JP2019171730A - Flexographic printing laminate, and flexographic printing method - Google Patents

Abstract

To provide a flexographic printing laminate with improved ink receiving property, that can produce printed matter having high definition and good image registration accuracy.SOLUTION: Provided is a flexographic printing laminate comprising a cushion material, a base material and a relief resin layer and in which, characterized, the Shore A hardness of the relief resin layer is 65 or more and 85 or less, and the Shore A hardness of the cushion material is larger than the Shore A hardness of 2 smaller than the Shore A hardness of the relief resin layer.SELECTED DRAWING: None

Description

  The present invention relates to a laminate for flexographic printing and a flexographic printing method.

  Flexographic printing, a type of letterpress printing, is characterized by high-speed printing using a flexible printing plate. In recent years, by increasing the resolution of anilox rolls that supply ink to flexographic printing plates, As a result, it is possible to reproduce a fine halftone dot image and to produce a high-definition printed matter. In a flexographic printing laminate for flexographic printing to produce such a high-definition printed matter, a cushioning material is obtained by fixing one surface of a cushioning material having an adhesive layer on both sides on a plate cylinder of a flexographic printing machine. It is possible to use a laminate in which a base material surface of a flexographic printing plate comprising a base material and a relief resin layer is disposed on the other surface of the material (for example, see Patent Document 1), but the conventional flexibility When a printing plate having a large size is used, the halftone dots are crushed by the printing pressure. Therefore, it is generally recommended to use a soft cushion material that relaxes the printing pressure. However, if a soft cushioning material that does not crush halftone dots due to printing pressure is used on a printing plate with high flexibility, the solid image other than the halftone image, for example, lacks printing pressure and lacks ink transferability. Insufficient density due to scumming is remarkable, and even when the same ink is used, it is necessary to print a halftone image and a solid image using different cushion materials, which is an inefficient printing method. In addition, when using a conventional printing plate with high flexibility, the combination of the printing plate and cushion material causes a difference in compression of the relief resin layer due to the pressure during printing, and the registration accuracy decreases during multicolor printing. There was a problem that the color reproducibility of was unstable.

JP 2004-322398 A WO2015 / 122515 WO2007 / 147803 JP 2014-182247 A JP2015-150798

  In view of the above problems, an object of the present invention is to provide a laminate for flexographic printing with improved ink deposition property that can produce a printed matter with high definition and good pattern registration accuracy.

  A flexographic printing laminate including a cushion material, a base material, and a relief resin layer, wherein the Shore A hardness of the relief resin layer is 65 or more and 85 or less, and the Shore A hardness of the cushion material is Shore A hardness of the relief resin layer It is a flexographically printed laminate characterized by having a Shore A hardness of less than 2 smaller.

  ADVANTAGE OF THE INVENTION According to this invention, the laminated body for flexographic printing which the ink deposit property improved which can produce the printed matter with the high-definition and favorable image registration precision can be provided.

  Embodiments of the present invention will be described below.

  The flexographic printing laminate of the present invention is a flexographic printing laminate comprising a cushion material, a base material and a relief resin layer, wherein the relief resin layer has a Shore A hardness of 65 or more and 85 or less, and the cushion material Shore A The hardness is larger than the Shore A hardness which is 2 smaller than the Shore A hardness of the relief resin layer. In addition, the measuring method of the Shore A hardness of the relief resin layer of a flexographic printing plate and a cushion material can be measured by the method prescribed | regulated to JISK7215.

  Examples of the cushioning material used in the present invention include those having elastic resilience, specifically, foamed synthetic rubber, foamed natural rubber, foamed polyurethane, foamed polyethylene, photosensitive resin cured by ultraviolet exposure, and elastomer resin. Etc. Further, such a cushion material has an adhesive layer on both sides, so that it is easy to fix the flexographic printing plate on the plate cylinder and the flexographic printing plate. Examples of the cushion material include, for example, a TESA print series manufactured by TESA, a DuploFLEX series manufactured by Lohmann, a Cushon-MountPlus series manufactured by 3M, an R / bak series manufactured by Rogers, and an Exafit series manufactured by SCAPA.

  Although the thickness of the cushioning material of the present invention is used in accordance with the characteristics of the printing press, the thickness is 50 to 1000 μm. When the thickness is 50 μm or more, high-definition halftone printing is possible by providing cushioning properties, and when the thickness is 1000 μm or less, the registration accuracy during printing is improved.

  The Shore A hardness of the cushion material is preferably larger than the Shore A hardness which is 2 smaller than the Shore A hardness of the relief resin layer of the flexographic printing plate. Since the Shore A hardness of the cushion material is larger than the Shore A hardness of 2 smaller than the Shore A hardness of the relief resin layer of the flexographic printing plate, it achieves both high-definition image reproduction in halftone images and good ink transfer in solid images. Effect can be obtained. Accordingly, the Shore A hardness of the cushion material is more preferably equal to or greater than the Shore A hardness of the relief resin layer of the flexographic printing plate, and more preferably greater than the Shore A hardness of the relief resin layer.

  Next, the Shore A hardness of the relief resin layer of the flexographic printing plate used in the laminate for flexographic printing of the present invention is preferably in the range of 65 to 85. When the relief resin layer is 65 or more, the halftone dots are not easily crushed by the pressure during printing, and high-definition halftone printing is possible. Further, it is preferably 85 or less because the solid portion exhibits good ink transferability, and more preferably 70 or more and 85 or less.

  The thickness of the relief resin layer of the aforementioned flexographic printing plate is preferably 300 to 1200 μm. When the thickness is 300 μm or more, it is possible to suppress the ink from adhering to a portion other than the printing portion in contact with the substrate surface during printing. In addition, when the thickness is 1000 μm or less, printing can be performed with high registration accuracy. In addition, More preferably, it is the range of 400-1000 micrometers. In addition, a floor layer made of a photosensitive resin layer can be formed on the relief resin layer of the flexographic printing plate as necessary.

  A flexographic printing plate having such a relief resin layer is formed, for example, by photocuring a flexographic printing plate precursor having a photosensitive resin layer containing a binder resin, an ethylenically unsaturated compound and a photopolymerization initiator. It is known.

  Examples of the binder resin used in the photosensitive resin layer include an ethylene-acrylic acid copolymer, a polyethylene oxide-polyvinyl alcohol graft copolymer, natural rubber, polybutadiene, polyisoprene, and styrene described in Patent Document 3. -An elastomeric binder such as butadiene rubber, nitrile-butadiene rubber, butyl rubber, styrene-isoprene rubber, styrene-butadiene-isoprene rubber, polynorbornene rubber, or ethylene-propylene-diene rubber (EPDM); Saponified polyvinyl acetate (partially saponified polyvinyl alcohol), cellulose resin, ethylene / vinyl acetate copolymer, polyamide resin having a hydrophilic group introduced therein, and modified products of these resins can be used.

  Of these, partially saponified polyvinyl acetate having a saponification degree of 40 to 90 mol% is preferable because it has a good film-forming property and can be developed with water after photocuring to develop a relief resin layer. Can be used. Further, by using 40 to 90 mol% partially saponified polyvinyl acetate having a reactive group introduced in the side chain, a photosensitive resin layer capable of forming a higher definition halftone dot can be produced. The reactive group is a functional group that can be crosslinked by radical reaction or the like. In general, as such a functional group, a non-aromatic unsaturated carbon-carbon bond, particularly an ethylenic double bond is often used, and examples thereof include a vinyl group and a (meth) acryloyl group.

  Examples of a method for introducing such a reactive group into the side chain of partially saponified polyvinyl acetate include the following methods.

  The following method is mentioned as a 1st method. The partially saponified polyvinyl acetate is reacted with an acid anhydride to introduce a carboxyl group into the polymer side chain starting from the hydroxyl group of the partially saponified polyvinyl acetate. A reactive group is introduced by reacting the carboxyl group with an unsaturated epoxy compound. The following method is mentioned as a 2nd method. A polymer is obtained by copolymerizing vinyl acetate with an unsaturated carboxylic acid or a salt thereof, or an unsaturated carboxylic acid ester. The polymer is partially saponified, and a reactive group is introduced by reacting a carboxyl group of the polymer with an unsaturated epoxy compound. Among these, partially saponified polyvinyl acetate obtained by the former method is preferably used since the effects of the present invention are remarkably exhibited.

  In addition, as a method for introducing a reactive group into the side chain of the above partially saponified polyvinyl acetate, the carboxyl group and unsaturated epoxy of partially saponified polyvinyl acetate having a carboxyl group as an anionic group which is an anionic polymer component The method of making it react with a compound is mentioned. When the partially saponified polyvinyl acetate synthesized by the above method is included, unreacted anionic groups derived from the anionic polymer component contained in the image-forming resin layer are included in the partially saponified polyvinyl acetate component. The number of cationic groups is preferably within a range not exceeding.

  Such reactive groups are preferably present in the partially saponified polyvinyl acetate in an amount of 0.08 to 0.72 mol / kg, more preferably 0.12 to 0.36 mol / kg. When the amount is more than 0.72 mol / kg, water solubility is deteriorated, and a level at which water developability is satisfactory cannot often be obtained. When the amount is less than 0.08 mol / kg, effects such as relief chipping during development, which are improved by the reaction of the reactive group, often do not appear. The modified partially saponified polyvinyl acetate having a reactive group thus obtained has at least the following structural units (I), (II), and (III).

(Here, R represents a hydrocarbon group having 1 to 20 carbon atoms, and X represents a functional group having an unsaturated carbon-carbon bond at the terminal.)
When the partially saponified polyvinyl acetate having a reactive group in the side chain requires water developability, the unit of structure (I) is preferably 60 to 99 mol%, more preferably 70 to 95 mol%. . When there are too few structural units of (I), water solubility may fall and sufficient water developability may not be obtained, and when too large, the solubility with respect to normal temperature water will fall, and sufficient water developability will be obtained. There are many cases that cannot be done. The average degree of polymerization of such partially saponified polyvinyl acetate is preferably in the range of 300 to 2000, more preferably 500 to 1000. If the average degree of polymerization is less than 300, the water resistance is lowered and sufficient water resistance cannot be obtained. When the average degree of polymerization exceeds 2000, water solubility is remarkably lowered, and sufficient water developability cannot be obtained. The number average molecular weight is preferably 10,000 to 150,000.

  In addition, it is preferable that 10-70 mass% of binder resin is contained in the photosensitive resin layer.

  The ethylenically unsaturated compound used for the photosensitive resin layer is a compound that can be cross-linked by radical polymerization, and has a function of imparting hardness and resistance to ink used during printing to the relief resin layer after curing. For example, benzyl (meth) acrylate, cyclohexyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, 2- (meth) acryloyloxyethyl hexahydrophthalic acid, phenoxydiethylene glycol (meth) acrylate, 2- (meth) acryloyl Roxyethylphthalic acid, neopentyl glycol- (meth) acrylic acid-benzoic acid ester, (meth) acryloylmorpholine, styrene and its derivatives, vinylpyridine, N-vinyl-2-pyrrolidone, β- (meth) acryloyloxyethyl Hydrogen phthalate, N-phenylmaleimide and derivatives thereof, N- (meth) acryloxysuccinimide, (meth) acrylic acid-2-naphthyl, N-phenyl (meth) acrylamide, divinylethyleneurea, Vinyl propylene urea, vinyl caprolactam, vinyl carbazole, bicyclopentenyl (meth) acrylate, 1-vinylimidazole, 2-methyl-1-vinylimidazole, (2-methyl-ethyldioxolan-4-yl) methyl acrylate, imide acrylate, (2-oxy-1,3-dioxolan-4-yl) methyl (meth) acrylate, 2- (oxydiimidazolidin-1-yl) ethyl (meth) acrylate, 2,2,6,6-tetramethyl- 4-piperidyl acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, isoamyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, Allyl (meth) acrylate, chloroethyl (meth) acrylate, chloropropyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, methoxytriethylene Glycol (meth) acrylate, methoxydipropylene glycol (meth) acrylate, (meth) acrylamide, diacetone (meth) acrylamide, N, N′-methylenebis (meth) acrylamide, 2,2-dimethylaminoethyl (meth) acrylate, 2 , 2-Diethylaminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamid A compound having only one ethylenic double bond such as 2-hydroxyethyl (meth) acrylate, a di (meth) acrylate of polyethylene glycol such as diethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, Pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, glycerol tri (meth) acrylate, ethylene glycol diglycidyl ether and compounds with ethylenic double bond and active hydrogen such as unsaturated carboxylic acid and unsaturated alcohol It can be obtained by addition reaction of unsaturated epoxy compounds such as polyvalent (meth) acrylates and glycidyl (meth) acrylates obtained by addition reaction of compounds with active hydrogen compounds such as carboxylic acids and amines. Compounds having two or more ethylenic double bonds, such as polyvalent (meth) acrylates, polyvalent (meth) acrylamides such as methylenebis (meth) acrylamide, polyvalent vinyl compounds such as divinylbenzene, and the like. . Two or more of these may be contained.

  Content of the ethylenically unsaturated compound in the composition of the photosensitive resin layer is 20 to 100 parts by weight with respect to 100 parts by weight of the binder resin. By setting it as 20 weight part or more, the photosensitive resin layer can be photocured and a relief resin layer can be formed. On the other hand, by setting it as 100 weight part or less, it can suppress that the hardness of a relief resin layer becomes large.

  The photopolymerization initiator that can be used for the photosensitive resin layer is not particularly limited as long as it has a function of generating radicals by self-cleavage or hydrogen abstraction. For example, known photopolymerization initiators such as acetophenones, benzoin ethers, benzophenones, thioxanthones, anthraquinones, benzyls, biacetyls and the like can be mentioned. Two or more of these may be contained.

  The content of the photopolymerization initiator (C) in the photosensitive resin layer is preferably 0.3% by weight or more, preferably 0.5% by weight or more in the photosensitive resin layer from the viewpoint of the photopolymerization reaction of the ethylenically unsaturated compound. Is more preferable. On the other hand, from the viewpoint of improving the depth of drawing, it is preferably 5% by weight or less in the photosensitive resin layer, and more preferably 3% by weight or less.

  Moreover, the photosensitive resin layer may contain a plasticizer. By containing the plasticizer, the Shore A hardness of the relief resin can be adjusted to an appropriate range. The plasticizer is preferably highly compatible with the binder resin. Generally, for hydrophilic polymers such as water-soluble polymers or water-swellable polymers, highly hydrophilic plasticizers have good compatibility. Examples of preferable plasticizers include polyhydric alcohols such as glycerin, polyglycerin, trimethylolpropane, and trimethylolethane, and ethylene glycols such as ethylene glycol, diethylene glycol, triethylene glycol, and tetraethylene glycol. . Two or more of these may be contained.

  The content of the plasticizer in the photosensitive resin layer is preferably 20 to 150 parts by weight with respect to 100 parts by weight of the binder resin from the viewpoint of adjusting the Shore A hardness to an appropriate range.

  In the relief resin layer of the flexographic printing plate used in the present invention, an organic fluorine compound and / or a silicone compound and / or a paraffin compound is added to the relief resin layer in order to enable high-definition dot printing. .1 wt% or more and 5 wt% or less.

  By containing the above-mentioned compound in the relief resin layer, it is possible to suppress the accumulation of ink in the halftone dot image portion provided in the relief resin layer of the flexographic printing plate during flexographic printing, and to obtain a higher-definition printed matter. it can.

  The organic fluorine compound here means a compound in which part or all of the hydrogen groups of the carbon hydrogen compound are substituted with fluorine. The silicone compound refers to an oligomer or polymer whose main skeleton is an alkylsiloxane having an alkyl group typified by a methyl group, and is generally a substance sometimes referred to as silicone oil.

  The organic fluorine compound and the silicone compound have a functional group that interacts and / or reacts with the binder resin and / or the ethylenically unsaturated compound in the relief forming layer of the flexographic printing plate of the flexographic printing laminate of the present invention. It is desirable. Specifically, hydroxyl groups, carbinol groups, epoxy groups, (meth) acrylic acid ester groups, carboxyl groups, carboxylic acid ester groups, amino groups, phosphonium groups, sulfonium groups, aromatic hydrocarbon groups including phenyl groups, methylsrityl groups Hydrocarbon groups substituted with aromatic hydrocarbons containing, aromatic hydrocarbon groups substituted with hydroxyl groups containing hydroxyphenyl groups, alkoxyl groups, (poly) ether groups, urethane groups, isocyanate groups, N-methylol groups, etc. These functional groups are preferable. Such fluorine compounds and / or silicone compounds having one or more modifying groups are referred to as modified silicone compounds and / or fluorine compounds. In these modified silicone compounds and / or fluorine compounds, one or more of the modifying groups described above may be directly bonded to silicon atoms and / or fluorine atoms, or bonded to silicon atoms and fluorine atoms. It may be substituted with one or more hydrogen atoms of the hydrocarbon group.

  Silicone compounds having no modifying groups, such as silicone oils having dimethylsiloxane as the main chain, and / or fluorine compounds such as fluorine oils such as perfluorocarbon, hydrofluoroether, and hydrofluorocarbon bleed out even when blended in the relief forming layer. It is difficult to fix to the relief resin layer.

  On the other hand, the paraffinic compound contained in the relief resin layer is a paraffin having a number average carbon number of 30 or more and a number average molecular weight of 400 or more. The number average carbon number is preferably 33 or more and the number average molecular weight 420 or more, more preferably the number average carbon number 36 or more and the number average molecular weight 460 or more. Although the upper limit of each is not limited, in reality, the number average carbon number is 80 and the number average molecular weight is about 1000. By using a paraffin having such a number average carbon number and number average molecular weight, it has plate surface anti-staining ability and durability, and enables high-quality mass printing. With paraffin that does not satisfy the number average carbon number and the number average molecular weight, it is difficult to exhibit the ability to prevent plate surface contamination.

  The mechanism by which the accumulation of ink in the halftone dot image portion due to the above-described compound is suppressed can be considered as follows. Plate stains generated by a long run are more likely to occur as the interaction between the ink and the printing plate surface increases. If a substance having a small surface energy is contained in the resin composition, the interaction between the ink and the printing plate surface is reduced, and the accumulation of ink in the halftone image portion can be suppressed.

  In addition, the photosensitive resin layer can contain a well-known polymerization inhibitor for the purpose of ensuring thermal stability. Preferable polymerization inhibitors include phenols, catechols, hydroquinones, nitrosamines and the like. In order to obtain sufficient photopolymerization reactivity of the photosensitive resin layer, the content of the polymerization inhibitor in the photosensitive resin composition of the present invention is preferably 0.5% by mass or less.

  Furthermore, the photosensitive resin layer is used for the purpose of further improving various properties, such as surfactants, antifoaming agents, ultraviolet absorbers, oxygen scavengers, sensitizers, and coloring agents (dyes, pigments, photochromic agents, coloring agents). Auxiliaries), fragrances, deodorants and the like.

  Next, the flexographic printing plate used for the flexographic printing laminate of the present invention comprises a flexographic printing plate in which the above-described relief resin layer is provided on a substrate.

  As the substrate, a plastic sheet such as polyester, a synthetic rubber sheet such as styrene-butadiene rubber, or a metal plate such as steel, stainless steel, or aluminum can be used. Among them, a plastic sheet such as polyester is preferably used from the viewpoint of flexibility, transparency, and dimensional stability, and a sheet of polyethylene terephthalate (hereinafter referred to as PET) is preferable from the viewpoint of heat resistance and chemical resistance.

The thickness of the substrate is not particularly limited, but is 0.10 to 0.35 m from the viewpoints of handleability and flexibility.
A range of m is preferred. If it is 0.10 mm or more, the handleability as a support is improved, and if it is 0.35 mm or less, it is easy to attach it to a flexographic printing machine in a cylindrical shape.

  The base material is preferably subjected to easy adhesion treatment for the purpose of improving adhesiveness with the relief resin layer. Examples of the method for easy adhesion treatment include mechanical treatment such as sandblasting, physical treatment such as corona discharge, chemical treatment such as coating, etc., but it is preferable from the viewpoint of adhesion to provide an easy adhesion layer by coating. .

  Next, a method for producing a flexographic printing plate precursor for producing a flexographic printing plate using the flexographic printing laminate of the present invention will be described. For example, after heat-dissolving partially saponified polyvinyl acetate in a mixed solvent composed mainly of water and alcohol, an ethylenically unsaturated compound, a photopolymerization initiator, and, if necessary, a plasticizer and other additives are added. The mixture is sufficiently mixed by stirring to obtain a photosensitive resin composition solution.

  The photosensitive composition solution obtained by the above-mentioned method can be obtained by optionally casting on a substrate having an easy-adhesion layer and drying. Thereafter, a flexographic printing plate precursor can be obtained by adhering a cover film optionally coated with a peeling auxiliary layer on the photosensitive resin layer. It is also possible to produce a flexographic printing plate precursor by producing a photosensitive resin sheet by dry film formation and laminating the photosensitive resin sheet and a cover film so as to be sandwiched between the photosensitive resin sheet and the cover film. In addition, it is also possible to provide a heat-sensitive mask layer on the photosensitive resin layer on the side opposite to the base as necessary.

  The flexographic printing plate of the present invention can be obtained by exposing and developing the flexographic printing plate precursor prepared by the above-described method, or by laser engraving after exposure.

  For example, a method for obtaining a flexographic printing plate by exposure and development is as follows. When the flexographic printing plate precursor does not have a thermal mask layer (hereinafter referred to as an analog plate) and a cover film is peeled off, A negative or positive original image film is brought into close contact with the photosensitive resin layer on the opposite side, and the photosensitive resin layer is photocured imagewise by irradiating with ultraviolet rays. In the case of a so-called CTP (computer to plate) plate having a thermal mask layer on the photosensitive resin layer, the image corresponding to the original film is drawn using a laser drawing machine after the cover film is peeled off. Then, the photosensitive resin layer is photocured by irradiating with ultraviolet rays. The ultraviolet irradiation is usually performed using a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a metal halide lamp, a xenon lamp, a carbon arc lamp, a chemical lamp, or the like that can irradiate a wavelength of 300 to 400 nm. When a flexographic printing plate requires the formation of a floor layer, it is possible to form a floor layer made of a photosensitive resin by performing exposure (back exposure) from the substrate side for a short time before peeling the cover film. It is.

  Next, a relief image is formed by a brush type developing device in which the photosensitive resin layer photocured imagewise is immersed in a developing solution, and an uncured portion is removed by rubbing with a brush. In addition to the brush type developing device, it is also possible to use a spray type developing device. The liquid temperature during development is preferably 15 to 40 ° C. After forming the relief layer, the flexographic printing plate can be obtained by drying at 50 to 70 ° C. for about 10 minutes. If necessary, actinic ray treatment may be performed in the air or in vacuum.

  The method of obtaining a flexographic printing plate by laser engraving can be manufactured through the following steps in sequence. That is, it comprises a step of irradiating the photosensitive resin layer with actinic rays to crosslink the photosensitive resin layer, and a step of engraving a part of the photosensitive resin layer photocured with actinic rays with a laser.

  In addition, if necessary, a step of rinsing the relief resin engraved with a liquid containing a solvent as a main component, a step of drying the relief resin layer engraved with a laser, and further crosslinking by irradiating the relief resin layer with actinic rays It is a process to make.

  In addition, when the uncrosslinked part of the photosensitive resin layer is laser engraved, the unintended part is easily melted and deformed due to the residual heat propagated around the laser irradiation part, and a sharp relief cannot be obtained. Moreover, as a general property of a raw material, as a low molecular weight thing, it becomes a liquid instead of solid, Therefore, adhesiveness becomes strong. Therefore, the engraving residue generated when engraving the photosensitive resin layer that forms the relief becomes stronger as the low-molecular material is used more. Since the polymerizable ethylenically unsaturated compound which is a low molecule becomes a polymer by crosslinking, the generated engraving residue tends to be less sticky.

  The flexographic printing laminate of the present invention can be obtained by the following steps.

  (1) A step of preparing a flexographic printing plate and a cushion material obtained by the above-described method, (2) a step of attaching one side of the cushion material on a plate cylinder of a flexographic printing machine, and (3) provided on the plate cylinder. Fixing the base of the flexographic printing plate to the opposite surface of the cushioning material.

  By using the flexographic printing laminate thus obtained and performing flexographic printing, it becomes possible to produce a printed matter with high definition and good picture registration accuracy. The flexographic laminate of the present invention can be printed using an ultraviolet curable ink, a solvent ink, and a water-based ink. In particular, when using an ultraviolet curable ink, a large-sized printing process is required. It is not necessary to use a drying facility, which is advantageous from the viewpoint of the installation space of the printing press and the running cost of printing.

  Hereinafter, the present invention will be described in detail with reference to examples.

Synthesis example of resin 1 contained in the relief resin layer:
Partially saponified polyvinyl acetate “KL-05” (degree of polymerization: about 500, degree of saponification: 80 mol%) manufactured by Nippon Synthetic Chemical Industry Co., Ltd. is swollen in acetone, and 1.0 mol% of succinic anhydride is added. Then, the mixture was stirred at 60 ° C. for 6 hours to add a carboxyl group to the molecular chain. The polymer was washed with acetone to remove unreacted succinic anhydride and dried. The acid value was measured and found to be 10.0 mgKOH / g. The resin obtained by this operation is hereinafter referred to as (resin 1).

Synthesis example of resin 2 contained in the relief resin layer:
60 parts by weight of an equimolar salt of α, ω-diaminopolyoxyethylene and adipic acid obtained by adding acrylonitrile to both ends of polyethylene glycol having a number average molecular weight of 600 and reducing this with hydrogen, and 20 parts by weight of ε-caprolactam And 20 parts by weight of an equimolar salt of hexamethylenediamine and adipic acid were melt-polymerized, and then water was removed to obtain a resin 2 having a hydrophilic group as component (A1) and a polyether segment in the main chain. .

Fabrication of substrate:
260 parts by weight of "Byron" (registered trademark) 31SS (toluene solution of unsaturated polyester resin, manufactured by Toyobo Co., Ltd.) and 2 parts by weight of "PS-8A" (benzoin ethyl ether, manufactured by Wako Pure Chemical Industries, Ltd.) The mixture was heated at 70 ° C. for 2 hours and then cooled to 30 ° C., and 7 parts by weight of ethylene glycol diglycidyl ether dimethacrylate was added and mixed for 2 hours. Further, 25 parts by weight of “Coronate” (registered trademark) 3015E (ethyl acetate solution of polyvalent isocyanate resin, manufactured by Nippon Polyurethane Industry Co., Ltd.) and “EC-1368” (industrial adhesive, manufactured by Sumitomo 3M Limited) 14 parts by weight was added and mixed to obtain an easy-adhesion layer coating solution 1.

  50 parts by weight of “Gohsenol” (registered trademark) KH-17 (polyvinyl alcohol having a saponification degree of 78.5 to 81.5 mol%, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) was added to “Solmix” (registered trademark) H— 11 (alcohol mixture, manufactured by Nippon Alcohol Co., Ltd.) In a mixed solvent of 200 parts by weight and 200 parts by weight of water at 70 ° C. for 2 hours, “Blemmer” (registered trademark) G (glycidyl methacrylate, Nippon Oil & Fats Co., Ltd.) 1.5 parts by weight added), mixed for 1 hour, and (dimethylaminoethyl methacrylate) / (2-hydroxyethyl methacrylate) copolymer having a weight ratio of 2/1 (manufactured by Kyoeisha Chemical Co., Ltd.) 3 weights Parts, "Irgacure" (registered trademark) 651 (benzylmethyl ketal, manufactured by Ciba-Geigy), "Epoxy ester 70PA" (propylene) 21 parts by weight of an acrylic acid adduct of recalled diglycidyl ether (manufactured by Kyoeisha Chemical Co., Ltd.) and 20 parts by weight of ethylene glycol diglycidyl ether dimethacrylate were added and mixed for 90 minutes. After cooling to 50 ° C., “Megafuck F 0.156 parts by weight of -556 "(manufactured by DIC Corporation) was added and mixed for 30 minutes to obtain a coating solution 2 for an easy adhesion layer.

  The easy-adhesion layer coating solution 1 was applied onto a 125 μm-thick “Lumirror” (registered trademark) T60 (polyester film, manufactured by Toray Industries, Inc.) with a bar coater so that the film thickness was 40 μm after drying. After removing the solvent by heating in an oven at ℃ for 3 minutes, the coating solution 2 for easy adhesion layer (H) is applied thereon with a bar coater so as to have a dry film thickness of 30 μm. It heated for 3 minutes and the base material which has an easily bonding layer was obtained.

[Example 1]
[Preparation of composition solution 1 for photosensitive resin 1]
In a three-necked flask equipped with a stirring spatula and a cooling tube, 40 parts by weight of Resin 1 “Solmix” H-11 (alcohol mixture, manufactured by Nippon Alcohol Co., Ltd.) and 50 parts by weight of water are mixed. After mixing the solvent, the mixture was heated at 80 ° C. for 2 hours with stirring to prepare a resin solution. After cooling to 70 degreeC, the other component shown in Table 1 was added, and it stirred for 30 minutes, and obtained the composition solution 1 for the photosensitive resin layer 1. FIG.

  The obtained composition solution 1 for photosensitive resins was cast on a support having the easy-adhesion layer and dried at 60 ° C. for 2.5 hours. At this time, the plate thickness after drying (polyester film + photosensitive resin layer) was adjusted to 1.14 mm. On the photosensitive resin layer thus obtained, a mixed solvent of water / ethanol = 50/50 (weight ratio) was applied, and 100 μm thick “Lumirror” (registered trademark) S10 (polyester film, Toray ( The flexographic printing plate precursor 1 was obtained by pressure bonding.

[Preparation method of flexographic printing plate]
The substrate surface opposite the cover film of the flexographic printing plate precursor 1 of 25 cm × 25 cm was exposed for 10 seconds with a chemical lamp FL20SBL-360 20 Watts (manufactured by Mitsubishi Electric OSRAM Co., Ltd.). Thereafter, only the cover film is peeled off, and a gray scale negative film for sensitivity measurement and a negative film for evaluation of printed images (having a 170-line 20% halftone dot and a 5 cm × 5 cm solid image) are vacuum-adhered on the photosensitive resin layer. Chemical lamp FL20SBL-360 20 Watt (manufactured by Mitsubishi Electric OSRAM Co., Ltd.) was exposed under the conditions of a gray scale sensitivity of 16 ± 1 stage (21 STEP SENSITIVITY GUIDE made by STOUFFER GRAPHIC ARTICS CO., LTD.). Then, after developing with water at a developer temperature of 25 ° C. with a brush type developing device and drying at 60 ° C. for 10 minutes, the same conditions as the main exposure with a chemical lamp FL20SBL-360 20 Watts (manufactured by Mitsubishi Electric OSRAM Co., Ltd.) After that, a flexographic printing plate 1 having a floor layer of 500 μm was obtained.

  The flexographic printing laminate 1 was obtained by arranging the cushion material 2 shown in Table 2 on a plate cylinder of a flexographic printing machine (EF340 manufactured by MPS) and fixing the flexographic printing plate 1 thereon. The evaluation results of the flexographic laminate 1 are shown in Table 3.

[Examples 2-7, Comparative Examples 1-6]
In the same manner as in Example 1, flexographic printing plate precursors 2 to 9 were obtained from the compositions shown in Table 1. Then, it made the plate similarly to Example 1 and obtained the flexographic printing plates 2-9. Furthermore, the flexographic printing laminates 2 to 13 were obtained by fixing the obtained flexographic printing plate on a plate cylinder using the combination of cushion tapes shown in Table 3. The evaluation results are shown in Table 3.

[Evaluation methods]
(1) Evaluation method of flexographic printing by flexographic printing laminate The evaluation of flexographic printing of the flexographic printing plate laminate was performed as follows.

  For the ink, UV flexo red PHA-LO3 / T & K TOKA, which is an ultraviolet curable ink, is used, and the flexographic laminate of the present invention is attached to a flexographic printing machine (MP340 manufactured by MPS) equipped with an anilox roll of 991 LPI. Printing was performed on mirror-coated paper (Oji Tack N Mirror 73 / P22 / G7B manufactured by Oji Paper Co., Ltd.) at a speed of 60 m / min. With respect to the obtained printed matter of 60 m and 3000 m, an image having a dot density of 20% was observed with a KEYENCE microscope VHX-2000. In the evaluation, the ratio (a / b) of the maximum width (a) in the flow direction of printing of the halftone image and the maximum width (b) in the width direction of the printing substrate was calculated as the printing aspect ratio. The printing aspect ratio is ◯ when the range is 1.00 to 1.05 or less, “Δ” when the printing aspect ratio is over 1.05 to 1.10 or less, and “X” is the range where the printing aspect ratio exceeds 1.10. did.

  The solid density was measured using a spectral densitometer model 508 series manufactured by X-RITE. The concentration at the time of showing good inking property was “1.65”, but the inking property was changed by the combination of the plate and the cushion tape. The density drop from “1.65” is 3% or more and less than 5%, and “Δ” is 5% or more is “x”. In addition, the evaluation of ink filling between the halftone dots was evaluated at the time of 60 m in 3,000 m printing and the area ratio of the ink deposited in the concave portions between the halftone dots after 3,000 m printing. A case where ink was not deposited was evaluated as 5, a case where ink deposition was 30% or less was evaluated as 3, and a case where ink was deposited over the entire surface was evaluated as 1.

(2) Measurement of Shore A Hardness of Relief Resin Layer and Cushion Material Shore A hardness was measured according to JIS K 7215 using a durometer GS-719 manufactured by Teclock Corporation. For this purpose, a relief resin layer was produced with a thickness of 1 mm and crosslinked by uniform exposure to UVA light for 6 minutes (exposure unit Dantex DQF-A1). In order to make the total layer thickness 6 mm, six layers of 1 mm thickness of each type were stacked in order, and the hardness of the layers was measured.

Claims (11)

  A flexographic printing laminate including a cushion material, a base material, and a relief resin layer, wherein the Shore A hardness of the relief resin layer is 65 or more and 85 or less, and the Shore A hardness of the cushion material is Shore A hardness of the relief resin layer A flexographic laminate characterized by being greater than 2 smaller Shore A hardness.   The flexographic printing laminate according to claim 1, wherein the Shore A hardness of the relief resin layer is 70 or more and 85 or less.   The flexographic printing laminate according to claim 1 or 2, wherein the Shore A hardness of the cushion material is equal to or greater than the Shore A hardness of the relief resin layer.   The flexographic laminate according to claim 1, wherein the relief resin layer has a thickness of 300 to 1200 μm.   The flexographic printing laminate according to any one of claims 1 to 4, wherein the cushion material has a thickness of 50 to 1000 µm.   The flexographic printing laminate according to any one of claims 1 to 5, wherein the relief resin layer contains at least one compound selected from an organic fluorine compound, a silicone compound, and a paraffin compound in the resin in an amount of 0.1 wt% to 5 wt%. body.   The flexographic printing laminate according to any one of claims 1 to 6, wherein the relief resin layer contains partially saponified polyvinyl acetate.   The flexographic printing laminate according to any one of claims 1 to 7, wherein a flexographic printing plate having a relief resin layer formed by developing with water after photocuring the flexographic printing plate precursor.   The flexographic printing laminate according to any one of claims 1 to 8, wherein the flexographic printing plate forms a relief resin layer by laser engraving a resin having a Shore A hardness of 65 to 85.   Printing using the flexographic printing laminated body in any one of Claims 1-9, The manufacturing method of the printed matter characterized by the above-mentioned. The method for producing a printed matter according to claim 10, wherein an ultraviolet curable ink is used.