JPS5825081B2 - Cheretojiyushinoseizohou - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for producing a novel chelate resin.

More specifically, the present invention contains a structural unit represented by formula (I) (wherein, R1 is a hydrogen atom or a methyl group, R2 is a hydrogen atom, a lower alkyl group, or a rogene atom, and A is an aminoalkyl group). A method for producing a chelate resin having a phosphomethylamino group, which is characterized by reacting (2) halomethanephosphonic acid or (2) formalin with phosphorous acid, and a phosphomethylamino group that can be produced in this way. The present invention relates to a metal scavenger made of a chelate resin having the following properties.

A large number of chelate resins that selectively adsorb and capture metals have been synthesized, and their properties have been investigated.

However, there are only a few practical chelate resins that have excellent adsorption properties for metals, particularly heavy metals in general, and that can rapidly elute adsorbed metals.

A typical example thereof is a resin having a polystyrene skeleton and an iminodiacetic acid group or a polyethylene polyamino group as a functional group.

These resins have a large adsorption capacity for heavy metals, a fast adsorption rate (and easy elution and regeneration), but they have the disadvantage that the resin volume undergoes large changes during the adsorption, elution, and regeneration steps.

For example, when iminodiacetic acid-based resin is used in the sodium form, it shrinks to about half its volume due to metal adsorption, and further shrinks due to elution.

On the other hand, if heavy metals are adsorbed in the acid form, expansion of 40% or more occurs.

On the other hand, in the case of polyethylene polyamino resin, a similar phenomenon is observed, although the degree of change is slightly smaller.

This large expansion of the resin volume makes it difficult to pass the processing liquid through the resin layer at a predetermined rate, and the expansion and contraction of the resin during adsorption and elution can lead to the resin being crushed, significantly shortening its service life. It's shortened.

On the other hand, chelate resins have been synthesized by phosphomethylation of crosslinked polymers of vinylamine or ethyleneimine.

Vinylamine crosslinked polymers are synthesized from vinyl isocyanate and hexate 5-diene-3,4 diol, but such raw materials have the disadvantage of being difficult to obtain industrially, and furthermore, chelate resins made from them have the disadvantage of being difficult to obtain by metal adsorption. For example, significant volumetric shrinkage is observed due to adsorption of copper, and when compared to resins that do not adsorb, the volume shrinks to one-half at pH 6 and one-third at pH 3.

It is very difficult to make ethyleneimine cross-linked polymers into spherical shapes or even spherical bodies with a giant network structure, and they are usually obtained as granules, but in this case, filling is not ideal, so it is difficult to make a spherical shape. It has disadvantages such as small adsorption capacity per unit volume, large pressure loss, and low wear resistance.

Furthermore, the volume of phosphomethylated chelate resin made from ethyleneimine crosslinked polymers has been observed to change depending on pH, and it shrinks by about 10% in a pH 2 solution compared to a neutral solution, so when eluted with an acidic solution, it shrinks by about 10%. Undesirable.

The present inventors have conducted extensive studies with the aim of creating a new chelate resin that improves the drawbacks of such known chelate resins, and as a result, a polymer compound containing a structural unit represented by formula (I) and (1) halo We succeeded in producing a new chelate resin by reacting methanephosphonic acid or (2) formalin with phosphorous.

The present inventors have discovered that the chelate resin thus produced has extremely excellent metal adsorption performance, and that metals are easily eluted when the chelate resin adsorbing metals is treated with acid.

The present inventors further discovered that there is no or very little change in the volume of the resin upon adsorption and elution of metals.

The present invention was completed after further study.

In the above formula, examples of the lower alkyl group represented by R2 include methyl and ethyl.

Examples of the aminoalkyl group represented by A include a group represented by (in the formula, m and n are positive integers), an amine group in the above formula, and a group in which part of the imino group is alkyl (for example, methyl). examples include a group substituted with CmH2m in the above formula, a group in which the straight chain alkyl represented by CmH2m is replaced with a branched or cyclic alkyl, etc., but in short, A is -
Alternatively, any linear, branched, or cyclic alkyl group having two or more amino groups (-NH2) or imino groups (-NH) may be used.

The polymer compound containing the structural unit represented by formula (I) is a known compound, and its production method has been well established, so it can be produced according to these known methods.

For example, an aromatic vinyl monomer represented by formula (II) (wherein R1 and R2 are the same as defined above) is polymerized in the presence or absence of a crosslinking monomer, or Alternatively, a polymer containing a structural unit represented by formula (n) (wherein R1 and R2 are the same as defined above) by copolymerizing the above aromatic vinyl monomer with another copolymerizable vinyl monomer. A molecular compound is prepared and halomethylated to form a compound of formula (III) (wherein R1 and R2
is the same as the above definition, X is a halogen atom), and then this is reacted with a compound represented by formula (IV) (wherein A is the same as the above definition). In this manner, the raw material compound of the present invention can be produced.

The polymerization or copolymerization in the first step may be carried out in the presence of a crosslinking monomer.

Aromatic vinyl monomers used to produce the polymer compound (base polymer) containing the structural unit of formula (n) include, for example, styrene, α-methylstyrene, and styrene derivatives having substituents other than the para-position, such as 0-chlorostyrene, 0-vinyltoluene, etc. are suitable, and in the case of copolymerization, the other vinyl monomer can be an aromatic vinyl monomer such as methyl methacrylate, vinyl acetate, acrylonitrile, allyl glycidyl ether, etc. by a conventional method. Any copolymerizable vinyl monomer can be used.

Both granular and spherical polymer shapes can be used, but in order to provide excellent metal adsorption ability and high mechanical strength as a chelate resin, cross-linked spherical polymers or even spherical polymers with a giant network structure are used. is more preferable.

Therefore, the polymerization in the first step may be carried out in the presence of a crosslinking monomer (for example, polyvinyl monomers such as divinylbenzene, divinyltoluene, ethylene glycol diacrylate, ethylene glycol dimethacrylate, etc.). I can give you my body.

These crosslinking monomers are used in a proportion of O to about 15 mole percent, preferably 1 to 10 mole percent, based on the aromatic vinyl monomer and the vinyl monomer copolymerized therewith.

Particulate polymers are usually produced by solution polymerization, and spherical polymers are produced by suspension polymerization, and catalysts are usually used during these polymerizations.

Such a catalyst may be appropriately selected from those commonly used in vinyl polymerization, and for example, radical polymerization catalysts such as benzoyl peroxide, azobisisobutyronitrile, lauroyl peroxide, and tertiary butyl peroxide may be used alone or in combination.

Furthermore, suspension polymerization can proceed more smoothly by using a suspension stabilizer, and for this purpose, for example, polyvinyl alcohol, sodium polymethacrylate, sodium polyacrylate, etc. are used.

Particulate polymers are produced by conventional solution polymerization methods.

That is, an aromatic vinyl monomer and other vinyl monomers selected as necessary are dissolved in a suitable solvent and polymerized by heating, usually in the presence of a radical polymerization catalyst.

The polymerization temperature is sufficient as long as it decomposes the catalyst (for example, a range of 60 to 90°C is often used).

As the polymerization solvent, toluene, benzene, dioxane, etc. are appropriately selected depending on the type of monomer used.

The polymer obtained by these reactions is purified by a method such as reprecipitation, and then subjected to drying and pulverization steps to become a granular pellet polymer.

To produce a spherical pace polymer by suspension polymerization, an aromatic vinyl monomer, a vinyl monomer, a polyvinyl monomer, a radical polymerization catalyst, etc. are added to an aqueous medium containing a suspension stabilizer, and the polymerization rate is usually 60 to 90%. This is carried out by polymerization at .degree. C. with stirring.

The thus obtained polymer is thoroughly washed with hot water and then dried.

When giving a giant network structure to these spherical bodies, as is generally used, it acts as a solvent for the monomer,
For the polymer, a liquid that acts as a swelling agent, such as isooctane, higher alcohol (e.g., octatool), etc. is added to the polymerization system, or a suitable linear polymer (e.g., polystyrene) is added to the polymerization system. After the polymerization reaction is completed, it is preferably extracted and removed from the resulting copolymer using a solvent.

Halomethylation of the base polymer thus obtained is usually carried out as follows.

That is, a halomethylating agent and a Lewis acid type catalyst are added to the base polymer, and the reaction is carried out by cooling or heating depending on the catalyst.

Examples of the methylating agent used include chloromethyl ether, chloromethyl ethyl ether, dichloromethyl ether, and bromomethyl ether.

Examples of the catalyst include anhydrous zinc chloride, aluminum chloride, and tin chloride.

Examples of solvents include ethylene dichloride, ethylene tetrachloride,
Halogenated hydrocarbons such as 1.1.1-trichloroethane are preferred.

In this way, a polymer compound having a structural unit represented by the formula (m) is produced, and the polymer compound is prepared by the formula (wherein R1, R2 and X are It may be produced by polymerizing an aromatic vinyl monomer (e.g., vinylbenzyl chloride, vinylbenzyl promite, etc.) shown in the same meaning as the above definition, or by copolymerizing it with the above vinyl monomer. .

Homopolymerization and copolymerization in this case may also be carried out according to known methods.

The reaction between the polymer compound having the structural unit represented by formula (m) and the compound represented by formula (IV) is carried out as follows.

Although it can be carried out without using a solvent, it is preferable to use the formula (IV)
The compound represented by formula (IV) is sufficiently swollen with an inert solvent such as toluene, benzene, nitrobenzene, monochlorobenzene, dioxane, etc., and the compound represented by formula (IV) is added thereto for reaction.

Examples of the compound represented by formula (IV) to be subjected to the reaction include polyethylene polyamines such as ethylenediamine, diethylenetriamine, triethylenetetramine, and tetraethylenepentamine, and their N-monoalkyl derivatives (e.g., N-methyl derivatives). .

Furthermore, polymethylene diamines such as trimethylene diamine, tetramethylene diamine, pentamethylene diamine, and their N-monoalkyl (eg, N-methyl) derivatives may be used.

In short, any compound having two or more amino groups (-NH2) and/or imino groups (-NH) in the molecule can be used.

Phosphomethylation of the polymer compound having the structural unit represented by the formula (I) thus obtained can be carried out by either Mannich type reaction using halomethanephosphonic acid or formalin and phosphorous acid.

First, in the case of halomethanephosphonic acid, the reaction is preferably carried out in the presence of a deoxidizing agent, such as an alkali such as sodium hydroxide.

When using an alkali as a deoxidizing agent, add alkali while the alkali is consumed during the reaction to adjust the pH of the liquid to approximately 10~10.
It is preferable to keep it at about 11.

Examples of the reaction solvent include water, and the reaction temperature is usually about 50 to 100°C, preferably about 75 to 90°C.
That's about it.

In this reaction, cupric salts and cupric complexes such as copper-tartaric acid complexes may be added to increase the reaction rate.

Halomethanephosphonic acid reacts with the amine group or imino group in the polymer compound molecule containing the structural unit represented by formula (I) to form a phosphomethylamino group as described below.

Therefore, the disadvantage of using halomethanephosphonic acid with a polymer compound containing the structural unit represented by formula (■) is that some or all of the amino groups and/or imino groups of the raw material polymer compound are converted into phosphomethylamine. You can choose to do so.

Phosphomethylation with formalin and phosphorous acid is carried out according to the so-called Mannich reaction.

In a preferred embodiment, a polymer compound containing the structural unit represented by formula (I) is suspended in water and swollen, and formalin and phosphorus are added in the presence of a small amount of mineral acid such as hydrochloric acid and sulfuric acid. The mixture is reacted with an acid, and the reaction is carried out with stirring if necessary.

The reaction temperature may be at a level that allows the reaction to proceed, but is preferably 70°C or higher.

Formalin may be added all at once or may be added dropwise gradually.

The above reaction converts the amino group and/or imino group into a phosphomethylamino group as described below.

Therefore, the amount of the reaction reagent may be selected according to the reaction formula so that some or all of the amine groups and/or imino groups of the raw polymeric substance are phosphomethylaminated.

The chelate resin obtained by the method of the present invention has a high affinity for water and is therefore compatible with aqueous solutions of heavy metal ions.

In addition, many types of heavy metals such as cadmium, copper, manganese,
It exhibits a large adsorption capacity for nickel, zinc, etc., and also has a high adsorption rate.

Furthermore, the resin that has adsorbed these heavy metals can be quickly desorbed by acid (more specifically, H+) at room temperature, and can be used repeatedly.

Furthermore, as mentioned above, the chelate resin produced at °C according to the method of the present invention exhibits excellent adsorption performance for heavy metal ions even in its acid form. There is no need to introduce a treatment step of converting the group (phosphomethylamino group) into an alkali salt form and then passing the adsorbed liquid through it.

Furthermore, when the resin in the acid form adsorbs heavy metal ions, the volume of the resin does not change at all or the volume change is extremely small, which is an extremely practical advantage.

In other words, when a conventional chelate resin (for example, an iminodiacetic acid type chelate resin) is made into an acid form and a heavy metal ion solution is passed through it, the resin volume expands by more than 40% as the heavy metal ions are adsorbed, so the initial flow rate must be adjusted. In some cases, operations such as backwashing are required.

Furthermore, in the case of desorption of heavy metals from the resin after adsorption in the chelate resin of the present invention, this can be easily carried out using an acid at room temperature as described above, but as in the case of adsorption, the volume change is extremely small or not observed at all. do not have.

Throughout the entire treatment process, there is no or very little change in volume, so no special equipment or operations are required to pass the liquid through, and the resin spheres do not break, making the resin extremely durable. improves.

Next, the method of the present invention will be described in more detail with reference to Examples.

Example 1 (a) Base polymer polyvinyl alcohol 0.125 f to distilled water 1007
711 and sufficiently dissolve at 50°C.

Then heat the whole thing up to an internal temperature of 80℃.

Styrene prepared in advance 20. OS', divinylbenzene 2.2, isooctane 10. A mixture consisting of 0.300 P of OS' benzoyl peroxide is added all at once, and the mixture is kept at 80°C and reacted for 10 hours with stirring.

After the reaction is completed, the mixture is slowly cooled with stirring, and the polymer is filtered off, washed thoroughly with hot water, and dried under reduced pressure and heat.

The obtained base polymer is white opaque spherical fine particles with a giant network structure.

(b) Base polymer 51 with a 16-48 mesh obtained by sieving the chelate resin was suspended and swollen in 15 ml of chloromethyl ether and 5 ynl of ethylene tetrachloride, then 3 f of anhydrous zinc chloride was added, and the mixture was heated at 50°C. The reaction was carried out for 10 hours.

After the reaction, the resin is collected by filtration, thoroughly washed with acetone and then water, and dried under reduced pressure and heat.

Benzene 507711 was added to the chloromethylated resin 5y thus obtained, and the resin was allowed to swell overnight. After that, 30 ml of ethylenediamine was added and the mixture was reacted at 80° C. for 5 hours.

Aminated resin 3′i? obtained in this way? , water 10
ml was weighed into a flask equipped with a cooling tube and allowed to suspend and swell, and then 15ml of phosphorous acid, 15ml of concentrated hydrochloric acid, and 30ml of a 37% formalin solution were weighed into a flask equipped with a cooling tube, and the oil was kept at 105°C. React on bath for 25 hours.

After the reaction, the resin is collected by filtration, thoroughly washed with hot water, and dried under reduced pressure and heat to obtain a slightly yellow and opaque chelate resin.

(c) Adsorption Capacity for Various Metals Six types of metal ion solutions containing 10% by volume of acetic acid-sodium acetate buffer (pH 4,60) and 8 mmol/l each were prepared.

Chelate resin 50m9 obtained in section (b) and metal solution 2
After precisely weighing 0rul into a centrifuge tube and shaking it at room temperature for an hour,
Weigh out 15 ml of the filtered filtrate and determine the adsorption capacity from the residual metal content.

The results are as follows. Adsorption capacity (mmoldag resin) Ca O, 45 Mn 0.57 Cb O, 73 Ni O, 82 Cu 1.01 Zn O, 78 * (d)
Column adsorption A glass column with an inner diameter of 6 mm and a length of 1501 m is filled with 1.2 f (3,111 Ll) of the resin obtained in section (b).

A 4 mmol/l copper solution containing 10 volume percent of acetic acid-sodium acetate buffer (pH 4,60) is flowed down at a rate of 5 VIO.

After passing a predetermined amount of liquid, the resin is eluted with 30 ml of 2N sulfuric acid at SV5 to regenerate the resin.

The resin can then be reused by washing the column with 307711 water using SV5.

Similar adsorption tests were repeated for nickel, cadmium, and zinc.

The leakage rate was determined for the passing liquid and the following results were obtained.

No volume change of the resin is observed in these column tests.

Example 2 0.125P of polyvinyl alcohol is added to 100ml of pure water and dissolved.

As in Example 1 (a), a mixture of 20.0 P of styrene, 1.0 P of divinylbenzene, and 0.300 S' of benzoyl peroxide is reacted to obtain a transparent spherical polymer.

The 32-48 mesh Pace Polymer 21 obtained by sieving was heated and swollen in 21 tetrachlorethylene.
1 of chloromethyl ether and 0.51 of anhydrous zinc chloride were added and reacted at 50°C for 10 hours.

Add 50 TL of cold water, filter, and rinse thoroughly.

2.5 parts of the aminated resin thus obtained, 10 parts of water
7711 was weighed into a flask equipped with a condenser tube, suspended and swollen, and then 6.01 of chloromethanephosphonic acid was added.
Adjust the pH to 10.5 with N sodium hydroxide.

Liquid pH 1O-11 on an oil bath kept at 90-100℃
Let it react for 20 hours while maintaining the temperature.

After the reaction, the resin is collected by filtration, thoroughly washed with hot water, and dried under reduced pressure and heat to obtain a slightly yellow transparent chelate resin.

Claims (1)

[Claims] (wherein, R1 is a hydrogen atom or a methyl group, R2 is a hydrogen atom, a lower alkyl group, or a chlorine atom, and A is an aminoalkyl group);
)... A method for producing a chelate resin having a phosphomethylamino group, which comprises reacting lomethanephosphonic acid or (2) formalin with phosphorous acid.