. The support has ultraviolet transmittance which does not hinder back exposure during plate making, and dimensional stability suitable for a flexographic printing plate. If it is, it is not particularly limited. The anti-halation layer, the ultraviolet transmittance of the laminate comprising the elastic foam layer and the support and the anti-halation layer, the adhesive layer, the ultraviolet transmittance of the laminate comprising the elastic foam layer and the support, for example, a photocurable resin layer The ultraviolet light emitted from an ultraviolet lamp generally used as an exposure light source is applied to an object to be measured, and the intensity of the ultraviolet light transmitted through the object is measured.
Specifically, for example, a dedicated filter "UV-42 (trade name); manufactured by Oak Manufacturing" is attached to a sensor of "UV intensity meter UV-MO1 (trade name); manufactured by Oak Manufacturing Co., Ltd." The laminate (object to be measured) is irradiated with ultraviolet light, and the intensity of the ultraviolet light transmitted through the laminate is measured. Next, the intensity of the ultraviolet light emitted from the exposure light source is measured, and the intensity is determined by calculating the ultraviolet light transmittance of the laminate as 100% of the ultraviolet light transmittance. The ultraviolet transmittance limited in the present invention is limited based on the result obtained by the above method using the above-mentioned apparatus.

Further, an antihalation layer may be formed by adding an antihalation agent to the photocurable resin layer. In this case, when an antihalation agent is contained in the entire photocurable resin layer, the sensitivity of the entire photocurable resin layer is reduced due to the absorption of ultraviolet rays by the antihalation agent, and the image formability is reduced. Therefore, in order to obtain excellent image forming properties, a photocurable resin layer containing no antihalation agent,
It is necessary to form a two-layered photocurable resin layer including a photocurable resin layer containing an antihalation agent.

According to the fifth aspect of the present invention, the photocurable resin layer contains an antihalation agent, and the ultraviolet curability of the photocurable resin layer itself is set to 10% or less.
Ultraviolet rays that have passed through the photocurable resin layer from the exposure light source and entered the photocurable resin layer containing the antihalation agent while exposing the photocurable resin layer and the photocurable resin layer containing the antihalation agent to a large extent. Portions are absorbed by the antihalation agent. Therefore, after exposing the photocurable resin layer and the photocurable resin layer containing the antihalation agent,
Ultraviolet rays reaching the elastic foam layer and the support are greatly reduced, so that the light reflected here and entering the photocurable resin layer is also reduced.

Here, if the ultraviolet ray reflectance of the photocurable resin layer containing the antihalation agent is 10% or less, the amount of the ultraviolet rays that enter the photocurable resin layer will contribute to the photochemical reaction of the photocurable resin layer. However, the amount does not adversely affect the formed relief image. On the other hand, when the ultraviolet ray reflectance of the photocurable resin layer containing the antihalation agent exceeds 10%, the amount of ultraviolet rays reaching the elastic foam layer and the support after the photocurable resin layer is exposed is sufficiently reduced. This makes it difficult for the photocurable resin layer to undergo a photochemical reaction, and the amount of ultraviolet light that decreases the reproduction accuracy of the formed relief image is introduced back into the photocurable resin layer.

Therefore, the ultraviolet reflectance of the photocurable resin layer containing the antihalation agent is limited to 10% or less. According to the invention of claim 6, the ultraviolet ray transmittance of the laminate comprising the photocurable resin layer, the elastic foam layer and the support containing the antihalation agent according to claim 5 is 1% or more. In addition to the function, effective back exposure can be performed. For this reason, further excellent relief image forming properties can be obtained.

According to the seventh aspect of the present invention, between the photocurable resin layer containing the antihalation agent according to the fifth or sixth aspect and the elastic foam layer,
Due to the interposition of the adhesive layer, in addition to the above-mentioned effects, even in the case of a photocurable resin layer having poor adhesion to the elastic foam layer, the adhesion to the elastic foam layer is improved by the excellent adhesiveness of the adhesive layer. Is done. Therefore, it becomes possible to use an antihalation layer having poor adhesion to the elastic foam layer.

Furthermore, according to the invention of claim 8, the ultraviolet transmittance of the laminate comprising the photocurable resin layer, the adhesive layer, the elastic foam layer and the support containing the antihalation agent according to claim 7 is provided. Is set to 1% or more, effective back exposure can be performed in addition to the above operation. For this reason, further excellent relief image forming properties can be obtained.

[0037]

Next, embodiments of the present invention will be described with reference to the drawings. (Embodiment 1) FIG. 1 is a sectional configuration view of a flexographic printing plate according to Embodiment 1 of the present invention. As support 1, thickness =
Thickness = 1.05 on a 0.1 mm polyester film
An elastic foam layer 2 made of urethane foam having a density of 0.38 g / cm ^{3 and} a thickness of 0.38 mm is adhered by a known method. Next, a composition having the following composition (weight ratio) is applied to the elastic foam layer 2 three times using a bar coater. Next, this is placed in a dryer at 60 ° C. and left for 2 hours to dry the composition, thereby forming the antihalation layer 3. Thus, a laminate 11 including the support 1, the elastic foam layer 2, and the antihalation layer 3 was obtained. (Composition) Ethyl acetate 50 parts (weight) Tetrahydrofuran 20 parts (weight) Cellosolve acetate 15 parts (weight) Styrene isoprene styrene elastomer 15 parts (weight) Antihalation agent 3 parts (weight) As styrene isoprene styrene elastomer, "TF -912 (trade name); manufactured by Asahi Kasei Kogyo Co., Ltd. as an antihalation agent;
H (trade name); manufactured by Orient Chemical Co., Ltd.].

The antihalation layer 3 having the above-mentioned composition has a high adhesiveness and also has a function as an adhesive layer. Therefore, even if an adhesive layer is not particularly provided between the elastic foam layer 2 and the antihalation layer 3 or between the antihalation layer 3 and the photocurable resin layer 4 to be bonded later.
Good adhesion is achieved between the layers. Next, using an "ultraviolet spectrophotometer UV2100S (trade name); Shimadzu Corporation" equipped with an "integrating sphere reflection device ISR-260 (trade name); Shimadzu Corporation", the ultraviolet reflectance from the antihalation layer 3 side When measured, 360-380
The average reflectance in nm was 10.0%.

Further, "UV lamp TL-80 /
10R (trade name) manufactured by Philips ”as the exposure light source,
The UV transmittance of the laminate 11 was measured using “UV meter MO2 (trade name); manufactured by Oak Manufacturing Co., Ltd.”
The average ultraviolet transmittance was 9.0%. Next, thickness =
As a 3.0-mm solid photocurable resin, "AFPXAR
-928 (trade name; manufactured by Asahi Kasei Kogyo Co., Ltd.), and peeling off the cover film on the side having no protective film, and pressure-bonding the anti-halation layer 3 of the laminate 11 to provide the photocurable resin layer 4. .

Thus, as shown in FIG. 1, the photocurable resin layer 4, the antihalation layer 3, the elastic foam layer 2,
And the support 1 are sequentially laminated, the total thickness = 4.06 m
m of flexographic printing plate 10 was obtained. Next, plate making of the flexographic printing plate 10 was performed by the following method. First,
Using "Ultraviolet lamp TL-80 / 10R (trade name); manufactured by Philips", back exposure is performed for 6 minutes at a distance of 13 cm from the support 1 side of the flexographic printing plate 10.

Next, after the cover film on the photocurable resin layer 4 side is peeled off, a negative film (negative original) is placed on the photocurable resin layer 4 so that the film surface side is on the photocurable resin layer 4 side. . The negative film has a screen ruling of 133 lines, a halftone density of 1%, a highlight halftone dot, and
Character size = 6 point outline characters and gothic characters were used. Next, after covering the negative film with a vacuum adhesive sheet, these are vacuum adhered. Next, using the same ultraviolet lamp as that for the back exposure, image exposure is performed over the vacuum contact sheet at a distance of 13 cm for 15 minutes.

Next, the flexographic printing plate 10 after exposure is
A developer having the following composition (volume ratio) (temperature = 2
5 ° C.) and brush development for 3 minutes. (Composition of developer) Trichloroethane 3 parts (volume) Isopropyl alcohol 1 part (volume) Next, after the brush development, the washed flexographic printing plate 10
Is lightly rinsed with a clean developer of the above composition,
Dry for 1 hour in a drier at ℃.

Next, the surface of the flexographic printing plate 10 is gently wiped with a soft cloth containing trichloroethane.
Leave overnight in a dryer at room temperature. Then, on the entire surface of the flexographic printing plate 10 using a germicidal lamp for 5 minutes,
Post-exposure for 5 minutes using an ultraviolet lamp, height =
A relief image of 0.9 mm was formed.

Also, thickness = 1.03 mm, density = 0.4
Except for using urethane foam of ² g / cm ² , in the same manner as in Example 1, the ultraviolet transmittance of the laminate 11 was
A flexographic printing plate (Example 1A) having 0.9% and an ultraviolet reflectance from the antihalation layer 3 side of 10.0% was manufactured, and a relief image having a height of 0.9 mm was formed in the same manner as in Example 1. Formed.

Next, for comparison, using the same method and raw materials as in Example 1, the ultraviolet reflectance from the antihalation layer 3 side was 13.0%, and the ultraviolet transmittance of the laminate 11 was 1
Flexographic printing plate of 2.0% (Comparative product 1), UV reflectance of 15.0%, UV transmittance of laminate 11 of 16.0
% Flexographic printing plate (Comparative product 2).

Next, a flexographic printing plate was manufactured using the same method and the same raw materials as in Example 1 except that the antihalation agent was removed from the antihalation layer 3 (Comparative product 3). In addition, the ultraviolet reflectance from the elastic foam side of the laminate of the comparative product 3 including the elastic foam layer and the support was 51.0%, and the ultraviolet transmittance was 40.0%. Next, the same exposure and development as in Example 1 were performed on Comparative Products 1 to 3 to form a relief image having a height of 0.9 mm. (Example 2) As a support 1, on a polyester film having a thickness of 0.125 mm, a thickness of 1.35 mm and a density of
An elastic foam layer 2 made of urethane foam of 0.45 g / cm ³ is adhered by a known method.

Next, a hot-melt adhesive “MU373 (trade name); manufactured by Konishi” containing the same antihalation agent as in Example 1 on a release paper in advance was applied to a thickness of 15 μm.
The antihalation layer 3 obtained by coating with m is transferred to the elastic foam layer 2 by heating. The composition of the antihalation layer 3 is shown below. (Composition) Hot melt adhesive 100 parts (weight) Antihalation agent 4 parts (weight) In this way, a laminate 11 composed of the support 1, the elastic foam layer 2 and the antihalation layer 3 was obtained.

Next, the UV reflectance from the antihalation layer 3 was measured in the same manner as in Example 1.
The average reflectance at 360 to 380 nm was 5.5%. When the ultraviolet transmittance of the laminate 11 was measured in the same manner as in Example 1, the average ultraviolet transmittance was 4.5%. Next, as a solid photocurable resin having a thickness of 1.7 mm, "AFPN-009 (trade name); manufactured by Asahi Kasei Corporation" was used, and the polyester film of the support having no protective film was peeled off. Then, the photocurable resin layer 4 is provided on the antihalation layer 3 of the laminate 11 by heating and pressure bonding at 50 ° C.

Thus, as shown in FIG. 1, the photocurable resin layer 4, the antihalation layer 3, the elastic foam layer 2
And a support 1 are sequentially laminated, a flexographic printing plate 1
0 was obtained. Next, plate making of the flexographic printing plate 10 was performed in the same manner as in Example 1 to form a relief image having a height of 0.9 mm. However, the back exposure time was 15 minutes and the image exposure time was 25 minutes.

Next, as a comparison, using the same method and raw materials as in Example 2, the ultraviolet reflectance from the antihalation layer 3 side was 14.0%, and the ultraviolet transmittance of the laminate 11 was 1
Flexographic printing plate of 1.0% (Comparative product 4), UV reflectance of 17.0%, UV transmittance of laminate 11 of 15.0
% Flexographic printing plate (Comparative product 5).

Next, a flexographic printing plate was produced in the same manner as in Example 2 except that the antihalation agent used in Example 2 was not used (Comparative product 6). The layer obtained by removing the antihalation agent from the antihalation layer 3 of Example 2 of the comparative product 6, the elastic foam layer 2 and the support 1
The UV reflectance from the layer from which the antihalation agent was removed from the antihalation layer 3 of Example 2 of the laminate of Example 2 was 54.0%, and the ultraviolet transmittance was 32.0%.

Next, the same exposure and development as in Example 2 were performed on Comparative Products 4 to 6 to form a relief image having a height of 0.9 mm. (Embodiment 3) FIG. 2 is a sectional view of a flexographic printing plate according to Embodiment 3 of the present invention. The antihalation layer 3 is provided on the elastic foam layer 2 by using the same method and the same material as in the second embodiment. Next, an adhesive dope excluding the antihalation agent similar to that of Comparative Example 3 was applied once on the antihalation layer 3 with a bar coater, and dried with a dryer at 60 ° C. for 2 hours. An adhesive layer 5 is provided.

In this way, a laminate 12 comprising the support 1, the elastic foam layer 2, the antihalation layer 3, and the adhesive layer 5 was obtained. Next, the UV reflectance from the adhesive layer 5 side was measured in the same manner as in Example 1, and it was 360 to 360.
The average reflectance at 380 nm was 7.0%. Also,
When the ultraviolet transmittance of the laminate 12 was measured in the same manner as in Example 1, the average ultraviolet transmittance was 4.1%.

Next, a photocurable resin layer 4 similar to that of the second embodiment is provided on the adhesive layer 5, and as shown in FIG. 2, the photocurable resin layer 4, the adhesive layer 5, the antihalation layer 3, A flexographic printing plate 20 was obtained in which the elastic foam layer 2 and the support 1 were sequentially laminated. Next, plate making of the flexographic printing plate 20 was performed in the same manner as in Example 2 to form a relief image having a height of 0.9 mm. (Embodiment 4) FIG. 3 is a sectional view of a flexographic printing plate according to Embodiment 4 of the present invention.

Using the adhesive dope except for the antihalation agent of Example 1 and using the same method and the same material as in Example 1, an adhesive containing no antihalation agent was formed on the elastic foam layer 2. After applying the dope once with a bar coater, the dope is dried with a drier at 60 ° C. for 2 hours to provide an adhesive layer 5. Next, the antihalation layer 3 having the same composition as in Example 2 is provided on the adhesive layer 5 in the same manner as in Example 2.

Thus, a laminate 13 comprising the support 1, the elastic foam layer 2, the adhesive layer 5, and the antihalation layer 3 was obtained. Next, when the ultraviolet reflectance from the antihalation layer 3 side was measured in the same manner as in Example 1, the average reflectance at 360 to 380 nm was 5.3%. When the ultraviolet transmittance of the laminate 13 was measured in the same manner as in Example 1, the average ultraviolet transmittance was 4.2%.
Met.

Next, Example 2 was applied on the antihalation layer 3.
3, a photocurable resin layer 4, an antihalation layer 3, an adhesive layer 5, an elastic foam layer 2, and a support 1 are sequentially laminated as shown in FIG. The printing plate 30 was obtained. Next, the flexographic printing plate 3
0 is performed in the same manner as in Example 2, and height = 0.
A 9 mm relief image was formed. (Embodiment 5) FIG. 4 is a sectional view of a flexographic printing plate according to Embodiment 5 of the present invention.

On the elastic foam layer 2 of the laminate 14 in which the elastic foam layer 2 used in Example 2 was bonded onto the support 1 used in Example 2, a composition having the following composition (weight ratio) The material is applied once with a bar coater. Next, this was charged into a dryer at 60 ° C. and left for 5 hours.
The composition is dried, and a photocurable resin layer 6 containing an antihalation agent is provided on the elastic foam layer 2. (Composition) Styrene butadiene block copolymer 60 parts (weight) Liquid polybutadiene 30 parts (weight) Dioctyl fumarate 8 parts (weight) Lauryl maleimide 2 parts (weight) 2,2-dimethoxy-2-phenylacetophenone 2 parts (weight) 2 2,6-di-tert-butyl cresol 0.2 parts (weight) Antihalation agent 2 parts (weight) Ethyl acetate / toluene / isopropyl alcohol 200 parts (weight)
"Tufprene A (trade name); manufactured by Asahi Kasei Kogyo", liquid polybutadiene "PB-2000 (trade name); manufactured by Nisso Corp.", antihalation agent "Diaresin BlueJ (trade name); Mitsubishi Chemical" Using ethyl acetate / toluene / isopropyl alcohol, ethyl acetate: toluene: isopropyl alcohol = 2: 1:
1 (capacity ratio).

In this way, as shown in FIG. 4, the support 1, the elastic foam layer 2, the antihalation layer 3, the photocurable resin layer 6 containing an antihalation agent, and the photocurable resin containing no antihalation agent A flexographic printing plate 40 composed of the resin layer 4 was obtained. When the ultraviolet reflectance from the photocurable resin layer 6 side containing the antihalation agent was measured in the same manner as in Example 1, the average reflectance at 360 to 380 nm was 8.5%. .

When the ultraviolet transmittance of the laminate 14 was measured in the same manner as in Example 1, the average ultraviolet transmittance was
3.0%. Next, plate making of the flexographic printing plate 40 was performed in the same manner as in Example 2, and height = 0.9 mm
Was formed. Next, using Examples 1 to 5 and Comparative Products 1 to 6, printing was performed using a known flexographic printing machine. The obtained printed matter was checked for fogging, for embedding of white characters, and for clearing of Gothic characters. (Image clarity) was investigated. In addition, evaluation was performed as shown below. (Evaluation method) Presence or absence of fogging Very good without fogging ◎ No fogging adversely affecting printed matter ○ Some fogging △ Fog is noticeable × White characters very clear ◎ Clear ○ Some occlusion △ Filling × Gothic characters are very clear ◎ Vivid ○ Some filling is observed △ Filling is noticeable × The results are shown in Table 1.

[0061]

[Table 1]

As can be seen from Table 1, Examples 1, 1A and 2 to 5 were free from fogging in the obtained printed matter, very clear in white characters and gothic characters, and were finished in high quality. From this, the flexographic printing plate according to the present invention,
It can reproduce minute and complicated original contents with high accuracy,
It was confirmed that it was possible to obtain higher-precision, higher-quality printed matter. Example 1A and other examples 1 to 5
When compared with the above, there was no great difference in the obtained printed matter, but Examples 1 to 5 had higher quality. This is the first embodiment
To 5 have an ultraviolet transmittance of the laminate 11 of 1% or more;
This is because effective back exposure was performed.

On the other hand, Comparative Examples 1 to 6 have an ultraviolet reflectance of 1
The closer to 0%, the better the results were obtained, but the quality of the printed matter obtained was significantly inferior to Examples 1-5. This is because, since the elastic foam layer 2 has fine bubbles, light that has passed through the photocurable resin layer is likely to be irregularly reflected by the elastic foam layer 2, even to a region that becomes a non-image portion of the photocurable resin layer. This is because the ultraviolet rays enter backward and are hardened to an unnecessary part. This phenomenon is more conspicuous when a large amount of light is required, such as forming a fine and highly accurate relief image. Therefore, in the case of a flexographic printing plate having no antihalation layer, it is considered that a blank image is buried or an undesired bulge occurs around a solid image, and the image is crushed or stained during printing.

In the flexographic printing plate according to the present invention, if the ultraviolet reflectance from the antihalation layer 3 side is 10% or less, in addition to the structures shown in Examples 1 to 5, as shown in FIG. And an adhesive layer 5A above and below the antihalation layer 3.
And 5B. At this time, it is preferable that the ultraviolet transmittance of the laminate 15 is 1% or more. Similarly, as shown in FIG. 6, an adhesive layer 5 may be interposed between the photocurable resin layer 6 containing the antihalation agent and the elastic foam layer 2. At this time, it is preferable that the ultraviolet transmittance of the laminate 16 is 1% or more.

In the first to fourth embodiments, the antihalation layer 3 is formed by applying and drying a composition in which an antihalation agent is dissolved in a desired solution in advance. However, the present invention is not limited to this. Further, the photocurable resin layer 6 containing the antihalation agent used in Example 5 was prepared by previously converting the antihalation agent into a liquid photocurable resin.
It may be provided directly or by dissolving with a solvent, and this may be provided by applying it on the elastic foam layer 2. It is composed of two layers of a photocurable resin added with an antihalation agent and a photocurable resin containing no antihalation agent. It can be provided by various methods, such as bonding it to the elastic foam layer 2.

The raw materials, the exposure method, the development method, and the like constituting each layer such as the support and the antihalation layer used in the present embodiment are merely examples, and the present invention is not limited thereto.

[0067]

As described above, according to the first aspect of the present invention, between the photocurable resin layer and the elastic foam layer,
Since the antihalation layer having an ultraviolet reflectance of 10% or less is provided, when the photocurable resin layer is subjected to image exposure, ultraviolet light reflected by the elastic foam layer or the support enters the photocurable resin layer again. Can be greatly suppressed.
As a result, fine and complicated original contents can be reproduced with high accuracy, and there is an effect that it is possible to obtain a printed matter with higher accuracy and higher quality.

According to the second aspect of the present invention, the laminate comprising the antihalation layer, the elastic foam layer and the support according to the first aspect has an ultraviolet transmittance of 1% or more. And effective back exposure.
As a result, there is an effect that more excellent relief image forming properties can be obtained. According to the third aspect of the invention, an adhesive layer is interposed between at least one of the photocurable resin layer and the antihalation layer, or between the antihalation layer and the elastic foam layer, In addition to the above-mentioned effects, there is an effect that even an antihalation layer having poor adhesion to the photocurable resin layer and adhesion (adhesion) to the elastic foam layer can be used.

Further, according to the invention of claim 4, the laminated body comprising the antihalation layer, the adhesive layer, the elastic foam layer and the support according to claim 3 has an ultraviolet transmittance of 1%.
As described above, an effective back exposure can be performed similarly to the flexographic printing plate according to the second aspect. For this reason, there is an effect that more excellent relief image forming properties can be obtained. According to the fifth aspect of the present invention, the photocurable resin layer contains an antihalation agent, and the photocurable resin layer itself has an ultraviolet reflectance of 10% or less. Ultraviolet rays incident on the resin layer can be absorbed by the antihalation agent by 90% or more. Therefore, after sensitizing the photocurable resin layer, the ultraviolet rays reaching the elastic foam layer and the support can be greatly reduced, so that the light reflected here and entering the photocurable resin layer is reduced. . As a result, fine and complicated original contents can be reproduced with high accuracy, and there is an effect that it is possible to obtain a printed matter with higher accuracy and higher quality.

According to the sixth aspect of the present invention, the ultraviolet light transmittance of the laminate comprising the photocurable resin layer, the elastic foam layer and the support containing the antihalation agent according to the fifth aspect is 1% or more. Therefore, in addition to the above-described effects, effective back exposure can be performed. As a result, there is an effect that more excellent relief image forming properties can be obtained. According to the seventh aspect of the present invention, the adhesive layer is interposed between the photocurable resin layer containing the antihalation agent according to the fifth or sixth aspect and the elastic foam layer. In addition to the effect, there is an effect that it is possible to use an antihalation layer having poor adhesion to the elastic foam layer.

Further, according to the invention of claim 8, the ultraviolet transmittance of the laminate comprising the photocurable resin layer, the adhesive layer, the elastic foam layer and the support containing the antihalation agent according to claim 7 is provided. Is set to 1% or more, effective back exposure can be performed in addition to the above effects. As a result, there is an effect that more excellent relief image forming properties can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional configuration diagram of a flexographic printing plate according to a first embodiment of the present invention.

FIG. 2 is a sectional configuration diagram of a flexographic printing plate according to a third embodiment of the present invention.

FIG. 3 is a sectional configuration diagram of a flexographic printing plate according to a fourth embodiment of the present invention.

FIG. 4 is a sectional configuration diagram of a flexographic printing plate according to a fifth embodiment of the present invention.

FIG. 5 is a sectional configuration view of a flexographic printing plate according to another embodiment of the present invention.

FIG. 6 is a sectional configuration diagram of a flexographic printing plate according to another embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 support 2 elastic foam layer 3 antihalation layer 4 photocurable resin layer 5 adhesive layer 6 photocurable resin layer containing antihalation agent 10 flexographic printing plate 11 laminate 12 laminate 13 laminate 14 laminate 15 laminate Body 16 Laminated body 20 Flexographic printing plate 30 Flexographic printing plate 40 Flexographic printing plate 50 Flexographic printing plate 60 Flexographic printing plate

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Koichi Kusakawa 1170-1 Ako, Komagane-shi, Nagano Japan Incorporated Company Inside (56) References JP-A-59-212298 (JP, A) JP-A-2-56554 (JP, A) JP-A-61-84289 (JP, A) JP-A-53-89501 (JP, A) JP-A-54-44902 (JP, A) JP-A-55-25046 (JP, A) ( 58) Field surveyed (Int.Cl. ⁷ , DB name) G03F 7/00 G03F 7/11

Claims (8)

(57) [Claims] 1. A flexographic printing method wherein a photocurable resin layer, an antihalation layer, an elastic foam layer and a support are sequentially laminated, and the antihalation layer has an ultraviolet reflectance of 10% or less. Board. 2. The flexographic printing plate according to claim 1, wherein the laminate comprising the antihalation layer, the elastic foam layer and the support has an ultraviolet transmittance of 1% or more. 3. Between the photocurable resin layer and the antihalation layer, between the antihalation layer and the elastic foam layer,
The flexographic printing plate according to claim 1, wherein an adhesive layer is interposed in at least one of the two. 4. The flexographic printing plate according to claim 3, wherein the laminate comprising the antihalation layer, the adhesive layer, the elastic foam layer and the support has an ultraviolet transmittance of 1% or more. 5. A photocurable resin layer, a photocurable resin layer containing an antihalation agent, an elastic foam layer and a support,
A flexographic printing plate, characterized in that the photocurable resin layer, which is sequentially laminated and contains the antihalation agent, has an ultraviolet reflectance of 10% or less. 6. The flexo according to claim 5, wherein the ultraviolet ray transmittance of the laminate comprising the photocurable resin layer containing the antihalation agent, the elastic foam layer and the support is 1% or more. Printing board. 7. The flexographic printing plate according to claim 5, wherein an adhesive layer is interposed between the photocurable resin layer containing the antihalation agent and the elastic foam layer. 8. The ultraviolet ray transmittance of a laminate comprising a photocurable resin layer containing an antihalation agent, an adhesive layer, an elastic foam layer and a support is 1% or more. 7. The flexographic printing plate according to 7.