Settling separation device, and producing method of reproduced developer using the same

Abstract

To provide a settling separation device capable of efficiently discharging a regenerated developer solution from a separation tank, by efficiently separating a water-dispersed resin, from a used developer solution generated in a development step of a photosensitive resin print original plate, and a method for producing regenerated developer solution using the settling separation device.SOLUTION: A settling separation device comprises: a separation tank 2 supplied with used developer solution; one or more inclined plates 6 provided in the separation tank 2; a floating resin filter 4 that can be installed above the inclined plates 6 in the separation tank 2; and a discharge section 8 provided in the separation tank 2 for discharging regenerated developer solution, wherein the floating resin filter 4 allows water-dispersed resin, which has a lower specific gravity than the developer solution floating above the inclined plates 6, to pass through, and has hole sizes capable of retaining the flocculated water-dispersed resin after passage.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a static separation device for regenerating waste developer liquid generated in the process of developing a photosensitive resin printing plate, and a method for producing a recycled developer liquid using the same. [Background technology]

[0002] In recent years, from the viewpoint of improving the working environment and reducing the environmental load, photosensitive resin printing original plates that can be developed with an aqueous developer have been widely used. These photosensitive resin printing original plates require a development step in which unexposed areas are removed with an aqueous developer after the exposure step, and in order to reduce the environmental load, there is a demand for recovering and reusing the developer waste liquid generated in the development step.

[0003] Furthermore, in the process of producing a photosensitive resin printing plate from a photosensitive resin printing master, it is known that rinsing is generally performed at the end of the development process to improve the quality of the photosensitive resin printing plate. For this rinsing process, new methods using water have been proposed (see, for example, Patent Document 1).

[0004] Therefore, a method has been developed in which the developer waste solution is concentrated to remove the photosensitive resin composition and produce a recycled developer solution (see, for example, Patent Document 2). However, the ultrasonic atomization separation described in Patent Document 2 requires a complex developer waste solution separation device and is not simple. Furthermore, the ultrasonic transmitter requires a lot of power, and a lot of energy is also required to separate the waste solution.

[0005] Furthermore, as a method that does not require energy to separate the waste liquid, a method has been investigated that utilizes the difference in specific gravity between the photosensitive resin composition and water, in which the developer waste liquid is left standing in a tank, the photosensitive resin composition is floated and coagulated, and solid-liquid separation is carried out using a static separation device (see, for example, Patent Document 3). This method is disclosed to be simple and does not require much energy.

[0006] Furthermore, a static separation device has been proposed in which an inclined plate is installed in a tank to increase separation efficiency (see, for example, Patent Document 4). It is disclosed that this method has good separation efficiency. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] International Publication No. 2021 / 042939 [Patent Document 2] International Publication No. 2022 / 173054 [Patent Document 3] International Publication No. 2022 / 196406 [Patent Document 4] Japanese Patent Application Laid-Open No. 2016-170323 Summary of the Invention [Problem to be solved by the invention]

[0008] Recently, waste developer liquid generated in the development process of a photosensitive resin printing plate may contain both a water-dispersible resin having a lighter specific gravity than the developer and a water-dispersible resin having a heavier specific gravity than the developer. In particular, when a water-developable flexographic printing plate is used as the photosensitive resin printing plate, the waste developer liquid often contains both a water-dispersible resin having a lighter specific gravity than the developer and a water-dispersible resin having a heavier specific gravity than the developer, making separation and recovery more difficult.

[0009] In Patent Document 3, when the photosensitive resin composition contains a water-dispersed resin, the separation efficiency is not very high, and there is a problem that the water-dispersed resin is contained in the regenerated developer. In Patent Document 4, there is a problem that it is difficult to efficiently remove the separated and floated photosensitive resin composition from the separation tank. Furthermore, when the developer contains a water-dispersed resin with a lighter specific gravity than the developer and a water-dispersed resin with a heavier specific gravity than the developer, separation takes time, and the water-dispersed resin accumulates at the bottom of the separation tank, which causes the problem of complicated removal of the inclined plate for discharge.

[0010] The present invention has been devised in view of the above-mentioned circumstances, and aims to provide a static separation device that can efficiently separate water-dispersed resin from waste developer generated in the development process of photosensitive resin printing original plates and efficiently discharge the recycled developer from the separation tank, and a method for producing recycled developer using the same. [Means for solving the problem]

[0011] That is, the present invention has the configurations and effects shown in the following [1] to

[11] .

[0012] [1] A static separation device for regenerating waste developer liquid generated in the development process of a photosensitive resin printing plate, a separation tank to which the waste developer is supplied; One or more inclined plates provided in the separation tank; a floating resin filter that can be installed above the inclined plate in the separation tank; a discharge part provided in the separation tank and capable of discharging the regenerated developer; Equipped with The floating resin filter is a static separation device that allows the water-dispersed resin, which has a specific gravity lighter than that of the developer floating above the inclined plate, to pass through, and has a hole size that is large enough to retain the water-dispersed resin that has aggregated after passing through.

[0013] According to the static separation device of the present invention, an inclined plate is provided in the separation tank, thereby increasing the speed at which the aqueous dispersion resin contained in the developer waste liquid that comes into contact with the plate separates into upper and lower portions according to its specific gravity. The aqueous dispersion resin with a higher specific gravity settles below the inclined plate. Furthermore, a floating resin filter with a hole size large enough to allow the aqueous dispersion resin with a lower specific gravity to pass through and retain the agglomerated aqueous dispersion resin can be installed above the inclined plate. In this state, the agglomerated aqueous dispersion resin can be retained after the aqueous dispersion resin has passed through. This allows the aqueous dispersion resin to be efficiently separated, and the developer with a low concentration of aqueous dispersion resin can be efficiently recycled and removed from the discharge section. As a result, the aqueous dispersion resin can be efficiently separated from the developer waste liquid generated during the development process of photosensitive resin printing original plates, and the recycled developer can be efficiently discharged from the separation tank.

[0014] [2] The static separation device according to [1], further comprising an inclined plate unit having a plurality of the inclined plates, the inclined plate unit being installable within the separation tank.

[0015] With this configuration, an inclined plate unit having multiple inclined plates can be installed inside the separation tank, so that the above-mentioned effects can be obtained by the multiple inclined plates when installed, and by removing the inclined plate unit, it becomes easier to discharge the water-dispersed resin that settles below the inclined plate unit and to perform maintenance inside the separation tank.

[0016] [3] The static separation apparatus according to [1] or [2], wherein a plurality of the inclined plates are installed at intervals of 0.5 to 20 mm in the vertical direction.

[0017] According to this configuration, by setting the interval to 20 mm or less, the separation efficiency of the water-dispersed resin is increased, and by setting the interval to 0.5 mm or more, it is more advantageous in terms of maintenance.

[0018] [4] The static separation device according to any one of [1] to [3], wherein the floating resin filter has a pore size of 0.1 mm to 10 mm.

[0019] According to this configuration, by making the hole size 0.1 mm or more, it is possible to allow the water-dispersed resin, which has a lighter specific gravity than the floating developer, to pass through appropriately, and by making the hole size 10 mm or less, it is possible to appropriately retain the aggregated water-dispersed resin.

[0020] [5] The static separation device according to any one of [1] to [4], wherein the floating resin filter has a porosity of 50% or more and 99% or less.

[0021] According to this configuration, by setting the porosity to 50% or more, it is possible to allow the water-dispersed resin, which has a lighter specific gravity than the floating developer, to pass through at an appropriate rate, and by setting the porosity to 99% or less, it is possible to ensure the strength to hold the aggregated water-dispersed resin.

[0022] [6] The static separation apparatus according to any one of [1] to [5], wherein the inclined plate is set at an angle of 30° to 60° with respect to the horizontal surface on which it is placed.

[0023] According to this configuration, by setting the angle of the inclined plate to 60° or less, the floating or sinking water-dispersed resin can be aggregated near the inclined plate, thereby enhancing the effect of floating or sinking. Also, by setting the angle of the inclined plate to 30° or more, the water-dispersed resin can be prevented from accumulating near the inclined plate, allowing the water-dispersed resin to be efficiently separated into upper and lower parts.

[0024] [7] The static separation device according to any one of [1] to [6], further comprising a settling resin reservoir below the inclined plate for retaining a water-dispersed resin having a higher specific gravity than the settled developer.

[0025] According to this configuration, the water-dispersed resin having a high specific gravity that has settled in the settled resin reservoir can be concentrated, and the developer having a low concentration of water-dispersed resin can be more efficiently recycled.

[0026] [8] The static separation device according to any one of [1] to [7], further comprising an opening through which waste developer can be supplied, at a height intermediate between the inclined plate of the separation tank and the floating resin filter.

[0027] This configuration reduces the influence of the flow of the waste developer supplied from the opening, thereby promoting the aggregation of the water-dispersed resin that has passed through the floating resin filter. It also reduces the influence of the inclined plate on the separation of the water-dispersed resin, improving separation efficiency.

[0028] [9] The static separation device according to [7] or [8], wherein the discharge section is provided at a height intermediate between the inclined plate and the settled resin reservoir.

[0029] According to this configuration, the developer with a low concentration of the water-dispersible resin can be more efficiently discharged from the position where the concentration of the water-dispersible resin is relatively low.

[0030]

[10] A method for producing a recycled developer from a waste developer generated in a developing process of a photosensitive resin printing plate, comprising: A method for producing a recycled developer, comprising the steps of: supplying the waste developer to a separation tank of a static separation device and bringing it into contact with an inclined plate provided in the separation tank; passing the water-dispersed resin, which has a lighter specific gravity than the developer that floats above the inclined plate, through a floating resin filter provided above the inclined plate and then flocculating it; allowing the water-dispersed resin, which has a heavier specific gravity than the developer, to settle below the inclined plate; and discharging the recycled developer.

[0031] According to the method for producing a recycled developer of the present invention, the developer waste is brought into contact with an inclined plate installed in a separation tank, thereby increasing the speed at which the aqueous dispersion resin contained in the developer waste is separated into upper and lower parts according to its specific gravity. Furthermore, by passing the aqueous dispersion resin that floats to the top of the inclined plate through a floating resin filter and then agglomerating it, backflow from the floating resin filter can be suppressed, thereby reducing the concentration of the aqueous dispersion resin with a low specific gravity below the floating resin filter. Furthermore, by allowing the aqueous dispersion resin with a higher specific gravity than the developer to settle below the inclined plate, the aqueous dispersion resin is efficiently separated into upper and lower parts, allowing the developer with a low concentration of aqueous dispersion resin to be efficiently recycled and discharged. As a result, the aqueous dispersion resin can be efficiently separated from the developer waste generated during the development process of photosensitive resin printing original plates, and the recycled developer can be efficiently discharged from the separation tank.

[0032]

[11] A method for producing a photosensitive resin printing plate, characterized in that the recycled developer obtained by the production method according to

[10] is used as part or all of the developer.

[0033] According to the method for producing a photosensitive resin printing plate of the present invention, the regenerated developer obtained by the method for producing a regenerated developer of the present invention is used, so that the water-dispersed resin can be efficiently separated from the recovered developer waste liquid, and the regenerated developer can be efficiently reused. [Effects of the Invention]

[0034] According to the present invention, it is possible to efficiently separate the water-dispersible resin in the waste developer generated in the development process of a photosensitive resin printing original plate, and to efficiently discharge the recycled developer from the separation tank. Therefore, the present invention is particularly useful as a separation and recycling technology for the waste developer generated in the development process of a photosensitive resin printing original plate, which contains, as a photosensitive resin composition, a water-dispersible resin having a specific gravity lighter than that of water and a water-dispersible resin having a specific gravity heavier than that of water.

[0035] Furthermore, according to the method for producing a photosensitive resin printing plate of the present invention, the regenerated developer obtained by the method for producing a regenerated developer of the present invention is used, so that the water-dispersed resin can be efficiently separated from the recovered developer waste liquid, and the regenerated developer can be efficiently reused. [Brief explanation of the drawings]

[0036] [Figure 1] FIG. 1 is a schematic diagram showing an example of a batch-type brush developing machine used for developing a photosensitive resin printing plate, the left side showing the state during development and the right side showing the state after development. [Figure 2] FIG. 1 is a schematic diagram showing an example of the configuration of an in-line brush developing machine used for developing a photosensitive resin printing plate. [Figure 3] FIG. 1 is a schematic diagram illustrating an example of a static separation apparatus according to a first embodiment. [Figure 4] FIG. 5 is a schematic diagram showing an example of a static separation apparatus according to a second embodiment. [Figure 5] FIG. 10 is a diagram showing another example of the static separation apparatus according to the second embodiment. [Figure 6] 6 is a schematic diagram showing the state in which the floating resin and the settling resin are accumulated in the static separation device of FIG. 5. [Figure 7] FIG. 6 is a schematic diagram showing an example of a state in which floating resin has been removed in the static separation device of FIG. 5. [Figure 8] FIG. 6 is a schematic diagram showing an example of a state in which the settled resin has been removed in the static separation apparatus of FIG. 5. [Figure 9] FIG. 4 is a schematic diagram showing the separation state of the water-dispersed resin in the inclined plate unit. [Figure 10] FIG. 4 is a schematic diagram for explaining an inclined plate. [Figure 11] FIG. 10 is a schematic diagram for explaining an inclined plate and a floating resin filter. [Figure 12] FIG. 4 is a schematic diagram showing an example of a connection state between a developing machine and a static separation device. [Figure 13] FIG. 10 is a schematic diagram showing another example of the connection state between the developing machine and the static separation device. [Figure 14] FIG. 10 is a schematic diagram showing another example of the connection state between the developing machine and the static separation device. [Figure 15] FIG. 10 is a schematic diagram showing another example of the connection state between the developing machine and the static separation device. [Figure 16] FIG. 2 is a schematic diagram showing a specific example 1 of a connection state between a developing machine and a static separation device. [Figure 17] FIG. 10 is a schematic diagram showing a specific example 2 of a connection state between a developing machine and a static separation device. [Figure 18] FIG. 10 is a schematic diagram showing a specific example 3 of a connection state between a developing machine and a static separation device. [Figure 19] FIG. 10 is a schematic diagram showing a fourth specific example of a connection state between a developing machine and a static separation device. DETAILED DESCRIPTION OF THE INVENTION

[0037] Hereinafter, each embodiment of the present application will be described with reference to the drawings. The following embodiments are merely preferred application examples, and the scope of application of the technology of the present application is not limited to these. In this specification, for ease of reference, components having equivalent functions may be designated by the same reference numerals, but these components do not necessarily refer to the same thing.

[0038] The static separation device of the present invention is a device for regenerating waste developer liquid generated in the developing process of a photosensitive resin printing plate. First, the photosensitive resin printing plate and the developing process will be described.

[0039] <Photosensitive resin printing original plate> The photosensitive resin printing original plate used in the development step is a photosensitive resin printing original plate having a structure in which a photosensitive resin composition layer obtained from a photosensitive resin composition is provided on a support, and can be developed with an aqueous developer. The static separation device of the present invention is more effective when recycling aqueous development waste liquid generated in the development step when the photosensitive resin composition contains a water-dispersed resin. It is even more effective when the photosensitive resin composition contains a water-dispersed resin with a lighter specific gravity than the developer and a water-dispersed resin with a heavier specific gravity than the developer.

[0040] The photosensitive resin composition described below contains a synthetic rubber polymer, a photopolymerizable unsaturated compound, and a photopolymerization initiator, but the same effect can be obtained even if a resin that is not dispersible in water is contained. The photosensitive resin composition may also contain a water-soluble or hydrophilic component.

[0041] <Support> The support used for the photosensitive resin printing plate precursor is preferably a material that is flexible but has excellent dimensional stability, and examples thereof include metal supports such as steel, aluminum, copper, and nickel, and thermoplastic resin films such as polyethylene terephthalate film, polyethylene naphthalate film, polybutylene terephthalate film, and polycarbonate film. Among these, polyethylene terephthalate film is particularly preferred because of its excellent dimensional stability and sufficiently high viscoelasticity.

[0042] <Photosensitive resin composition> The synthetic rubber polymer used in the photosensitive resin composition is used to impart appropriate rubber elasticity to the photosensitive resin composition layer. The synthetic rubber polymer is preferably solid at room temperature to impart rubber elasticity. Examples of the synthetic rubber polymer include polyacrylic resin, polyurethane resin, and conjugated diene polymer. Of these, conjugated diene polymers are preferred. Specific examples of the conjugated diene polymer include polymers obtained by polymerizing conjugated diene hydrocarbons, and copolymers obtained by copolymerizing conjugated diene hydrocarbons and monoolefin-based unsaturated compounds. Examples include butadiene polymers, isoprene polymers, chloroprene polymers, styrene-butadiene copolymers, styrene-butadiene-styrene copolymers, styrene-isoprene copolymers, styrene-isoprene-styrene copolymers, styrene-chloroprene copolymers, acrylonitrile-butadiene copolymers, acrylonitrile-isoprene copolymers, methyl methacrylate-butadiene copolymers, methyl methacrylate-isoprene copolymers, acrylonitrile-butadiene-styrene copolymers, acrylonitrile-isoprene-styrene copolymers, etc. These polymers may be copolymerized with a hydrophilic group such as a carboxy group, a sulfonic acid group, or a polyalkylene glycol, or may have a hydrophilic functional group obtained by emulsion polymerization.

[0043] From the viewpoints of the properties of a photosensitive resin printing plate, i.e., the impact resilience, strength-elongation properties, and hardness of the printing plate surface, and the properties of a photosensitive resin printing plate blank, i.e., dimensional stability when unexposed, and water developability, the synthetic rubber polymer is preferably a water-dispersible resin, and more preferably a water-dispersible resin having a butadiene skeleton and / or a styrene skeleton. A water-dispersible resin is preferably a water-dispersible latex. The water-dispersible latex may be a latex having a crosslinked structure within the molecule, as expressed by the gelation degree. When a latex having a crosslinked structure within the molecule is used, a water-dispersible latex with a weight-average gelation degree of 20 to 80% is preferred. These may be used alone or in combination of two or more. A water-dispersible latex is a stable suspension in which rubber polymer fine particles are dispersed in water. A polymer obtained by removing water from this water-dispersible latex is more preferred. The water-dispersible latex preferably contains one or more latexes selected from the group consisting of butadiene latex, acrylonitrile-butadiene latex, styrene-butadiene latex, and isoprene latex, and more preferably contains two or more latexes. From the viewpoint of water developability, it is even more preferable to contain both butadiene latex and acrylonitrile-butadiene latex.

[0044] The static separation device of the present invention is effective when the photosensitive resin composition contains a water-dispersed resin as the synthetic rubber polymer, and is more effective when two or more types of water-dispersed resins are contained, and is particularly effective when a water-dispersed resin with a specific gravity lighter than that of the developer and a water-dispersed resin with a specific gravity heavier than that of the developer are present. From the viewpoint of the usefulness of the developer recycled by the static separation device, the content of the water-dispersed resin in 100% by mass of the photosensitive resin composition is preferably 70% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more.

[0045] The dispersed particle size of the water-dispersible resin is preferably 0.01 to 100 μm, more preferably 0.05 to 10 μm, and even more preferably 0.1 to 1 μm, from the viewpoint that if the particle size is small, separation in a static separation device takes a long time, and if it is large, debris will be generated in the developer and will easily adhere to the photosensitive resin printing plate.

[0046] The photosensitive resin composition may contain a water-insoluble synthetic rubber polymer to the extent that it does not adversely affect performance. Examples of water-insoluble synthetic rubber polymers include elastomers such as butadiene polymers, chloroprene polymers, acrylonitrile-butadiene polymers, polyurethane resins, isoprene polymers, polystyrene-isoprene copolymers, and polystyrene-butadiene copolymers. The inclusion of a water-insoluble elastomer is preferred because it improves the physical properties and water resistance of the printing plate.

[0047] The photosensitive resin composition may further contain a water-soluble or water-dispersible polymer, such as a water-soluble or water-dispersible polyamide in which a hydrophilic group has been introduced into a polyamide, a partially saponified polyvinyl acetate or a derivative thereof, or an anionic acrylic polymer.

[0048] The photopolymerizable unsaturated compound contained in the photosensitive resin composition is contained for crosslinking and curing by actinic rays. The photopolymerizable unsaturated compound is preferably a compound having an ethylenically unsaturated bond. It may be a compound having only one ethylenically unsaturated bond, or a compound having two or more ethylenically unsaturated bonds. The photopolymerizable unsaturated compound may also contain an oligomer into which a photopolymerizable group has been introduced or a polymer into which a photopolymerizable group has been introduced. In terms of compatibility with synthetic rubber-based polymers, the photopolymerizable unsaturated compound preferably contains one having a skeleton common to that of synthetic rubber-based polymers. These photopolymerizable unsaturated compounds may be used alone or in combination of two or more.

[0049] Specific examples of the ethylenically unsaturated compound having only one ethylenically unsaturated bond include (meth)acrylates having a hydroxyl group such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, and β-hydroxy-β'-(meth)acryloyloxyethyl phthalate, propyl (meth)acrylate, butyl (meth)acrylate, isoamyl (meth)acrylate, and 2-ethyl (meth)acrylate. Examples of the alkyl (meth)acrylate include alkyl (meth)acrylates such as ethylhexyl (meth)acrylate, lauryl (meth)acrylate, and stearyl (meth)acrylate; phenoxyalkyl (meth)acrylates such as phenoxyethyl acrylate and nonylphenoxyethyl (meth)acrylate; and alkoxyalkylene glycol (meth)acrylates such as ethoxydiethylene glycol (meth)acrylate, methoxytriethylene glycol (meth)acrylate, and methoxydipropylene glycol (meth)acrylate.

[0050] Specific examples of the ethylenically unsaturated compound having two or more ethylenically unsaturated bonds include alkyl diol di(meth)acrylates such as 1,9-nonanediol di(meth)acrylate, polyethylene glycol di(meth)acrylates such as diethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylates such as dipropylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, glycerin, and the like. Examples of suitable (meth)acrylates include polyhydric (meth)acrylates of polyhydric alcohols such as methyl tri(meth)acrylate, urethane (meth)acrylates, polyhydric (meth)acrylates obtained by adding an unsaturated carboxylic acid to ethylene glycol diglycidyl ether, polyhydric (meth)acrylates obtained by adding an unsaturated carboxylic acid to a conjugated diene polymer, polyhydric (meth)acrylates obtained by adding an unsaturated epoxy compound such as glycidyl (meth)acrylate to a carboxylic acid or an amine, and polyhydric (meth)acrylamides such as methylene bis(meth)acrylamide.

[0051] As the photopolymerization initiator used in the photosensitive resin composition, any initiator that can polymerize a polymerizable unsaturated group by irradiation with actinic rays can be used, but in particular, initiators that have the function of generating radicals by self-decomposition or hydrogen abstraction upon light absorption are preferably used.Specific examples that can be used include benzoin alkyl ethers, benzophenones, anthraquinones, benzils, acetophenones, and diacetyls.Furthermore, the photopolymerization initiator may be used alone or in combination of two or more.

[0052] <Water-based developer> The aqueous developer according to this embodiment may be water alone, or may be an aqueous solution mainly composed of water and containing a water-soluble development accelerator. Examples of the development accelerator include surfactants, acids, bases, and salts. From the viewpoint of development speed, it is preferable to add a water-soluble development accelerator. Commercially available soaps and detergents may be used as the development accelerator. Not only one type of development accelerator but also two or more types of development accelerators may be used in combination.

[0053] The surfactant may include a cationic surfactant, an anionic surfactant, and a nonionic surfactant.

[0054] Examples of the acid include inorganic acids such as sulfuric acid, nitric acid, and phosphoric acid, and organic acids such as formic acid, acetic acid, oxalic acid, succinic acid, citric acid, maleic acid, and paratoluenesulfonic acid. Examples of the base include lithium hydroxide, sodium hydroxide, potassium hydroxide, and calcium hydroxide.

[0055] The aqueous developer may contain a water-soluble organic solvent other than water, such as methanol, ethanol, isopropyl alcohol, cellosolve, glycerin, ethylene glycol, and polyethylene glycol.

[0056] The aqueous developer may further contain an antifoaming agent to suppress foaming. Any water-soluble antifoaming agent may be used, and examples of the antifoaming agent include higher alcohols, fatty acid derivatives, silica, alumite, and silicone.

[0057] <Developing machine> The developing machine is a device that removes the unexposed photosensitive resin composition layer when producing a photosensitive resin printing plate from a photosensitive resin printing master plate. There are no particular restrictions on the developing machine as long as it has a developing process that can remove the photosensitive resin composition layer, but specific shapes include a batch-type brush developing machine as shown in Figure 1 and an in-line brush developing machine as shown in Figure 2.

[0058] The batch-type brush developing machine of Figure 1 has a mechanism for rubbing a setter 22 and a brush 23 together in a developing machine 20 filled with developer 27, and a photosensitive resin printing original plate 25 is attached to the setter 22, and the unexposed photosensitive resin composition layer is removed before the setter is removed. In the example shown, there is a mechanism for reciprocating the setter 22 to which the photosensitive resin printing original plate 25 is attached by the rotation of a developing motor 21, and there is also a mechanism for circulating the developer 27 with a circulation pump 24.

[0059] In the inline brush developing machine shown in FIG. 2, a photosensitive resin printing plate 25 is transported from upstream to downstream in a transport direction 26. During transport, a developer 27 is poured onto the photosensitive resin printing plate 25 while rubbing it with a brush 23. The unexposed photosensitive resin composition layer is removed, and the photosensitive resin printing plate 25 is discharged. In the illustrated example, the developer 27 is supplied from a developer outlet 27a having a nozzle or the like, and after development, it flows down and is collected in a developer tank 29. A rinse brush 28 is often disposed downstream in the transport direction. After removing the unexposed photosensitive resin composition layer, this rinse brush performs a rinse wash to prevent debris from remaining on the photosensitive resin printing plate 25 within the developing machine 20. While either an aqueous developer or fresh tap water can be used for the rinse wash, using fresh aqueous developer is preferable for debris removal. However, if new water is used in this rinsing, the amount of wastewater will increase. Therefore, it is preferable to use a regenerated developer obtained by removing debris and water-dispersible resin from an aqueous developer containing debris and water-dispersible resin used in developing an unexposed photosensitive resin composition layer.

[0060] Both batch-type brush developing machines and in-line brush developing machines often have a circulation pump 24 or a developing pump 30 that circulates the developer 27 in the developer tank 29 or the developing machine, and the aqueous developer 27 is constantly stirred in the developer tank 29 or the developing machine, preventing the photosensitive resin composition suspended in the developer 27 from separating. Once the water-dispersed resin suspended in the developer 27 separates and forms clumps, the water-dispersed resin does not redisperse and contaminates the inside of the developing machine 20 as debris, and adheres to the photosensitive resin printing plate, reducing the quality of the printing plate.

[0061] <Developing waste liquid> When preparing a photosensitive resin printing plate from the photosensitive resin printing plate blank, the developing process involves using an aqueous developer to clean the photosensitive resin printing plate blank while rubbing it with a brush or the like in the developing machine, thereby removing unexposed photosensitive resin composition. The aqueous developer used in this developing process is stored in a fixed amount within the developing machine. Repeated cleaning of the photosensitive resin printing plate blank increases the photosensitive resin composition concentration in the aqueous developer. Aqueous developers with high photosensitive resin composition concentrations tend to separate the photosensitive resin composition, making it difficult to redisperse, and are prone to generating debris. Debris is also generated even after drying. The generated debris can contaminate the developing machine and adhere to the photosensitive resin printing plate, potentially reducing the quality of the printing plate. Therefore, the developing machine is operated so that the photosensitive resin composition concentration does not exceed a certain level. If the photosensitive resin composition concentration becomes too high, it is discarded and becomes developer waste.

[0062] The concentration of the photosensitive resin composition can be calculated by dividing the weight (g) of the developed photosensitive resin composition by the weight (g) of the developer waste. The concentration of the photosensitive resin composition in the developer waste is not particularly limited, but a high concentration of the photosensitive resin composition can lead to problems such as debris being easily generated and poor platemaking quality, while a low concentration of the photosensitive resin composition can lead to problems such as an increased amount of developer waste relative to the photosensitive resin printing plate produced. The photosensitive resin composition concentration is usually 20% by mass or less, often 1 to 10% by mass, and almost always 3 to 5% by mass.

[0063] <Regenerated developer> The recycled developer is a developer obtained by removing the photosensitive resin composition from the above-mentioned developer waste in a static separation device to reduce the concentration of the photosensitive resin composition. The recycled developer can be returned from the static separation device to the developing machine for use. The returning process is not particularly limited, but in the device shown in Figures 1 and 2, for example, it is effective to return the developer to the developer tank 29, brush 23, or rinse brush 28. By using recycled developer in the developing machine, the amount of developer waste can be reduced compared to when fresh developer is prepared, thereby reducing the environmental impact.

[0064] The regenerated developer may contain less surfactant components than the aqueous developer, and this may be added as needed, or it may be used without adding any additional surfactants.

[0065] <Static separation device> As shown in Figure 3, the static separation apparatus of the present invention includes a separation tank 2 to which waste developer is supplied, one or more inclined plates 6 provided in the separation tank 2, a floating resin filter 4 that can be installed above the inclined plates 6 in the separation tank 2, and a discharge section 8 provided in the separation tank 2 and capable of discharging the recycled developer. The floating resin filter 4 has a hole size that allows water-dispersed resin 16, which has a lighter specific gravity than the developer that floats above the inclined plates 6, to pass through, while retaining the water-dispersed resin 16 that has aggregated after passing through. This allows the water-dispersed resin in the waste developer generated in the development process of a photosensitive resin printing original plate 25 to be separated and removed, and developer 27 to be recycled.

[0066] Photosensitive resin compositions in developer waste often contain water-dispersed resins. Given sufficient time, water-dispersed resins will separate from the developer. Depending on the components of the photosensitive resin composition, the water-dispersed resin may contain a mixture of components with a heavier specific gravity than the developer and components with a lighter specific gravity than the developer. The heavier components will settle, while the lighter components will float. The water-dispersed resins that float and settle form clumps, known as floating resin 3 and settling resin 11, respectively. Since floating resin 3 and settling resin 11 are not easily redispersed, recovering only the developer in the middle yields a recycled developer with a reduced concentration of photosensitive resin composition. A device that utilizes this principle to produce recycled developer from developer waste is called a static separation device.

[0067] The static separation apparatus of the present invention can be broadly divided into a static separation apparatus 36 according to a first embodiment, which discharges the heavy water-dispersed resin 17 from the separation tank 2 together with the developer 27 after static separation, as shown in Fig. 3, and a static separation apparatus 36 according to a second embodiment, which is provided with a settling resin reservoir 9 for accumulating the water-dispersed resin 17 having a higher specific gravity than the settled developer 27, as shown in Fig. 4, etc. The static separation apparatus 36 according to the first embodiment is suitable when the content of the heavy water-dispersed resin 17 is small, and the static separation apparatus 36 according to the second embodiment is more suitable when the content of the heavy water-dispersed resin 17 is large.

[0068] First Embodiment In the static separation device 36 according to the first embodiment, as shown in FIG. 3 , the separation tank 2 that separates the supplied waste developer is provided with an outlet 8 for the recycled developer 27 as a discharge section that can discharge the recycled developer 27. When the content of the heavy water-dispersible resin 17 is small, the recycled developer 27 can be discharged from the outlet 8 while the developer 27 having a relatively high concentration of the water-dispersible resin 17 is appropriately extracted from the separation tank drain outlet 13. Note that even when the developer 27 discharged from the outlet 8 contains the heavy water-dispersible resin 17, it is possible to further separate the heavy water-dispersible resin 17 from the developer 27 using a filter or another separation layer.

[0069] In the illustrated example, an inclined plate unit 7 having a plurality of inclined plates 6 is provided in the separation tank 2, and the inclined plate unit 7 can be installed in the separation tank 2. In the illustrated example, the floating resin filter 4 is provided near the bottom of the floating resin removal tool 5, and is installed at a position below the water surface above the inclined plate 6 in the separation tank 2, and the floating resin removal tool 5 can be removed upward.

[0070] The static separation device 36 according to the first embodiment preferably includes, as shown in FIG. 3, a supply port 1 for supplying the developer waste liquid generated in the development process of the photosensitive resin printing original plate 25, a separation tank 2 through which the developer waste liquid passes and which separates the photosensitive resin composition in the developer waste liquid, and an outlet 8 for recovering the recycled developer liquid, and the separation tank 2 includes an inclined plate unit 7 having at least one inclined plate 6, and a floating resin filter 4 located above the inclined plate unit 7 and below the water surface for allowing the floating components having a lighter specific gravity than the water to pass through and then recovering them.

[0071] The static separation device 36 shown in Figure 3 receives developer waste from a supply port 1 and separates the photosensitive resin composition from the developer waste in a separation tank 2. The photosensitive resin composition in the developer waste often contains a water-dispersed resin. Because the water-dispersed resin is dispersed in the developer waste, separation takes time. In this case, the water-dispersed resin can be efficiently separated using an inclined plate unit 7 equipped with an inclined plate 6 in the separation tank 2. As shown in Figure 9, the water-dispersed resin 16, which has a lower specific gravity than the separated developer, floats up in a dispersed state in the aqueous developer waste. The dispersed water-dispersed resin 16 passes through the holes in the floating resin filter 4, aggregates on the upper side of the floating resin filter 4, and accumulates on top of the floating resin filter 4. The water-dispersed resin 17, which has a higher specific gravity than the developer 27, sinks down the inclined plate 6, and the concentration of the water-dispersed resin 17 increases at the bottom of the separation tank 2 below the inclined plate unit 7. Therefore, the developer 27 having a relatively high concentration of the water-dispersible resin 17 can be appropriately extracted from the separation tank drain outlet 13.

[0072] In the first embodiment, as shown in FIG. 3, it is preferable to provide an opening for the supply port 1 for supplying the waste developer at a position above the inclined plate unit 7 and below the floating resin filter 4. In other words, it is preferable to provide an opening for supplying the waste developer at a height midway between the inclined plate 6 of the separation tank 2 and the floating resin filter 4. By providing an opening for the supply port 1 at a position below the floating resin filter 4, it is possible to prevent the liquid flow from the supply port 1 from hindering the aggregation of the floating resin. By providing the supply port 1 above the inclined plate unit 7, the effective volume of the inclined plate unit 7 can be fully utilized, improving the separation efficiency of the water-dispersed resin. The supply ports 1 may be provided in multiple locations.

[0073] Second Embodiment 4, in addition to the components of the static separation device 36 shown in FIG. 3, a settling resin reservoir 9 for accumulating a component (water-dispersible resin 17) having a higher specific gravity than the settled developer 27 is provided below the inclined plate unit 7. In other words, the settling resin reservoir 9 for retaining the water-dispersible resin 17 having a higher specific gravity than the settled developer 27 is provided below the inclined plate 6.

[0074] The settling separation device 36 shown in FIG. 4 can efficiently separate the water-dispersed resin in the inclined plate unit 7 equipped with the inclined plate 6 in the separation tank 2. The water-dispersed resin 16, which has a lighter specific gravity than the developer 27, floats up in a dispersed state, passes through the holes in the floating resin filter 4, aggregates on the upper side of the floating resin filter 4, and accumulates on the upper side of the floating resin filter 4. The water-dispersed resin 17, which has a heavier specific gravity than the developer 27, sinks down the inclined plate 6 and accumulates as settled resin 11 in the settled resin reservoir 9 at the bottom of the inclined plate unit 7. The recycled developer is then discharged from the discharge port 8. Providing the settled resin reservoir 9 at the bottom of the inclined plate unit 7 simplifies the process of removing the settled resin 11 by removing the inclined plate 6.

[0075] In the second embodiment, too, it is preferable to provide an opening for the supply port 1 for supplying the waste developer at a position above the inclined plate unit 7 and below the floating resin filter, as shown in FIG. 4. By providing an opening for the supply port 1 at a position below the floating resin filter 4, it is possible to prevent the liquid flow from the supply port 1 from hindering the aggregation of the floating resin. By providing the supply port 1 above the inclined plate unit 7, the effective volume of the inclined plate unit 7 can be fully utilized, improving the separation efficiency of the water-dispersed resin. The supply ports 1 may be provided in multiple locations.

[0076] In the second embodiment, as shown in Fig. 4, it is preferable to provide an opening for a discharge port 8 for discharging the recycled developer at a position above the settling resin reservoir 9. In other words, the discharge portion capable of discharging the recycled developer is preferably provided at a position midway between the height of the inclined plate 6 and the settling resin reservoir 9. It is also preferable that the discharge port 8 is installed on the opposite side of the inclined plate unit 7 of the separation tank 2 from the position where the supply port 1 is located. In this case, the separation efficiency of the photosensitive resin composition is improved.

[0077] <Another embodiment of the static separation device> (1) In the first or second embodiment, as shown in FIG. 5, in addition to the static separation device 36 shown in FIG. 4, a space may be provided in which the waste developer is supplied from the supply port 1 and where the waste developer temporarily accumulates before being passed through the separation tank 2.

[0078] (2) In the first or second embodiment, as shown in Fig. 6, the floating resin 3 accumulated on the floating resin filter 4 aggregates and accumulates above the floating resin filter 4 and below the water surface. For this reason, it is preferable that the water level in the separation tank 2 is always higher than the floating resin filter 4 and is controlled so that the water developer waste liquid does not overflow from the separation tank 2.

[0079] (3) In the first or second embodiment, when the floating resin 3 accumulates on the floating resin filter 4, it becomes as shown in Figure 6. However, it is preferable to remove the floating resin filter 4 from the separation tank 2 as shown in Figure 7 when the bottom end of the floating resin 3 does not fall below the floating resin filter 4, and remove the floating resin 3. In this case, the floating resin 3 can be removed efficiently. After removing the floating resin 3 from the removed floating resin filter 4, the floating resin filter 4 can be installed again in the separation tank 2, and the static separation device 36 can be operated again.

[0080] (4) In the first or second embodiment, the floating resin filter 4 may be provided in the floating resin removal tool 5. In this case, the floating resin 3 can be removed from the separation tank 2 together with the floating resin filter 4 together with the floating resin removal tool 5, which is preferable because it allows for easier and more efficient removal of the floating resin 3. It is also preferable to fix the floating resin filter 4 to the floating resin removal tool 5. The floating resin filter 4 alone may not be strong enough to lift the floating resin 3, so the floating resin removal tool 5 is useful as a framework to support the floating resin filter 4. After removing the floating resin 3 from the floating resin filter 4 removed together with the floating resin removal tool 5, the floating resin removal tool 5 equipped with the floating resin filter 4 can be reinstalled in the separation tank 2, allowing the static separation device 36 to continue operating.

[0081] (5) In the second embodiment, when settling resin 11 accumulates in settling resin reservoir 9, as shown in Fig. 7, after removing floating resin 3 by the above-mentioned method, the flow is stopped by closing the valves at supply port 1 and discharge port 8, and the waste developer in separation tank 2 is then extracted from drain port 12 and separation tank drain port 13. In this way, the waste developer in separation tank 2 is discharged, and settling resin reservoir 9 can be removed from separation tank 2, and the settled resin 11 accumulated in settling resin reservoir 9 can be removed.

[0082] Furthermore, the sedimentation resin reservoir 9 may be provided inside the sedimentation resin reservoir drawer 10. In this case, as shown in Figure 8, the sedimentation resin 11 can be removed from the separation tank 2 together with the sedimentation resin reservoir 9, which is preferable because it allows for easier removal. After the sedimentation resin 11 has been removed, waste developer is added to the separation tank 2 through the supply port 1, and once the liquid level has returned to a position higher than the floating resin filter 4, the settling separation device 36 can be restarted.

[0083] <Inclined plate unit, inclined plate> The separation tank 2 of the settling separation device 36 is preferably equipped with an inclined plate unit 7 having at least one inclined plate 6. The inclined plate unit 7 preferably has multiple inclined plates 6. The inclined plate unit 7 is installed to shorten the time it takes for the water-dispersed resin in the waste developer solution to rise to the surface or sink to the water surface, thereby efficiently separating the water-dispersed resin. As shown in Figure 9, when the water-dispersed resin solution contains water-dispersed resins 16 with a lighter specific gravity than the developer and water-dispersed resins 17 with a heavier specific gravity than the developer, the water-dispersed resins 16 with a lighter specific gravity than the developer float in the separation tank 2, while the water-dispersed resins 17 with a heavier specific gravity than the developer sink. If an inclined plate 6 is present in the separation tank 2, the water-dispersed resins will collide with the inclined plate 6 as they rise or sink, sliding along the inclined plate 6 and rising or sinking. The speed at which the water-dispersed resin rises or sinks depends on the particle size and specific gravity of the water-dispersed resin in the same developer, and the larger the particle size, the faster it will rise or sink. The inclined plate unit 7 is intended to accelerate the speed at which the water-dispersed resin rises or sinks by causing the particles to stick together as they slide on the inclined plate 6.

[0084] As shown in Figure 10, the inclined plates 6 are installed in the inclined plate unit 7 at an angle to the horizontal installation direction. The inclined plate interval d is the distance between the plates in the vertical direction, and the inclined plate angle θ is the angle of the inclined plate surface with respect to the horizontal installation plane. As long as the inclined plates 6 do not interfere with or intersect with each other, it does not matter if the inclined plate interval d and inclined plate angle θ are different for each inclined plate 6.

[0085] It is preferable that multiple inclined plates 6 are installed at intervals of 0.5 to 20 mm in the vertical direction. The smaller the inclined plate interval d, the shorter the separation time, but if it is too small, the device design and maintenance become difficult, and if it is too large, the separation time tends to be longer. It is more preferable that the inclined plate interval d is 1 to 10 mm.

[0086] The inclined plate 6 is preferably set at an angle of 30° to 60° with respect to the horizontal installation surface. The inclined plate angle θ is usually greater than 0° and less than 90°. If the inclined plate angle θ is small, the water-dispersed resin does not slide on the inclined plate 6, whereas if the inclined plate angle θ is large, a larger number of plates per volume must be added. Therefore, the inclined plate angle θ is more preferably 35° to 55°.

[0087] The material of the inclined plate 6 is not particularly limited as long as it does not swell or deform significantly in the developer, but examples include polyethylene (PE), high density polyethylene (HDPE), polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polycarbonate (PC), nylon, polyamide, melamine, epoxy, fluororesin, stainless steel, aluminum, steel plate, glass, ceramics, cement, rubber, etc.

[0088] The thickness of the inclined plate 6 is not particularly limited, and may be thin as long as this embodiment can be implemented, but if it is too thick, it will occupy a large volume and may reduce the efficiency inside the separation tank 2. The specific thickness depends on the material; for example, in the case of stainless steel, it is preferably 0.1 mm or more and 5 mm or less.

[0089] <Floating resin filter> The floating resin filter 4 is preferably located above the inclined plate unit 7 in the separation tank 2, below the water surface. The floating resin filter 4 is installed above the opening of the inclined plate unit 7 in the separation tank 2, and as shown in Figure 11, it passes the water-dispersed resin 16, which has a lighter specific gravity than the developer that has slid up the inclined plate 6 and floated up, while still dispersed in water, causing the water-dispersed resin to agglomerate below the water surface. As shown in Figure 7, it is preferable to remove the floating resin 3 accumulated on the floating resin filter 4 from the separation tank 2 together with the floating resin filter 4, and recover the floating resin 3. The floating resin filter 4 is preferably made of textiles such as mesh or nonwoven fabric that can lift the agglomerated floating resin 3 below the water surface.

[0090] The hole size of the floating resin filter 4 is preferably 0.1 mm to 10 mm. In this case, the water-dispersed resin 16, which has a lighter specific gravity than the floating developer, can pass through more efficiently, and the aggregated floating resin 3 can be more efficiently retained. The hole size of the floating resin filter 4 is determined by converting the area of ​​the hole into a circle and calculating the diameter of the circle. If the hole size of the floating resin filter 4 is too small, the water-dispersed resin 16 will not pass through easily, and if it is too large, the strength may be insufficient when lifting the aggregated floating resin 3 together with the floating resin filter 4. The hole size is preferably 0.3 mm to 8 mm, and more preferably 0.5 mm to 6 mm.

[0091] The porosity of the floating resin filter 4 is preferably 50% or more and 99% or less. The porosity of the holes is determined by the ratio of the area of ​​the holes per unit area. In this case, the water-dispersed resin 16, which has a lighter specific gravity than the floating developer, can be passed through more efficiently, and the aggregated floating resin 3 can be more efficiently retained. More preferably, the porosity is 55% or more and 95% or less, and even more preferably, the porosity is 60% or more and 90% or less. The floating resin filter 4 is not particularly limited, but specific examples include drain nets, grease trap nets, stockings, screen doors, wire mesh, polyester nonwoven fabric, punched metal, and perforated plastic sheets.

[0092] The material of the floating resin filter 4 is not particularly limited as long as it does not swell or significantly deform in the developer, and examples include polyethylene (PE), high-density polyethylene (HDPE), polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polycarbonate (PC), nylon, polyamide, melamine, epoxy, fluororesin, stainless steel, aluminum, steel, glass, ceramics, cement, rubber, etc.

[0093] <Settled resin reservoir> In the second embodiment, a settling resin reservoir 9 is preferably provided below the inclined plate unit 7. The settling resin reservoir 9 is a space for accumulating settling resin 11, which is formed by settling components in the waste developer solution, including water-dispersible resin 17, which has a higher specific gravity than the developer. It is installed below the opening of the inclined plate unit 7 of the separation tank 2. The size, shape, and material of the settling resin reservoir 9 are not particularly limited, and the size can be determined appropriately based on the size of the separation tank 2 and the amount of settling resin 11. The settling resin reservoir 9 may be rectangular in shape, covering the opening of the inclined plate 6. The settling resin reservoir 9 may also have a sloped bottom. The material may be any material commonly used for tanks, such as polyethylene (PE), high-density polyethylene (HDPE), polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polycarbonate (PC), nylon, polyamide, melamine, epoxy, fluororesin, stainless steel, aluminum, steel, glass, ceramics, cement, or rubber.

[0094] <Separation tank> The liquid flow rates through the supply port 1 and the discharge port 8 are preferably constant in order to maintain the liquid level in the separation tank 2 above the floating resin filter 4. Specifically, the flow rate of the discharged developer may be set to a constant value, or the liquid level may be monitored by a sensor, and when the liquid level drops below a specified level, liquid is added to maintain the liquid level within a constant range. The developer discharge rate is not particularly limited, but when the volume of the inclined plate unit 7 is V (L), controlling the flow rate to V / 36 (L / hour) or more and V / 2 (L / hour) or less allows for more efficient separation of the water-dispersed resin. A rate of V / 24 (L / hour) or more and V / 3 (L / hour) or less is more preferred. If the developer discharge rate is too fast, the water-dispersed resin will not be sufficiently removed, resulting in a regenerated developer. If the developer discharge rate is too slow, the production of the regenerated developer will take too long, reducing efficiency.

[0095] The temperature of the waste developer in the separation tank 2 is not particularly limited, but is preferably 10°C or higher. At this temperature or higher, the dispersed resin can be separated more efficiently. More preferably, it is 20°C or higher. A heating device or a heat retaining device may be provided to adjust the temperature in the separation tank 2. From the viewpoint of energy costs, the temperature is preferably 70°C or lower, and more preferably 50°C or lower.

[0096] <Method of manufacturing recycled developer> The method for producing a recycled developer of the present invention, as shown in Figures 3 to 4, 9, and 12, is a method for producing a recycled developer from a developer waste generated in the development process of a photosensitive resin printing original plate 25, and includes the steps of supplying the developer waste to a separation tank 2 of a static separation device 36 and contacting it with an inclined plate 6 provided in the separation tank 2, passing water-dispersed resin 16, which has a lighter specific gravity than the developer that floats above the inclined plate 6, through a floating resin filter 4 provided above the inclined plate and then flocculating it, allowing water-dispersed resin 17, which has a heavier specific gravity than the developer, to settle below the inclined plate 6, and discharging the recycled developer. The method for producing a recycled developer of the present invention can be suitably carried out using the static separation device 36 of the present invention described above.

[0097] First, as shown in Figures 3 and 4, for example, the developer waste liquid in which the photosensitive resin composition is dispersed is supplied from the supply port 1 of the separation tank 2 to the static separation device 36, and then sent to the separation tank 2 in the static separation device 36. The photosensitive resin composition in the developer waste liquid may contain solid components such as debris in addition to the water-dispersed resin, and the solid components may be removed in advance using a filter or the like before being sent to the static separation device 36.

[0098] The separation tank 2 is equipped with an inclined plate unit 7, which is equipped with at least one inclined plate 6. The photosensitive resin composition is separated in the inclined plate unit 7 of the separation tank 2. The water-dispersed resin in the photosensitive resin composition is delivered to the separation tank 2 in an aqueous dispersion state, and water-dispersed resin 16, which has a lighter specific gravity than the developer, floats. Water-dispersed resin 17, which has a heavier specific gravity than the developer, becomes sedimented resin 11 and settles. The floating resin 3 passes through a floating resin filter 4, which is located above the inclined plate unit 7 and below the water surface, and then aggregates and accumulates above the floating resin filter 4, below the water surface. The settling resin 11 flows down the inclined plate unit 7 and accumulates in a settling resin reservoir 9. The developer waste from which the photosensitive resin composition has been removed is discharged from the discharge outlet 8 of the separation tank 2, and a recycled developer is produced. In this way, the recycled developer is efficiently produced and can be used as a developer.

[0099] <Method for manufacturing photosensitive resin printing plates> The method for producing a photosensitive resin printing plate of the present invention is characterized in that the recycled developer obtained by the above-mentioned production method of the present invention is used as part or all of the developer. The method for producing a photosensitive resin printing plate of the present invention includes, for example, a developing step of developing an exposed photosensitive resin printing original plate, a step of supplying the waste developer generated by the developing step to a separation tank of a static separation device and bringing it into contact with an inclined plate provided in the separation tank, a step of passing the water-dispersed resin having a lighter specific gravity than the developer floating above the inclined plate through a floating resin filter provided above the inclined plate and then flocculating it, a step of allowing the water-dispersed resin having a heavier specific gravity than the developer to settle below the inclined plate, a step of discharging the recycled developer, and a step of returning part or all of the recycled developer to the developing step.

[0100] In the method for producing a photosensitive resin printing plate according to this embodiment, first, an exposed photosensitive resin printing blank is transported to a developing machine. The photosensitive printing blank is developed in the developing machine supplied with a recycled developer, and a photosensitive printing plate having an image area and an image area formed therein is produced. The recycled developer can be used as both a developer and a rinse cleaning solution. Furthermore, the used recycled developer can be further recycled after being used as a developer. <Method of connecting the static separation device and the developing machine> As shown in FIGS. 12, 13, 14, and 15, the static separation device 36 and the developing machine 20 can be connected in a suitable combination depending on the operation method.

[0101] Below are some specific examples of how to operate the flow, but the present invention is not limited to these.

[0102] FIG. 12 shows a flow in which the developing machine 20 is connected to the waste liquid tank 18, then the static separation device 36 is connected, and then the recycled developer tank 19 is connected to the developing machine 20.

[0103] 12, in developing machine 20, waste developer liquid generated in the process of developing photosensitive resin printing plate 25 is transferred to waste liquid tank 18 and stored therein. Next, the waste developer liquid is transferred from waste liquid tank 18 to static separation device 36, where the photosensitive resin composition in the waste developer liquid is separated and removed, and the recovered recycled developer liquid is transferred to recycled developer tank 19 and stored therein. Next, the flow shows how the required amount is supplied to developing machine 20.

[0104] For example, Figure 16 shows a specific example of how to connect the developing machine 20 and the static separation device 36. While the flow shown in Figure 16 requires an increased number of tanks and takes up space, it has the advantage of allowing greater flexibility in the transfer flow rate, making it easier to design the static separation device 36. The recycled developer is temporarily stored in the recycled developer tank 19, and can be supplied to the developer's rinse brush 28 through the rinse outlet 35 by opening the recycled developer pump 32. This makes it suitable for use in an inline brush developing machine. The developer 27 in the developing machine 20 is transferred to the waste liquid tank 18 by the transfer switching valve 31, and then supplied to the static separation device 36 by the input pump 33. The recycled developer regenerated in the static separation device 36 is transferred to the recycled developer tank 19 by the discharge pump 34.

[0105] FIG. 13 shows a flow in which the developing machine 20 and the static separation device 36 are connected, then the recycled developer tank 19 is connected, and then the recycled developer tank 19 and the developing machine 20 are connected.

[0106] As a specific example, as shown in Figure 17, compared to Figure 16, this has the advantage of being simpler because it does not have a waste liquid tank 18 for storing the waste developer generated in the process of developing a photosensitive resin printing plate 25. However, since the liquid level in the developing machine 20 must be kept constant while the developing machine 20 is operating, there are limitations to operation, as recycled developer must be constantly supplied to the developing machine 20. While the developing machine is down, such as at night when no printing plate making work is being performed, the liquid in the developing machine 20 can be gradually poured into the static separation device 36, and the generated recycled developer can be stored in the recycled developer tank 19. The recycled developer can then be supplied to the developing machine 20 the next day to start development, and this operation is suitable for use in batch-type brush developing machines.

[0107] FIG. 14 shows a flow in which the developing machine 20 and the waste liquid tank 18 are connected, then the static separation device 36 is connected, and then the developing machine 20 is connected to the static separation device 36.

[0108] A specific example of this case is shown in Figure 18, which has the advantage of being simpler than Figure 16 because it does not have a recycled developer tank 19. In this flow, there is a restriction that recycled developer discharged from the static separation device 36 must be supplied directly to the developing machine 20. In the case of a machine such as a batch-type brush developing machine as shown in Figure 1, it is possible to transfer all of the liquid in the developing machine 20 to the waste liquid tank 18 while the developing machine is idle, such as at night when platemaking work is not being performed, and then gradually transfer recycled developer from the static separation device 36 to the empty developing machine 20, so that recycled developer is supplied by the next day and development can begin.

[0109] As shown in Figure 15, a configuration consisting of only the developing machine 20 and the static separation device 36 is also possible. For example, there is a connection example as shown in Figure 19. The advantage is that it has the fewest number of tanks and is the simplest. In this flow, it is necessary to continue transferring recycled developer to the developing machine 20 while feeding waste developer into the static separation device 36, which means that there is a restriction that neither tank can be emptied.

[0110] This embodiment is basically configured as described above. While the processing apparatus and processing method of this embodiment have been described in detail above, the present invention is not limited to the above-described embodiment, and various improvements and modifications may be made without departing from the spirit and scope of the present invention. [Example]

[0111] In order to explain the embodiments of the present invention in more detail, examples and comparative examples are shown below, but the materials, reagents, amounts and proportions of substances, procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the following examples.

[0112] The materials, equipment, and chemicals used in the examples and comparative examples are listed below.

[0113] <Photosensitive resin printing original plate> CosmoLight QZ144U (670mm x 560mm size plate, manufactured by Toyobo MC Co., Ltd.: The photosensitive resin composition layer contains a water-dispersible resin with a lighter specific gravity than the developer and a water-dispersible resin with a heavier specific gravity than the developer) <Developer> Aqueous solution (concentration: 2% by mass) of additive-free dishwashing soap (manufactured by Miyoshi Soap Co., Ltd.) <Developing machine> Iwasaki Steel Co., Ltd. A4 developing machine (batch type brush developing machine: developer volume 12L) <Slanted plate> Sunday Sheet Hard PVC Board: Thickness 0.5mm <Floating resin filter> Type A: Asahi Kasei Home Grist Net L (hole size 2mmΦ, net wire diameter 0.1mm, opening rate 91%) B: Toyobo MC, polyester nonwoven fabric 3201A (hole size 0.1 mm, porosity 70%) C: SUS304 (0.8mm thick plate, 10mm diameter punched holes, 60° staggered, 12mm pitch (opening rate 63%)) D: Toyobo MC, polyester nonwoven fabric 6701A (hole size 0.05 mm, porosity 63%) E: SUS304 (0.8mm thick plate, 15mm diameter punching, 60° staggered, 22mm pitch (opening rate 42%)) High-density polyethylene bird netting (wire diameter 0.03 mm, mesh spacing 20 mm (opening rate 99.7%))

[0114] <Static separation device> A static separation device with the shape shown in Figure 4 was used, with the water level in the separation tank controlled by a level gauge to always be 18 L, the inclined plate unit being 12 L, the floating resin filter being 10 mm above the inclined plate unit, the water level being a further 100 mm above the floating resin filter, and the volume of the settled resin reservoir being 2 L. The inclined plate units were each manufactured to meet the specified conditions. A metering pump (Takumina solenoid-driven metering pump PW) was used to transport the liquid at the inlet and outlet.

[0115] <Method for measuring component concentration of photosensitive resin composition> 1 mL of the sample from which the suspended matter (solids) had been removed was weighed into an aluminum dish, and the weight [g] of the sample before drying was precisely measured. The vacuum dryer was preheated to a set temperature of 80°C, and the sample, including the aluminum dish, was placed in the vacuum dryer and dried for 2 hours. After drying, the sample was removed from the vacuum dryer, and the weight [g] after drying was precisely measured using an analytical balance. The concentration of the photosensitive resin composition components in the sample was calculated using the following formula (1).

[0116] Photosensitive resin composition component concentration [%] = (weight after drying / weight before drying) × 100 (1)

[0117] <How to make recycled developer> Ten unexposed 20 cm × 30 cm CosmoLight QZ114U plates were developed in a developing machine, and the photosensitive resin composition was dispersed in a total of 0.6 kg of developer solution, producing 12 L of developer waste solution with a 5% concentration of the photosensitive resin composition components in the first cycle.

[0118] This first cycle of waste developer was stored in a waste liquid tank, and while maintaining the liquid level, it was fed into the inlet of the static separation device, the regenerated developer was extracted from the outlet, and the resulting regenerated developer was stored in the regenerated developer tank, making it the first cycle of regenerated developer. At this time, the static separation device was filled with new developer when the evaluation began, and agitators were attached to the waste liquid tank and regenerated developer tank to prevent separation, and the liquid was transferred continuously at the specified flow rate using a metering pump.

[0119] Using the regenerated developer obtained from the first cycle, 12 L of developer waste solution for the second cycle, having a photosensitive resin composition component concentration of 5%, was prepared in the same manner as in the first cycle of developer waste solution.

[0120] This second cycle of waste developer was stored in a waste liquid tank, and in the same manner as the first cycle, it was fed into the inlet of the static separation device while maintaining the liquid level, and the regenerated developer was extracted from the outlet, and the resulting regenerated developer was stored in the regenerated developer tank to form the second cycle of regenerated developer. At this time, the evaluation began with the static separation device still filled with the liquid from the first cycle, and agitators were attached to the waste liquid tank and regenerated developer tank to prevent separation, and the liquid was transferred continuously at a specified flow rate using a metering pump.

[0121] This cycle was repeated up to the fifth cycle of the regenerated developer.

[0122] <Method for measuring photosensitive resin composition component removal rate> The concentrations of the photosensitive resin composition components of the following samples were measured. Concentration of photosensitive resin composition components in developer wastewater at the nth cycle: C waste n Concentration of the photosensitive resin composition component in the regenerated developer in the nth cycle: C re n The removal rate of the photosensitive resin composition component was calculated using the following formula (2).

number

[0123] <Evaluation method for floating resin removal rate> Immediately after the fifth cycle of regenerated developer was completed, the floating resin filter, which had been installed 10 mm above the inclined plate unit before the first cycle began, was pulled up as shown in Figure 7 to remove the floating resin. The weight of the floating resin removed by the floating resin filter was measured and recorded as the weight of the floating resin removed by the filter [kg]. The floating resin that was not removed by the filter and remained in the separation tank was scooped up using an ornamental fish net (GEX, fish-friendly net, size L, manufactured by GEX Co., Ltd.), and its weight was measured and recorded as the weight of the remaining floating resin [kg]. The floating resin removal rate was calculated using the following equation (3).

[0124] Floating resin removal rate [%] = weight of floating resin removed by the filter / (weight of floating resin removed by the filter + weight of remaining floating resin) × 100 (3)

[0125] <Inclined plate stain evaluation method> After the fifth cycle of recycled developer is made and the floating resin is removed, the inclined plates are pulled out and checked. If lumps of floating or settled resin can be visually confirmed between the inclined plates, it is marked as ×. If not, it is marked as ○.

[0126] Example 1 As shown in Table 1, an inclined plate unit was prepared with the inclined plates spaced equally apart at a distance d of 0.5 mm and at an angle θ of 45° relative to the horizontal plane, and installed in a separation tank. After installing a floating resin filter A, the fifth cycle of recycled developer was prepared using the above-mentioned recycled developer preparation method, and evaluations were carried out according to the above-mentioned photosensitive resin composition component removal rate measurement method, the above-mentioned floating resin removal rate evaluation method, and the above-mentioned inclined plate contamination evaluation method. It was also confirmed that the water-dispersed resin was efficiently removed, the floating resin could be easily discharged, and no dirt adhered to the inclined plate.

[0127] Examples 2 to 11 will be described, each showing the results of experiments carried out in the same manner as in Example 1. Detailed conditions and results are summarized in Table 1.

[0128] <Example 2> The same procedure as in Example 1 was carried out under the conditions shown in Table 1. This example revealed that photosensitive resin composition components could be efficiently removed even when the inclined plate interval d was 20 mm.

[0129] Example 3 The same procedure as in Example 1 was carried out under the conditions shown in Table 1. This example showed that the water-dispersible resin could slide on the inclined plate and be removed even when the inclined plate angle θ was 30°.

[0130] Example 4 The same procedure as in Example 1 was carried out under the conditions shown in Table 1. This example revealed that photosensitive resin composition components could be efficiently removed even when the inclined plate angle θ was 60°.

[0131] <Example 5> The procedure was the same as in Example 1 under the conditions shown in Table 1. This example demonstrated that the floating resin can be efficiently discharged even with a filter hole size of 0.1 mm.

[0132] Example 6 The same procedure as in Example 1 was carried out under the conditions shown in Table 1. This example demonstrated that the floating resin could be efficiently discharged even with a filter hole size as large as 10 mm and a filter porosity of 63%.

[0133] <Examples 7 to 9> The same procedure as in Example 1 was carried out under the conditions shown in Table 1. Examples 7 to 9 revealed that the photosensitive resin composition can be efficiently removed when the discharge flow rate is in the range of 0.5 to 5 L / h.

[0134] Example 10 The same procedure as in Example 1 was carried out under the conditions shown in Table 1. In this example, when the inclined plate interval d was as small as 0.1 mm, dirt was observed on the inclined plate, but the photosensitive resin composition was able to be removed efficiently.

[0135] Example 11 The same procedure as in Example 1 was carried out under the conditions shown in Table 1. In this example, when the inclined plate angle θ was as small as 20°, the photosensitive resin composition did not slide easily on the inclined plate, but it was still able to be removed efficiently.

[0136] [Table 1]

[0137] <Comparative Example 1> As shown in Table 2, the same operation as in Example 1 was carried out using a static separation device that did not have an inclined plate unit or a floating resin filter in the separation tank used in Example 1. Because there was no inclined plate unit, the photosensitive resin composition was not sufficiently removed from the developer waste solution of the photosensitive resin printing plate, and because there was no floating resin filter, removal of the floating resin had to be done manually using this evaluation method, which was difficult. Furthermore, because there was no inclined plate, no dirt adhered to the inclined plate.

[0138] Comparative Examples 2 and 3 are described below, which are results of experiments carried out in the same manner as in Comparative Example 1. Detailed conditions and results are shown in Table 2.

[0139] <Comparative Example 2> The same procedure as in Example 1 was carried out using a static separation device equipped with an inclined plate unit in the separation tank and no floating resin filter under the conditions shown in Table 2. In Comparative Example 2, like Comparative Example 1, the floating resin filter was not provided, so removal of the floating resin had to be done manually using this evaluation method, which was difficult. However, the presence of the inclined plate unit revealed a high removal rate of photosensitive resin composition components.

[0140] <Comparative Example 3> The same procedure as in Example 1 was carried out using a static separation device equipped with a floating resin filter and no inclined plate unit in the separation tank under the conditions shown in Table 2. In Comparative Example 3, as in Comparative Example 1, the absence of an inclined plate unit meant that the photosensitive resin composition components were not sufficiently removed from the developer waste solution of the photosensitive resin printing plate. However, the presence of the floating resin filter meant that the floating resin could be removed efficiently.

[0141] [Table 2] [Industrial Applicability]

[0142] The static separation method of the present invention and the method for producing a recycled developer using the same can efficiently separate and remove the water-dispersible resin from the waste developer, enable the production of a recycled developer, and reduce the amount of waste by reusing the recycled developer, thereby greatly contributing to reducing the environmental load. Therefore, the present invention is extremely useful. [Explanation of symbols]

[0143] 1 supply inlet 2 Separation tank 3. Floating resin 4 Floating resin filter 5. Floating resin removal tool 6 Inclined plate 7 Inclined Plate Unit 8 Discharge port (discharge part) 9 Settled resin reservoir 10 Settled resin reservoir drawer 11. Sedimentation Resin 12 Drain 13 Separation tank drain port 16 Water-dispersible resin with a lighter specific gravity than developer 17 Water-dispersible resin with a higher specific gravity than the developer 18 Waste liquid tank 19 Recycled developer tank 20 Developing machine 21 Development motor 22 Setter 23 Brush 24 Circulation Pump 25 Photosensitive resin printing plate 26 Conveying direction 27 Developer 27a Developer solution outlet 28 Rinse Brush 29 Developer tank 30 Developer pump 31 Transfer switching valve 32 Regenerated developer pump 33 Injection pump 34 Discharge pump 35 Rinse outlet 36 Static separation device d Inclined plate spacing θ Inclined plate angle

Claims

1. A static separation device for regenerating waste developer liquid generated in a development process of a photosensitive resin printing plate, a separation tank to which the waste developer is supplied; One or more inclined plates provided in the separation tank; a floating resin filter that can be installed above the inclined plate in the separation tank; a discharge part provided in the separation tank and capable of discharging the regenerated developer; Equipped with The floating resin filter is a static separation device that allows the water-dispersed resin, which has a specific gravity lighter than that of the developer floating above the inclined plate, to pass through, and has a hole size that is large enough to retain the water-dispersed resin that has aggregated after passing through.

2. 2. The still separation apparatus according to claim 1, further comprising an inclined plate unit having a plurality of the inclined plates, the inclined plate unit being installable within the separation tank.

3. 2. The static separation apparatus according to claim 1, wherein a plurality of the inclined plates are installed at intervals of 0.5 to 20 mm in the vertical direction.

4. 2. The static separation device according to claim 1, wherein the floating resin filter has a hole size of 0.1 mm to 10 mm.

5. 2. The static separation apparatus according to claim 1, wherein the floating resin filter has a porosity of 50% or more and 99% or less.

6. 2. The static separation apparatus according to claim 1, wherein the inclined plate is set at an angle of 30° to 60° with respect to the horizontal plane.

7. 2. The static separation apparatus according to claim 1, further comprising a settled resin reservoir below the inclined plate for retaining the water-dispersed resin having a specific gravity greater than that of the settled developer.

8. 2. The static separation apparatus according to claim 1, further comprising an opening through which the waste developer can be supplied, at a position at an intermediate height between the inclined plate of the separation tank and the floating resin filter.

9. The static separation apparatus according to claim 7 , wherein the discharge section is provided at a position at an intermediate height between the inclined plate and the settled resin reservoir.

10. A method for producing a recycled developer from a developer waste liquid generated in a development process of a photosensitive resin printing original plate, comprising: A method for producing a recycled developer, comprising the steps of: supplying the waste developer to a separation tank of a static separation device and bringing it into contact with an inclined plate provided in the separation tank; passing the water-dispersed resin, which has a lighter specific gravity than the developer that floats above the inclined plate, through a floating resin filter provided above the inclined plate and then flocculating it; allowing the water-dispersed resin, which has a heavier specific gravity than the developer, to settle below the inclined plate; and discharging the recycled developer.

11. A method for producing a photosensitive resin printing plate, comprising using a regenerated developer obtained by the method according to claim 10 as a part or all of a developer.

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