JPH1170301A - Treatment agent for water containing waste coating material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a treatment agent for water containing waste coating material and which sufficiently crosslinks flocs and is excellent in various effects. SOLUTION: This treatment agent for water containing waste coating material, as an effective component, a compound produced by an addition reaction of a high molecular polyamine compound having a large number of amino groups and a molecular weight of 10,000 to 10 million with a compound having a polar group importing anionic property. Polyalkyleneimines, poly(vinyl allylamine), polyglucosamine (polychitosan), poly(vinyl pyrrolidone), poly(vinyl allylpiperidine) with molecular weights of 10,000 to 10 million (number average molecular weight), preferably 50,000 to 2 million, and the likes are used as the polyamine compound. In the case the molecular weight is 10,000 or lower, the flocculating function is low and the effect is insufficient. The amino groups may be any one of primary, secondary, and tertiary amino groups. The number of amino groups may preferably be l-40% in terms of the density.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to paint scum by adding it to water containing waste paint such as washing water for unpainted paint in a wet painting booth, and waste water generated from the process of producing paint and handling paint such as painting. The present invention relates to an improved water treatment agent which is cohesive in a sponge form having no tackiness and easy to float so as to be easily separated into solid and liquid.

[0002]

2. Description of the Related Art Spray coating is widely used for coating mass-produced products such as automobiles and home electric appliances because a smooth and uniform coating film can be obtained with good work efficiency. However, the paint is scattered a lot, and the uncoated ratio is 40 to 70% in the case of the normal air spray type.
Extend to

[0003] The unpainted paint is collected by a washing water film or stored water in a paint booth, but the paint suspended in water becomes a sticky agglomerate, adheres to a tank or pipe, and is circulated. Clog pumps and shower heads.

Therefore, conventionally, a coagulant has been introduced into washing water to coagulate the uncoated paint, and the generated flocs have been removed by solid-liquid separation. Also, in the case of a coating process or a paint production by another method, wastewater containing waste paint is generated due to cleaning of an apparatus and a floor surface. In such a case as well, it is necessary to perform coagulation of the waste paint and other treatments to perform solid-liquid separation and discharge purified water.

As the flocculant, inorganic compounds such as caustic soda and soluble salts of polyvalent metals have been used.
Post-treatment was difficult because the aggregates settled and hardened, or the tackiness of the aggregates could not be suppressed. Therefore, at present, various organic coagulants are used in combination with these inorganic coagulants for the purpose of suppressing the adhesiveness of the aggregates. But,
Conventional organic coagulants have poor compatibility with inorganic coagulants, have foaming properties, cohesion is not always good,
Solid and liquid separation cannot be performed satisfactorily because the floc generated by agglomeration is soft and has a strong adhesiveness.The generated floc is too hard to be so-called concrete and it is difficult to handle the separation and removal. Less effective,
When the type of the target paint changes, the cohesion greatly changes and there is no so-called versatility.

In order to solve this problem, the applicant has developed a low-molecular-weight amine compound and has already filed a patent (Japanese Patent Publication No. 6-7886).
Have also acquired. In the case of this low-molecular-weight amine compound, the above-mentioned disadvantages are eliminated, and the compound is excellent.

[0007]

However, even with this low-molecular-weight amine compound, cross-linking between flocs is not yet satisfactory, and there is a drawback in terms of effect.

[0008]

DISCLOSURE OF THE INVENTION The present invention has been accomplished as a result of intensive studies to solve the above-mentioned drawbacks, and has completed the treatment agent of the present invention. It is characterized by a molecular weight of 10,000 to 1000 having a large number of amino groups. A compound obtained by subjecting a polyamine compound having an anionic property to a compound containing a polar group imparting an anionic property to an addition reaction is used as an active ingredient.

Examples of the high molecular weight amine compound include polyalkyleneimine, polyvinyl (allyl) amine, polyglucosamine (chitosan), polyvinylpyrrolidone, polyvinyl (allyl) piperidine and the like, and have a molecular weight (number average molecular weight).
10,000 to 10 million, more preferably 50,000 to 200
It is ten thousand. When the molecular weight is 10,000 or less, the aggregation effect is small and the effect is small. The amino group itself may be primary, secondary, or tertiary.

The number of amino groups is 1 to 4 in terms of the density.
About 0% is good. The calculation of the density of the amino group is, for example, 15/43 = 0.349 (the molecular weight of the amino group in the monomer / the molecular weight of the monomer) in the case of ethyleneimine, and is about 35
%. When this value exceeds 40%, the effect decreases.

In the present invention, the amphoteric conversion of the high molecular weight amine compound may be carried out by a known reaction using a compound having a polar group that imparts anionicity to the high molecular weight amine compound (amphoteric agent). As the amphoteric agent, betaine-type amphoteric agents such as monochloroacetic acid, sodium monochloroacetate, sodium monochloropropionate, (meth) acrylic acid, and sodium (meth) acrylate are used. Further, a hydrolyzate of an alkyl (meth) acrylate ester having 1 to 3 carbon atoms is also used. Further, aminosulfonic acid-type amphoteric agents such as bromoethanesulfonic acid and propane sultone are also used.

The treating agent of the present invention is effective when used alone, but when used in combination with a known water-soluble monovalent or polyvalent metal salt, the aggregates are coarsened and the effect of solid-liquid separation is obtained. Is exhibited more.

The monovalent or polyvalent metal salts used include sodium, potassium, zinc, iron, aluminum,
And water-soluble salts such as calcium and magnesium.
Specifically, sodium aluminate, potassium carbonate, zinc chloride, zinc sulfate, zinc acetate, zinc nitrate, iron chloride, iron sulfate, iron nitrate, aluminum chloride, PAC, aluminum sulfate, aluminum acetate, aluminum phosphate, aluminum nitrate , Calcium chloride, magnesium sulfate, magnesium chloride, magnesium acetate, magnesium nitrate and the like, and these are used alone or in combination of two or more.

The mixing ratio of the polyvalent metal salt to the amine-based amphoteric compound and the imine-based amphoteric compound depends on the type of the coating material, the type of the polyvalent metal salt and the type of the amphoteric compound.
90:10, particularly preferably about 20:80 to 60:40. In addition, the amount mixed with the washing water is 1 to 30% by weight, especially 5 to 10% with respect to the paint.
However, since it is consumed by reacting with the paint, it may be always added when circulating the washing water. In addition to the above polyvalent metal salts and amine-based amphoteric compounds, and also imine-based amphoteric compounds, neutralizing agents such as sodium hydroxide and potassium hydroxide, flocculants such as calcium hydroxide, and other preservatives The use of various agents such as an agent and an anti-algal agent may be added.

[0015]

【Example】

[Synthesis Example] Next, a synthesis example of the organic coagulant used in the present invention will be described. This synthesis example is an exemplification, and it goes without saying that it can be similarly synthesized using the various amines and imines described above. Synthesis Example 1 In a flask equipped with a stirrer, 21 g of polyethyleneimine (molecular weight: about 70,000, 30% aqueous solution) (0.16 mol in terms of ethyleneimine monomer) was added, and 18.7 g of sodium monochloroacetate was added to a flask kept at 50 to 60 ° C. 0.16mol) in water 60
g is added dropwise over 2 hours with stirring. After the end of the dropping, when the heat generation stops, the temperature is 6 to 70-80 ° C.
After aging for a while, a slightly acidic yellow transparent liquid was obtained. Synthesis Example 2 In a flask with a stirrer, add polyvinylamine (molecular weight: about 2).
69,000, 5% aqueous solution) 69g (0.08mol in monomer conversion)
And 860 g of water, and 6.2 g (0.08 mol) of methyl acrylate was added dropwise over 1 hour while stirring at 50 to 60 ° C. After the end of the dropping, when the heat generation stops, the temperature is raised to 60 to 70 ° C., and after aging for 2 hours, 64 g of a 50% aqueous solution of caustic soda
(0.08 mol) is added dropwise, paying attention to heat generation. Then 6
The saponification reaction was completed by aging at 5 to 75 ° C for 30 minutes to obtain an alkaline yellow transparent liquid. Synthesis Example 3 5 g of chitosan (molecular weight of glucosamine unit of 100 or more, average molecular weight of 500,000) and 900 g of water in a flask with a stirrer
g of acrylic acid.
9 g (0.026 mol) are added dropwise over 1 hour. After the end of the dropping, when heat generation stops, the mixture is aged for 2 hours at 30 to 40 ° C., and 6.2 g (0.053 mol) of sodium monochloroacetate is added to water 1
The solution dissolved in 00 g was added dropwise over 2 hours with stirring. After completion of the dropwise addition, the temperature was raised to 70 to 80 ° C., and the mixture was aged for 4 hours to obtain a weakly acidic yellow transparent liquid.

Next, Table 1 shows the polyamine amphoteric compounds obtained in the above synthesis examples alone, and Table 2 shows the combinations shown in Table 2 when used in combination with some of the metal water-soluble salts (Examples 1 to 3).
8. Performance tests were performed on the following items in Comparative Examples 1 to 6). These performance tests were performed using treated water obtained using the paint collection model booth apparatus shown in FIG.
1, reference numeral 1 is a spray gun, 2 is a compressor, 3 is a paint tank, 4 is a water overflow tank, 5
Is a wall for running water, 6 is a washing water tank (water reservoir), 7 is a washing water pump, 8 is a drain valve, and 9 is a workpiece.

The booth water is prepared by dissolving 25 g of the water treatment agents of Examples and Comparative Examples shown in Table 1 in tap water and adjusting the pH to about 8 to 9 with caustic soda or acetic acid. The total volume of the booth water is 90 liters and is circulated at a rate of 10 liters per minute. And, circulating the booth water 500
g of paint is sprayed over one hour. Water is circulated for 30 minutes after paint injection. Thereafter, a mixed solution of water and paint (treated water) was collected, and the performance of the water treatment agent was evaluated. In addition, the test was carried out using an acrylic white paint and a melamine white paint (manufactured by Rock Paint Co., Ltd.) which are commonly used. Cohesiveness of waste paint To the extent that paint slag in the wash water agglomerates and becomes non-adhesive.
Judgment was made based on the degree to which paint residue adhered to the booth wall surface in an adhesive state. (Evaluation criteria) ◎ No or almost no adhesion ○ Very slight adhesion △ Somewhat adhesion × No adhesion Solid-liquid separability 1000cc of booth water after removal of floating flocs was collected.
The mixture is filtered with a black filter paper, and the whiteness of the black filter paper is determined based on the W (LAB) value of a color difference meter. It is determined that the smaller the W value, the better the floating property and solid-liquid separation property. The mark "-" means that the coating does not become tack-free and agglomerates due to the viscosity of the coating, and thus cannot be evaluated.

[0018]

[Table 1]

[Table 2]

[0019]

As described above, the water treating agent containing waste paint of the present invention has a molecular weight of 10,000 to 100 having a large number of amino groups.
A compound obtained by subjecting a compound containing a polar group imparting anionic properties to an addition reaction to 10,000 polyamine compounds is used as an active ingredient. Incidentally, a so-called amine-based amphoteric compound and a so-called imine-based amphoteric compound may be used in combination as the polymer polyamine compound. Thus, a floc having no tackiness and easily floating is generated (see Examples). When a metal salt is used, its main functions are a tack-free assisting action and an agglomeration assisting action between paint particles.

Further, the treating agent of the present invention has little foaming and is easy to handle. Further, since the paint and the solvent containing the same are made into flocs which do not dissolve in water, the generation of water pollution and odor can be completely prevented. In addition, various types of solvent-based and water-based (water-soluble, emulsion-based) paints are used for spray coating, and the main resin of the paint is also alkyd, acrylic, melamine, urethane, polyester, etc., depending on the purpose and application. Are used, and the treating agent of the present invention exhibits the above-mentioned effects on any of these.

[Brief description of the drawings]

FIG. 1 is a block diagram of a paint collection model booth apparatus for obtaining treated water used in an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Spray gun 2 Compressor 3 Paint tank 4 Water overflow tank 5 Running water wall 6 Washing water tank

Claims (2)

[Claims] Claims: 1. A molecular weight of 10,000 to 10 having a large number of amino groups
A treatment agent for waste paint-containing water, comprising, as an active ingredient, a compound obtained by addition-reaction of a compound containing a polar group imparting anionic property to 100,000 high molecular weight polyamine compounds. 2. The treatment agent for waste paint-containing water according to claim 1, wherein the amino group density of the high molecular weight polyamine compound is 1 to 40%.