EP4222182A1

EP4222182A1 - Novel chelate resins

Info

Publication number: EP4222182A1
Application number: EP21782987.8A
Authority: EP
Inventors: Bernd Koop; Dirk Steinhilber; Joachim Kralik
Original assignee: Lanxess Deutschland GmbH
Current assignee: Lanxess Deutschland GmbH
Priority date: 2020-09-30
Filing date: 2021-09-27
Publication date: 2023-08-09
Also published as: KR20230078679A; CN116323693A; WO2022069389A1; JP2023543516A; US20230374180A1

Abstract

The invention relates to chelate resins containing aminoalkylphosphinic acid derivatives, to a process for the preparation therof, and to their use in the recovery and purification of metals, preferably heavy metals, noble metals and rare earths.

Description

New chelating resins

The present invention relates to chelating resins containing aminoalkylphosphinic acid derivatives, a process for their preparation and their use for the recovery and purification of metals, preferably heavy metals, noble metals and rare earths.

The development of new chelating resins continues to be of great importance in the field of research. These can have considerable potential for use in the extraction of metals and in the field of water purification. In particular, the removal of zinc from nickel electrolytes for the manufacture of battery cathode materials remains a relevant topic.

Chelating resins containing aminoalkylphosphonic acid groups are known from DE-A 102009047848 and EP-A 1078690. DE-A 102009047848 describes in particular the use of these resins for the adsorption of calcium.

DE-A 2848289 describes the preparation of chelating resins containing aminomethylhydroxymethylphosphinic acid groups by reacting a chloromethylated polystyrene copolymer with a polyamine and its subsequent reaction with formalin and a hypophosphite. These resins are used to remove tungsten ions.

A disadvantage of the prior art is that the zinc capacity of the chelate resins that can be used is not sufficient. There has therefore been a further need for a chelate resin with which zinc is adsorbed in large amounts. Surprisingly, it has now been found that specific chelating resins containing aminomethylphosphinic acid derivatives are particularly suitable for removing zinc.

The present invention is therefore a chelating resin containing functional groups of the structural element (I) wherein is the polystyrene copolymer backbone and R ¹ and R ² independently represent hydrogen or -CH2-PO(OR ³ )R ⁴ , where R ¹ and R ² cannot both be hydrogen at the same time and R ³ = hydrogen or Cr Ci ₅ -alkyl and R ⁴ represents Ci-Ci ₅ alkyl, Ce-Cs ryl, C ₇ -Ci ₅ arylalkyl or Cs-C alkenyl, each of which may be substituted one or more times by Ci-Cs-alkyl.

Preferably R ¹ and R ² = -CH ₂ -PO(OR ³ )R ⁴ .

R ³ is preferably hydrogen and Ci-Cs-alkyl. R ³ is particularly preferably methyl, ethyl, n-propyl, isopropyl, n-, i-, s- or t-butyl, cyclopropyl, cyclobutyl, cyclopentyl, n-hexyl, cyclohexyl, n-pentyl and hydrogen. Even more preferably, R ³ = hydrogen.

R ⁴ is preferably = Ci-Ci ₅ -alkyl or Ce-Cs ryl, which can be substituted one or more times by Ci-Cs-alkyl. R ⁴ is particularly preferably = Ci-Cs-alkyl, phenyl and benzyl, which can be substituted by one, two or three Ci-Cs-alkyl. R ⁴ is very particularly preferably = Ci-Cs-alkyl and phenyl, which can be mono-, di- or tri-substituted by methyl or ethyl. Even more preferably, R ⁴ = ethyl, 2,4,4-trimethylpentyl, 2-methylpentyl, benzyl or phenyl.

In the context of the invention, Ci-Cis-alkyl represents a straight-chain, cyclic or branched alkyl radical having 1 to 15 (C1-C15), preferably 1 to 12 (C1-C12), particularly preferably 1 to 8 (Ci-Cs) carbon atoms, even more preferably having 1 to 6 (Ci-Cs) carbon atoms. Ci-Cis-alkyl is preferably methyl, ethyl, n-propyl, isopropyl, n-, i-, s- or t-butyl, cyclopropyl, cyclobutyl, cyclopentyl, n-hexyl, cyclohexyl, n-pentyl, 1-methylbutyl , 2-methylbutyl, 3-methylbutyl, 2,2-dimethylpropyl, 1-ethylpropyl, cyclohexyl, 2,4,4-trimethylpentyl and 2-methylpentyl. Ci-Cis-alkyl is particularly preferably methyl, ethyl, n-propyl, isopropyl, n-, i-, s- or t-butyl, n-pentyl, n-hexyl, 2,4,4-trimethylpentyl and 2- methylpentyl. Ci-Ci ₅ -alkyl or Ci-Cis-alkyl or Ci-Cs-alkyl or Ci-Cs-alkyl is very particularly preferably ethyl, 2,4,4-trimethylpentyl and 2-methylpentyl.

In the context of the invention, Ce-C24-aryl represents an aromatic radical having 6 to 24 skeletal carbon atoms in which none, one, two or three skeletal carbon atoms per cycle, but at least one skeletal carbon atom in the entire molecule, are replaced by heteroatoms selected from the group consisting of nitrogen, sulfur or oxygen, but preferably for a carbocyclic aromatic radical having 6 to 24 backbone carbon atoms. The same applies to the aromatic part of an arylalkyl radical. Furthermore, the carbocyclic aromatic or heteroaromatic radicals can be substituted with up to five identical or different substituents per cycle, selected from the group: Ci-Cs-alkyl, Cs-C-alkenyl and C ₇ -Ci ₅ -arylalkyl. preferred Ce-C24-Aryl are phenyl, o-, p-, m-tolyl, naphthyl, phenanthrenyl, anthracenyl or fluorenyl. Preferred heteroaromatic Ce-C24-aryl in which one, two or three skeletal carbon atoms per cycle, but at least one skeletal carbon atom in the entire molecule, can be substituted by heteroatoms selected from the group consisting of nitrogen, sulfur or oxygen are pyridyl, pyrimidyl, pyridazinyl, pyrazinyl, thienyl, furyl, pyrrolyl, pyrazolyl, imidazolyl, thiazolyl, oxazolyl or isoxazolyl, indolizinyl, indolyl, benzo[b]thienyl, benzo[b]furyl, indazolyl, quinolyl, isoquinolyl, naphthyridinyl, quinazolinyl, benzofuranyl or dibenzofuranyl.

C ₇ -C ₁₅ -Arylalkyl, independently of one another, means a straight-chain, cyclic or branched C ₇ -C 15 -alkyl radical as defined above, which can be monosubstituted, polysubstituted or completely substituted by aryl radicals as defined above. A is preferably C ₇ -Ci ₅ -arylalkyl = benzyl.

In the context of the invention, C2-C6-alkenyl is a straight-chain, cyclic or branched alkenyl radical having 2 to 10 (C2-C10), preferably having 2 to 6 (C2-C6) carbon atoms. By way of example and preference, alkenyl is vinyl, allyl, isopropenyl and n-but-2-en-1-yl.

The scope of the invention encompasses all radical definitions, parameters and explanations given above and below, in general or in preferred areas, ie also between the respective areas and preferred areas in any combination.

As polystyrene copolymers in the chelate resin containing functional groups of the structural element (I) are preferably copolymers of monovinyl aromatic monomers selected from the group styrene, vinyl toluene, ethyl styrene, α-methyl styrene, chlorostyrene or chloromethyl styrene and mixtures of these monomers with polyvinyl aromatic compounds (crosslinkers). from the group of divinylbenzene, divinyltoluene, trivinylbenzene, divinylnaphthalene and/or trivinylnaphthalene.

A styrene/divinylbenzene copolymer is particularly preferably used as the polystyrene copolymer structure. A styrene/divinylbenzene copolymer is a copolymer crosslinked through the use of divinylbenzene. The polymerizate of the chelate resin preferably has a spherical shape.

In the polystyrene copolymer backbone, the -CH2-NR ¹ R ² group is attached to a phenyl radical. The chelating resins containing functional groups of structural element (I) used according to the invention preferably have a macroporous structure.

The terms microporous or gel-like or macroporous have already been described in detail in the specialist literature, for example in Seidl, Malinsky, Dusek, Heitz, Adv. Polymer Sci., 1967, Vol. 5, pp. 113 to 213. The possible measuring methods for macroporosity, e.g. mercury porosimetry and BET determination, are also described there. In general and preferably, the pores of the macroporous polymers of the chelating resins used according to the invention containing functional groups of the structural element (I) have a diameter of 20 nm to 100 nm.

The chelating resins containing functional groups of structural element (I) used according to the invention preferably have a monodisperse distribution.

In the present application, substances are referred to as monodisperse if at least 90% by volume or mass of the particles have a diameter that lies in the interval with a width of +/-10% of the most common diameter around the most common diameter.

For example, for a substance with a most common diameter of 0.5 mm, at least 90% by volume or mass lies in a size interval between 0.45 mm and 0.55 mm, for a substance with a most common diameter of 0.7 mm, at least 90% by volume or mass in a size interval between 0.77 mm and 0.63 mm.

The chelate resin containing functional groups of the structural element (I) preferably has a diameter of 200 to 1500 μm.

The chelating resins containing functional groups of structural element (I) used in the process are preferably prepared by: a) reacting monomer droplets of at least one monovinylaromatic compound and at least one polyvinylaromatic compound and at least one initiator, b) the polymer from step a) phthalimidomethylated with phthalimide or derivatives thereof, c) reacting the phthalimidomethylated polymer from step b) with at least one acid or at least one base and d) the aminomethylated polymer from step c) by reaction with formaldehyde or its derivatives in the presence of at least one suspension medium and at least one acid and at least one compound of the formula (II) or salts thereof, where R ³ = hydrogen or Ci-Ci ₅ alkyl and R ⁴ is Ci -Ci ₅ alkyl, C6-C24 aryl, C ₇ - Ci ₅ arylalkyl or Cs-C alkenyl, which is one or more times may be substituted by Ci-Cs-alkyl, functionalized to form a chelate resin with functional groups of the formula (I).

At least one monovinylaromatic compound and at least one polyvinylaromatic compound are used in process step a). However, it is also possible to use mixtures of two or more monovinylaromatic compounds and mixtures of two or more polyvinylaromatic compounds.

Styrene, vinyl toluene, ethyl styrene, α-methyl styrene, chlorostyrene or chloromethyl styrene are preferably used as monovinylaromatic compounds for the purposes of the present invention in process step a).

The monovinylaromatic compounds are preferably used in amounts >50% by weight, based on the monomer or its mixture with other monomers, particularly preferably between 55% by weight and 70% by weight, based on the monomer or its mixture with other monomers.

Particular preference is given to using styrene or mixtures of styrene with the aforementioned monomers, preferably with ethyl styrene.

Preferred polyvinylaromatic compounds for the purposes of the present invention for process step a) are divinylbenzene, divinyltoluene, trivinylbenzene, divinylnaphthalene or trivinylnaphthalene, particularly preferably divinylbenzene.

The polyvinylaromatic compounds are preferably used in amounts of 1-20% by weight, particularly preferably 2-12% by weight, particularly preferably 4-10% by weight, based on the monomer or its mixture with other monomers. The kind of polyvinylaromatic compounds (crosslinkers) is selected with regard to the subsequent use of the polymer. If divinylbenzene is used, commercial grades of divinylbenzene which also contain ethylvinylbenzene in addition to the isomers of divinylbenzene are sufficient.

Macroporous polymers are preferably formed by adding inert materials, preferably at least one porogen, to the monomer mixture during the polymerization in order to produce a macroporous structure in the polymer. Particularly preferred porogens are hexane, octane, isooctane, isododecane, pentamethylheptane, methyl ethyl ketone, butanol or octanol and their isomers. Above all, organic substances are suitable which dissolve in the monomer but dissolve or swell the polymer poorly (precipitating agent for polymers), for example aliphatic hydrocarbons (Bayer paint factory DBP 1045102, 1957; DBP 11 13570, 1957).

In US Pat. No. 4,382,124, the alcohols having 4 to 10 carbon atoms, which are likewise to be used with preference in the context of the present invention, are used as porogens for the production of macroporous polymers based on styrene/divinylbenzene. Furthermore, an overview of the production methods for macroporous polymers is given.

Porogens are preferably used in an amount of 25% by weight to 45% by weight, based on the amount of the organic phase.

At least one porogen is preferably added in process step a).

The polymers prepared according to process step a) can be prepared in heterodisperse or monodisperse form.

Heterodisperse polymers are prepared by general processes known to those skilled in the art, e.g. with the aid of suspension polymerization.

Monodisperse polymers are preferably prepared in process step a).

In a preferred embodiment of the present invention, microencapsulated monomer droplets are used in process step a) in the production of monodisperse polymers.

The materials known for use as complex coacervates are suitable for the microencapsulation of the monomer droplets, in particular polyesters, natural and synthetic polyamides, polyurethanes or polyureas. Gelatine is preferably used as the natural polyamide. This is used in particular as a coacervate and complex coacervate. Within the meaning of the invention, gelatin-containing complex coacervates are understood to mean, in particular, combinations of gelatin with synthetic polyelectrolytes. Suitable synthetic polyelectrolytes are copolymers with built-in units of, for example, maleic acid, acrylic acid, methacrylic acid, acrylamide and methacrylamide. Acrylic acid and acrylamide are particularly preferably used. Capsules containing gelatine can be hardened with conventional hardening agents such as formaldehyde or glutaric dialdehyde. The encapsulation of monomer droplets with gelatin, gelatin-containing coacervates and gelatin-containing complex coacervates is described in detail in EP-A 0 046 535. The methods of encapsulation with synthetic polymers are known. Phase interface condensation is preferred, in which a reactive component (in particular an isocyanate or an acid chloride) dissolved in the monomer droplet is reacted with a second reactive component (in particular an amine) dissolved in the aqueous phase.

The heterodisperse or optionally microencapsulated, monodisperse monomer droplets contain at least one initiator or mixtures of initiators (initiator combination) to initiate the polymerization. Initiators preferred for the process according to the invention are peroxy compounds, particularly preferably dibenzoyl peroxide, dilauroyl peroxide, bis(p-chlorobenzoyl) peroxide, dicyclohexyl peroxydicarbonate, tert-butyl peroctoate, tert-butyl peroxy-2-ethylhexanoate, 2,5-bis(2-ethylhexanoylperoxy )-2,5-dimethylhexane or tert-amylperoxy-2-ethylhexane, and azo compounds such as 2,2'-azobis(isobutyronitrile) or 2,2'-azobis(2-methylisobutyronitrile).

The initiators are preferably used in amounts of from 0.05 to 2.5% by weight, particularly preferably from 0.1 to 1.5% by weight, based on the monomer mixture.

The optionally monodisperse, microencapsulated monomer droplet can optionally also contain up to 30% by weight (based on the monomer) of crosslinked or uncrosslinked polymer. Preferred polymers are derived from the aforementioned monomers, particularly preferably from styrene.

In the preparation of monodisperse polymers in process step a), the aqueous phase can, in a further preferred embodiment, contain a dissolved polymerization inhibitor. In this case, both inorganic and organic substances can be considered as inhibitors. Preferred inorganic inhibitors are nitrogen compounds, particularly preferably hydroxylamine, hydrazine, sodium nitrite and potassium nitrite, salts of phosphorous acid such as sodium hydrogen phosphite and sulfur-containing compounds such as sodium dithionite, sodium thiosulfate, sodium sulfite, sodium bisulfite, sodium thiocyanate and ammonium thiocyanate. Examples of organic inhibitors are phenolic compounds such as hydroquinone, hydroquinone monomethyl ether, resorcinol, pyrocatechol, tert-butylpyrocatechol, pyrogallol and condensation products of phenols with aldehydes. Other preferred organic inhibitors are nitrogen-containing compounds. Particularly preferred are hydroxylamine derivatives such as N,N-diethylhydroxylamine, N-isopropylhydroxylamine and sulfonated or carboxylated N-alkylhydroxylamine or N,N-dialkylhydroxylamine derivatives, hydrazine derivatives such as N,N-hydrazinodiacetic acid, nitroso compounds such as N-nitrosophenylhydroxylamine, N-nitrosophenylhydroxylamine ammonium salt or N-nitrosophenylhydroxylamine aluminum salt. The concentration of the inhibitor is 5-1000 ppm (based on the aqueous phase), preferably 10-500 ppm, particularly preferably 10-250 ppm.

The polymerization of the optionally microencapsulated monodisperse monomer droplets to form the monodisperse polymer preferably takes place in the presence of one or more protective colloids in the aqueous phase. Natural or synthetic water-soluble polymers, preferably gelatin, starch, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic acid, polymethacrylic acid or copolymers of (meth)acrylic acid and (meth)acrylic acid esters are suitable as protective colloids. Also preferred are cellulose derivatives, in particular cellulose esters and cellulose ethers, such as carboxymethyl cellulose, methylhydroxyethyl cellulose, methylhydroxypropyl cellulose and hydroxyethyl cellulose. Gelatin is particularly preferred. The amount of protective colloid used is generally from 0.05 to 1% by weight, based on the aqueous phase, preferably from 0.05 to 0.5% by weight.

In an alternative preferred embodiment, the polymerization to give the monodisperse polymer can be carried out in the presence of a buffer system. Buffer systems which adjust the pH of the aqueous phase to a value between 14 and 6, preferably between 12 and 8, at the beginning of the polymerization are preferred. Under these conditions, protective colloids with carboxylic acid groups are wholly or partly in the form of salts. In this way, the effect of the protective colloids is favorably influenced. Particularly suitable buffer systems contain phosphate or borate salts. The terms phosphate and borate within the meaning of the invention also include the condensation products of the ortho forms of corresponding acids and salts. The concentration of the phosphate or borate in the aqueous phase is preferably 0.5-500 mmol/l, particularly preferably 2.5-100 mmol/l.

The stirring speed during the polymerisation to form the monodisperse polymer is less critical and, in contrast to conventional polymerisation, has no influence on the particle size. Low agitation speeds are used, sufficient to keep the suspended monomer droplets in suspension and to aid in the removal of the heat of polymerization. Various stirrer types can be used for this task. Grid stirrers with an axial effect are particularly suitable.

The volume ratio of encapsulated monomer droplets to aqueous phase is preferably 1:0.75 to 1:20, particularly preferably 1:1 to 1:6.

The polymerization temperature to give the monodisperse polymer depends on the decomposition temperature of the initiator used. It is preferably between 50 and 180.degree. C., particularly preferably between 55 and 130.degree. The polymerization preferably lasts from 0.5 to about 20 hours. It has proven useful to use a temperature program in which the polymerization is started at a low temperature, preferably 60° C., and the reaction temperature is increased as the polymerization conversion progresses. In this way, for example, the requirement for a safe course of the reaction and high polymerization conversion can be met very well. After the polymerization, the monodisperse polymer is isolated using customary methods, for example by filtering or decanting, and washed if necessary.

The preparation of the monodisperse polymers using the jetting principle or the seed-feed principle is known from the prior art and is described, for example, in US Pat. No. 4,444,961, EP-A 0,046,535, US Pat described.

The monodisperse polymers are preferably prepared using the jetting principle or the seed-feed principle.

A macroporous, monodisperse polymer is preferably prepared in process step a).

In process step b), the amidomethylation reagent is preferably prepared first. To this end, a phthalimide or a phthalimide derivative is preferably dissolved in a solvent, and formaldehyde or its derivatives are added. A bis(phthalimido)ether is then formed therefrom with elimination of water. Preferred phthalimide derivatives for the purposes of the present invention are phthalimide itself or substituted phthalimides, such as preferably methylphthalimide. For the purposes of the invention, derivatives of formaldehyde are also, for example and preferably, aqueous solutions of formaldehyde. An aqueous solution of the formaldehyde is preferably formalin. Formalin is preferably a solution of formaldehyde in water. Preferred derivatives of formaldehyde are formalin or paraformaldehyde. In Process step b) could therefore also be reacted with the polymer from step a) the phthalimide derivative or the phthalimide in the presence of paraformaldehyde.

In general, the molar ratio of the phthalimide derivatives to the aromatic groups present in the polymer in process step b) is from 0.15:1 to 1.7:1, although other molar ratios can also be selected. The phthalimide derivative is preferably used in a molar ratio of from 0.7:1 to 1.45:1 to the aromatic groups present in the polymer in process step b).

Formaldehyde or its derivatives are usually used in excess, based on the phthalimide derivative, but other amounts can also be used. Preference is given to using 1.01 to 1.2 mol of formaldehyde or its derivatives per mole of phthalimide derivative.

In general, in process step b), inert solvents are used which are suitable for swelling the polymer, preferably chlorinated hydrocarbons, particularly preferably dichloroethane or methylene chloride. However, methods that can be carried out without using solvents are also conceivable.

In process step b), the polymer is condensed with phthalimide or its derivatives and formaldehyde. The catalyst used here is preferably oleum, sulfuric acid or sulfur trioxide in order to produce an SOs adduct of the phthalimide derivative in an inert solvent. In process step b), the catalyst is usually added in excess to the phthalimide derivative, although larger amounts can also be used. The molar ratio of the catalyst to the phthalimide derivatives is preferably from 0.1:1 to 0.45:1. The molar ratio of the catalyst to the phthalimide derivatives is particularly preferably 0.2:1 to 0.4:1.

Process step b) is carried out at temperatures of preferably from 20.degree. C. to 120.degree. C., particularly preferably from 60.degree. C. to 90.degree.

The elimination of the phthalic acid residue and thus the exposure of the aminomethyl group takes place in process step c) by treatment with at least one base or at least one acid. The bases used in process step c) are preferably alkali metal hydroxides, alkaline earth metal hydroxides, ammonia or hydrazine. The acids used in process step c) are preferably nitric acid, phosphoric acid, sulfuric acid, hydrochloric acid, sulphurous acid or nitrous acid. In process step c), preference is given to using at least one base to split off the phthalic acid residue and thus to expose the aminomethyl group. The elimination of the phthalic acid radical and thus the exposure of the aminomethyl group in process step c) is particularly preferably carried out by treating the phthalimidomethylated polymer with aqueous or alcoholic solutions of an alkali metal hydroxide, such as preferably sodium hydroxide or potassium hydroxide, at temperatures of 100° C. and 250° C., preferably 120 °C to 190 °C. The concentration of the sodium hydroxide solution is preferably 20% by weight to 40% by weight, based on the aqueous phase. This process makes it possible to produce polymers containing aminoalkyl groups, preferably a polymer containing aminomethyl groups.

The aminomethylated polymer is generally washed alkali-free with deionized water. However, it can also be used without post-treatment.

The process described in steps a) to c) is known as the phthalimide process. In addition to the phthalimide process, there is also the possibility of using the chloromethylation process to produce an aminomethylated polymer. According to the chloromethylation process, which is described, for example, in EP-A 1 568 660, polymers - mostly based on styrene/divinylbenzene - are first produced, chloromethylated and then reacted with amines (Helfferich, ion exchanger, page 46-58, Verlag Chemie, Weinheim , 1959) and EP-A 0 481 603). The ion exchanger containing chelating resin having functional groups represented by the formula (I) can be prepared by the phthalimide method or the chloromethylation method. The ion exchanger according to the invention is preferably prepared by the phthalimide process, according to process steps a) to c), which is then functionalized according to step d) to give the chelate resin.

The reaction of the aminomethyl-containing polymers obtained in process step c) to give the chelating resins containing functional groups of the structural element (I) takes place in process step d) with formaldehyde or its derivatives in the presence of at least one suspension medium and at least one acid, in combination with at least one compound of the formula (II) or their salts where R ³ = hydrogen or Ci-Ci ₅ alkyl and R ⁴ = Ci-Ci ₅ alkyl, C6-C24 aryl, C7-C15 arylalkyl or Cs-C alkenyl, optionally multiply by Ci-Cs -alkyl may be substituted.

Formaldehyde, formalin or paraformaldehyde are preferably used as formaldehyde or its derivatives in process step d). Formalin is particularly preferably used in process step d).

Phenylphosphinic acid, 2,4,4-trimethylpentylphosphinic acid, ethylphosphinic acid or 2-methylpentylphosphinic acid or mixtures of these compounds are preferably used as compounds of the formula (II) in process step d). The compounds of the formula (II) can also be used in the salt form in process step d). The sodium, potassium or lithium salts are preferably used as salts.

The compounds of formula (II) are commercially available or can be prepared by methods known to those skilled in the art.

The reaction takes place in process step d) in a suspension medium. Water or alcohols, or mixtures of these solvents, are used as the suspension medium. The alcohols used are preferably methanol, ethanol or propanol. Inorganic acids are preferably used as acids. However, organic acids can also be used. Hydrochloric acid, nitric acid, phosphoric acid or sulfuric acid or mixtures of these acids are preferably used as inorganic acids. The inorganic acids are preferably used in concentrations of from 10 to 90% by weight, particularly preferably from 40 to 80% by weight.

In process step d), preferably 1 to 4 mol of the compound of the formula (II) are used per mol of aminomethyl groups of the aminomethylated polymer from process step c).

In process step d), preferably 2 to 8 moles of formaldehyde are used per mole of aminomethyl groups in the aminomethylated polymer from process step c).

In process step d), preferably 2 to 12 moles of inorganic acid are used per mole of aminomethyl groups in the aminomethylated polymer from process step c). The reaction of the aminomethyl-containing polymer to form chelate resins containing functional groups of structural element (I) in process step d) is preferably carried out at temperatures in the range from 70 to 120°C, particularly preferably at temperatures in the range from 85 to 110°C.

In one embodiment of the invention, process step d) can be carried out by initially introducing the aminomethylated polymer and the compound of the formula (II) in water. Then formaldehyde or its derivatives are added, preferably with stirring. Then the inorganic acid is added. It is then heated to the reaction temperature. After the reaction has ended, the reaction mixture is cooled, the liquid phase is separated off and the resin is washed, preferably with deionized water.

In a further embodiment of the invention, process step d) can be carried out by initially introducing the aminomethylated polymer, the compound of the formula (II) and formaldehyde or its derivatives in water and then adding the inorganic acids at the reaction temperature. After the reaction has ended, the reaction mixture is cooled, the liquid phase is separated off and the resin is washed, preferably with deionized water.

In a further embodiment of the invention, in process step d), the aminomethylated polymer, the inorganic acid and formaldehyde or its derivatives are initially taken in water and the compound of the formula (II) is then added at the reaction temperature. After the reaction has ended, the reaction mixture is cooled, the liquid phase is separated off and the resin is washed, preferably with deionized water.

In a further embodiment of the invention, in process step d), the aminomethylated polymer, the compound of the formula (II), formaldehyde or its derivatives and the inorganic acid are initially taken in water and then heated to the reaction temperature. After the reaction has ended, the reaction mixture is cooled, the liquid phase is separated off and the resin is washed, preferably with deionized water.

Preferably, in all embodiments of the invention, the reaction mixture is stirred at the reaction temperature for about 3 to 15 hours. possibly it is also possible to convert the resin produced in process step d) into the salt form. This can preferably by reaction with alkali metal hydroxides. Sodium hydroxide, potassium hydroxide or lithium hydroxide and the corresponding aqueous solutions are particularly preferably used as alkali metal hydroxides.

In a preferred embodiment of the invention, the aminomethylated polymer is suspended in water in process step d). The compound of the formula (II) and the inorganic acid are added to this suspension. The reaction mixture obtained in this way is heated to the reaction temperature, and formaldehyde or its derivatives are slowly added at this temperature while stirring. After the formaldehyde or its derivatives have been added, the reaction mixture is stirred at the reaction temperature for a further 3 to 15 hours. The reaction mixture is then cooled, the liquid phase is separated off and the resin is washed with deionized water.

The average degree of substitution of the chelating resin according to the invention can be between 0 and 2. The average degree of substitution indicates the statistical molar ratio between unsubstituted, mono-substituted and disubstituted aminomethyl groups in the resin. With a degree of substitution of 0, no substitution would have taken place and the aminomethyl groups of structural element (I) would be present as primary amino groups in the resin. With a degree of substitution of 2, all of the amino groups in the resin would be disubstituted. Statistically, with a degree of substitution of 1, all the amino groups in the chelating resin according to the invention would be monosubstituted.

The average degree of substitution of the aminomethyl groups of the chelating resin according to the invention containing functional groups of the structural element (I) is preferably from 0.5 to 2.0. The average degree of substitution of the amine groups of the chelating resin according to the invention containing functional groups of the structural element (I) is particularly preferably from 1.0 to 1.5.

The chelating resins according to the invention containing functional groups of the structural element (I) are outstandingly suitable for the recovery and purification of metals, preferably heavy metals, noble metals and rare earths.

In a particularly preferred embodiment of the invention, the chelating resins according to the invention containing functional groups of the structural element (I) are suitable for the adsorption of rare earths selected from the group: scandium, lanthanum, yttrium, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium. In a Another embodiment of the invention, the chelating resins according to the invention containing functional groups of the structural element (I) are suitable for the adsorption of iron, vanadium, copper, zinc, aluminum, cobalt, nickel, manganese, magnesium, calcium, lead, cadmium, uranium, mercury, elements of platinum group as well as gold or silver.

The chelating resins according to the invention containing functional groups of the structural element (I) are very particularly preferably suitable for the adsorption of zinc, iron, vanadium, aluminum, tungsten, manganese, magnesium, calcium, cobalt and nickel. Even more preferably, the chelating resins according to the invention containing functional groups of the structural element (I) are used for the adsorption of zinc, cobalt and nickel.

Adsorption from concentrated nickel and cobalt concentrate solutions for cleaning battery chemicals is particularly preferred.

In a further preferred embodiment of the invention, the chelating resins according to the invention are used for the purification of inorganic acids.

In a further preferred embodiment, the chelating resins according to the invention containing functional groups of structural element (I) are suitable for removing alkaline earth metals, e.g. calcium, magnesium, barium or strontium, from aqueous sols, such as are used, for example, in chloralkali electrolysis.

In a further preferred embodiment, the chelating resins according to the invention containing functional groups of the structural element (I) are suitable for the adsorption and desorption of iron(III) cations. It has been shown that iron(III) cations can be desorbed again in large amounts by acids from the chelating resins according to the invention containing functional groups of the structural element (I).

In a further preferred embodiment of the invention, the chelating resins according to the invention containing functional groups of the structural element (I) are suitable in a process for the production and purification of silicon, preferably silicon with a purity of greater than 99.99%.

Furthermore, the chelating resins according to the invention can preferably be used to remove metals from water for water purification.

With the chelate resins according to the invention, new resins with good adsorption properties for metals, in particular for the adsorption of zinc ions, are provided. Determination of the amount of basic groups

100 ml of the aminomethylated polymer are shaken in on the ram volumeter and then rinsed into a glass column with deionized water. 1000 ml of 2% strength by weight sodium hydroxide solution are filtered over in 1 hour and 40 minutes. Deionized water is then filtered over until 100 ml of eluate mixed with phenolphthalein have a maximum consumption of 0.1 N (0.1 normal) hydrochloric acid of 0.05 ml.

50 ml of this resin are mixed with 50 ml of deionized water and 100 ml of 1N hydrochloric acid in a beaker. The suspension is stirred for 30 minutes and then filled into a glass column. The liquid is drained. A further 100 ml of 1N hydrochloric acid are filtered over the resin in 20 minutes. Then 200 ml of methanol are filtered through. All eluates are collected and combined and titrated against methyl orange with 1N sodium hydroxide solution.

The amount of aminomethyl groups in 1 liter of aminomethylated resin is calculated using the following formula: ( 200 - V ) ■ 20 = moles of aminomethyl groups per liter of resin, where V is the volume of 1N sodium hydroxide solution consumed in the titration.

The amount of basic groups corresponds to the molar amount of aminomethyl groups in the chelating resin.

Determination of total Zn capacity

50 ml of the resin are shaken in on the ram volumeter and then rinsed into a glass column with deionized water. 150 ml of 5% strength by weight sulfuric acid are then applied to the resin using a dropping funnel. Then the acid is displaced from the filter with 250 ml of deionized water. Then 500 ml zinc acetate solution (15 g Zn(CH ₃ COO)2 are dissolved in 950 ml deionized water, adjusted to pH= 5 with concentrated acetic acid and made up to 1000 ml with deionized water) are applied to the resin and 250 ml Rinsed with deionized water. The adsorbed zinc is eluted with 250 ml of 5% strength by weight sulfuric acid. It is rinsed with 200 ml of deionized water. The collected eluate is collected in a 500 ml volumetric flask and, if necessary, made up to the mark with deionized water. The Zn concentration is determined from the 500 ml acid eluate using ICP-OES and converted to the total Zn capacity.

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examples

example 1

1 a) Production of the monodisperse, macroporous polymer based on styrene, divinylbenzene and ethylstyrene

3000 g of deionized water are placed in a 10 l glass reactor and a solution of 10 g of gelatin, 16 g of disodium hydrogen phosphate dodecahydrate and 0.73 g of resorcinol in 320 g of deionized water is added and mixed. The mixture is heated to 25°C. A mixture of 3200 g of microencapsulated monomer droplets with a narrow particle size distribution of 3.1% by weight divinylbenzene and 0.6% by weight ethylstyrene (used as a commercial isomer mixture of divinylbenzene and ethylstyrene with 80% divinylbenzene), 0, 4 wt. % dibenzoyl peroxide, 58.4 wt. % styrene and 37.5 wt Acrylamide and acrylic acid, and added to 3200 g of aqueous phase with a pH of 12.

The mixture is polymerized with stirring by increasing the temperature according to a temperature program starting at 25°C and ending at 95°C. The batch is cooled, washed through a 32 μm sieve and then dried at 80° C. in vacuo.

1893 g of a polymer with a monodisperse particle size distribution are obtained.

1b) Preparation of an amidomethylated polymer

1779 g of 1,2-dichloroethane, 588.5 g of phthalimide and 340.3 g of 36% strength by weight formalin are introduced at room temperature. The pH of the suspension is adjusted to 5.5 to 6 with sodium hydroxide solution. The water is then removed by distillation. Then 43.2 g of sulfuric acid (98% by weight) are metered in. The resulting water is removed by distillation. The batch is cooled. At 30° C., 157.7 g of 65% strength oleum and then 422.8 g of monodisperse polymer, prepared according to process step 1a), are metered in. The suspension is heated to 65° C. and stirred at this temperature for a further 6.5 hours. The reaction broth is drawn off, deionized water is metered in and residual amounts of 1,2-dichloroethane are removed by distillation.

Yield of amidomethylated polymer: 1900 ml 1 c) Preparation of an aminomethylated polymer

904.3 g of 50% strength by weight sodium hydroxide solution and 1680 ml of deionized water are metered into 1884 ml of amidomethylated polymer from 1b) at room temperature. The suspension is heated to 180° C. in 2 hours and stirred at this temperature for 8 hours. The polymer obtained is washed with deionized water.

Yield of aminomethylated polymer: 1760 ml

Determination of the amount of basic groups: 2.05 mol/liter of resin

1 d) Reaction of aminomethylated resin with phenylphosphinic acid

100 ml of deionized water and 100 ml of aminomethylated polymer (0.21 mol of aminomethyl groups) from Example 1 are placed in a reactor. 76.5 g of phenylphosphinic acid (99% strength, 0.53 mol) are then added in portions and the mixture is then stirred for 15 minutes. 164 g of 98% sulfuric acid (1.64 mol) are added dropwise over the course of 2 hours, and the suspension is then heated to 95.degree. At this temperature, 59.8 g of 36% formalin solution (0.72 mol) are added over the course of 1 hour and the mixture is then stirred at 95° C. for 4 hours. After cooling, the resin is washed neutral on a sieve with deionized water, transferred to a glass column and converted to the Na form with 4% sodium hydroxide solution.

Resin yield in Na form: 260 ml

Elemental analytical composition (dried resin):

Nitrogen= 3.4%

Phosphorus= 1 1%

Substitution on the nitrogen (from elemental analysis, ratio P:N): 1.47

Total Zn capacity (H-form): 36.7 g/l

example 2

Reaction of aminomethylated resin with ethylphosphinic acid 100 ml of deionized water and 100 ml of aminomethylated polymer (0.21 mol of aminomethyl groups) from Example 1c) are placed in a reactor. 55.2 g of ethylphosphinic acid (91% strength, 0.53 mol) are then added in portions and the mixture is then stirred for 15 minutes. 164 g of 98% sulfuric acid (1.64 mol) are added dropwise over the course of 2 hours, and the suspension is then heated to 95.degree. At this temperature, 59.8 g of 36% formalin solution (0.72 mol) are added over the course of 1 hour and the mixture is then stirred at 95° C. for 4 hours. After cooling, the resin is washed neutral on a sieve with deionized water, transferred to a glass column and converted to the Na form with 4% sodium hydroxide solution.

Resin yield in Na form: 216 ml

Elemental analytical composition (dried resin):

Nitrogen= 4.2%

Phosphorus= 11%

Substitution on the nitrogen (from elemental analysis, ratio P:N): 1.19

Total Zn capacity (H-form): 32.8 g/l

Example 3

Reaction of aminomethylated resin with 2-methylpentylphosphinic acid

40 ml of deionized water and 40 ml of aminomethylated polymer (0.08 mol of aminomethyl groups) from Example 1c) are placed in a reactor. 34 g of 2-methylpentylphosphinic acid (94% strength, 0.21 mol) are then added in portions and the mixture is then stirred for 15 minutes. 66 g of 98% sulfuric acid (0.66 mol) are added dropwise over the course of 2 hours, and the suspension is then heated to 95.degree. At this temperature, 23.9 g of 36% formalin solution (0.29 mol) are added over the course of 1 hour and the mixture is then stirred at 95° C. for 4 hours. After cooling, the resin is washed neutral on a sieve with deionized water, transferred to a glass column and converted to the Na form with 4% sodium hydroxide solution.

Resin yield in Na form: 91 ml

Elemental analytical composition (dried resin):

Nitrogen= 4.0% Phosphorus= 9.1%

Substitution on the nitrogen (from elemental analysis, ratio P:N): 1.03

Total Zn capacity (H form): 21.8 g/l

Comparative example to DE-A 2848289

Reaction aminomethylated resin with phosphinic acid

50 ml of deionized water and 100 ml of aminomethylated polymer (0.21 mol of aminomethyl groups) from Example 1c) are placed in a reactor. 71.4 g of phosphinic acid (50% strength in water, 0.54 mol) are then added in portions and the mixture is then stirred for 15 minutes. 167 g of 98% sulfuric acid (1.66 mol) are added dropwise over the course of 2 hours, and the suspension is then heated to 95.degree. At this temperature, 60.7 g of 36% formalin solution (0.73 mol) are added over the course of 1 hour and the mixture is then stirred at 95° C. for 4 hours. After cooling, the resin is washed neutral on a sieve with deionized water, transferred to a glass column and converted to the Na form with 4% sodium hydroxide solution.

Resin yield in Na form: 130 ml

Elemental analytical composition (dried resin):

Nitrogen= 6.7%

Phosphorus= 10%

Substitution on nitrogen (from elemental analysis, P:N ratio): 0.68

Zn total capacity (H form): 15 g/L

result

Table 1 : R ³ is in the examples = hydrogen.

Examples 1 to 3 show that the claimed compounds surprisingly have a significantly higher total Zn capacity (TK) than the resin that is known from DE-A 2848289 and was produced with phosphinic acid.

Claims

23 patent claims

1 . Chelating resins containing functional groups of structural element (I) wherein stands for the polystyrene copolymer backbone and

R ¹ and R ² independently represent hydrogen or -CH2-PO(OR ³ )R ⁴ , where R ¹ and R ² cannot both be hydrogen at the same time and R ³ = hydrogen or Ci-Ci ₅ -alkyl and R ⁴ stands for Ci-Ci ₅ -alkyl, Ce-C24-aryl, C7-C15- arylalkyl or C2-Cio-alkenyl, each of which can be substituted one or more times by Ci-Cs-alkyl.

2. Chelating resins containing functional groups of the structural element (I) according to claim 1, characterized in that R ⁴ = Ci-Ci ₅ -alkyl or Cs-C24-aryl, which can be substituted one or more times by Ci-Cs-alkyl, is.

3. Chelating resins containing functional groups of the structural element (I) according to claim 1, characterized in that R ⁴ = Ci-Cs-alkyl or phenyl, which can be mono-, di- or tri-substituted by methyl or ethyl.

4. chelate resins containing functional groups of the structural element (I) according to claim 1, characterized in that R ⁴ = ethyl, 2,4,4-trimethylpentyl, 2-methylpentyl, benzyl and phenyl.

5. Chelating resins containing functional groups of the structural element (I) according to at least one of claims 1 to 4, characterized in that R ¹ and R ² = -CH ₂ -PO(OR ³ )R ⁴ are.

6. chelate resins containing functional groups of the structural element (I) according to at least one of claims 1 to 5, characterized in that R ³ = hydrogen or Ci-Cs-alkyl.

7. A process for preparing the chelate resins containing functional groups of the structural element (I) according to claim 1, characterized in that a) monomer droplets of at least one monovinylaromatic compound and at least one polyvinylaromatic compound and at least one initiator, b) phthalimidomethylated the polymer from step a) with phthalimide or its derivatives, c) the phthalimidomethylated polymer from step b) with at least one base or at least one Acid reacts and d) the aminomethylated polymer from step c) by reaction with formaldehyde or its derivatives in the presence of at least one suspension medium and at least one acid and at least one compound of the formula (II) or salts thereof where R ³ and R ⁴ are as defined in claim 1, functionalized to give a chelating resin having functional groups of formula (I).

8. Process for preparing the chelating resins with functional groups of the structural element (I) according to Claim 7, characterized in that formalin is used as formaldehyde or its derivatives in process step d).

9. Process for the preparation of the chelate resin containing functional groups of the structural element (I) according to at least one of claims 7 or 8, characterized in that in process step d) formaldehyde or its derivatives and the aminomethylated polymers from step c) are used in a molar ratio of 2 to 8 based on the molar amount of the aminomethyl groups are used.

10. A process for preparing the chelating resin as claimed in at least one of claims 7 to 9, characterized in that in process step d) 2 to 12 moles of inorganic acid are used per mole of aminomethyl groups in the aminomethylated polymer.

11 . Process for preparing the chelating resin according to at least one of Claims 7 to 10, characterized in that in process step d.) the molar ratio of the compounds of the formula (II) used to the amount of aminomethyl groups in the aminomethylated polymer is 1 to 4.

12. Use of the chelating resins according to claim 1 for the adsorption of metals, preferably heavy metals, precious metals and rare earths.

13. Use according to claim 12, characterized in that the metals are selected from the group consisting of iron, vanadium, zinc, aluminium, cobalt, tungsten, copper, nickel, manganese, magnesium, calcium, lead, cadmium, uranium, mercury and scandium , lanthanum, yttrium, cerium, praseodymium, neodymium, promethium,

Samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, platinum group elements, and gold or silver.

14. Use according to claim 13, characterized in that the metals are selected from the group consisting of zinc, cobalt and nickel.

15. Use of the chelate resins containing functional groups of the structural element (I) from claim 1 for the production and purification of silicon.