JP2009208000A - Method for treating wastewater from automatic developing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developing method for reducing a further load on the purification apparatus of the company by treating wastewater overflowing developing section and rinsing section of an automatic developing device to make the quality of the wastewater tolerable enough to discharge the wastewater to a river. <P>SOLUTION: (1) The developing method includes the process wherein a planographic printing plate having a silicone layer is developed in the automatic developing device having a pretreatment section, developing section, posttreatment section, and rinsing section, and also wherein the wastewater from the developing section and rinsing section undergoes an adsorbing treatment in an activated carbon treatment tank containing only activated carbon. (2) The developing method of (1) further includes the process wherein the wastewater which has undergone the adsorbing treatment in the activated carbon treatment tank is charged again to the developing section and rinsing section of the automatic developing device. (3) The developing method of (1) or (2) further includes the process wherein the wastewater from the developing section and rinsing section is delivered to the activated carbon treatment tank only when the wastewater stored beforehand in a wastewater storing tank reaches a specified volume. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to treatment of waste water discharged from a developing unit and a washing unit of a lithographic automatic developing device.

  Currently, lithographic development processing is generally carried out using an automatic processor. Such an automatic processor consists of a process of pre-processing part → developing part → post-processing part → water washing part after exposure. In order not to deteriorate the developability, new water is continuously supplied at the time of development and washing, and the overflowing developing water and washing water are discharged to the sewer as they are.

  However, platemakers that do not have sewer facilities at the locations where automatic processors are installed are discharged into public water areas after purification by their own purification equipment. In these cases, the Water Pollution Control Law is applied, and more stringent regulations are set for the Sewerage Law, such as biological oxygen demand (BOD) and chemical oxygen demand (COD). In addition, the regulation values for each item are set by each local government, and it is obliged not to exceed the regulation values.

  Further, in recent years, from the viewpoint of CSR (Corporate Social Responsibility-corporate social responsibility), the number of platemakers that independently manage by providing a regulation value that is further increased from the regulation value of the local government is increasing.

  Furthermore, water saving is demanded from the viewpoint of resource saving, and this demand is getting stronger due to the problem of regulation of the total amount of wastewater at the plate making plant.

  In order to save water, it is conceivable to use an automatic processor in a circulating manner (stopping the supply of new water), but in this case, developability deteriorates. That is, the reproducibility of minute halftone dots gradually deteriorates.

  Further, as another method of saving water, it is conceivable to save water by supplying a new amount of washing water. However, according to this method, the pollution degree of waste water is increased. In other words, the value of biological oxygen demand (BOD), chemical oxygen demand (COD), etc. that are discharged becomes high, and platemakers that purify wastewater with their own purification equipment have a problem of increasing the load on the purification equipment. Had.

  Therefore, biological, physical, and chemical treatment of the development waste water can be considered, and methods disclosed in Patent Document 1 and Patent Document 2 have been proposed.

Patent Document 1 discloses a method of performing activated carbon adsorption treatment after biological treatment, and Patent Document 2 discloses a method of performing filtration treatment.
JP-A-9-85233 (Claims) JP 2006-218419 A (Claims)

  An object of the present invention is to provide a new method for effectively solving the above problems. In other words, the present invention provides a method for reducing the load on the purification equipment of the company by treating the waste water discharged from the developing water and the washing water into an overflow and making the water quality that can be discharged into the river. It is. In other words, an object of the present invention is to establish a wastewater treatment method that can purify wastewater that has become highly polluted by water-saving before it can be drained into a river.

In order to solve the above problems, the present invention
(1) In the process of developing a lithographic plate having a silicone layer with an automatic developing device having a pre-processing unit, a developing unit, a post-processing unit, and a washing unit, activated carbon treatment having only activated carbon for wastewater discharged from the developing unit and the washing unit A developing method characterized by performing adsorption treatment in a tank.
(2) The developing method as described in (1) above, wherein the wastewater adsorbed in the activated carbon treatment tank is reintroduced into the developing unit and the washing unit of the automatic developing device.
(3) The developing method as described in (1) or (2) above, wherein a certain amount of waste water discharged from the developing section and the washing section is stored in a waste water storage tank and then sent to an activated carbon treatment tank.

  With the wastewater treatment apparatus of the present invention, it is possible to reduce the amount of water required in the lithographic developing section and improve the quality of the discharged wastewater. Further, by using the treated wastewater again in the developing device, the developing device becomes a circulation type device, and the wastewater can be prevented from being discharged.

  Hereinafter, the present invention will be described in detail. In the present invention, the lithographic plate to be treated has a silicone layer, and is preferably applied to, for example, drainage discharged with the processing of the printing lithographic plate.

  A lithographic plate having a silicone rubber layer used in the present invention will be described. The lithographic plate having the silicone rubber layer of the present invention preferably has a structure having a layer on which the adhesive force between adjacent layers changes at least by exposure and a layer mainly composed of silicone rubber. More specifically, waterless lithographic printing plate precursors described in JP-A-2005-309126 and JP-A-2000-47377 can be mentioned.

  Next, a method for making a lithographic plate having a silicone rubber layer will be described. In the case of a negative type lithographic plate where the exposed area is the image area and a positive type lithographic plate where the exposed area is the non-image area, the original film is usually placed on the protective film and image exposure is performed with actinic rays, and then the protective film is After removal, an image can be formed by development. In the case of a direct-drawing lithographic plate, the original image having a protective film is exposed as it is or after the protective film is peeled off, and then the image is exposed with a laser beam. Thereafter, an image having a protective film is peeled off, and an image having no protective film is developed as it is to form an image.

  The waste water treatment apparatus and waste water treatment method according to the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic view of a wastewater treatment apparatus according to the present invention.

  The wastewater treatment apparatus 1 includes a strainer 2, a wastewater storage tank 3, a liquid feed first pump 4, a cushion tank 5, a flow meter 6, an activated carbon treatment tank 7, a treated wastewater storage tank 8, and a liquid feed second pump 9. .

  The waste water discharged from the developing unit and the water washing unit of the automatic processor a passes through the strainer 2 and is temporarily stored in the waste water storage tank 3 after the solid content is removed.

  The automatic developing machine is not limited as long as it can develop a lithographic plate, but preferably an automatic developing machine in which at least a pre-processing unit, a developing unit, a post-processing unit and a washing unit are provided in this order is used. Is good. Specific examples of the automatic developing machine include an automatic developing machine such as TWL-1160F, TWL-860F, and TWL-650F manufactured by Toray Industries, Inc., or JP-A-5-2272 and JP-A-5-6000. Mention may be made of automatic developing machines which are disclosed in the publication.

  The pre-processing section of the automatic processor includes, for example, plate-making treatment liquid 1 that is a plate-making treatment liquid described in JP-A-2005-338580, that is, (i) diethylene glycol mono-2-ethylhexyl ether: 19 parts by weight, ( ii) Polypropylene glycol # 200: 72 parts by weight; (iii) 2- (2-aminoethylamino) ethanol: 9 parts by weight; (iv) Water: 1 part by weight; In order to facilitate confirmation of development, for example, the dyeing solution described in Example 3 of JP-A-9-34132, for example, (i) crystal violet (basic dye, Hodogaya Chemical Co., Ltd.), 0.10 parts by weight, (ii) Brilliant Basic Cyanine 6GH (basic dye, soil preservation) Chemical Industry Co., Ltd.), 0.40 parts by weight, (iii) Sinoline SO-35 (2-ethylhexyl sodium sulfate, 40% aqueous solution, anionic surfactant, Shin Nippon Rika Co., Ltd.) 5.00 parts by weight , (Iv) 10 parts by weight of butyl carbitol, (v) KS-502 (manufactured by Shin-Etsu Chemical Co., Ltd., defoaming agent) 0.002 parts by weight, (vi) 84.498 parts by weight of pure water, and washed with water Part is developed with water.

  The type of piping connected from the automatic processor a to the waste water storage tank 3 is not limited, but the size is preferably 20A or more, and a slope is provided so that the waste water flows into the waste water storage tank 3 without flowing back. It is preferable. Preferably, the difference between the height of the inlet of the waste water storage tank 3 and the height of the outlet pipe of the waste water of the automatic processor is preferably 10 mm or more. In addition, 20A shows the nominal diameter of piping, for example, in the case of hard polyvinyl chloride piping for water supply described in JIS K 6742, 20A shows piping with an outer diameter of 26.0 mm and a thickness of 3.0 mm.

  The material and openings of the strainer 2 are not limited, but are preferably 0.10 mm to 2.00 mm. The number of strainers includes two or more openings that are changed to prevent clogging. Is preferred. A specific example is a PVC Y-strainer.

  The material and size of the drainage storage tank 3 are not limited, but examples thereof include a 120 L tank made of FRP.

  When a predetermined amount of waste water stored in the waste water storage tank 3 is stored in advance, the liquid feeding first pump 4 is automatically operated and sent to the activated carbon treatment tank 7 through the cushion tank 5 and the flow meter 6.

  Although the pump used for the liquid feeding first pump 4 is not limited, it is preferable to select a pump of variable speed type according to the limit processing speed of the activated carbon treatment tank 7. A specific example is ZD1-63-VTCE-FW manufactured by Takumina Co., Ltd.

  The water level meter for setting the start of operation of the pump is not limited, and examples thereof include an electrode type level meter. When the drainage reaches the set water level, a signal is sent to the control panel b, and the control panel b activates the liquid feeding first pump 4.

  Details of the cushion tank 5 are shown in FIG. The wastewater sent from the top flows according to the wastewater flow 10. It is temporarily stored in the cushion tank 5 and flows out from the lower part to the flow meter 6 by the head pressure, and is provided with an air escape pipe 11. The length of the air escape pipe 11 is not limited, but if it is too short, it will be ejected to the drainage together with the air, so 100 mm or more is preferable. Further, the size of the cushion tank 5 depends on the amount of liquid fed by the first liquid feed pump 4 and the variation in the amount of liquid delivered. For example, the amount of liquid delivered by a pump of ZD1-63-VTCE-FW manufactured by Takumina Co., Ltd. In this case, the dispersion of liquid feeding is reduced from 9 to 24 L / min to 8.4 to 8.7 L / min without drainage from the air escape pipe 11 by the installation of the 6 L tank.

  The cushion tank 5 is effective when there is a variation in the liquid discharge of the waste water by the liquid supply first pump 4. If there is a variation in the amount of liquid delivered by the pump, at the moment when the amount of delivered liquid is large, the surface of the activated carbon inside the activated carbon treatment tank 7 is struck with water pressure, which may shorten the life of the activated carbon. is there. This is a problem that occurs particularly when a pump having a large pulsation such as a diaphragm pump is used as the first liquid-feeding pump 4, and this problem can be solved by using the cushion tank 5.

In addition, it is possible to always check whether or not the amount of liquid fed is being supplied with a stable flow rate by the flow meter 6 installed downstream of the cushion tank 5.
Although this flow meter 6 is not limited, an integrated flow meter is preferable for use as a guideline for the replacement timing of the activated carbon, and when the set amount of waste water is sent to the activated carbon treatment tank 7, the signal is controlled. The control panel b stops the pump. In the meantime, the activated carbon can be exchanged.

  The type of activated carbon used in the activated carbon treatment tank 7 is not limited, and any activated carbon having an adsorption ability may be used. In other words, the raw materials for activated carbon include wood, coal, and coconut shell materials such as pine trees, bamboo, coconut shells and walnut shells, as well as coal, petroleum and special ones such as animal bones and blood. Such animal raw materials may be used. Moreover, as a kind of activated carbon, any of powder, a granular form, a fiber form, and plate shape may be sufficient. An example is Mitsubishi Chemical Calgon F-400, a coal-based crushed coal.

  A valve is installed at the outlet of the activated carbon treatment tank 7, and in order to extend the life of the activated carbon, by adjusting the opening of the valve, the treated waste water flows in the same amount as the supply amount. It is preferable to keep the water level constant.

  When the waste water in the waste water storage tank 3 is supplied to the activated carbon treatment tank 7, the pump is automatically stopped to prevent empty pumping. Although the water level meter for preventing empty pumping is not limited, for example, an electrode type level meter can be mentioned.

  The treated wastewater discharged from the activated carbon treatment tank 7 is stored in the treated wastewater storage tank 8 and is again put into the automatic processor a by the liquid feed second pump 9. Further, when the treated wastewater is not reused, it is possible to flow from the activated carbon treatment tank 7 to the sewage or the river by switching the valve.

  Although the material and size of the treated wastewater storage tank 8 are not limited, for example, a 120 L tank made of FRP can be mentioned. Moreover, the liquid feeding 2nd pump 9 is not limited.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these.

<Used drainage>
The waste water used for processing was water discharged from the developing section in the course of processing the photosensitive material for printing with the following settings.
Automatic processor: TWL-1160F (manufactured by Toray Industries, Inc.)
Pretreatment liquid: CP-1 (manufactured by Toray Industries, Inc.) Temperature: 44 ° C
Developing water: tap water temperature 25 ° C
Post-treatment liquid: PA-F (manufactured by Toray Industries, Inc.)
Photosensitive material: Waterless CTP version VG5 (manufactured by Toray Industries, Inc.)
Number of processed sheets: 1030 mm × 800 mm 150 sheets / day Continuous plate halftone dot area ratio: 30%

  Next, details of the production, plate making, exposure and development of the waterless CTP plate used in the test will be described.

<Manufacturing method>
A composition for forming each layer was applied on the substrate. The primer layer composition coating solution was applied and thermally cured at 200 ° C. for 2 minutes, and then the ink deposit layer composition coating solution was applied and thermally cured at 140 ° C. for 2 minutes. A silicone rubber layer composition coating solution was applied thereon and treated at a temperature of 135 ° C. for 2 minutes to cure the rubber. Thereafter, a protective film was laminated.

<Plate making process>
Next, a method for making a waterless CTP plate will be described. Platemaking refers to the process from the exposure process (image formation process) in which the lithographic printing plate precursor is imagewise irradiated with actinic rays to the development process in which the exposed lithographic printing plate is developed and the printing plate is patterned. Say. In the development process, pre-processing and post-processing are also performed before and after development, respectively. In this case, the pre-processing unit, the developing unit, and the post-processing unit are subdivided.

<Exposure process>
After the protective film is peeled off or exposed on the protective film with a laser beam in an image form. Here, a laser beam having a wavelength of 830 nm was used as a laser light source.

<Development process>
As the developing means, an automatic developing device provided with a pre-processing unit, a developing unit, and a post-processing unit in this order was used. Processing was carried out using “TWL-1160F” manufactured by Toray Industries, Inc. as an automatic developing device, and using water discharged from the developing section.
The analysis values of the waste water are as follows.
PH 8.6
COD 300ppm
BOD 430ppm
SS 1ppm
n-hexane extract (mineral oil) <0.5ppm
n-hexane extract (animal and vegetable oil) 19ppm

The measuring method of each analytical value is shown below.
PH (hydrogen ion concentration): Measured according to a glass electrode method corresponding to JIS K0102-1998 12.1.
COD (chemical oxygen demand): Measured according to the method (CODMn) using sulfuric acid potassium permanganate corresponding to JIS K0102-199817.
BOD (Biochemical Oxygen Demand): Measured according to a dilution method winker sodium azide modification corresponding to JIS K0102-199821.
SS (Amount of suspended solids): Measured according to the filtration method corresponding to Environment Agency Notification No. 64.
n-Hexane extract content (mineral oil): JIS K0102-1998 24.2 Reference II. It was measured according to the column chromatography method corresponding to 1.
n-Hexane extract content (animal and vegetable oil): JIS K0102-1998 24.2 Reference II. It was measured according to the column chromatography method corresponding to 2.

  The above contaminated waste water was treated with activated carbon. The apparatus used for the treatment was a coal-based activated carbon treatment apparatus (200L Calsorb DRUM manufactured by Mitsubishi Chemical Calgon Co., Ltd.). At this time, 10 L / min was continuously passed through the activated carbon treatment apparatus, and the same amount of treated wastewater was discharged from the lower part of the treatment tank.

The main analysis results of the treated wastewater at this time are as follows.
PH 6.7ppm
COD (manganese dioxide method) 2ppm
BOD 2.8ppm
SS <1ppm
n-hexane extract (mineral oil) <0.5ppm
n-hexane extract (animal and vegetable oil) <0.5ppm

  As described above, it can be seen that the values are reduced for each measured value. For this reason, this treatment makes it possible to flow into rivers as well as sewage. Furthermore, by supplying this treated wastewater to an automatic processor, it can be reused without deteriorating developability.

It is the schematic which shows an example of the waste water treatment equipment concerning this invention. It is the schematic which shows an example of the cushion tank 5 of this invention.

Explanation of symbols

W: Water supply source a: Automatic processor a1: Pre-processing unit a2: Development unit a3: Post-processing unit a4: Washing unit b: Control panel 1: Wastewater treatment device 2: Strainer 3: Wastewater storage tank 4: Liquid supply 1 pump 5: cushion tank 6: flow meter 7: activated carbon treatment tank 8: treated wastewater storage tank 9: liquid feed second pump 10: wastewater flow 11: air vent pipe

Claims (3)

  In the process of developing a lithographic plate having a silicone layer with an automatic developing device having a pre-processing unit, a developing unit, a post-processing unit, and a washing unit, the waste water discharged from the developing unit and the washing unit is adsorbed in an activated carbon treatment tank having only activated carbon. A developing method characterized by processing.   2. The developing method according to claim 1, wherein the waste water adsorbed in the activated carbon treatment tank is re-introduced into a developing unit and a washing unit of an automatic developing device.   The developing method according to claim 1 or 2, wherein a certain amount of waste water discharged from the developing unit and the washing unit is stored in a waste water storage tank and then sent to an activated carbon treatment tank.

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