JP5238557B2 - Cleaning liquid - Google Patents

Description

  The present invention relates to a cleaning solution for a developing tank of an automatic developing machine for photopolymerization lithographic printing plates, and more particularly to cleaning a developing tank of an automatic developing machine for processing a photopolymerization CTP (computer tow plate) plate material. It relates to a suitable cleaning solution.

  In the photosensitive composition, the molecular structure undergoes a chemical change by a photoreaction, and as a result, a physical phenomenon (physical property) changes. This chemical change by the action of light includes cross-linking, polymerization, decomposition, depolymerization, functional group conversion, etc., and there are various such as solubility, adhesiveness, refractive index, substance permeability and phase change. Such photosensitive compositions have been put into practical use in a wide range of fields such as printing plates, resists, paints, coating agents, and color filters. Furthermore, it has been utilized and developed in the field of photoresist using photoengraving technology (photolithography). Photoresists utilize changes in solubility due to photoreactions, and more precise material design is required due to high resolution requirements.

  A widely used type of photopolymerizable lithographic printing plate has a photosensitive coating applied to an aluminum support. In this coating film, the exposed coating film portion is cured, and the unexposed coating film portion is eluted by the development process. Lithographic printing utilizes the oleophilic and hydrophilic surface properties of the pattern and background formed on the printing plate surface, and simultaneously supplies ink and fountain solution to the printing plate on the printing press. This utilizes the phenomenon of selective transfer on a pattern having s. The ink transferred onto the pattern is then transferred to an intermediate body called a blanket, and further transferred to a printing paper for printing.

  In order to produce a photosensitive lithographic printing plate, conventionally, the photosensitive coating film (photosensitive layer) was generally exposed to ultraviolet rays through a light-transmitting negative film original, but the work was complicated. Met. Therefore, a method is disclosed in which a printing plate having a high-sensitivity photosensitive layer is used to scan a thin laser beam on the plate surface and form an original directly on the plate surface (for example, patent document). 1).

  As a printing plate suitable for the above scanning exposure, a photopolymerization planographic printing plate comprising a compound capable of addition polymerization or crosslinking and a borate complex of a cationic dye having near infrared absorption ability (Patent Document 2) ), A photopolymerizable lithographic printing plate having a photopolymerizable photosensitive layer containing an ethylenically unsaturated compound, a photopolymerization initiation system, and a polymer binder, wherein the acid value of the photosensitive layer is adjusted to a specific range (Patent Document 3), a photopolymerization planographic printing plate (Patent Document 4) that uses a copolymer having an allyl-type or vinyl-type unsaturated bond and a copolymer containing a (meth) acrylic ester is known. Yes.

  Further, the photopolymerization lithographic printing plate as described above is provided with an over layer made of polyvinyl alcohol or the like for the purpose of enhancing the stability of sensitivity and image strength by enhancing the oxygen barrier property. Prior to development, there is a problem that a pre-water washing step for removing the over layer is necessary, and light scattering occurs due to the presence of the over layer during scanning exposure, resulting in a decrease in image quality. On the other hand, a photosensitive composition containing a polymer having a phenyl group substituted with a vinyl group in the side chain and a photopolymerization initiator sensitive to light, and a photopolymerization planographic printing plate using the same are disclosed. (Patent Document 5). In this invention, since the polymerization reaction proceeds more effectively by recombination of styryl radicals generated by radicals generated by scanning exposure, an over layer is not required and high image strength is obtained because of high sensitivity. A photopolymerization lithographic printing plate is disclosed that provides an excellent printing durability when applied to a printing plate.

  On the other hand, the photopolymerization lithographic printing plate as described above is subjected to a scanning exposure and then generally developed using an automatic developing machine. However, since the photosensitive layer of the printing plate suitable for scanning exposure has high sensitivity, when a long-term development process is performed using an automatic developing machine, the highly sensitive photosensitive layer dissolved and removed is contained in the developer. Development debris that can be visually recognized by staying is formed, and adheres to the wall surface of the developing tank, the transport roll, and the wall surface of the developer circulation path, which may transfer to the printing plate and stain the printing plate. . In order to prevent this, the frequency of cleaning of the developing tank of the automatic developing machine and replacement of the developing solution has increased, which has been a burden on the operator.

  Conventionally, as a method of removing deposits adhering to a wall surface or a transport roll in a developing tank of an automatic processor, a household detergent containing a commercially available abrasive is used, and an operator manually removes deposits. However, it is a work that requires a great amount of labor, and there is a risk of damaging parts in the developing machine, and it is difficult to carry out the cleaning within the circulation path and the circulation pump. For such problems, a cleaning liquid containing a sequestering agent, an abrasive and a fluorosurfactant is disclosed (Patent Document 6), and it is known that the cleaning temperature is 45 ° C. or higher ( Patent Document 7). Further, there is known a cleaning solution containing a chelating agent, an anionic surfactant, an organic solvent, n-alkanoic acid or a salt thereof, which is effective for cleaning an automatic processor which has developed a photopolymerization planographic printing plate containing a titanocene compound. (Patent Document 8).

  In addition, a photosensitive composition containing a polymer having a phenyl group substituted with a vinyl group in the side chain and a photopolymerization initiator sensitive to light, and a photopolymerization planographic printing plate using the same are also developed. The problem of dullness is still present, and since it has high sensitivity, the curing reaction proceeds due to light leakage from the outside of the automatic developing machine, dark reaction, etc., resulting in extremely strong deposits. A sufficient cleaning effect could not be obtained with the cleaning liquid. For this problem, a cleaning liquid containing alkanolamine has been disclosed (Patent Document 9). Thereby, it became possible to remove a strong deposit.

  Due to the recent increase in awareness of environmental issues, the reduction of waste liquid has become a major concern in the printing field. One effective method for reducing the waste liquid is to suppress the frequency of replacement of the developer in the developing tank. Reducing the amount of developer containing a large amount of photosensitive layer component reduces the environmental burden and reduces the burden on workers. However, the presence of the developer in which the photosensitive layer component stays for a long period in the development layer causes the curing reaction of the deposit to proceed, resulting in a stronger deposit. Therefore, a sufficient cleaning effect could not be obtained even when the above cleaning liquid was used.

Japanese Patent Laid-Open No. 7-333847 JP-A-5-197139 JP 2002-214780 A JP 2002-244277 A JP 2001-290271 A Japanese Patent Laid-Open No. 9-151394 Japanese Patent Laid-Open No. 10-3172 JP 2001-255667 A JP 2008-83224 A

  The object of the present invention is to easily and easily damage the parts in the automatic developing machine, even if a high-sensitivity photopolymerization lithographic printing plate is developed over a long period of time by an automatic developing machine. It is an object of the present invention to provide a developing tank cleaning solution for an automatic developing machine that can be removed without the need for cleaning.

  The object of the present invention is to provide a developing tank for an automatic developing machine for photopolymerization planographic printing plates, comprising a compound represented by the following general formula (1) and a compound represented by the general formula (2): Can be achieved with the following washing solution.

In formula, R < ₁₁ >, R < ₁₂ >, R < ₁₃ >, R < ₁₄ > represents the C1-C8 alkyl group which may have a hydroxyl group, respectively.

In the formula, R ₂₁ represents an alkyl group having 8 to 20 carbon atoms, and a1, a2, b1, and b2 each represent an integer of 1 to 60. In addition, the bonding order of the ethyleneoxy part and the propyleneoxy part to the nitrogen atom is arbitrary, and when any of a1, a2, b1, and b2 is 2 or more, the bonding order of the ethyleneoxy part and the propyleneoxy part is arbitrary. It is.

  According to the present invention, even if a high-sensitivity photopolymerization lithographic printing plate is developed with an automatic processor for a long period of time, deposits generated by the generated development residue can be easily and damage parts in the automatic processor. It is possible to provide a cleaning solution for a developing tank of an automatic processor that can be removed without any problems.

  Hereinafter, the present invention will be described in detail. A cleaning liquid for a developing tank of an automatic developing machine for photopolymerization planographic printing plates according to the present invention contains a compound represented by the following general formula (1) and a compound represented by the general formula (2): To do.

In general formula (1), R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ may have a hydroxyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, an octyl group, or a 2-hydroxyethyl group. A good alkyl group having 1 to 8 carbon atoms is represented.

In General Formula (2), R ₂₁ represents an alkyl group having 8 to 20 carbon atoms, a1, a2, b1, and b2 each represent an integer of 1 to 60, and a1 + a2 is preferably 12 or less. In addition, the bonding order of the ethyleneoxy part and the propyleneoxy part to the nitrogen atom is arbitrary, and when any of a1, a2, b1, and b2 is 2 or more, the bonding order of the ethyleneoxy part and the propyleneoxy part is arbitrary. It is.

  Examples of the compound represented by the general formula (1) include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, methyltriethylammonium hydroxide, trimethylethylammonium hydroxide, Dimethyldiethylammonium hydroxide, trimethyl (2-hydroxyethyl) ammonium hydroxide, triethyl (2-hydroxyethyl) ammonium hydroxide, dimethyldi (2-hydroxyethyl) ammonium hydroxide, diethyldi (2-hydroxyethyl) ammonium hydroxide, Examples thereof include methyl tri (2-hydroxyethyl) ammonium hydroxide, ethyl tri (2-hydroxyethyl) ammonium hydroxide, and tetra (2-hydroxyethyl) ammonium hydroxide. Particularly preferred are tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, and tetrabutylammonium hydroxide. Of these, tetramethylammonium hydroxide is preferred. The compounds represented by the general formula (1) can be used alone or in combination of two or more. In the cleaning liquid of the present invention, the pH of the cleaning liquid is preferably adjusted to pH 8 to 14, more preferably pH 10 to 13, depending on the compound represented by the general formula (1). Since the use of an inorganic alkaline compound is not preferable because it reduces the removability of deposits, it is preferably added at 1% by mass or less of the total mass of the cleaning liquid.

  Examples of the compound represented by the general formula (2) are shown in Table 1 below, but are not limited thereto. Of these, the compound (N-1) is preferred. The compound represented by General formula (2) can be used individually or in combination of 2 or more types.

  The content of the compound of general formula (1) or general formula (2) contained in the cleaning liquid is 0.1 to 20% by mass, particularly preferably 1 to 15% by mass, based on the total mass of the cleaning liquid. If the ratio is less than this, the introduction effect may not be recognized. In addition, when the content exceeds this range, liquid leakage from the developing tank due to foaming during cleaning may occur. Although the content ratio of the compound of the general formula (1) or the general formula (2) can be added at any content ratio as long as it is within the above concentration range, the compound represented by the general formula (1) and more generally The mass ratio of the compound represented by the formula (2) is added in the range of 1:10 to 10: 1.

  Various surfactants can be added to the cleaning liquid of the present invention as needed for the purpose of improving the cleaning performance. Preferred surfactants include anionic, cationic, nonionic and amphoteric surfactants. Specifically, nonionic interfaces such as polyoxyethylene glycerin fatty acid esters, polyoxyethylene-polyoxypropylene block copolymers, polyoxyethylene-polyoxypropylene block copolymer adducts of ethylenediamine, and fatty acid diethanolamides Activators, fatty acid salts, abietic acid salts, hydroxyalkane sulfonic acid salts, alkane sulfonic acid salts, dialkyl sulfosuccinic acid ester salts, linear alkyl benzene sulfonic acid salts, alkyl naphthalene sulfonic acid salts, alkyl diphenyl ether sulfonic acid salts, polyoxyethylene alkyl Sulfophenyl ether salts, N-methyl-N-oleyl taurine sodium salt, N-alkylsulfosuccinic acid monoamide disodium salt, petroleum sulfonates, sulfuric acid Beef tallow oil, fatty acid alkyl ester sulfate ester salt, polyoxyethylene alkyl ether sulfate ester salt, fatty acid monoglyceride sulfate ester salt, polyoxyethylene alkylphenyl ether sulfate ester salt, polyoxyethylene styryl phenyl ether sulfate ester salt, alkyl sulfate ester salt , Alkyl phosphate ester salts, polyoxyethylene alkyl ether phosphate ester salts, polyoxyethylene alkyl phenyl ether phosphate ester salts, partially saponified styrene / maleic anhydride copolymers, olefin / maleic anhydride copolymers Quaternary anions such as partially saponified products, anionic surfactants such as naphthalenesulfonate formalin condensate, alkylamine salts, and tetrabutylammonium bromide Iodonium salts, cationic surfactants such as polyethylene polyamine derivatives, carboxy betaines, aminocarboxylic acids, sulfobetaines, amino sulfate esters, amphoteric surfactants such as imidazolines. Among the surfactants listed above, those having polyoxyethylene can be read as polyoxyalkylenes such as polyoxymethylene, polyoxypropylene and polyoxybutylene. Another preferred surfactant is a fluorosurfactant containing a perfluoroalkyl group in the molecule. Such fluorosurfactants include perfluoroalkyl carboxylates, perfluoroalkyl sulfonates, anionic types such as perfluoroalkyl phosphates, amphoteric types such as perfluoroalkyl betaines, and perfluoroalkyltrimethylammonium salts. Cationic and perfluoroalkylamine oxides, perfluoroalkylethylene oxide adducts, perfluoroalkyl group and hydrophilic group-containing oligomers, perfluoroalkyl group and lipophilic group-containing oligomers, perfluoroalkyl groups, hydrophilic and lipophilic groups Nonionic types such as group-containing oligomers, perfluoroalkyl groups, and lipophilic group-containing urethanes can be mentioned. The above surfactants can be used singly or in combination of two or more, but liquid leakage from the developing tank due to foaming at the time of cleaning may occur, so that it is 10% by mass or less of the total mass of the cleaning liquid. It is preferable to be added.

  It is advantageous in production, transportation, storage, etc. that the cleaning liquid used in the present invention is a concentrated liquid in which the water content is less than that in use, and is diluted with water at the time of use. The degree of concentration in this case is suitably such that each component does not cause separation or precipitation, and although it depends on the liquid composition, it is usually preferable to concentrate to about concentrated liquid: water = 1: 0 to 1:10. In addition, since the container for the cleaning liquid and its concentrated liquid is alkaline, it is preferable to use a material that does not permeate carbon dioxide and that does not break during transportation for safety. Usually, it is made of a resin such as a hard bottle or cubitner. A container is preferably used.

  As the cleaning method of the cleaning solution of the present invention, the developing solution to be cleaned is filled to the extent that the cleaning solution overflows, and is left for several tens of minutes or circulated in the bath, or lightly rubbed with a sponge soaked with the cleaning solution. It can wash | clean by the method of etc.

  The automatic processor according to the present invention will be described. The automatic processor for processing a photopolymerization planographic printing plate that is cleaned with the cleaning liquid of the present invention preferably has a structure comprising a developing tank and a washing tank and a finisher tank. The printing plate developed with the developing solution in the developing tank may be subjected to post-processing with a washing water, a rinsing solution containing a surfactant, a finisher mainly composed of gum arabic or starch derivatives, or a protective gum solution. Preferably, this post-treatment can be used in various combinations. For example, development-> water-washing-> rinse solution treatment containing a surfactant and development-> water washing-> finisher solution treatment are preferable because the rinse solution and finisher solution are less fatigued. In such processing, each processing solution can be processed while being replenished with each replenishing solution according to the processing amount and operating time. The printing plate obtained by such processing is loaded on an offset printing machine and used for printing. The cleaning liquid of the present invention can wash not only the developing tank but also the deposits brought into the water washing tank. The cleaning liquid of the present invention is not limited to an automatic processor having a specific structure, and can be used for a general automatic processor.

  The photopolymerization planographic printing plate according to the present invention has a photopolymerizable photosensitive layer on a support. Specifically, the photosensitive layer is a photopolymerizable photosensitive layer containing at least a polymerizable compound having an ethylenically unsaturated group and a photopolymerization initiator sensitive to light.

  Examples of the polymerizable compound having an ethylenically unsaturated group include JP-A-51-37193, JP-B-2-32293, JP-B-2-16765, JP-A-48-64183, and JP-B. 49-43191, JP-B-52-30490, JP-A-2001-290271, and JP-A-2006-111860, and the like. Particularly, a phenyl group substituted with a vinyl group is a side chain. It is preferable to have a polymer. By having a phenyl group substituted with a vinyl group in the side chain, it effectively crosslinks by recombination of styryl radicals generated by the generated radicals. Printing plates that do not require heat treatment with sensitivity can be produced. However, as a result of increasing the sensitivity by using the above polymer and further using an organic boron salt, a sensitizing dye, and a trihaloalkyl-substituted compound as described below, the dissolved and removed photosensitive layer stays in the developer. If the development waste generated by this stays for a long period of time, it becomes a hard deposit and becomes difficult to clean, but the cleaning solution of the present invention is particularly effective in such a system.

  The phenyl group that the polymer has in the side chain may be substituted with a group or atom that can replace the hydrogen atom that the phenyl group has, and the vinyl group that the polymer has in the side chain is a halogen atom or a carboxy group. , A sulfo group, a nitro group, a cyano group, an amide group, an amino group, an alkyl group, an aryl group, an alkoxy group, an aryloxy group and the like. More specifically, the polymer having a phenyl group substituted with a vinyl group in the side chain has a group represented by the following in the side chain.

In the formula, Z ₁ represents a linking group, and R ₃₁ , R ₃₂ and R ₃₃ are a hydrogen atom, a halogen atom, a carboxy group, a sulfo group, a nitro group, a cyano group, an amide group, an amino group, an alkyl group, an aryl group, An alkoxy group, an aryloxy group, and the like, and these groups may be substituted with an alkyl group, an amino group, an aryl group, an alkenyl group, a carboxy group, a sulfo group, a hydroxy group, or the like. R ₃₄ represents a group or an atom capable of substituting for a hydrogen atom. n ₃ represents 0 or 1, m ₃ represents an integer of 0 to 4, and k ₁ represents an integer of ₁ to 4.

The above groups will be described in more detail. The linking group Z ₁ preferably contains a heterocyclic ring, and other groups and atoms such as oxygen atom, sulfur atom, alkylene group, alkenylene group, arylene group, —N (R ₃₅ ) —, —C (O) —O. -, -C (R < ₃₆ >) = N-, -C (O)-, a sulfonyl group, the group shown below, etc. may be contained individually or in the state which 2 or more combined. Here, R ₃₅ and R ₃₆ represent a hydrogen atom, an alkyl group, an aryl group, or the like. Furthermore, the above-described linking group may have a substituent such as an alkyl group, an aryl group, or a halogen atom.

  Examples of the heterocyclic group include pyrrole ring, pyrazole ring, imidazole ring, triazole ring, tetrazole ring, isoxazole ring, oxazole ring, oxadiazole ring, isothiazole ring, thiazole ring, thiadiazole ring, thiatriazole ring, indole ring. , Indazole ring, benzimidazole ring, benzotriazole ring, benzoxazole ring, benzthiazole ring, benzselenazole ring, benzothiadiazole ring, pyridine ring, pyridazine ring, pyrimidine ring, pyrazine ring, triazine ring, quinoline ring, quinoxaline ring, etc. A nitrogen-containing heterocyclic ring, a furan ring, a thiophene ring and the like, and a substituent may be bonded to these heterocyclic rings. Although the example of group which a polymer has in a side chain is shown below, it is not limited to these examples.

Among the groups that the polymer has in the side chain, preferred ones exist. That is, it is preferable that R ₃₁ and R ₃₂ are hydrogen atoms and R ₃₃ is a hydrogen atom or a lower alkyl group having 4 or less carbon atoms (methyl group, ethyl group, etc.). The k ₁ is preferably 1 or 2.

  There is a preferred range for the molecular weight of the polymerizable compound having an ethylenically unsaturated group, and the mass average molecular weight is preferably in the range of 10,000 to 1,000,000, and more preferably in the range of 10,000 to 300,000. Particularly preferred.

  The polymerizable compound having an ethylenically unsaturated group preferably contains a carboxyl group-containing monomer as a copolymerization component in order to impart solubility to an alkaline aqueous solution. The proportion of the carboxyl group-containing monomer in the polymer is preferably 5% by mass or more and 99% by mass or less. If the proportion is less than this, the copolymer may not be dissolved in the alkaline aqueous solution. Examples of the carboxyl group-containing monomer include acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, 4-carboxystyrene, and the like.

  Preferred examples of the polymerizable compound having an ethylenically unsaturated group are shown below. In the formula, the number represents the mol% of each repeating unit in the total copolymer composition.

  The photopolymerization lithographic printing plate according to the present invention comprises an organic boron salt, a trihaloalkyl-substituted compound (for example, a trihaloalkyl-substituted nitrogen-containing heterocyclic compound, an s-triazine compound and an oxadi) as a photopolymerization initiator sensitive to light. Commonly used photopolymerization initiators such as azole derivatives, trihaloalkylsulfonyl compounds), hexaarylbiimidazoles, titanocene compounds, ketoxime compounds, thio compounds, onium salts, organic peroxides, etc. are preferably used. It is highly sensitive and is preferably used. More preferably, an organic boron salt and a trihaloalkyl-substituted compound are used in combination.

  The organic boron anion constituting the organic boron salt is represented by the following.

In the formula, each of R ₄₁ , R ₄₂ , R ₄₃ and R ₄₄ may be the same or different, and represents an alkyl group, aryl group, aralkyl group, alkenyl group, alkynyl group, cycloalkyl group or heterocyclic group. Represent. Of these, it is particularly preferred that one of R ₄₁ , R ₄₂ , R ₄₃ and R ₄₄ is an alkyl group and the other substituent is an aryl group.

  In the above-mentioned organoboron anion, a cation that forms a salt is simultaneously present. Examples of the cation in this case include alkali metal ions, onium ions, and cationic sensitizing dyes. Onium ions include ammonium, sulfonium, iodonium and phosphonium salts. When using a salt of an alkali metal ion or onium ion and an organic boron anion, it is preferable to add a sensitizing dye to impart photosensitivity in the wavelength range of light absorbed by the dye. Further, when an organic boron anion is contained as a counter anion of the cationic sensitizing dye, photosensitivity is imparted according to the absorption wavelength of the sensitizing dye. Further, when an organic boron anion is contained as a counter anion of the cationic sensitizing dye, an organic boron anion can be further contained as a counter anion of an alkali metal or onium salt.

  As one of the most preferable modes of the photosensitive layer of the photopolymerization lithographic printing plate according to the present invention, a photosensitive layer containing both the organic boron salt and a dye for sensitizing the organic boron salt can be mentioned. It does not show photosensitivity in the 900 nm wavelength region, and shows high photosensitivity to light in such a wavelength region only by adding a sensitizing dye described later.

  The organic boron salt is a salt containing the organic boron anion shown above, and alkali metal ions and onium compounds are preferably used as cations forming the salt. Particularly preferable examples of the onium salt with an organic boron anion include ammonium salts such as tetraalkylammonium salts, sulfonium salts such as triarylsulfonium salts, and phosphonium salts such as triarylalkylphosphonium salts. Examples of particularly preferred organic boron salts are shown below.

  A trihaloalkyl-substituted compound can be used as a photopolymerization initiator that can be used together with an organic boron salt to achieve higher sensitivity and higher contrast. Specifically, the trihaloalkyl-substituted compound is a compound having at least one trihaloalkyl group such as a trichloromethyl group or a tribromomethyl group in the molecule. As a preferable example, the trihaloalkyl group is a nitrogen-containing complex. Examples of the compound bonded to the ring group include s-triazine derivatives and oxadiazole derivatives, or trihaloalkylsulfonyl compounds in which the trihaloalkyl group is bonded to an aromatic ring or a nitrogen-containing heterocycle via a sulfonyl group. .

  Particularly preferred examples of trihaloalkyl-substituted nitrogen-containing heterocyclic compounds and trihaloalkylsulfonyl compounds are shown below.

  The content of the photopolymerization initiator as described above is preferably in the range of 1% by mass to 50% by mass with respect to the solid content of the entire photosensitive layer.

  The photopolymerization lithographic printing plate according to the present invention is very suitably used for scanning exposure using near infrared to infrared light, that is, laser light having a wavelength region of 750 to 900 nm. Cyanine, polymethine, squarylium dye, and the like can be used as the sensitizing dye used for sensitizing to the near infrared, and the following sensitizing dyes are preferably used.

The content of the sensitizing dye exemplified above is suitably about 3 to 300 mg per 1 m ² of the photosensitive layer. Preferably from 10 to 200 mg / ^{m 2.}

  The photopolymerization lithographic printing plate according to the present invention preferably contains a polyfunctional polymerizable monomer or oligomer polymerizable compound having two or more polymerizable double bonds in the molecule. The molecular weight of the polymerizable compound is less than 10,000, preferably 5000 or less. Examples of the compound include compounds having two or more polymerizable double bonds such as an acryloyl group, a methacryloyl group, and a phenyl group substituted with a vinyl group. By adding these compounds, it is possible to obtain a printing plate that is efficiently subjected to a crosslinking reaction and excellent in printing durability.

  Examples of the compound having an acryloyl group or a methacryloyl group as a polymerizable double bond include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, and neopentyl glycol di (meth) acrylate. , Tetraethylene glycol di (meth) acrylate, trisacryloyloxyethyl isocyanurate, tripropylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, pentaerythritol tri (meth) Acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipenta Risuri penta (meth) acrylate include dipentaerythritol hexa (meth) acrylate, pyrogallol triacrylate.

  When a polymerizable compound having two or more phenyl groups substituted with vinyl groups in the molecule is used, crosslinking is effectively performed by recombination of styryl radicals generated by the generated radicals. A photopolymerization planographic light-sensitive material that is not required can be produced. A compound having a phenyl group substituted with a vinyl group as a polymerizable double bond is typically represented by the following general formula.

In the formula, Z ₂ represents a linking group, R ₅₁ and R ₅₂ are a hydrogen atom, a halogen atom, a carboxy group, a sulfo group, a nitro group, a cyano group, an amide group, an amino group, an alkyl group having 1 to 4 carbon atoms, An alkoxy group having 1 to 4 carbon atoms or the like is represented. R ₅₃ is a hydrogen atom, a halogen atom, a carboxy group, a sulfo group, a nitro group, a cyano group, an amide group, an amino group, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or the like. Group, amino group, aryl group, alkenyl group, carboxy group, sulfo group, hydroxy group and the like. R ₅₄ represents a group or an atom capable of substituting for a hydrogen atom. m ₅ represents an integer of 0 to 4, _{k 2} is an integer of 2 or more. When m ₅ is 2 or more, R ₅₄ may be the same or different.

The above general formula will be described in more detail. As the linking group for Z ₂ , an oxygen atom, a sulfur atom, an alkylene group, an alkenylene group, an arylene group, —N (R ₅₅ ) —, —C (O) —O—, —C (R ₅₆ ) ═N—, Examples include —C (O) —, a sulfonyl group, a heterocyclic group, or a group in which two or more are combined. Here, R ₅₅ and R ₅₆ represent a hydrogen atom, an alkyl group, an aryl group, or the like. Furthermore, the above-described linking group may have a substituent such as an alkyl group, an aryl group, or a halogen atom.

  Examples of the heterocyclic group include pyrrole ring, pyrazole ring, imidazole ring, triazole ring, tetrazole ring, isoxazole ring, oxazole ring, oxadiazole ring, isothiazole ring, thiazole ring, thiadiazole ring, thiatriazole ring, indole ring. , Indazole ring, benzimidazole ring, benzotriazole ring, benzoxazole ring, benzthiazole ring, benzselenazole ring, benzothiadiazole ring, pyridine ring, pyridazine ring, pyrimidine ring, pyrazine ring, triazine ring, quinoline ring, quinoxaline ring, etc. A nitrogen-containing heterocyclic ring, a furan ring, a thiophene ring and the like, and a substituent may be bonded to these.

Among the compounds represented by the above general formula, there are preferable compounds. That is, R ₅₁ and R ₅₂ are hydrogen atoms, R ₅₃ is a hydrogen atom or a lower alkyl group having 4 or less carbon atoms (methyl group, ethyl group, etc.), and k ₂ is preferably a compound having 2-10. Although a specific example is shown below, it is not limited to these examples.

  The addition amount of the polymerizable compound described above is preferably included in the range of 0.01 to 10 parts by mass and more preferably in the range of 0.05 to 1 part by mass with respect to 1 part by mass of the polymer. It is particularly preferred that

  In addition, polymerization accelerators such as amines, thiols, and disulfides, chain transfer catalysts, and the like can be added as polymerization accelerators. Specific examples include, for example, amines such as N-phenylglycine, triethanolamine, N, N-diethylaniline, and thiols described in US Pat. No. 4,414,312 and JP-A No. 64-13144. Disulfides described in JP-A-2-29161, thiones described in US Pat. No. 3,558,322 and JP-A 64-17048, and o-acylthio described in JP-A-2-291560. Examples include hydroxamate and N-alkoxypyridinethiones. The addition amount of the polymerization accelerator is preferably 0.1 to 5% by mass of the total solid content of the photosensitive layer. If it is less than this range, the effect cannot be expected. On the other hand, if the amount is too large, the film quality of the photosensitive layer tends to deteriorate.

  In the photopolymerization lithographic printing plate according to the present invention, other components may be preferably added for various purposes in addition to the components described above. In particular, it is preferable to add various polymerization inhibitors for the purpose of preventing thermal polymerization or thermal crosslinking of styryl groups and improving long-term storage stability. As the polymerization inhibitor in this case, compounds having various phenolic hydroxyl groups such as hydroquinones, catechols, naphthols, and cresols, quinone compounds, and the like are preferably used, and hydroquinone is particularly preferably used. In this case, the addition amount of the polymerization inhibitor is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the polymer.

  As an element constituting the photopolymerization lithographic printing plate according to the present invention, other inorganic fine particles are added for the purpose of adding various dyes and pigments for the purpose of enhancing the visibility of the image and for preventing the photosensitive layer from blocking. Alternatively, addition of organic fine particles is also preferably performed.

  Regarding the thickness of the photosensitive layer itself of the photopolymerization planographic printing plate, it is preferably formed on the support with a dry thickness in the range of 0.5 μm to 10 μm, and more preferably in the range of 1 μm to 5 μm. It is extremely preferable for a significant improvement. The photosensitive layer is prepared by preparing a photosensitive coating solution, and coating and drying on a support using various known coating methods. As the support, for example, a film having a hydrophilic layer or polyethylene-coated paper may be used, but a more preferable support is an aluminum plate that is polished and has an anodized film.

  In order to use a material having a photosensitive layer formed on a support as described above as a printing plate, an alkaline developer is obtained by subjecting the exposed part to exposure or laser scanning exposure and crosslinking the exposed part. Therefore, the pattern formation is performed by eluting unexposed portions with the following developer using an automatic developing machine.

  Next, the alkaline developer will be described. There is no particular limitation as long as it is a solution that dissolves the polymer contained in the photosensitive layer, but preferably sodium hydroxide, potassium hydroxide, sodium silicate, potassium silicate, sodium metasilicate, potassium metasilicate, monoethanolamine, diethanolamine An aqueous developer in which an alkaline compound such as triethanolamine or tetramethylammonium hydroxide is dissolved is generally used, and a developer adjusted to pH 9-13 selectively dissolves unexposed portions well. It is very preferable because the surface of the support can be exposed. Furthermore, it is also preferable to add various organic solvents such as ethanol, propanol, isopropanol, ethylene glycol, diethylene glycol, triethylene glycol, glycerin and benzyl alcohol to the alkaline developer. After developing with such an alkaline developer, normal gumming is preferably performed using gum arabic or the like.

  The developer of the present invention preferably contains an alkanolamine represented by the following general formula for the purpose of improving the printing durability of the image area and the elution of the non-image area. The following alkanolamines can be used alone or in combination of two or more, and are added in an amount of 0.01 to 10% by mass, more preferably 0.1 to 5% by mass, based on the total mass of the developer.

In the formula, R ₆₁ represents an alkyl group having 10 or less carbon atoms. R ₆₂ represents a hydrogen atom or an alkyl group having 10 or less carbon atoms, and the alkyl group of R ₆₁ and R ₆₂ may have a hydrophilic substituent such as a hydroxyl group, a carboxylic acid group, or a sulfonic acid group. R ₆₁ and R ₆₂ are more preferably an alkyl group having 1 to 6 carbon atoms as an alkyl group. n ₆₁ and n ₆₂ each represent an integer of 2 or more, and may be the same or different. A preferred range of n ₆₁ and _{n 62} is 2-6. Although a specific example is shown below, it is not limited to these examples.

  Various surfactants can be added to the developer of the present invention as needed for the purpose of promoting developability, dispersing development debris and improving ink affinity of the printing plate image area. Preferred surfactants are synonymous with anionic, cationic, nonionic and amphoteric surfactants that may be added to the above-described cleaning solution. These surfactants can be used alone or in combination of two or more, and are added in the range of 0.001 to 10% by mass, more preferably 0.01 to 5% by mass, based on the total mass of the developer. The

  Next, a synthesis example of a typical polymer compound having a phenyl group substituted with a vinyl group in the side chain is shown below.

Synthesis Example 1 (Synthesis Example of Polymer P-1)
150 g of bismuthiol (2,5-dimercapto-1,3,4-thiadiazole) was suspended in 600 ml of methanol, and 101 g of triethylamine was gradually added while cooling to obtain a uniform solution. While maintaining the temperature at room temperature, 153 g of p-chloromethylstyrene (manufactured by AGC Seimi Chemical Co., CMS-14) was added dropwise over 10 minutes, and stirring was further continued for 3 hours. The reaction product gradually precipitated. After stirring, the reaction product was transferred to an ice bath, the internal temperature was cooled to 10 ° C., and the product was separated by suction filtration. After washing with methanol and drying for one day in a vacuum dryer, the following compounds were obtained with a yield of 75%.

  40 g of the above monomer is placed in a 1 liter four-necked flask equipped with a stirrer, a nitrogen inlet tube, a thermometer, and a reflux condenser, 20 g of methacrylic acid, 200 ml of ethanol, and 50 ml of distilled water are added, and 40 g of triethylamine is stirred on a water bath. Was added. Under nitrogen atmosphere, the internal temperature was heated to 70 ° C., and 1 g of azobisisobutyronitrile (AIBN) was added at this temperature to initiate polymerization. The mixture was heated and stirred for 6 hours, and then the polymerization system was cooled to room temperature. 100 g of 1,4-dioxane and 23 g of p-chloromethylstyrene were added to the polymer solution, and stirring was continued for another 15 hours at room temperature. Thereafter, 80 to 90 g of concentrated hydrochloric acid (35 to 37% aqueous solution) was added, and after confirming that the pH of the system was 4 or less, the whole was transferred into 3 liters of distilled water. The precipitated polymer was separated by filtration, washed repeatedly with distilled water, and then dried for one day in a vacuum dryer. The target polymer was obtained with a yield of 90%. It was a polymer having a mass average molecular weight of 90,000 (in terms of polystyrene) by molecular weight measurement by gel permeation chromatography, and further supported by the analysis by proton NMR.

  The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to these examples as well as the effects.

(Photopolymerization planographic printing plate)
Using an anodized aluminum plate having a graining treatment with a thickness of 0.24 mm, a photosensitive coating solution represented by the following prescription is applied thereon so that the dry thickness is 2.0 μm, Drying was performed in a dryer at 75 ° C. for 6 minutes.
<Photosensitive coating solution>
Polymer (P-1) 12 parts by mass polymerization initiator (BC-6) 1 part by mass trihaloalkyl-substituted compound (T-4) 0.5 parts by mass polymerizable compound (C-5) 3 parts by mass sensitizing dye ( S-1) 0.5 parts by mass dioxane 70 parts by mass cyclohexanone 20 parts by mass

Using the photopolymerization lithographic printing plate produced as described above, a thermal output machine (Image Setter PT-R4000 (Oscillation wavelength 830 nm, output 100 mW) manufactured by Dainippon Screen Mfg. Co., Ltd.) was used for 120 mJ / After exposing so that an image part and an unexposed part are halved with the exposure amount of cm < ² >, it uses a processor PD-1310 (made by Dainippon Screen Mfg. Co., Ltd.) for 2 months ( 100 m ² treatment per day) Repeated use. Thereafter, the inside of the developing tank in which the deposits were deposited was washed in the developing tank with a cleaning solution shown below under white light, and circulated in the tank at a temperature of 30 ° C. for 30 minutes. Further, the cleaning effect was confirmed by lightly rubbing with a sponge soaked with the following cleaning solution.
<Developer>
Potassium hydroxide 25g
Surfactant (Perex NBL, manufactured by Kao Corporation) 30g
Alkanolamine (A-5) 20g
1L with water <Preparation of cleaning liquid A>
Compound (1) (tetramethylammonium hydroxide) 20 g
Compound (2) (N-1) 10 g
Made up to 1 L with water. The pH was 12.6.

  In the above-mentioned cleaning liquid A, (N-1) is 0 g (pH 12.0) (Comparative Example 1), 1 g (pH 12.5) (Invention 2), 100 g (pH 12.7) (Invention 3), and water is added. In addition, a cleaning solution of 1 L was prepared.

  In the above-mentioned cleaning solution A, a cleaning solution was prepared in which tetramethylammonium hydroxide was changed to 0 g (pH 9.6) (Comparative Example 2) and water was added to 1 L.

  In the cleaning solution A, tetramethylammonium hydroxide is converted to tetraethylammonium hydroxide (pH 12.3) (present invention 4), tetrabutylammonium hydroxide (pH 12.2) (present invention 5), sodium hydroxide (pH 12.9). (Comparative Example 3) A cleaning solution was prepared by adding water to 1 L.

  In the above-described cleaning liquid A, (N-1) is changed to (N-2) (Invention 6), (N-3) (Invention 7), (N-4) (Invention 8), (N-5). (Invention 9) A water cleaning solution was prepared to 1 L by adding water. Both were pH 12.6.

  2-Phenoxyethanol, 10 g of diethylene glycol phenyl ether, 90 g of pelargonic acid, 30 g of PELEX NBL (manufactured by Kao Corporation), 20 g of potassium hydroxide, 20 g of tris (hydroxymethyl) aminomethane, and a cleaning solution to which 1 L was added by adding water was prepared. . (Comparative Example 4)

  A cleaning liquid was prepared by adding 10 g of ethylenediaminetetraacetic acid and adding water to 1 L. (Comparative Example 5)

  A cleaning solution was prepared by adding 10 g of PELEX NBL (manufactured by Kao Corporation), 6 g of triethylene glycol monobutyl ether, and 15 g of potassium hydroxide to 1 L by adding water. (Comparative Example 6)

The observation of the deposits in the developing tank washed with the washing liquid was specifically evaluated on the following criteria for the dirt removal property of the guide roller, the wall surface, and the inside of the circulation pump. The results are shown in Table 2. Furthermore, the dirt removal property inside the circulation pump is set such that the flow rate of the developer measured in advance before starting the development processing of the photopolymerization planographic printing plate is 100%, and the developer is newly added to the developer tank after washing. The flow rate of the circulation pump at that time was measured and evaluated as a relative value with the flow rate before the start. The flow rate of the circulation pump after repeated use for 2 months was 50%.
◎ ・ ・ ・ Adherents could be removed without rubbing.
○: The deposits could be removed by rubbing lightly.
Δ: Some deposits were present even when rubbed lightly.
X: Adherent removal was insufficient.

  As is clear from the results in Table 2, according to the present invention, even if a highly sensitive photopolymerization lithographic printing plate is developed for a long period of time by an automatic developing machine, the deposits generated by the generated development residue can be easily reduced. It is also possible to provide a cleaning solution for the developing tank of the automatic processor that can remove the parts in the automatic processor without damaging them.

Claims (1)

A cleaning solution for a developing tank of a photopolymerization planographic printing plate automatic developing machine, wherein the cleaning solution contains a compound represented by the following general formula (1) and a compound represented by the general formula (2) A cleaning solution.

(In formula, R < ₁₁ >, R < ₁₂ >, R < ₁₃ >, R < ₁₄ > represents the C1-C8 alkyl group which may have a hydroxyl group, respectively.)

(In the formula, R ₂₁ represents an alkyl group having 8 to 20 carbon atoms, and a1, a2, b1, and b2 each represent an integer of 1 to 60. In addition, a bond to a nitrogen atom of an ethyleneoxy part and a propyleneoxy part) The order is arbitrary, and when any of a1, a2, b1, and b2 is 2 or more, the bonding order of the ethyleneoxy part and the propyleneoxy part is arbitrary.)