JPH0686680B2 - Purifying method of Metsuki bath - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a method for refining a plating bath. More specifically, it relates to a method for efficiently removing impurity metal ions in a plating bath by using a special chelate resin.

<Prior Art> Zinc plating is preferred because it is inexpensive and has excellent corrosion resistance among platings used for rust prevention.

Two types of baths, an alkaline bath and an acidic bath, are generally used for galvanizing, but an acidic plating bath that can obtain a uniform and glossy film is often used. However, in the case of an acidic plating bath, if the bath is used for a long time, iron ions and the like accumulate due to the dissolution of the plated material, which causes hindrance and unevenness on the plated surface.

In order to solve such inconvenience, some methods of removing iron ions and the like have been proposed. Among them, the adsorption treatment method using a chelate resin is a preferable method because the operation is simple and the equipment cost is low, and the iron ion in the plating bath is adsorbed and removed by the chelate resin having an iminodiacetic acid group as a ligand. Method (JP-A-54-74224, JP-A-54-1)
21241) is known.

<Problems to be Solved by the Invention> When chelating and removing iron ions from a plating bath, known chelate resins are not always satisfactory in terms of adsorption selectivity and adsorption rate. . Therefore, when a large amount of liquid is adsorbed, the treatment amount per unit time becomes small, a large number of treatment devices are required, and construction costs and operating costs increase.

In view of such circumstances, the present inventors have conducted intensive studies to find a method for efficiently removing impurity metal ions in a plating bath, and as a result, completed the present invention.

<Means for Solving the Problem> That is, the present invention is a method for removing impurity metal ions contained in a plating bath, which comprises contacting the plating bath with a chelating resin having an aminocarboxylic acid group having a specific structure. .

The chelate resin used in the present invention has the general formula A chelate resin having an aminocarboxylic acid group represented by, a resin substrate having a resin having such a functional group,
The shape and manufacturing method are not particularly limited.

X is, as described above, a reactant consisting of hydrazine, polyalkylene polyamine, guanidine and derivatives thereof, and specifically, depending on the below-mentioned amino compound used in the reaction, And the like. Here, Y is a hydrogen atom or CH _{2 n} COOM (n and M are as described above) depending on the progress of the reaction of an aminocarboxylic acid compound, a halogenated alkylcarboxylic acid compound, and an acrylic acid-based compound described later. Become. If the progress of the reaction is small, it becomes a hydrogen atom, and if it is large, it becomes CH _{2 n} COOM.

General formula in resin substrate The chelating resin of the present invention having a functional group represented by the formula (wherein X, n, m and M are as described above) has a metal ion adsorption capacity higher than that of a known chelating resin having an aminocarboxylic acid group. And has a characteristic that the adsorption rate is extremely high.

It is not clear why the chelate resin of the present invention has a large adsorption capacity for metal ions and a higher adsorption rate as compared with known resins having an aminocarboxylic acid group. (Where X is as described above) is bound to the polymer main chain via the spacer, and is sterically stable with the metal ion forming a hydrated ion with a large ionic radius in an aqueous solution. It is easy to form various coordination bonds and the adsorption capacity increases, while (In the formula, X is as described above.) Is a hydrophilic amide group, and it is considered that the hydrophilicity of the resin substrate itself is improved, and as a result, the adsorption rate is improved.

The chelate resin of the present invention is not particularly limited as long as it is a chelate resin having a functional group represented by the general formula, its shape, manufacturing method, type of resin substrate, etc. Manufactured.

(1) A method of reacting a resin having a carbonyl chloride group with an aminocarboxylic acid compound.

Styrene-divinylbenzene copolymer having a carbonyl chloride group, phenolic resin, polyethylene, a polymer of polypropylene or polymethacrylic acid, a polymer of an acid salt compound of polymethylmethacrylic acid (hereinafter, having a carbonyl chloride group Referred to as resin) to 5-amino-3
-Azapentanoic acid, 8-amino-3,6-diazaoctanoic acid, 11-amino-3,6,8-triazaundecanoic acid, 9-
A method of reacting an aminocarboxylic acid compound such as amino-3-azanonanoic acid, guanidinoacetic acid and their alkali metal or alkaline earth metal salts.

(2) A method in which an amidine hydrolyzed resin obtained by reacting a resin having a nitrile group with an amino compound is reacted with a halogenated alkylcarboxylic acid compound or an acrylic acid compound.

Acrylonitrile, α-chloroacrylonitrile, vinylidene diane, methacrylonitrile, ethacrylonitrile, fumardinitrile, crotonnitrile, 2-
Polymers of vinyl cyanide-based monomers such as dianoethyl acrylate and 2-cyanoethyl methacrylate, or other ethylenically unsaturated monomers copolymerizable with vinyl cyanide-based monomers, such as divinylbenzene, Copolymers of diethylene glycol dimethacrylate, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, vinyl acetate and the like (hereinafter referred to as a resin having a nitrile group), ethylenediamine, trimethylenediamine, tetramethylenediamine, hexamethylenediamine , Polyethylenepolyamines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine and hexamethyleneheptamine, and amino compounds such as hydrazine and granidine are reacted in an aqueous solvent. Performed, whether to further hydrolysis reactions simultaneously or after the reaction, carried out the reaction of the amino compound in a non-aqueous system, (hereinafter referred to as amidine hydrolysis resin) then hydrolysis was added so the amino compound by performing resin
To get Monochloroacetic acid,
A method for reacting a halogenated alkylcarboxylic acid compound such as monobromoacetic acid, monochloropropionic acid, monobromopropion and salts of these alkali metals or alkaline earth metals. Alternatively, the amidine hydrolyzed resin is reacted with acrylic acid, methacrylic acid, alkali metal or alkaline earth metal salts of these acids, or methyl, ethyl ester and the like (hereinafter referred to as acrylic acid compound), and in the case of ester, A method of causing hydrolysis.

(3) A method in which an acid amide resin obtained by reacting a resin having a carbonyl chloride group with an amino compound is reacted with a halogenated alkylcarboxylic acid compound or an acrylic acid compound.

In this reaction, an amino compound reaction resin (hereinafter referred to as an acid amide resin) having active hydrogen in the resin obtained by reacting the resin having a carbonyl chloride group with the amino compound is treated in the same manner as in (2) above. It is a method of reacting a modified alkylcarboxylic acid compound or an acrylic acid compound.

(4) A method of reacting a resin obtained by reacting an acrylic acid resin with an amino compound with a halogenated alkylcarboxylic acid compound or an acrylic acid compound. Polyacrylic acid, polymethacrylic acid, and esters of these acids such as methyl and ethyl (hereinafter referred to as acrylic acid-based resin) are subjected to a condensation reaction with the amino compound (hereinafter referred to as condensation reaction acid amide resin) A method of reacting a halogenated alkylcarboxylic acid compound or an acrylic acid compound in the same manner as in the above (2) and (3).

The reaction will be described in detail below.

About the reaction method of (1) The reaction of the resin having a carbonyl chloride group and the aminocarboxylic acid compound is water, N, N-dimethylformamide,
Solvents such as methyl alcohol or ethyl alcohol, caustic soda, caustic potash, triethylamine, N, N-
The heating is performed at about 40 ° C or higher, preferably at about 50 to 90 ° C in the presence of a neutralizing agent such as dimethylaniline or N, N-diethylaniline. When the reaction temperature is low at about 40 ° C, the reaction rate becomes slow and the reaction takes a long time, which is not preferable.

The reaction is carried out at the above temperature for about 0.1 to 7 hours. The optimum time within that range is appropriately determined depending on the reaction temperature, the concentration of the reaction solution, the solvent used, the type of the aminocarboxylic acid compound, and the like. However, it is possible to react for a longer time.

The reaction is generally carried out at normal pressure, but it can be carried out under pressure.

The reaction ratio between the resin having a carbonyl chloride group and the aminocarboxylic acid compound is about 0.25 mol or more based on 1 mol of the carbonyl chloride group in the resin. If more aminocarboxylic acid compounds are used than required, the recovery process after the reaction is accompanied, the processing operation becomes complicated, and the amount of the aminocarboxylic acid compound used for the resin having a carbonyl chloride group becomes less than about 0.25 mol. Since the substitution of the aminocarboxylic acid compound is reduced and the metal-capturing ability of the resulting chelate resin obtained by the reaction is reduced, it is preferably used in an amount of about 0.5 to 0.3 mol per 1 mol of the carbonyl chloride group in the resin.

The neutralizing agent used in the production of the chelate resin of the present invention is a hydrochloric acid by-produced by the reaction of a carbonyl chloride group and an aminocarboxylic acid compound with the neutralizing agent, thereby neutralizing the carbonyl chloride group and the amino group. Since it has the effect of promoting the reaction of the carboxylic acid compound, the reaction ratio of the neutralizing agent is
It is used in approximately the same amount as the amount of hydrochloric acid produced as a by-product.

However, since the aminocarboxylic acid compound that does not directly react with the carbonyl chloride group also acts as a dehydrochlorinating agent, there is no particular problem in the reaction even if it is less than the equimolar amount, and there is no problem in the reaction when it is used in an excess amount. An appropriate amount can be decided.

Regarding the reaction method of (2), the amidine hydrolyzed resin used as the base resin of the chelate resin of the present invention contains a resin having a nitrile group and an amino compound such as the polyalkylene polyamine, hydrazine and guanidine under an aqueous solvent or containing water. Dimethylformamide, dimethyl sulfoxide, toluene, 1,
It is produced at a reaction temperature of 100 ° C or higher, preferably 120 ° C or higher in the presence of a solvent such as 2-dichloroethane. Reaction temperature is 100 ℃
If it is lower, the reaction becomes slower and the reaction takes a long time, which is not preferable.

In the reaction, a reaction of an amino compound with a nitrile group and a reaction of hydrolyzing an amidine produced by the nitrile group and the amino compound to an imino group to produce ammonia as a by-product proceed in parallel.

The reaction with an amino compound may be carried out in a non-aqueous system, and hydrolysis may be carried out after the reaction.

The reaction time is such that the amount of ammonia generated by the by-product reaction is 0.25 mol or more per 1 mol of the nitrile group.

Generally 0.5 to 50 hours at the above temperature, preferably 1 to 12
The reaction is carried out for a time, and the optimum time within that range is appropriately determined depending on the reaction temperature, the reaction solution concentration, the solvent used, the type of amino compound, and the like. However, it is possible to react for a longer time.

The reaction is generally carried out at normal pressure, but it can be carried out under pressure.

The reaction ratio of the amino compound to the resin having a nitrile group is 0.5 mol or more with respect to the nitrile group in the resin. The use of more reaction reagents than necessary involves a recovery process after the reaction, and the processing operation becomes complicated, and the amount of the amino compound used for the resin having a nitrile group is
When the amount is less than the above, the amount of carboxylic acid groups introduced in the next step is small and the metal adsorption capacity of the resulting reaction-produced chelate resin is reduced, and when the amount of water is less than the above, the amount of hydrolysis of the imino group of amidine is reduced. Since the metal adsorption rate of the resulting reaction-generated chelate resin becomes slower, the amino compound and water are preferably used in an amount of about 1 to 6 times mol and about 1 to 30 times mol per mol of the nitrile group in the resin. .

The amidine hydrolyzed resin reacted as described above is then used as it is, or after separating and removing the solvent and unreacted amino compound, or if necessary, after washing and drying, the halogenated alkylcarboxylic acid compound, the alkyl The reaction with an acid compound or the acrylic ester is performed.

Reaction of amidine hydrolyzed resin with halogenated alkylcarboxylic acid compounds such as monochloroacetic acid, monobromoacetic acid, monochloropropionic acid, monobromopropionic acid
Water, N, N-dimethylformamide, ethyl alcohol,
Methyl alcohol, 1,2-dichloroethane, chloroform and the like solvent and caustic soda, caustic potash, triethylamine, N, N-dimethylaniline, N, N-diethylaniline and the like in the presence of a neutralizing agent at about 40 ℃ or more, preferably about 50 ~ 90 ℃
Heat to. If the reaction temperature is lower than about 40 ° C, the reaction rate becomes slow and the reaction takes a long time, which is not preferable.

The reaction is carried out at the above temperature for about 0.1 to 7 hours. The optimum time within the range is appropriately determined depending on the reaction temperature, the reaction solution concentration, the kind of the halogenated alkylcarboxylic acid compound, and the like. However, it is possible to react for a longer time.

The reaction is generally carried out at normal pressure, but it can be carried out under pressure.

The reaction ratio of the amidine hydrolysis resin and the halogenated alkylcarboxylic acid compound is based on 1 equivalent of the basic group in the resin.
It may be used in an amount of 0.5 mol or more, preferably 1.0 mol or more.However, the use of more than necessary halogenated alkylcarboxylic acid compound complicates the processing operation accompanied by the recovery process after the reaction, and the basic group in the amidine hydrolyzed resin is When the amount of the halogenated alkylcarboxylic acid compound to be used is less than the above amount, the addition amount of the alkylcarboxylic acid decreases, and the metal-capturing ability of the resulting reaction-generated chelate resin decreases. Therefore, the basic group 1 or the like in the resin is preferably used. The halogenated alkylcarboxylic acid compound is used in an amount of 1.0 to 3 mol based on the amount.

The neutralizing agent used in the present invention is a hydrogen halide and a basicity of a halogenated alkylcarboxylic acid compound which are by-produced by a reaction between the basic group in the amidine hydrolyzed resin and the halogenated alkylcarboxylic acid compound. The salt serves to neutralize the reaction, and the reaction ratio of the neutralizing agent is preferably a total equivalent of the amount of hydrogen halide by-produced and the amount of carboxylic acid of the halogenated alkylcarboxylic acid.

Generally, a carboxylic acid of a halogenated alkyl carboxylic acid compound and an equivalent amount of a neutralizing agent are added in advance to form a salt of a halogenated alkyl carboxylic acid compound, and a by-product is produced by reacting the salt of a halogenated alkyl carboxylic acid compound with an amidine hydrolysis resin. Depending on the amount of halogen acid to be used, a method of gradually adding a neutralizing agent is adopted.

The amount and method of addition of the neutralizing agent differ depending on the reaction conditions of the amidine hydrolyzed resin and the halogenated alkylcarboxylic acid compound, and therefore appropriate addition conditions are adopted by preliminary experiments.

The reaction between the amidine hydrolyzed resin and the acrylic acid compound is a known reaction known as a so-called Michael addition reaction.

The reaction is carried out in a solvent such as water, ethyl alcohol, methyl alcohol, dimethylformamide or the like at about 50 ° C or higher, preferably about 60-100 ° C. If the reaction temperature is lower than 50 ° C, the reaction rate becomes slow and the reaction takes a long time, which is not preferable.

The reaction is preferably carried out at the above temperatures for about 0.5-10 hours.

The reaction is generally carried out at normal pressure, but it can be carried out under pressure.

The reaction ratio between the amidine hydrolyzed resin and the acrylic acid-based compound may be about 0.25 mol or more, preferably about 0.5 mol or more, based on 1 equivalent of the basic group in the resin. If it is used, the treatment operation without the recovery treatment after the reaction becomes complicated, and the acrylic acid compound used for the resin that hydrolyzes amidine is not used.
If the amount is less than 0.25 mol, the addition amount of the acrylic acid compound decreases and the metal-capturing ability of the resulting reaction-generated chelate resin decreases. Therefore, the acrylic acid compound in the resin is preferably contained in 1 equivalent of the basic group. About 0.5-3.0 moles are used.

The above-mentioned amidine hydrolysis resin and acrylic acid compound, or
Among the resins obtained by the reaction with acrylic acid ester, in the case of the reaction with acrylic acid ester, during the above reaction,
Alternatively, after the reaction, hydrolysis treatment is performed under normal ester hydrolysis conditions.

The hydrolysis treatment of ester is generally performed in the presence of ca. 2 times or more molar amount of caustic alkali metal or caustic alkaline earth metal with respect to acrylic acid ester at a temperature of about 80.degree.
5 hours or more.

If the amount of caustic alkali metal or caustic alkaline earth metal, the reaction temperature, or the reaction time is lower than the above conditions, hydrolysis of the ester is not sufficiently performed, which is not preferable.

The amount of caustic alkali metal or caustic alkaline earth metal is about 2 times or more, and usually about 3 to 10 times the molar amount of acrylic acid ester.

The reaction temperature is about 80 ° C. or higher, preferably about 90 to 150 ° C. When the reaction temperature is 150 ° C. or higher, the elimination reaction of the acrylic acid group introduced by the reaction occurs concurrently, which is not preferable.

The reaction time is generally about 0.5 hours or longer, preferably about 1 to
It is carried out for 8 hours, and the optimum time within that range is appropriately determined depending on the reaction temperature, the amount and concentration of caustic alkali metal, caustic alkaline earth metal, and the like. However, the reaction can be continued for a longer time.

The reaction is generally carried out at normal pressure, but it can be carried out under pressure.

Regarding the reaction method of (3), the acid amide resin used as the base resin of the chelate resin of the present invention is ethylenediamine instead of the aminocarboxylic acid compound in the reaction of the resin having the carbonyl chloride group and the aminocarboxylic acid compound. Other than using amino compounds such as polyalkylene polyamines such as trimethylenediamine, tetramethylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine and hexamethyleneheptamine, hydrazine and granidine. The molar ratio, the use of the solvent, the reaction temperature, the reaction time and the like are almost the same as described above.

The acid amide resin which is the base resin of the chelate resin of the present invention produced as described above is almost the same as the reaction between the amidine hydrolysis resin and the halogenated alkylcarboxylic acid compound or the amidine hydrolysis resin and the acrylic acid compound. Similarly, the alkylcarboxylic acid group is introduced into the basic group in the acid amide resin to produce the chelate resin having the aminocarboxylic acid group of the present invention.

Regarding the reaction method of (4), the condensation reaction acid amide resin used as the base resin of the chelate resin of the present invention is ethylenediamine, trimethylenediamine, tetramethylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine to the acrylic acid resin. , Polyethylene polyamines such as tetraethylene pentamine, pentaethylene hexamine, hexamethylene heptamine, solvent-free amino compounds such as hydrazine and guanidine, or toluene,
Benzene, xylene, dimethylformamide, cyclohexane in a solvent such as about 130 ℃ or more, preferably about 150 ~ 180
Perform the reaction at ℃. If the reaction temperature is 130 ° C. or lower, the dehydration condensation reaction rate of the acrylic acid group or acrylic acid ester group of the acrylic acid resin and the amino compound becomes slow, and a long reaction time is required, which is not preferable.

The reaction is preferably carried out at the above temperature for 0.5 to 10 hours. The optimum time within the range is appropriately determined depending on the reaction temperature, the reaction solution concentration, the type of amino compound, and the like. However, it is possible to react for a longer time.

The reaction can be carried out under normal pressure as long as the temperature is 130 ° C. or higher, but it is generally carried out under pressure.

The reaction ratio of the acrylic acid resin and the amino compound is about 0.5 mol or more based on 1 mol of the acrylic acid or acrylate group in the resin.

The use of more amino compounds than necessary complicates the processing operation accompanied by recovery treatment after the reaction, and when the amount of the amino compound used for the acrylic acid resin is less than the above, the substitution of the amino compound is reduced and the next step is performed. Since the amount of carboxylic acid groups introduced in the resin becomes small and the metal adsorption capacity of the resulting chelate resin obtained by the reaction decreases, it is preferable that the amount of the amino compound is about 1 to 3 with respect to 1 mol of acrylic acid or acrylate group in the resin. Used in moles.

The condensation reaction acid amide resin, which is the base resin of the chelate resin of the present invention produced as described above, is obtained by reacting the amidine hydrolysis resin with a halogenated alkylcarboxylic acid compound or the amidine hydrolysis resin with an acrylic acid compound. Almost in the same manner as described above, the alkylcarboxylic acid group is introduced into the basic group in the condensation reaction acid amide resin to produce the chelate resin having the aminocarboxylic acid group of the present invention.

The chelate resin having an aminocarboxylic acid group of the present invention produced as described above can be used as it is or after washing and drying, but if necessary, the chelate resin is further treated with a base or an acid before use. You can also

In the present invention, a chelating resin having an aminocarboxylic acid group having the above-mentioned specific structure is brought into contact with a plating bath,
The plating bath refers to an acidic plating bath such as an acidic plating bath of nickel, copper or zinc, an electrolytic coloring bath of aluminum or aluminum alloy, an alumite dyeing bath of aluminum or aluminum alloy, a chromate treatment bath, or the like.

The impurity metal ions of the present invention depend on the composition of the material to be plated, but the metal ion components that are generally problematic include iron, nickel, copper, aluminum, manganese, vanadium, zinc, lead, and cadmium.

The chelating resin having an aminocarboxylic acid group having a specific structure used in the present invention has a high selective adsorptivity for iron ions and copper ions, while having little adsorptivity for nickel and zinc. Therefore, the present invention is preferably used for removing iron ions and copper ions contained in nickel and zinc plating baths.

In carrying out the contact treatment between the plating bath and the chelate resin, the pH of the plating bath is preferably in the range of about 0.5 to 4 in order to prevent the adsorption of impurity metal ions in the plating bath from the chelate resin from being lowered. When the pH of the plating bath is less than about 0.5, the adsorbed amount of the impurity metal ions decreases, and when the pH becomes about 4 or more, the adsorbed amount of nickel and zinc increases, which is not preferable.

The method of contacting the plating bath with the chelate resin is not particularly limited, and for example, a method of passing the plating bath through a tower filled with the chelate resin, immersing the chelate resin in the plating bath, and then separating by filtration. The method of doing is adopted.

The contact temperature between the plating bath and the chelate resin is not particularly limited, and is usually 0 to 100 ° C. Moreover, the contact time is not particularly limited.

The amount of chelating resin to be used with respect to the plating bath amount, the contact temperature, the contact time, and the like can be set by appropriately performing preliminary experiments.

Impurity metal ions adsorbed by the chelate resin of the present invention can be eluted and recovered by using an appropriate eluent.
An acidic aqueous solution of hydrochloric acid, nitric acid, phosphoric acid, sulfuric acid or the like is used as the eluent.

In this way, the chelate resin after desorbing the impurity metal ions is used as it is or if necessary, with water and / or sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium hydroxide, or a basic aqueous solution of ammonia. After the treatment, it can be repeatedly used to adsorb the impurity metal ions in the plating bath again.

<Effects of the Invention> The chelate resin having an aminocarboxylic acid group of the above-described specific structure of the present invention has a large adsorption capacity for impurity metal ions such as iron ions in a plating bath, and significantly reduces the adsorption equilibrium concentration of impurity metal ions. Therefore, its industrial value is extremely high.

<Examples> The present invention will be described in more detail with reference to Examples below, but the present invention is not limited to the following Examples unless the gist thereof is exceeded.

Example 1 2060 parts by weight of diethylenetriamine, which is an amino compound, and 360 parts by weight of water were added to 640 parts by weight of an acrylonitrile-divinylbenzene copolymer having a degree of crosslinking of 6 mol%, and 135 to 150
When the reaction was carried out at 6 ° C for 6 hours, 136 parts by weight of ammonia was generated. When the reaction product was filtered and washed with water, 2310 parts by weight (undried) of amidine hydrolyzed resin was obtained.

Next, to 231 parts by weight of the obtained amidine hydrolyzed resin, 144 parts by weight of acrylic acid and 500 parts by weight of water were added, reacted at 70 ° C. for 6 hours, filtered and washed with water. Next, the obtained resin was immersed in 500 parts by weight of a 10% by weight aqueous caustic soda solution at room temperature for 30 minutes and then filtered and washed with water to obtain 339 parts by weight (undried) of the chelate resin.

In the obtained chelate resin, 2.2 mol /-resin The functional group of was recognized.

120 ml of Zn ^{2+ and} 500 m of Fe ^{3+ in} 2 ml of the obtained chelating resin
50m zinc coating bath with pH 1.8 containing g /, 400mg / of Cu ²⁺
In addition to 1, the mixture was shaken for 3 hours and then separated into a chelate resin and an aqueous layer. First analysis of Fe and Cu concentrations in the water layer
The results shown in the table were obtained.

Examples 2 and 3 The resin production and adsorption test were performed in the same manner as in Example 1 except that the type and amount of the amino compound used in Example 1 were changed. The results are shown in Table 2.

Example 4 1250 parts by weight of a methyl methacrylate-divinylbenzene copolymer having a degree of crosslinking of 10 mol% and 4120 parts by weight of an amino compound, diethylenetriamine, were reacted in an autoclave at 170 ° C. for 7 hours to carry out a dehydration condensation reaction. Part (undried) condensation reaction acid amide resin was obtained.

Next, 141 parts by weight of monochloroacetic acid, which is a halogenated alkylcarboxylic acid compound, and 353 parts by weight of a condensation reaction acid amide resin obtained by previously dissolving 60 parts by weight of caustic soda in 1000 parts by weight of water are added, and the mixture is treated at 70 ° C. for 6 hours. Was carried out.

During the reaction, 480 parts by weight of a 10% by weight aqueous sodium hydroxide solution was added over about 3 hours. After the reaction, filtration and washing with water yielded 43.5 parts by weight (undried) of the chelate resin.
The resulting chelate resin contained 1.5 mol / -resin The following functional groups were recognized.

Then, an adsorption test was conducted on the obtained resin in the same manner as in Example 1. The concentrations of Fe and Cu on the aqueous layer side were 132 and 76 mg /, respectively.

Example 5 100 parts by weight of N, N-dimethylformamide and 3000 parts by weight of 1,2-dichloroethane were added to 1000 parts by weight of a crosslinked 8 mol% acrylic acid-glycidyl methacrylate copolymer, and the mixture was heated at 90 ° C.
While maintaining the temperature at 1978, 1978 parts by weight of carbonyl chloride was blown in for 14 hours to chlorinate the carboxylic acid group of the acrylic acid-glycidyl methacrylate copolymer, which was filtered and dried.
A resin having 80 parts by weight of carbonyl chloride group was obtained.
Next, 162 parts by weight of 8-amido-3,6-azaoctanoic acid and 112 parts by weight of caustic potash were dissolved in 1000 parts by weight of water in advance, and 118 parts by weight of a resin having a carbonyl chloride group obtained was added at 60 ° C. The reaction was carried out for 2 hours. After the reaction, filtration and washing with water gave 453 parts by weight (undried) of the chelate resin.

In the obtained chelate resin, 1.4 mol / − resin The functional group of was recognized.

An adsorption test was performed on the obtained chelate resin in the same manner as in Example 1. The concentrations of Fe and Cu in the water tank were 149 and 73 mg /
Met.

Comparative Example 1 To 1090 parts by weight of 4% by weight divinylbenzene-crosslinked polystyrene, 2730 parts by weight of chloromethyl methyl ether and 3540 parts by weight of tetrachloroethylene were added, and the mixture was stirred at room temperature for 30 minutes to swell the polystyrene and then to 50 ° C. The temperature was raised.

Anhydrous zinc chloride (550 parts by weight) was added thereto over 1 hour, and the mixture was reacted at this temperature for 2 hours and dried to obtain 1440 parts by weight of chloromethylated polystyrene.

To 720 parts by weight of the chloromethylated polystyrene obtained above, 358 parts by weight of sodium iminodiacetate and 2000 parts by weight of water were added and the reaction was carried out at 70 to 80 ° C. for 6 hours.

After the reaction was started, 1000 parts by weight of 1N aqueous sodium hydroxide solution was added over 3 hours.

After the reaction, filtration and washing with water yielded 2338 parts by weight (undried) of the chelate resin.

The resulting Chelating resin, 2.2 mol / - is _{-CH 2 -N (CH 2 COONa)} 2 functional groups of the resin was observed.

An adsorption test was conducted on the obtained chelate resin in the same manner as in Example 1. The FeCu concentrations on the aqueous layer side were 242 and 196 mg /
Met.

Comparative Example 2 A mixed aqueous solution of 47.0 parts by weight of phenol, 66.5 parts by weight of iminodiacetic acid and 40.5 parts by weight of 37% by weight formalin was heated to 70 ° C. from room temperature.
The temperature is raised to 40 minutes, and the mixture is heated and stirred at 70 to 73 ° C for 2 hours, then cooled to 40 ° C and 60 parts by weight of caustic soda is added to the ion-exchanged water.
What was melt | dissolved in 0 weight part was added, and pH of the reaction system was adjusted to 12.8.

Next, 162.0 parts by weight of 37% by weight formalin was added, gradually heated and heated to 70 ° C. 40 minutes later, reacted at 70 to 90 ° C. for 3 hours, and then 47.0 parts by weight of phenol was added, followed by 70% by weight.
After reacting at 90 ° C for 1 hour, the reaction system was kept at 90 ° C to 100 ° C and 115.0 parts by weight of water was distilled off under reduced pressure to obtain 249 parts by weight of a viscous reddish brown resin composition. The obtained resin composition was heat-cured for 3 hours at 130 ° C. in a hot air dryer and then pulverized to obtain 243 parts by weight of a chelate resin.

The resulting chelate resin, 2.3 mol / - is _{-CH 2 N (CH 2 COONa)} 2 functional groups of the resin was observed.

An adsorption test was conducted on the obtained chelate resin in the same manner as in Example 1, and the Fe and Cu concentrations in the water tank were 196 and 172 mg /
Met.

Examples 6 to 11 and Comparative Examples 3 to 5 Adsorption test was conducted in the same manner as in Example 1 except that the same chelating resin as that used in Examples 1, 4 and Comparative Example 1 was used and the pH of the solution was changed. It was The results are shown in Table 3.

Examples 12 and 13 Comparative Examples 6 and 7 10 ml of the same chelating resin as used in Examples 1 and 4 and Comparative Example 2 was packed in a glass column having an inner diameter of 9 mmφ, and
The plating bath 1 having the composition shown in the table is passed through at SV = 10 Hr ⁻¹ , and Fe
^{After 3+} was adsorbed, it was washed with water. Then, 2N-H ₂ SO ₄ 50m
1 was passed through with SV = 10 Hr ⁻¹ to elute the metal ions adsorbed on the chelate resin. The results are shown in Table 5.

From Examples 1 to 14 and Comparative Examples 1 to 7, the chelate resin of the present invention has a higher adsorption capacity for impurity metal ions in the plating bath than known chelate resins, and selective adsorption for impurity metal ions. Clearly,

Claims (4)

[Claims] 1. A general formula A method for purifying a plating bath, which comprises contacting a chelating resin having an aminocarboxylic acid group with an acidic plating bath to adsorb and remove impurity metal ions in the plating bath. 2. The pH of the plating bath contacted with the chelating resin is
The method for purifying a plating bath according to claim 1, wherein the method is 0.5 to 4. 3. The method for purifying a plating bath according to claim 1, wherein the plating bath is a zinc or nickel plating bath. 4. The method for purifying a plating bath according to claim 1, wherein the impurity metal ions in the plating bath are iron ions and steel ions.