Method for purifying photoacid generator for photoresist

Abstract

The invention relates to a method for purifying a photoacid generator for photoresist, which comprises the following steps: adding an alcohol solvent into the photoacid generator, stirring and dissolving, then adding bismuth salt, and continuously stirring; filtering, concentrating filtrate, adding an organic solvent for dissolving, and then adding an adsorbent for adsorbing; the method comprises the following steps: filtering, concentrating a filtrate, dissolving with an alcohol solvent, adding into an aqueous solution containing a chelating agent, reacting, separating out a solid, filtering, washing a filter cake, and drying to obtain the purified photoacid generator, so that the removal of tungsten ions in the photoacid generator is realized, the concentration of tungsten in the purified photoacid generator is less than 5ppb through detection, and the yield of tungsten ions in the photoacid generator is more than or equal to 90%. And the product can be qualified and applied to the next section.

Description

Technical Field

[0001] The invention relates to the field of photoresists, and in particular to a method for purifying a photoacid generator in the photoresist. Background Art

[0002] Photoresist, also known as photoresist, is a photolithographic material that undergoes chemical reactions under the action of visible light, ultraviolet light, electron beams, etc., so that the illuminated part and the non-illuminated part form a dissolution contrast in the developer, thereby forming a specific pattern. The main components of photoresist are resin, photoacid generator (PAG), and corresponding additives and solvents. Photoacid generator is a light-sensitive compound that can produce strong acid when decomposed under light. The strong acid produced can cause chemical reactions such as decomposition and cross-linking of acid-sensitive resins or acid-labile groups.

[0003] During the synthesis of the photoacid generator, raw materials containing tungsten are required, resulting in a high concentration of tungsten in the synthesized photoacid generator. Since excessive metal ions can damage the wafers of the Feb factory, resulting in immeasurable losses, the requirements for raw materials in the wafer photoresist formulation are very high, especially the metal ion impurity content in the raw materials; and the proportion of photoacid generators in the photoresist formula is very high. In order to ensure the quality of the wafer and reduce unnecessary losses, it is necessary to remove the residual metal ions in the photoacid generator. Summary of the invention

[0004] In order to solve the problems existing in the prior art, the present invention provides a method for removing tungsten in a photoacid generator, which has the advantages of being economical and highly efficient.

[0005] A method for purifying a photoacid generator, characterized in that it comprises the following steps:

[0006] S1. Add an alcohol solvent to the photoacid generator, stir to dissolve, then add a bismuth salt, and continue stirring;

[0007] S2 is filtered, the filtrate is concentrated, an organic solvent is added, stirred and dissolved, and then an adsorbent is added for adsorption;

[0008] S3 is filtered, the filtrate is concentrated and then dissolved with an alcohol solvent, added to an aqueous solution containing a chelating agent for reaction, and the solid is filtered after precipitation, and the filter cake is washed and dried to obtain a purified photoacid generator.

[0009] Furthermore, the photoacid generator is selected from at least one of an iodine salt photoacid generator or a sulfonate salt photoacid generator; preferably, the photoacid generator is selected from At least one of .

[0012] And / or, the bismuth salt is selected from one or a combination of BiCl2, BiCl3, bismuth nitrate, and bismuth acetate;

[0013] And / or, the adsorbent is at least one of modified silica gel, Al2O3 adsorbent, molecular sieve, and activated carbon.

[0014] And / or, the chelating agent is selected from one or a combination of hydroxyethylidene diphosphonic acid (HEDP), ethylenediaminetetramethylenephosphonic acid (EDTMPA), sodium ethylenediaminetetraacetate (EDTA-Na), sodium diethylenetriaminepentaacetate (DTPA-Na), sodium ethylenediaminedi-o-phenylacetate (EDDHA-Na), sodium gluconate, potassium tartrate or sodium citrate; wherein sodium ethylenediaminetetraacetate may be disodium ethylenediaminetetraacetate or tetrasodium ethylenediaminetetraacetate; sodium diethylenetriaminepentaacetate includes pentasodium diethylenetriaminepentaacetate;

[0015] Further, the concentration of tungsten in the photoacid generator is 500ppb-10000ppm;

[0016] and / or, the concentration of tungsten in the purified photoacid generator is less than 5 ppb;

[0017] Furthermore, the alcohol solvent is selected from one or a combination of methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, n-pentanol, and isopentanol;

[0018] And / or, the organic solvent is selected from one or a combination of dichloromethane, chloroform, tetrahydrofuran, 2-methyltetrahydrofuran, n-butanol, isobutanol, n-pentanol, and isopentanol;

[0019] Furthermore, in the step S1, the amount of the bismuth salt is 0.5-4 g per gram of the photoacid generator, preferably 0.75-2 g;

[0020] And / or, in step S1, the amount of the alcohol solvent added is 4-10 mL per gram of the photoacid generator;

[0021] And / or, in step S1, the stirring rate is 100-200 r / min;

[0022] And / or, in step S2, the amount of the organic solvent added is 2.5 to 10 mL per gram of the photoacid generator,

[0023] And / or, in the step S2, the amount of the adsorbent used is 1 to 10 g per gram of the photoacid generator added.

[0024] And / or, in step S2, the stirring rate is 100-200 r / min;

[0025] And / or, the amount of the alcohol solvent in step S3 is 2.5-10 mL relative to the amount of the photoacid generator added per gram, the concentration of the aqueous solution containing the chelating agent is 0.5%-5% by mass, and the amount of the aqueous solution containing the chelating agent is 50-100 mL relative to the amount of the photoacid generator added per gram;

[0026] And / or, in step S3, the reaction temperature is 25-45° C., and the reaction time is 8-12 hours.

[0027] Furthermore, the purification method of the photoacid generator of the present invention comprises the following steps:

[0028] S1 Weigh the newly synthesized photoacid generator (tungsten concentration is 500ppb-10000ppm) into an eggplant-shaped bottle, add a stirrer, and then add 4-10mL of alcohol solvent per gram of photoacid generator; start stirring until the solution is clear and there is no impurity to the naked eye, continue stirring, and then add 0.75-2g of bismuth salt solid per gram of photoacid generator, and continue stirring; prepare a filtering device, slowly pour the reaction solution into the filtering device, filter until the organic phase is clear, and then rinse the filter cake with alcohol solvent to collect all the organic phase. The organic phase is concentrated to a viscous oil;

[0029] S2: Add 2.5-10 mL of organic solvent per gram of photoacid generator to the viscous oil obtained in step S1, stir and dissolve, then add adsorbent, start stirring, raise the temperature to 40°C, stir for a period of time, slowly pour the reaction solution into a filter device and filter until the organic phase is clear, then rinse the filter cake with an organic solvent, and collect all the organic phases. The organic phase is concentrated to a viscous oil.

[0030] S3 uses 2.5-10mL of alcohol solvent per gram of photoacid generator to dissolve the viscous oil, add it to 50-100mL of aqueous solution containing chelating agent per gram of photoacid generator, the concentration of the aqueous solution containing chelating agent is 0.5%-5% by mass fraction, and stir it thoroughly at 25-45°C. After reacting for 8-12 hours, a large amount of solid precipitates. Prepare a filtering device, slowly pour the reaction solution into the filtering device, filter to obtain a white solid, rinse the white solid with ultrapure water, collect the filter cake, and dry it in an oven to obtain the product.

[0031] Beneficial effects:

[0032] The present invention provides a method for purifying a photoacid generator, which can remove tungsten ion impurities simply, quickly and effectively through chemical removal, adsorption removal and chelating agent removal in sequence, and the loss of the photoacid generator is small, which is suitable for industrial-scale operation.

[0033] The newly synthesized photoacid generator is purified by chemical removal, adsorption removal and chelation removal in sequence, and the concentration of tungsten can be controlled below 5 ppb, with good tungsten removal effect, and can be qualified for use in the next process stage;

[0034] By adjusting the reagent dosage and process parameters in each step, the purity of the product can be maximized and the loss of the product can be reduced. DETAILED DESCRIPTION

[0035] The embodiments of the present invention will be described in detail below in conjunction with the examples, but those skilled in the art will appreciate that the following examples are only used to illustrate the present invention and should not be considered to limit the scope of the present invention. Where specific conditions are not indicated in the examples, they are carried out under conventional conditions or under conditions recommended by the manufacturer. Where the manufacturer of the reagents or instruments used is not indicated, conventional products that can be purchased commercially are available.

[0036] The embodiment of the present invention provides a method for purifying a photoacid generator, comprising the following steps:

[0037] S1. Add an alcohol solvent to the photoacid generator, stir to dissolve, then add a bismuth salt, and continue stirring;

[0038] S2 is filtered, the filtrate is concentrated, an organic solvent is added to dissolve it, and then an adsorbent is added to adsorb it;

[0039] S3 is filtered, the filtrate is concentrated and then dissolved with an alcohol solvent, added to an aqueous solution containing a chelating agent for reaction, and then filtered after solids are precipitated, and the filter cake is washed and dried to obtain a purified photoacid generator.

[0040] In the present invention, the newly synthesized photoacid generator contains ionic impurities such as W, K, Ca, Na, Fe, Zn, and Mg, wherein the concentration of W is relatively high, ranging from 500 ppb to 10000 ppm; the structure of the photoacid generator can be a photoacid generator in the art, including iodine salts and sulfur salts, including but not limited to the following photoacid generators:

[0041] wait.

[0044] The alcohol solvent in step S1 of the present invention is preferably at least one of C1-C5 alcohol solvents, such as one or a combination of methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, n-pentanol, and isopentanol;

[0045] In step S1 of the present invention, the bismuth salt is selected from at least one of BiCl2, BiCl3, bismuth nitrate and bismuth acetate, and the amount of the bismuth salt is 0.5-4g, preferably 0.75-2g, relative to the amount of the photoacid generator added per gram; the amount of the alcohol solvent is 4-10mL relative to the amount of the photoacid generator added per gram; in step S1, the stirring speed is 100-200r / min;

[0046] Specifically, step S1 in the embodiment of the present invention is: weighing a newly synthesized photoacid generator (the content of tungsten is 500ppb-10000ppm) and putting it into a bottle, then adding 4-10mL of alcohol solvent per gram of photoacid generator, stirring at 100-200r / min until the solution is clear and no impurities are visible to the naked eye, and then adding 0.75-2g of bismuth salt solid per gram of photoacid generator, and continuing to stir; preparing a filtering device, slowly pouring the reaction solution into the filtering device, filtering until the organic phase is clear, and then eluting the filter cake with an alcohol solvent, collecting all the organic phases, and concentrating the organic phase to a viscous oil;

[0047] In step S2 of the present invention, the adsorbent is modified silica gel, Al2O3 adsorbent, molecular sieve, activated carbon, etc.; the organic solvent is selected from one or a combination of dichloromethane, chloroform, tetrahydrofuran, 2-methyltetrahydrofuran, n-butanol, isobutanol, n-pentanol, and isopentanol; the amount of the organic solvent added is 2.5-10 mL per gram of the photoacid generator, the amount of the adsorbent added is 1-10 g per gram of the photoacid generator, and the stirring rate is 100-200 r / min;

[0048] Specifically, step S2 of the present invention is: adding 2.5-10 mL of organic solvent per gram of photoacid generator to the viscous oil obtained in step S1, stirring and dissolving, then adding adsorbent, stirring at 100-200 r / min, stirring for about 5 minutes, heating to 40° C., stirring for a period of time, slowly pouring the reaction solution into a filter device for filtration until the organic phase is clear, then eluting the filter cake with an organic solvent, and collecting all the organic phases. The organic phase is concentrated to a viscous oil.

[0049] In step S3 of the present invention, the chelating agent is selected from hydroxyethylidene diphosphonic acid (HEDP), ethylenediaminetetramethylenephosphonic acid (EDTMPA), sodium ethylenediaminetetraacetate (EDTA-Na), sodium diethylenetriaminepentaacetate (DTPA-Na), sodium ethylenediaminedi-o-phenylacetate (EDDHA-Na), sodium gluconate, potassium tartrate or sodium citrate, etc.; wherein sodium ethylenediaminetetraacetate can be disodium ethylenediaminetetraacetate or tetrasodium ethylenediaminetetraacetate; sodium diethylenetriaminepentaacetate includes pentasodium diethylenetriaminepentaacetate.

[0050] In step S3 of the present invention, the alcohol solvent is selected from one or a combination of methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, n-pentanol, and isopentanol;

[0051] In step S3 of the present invention, the amount of alcohol solvent used is 2.5-10 mL per gram of photoacid generator added, the concentration of the aqueous solution containing the chelating agent is 0.5%-5% by mass, and the amount of the aqueous solution containing the chelating agent used is 50-100 mL per gram of photoacid generator added.

[0052] In step S3 of the present invention, the reaction temperature is 25 to 45° C., and the reaction time is 8 to 12 hours.

[0053] The inventors found in the study that the temperature and time of the reaction in step S3 have a certain influence on the purity and yield of the photoacid generator, and an ideal yield and purity can be obtained within the temperature and time range of the present invention. In addition, in step S3, the amount of the aqueous solution containing the chelating agent and the amount of the alcohol solvent have a great influence on the yield of the product, and it is necessary to comprehensively control the amount of the aqueous solution, the alcohol solvent and the concentration of the chelating agent, so as to minimize the loss of the product while performing a good chelation effect on the tungsten-containing ions.

[0054] Specifically, step S3 of the present invention is: dissolving viscous oil with 2.5-10 mL of alcohol solvent per gram of photoacid generator, adding to 50-100 mL of aqueous solution containing chelating agent per gram of photoacid generator, wherein the concentration of the aqueous solution containing chelating agent is 0.5%-5% by mass, stirring evenly at 25-45° C., reacting for 8-12 hours, a large amount of solid precipitates, preparing a filtering device, slowly pouring the reaction solution into the filtering device, filtering to obtain a white solid, and then rinsing the white solid with ultrapure water for 3 times, collecting the filter cake, and drying in an oven to obtain the product.

[0055] In the embodiment of the present invention, the content of tungsten in the purified photoacid generator is less than 5 ppb.

[0056] It should be noted that, according to the explanation and elaboration of the above description, those skilled in the art to which the present invention belongs may also make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some equivalent modifications and changes to the present invention should also be within the scope of protection of the claims of the present invention. In addition, although some specific terms are used in this specification, these terms are only for the convenience of description and do not constitute any limitation to the invention.

[0057] In the following examples, unless otherwise specified, the raw materials, reagents or processing techniques used are all commercially available raw materials or conventional processing techniques commonly used in the art.

[0058] Example

[0059] The structure of the photoacid generator used in the embodiment is shown in Table 1. The photoacid generator is commercially available and can be synthesized by methods known in the art. In the synthesis process of the photoacid generator, sodium sulfinate is oxidized to sodium sulfonate using hydrogen peroxide and sodium tungstate, so there will be residual tungstate ions in the newly synthesized photoacid generator. The tungsten content is quantitatively tested by inductively coupled plasma optical emission spectrometry (ICP-OES) to obtain the concentration of tungsten in the newly synthesized photoacid generator.

[0060] After purification, the concentration of tungsten was quantified using inductively coupled plasma mass spectrometry (ICP-MS) in parts per billion (ppb, μg / L).

[0061] Example 1

[0062] S1 Weigh 20g of newly synthesized photoacid generator (W content 5365ppm) into a 500mL eggplant-shaped bottle, add a stirrer, and then add 150mL of ethanol; start stirring at 100-200r / min until the solution is clear and there are no impurities in the naked eye, continue stirring for 10min, then add 25g of BiCl2 solid, and continue stirring for 12 hours; prepare a filtration device, slowly pour the reaction solution into the filtration device, filter twice until the organic phase is clear, then rinse the filter cake with 30mL of ethanol, and collect all the organic phases. The organic phase is concentrated to a viscous oil at 45°C on a rotary evaporator;

[0063] S2 adds 100 mL of dichloromethane to the viscous oil obtained in the bottle, stirs to dissolve, then adds 100 g of 200 mesh activated carbon, starts stirring at 100-200 r / min, stirs for 5 min, heats to 40°C, reacts for 12 h, prepares a filter device, slowly pours the reaction solution into the filter device, filters twice until the organic phase is clear, then rinses the filter cake with 30 mL of dichloromethane, collects all the organic phases. The organic phase is concentrated to a viscous oil on a rotary evaporator at 45°C; set aside.

[0064] S3 obtained a viscous oil, which was dissolved in 100 mL of methanol and added to 1.5 L of a chelating agent aqueous solution (mass fraction of 1%) containing hydroxyethylidene diphosphonic acid (HEDP). At room temperature, the mixture was stirred thoroughly and evenly. After reacting for 12 hours, a large amount of solid precipitated out. A filtering device was prepared, and the reaction solution was slowly poured into the filtering device. The mixture was filtered twice to obtain a white solid. The white solid was then rinsed three times with 100 mL of ultrapure water. The filter cake was collected and dried in an oven for 12 hours to obtain 15.61 g of the product. A sample was taken and sent to ICP-Ms. The result showed that the W content was 1.536 ppb, which was qualified for the next stage.

[0065] Example 2

[0066] S1 Weigh 20g of newly synthesized photoacid generator (W content 649ppm) into a 500mL eggplant-shaped bottle, add a stirrer, and then add 150mL of isopropanol; start stirring at 100-200r / min until the solution is clear and there are no impurities to the naked eye, continue stirring for 10min, then add 40g of BiCl2 solid, and continue stirring for 12h; prepare a filter device, slowly pour the reaction solution into the filter device, filter twice until the organic phase is clear, then rinse the filter cake with 25mL of ethanol, and collect all the organic phases. The organic phase is concentrated to a viscous oil on a rotary evaporator at 45°C;

[0067] S2 adds 100 mL of dichloromethane to the viscous oil obtained in the bottle, stirs to dissolve, then adds 100 g of modified silica gel, stirs at 100-200 r / min, stirs for 5 min, heats to 40°C, reacts for 12 h, prepares a filter, slowly pours the reaction solution into the filter, filters twice until the organic phase is clear, then rinses the filter cake with 50 mL of dichloromethane, collects all the organic phases. The organic phase is concentrated to a viscous oil on a rotary evaporator at 45°C; set aside.

[0068] S3 obtains a viscous oil, which is dissolved in 200 mL of ethanol and added to 2 L of a chelating agent aqueous solution (mass fraction of 0.5%) containing ethylenediaminetetramethylenephosphonic acid (EDTMPA). The mixture is stirred evenly at room temperature. After reacting for 12 hours, a large amount of solid precipitates. A filtering device is prepared, and the reaction solution is slowly poured into the filtering device. The mixture is filtered twice to obtain a white solid. The white solid is then rinsed three times with 200 mL of ultrapure water. The filter cake is collected and dried in an oven for 12 hours to obtain 13.64 g of the product. A sample is taken and sent to ICP-Ms. The result shows that the W content is 1.536 ppb, which is qualified for the next stage.

[0069] Example 3

[0070] S1 Weigh 20g of newly synthesized photoacid generator (W content 594ppb) into a 500mL eggplant-shaped bottle, add a stirrer, and then add 80mL of methanol; start stirring at 100-200r / min until the solution is clear and there are no impurities in the naked eye, continue stirring for 10min, then add 15g of BiCl3 solid, and continue stirring for 12h; prepare a filter device, slowly pour the reaction solution into the filter device, filter twice until the organic phase is clear, then rinse the filter cake with 20mL of ethanol, and collect all the organic phases. The organic phase is concentrated to a viscous oil at 45°C on a rotary evaporator;

[0071] S2 Add 50mL of 2-methyltetrahydrofuran to the bottle, stir to dissolve, then add 20g of molecular sieve, start stirring at 100-200r / min, stir for 5min, heat to 40℃, react for 12h, prepare the filter device, slowly pour the reaction solution into the filter device, filter twice until the organic phase is clear, then rinse the filter cake with 20mL of dichloromethane, collect all the organic phase. The organic phase is concentrated to a viscous oil on a rotary evaporator at 45℃; set aside.

[0072] The S3 viscous oil was dissolved in 50 mL of methanol and added to 1 L of chelating agent aqueous solution (mass fraction: 2%) containing disodium ethylenediaminetetraacetic acid. The mixture was stirred thoroughly at 45 °C. After 8 hours of reaction, a large amount of solid precipitated. A filtering device was prepared and the reaction solution was slowly poured into the filtering device. The mixture was filtered twice to obtain a white solid. The white solid was then rinsed three times with 200 mL of ultrapure water. The filter cake was collected and dried in an oven for 12 hours to obtain 16.24 g of the product. The sample was sent to ICP-Ms. The result showed that the W content was 0.953 ppb, which was qualified for the next stage.

[0073] Example 4

[0074] S1 Weigh 20g of newly synthesized photoacid generator (W content 10354ppm) and put it into a 500mL eggplant-shaped bottle, add a stirrer, and then add 80-200mL of ethanol; start stirring at 100-200r / min until the solution is clear and there are no impurities to the naked eye, continue stirring for 10min, then add 30g of bismuth nitrate solid, and continue stirring for 12h; prepare a filter device, slowly pour the reaction solution into the filter device, filter twice until the organic phase is clear, then rinse the filter cake with 50mL of ethanol, and collect all the organic phases. The organic phase is concentrated to a viscous oil at 45°C on a rotary evaporator;

[0075] S2 Add 200mL of dichloromethane to the bottle, stir to dissolve, then add 200g of activated carbon, start stirring at 100-200r / min, stir for 5min, heat to 40℃, react for 12h, prepare the filter device, slowly pour the reaction solution into the filter device, filter twice until the organic phase is clear, then rinse the filter cake with 50mL of dichloromethane, collect all the organic phase. The organic phase is concentrated to a viscous oil on a rotary evaporator at 45℃; set aside.

[0076] The S3 viscous oil was dissolved in 100 mL of ethanol and added to 2 L of chelating agent aqueous solution containing HEDP (mass fraction of 5%). The mixture was stirred thoroughly at 25°C. After reacting for 12 hours, a large amount of solid precipitated. A filtering device was prepared and the reaction solution was slowly poured into the filtering device. The mixture was filtered twice to obtain a white solid. The white solid was then rinsed three times with 50-200 mL of ultrapure water. The filter cake was collected and dried in an oven for 12 hours to obtain 14.87 g of the product. A sample was taken and sent to ICP-Ms. The result showed that the W content was 2.328 ppb, which was qualified for the next stage.

[0077] Example 5

[0078] S1 Weigh 20g of newly synthesized photoacid generator (W content 1351ppm) into a 500mL eggplant-shaped bottle, add a stirrer, and then add 100mL of isopropanol; start stirring at 100-200r / min until the solution is clear and there are no impurities to the naked eye, continue stirring for 10min, then add 25g of bismuth acetate solid, and continue stirring for 12h; prepare a filter device, slowly pour the reaction solution into the filter device, filter twice until the organic phase is clear, then rinse the filter cake with 20mL of ethanol, and collect all the organic phases. The organic phase is concentrated to a viscous oil at 45°C on a rotary evaporator;

[0079] S2 Add 50mL of 2-methyltetrahydrofuran to the bottle, stir to dissolve, then add 100g of Al2O3 molecular sieve, start stirring at 100-200r / min, stir for 5min, heat to 40℃, react for 12h, prepare the filter device, slowly pour the reaction solution into the filter device, filter twice until the organic phase is clear, then rinse the filter cake with 20mL of dichloromethane, collect all the organic phase. The organic phase is concentrated to a viscous oil on a rotary evaporator at 45℃; set aside.

[0080] S3 viscous oil was dissolved with 50 mL of ethanol, added to 1 L of chelating agent aqueous solution containing sodium citrate, and stirred thoroughly at room temperature. After reacting for 12 hours, a large amount of solid precipitated out. Prepare a filtration device, slowly pour the reaction solution into the filtration device, filter twice, and obtain a white solid. The white solid was then rinsed three times with 50-200 mL of ultrapure water, and the filter cake was collected. After drying in an oven for 12 hours, 13.84 g of product was obtained. Samples were taken and sent to ICP-Ms. The results showed that W, K, Ca, and Na were all less than 1.811 ppb, which was qualified for the next stage.

[0081] Example 6

[0082] S1 Weigh 20g of newly synthesized photoacid generator (W content 5365ppm) into a 500mL eggplant-shaped bottle, add a stirrer, and then add 150mL of ethanol; start stirring at 100-200r / min until the solution is clear and there are no impurities in the naked eye, continue stirring for 10min, then add 25g of BiCl2 solid, and continue stirring for 12h; prepare a filter device, slowly pour the reaction solution into the filter device, filter twice until the organic phase is clear, then rinse the filter cake with 30mL of ethanol, and collect all the organic phases. The organic phase is concentrated to a viscous oil at 45°C on a rotary evaporator;

[0083] S2 Add 100mL of dichloromethane to the bottle, stir to dissolve, then add 100g of 200-mesh activated carbon, start stirring at 100-200r / min, stir for 5min, heat to 40℃, react for 12h, prepare the filter device, slowly pour the reaction solution into the filter device, filter twice until the organic phase is clear, then rinse the filter cake with 30mL of dichloromethane, collect all the organic phase. The organic phase is concentrated to a viscous oil on a rotary evaporator at 45℃; set aside.

[0084] The S3 viscous oil was dissolved in 300 mL of methanol and added to 1.3 L of a chelating agent aqueous solution (mass fraction of 1.15%) containing hydroxyethylidene diphosphonic acid (HEDP). The mixture was stirred thoroughly at room temperature. After reacting for 12 hours, a large amount of solid precipitated. A filtering device was prepared and the reaction solution was slowly poured into the filtering device. The mixture was filtered twice to obtain a white solid. The white solid was then rinsed three times with 100 mL of ultrapure water. The filter cake was collected and dried in an oven for 12 hours to obtain 12.39 g of the product. A sample was taken and sent to ICP-Ms. The result showed that the W content was 2.012 ppb, which was qualified for the next stage.

[0085] Comparative Example 1

[0086] The purification method of Comparative Example 1 is the same as that of Example 1, except that the chemical tungsten removal step and the adsorption tungsten removal step are exchanged, as follows:

[0087] S1 Weigh 20g of newly synthesized photoacid generator (W content 5365ppm) and put it into a 500mL eggplant-shaped bottle, add 100mL of dichloromethane to the bottle, add a stirrer, stir to dissolve, then add 100g of 200-mesh activated carbon, start stirring at 100-200r / min, stir for 5min, heat to 40℃, react for 12h, prepare a filtration device, slowly pour the reaction solution into the filtration device, filter twice until the organic phase is clear, then rinse the filter cake with 30mL of dichloromethane, and collect all the organic phases. The organic phase is concentrated to a viscous oil at 45℃ on a rotary evaporator; set aside.

[0088] S2 adds 150mL of ethanol; starts stirring at 100-200r / min until the solution is clear and there are no impurities to the naked eye, continues stirring for 10min, then adds 25g of BiCl2 solid (bismuth chloride, bismuth nitrate, bismuth acetate), continues stirring for 12h; prepares a filter device, slowly pours the reaction solution into the filter device, filters twice until the organic phase is clear, then rinses the filter cake with 30mL of ethanol, and collects all the organic phase. The organic phase is concentrated to a viscous oil at 45°C on a rotary evaporator;

[0089] S3 used 100mL of methanol to dissolve the viscous oil, added to 1.5L of chelating agent aqueous solution containing HEDP (mass fraction of 1%), and stirred thoroughly at room temperature. After reacting for 12 hours, a large amount of solid precipitated. Prepare a filtration device, slowly pour the reaction solution into the filtration device, filter twice, and obtain a white solid. The white solid was rinsed three times with 100mL of ultrapure water, and the filter cake was collected. After drying in an oven for 12 hours, 13.54g of the product was obtained. Samples were taken and sent to ICP-Ms. The results showed that the W content was 234ppb.

[0090] Comparative Example 2

[0091] The purification method of Comparative Example 2 is the same as that of Example 1, except that the step of adding bismuth salt for chemical tungsten removal is omitted, and is specifically as follows:

[0092] S1 Weigh 20g of newly synthesized photoacid generator (W content 5365ppm) and put it into a 500mL eggplant-shaped bottle, add 100mL of dichloromethane to the bottle, add a stirrer, stir to dissolve, then add 100g of 200-mesh activated carbon, start stirring at 100-200r / min, stir for 5min, heat to 40℃, react for 12h, prepare a filtration device, slowly pour the reaction solution into the filtration device, filter twice until the organic phase is clear, then rinse the filter cake with 30mL of dichloromethane, and collect all the organic phases. The organic phase is concentrated to a viscous oil at 45℃ on a rotary evaporator; set aside.

[0093] S2 used 100mL of methanol to dissolve the viscous oil, added to 1.5L of chelating agent aqueous solution containing HEDP (mass fraction of 1%), and stirred thoroughly at room temperature. After reacting for 12 hours, a large amount of solid precipitated. Prepare a filtration device, slowly pour the reaction solution into the filtration device, filter twice, and obtain a white solid. The white solid was rinsed three times with 100mL of ultrapure water, and the filter cake was collected. After drying in an oven for 12 hours, 16.07g of product was obtained. Samples were taken and sent to ICP-Ms. The results showed that the W content was 945ppb.

[0094] Comparative Example 3

[0095] The purification method of Comparative Example 3 is the same as that of Example 1, except that the adsorption step is omitted, as follows:

[0096] S1 Weigh 20g of newly synthesized photoacid generator (W content 5365ppm) into a 500mL eggplant-shaped bottle, add a stirrer, and then add 150mL of ethanol; start stirring at 100-200r / min until the solution is clear and there are no impurities in the naked eye, continue stirring for 10min, then add 25g of BiCl2 solid, and continue stirring for 12h; prepare a filter device, slowly pour the reaction solution into the filter device, filter twice until the organic phase is clear, then rinse the filter cake with 30mL of ethanol, and collect all the organic phases. The organic phase is concentrated to a viscous oil at 45°C on a rotary evaporator;

[0097] S2 was dissolved in 100 mL of methanol and added to 1.5 L of chelating agent aqueous solution containing HEDP (mass fraction of 1%). The mixture was stirred thoroughly at room temperature. After 12 h of reaction, a large amount of solid precipitated. A filtration device was prepared and the reaction solution was slowly poured into the filtration device. The mixture was filtered twice to obtain a white solid. The white solid was then rinsed three times with 100 mL of ultrapure water. The filter cake was collected and dried in an oven for 12 h to obtain 16.27 g of the product. A sample was taken and sent to ICP-Ms. The result showed that the W content was 635 ppb.

[0098] Comparative Example 4

[0099] The purification method of Comparative Example 4 is the same as that of Example 1, except that the step of adding a chelating agent is omitted, as follows:

[0100] S1 Weigh 20g of newly synthesized photoacid generator (W content 5365ppm) into a 500mL eggplant-shaped bottle, add a stirrer, and then add 150mL of ethanol; start stirring at 100-200r / min until the solution is clear and there are no impurities in the naked eye, continue stirring for 10min, then add 25g of BiCl2 solid, and continue stirring for 12h; prepare a filter device, slowly pour the reaction solution into the filter device, filter twice until the organic phase is clear, then rinse the filter cake with 30mL of ethanol, and collect all the organic phases. The organic phase is concentrated to a viscous oil at 45°C on a rotary evaporator;

[0101] S2 Add 100mL of dichloromethane to the bottle, add a stirrer, stir to dissolve, then add 100g of 200 mesh activated carbon, start stirring at 100-200r / min, stir for 5min, heat to 40℃, react for 12h, prepare a filter, slowly pour the reaction solution into the filter, filter twice until the organic phase is clear, then rinse the filter cake with 30mL of dichloromethane, and collect all the organic phases. The organic phase is concentrated to a viscous oil at 45℃ on a rotary evaporator; dissolve it with 100mL of methanol, add it to 1.5L of water, stir it thoroughly at room temperature, and a large amount of solid precipitates out. Prepare a filter, slowly pour the reaction solution into the filter, filter twice, and obtain a white solid. The white solid is then rinsed 3 times with 100mL of ultrapure water, collect the filter cake, and after drying in an oven for 12h, 17.41g of the product is obtained. Samples are taken and sent to ICP-Ms. The results show that the concentration of W is 519ppb.

[0102] Table 1 Tungsten removal effect of the purification method of Examples 1-6 and Comparative Examples 1-4

[0103]

[0104]

Claims

1. A method for purifying a photoacid generator, characterized in that: The following steps are involved: S1. Add an alcohol solvent to the photoacid generator, stir to dissolve, then add a bismuth salt, and continue stirring; S2 is filtered, the filtrate is concentrated and then added to an organic solvent for stirring and dissolution, and then an adsorbent is added for adsorption; S3 is filtered, the filtrate is concentrated and then dissolved with an alcohol solvent, added to an aqueous solution containing a chelating agent for reaction, and then filtered after solids are precipitated, and the filter cake is washed and dried to obtain a purified photoacid generator.

2. The method according to claim 1, characterized in that: The photoacid generator is selected from at least one of an iodine salt photoacid generator or a sulfonate salt photoacid generator.

3. The method according to claim 1 or 2, characterized in that: The bismuth salt is selected from one or a combination of BiCl2, BiCl3, bismuth nitrate, and bismuth acetate; and / or, in step S1, the amount of the bismuth salt is 0.5 to 4 g per gram of the photoacid generator added.

4. The method according to any one of claims 1 to 3, characterized in that: The adsorbent is at least one of modified silica gel, Al2O3 adsorbent, molecular sieve, and activated carbon adsorbent; and / or, in step S2, the amount of the adsorbent is 1 to 10 g per gram of the photoacid generator added.

5. The method according to any one of claims 1 to 4, characterized in that: The chelating agent is selected from one or a combination of hydroxyethylidene diphosphonic acid (HEDP), ethylenediaminetetramethylenephosphonic acid (EDTMPA), sodium ethylenediaminetetraacetate (EDTA-Na), sodium diethylenetriaminepentaacetate (DTPA-Na), sodium ethylenediaminedi-o-phenylacetate (EDDHA-Na), sodium gluconate, potassium tartrate or sodium citrate.

6. The method according to any one of claims 1 to 5, characterized in that: In step S3, the amount of alcohol solvent used is 2.5-10 mL per gram of photoacid generator added, the concentration of the aqueous solution containing chelating agent is 0.5%-5% by mass, and the amount of the aqueous solution containing chelating agent used is 50-100 mL per gram of photoacid generator added.

7. The method according to any one of claims 1 to 6, characterized in that: In the step S1, the concentration of tungsten in the photoacid generator is 500 ppb-10000 ppm; and / or, in the step S3, the concentration of tungsten in the purified photoacid generator is less than 5 ppb.

8. The method according to any one of claims 1 to 7, characterized in that: In the step S3, the reaction temperature is 25 to 45° C., and the reaction time is 8 to 12 hours.

9. The method according to any one of claims 1 to 8, characterized in that: The stirring rate is 100-200 r / min; the amount of the organic solvent is 2.5-10 mL per gram of the photoacid generator.

10. The method according to any one of claims 1 to 9, characterized in that: The alcohol solvent is selected from one or a combination of methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, n-pentanol, and isoamyl alcohol; and / or the organic solvent is selected from one or a combination of dichloromethane, chloroform, tetrahydrofuran, 2-methyltetrahydrofuran, n-butanol, isobutanol, n-pentanol, and isoamyl alcohol.

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