JPH086258A - Treatment of wash out liquid for photosensitive resin plate - Google Patents

Abstract

PURPOSE:To make it possible to carry out wash out operation of many sheets of photosensitive resin sheets stably over a long period of time without discarding a wash out liquid by maintaining this wash out liquid clean at all times. CONSTITUTION:This method of treating the wash out liquid contg. resins generated in a method of developing the photosensitive resin plates by rubbing out their unexposed parts while immersing the resin plates into the wash out liquid after exposure is the treatment method of the wash out liquid for the photosensitive resin plates by filtering the wash out liquid contg. the resins by using a non-woven fabric satisfying the following conditions, removing the resins in the wash out liquid, and reusing the filtrate as the wash out liquid. (1) A fiber diameter <=10mum, (2) air permeability 3 to 300cm<3>/cm<2>/sec (JIS L-1096 Firazir method), (3) METSUKE (unit) weight 5 to 100g/m<2>.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating a wash-out liquid generated during development of a photosensitive resin plate, and in particular, a resin generated by a method of rubbing out an unexposed portion while being immersed in the wash-out liquid to develop the resin. The present invention relates to a method of removing a dispersed resin from a wash-out liquid containing a water and using the wash-out liquid again. More specifically, the washing solution containing unexposed resin generated in the washing step of the photosensitive resin in a dispersed state is filtered through a specific non-woven fabric to efficiently remove the resin from the washing solution, and then filtered. By using the washout liquid for washing out again, the washout liquid is always kept clean, and it is possible to stably wash out a large number of photosensitive resin plates for a long time without discarding the washout liquid. The present invention relates to a method for treating a resin plate washout liquid.

[0002]

2. Description of the Related Art A printing plate using a photosensitive resin is excellent in operability, productivity, price and printing characteristics as compared with a conventional printing plate, and has recently been rapidly spread in various printing fields. As a method of developing the photosensitive resin plate, a method of forming a relief by blowing off the unexposed portion with compressed air, a method of spraying a washout liquid on the plate surface at a constant pressure to create a relief, a plate in the washout liquid A method has been devised and put into practical use, in which the unexposed portion is dipped and the unexposed portion is washed out with a brush or the like and rubbed into the liquid.

The wash-out liquid for washing out the photosensitive resin plate by the developing method as described above exists in a state where the resin of the unexposed portion washed out after washing is dispersed, and is washed out when a large number of photosensitive resin plates are washed out. The concentration of resin in the liquid increases,
As a result, problems such as slow wash-out speed and dispersion of dispersed resin that form scum and adhere to the plate or brush occur. Frequently used wash-out liquid is discarded and new wash-out liquid is prepared. There was a need. This method is not only disadvantageous in terms of cost because it costs a lot to process the waste liquid of the wash-out liquid and the cost of a new wash-out liquid, but also has a big problem that a large amount of waste is generated in terms of the environment. . In order to solve these problems, several methods have been devised in which the dispersed resin is removed from the resin-containing washing liquid and the washing liquid is reused. For example, a cartridge filter is installed in the circulation system of the washout liquid to remove scum, and further, a part of the washout liquid during the washout or the whole amount after the washout is taken out and left to stand to disperse and disperse the dispersed resin, There is a method of reusing the supernatant as a wash-out solution (JP-A-4-185363), or a method of adding a coagulant to the wash-out solution after completion of the wash-out to coagulate and remove the resin, and then reuse the wash-out solution. However, the cartridge filter only removes the scum that has agglomerated and generated, and it takes a long time to stand and remove the dispersed particles by agglomeration and sedimentation, which is not suitable for continuously washing out a large amount of the photosensitive resin plate. Met. Further, when the coagulant is added to the wash-out liquid, the regenerated wash-out liquid also contains the coagulant, which causes problems such as a decrease in the wash-out speed and a tendency to generate scum, which is not suitable for practical use.

[0004]

DISCLOSURE OF THE INVENTION The present invention is intended to solve the above-mentioned conventional problems, that is, a large amount of wash-out liquid is treated by a specific method and always kept clean so that the wash-out liquid can be kept clean. It is an object of the present invention to stably wash out a large number of photosensitive resin plates for a long period of time without discarding them.

[0005]

The present inventors have diligently studied, studied, and investigated a method for solving the above-mentioned problems, that is, a method of treating a wash-out solution containing a resin in an unexposed portion of a photosensitive resin plate in a dispersed state. As a result, by removing the resin by filtering the washout liquid containing the resin using a specific nonwoven fabric, by using the filtered washout liquid as the washout liquid again,
The present invention has been completed by discovering that it is possible to stably wash out a large number of photosensitive resin plates for a long period of time without keeping the washout liquid clean and discarding the washout liquid. That is, the present invention is a method for treating a wash-out solution containing a resin, which is generated by a method of exposing a photosensitive resin plate to light and then developing it by rubbing out an unexposed portion while immersing it in a wash-out solution. A method for treating a wash-out liquid of a photosensitive resin plate, characterized in that the wash-out liquid containing a resin is filtered using a non-woven fabric to remove the resin in the wash-out liquid, and the filtrate is reused as the wash-out liquid. . (1) Fiber diameter 10 μm or less (2) Air permeability ^{3 to} 300 cm ³ / cm ² / sec (JIS L-1096 Frazier method) (3) Unit weight 5 to 100 g / m ²

The photosensitive resin plate used in the present invention may be a solvent-developable photosensitive resin plate using a solvent such as a CFC solvent, a chlorine solvent, a petroleum solvent, an alcohol solvent as a washout solution, A water-developable photosensitive resin plate which uses water, a surfactant aqueous solution, an alkaline aqueous solution, an aqueous acid solution or the like as a washout solution is preferred from the environmental and local environmental aspects. As the water-developable photosensitive resin composition, a polyamide-based photosensitive resin composition containing polyamide as an essential component, a polyvinyl alcohol-based photosensitive resin composition containing polyvinyl alcohol as an essential component, and a low-molecular unsaturated group-containing polyester. Examples thereof include a polyester-based photosensitive resin composition that contains an essential component, an acrylic photosensitive resin composition that contains an acrylic low-molecular monomer as an essential component, and a polyurethane-based photosensitive resin composition that contains polyurethane as an essential component. Photosensitivity is imparted by adding a photopolymerizable unsaturated monomer, a photosensitizer and the like to these photosensitive resin compositions.

Also, as a photosensitive flexographic plate, there have recently been proposed ones which can be developed in an aqueous washout solution from the viewpoint of toxicity and safety, and these are preferably used as the photosensitive resin plate of the present invention. For example, a conjugated diene hydrocarbon and α, β-ethylenically unsaturated carboxylic acid or a salt thereof as an essential component, a copolymer containing a monoolefin unsaturated compound therein and a photopolymerizable unsaturated monomer, Photosensitive resin composition containing a photosensitizer, conjugated diene hydrocarbon polymer or copolymer of conjugated diene hydrocarbon and monoolefin unsaturated compound, hydrophilic polymer compound, non-gaseous ethylenic compound A photosensitive elastomer composition containing an unsaturated compound and a photopolymerization initiator as essential components, a hydrophobic oligomer containing an α, β-ethylenically unsaturated group, an elastomer water-swelling substance, and a photoassembly initiator as essential components There is a photosensitive resin composition to be contained. In addition, for the purpose of improving the mechanical strength of the printing plate, performance such as impact resilience, imparting a photosensitive resin composition containing hard organic fine particles and water developability, imparting water-based ink resistance, and printability. For the purpose of improving the ink receptivity of the photosensitive resin composition or the printing plate containing the crosslinkable resin fine particles, and having a two-phase structure,
There are photosensitive resin compositions containing a diazo compound and a dichromate in a continuous phase and particles having a dispersed phase of 10 μm or less, and the like, and both can be preferably used as the photosensitive resin composition of the present invention.

As described above, various types of photosensitive resin plates can be used in the present invention. As a method for imparting a hydrophilic component to a hydrophobic component, a hydrophobic polymer is modified with a carboxylic acid or a salt thereof. The main component is a resin, the main component is a mixture of a hydrophobic component having a hydrophobic polymer as a main component and the hydrophilic component having a hydrophilic polymer as a main component, and the hydrophobic polymer and the hydrophilic polymer are Chemically bonded ones as a main component, hydrophobic monomer as a raw material of a hydrophobic polymer and hydrophilic monomer as a raw material of a hydrophilic polymer as a main component of a block copolymer, As a particularly preferable example, a combination of a hydrophobic component with a hydrophilic component in some form to form a dispersion type photosensitive flexographic plate in an aqueous developer is preferable. And the like Te.

Next, the content of the present invention will be described in detail by taking a flexographic plate of a water-developable photosensitive resin, which is particularly preferably used as the photosensitive resin plate of the present invention, as an example. First, as the photosensitive resin plate, as the hydrophobic polymer used in the photosensitive flexo plate particularly preferable for use in the present invention, examples of the hydrophobic polymer include 1,4-polybutadiene, 1,2-polybutadiene, acrylonitrile rubber, and 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, silicon Polymers such as rubber, polyoxypropylene glycol, polyoxytetramethylene glycol, etc. that impart rubber elasticity to the plate, polymethyl (meth) acrylate, polyethyl (meth) acrylate, polyisopropyl (meth) acrylate, poly n-butyl ( Acrylic resin such as (meth) acrylate,
Add hardness and stability to plates such as polystyrene, polypropylene, polyethylene, chlorinated polyethylene, polyacrylonitrile, polyvinyl chloride, polyvinyl acetate and their copolymers, polyurethane resin, polyester resin, polyamide resin, epoxy resin, etc. The polymers to be given may be mentioned, and these may be used alone or in combination as necessary. Further, these resins can be modified so that they can react with a monomer or a cross-linking agent or with each other.

Examples of hydrophilic polymers include polymers of poly (meth) acrylic acid or salts thereof, (meth) acrylic acid or salts thereof-alkyl (meth) acrylate copolymers, (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, polyvinyl alcohol, carboxymethyl cellulose, polyacrylamide, hydroxyethyl cellulose, polyethylene oxide, polyethyleneimine, -COOM group-containing polyurethane,-
COOM group-containing polyureaurethane, -COOM group-containing polyester, -COOM group-containing epoxy compound, -C
Examples thereof include an OOM group-containing polyamic acid and salts and derivatives thereof (where M is a hydrogen atom, a monovalent metal atom, a divalent metal atom, a trivalent metal atom, or an ammonium compound). Shown). Similarly, a plurality of hydrophilic components may be used in combination, and may be modified as necessary.

As the raw material of the photosensitive resin composition, in addition to the above, 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, if necessary. Examples of the radical-polymerizable monomer include styrene, vinyltoluene, 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, sec-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, polypolypropylene glycol monomethyl ether mono (meth ) Acrylate, polyethylene glycol monoethyl ether mono (meth) acrylate,
Polypropylene glycol monoethyl ether mono (meth) acrylate, n-butoxyethyl (meth) acrylate, phenoxyethyl (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-dimethyl acrylamide, N, N-diethyl acrylamide, etc. are mentioned.

Examples of the cross-linking agent include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate and dipropylene glycol di (meth).
Acrylate, 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, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, glycerol di (meth) acrylate, glycerol allyloxy ( (Meth) acrylate, 1,1,1-trishydroxymethylethanedi (meth) acrylate, 1,1,1-
Trishydroxymethylethane tri (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)
Examples include compounds having two or more radically polymerizable ethylene groups in one molecule such as acrylate and polyester (meth) acrylate. In addition, ethylene group, epoxy group, isocyanate group, amino group in one molecule, A compound having a plurality of reactive functional groups such as a hydroxyl group and a carboxyl group is also included.

A preferred structure of such a photosensitive resin composition is a structure in which a hydrophobic component (polymer) is a particulate dispersed phase and a hydrophilic component (polymer) surrounds it to form a continuous phase, and a hydrophobic structure. A structure in which a core-shell particle in which a hydrophilic component (polymer) is a core and a hydrophilic component (polymer) is a shell, and another hydrophobic component (polymer) is a continuous phase,
A structure in which the hydrophilic component (polymer) is a particulate dispersed phase and the hydrophobic component (polymer) is a continuous phase, and both the hydrophobic component (polymer) and the hydrophilic component (polymer) are entwined with each other in the continuous phase Examples thereof include a mosaic structure and a structure in which a hydrophobic component (polymer) and a hydrophilic component (polymer) are uniformly compatible with each other. In these cases, the continuous phase needs to be uncrosslinked in the uncured state, but the particulate hydrophobic component may or may not be crosslinked in the uncured state.

The process for producing the photosensitive resin composition is as follows: the components of the dispersed phase obtained by emulsion polymerization or suspension polymerization or by pulverizing the polymer are mixed alone or together with the components of the continuous phase in a kneader or an extruder. Molding method, hydrophobic component and hydrophilic component are kneaded in a kneader or extruder in a kneader or extruder to perform phase separation / dispersion before molding, and hydrophobic component and hydrophilic component are kneaded or extruded in a lump. Various methods are used, such as a method of kneading with a machine to make them compatible with each other and then molding. Further, by appropriately selecting these raw materials and methods,
A photosensitive resin composition can be produced according to the physical properties and performance required for the plate. For example, the physical properties required for printing plates include JIS A hardness of 30-8.
It is desirable from the viewpoint of printing characteristics that the impact resilience is 0 to 60%. Such a photosensitive resin composition is cured by ultraviolet light, and the ultraviolet light used for curing is 15
A wavelength of 0 to 500 nm, particularly a wavelength of 300 to 400 nm is effective, and a low pressure mercury lamp, a high pressure mercury lamp, a carbon arc lamp, an ultraviolet fluorescent lamp, a chemical lamp, and a xenon lamp zirconium lamp are preferable as a light source used.

Next, the developing method of the photosensitive flexographic plate which is particularly preferably used in the present invention will be described. The photosensitive resin plate obtained as described above is subjected to image exposure by irradiating UV with a negative film having a transparent image under the above light source, and then fixing the photosensitive resin plate to a flat plate or a cylinder. While immersing in the washout solution or spraying the washout solution in a shower shape, a relief image is obtained by rubbing with a brush or the like if necessary to remove the non-image areas that are not exposed, while the uncured photosensitive resin removed Becomes an emulsion or suspension and remains in the washing tank.
The relief thus obtained, in which the cured portion has a convex shape, is dried and, if necessary, further exposed to ultraviolet rays as post-exposure to be used as a printing plate for printing.

As the washout liquid, water alone, an aqueous solution of a surfactant, an aqueous solution of an inorganic or organic alkali, acid or salt, or an aqueous solution of a water-soluble compound is used. As the surfactant used, anionic surfactants, cationic surfactants, nonionic surfactants, amphoteric surfactants and the like can be widely used. Specific 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 sulfate. Primary and secondary alkyl sulfates such as triethanolamine, primary and secondary polyoxyethylene alkyl ether sulfates such as sodium polyoxyethylene lauryl ether sulfate and triethanolamine polyoxyethylene lauryl ether sulfate, lauryl Alkylbenzenesulfonates such as sodium benzenesulfonate and sodium stearylbenzenesulfonate, alkylnaphthalenesulfonates such as sodium propylnaphthalenesulfonate and sodium butylnaphthalenesulfonate, polyoxyethylene Polyoxyethylene alkyl phenyl ether sulfonates such as sodium lauryl phenyl ether sulfonate, sulfated oils such as sulfated castor oil and sulfated beef oil, sulfated fatty acid esters such as sulfated butyl oleate, dioctyl sulfo amber Alkyl sulfosuccinates represented by acid soda, α-olefin sulfonates, hydroxyalkane sulfonates, N-methyl-
N-alkyl taurine salts, N-alkyl sulfosuccinic acid monoamide salts, fatty acid monoglyceride sulfate ester salts, alkyl diphenyl ether disulfonate salts,
Salts of alkyl phosphates such as lauryl alcohol phosphate monoester disodium salt and lauryl alcohol phosphate diester sodium salt, polyoxyethylene alkyl phosphates such as polyoxyethylene lauryl ether phosphate monoester disodium salt and polyoxyethylene lauryl ether phosphate diester sodium salt And salts of naphthalene sulfonate formalin condensates, salts of partially saponified styrene-maleic anhydride copolymer, salts of partially saponified olefin-maleic anhydride copolymer, and the like.
Although sodium salt is mainly mentioned as a specific example, potassium salt, ammonium salt, magnesium salt, calcium salt and the like are also possible, and are not particularly limited thereto.

Specifically as the cationic surfactant,
Primary and secondary and tertiary amine salts such as monostearyl ammonium chloride, distearyl ammonium chloride and tristearyl ammonium chloride, quaternary ammonium salts such as stearyl trimethyl ammonium chloride, distearyl dimethyl ammonium chloride and stearyl dimethyl benzyl ammonium chloride, Alkylpyridinium salts such as N-cetylpyridinium chloride and N-stearylpyridinium chloride, N, N dialkylmorpholinium salts, fatty acid amide salts of polyethylene polyamine, acetate salts of urea amide compounds of aminoethylethanolamine and stearic acid, 2-alkyl-1-alkyl-1-hydroxyethyl imidazolinium chloride and the like can be mentioned. In addition, although chloride was mainly mentioned as a specific example, bromide, alkyl sulfate, acetate, etc. are also possible and are not particularly limited thereto. Specific examples of the nonionic surfactant include polyoxyethylene alkyl ethers such as polyoxyethylene oleyl ether and polyoxyethylene lauryl ether, and polyoxyethylene alkyl such as polyoxyethylene nonylphenyl ether and polyoxyethylene octylphenyl ether. Mono and diesters of fatty acids and polyethylene glycols such as phenyl ethers, polyoxyethylene polyoxypropylene glycols, polyethylene glycol monostearate, polyethylene glycol monooleate, polyethylene glycol dilaurate, sorbitan monolaurate and sorbitan monooleate Esters of fatty acids and sorbitan, polyoxyethylene sorbitan monolaurate,
Esters of polyoxyethylene adducts of sorbitan such as polyoxyethylene sorbitan monostearate and polyoxyethylene sorbitan trilaurate with fatty acids, esters of fatty acids such as sorbit monopalmititate and sorbit dilaurate and sorbit, poly Esters of sorbitol polyoxyethylene adducts such as oxyethylene sorbit monostearate and polyoxyethylene sorbitdiolate with fatty acids, esters of fatty acids such as pentaerythritol monostearate with pentaerythritol, glycerin monolaurate, etc. Of fatty acids with glycerin, fatty acid esters of sugar and sucrose, aliphatic alkanols such as lauric acid diethanolamide and lauric acid monoethanolamide Bromide compound, amine oxides such as lauryl dimethyl amine oxide, aliphatic alkanol amines such as stearyl diethanolamine, polyoxyethylene alkyl amines, and triethanolamine fatty acid esters.

Specific examples of the amphoteric surfactant include amino acid type double-sided surfactants such as sodium laurylaminopropionate, carboxybetaine type double-sided surfactants such as lauryl dimethyl betaine and lauryl dihydroxyethyl betaine, and stearyl dimethyl sulfo. Examples thereof include sulfobetaine type amphoteric surfactants such as ethylene ammonium ethylene ammonium betaine, imidazolinium betaine type amphoteric surfactants, and lecithin.

Examples of inorganic or organic alkalis, acids, salts and other water-soluble compounds include alkalis such as lithium hydroxide, sodium hydroxide, potassium hydroxide and calcium hydroxide, hydrochloric acid, sulfuric acid and nitric acid. Acids such as, phosphoric acid, formic acid, acetic acid, oxalic acid, succinic acid, citric acid, maleic acid, paratoluenesulfonic acid, sodium carbonate, sodium hydrogen carbonate, sodium tripolyphosphate, potassium pyrophosphate, sodium silicate, sodium sulfate, chloride Salts of sodium, sodium borate, sodium acetate, magnesium acetate, sodium citrate, sodium succinate, etc. and sodium benzenesulfonate, sodium toluenesulfonate, sodium xylenesulfonate, sodium styrenesulfonate, sodium phenol 2,4-disulfonate , Methylsul Sulfonates and salts of alkyl sulfates such as sodium phosphate, high molecular compounds such as carboxymethyl cellulose and methyl cellulose, and the like. In addition, in an aqueous solution of a surfactant, these alkalis, acids or salts, water-soluble compounds, other viscosity modifiers,
Various additives such as a dispersion stabilizer, an aggregating agent, and a zeolite can be added as necessary. Although it is a water-based wash-out solution, other organic solvents soluble in water, such as ethanol, isopropanol, cellosolve, glycerin, polyethylene glycol, dimethylformamide, dimethylacetamide, and acetone, can be mixed if necessary.

The pH of the wash-out liquid is not particularly limited, but it is preferably in the range of 3 to 12 from the viewpoint of work safety. The temperature during development is preferably 10 to 50 ° C. In the present invention, when the photosensitive resin plate is washed out in this way, the resin in the washout liquid is removed by filtering the washout liquid containing the unexposed portion of the resin in a dispersed state with a non-woven fabric to obtain a filtrate. Reuse as washout liquid.
The fiber diameter of the non-woven fabric used in the present invention is preferably 10 μm or less, and when it exceeds 10 μm, the pore size of the non-woven fabric as a filter becomes large (10 μm or more) and the trapping ability of the resin at the time of filtration becomes unfavorable. In particular, it is preferably 7 μm or less. Air permeability is JIS L
³ to 300 cm ³ measured by the Frazier method of -1096
/ Cm ² / sec is preferable and 3 cm ³
If it is less than / cm ² / sec, the filtration flow rate of the wash-out solution will be low, making it difficult to use, while 300 cm ³ /
If it exceeds cm ² / sec, even if the fiber system is thin, the pore size is large and the resin capturing ability is poor. Particularly preferably, it is 5 to 150 cm ³ / cm in terms of ease of use and particle capturing ability.
The range is ² / sec. Furthermore, the basis weight is 5 to 100
g / m ² is preferable, and if it is less than 5 g / m ² , the tensile strength of the nonwoven fabric is insufficient (300 gf /
(Less than 5 cm), the nonwoven fabric breaks during filtration and becomes unusable for practical use, and when it exceeds 100 g / m ² , the thickness of the nonwoven fabric becomes 1 mm or more, and filtration is performed only in the surface layer of the nonwoven fabric, and the depth of 1 mm or more from the surface. This is essentially useless for filtration and is wasted. In order to effectively use the non-woven fabric without waste, it is particularly preferable that the amount is 50 g / m ² or less.

The materials for the non-woven fabric include polyethylene, polypropylene, nylon, polyamide, polyimide, polyester, acrylic, polyvinyl chloride, polystyrene, polycarbonate, rayon, cotton, pulp,
Examples include wool, glass, carbon fiber, and the like, and these materials may be used alone or in combination of two or more. The length of the fibers used as the nonwoven fabric of these materials is not particularly limited as long as it is from several mm to continuous fibers depending on the manufacturing method of the nonwoven fabric. These fibers are processed as a non-woven fabric by a method such as a needle punch method, a water jet method, a stitch bond method, a binder bonding method, a melt blown method, a method of heat fusion by hot embossing, a wet method, etc. The processing method is not limited as long as it falls within the preferable range described in the invention, but in order to produce a nonwoven fabric having the preferable characteristics of the present invention, melted polyethylene, polypropylene, nylon, polyester, polystyrene, polycarbonate, A melt blown method in which a synthetic fiber material such as the above is blown together with air from a nozzle is preferably used. In addition, these non-woven fabrics
In addition to being used as a filter cloth by itself, a plurality of different kinds of non-woven fabrics may be layered or pasted together for the purpose of increasing tensile strength and filtering efficiency. Further, these non-woven fabrics may be used by adhering other mesh-like objects, cloths, strings, tapes or the like.

As a method for filtering the wash-out liquid using these non-woven fabrics, generally, the same methods as various methods for filtering liquids using non-woven fabrics can be used. Particularly in the case of the present invention, the non-woven fabrics can be easily replaced. A shape that can be formed is preferable. Next, the method of the present invention will be specifically described with reference to the drawings.
FIG. 1 and FIG. 2 are examples of one embodiment of a processing apparatus used for carrying out the method of the present invention. For example, in FIG. 1, a nonwoven fabric 1 is set on a filtration belt 10 of a small belt filter, and a washing liquid containing a resin is supplied from the washing tank to the nonwoven fabric 1. The washing liquid is filtered with a non-woven fabric and stored in the storage tank 6. The washout liquid stored in the storage tank is sent back to the washout tank by the pump 5. Further, the non-woven fabric winding roll has a chain 7 and a gear 9 so as to interlock with the roller 11 of the belt filter and the drive motor 8.
It is designed to span. As a result, a new nonwoven fabric is automatically supplied from the nonwoven fabric roll 2 to the filtration unit by moving the drive motor, and the labor of replacing the nonwoven fabric can be saved even during continuous operation for a long time. The apparatus shown in FIG. 1 performs the filtration by gravity fall, but by attaching the headers 15 and 16 so as to sandwich the non-woven fabric and the net as shown in FIG. 2, the vacuum filtration or the pressure filtration can be performed intermittently. .

The method of treating the wash-out liquid of the present invention is also a batch treatment method in which a plurality of photosensitive resin plates are washed out, the wash-out liquid is withdrawn from the wash-out tank, and after filtering the total amount, the filtered wash-out liquid is supplied to the wash-out tank and reused. Alternatively, a continuous treatment method in which a part of the wash-out liquid is withdrawn during the wash-out and immediately returned to the wash-out tank after the filtration treatment may be used. In particular, when it is necessary to continuously wash out a large amount of the photosensitive resin plate, the continuous processing method is preferable because it is not necessary to stop the workability and washing out.

[0024]

EXAMPLES The present invention will now be described in detail with reference to examples, but the present invention is not limited to these examples.

Reference Example 1 (Production Example of Photosensitive Resin Plate (a)) Hexamethylene diisocyanate 21.8 parts, dimethylol propionic acid 15.4 parts polytetramethylene glycol 7.6 parts, and dilaurylate di-n-butyltin. A solution prepared by dissolving 1.0 part in 300 parts of tetrahydrofuran was placed in a 1 liter flask equipped with a stirrer, heated to 65 ° C. while continuing stirring, and the reaction was continued for 3 hours. In a separate container, a solution prepared by dissolving 55.3 parts of acrylonitrile / butadiene oligomer containing terminal amino groups in 100 parts of methyl ethyl ketone 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 and methyl ethyl ketone to obtain a polymer having a number average of 21,000. Next, a solution prepared by dissolving 4.8 parts of lithium hydroxide in 100 parts of methyl alcohol was added to a solution prepared by dissolving 100 parts of the polymer in 100 parts of methyl ethyl ketone at room temperature with stirring, and further stirred for 30 minutes to obtain hydrophilicity. A polymerizable polymer was obtained. 10 parts of the above hydrophilic polymer, 45 parts of chlorinated polyethylene as a hydrophobic polymer, 15 parts of styrene-butadiene rubber, 28.5 parts of terminal acrylic modified butadiene oligomer, 1 part of benzyl dimethyl ketal, and 0.5 part of hydroquinone monomethyl ether in toluene. Dissolve, disperse, knead, and defoam in 40 parts of water and 10 parts of water, sandwich the resulting mixture on a polyethylene terephthalate film and press at 80 ° C. for 15 seconds to obtain a photosensitive resin plate (a) having a thickness of 3 mm. Obtained.

Reference Example 2 (Production Example of Photosensitive Resin Plate (b)) Maleated polybutadiene obtained by reacting 100 parts of polybutadiene having a molecular weight of 40,000 with 6 parts of maleic anhydride was mixed with 5 parts of 2-hydroxyethyl methacrylate and poly. 9 parts of oxyethylene nonyl phenyl ether, 0.5 part of dimethylbenzylamine and 0.2 part of hydroquinone as a polymerization inhibitor were added, and the mixture was reacted in toluene at 115 ° C. for 2 hours. After the reaction, it was neutralized with triethanolamine and the solvent was distilled off to obtain a resin. After mixing 100 parts of the obtained resin, 15 parts of methyl methacrylate and 1 part of ethylene glycol dimethacrylate, 400 parts of ion-exchanged water and 30 parts of methanol were added and stirred to emulsify, and then 1 part of ammonium persulfate was further added. In addition, emulsion polymerization was performed at 80 ° C. After 4 hours, 5% calcium chloride aqueous solution was gradually added to precipitate the particles, which was filtered, washed with water and dried under reduced pressure to obtain water-insoluble particles having an average particle size of 0.2 μm. Thus obtained particles 60 parts, methacrylic acid 6 parts propylene glycol monomethyl monoacrylate 10 parts, polyethylene glycol diacrylate 5 parts, trimethylolpropane triacrylate 4 parts, 2,2-dimethoxy-2-
2 parts of phenylacetophenone and 7 parts of polyethylene glycol nonyl phenyl ether were uniformly mixed by a biaxial mixing kneader, and the resulting mixture was sandwiched on a polyethylene terephthalate film and pressed at 80 ° C. for 15 seconds,
A photosensitive resin plate (b) having a thickness of 3 mm was obtained.

Reference Example 3 (Production Example of Photosensitive Resin Plate (c)) 2-Ethylhexyl acrylate 500 parts, allyl methacrylate 6 parts, 1,6-hexanediol diacrylate 6.5 parts 0.5% dodecylbenzene sulfone Emulsion polymerization (temperature 80-90 ° C.) was carried out in 1000 ml of an aqueous solution of ion exchange water of acid soda using ammonium persulfate, and the obtained emulsion was further added with an aqueous solution of ion exchange water of 0.5% sodium dodecylbenzenesulfonate 100.
0 ml and 3 parts of t-butyl perbivalate were added, and after substituting with nitrogen, a mixture of 150 parts of n-butyl acrylate and 33 parts of methacrylic acid was added dropwise thereto and reacted at 70 ° C. After 4 hours, a 5% calcium chloride aqueous solution was gradually added to precipitate the particles, which was filtered, washed with water, and dried under reduced pressure to obtain rubber-like aggregates of water-insoluble particles having an average particle diameter of 0.15 μm. To 100 parts of this, 3 parts of 2,2-dimethoxy-2-phenylacetophenone and 30 parts of trimethylolpropane ethoxytriacrylate were added and uniformly mixed with a biaxial mixing kneader, and the resulting mixture was applied on a polyethylene terephthalate film. Pressed at 80 ° C. for 15 seconds to obtain a photosensitive resin plate (c) having a thickness of 3 mm.

Reference Example 4 (Production Example of Photosensitive Resin Plate (d)) Styrene-isoprene-styrene block copolymer 50
Parts, methacrylic acid-acrylonitrile-butadiene copolymer 50 parts, distearyl fumarate 20 parts, phenyl maleimide 3 parts, benzyl dimethyl ketal 3 parts, and hydroquinone monomethyl ether 0.5 part are uniformly kneaded by a biaxial mixing kneader, The obtained mixture was sandwiched between polyethylene terephthalate films and pressed at 80 ° C. for 15 seconds to obtain a photosensitive resin plate (d) having a thickness of 3 mm.

Reference Example 5 (Production Example of Photosensitive Resin Plate (e)) Methacrylic acid-isoprene-methacrylic acid block copolymer (methacrylic acid / isoprene = 1/4 (molar ratio))
100 parts of it was dissolved in 600 parts of tetrahydrofuran, to which was added 13 parts of sodium hydroxide dissolved in 50 parts of methanol, and the mixture was stirred at room temperature for 30 minutes. 40 parts of the resin obtained by removing the solvent under reduced pressure, 1 part of hexanediol diacrylate part of benzyl dimethyl ketal, and 0.5 part of hydroquinone monomethyl ether were uniformly kneaded with a biaxial mixing kneader to obtain a mixture. 15 at 80 ℃ sandwiched over polyethylene terephthalate film
Second pressing was performed to obtain a photosensitive resin plate (e) having a thickness of 3 mm.

Examples 1 to 11 and Comparative Examples 1 to 6 The photosensitive resin plates (a) to (e) obtained in Reference Examples 1 to 5 were each cut into a size of A2, and thin lines and solid portions of each line width were cut. An appropriate negative film (exposed portion 50%) having the above was brought into close contact, and irradiation was performed for 5 minutes with a mercury lamp having an illuminance of 25 W / m ² to print a pattern. After removing the negative film, the film was developed in various washout liquids (50 liters) at 40 ° C. by a nylon brush rubbing so that the relief depth was about 1 mm. Wash out once every 30 minutes,
A total of 10 sheets were washed out. During the washing, the washing liquid is always taken out from the washing tank by a certain amount during the washing, and the non-woven fabric (width 50 cm, filtration part area 40 cm × 60
cm, non-woven fabric moving speed 3 cm / sec, filter cloth belt is 2
It was filtered using a 5 mesh nylon net), and the filtered washout liquid was immediately returned to the washout tank. The washout solution was sampled from the washout tank every 30 minutes, and the solid content concentration in the washout solution was measured. The results are summarized in Table 1 and FIGS. The air permeability is JIS L-1.
It was measured according to the 096 Frazier method.

[0031]

[Table 1] In Table 1, * 1 A melt blown non-woven fabric was sprayed on a heat-bonded polyester spun-bonded non-woven fabric having a fiber diameter of 50 μm and a basis weight of 40 g. * 2 Flow rate of the washout liquid when the treatment device shown in Fig. 1 is adjusted so that the washout liquid does not overflow. * 3 The value obtained by subtracting the solid content concentration of the unused wash-out solution from the solid content concentration of the wash-out solution after washing 10 sheets.

[0032]

As is clear from Table 1 and FIGS. 3 to 6, in the embodiment of the present invention, the resin concentration of the wash-out liquid is kept constant even after the washing of 10 sheets is continued.
In the comparative example, it can be seen that the number increases further. As described above, by filtering the washout liquid of the photosensitive resin plate containing the resin of the unexposed portion using the nonwoven fabric shown in the present invention, the resin in the washout liquid is removed, and the filtrate is reused as the washout liquid,
The resin concentration in the washout liquid is always kept below a certain level, and stable washing out of a large number of photosensitive resin plates can be performed for a long period of time. Also, since it is not necessary to discard the washout liquid,
It is advantageous in terms of cost, pollution-free, and can greatly contribute to local environmental conservation.

[Brief description of drawings]

FIG. 1 is a schematic view of an example of one embodiment of an apparatus used for carrying out the method of the present invention.

FIG. 2 is a schematic view of an example of one embodiment of an apparatus used for carrying out the method of the present invention.

FIG. 3 is a graph showing the relationship between the number of washouts and the resin concentration in the washout liquid.

FIG. 4 is a graph showing the relationship between the number of washouts and the resin concentration in the washout liquid.

FIG. 5 is a graph showing the relationship between the number of washouts and the resin concentration in the washout liquid.

FIG. 6 is a graph showing the relationship between the number of washouts and the resin concentration in the washout liquid.

[Explanation of symbols]

 1, 1 ': Non-woven fabric 2, 2': Non-woven fabric winding roll 3, 3 ': Non-woven fabric winding roll 4: Liquid supply port 5, 5': Liquid return pump 6: Filtrate storage tank 7, 7 ': Chain 8, 8 ': Drive motor 9, 9': Gear 10, 10 ': Belt filter 11, 11': Roll 13: Filtrate 14: Washout liquid 15, 16: Header (movable)

Claims (1)

[Claims] 1. A method for treating a wash-out solution containing a resin, which is generated by a method of exposing a photosensitive resin plate to light and then developing it by rubbing out an unexposed portion while immersing it in a wash-out solution. A method for treating a wash-out liquid of a photosensitive resin plate, characterized in that a wash-out liquid containing a resin is filtered using a non-woven fabric to remove the resin in the wash-out liquid, and the filtrate is reused as the wash-out liquid. (1) Fiber diameter 10 μm or less (2) Air permeability ^{3 to} 300 cm ³ / cm ² / sec (JIS L-1096 Frazier method) (3) Unit weight 5 to 100 g / m ²