WO2020203013A1 - Method for manufacturing printed matter - Google Patents

Abstract

The present invention provides a method for manufacturing printed matter that improves the adhesiveness of ink on a base material. This manufacturing method for printed matter uses a lithographic printing plate that applies an active energy ray curable lithographic printing ink on to the base material and irradiates same. The manufacturing method uses a dampening agent having a dissolved oxygen concentration of no more than 5 ppm.

Description

Printed matter manufacturing method

The present invention relates to a method for producing a printed matter.

With the global population increase, demand for flexible packaging used for packaging mainly for food and daily necessities is expected to continue to grow. At present, gravure printing, which is the mainstream in flexible packaging printing, can obtain printed matter with a vivid appearance. On the other hand, since gravure printing uses ink containing a large amount of solvent, a large amount of energy is required for drying the ink solvent and exhaust treatment, which has a large environmental load. Furthermore, as market needs are changing from conventional mass production and mass consumption to small lots, high-mix, and short delivery times, plate and plate making costs are expensive, and gravure printing, which was good at large lots, It also leads to an increase in production costs. Therefore, in recent years, attempts have begun to carry out flexible wrapping printing using lithographic printing, which is inexpensive in terms of plate cost and plate making cost and is superior in terms of cost in terms of small lots and short delivery time (Patent Document 1).

Planographic printing is a printing method that is widely used as a system for supplying printed matter at high speed, in large quantities, and at low cost. In addition, in recent years, there has been a demand to reduce the volatile components contained in lithographic printing inks in order to deal with environmental problems. For this reason, the use of lithographic printing inks that do not contain volatile components and are instantly cured by irradiation with active energy rays (hereinafter referred to as "active energy ray-curable lithographic printing inks") is being promoted. In flexible packaging printing, roll-to-roll printing is performed, so quick-drying of the ink is important. In addition to environmental advantages, active energy ray-curable lithographic printing using ink for active energy ray-curable lithographic printing has energy saving and high productivity because it shortens the drying process without using thermal energy. It is a thing.

In addition, since the main use of flexible package printed matter is food packaging, it is desirable that the radiation-curable lithographic printing ink does not contain a polymerization initiator from the viewpoint of preventing content contamination.

Japanese Patent Application Laid-Open No. 2004-358788

However, in general, the radiation-curable lithographic printing ink has low adhesion to the base material, and the adhesion to the base material is insufficient as compared with gravure printing.
Therefore, the present invention provides a method for producing a printed matter, which can improve the adhesion between the ink and the base material even when the active energy ray-curable lithographic printing ink is used.

As a result of diligent studies, the present inventors have found that the above problems can be solved by reducing the concentration of dissolved oxygen contained in the dampening water. That is, the present invention has the following configuration.
A method for producing a printed matter using a lithographic printing plate in which active energy ray-curable lithographic printing ink is transferred onto a substrate and irradiated with radiation, using dampening water having a dissolved oxygen concentration of 5 ppm or less. Printed matter manufacturing method.

According to the method for producing a printed matter according to the present invention, the adhesion of ink to a substrate can be improved.

Hereinafter, the present invention will be specifically described.
In the present invention, the active energy ray-curable lithographic printing ink refers to the ink in the state before curing, and the ink refers to the ink in the state after curing.

The method for producing a printed matter according to the present invention relates to a method for producing a printed matter using a lithographic printing plate, which includes a step of transferring an active energy ray-curable lithographic printing ink onto a substrate and irradiating it with radiation. That is, dampening water is attached to the non-image area of the lithographic printing plate, active energy ray-curable lithographic printing ink is attached to the image area of the lithographic printing plate, transferred onto the substrate, and irradiated. The present invention relates to a method for manufacturing a printed matter using a lithographic printing plate.

The method for producing a printed matter according to the present invention is characterized by using dampening water having a dissolved oxygen concentration of 5 ppm or less in the fountain solution. In printing, when the active energy ray-curable lithographic printing ink and the fountain solution, which are adjacently arranged on the lithographic printing plate, come into contact with each other, the fountain solution is emulsified by the active energy ray-curable lithographic printing ink and the active energy. It is dispersed in line-curable lithographic printing ink. Therefore, the higher the concentration of dissolved oxygen contained in the dampening water, the more easily the radicals generated on the surface of the base material due to irradiation are captured by the dissolved oxygen and deactivated. The dissolved oxygen concentration in normal dampening water is around 10 ppm because the water temperature is kept at a low temperature of around 15 ° C. On the other hand, in the method for producing a printed matter according to the present invention, the deactivation of radicals can be reduced by setting the dissolved oxygen concentration in the dampening water at 1 atm 15 ° C. to 5 ppm or less, and as a result, the active energy ray-curable type. Radical cross-linking between the lithographic printing ink and the base material progresses, and the adhesion of the ink to the base material is improved. The dissolved oxygen concentration is more preferably 1 ppm or less. Examples of the method for reducing the dissolved oxygen concentration in the dampening water include a bubbling method using an inert gas such as nitrogen and argon, a degassing method using hollow thread film separation, and a method using a deoxidizer. Further, these methods may be combined to reduce the dissolved oxygen concentration in the dampening water. The bubbling method is preferable because it is a method for simply reducing the dissolved oxygen concentration in the dampening water to 5 ppm or less. The degassing method is more preferable because it can reduce the dissolved oxygen concentration in the dampening water to 1 ppm or less. For the above reasons, the lower the dissolved oxygen concentration in the dampening water, the more preferable, but from the viewpoint of the detection sensitivity of the measuring device, 0.01 ppm or more is preferable.

Furthermore, it is preferable that the dampening water does not substantially contain an antioxidant. When the content of the antioxidant is substantially free, the content of the antioxidant is preferably 0.05% by mass or less, and more preferably 0.01% by mass or less. Originally, an antioxidant was added to the dampening water in order to suppress the oil sensitivity of the printing plate. The term "greasy" here means that the aluminum in the non-image area of the printing plate is oxidized and the hydrophilicity is lowered. Oxidation occurs when oxygen is added to the radicals generated in the compound. Since the antioxidant has a stronger radical scavenging ability than oxygen, it is preferable that the dampening water contains substantially no antioxidant. When the dampening water contains substantially no antioxidant, radical cross-linking between the active energy ray-curable lithographic printing ink and the base material proceeds, and the adhesion of the ink to the base material can be improved.

In the present invention, examples of the antioxidant include phenol-based, amine-based, and phosphorus-based organic antioxidants, metal-based antioxidants, and natural product-derived antioxidants. For example, examples of phenolic antioxidants include 2,6-di-t-butyl-p-cresol, 2,6-diphenyl-4-octadesiloxyphenol, and stearyl- (2,5-dimethyl-4-hydroxybenzyl). ) Thioglycolate, stearyl-β- (4-hydroxy-3,5-di-t-butylphenyl) propionate, distearyl-3,5-di-t-butyl-4-hydroxybenzylphosphonate, triethylene glycol bis [Β- (3-t-Butyl-4-hydroxy-5-methylphenyl) propionate], 3,9-bis [1,1-dimethyl-2- (β-3-t-butyl-4-hydroxy-5) -Methylphenyl) propionyloxyethyl] -2,4,8,10-tetraoxaspiro [5.5] undecane, 2,2'-methylenebis (4-methyl-6-t-butylphenol), bis [3,5 -Bis (4-hydroxy-3-t-butylphenyl) butyric acid] glucole ester, bis [2-t-butyl 4-methyl-6- (2-hydroxy-3-t-butyl-5-methylbenzyl) ) Phenyl] terephthalate, 2-t-butyl 4-methyl-6- (2-hydroxy-3-t-butyl-5-methylbenzyl) phenyl acrylate, 1,3,5-tris [β- (3,5-) Di-t-butyl 4-hydroxyphenyl) propionyloxyethyl] isocyanurate and the like.

Examples of amine-based antioxidants include monoalkyldiphenylamines having an alkyl group having 1 to 10 carbon atoms, dialkyldiphenylamines, polyalkyldiphenylamines, alkyl-substituted phenyl-α-naphthylamines, and the like. Monobutyldiphenylamine, monooctyldiphenylamine, monononyldiphenylamine, 4,4'-dibutyldiphenylamine, 4,4'-dipentyldiphenylamine, 4,4'-dihexyldiphenylamine, 4,4'-diheptyldiphenylamine, 4,4'- Dioctyldiphenylamine, 4,4'-dinonyldiphenylamine, 4-butyl-4'-octyldiphenylamine, tetrabutyldiphenylamine, tetrahexyldiphenylamine, tetraoctyldiphenylamine, tetranonyldiphenylamine, di (2,4-diethylphenyl) amine, di (2-Ethyl-4-nonylphenyl) amine, methylphenyl-α-naphthylamine, ethylphenyl-α-naphthylamine, butylphenyl-α-naphthylamine, hexylphenyl-α-naphthylamine, heptylphenyl-α-naphthylamine, octylphenyl- Examples thereof include α-naphthylamine, nonylphenyl-α-naphthylamine, dodecylphenyl-α-naphthylamine, phenyl-α-naphthylamine and the like.

Examples of phosphorus-based antioxidants include triphenyl phosphite, tris (nonylphenyl) phosphite, tris (monononylphenyl) phosphite, tris (dinonylphenyl) phosphite, and tris (2,4-dibutylphenyl). Phosphite, Octyldiphenylphosphite, Tetraalkylbisphenol A Diphosphite, Tetra (tridecyl) -4,4'-butylidenebis (3-methyl-6-t-butylphenol) diphosphite, Hexa (tridecyl) -1,1,3-tris (2-Methyl-5-t-butyl-4-hydroxyphenyl) butanetriphosphite, bis (nonylphenyl) pentaerythritol diphosphite, phenyl bisphenol A pentaerythritol diphosphite, bis (2,4-dit- Examples thereof include butylphenyl) pentaerythritol diphosphite and bis (2,6-dit-butyl-4-methylphenyl) pentaerythritol diphosphite.

Examples of the metal-based antioxidant include zinc-based and molybdenum-based antioxidants, and specific examples thereof include zinc dithiophosphate, molybdenum dialkyldithiophosphate, and molybdenum dithiocarbamate.

Examples of antioxidants derived from natural products include tocopherol, L-ascorbic acid stearate, L-ascorbic acid palmitate, and the like.

Examples of the radiation source in the method for producing a printed matter of the present invention include electron beams and gamma rays. Radiation generates high-energy secondary electrons in the irradiated material, excites surrounding molecules, and produces reactive species represented by radicals. Depending on the chemical structure of the irradiated substance, the produced reactive species cause various reactions such as cross-linking and decomposition. When the material to be irradiated is an active energy ray-curable lithographic printing ink, radicals are generated in the active energy ray-curable lithographic printing ink, radical polymerization proceeds, and a curing / ink film is formed. Radiation also acts on the substrate through the transferred active energy ray-curable lithographic printing ink. Radicals are also generated in the polymers that make up the base material, causing reactions such as cross-linking and decomposition between molecules. In particular, when radical polymerization proceeds between the active energy ray-curable lithographic printing ink and the base material, a covalent bond is formed between the ink and the base material, and high adhesion is exhibited.

The dampening water is preferably 90% by mass to 99% by mass.
The dampening water preferably contains an acid to make its pH acidic. Specific examples of the acid include acetic acid, citric acid, oxalic acid, malic acid, tartaric acid, lactic acid, ascorbic acid, gluconic acid, hydroxyacetic acid, malonic acid, sulfanilic acid, p-toluenesulfonic acid, organic phosphonic acid, and phosphoric acid. Examples include citric acid, sulfuric acid and polyphosphoric acid. Further, by containing an alkali metal salt, an alkaline earth metal salt, an ammonium salt, an organic amine salt and the like of these acids, it is possible to impart a buffering ability to the dampening water.

The dampening water can also contain alcohols and glycols in order to reduce the dynamic surface tension and make it easier to get wet on the printing plate surface. Specific examples include 3-methyl-1-butyne-3-ol, 2-butyne-1,4-diol, 3-methyl-1-pentyne-3-ol, and 2,5-dimethyl-3-hexyne-2. , 5-diol, 3,5-dimethyl-1-hexin-3-ol, 3,6-dimethyl-4-octyne-3,6-diol, 2,4,7,9-tetramethyl-5-decine- Examples thereof include 4,7-diol, 2,5,8,11-tetramethyl-6-dodecine-5,8-diol, and ethylene oxide adducts and propylene oxide adducts thereof.

The radiation used in the present invention is preferably an electron beam. In particular, it is preferable to use an electron beam with a low accelerating voltage because it has low permeability, energy is intensively applied to the surface layer of the object, and it is easy to handle without special qualification at the time of use. Since the transmission depth of the electron beam is determined by the accelerating voltage, 50 kV or more is preferable, 90 kV or more is more preferable, and 110 kV or more is further preferable, since a sufficient dose is transmitted through the ink film. Further, as the depth of transmission increases, the dose given to the inside of the base material also increases, so 300 kV or less is preferable, 200 kV or less is more preferable, and 150 kV or less is further preferable. Further, the higher the irradiation intensity of the electron beam, the greater the amount of radical species generated in the target substance, while the damage to the base material also increases. Therefore, the irradiation intensity is preferably 10 kGy or more and 100 kGy or less, and more preferably 20 kGy or more and 50 kGy or less. ..

The base material used in the present invention is preferably a plastic film. Examples of the plastic film include plastic films such as polyethylene, polyester, polyamide, polyimide, polyalkyl (meth) acrylate, polystyrene, polyα-methylstyrene, polypropylene, polycarbonate, polyvinyl alcohol, polyvinyl acetal, polyvinyl chloride, and polyvinylidene fluoride. Examples thereof include a plastic film laminated paper in which a plastic film is laminated on a paper, a metal-deposited plastic film in which a metal such as aluminum, zinc, and copper is vapor-deposited on the plastic. The plastic film preferably contains a radiation-crosslinked polymer, and more preferably one in which the radiation-crosslinked polymer is present on the outermost surface of the plastic film. Here, the radiation-crosslinked polymer refers to a polymer that does not decompose and undergoes a cross-linking reaction when irradiated with radiation. Specific examples thereof include polyethylene, polyester, polyamide, polyalkyl acrylate, polystyrene, polypropylene, polyvinyl alcohol, polyvinyl chloride, polyvinylidene fluoride, etc. Among them, polyethylene, which is a main base material in flexible packaging printing, Polyester and polyamide are preferable.

Further, it is preferable that these plastic films are surface-treated by an easy-adhesion coating or corona treatment. The more easily the material on the outermost surface of the plastic film generates radicals by irradiation, the more covalent bonds are formed by radical polymerization between the ink and the base material, and the adhesion is improved. As the easy-adhesion coat, an acrylic coat or a urethane coat is preferable. In particular, an acrylic coat containing an acrylic group, which is a functional group in which radicals are easily generated by electron beam irradiation, is more preferable.

The thickness of the base material is preferably 5 μm or more, more preferably 10 μm or more, from the mechanical strength of the base material required for printing. Further, the cost of the base material is preferably 50 μm or less, and more preferably 30 μm or less.

The active energy ray-curable lithographic printing ink used in the present invention contains a resin having an ethylenically unsaturated group because the reactivity with radicals existing on the film surface is improved and the adhesion is further improved. Is preferable.

Resins having an ethylenically unsaturated group include acrylic resin, styrene acrylic resin, styrene maleic acid resin, rosin-modified maleic acid resin, rosin-modified acrylic resin, epoxy resin, polyester resin, polyurethane resin, phenol resin and the like. Examples thereof include those having an ethylenically unsaturated group introduced therein and phthalate resins. For example, an acrylic resin having an ethylenically unsaturated group, a styrene acrylic resin, and a styrene maleic acid resin can be produced by the following method. That is, carboxyl group-containing monomers such as (meth) acrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, vinyl acetate or their acid anhydrides, hydroxyl group-containing monomers such as 2-hydroxyethyl (meth) acrylate, Amino group-containing monomers such as dimethylaminoethyl (meth) acrylate, mercapto group-containing monomers such as (meth) acrylic acid-2- (mercaptoacetoxy) ethyl, and sulfo group-containing monomers such as (meth) acrylamide-t-butylsulfonic acid. , 2-A compound selected from a phosphate group-containing monomer such as (meth) acryloxyethyl acid phosphate, (meth) acrylic acid ester, styrene, (meth) acrylonitrile, vinyl acetate, etc., is used as a radical polymerization initiator. A resin having a hydrophilic group can be obtained by polymerizing or copolymerizing with the above. Further, with respect to the mercapto group, amino group, hydroxy group and carboxy group which are active hydrogen-containing groups in the resin having a hydrophilic group, an ethylenically unsaturated compound having a glycidyl group and an isocyanate group, acrylic acid chloride and methacrylic acid By adding chloride or allyl chloride, a resin having an ethylenically unsaturated group can be obtained. However, the method is not limited to these methods.

Specific examples of the ethylenically unsaturated compound having a glycidyl group include glycidyl (meth) acrylate, allyl glycidyl ether, glycidyl crotonate, and glycidyl isocrotonate.

Specific examples of the ethylenically unsaturated compound having an isocyanate group include (meth) acryloyl isocyanate and (meth) acryloyl ethyl isocyanate.

As the phthalate resin, either one or two of diallyl orthophthalate and diallyl isophthalate can be mixed and obtained by carrying out a polymerization reaction in an organic solvent in the presence of a polymerization initiator. Of these, the unreacted portion remains in the resin as an ethylenically unsaturated group. As the phthalate resin, a commercially available product can be used in addition to the synthetic compound, and specific examples thereof include the Daiso Dapp (registered trademark) series manufactured by Osaka Soda Co., Ltd. and the Daiso Isodap (registered trademark).

The acrylic equivalent of the resin having an ethylenically unsaturated group is preferably 300 g / eq or more and 2000 g / eq or less, which improves sensitivity and provides good storage stability. In the present specification, the acrylic equivalent of the resin is the bromine value of the ink (the number of g of bromine added to the unsaturated component in 100 g of the sample) measured based on JIS K 2605, and the ink per mole of the acryloyl group. Represents a value (unit: g / eq) converted into the number of g of.

The weight average molecular weight of the resin having an ethylenically unsaturated group is preferably 5,000 or more and 100,000 or less, which keeps good printability of the active energy ray-curable lithographic printing ink. The weight average molecular weight of the resin can be obtained by measuring in terms of polystyrene using gel permeation chromatography (GPC).

In the method for producing a printed matter of the present invention, good printability can be maintained by containing 5% by mass or more and 40% by mass or less of a resin having an ethylenically unsaturated group in the active energy ray-curable lithographic printing ink. preferable.

Specific examples of commercially available products as active energy ray-curable lithographic printing inks include EC DEVELOPMENT manufactured by Sun Chemical and XCURA EVO manufactured by Flint.

When producing an active energy ray-curable lithographic printing ink, it is obtained by adding a pigment and an auxiliary agent to a resin varnish in which a resin is dissolved in a polyfunctional (meth) acrylate and kneading it with a three-roll mill.

In bifunctionality, the polyfunctional (meth) acrylate includes ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, and tripropylene glycol di (meth) acrylate. ) Acrylate, 1,3-butylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate and the like. Be done. Examples of the trifunctional include trimethylolpropane tri (meth) acrylate, glycerin tri (meth) acrylate, tri (meth) acrylate of isocyanuric acid, and these ethylene oxide adducts and propylene oxide adducts. Examples of the tetrafunctional include pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, diglycerin tetra (meth) acrylate, and these ethylene oxide adducts and propylene oxide adducts. Examples of the five-functionality or higher include dipentaerythritol hexa (meth) acrylate, these ethylene oxide adducts, and propylene oxide adducts. Preferred specific examples of the polyfunctional (meth) acrylate having a hydroxy group include poly (meth) of polyhydric alcohols such as trimethylolpropane, glycerin, pentaerythritol, diglycerin, dimethylolpropane, isocyanuric acid, and dipentaerythritol. ) Acrylate and these alkylene oxide adducts. More specifically, trimethylolpropane di (meth) acrylate, glycerin di (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, diglycerin di (meth) acrylate, diglycerin tri (meth). Acrylate, ditrimethylolpropane di (meth) acrylate Ditrimethylolpropane di (meth) acrylate, dipentaerythritol di (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta Examples thereof include (meth) acrylates and their ethylene oxide adducts, propylene oxide adducts, tetraethylene oxide adducts and the like. Moreover, these may contain 2 or more types.

The active energy ray-curable lithographic printing ink used in the present invention preferably contains a urethane compound from the viewpoint of further improving the adhesion to the substrate. The urethane compound refers to a compound that can be synthesized by reacting a polyisocyanate compound with a polyol compound, and urethane (meth) acrylate having a (meth) acrylic group is particularly preferable from the viewpoint of curability.

Urethane (meth) acrylate can be synthesized by reacting a hydroxyl group-containing (meth) acrylic acid ester, a polyisocyanate compound, and a polyol compound. The hydroxyl group-containing (meth) acrylic acid ester is not particularly limited, but is a polyhydric alcohol such as trimethylolpropane, glycerin, pentaerythritol, diglycerin, trimethylolpropane, isocyanuric acid, and dipentaerythritol. Examples include (meth) acrylates and these alkylene oxide adducts. More specifically, trimethylolpropane di (meth) acrylate, glycerin di (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, diglycerin di (meth) acrylate, diglycerin tri (meth). Acrylate, ditrimethylolpropane di (meth) acrylate, ditrimethylolpropane di (meth) acrylate, dipentaerythritol di (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol Examples thereof include penta (meth) acrylates, and these ethylene oxide adducts, propylene oxide adducts, tetraethylene oxide adducts and the like. Of these, pentaerythritol triacrylate can be particularly preferably used. One type or a combination of two or more types of hydroxyl group-containing acrylic acid esters having two or more of these acrylic groups can be used.

As the polyisocyanate compound, it is preferable to use diisocyanate in order to suppress the viscosity of the urethane compound formed by the reaction between the hydroxyl group of the polyol compound and the isocyanate group of the polyisocyanate compound and to maintain the compatibility with the resin and the monomer in the ink. .. The diisocyanate is not particularly limited, and examples of the compound having an aromatic ring structure include toluene diisocyanate, diphenylmethane diisocyanate, and xylylene diisocyanate. Examples of the compound having an alicyclic structure include isophorone diisocyanate, 4,4-methylenebiscyclohexyldiisocyanate, and hydrogenated xylylene diisocyanate. In addition, hexamethylene diisocyanate and the like can be mentioned as a compound having an aliphatic structure. These diisocyanates can be used alone or in combination of two or more.

Examples of the polyol compound include those having an ester structure, a carbonate structure, and a polyalkylene oxide structure. The dicarboxylic acid that gives an ester structure is not particularly limited, and examples thereof include phthalic acid, isophthalic acid, terephthalic acid, adipic acid, oxalic acid, maleic acid, fumaric acid, and a reaction product of sebacic acid and diol. .. Of these, isophthalic acid and adipic acid are particularly preferable because they are relatively inexpensive, have good heat resistance, and maintain good compatibility with ink. Specific examples of the carbonate structure include pentamethylene carbonate diol, hexamethylene carbonate diol, hexane carbonate diol, and decane carbonate diol.

Pigments include phthalocyanine pigments, soluble azo pigments, insoluble azo pigments, lake pigments, quinacridone pigments, isoindolin pigments, slene pigments, metal complex pigments, titanium oxide, zinc oxide, alumina white, calcium carbonate, Barium sulfate, red iron oxide, cadmium red, yellow lead, zinc yellow, dark blue, ultramarine, oxide-coated glass powder, oxide-coated mica, oxide-coated metal particles, aluminum powder, gold powder, silver powder, copper powder, zinc powder, stainless powder , Nickel powder, organic bentonite, iron oxide, carbon black, graphite and the like.

In addition, the ink may contain additives such as a photopolymerization initiator, a pigment dispersant, a defoaming agent, and a leveling agent. Although an ultraviolet curable ink can be used, it is preferable to use an ink that does not contain such a photopolymerization initiator because a photopolymerization initiator is not required for curing by radiation. This is because the decomposed products and unreacted products of the photopolymerization initiator cause odor and contamination of the contents.

As a printing machine used in the method for producing a printed matter according to the present invention, even if the base material is a thin plastic film, multicolor printing can be performed with high register accuracy, and batch curing by a radiation source becomes possible. It is preferable to use a rotary printing press equipped with a center impression cylinder. Specific examples thereof include CI-8 manufactured by COMEXI.

Hereinafter, the present invention will be specifically described with reference to Examples. However, the present invention is not limited thereto.

<Making dampening water>
Damping water 1: 90 parts by mass of pure water, 5 parts by mass of isopropanol, 4 parts by mass of propylene glycol monobutyl ether, 0.5 parts by mass of arabic gum, 0.2 parts by mass of phosphoric acid, 0.2 parts by mass of sodium phosphate, t -Butylhydroquinone 0.1 parts by mass was mixed to prepare 18 L of dampening water.
Damping water 2: It was prepared in the same manner as dampening water 1 except that t-butylhydroquinone was removed.
Damping water 3: It was prepared in the same manner as dampening water 1 except that t-butylhydroquinone was changed to 0.01 parts by mass.

The dissolved oxygen concentration is adjusted at 1 atm 15 ° C., and the reduction to 3 ppm is performed by nitrogen bubbling. If the concentration is less than that, use a deoxidizer (dissolved oxygen remover manufactured by Kyowa Co., Ltd.) to remove the dissolved oxygen. went. The dissolved oxygen concentration was adjusted by measuring at any time with a dissolved oxygen meter (DOM2000 manufactured by GS). Further, in Comparative Example 2, the dissolved oxygen concentration was not adjusted, and in Comparative Example 3, the saturated oxygen concentration was adjusted by oxygen bubbling.

<Manufacturing ink for active energy ray-curable lithographic printing>
Ink 1: 30 parts by mass of Daisodap (registered trademark) K manufactured by Osaka Soda Co., Ltd. as a resin having an ethylenically unsaturated group, 25 parts by mass of M600 manufactured by Miwon Co., Ltd. as a polyfunctional (meth) acrylate, and M3130 manufactured by Miwon Co., Ltd. 23 parts by mass, 18 parts by mass of MogulE manufactured by Cabot as an ink pigment, 2 parts by mass of Microace P-8 manufactured by Nippon Tarku as an extender pigment, 1 part by mass of Disper BYK2013 manufactured by BYK as a dispersant, and Kitamura as a wax. It was produced by kneading an active energy ray-curable flat plate printing ink having 1 part by mass of KTL-4N manufactured by KTL-4N with a three-roll mill.

Ink 2: 24 parts by mass of Hirosu (registered trademark) VS-1259 manufactured by Seikou PMC as a resin having no ethylenically unsaturated group, 34 parts by mass of M4004 manufactured by Miwon as a polyfunctional (meth) acrylate, and Miwon. 20 parts by mass of M262, 18 parts by mass of MogulE manufactured by Cabot as an ink pigment, 2 parts by mass of Microace P-8 manufactured by Nippon Tarku as an extender pigment, 1 part by mass of Disper BYK2013 manufactured by BYK as a dispersant, as a wax. KTL-4N manufactured by Kitamura Co., Ltd. was produced by kneading an active energy ray-curable flat plate printing ink consisting of 1 part by mass with a three-roll mill.

Ink 3: 28 parts by mass of Daisodap (registered trademark) K manufactured by Osaka Soda as a resin having an ethylenically unsaturated group, 22 parts by mass of M600 manufactured by Miwon as a polyfunctional (meth) acrylate, and M3130 manufactured by Miwon. 21 parts by mass, 8 parts by mass of Aronix (registered trademark) M-1200 manufactured by Toa Synthetic Co., Ltd. as a urethane compound, 18 parts by mass of MogulE manufactured by Cabot as a black pigment, and 2 parts by mass of Microace P-8 manufactured by Nippon Tarku Co., Ltd. It was produced by kneading an active energy ray-curable flat plate printing ink consisting of 1 part by mass of Disper BYK2013 manufactured by BYK as a dispersant and 1 part by mass of KTL-4N manufactured by Kitamura as a wax with a three-roll mill. ..

<Base material used>
Base material 1 (PET): PTM (manufactured by Unitika, thickness 12 μm), film base material 2 (OPP) whose surface is polyester-coated, P2111 (manufactured by Toyobo Co., Ltd., thickness 20 μm), film base material 3 (thickness 20 μm) whose surface is corona-treated. Polyamide): ONM (manufactured by Unitica, thickness 15 μm), film base material 4 (PET) whose surface is urethane-coated, S-46 (manufactured by polyplex, thickness 12 μm), film base material 5 (OPP) whose surface is acrylic-coated. : P2002 (manufactured by Toyobo Co., Ltd., thickness 40 μm), untreated surface film base material 6 (polyvinyl alcohol): EVAL EF-XL (manufactured by Kuraray Co., Ltd., thickness 12 μm), untreated surface film

<Printing test>
A lithographic printing plate (XP-F, manufactured by Fuji Film Co., Ltd.) is mounted on a flexible packaging lithographic printing machine (CI-8, manufactured by Comexi), and it is activated at 150 m / min on various raw fabrics using dampening water. An energy ray-curable lithographic printing ink was printed. Then, using an electron beam irradiator manufactured by e-beam, electron beam irradiation was performed at an accelerating voltage of 110 kV and an irradiation dose of 30 kGy to cure the active energy ray-curable lithographic printing ink to obtain a printed matter.

<Measurement of adhesion>
Takelac A969V / Takenate A-5 (mass ratio 5/1) mixed laminate adhesive manufactured by Mitsui Kagaku Co., Ltd. was applied to the printed matter obtained in the printing test at a thickness of 3.0 g / m ² , and unstretched polypropylene. It was laminated with a film (CPP, P1128 manufactured by Toyo Boseki Co., Ltd., thickness 30 μm). Then, it was aged at 40 ° C. for 3 days to obtain a laminated sample. Peeling strength when a solid part with 100% ink concentration in a laminate sample is cut into strips with a width of 15 mm and peeled off at a 300 mm / min 90 degree angle with a Tensilon universal tester (RTG-1210 manufactured by Orientec). Was measured. A peel strength of 1N / 15 mm or more is a good result, and a peel strength of 3N / 15 mm or more or a substrate breakage is an extremely good result.

[Examples 1 to 5 and Comparative Examples 1 to 3]
When the ink 1 prepared above and the dampening water 1 or the dampening water 2 having the dissolved oxygen concentration shown in Table 1 were used for lithographic printing on the base material 1, the dissolved oxygen concentration in the dampening water decreased. , There was a tendency for the adhesion to improve. The dissolved oxygen concentration was 5 ppm or less, and the laminate peeling strength exceeded 1 N / 15 mm, which was good. The results are shown in Table 1.

[Examples 6 to 10]
From the conditions of Example 3, the base material 1 was changed to any of the base materials 2 to 6 and printing was performed. A film that easily generates radicals on the outermost surface tends to have higher adhesion. The results are shown in Table 2.

[Example 11]
From the conditions of Example 3, the dampening water 1 was changed to the dampening water 3 and printing was performed. By reducing the amount of antioxidant in the dampening water, a slight improvement in adhesion was observed. The results are shown in Table 3.

[Examples 12 and 13]
Printing was performed by changing ink 1 to ink 2 or ink 3 from the conditions of Example 3. The results are shown in Table 3.

The method for producing a printed matter according to the present invention can improve the adhesion of ink to a base material.

Claims (10)

1. A method for producing a printed matter using a lithographic printing plate in which active energy ray-curable lithographic printing ink is transferred onto a substrate and irradiated with radiation, and using dampening water having a dissolved oxygen concentration of 5 ppm or less. Printed matter manufacturing method.
2. The method for producing a printed matter according to claim 1, wherein the dampening water does not substantially contain an antioxidant.
3. The method for producing a printed matter according to claim 1 or 2, wherein the radiation is an electron beam.
4. The method for producing a printed matter according to any one of claims 1 to 3, wherein the base material is a plastic film.
5. The method for producing a printed matter according to claim 4, wherein the plastic film contains a radiation-crosslinked polymer.
6. The method for producing a printed matter according to claim 4 or 5, wherein the plastic film is surface-treated by an easy-adhesion coating or a corona treatment.
7. The method for producing a printed matter according to claim 6, wherein the easy-adhesion coating is a urethane coating or an acrylic coating.
8. The method for producing a printed matter according to any one of claims 1 to 7, wherein the active energy ray-curable lithographic printing ink contains a resin having an ethylenically unsaturated group.
9. The method for producing a printed matter according to any one of claims 1 to 8, wherein the active energy ray-curable lithographic printing ink contains a urethane compound.
10. The method for producing a printed matter according to any one of claims 1 to 9, wherein a rotary printing press provided with a center impression cylinder is used.