JP2012154994A - Treatment method of development wastewater in color filter manufacturing process - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a treatment method of color filter development wastewater which can process color filter development wastewater with excellent flocculation filterability and operation stability.SOLUTION: A treatment method of development wastewater in a color filter manufacturing process includes a heating step of heating the development wastewater to be 50°C or higher and a pH adjustment step of adjusting pH of the development wastewater to be 7 or lower, in which the development wastewater is subjected to solid-liquid separation in the state of heating and pH adjustment.

Description

  The present invention relates to a method for treating development waste water in a color filter manufacturing process.

Conventionally, in the production of color filters, a pattern forming method by photolithography of a resist in which a pigment is dispersed, that is, a color resist method is known.
In developing a color resist in the color filter manufacturing process, a color resist solution containing a pigment, an alkali-soluble resin (alkali-soluble polymer), a photopolymerization component (monomer), a photopolymerization initiator, a dispersant, a solvent and the like is generally used. It is used.
For example, after forming a black matrix (BM) on a substrate, this color resist solution (for example, red) is applied on the substrate on which the BM is formed to form a film; pattern exposure through a photomask and UV curing Exposure process; removing unnecessary portions of the color resist with a developer, and then performing film formation, exposure, development, and baking processes such as development and baking processes that are cured by baking, and color resist liquids of other colors In general, this process is repeatedly performed using three colors to finally form RGB three colors, and a transparent conductive (ITO) film is formed by a sputtering method to produce a color filter (for example, non-patent literature). 1).
In addition to the method of forming a pattern by etching by vapor deposition of chromium on a glass substrate, BM includes a method of forming a BM pattern by photolithography with a resist solution using a black pigment as in the case of a color resist. Further, in addition to the RGB three colors, RGBY four-color filters for improving the performance by expanding the color gamut have been put to practical use, and there are also CMY-based color separation filters.
In any case, during these development steps, the unexposed color resist (uncured color resist) is developed by a developer mainly composed of a high concentration nonionic surfactant and an alkali component. Washed away. That is, at this time, color filter developing waste water mainly containing uncured color resist and developer is generated.

By the way, as a conventional color filter developing wastewater treatment method, for example, a coagulation-precipitation method or an activated carbon method may be mentioned.
Further, a method has been proposed in which cleaning wastewater containing tetraalkylammonium and a small amount of photoresist after substrate cleaning in a photolithography method is pressurized and supplied to a reverse osmosis membrane device under conditions of pH 5 or more and less than 9. (Patent Document 4).
In addition, a method is proposed in which the pH of the photoresist-containing wastewater is adjusted to acidity, and then adjusted to be alkaline and then neutral so as to be suitable for photoresist coagulation and precipitation, and the photoresist is coagulated and precipitated to perform film treatment. (Patent Document 5)

JP 2009-128518 A JP 2010-102346 A JP 2008-246372 A JP 2001-276824 A JP 2006-255668 A

State-of-the-art color filter process technology and chemicals, supervised by: Kunihiro Ichimura, CMC Publishing Co., Ltd., April 1, 2006, 2nd edition, p1-300

The development wastewater of the color filter is rich in pigments derived from color resists and various compounds, and surfactants derived from the developer. For this reason, the development wastewater contains pigments (chromaticity, turbidity, appearance), surfactants, and organic substances derived from the color resist in a very high concentration.
In order to reduce these concentrations for the purpose of discharging and collecting the development waste water of the color filter, the color components by the coagulation sedimentation treatment and the organic matter removal by the activated carbon treatment are performed.
However, since the dispersibility of the pigment is very high, it is difficult to perform the coagulation precipitation treatment (see Examples [Table 6] described later). In addition, the consumption of activated carbon is severe due to the high surfactant concentration. As a result, there is a problem that economy is under pressure and driving stability is poor.
Further, in membrane filtration methods such as reverse osmosis membranes and NF membranes, when the above pigment treatment and surfactant treatment are insufficient, membrane clogging occurs, and stable operation cannot be realized.

  Therefore, an object of the present invention is to provide a treatment capable of separating and removing a color resist and a surfactant from a color filter developing waste water and improving operational stability and economy.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have conducted a post-separation process if solid-liquid separation is performed with the color filter developing wastewater heated to a specific temperature or higher and adjusted to pH 7 or lower. It has been found that not only the color resist in water can be reduced, but also the surfactant and alkali-soluble polymer contained in the color filter developing waste water before processing can be reduced.

  That is, the present invention is a processing method of developing wastewater in a color filter manufacturing process, a heating step of heating the developing wastewater to 50 ° C. or higher, and a pH adjusting step of adjusting the pH of the developing wastewater to 7 or lower. And a developing wastewater treatment method, wherein the development wastewater is subjected to solid-liquid separation in a heated and pH-adjusted state.

It is preferable that the developing wastewater is heated to 60 to 100 ° C. in the warming step and / or the pH of the developing wastewater is made 2 to 6 acidic in the pH adjusting step.
It is preferable to use a coagulant together.
It is preferable to recover the heat of the heated treatment water after the solid-liquid separation and reuse it for heating the development waste water in the heating step.

  According to the present invention, the color filter developing waste water can be processed with good aggregation filterability and operation stability.

It is the flowcharts 1 and 2 which show the processing method of the color filter development waste_water | drain of this invention. 4 is a flowchart 3 and 4 showing a method for treating color filter developing waste water according to the present invention. It is the flowcharts 5 and 6 which show the processing method of the color filter development waste_water | drain of this invention. It is the flowchart 7 which shows the processing method of the color filter image development waste_water | drain of this invention. The color filter developing wastewater is adjusted to pH and heated. The state of the color filter developing waste water with respect to pH adjustment is shown.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments for carrying out the invention will be described with reference to the drawings. In addition, embodiment described below shows an example of typical embodiment of this invention, and, thereby, the range of this invention is not interpreted narrowly.

The processing method of the development wastewater (hereinafter referred to as “color filter development wastewater” or “development wastewater”) in the color filter manufacturing process of the present invention includes a heating step for heating the color filter development wastewater to 50 ° C. or higher, and a color filter. And a pH adjusting step for adjusting the pH of the developing wastewater to 7 or less, and solid-liquid separation is performed in a state of heating and pH adjustment. This makes it possible to obtain treated water with reduced color resist, surfactant, and the like.
At this time, the order of the heating step and the pH adjustment step (hereinafter, also referred to as “acidification treatment step”) is not particularly limited, and either may be first or may be simultaneous. . For example, a heating step, then a pH adjustment step; a pH adjustment step, then a heating step; a pH adjustment and a heating step, etc. In addition to these steps, other steps may be included as appropriate, and other steps may be included between these steps.

In the heating step, the color filter developing waste water is heated to 50 ° C. or higher.
As shown in [Examples] below, when the temperature is lower than 50 ° C., the color resist and the surfactant (especially nonionic surfactant) are not co-precipitated even when the acid treatment is performed. Cannot be reduced. On the other hand, if it is 50 degreeC or more, since these coprecipitation becomes possible, it is suitable.
The heating temperature of the development waste water is preferably 50 to 100 ° C, more preferably 60 to 99 ° C, still more preferably 70 to 95 ° C, and particularly preferably 80 to 85 ° C. More preferable in terms of economy and performance stabilization.
Although the heating time at this time is not particularly limited, it is preferably about 1 minute or more, but depending on the properties of the drainage, it may be a reaction in the pipe of about several seconds (3 to 10 seconds). And after heating development waste_water | drain, it is suitable to improve a coagulation filterability and driving | operation stability to maintain a heating state until solid-liquid separation.

The heating means in the heating step is not particularly limited, and for example, a heating device such as a heat exchanger or a heater may be used alone or in combination as appropriate.
The heating method at this time is not particularly limited, and the development wastewater may be heated directly and / or indirectly. For example, mixing steam (saturated water vapor, superheated steam, etc.) directly into development wastewater; placing a heater directly in development wastewater; passing development wastewater through a heat exchanger; in piping through which development wastewater passes Directly mixing steam; heating the outside of the pipe through which the development wastewater passes; electromagnetically heating the development wastewater. In addition, you may stir suitably so that a precipitate may arise easily from development waste_water | drain.

  When heating the development wastewater, it is preferable to recover and reuse the heat from the treated water after the solid-liquid separation because it is possible to reduce the cost and simultaneously cool the treated water. is there. Then, the heated developing waste water after the heat exchange may be further heated as necessary to the above-mentioned specific heating temperature. As an example of this heat exchange step, heated treated water is passed through a heat exchange system, heat is recovered from the treated water, the treated water is cooled, and the recovered heat is reused for heating the development waste water, etc. Is mentioned.

  In addition, it is suitable that the temperature of the development waste water from the heating treatment to the solid-liquid separation step is within the above-mentioned specific heating temperature range. The heating temperature at this time is preferably 75 to 90 ° C. in terms of performance stability.

In the pH adjustment step (acidification treatment step), the color filter developing waste water is adjusted in the acidic direction to adjust to pH 7 or less. When the pH is in the alkaline region of 8 or more, the color resist and the surfactant (especially nonionic surfactant) do not co-precipitate even if the above-described heating step is performed, and these should be sufficiently reduced. I can't. The pH range is preferably an acidic region, more preferably less than 1 to 7, more preferably 1 to 6, still more preferably 2 to 6, particularly 4 to 5.5. Is more preferable.
The acid used for the acidification treatment is not particularly limited, and may be one or more selected from inorganic acids such as sulfuric acid and hydrochloric acid; and organic acids such as acetic acid and phosphoric acid. In addition, you may adjust pH so that it may become in the above-mentioned range with alkalis, such as sodium hydroxide, suitably.
The treatment time for pH adjustment at this time is not particularly limited, but is preferably about 3 minutes or more for stabilizing the performance. After acidifying the development wastewater, the acidic state is maintained until solid-liquid separation. It is preferable to improve the aggregation filterability and the operational stability.

  The acidification means is not particularly limited, and examples thereof include a batch type and a continuous type. Also, in order to mix the development wastewater and the acid so that they easily react, for example, a pipe is connected so that the acid is mixed in the pipe through which the development wastewater passes; the development wastewater and the acid are easy to mix. A reaction system having an apparatus for adding acid to the pooled development wastewater and stirring; adjusting pH in two or more stages so that the pH is stabilized; and the like.

  In addition, it is preferable that the pH of the development waste water after the acidification treatment until the solid-liquid separation step is within the specific pH range (pH 7 or less) as described above. The pH at this time is preferably 4 to 5.5 from the viewpoint of reducing the amount of drug added.

In the solid-liquid separation step, the solid-liquid separation from the development wastewater into the concentrated water and the treated water is performed in a state of heating and pH adjustment. This state means that the temperature is adjusted within the specific temperature range and the specific pH range as described above.
Here, the concentrated water refers to water in which the color resist and surfactant precipitates are concentrated, and the treated water refers to water in which these unnecessary substances are reduced.
In addition, a solid-liquid separation means is not specifically limited, Membrane separation, a filter, centrifugation, pressurization floating separation, sedimentation separation, etc. are mentioned.

Further, in the solid-liquid separation step, treated water that satisfies water quality standards other than pH and temperature and has reduced color resist and the like can be discharged after pH and temperature adjustment. When the water quality standard is not satisfied or when harmful substances are further removed, other processing steps may be performed as appropriate.
For example, when the treated water before discharge is in a heated state, it is preferable to cool it. As the cooling means, for example, it may be allowed to cool, but it is preferable to cool by providing a heat exchange system that collects and reuses heat so that heat can be exchanged with the developing waste liquid heated in the heating step. .
In addition, when the treated water before discharge is in an acidic state, the pH region satisfies the water quality standard with an alkali such as an alkali metal salt such as potassium hydroxide or sodium hydroxide or an alkaline earth metal salt such as calcium hydroxide. For example, it is preferable to adjust near neutral.

  Depending on the final purpose of the treatment of the color filter developing waste water of the present invention, ultraviolet irradiation, ozone treatment, biological treatment (for example, activated sludge method), coagulation sedimentation or flotation treatment, reverse osmosis membrane treatment, activated carbon treatment, ion exchange treatment, electricity Desalination treatment, adsorbent treatment, etc. may be used in combination.

  Furthermore, it is preferable to add a flocculant to the above-mentioned development waste water in the processing step of the development waste water of the present invention. For example, a coagulant or a coagulant may be used as an optional component. Furthermore, you may add a disinfectant, a deodorant, an antifoamer, an anticorrosive, etc. as needed.

Use of the aggregating agent in combination is preferable because the effect of the present invention is increased.
The timing for adding the flocculant may be any of the above-described steps, and may be between steps or before and after the steps. As an example, it may be before or after the heating step or the pH adjustment step, or during the adjustment.

The flocculant is not particularly limited, and any of inorganic and / or organic flocculants may be used.
Examples of the inorganic flocculant include aluminum salts such as sulfuric acid band and polyaluminum chloride; iron salts such as ferric chloride and ferrous sulfate. These may be used alone or in combination.
Moreover, there is no restriction | limiting in particular in the addition amount of an inorganic flocculant, What is necessary is just to adjust according to the property of the said development waste_water | drain, However, 1-500 mg / L is suitable with respect to the said development waste_water | drain generally in aluminum or iron conversion. is there.
Further, as the organic flocculant, a polymer organic flocculant is preferable, and the use of the polymer organic flocculant increases the aggregation block, and thus the treatment efficiency is often increased. There is no limitation in particular in the kind of this polymeric organic flocculant, What is necessary is just what is normally used by water treatment. Examples of the polymer organic flocculant include anionic polymer flocculants such as poly (meth) acrylic acid, copolymers of (meth) acrylic acid and (meth) acrylamide, and alkali metal salts thereof; Nonionic polymer flocculants such as (meth) acrylamide are listed.
Moreover, there is no restriction | limiting in particular in the addition amount of an organic coagulant | flocculant, What is necessary is just to adjust in the property of to-be-processed water, but 0.01-10 mg / L is generally solid with respect to to-be-processed water.

It is suitable to use the flocculant, preferably an organic flocculant in combination. The organic flocculant is not particularly limited. For example, a polymer having a quaternary ammonium salt of polyethyleneimine, ethylenediamine epichlorohydrin polycondensate, polyalkylene polyamine, diallyldimethylammonium chloride or dimethylaminoethyl (meth) acrylate as a constituent monomer. Etc .; Cationic organic polymers usually used in water treatment and the like. These can be used alone or in combination.
Moreover, there is no restriction | limiting in particular in the addition amount of an organic flocculant, What is necessary is just to adjust according to the property of development waste_water | drain, However, 0.01-10 mg / L in solid content with respect to development waste_water | drain is suitable in general.

Here, the development wastewater in the color filter manufacturing process is a pigment, an alkali-soluble resin (alkali-soluble polymer), a photopolymerization component (curable monomer), a photopolymerization initiator (start) used in the color filter manufacturing process. Agent), a surfactant and a solvent, a developer, and the like. This development waste water may contain a cured resist component and the like. In general, most of the solvent used in the color resist solution evaporates in a pre-bake process before resist application and development.
Specific examples include waste water from a color filter manufacturing apparatus, a color filter manufacturing line, a developing apparatus used in the color filter manufacturing process, the line, and the like.
For example, the color filter developing waste water by the pigment dispersion method (preferably a photolithography method using a color resist) includes a color resist solution component and a waste solution mainly containing a developing solution. Specifically, after the color resist is applied, the unexposed portion includes a developer peeling waste water and the like, which are washed away with a developer mainly containing a nonionic surfactant as a main component and an alkali component at a high concentration. It is.

As the water quality of normal color filter development waste water, it is general that alkali components (NaOH, KOH, etc.) have a high concentration. As the surfactant, nonionicity is mainly contained, and other cationicity, anionicity and amphotericity are generally contained as required. Examples of this surfactant are surfactants mainly used in developers, such as polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, oxyethylene-oxypropylene block copolymer, polyoxyethylene fatty acid. Examples thereof include esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene styrenated phenyl ether, polyoxyethylene distyrenated phenyl ether, polyoxyethylene tristyrenated phenyl ether, and the like. As metals, it is common that copper, nickel, zinc, etc. are contained as an organic compound.
Examples of the general water quality of the color filter developing waste water include those shown in Table 1.

The components of the color resist solution are designed so that the pigment component (mainly organic pigment) has an affinity with an alkali-soluble polymer (a binder resin or a polymer dispersant mixed with this). In addition to these, the components of the color resist liquid are composed of a dispersant (an anionic dispersion polymer, etc.), a curable polymer (an oligomer or a polymer and an initiator for fixing a pigment), a solvent as a solvent, and the like. ing.
This color resist solution can be obtained by a known method (for example, see Non-Patent Document 1). As an example, in a process of blending a pigment, a dispersant and a solvent, pulverizing the pigment into small particles, and a process of preparing a resist solution by mixing photosensitive components such as an alkali-soluble polymer, a monomer and an initiator. And get it.
In addition, although the compounding quantity (mass%) of each component in a color resist liquid is suitably changed with the desired color filter, the general compounding quantity is 2-8 mass% of pigment, alkali-soluble polymer 3 7 mass%, dispersant 0.5-3 mass%, monomer 2-6 mass%, initiator 0.1-4 mass%, solvent 70-85 mass% (residue) (for example, see Non-Patent Document 1) ).

The pigment component is not particularly limited as long as it is generally used in the color filter manufacturing process. Typically, a black pigment and a chromatic pigment are used, and these are appropriately used as an organic pigment and an inorganic pigment. Chosen from.
The black pigment is mainly used in a resin black matrix, and examples thereof include carbon black, aniline black, anthraquinone black pigment, perylene black pigment, and titanium black. The particle size of the black pigment is 200 nm or less, more preferably 3 to 100 nm.
The chromatic pigments are, for example, main color pigments of red (R), green (G), and blue (B) for RGB filters and indigo (C), red (M), and yellow (Y) for CMY filters. It is used as an auxiliary pigment for correcting the target chromaticity as required. Organic pigments are often used for these, and typical pigment components include, for example, azo lakes, insoluble azos, condensed azos, phthalocyanines, quinacridones, dioxazines, isoindolinones, anthraquinones, perinones, A thioindigo type, a perylene type, etc. are mentioned, and 1 type or 2 types or more are selected for each color.
For example, diketopyrrolopyrrole (PR254), anthraquinone (PR177), etc. as red (R) main color pigments, and chlorinated copper phthalocyanine (PG7) or bromine as green (G) main color pigments. Zinc phthalocyanine (PG58) and the like, and blue (B) main color pigments include ε-type copper phthalocyanine (PB15: 6) and the like, and yellow such as isoindoline (PY139) and nickel complex (PY150). Pigments; secondary pigments such as purple pigments such as dioxazine (PV23) and the like.
The particle size of the organic pigment is preferably 100 nm or less, more preferably 10 to 60 nm.

The dispersant is not particularly limited as long as it is generally used in the color filter manufacturing process, and a dispersant that can control the pigment particle size to 0.1 μm or less and can stabilize the dispersion is generally used. ing.
Examples of the dispersant include an anionic dispersant, a cationic dispersant, a nonionic dispersant, and the like. Specifically, a polyoxyethylene alkylphenyl ether type; a polyethylene glycol diester type; a sorbitan fatty acid ester type Fatty acid-modified polyester series; tertiary amine-modified polyurethane series; (low / high molecular weight) active pigment derivatives and the like.
More specifically, one or two or more selected from the following can be mentioned.
Examples of the anionic dispersant include styrene / maleic anhydride copolymer, naphthalene sulfonate formalin condensate, polyacrylate, carboxymethyl cellulose, olefin / maleic anhydride copolymer, polystyrene sulfonate, Examples include acrylamide / acrylic acid copolymer and sodium alginate.
Examples of the nonionic dispersant include polyvinyl alcohol, polyoxyethylene alkyl ether, polyoxypropylene / polyoxyethylene block (pluronic dispersant), and polymer starch.
Examples of the cationic dispersant include polyethyleneimine, aminoalkyl (meth) acrylate copolymer, polyvinyl imidazoline, satkinsan (chitosan), polyalkylene polyamine, and polyacrylamide.

The alkali-soluble polymer is not particularly limited as long as it is generally used in the color filter manufacturing process, and it binds pigment particles in the color resist or fixes the developed resist film to the substrate. I just need it.
Examples of the alkali-soluble polymer include copolymer acrylic type such as (meth) acrylic acid and (meth) acrylic acid ester, polyimide type, cardo type and the like. Usually, a copolymer such as (meth) acrylic acid or (meth) acrylic acid ester has a basic structure, and a carboxy group-containing acrylic resin obtained by copolymerizing (meth) acrylic acid or the like with (meth) acrylic acid or the like is used. Is preferred.
As specific examples, (meth) acrylic acid / benzyl (meth) acrylate copolymer, (meth) acrylic acid / benzyl (meth) acrylate / styrene copolymer, (meth) acrylic acid / methyl (meth) acrylate One type or two or more types selected from a copolymer, a (meth) acrylic acid / methyl (meth) acrylate / styrene copolymer, and the like can be given.
The molecular weight is preferably from 5,000 to 100,000, and the acid value of the resin is preferably from 60 to 150 mgKOH / g.

The curable monomer (one that is polymerized by decomposition of the initiator by UV exposure to form a polymer (resin)) is not particularly limited as long as it is generally used in the color filter manufacturing process.
Examples of the curable monomer include acrylic acid, methacrylic acid, acrylic ester, methacrylic ester, polyacrylic acid, novolac phenol epoxy resin, novolac cresol epoxy resin, and polyfunctional polyester acrylate. 1 type or 2 types or more selected from polyimide, polyvinyl alcohol, polyfunctional polyol acrylate, polyfunctional urethane acrylate, etc. Among them, it is preferable to use a monomer having a polyfunctional group. .

Examples of the initiator include one or more compounds selected from acetophenone, benzoin, benzophenone, triazine, imidazole, oxime, and the like.
Specific examples thereof include 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2-methyl-1-[[(methylthio) phenyl] -2. -Monfosonoprothrin-1, 2-benzyl-2-dimethylamino-1- (4-monoforiphenyl) -butanone-1, etc., are selected from one or more.
Moreover, you may contain a silane coupling agent etc. as a sensitizer and adhesion | attachment adjuvant.

  The solvent is not particularly limited as long as it is generally used in the color filter manufacturing process, and typical solvents include propylene glycol monomethyl ether acetate (PGMEA), methyl 3-methoxypropionate ( MMP), ethyl lactate (EL), n-butyl acetate (NBA), ethyl 3-ethoxypropionate (EEP) and the like. Other solvents include diethylene dimethyl ether, ethyl 3-ethoxypropionate, benzyl alcohol and the like. In general, most of these solvents evaporate in a pre-bake process before resist application and development.

The developer is an alkaline aqueous solution (pH 8 to 14, preferably pH 10 to 13) for removing unnecessary portions of the color resist (uncured color resist component) or washing the substrate in the development step. It will not be specifically limited if it is generally used in the color filter manufacturing process.
Developers are alkali metal salts such as sodium carbonate, sodium hydroxide and potassium hydroxide; alkaline earth metal salts such as calcium carbonate; amines such as tetraammonium hydroxide, N, N-dimethylbenzylamine and triethanolamine It is an aqueous solution containing one or more inorganic and / or organic alkali components selected from the above, an antifoaming agent, a surfactant and the like as appropriate. Examples of the surfactant include polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, oxyethylene-oxypropylene block copolymer, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene Examples thereof include styrenated phenyl ether, polyoxyethylene distyrenated phenyl ether, polyoxyethylene tristyrenated phenyl ether, and the like.

  An embodiment of the color filter developing wastewater treatment method of the present invention will be described below with reference to FIGS. 1 to 4 (flows 1 to 7). In addition, embodiment described below shows an example of typical embodiment of this invention, and, thereby, the range of this invention is not interpreted narrowly.

<Flow 1>
Development waste water (20 to 30 ° C.) is transferred to a heat exchange system (heat exchange) and heated (preferably about 60 to 75 ° C.). The heated development waste water is further heated to 50 ° C. or higher (preferably 70 to 95 ° C., more preferably 80 to 85 ° C.) in a heating system (heating) as necessary. At this time, in the heating system, the development wastewater may be heated by spraying water vapor (about 100 ° C.) into the development wastewater. Furthermore, the heated development wastewater is a neutral to acidic region (pH 7 or less, preferably less than pH 7, more preferably 1 to 6, more preferably 2 to 2) in the reaction system (reaction) while acid is added. 6) is adjusted. At this time, the reaction system is maintained at 50 ° C. or higher (preferably 70 to 95 ° C., more preferably 80 to 85 ° C.). The reaction here may be in the reactor or in the reaction tube. The development wastewater in a specific warming and neutral to acidic (preferably acidic) state is reduced in concentrated water containing precipitates such as color resists and surfactants in a solid-liquid separation system. Separated into treated water. The concentrated water is transferred to the concentrate storage.
Since the treated water has a temperature of 50 ° C. or higher (preferably 70 to 95 ° C., particularly 80 to 85 ° C.), it is transferred to a heat exchange system where the heat is recovered and cooled and transferred there. Reuse heat to the developed wastewater to heat the wastewater.
Further, when the heat exchange system is not provided or when the heat treatment water is not transferred from the solid-liquid separation, the development wastewater transferred by the heating system is heated. For this reason, it is desirable to arrange a heat exchange system in front of the heater and reuse the heat of the treated water.

<Flow 2>
Portions overlapping with the flow 1 described above are omitted as appropriate.
The development wastewater is transferred to the reaction system while acid is added. It is adjusted so as to be in a specific neutral to acidic region in the reaction system. The developing wastewater that has become neutral to acidic in this way is heated to 50 ° C. or higher in a heat exchange system and then in a heating system. Then, the developing wastewater in a heated and neutral to acidic state is solid-liquid separated into concentrated water containing precipitates and treated water in a solid-liquid separation system. Since the treated water has a temperature of 50 ° C. or higher, it is transferred to a heat exchange system where it is cooled and warms the development waste water.

<Flow 3>
Portions overlapping with the flow 1 described above are omitted as appropriate.
The development wastewater passes through a heat exchange system, a heating system, and a reaction system, and is separated into solid-liquid separation 1 in solid-liquid separation 1 in a specific heating and neutral to acidic state, and into concentrated water 1 and treated water 1 containing precipitates. To be separated. Since this treated water 1 has a temperature of 50 ° C. or higher, it is transferred to a heat exchange system, where it is cooled and warms the development waste water. Moreover, in order to maintain the concentrated water 1 containing the precipitate concentrated in the solid-liquid separation 1 in a specific warming state, the temperature loss is reheated with steam, and the neutral to acidic state is maintained. Solid-liquid separation is further performed in solid-liquid separation 2 to separate into concentrated water 2 and treated water 2 containing precipitates such as a color resist and a surfactant. Since this treated water 2 is heated, it may be used for heat conversion. Moreover, as an example, the treated water 2 may be merged with the treated water 1 and transferred to the heat exchange system.

<Flow 4>
Portions overlapping with the flow 1 described above are omitted as appropriate.
The development wastewater goes through a heat exchange system, a heating system, and a reaction system. Add flocculant before solid-liquid separation. The development wastewater in a specific warming and acidic state containing the flocculant is separated into solid and liquid by a solid-liquid separation system and separated into concentrated water and treated water containing precipitates.

<Flow 5>
Portions overlapping with the flow 1 described above are omitted as appropriate.
The development waste water is separated into concentrated water containing precipitates and treated water through a heat exchange system, a heating system, a reaction system, and a solid-liquid separation system. A flocculant is added to the concentrated water, and a precipitate containing a color resist and a surfactant is recovered. At this time, the concentrated solution may be in a specific warming and neutral to acidic state, and the temperature and pH may be appropriately adjusted according to the substance to be removed. For example, in the case of removing heavy metals, the alkali region is adjusted.

<Flow 6>
Portions overlapping with the flow 1 described above are omitted as appropriate.
The development waste water is separated into concentrated water and treated water containing precipitates through a heat exchange system, a heating system, a reaction system, and solid-liquid separation. Steam is added to this concentrated water, and the concentrated water is made into a specific warming and neutral to acidic state, and a precipitate containing a color resist, a surfactant and the like is collected.

<Flow 7>
Portions overlapping with the flow 1 described above are omitted as appropriate.
The development waste water is separated into concentrated water containing precipitates and treated water 1 through a heat exchange system, a heating system, a reaction system, and solid-liquid separation. The treated water 1 is further discharged as treated water 2 through a biological treatment system. In this biological treatment system, biological treatment (activated sludge method), agglomeration / precipitation system, filtration system, and activated carbon system are arranged. In addition to the treated water 1, scrubber waste water, washing waste water, and the like may be transferred to this biological treatment system for treatment.
Further, the treated water 1 may be those of the above-described flows 2 to 6, and may be any one that has been treated by the treatment method of the present invention. In addition, water may be recovered by applying a reverse osmosis membrane to the treated water 2.

The molecular weight of the resin may be measured with a high temperature GPC apparatus.
The acid value of the resin may be determined based on “JIS K 2501-2003 Petroleum products and lubricants—Neutralization test method”.
A sample is dissolved in a titration solvent in which xylene and dimethylformamide (1 + 1) are mixed, and titrated with a 0.1 mol / L potassium hydroxide / ethanol solution by potentiometric titration, and the inflection point on the titration curve is set as the end point. The acid value is calculated from the titration amount until the end point of the potassium hydroxide solution.

The water quality may be measured by a known measurement method (JIS, sewage test method, clean water test method), and examples thereof include the following measurement methods.
Electrical conductivity: JIS-K0102.13, pH: JIS-K-0102.12.1, TOC: JIS-K-0102.22.1, Turbidity: JIS-K-01019.2, Interface These measurements are performed according to Activator: JIS-K0102.30.3.2.1, Metals: JIS-K0102.
About MFF value, it filtered using 5A filter paper (made by Advantech), then filtered using a Millipore filter (pore diameter: 0.45 μm, manufactured by Japan Millipore), and filtered time and filtered time (filtered). Start-500 mL filtration time: T1,500 mL filtration time-1000 mL filtration time: T2) is measured. From the filtration time by this filter, the Micro Filter Function (MFF) value (T2 / T1) is calculated. The MFF value is an index indicating the presence or absence of a substance that occludes a 0.45 μm film.

  Specific examples will be described below, but the present invention is not limited thereto.

[Aggregation test]
A 500 mL beaker containing 500 mL of color filter drainage raw water (also referred to as “raw water”) was set on a stirrer base equipped with a heating heater, and the test was performed as follows.

[Examples 1-3 and Comparative Examples 1-3]
Example 1
After setting, the mixture is stirred at 150 rpm, adjusted to pH 5 by adding sulfuric acid, heated to 80 ° C., kept at 80 ° C. for about 3 minutes, and then the heated solution (pH 5 and about 80 ° C.) is No5A. The TOC and turbidity of the filtrate which was filtered with a filter paper (Advantech) and allowed to cool to about room temperature were measured.

The “color filter drainage raw water” of this agglomeration test is a developer containing a high concentration of a surfactant mainly composed of a nonionic surfactant and an alkali component after coating a color resist. The washed off developer release effluent was used.
The raw water quality was as shown in Table 2.

Example 2
The procedure was the same as in Example 1 except that the pH was adjusted to 7.
Example 3
After adjustment to pH 7, except that further _Na 2 SO ₄ was added salts to be 0.4 mol / L, it was made in the same manner as in Example 1.
Comparative Example 1
The procedure was the same as in Example 1 except that the pH was adjusted to 12.
Comparative Example 2
After adjusting to pH 5, it heated up to 40 degreeC, hold | maintained at 40 degreeC for 3 minute (s), and performed like Example 1 except filtering the solution of the heating state about 40 degreeC.
Comparative Example 3
After adjusting the pH to 5, it was carried out in the same manner as in Example 1 except that the solution was filtered without heating.

  Table 3 shows the results of Examples 1 to 3 and Comparative Examples 1 to 3.

[Comparative Examples 4 to 7]
Moreover, after adjusting the pH of raw | natural water to 5, 7, 9, and 11.5, respectively, it carried out like Example 1 except not heating, but filtering the solution (respectively Comparative Examples 4- 7).

[Examples 4 to 6 and Comparative Examples 8 to 11]
Example 4
The same procedure as in Example 1 was performed except that the pH of the raw water was adjusted to 3.
Example 5
The same operation as in Example 1 was performed.
Example 6
After adjusting to pH 5, it heated up to 60 degreeC, hold | maintained at 60 degreeC for 3 minute (s), and performed like Example 1 except filtering the solution of the heating state about 60 degreeC.
Comparative Example 8
After adjusting to pH 5 and heating to 80 ° C., maintaining for 3 minutes, further cooling to 25 ° C., and performing the same procedure as in Example 1 except that the cooled product was filtered.
Comparative Example 9
After adjusting the pH of the raw water to 7, it was heated to 80 ° C., maintained for 3 minutes, cooled to 25 ° C., and this cooled product was filtered in the same manner as in Example 1.
Comparative Example 10
The same procedure as in Example 1 was performed except that the pH of the raw water was adjusted to 12.
Comparative Example 11
After adjusting the pH of the raw water to 12, it was heated to 80 ° C., maintained for 3 minutes, cooled to 25 ° C., and this cooled product was filtered in the same manner as in Example 1.
Table 5 shows the results of Examples 4 to 6 and Comparative Examples 8 to 11.

[Comparative Example 12]
An organic flocculant of polydiallyldimethylammonium chloride (P-DADMAC; molecular weight 750,000) was added to the color filter wastewater of Example 1 and stirred at 25 ° C. and pH 12 at 150 rpm for 90 seconds, and then the floc diameter and supernatant turbidity ( NTU). The results are shown in Table 6.

As described above, only the aggregation filtration by adding the flocculant (see Table 6), the pH adjustment only (see FIG. 6), and the heating only (see Table 5, Comparative Examples 10 and 11) with respect to the development wastewater of the color filter. The color resist (turbidity) and surfactant (TOC, COD) could not be reduced.
In addition, as shown in FIG. 6, only by pH adjustment, coloring does not change at all, and since the turbidity has an MFF value of 1.1 or less, the turbidity is in a dispersed state.
On the other hand, when the color filter development wastewater is heated to a pH of 7 or less and heated, an insoluble pigment (color resist) and a surfactant are generated and separated in the heated state. Thus, it was confirmed that both the pigment and the surfactant can be removed (see FIG. 5 and Example 1).

  As described above, the present invention can treat not only the color resist in the development wastewater but also the surfactant satisfactorily by treating the color filter development wastewater in a heated and neutral / acidic state. As a result, the color filter developing waste water can be processed with good aggregation filterability and operational stability. In other words, the operational stability of stabilizing the coagulation and stabilizing the COD value of the discharge becomes good. In addition, since it is possible to recover and reuse the heated heat, it is desirable in terms of operational stability and economy. In addition, COD removal efficiency is high, and the current situation can be greatly improved in terms of economy when performing advanced treatment as wastewater discharge treatment or wastewater recovery treatment. Furthermore, since it is possible to reduce the capacity of the biological reaction tank and the use amount of the flocculant and activated carbon, it is possible to reduce the cost of wastewater treatment.

Claims (4)

A method for treating development wastewater in a color filter manufacturing process,
A heating step of heating the development waste water to 50 ° C. or higher;
A pH adjusting step for adjusting the pH of the development waste water to 7 or less,
A processing method for developing waste water, wherein the developing waste water is subjected to solid-liquid separation in a state of heating and pH adjustment.   2. The development according to claim 1, wherein the developing wastewater is heated to 60 to 100 [deg.] C. in the heating step and / or the pH of the developing wastewater is made 2 to 6 acidic in the pH adjusting step. Wastewater treatment method.   The processing method of the development waste_water | drain of Claim 1 or 2 using a coagulant | flocculant together.   The development wastewater according to any one of claims 1 to 3, wherein heat of the heated treated water after the solid-liquid separation is recovered and reused for heating the development wastewater in the heating step. Processing method.