Laminate for manufacturing water-developable flexographic printing original plate

Abstract

Also provided is a water-developable laminate for manufacturing a flexographic printing original plate in which the functional resin layer including a photosensitive resin layer having a strong surface adhesive force is additionally provided, and in which even when stored in an environment in which there is a large change in temperature and humidity, the laminate does not exhibit undesirable water-developable flexographic printing original plate production, and the water-developable flexographic printing original plate production does not exhibit high adhesion to the functional resin layer, even if stored in an environment in which there is a large change in temperature and humidity. It is also possible to appropriately peel off the coating film from the photosensitive resin layer. The present invention relates to a laminate for manufacturing a water-developable flexographic printing original plate in which a base film, a photosensitive resin layer, and a coating film are laminated in this order, and in which a release layer is provided between the photosensitive resin layer and the coating film so as to be in contact with the photosensitive resin layer and the coating film, and the release layer contains an addition-type silicone polymer and a curing catalyst.

Description

Technical Field

[0001] The present invention relates to a laminate for producing a high-resolution water-developable flexographic printing plate, which is formed by sequentially laminating a base film, a photosensitive resin layer, and a cover film, wherein the cover film can be appropriately peeled from the photosensitive resin layer. Background Art

[0002] like Figure 1 As shown in FIG, a conventional flexographic printing plate is composed of a laminated body in which a base film, a photosensitive resin layer, a mask layer, and a cover film are sequentially stacked. The cover film is used to prevent the mask layer from being contaminated or damaged during the storage period from the time the flexographic printing plate is manufactured until it is actually used to make printing plates. Therefore, the cover film is removed when it is used. Figure 2 As shown, an infrared laser is used to draw a desired pattern on the mask layer, and then ultraviolet rays are irradiated from the mask layer side to cure the photosensitive resin layer according to the pattern of the mask layer. Finally, the flexible printing plate is obtained by developing with a developer such as water.

[0003] In this conventional method, a release layer (not shown) is provided between the film and the mask layer to facilitate proper removal of the film. The release layer may be made of an amino resin (see Patent Document 1) or an acrylic resin (see Patent Document 2) that can form a uniform layer between the film and the mask layer.

[0004] On the other hand, in recent years, the demand for higher-resolution flexographic printing plates has been increasing. In the conventional flexographic printing plates mentioned above, the resolution of the mask layer is limited and needs to be improved. In response to this demand, the following method has been proposed: the mask layer is separated from the photosensitive resin layer, and the mask layer is provided as another laminated body on the polarizing film. After the mask layer in the other laminated body is patterned, it is laminated on the photosensitive resin layer (see Patent Document 3). Specifically, Figure 3 As shown, a laminate 1 in which a base film, a photosensitive resin layer, and a coating are laminated in sequence and a laminate 2 in which a mask layer and a polarizing film are laminated in sequence are prepared. Figure 4 As shown, a desired pattern is drawn on the mask layer of the laminate 2 using a high-resolution laser, and the laminate 2 is stacked on the photosensitive resin layer of the laminate 1 with the coating removed so that the drawn mask layer side faces the photosensitive resin layer to form an integral body, and then ultraviolet rays are irradiated from the polarizing film side of the laminate 2 to cure the photosensitive resin layer according to the pattern of the drawn mask layer, and finally developed to obtain a flexible printing plate.

[0005] In addition, as a mask layer separated from the photosensitive resin layer, a method of using only a mask layer in which an image such as a high-resolution negative film is formed or a thermal mask layer in which an image is formed by laser ablation is known other than the method of Patent Document 3 described above; a method of using a product in which other photosensitive resin layers having different resin hardnesses from the photosensitive resin layer, other photosensitive resin layers having different concentrations of photopolymerizable unsaturated groups or different concentrations of photoinitiators from the resin of the photosensitive resin layer, or other photosensitive resin layers having different surface energies from the resin of the photosensitive resin layer are further laminated on these mask layers. In the present application, these mask layers or other photosensitive resin layers are collectively referred to as "functional resin layers".

[0006] In such a method in which the functional resin layer is additionally provided, unlike the usual method, a protective film for storage is provided on the photosensitive resin layer of the laminate 1. In the case where storage is performed in an environment in which temperature and humidity change little, peeling of the protective film from the photosensitive resin layer of the laminate 1 is basically almost not a problem. Therefore, in the method in which the existing functional resin layer is additionally provided, a release layer is not provided.

[0007] However, the photosensitive resin layer has a tendency to increase in surface adhesion in the case where storage is performed in an environment in which temperature and humidity change much because the photosensitive resin layer contains liquid components such as crosslinking monomers or low-Tg polymers. In particular, in recent years, as environmental concerns have increased, the demand for water-developable flexible printing precursors that do not use organic solvents but use water as a developing solution has increased, but when the photosensitive resin layer is made into a high water developability that is hydrophilic in order to make the flexible printing precursor water-developable, the photosensitive resin layer has a tendency to further increase in surface adhesion. Therefore, in the laminate used in the production of a water-developable flexible printing precursor of the method in which the functional resin layer is additionally provided, during storage in an environment in which temperature and humidity change much, the photosensitive resin layer of the laminate 1 firmly adheres to the protective film, which can cause a problem that peeling of the protective film from the photosensitive resin layer cannot be properly performed. Prior Art Documents Patent Documents

[0008] Patent Document 1: Japanese Patent No. 5903854 Patent Document 2: Japanese Patent No. 6135040 Patent Document 3: Japanese Patent Application Laid-Open No. 2010-534345 SUMMARY PROBLEMS TO BE SOLVED BY THE INVENTION

[0009] The present application has been made to solve the problems of the prior art, and has an object to provide a flexible printing original plate manufacturing laminate which is a water-developable flexible printing original plate manufacturing laminate of the functional resin layer type in which a photosensitive resin layer having strong surface adhesion is provided separately, and in which peeling of a cover film from the photosensitive resin layer can be properly performed even when stored in an environment in which temperature and humidity greatly change. Technical solution to the problem

[0010] The present inventors first studied providing a release layer between the photosensitive resin layer and the cover film in order to achieve the object. Next, as the release layer, when a release layer composed of an amino resin (Patent Document 3) or an acrylic resin (Patent Document 4) used as a release layer in the general type described above was used, it was found as a result that the surface adhesion of the water-developable photosensitive resin layer was too strong, and thus peeling of the cover film could not be properly performed even when such a release layer was provided. Thus, the present inventors found that peeling of the cover film could be properly performed even for a water-developable photosensitive resin layer when a release layer containing an addition-type silicone polymer and a curing catalyst, which could not be used as a release layer in the general type, was used, and thus completed the present application.

[0011] That is, the present application is an application completed based on the above findings, and has the following (1) to (7). (1) A flexible printing original plate manufacturing laminate characterized by being a water-developable flexible printing original plate manufacturing laminate in which a base film, a photosensitive resin layer, and a cover film are sequentially laminated, in which a release layer is provided in contact with both the photosensitive resin layer and the cover film between the photosensitive resin layer and the cover film, and the release layer contains an addition-type silicone polymer and a curing catalyst. (2) The flexible printing original plate manufacturing laminate according to (1), characterized in that the addition-type silicone polymer contains an alkenyl group at a terminal and / or a side chain thereof. (3) The flexible printing original plate manufacturing laminate according to (1), characterized in that the curing catalyst is a hydrosilylation catalyst. (4) The flexible printing original plate manufacturing laminate according to any one of (1) to (3), characterized in that the surface roughness (Ra) of the surface of the release layer in contact with the photosensitive resin layer is 0.01 to 0.2 μm. (5) The flexible printing original plate manufacturing laminate according to any one of (1) to (3), characterized in that the peeling strength when the cover film is pulled along 90° at a speed of 1000 mm / minute from the flexible printing original plate manufacturing laminate together with the release layer is 2.0 g / 20 mm to 50.0 g / 20 mm. (6) The flexible printing plate precursor manufacturing laminate according to any one of (1) to (3), characterized in that the photosensitive resin layer contains a conjugated diene-based polymer, a photopolymerizable unsaturated compound, and a photopolymerization initiator. (7) A manufacturing method of a flexible printing plate, characterized by peeling off the cover film together with the release layer from the flexible printing plate precursor manufacturing laminate according to any one of (1) to (3), and then directly laminating a resin layer face of a functional resin layer on the photosensitive resin layer, thereby manufacturing the flexible printing plate. Effects of Invention

[0012] The flexible printing plate precursor manufacturing laminate of the present application is excellent in release property and storage stability of the release layer even when stored in an environment where temperature and humidity greatly change, and peeling off the cover film from the photosensitive resin layer can be properly performed. Therefore, the flexible printing plate precursor manufacturing laminate of the present application can be combined with a functional resin layer, and is suitable for stably manufacturing a high-resolution water-developable flexible printing plate. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 An example showing the layer constitution of a laminate which constitutes a flexible printing plate precursor used in a usual manner. Figure 2 An example showing a manufacturing process of a flexible printing plate manufactured using the laminate of Figure 1 . Figure 3 An example showing the layer constitution of a flexible printing plate precursor manufacturing laminate used in a manner that a functional resin layer is additionally provided. Figure 4 An example showing a manufacturing process of a flexible printing plate manufactured using the laminate of Figure 3 . Figure 5 An example showing the layer constitution of a flexible printing plate precursor manufacturing laminate of the present application. DETAILED DESCRIPTION

[0014] The flexible printing plate precursor manufacturing laminate of the present application has the same effect as the laminate 1 for manufacturing a flexible printing plate precursor in a manner that a functional resin layer is additionally provided (refer to Figure 3 ), and specifically, as shown on the upper side of Figure 5 , characterized in that a release layer is provided in contact with both a photosensitive resin layer and a cover film between the photosensitive resin layer and the cover film in a laminate in which a base film, the photosensitive resin layer, and the cover film are sequentially laminated. Further, it is characterized in that the release layer contains an addition-type silicone polymer and a curing catalyst.

[0015] As the base film of the laminate of the present application, a material which is flexible and excellent in dimensional stability, such as a polyethylene terephthalate film, a polyethylene naphthalate film, a polybutylene terephthalate film, or a polycarbonate film, etc., can be used. Among these, a polyethylene terephthalate film which is excellent in dimensional stability and has high viscoelasticity is particularly preferable. The thickness of the base film is preferably 50 to 350 μm, and more preferably 100 to 350 μm, from the viewpoint of mechanical properties, shape stability, or handling properties of the printing plate, etc. In addition, if necessary, a publicly known adhesive layer can be provided between the base film and the photosensitive resin layer in order to improve adhesion therebetween.

[0016] The photosensitive resin layer of the laminate of the present application is not particularly limited as long as it is water-developable, and for example, a photosensitive resin layer containing (a) a conjugated diene-based polymer, (b) a photopolymerizable unsaturated compound, and (c) a photopolymerization initiator can be used. In the present application, in order to perform the developing step with an aqueous developer, the photosensitive resin layer further preferably contains (d) a hydrophilic compound. As the photosensitive resin composition containing the components of (a) to (d), a photosensitive resin composition described in Japanese Patent Application Publication No. 2005-148588, for example, can be appropriately used.

[0017] As the (a) conjugated diene-based polymer, a conjugated diene-based polymer obtained from a water-dispersed latex is preferable, and a publicly known synthetic high-molecular compound used in a flexographic printing plate precursor can be used. As the water-dispersed latex, a latex containing one or more selected from the group consisting of a butadiene latex, an acrylonitrile-butadiene latex, a styrene-butadiene latex, and an isoprene latex is preferable, and a latex containing both a butadiene latex and an acrylonitrile-butadiene latex is further preferable from the viewpoint of water developability. In the case where a conjugated diene-based polymer obtained from a water-dispersed latex is used, a conjugated diene-based polymer which is intramolecularly crosslinked is preferable. In addition, it can be modified with (meth)acrylic acid or a carboxyl group, silicone, fluorine, etc. as desired. Note that since a variety of synthetic latexes and natural latexes are commercially available, an appropriate product can be selected therefrom.

[0018] As the (b) photopolymerizable unsaturated compound, a publicly known compound used in a flexographic printing plate precursor can be used, but a photopolymerizable monomer such as a (meth)acrylate having a number average molecular weight of 100 or more and 600 or less is preferable, and further, a photopolymerizable oligomer having a number average molecular weight of more than 600 and 20,000 or less in addition to the above is preferable. The photopolymerizable oligomer is not particularly limited as long as it has a number average molecular weight in the range of more than 600 and 20,000 or less, and for example, a product in which a (meth)acrylate group is imparted to a butadiene oligomer or an isoprene oligomer, a urethane (meth)acrylate can be cited.

[0019] (c) The photopolymerization initiator preferably has a function of causing self-decomposition by light absorption or generating radicals by hydrogen abstraction. As such a photopolymerization initiator, for example, benzoin alkyl ethers, benzophenones, anthraquinones, benzils, phenylethanones, diacetyls, and the like can be mentioned. For example, benzophenone, chlorobenzophenone, benzoin, phenylethanone, benzil, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzil dimethyl ketal, benzil diethyl ketal, benzil diisopropyl ketal, anthraquinone, 2-ethylanthraquinone, 2-methylanthraquinone, 2-allyl anthraquinone, 2-chloroanthraquinone, thioxanthone, 2-chlorothioxanthone, 1-hydroxycyclohexane-1-yl phenyl ketone, and the like can be mentioned. In order to use the light energy of the post-exposure and the exposure using a germicidal lamp without waste, the photopolymerization initiator is preferably a compound composed of both benzil alkyl ketal and benzophenone.

[0020] (d) The hydrophilic compound is used in order to improve water developability, and for example, a compound having a hydrophilic group such as a carboxylic acid, a carboxylic acid salt, a sulfonic acid, a sulfonic acid salt, a hydroxyl group, an amino group, a phosphoric acid group, an oxirane, an oxetane, or the like in the molecule, which is water-soluble or water-dispersible by itself. As the hydrophilic compound, a low-molecular compound, an oligomer, a high-molecular compound, or a hydrophilic polymer can also be used. As a specific hydrophilic compound, a polyhydric alcohol, a polybasic carboxylic acid, an ester compound of a polybasic carboxylic acid, an acrylic polymer, a polyalkylene glycol-modified polymer, a urethane polymer, a polyamide polymer, a polyester polymer, and the like can be mentioned. In the case where a hydrophilic copolymer is used, a polymer particle formed by internal crosslinking including a unit derived from a hydrophilic unsaturated monomer is preferred. As such a polymer particle, for example, a water-dispersible latex formed by dispersing in water a polymer particle obtained by emulsion polymerization of a hydrophilic unsaturated monomer, and, as necessary, other monomers copolymerizable therewith, as a dispersoid can be mentioned.

[0021] In the photosensitive resin layer of the laminate of the present application, in addition to the components (a) to (d) described above, other components such as a plasticizer, an ultraviolet absorber, a thermal polymerization inhibitor (stabilizer), a surface tension adjusting agent, a thermoplastic resin elastomer, a solid rubber, a dye, a pigment, an antifoaming agent, an anti-aggregation agent, and the like can be appropriately contained within a range not impeding the effects of the present application for the purpose of improving various characteristics.

[0022] As the cover film of the laminate of the present application, a material which is flexible and excellent in dimensional stability is preferred, and a thermoplastic resin support such as a polyethylene terephthalate film, a polyethylene naphthalate film, a polybutylene terephthalate film, and the like can be mentioned. Among these, a polyethylene terephthalate film which is excellent in dimensional stability and has high viscoelasticity is particularly preferred. The thickness of the cover film is preferably 50 to 350 μm, and more preferably 70 to 250 μm, from the viewpoint of mechanical properties, shape stability, or handleability at the time of printing plate making, and the like.

[0023] The release layer of the laminate of the present application contains an addition type silicone polymer, a curing catalyst as a curing agent. As the addition type silicone polymer, a silicone polymer having an alkenyl group at the terminal and / or side chain is preferable. As the alkenyl group, a vinyl group, an allyl group, a propenyl group, a hexenyl group, an octenyl group, a decenyl group, etc. are exemplified, and from the viewpoint of curability, a vinyl group, an allyl group, a hexenyl group are preferable. As commercially available examples of the addition type silicone polymer, KS-3650, KS-774, KS-775, KS-778, KS-779H, KS-843, KS-847, KS-847H, KS-847T, KS-838, KS-856, X-62-2422, X-62-2461, X62-2829, X-62-1387, X-62-5039, X-62-5040, KNS-3051, X-62-1496, KNS320A, KNS316, X-62-1574A / B, X-62-7052, X-62-7028A / B, X-62-7619, X-62-7213 manufactured by Shin-Etsu Chemical Co., Ltd.; SD7220, SD7226, SD7223, SD7292, SD7333, SRX211, SRX357, SRX345, LTC750A, LTC760A, LTC851, LTC759, LTC755, LTC761, LTC856, LTC310, LTC303E, LTC300B, LTC350G manufactured by Dow Corning Toray Co., Ltd. are exemplified.

[0024] The addition type silicone polymer having an alkenyl group can also contain a hydrosilyl group (SiH) within the molecule. As commercially available examples, KS-3650, KS-843, KS-847, KS-847H, KS-847T, X62-2829, KS838 manufactured by Shin-Etsu Chemical Co., Ltd.; SD7333, SRX357, SRX345, LTC310, LTC303E, LTC300B, LTC350G, LTC750A, LTC851, LTC759, LTC755, LTC761, LTC856 manufactured by Dow Corning Toray Co., Ltd. are exemplified.

[0025] These addition type silicone polymers can be used alone or in combination of two or more. Furthermore, an addition type silicone polymer not having an alkenyl group can also be contained within a range not deteriorating the performance. In this case, a polymer of high molecular weight which is less likely to cause bleeding is preferable.

[0026] The release layer preferably contains a polyorganosiloxane compound having a hydrogen silyl group (crosslinking agent) because it contains an addition-type silicone polymer. By containing the polyorganosiloxane compound (crosslinking agent), an addition reaction proceeds easily, and as a result, excellent release properties can be imparted. As a specific compound, 1,3,5,7-tetramethylcyclotetrasiloxane can be given.

[0027] The curing catalyst has the effect of forming a crosslinked structure of the silicone polymer and inhibiting the silicone polymer from coagulating on the surface of the release layer or in the release layer. As the curing catalyst, a hydrosilylation catalyst is preferred. As the hydrosilylation catalyst, there is no particular limitation as long as it is catalytically active for a hydrosilylation reaction, and for example, a catalyst in which solid platinum is supported on a carrier of platinum monomer, alumina, silica, carbon black, or the like, chloroplatinic acid, a complex of chloroplatinic acid with an alcohol, an aldehyde, a ketone, or the like, a platinum-olefin complex, a platinum-vinylsiloxane complex, a platinum-phosphine complex, a platinum-phosphite complex, or the like can be given. Further, as examples of catalysts other than platinum compounds, RhCl(PPh)3, RhCl3, RhAl203, RuCl3, IrCl3, FeCl3, AlCl3, PdCl2-2H2O, NiCl2, TiCl4, or the like can be given. Of these, from the viewpoint of release effect, a platinum catalyst of a catalyst in which solid platinum is supported on a carrier of platinum monomer, alumina, silica, carbon black, a platinum-olefin complex, a platinum-vinylsiloxane complex, a platinum-phosphine complex, a platinum-phosphite complex is preferred. Further preferred is a platinum complex of a platinum-vinylsiloxane complex or a platinum-olefin complex. Further, these catalysts can be used alone or in combination with two or more.

[0028] A specific platinum catalyst can be produced by a publicly known production method or purchased as a commercial product. A platinum-vinylsiloxane complex can be produced by a conventional method such as the production method disclosed in Japanese Patent Application Publication No. S47-23679 or Japanese Patent Application Publication No. H11-128748, or the like. Further, as commercial products, PL-3 or CAT-PL-50T manufactured by Shin-Etsu Chemical Co., Ltd., SRX212 manufactured by Dow Corning Toray Co., Ltd. can be given.

[0029] The amount of the curing catalyst in the release layer is preferably 0.01 to 5.0 parts by mass, more preferably 0.015 to 4.0 parts by mass, and further preferably 0.02 to 3.0 parts by mass, relative to 100 parts by mass of the addition-type silicone polymer. When the amount of the curing catalyst is small, the curing reaction does not sufficiently proceed, and the amount of the remaining Si-H group becomes large, so the release force becomes high. In addition, unreacted organopolysiloxane becomes a migration component, so the unreacted organopolysiloxane migrates to the photosensitive resin layer to which the functional resin is attached, and it is possible that the adhesion strength is reduced. Further, in the case where the functional resin layer is provided on the photosensitive resin layer, it is easy to cause scattering of the irradiated ultraviolet rays, so the image reproducibility is reduced, or the functional resin layer is peeled off due to poor adhesion between the photosensitive resin layer and the functional resin layer.

[0030] The release layer can contain a resin other than the addition-type silicone polymer as long as the release property is not impaired. For example, an acrylic resin, a photocurable resin having a photopolymerizable unsaturated group, a phenol resin, an epoxy resin, a melamine resin, or the like can be contained. By containing a resin other than the addition-type silicone polymer, it is possible to easily control the adhesion to the coating film or the release strength of the release layer.

[0031] The release layer can contain a release strength adjusting agent such as a silane coupling agent, a crosslinking agent, an adhesion promoter, a plasticizer, a softening agent, or the like in addition to the addition-type silicone polymer or the curing catalyst for the purpose of adjusting the release strength. Further, other additives can be incorporated within a range that does not impair the release property. For example, a deterioration preventing agent, a filler, a coloring agent, an antioxidant, a surfactant, an antistatic agent, or the like can be incorporated.

[0032] The release layer can be produced by applying a release layer-forming coating liquid to the coating film. As the application method, a reverse gravure coating method, a direct gravure coating method, a roll coating method, a die coating method, a bar coating method, a curtain coating method, or the like can be used. The release layer-forming coating liquid can be prepared, for example, by mixing the addition-type silicone polymer and the curing catalyst with a solvent. As the solvent, a ketone such as methyl ethyl ketone, an aromatic compound such as toluene, or the like can be used. These can be used alone or in combination of two or more.

[0033] The thickness of the release layer is preferably 0.01 μm to 2 μm, more preferably 0.03 μm to 1.5 μm, and further preferably 0.05 μm to 1 μm. When the thickness is too small, it is possible that the release strength cannot be sufficiently adjusted. On the other hand, when the thickness is too large, it is easy to cause streaks at the time of production.

[0034] The surface roughness (Ra) of the surface of the release layer which contacts the photosensitive resin layer is preferably 0.01 to 0.2 μm. By setting the surface roughness to this range, the surface roughness of the photosensitive resin layer can be reduced. As a result thereof, in the adhesion to the functional resin layer, the mixing of air bubbles or the generation of wrinkles can be prevented, and the generation of defects on the laminated surface with the functional resin layer can be reduced. The surface roughness of the release layer of the present application which contacts the photosensitive resin layer refers to the surface roughness of the release layer which contacts the photosensitive resin layer.

[0035] The laminate of the present application preferably has a peeling strength of 2.0 g / 20 mm to 50.0 g / 20 mm when the film and the release layer are pulled at 90° at a speed of 1000 mm / min. Further preferably, the peeling strength is 3.0 g / 20 mm to 20.0 g / 20 mm. By setting the peeling strength to this range, the release layer can be peeled from the photosensitive resin layer appropriately and uniformly.

[0036] In addition, the peeling strength is preferably low in temperature dependence of the measured value (10°C measured value - 30°C measured value). By reducing the temperature dependence of the measured value, the variation in the peeling strength due to temperature can be reduced. Specifically, the difference between the measured values at each of 10°C and 30°C (10°C measured value - 30°C measured value) of the peeling strength is preferably 30.0 g / 20 mm or less, and more preferably 10.0 g / 20 mm or less.

[0037] Next, a method for manufacturing a flexographic printing master from the laminate of the present application will be described. Figure 5 The laminate of the present application shown on the upper side of FIG. 1 is removed by peeling the film and the release layer together, and the photosensitive resin layer is directly laminated on the support film Figure 5 The resin layer of the functional resin layer shown on the lower side of FIG. 1 is laminated on the photosensitive resin layer, and thus a flexographic printing master for manufacturing a printing plate can be efficiently manufactured. As the functional resin layer, a resin layer conventionally known in the field can be used, but for example, a mask layer on which an image such as a high-resolution negative film is formed, a thermal mask layer on which an image is formed by laser ablation, another photosensitive resin layer having a different resin hardness from the photosensitive resin layer, another photosensitive resin layer having a different concentration of a photopolymerizable unsaturated group or a photoinitiator from the photosensitive resin layer, another photosensitive resin layer having a different surface energy from the photosensitive resin layer, and the like can be given. The functional resin layer can also be laminated on a support film. The support film also functions as an oxygen barrier layer. As the functional resin layer, particularly in the case where a high-resolution negative film is used, the effects of the present application are easily obtained. In the present application, the negative film is a mask layer on which an image for lamination on the photosensitive resin layer is formed, and generally refers to a negative film on which a mask layer is provided on a support film.

[0038] In the present application, a high-resolution negative film refers to a film capable of reproducing 1% to 95% with 200 lines of dots. As a high-resolution negative film, a negative film for forming a mask image by laser is preferred. As a negative film for forming a mask image by laser, a negative film in which the ultraviolet transmittance of a thermosensitive mask layer is locally increased by a change in color development or light transparency accompanying heating by laser is preferred because it enables the formation of finer halftone dots. As described above, the support film in the negative film also functions as an oxygen barrier layer for reducing the effects of oxygen. In addition, in order to reduce ultraviolet scattering caused by the support film, a polarizing film can also be used as the support film, and an ultraviolet absorber or a dye having ultraviolet absorbency can also be contained in the support film. A high-resolution negative film can be manufactured using a commercially available product or by a known method. As a commercially available resolution negative film, DITR4401 film manufactured by Kodak, and the like can be given. As a known high-resolution negative film, a mask layer in which the refractive index of the support film is controlled (Patent No. 5368432), a thermosensitive mask layer provided with a barrier layer containing an infrared absorbing compound on the support film (Patent No. 6449854), a mask layer in which the support of the mask layer is peelably removed (Patent No. 4971311), and the like can be given.

[0039] As a specific printing master obtained from the laminate of the present application, a flexible printing master in which a mask layer in which an image such as a high-resolution negative film is formed on a photosensitive resin layer or a thermosensitive mask layer in which an image is formed by laser ablation is provided as a functional resin layer; a flexible printing master in which a photosensitive resin layer having a resin hardness different from that of the photosensitive resin layer, a photosensitive resin layer having a concentration of a photopolymerizable unsaturated group or a concentration of a photoinitiator different from those of the resin of the photosensitive resin layer, or a photosensitive resin layer having a surface energy different from that of the resin of the photosensitive resin layer is provided as a functional resin layer. Specifically, the laminate of the present application can be used to manufacture a printing plate by directly laminating a resin layer surface of a functional resin layer on a photosensitive resin layer to manufacture a flexible printing master, and in the case where the functional resin layer is another photosensitive resin layer, a mask layer is provided thereon thereafter, and a printing plate is manufactured by a plate-making process such as usual ultraviolet exposure, development, drying, and post-exposure. The functional resin layer can be removed in the plate-making process, or can remain on the photosensitive resin layer as a resin layer without being removed. Example

[0040] Hereinafter, the present application will be specifically described by examples, but the present application is not limited to these examples.

[0041] [Example 1] Manufacture of release film A release layer coating liquid was prepared by diluting 99 parts by mass of a vinyl group-containing addition-type silicone polymer (KS-847T, manufactured by Shin-Etsu Chemical Co., Ltd.) and 1 part by mass of a curing catalyst (CAT-PL-50T, manufactured by Shin-Etsu Chemical Co., Ltd.) with a methyl ethyl ketone / toluene mixed solvent (mixed mass ratio 1:1) to a concentration of 2% by mass. Next, the above-mentioned coating liquid was applied to a polyethylene terephthalate film (manufactured by Toyobo Co., Ltd.) having a thickness of 100 μm as a coating film using a wire bar, and the coating layer thickness after drying was made to be 0.1 μm. The coating film was dried and cured at 120°C for 40 seconds to obtain a release film composed of a release layer and a coating film.

[0042] Manufacture of photosensitive resin composition A dope was prepared by mixing (a) 39 parts by mass of a butadiene latex (Nipol LX111NF, non-volatile content 55% by mass, manufactured by Zeon Corporation) as a conjugated diene polymer obtained from a water dispersion latex, 6 parts by mass of a carboxyl-modified acrylonitrile-butadiene latex (Nipol SX1503, non-volatile content 42% by mass, manufactured by Zeon Corporation), (b) 17 parts by mass of an oligomeric butadiene acrylate (ABU-4, manufactured by Gohsen Co., Ltd.) as a photopolymerizable unsaturated compound, 6.4 parts by mass of trimethylolpropane trimethacrylate (LIGHT ESTER TMP, manufactured by Gohsen Co., Ltd.), 25 parts by mass of the above-mentioned metal chloride of a diene polymer having a carboxyl group at the terminal, (c) 1 part by mass of a photopolymerization initiator (Irgacure 651), (d) 5.5 parts by mass of a butadiene oligomer (LBR-352, manufactured by Kuraray Co., Ltd.), and 0.1 parts by mass of a heat stabilizer (4-methoxy phenol aldehyde) in a container. The dope was charged into a pressure kneader, and tetrahydrofuran and water were removed under reduced pressure at 80°C to obtain a photosensitive resin composition.

[0043] Manufacture of a laminate for a flexible printing original plate A photosensitive resin layer was formed by disposing the above-mentioned photosensitive resin composition on a polyethylene terephthalate base film (support) (Toyobo Co., Ltd., E5000, thickness 125 μm) coated with a copolymerized polyester-based adhesive. Next, the above-mentioned release film was laminated thereon in such a manner that the release layer faces the photosensitive resin layer. They were pressure-bonded at 100°C using a hot press to obtain a laminate for a flexible printing original plate. The total thickness of the laminate was 1.14 mm.

[0044] Manufacture of functional resin layer As a functional resin layer, a high-resolution negative film (a mask layer in which the ultraviolet transmittance is locally increased by a change in color development or light transparency accompanying heating by a laser) was produced. Specifically, using a TRENDSETTER imager (manufactured by Kodak) capable of heat-sensitive imaging with a square spot (SQUARE spot) of an 830 nm infrared laser diode, a negative film was produced from a DITR4401 film (manufactured by Kodak), which is a high-resolution negative film corresponding to a printing resolution of up to 200 lines, provided on a support film having a thickness of 100 μm with dots of 200 lines at 1 to 95%, a minimum independent dot diameter of 100 μm, a minimum raised character of 1 pt, a minimum hollow character of 1 pt, and a solid color image.

[0045] Manufacture of flexographic printing original plate and flexographic printing plate A flexible printing original plate was obtained by peeling the cover film together with the release layer from the flexible printing original plate manufacturing laminate and laminating the resin layer face (the face opposite to the support film) of the functional resin layer on the photosensitive resin layer of the flexible printing original plate manufacturing laminate. The obtained printing original plate was produced into a printing plate by the following method. First, back exposure was performed for 10 seconds from the support (base film of polyethylene terephthalate) side of the printing original plate. Subsequently, main exposure was performed for 7 minutes. Then, development was performed in a developing machine (Stuck System, 1% aqueous washing soap solution, 40°C) manufactured by A&V Co., Ltd. for 8 minutes, and water droplets on the plate surface were removed with a water removal bar. Then, drying was performed in a drying machine at 60°C for 10 minutes. Subsequently, post exposure was performed for 7 minutes, and finally, irradiation was performed with a germicidal lamp for 5 minutes, to obtain a flexible printing plate.

[0046] [Example 2] In the production of the coating solution for the release layer, a release film was produced in the same manner as in Example 1, except that the addition-type vinyl group-containing silicone polymer (KS-847T, manufactured by Shin-Etsu Chemical) was changed to a 30% by mass toluene solution of an addition-type hexenyl group-containing silicone polymer (KS-774 manufactured by Shin-Etsu Chemical). Next, using the obtained release film, a flexible printing original plate manufacturing laminate was produced in the same manner as in Example 1.

[0047] [Example 3] In the production of the coating solution for the release layer, a release film was produced in the same manner as in Example 1, except that the addition-type vinyl group-containing silicone polymer (KS-847T, manufactured by Shin-Etsu Chemical) was changed to an addition-type hexenyl group-containing silicone polymer (LTC750A manufactured by DOW CORNING TORAY SILICONE CO., LTD.). Next, using the obtained release film, a flexible printing original plate manufacturing laminate was produced in the same manner as in Example 1.

[0048] [Example 4] In the production of the coating liquid for the release layer, the solidification catalyst (CAT-PL-50T, manufactured by Shin-Etsu Chemical) was changed to a solidification catalyst (PL-3, manufactured by Shin-Etsu Chemical), and a release film was produced in the same manner as in Example 1. Next, using the obtained release film, a flexible printing original plate manufacturing stack was produced in the same manner as in Example 1.

[0049] [Example 5] In the production of the coating liquid for the release layer, the solidification catalyst (CAT-PL-50T, manufactured by Shin-Etsu Chemical) was changed to a solidification catalyst (SRX212, manufactured by Dow Corning Toray Co., Ltd.), and a release film was produced in the same manner as in Example 1. Next, using the obtained release film, a flexible printing original plate manufacturing stack was produced in the same manner as in Example 1.

[0050] [Example 6] In the production of the coating liquid for the release layer, in addition to the addition type silicone polymer and the solidification catalyst, a cross-linking agent (1,3,5,7-tetramethylcyclotetrasiloxane) was added in the proportions shown in Table 1, and a release film was produced in the same manner as in Example 1. Next, using the obtained release film, a flexible printing original plate manufacturing stack was produced in the same manner as in Example 1.

[0051] [Example 7] In the production of the coating liquid for the release layer, the addition type silicone polymer containing a vinyl group (KS-847T, manufactured by Shin-Etsu Chemical) was changed to an addition type silicone polymer containing a vinyl group (KS-847T, manufactured by Shin-Etsu Chemical) and an addition type silicone polymer containing a hexenyl group (LTC750A manufactured by Dow Corning Toray Co., Ltd.) in a mass ratio of 70 / 30 of the solid content components, and a release film was produced in the same manner as in Example 1. Next, using the obtained release film, a flexible printing original plate manufacturing stack was produced in the same manner as in Example 1.

[0052] [Example 8] A release film was produced in the same manner as in Example 1, except that the addition proportion of the solidification catalyst was reduced as shown in Table 1. Next, using the obtained release film, a flexible printing original plate manufacturing stack was produced in the same manner as in Example 1.

[0053] [Comparative Example 1] A flexible printing original plate manufacturing stack was produced in the same manner as in Example 1, except that a film was used in which no release layer was provided.

[0054] [Comparative Example 2] A release film was formed in the same manner as in Example 1, except that the addition type silicone resin containing a vinyl group (KS-847T, manufactured by Shin-Etsu Chemical Co., Ltd.) was changed to a non-addition type silicone polymer (X-52-8046, manufactured by Shin-Etsu Chemical Co., Ltd.) in the preparation of the coating solution for the release layer. Using the obtained release film, a flexible printing original plate manufacturing stack was manufactured in the same manner as in Example 1.

[0055] [Comparative Example 3] A release film containing an amino resin was manufactured according to the method for manufacturing a release force adjusting layer described in Patent No. 5903854. Subsequently, using the obtained release film, a flexible printing original plate manufacturing stack was manufactured in the same manner as in Example 1.

[0056] [Comparative Example 4] An acrylic resin release film was manufactured according to the method for manufacturing a release force adjusting layer described in Patent No. 6135040. Subsequently, using the obtained release film, a flexible printing original plate manufacturing stack was manufactured in the same manner as in Example 1.

[0057] [Comparative Example 5] A release film was formed in the same manner as in Example 1, except that no curing catalyst (CAT-PL-50T, manufactured by Shin-Etsu Chemical Co., Ltd.) was added to the coating solution for the release layer in Example 1. Subsequently, using the obtained release film, a flexible printing original plate manufacturing stack was manufactured in the same manner as in Example 1.

[0058] [Reference Example 1] As the photosensitive resin layer, a photosensitive resin layer of a type that is not water-developable and is developed by a solvent was used. First, a kneader was used to knead 100 parts by mass of a block copolymer (TUFPRENE 912, manufactured by Asahi Kasei Corporation), 10 parts by mass of a liquid polybutadiene (NISSO-PB-B-1000, manufactured by Nippon Soda Co., Ltd.), and 2 parts by mass of 2,6-di-tert-butyl-p-cresol at 170°C, and then the temperature was lowered to 130°C, 10 parts by mass of 1,6-hexanediol dimethacrylate, 0.01 parts by mass of methylhydroquinone, and 1 part by mass of a photopolymerization initiator (Irgacure 651) were added and kneaded, to obtain a photosensitive resin composition of a type that is developed by a solvent. A photosensitive resin layer was formed by disposing the above photosensitive resin composition on a base film of polyethylene terephthalate (Toyobo Co., Ltd., E5000, 125 μm thick) to which a copolymer polyester-based adhesive was applied. Subsequently, a film (Toyobo Co., Ltd., E5000, 100 μm thick) on which no release coating was provided was laminated thereon. These were subjected to pressure bonding at 100°C using a hot press to obtain a flexible printing plate precursor manufacturing laminate. The total thickness of the laminate was 1.14 mm. A flexible printing plate was obtained by peeling the cover film from the obtained flexible printing plate precursor manufacturing laminate and laminating a resin layer face of a functional resin layer identical to that of Example 1 on the photosensitive resin layer of the flexible printing plate precursor manufacturing laminate. The obtained printing plate was made into a printing plate by plate making according to the following method. First, back exposure was performed for 10 seconds from the polyester support side of the printing plate. Subsequently, main exposure was performed for 7 minutes. Then, development was performed in a developing machine (Stuck System, manufactured by A&V Co., Ltd., using mineral oil in the developer) for 8 minutes. Then, drying was performed in a drying machine at 60°C for 120 minutes. Subsequently, post exposure was performed for 7 minutes, and finally irradiation with a germicidal lamp was performed for 5 minutes to obtain a flexible printing plate.

[0059] The laminates and printing plates of each of the above examples, comparative examples and reference examples were evaluated for the following (1) to (6) properties. Each evaluation method is described below.

[0060] (1) Cover film peel strength (10°C, 30°C) The flexible printing plate precursor manufacturing laminate prepared was cut into a test piece of 120 mm x 20 mm, the end portion of the cover film was peeled off with the fingertips, and mounted on a peel tester, and the peel strength (g / 20 mm) was measured by pulling at a speed of 10,000 mm / min and at an angle of 90°. Note that the measurement was performed at each of 10°C and 30°C. The determination of the peel strength was performed by the following method. ◎: when the peel strength was in the range of 3.0 g / 20 mm or more and 20.0 g / 20 mm or less; O: when the peel strength was not in the above range of, but was in the range of 2.0 g / 20 mm or more and 50.0 g / 20 mm or less; X: when the peel strength was not in either of the above ranges of and.

[0061] (2) Temperature dependence of peel strength (10°C measured value - 30°C measured value) To evaluate the temperature dependency of the release strength of the release layer, the release strength at each of 10°C and 30°C was measured, and the difference between the measured values was evaluated. The smaller the difference between the measured values of the release strength (10°C measured value - 30°C measured value) was, the smaller the temperature dependency of the release strength was. The evaluation was performed by the following method. : The difference between the measured values of the release strength was 10 g / 20 mm or less; : The difference between the measured values of the release strength was more than 10 g / 20 mm and 20 g / 20 mm or less; : The difference between the measured values of the release strength was more than 20 g / 20 mm.

[0062] (3) Storage stability of release strength (3 months) After the obtained laminate was stored at 30°C, RH 80% for 3 months, the release strength of the laminate was measured at 10°C by the same method as (1) film release force (10°C, 30°C), and the release force was evaluated.

[0063] (4) Presence or absence of bleeding After the obtained laminate was stored at each of 20°C, RH 65% and 30°C, RH 80% for 1 month, respectively, and alone, at the time of release of the film, it was visually determined whether or not the resin had bled from the release layer. The evaluation was performed according to the presence or absence of bleeding as follows. : No bleeding; : Bleeding.

[0064] (5) Surface roughness (Ra) of release layer The surface roughness (Ra) of the release layer is the surface roughness (Ra) of the surface of the release layer of the release film. The measurement was performed by a method of a confocal method using a laser confocal microscope. Specifically, as the laser confocal microscope, a laser confocal microscope VK9510 manufactured by KEYENCE was used. The magnification of the objective lens was set to 50 times. A sample of 10 cm in length x 10 cm in width was cut out from the release layer, and the sample was placed on the measurement stage of the laser confocal microscope, and the surface roughness (Ra) was measured at a total of 20 places while moving at about 5 mm at a time in the length direction and / or the width direction. The average of the measured values of the surface roughness (Ra) was used as the surface roughness (Ra) of the release layer.

[0065] (6) Image reproducibility of printing plate After the obtained laminate was stored at each of 20°C, RH 65% and 30°C, RH 80% for 1 month, respectively, and alone, a flexographic printing master was produced as described above, and the obtained each flexographic printing master was used to evaluate the image reproducibility. The case where there was no uneven adhesion (scattering of ultraviolet rays) was marked as 0, the case where there was partial uneven adhesion was marked as △, and the case where there was overall uneven adhesion was marked as ×.

[0066] Table 1 shows the details and evaluation results of the laminated bodies of each example, comparative example, and reference example.

[0067] [Table 1]

[0068] As shown in Table 1, the laminates of Examples 1 to 8, which meet the requirements of the present invention, all have peel strengths within an appropriate range and exhibit a low temperature-dependent difference in peel strength (measured value at 10°C minus measured value at 30°C) (i.e., low temperature dependence). Furthermore, even after storage at 30°C for three months, the peel strength of the laminates exhibited minimal change, demonstrating excellent storage stability. Therefore, the laminates of Examples 1 to 8 can be readily laminated with a functional resin layer without being affected by seasonal variations, resulting in high-quality printing plates with excellent image reproducibility.

[0069] In contrast, in Comparative Example 1, the film could not be peeled off due to the lack of a release layer. In Comparative Example 2, the release layer did not contain an addition-type silicone polymer, so the peel strength could not be properly adjusted and bleed could not be suppressed. As a result, the printing plate had poor image reproducibility and could not be used as a printing plate. Furthermore, in Comparative Example 3, which used a release layer containing an amino resin, or Comparative Example 4, which used a release layer containing an acrylic resin, the peel strength of the film was not within the appropriate range, and peeling of the film was particularly difficult at low temperatures of 10°C. In Comparative Example 5, the release coating composition did not contain a curing catalyst, so the peel strength could not be properly adjusted and bleed could not be suppressed. Industrial applicability

[0070] The laminate for producing a flexographic printing plate of the present invention exhibits excellent film releasability even when stored in an environment subject to temperature and humidity fluctuations. This allows for the provision of a water-developable flexographic printing plate that does not suffer from surface anomalies such as silicone polymer migration, which can cause quality degradation, on the photosensitive resin layer. Therefore, the present invention is extremely useful in the industry, which demands high-resolution water-developable flexographic printing plates.

Claims

1. A laminate for a flexible printing original plate manufacturing, characterized by, The laminate is a water-developable flexible printing original plate manufacturing laminate in which a base film, a photosensitive resin layer, and a cover film are sequentially laminated, a release layer is provided between the photosensitive resin layer and the cover film in contact with both, and the release layer contains an addition type silicone polymer and a curing catalyst.

2. The flexible printing original plate manufacturing laminate according to claim 1, characterized by, The addition type silicone polymer contains an alkenyl group at a terminal and / or a side chain thereof.

3. The flexible printing original plate manufacturing laminate according to claim 1, characterized by, The curing catalyst is a hydrosilylation catalyst.

4. The flexible printing original plate manufacturing laminate according to any one of claims 1 to 3, characterized by, A surface roughness Ra of a surface of the release layer in contact with the photosensitive resin layer is 0.01 to 0.2 μm.

5. The flexible printing original plate manufacturing laminate according to any one of claims 1 to 3, characterized by, A peeling strength when the cover film is pulled along 90° at a speed of 1000 mm / min together with the release layer from the flexible printing original plate manufacturing laminate is 2.0 g / 20 mm to 50.0 g / 20 mm.

6. The flexible printing original plate manufacturing laminate according to any one of claims 1 to 3, characterized by The photosensitive resin layer contains (a) a conjugated diene-based polymer, (b) a photopolymerizable unsaturated compound, and (c) a photopolymerization initiator.

7. A method for manufacturing a flexible printing master, characterized by, A flexible printing original plate is manufactured by peeling the cover film together with the release layer from the flexible printing original plate manufacturing laminate of any one of claims 1 to 3, and then directly laminating a resin layer face of a functional resin layer on the photosensitive resin layer.

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