WO2008010393A1

WO2008010393A1 - Method of plate making and printing plate

Info

Publication number: WO2008010393A1
Application number: PCT/JP2007/062889
Authority: WO
Inventors: Hirotaka Iijima
Original assignee: Konica Minolta Holdings, Inc.
Priority date: 2006-07-20
Filing date: 2007-06-27
Publication date: 2008-01-24
Also published as: JPWO2008010393A1

Abstract

A method of plate making in which while utilizing the characteristics of convenience and high productivity attained by inkjet process, there are improved the plate life and resolving power having been problems of inkjet process plate making, and in which realizing high hardening sensitivity, plate making can be accomplished by a simple apparatus with the use of low-viscosity inkjet ink. There is provided a method of plate making through the sequential procedure of applying a plate making ink onto a printing plate material according to an inkjet recording technique, irradiating the ink with actinic energy rays, evaporating the ink solvent and drying to thereby attain image forming and thus obtain a printing plate, characterized in that the plate making ink contains at least water, an actinic energy ray crosslinking compound capable of hardening with actinic energy ray irradiation amounting to 0.8 to 30 mass% based on the total mass of the ink and resin microparticles of 5 to 150 nm average particle diameter amounting to 0.1 to 7 mass%.

Description

Specification

Plate making method and printing plate

Technical field

The present invention relates to a plate making method and a printing plate, and further relates to a plate making method using an ink jet recording method and a printing plate.

Background art

In general, the printing method is a recording method in which ink is applied to a printing plate and transferred to a medium by pressure. In lithographic printing, a hydrophilic part and a lipophilic part are formed on the surface of the printing plate according to image information. In this case, dampening water is attached to the hydrophilic part, and printing is performed with the printing ink attached only to the oleophilic part.

[0003] As a manufacturing (plate making) method of these printing plates, ultraviolet rays are irradiated to a PS plate in which photosensitive resin is applied on an aluminum plate through a mask prepared by a silver salt method or the like according to image information. A method of forming an oleophilic rosin on an image by washing an uncured portion with an alkali or the like is known. Recently, CTP (Computer to Plate) has also appeared, in which a plate is directly written on a plate material using a laser beam or the like according to image information in the computer without forming a mask, and a plate is developed by development. .

[0004] With the advent of CTP, the printing process is reduced and it is simple and quick. However, CTP also requires development in the plate-making process, which requires a lot of work, and there is a problem that processing waste liquid and waste materials are generated. Atsuta o

[0005] As another method, a plate making method using an ink jet recording method is disclosed (for example, see Patent Document 1). In this method, oil-based ink is applied on a printing plate material by an ink jet recording method. Is a plate in which the resin remaining after drying is made to correspond to the image, but the printing durability is insufficient, and before the ink droplets adhering to the printing plate are dried, a so-called bead is obtained. There was a problem that resolution was lowered due to dating.

[0006] As a method for improving printing durability, a plate making method is disclosed in which a photocurable ink is attached to a printing plate material that has been subjected to a hydrophilic treatment by an inkjet method, and then the entire surface is exposed (for example, See Patent Document 2.). However, this method does not provide a certain level of printing durability. However, there are problems that ink beading occurs immediately before exposure and beading occurs immediately before exposure, and that resolution tends to decrease and dot gain tends to occur. Furthermore, there is a problem that a special ink jet recording head having a high discharge viscosity and a high ink viscosity is required.

[0007] As another method using an ink jet method, an acrylate compound is used as a photocurable monomer, and a photocurable ink comprising a reactive diluent, a photopolymerization initiator, a solvent and a dye is used as a printing plate material. A plate making method using a solvent-containing type ultraviolet curable ink is disclosed in which an image is formed by applying and curing an image portion by light irradiation (see, for example, Patent Document 3). However, although this method provides a certain level of printing durability, there is a problem in that beading occurs between landing and exposure, and the resolution is likely to decrease immediately. Furthermore, although the viscosity decreases due to the decrease in the solvent, only a small amount of solvent can be added to obtain sufficient curing sensitivity. As a result, the decrease in the viscosity of the ink is significantly higher than that of the solventless UV curable ink. However, there was a problem that a special ink jet recording head having a large ejection force was required.

[0008] Furthermore, a water-based ultraviolet curable ink containing an a-heterometathalyl compound as a water-soluble polymerization compound and containing a coloring material is ejected onto a hydrophilic support and irradiated with ultraviolet rays. by curing and, (if example embodiment, see Patent Document 4.) plate-making method is disclosed for forming an image of hydrophobic while ₀ tooth force, in this way, bi until even exposure impact force There was a problem that the resolution was liable to decrease as soon as the recording occurred. Another problem is that the ink density of the printing ink in the image area is insufficient and the density of the printed image varies.

[0009] In addition, the use of water-based ink is environmentally good. The water resistance of the stencil tends to be a problem. There was a problem of being easy to become.

Patent Document 1: Japanese Patent Laid-Open No. 56-62157

Patent Document 2: JP-A-4-69244

Patent Document 3: Japanese Patent Laid-Open No. 63-102936

Patent Document 4: Column 2006-117795 Disclosure of the invention

Problems to be solved by the invention

[0010] The present invention has been made in view of the above problems, and its purpose is to make use of the convenience and productivity of the ink jet system and the features of the plate making of the ink jet system, which is a problem in printing durability. An object of the present invention is to provide a plate making method and a printing plate that improve the resolution and enable high-sensitivity, low-viscosity ink-jet ink making with a simple apparatus.

Means for solving the problem

The above object of the present invention is achieved by the following configurations.

[0012] 1. A printing plate is formed by depositing a plate-forming ink on a printing plate by an inkjet recording method, irradiating active energy rays, and evaporating and drying the ink solvent to form an image. In the plate-making method for producing the ink, the plate-forming ink comprises at least water and an active energy ray crosslinkable compound that is cured by irradiation with the active energy ray, based on 0.8% by mass of the total mass of the ink. A plate making method characterized by containing 0.1% by mass or more and 7% by mass or less of fine resin particles containing 30.0% by mass or less and having an average particle diameter of 5 nm or more and 150 nm or less.

[0013] 2. Active energy ray crosslinkable compound cured by irradiation of the active energy ray Force The main chain has a plurality of side chains, and the active energy ray is irradiated to bridge between the side chains. 2. The plate-making method as described in 1 above, which is a bondable polymer compound, and the polymer compound is contained in an amount of 0.8% by mass or more and 5.0% by mass or less based on the total mass of the ink. .

[0014] 3. The plate-making method according to 1 or 2 above, wherein the glass transition temperature of the fine resin particles is -20 ° C or higher and 70 ° C or lower.

[0015] 4. The main chain of the polymer compound is a polyvinyl acetate kenich, and the degree of saponification is

4. The plate-making method according to 2 or 3 above, wherein the plate-making method is 77% or more and 99% or less and the degree of polymerization is 200 or more and 4000 or less.

[0016] 5. The modification 1 described in any one of 2 to 4 above, wherein the modification rate of the side chain with respect to the main chain of the polymer compound is 0.8 mol% or more and 6 mol% or less. Plate making method. [0017] 6. A printing plate produced by the plate making method according to any one of 1 to 5 above.

The invention's effect

[0018] According to the present invention, taking advantage of the convenience and high productivity of the ink jet system, the printing durability and resolution, which were problems in the ink jet system platemaking, are improved, and the composition has high curing sensitivity and low viscosity. With this inkjet ink, it was possible to provide a plate making method and a printing plate that enable plate making with a simple apparatus.

Brief Description of Drawings

FIG. 1 is a perspective view showing an example of an ink jet printer applicable to the plate making method of the present invention.

Explanation of symbols

[0020] 1 Carriage

2 UV irradiation light source

3 Transport roller

4 Plate material

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the best mode for carrying out the present invention will be described in detail.

[0022] As a result of intensive studies in view of the above problems, the present inventor has applied an active energy ray after depositing a plate-forming ink on a printing plate material by an ink jet recording method. In the plate making method for producing a printing plate by forming an image by evaporating and drying an ink solvent, the plate forming ink is at least water and an active energy ray crosslinkable material that is hardened by irradiation of the active energy ray. The resin fine particles containing 0.8% by mass or more and 30.0% by mass or less of the total amount of the ink with respect to the total mass of the ink and having an average particle size of 5 nm or more and 150 nm or less are 0.1% by mass. The plate-making method is characterized by the fact that it contains at least 7% by mass and up to 7% by mass, making use of the high convenience and productivity of the ink jet method, and the printing durability and resolving power that were problems in ink-jet method plate making. Improved hardening feeling A plate-making method that enables plate-making with a simple device using inkjet ink with low viscosity and low viscosity. I was able to.

[0023] The conventional active energy ray-curable inkjet ink has a curable resin content even when all of the constituent materials are composed of a curable component or contain an organic solvent or water. If it is not increased, it will harden, and there is a problem that practical sensitivity (the amount of light required to reach a hardness with sufficient printing durability) cannot be obtained. When the amount of curable resin necessary for curing is added, the viscosity of the ink jet ink exceeds 20 mPa · s, and there are many problems in ejection by the ink jet recording method.

[0024] In the present invention, a water-soluble active energy ray crosslinkable compound is used, and the active energy line crosslinkable compound is not less than 0.8% by mass based on the total mass of the ink. One of the characteristics is to contain 0% by mass or less.

[0025] The water-soluble active energy ray crosslinkable compound according to the present invention is lyophilic before cross-linking and dissolves in water or a water-soluble organic solvent. As a result, the printing durability and water resistance can be improved.

[0026] Further, in the plate making method of the present invention, the water-soluble active energy ray crosslinkable compound is increased in hydrophobicity by cross-linking and forms an image portion to which ink adheres.

[0027] The curing component used in the conventional active energy ray-curable ink has a small molecular weight of the curing component and does not have hardness unless many curing components are crosslinked. It is necessary, and if the addition amount is small, the sensitivity is lowered. Accordingly, since a large amount of the curing component is required, the viscosity of the ink is inevitably increased.

On the other hand, the water-soluble active energy ray crosslinkable compound according to the present invention is a small amount of 0.8 mass% or more and 30.0 mass% or less with respect to the total mass of the plate forming ink. Curing became possible. Furthermore, the curing component contained in the plate-forming ink according to the present invention preferably has a structure in which a crosslinking group is added as a side chain to the main chain of the high molecular weight component. Although the mechanism is unknown due to this structure, curing was possible in an extremely small amount of 0.8% by mass or more and 5.0% by mass or less based on the total mass of the plate forming ink.

[0029] Further, when the polymer compound is a saponified product of polyacetic acid bull, the degree of saponification is 77 to 99%, and the degree of polymerization is 200 or more and 4000 or less, the sensitivity is remarkably improved. If the degree of polymerization is less than S4000, an excessive increase in ink viscosity can be suppressed and stable irradiation can be prevented. Output performance can be obtained. In addition, when the side chain modification rate is 0.8 mol% or more and 6 mol% or less, the sensitivity is remarkably improved.

[0030] Further, since the plate-forming ink according to the present invention has a small amount of the curing component, it is possible to contain a large amount of the evaporation component in the plate-forming ink. By containing a large amount of evaporating components, the thickness of the image formed on the printing plate after drying and curing is reduced, making it possible to produce a high-quality printing plate with reduced dot gain. .

[0031] In the plate making method of the present invention, the plate forming ink according to the present invention comprises 0.1% by mass or more of fine resin particles having an average particle diameter of 5 nm or more and 150 nm or less with respect to the total mass of the ink. It is characterized by containing 7% by mass or less, and by adopting these constitutions, the ink-inking property of printing ink is improved. The average particle diameter of the fine resin particles is one of the important factors in the plate making method using ink jet. If the average particle size of the resin fine particles is 5 nm or more, an effect of improving the ink landing property can be obtained. If the average particle size is 150 nm or less, stable emission from the ink jet head can be maintained, and high landing accuracy can be achieved. In the production of the required printing plate, sufficient effects can be obtained with reproducibility of fine lines and reproducibility of small characters. Further, the addition amount of the fine resin particles is a factor affecting the inking property itself, and if it is 0.1% by mass or more, an effect on the inking property can be obtained, and if it is 7% by mass or less. Sufficient fillability can be obtained, and nozzle clogging and the like during intermittent emission can be suppressed, and excellent emission stability can be realized.

[0032] Further, among the properties of the fine resin particles, if the fine resin particles having a glass transition temperature of 20 ° C or higher and 70 ° C or lower are used, the fine resin particles are fused to each other on the plate material. Think V. This is presumed to improve ink fillability and scratch resistance.

[0033] The details of the present invention will be described below.

[0034] First, a plate forming ink (hereinafter also simply referred to as ink) according to the plate making method of the present invention will be described.

[Active energy ray crosslinkable polymer compound]

In the plate making method of the present invention, the plate-forming ink contains at least water and an active energy ray crosslinkable compound that cures upon irradiation of the active energy line with respect to the total mass of the ink. It is characterized by containing 30.0 mass% or less. Examples of the water-soluble active energy ray crosslinkable compound applicable to the present invention include, for example, a radical polymerizable compound having a radical polymerizable ethylenically unsaturated bond (for example, an acrylate compound). Cationic polymerizable compounds (for example, oxetane compounds, epoxy compounds, vinyl ether compounds, etc.) can be mentioned, among which, for example, described in JP-A-2006-117795 A-heterometathalyl compounds and a polymer compound having a plurality of side chains in a hydrophilic main chain and capable of crosslinking between the side chains by irradiation with active energy rays. In the present invention, among them, the amount of the active energy line crosslinkable compound can be reduced. In particular, the active energy line crosslinkable compound contains a plurality of active energy line crosslinkable compounds in the main chain. With side chains The Rukoto be irradiated with an active energy ray, preferably a crosslinkable polymer compound between the side chains.

[0036] The polymer compound having a plurality of side chains in the main chain according to the present invention and capable of being cross-linked between the side chains by irradiating with active energy rays is a polyvinyl acetate cane or polyvinyl acetal. , Polyethylene oxide, polyalkylene oxide, polybutylpyrrolidone, polyacrylamide, polyacrylic acid, hydroxyethyl cellulose, methyl cellulose, hydroxypropyl cellulose, or derivatives of these resins, and copolymers thereof are also selected from the group consisting of At least one kind of rosin is introduced with a modifying group such as a photodimerization type, a photodecomposition type, a photopolymerization type, a photomodification type, and a photodepolymerization type in the side chain. Among them, the photopolymerizable crosslinkable group is desirable from the viewpoint of sensitivity and image performance to be formed.

[0037] As the main chain, the degree of polymerization is preferably 200 or more, 4000 or less, force S, preferably 200 from the viewpoint of ease of introduction of side chains and handling! As mentioned above, the viewpoint power of handling is more preferably 2 000 or less. The modification rate of the side chain with respect to the main chain is preferably 0.3 mol% or more and 6 mol% or less, but more preferably 0.8 mol% or more and 6 mol% or less from the viewpoint of reactivity. If the modification rate of the side chain with respect to the main chain is 0.3 mol% or more, sufficient crosslinkability can be obtained and the effects of the present invention can be exerted. If it is 6 mol% or less, the crosslink density is low. Generation of a hard and brittle film that does not increase excessively and a decrease in film strength can be prevented.

[0038] Preferred examples of the photodimer type modifying group include those having a diazo group, a cinnamoyl group, a stilbazonium group, a stilquinolium group or the like introduced therein, for example, JP-A-60-129742. Photosensitive resin (composition) described in the above publications.

[0039] The photosensitive resin described in JP-A-60-129742 is a compound represented by the following general formula (1) in which a stilbazome group is introduced into a polyvinyl alcohol structure.

[0040] [Chemical formula 1] General formula (1)

[0041] In the above general formula (1), R represents an alkyl group having 1 to 4 carbon atoms,

1

Represents key-on.

[0042] The photosensitive resin described in JP-A-56-67309 has a 2 azide 5 -trophenyl-carboxylethylene structure represented by the following general formula (2) in a polyvinyl alcohol structure, or It is a resin composition represented by the following general formula (3) and having a 4 azido 3-tro-phenol-carboxyethylene structure.

[0043] [Chemical 2]

—General formula (2)

[0044] A modifying group represented by the following general formula (4) is also preferably used. [0045] [Chemical 3]

-General formula (4>

[0046] In the general formula (4), R represents an alkylene group or an aromatic ring. A benzene ring is preferred.

[0047] Examples of the photopolymerization-type modifying group include, for example, JP-A-2000-181062 and JP-A-2004-189.

A coffin represented by the following general formula (5) shown in No. 841 is preferred from the viewpoint of reactivity.

[0048] [Chemical formula 4] General formula (5)

[0049] In the above general formula (5), R represents a methyl group or a hydrogen atom, and n represents 1 or 2.

2

X represents — (CH 2) —COO— or —O—, and Y represents an aromatic ring or a single bond.

2 m

M represents an integer of 0-6.

[0050] It is also preferable to use a photopolymerizable modifying group represented by the following general formula (6) described in JP-A No. 2004-161942 in a conventionally known water-soluble resin.

[0051] [Chemical formula 5] General formula)

[0052] In the above general formula (6), R represents a methyl group or a hydrogen atom, and R represents 2 to 1 carbon atoms.

3 4

0 represents a linear or branched alkylene group.

[0053] One of the characteristics of the active energy ray-crosslinking type resin is that it is 0.8% by mass or more and 30.0% by mass or less based on the total mass of the ink. When present in an amount of 8% by mass or more, the crosslinking efficiency is improved, and beading or force bleed is more preferable due to a rapid increase in ink viscosity after crosslinking. If it is 5.0% by mass or less, it will adversely affect the physical properties of the ink and the internal state of the ink head, which is preferable from the viewpoint of the emission properties and the ink storage stability.

[0054] In the active energy ray-crosslinking polymer compound according to the present invention, the main chain originally having a certain degree of polymerization is crosslinked via a crosslink between side chains. Therefore, the effect of increasing the molecular weight per photon is remarkably large with respect to the active energy ray-curable resin that is polymerized through a general chain reaction. On the other hand, in the conventionally known active energy ray-curable resin, the number of cross-linking points cannot be controlled, so the physical properties of the cured film cannot be controlled.

In the resin used in the present invention, the number of crosslinking points can be completely controlled by the length of the main chain and the amount of side chains introduced, and the physical properties of the ink film can be controlled according to the purpose.

[0056] Further, almost all of the conventionally known active energy ray-curable ink other than the colorant is curable, and as a result, the dots after curing rise to increase the thickness of the plate and generate dot gain. On the other hand, in the plate-making method using the ink using the resin used in the present invention, the addition amount of the resin is only a small amount, and the dry component ratio is high, so that the dots do not rise unnecessarily after curing. A printing plate with good finish can be formed.

[Photopolymerization initiator, sensitizer]

In the present invention, a photopolymerization initiator and a sensitizer can be added. These compounds may be dissolved or dispersed in a solvent, or may be chemically bonded to the photosensitive resin.

[0058] Conventionally known photopolymerization initiators and photosensitizers to be applied are not particularly limited.

[0059] The photopolymerization initiator and the photosensitizer to be applied are not particularly limited, but a water-soluble material is preferable from the viewpoints of miscibility and reaction efficiency. In particular, 4- (2-hydroxyethoxy) ferro- (2 -Hydroxy 2-propyl) ketone (HMPK), thixanthone ammonium salt (QTX), and benzophenone ammonium salt (ABQ) are preferred from the viewpoint of miscibility with aqueous solvents.

[0060] Furthermore, from the viewpoint of compatibility with rosin, 4- (2-hydroxyethoxy) ferro- (2-hydroxy-1-2-propyl) ketone (n = l, represented by the following general formula (7): HMPK) and its ethylene oxide adduct (n = 2 to 5) are more preferable.

[0061] [Chemical formula 6] General formula (7)

[0062] In the formula, n represents an integer of 1 to 5.

[0063] Further, as another example, benzophenones such as benzophenone, hydroxybenzophenone, bis-N, N-dimethylaminobenzophenone, bis-N, N-demethylaminobenzophenone, 4-methoxy-A! -Dimethylaminobenzophenone. Thioxanthones such as thixatone, 2,4-diethylthioxanthone, isopropyl thixanthone, black thioxanthone and isopropoxycyclo thixanthone. Anthraquinones such as ethylanthraquinone, benzanthraquinone, aminoanthraquinone, black anthraquinone; Acetophenone. Benzoin ethers such as benzoin methyl ether. 2, 4, 6 Trihalomethyltriazines, 1-Hydroxycyclohexyl phenyl ketone, 2— (o chlorophenyl) 4,5 diphenylimidazole dimer, 2— (o chlorophenol) 4, 5 Di (m-methoxyphenyl) imidazole dimer, 2- (o fluorophenol) —4, 5 Phenolimidazole dimer, 2— (o-methoxyphenol) —4, 5 Phenylimidazole dimer, 2- (P-methoxyphenol) -1,4,5 Diphenylimidazole dimer, 2, —Di (p-methoxyphenol) -5 phenolimidazole dimer , 2— (2,4 dimethoxyphenol) —4,5-diphenylimidazole dimer 2,4,5 triarylimidazole dimer, benzyl dimethyl ketal, 2-benzyl-2-dimethylamino-1 — (4—Morpholinophenol) Butane 1-on, 2 Methyl 1 [4 (Methylthio) phenol] 2 Horino 1 —Propanone, 2-hydroxy-1,2-methyl 1—phenol-propane, 1—one, 1— [4- (2-hydroxyethoxy) mono-phenol] —2 hydroxy, 2-methyl, 1-propane, one year old , Phenanthrenequinone, 9, 10 phenanthrenequinone, methenolevenzoin, benzoin such as ethylbenzoin, 9 phenolacridine, 1,7 bis (9,9'-acrylicyl) heptane, etc. Atalidine derivatives, bisacylphosphine oxide, and mixtures thereof are preferably used, and the above may be used alone or in combination.

[0064] In addition to these photopolymerization initiators, accelerators and the like can also be added. Examples of these include ethyl dimethylaminobenzoate, isoamyl pdimethylaminobenzoate, ethanolamine, diethanolamine, triethanolamine and the like. These photopolymerization initiators are preferably grafted onto the side chain with respect to the main chain.

[0065] [Fabric fine particles]

The resin fine particles according to the present invention are not particularly limited, but are preferably polyurethane, polystyrene acrylic, polystyrene butadiene, polystyrene maleic acid, polyester, polyether, polycarbonate, polyamide, polyacrylonitrile, polystyrene, polybutadiene, polyacrylic. Fine particles of acid, polymethacrylic acid, polyvinyl chloride, polyvinyl chloride, polyvinyl acetate, acrylic modified silicone resin, acrylic modified fluorine resin, copolymers thereof and salts thereof Examples of the resin fine particles include a copolymer selected from at least one of polyurethane, polystyrene monoacrylic, polystyrene monobutadiene, and polystyrene maleic acid.

In the ink according to the present invention, one of the characteristics is that the average particle diameter of the fine resin particles is 5 nm or more and 150 nm or less. If the average particle size of the resin fine particles is 5 nm or more, an improvement effect on the ink-inking properties can be obtained, and if the particle size is 150 nm or less, the emission stability from the ink jet head can be maintained. In addition, it is possible to achieve improvements in fine line reproducibility and small character reproducibility in the production of printing plates that require a high landing system. The average particle diameter of the fine resin particles according to the present invention can be determined by a commercially available particle size measuring instrument using a light scattering method, an electrophoresis method, a laser Doppler method or the like.

[0067] In the ink according to the present invention, the content of the fine resin particles according to the present invention includes: One characteristic is that it is 0.1% by mass or more and 7% by mass or less with respect to the total mass of the ink. 1S 0.1% by mass or more and 5% by mass or less is more preferable. When the content of the fine resin particles according to the present invention is 0.1% by mass or more, the effect of excellent inking property can be exhibited, and when it is 7% by mass or less, sufficient inking property is obtained. In addition, it is possible to prevent nozzle clogging caused by resin fine particles during intermittent emission. Furthermore, in general, the viscosity of the ink increases due to the addition of the resin fine particles, and as the ink viscosity increases, it becomes impossible to eject at a high driving frequency, leading to a decrease in productivity. become. Therefore, when the ink viscosity is taken into consideration, the addition amount is preferably 5% by mass or less.

[0068] The fine resin particles according to the present invention may be either a forced emulsification type forcibly emulsified with an emulsifier, or a self-emulsification type in which a hydrophilic group or a hydrophilic segment is added to the resin and dispersed. Good. Surfactant is often used as an emulsifier A polymer having a hydrophilic group such as a sulfonic acid group or a carboxylic acid group (for example, a polymer having a hydrophilic group grafted thereto, a monomer having a hydrophilic part, It is also preferable to use a polymer obtained from a monomer having a hydrophobic portion.

[0069] In recent years, as latex polymer particles, in addition to latex in which polymer particles that are uniform throughout the particle are dispersed, latex in which core-shell type polymer particles having different compositions at the center and outer edges of the particles are dispersed. This type of latex can also be used favorably.

[0070] The resin fine particles according to the present invention are preferably noon or arion from the viewpoint of storage stability, and more preferably arion.

In the case of anionic resin fine particles, anionic groups are neutralized with a base and used. As the base at this time, an organic base such as ammonia or dimethylethanolamine is preferably used. The organic base is volatile and evaporates after plate formation, but after the organic base evaporates, water solubility decreases and water resistance improves. This can be expected to improve the durability of printing plates that are constantly exposed to water.

[0072] The fine resin particles according to the present invention preferably have a glass transition point (Tg) of -20 ° C or higher and 70 ° C or lower. If the glass transition point is -20 ° C or higher, the scratch resistance and abrasion resistance when used as a plate can be maintained, and if the glass transition point is 70 ° C or lower, Smoothness can be achieved without leaving the shape of the fine oil particles, and the resin can have a sufficient hardness range. The glass transition point (Tg) can be measured by a known method utilizing the fact that the coefficient of thermal expansion and specific heat change discontinuously in the process of changing the temperature.

[0073] [Colorant]

The ink used in the plate-making method of the present invention may be a clear ink that does not contain a colorant, but preferably contains a colorant for the purpose of easily identifying a pattern drawn on a printing plate.

[0074] The content of the colorant may be smaller than that of the inkjet ink used for image formation. The content is preferably 0.1% by mass or more and 3% by mass or less based on the total amount of the ink. The colorant may be a dye or a pigment.

[0075] (Dye)

Examples of the dye that can be used in the present invention include acidic dyes, direct dyes, water-soluble dyes such as reactive dyes, disperse dyes, and the like that are not particularly limited.

[0076] Specific examples of dyes applicable to the ink according to the present invention will be listed below.

It is not limited to these exemplified dyes.

[0077] [Water-soluble dye]

Examples of water-soluble dyes that can be used in the present invention include azo dyes, methine dyes, azomethine dyes, xanthene dyes, quinone dyes, phthalocyanine dyes, triphenylmethane dyes, diphenylmethane dyes, and the like.

[0078] Further, as the dye, a compound represented by the following general formula (8) or a compound represented by the general formula (9) may be used.

[0079] [Chemical 7]

[0080] In the above general formula (8), R represents a hydrogen atom or a substitutable substituent,

1

Child or phenyl carbonyl groups are preferred. R may be different hydrogen atom or substitution

2

Represents a possible substituent and is preferably a hydrogen atom. R is a hydrogen atom or a substitutable substituent

Three

Represents a hydrogen atom or an alkyl group. R is a hydrogen atom or a replaceable position

Four

A hydrogen atom and an aryloxy group are preferable. R may be different and may be a hydrogen atom.

Five

Alternatively, it represents a substitutable substituent, and a sulfonic acid group is preferable. n represents an integer of 1 to 4, and m represents an integer of 1 to 5.

[0081] In the general formula (9), X represents a phenyl group or a naphthyl group, which may be substituted with a substitutable substituent, substituted with a sulfonic acid group or a carboxyl group! It is preferable to speak. Y represents a hydrogen ion, a sodium ion, a potassium ion, a lithium ion, an ammonium ion or an alkyl ammonium ion. R may be different hydrogen

6

The substituent which can be substituted on an atom or a naphthalene ring is represented. q represents 1 or 2; p represents an integer of 1 to 4. However, q + p = 5. Z represents a substitutable substituent, and represents a carbonyl group, a sulfonyl group or a group represented by the following general formula (10), and particularly preferably a group represented by the following general formula (10).

[0082] [Chemical 8] —General formula (10)

[0083] In the above general formula (10), W and W may be different halogen atoms,

1 2

Represents an amino group, a hydroxyl group, an alkylamino group or an arylamino group, preferably a halogen atom, a hydroxyl group or an alkylamino group;

[0084] [Disperse dye]

As the disperse dye, various disperse dyes such as azo disperse dyes, quinone disperse dyes, anthraquinone disperse dyes, and quinophthalone disperse dyes can be used.

[0085] (Pigment)

As the pigment that can be used in the present invention, conventionally known pigments can be used without particular limitation, and any of water-dispersible pigments, solvent-dispersible pigments and the like can be used, for example, organic pigments such as insoluble pigments and lake pigments, An inorganic pigment such as carbon black can be preferably used. This pigment is present in a state of being dispersed in the ink, and the dispersion method may be any of self dispersion, dispersion using a surfactant, polymer dispersion, and microcapsule dispersion.

[0086] Examples of insoluble pigments include, but are not limited to, for example, azo, azomethine, methine, diphenylenomethane, triphenylenomethane, quinacridone, anthraquinone, perylene, indigo, quinophthalone, isoindolinone, Preference is given to isoindoline, azazine, tadazine, thiazine, dioxazine, thiazole, phthalocyanine, diketopyrrolopyrrole and the like.

[0087] Specific pigments that can be preferably used include the following pigments.

[0088] Examples of pigments for magenta or red include CI pigment red 2, CI pigment red 3, CI pigment red 5, CI pigment red 6, CI pigment red 7, CI pigment red 15, CI Pigment Red 16, CI Pigment Red 48: 1, CI Pigment Red 53: 1, CI Pigment Red 57: 1, CI Pigment Red 122, C.I. Pigment 卜 Red 123, CI Pigment 卜 Red 139 , CI Big Men 卜 Red 144, CI CI Meng Red 149, CI Big Men Red 166, CI Big Men Red 177, CI Pigmen Red 178, CI Big Men Red 202, CI Big Men Red 222, CI Big Men Red Violet 19 and the like.

[0089] Examples of pigments for orange or yellow include CI pigment orange 31, CI pigment orange 43, CI pigment yellow 12, CI pigment yellow 13, CI pigment yellow 14, CI pigment Yellow 15, CI pigment yellow 15: 3, CI pigment yellow 17, CI pigment yellow 74, CI pigment yellow 93, CI pigment yellow 128, CI pigment yellow 94, CI pigment yellow 138, etc. .

[0090] Examples of pigments for green or cyan include CI pigment blue 15, CI pigment blue 15: 2, CI pigment blue 15: 3, CI pigment blue 16, CI pigment blue 60, CI pigment Gmento Green 7 and so on.

[0091] Examples of the pigment for black include C.I. pigment black 1, C.I. pigment black 6, C.I. pigment black 7, and the like.

[0092] The average particle diameter in the dispersed state of the pigment contained in the ink according to the present invention is preferably 50 nm or more and less than 200 nm.

[0093] The particle size of the pigment dispersion can be determined by a commercially available particle size measuring instrument using a dynamic light scattering method, an electrophoresis method, or the like. The accuracy of the diameter region is frequently used.

[0094] The pigment used in the ink according to the present invention is preferably used after being dispersed by a disperser together with a dispersant and other additives required depending on the desired properties. As the disperser, a conventionally known ball mill, sand mill, line mill, high-pressure homogenizer, or the like can be used. Among them, the dispersion method using a sand mill is preferable because the particle size distribution of the ink to be produced is sharp. The material of the beads used for sand mill dispersion is preferably zircon or zircon from the viewpoint of contamination of bead fragments and ionic components. Furthermore, the bead diameter is 0.3mn! ~ 3mm is preferred.

[0095] In dispersing the pigment contained in the ink according to the present invention, a surfactant or a polymer dispersant may be used alone or in combination as the dispersant. [Water-soluble solvent]

The solvent constituting the ink according to the present invention contains at least water, and may further contain a water-soluble organic solvent.

Examples of the water-soluble solvent applicable to the ink according to the present invention include alcohols (eg, methanol, ethanol, propanol, isopropanol, butanol, isobutanol, secondary butanol, tertiary butanol), polyhydric alcohols (For example, ethylene glycolate, diethylene glycol, triethylene glycol, polyethylene glycolate, propylene glycol, dipropylene glycol, polypropylene glycol, butylene glycol, hexanediol, pentanediol, glycerin, hexanetriol, thiodiglycol), Polyhydric alcohol ethers (for example, ethylene glycol monomethylenoatenore, ethyleneglycolenomethinoleatenore, ethyleneglycolenoremo knob Noleyatenore, diethylene glycol monomethyl ether, diethylene glycol monoethinoreateenore, diethyleneglycolenomonobutenoreatenore, propylene glycol noremonomethinoreatenore, propylene glycol noremonobutenoreatenore, ethylene glycol monomethyl ether acetate, Triethylene glycol monomethyl ether, triethylene glycol monomethino enoate, triethylene glycol mono mono butyl ether, ethylene glycol mono mono vinyl ether, propylene glycol mono mono ether, amines (for example, , Ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N-ethyljetanolamine, morpho , N-ethylmorpholine, ethylenediamine, diethylenediamine, triethylenetetramine, tetraethylenepentamine, polyethyleneimine, pentamethylgerylenetriamine, tetramethylpropylenediamine), amides (eg, formamide, N, N-dimethyl) Formamide, N, N-dimethylacetamide, etc.), heterocyclics (eg 2-pyrrolidone, N-methyl-2-pyrrolidone, cyclohexylpyrrolidone, 2-oxazolidone, 1,3-dimethyl-1-imidazolidino And sulfoxides (eg, dimethyl sulfoxide).

[0098] The total amount of the solvent (water alone or a mixture of water and a water-soluble organic solvent) contained in the ink according to the present invention is preferably 50% by mass or more and 98% by mass or less based on the total amount of the ink. More preferably, it is at least 98% by mass. Furthermore, water is 5% of the total ink. The content is preferably 0% by mass or more and 80% or less.

[0099] [Surfactant]

The ink according to the present invention may contain a surfactant.

[0100] Surfactants preferably applied to the ink according to the present invention include alkyl sulfates, alkyl ester sulfates, dialkyl sulfosuccinates, alkyl naphthalene sulfonates, alkyl phosphates, and polyoxyalkylene alkyls. Nonionic surfactants such as ether phosphates and fatty acid salts, polyoxyethylene alkyl ethers, polyoxyalkylene alkyl phenol ethers, acetylene glycols, polyoxyethylene polyoxypropylene block copolymers, etc. Examples thereof include cationic surfactants such as ionic surfactants, darinsyl esters, sorbitan esters, polyoxyethylene fatty acid amides, amine oxides, alkylamine salts, and quaternary ammonium salts.

[0101] These surfactants can also be used as dispersants for pigments. In particular, anionic and nonionic surfactants can be preferably used.

[0102] [Various additives]

In the present invention, other conventionally known additives can be contained. For example, fluorescent brighteners, antifoaming agents, lubricants, preservatives, thickeners, antistatic agents, matting agents, water-soluble polyvalent metal salts, acid bases, buffer solutions, etc.pH adjusters, antioxidants, surfaces These are tension adjusting agents, specific resistance adjusting agents, antifungal agents, inorganic pigments and the like.

[Ink physical properties]

The ink according to the present invention has a preferable range of physical properties of the ink in order to stably produce a high-definition printing plate by an ink jet method.

[0104] The viscosity of the ink is preferably from ImPa's to 15 mPa's, particularly preferably from 2 mPa's to 8 mPa's. If the viscosity is ImPa's or higher, stable injection is possible, and if the viscosity is 15 mPa's or lower, satellites can be prevented from being generated, and ink can be ejected at a fast repetition cycle, resulting in an increase in production speed. To do.

[0105] The surface tension of the ink is preferably 25 mNZm or more and 50 mNZm or less, more preferably 30 mNZm or more and 45 mNZm or less. If it is 25mNZm or more, it will land on the printing plate. It is possible to control the wetting and spreading of the dots, and to achieve a good resolution. On the other hand, if it is 50 mN / m or less, bubbles are sufficiently removed from the ink jet recording head, and good ejection stability can be maintained.

[Ink production method]

The ink according to the present invention is preferably subjected to filtration in the course of a force production process that can be produced by a conventionally known method. As a filtration method, for example, force that can be performed with a metal mesh filter, it is also preferable to perform filtration with a volume filtration filter made of a resin such as polypropylene in combination with this.

[0107] Further, the ink according to the present invention is preferably subjected to a deaeration process. Degassing methods include, for example, a method of performing deaeration by stirring in a vacuum chamber, a method of sealing and degassing after heating the ink, and a method of using a degassing module using hollow fibers. The method using a force degassing module is particularly preferred.

[0108] [Printing plate]

The printing plate material used in the plate making method of the present invention preferably has a hydrophilic surface. As the support used for the printing plate material, conventionally known plate materials used for lithographic printing plates can be used without limitation. For example, paper, paper laminated with plastic (eg, polyethylene, polypropylene, etc.), metal plate (eg, aluminum, etc.), plastic film (eg, cellulose triacetate, cellulose butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene naphthalate) Phthalate).

[0109] Particularly preferred! / Examples of the support include paper, polyester film, polyethylene terephthalate or aluminum plate.

[0110] In order to impart hydrophilicity to these supports, physical treatments such as plasma treatment and corona discharge, coating with a hydrophilic resin, immersion in a surfactant solution, and other chemicals The treatment is preferably performed alone or in combination. Furthermore, it is preferable that the surface is roughened so that dampening water can be easily applied. As a roughening method, there is a method in which organic or inorganic fine particles are attached to the surface by coating or the like, and a micro uneven shape is imparted by this network structure. Other preferred examples include those in which a water-resistant hydrophilic layer is provided as a surface layer on an arbitrary support. As such a surface layer, For example, a layer composed of an inorganic pigment and a binder described in US Pat. No. 3,055,295 or JP-A-56-13168, a hydrophilic swelling layer described in JP-A-9-80744, and JP-T-8 — Sol-gel films such as titanium oxide, polyvinyl alcohol, and silicic acid salts described in No. 507727.

[0111] Further, when an aluminum plate widely used as a printing plate material is used as a support, roughening treatment, immersion treatment in an aqueous solution such as sodium silicate, potassium fluorinated zirconate, phosphate, etc. Or surface treatment such as anodic acid treatment is preferred.

[0112] The surface of the aluminum plate can be roughened by various methods. For example, it is carried out by a method of mechanically roughening, a method of electrochemically dissolving and roughening the surface, and a method of selectively dissolving the surface. As the mechanical method, a known method such as a ball polishing method, a brush polishing method, a blast polishing method, or a puff polishing method can be used. Further, as an electrochemical surface roughening method, there is a method of performing alternating current or direct current in an electrolyte such as hydrochloric acid or nitric acid. In addition, prior to roughening the aluminum plate, a degreasing treatment with, for example, a surfactant, an organic solvent, an alkaline aqueous solution, or the like is performed in order to remove the rolling oil on the surface, if desired.

[0113] Further, after these treatments, water-soluble rosin such as polyvinylphosphonic acid, polymers and copolymers having sulfonic acid groups in the side chain, polyacrylic acid, water-soluble metal salts (for example, Zinc borate) or a primer coated with a yellow dye, amine salt or the like is also suitable.

[0114] [Ink jet recording method]

In the plate-making method of the present invention, ink is ejected as droplets from an ink-jet recording head based on image information by an ink-jet printer loaded with plate-forming ink, and is attached to a printing plate material. After curing, an ink solvent is evaporated and dried to form a printing plate.

[0115] The ink jet recording head used in the plate making method of the present invention may be an on-demand system or a continuous-use system. Discharge methods include electromechanical conversion methods (eg, single-cavity type, double-cavity type, bender type, piston type, shear mode type, shared wall type, etc.), electrothermal conversion type (for example, thermal-in type) 1) A misaligned discharge method may be used.

[0116] Head force The amount of ejected ink droplets is preferably 0.5 picoliters or more and 7 picoliters or less, and more preferably 0.8 picoliters or more and 4 picoliters or less. If the amount of ink droplets is 0.5 picoliter or more, the droplets ejected from the head can have a stable flying performance without being affected by air resistance, and the accuracy of the landing position is improved. In addition, if the amount of ink liquid is 7 picoliters or less, one dot size can be prevented from becoming too large, and high resolution as a printing plate can be realized.

[0117] In addition, it is possible to devise ejection and eject a plurality of droplet amounts from one head, and then eject a plurality of droplets continuously and coalesce them during flight.

[0118] The form of the ink jet printer applicable to the present invention may be any system, but it is preferable to use a flat bed system or a drum system when producing a high-quality printing plate. It is also preferable to incorporate an ink jet printer into the printing press and make a plate on the printing press.

[0119] [Active energy rays, irradiation method]

The active energy ray as used in the present invention means, for example, electron beam, ultraviolet ray, α ray, j8 ray, γ ray.

X-rays and the like can be mentioned, but handling with low risk to the human body is easy, and its use is widespread industrially, and electron beams and ultraviolet rays are preferred.

[0120] When an electron beam is used, the amount of electron beam to be irradiated is preferably in the range of 0.1 to 30 Mrad. If it is 0.1 Mrad or more, a sufficient irradiation effect can be obtained, and if it is 30 Mrad or less, adverse effects on the support and the like can be eliminated, which is preferable.

[0121] When ultraviolet light is used, the light source is, for example, a low pressure, medium pressure, high pressure mercury lamp, metal halide lamp, xenon lamp having a light emission wavelength in the ultraviolet region, or a cold cathode tube having an operating pressure of 0.1 lkPa to IMPa. Conventionally known materials such as hot cathode tubes and LEDs are used.

[0122] [Light irradiation conditions after ink landing]

The irradiation condition of the active energy ray is preferably 0.001 to 0.5 seconds, more preferably 0.001 to 1.0 seconds after the ink landing. In order to form a high-definition image, it is particularly important that the irradiation timing is as early as possible. [0123] [Installation of lamps]

As a method of irradiating active energy rays, the basic method is disclosed in Japanese Patent Laid-Open No. 60-132767. According to this, light sources are provided on both sides of the head unit, and the head and light sources are scanned by the shuttle method. Irradiation is performed after a certain period of time after ink landing. Further, the curing is completed by another light source that is not driven. US Pat. No. 6,145,979 discloses a method of using an optical fiber as an irradiation method and a method of irradiating a recording unit with UV light by applying a collimated light source to a mirror surface provided on the side of the head unit. It has been. Any of these irradiation methods can be used in the image forming method of the present invention.

[0124] Further, the irradiation of active energy rays is divided into two stages. First, the active energy rays are irradiated by the above-described method within 0.001 to 2.0 seconds after ink landing, and further the active energy rays are irradiated. Also preferred is one of the embodiments.

Example

[0125] Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In the examples, “part” or “%” is used as a force to indicate “part by mass” unless otherwise specified. “/” Represents “% by mass”.

[0126] Synthesis of polymer compound

56 g of glycidyl metatalylate, 48 g of p-hydroxybenzaldehyde, 2 g of pyridine, and N nitroso-phenylhydroxyamine ammonium salt lg were placed in a reaction vessel and stirred in a hot water bath at 80 ° C. for 8 hours.

[0127] Next, 45 g of a polyacetic acid saponified product having a degree of polymerization of 300 and a saponification rate of 88% was dispersed in 25 g of ion-exchanged water, and then 4.5 g of phosphoric acid and p- ( 3-Methacryloxy 2-hydroxypropyloxy) benzaldehyde was added with respect to polybutyl alcohol so that the modification rate was 3 mol%, and the mixture was stirred at 90 ° C for 6 hours. After cooling the resulting solution to room temperature, 30 g of basic ion exchange resin was added and stirred for 1 hour. Thereafter, the ion exchange resin is filtered, and Ilgacure 2959 (manufactured by Chino Specialty Chemicals) is mixed as a photopolymerization initiator at a rate of 0.1 lg with respect to 15% aqueous solution lOOg, followed by ion exchange. Dilution with water gave a 10% polymer compound 1 aqueous solution. Next, in the preparation of the polymer compound 1 aqueous solution, the degree of polymerization and the degree of polymerization of the polyvinylacetate were changed as necessary, and the amount of p- (3-methacryloxy-2-hydroxypropyl) benzaldehyde charged was adjusted. The modification rate was adjusted to obtain 10% aqueous solutions of polymer compounds 2 to 11 shown in Tables 2 and 3.

[Preparation of plate forming ink]

(Preparation of ink 1)

10% polymer compound 1 aqueous solution 30 parts Joncrill 734 (Johnson polymer) 4. 76 parts

Ethylene glycol 13 parts

Diethylene glycol monobutyl ether 2 parts Orphin E1010 (Nisshin Chemical Co., Ltd.) 0.15 parts

Ion exchanged water was added to the above, and the whole amount was stirred and mixed.

[0130] Next, filtration with a # 3500 mesh metal filter and deaeration with a hollow fiber module were performed to prepare ink 1.

(Preparation of ink 2)

Cyan pigment dispersion: Cab- o- jet250C 6 parts

Ethylene glycol 13 parts

The total amount of ion-exchanged water was 100 parts as described above, and ink 2 was prepared by filtration and deaeration in the same manner as ink 1.

[0132] (Preparation of ink 3 to 30)

Inks 3 to 30 were prepared in the same manner as in the preparation of Ink 2, except that the polymer compound, the resin fine particles, and the ink composition were replaced with the compounds shown in Tables 2 and 3.

[0133] (Preparation of ink 31) Polymerizable compound B 25 parts Photopolymerization initiator A 1 part

Cyan pigment dispersion: Cab- o- jet250C 6 parts

Ethylene glycol 13 parts

The total amount of ion-exchanged water was 100 parts as described above, and ink 31 was prepared by filtration and deaeration in the same manner as ink 1.

[0134] (Preparation of ink 32-35)

Inks 32 to 35 were prepared in the same manner as in the preparation of the ink 31 except that the polymer compound, the resin fine particles, and the ink composition were changed to the respective compounds shown in Table 3.

[0135] [Chemical 9]

[0136] Table 1 shows the details of each resin fine particle used in the preparation of the inks:! To 31.

[0137] It should be noted that in the fine resin particles shown in Table 1, the Jonkrill series is manufactured by Johnson Polymer Co., Ltd., the Superflex series is manufactured by Daiichi Kogyo Seiyaku Co., Ltd., and the SX series is manufactured by Nippon Zeon Co., Ltd. .

[0138] [Table 1] Resin Resin fine particles

Fine particle Tg Average particle size Solid content concentration

Number Name Acid value

(.C) (nmj

1 Jongkrill 7U 0 100 100 48

2 Jonkrill 7001 1 2 87 80 42

3 Jongkrill 450 16 100 60 42

4 Jongkrill 734 30 87 80 42

5 Jongkrill 775 37 55 80 45

6 Jongkrill 352 56 51 100 45

7 Jongkrill 790 30 30 200 47

8 Jongkrill 780 46 46 100 48

9 Superflex n o 48-90 30

10 Superflex 300 -42-70 30

1 1 Superflex 410-16 ― 200 40

12 Superflex 420-10-10 32

13 Superflexus 130 101-20 35

14 SX1706 0 ― 100 48

15 SX1 105 0-100 45

[0139] Details of each additive used for the preparation of inks 1 to 31 described in abbreviations in Tables 2 and 3 are as follows.

Is as follows.

[0140] * 1: Solid content of polymer compound in ink (%)

* 2: Solid content of resin fine particles in ink (%)

EG: Ethylene glycol

PG: Propylene glycol

DEGBE: Diethylene glycol monobutyl ether

CAB: Cab o -jet250C (cyan pigment)

E 1010: Orphin E 1010 (Nisshin Chemical)

[0141] [Table 2]

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(Inkjet printer)

The inkjet printer shown in Fig. 1 was used. Nozzle diameter 20 im Nozzle number 512 Slurry, nozzle resolution 300dpi (dpi in the present invention means 2.5 dots per 54cm) is mounted on carriage 1 with 8 piezo inkjet heads, and UV irradiation light source 2 on both sides of carriage 1 This is a flatbed ink jet printer. Carriage 1 moves in the X direction in Fig. 1 and moves in the Y direction by moving plate 4 with transport roller 3 on the flat bed.

[0144] (Preparation of printing plate)

Images were formed on a grained aluminum substrate as a printing plate in Fig. 1 with a resolution of 2400 dpi x 2400 dpi with an appropriate amount of 1 picoliter of each ink. For the comprehensive evaluation, we used a 10cm x 10cm solid image, a thin line layer, a 3 to 10 point Mincho font image, and a natural image (photo) image.

[0145] The ink was cured under conditions of 120 WZcm from a metal halide lamp (MAL 400NL power supply power 3 kW 'manufactured by Nippon Battery Co., Ltd.) installed on both sides of the carriage.

[0146] Since the viscosity differs for each ink, the voltage applied to the piezo element of the printer was adjusted so that the appropriate amount of liquid for each ink was 1 picoliter.

[0147] <Evaluation of ink>

(Evaluation of intermittent emission)

Nose, Nore caliber 20 m, Nos, Nore 512 Nos, Nore, Nos, Nore Resolution 300dpi (In this invention! /, Dpi means 2.5 dots per 54cm) Piezo-type inkjet head The injection test was performed by adjusting the driving voltage so that the liquid amount was 1pl. In an environment with a temperature of 20 ° C and a humidity of 30% RH, after emitting continuously for 1 minute at a drive frequency of 12 kHz, the injection was stopped for a certain period of time, and the state when continuous injection was resumed was observed. The intermittent emission performance was evaluated according to the criteria shown.

[0148] ○: After stopping for 3 minutes, the emission from all nozzles was confirmed.

△: Force with missing nozzles seen when stopped for 3 minutes.

X: Nozzle missing after 1 minute stop

(Evaluation of water rub resistance) A 1% aqueous solution of isopropyl alcohol was applied to the sponge, and the entire printing plate was rubbed strongly. Look at the state of the plate image after rubbing? Observation and observation were carried out, and water scratch resistance was evaluated according to the following criteria.

[0149] A: The image of the entire printing plate does not peel off at all even after rubbing 200 times.

○: The image of the entire printing plate does not peel off at all even after rubbing 50 times

Δ: A part of the thin line was found to be hung after 50 times of rubbing

X: 3 point characters become illegible after rubbing 50 times

(Evaluation of inking properties)

The prepared printing plate was placed on a printing machine and printed on coated paper (SA Kanofuji: Oji Paper Co., Ltd.). The state of the solid image portion that was printed was visually observed, and the inking property was evaluated according to the following criteria.

[0150] A: The density of the solid part that has been printed is high and good, and no unevenness is observed in the solid image part. O: The density of the solid part that has been printed is slightly uneven in the solid image part. Δ: The density of the printed solid part is slightly low and unevenness is observed.

X: Severe unevenness with low density in the printed solid part

(Evaluation of printing durability)

The prepared printing plate was placed on a printing machine and printed on coated paper (OK Kanfuji: made by Oji Paper Co., Ltd.). The printing durability was evaluated according to the criteria shown in.

[0151] (§): There is no chipping or crushing on the 15,000th printed material

0: Slight chipping was seen on the 15,000th printed material, but no chipping or crushing was seen on the 10,000th printed material! /,

Δ: Chipping or crushing was observed on the 10,000th printed material

X: Chipping or crushing was observed on the 3,000th printed material

(Evaluation of dot gain)

Printing plates for printing 3cm x 3cm 15% halftone patches were prepared at the four corners of A3 size printing plates, and printed on coated paper (OK Kanfuji: made by Oji Paper Co., Ltd.). [0152] The dot percentage of the printed patch was measured using X-rite 528 (manufactured by X-rite), and the dot gain was evaluated according to the following criteria.

[0153] ○: dot ^_0/0 was 15% ± 3%

△: dot ^_0/0 was 15% workers 5%

X: dot ^_0/0 was more than 15% ± 5%

(Evaluation of ink viscosity suitability)

The ink viscosity at 25 ° C was measured using VM-1AL (manufactured by CBC Materials) as a vibratory viscometer, and ink viscosity suitability was evaluated according to the following criteria.

[0154] ○: 2mPa · s or more, less than 8mPa · s

Δ: Less than 2mPa · s or 8mPa · s or more, less than 15mPa · s

X: 15mPa's or more

Table 4 shows the results obtained as described above.

[0155] [Table 4]

In sync intermittent

Water rub resistance Inking property Dot gain Printing durability Remarks Number Viscosity suitability Outgoing property

2 ◎ O ○ ◎ ○ ○ The present invention

3 Δ X ○ Δ ○ ○ Comparative example

4 ◎ ○ ○ ◎ ○ ○ The present invention

5 ◎ ○ ○ ◎ ○ ○ The present invention

6 ○ ○ ○ ◎ Δ ○ The present invention

7 ○ ○ ○ ◎ ○ ○ The present invention

8 ○ ○ ○ ◎ ○ ○ The present invention

9 ◎ ○ ○ ◎ ○ ○ The present invention

11 ◎ ○ ○ ◎ ○ ○ The present invention

12 ◎ O ○ ○ ○ The present invention

13 Δ ○ ○ ○ ○ ○ The present invention

14 ○ ○ Δ ○ X Δ Comparative example

15 ○ ○ ○ ○ Δ Δ The present invention

16 ◎ ◎ O ◎ ○ ○ The present invention

17 ◎ ◎ ○ ◎ ○ ○ The present invention

18 Δ △ △ △ 〇 X Comparative example

20 Δ X ○ Δ ○ ○ Comparative example

21 Δ ◎ ○ Δ ○ ○ The present invention

22 ○ Δ ○ △ △ X Comparative example

23 ○ Δ Δ ○ ○ X Comparative example

24 ○ ○ ○ ○ ○ ○ The present invention

25 ○ ○ ○ ○ O ○ The present invention

26 ○ ○ ○ ○ ○ ○ The present invention

27 ○ △ O △ Δ X Comparative example

28 Δ ○ ○ Δ Δ Δ The present invention

29 ○ ○ O Δ ○ ○ The present invention

30 Δ ○ ○ ○ ○ ○ The present invention

31 ○ X Δ X Δ ○ Comparative example

32 ○ ○ Δ ○ ○ ○ The present invention

33 ○ ○ Δ ○ ○ ○ The present invention

34 ○ ○ X ○ X X Comparative example

35 O 〇 X △ XX Comparative Example As is clear from the results shown in Table 4, the present invention uses a plate-forming ink containing the polymer compound according to the present invention and the fine particles of the resin in the amounts specified in the present invention. The plate-making method of the invention is superior to the comparative examples in all of water rub resistance, fleshing property, printing durability and dot gain. Click is provided with a proper viscosity characteristics, Rukoto be seen _c

Claims

The scope of the claims

[1] After the plate-forming ink is deposited on the printing plate by the inkjet recording method, an active energy ray is irradiated, and the ink solvent is evaporated and dried to form an image to form a printing plate. In the plate-making method for producing the ink, the plate-forming ink contains at least water and an active energy ray crosslinkable compound that is cured by irradiation with the active energy ray, with respect to the total mass of the ink, 0.8 mass. % And 30.0% by mass or less, and the average particle size of 0.1 to 150% by mass of fine resin particles having an average particle diameter of 5 nm to 150 nm. .

[2] Active energy ray crosslinkability that is hardened by irradiation of the active energy ray. Compound strength The main chain has a plurality of side chains, and irradiation with active energy rays enables high crosslinkage between the side chains. The plate-making process according to claim 1, wherein the plate-making process is a molecular compound and the polymer compound is contained in an amount of 0.8% by mass or more and 5.0% by mass or less based on the total mass of the ink. Method.

[3] The plate making method according to claim 1 or 2, wherein a glass transition temperature of the fine resin particles is -20 ° C or higher and 70 ° C or lower.

[4] The main chain of the polymer compound is a polyvinyl acetate cane and has a saponification degree of 77

4. The plate-making method according to claim 2 or 3, wherein the degree of polymerization is not less than 99% and not more than 99%, and the degree of polymerization is not less than 200 and not more than 4000.

[5] The modification rate of the side chain with respect to the main chain of the polymer compound is 0.8 mol% or more, 6 mol.

The plate making method according to any one of claims 2 to 4, wherein the force is 1% or less.

[6] A printing plate produced by the plate making method according to any one of the items 1 to 5 of claim 1.