JP2013154266A - Wastewater processing method, wastewater processing device, and method for making planographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wastewater processing method and a wastewater processing device, capable of processing wastewater discharged in a developing step of a planographic printing plate in a short time and in large amounts and circulatingly using the same by effectively utilizing activated carbon in a tank.SOLUTION: In a wastewater processing method, wastewater discharged in a step developing a planographic printing plate is subjected to adsorbing processing in an activated carbon processing tank, and thereafter is further subjected to adsorbing processing in another activated carbon processing tank.

Description

  The present invention relates to treatment of waste water discharged from an automatic developing device for a lithographic printing plate.

  Currently, the development processing of a lithographic printing plate is generally carried out using an automatic processor, but such an automatic processor is often used in a process using chemicals and a cleaning process using water. Therefore, in the cleaning process, in order to suppress the increase in the concentration of the chemical solution to a constant amount, new water is continuously supplied to the water to be circulated and the overflowing water is discharged to the sewer as it is.

  However, platemakers that do not have sewer facilities at the locations where automatic processors are installed either discharge them to public water areas after purification with their own purification facilities, or collect all wastewater and treat it as industrial waste.

  On the other hand, water conservation is demanded from the viewpoint of resource saving, and this demand is getting stronger from the point of regulation of the total amount of wastewater at the platemaking plant.

  In order to save water, it is conceivable to use an automatic processor in a completely 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 for saving water, conserving water with a new water supply amount of flush water is conceivable. However, according to this method, the pollution degree of waste water is increased. In other words, the value of the biological oxygen demand (BOD), chemical oxygen demand (COD), etc., of the wastewater becomes high, and platemakers that purify wastewater with their own purification equipment have the problem of increasing the load on the purification equipment. Had.

  Moreover, although the method of circulating-utilizing waste water using activated carbon was also devised, it had problems such as a large and expensive treatment device (Patent Documents 1 to 4). Although Patent Document 2 describes that a photographic waste liquid can be processed in a short time by biological activated carbon treatment and adsorption treatment with activated carbon, the liquid to be processed is a photographic waste liquid. Since organic matter is oxidatively decomposed by microorganisms adsorbed and grown on the activated carbon surface and then subjected to activated carbon adsorption treatment, it takes a total of 2 hours to treat only 500 ml of waste liquid.

JP-A-8-82937 (Claims) JP-A-9-85233 (Claims, Example 3) JP 2006-218419 A (Claims) JP 2009-208000 A (Claims)

  The present invention aims to solve the above problems, that is, the wastewater discharged in the development process of a lithographic printing plate is processed in a large amount in a short time by effectively using activated carbon in the tank, and is recycled. It is an object of the present invention to provide a wastewater treatment method and a wastewater treatment apparatus that can also be used.

The present invention for solving the above problems employs any of the following configurations.
(1) A wastewater treatment method characterized in that the wastewater discharged in the step of developing the lithographic printing plate is subjected to an adsorption treatment in another activated carbon treatment tank after the adsorption treatment in the activated carbon treatment tank.
(2) It has a flow path of drainage discharged in the step of developing a lithographic printing plate and a plurality of activated carbon treatment tanks having activated carbon, and the plurality of activated carbon treatment tanks are provided in series with each other in the flow direction of the drainage. Wastewater treatment equipment characterized by that.
(3) A method for making a lithographic printing plate, wherein the lithographic printing plate is developed with a developer containing wastewater treated by the method of claim 1 or the apparatus of claim 2.

  According to the present invention, the wastewater discharged in the development process of the lithographic printing plate can be processed in a large amount in a short time by effectively using the activated carbon in the tank, so that the development cost can be reduced. Further, since it is possible to circulate and use the development wastewater, it is possible to reduce the amount of water required by the automatic developing machine for planographic printing plates.

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

  Hereinafter, the present invention will be described in detail.

  In the present invention, the wastewater to be treated is discharged in the step of developing the lithographic printing plate, and is discharged along with the development processing of the lithographic printing plate having a silicone layer, which has many steps using water in particular. An example is drainage.

  As the lithographic printing plate having a silicone rubber layer, one having at least a layer whose adhesive force changes with a layer adjacent to the substrate upon exposure and a layer mainly composed of silicone rubber is preferable. More specifically, waterless lithographic printing plate precursors described in JP-A-2005-309126 and JP-A-2000-47377 can be exemplified.

  Next, a method for making a lithographic printing plate having a silicone rubber layer will be described.

  In the case of negative lithographic printing plates where the exposed area is the image area and positive lithographic printing plates where the exposed area is the non-image area, the original image film is usually placed on the protective film and image exposure is performed with actinic rays. Then, after removing the protective film, an image can be formed by development. On the other hand, in the case of a direct drawing type lithographic printing plate, the image is exposed with a laser beam as it is or after the protective film is peeled off from the original plate having the protective film. 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.

  For example, plate making is performed by the apparatus shown in FIG.

  The apparatus shown in FIG. 1 includes an automatic processor 10 that performs the above development and a wastewater treatment apparatus 1 that is an embodiment of the present invention.

  The automatic processor 10 is not limited as long as it can develop a lithographic printing plate, but preferably, at least a pre-processing unit 11 that swells the silicone layer of the image line unit to facilitate development, and the image line A developing unit 12 that removes the silicone layer of the part with a brush, a post-processing unit 13 that dyes the image area and imparts plate inspection properties, and a water washing unit 14 that removes excess post-processing liquid are provided in this order. It is preferable to use a developing machine. Specific examples of the automatic developing machine include automatic developing machines 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.

  In the pre-processing unit 11 of the automatic developing machine, for example, a plate-making treatment liquid 2 which is a plate-making treatment liquid described in JP-A-2008-015065, that is, (i) 97% by weight of triethylene glycol, (2) poly 3% by weight of oxypropylenediamine ("Jefamine" (registered trademark) D-230 (manufactured by Mitsui Chemical Fine Co., Ltd.)) is added, water is added to the developing unit 12, and development is confirmed in the post-processing unit 13. As a dyeing solution for dyeing other than the silicone rubber layer, for example, the dyeing solution described in Example 3 of JP-A-9-34132, that is, (i) Crystal Violet (basic dye, Hodogaya Chemical Co., Ltd.) 0.10 parts by weight, (ii) Brilliant Basic Cyanine 6GH (basic dye, manufactured by Hodogaya Chemical Co., Ltd.) 0.40 parts by weight, (iii) Sinoline SO-35 (2-ethylhexyl sulfate) Acid sodium) 40% aqueous solution, anionic surfactant, Shin Nippon Rika Co., Ltd.) 5.00 parts by weight, (iv) butyl carbitol 10 parts by weight, (v) KS-502 (Shin-Etsu Chemical Co., Ltd.) (Production, antifoaming agent) 0.002 parts by weight, (vi) 84.498 parts by weight of pure water are added, and the washing unit 14 is filled with water for development.

  In the present invention, waste water discharged from such a developing unit and a water washing unit is processed by the waste water treatment apparatus 1. The waste water treatment device 1 includes a strainer 2, a waste water storage tank 3, a liquid feed first pump 4, an activated carbon treatment device group 5, a liquid feed second pump 6, and the like. The waste water treatment apparatus 1 is connected to an automatic processor 10, and after the waste water discharged from the developing unit and the water washing unit of the automatic processor 10 passes through the strainer 2, the solid content is removed and then temporarily stored in the waste water storage tank 3. It is configured to be stored.

  The type of piping connected from the automatic processor 10 to the waste water storage tank 3 is not limited, but the size is preferably 20A or more, for example, so that the waste water flows into the waste water storage tank 3 without flowing back. It is preferable. Preferably, the height of the inlet of the wastewater storage tank 3 is 10 mm or more higher than the height of the outlet pipe for drainage of the automatic processor. “20A” indicates the nominal diameter of the pipe. For example, in the case of hard polyvinyl chloride pipe for water supply described in JIS K 6742 (2007), 20A is a pipe having an outer diameter of 26.0 mm and a thickness of 3.0 mm. Indicates.

  The material and aperture of the strainer 2 are not limited, but are preferably 0.10 mm to 2.00 mm. Moreover, in order to suppress clogging, it is preferable to provide two or more strainers having different openings. Specific examples of the strainer 2 include a PVC Y-type strainer.

  The material and size of the drainage storage tank 3 are not limited, but for example, a 60 L tank made of FRP can be mentioned.

  The pump used for the liquid feeding first pump 4 is not limited, but the water in the drainage storage tank 3 can be circulated in a time during which one lithographic printing plate is processed by the automatic processor. It is preferable to select one that exceeds the speed. Specific examples include MD-30R manufactured by Iwaki Corporation.

  Further, the method for setting the start of operation of the pump is not limited, but it is also preferable to work with an automatic processor, for example. That is, it is also preferable that a signal is sent to the control panel 15 when the automatic developing machine starts to operate, and the control panel 15 operates the liquid feeding first pump 4 and the liquid feeding second pump 6.

  It is preferable to select a second liquid feed pump 6 that exceeds the amount of water used by the automatic processor. Specific examples include MD-15R manufactured by Iwaki Corporation.

  The activated carbon treatment device group 5 includes a plurality of activated carbon treatment tanks F connected in series. The lines of the plurality of activated carbon treatment tanks F connected in series may be a single row or a plurality of rows.

  The type of activated carbon stored in each activated carbon treatment tank F 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 raw 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. For example, coconut shell MOF-250C1 manufactured by Futamura Chemical Co., Ltd. may be mentioned.

  Each activated carbon treatment tank F preferably uses a thicker filter such as a 20 inch length type or MOF-BIG manufactured by Futamura Chemical to further increase the filter life. By doing so, the amount of improvement in capacity at the time of multi-stage increases, which is more preferable.

  The activated carbon treatment in the present invention does not include so-called biological activated carbon treatment in which microorganisms are grown on activated carbon to oxidatively decompose organic components.

  Moreover, it is preferable to install a flow rate adjusting valve at the inlet of the activated carbon treatment device group 5 and adjust the opening of the valve to extend the life of the activated carbon so that a certain amount of treated waste water flows out.

  In the apparatus shown in FIG. 1 configured as described above, plate making (development / drainage treatment) is performed, for example, as follows.

  When the automatic developing machine 10 starts operating, development is performed and the wastewater begins to be discharged, the first liquid feed pump 4 is automatically activated, and the wastewater stored in the wastewater storage tank 3 is activated carbon treatment apparatus group 5. Sent to. The wastewater sent to the activated carbon treatment apparatus group 5 is adsorbed in the activated carbon treatment tank F on the upstream side and then adsorbed in the activated carbon treatment tank F on the downstream side. In this way, the treated waste water from which the organic components have been adsorbed and removed is discharged from the activated carbon treatment device group 5 and returned to the waste water storage tank 3. The water stored in the drainage storage tank 3 is again put into the automatic processor a by the liquid supply second pump 6. By mixing the treated wastewater from which organic components have been removed by adsorption with the wastewater before the adsorption treatment, the circulation flow rate can be made larger than the amount of water supplied to the automatic processor 10, and while the automatic processor is not operating. There is an advantage that the adsorption performance can be improved by the adsorption treatment.

  In this way, in the present invention, the wastewater discharged in the development process of the lithographic printing plate is treated in multiple stages by a plurality of activated carbon treatment tanks provided in series with respect to the flow direction of the wastewater, so that the activated carbon in the tank is effectively used. Thus, the life of the activated carbon treatment tank can be extended, and organic components contained in a large amount of waste water can be adsorbed and removed in a short time without increasing the size of the apparatus. In addition, since it is possible to circulate and use the development wastewater, it is possible to reduce the amount of water required by an automatic developing machine for lithographic printing plates. As a result, development cost can be reduced, and a developed lithographic printing plate can be produced at low cost. Although the reason why the above effects can be obtained by multi-stage treatment is not certain, the activated carbon treatment tank can be used more evenly, so the life of the activated carbon treatment tank is extended, and the upstream side Since the wastewater whose organic substance concentration and the like are reliably reduced in the activated carbon treatment tank is treated in the downstream activated carbon treatment tank, it is considered that the adsorption function of the activated carbon on the downstream side functions more and the removal performance is improved.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these.
(Comparative Example 1)
As an automatic processor, a waterless lithographic printing plate automatic processor TWL-1160F (manufactured by Toray Industries, Inc.) is prepared, and MOF-250C1 (activated carbon treatment tank manufactured by Phutamura Chemical Co., Ltd.) is used as a device for treating waste water from the automatic processor. ) Was prepared, and these were connected. That is, in the apparatus shown in FIG. 1, the apparatus which comprised the activated carbon treatment tank F contained in the activated carbon treatment apparatus group was comprised. CP-Y (manufactured by Toray Industries Co., Ltd., waterless lithographic printing plate pretreatment solution) is placed in the pre-processing section of the automatic processor, water is used in the developing process section, and PA-F is used in the post-processing process section. (Toray Industries, Inc., post-development processing solution for waterless lithographic plate) was put in water in the washing step.

  Wrap and fix TAC-VG5 (manufactured by Toray Industries Co., Ltd., direct-drawing waterless flat plate) 800 mm long by 1030 mm wide around an image setter GX3940 (manufactured by Matsushita Electric Power System Co., Ltd.), 2400 dpi, 175 lines / inch, 175 mJ After outputting an image so that the image area was 50% at / cm 2, the protective film was peeled off from the plate. The plate from which the protective film has been peeled is passed through the automatic processor, the waste water discharged from the automatic processor is adsorbed by the circulating filtration device, and the total of 7L is again added to the developing unit and the washing unit of the automatic processor. The development process was carried out with the addition of / min. During this period, fresh water was not replenished to either the automatic developing machine or the circulating filtration device.

  We investigated the increase in the items related to the sewerage law in the wastewater storage tank 3 for each fixed version.

The regulation values for the items related to the Sewerage Law are as follows.
pH 5-9
BOD 600 ppm or less SS 600 ppm or less n-hexane extract (animal or vegetable oil) 5 ppm or less n-hexane extract (mineral oil) 30 ppm or less Iodine consumption 220 ppm or less.

On the other hand, the pH value exceeded the standard value of the sewerage system at the time when the 50th plate was continuously treated, and this value could be judged as the life of the activated carbon treatment tank this time. Moreover, the analysis value of the treated water at the time when the pH value exceeded the standard value of the sewerage law (at the end of the life of the activated carbon treatment tank) was as follows.
pH 9.1
BOD 27ppm
SS 9.5ppm
n-hexane extract (animal and vegetable oil) <0.5ppm
n-hexane extract (mineral oil) 0.67ppm
Iodine consumption 5.1ppm
The measuring method of each analytical value is shown below.
PH (hydrogen ion concentration): glass electrode method corresponding to JIS K0102-1998 12.1 BOD (biochemical oxygen demand): dilution method corresponding to JIS K0102-1998 21 modified winker sodium azide modified method
SS (Amount of suspended solids): Filtration method n-hexane extract content (mineral oil) corresponding to Environment Agency Notification No. 64: JIS K0102-1998 24.2 Reference II. Column chromatography method n-hexane extract content corresponding to 1 (animal and vegetable oil): JIS K0102-1998 24.2 Reference II. Column chromatography method corresponding to 2
Iodine consumption: A method that falls under Article 7 of the Sewerage Law Enforcement Ordinance.

(Comparative Example 2)
Except that the test was carried out without attaching any activated carbon treatment tank to the circulation filtration device, an experiment was conducted in the same manner as in Comparative Example 1 to confirm the number of continuously treated plates whose pH value reached the sewer standard value. The results are shown in Table 1.

Example 1
An experiment was conducted to confirm the number of continuously treated plates in which the pH value reached the sewage standard value in the same manner as in Comparative Example 1 except that three MOF-250C1s were attached in series to the circulation filter. The results are shown in Table 1. Despite processing at a flow rate of 7 L / min, the number of activated carbon treatment tanks reached 200 was 200.

(Example 2)
An experiment was conducted to confirm the number of continuously treated plates in which the pH value reached the sewage standard value in the same manner as in Comparative Example 1 except that five MOF-250C1s were attached in series to the circulation filter. The results are shown in Table 1. Despite processing at a flow rate of 7 L / min, the number of activated carbon treatment tanks reaching the end of life was 450.

(Comparative Example 3)
Confirmed the number of continuous treatment plates in which the pH value reached the sewage standard value in the same manner as in Comparative Example 1 except that one MOF-BIG10M containing three times the amount of activated carbon compared to MOF-250C1 was installed in the circulating filter. An experiment was conducted. The results are shown in Table 1.

(Example 3)
The number of continuously treated plates in which the pH value reaches the sewage standard value in the same manner as in Comparative Example 1 except that two MOF-BIG10M containing three times the amount of activated carbon in MOF-250C1 are attached in series to the circulating filter. An experiment was conducted to confirm the above. The results are shown in Table 1. Despite processing at a flow rate of 7 L / min, the number of activated carbon treatment tanks reaching the end of life was 500.

Example 4
The number of continuously treated plates in which the pH value reaches the sewer standard value in the same manner as in Comparative Example 1 except that three MOF-BIG10M containing three times the amount of activated carbon in MOF-250C1 are installed in series in the circulating filter. An experiment was conducted to confirm the above. The results are shown in Table 1. Despite processing at a flow rate of 7 L / min, the number of activated carbon treatment tanks reaching the life was 840.

  It can be suitably used for the treatment of wastewater discharged from an automatic developing device for lithographic printing plates.

1: Waste water treatment device 2: Strainer 3: Waste water storage tank 4: Liquid feed first pump 5: Activated carbon treatment device group 6: Liquid feed second pump 10: Automatic processor 11: Pre-processing unit 12: Development unit 13: Rear Processing unit 14: Washing unit 15: Control panel

Claims (3)

  A wastewater treatment method, wherein the wastewater discharged in the step of developing a lithographic printing plate is subjected to an adsorption treatment in an activated carbon treatment tank and further subjected to an adsorption treatment in another activated carbon treatment tank.   It has a flow path of drainage discharged in the process of developing a lithographic printing plate and a plurality of activated carbon treatment tanks having activated carbon, and the plurality of activated carbon treatment tanks are provided in series with each other with respect to the flow direction of drainage. Wastewater treatment equipment characterized by.   A lithographic printing plate making method comprising developing the lithographic printing plate using waste water treated by the method of claim 1 or the apparatus of claim 2.

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