Method for removing residual metal in acrylate polymer through three-phase method

Abstract

The invention provides a method for removing residual metal in an acrylate polymer by a three-phase method. The method comprises the following steps: quenching an acrylate polymer glue solution, introducing carbon dioxide gas, adding a chelating acid solution, uniformly mixing, standing and separating to obtain an organic phase and a water phase, and concentrating and drying the organic phase, thereby obtaining the product, the molar ratio of chelating acid in the chelating acid solution to residual metal elements in the acrylate polymer glue solution is (0.1-200): 1. The gas-phase carbon dioxide, the chelating acid aqueous solution and the acrylate polymer glue solution form a three-phase system, so that residual metal is mildly and thoroughly transferred into a water phase from the glue solution, metal ions can be thoroughly removed without heating, the carbon dioxide can be recycled in the process, and waste is avoided; the method has the advantages of simple process, environment friendliness, low cost and the like, and can effectively solve the problems of high energy consumption, incomplete removal and the like of residual metal removal in the acrylate polymer.

Description

Technical Field

[0001] The present invention relates to a method for removing residual metals in an acrylate polymer, and specifically to a method for removing residual metals in an acrylate polymer by a three-phase method, belonging to the technical field of acrylate polymers. Background Art

[0002] An acrylate polymer is a product obtained by homopolymerization or copolymerization of acrylate as the main monomer. The main chain of this polymer is a saturated alkane, and the side group is a polar ester group, which endows the material with excellent properties such as heat resistance, oil resistance, ozone resistance, aging resistance, and ultraviolet resistance, and has clear demands in the fields of national defense, aerospace, medical materials, and automotive parts. At the same time, acrylate polymer is also a material with excellent light transmission performance and has wide applications in optical devices and signal transmission materials. The residues of impurities, especially metal ions, in acrylate elastomers may have an important impact on the macroscopic properties such as the light transmittance and aging resistance of the material. Therefore, for the development of high-performance acrylate materials, the removal of impurities such as metals in the polymer is the key to ensuring the stable performance of the material.

[0003] At present, the exploration of methods for removing residual metal ions in polymers mainly focuses on conjugated diene polymerization products, and there is little research on methods for removing metal ions in acrylate polymerization products. China Petroleum & Chemical Corporation reported a method for removing residual metal nickel, lithium, and aluminum catalysts from a hydrogenated polymer latex in the published patent (CN 104072645A). This patent mainly performs metal ion removal treatment on the polymer latex obtained by anionic polymerization, but this treatment method requires the addition of corresponding H 2 O 2 oxidant and heating to 70 °C at the same time; Patent CN111533831 discloses a method for removing residual metals after hydrogenation of unsaturated polymers. This method mainly uses different types of carboxylic acids or chelating acids to remove residual metal ions nickel, lithium, and aluminum in the polymer, but the entire process of removing metal ions needs to be carried out at 60 °C. This heating operation is not friendly for industrialization, which means that the whole process requires higher energy consumption. Acrylate polymers already have excellent mechanical properties, processing properties, and good light transmittance without removing metal ions. Further removal of residual metal ions in the polymer will obtain high-value-added materials with higher transparency. However, there is currently little research on methods for removing residual metals in acrylate polymers, which may be related to the technical barriers in the preparation technology of high-performance block acrylate elastomers. How to find a simple, controllable, and efficient method for removing residual metal ions to effectively remove residual lithium and aluminum metal ions in acrylate polymers will play an important and key guiding role in the future preparation technology of high-performance acrylate elastomers. Summary of the Invention

[0004] Aiming at the problems existing in the prior art, the present invention provides a method for removing residual metals in acrylate polymers by a three-phase method. The present invention uses gaseous carbon dioxide and an aqueous solution of a chelating acid to form a three-phase system with the acrylate polymer solution, so as to gently and thoroughly transfer the residual metals from the solution to the aqueous phase. On the one hand, carbon dioxide can be recycled in the process to avoid the problem of difficult treatment of subsequent polyacid solutions. On the other hand, carbon dioxide gas can also play a role in stirring and reducing the activation energy for removing metal ions during the transfer of residual metals, and the complete removal of metal ions can be achieved without heating. This method has the advantages of simple process, environmental friendliness and low cost, and can effectively solve the problems such as high energy consumption and incomplete removal of residual metals in acrylate polymers.

[0005] In order to achieve the above technical purpose, the present invention provides a method for removing residual metals in acrylate polymers by a three-phase method. After the acrylate polymer solution is quenched, carbon dioxide gas is introduced, and then a chelating acid solution is added and mixed evenly, and then left to stand for separation to obtain an organic phase and an aqueous phase. The organic phase is concentrated and dried to obtain the product; the process of adding the chelating acid solution for mixing and standing is repeated 1 to 10 times;

[0006] The amount of carbon dioxide introduced is 5 to 50 L / min; the molar ratio of the chelating acid in the chelating acid solution to the residual metal elements in the acrylate polymer solution is 0.1 to 200:1.

[0007] As a preferred solution, the process of adding the chelating acid solution for mixing and standing is repeated 1 to 5 times. Further preferably, the process of adding the chelating acid solution for mixing and standing is repeated 1 to 3 times.

[0008] As a preferred solution, the acrylate polymer solution is at least one of a product obtained by anionic polymerization of an alkyl methacrylate, a product obtained by anionic polymerization of an alkyl acrylate, and a copolymer obtained by anionic polymerization of an alkyl methacrylate and an alkyl acrylate.

[0009] As a preferred solution, the alkyl methacrylate is one or two of methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, tert-butyl methacrylate, cyclohexyl methacrylate, n-hexyl methacrylate, n-octyl methacrylate, isooctyl methacrylate, dodecyl methacrylate, tridecyl methacrylate and stearyl methacrylate. Further preferably, the alkyl methacrylate is one of methyl methacrylate, ethyl methacrylate, propyl methacrylate and n-butyl methacrylate.

[0010] As a preferred embodiment, the alkyl acrylate is one or two of n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, n-hexyl acrylate, n-octyl acrylate and isooctyl acrylate. Further preferably, the alkyl acrylate is n-butyl acrylate, isobutyl acrylate or isooctyl acrylate.

[0011] As a preferred embodiment, the residual metal is the residual metal ions of the catalyst used in the synthesis process of the acrylate polymer, and is at least one of lithium, aluminum, nickel and cobalt.

[0012] As a preferred embodiment, the chelating acid solution is one or two of tartaric acid solution, citric acid solution, malic acid solution, aconitic acid solution, succinic acid solution, hydroxyethyl ethylenediamine triacetic acid solution and ethylenediaminetetraacetic acid solution. Further preferably, the chelating acid solution is one or two of tartaric acid solution, malic acid solution, citric acid solution and aconitic acid solution. Most preferably, the chelating acid solution is citric acid solution.

[0013] As a preferred embodiment, the mixing method of the acrylate polymer glue solution and the chelating acid solution is centrifugal stirring, and the conditions are: the rotation speed is 500-5000 rpm, and the time is 1 min-6 h. Further preferably, the rotation speed of the centrifugal stirring is 2000 rpm, and the time is 20 min.

[0014] As a preferred embodiment, the drying method is one of freeze-drying, vacuum drying and baking.

[0015] As a preferred embodiment, when the drying method is vacuum drying, the conditions are: the vacuum degree is 0.001-0.1 mBar, the temperature is 40-100 °C, and the time is 6-24 h. Further preferably, the conditions of the vacuum drying are: the vacuum degree is 0.01 mBar, the temperature is 60 °C, and the time is 12 h.

[0016] As a preferred embodiment, the mass concentration of the aqueous chelating acid solution is 0.1-99%. Further preferably, the mass concentration of the aqueous chelating acid solution is 2-20%.

[0017] As a preferred embodiment, the molar ratio of the chelating acid in the chelating acid solution to the residual metal element in the acrylate polymer glue solution is 20-100:1. Further preferably, the molar ratio of the chelating acid in the chelating acid solution to the residual metal element in the acrylate polymer glue solution is 50-100:1. Most preferably, the molar ratio of the chelating acid in the chelating acid solution to the residual metal element in the acrylate polymer glue solution is 50:1.

[0018] As a preferred embodiment, the carbon dioxide is high-purity carbon dioxide with a purity ≥99.99%.

[0019] Compared with the prior art, the excellent technical effects of the present invention are as follows:

[0020] 1) The method provided by the present invention uses gaseous carbon dioxide and an aqueous solution of chelating acid to form a three-phase system with the acrylate polymer solution, thereby gently and thoroughly transferring the residual metal from the solution to the aqueous phase. On the one hand, carbon dioxide can be recycled during the process, avoiding the problem of difficult subsequent treatment with polyacid solution. On the other hand, carbon dioxide gas can also play a role in stirring and reducing the activation energy for metal ion removal during the transfer of residual metal, enabling the complete removal of metal ions without heating.

[0021] 2) In the technical solution provided by the present invention, carbon dioxide first reacts with metal ions in the solution to form metal carbonate particle precipitates. These metal carbonates decompose into metal ions and carbon dioxide when contacting with the chelating acid solution. The metal ions chelate with the chelating acid to form a chelate that is soluble in the aqueous phase and insoluble in the organic phase, and is enriched in the aqueous phase during the standing process. The decomposed carbon dioxide can be recycled, and the solution is obtained as the final product after concentration and drying treatment.

[0022] 3) In the technical solution provided by the present invention, with carbon dioxide as the medium, the requirements for temperature and acidity during the metal ion removal process are greatly reduced. It not only effectively removes the residual metal ions in the acrylate polymer, but also significantly improves the light transmittance of the material. After testing, the residual lithium content of the polymer obtained by this treatment method can be reduced to a minimum of 1 ppm, and the residual aluminum content can be reduced to a minimum of 20 ppm. The metal ion removal rate is above 99%, and the light transmittance can reach 93.0%. Description of the Drawings

[0023] Figure 1 It is a picture of the acrylate polymer before demetallization in Example 1 of the present invention;

[0024] Figure 2 It is a picture of the acrylate polymer after demetallization in Example 1 of the present invention;

[0025] Figure 3 It is an ICP result chart of the acrylate polymer before and after demetallization in Example 1 of the present invention. Detailed Embodiments

[0026] The present invention will be further described below in conjunction with specific embodiments, but the present invention is not limited by the embodiments.

[0027] Example 1

[0028] (1) Prepare 100 mL of acrylate polymer solution according to the anionic polymerization method, add 1 mL of methanol to quench it. The initial acrylate polymer solution contains 3000 ppm of aluminum element and 150 ppm of lithium element; (2) Pass a stable carbon dioxide gas stream (10 L / min) into the acrylate polymer solution to form lithium carbonate and aluminum carbonate precipitates; (3) Add a citric acid solution (20% concentration) that is 50 times the total molar amount of metal elements in the system to the acrylate solution; (4) Centrifuge and stir the mixture of the acid solution and the polymer solution at room temperature for 20 min at a speed of 2000 rpm. The metal precipitate dissolves, and lithium and aluminum metal ions are extracted into the aqueous phase; (5) Let it stand for stratification and collect the upper-layer polymer solution; (6) Repeat steps (3) and (4) once again; (7) After centrifugal separation, pour out the upper-layer clear liquid, and obtain a polymer sample with residual metals removed after drying. The light transmittance of the polymer before deionization is measured to be 87.3% by a light transmittance and haze meter, and the light transmittance after deionization is 92.0%. The residual metal content of the polymer is measured by an inductively coupled plasma emission spectrometer (ICP), and the results are shown in Table 1. The final content of aluminum element is 63 ppm, and the final content of lithium element is 11 ppm.

[0029] Comparative Example 1

[0030] (1) Prepare 100 mL of acrylate polymer solution according to the anionic polymerization method, add 1 mL of methanol to quench it. The initial acrylate polymer solution contains 3000 ppm of aluminum element and 150 ppm of lithium element; (2) Add a citric acid solution (20% concentration) that is 50 times the total molar amount of metal elements in the system to the acrylate solution; (3) Centrifuge and stir the mixture of the acid solution and the polymer solution at room temperature for 20 min at a speed of 2000 rpm. The metal precipitate dissolves, and lithium and aluminum metal ions are extracted into the aqueous phase; (4) Let it stand for stratification and collect the upper-layer polymer solution; (5) Repeat steps (2) and (3) once again; (6) After centrifugal separation, pour out the upper-layer clear liquid, and obtain a polymer sample with residual metals removed after drying. The light transmittance of the polymer before deionization is measured to be 87.3% by a light transmittance and haze meter, and the light transmittance after deionization is 89.4%. The residual metal content of the polymer is measured by an inductively coupled plasma emission spectrometer (ICP), and the results are shown in Table 1. The final content of aluminum element is 98 ppm, and the final content of lithium element is 32 ppm.

[0031] Comparative Example 2

[0032] (1) Prepare 100 mL of an acrylate polymer solution according to the anionic polymerization method, and add 1 mL of methanol to quench it. The initial acrylate polymer solution contains 3000 ppm of aluminum element and 150 ppm of lithium element; (2) Pass a stable carbon dioxide gas stream (10 L / min) into the acrylate polymer solution to form lithium carbonate and aluminum carbonate precipitates; (3) Centrifuge and stir the polymer solution at room temperature for 20 min at a speed of 2000 rpm; (4) Let it stand for stratification and collect the upper polymer solution; (5) Repeat steps (2) and (3) once again; (6) After centrifugal separation, pour out the upper clear liquid, and obtain a polymer sample with residual metals removed after drying. The light transmittance of the polymer before deionization is measured to be 87.3% by a light transmittance and haze meter, and the light transmittance after deionization is 89.0%. The residual metal content of the polymer is measured by an inductively coupled plasma emission spectrometer (ICP), and the results are shown in Table 1. The final content of aluminum element is 152 ppm, and the final content of lithium element is 46 ppm.

[0033] Example 2

[0034] (1) Prepare 100 mL of an acrylate polymer solution according to the anionic polymerization method, and add 1 mL of methanol to quench it. The initial acrylate polymer solution contains 3000 ppm of aluminum element and 150 ppm of lithium element; (2) Pass a stable carbon dioxide gas stream (10 L / min) into the acrylate polymer solution to form lithium carbonate and aluminum carbonate precipitates; (3) Add a tartaric acid solution (20% concentration) that is 50 times the total molar amount of metal elements in the system to the acrylate solution; (4) Centrifuge and stir the mixture of the acid solution and the polymer solution at room temperature for 20 min at a speed of 2000 rpm. The metal precipitate dissolves, and lithium and aluminum metal ions are extracted into the aqueous phase; (5) Let it stand for stratification and collect the upper polymer solution; (6) Repeat steps (3) and (4) once again; (7) After centrifugal separation, pour out the upper clear liquid, and obtain a polymer sample with residual metals removed after drying. The light transmittance of the polymer before deionization is measured to be 87.8% by a light transmittance and haze meter, and the light transmittance after deionization is 91.4%. The residual metal content of the polymer is measured by an inductively coupled plasma emission spectrometer (ICP), and the results are shown in Table 1. The final content of aluminum element is 66 ppm, and the final content of lithium element is 119 ppm.

[0035] Example 3

[0036] (1) Prepare 100 mL of acrylate polymer solution according to the anionic polymerization method, and add 1 mL of methanol to quench. The initial acrylate polymer solution contains 3000 ppm of aluminum element and 150 ppm of lithium element; (2) Pass a stable carbon dioxide gas stream (10 L / min) into the acrylate polymer solution to generate lithium carbonate and aluminum carbonate precipitates; (3) Add a malic acid solution (20% concentration) that is 50 times the total molar amount of metal elements in the system to the acrylate solution; (4) Centrifuge and stir the mixture of the acid solution and the polymer solution at room temperature for 20 min at a rotation speed of 2000 rpm. The metal precipitate dissolves, and lithium and aluminum metal ions are extracted into the aqueous phase; (5) Let it stand for layering, and collect the upper-layer polymer solution; (6) Repeat steps (3) and (4) once again; (7) After centrifugal separation, pour out the upper-layer clear liquid, and obtain a polymer sample with residual metals removed after drying. The light transmittance of the polymer before deionization was measured to be 88.1% by a light transmittance and haze meter, and the light transmittance after deionization was 90.8%. The residual metal content of the polymer was measured by an inductively coupled plasma emission spectrometer (ICP), and the results are shown in Table 1. The final content of aluminum element is 89 ppm, and the final content of lithium element is 5 ppm.

[0037] Example 4

[0038] (1) Prepare 100 mL of acrylate polymer solution according to the anionic polymerization method, and add 1 mL of methanol to quench. The initial acrylate polymer solution contains 3000 ppm of aluminum element and 150 ppm of lithium element; (2) Pass a stable carbon dioxide gas stream (10 L / min) into the acrylate polymer solution to generate lithium carbonate and aluminum carbonate precipitates; (3) Add an aconitic acid solution (20% concentration) that is 50 times the total molar amount of metal elements in the system to the acrylate solution; (4) Centrifuge and stir the mixture of the acid solution and the polymer solution at room temperature for 20 min at a rotation speed of 2000 rpm. The metal precipitate dissolves, and lithium and aluminum metal ions are extracted into the aqueous phase; (5) Let it stand for layering, and collect the upper-layer polymer solution; (6) Repeat steps (3) and (4) once again; (7) After centrifugal separation, pour out the upper-layer clear liquid, and obtain a polymer sample with residual metals removed after drying. The light transmittance of the polymer before deionization was measured to be 87.7% by a light transmittance and haze meter, and the light transmittance after deionization was 90.1%. The residual metal content of the polymer was measured by an inductively coupled plasma emission spectrometer (ICP), and the results are shown in Table 1. The final content of aluminum element is 98 ppm, and the final content of lithium element is 8 ppm.

[0039] Comparative Example 3

[0040] (1) Prepare 100 mL of an acrylate polymer solution according to the anionic polymerization method, and add 1 mL of methanol to quench it. The initial acrylate polymer solution contains 3000 ppm of aluminum element and 150 ppm of lithium element; (2) Pass a stable carbon dioxide gas stream (10 L / min) into the acrylate polymer solution to form lithium carbonate and aluminum carbonate precipitates; (3) Add a citric acid solution (20% concentration) 40 times the total molar amount of metal elements in the system and 10 equivalents of tartaric acid (20% concentration) to the acrylate solution; (4) Centrifuge and stir the mixture of the acid solution and the polymer solution at room temperature for 20 min at a speed of 2000 rpm. The metal precipitate dissolves, and lithium and aluminum metal ions are extracted into the aqueous phase; (5) Let it stand for layering, and collect the upper-layer polymer solution; (6) Repeat steps (3) and (4) once again; (7) After centrifugal separation, pour out the upper-layer clear liquid, and obtain a polymer sample with residual metals removed after drying. The light transmittance of the polymer before deionization was measured to be 87.3% by a light transmittance haze meter, and the light transmittance after deionization was 91.8%. The residual metal content of the polymer was tested by an inductively coupled plasma emission spectrometer (ICP), and the results are shown in Table 1. The final content of aluminum element was 65 ppm, and the final content of lithium element was 26 ppm.

[0041] Example 5

[0042] (1) Prepare 100 mL of an acrylate polymer solution according to the anionic polymerization method, and add 1 mL of methanol to quench it. The initial acrylate polymer solution contains 3000 ppm of aluminum element and 150 ppm of lithium element; (2) Pass a stable carbon dioxide gas stream (10 L / min) into the acrylate polymer solution to form lithium carbonate and aluminum carbonate precipitates; (3) Add a citric acid solution (20% concentration) 20 times the total molar amount of metal elements in the system to the acrylate solution; (4) Centrifuge and stir the mixture of the acid solution and the polymer solution at room temperature for 20 min at a speed of 2000 rpm. The metal precipitate dissolves, and lithium and aluminum metal ions are extracted into the aqueous phase; (5) Let it stand for layering, and collect the upper-layer polymer solution; (6) Repeat steps (3) and (4) once again; (7) After centrifugal separation, pour out the upper-layer clear liquid, and obtain a polymer sample with residual metals removed after drying. The light transmittance of the polymer before deionization was 88.2%, and the light transmittance after deionization was 90.1%. The residual metal content of the polymer was tested by an inductively coupled plasma emission spectrometer (ICP), and the results are shown in Table 2. The final content of aluminum element was 96 ppm, and the final content of lithium element was 11 ppm.

[0043] Example 6

[0044] (1) Prepare 100 mL of acrylate polymer solution according to the anionic polymerization method, add 1 mL of methanol to quench it. The initial acrylate polymer solution contains 3000 ppm of aluminum element and 150 ppm of lithium element; (2) Pass a stable carbon dioxide gas stream (10 L / min) into the acrylate polymer solution to generate lithium carbonate and aluminum carbonate precipitates; (3) Add a citric acid solution (20% concentration) that is 80 times the total molar amount of metal elements in the system to the acrylate solution; (4) Centrifuge and stir the mixed solution of the acid solution and the polymer solution at room temperature for 20 min at a rotation speed of 2000 rpm. The metal precipitate dissolves, and lithium and aluminum metal ions are extracted into the aqueous phase; (5) Let it stand for layering and collect the upper-layer polymer solution; (6) Repeat steps (3) and (4) once again; (7) After centrifugal separation, pour out the upper-layer clear liquid, and obtain a polymer sample with residual metals removed after drying. The light transmittance of the polymer before deionization is 88.2%, and the light transmittance after deionization is 92.3%. Use an inductively coupled plasma emission spectrometer (ICP) to test the residual metal content of the polymer. The results are shown in Table 2, where the final content of aluminum element is 20 ppm and the final content of lithium element is 1 ppm.

[0045] Table 1 Residual metal content and light transmittance of acrylate polymer removed by different chelating acids

[0046]

[0047] [Ch] / [M] a Represents the ratio of the water-soluble chelating acid to the total molar amount of metals in the system

[0048] The above examples and comparative examples studied the ion removal effects under different chelating acids and the presence or absence of CO 2 conditions, and the summary is shown in Table 1. As can be seen from the table, in the chelating acid + CO 2 system, citric acid shows the best ion removal effect. At 50 equivalents of acid, the Al removal rate is 98% and the lithium removal rate is 87%; It can be seen from Examples 1-4 that when the Al removal rate is higher, it has a better effect on the light transmittance of the material; Under the same conditions, without adding CO 2 the removal effects of lithium and aluminum decrease significantly, and only adding CO 2 the removal effects of lithium and aluminum are limited; In addition, the removal efficiency has not been significantly improved by using a mixture of multiple chelating acids, indicating that a single chelating acid has more removal advantages.

[0049] Table 2 Residual metal content and light transmittance of acrylate polymer removed by different addition amounts of chelating acids

[0050]

[0051] [Ch] / [M] aRepresents the ratio of the total molar amount of water-soluble chelating acid to the metal in the system

[0052] Table 2 studied the effects of different acid dosages under the citric acid + CO 2 system. When the dosage of citric acid was 80 equivalents, 99% of Al could be removed and more than 99% of Li could be removed; the highest light transmittance could reach 93.0%. However, it should be noted that when the equivalent of citric acid increased from 20 to 50, the light transmittance increased by 1.9%, and when the equivalent of citric acid increased from 50 to 80, the light transmittance increased by 1%. This indicates that although the increase in citric acid can improve the light transmittance, the effect of increasing the light transmittance by adding excessive citric acid becomes weaker and weaker. Therefore, the optimal equivalent of citric acid is 50.

Claims

1. A three-phase method for removing residual metals from acrylic ester polymers, characterized in that: After the acrylic ester polymer glue is quenched, carbon dioxide gas is introduced, and then a chelating acid solution is added, mixed evenly, and then allowed to stand for separation to obtain an organic phase and an aqueous phase. The organic phase is concentrated and dried to obtain the product; the process of adding the chelating acid solution, mixing and standing is repeated 1 to 10 times; the amount of carbon dioxide introduced is 5 to 50 L / min; the molar ratio of the chelating acid in the chelating acid solution to the residual metal elements in the acrylic ester polymer glue is 0.1 to 200:1; and the removal step is carried out at 20 to 30° C.

2. The method for removing residual metals from acrylate polymers by a three-phase method according to claim 1, characterized in that: The acrylic acid ester polymer glue is at least one of a product obtained by anionic polymerization of alkyl methacrylate, a product obtained by anionic polymerization of alkyl acrylate, and a copolymer obtained by anionic polymerization of alkyl methacrylate and alkyl acrylate.

3. The method for removing residual metals from acrylate polymers by a three-phase method according to claim 2, characterized in that: The alkyl methacrylate is one or two of methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, tert-butyl methacrylate, cyclohexyl methacrylate, n-hexyl methacrylate, n-octyl methacrylate, isooctyl methacrylate, dodecyl methacrylate, tridecyl methacrylate and stearic methacrylate.

4. The method for removing residual metals from acrylate polymers by a three-phase method according to claim 2, characterized in that: The alkyl acrylate is at least one of n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, n-hexyl acrylate, n-octyl acrylate and isooctyl acrylate.

5. The method for removing residual metals from acrylate polymers by a three-phase method according to claim 1, characterized in that: The residual metal is the residual metal ion of the catalyst used in the synthesis process of the acrylic ester polymer, which is one or two of lithium, aluminum, nickel and cobalt.

6. The method for removing residual metals from acrylate polymers by a three-phase method according to claim 1, characterized in that: The chelating acid solution is one or two of tartaric acid solution, citric acid solution, malic acid solution, aconitic acid solution, succinic acid solution, hydroxyethylethylenediaminetriacetic acid solution and ethylenediaminetetraacetic acid solution.

7. The method for removing residual metals from acrylate polymers by a three-phase method according to claim 1, characterized in that: The acrylate polymer glue and the chelating acid solution are mixed by centrifugal stirring, and the conditions are: a rotation speed of 500 to 5000 rpm and a time of 1 minute to 6 hours.

8. The method for removing residual metals from acrylate polymers by a three-phase method according to claim 1, characterized in that: The drying method is one of freeze drying, vacuum drying and baking. When the drying method is vacuum drying, the conditions are: vacuum degree is 0.001-0.1 mBar, temperature is 40-100° C., and time is 6-24 hours.

9. The method for removing residual metals from acrylate polymers by a three-phase method according to claim 1, characterized in that: The molar ratio of the chelating acid in the chelating acid solution to the residual metal elements in the acrylic ester polymer glue is 20-100:

1.

10. The method for removing residual metals from acrylate polymers by a three-phase method according to claim 1, characterized in that: The carbon dioxide is high-purity carbon dioxide with a purity of ≥99.99%.

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