JPH10301298A - Developer for photosensitive resin plate and developing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the developing rate and image reproducibility even when water with high hardness or low hardness is used, by incorporating a hydrophilic component containing ionic hydrophilic groups. SOLUTION: The developer is used to remove an unexposed part of a photosensitive resin plate after exposure, and the resin plate has a photosensitive resin compsn. layer which contains one of ionic hydrophilic groups expressed by (a) -COOM, (b) -SO3 M- (c) -SO4 M, and (d) (-O)3-n PO(OM)M. To the developer, a compd. having an ability to form a chelate compd. with polyvalent metal ions and/or phosphoric acids are added. In the formulae, M is a uni- or bivalent metal atom or an ammonium compd. and (n) is 1 or 2. As for the photosensitive resin compsn., it contains a hydrophilic component containing ionic hydrophilic groups in order to have developing property with a water-based developer. Photosensitivity is given to the components above described by adding photopolymerizable unsatd. monomers, photosensitizer and other additives.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a developer for developing a photosensitive resin plate, and more particularly to a relief plate which can be developed with water and has excellent ink resistance and which is useful for flexographic printing. And a developing method. More specifically, in the developing step of a photosensitive resin plate with an aqueous developer, a developer and a method of developing a photosensitive resin plate that can enhance the development speed and image reproducibility even when using water having high hardness. It is about.

[0002]

2. Description of the Related Art In recent years, water,
Water-developable photosensitive resin plates using a surfactant aqueous solution, an alkaline aqueous solution, an acid aqueous solution or the like as a developer have been widely used. In recent years, photosensitive flexographic plates have also been proposed which can be developed in an aqueous developer from the viewpoint of toxicity and safety. These compounds are prepared by introducing a carboxyl group or a salt thereof into the plate composition to form sodium carbonate or This enables development with an alkaline aqueous solution containing borax or the like or neutral water. However, these compositions require a long development time to develop to a practically usable development depth (1 mm), or lack image reproducibility such as lack of fine lines and halftone dots on the developed plate. Further, there is a serious problem that the developed resin adheres to the plate as a scum to disturb the image, which has hindered the spread of the water-developed photosensitive resin plate.

[0003] In order to solve these problems, a developing solution obtained by adding a surfactant to water has been devised and put to practical use. However, in a developer containing these surfactants, an alkali metal salt of a fatty acid or an inorganic alkali salt added to a nonionic surfactant, or a fatty acid ethanol in which the raw material ethanolamines are slightly excessive. Amides, which have an alkaline property such as amides, have a high developing speed.However, when water having high hardness is used as the water for the developing solution, the developing speed is reduced or the washed-out resin or polyvalent metal salt of fatty acid is removed. Satisfactory results were not obtained due to scum and adhesion to the washed plate surface.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to find a developer and a method for developing a photosensitive resin plate which can enhance the development speed and the image reproducibility even with high or low hardness water. Is the subject.

[0005]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have repeatedly and intensively studied and studied a developing solution. As a result, the present invention has been finally completed. That is, the present invention provides a method for exposing a photosensitive resin plate having a photosensitive resin composition layer containing at least one ionic hydrophilic group represented by the following formulas (a), (b), (c), and (d): A developer used for removing unexposed portions, comprising a compound having an ability to form a chelate compound with a polyvalent metal ion and / or a phosphoric acid. A developing solution and a developing method. (A) -COOM (b) -SO 3 M (c) -SO 4 M (d) (- O) 3-n PO (OM) n (M is a monovalent or divalent metal atom, ammonium compounds And n is 1 or 2.

The photosensitive resin composition used in the present invention is characterized in that it contains a hydrophilic component containing an ionic hydrophilic group in order to have developability in an aqueous developer. . The photosensitivity is imparted by adding a photopolymerizable unsaturated monomer, a photosensitizer and the like to any of these. Various examples of the photosensitive resin composition used in the present invention include, in particular, a resin obtained by modifying a hydrophobic polymer with an ionic hydrophilic group in order to impart a hydrophilic or water-swellable component to the hydrophobic component. A mixture of a hydrophobic component mainly composed of a hydrophobic polymer and a hydrophilic or water-swellable component mainly composed of a hydrophilic or water-swellable polymer containing an ionic hydrophilic group. , Hydrophilic or water-swellable polymer containing hydrophobic polymer and ionic hydrophilic group as a main component, hydrophobic monomer and ionic hydrophilic group as raw material of hydrophobic polymer As a main component of a polymer obtained by block copolymerizing an ionic hydrophilic group-containing hydrophilic monomer as a raw material of a hydrophilic or water-swellable polymer containing A combination of hydrophilic or water-swellable components somehow hydrophobic component,
A preferable example is a type in which a photosensitive flexographic printing plate is dispersed in an aqueous developer.

Examples of the hydrophobic polymer mentioned here include 1,4-polybutadiene, 1,2-polybutadiene, acrylonitrile rubber, butadiene acrylonitrile rubber, chloroprene rubber, polyurethane rubber, butadiene styrene copolymer, styrene-butadiene-styrene block copolymer. , Styrene-isoprene-styrene block copolymer, polyamide resin, unsaturated polyester resin, butadiene- (meth) acrylic acid copolymer, butadiene- (meth) acrylic acid-acrylic ester copolymer, silicone rubber, polyoxypropylene glycol, polyoxytetramethylene Glycols and other polymers that give rubber elasticity to the plate, polymethyl (meth) acrylate, polyethyl (meth) acrylate, polyisopropyl Meth) acrylate, poly n-
Acrylic resin such as butyl (meth) acrylate, polystyrene, polypropylene, polyethylene, chlorinated polyethylene, polyacrylonitrile, polyvinyl chloride, polyvinyl acetate and copolymers thereof, polyurethane resin, polyester resin, polyamide resin, epoxy resin, etc. Such a plate may be provided with a polymer that imparts hardness and stability to the plate, and these may be used alone or in combination as necessary. These resins can also be modified so that they can react with a monomer or a crosslinking agent or between polymers.

The hydrophilic or water-swellable polymers include:
For example, polymers of poly (meth) acrylic acid or salts thereof, (meth) acrylic acid or salts thereof-alkyl (meth) acrylate copolymer, (meth) acrylic acid or salts thereof-styrene copolymer, (meth) acrylic Acid or salts thereof-vinyl acetate copolymer, (meth) acrylic acid or salts thereof-acrylonitrile copolymer, -COO
M group or -SO ₃ M group and -SO ₄ M groups and (-O) _3-n PO
(OM) _n (where n is 1 or 2) a polyacrylate, a polyvinyl compound, a polyurethane, a polyureaurethane, a polyester, an epoxy compound, a polyamide, a salt or a derivative thereof, etc. containing a group (where M is a group described herein). A monovalent or divalent metal atom or an ammonium compound). Similarly, a plurality of hydrophilic components can be used in combination, and may be modified as needed.

In addition to the raw materials for the photosensitive resin composition, a radical polymerizable monomer, a crosslinking agent, a photoreaction initiator,
An oxidation stabilizer, a polymerization inhibitor and the like may be added to the above-mentioned polymers as needed. Examples of the radical polymerizable monomer include styrene, vinyl toluene, chlorostyrene, t-butylstyrene, α-methylstyrene, acrylonitrile, acrylic acid, methacrylic acid,
Methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, iso-propyl (meth) acrylate, n-butyl (meth) acrylate, iso-butyl (meth) acrylate, se
c-butyl (meth) acrylate, t-butyl (meth)
Acrylate, 2-ethylhexyl (meth) acrylate, n-nonyl (meth) acrylate, n-decyl (meth) acrylate, lauryl (meth) acrylate, n
-Tridecyl (meth) acrylate, stearyl (meth) acrylate, ethylene glycol mono (meth) acrylate, propylene glycol mono (meth) acrylate, diethylene glycol mono (meth) acrylate, dipropylene glycol mono (meth) acrylate, polyethylene glycol mono (meth) ) Acrylate, polypropylene glycol mono (meth) acrylate, polyethylene glycol monomethyl ether mono (meth) acrylate, polypropylene glycol monomethyl ether mono (meth) acrylate, polyethylene glycol monoethyl ether mono (meth) acrylate, polypropylene glycol monoethyl ether mono ( (Meth) acrylate, n-butoxyethyl (meth) acrylate, pheno Shiechiru (meth) acrylate, 2-phenoxypropyl (meth) acrylate,
Cyclohexyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, glycidyl (meth) acrylate, allyl (meth) acrylate, benzyl (meth) acrylate, tribromophenyl (meth) acrylate, 2,3-dichloropropyl (meth) acrylate , 3-chloro-2-hydroxypropyl (meth)
Acrylate, N, N-diethylaminoethyl (meth)
Acrylate, N, N-dimethylaminoethyl (meth)
Acrylate, Nt-butylaminoethyl (meth) acrylate, acrylamide, N, N-dimethylacrylamide, N, N-diethylacrylamide and the like can be mentioned.

Examples of the crosslinking agent include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, and polypropylene. Glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, 1,4-butanediol di (meth) acrylate,
Neopentyl glycol di (meth) acrylate, 1,
6-hexanediol di (meth) acrylate, 1,9
-Nonanediol di (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, glycerol di (meth)
Acrylate, glycerol allyloxydi (meth) acrylate, 1,1,1-trishydroxymethylethanedi (meth) acrylate, 1,1,1-trishydroxymethylethanetri (meth) acrylate, 1,1,
1-trishydroxymethylpropane di (meth) acrylate, 1,1,1-trishydroxymethylpropane tri (meth) acrylate, triallyl cyanurate,
Triallyl isocyanurate, triallyl trimellitate, diallyl terephthalate, diallyl phthalate, divinylbenzene, polyurethane (meth) acrylate,
Compounds having two or more radically polymerizable ethylene groups in one molecule, such as polyester (meth) acrylate, may be mentioned. In addition, ethylene group, epoxy group, isocyanate group, amino group, hydroxyl group in one molecule ,
Compounds having a plurality of reactive functional groups such as a carboxyl group are also included.

A preferable structure of such a photosensitive resin composition is such that a hydrophobic component (polymer) is a particulate dispersed phase and a hydrophilic or water-swellable component (polymer) surrounds it to form a continuous phase. Core-shell particles in which a hydrophobic component (polymer) is a core and a hydrophilic or water-swellable component (polymer) is a shell, and a structure in which another hydrophobic component (polymer) is a continuous phase, hydrophilic or A structure in which the water-swellable component (polymer) becomes a particulate dispersed phase and the hydrophobic component (polymer) becomes a continuous phase. Both the hydrophobic component (polymer) and the hydrophilic or water-swellable component (polymer) are continuous. Examples include a structure in which the phases are entangled with each other to form a mosaic, and a structure in which the hydrophobic component (polymer) and the hydrophilic or water-swellable component (polymer) are uniformly compatible. In these cases, the continuous phase needs to be uncured and not crosslinked, but the particulate hydrophobic component may or may not be crosslinked in the uncured state.

The photosensitive resin composition is produced by mixing the components of the dispersed phase obtained by emulsion polymerization or suspension polymerization or by pulverizing the polymer alone or together with the components of the continuous phase in a kneader or an extruder. A method of molding, a method of kneading a hydrophobic component and a hydrophilic component in a lump state with a kneader or an extruder, and separating and dispersing the phases, followed by molding.A method of kneading or extruding a hydrophobic component and a hydrophilic component in a lump. Various methods are used, such as kneading with a machine, uniformly dissolving and molding.

By appropriately selecting these raw materials and methods as needed, a photosensitive resin composition can be produced in accordance with the physical properties and performance required of the plate.
For example, physical properties required for a printing plate include JIS
A It is desirable in terms of printing characteristics that the hardness is 30 to 80 degrees and the rebound resilience is 20% or more. Such a photosensitive resin composition is cured by ultraviolet rays. The ultraviolet light used for curing has a wavelength of 150 to 500 nm, particularly 300
A light source having a wavelength of about 400 nm is effective, and the light source used is a low-pressure mercury lamp, high-pressure mercury lamp, carbon arc lamp, ultraviolet fluorescent lamp, chemical lamp, xenon lamp,
Zirconium lamps are preferred.

Next, in the present invention, the photosensitive resin plate is exposed to ultraviolet light by irradiating a negative film having a transparent image under the above-mentioned light source, and then exposing the non-image portion which is not exposed to light by using a developing solution. As a result, a relief image is obtained, while the uncured photosensitive resin dissolved and removed remains in the developing tank as an emulsion or a suspension.

The developer used in the present invention is characterized in that a compound capable of forming a chelate compound with a polyvalent metal ion and / or a phosphoric acid are added. Compounds that have the ability to form chelate compounds with polyvalent metal ions are formed as chelate compounds with ions of calcium, magnesium, aluminum, iron, zinc, chromium, and other elements that become divalent or more cationic in water. Such as condensed phosphoric acids such as pyrophosphoric acid, triphosphoric acid, and polyphosphoric acid, sodium dihydrogen diphosphate, tetrasodium diphosphate, pentasodium triphosphate, sodium hexametaphosphate, and polyphosphoric acid Condensed phosphates such as sodium, iminodiacetic acid, nitrilotriacetic acid, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, triethylenetetraminehexaacetic acid, 1,2-diaminocyclohexanetetraacetic acid, n-hydroxyethylethylenediaminetriacetic acid, ethylene glycol Amino acids such as Le diethyl ether diamine tetraacetic acid and ethylene diamine tetra acid, their alkali metal, ammonium salts, tartaric, citric acid, succinic acid, oxalic acid,
Polycarboxylic acids such as malonic acid and gluconic acid and salts thereof, ethyleneamines such as ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine and polyethyleneimine, amino acids such as glycine and salts thereof, oxines and Salts thereof, 2-oxyazo compounds and salts thereof, salicylic acids and salts thereof, salicylaldehydes and salts thereof, catechols and salts thereof, β-diketones such as acetylacetone and dibenzoylmethane, dithiooxamide, bipyridines, and glyoxime , Dyes,
Examples thereof include polyacrylic acids and salts thereof, and various cation ion exchange resins.

Next, the phosphoric acid used in the present invention does not have the ability to form a chelate compound with a polyvalent metal ion like the above-mentioned condensed phosphoric acid and condensed phosphate, but the water binds to the polyvalent metal ion to form water. And phosphoric acid, such as sodium dihydrogen phosphate, disodium hydrogen phosphate and trisodium phosphate, and salts thereof. The salts are exemplified by sodium salts, but potassium salts and ammonium salts are also possible and are not limited to these. Among the above-mentioned chelating agents and phosphoric acids, phosphoric acid, salts thereof, condensed phosphoric acids and salts thereof, and aminocarboxylic acids and salts thereof which are firmly bound to calcium and magnesium are preferably used.

The preferred amount of the compound having the ability to form a chelate compound with a polyvalent metal ion used in the present invention and / or the amount of phosphoric acid to be added depends on the hardness of the water used and the ability to form a chelate compound with the polyvalent metal ion. The amount is 0.001% or more and 10% or less with respect to the total amount of the developing solution, though it depends on the type of the compound having More preferably, it is 0.01% or more and 5% or less.

Further, the developer used in the present invention may be a solution obtained by simply adding a compound having the ability to form a chelate compound with the above-mentioned polyvalent metal ion and / or phosphoric acid to water. Various additives can be added to increase the speed and to enhance the solubility and dispersibility of the washed resin. As additives, inorganic acids such as hydrochloric acid, sulfuric acid and nitric acid, organic acids such as acetic acid and lactic acid,
Inorganic alkalis such as sodium hydroxide, organic alkalis such as amines, acidic and alkaline inorganic and organic salts such as sodium hydrogen sulfate, sodium carbonate, sodium borate, sodium silicate, sodium acetate, sodium methylate, anionic Various additives such as a nonionic or cationic surfactant, an anion exchange resin, other viscosity modifiers, dispersion stabilizers, and flocculants can be added as necessary.

Examples of the anionic surfactant include aliphatic carboxylic acid salts such as sodium laurate, sodium stearate, and sodium oleate, resin soaps such as sodium abietic acid and sodium rosinate, sodium lauryl sulfate, and lauryl. Primary and secondary alkyl sulfates such as triethanolamine sulfate; primary and secondary polyoxyethylene alkyl ether sulfates such as polyoxyethylene lauryl ether sodium sulfate and polyoxyethylene lauryl ether triethanolamine sulfate;
Alkylbenzenesulfonates such as sodium laurylbenzenesulfonate and sodium stearylbenzenesulfonate; alkylnaphthalenesulfonates such as sodium propylnaphthalenesulfonate and sodium butylnaphthalenesulfonate; polyoxyethylenes such as polyoxyethylene laurylphenylethersulfonate Sulfated oils such as ethylene alkyl phenyl ether sulfonates, sulfated castor oil and sulfated beef oil, sulfated fatty acid esters such as sulfated butyl oleate, and alkyl sulfosuccinates represented by sodium dioctyl sulfosuccinate ,
α-olefin sulfonates, hydroxyalkane sulfonates, N-methyl-N-alkyltaurine salts, N-alkylsulfosuccinic acid monoamide salts, fatty acid monoglyceride sulfate salts, alkyl diphenyl ether disulfonate salts, lauryl alcohol phosphate monoester diester salts Salts of alkyl phosphates such as soda salt and lauryl alcohol phosphate diester soda salt, salts of polyoxyethylene alkyl phosphate such as polyoxyethylene lauryl ether phosphate monoester disoda salt and polyoxyethylene lauryl ether phosphate diester soda salt, and naphthalenesulfonic acid Salts include formalin condensates, salts of partially saponified styrene-maleic anhydride copolymers, and salts of partially saponified olefin-maleic anhydride copolymers. It is. In addition, although a sodium salt was mainly mentioned as a specific example, a potassium salt, an ammonium salt, etc. are also possible, and are not particularly limited to these.

Examples of the nonionic activator include polyoxyethylene alkyl ethers such as polyoxyethylene oleyl ether and polyoxyethylene lauryl ether, and polyoxyethylene such as polyoxyethylene nonyl phenyl ether and polyoxyethylene octyl phenyl ether. Alkyl phenyl ethers, polyoxyethylene polyoxypropylene glycols,
Mono and diesters of fatty acids such as polyethylene glycol monostearate, polyethylene glycol monooleate, polyethylene glycol dilaurate and polyethylene glycol, esters of sorbitan with fatty acids such as sorbitan monolaurate and sorbitan monooleate, polyoxyethylene sorbitan monolau Rate, polyoxyethylene sorbitan monostearate,
Esters of fatty acids with sorbitan polyoxyethylene adducts such as polyoxyethylene sorbitan trilaurate and fatty acids, esters of fatty acids with sorbite such as sorbit monopartitate and sorbit dilaurate,
Esters of polyoxyethylene adducts of sorbit such as polyoxyethylene sorbit monostearate and polyoxyethylene sorbite diolate with fatty acids,
Esters of fatty acids such as pentaerythritol monostearate and pentaerythritol, esters of fatty acids such as glycerin monolaurate and glycerin,
Fatty acid esters of sugar and sucrose, aliphatic alkanolamides such as lauric acid diethanolamide and lauric acid monoethanolamide, amine oxides such as lauryl dimethylamine oxide, aliphatic alkanolamines such as stearyl diethanolamine,
Examples include polyoxyethylene alkylamines and triethanolamine fatty acid esters. Further, if necessary, other organic solvents that are soluble in water, such as ethanol, isopropanol, cellosolve, glycerin, polyethylene glycol, dimethylformamide, dimethylacetamide, and acetone, may be added to the developer.

Necessary components of these developing solutions may be separately prepared and added separately when adjusting the developing solution, or these components may be mixed in advance. further,
As long as these developer components are contained, detergents and cleaners for various types of clothing, tableware, and housing, which are commercially available,
It is also possible to use various kinds of detergents and cleaning agents for industrial use alone or in combination.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION The developing method of the present invention is a method of immersing a photosensitive resin composition in the developing solution of the present invention and, if necessary, rubbing the photosensitive resin composition with a brush to remove uncured portions. A method in which the developer of the present invention is brought into direct contact with the uncured portion by spraying or the like to remove the developer, or a method in which the two are combined can be adopted. The temperature during development is 10 to 50
C is preferred. Further, the developer containing the photosensitive resin after the development may be discarded after appropriate processing, or the resin may be separated by settling, filter filtration, membrane filter filtration,
After removal by some method, such as centrifugation or separation with a flocculant, it may be reused as a developer. In this case, if necessary, a deficient developing component can be added.

[0023]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples. The developing speed in Examples and Comparative Examples is 15
It represents the relief depth after development for one minute, and indicates the depth at which the uncured portion is dug out by development as compared with the cured portion.

Reference Example 1 119.0 parts of hexamethylene diisocyanate (manufactured by Nippon Polyurethane Industry Co., Ltd.), 62.0 parts of dimethylolpropionic acid (Fujii Yoshitsusho) polytetramethylene glycol (G-850 Hodogaya Chemical Co., Ltd.) 29.0 parts) and a solution prepared by dissolving 5.0 parts of di-n-butyltin dilaurate in 300 parts of tetrahydrofuran are placed in a 1-liter flask equipped with a stirrer, and heated to 65 ° C. while stirring continuously for 2 hours. The reaction continued. In another container, an acrylonitrile-butadiene oligomer having a terminal amino group (Hyc
ar ATBNX 1300 X16 Ube Industries, Ltd.
A solution prepared by dissolving 184.0 parts of styrene in 270 parts of tetrahydrofuran was added to the above 1-liter flask with stirring at room temperature. The obtained polymer solution was dried under reduced pressure to remove tetrahydrofuran.
00 polymer was obtained. Next, a solution of 2.4 parts of lithium hydroxide and 6.1 parts of magnesium acetate dissolved in 100 parts of methyl alcohol was added to a solution of 100 parts of the polymer dissolved in 100 parts of methyl ethyl ketone while stirring at room temperature. The hydrophilic polymer [1] was obtained by stirring for 30 minutes.

10 parts of the above hydrophilic polymer [1] and chlorinated polyethylene (Eslan 352F) as the hydrophobic polymer
A 45 parts by Showa Denko KK, styrene-butadiene rubber (SBR 1507 manufactured by Nippon Synthetic Rubber Co., Ltd.) 15
Parts, 28.5 parts of butadiene oligoacrylate (manufactured by Kyoeisha K.K.), 1 part of benzyl dimethyl ketal (manufactured by Irgacure 651 Ciba Geigy), and 0.5 part of hydroquinone monomethyl ether in 40 parts of toluene, 10 parts of water Was melted and dispersed in the mixture, kneaded at 105 ° C. using a heating kneader, and after defoaming, the obtained photosensitive resin composition was heated at 105 ° C. and 100 kg / cm by a heat press.
^At a pressure of ² , a polyethylene terephthalate film having a thickness of 125 μm and 2 μm on the same polyester film
Was heated and pressurized for 1 minute so that the polyvinyl alcohol coat layer was in contact with the photosensitive resin to form a sheet (printing plate) having a thickness of 2.8 mm.

Examples 1 to 18 and Comparative Examples 1 to 8 The photosensitive flexographic plates obtained in Reference Example 1 were cut into A2 size sheets, and an appropriate negative film having fine lines or solid portions of each line width was adhered. And a mercury lamp with an illuminance of 50 W / m ²
Irradiation was performed for 10 minutes to print the pattern. After removing the negative film, 40
After developing by rubbing with a nylon brush at 15 ° C. for 15 minutes, the film was dried at 60 ° C. for 30 minutes, and further post-cured with the same mercury lamp for 10 minutes to form a relief. A2 in total
Was developed for 10 sheets, the developing speeds of the first sheet and the tenth sheet were measured, and the scum adhesion of the tenth plate was observed. The results are shown in Tables 1 and 2.

[0027]

[Table 1]

[0028]

[Table 2]

[0029]

As is clear from Tables 1 and 2, the use of the developing solution and the developing method of the present invention allows the developing speed to be improved even when using water having a higher hardness than before. The amount of scum generated due to the aggregation of the resin flowing out into the developer is small, and the scum adheres to the developed printing plate and the trouble of disturbing the image at the time of printing can be suppressed. I understand. Further, according to the present invention, it is possible to prevent troubles caused by adhesion of scale, scum, and the like at a liquid contact portion such as a brush, a pipe, and a filter of a developing machine. Furthermore, since the developer of the present invention is aqueous, it is a great advantage that it can be easily treated by a known waste liquid treatment technique such as pH adjustment, addition of an adsorbent or a flocculant, and microbial treatment, which greatly contributes to the industry. is there.

Claims (2)

[Claims] 1. After exposing a photosensitive resin plate having a photosensitive resin composition layer containing at least one ionic hydrophilic group represented by the following formulas (a), (b), (c) and (d): A developer used for removing unexposed portions, comprising a compound having an ability to form a chelate compound with a polyvalent metal ion and / or a phosphoric acid. Developer. (A) -COOM (b) -SO 3 M (c) -SO 4 M (d) (- O) 3-n PO (OM) n (M is a monovalent or divalent metal atom, ammonium compounds And n is 1 or 2. 2. The method for developing a photosensitive resin plate according to claim 1, wherein a compound having an ability to form a chelate compound with a polyvalent metal ion and / or a phosphoric acid are added. A method for developing a photosensitive resin plate, comprising washing out with a developer.