JPH07213897A - Polymer heavy metal collecting agent, alkali metal dithiocarbramate polymer and their production - Google Patents

Abstract

PURPOSE:To efficiently remove heavy metal ions by using such a specified polyallylamine polymer as a heavy metal collecting agent that a specified ratio of the total amt. of primary and secondary amino groups (NH) is changed into alkali metal dithiocarbamate. CONSTITUTION:This collecting agent contains such a polymer of polyallylamine polymer expressed by formula I or formula II that 70-100% of total of the primary and secondary amino groups (NH) of the polymer are changed into alkali metal dithiocarbamate expressed by N-C(=S)-SM wherein M is Li, Na, or K. In formula I, R<2> is a 1-6C alkyl group or a 5-7C cycloalkyl group, (m) is the polymn. degree, (j) is 0<=j<=1. In formula II, R<1> is H, a 1-6C alkyl group or a 5-7C cycloalkyl group, R<2> is H or methyl, (m) is the polymn. degree and (j) is 0<=j<=1. The polymer collecting agent for heavy metals has excellent sedimentation property of the produced collecting agent-heavy metal complex and has good removing performance for heavy metal ions. Even when an amt. of the collecting agent more than the equiv. of the heavy metal ions is used, the collecting effect is neary unchanged.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polymer heavy metal scavenger,
TECHNICAL FIELD The present invention relates to an alkali metal dithiocarbamate chlorinated polymer and a method for producing the same. More specifically, the present invention relates to a high molecular weight heavy metal scavenger, an alkali metal dithiocarbamate chlorinated polymer, which has a good ability to remove heavy metal ions and an excellent sedimentation / separation property of a formed metal complex, and a method for producing them.

[0002]

2. Description of the Related Art Heavy metal ions are highly toxic
For wastewater treatment at plating factories and wastewater treatment at garbage incinerators, etc.
An efficient method for removing heavy metal ions is required. Conventionally,
As a method for treating wastewater containing heavy metal ions, a neutralization coagulation sedimentation method, a sodium sulfide method, an adsorption method with a chelate resin, a method with a high molecular weight heavy metal scavenger, etc. are known (Fine Chemical, August 1, 1985). No., p. 16).

The neutralization coagulation sedimentation method has a low running cost. However, although the insoluble metal hydroxide produced is stable on the alkaline side, it has the drawback of being re-eluted on the acidic side. Further, the sodium sulfide method has a problem of secondary pollution because it produces hydrogen sulfide. On the other hand, in the adsorption method using a chelate resin, since organic substances are also adsorbed, the efficiency of collecting heavy metal ions is reduced.

On the other hand, the method using a polymer heavy metal scavenger does not cause re-elution on the acidic side, does not cause secondary pollution, and does not adsorb with organic substances. Also, the processing operation is simple (Japanese Patent Laid-Open No. 60-193585). Therefore, an excellent treatment effect is recognized (Fine Chemical, August 1, 1985, p. 16). Known examples of the heavy metal heavy metal scavenger include polyethyleneimine sodium dithiocarbamate polymer, polyvinylamine sodium dithiocarbamate polymer, sodium cellulose xanthate, and sodium polyglutamate.

Among these high molecular weight heavy metal scavengers, a sodium dithiocarbamate polymer of polyethyleneimine is practically used because it is easy to produce. However, the sodium dithiocarbamate polymer of polyethyleneimine has some problems. That is, this polymer has a poor ability to remove heavy metal ions because of insufficient reaction with heavy metal ions. In addition, since the complex formed with the metal is not well precipitated and separated, it takes a long time to remove heavy metal ions. Further, usually, a slight excess of the amount of the polymer is used for the removal of the heavy metal as compared with the heavy metal ions present. However, if this polymer is used in an excessive amount, the formed precipitate is dissolved and redispersion occurs. Therefore, the sedimentation and separability becomes worse. As a result, the removal of heavy metal ions is insufficient and it takes time.

[0006]

The problem to be solved by the present invention is to provide a polymer heavy metal scavenger which is excellent in the sedimentation / separation property of the formed metal complex and has a good ability to remove heavy metal ions.
An object is to provide an alkali metal dithiocarbamate polymer and a method for producing the same. In particular, even when using a slight excess of the scavenger compared to the existing heavy metal ions, the ability to remove heavy metal ions does not decrease, redispersion does not occur, and
It is an object of the present invention to provide a high molecular weight heavy metal scavenger excellent in sedimentation / separation property, an alkali metal dithiocarbamate polymer, and a method for producing the same.

[0007]

[Means for Solving the Problems] The inventors of the present invention have conducted extensive studies on a polymeric heavy metal scavenger and a method for producing the same. As a result, surprisingly, 70 to 100% of the total amount of primary and secondary amino groups (NH) of a certain polyallylamine-based polymer is dithiocarbamate alkali metal chloride (NC (= It was found that heavy metal ions can be efficiently removed by using a polymer obtained by S) -SM, where M represents an alkali metal) as a heavy metal scavenger. The present invention has been achieved by such knowledge.

The polymeric heavy metal scavenger of the present invention has the general formula

[Chemical 13] (In the formula, R ¹ is alkyl having ¹ to 6 carbons and 5 to 7 carbons.
Selected from cycloalkyl of m, m represents the degree of polymerization, and j represents 0 ≦ j ≦ 1) or the general formula

[Chemical 14] (In the formula, R ¹ is selected from hydrogen, alkyl having ^{1 to} 6 carbons and cycloalkyl having 5 to 7 carbons, R ² is selected from hydrogen and methyl, m is the degree of polymerization, and j is 0 < In the polyallylamine-based polymer represented by j ≦ 1), the total of primary and secondary amino groups (NH) is 70-100.
% Is an alkali metal dithiocarbamate chloride (NC)
(= S) -SM, where M is a polymer selected from alkali metals such as Li, Na, and K) (hereinafter sometimes referred to as the polymer of the present invention). That is, the polymer of the present invention is 70-100 mol% based on the monomer incorporated in the polyallylamine polymer.
N-dithiocarbamate alkali metal chloride.

The polymer heavy metal scavenger of the present invention or the polymer of the present invention has the general formula

[Chemical 15] (In the formula, R ¹ is alkyl having ¹ to 6 carbons and 5 to 7 carbons.
Selected from cycloalkyl of m, m represents the degree of polymerization, and j represents 0 ≦ j ≦ 1) or the general formula

[Chemical 16] (In the formula, R ¹ is selected from hydrogen, alkyl having ^{1 to} 6 carbons and cycloalkyl having 5 to 7 carbons, R ² is selected from hydrogen and methyl, m is the degree of polymerization, and j is 0 < A polyallylamine-based polymer represented by j ≦ 1) can be synthesized as a starting material.

Usually, the salt of the raw material polyallylamine-based polymer can be produced by a known method in which a salt of one or two suitable allylamine-based monomers is radically polymerized. The free polyallylamine-based polymer as a raw material can be obtained by neutralizing the salt of the polyallylamine-based polymer with an alkali such as sodium hydroxide and then removing the salt produced by the dialysis treatment. For example, starting polyallylamine polymers and salts thereof are disclosed in Japanese Patent Publication No. 2-14364 and Japanese Patent Publication No. 2-056.
361, Japanese Patent Publication No. 2-052362, Japanese Patent Publication No. 63-043
402, Japanese Patent Publication 2-056365, Japanese Patent Publication 2-0570
84, JP-B-4-041686 and JP-A-63-286.
It can be manufactured by the method described in 405. Alternatively, a commercially available product from Nitto Boseki Co., Ltd. may be used. Salt is
Although not particularly limited, hydrochloride, phosphate, acetate or the like can be used.

The heavy metal heavy metal scavenger of the present invention or the polymer of the present invention is obtained by adding the polyallylamine polymer or its salt as a raw material to an alkali metal N-dithiocarbamate in the presence of carbon disulfide (CS ₂ ) and an alkali. Chloride (N-C (= S)-
SM, provided that M is selected from the alkali metals Li, Na and K). The production method applies that the primary or secondary amino group reacts with carbon disulfide in the presence of an alkali to form an N-dithiocarbamic acid alkali metal salt.

[Chemical 17] However, X is selected from alkyl and Y is selected from hydrogen and alkyl.

In the production method of the present invention, the raw material polyallylamine-based polymer is dissolved or suspended in a suitable solvent and reacted. The solvent is the solubility of the raw material alkali,
Water is preferred. The amount of solvent is not particularly limited,
Usually, it is used in a concentration range such that the starting polyallylamine polymer is 5-70% by weight, preferably 10-50% by weight. When a salt of a polyallylamine polymer is used as a raw material, it can be used at a higher concentration.

The amount of carbon disulfide is usually 7 based on the monomer incorporated in the raw material polyallylamine polymer.
0-1000 mol%, preferably 70-120 mol%,
More preferably, 80-110 mol% is used. The amount of carbon disulfide is determined by using a polymer heavy metal scavenger N-dithiocarbamate alkali metal chloride (N-C (= S) -SM,
However, M affects the ratio of Li, Na, and K selected from alkali metals. When the amount of carbon disulfide is small, a polymer heavy metal scavenger with a low proportion of alkali metal N-dithiocarbamate is formed. If the amount is too large, substantially 100% of amino groups can be chlorinated by alkali metal N-dithiocarbamate, but carbon disulfide is wasted and at the same time post-treatment is difficult. When producing a high molecular weight heavy metal scavenger in which the amino group of the polyallylamine-based polymer is substantially 100% alkali metal N-dithiocarbamate, carbon disulfide is incorporated into the raw material polyallylamine-based polymer. Normally, 100-1
20 mol%, preferably 100-110 mol% is used.

As the alkali, usually sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, potassium carbonate can be used. Preferably sodium hydroxide is used. The amount of alkali is usually equimolar equivalent to carbon disulfide. The solvent that dissolves the alkali is usually water. The amount of solvent depends on the alkali used. In the case of sodium hydroxide, it is used by dissolving it in water so that the alkali concentration becomes 5 to 50% by weight, preferably 10 to 50% by weight. When the raw material polymer is a salt, the salt is freed and added in excess.

The reaction time and reaction temperature can be appropriately changed depending on the polymer heavy metal scavenger to be obtained. However, the reaction temperature is usually because the boiling point of carbon disulfide is low.
The temperature of the reaction system is 60 ° C or lower, preferably 10-55 ° C,
More preferably, the temperature is 20-50 ° C. The reaction time is usually 10 hours or less.

The order of adding the reagents is not particularly limited,
Be careful of exothermic reactions. For example, the polymer heavy metal scavenger can be produced by the following procedure. Carbon disulfide is added to an aqueous solution or suspension of a polyallylamine-based polymer as a raw material.
Next, while stirring at an internal temperature of 20 to 50 ° C., an alkaline aqueous solution is added and reacted. At this time, paying attention to heat generation, the temperature of the reaction system is adjusted so that the temperature does not exceed 50 ° C. After completion of the dropping, the reaction is continued at 20-50 ° C for 2-5 hours. At this time, it is more preferable to set the temperature to 25-40 ° C. from the viewpoint of reaction efficiency and safety. In this manufacturing operation, alkali was added before adding carbon disulfide,
While maintaining the temperature at 45 ° C, carbon disulfide may be added while paying attention to heat generation. Further, while maintaining the reaction system at 20 to 45 ° C., carbon disulfide and alkali may be dropped simultaneously from separate dropping ports. Further, in the case of a small scale, carbon disulfide and alkali can be added all at once at 30 ° C. or lower, cooled to maintain the temperature at 25-40 ° C., and the reaction can be carried out for 2-7 hours.

The solution after completion of the reaction can be used as it is as a high molecular weight heavy metal scavenger. The solution was added to a large amount of acetone to cause precipitation, which was collected by filtration and dried,
The polymer of the present invention can be obtained. The polymer of the present invention is usually obtained as a yellow powder.

The weight average molecular weight of the polymer of the present invention depends on the weight average molecular weight of the raw material polyallylamine polymer or its salt and the amount of carbon disulfide. The weight average molecular weight of the polymer of the present invention is not particularly limited, but is usually 1000-
10,000,000, preferably 1500-5,00
10,000, more preferably 2000-2,000,0
00. If the weight average molecular weight is too small, the heavy metal scavenger has poor sedimentation and separation properties. If it is too large, it is difficult to dissolve and the workability deteriorates.

The repeating unit of the polymer of the present invention depends on the repeating unit of the raw material polyallylamine polymer. Further, the proportion of the polymer of the present invention salified with an alkali metal N-dithiocarbamate is usually 70-100%, preferably 80-100%, more preferably 90-100%. The ratio can usually be determined from elemental analysis values. The ratio is determined by decomposing the polymer of the present invention with dilute sulfuric acid, quantitatively generating carbon disulfide as xanthate, and titrating with iodine (Industrial Chemistry Magazine, Vol. 69, 766).
Page, 1966). In the infrared spectrum of the polymer of the present invention, a strong absorption is usually observed near 960 cm ⁻¹ based on the C═S bond and a strong absorption near 1375 cm ⁻¹ based on the N—C═S N—C bond.

The polymeric metal scavenger of the present invention contains the polymer of the present invention as an essential component. The polymeric metal scavenger of the present invention can be used alone as an aqueous solution of preferably 0.05-10%, more preferably 1-5%. The amount added depends on the content of heavy metal ions in the waste water and can be calculated by the following formula. Addition amount = (Mw x amount g of heavy metal ion of waste water) / equivalent g of metal ion. However, 1 equivalent of metal ion = atomic weight / charge number, Mw =
The weight average molecular weight of the polymer of the present invention / (degree of polymerization of the polymer of the present invention x ratio of N-dithiocarbamic acid alkali metal chloride).

The polymeric heavy metal scavenger of the present invention may contain a substance which is usually added to the scavenger, if necessary. For example, you may use together with sodium sulfide, sodium polysulfide, and sodium hydrosulfide. It is also possible to use together with conventionally known anionic, nonionic and cationic polymer flocculants. On the other hand, the heavy metal ion concentration in the waste water varies, so the polymer of the present invention can be added in a slightly larger amount. Ferric chloride or the like can also be used for insolubilization with this excess amount of the polymer of the present invention. The polymeric heavy metal scavenger of the present invention has a higher removal rate of heavy metal ions than the conventional scavengers, for example, a sodium dithiocarbamate polymer of polyethyleneimine, and has a very good sedimentation / separation property of the resulting complex. is there.

[0022]

The polymer of the present invention is similar to the conventional heavy metal heavy metal scavenger (Fine Chemical, August 1, 1985, 16).
Page), and is believed to form a 1: 1 complex with heavy metal ions. As shown in Table 2 of Example 7, the 1: 1 complex is supported because most of the metal is removed when the amount of the polymer of the present invention added is 1 equivalent to the heavy metal ion. It It is believed that the structure of this complex is related to the good heavy metal collecting ability of the present invention. Allylamine unit CH ₂ C (R
² ) CH ₂ N (wherein R ² is selected from hydrogen and methyl) is an ethyleneimine unit CH ₂ CH _{2 of a} sodium dithiocarbamate polymer of polyethyleneimine.
The structure is more hydrophobic than N. Therefore, the complex formed by the reaction between the polymer of the present invention and the heavy metal ion is also more hydrophobic than the conventional scavenger-metal complex. Therefore, it is considered that the produced complex is easy to hold as a precipitate and does not dissolve in water. Furthermore, the reason why the heavy metal scavenging ability is not decreased by using the excess heavy metal scavenger of the present invention is considered to be because the complex becomes more insoluble.

The heavy metal scavenger of the present invention is 70-100%
And the ratio of alkali metal dithiocarbamate (hereinafter,
(Also referred to as the substitution rate) is high. This is considered to be one of the reasons for the high ability to remove heavy metals. On the other hand, in the case of a sodium dithiocarbamate polymer of polyethyleneimine, the substitution rate is low. The reason for this is that a considerable part of the amino group of polyethyleneimine as a raw material has a branched structure, that is, a tertiary amino group and does not react with carbon disulfide. Also, the secondary amino group part of the raw material polyethyleneimine is a part that forms the main chain of the polymer, so the reactivity is poor, so the secondary amino group that does not react with carbon disulfide also acts as a scavenger. It is possible that they will exist. In any case, the polyethyleneimine sodium dithiocarbamate polymer has a high proportion of free amine that is not sodium dithiocarbamate. Therefore, the formed complex with a heavy metal has high hydrophilicity and is easily dissolved in water. Therefore, it can be considered that the sodium dithiocarbamate polymer of polyethyleneimine does not have a high heavy metal removing ability due to the hydrophobicity, unlike the polymer of the present invention. As described above, the excellent heavy metal removing ability of the heavy metal scavenger of the present invention is considered to be due to the structure peculiar to the polymer of the present invention.

[0024]

EXAMPLES The polymer heavy metal scavenger of the present invention, the polymers of the present invention, and the methods for producing them will be shown below in Examples. Of course, the invention is not limited to these examples.

Example 1 Known polyallylamine as a raw material was polyallylamine hydrochloride (manufactured by Nitto Boseki Co., Ltd., code PAA-HCl-10L, weight average molecular weight 100,000) as disclosed in JP-A-63-286.
After neutralizing with sodium hydroxide by the method described in No. 405, it was dialyzed to remove salt by-product and used. 380.64 g of a 15% aqueous solution of polyallylamine and 378.00 g of distilled water are placed in a 2 liter reactor equipped with stirrer, dropping funnel, thermometer and reflux condenser. To this was added 200 g of a 20% aqueous solution of sodium hydroxide. Next, while maintaining the temperature at 30 ° C. under stirring, 76.14 g of carbon disulfide was gradually added dropwise. 40 after the dropping
When the reaction was continued at 4 ° C for 4 hours, a transparent and pale yellow solution was obtained. This solution can be used as it is as a polymer heavy metal scavenger. This solution was added to a large amount of acetone, and the precipitated product was filtered off. When dried at room temperature under reduced pressure, 1
49.6 g (96%) of polyallylamine sodium dithiocarbamate polymer was obtained. The elemental analysis results are
C = 30.64%, H = 3.95%, N = 9.05%,
It was S = 41.07%. These values are calculated values C ₄
Value based on H ₆ NS ₂ Na, C = 30.95%, H =
It was in agreement with 3.90%, N = 9.02%, and S = 41.32%. This result shows that the obtained sodium dithiocarbamate polymer is substantially 100% sodium dithiocarbamate.

Example 2 A raw material copolymer of allylamine and diallylamine (molar ratio 4: 1) was a copolymer of allylamine hydrochloride and diallylamine hydrochloride (molar ratio 4: 1, Japanese Patent Publication No. 2-563).
Weight average molecular weight 1 produced by the method described in 65.
50,000) was neutralized and dialyzed by the method described in JP-A-63-286405. Copolymer of allylamine and diallylamine (molar ratio 4:
43% of a 15% aqueous solution of 1) and distilled water of 378.0
0 g was placed in the same reaction vessel as in Example 1, and 200 g of a 20% aqueous solution of sodium hydroxide was added thereto. next,
While maintaining the temperature at 30 ° C. under stirring, carbon disulfide 76.
14 g was gradually added dropwise. After the dropping was completed, the reaction was continued at 40 ° C. for 4 hours to obtain a transparent, pale yellow polymer heavy metal scavenger solution. This solution was post-treated in the same manner as in Example 1 to obtain 158.4 g (97%) of a copolymer of allylamine and diallylamine (molar ratio 4: 1) of sodium dithiocarbamate polymer. Elemental analysis result is C =
33.81%, H = 4.25%, N = 8.55%, S =
It was 39.15%. These values are the calculated values of C ₂₃ H of the polymer converted to 100% sodium dithiocarbamate.
Value based on ₃₄ N ₅ S ₁₀ Na ₅ , C = 33.85%, H =
It was in agreement with 4.20%, N = 8.58%, and S = 39.29%.

Example 3 As a raw material, a copolymer of allylamine and diallylamine (molar ratio 1: 2) was a copolymer of allylamine hydrochloride and diallylamine hydrochloride (molar ratio 1: 2, Japanese Patent Publication No. 2-5).
A polymer having a weight average molecular weight of 80,000 produced by the method described in JP-A No. 63-286405.
After being neutralized by the method described in 1., the dialyzed product was used. 558.71 g of a 15% aqueous solution of a copolymer of allylamine and diallylamine (molar ratio 1: 2) and distilled water 37
8.00 g was put in the same reaction vessel as in Example 1, and 200 g of a 20% aqueous solution of sodium hydroxide was added thereto.
Next, while maintaining the temperature at 30 ° C. under stirring, 76.14 g of carbon disulfide was gradually added dropwise. After the dropping was completed, the reaction was continued at 40 ° C. for 4 hours to obtain a transparent, pale yellow polymer heavy metal scavenger solution. This solution was post-treated in the same manner as in Example 1 to obtain a copolymer of allylamine and diallylamine (molar ratio 1: 2), a sodium dithiocarbamate polymer. Elemental analysis result is C = 39.56%, H
= 4.84%, N = 7.65%, S = 35.19%. These values are the calculated values of C ₁₈ H ₂₆ N ₃ S ₆ Na of the polymer polymerized with 100% sodium dithiocarbamate.
Value based on ₃ , C = 39.61%, H = 4.80%, N
= 7.70% and S = 35.25%. In Figure 1,
The infrared absorption spectrum of the obtained sodium dithiocarbamate polymer of the copolymer of allylamine and diallylamine (molar ratio 1: 2) is shown. In the spectrum,
No characteristic absorption due to primary amines and secondary amines was observed, and 960 cm ⁻¹ due to C = S bond, N—C =
There is an absorption at 1375 cm ⁻¹ due to the S—N—C bond.

Example 4 226.0 60% aqueous solution of poly (N-isopropylallylamine hydrochloride) (polymer having a weight average molecular weight of 5,000 produced by the method described in JP-B-2-57084)
6 g and 613.12 g of distilled water were placed in the same reaction vessel as in Example 1, 400 g of a 20% aqueous solution of sodium hydroxide and 76.14 g of carbon disulfide were added while keeping the temperature at 30 ° C. under stirring. At the same time, it was dripped slowly. After the dropping was completed, the reaction was continued at 40 ° C. for 4 hours to obtain a transparent, pale yellow polymer heavy metal scavenger solution. Since this solution contained salt as a by-product, it was removed. A part of this solution is used as a dialysis tube (Spectra / Spectra /
Pore 6, No. 132590, cutoff molecular weight 3,5
00) and dialyzed in distilled water. The dialysate was concentrated, added to acetone, and post-treated in the same manner as in Example 1 to obtain a poly (N-isopropylallylamine) sodium dithiocarbamate polymer. The elemental analysis results are
C = 42.54%, H = 6.19%, N = 7.05%,
It was S = 32.43%. These values are calculated values C of the polymer converted to 100% sodium dithiocarbamate.
Value based on ₇ H ₁₂ NS ₂ Na, C = 42.61%, H =
It was in agreement with 6.13%, N = 7.10%, and S = 32.50%.

Example 5 A 60% aqueous solution of poly (N-cyclohexylallylamine hydrochloride) (polymer having a weight average molecular weight of 4,000 produced by the method described in JP-B-2-57084) 292.
84 g and 813.44 g of distilled water were placed in the same reaction vessel as in Example 1, and the temperature was kept at 30 ° C. under stirring,
400 g of a 20% aqueous solution of sodium hydroxide and 76.14 g of carbon disulfide were gradually added dropwise at the same time. After the dropping is completed,
When the reaction was continued at 40 ° C. for 4 hours, a transparent light yellow polymer heavy metal scavenger solution was obtained. Since this solution contained salt as a by-product, it was removed. That is, a part of this solution was put into a dialysis tube (Spectra / Pore 6, No. 132590, cutoff molecular weight 3,500 manufactured by Spectrum Co.) and dialyzed in distilled water. The dialysate was concentrated, added to acetone, and post-treated in the same manner as in Example 1 to obtain a poly (N-cyclohexylallylamine) sodium dithiocarbamate polymer. Elemental analysis results show that C = 50.54%, H = 6.84%, N = 5.
It was 86% and S = 26.96%. These values are 1
Calculated value for polymer polymerized with 00% sodium dithiocarbamate C ₁₀ H ₁₆ NS ₂ Na, C = 50.60
%, H = 6.79%, N = 5.90%, S = 27.00
Coincided with%.

Comparative Example Polyethyleneimine (Epomin P manufactured by Nippon Shokubai Co., Ltd.)
Example 1 was prepared by adding 143.56 g of a 30% aqueous solution of -1000 and a weight average molecular weight of 70,000) and 427.07 g of distilled water.
Into the same reaction vessel as above, 150 g of a 20% aqueous solution of sodium hydroxide was added. Next, while maintaining the temperature at 30 ° C. under stirring, 57.10 g of carbon disulfide was gradually added dropwise. After the dropping was completed, the reaction was continued at 40 ° C. for 4 hours to obtain a transparent and pale yellow solution. This solution was post-treated in the same manner as in Example 1 to obtain a sodium dithiocarbamate polymer of polyethyleneimine. The elemental analysis results are
C = 28.00%, H = 3.81%, N = 11.66
%, S = 40.75%. These values are based on the calculated value C ₁₁ H ₁₇ N ₄ S ₆ Na ₃ , C = 28.31.
%, H = 3.67%, N = 12.01%, S = 41.2
Consistent with 3%, 75% of the total number of amino groups of polyethyleneimine was converted to sodium dithiocarbamate.

Example 6 Precipitation Separability of the Cadmium Complex Scavenger of the Polymer Heavy Metal Scavenger of the Present Invention Obtained in Examples 1-5 and the Polymer Heavy Metal Scavenger Obtained in Comparative Examples A comparative experiment was conducted.
The test method is as follows. Example 1 was added to 50 ml of an aqueous cadmium sulfate solution containing 100 ppm of Cd ²⁺ ions.
5 and Mw of the high molecular weight heavy metal scavengers obtained in Comparative Examples = (average molecular weight of the polymer of the present invention) / (degree of polymerization of the polymer of the present invention)
x Proportion of N-dithiocarbamate alkali metal chloride)
A 0.089 mol / l aqueous solution prepared on the basis of Cd ²⁺
It was added so that it would be 0.8, 1.0 and 1.2 times the equivalent of the ions. The pH was adjusted to 7.0, the mixture was stirred for 10 minutes, and then allowed to stand for 10 minutes. The degree of turbidity of the supernatant of these test solutions was visually determined. The results are shown in Table 1.

In the table, the sedimentation separability is good: the complex is completely precipitated and the supernatant is transparent; Normal: the complex is not completely precipitated and the supernatant is slightly turbid; Bad: the complex is completely Represents a state in which the supernatant does not settle and the supernatant is heavily turbid. The polymeric heavy metal scavengers of the present invention obtained in Examples 1-5 have good sedimentation and separability of the complex at the addition amounts of 0.8, 1.0 and 1.2 equivalents, but the scavengers of Comparative Examples. Had poor results when used at 1.2 equivalents.

[Chemical 18]

Example 7 A comparative experiment was conducted on the ability of the polymeric heavy metal scavengers of the present invention obtained in Examples 1-5 and the polymeric heavy metal scavengers obtained in Comparative Examples to capture Cd ²⁺ ions. went. The test method is as follows. The precipitate of the cadmium complex formed in Example 6 was used as Toyo Filter Paper No. 5A was used for filtration, and the Cd ²⁺ ion concentration contained in the filtrate was measured by the atomic absorption method. The measurement was carried out using a Hitachi Model 170-30 atomic absorption spectrophotometer. The absorbance of a standard solution of cadmium sulfate containing 1-4 ppm of Cd ²⁺ ions was measured to obtain a calibration curve having a linear relationship between the absorbance and the concentration. 4 sample solutions
When it was above ppm, the sample was measured by appropriately diluting it to 1-4 ppm. From the results, the removal rate of Cd ²⁺ ions by the high molecular weight heavy metal scavenger was obtained, and the scavenging ability of Cd ²⁺ ions was compared. The results are shown in Table 2.
Shown in.

[Chemical 19] The polymeric heavy metal scavenger of the present invention obtained in Example 1-5 captures 100% of Cd ²⁺ ions at an addition amount of 1.0 equivalent, and even at 1.2 equivalents, captures 97-100%. did. on the other hand,
The high molecular weight heavy metal scavenger of the comparative example captures 98% of Cd ²⁺ ions with an addition amount of 1.0 equivalent, but with 1.2 equivalents,
Reduced to 87% capture.

[0034]

The polymeric heavy metal scavenger of the present invention is superior to the conventional polymeric heavy metal scavengers in the ability to trap heavy metal ions and the sedimentation / separation property of the formed metal complex. In particular, even if the scavenger is used in excess of the equivalent amount of heavy metal ions, the scavenging ability remains almost unchanged. The concentration of heavy metal ions in wastewater usually fluctuates. However, if an excess of the heavy metal scavenger of the invention is used, it can always be treated in the same way. Further, when removing heavy metal ions of unknown concentration, it is not necessary to accurately quantify the heavy metal ions, but only roughly. This is because if the heavy metal scavenger of the present invention is used in excess, the removal rate of heavy metal ions will not decrease.

[0035]

[Brief description of drawings]

FIG. 1 shows an infrared absorption spectrum of a copolymer of allylamine and diallylamine (molar ratio 1: 2), a sodium dithiocarbamate polymer (polymer of Example 3) by a KBr method. The horizontal axis represents wave number (cm ⁻¹ ) and the vertical axis represents transmittance or absorbance.

Claims (6)

[Claims] 1. A general formula: (In the formula, R ¹ is alkyl having ¹ to 6 carbons and 5 to 7 carbons.
Selected from cycloalkyl of m, m is the degree of polymerization, and j is 0 ≦ j ≦ 1) or the general formula: (In the formula, R ¹ is selected from hydrogen, alkyl having ^{1 to} 6 carbons and cycloalkyl having 5 to 7 carbons, R ² is selected from hydrogen and a methyl group, m is the degree of polymerization, and j is 0. 70-100% of the total of the primary and secondary amino groups (NH) of the polyallylamine-based polymer represented by <indicating j ≦ 1)
However, dithiocarbamate alkali metal chloride (NC (=
S) -SM, where M is a polymer heavy metal scavenger containing a polymer selected from the alkali metals Li, Na, and K). 2. A general formula: (In the formula, R ¹ is alkyl having ¹ to 6 carbons and 5 to 7 carbons.
Selected from cycloalkyl of m, m represents the degree of polymerization, and j represents 0 ≦ j ≦ 1) or the general formula: (In the formula, R ¹ is selected from hydrogen, alkyl having ^{1 to} 6 carbons and cycloalkyl having 5 to 7 carbons, R ² is selected from hydrogen and methyl, m is the degree of polymerization, and j is 0 < 70-100% of the total of primary and secondary amino groups (NH) in the polyallylamine-based polymer represented by
Alkali metal chloride dithiocarbamate (NC (= S)
-SM, where M is selected from the alkali metals Li, Na and K). 3. A general formula: (In the formula, R ¹ is alkyl having ¹ to 6 carbons and 5 to 7 carbons.
Selected from cycloalkyl of M, selected from alkali metals of Li, Na, and K, m represents a degree of polymerization, and j is 0 ≦ j.
≦ 1) or the general formula: (In the formula, R ¹ is selected from hydrogen, alkyl having ^{1 to} 6 carbons and cycloalkyl having 5 to 7 carbons, M is Li, Na,
A heavy polymer scavenger containing a polymer selected from the alkali metals of K, R ² selected from hydrogen and methyl, m represents the degree of polymerization, and j represents 0 <j ≦ 1). 4. A general formula: (In the formula, R ¹ is alkyl having ¹ to 6 carbons and 5 to 7 carbons.
Selected from cycloalkyl of M, selected from alkali metals of Li, Na, and K, m represents a degree of polymerization, and j is 0 ≦ j.
≦ 1) or the general formula: (In the formula, R ¹ is selected from hydrogen, alkyl having ^{1 to} 6 carbons and cycloalkyl having 5 to 7 carbons, M is Li, Na,
Alkali metal chlorinated polymer of dithiocarbamate represented by the formula: K selected from alkali metals, R ² selected from hydrogen and methyl, m represents the degree of polymerization, and j represents 0 <j ≦ 1. 5. A general formula: (In the formula, R ¹ is alkyl having ¹ to 6 carbons and 5 to 7 carbons.
Selected from cycloalkyl of m, m represents the degree of polymerization, and j represents 0 ≦ j ≦ 1) or the general formula: (In the formula, R ¹ is selected from hydrogen, alkyl having ^{1 to} 6 carbons and cycloalkyl having 5 to 7 carbons, R ² is selected from hydrogen and methyl, m is the degree of polymerization, and j is 0 < The polymer heavy metal scavenger according to claim 1 or 3, wherein a polyallylamine-based polymer represented by j <1) or a salt thereof is reacted with carbon disulfide in the presence of an alkali. Manufacturing method. 6. A general formula: (In the formula, R ¹ is alkyl having ¹ to 6 carbons and 5 to 7 carbons.
Selected from cycloalkyl of m, m represents the degree of polymerization, and j represents 0 ≦ j ≦ 1) or the general formula: (In the formula, R ¹ is selected from hydrogen, alkyl having ^{1 to} 6 carbons and cycloalkyl having 5 to 7 carbons, R ² is selected from hydrogen and methyl, m is the degree of polymerization, and j is 0 < 5. The polyallylamine-based polymer represented by the formula (j ≦ 1) or a salt thereof is reacted with carbon disulfide in the presence of an alkali. Manufacturing method of coalescence.