JP2001038367A - Method of processing waste liquid of photosensitive resin plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To flocculate, separate and filter a resin waste liquid in an simple device in a short time by blending a cationic flocculant having several hundreds to several millions molecular weight into the resin waste liquid in the process of treating the resin waste liquid which is produced by removing an unhardened resin of a photosensitive resin plate containing a specified ionic hydrophilic groups with a developer. SOLUTION: In the process of treating a resin waste liquid produced by removing an unhardened resin from a photosensitive resin plate containing ionic hydrophilic groups expressed by the formulae of -COOM, -SO3M, -SO4M, -nPO(OM)n and (O)3-nPO(OM)n with a developer, a cationic flocculant having several hundreds to several millions molecular weight is blended into the resin waste liquid. In the formulae, M is a hydrogen atom, I to III group element in the periodic table, amine or the like, and n is 1 or 2. As for the cationic flocculant to be used, for example, a cationically modified polyacrylamide prepared by modifying a polyacrylamide with formalin and amines, cationic vinyl lactam-acrylamide copolymer or the like can be used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for coagulating and separating a resin waste liquid (including an uncured resin and a developing solution) obtained by treating an uncured resin of a photosensitive resin plate with a developer by a simple treatment. The present invention relates to a simple waste liquid treatment of a photosensitive resin plate for obtaining small sludge. More specifically, the present invention relates to a simple waste liquid treatment method for aggregating and separating a resin waste liquid obtained by removing an uncured resin with an anionic developer mainly using a photosensitive resin plate for flexographic printing capable of aqueous development.

[0002]

2. Description of the Related Art In recent years, aqueous development type photosensitive resin plates which can be developed with a developing solution such as water, an aqueous solution of a surfactant, an aqueous solution of an alkaline solution, an aqueous solution of an acidic solution, and the like have come to be widely used in view of working environment and local environment. Similarly, photosensitive flexographic plates which can be developed with an aqueous developer are disclosed in, for example, JP-A-63-28551 and JP-A-7-11418.
No. 0, JP-A-6-289610, JP-A-6-289610
No. 3,399,951.

[0003] On the other hand, after exposure using these aqueous development type photosensitive resin plates, the resin waste liquid whose unexposed portion has been treated with a developing solution is also important in terms of environmental aspects, handling properties, etc., as described above. For example, Japanese Patent Application Laid-Open Nos. 51-121959, 49-100842, and 8-2
No. 99965, JP-A-6-194824, JP-A-7-333860, JP-A-8-006258
JP, JP-A-7-328620, JP-A-10-108
No. 34147 discloses a waste liquid treatment system and treatment method. However, these methods have drawbacks such as large-scale equipment, long processing time, poor coagulation / separation effect, poor adhesiveness of the obtained sludge, poor workability, and poor filterability. Therefore, a coagulation separation method that satisfies a simple method has been desired.

[0004]

DISCLOSURE OF THE INVENTION The present invention is to provide a sludge having low tackiness, which can be subjected to coagulation separation filtration with a simple apparatus in a short time in treating a resin waste liquid of a photosensitive resin plate which can be developed with an aqueous system. It is an object of the present invention to find a method capable of draining filtration waste liquid to a sewer as well as wastewater.

[0005]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have earnestly studied, studied, and studied a simple wastewater treatment method, and have finally completed the present invention. That is, the present invention provides the following formulas (a), (b), (c),
(D) When the photosensitive resin plate containing at least one ionic hydrophilic group shown in (e) is treated with a developer to remove the uncured resin from the resin waste liquid, the resin waste liquid has a molecular weight of several hundreds to several hundreds. A method for treating a waste liquid of a photosensitive resin plate, which comprises adding millions of cationic flocculants, and the photosensitive resin according to the above, wherein a weak anionic or nonionic flocculant is added as a cationic flocculant and an auxiliary agent. This is a method for treating wastewater from a plate. (A) -COOM (b) -SO 3 M (c) -SO 4 M (d) -nPO (OM) n (e) (O) 3 -nPO (OM) n (M is a hydrogen atom, a periodic table It represents a group I, II, or III element, an amine or an ammonium group, and n is 1 or 2.)

The photosensitive resin plate used in the present invention has at least a support and a photosensitive resin composition layer, and has a developing property with respect to an aqueous developing solution. Contains a hydrophilic component containing an ionic hydrophilic group, and is further provided with photosensitivity by blending a photopolymerizable unsaturated monomer, a photosensitizer and the like. Examples of the photosensitive resin composition used in the present invention include the compositions described in the above-mentioned publications. Particularly, in order to impart a hydrophilic or water-swelling component to a hydrophobic component, a hydrophobic polymer is used. A resin mainly composed of a resin modified with an ionic hydrophilic group, a hydrophobic component mainly composed of a hydrophobic polymer and a hydrophilic substance mainly composed of a hydrophilic or water-swellable polymer containing an ionic hydrophilic group. Based on a mixture of hydrophilic or water-swellable components, or based on a chemical combination of a hydrophobic polymer and a hydrophilic or water-swellable polymer containing an ionic hydrophilic group As mentioned above, as a main component, a polymer obtained by block copolymerizing a hydrophobic monomer serving as a raw material of a hydrophobic polymer and a hydrophilic monomer serving as a raw material of a hydrophilic polymer,
A preferable example is a type in which a hydrophilic or water-swellable component is combined with a hydrophobic component in some form to form a photosensitive flexographic plate of a dispersion type in an aqueous developer.

Examples of the hydrophobic polymer mentioned here include 1,4-polybutadiene, 1,2-polybutadiene, acrylonitrile rubber, butadiene acrylonitrile rubber, chloroprene rubber, polyurethane rubber, butadiene styrene copolymer, styrene-butadiene-styrene. Block copolymer, styrene-isoprene-styrene block copolymer, polyamide resin, unsaturated polyester resin, (meth) acrylic acid copolymer, butadiene- (meth) acrylic acid-acrylic ester copolymer, silicon rubber, polyoxypropylene glyco- ,
Polymers that impart rubber elasticity to plates such as isoprene rubber, butadiene rubber, styrene-butadiene rubber, butyl rubber, ethylene-propylene rubber, epichlorohydrin rubber, and acrylic resins, polyurethane resins, and polyester resins that impart hardness and stability. And these may be used alone or in combination as necessary. These resins can also be modified so that they can react with monomers or cross-linking agents or between polymers.

The hydrophilic or water-swellable polymer used in the present invention includes, for example, a polymer of (meth) acrylic acid or a salt thereof, and a polymer of (meth) acrylic acid or a salt thereof.
Alkyl (meth) acrylate copolymer, (meth) acrylic acid or salts thereof-styrene copolymer, (meth) acrylic acid or salts thereof-vinyl acetate copolymer, (meth) acrylic acid or salts thereof-acrylonitrile copolymers, -COOM group or -SO ₃ M group and -SO ₄ M group or -n
PO (OM) n or (O) _3- nPO (OM) n (n is 1
Or 2) group-containing polyacrylates, polyvinyl compounds, polyurethanes, polyureaurethanes, polyesters, epoxy compounds, polyamides, and salts and derivatives thereof (where M is the periodic table I, II, II)
Indicate group I element, amine or ammonium group). Similarly, a plurality of hydrophilic components can be used in combination, and may be modified as needed.

As the photosensitive resin composition, in addition to the polymer, a crosslinking agent, an antioxidant, a polymerization inhibitor, a plasticizer and the like are optionally added to and blended with the polymer.

Specific examples of the crosslinking agent include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, Trimethylolpropane tri (meth) acrylate, glycerin di (meth) acrylate, triethylene glycol di (meth) acrylate,
PEG # 200 di (meth) acrylate, PEG # 400 di (meth)
Acrylate, 1,3-butanediol dimethacrylate, neopentyl glycol di (meth) acrylate,
1,10-decanediol dimethacrylate, bisphenol A ethylene oxide adduct di (meth) acrylate, ethylene oxide modified trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, 1,9 -Nonanediol di (meth) acrylate, light ester P-2M (manufactured by Kyoeisha Chemical Co., Ltd.), triacrylate of 3-mol ethylene oxide adduct of pentaerythritol, oligopropylene glycol di (meth) acrylate, polytetramethylene glycol di (Meth) acrylates and the like are preferred, and alkylene glycol-based and alkylene ether-based crosslinking agents are particularly preferred.

As a method for producing a photosensitive resin plate, the raw materials such as the above-mentioned hydrophobic polymer, hydrophilic or water-swellable polymer, crosslinking agent and antioxidant are kneaded with a kneader or an extruder. A photosensitive resin is produced by doing so, and further sandwiched between a support having an adhesive layer coated on a support and a cover film having an anti-adhesion layer coated thereon, with the photosensitive resin layer as a center, An original photosensitive resin plate can be obtained by sequentially laminating by a method such as hot pressing or calendar molding.

As a method for curing the obtained photosensitive resin master, 150 to 500 nm, especially 300 to 400 n
Cured by irradiation with ultraviolet light having a wavelength of m. Its light sources include low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps,
Metahalide lamps, xenon lamps, zirconium lamps, carbon arc lamps, ultraviolet fluorescent lamps and the like are preferably used.

Next, in the present invention, the photosensitive resin plate is formed by applying a negative film having a transparent image under the above-mentioned light source, irradiating ultraviolet rays to expose the image, and removing a non-image portion which is not exposed using a developing solution. An image is obtained, while the uncured photosensitive resin dissolved and removed remains in the developing tank as an emulsion or a suspension.

The developer used in the present invention may be water alone or may further contain the following compounds, for example, sodium laurate, sodium stearate, sodium oleate. Fatty acid carboxylate salts such as sodium bicarbonate, resin soaps such as sodium abietic acid and sodium rosin acid, sodium lauryl sulfate, and triethano lauryl sulfate.
And primary and secondary polyoxyethylene lauryl ethers such as polyoxyethylene lauryl ether soda sulfate and polyoxyethylene lauryl ether triethanol sulfate. Tersulfates, sodium laurylbenzenesulfonate
And alkyl benzene sulfonates such as sodium stearylbenzenesulfonate; alkyl naphthalene sulfonates such as sodium propylnaphthalenesulfonate and sodium butylnaphthalenesulfonate; Polyoxyethylene lauryl phenyl ether sulfonates, sulfated castor oil, sulfated beef oil and other sulfated oils,
Sulfated fatty acid esters such as sulfated butyl oleate, alkyl sulfo laurates represented by dioctyl sulfo succinate soda, a-olefin sulfonates,
Hydroxyalkanesulfonates, N-methyl-N-
Alkyl tauric acid salts, N-alkylsulfo phthalic acid monoamide salts, fatty acid monoglyceride sulfate salts, alkyl diphenyl ether disulfonic acid salts, rauryl alcohol phosphoric acid monoester disodium salt, lauryl alcohol phosphoric acid diester soda salt, etc. Salts of polyoxyethylene alkyl phosphates such as polyoxyethylene lauryl ether phosphate monoester disodium salt and polyoxyethylene lauryl ether phosphate diester soda salt; naphthalene Anionic surfactants such as sulfonate formalin condensates, styrene-maleic anhydride copolymer partially saponified salts, and olefin-maleic anhydride copolymer partially saponified salts are preferably used. Specific examples are mainly sodium salts, but potassium salts and ammonium salts are also possible and are not particularly limited. A developer containing 5% or less of a nonionic surfactant in addition to these anionic surfactants may be used.

Next, the uncured non-image area resin which is not exposed to the developer is dissolved and removed, and is repeatedly used as a developer while the resin is contained in the developing tank. The deterioration of the developing performance, the discoloration of the developing solution, the fluctuation of the pH, and the like due to the increase in the resin concentration become remarkable. Therefore, it is necessary to treat the deteriorated developing solution with a waste liquid and renew the developing solution. The liquid is exchanged when the concentration of the resin subjected to the waste liquid treatment becomes about 6 to 7% or when the PH becomes 10 or less. This used developing waste liquid contains a photosensitive resin, a surfactant, an antifoaming agent and the like. Transfer these resin waste liquids to a simple waste liquid treatment tank, add a polymeric cationic flocculant, stir and agglutinate and separate the resin component in the development waste liquid from the developer to obtain a small-adhesive sludge, and in the same treatment bath. Drainage treatment to the sewer can be performed by acid neutralization treatment.

Examples of the cationic flocculant used in the present invention include cationized modified polyacrylamide obtained by modifying polyacrylamide with formalin and amines, cationic vinyl lactam-acrylamide copolymer, and diallyl ammonium halide. A saponified polymer, a copolymer obtained by reacting a diamine with a copolymer of isobutylene and maleic anhydride, a vinyl imidazoline polymer, a polymer of dialkylaminoethyl acrylate, polyethylene imine, an alkylene dichloride and an alkylene polyamine. Polycondensate of dicyandiamide and formalin; polycondensate of aniline and formalin; copolymer of amines and epichlorohydrin; copolymer of ammonia and epichlorohydrin; copolymer of amines and aspartic acid Polymer Acrylic polymers having a quaternary ammonium salt in the side chain - and the like, with preference given to a copolymer of an amine and epichlorohydrin.

The amines used herein include, for example, methylamine, ethylamine, n-propylamine, isopropylamine, methoxypropylamine, butyramine,
Amylamine, allylamine, hexylamine, caprylamine, laurylamine, stearylamine, oleylamine, monomethylaminopropylamine, benzylamine, piperidine, alkyl and cyclic amines such as pyrrolidine, polyethylenepolyamines, aminopropylethanolamine, methyliminobis Propylamine,
Monomethylaminopropylamine, dialkylaminopropylamine, hydroxyethylaminopropylamine, diethylaminoethylamine, tetramethylenediamine, hexamethylenediamine and the like can be mentioned.

The action of the cationic flocculant in the present invention is as follows. The cationic flocculant (positive charge) is adsorbed on the suspended particles of the anionic resin developed by the anionic developer (negative charge) (or the cationic flocculant is adsorbed). Conversely, it is considered that each particle aggregates due to the action of neutralizing the charge on the particle surface.

In the present invention, the weakly anionic or nonionic flocculant which is further added as an auxiliary agent in addition to the above-mentioned cationic flocculant includes polyacrylamides, anionic polyacrylamides, partially hydrolyzed polyacrylamides and the like. Nonionic floc agents such as weak anionic floc agents, polyacrylamides, polyethylene oxides, and polyalkanolamines can be used, and polymers having a molecular weight of hundreds of thousands to tens of millions are preferred. These auxiliaries are used in an amount equal to or less than the cationic flocculant.

In the present invention, in order to treat the waste liquid from which the solids have been removed to the sewer, it is preferable to further add an acidic compound to adjust the pH to 5.0 to 9.0. Examples of the acidic compound include acidic compounds having a pH of about 3 such as formic acid, hydrochloric acid, sulfuric acid, acetic acid, phosphoric acid, oxalic acid, citric acid, nitric acid, and monochloroacetic acid.

[0021]

DETAILED DESCRIPTION OF THE INVENTION As described above, the operation method of the present invention for treating a resin waste liquid by using a cationic flocculant includes, for example, preparing a simple waste liquid treatment bath containing 50 l (50 liters) of resin waste liquid, A waste liquid having a concentration of about 3% or more is charged and stirring is started. Next, 5 to 10 ml / l, preferably 6 to 8 ml / l, of a cationic flocculant composed of a copolymer of dimethylamine and epichlorohydrin is added to the mixture to obtain about 2 ml.
Stir for ~ 3 minutes to generate aggregates. In order to further react the treating agent completely, if the stirring is continued for about 2 minutes, sludge having low adhesiveness floats. When the concentration of the waste liquid resin is about 3% or less, the aggregated particles are small and the filterability is slightly lowered. On the other hand, when the amount of the cationic flocculant is less than 5 ml / l, it is difficult to obtain agglomerated particles and the adhesiveness is strong, so
In the case of the above addition, the aggregated particles become small and the filterability is lowered, which is not preferable. While continuing stirring, acid was added to 2-3 ml /
Addition and continued for 2 to 3 minutes, the waste liquid will be regulated by sewer drainage (PH 5.0 to 9.0, BOD 1200 mg / l or less)
And can be drained to the sewer. Further, after the stirring is stopped and the mixture is allowed to stand, the mixture is filtered using a filter cloth to remove sludge, and the operation is easy.

[0022]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited to these Examples. In the examples, “parts” means “parts by weight”. Example 1 A photosensitive resin master plate (Cosmolite manufactured by Toyobo Co., Ltd.) was used, and a negative film was used at 40 ° C. for 15 minutes in a developer containing 1% of Nissan powder soap (manufactured by Nissan Soap Co., Ltd.). The unexposed portions which were not exposed after the pattern exposure were brush-developed. When the resin concentration of the developer reaches about 5%, 50 l
(50 liters) was transferred to a resin waste liquid treatment bath, and stirring was started with a stirrer. Next, a cationic flocculant (copolymer of dimethylamine and epichlorohydrin (molecular weight of about 3
00,000): 6 ml / l of Procedim 4525)
The stirring was continued. When the mixture was stirred for about 2 to 3 minutes, large aggregates were generated, and the cohesion itself was small and easy to handle. Next, formic acid was added under agitation with 2-3 ml /
After stirring for about 2 to 3 minutes, stirring was stopped and the mixture was allowed to stand. After standing, filtration was performed in a filtration tank covered with a filter cloth, and sludge was easily taken out. Further, when the pH of the treated waste liquid was measured, the pH was 6.8, SS 191 mg / l, B
The OD was 134 mg / l and the COD was 850 mg / l, which was a value that could be drained to the sewer.

Example 2 In Example 1, Cliffloc LC-551 was used instead of Procedim 4525 as a cationic flocculant.
Except for using a molecular weight of about 10,000 (produced by Kurita Kogyo Co., Ltd.), all treatments were carried out in the same manner as in Example 1 to obtain large agglomerated particles, small adhesiveness and good filterability.
The pH of the treatment waste liquid was 6.8.

Example 3 In Example 1, except that Procedim 4525 was used as the cationic floc agent instead of Sunfloc 700 (molecular weight of about several hundred to several thousand manufactured by Sanyo Kasei Kogyo Co., Ltd.), all examples were used. When treated in the same manner as in Example 1, large aggregated particles were obtained, the adhesiveness was small, and the filterability was good. The pH of the treatment waste liquid was 6.8.

Example 4 In the same manner as in Example 1, the developer was supplied with an eco-bar (eco-bar).
Developing resin waste liquid by the same operation except using the above method, a cationic floc (Procedim 452)
When treated in the same manner as in Example 1 using 5), large aggregated particles were obtained, the adhesion was small, and the filterability was good. The pH of the treatment waste liquid was 6.8.

Example 5 In the same manner as in Example 1, a developing solution was added to Feyley (P Co., Ltd.).
& G) to produce a resin waste liquid, using a cationic floc (Procedim 452).
When treated in the same manner as in Example 1 using 5), large aggregated particles were obtained, the adhesion was small, and the filterability was good. The pH of the treatment waste liquid was also 7.0.

Example 6 In the same manner as in Example 1, the developer was cascaded (P Co., Ltd.).
& G) to produce a resin waste liquid, using a cationic floc (Procedim 452).
When treated in the same manner as in Example 1 using 5), large aggregated particles were obtained, the adhesion was small, and the filterability was good. The pH of the treatment waste liquid was 6.9.

Example 7 In the same manner as in Example 1, the developing solution was purified by Sun (P & G Co., Ltd.).
The resin was developed by the same operation except that the above method was used to prepare a resin waste liquid, and treated with a cationic floc (Procedim 4525) in the same manner as in Example 1 to obtain coarse agglomerated particles. It was small and the filterability was good. The pH of the treatment waste liquid was 6.9.

Example 8 A developing treatment was carried out in the same manner as in Example 1 to prepare a resin waste liquid. Next, a cationic flocculant (Procedim 452)
5) was added and stirred at 10 ml / l, and a polymer nonionic floc agent (Sanfloc 520P, molecular weight several million,
When 4 ml / l of Sanyo Kasei Co., Ltd.) was added and the mixture was stirred for about 1 hour, large aggregates were obtained, the adhesiveness was small, and the filterability was good. The pH was adjusted to 9.4 in the same manner as in Example 1 to obtain a treated waste liquid.

Example 9 A developing treatment was performed in the same manner as in Example 1 to prepare a resin waste liquid. Next, a polymeric cationic floc (Procedim 4
525) was added at 10 ml / l and the mixture was stirred. Further, 4 ml / l of a high-molecular weak anionic flocculant, Sanfloc AS-110P (molecular weight: several million, manufactured by Sanyo Chemical Co., Ltd.) was added, and the mixture was added to about 1 ml.
When the mixture was stirred for a long time, a large aggregate was obtained, the adhesiveness was small, and the filterability was good.

Example 10 Development and waste liquid treatment were carried out in the same manner as in Example 1 except that the photosensitive resin original used in Example 1 was replaced with an aqueous development type flexographic original AQS (manufactured by DuPont). Was performed, the same good results as in Example 1 were obtained.

Example 11 In place of the photosensitive resin master used in Example 1, an aqueous development type flexographic master Flexide SGX (Nippon Paint Co., Ltd.)
Developing and waste liquid treatment were carried out in the same manner as in Example 1 except that the same good results as in Example 1 were obtained.

Comparative Example 1 Development and waste liquid treatment were performed in the same manner as in Example 1 except that the cationic floc agent (Procedim 4525) was not used. As a result, coarse aggregated particles were not obtained, the tackiness was large, and the workability was high. Inferior filtration was not enough.

Comparative Example 2 Development and waste liquid treatment were carried out in the same manner as in Example 1 except that Catiogen L (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was used instead of the cationic floc agent (Procedim 4525). As a result, coarse aggregated particles were not obtained, the tackiness was large, the workability was poor, and the filtration was not sufficient.

Comparative Example 3 Development and waste liquid treatment were performed in the same manner as in Example 1 except that aluminum chloride was used instead of the cationic floc agent (Procedim 4525). And the workability was poor.

Table 1 shows the results of Examples 1 to 11 and Comparative Examples 1 to 3.

[0037]

[Table 1]

[0038]

As is clear from Table 1, by using the cationic flocculant of the present invention as an aggregating / separating agent for developing resin waste liquid, it is possible to perform a satisfactory treatment in a simple waste liquid treating bath. Thus, the treated sludge also has low tackiness and improves its workability.
Further, by adding the cationic floc agent of the present invention mainly as a weak anionic and nonionic floc agent as an auxiliary, the filterability is further improved. Wastewater treatment is also possible,
There is a great advantage that the processing capacity can be satisfied with inexpensive equipment, which greatly contributes to the industry.

Continuation of the front page F term (reference) 4D062 BA09 BA19 BB05 CA08 DB03 DB08 DB19 DB23 DB25 DB46 DC06 DC07 DC08 EA06 EA35

Claims (2)

[Claims] 1. The following formulas (a), (b), (c), (d),
In treating the resin waste liquid obtained by removing the uncured resin from the photosensitive resin plate containing at least one ionic hydrophilic group shown in (e) with a developer, the resin waste liquid has a molecular weight of several hundreds to several hundreds.
A method for treating a waste liquid of a photosensitive resin plate, comprising adding millions of cationic flocculants. (A) -COOM (b) -SO 3 M (c) -SO 4 M (d) -nPO (OM) n (e) (O) 3 -nPO (OM) n (M is a hydrogen atom, a periodic table It represents a group I, II, or III element, an amine or an ammonium group, and n is 1 or 2.) 2. The method according to claim 1, wherein a weakly anionic or nonionic flocculant is added as a cationic flocculant and an auxiliary agent.