Treatment liquid for resin printing plates, resin printing plate including the same, and method for producing printed material

Abstract

To provide a treatment liquid for resin printing plates that yields a resin printing plate with superior printing quality, which exhibits resistance to printing omissions due to foreign matter, without requiring organofluorine compounds.SOLUTION: A treatment liquid for resin printing plates contains a cationic surfactant (A) with a hydrocarbon group of 10 or more carbon atoms.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a treatment liquid for a resin printing plate, and a method for producing a resin printing plate and a printed matter using the same. [Background technology]

[0002] Letterpress printing, such as flexographic printing and resin letterpress printing, is widely used for paper containers, labels, soft packaging, electronics, etc. Resin letterpress printing is a printing method in which ink is applied to the apexes of the raised relief of a resin printing plate and the relief is pressed against the substrate, thereby transferring the ink from the relief to the substrate. If foreign matter such as dust, dirt, or paper powder adheres to the relief at this time, the ink does not adhere to the area around the foreign matter, so the ink is not transferred to the substrate, resulting in a printing defect called a print defect.

[0003] Therefore, as a technology for reducing adhesion of foreign matter such as dust, dirt, and paper powder to the relief, a plate surface treatment liquid containing a fluorine-containing polymer having perfluoroalkyl groups with an average carbon number of 7 or less has been proposed for treating the plate surface of a photosensitive resin plate or letterpress printing plate having an uneven surface (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2008 / 133055 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, there has been an international movement to restrict the use of artificially produced organic fluorine compounds (PFAS), which are difficult to decompose in nature, in consideration of their impact on the environment and human health, and there is a demand for a processing liquid that does not use organic fluorine compounds, as an alternative to the plate surface processing liquid described in Patent Document 1.

[0006] In view of the above problems, an object of the present invention is to provide a treatment liquid for a resin printing plate, which does not require an organic fluorine compound and is capable of producing a resin printing plate having excellent printability and which is less susceptible to printing defects caused by foreign matter. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention mainly has the following configuration. <1> A treatment liquid for resin printing plates, comprising a cationic surfactant (A) having a hydrocarbon group having 10 or more carbon atoms. <2> The cationic surfactant (A) has a structure represented by the following general formula (1): <1> 2. The processing liquid for resin printing plates according to claim 1 .

[0008] [ka]

[0009] (In the above general formula (1), R1 represents an alkyl group or an alkenyl group having 10 or more carbon atoms. R2 represents a hydrogen atom, an alkyl group having 1 to 28 carbon atoms, or a benzyl group. R3 and R4 may be the same or different and represent an alkyl group having 1 to 5 carbon atoms. An- represents a monovalent anion.) <3> Further, it contains hydroxycarboxylic acid (B). <1> or <2> 2. The processing liquid for resin printing plates according to claim 1 . <4> The hydroxycarboxylic acid (B) contains diglucosyl gallic acid. <3> 2. The processing liquid for resin printing plates according to claim 1 . <5> A step of forming a relief by partially removing a relief-forming layer of a resin printing plate precursor having a relief-forming layer on a support; <1> ~ <4> 2. A method for producing a resin printing plate, comprising the step of contacting a printing plate with the processing liquid according to any one of claims 1 to 11. <6> <5> 2. A method for producing a printed matter, comprising the steps of obtaining a resin printing plate by the method described in 1., depositing ink on the relief, and transferring the ink to a substrate. <7> The ink is an ultraviolet-curable ink and / or an electron beam-curable ink. <6> A method for producing a printed matter according to claim 1. Effect of the Invention

[0010] The printing plate treating liquid of the present invention makes it possible to obtain a resin printing plate having excellent printability and which is less susceptible to printing voids caused by foreign matter. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The treatment liquid for resin printing plates according to the present invention (hereinafter sometimes abbreviated as "treatment liquid") is suitably used for letterpress printing plates such as resin letterpress printing plates and flexographic printing plates, and is particularly suitably used for flexographic printing plates which have a soft relief and are prone to foreign matter adhering thereto.

[0012] The treatment liquid of the present invention contains a cationic surfactant (A) having a hydrocarbon group having 10 or more carbon atoms (hereinafter, may be abbreviated as "surfactant (A)"). The surfactant (A) has the effect of suppressing the adhesion of dust, dirt, paper powder, etc., which are the cause of printing defects due to foreign matter, to the relief. It is preferable that the treatment liquid further contains water, which acts as a solvent for the surfactant (A). The surfactant (A) may be present in an ionized state by dissolving in water in the treatment liquid.

[0013] The cationic surfactant (A) refers to a surfactant in which the atomic group exhibiting surface activity is a cationic group, and examples of the cationic group include quaternary ammonium, tertiary amine, and salts thereof. Two or more of these may be included. Among these, quaternary ammonium salts are preferred.

[0014] The relief of a resin printing plate generally has anionic groups derived from a binder resin or the like. Since the surfactant (A) has cationic groups, it is held on the relief surface by ionic bonds with the anionic groups of the relief of the resin printing plate. Here, the surfactant (A) has a hydrocarbon group having 10 or more carbon atoms, which can suppress interactions with hydroxyl groups of, for example, cellulose fibers of paper powder. This can suppress the adhesion of the relief to the relief in the printing plate, and suppress the adhesion of dust, dirt, paper powder, etc., which cause print omissions due to foreign matter, to the relief, thereby suppressing print omissions due to foreign matter and improving printability.

[0015] Examples of the hydrocarbon group having 10 or more carbon atoms in the surfactant (A) include an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, an aryl group, and an arylalkyl group. Some of these hydrogen atoms may be substituted, and examples of the substituent include a nitro group, a thiol group, and an amino group. From the viewpoint of suppressing adhesion of dust, dirt, paper powder, etc., which cause printing defects due to foreign matter, to the relief, suppressing printing defects due to foreign matter, and improving printability, the number of carbon atoms in the hydrocarbon group is 10 or more, and preferably 16 or more. On the other hand, from the viewpoint of solubility in the treatment liquid, the number of carbon atoms in the hydrocarbon group is preferably 24 or less.

[0016] Examples of the surfactant (A) include quaternary ammonium salts such as alkyl quaternary ammonium salts and alkyl ether quaternary ammonium salts, tertiary amines such as hydroxyether alkylamines, ether amines, and alkylamidoamines, and salts thereof. Two or more of these may be contained. Among these, alkyl quaternary ammonium salts are preferred.

[0017] The cationic surfactant (A) preferably has a structure represented by the following general formula (1).

[0018] [ka]

[0019] In the above general formula (1), R1 represents an alkyl group or an alkenyl group having 10 or more carbon atoms. Among these, an alkyl group is preferable, and a linear alkyl group is more preferable. The number of carbon atoms of the alkyl group is preferably 16 or more and 28 or less.

[0020] R2 represents a hydrogen atom, an alkyl group having 1 to 28 carbon atoms, or a benzyl group. Among these, an alkyl group is preferable, and a linear alkyl group is more preferable. The number of carbon atoms in the alkyl group is preferably 1 to 6, and more preferably 1.

[0021] R3 and R4 may be the same or different and each represents an alkyl group having 1 to 5 carbon atoms. The alkyl group is preferably a linear alkyl group. The number of carbon atoms in the alkyl group is more preferably 1.

[0022] An - represents a monovalent anion. Examples of the monovalent anion include halide ions such as chloride ion and bromide ion, and organic anions such as ethyl sulfate ion and methyl carbonate ion. Among these, halide ions are preferred, and chloride ions are more preferred.

[0023] As the surfactant (A) having a structure represented by the general formula (1), for example, mono-long chain alkyl quaternary ammonium salts (wherein R1 is an alkyl group having 10 to 28 carbon atoms, R2 is an alkyl group having 1 to 6 carbon atoms, and R3 and R4 are alkyl groups having 1 to 5 carbon atoms) are preferred, and specific examples thereof include alkyl trimethyl ammonium chlorides such as lignoceryl trimethyl ammonium chloride, behenyl trimethyl ammonium chloride, stearyl trimethyl ammonium chloride, cetyl trimethyl ammonium chloride, lauryl trimethyl ammonium chloride, and decyl trimethyl ammonium chloride. Two or more of these may be contained. Among these, behenyl trimethyl ammonium chloride, stearyl trimethyl ammonium chloride, and cetyl trimethyl ammonium chloride are preferred.

[0024] The content of solids in the surfactant (A) in the treatment liquid is preferably 0.1% by weight or more, more preferably 0.5% by weight or more, and even more preferably 1.0% by weight or more, from the viewpoints of further suppressing adhesion of dust, dirt, paper powder, etc., which cause printing defects due to foreign matter, to the relief and further improving printability. On the other hand, the content of solids in the surfactant (A) is preferably 90% by weight or less, more preferably 50% by weight or less, and even more preferably 10% by weight or less, from the viewpoints of reducing the viscosity of the treatment liquid and economic efficiency.

[0025] The treatment liquid preferably further contains a hydroxycarboxylic acid (B). The cationic group of the surfactant (A) and the carboxyl group of the hydroxycarboxylic acid (B) form an electrically neutralized stable compound by ionic bonding. When the relief of the resin printing plate contains partially saponified polyvinyl alcohol, the hydroxyl group of the partially saponified polyvinyl alcohol and the hydroxyl group of the hydroxycarboxylic acid (B) form hydrogen bonds to hold the hydroxycarboxylic acid (B) in the relief. This action makes it possible to further suppress adhesion of dust, dirt, paper powder, etc., which cause print voids due to foreign matter, to the relief, thereby further suppressing print voids due to foreign matter and further improving printability. This effect can also be maintained in long-run printing.

[0026] Examples of the hydroxycarboxylic acid (B) include aliphatic hydroxycarboxylic acids such as lactic acid, citric acid, tartaric acid, malic acid, hydroxyacetic acid, 3-hydroxypropionic acid, 8-hydroxyoctanoic acid, 15-hydroxypentadecanoic acid, and 16-hydroxyhexadecanoic acid, and aromatic hydroxycarboxylic acids such as gallic acid, salicylic acid, 3-hydroxy-2-phenylpropanoic acid, benzilic acid, 4-hydroxybenzoic acid, and γ-resorcylic acid. , hyaluronic acid oligosaccharides such as hyaluronic acid tetrasaccharide, hyaluronic acid hexasaccharide, hyaluronic acid octasaccharide, hyaluronic acid decasaccharide, and hyaluronic acid dodecasaccharide; colominic acid oligosaccharides such as N-acetylneuraminic acid dimer α(2-8), N-acetylneuraminic acid trimer α(2-8), N-acetylneuraminic acid tetramer α(2-8), and N-acetylneuraminic acid pentamer α(2-8); monoglucosyl gallic acid, diglucosyl gallic acid, and the like. Two or more of these may be included. Among these, those having two or more hydroxyl groups per carboxyl group in the molecule are preferred, and when partially saponified polyvinyl alcohol is used as the resin for the relief of the printing plate, the hydroxyl carboxylic acid (B) is strongly held by the relief due to multiple hydrogen bonds between the hydroxyl group of the partially saponified polyvinyl alcohol and the hydroxyl group of the hydroxyl carboxylic acid (B), and therefore the surfactant (A) is stably held by the relief. More preferably, it has 3 or more hydroxyl groups, and even more preferably, it has 6 or more hydroxyl groups. Examples of hydroxycarboxylic acids having 2 or more hydroxyl groups per carboxy group in the molecule include γ-resorcylic acid, monoglucosyl gallic acid, citric acid, gallic acid, hyaluronic acid oligosaccharide, colominic acid oligosaccharide, and diglucosyl gallic acid. Among these, diglucosyl gallic acid having 6 or more hydroxyl groups per carboxy group in the molecule is more preferred.

[0027] The content of hydroxycarboxylic acid (B) in the treatment liquid is preferably 0.1% by weight or more, more preferably 0.5% by weight or more, and even more preferably 1.0% by weight or more, from the viewpoints of further suppressing adhesion of dust, dirt, paper powder, etc., which cause printing defects due to foreign matter, to the relief and further improving printability. On the other hand, the content of hydroxycarboxylic acid (B) is preferably 10% by weight or less, more preferably 5% by weight or less, and even more preferably 3% by weight or less, from the viewpoints of solubility in the treatment liquid, storage stability, and economic efficiency.

[0028] The treatment liquid may further contain, as necessary, a solvent such as an ether, an ester, an alcohol or a ketone, a dye, a pigment, a defoaming agent, an ink repellent, a fragrance, and the like.

[0029] Next, a method for producing a resin printing plate according to the present invention will be described. The method for producing a resin printing plate according to the present invention includes a step of forming a relief by partially removing a relief-forming layer of a resin printing plate precursor having a relief-forming layer on a support (a relief-forming step), and a step of contacting the relief with the above-mentioned processing liquid (a processing step).

[0030] The resin printing plate precursor preferably has at least a support and a relief-forming layer in this order, and the relief-forming layer is a layer that becomes a relief in the resin printing plate. Examples of the relief-forming layer include a photosensitive resin layer that undergoes polymerization by absorption of electromagnetic energy rays such as ultraviolet light and becomes insoluble in a developer, and a resin layer that can be engraved into a desired shape by electromagnetic energy rays such as laser light. The photosensitive resin layer can form a desired relief by, for example, irradiating it with ultraviolet light imagewise. Among these, a photosensitive resin layer that can be developed with water is preferred from the viewpoints of environmental load, productivity of the printing plate, and image reproducibility.

[0031] The water-developable photosensitive resin layer preferably contains, as a binder resin, a partially saponified polyvinyl alcohol having an anionic group such as a carboxy group or a carboxylate. Examples of resin printing plate precursors having a photosensitive resin layer containing such a binder resin include the photosensitive resin printing plate precursors described in WO 2018 / 088336.

[0032] Examples of the relief forming step include a method of engraving a relief forming layer into a desired shape by electromagnetic energy rays such as laser light, and when the relief forming layer is a photosensitive resin layer, a method having an exposure step of partially photocuring the photosensitive resin layer and a development step of removing uncured parts of the photosensitive resin layer with a developer, etc. Among these, from the viewpoints of productivity and image reproducibility of the printing plate, a method having an exposure step and a development step using a photosensitive resin layer as the relief forming layer is preferred.

[0033] First, the exposure step will be described. In the case where the printing plate precursor has a heat-sensitive mask layer, that is, a so-called CTP plate, the cover film is peeled off if it has one, and an image corresponding to the original film is drawn using a laser drawing machine, and then the photosensitive resin layer is photocured by irradiating it with ultraviolet light. In the case where the printing plate precursor does not have a heat-sensitive mask layer, the photosensitive resin layer is photocured by irradiating it with ultraviolet light through the original film. As the ultraviolet light, light with a wavelength of 300 to 400 nm is preferable, and examples of lamps used for ultraviolet light irradiation include high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, xenon lamps, carbon arc lamps, and chemical lamps. In particular, when reproducibility of fine thin lines and independent points is required, it is also possible to form a floor layer by short-time exposure (back exposure) from the support side before peeling off the cover film.

[0034] Next, the developing step will be described. The exposed printing plate precursor is immersed in a developer, and the uncured portion of the photosensitive resin layer is removed by the developer using a brush-type developer or a spray-type developer, thereby forming a relief image on the substrate. The developer preferably contains water, and may contain additives as necessary. The developer temperature during development is preferably 15 to 40°C.

[0035] After development, it is preferable to dry the film for about 10 minutes at 50 to 70° C. If necessary, post-exposure may be performed by irradiating the film with actinic rays in the atmosphere or in a vacuum.

[0036] Next, the processing step will be described. The processing step is preferably carried out after the relief forming step, but may be carried out before the above-mentioned drying or post-exposure. In addition, the developing step and the processing step may be carried out simultaneously by using a processing solution as a developer in the developing step.

[0037] Examples of the method for bringing the relief into contact with the processing liquid include a method using the processing liquid as a developer in the development step, a method of immersing the formed relief in the processing liquid, a method of wiping the relief with a sponge or cloth soaked in the processing liquid, a method of spraying the processing liquid onto the relief, etc. These methods may be performed continuously or batchwise.

[0038] The temperature of the treatment liquid in the treatment step is preferably 10° C. or higher, more preferably 20° C. or higher, from the viewpoint of suppressing precipitation of the surfactant (A) and the hydroxycarboxylic acid (B). On the other hand, the temperature of the treatment liquid in the treatment step is preferably 100° C. or lower, more preferably 80° C. or lower, from the viewpoint of suppressing volatilization of the treatment liquid.

[0039] The contact time between the relief and the processing solution in the processing step is preferably 10 seconds or more, more preferably 1 minute or more, from the viewpoint of further suppressing adhesion of foreign matter to the relief, whereas the contact time between the relief and the processing solution in the processing step is preferably 1 hour or less, from the viewpoint of work efficiency.

[0040] It is preferable to have a drying step for removing the treatment liquid remaining on the relief surface of the printing plate after the treatment step. In the drying step, the surfactant (A) reacts with the resin contained in the relief to form a dense film, which can further suppress adhesion of foreign matter to the relief during printing. Examples of drying methods include natural drying, air drying, heat drying, vacuum drying, and freeze drying. Among these, heat drying is preferred from the viewpoint of work efficiency. The heating temperature for heat drying is preferably 30° C. or higher, more preferably 50° C. or higher, from the viewpoint of drying speed. The drying time is preferably 5 minutes or longer.

[0041] Next, a method for producing a printed matter of the present invention will be described. The method for producing a printed matter of the present invention includes a step of adhering ink to the relief of the resin printing plate obtained by the above-mentioned method, and a step of transferring the ink to a printing medium. Examples of flexographic printing machines include in-line type, center drum type, and stack type.

[0042] The ink is preferably an ultraviolet curable ink or an electron beam curable ink. The ultraviolet curable ink is preferably one containing, for example, a pigment, a resin such as an acrylic oligomer, an acrylate monomer, a polymerization initiator, etc., and more specifically, for example, commercially available flexographic printing inks such as PHA (manufactured by T&K TOKA Co., Ltd.), "FLASH DRY" (registered trademark) (manufactured by Toyo Ink Co., Ltd.), and "UVAFLEX" (registered trademark) Y77 (manufactured by Zeller+Gmelin). The electron beam curable ink is preferably one containing, for example, a pigment, a resin such as an acrylic oligomer, an acrylate monomer, etc., and more specifically, for example, flexographic printing inks such as "GelFlex EB" (registered trademark) (manufactured by SAKATA INX). EXAMPLES

[0043] The materials used in each of the examples and comparative examples are shown below.

[0044] (Cationic Surfactant) · TMO (cationic surfactant, octyltrimethylammonium chloride, manufactured by Tokyo Chemical Industry Co., Ltd.) "Kachiogen" (registered trademark) TML (cationic surfactant, 30% by weight aqueous solution of lauryl trimethyl ammonium chloride, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) "Kachiogen" (registered trademark) TMP (cationic surfactant, 30% by weight aqueous solution of cetyltrimethylammonium chloride, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) "Kachiogen" (registered trademark) TMS (cationic surfactant, 25% by weight aqueous solution of stearyl trimethyl ammonium chloride, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) "Nissan Cation" (registered trademark) VB-F (cationic surfactant, 80% by weight ethanol solution of behenyl trimethyl ammonium chloride, manufactured by NOF Corporation) (Hydroxycarboxylic acid (B)) Citric acid (Tokyo Chemical Industry Co., Ltd.) DGA (diglucosyl gallic acid, Mitsui Chemicals Fine Co., Ltd.) (others) ·Water (high purity purified water, product number W10-A2, JIS standard A2~A3, manufactured by Trusco Co., Ltd.) Ethanol (Ethanol (99.5%), Specification: Special grade, Produced by Yoneyama Pharmaceutical Industry Co., Ltd.).

[0045] (Production Example 1: Preparation of Flexographic Printing Plate Precursor 1) [Preparation of a support having a primer layer and an adhesive layer] A mixture of 260 parts by weight of "Vylon" (registered trademark) 31SS (toluene solution of saturated 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.) was heated at 70°C for 2 hours, cooled to 30°C, and 7 parts by weight of ethylene glycol diglycidyl ether dimethacrylate was added and mixed for 2 hours. Furthermore, 25 parts by weight of "Coronate" (registered trademark) 3015E (ethyl acetate solution of polyisocyanate resin, manufactured by Tosoh Co., Ltd.) and 14 parts by weight of EC-1368 (industrial adhesive, manufactured by Sumitomo 3M Co., Ltd.) were added and mixed to obtain a primer layer composition solution.

[0046] The primer layer composition solution was applied using a bar coater onto a 188 μm-thick "Lumirror" (registered trademark) T60 (polyester film, manufactured by Toray Industries, Inc.) so that the thickness after drying would be 40 μm. The solution was then heated in an oven at 180° C. for 3 minutes to remove the solvent, forming a primer layer.

[0047] 50 parts by weight of "GOHSENOL" (registered trademark) KH-17 (partially saponified polyvinyl alcohol with a saponification degree of 78.5 to 81.5 mol%, weight average molecular weight 165,000, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) were mixed in a mixed solvent of 200 parts by weight of "SOLMIX" (registered trademark) H-11 (alcohol mixture, manufactured by Nippon Alcohol Co., Ltd.) and 200 parts by weight of water at 70°C for 2 hours, and then 1.5 parts by weight of "BLEMMER" (registered trademark) G (glycidyl methacrylate, manufactured by NOF Corporation) was added and mixed for 1 hour. A mixture of 3 parts by weight of "Irgacure" (registered trademark) 651 (benzyl methyl ketal, manufactured by BASF), 21 parts by weight of Epoxy Ester 70PA (acrylic acid adduct of propylene glycol diglycidyl ether, manufactured by Kyoeisha Chemical Co., Ltd.) and 20 parts by weight of ethylene glycol diglycidyl ether dimethacrylate was added and mixed for 90 minutes. The mixture was then cooled to 50°C, after which 0.1 parts by weight of "Megafac" (registered trademark) F-556 (manufactured by DIC Corporation) was added and mixed for 30 minutes to obtain an adhesive layer composition solution.

[0048] The adhesive layer composition solution was applied onto the primer layer using a bar coater so that the thickness after drying would be 30 μm, and the solution was heated in an oven at 160° C. for 3 minutes to remove the solvent, thereby forming an adhesive layer.

[0049] After that, an ultra-high pressure mercury lamp (JP2000T, Oak Manufacturing Co., Ltd.) was used from the adhesive layer side to illuminate the adhesive layer with a cumulative light intensity of 1,000 mJ / cm. 2 The above exposure treatment was carried out to obtain a support composed of an adhesive layer / primer layer / PET film.

[0050] [Formation of photosensitive resin layer] "GOHSENOL" (registered trademark) KL-05 (partially saponified polyvinyl alcohol with a saponification degree of 78.5 to 82.0 mol%, weight average molecular weight 38,000, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) was swollen in acetone, and 1.0 mol% of succinic anhydride was added and stirred at 60°C for 6 hours to add carboxyl groups to the molecular chains. This polymer was washed with acetone to remove unreacted succinic anhydride and dried to obtain a resin having carboxyl groups as anionic groups. The acid value was measured to be 10.0 mgKOH / g.

[0051] Into a three-neck flask equipped with a stirring spatula and a cooling tube, 40 parts by weight of the obtained resin, 30 parts by weight of trimethylolpropane (weight average molecular weight: 134) as a plasticizer, 40 parts by weight of an alcohol mixture ("Solmix" (registered trademark) H-11, manufactured by Japan Alcohol Co., Ltd.) as a solvent, and 60 parts by weight of distilled water were placed, and the mixture was heated at 77°C for 2 hours with stirring to dissolve the resin and plasticizer.

[0052] After the melt was cooled to 70° C., 5 parts by weight of glycidyl methacrylate was added and stirred for 1 hour.

[0053] Next, 10 parts by weight of polyethylene glycol monomethacrylate (monofunctional hydroxyl group, NOF Corporation, "Blenmer" (registered trademark) AE400) and 10 parts by weight of polyethylene glycol dimethacrylate (NOF Corporation, "Blenmer" (registered trademark) AD400), as compounds having an ethylenic double bond, 1.3 parts by weight of benzyl dimethyl ketal as a photopolymerization initiator, and 0.05 parts by weight of 2-(2'-hydroxy-3'-t-butyl-5'-methylphenyl)-5-chlorobenzotriazole as an ultraviolet absorber were added and stirred for 60 minutes to obtain a photosensitive resin layer composition solution.

[0054] [Cover film production for CTP plates] Eleven parts by weight of "GOHSENOL" (registered trademark) KL-05 (partially saponified polyvinyl alcohol with a saponification degree of 78.5 mol% to 82.0 mol%, weight average molecular weight of 38,000, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) were dissolved in 55 parts by weight of water, 14 parts by weight of methanol, 10 parts by weight of n-propanol, and 10 parts by weight of n-butanol to obtain a peeling auxiliary layer composition solution.

[0055] A carbon black dispersion was prepared by kneading and dispersing a mixture of 23 parts by weight of carbon black MA100 (manufactured by Mitsubishi Chemical Corporation), 15 parts by weight of "DIANAL" (registered trademark) BR-95 (an alcohol-insoluble acrylic resin, manufactured by Mitsubishi Rayon Co., Ltd.), 1 part by weight of plasticizer ATBC (acetyl tributyl citrate, manufactured by J-Plus Corporation) and 30 parts by weight of methyl isobutyl ketone in advance using a three-roll mill.

[0056] To the carbon black dispersion, 1 part by weight of AER6071 (epoxy resin, manufactured by Asahi Kasei Chemicals Corporation), 1 part by weight of "U-Ban" (registered trademark) 20SE60 (melamine resin, manufactured by Mitsui Chemicals, Inc.), 0.05 part by weight of Light Ester P-1M (phosphate monomer, manufactured by Kyoeisha Chemical Co., Ltd.), and 100 parts by weight of methyl isobutyl ketone were added and stirred for 30 minutes to obtain a heat-sensitive mask layer composition solution.

[0057] "GOHSENOL" (registered trademark) AL-06 (partially saponified polyvinyl alcohol with a saponification degree of 91 to 94 mol%, weight average molecular weight of 46,500, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) was dissolved in a mixed solvent of water:ethanol = 50:50 (weight ratio) to obtain an adhesion adjusting layer composition solution.

[0058] The peeling auxiliary layer composition solution was applied using a bar coater onto a 100 μm thick polyester film "Lumilar" (registered trademark) S10 (manufactured by Toray Industries, Inc.) so that the thickness after drying would be 0.1 μm, and the coating was dried at 120° C. for 20 seconds to form a peeling auxiliary layer.

[0059] Next, the heat-sensitive mask layer composition solution was applied onto the peeling auxiliary layer using a bar coater so as to give a dried thickness of 1.0 μm, and dried at 140° C. for 20 seconds to form a heat-sensitive mask layer.

[0060] Further, the adhesive strength adjusting layer composition solution was applied onto the heat-sensitive mask layer using a bar coater so that the thickness after drying would be 1.0 μm, and the solution was dried for 20 seconds at 120° C. to form an adhesive strength adjusting layer. In this way, a cover film for a CTP plate, which is a laminate of an adhesive strength adjusting layer / heat-sensitive mask layer / peeling auxiliary layer / protective layer, was obtained.

[0061] [Preparation of flexographic printing plate precursor 1] A mixed solvent of water / ethanol = 50 / 50 (weight ratio) was applied onto the photosensitive resin layer obtained by the method described above, and the cover film for the CTP plate obtained by the method described above was pressed onto the photosensitive resin layer with the adhesion adjustment layer facing the photosensitive resin layer, thereby obtaining flexographic printing plate precursor 1.

[0062] (Production Example 2: Preparation of Flexographic Printing Plate Precursor 2) [Preparation of a support having a primer layer and an adhesive layer] and [Formation of a photosensitive resin layer] were carried out in the same manner as in Production Example 1. A mixed solvent of water / ethanol = 50 / 50 (weight ratio) was applied onto the photosensitive resin layer, and a polyester film "Lumirror" (registered trademark) S10 (manufactured by Toray Industries, Inc.) having a thickness of 100 μm was pressed as a cover film. Next, a high-intensity chemical lamp (TL-K 40W / 10R manufactured by Philips) was used from each of the support side and the cover film side, with an accumulated light amount of 12,000 mJ / cm2 for each. 2 Thus, a flexographic printing plate precursor 2 for engraving was obtained.

[0063] (Production Example 3: Preparation of resin letterpress printing plate precursor) The same procedure as in Production Example 1 was carried out for [Preparation of a support having a primer layer and an adhesive layer].

[0064] "GOHSENOL" (registered trademark) KL-05 (partially saponified polyvinyl alcohol with a saponification degree of 78.5 to 82.0 mol%, weight average molecular weight 38,000, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) was swollen in acetone, and 1.0 mol% of succinic anhydride was added and stirred at 60°C for 6 hours to add carboxyl groups to the molecular chains. This polymer was washed with acetone to remove unreacted succinic anhydride and dried to obtain a resin having carboxyl groups as anionic groups. The acid value was measured to be 10.0 mgKOH / g.

[0065] Into a three-neck flask equipped with a stirring spatula and a cooling tube, 50 parts by weight of the obtained resin, 10 parts by weight of pentaerythritol polyoxyethylene ether as a plasticizer, 50 parts by weight of an alcohol mixture ("Solmix" (registered trademark) H-11, manufactured by Japan Alcohol Co., Ltd.) as a solvent, and 50 parts by weight of distilled water were placed, and the mixture was heated at 90°C for 2 hours with stirring to dissolve the resin and plasticizer.

[0066] After cooling this solution to 70°C, 8 parts by weight of 2-hydroxy-3-phenoxypropyl acrylate, 4 parts by weight of 3-acryloyloxy-2-hydroxypropyl methacrylate, 10 parts by weight of glycerol dimethacrylate, and 6 parts by weight of an acrylic acid adduct of propylene glycol diglycidyl ether as compounds having an ethylenic double bond, 1.3 parts by weight of 2,2-dimethoxy-1,1-diphenylethan-1-one as a photopolymerization initiator, and 0.02 parts by weight of 2-(2'-hydroxy-3'-t-butyl-5'-methylphenyl)-5-chlorobenzotriazole as an ultraviolet absorber were added and stirred for 60 minutes to obtain a photosensitive resin layer composition solution.

[0067] A resin letterpress printing plate precursor was produced by carrying out [Formation of photosensitive resin layer] and [Preparation of cover film for CTP plate] in the same manner as in Production Example 1, except that the obtained photosensitive resin composition solution was used.

[0068] (Manufacturing Example 4: Preparation of Flexographic Printing Plate 1) For the flexographic printing plate precursor 1 obtained in Production Example 1, the protective layer of the cover film was peeled off, and the plate was attached to an external drum type plate setter CDI SPARK (manufactured by Esko Graphics Co., Ltd.) equipped with a fiber laser having an infrared light emission region, with the support side in contact with the drum, and a test pattern (having 150 lines, 4% dots and a 10 cm x 10 cm solid area) was drawn to form an image mask on the heat-sensitive mask layer.

[0069] Next, a batch-type exposure and development machine, Tomiflex (manufactured by Tomihaku Sangyo Co., Ltd.), was used to develop the film with an integrated light dose of 16,000 mJ / cm. 2 After exposure to light of about 1000 mJ / cm2, the film was developed for 60 seconds using tap water adjusted to 25°C as the developer. The film was then dried in an oven at 60°C for 10 minutes. 2 This resulted in the production of flexographic printing plate 1. The halftone dots of the resulting flexographic printing plate 1, 150 lines / 4% halftone dots formed in an area of ​​1 cm x 1 cm, were observed using a 10x magnifying glass, and no chipping was observed.

[0070] (Production Example 5: Preparation of Flexographic Printing Plate 2) The cover film was peeled off from the flexographic printing plate precursor 2 obtained in Production Example 2, and a test pattern (having 150 line 4% dots and a 10 cm x 10 cm solid area) was laser engraved using a direct laser engraving system Adflex Direct 250L (manufactured by Comtex Co., Ltd.). Next, using a platemaking device DX-A3 (manufactured by Takano Co., Ltd.), the plate was rinsed with tap water at 25°C for 1.5 minutes, and then dried in a hot air dryer at 60°C for 10 minutes to obtain a flexographic printing plate 2. The dots of the obtained flexographic printing plate 2: 150 line 4% dots formed in an area of ​​1 cm x 1 cm were observed using a magnifying glass with a magnification of 10 times, and no chipping was observed.

[0071] (Production Example 6: Preparation of resin letterpress printing plate) For the resin letterpress printing plate precursor obtained in Production Example 3, the protective layer of the cover film was peeled off, and the plate was attached to an external drum-type platesetter CDI SPARK (manufactured by Esko Graphics Co., Ltd.) equipped with a fiber laser having an infrared light emission region, with the support side in contact with the drum, and a test pattern (having 150 lines, 4% dots and a 10 cm x 10 cm solid area) was drawn to form an image mask on the thermal mask layer.

[0072] Next, using a batch-type exposure and development machine Tomiflex (manufactured by Tomihaku Sangyo Co., Ltd.), the film was exposed to light with an accumulated light dose of about 16,000 mJ / cm2, and then developed for 60 seconds using tap water adjusted to a temperature of 25°C as the developer. Then, the film was dried for 10 minutes at 60°C in an oven. After that, the film was dried at an accumulated light dose of 16,000 mJ / cm2. 2 The resin letterpress printing plate was then exposed (post-exposed) to obtain a resin letterpress printing plate. The halftone dots of the obtained resin letterpress printing plate, 150 lines / 4% halftone dots formed in an area of ​​1 cm x 1 cm, were observed using a 10x magnifying glass, and no chipping was observed.

[0073] The evaluation methods used in each of the Examples and Comparative Examples are shown below.

[0074] (1) Printability The flexographic printing plate or resin letterpress printing plate after the treatment obtained in each Example and Comparative Example was mounted on a flexographic printing machine (MPS EF340) equipped with a 991LPI anilox roll. Using UV Flexo Red PHA-LO3 / T&K TOKA, which is an ultraviolet-curing ink, the solid density was adjusted to 1.65, and 20,000m was printed on mirror-coated paper (Oji Tack N Mirror 73 / P22 / G7B, Oji Paper Co., Ltd.) at a speed of 60m / min. The number of print defects in a 10cm x 10cm solid area was observed using a 10x magnifying glass for the prints at 5,000m, 10,000m, and 20,000m. Print defects were evaluated according to the following criteria, and a score of 4 or more at the time of printing 5,000m was considered to be acceptable. 5: Fewer than 5 missing prints 4: The number of printing defects is between 5 and 10. 3: The number of printing defects is between 10 and 15. 2: The number of printing defects is between 15 and 20. 1: There are 20 or more printing defects.

[0075] Example 1 A treatment liquid was obtained by mixing 8.0 parts by weight of TMS as the cationic surfactant (A) and 92.0 parts by weight of water at room temperature. Here, the content of the surfactant having the structure represented by the general formula (1), which is the solid content of the cationic surfactant (A) in the treatment liquid, was 2.0% by weight. The temperature of the prepared treatment liquid was kept at 30°C, and the flexographic printing plate 1 obtained in Production Example 4 was immersed together with the support for 2 minutes. The flexographic printing plate was then dried by heating at 60°C for 30 minutes. The results of the evaluation by the above-mentioned method are shown in Table 1.

[0076] Example 2 As the cationic surfactant (A), 6.7 parts by weight of TML and 93.3 parts by weight of water were mixed at room temperature to obtain a treatment liquid. Here, the content of the surfactant having the structure represented by general formula (1), which is the solid content of the cationic surfactant (A) in the treatment liquid, was 2.0% by weight. The prepared treatment liquid was used to treat a flexographic printing plate 1 in the same manner as in Example 1, and evaluation was performed. The results are shown in Table 1.

[0077] Example 3 As the cationic surfactant (A), 6.7 parts by weight of TMP and 93.3 parts by weight of water were mixed at room temperature to obtain a treatment liquid. Here, the content of the surfactant having the structure represented by general formula (1), which is the solid content of the cationic surfactant (A) in the treatment liquid, was 2.0% by weight. The prepared treatment liquid was used to treat a flexographic printing plate 1 in the same manner as in Example 1, and evaluation was performed. The results are shown in Table 1.

[0078] Example 4 2.5 parts by weight of VB-F as cationic surfactant (A), 78.0 parts by weight of water, and 19.5 parts by weight of ethanol were mixed at room temperature to obtain a treatment liquid. Here, the content of the surfactant having a structure represented by general formula (1), which is the solid content of surfactant (A) in the treatment liquid, was 2.0% by weight, and the content of ethanol was 20.0% by weight. Flexographic printing plate 1 was treated and evaluated using the prepared treatment liquid in the same manner as in Example 1. The results are shown in Table 1.

[0079] Example 5 0.4 parts by weight of TMS as cationic surfactant (A) and 99.6 parts by weight of water were mixed at room temperature to obtain a treatment liquid. Here, the content of the surfactant having a structure represented by general formula (1), which is the solid content of surfactant (A) in the treatment liquid, was 0.1% by weight. Flexographic printing plate 1 was treated and evaluated using the prepared treatment liquid in the same manner as in Example 1. The results are shown in Table 1.

[0080] Example 6 As the cationic surfactant (A), 60.0 parts by weight of TMS and 40.0 parts by weight of water were mixed at room temperature to obtain a treatment liquid. Here, the content of the surfactant having a structure represented by general formula (1), which is the solid content of the surfactant (A) in the treatment liquid, was 15.0% by weight. The prepared treatment liquid was used to treat flexographic printing plate 1 in the same manner as in Example 1, and evaluation was performed. The results are shown in Table 1.

[0081] Comparative Example 1 2.0 parts by weight of TMO as a cationic surfactant and 98.0 parts by weight of water were mixed at room temperature to obtain a treatment liquid. Here, the solid content of the cationic surfactant in the treatment liquid was 2.0% by weight. Flexographic printing plate 1 was treated and evaluated using the prepared treatment liquid in the same manner as in Example 1. The results are shown in Table 1.

[0082] Example 7 A treatment liquid was obtained by mixing 8.0 parts by weight of TMS as the cationic surfactant (A), 90.5 parts by weight of water, and 1.5 parts by weight of DGA as the hydroxycarboxylic acid (B) at room temperature. Here, the content of the surfactant having the structure represented by the general formula (1), which is the solid content of the cationic surfactant (A) in the treatment liquid, was 2.0% by weight, and the content of the hydroxycarboxylic acid (B) was 1.5% by weight. The prepared treatment liquid was used to treat a flexographic printing plate 1 in the same manner as in Example 1, and evaluation was performed. The results are shown in Table 2.

[0083] Example 8 A treatment liquid was obtained by mixing 6.7 parts by weight of TML as cationic surfactant (A), 91.8 parts by weight of water, and 1.5 parts by weight of DGA as hydroxycarboxylic acid (B) at room temperature. Here, the content of the surfactant having a structure represented by general formula (1), which is the solid content of the cationic surfactant (A) in the treatment liquid, is 2.0% by weight, and the content of the hydroxycarboxylic acid (B) is 1.5% by weight. The prepared treatment liquid was used to treat a flexographic printing plate 1 in the same manner as in Example 1, and evaluation was performed. The results are shown in Table 2.

[0084] Example 9 A treatment liquid was obtained by mixing 6.7 parts by weight of TMP as the cationic surfactant (A), 91.8 parts by weight of water, and 1.5 parts by weight of DGA as the hydroxycarboxylic acid (B) at room temperature. Here, the content of the surfactant having a structure represented by general formula (1), which is the solid content of the cationic surfactant (A) in the treatment liquid, was 2.0% by weight, and the content of the hydroxycarboxylic acid (B) was 1.5% by weight. The prepared treatment liquid was used to treat a flexographic printing plate 1 in the same manner as in Example 1, and evaluation was performed. The results are shown in Table 2.

[0085] Example 10 2.5 parts by weight of VB-F as cationic surfactant (A), 76.5 parts by weight of water, 1.5 parts by weight of DGA as hydroxycarboxylic acid (B), and 19.5 parts by weight of ethanol were mixed at room temperature to obtain a treatment liquid. Here, the content of the surfactant having a structure represented by general formula (1), which is the solid content of the cationic surfactant (A) in the treatment liquid, is 2.0% by weight, and the content of the hydroxycarboxylic acid (B) is 1.5% by weight. The prepared treatment liquid was used to treat flexographic printing plate 1 in the same manner as in Example 1, and evaluation was performed. The results are shown in Table 2.

[0086] Example 11 0.4 parts by weight of TMS as cationic surfactant (A), 98.1 parts by weight of water, and 1.5 parts by weight of DGA as hydroxycarboxylic acid (B) were mixed at room temperature to obtain a treatment liquid. Here, the content of the surfactant having a structure represented by general formula (1), which is the solid content of the cationic surfactant (A) in the treatment liquid, was 2.0% by weight, and the content of the hydroxycarboxylic acid (B) was 1.5% by weight. The prepared treatment liquid was used to treat flexographic printing plate 1 in the same manner as in Example 1, and evaluation was performed. The results are shown in Table 2.

[0087] Example 12 A treatment liquid was obtained by mixing 60.0 parts by weight of TMS as the cationic surfactant (A), 38.5 parts by weight of water, and 1.5 parts by weight of DGA as the hydroxycarboxylic acid (B) at room temperature. Here, the content of the surfactant having the structure represented by the general formula (1), which is the solid content of the cationic surfactant (A) in the treatment liquid, was 15.0% by weight, and the content of the hydroxycarboxylic acid (B) was 1.5% by weight. The prepared treatment liquid was used to treat a flexographic printing plate 1 in the same manner as in Example 1, and evaluation was performed. The results are shown in Table 2.

[0088] Example 13 A treatment liquid was obtained in the same manner as in Example 7, except that DGA was replaced with citric acid as the hydroxycarboxylic acid (B). Flexographic printing plate 1 was treated with the prepared treatment liquid in the same manner as in Example 1, and evaluation was carried out. The results are shown in Table 3.

[0089] Example 14 A treatment liquid was obtained by mixing 8.0 parts by weight of TMS as the cationic surfactant (A), 87.0 parts by weight of water, and 5.0 parts by weight of DGA as the hydroxycarboxylic acid (B) at room temperature. Here, the content of the surfactant having a structure represented by general formula (1), which is the solid content of the cationic surfactant (A) in the treatment liquid, was 2.0% by weight, and the content of the hydroxycarboxylic acid (B) was 5.0% by weight. The prepared treatment liquid was used to treat a flexographic printing plate 1 in the same manner as in Example 1, and evaluation was performed. The results are shown in Table 3.

[0090] Example 15 A treatment liquid was prepared in the same manner as in Example 7. The resulting treatment liquid was used to treat and evaluate the flexographic printing plate 2 obtained in Production Example 5 in the same manner as in Example 1. The results are shown in Table 3.

[0091] (Example 16) For the flexographic printing plate precursor 1 obtained in Production Example 1, an image mask was formed on the heat-sensitive mask layer in the same manner as in Production Example 4. A flexographic printing plate was produced by exposure, development, drying, and post-exposure in the same manner as in Production Example 4, except that the processing solution obtained in the Example was used instead of tap water adjusted to 25°C as the developer for the batch-type exposure and development machine Tomiflex (manufactured by Tomihaku Sangyo Co., Ltd.). In this example, development and processing with the processing solution were carried out simultaneously. The halftone dots of the obtained flexographic printing plate: 150 lines 4% halftone dots formed in an area of ​​1 cm x 1 cm were observed using a magnifying glass with a magnification of 10 times, and no chipping was observed. The results of evaluation by the above-mentioned method are shown in Table 3.

[0092] (Example 17) A treatment liquid was prepared in the same manner as in Example 7. The resin letterpress printing plate obtained in Production Example 6 was treated and evaluated using the treatment liquid in the same manner as in Example 1. The results are shown in Table 3.

[0093] [Table 1]

[0094]

Table 2

[0095]

Table 3

Claims

1. A treatment liquid for resin printing plates, comprising a cationic surfactant (A) having a hydrocarbon group having 10 or more carbon atoms.

2. The treatment liquid for resin printing plates according to claim 1 , wherein the cationic surfactant (A) has a structure represented by the following general formula (1): 【Chemistry 1】 (In the above general formula (1), R1 represents an alkyl group or an alkenyl group having 10 or more carbon atoms. R2 represents a hydrogen atom, an alkyl group having 1 to 28 carbon atoms, or a benzyl group. R3 and R4 may be the same or different and represent an alkyl group having 1 to 5 carbon atoms. An － indicates a monovalent anion.)

3. The treatment liquid for resin printing plates according to claim 1 or 2, further comprising a hydroxycarboxylic acid (B).

4. 4. The processing liquid for resin printing plates according to claim 3, which contains diglucosyl gallic acid as the hydroxycarboxylic acid (B).

5. 3. A method for producing a resin printing plate, comprising: a step of forming a relief by partially removing a relief-forming layer of a resin printing plate precursor having a relief-forming layer on a support; and a step of contacting the relief with the treatment liquid according to claim 1.

6. A method for producing a printed matter, comprising the steps of obtaining a resin printing plate by the method according to claim 5, depositing ink on the relief, and transferring the ink to a substrate.

7. The method for producing a printed matter according to claim 6, wherein the ink is an ultraviolet-curable ink and / or an electron beam-curable ink.

Images