TWI710544B - Ion exchange resins, purification methods and methods of making ionic resins - Google Patents

Abstract

An ion exchange resin comprises a crosslinked resin and a salt covalently bonded to a carbon of the resin, wherein the salt comprises a first non-metallic cation and a first counteranion, wherein the first counteranion comprises a second non-metallic cation and a thiosulfate counteranion, and wherein the ion exchange resin is essentially free of metals. The ion exchange resin finds particular use in the removal of impurities from solutions that are useful in the manufacture of semiconductor devices.

Description

Ion exchange resin, purification method and method for preparing ion resin

The present invention generally relates to the purification of chemicals with ionic resins. More specifically, the present invention relates to ion exchange resins, preparation methods thereof, purification media formed of such ion exchange resins, and purification methods using such ion exchange resins. The invention is particularly suitable for the purification of materials used in the electronics industry.

In the semiconductor manufacturing industry, process materials and related raw materials used in device manufacturing may contain peroxide impurities, such as hydrogen peroxide or organic peroxides. Such peroxide impurities may be present as a result of chemical manufacturing processes or may be generated during storage of the material. Organic solvents (such as ethers and esters) are particularly prone to form organic peroxides in the presence of atmospheric oxygen. The sensitive solvents include ethyl lactate, PGME and PGMEA, which are commonly used in lithographic printing materials.

From a safety point of view, the presence of peroxides in semiconductor process chemicals may be problematic. In particular, peroxides can cause serious fire and explosion hazards, and they can also be toxic and corrosive. In addition to such potential safety hazards, the presence of peroxides in the process materials can have a harmful effect on the resulting semiconductor devices.

In an effort to minimize the formation of peroxides in solvents, it is known to add peroxide inhibitors to solvents. It is also known to use peroxide scavengers to remove peroxides from organic solvents. (See, for example, US Patent No. 3,221,030). However, adding additive inhibitors or scavengers to solvents, raw materials, and compositions can produce unreacted additives and oxidation by-products in the material. The presence of such additives will adversely affect the performance of process materials, and may require original additive-free materials, especially in the case of advanced semiconductor device manufacturing, where the reduction of impurities in process chemicals is becoming more and more important .

Another problem in semiconductor manufacturing involves the presence of metal contaminants in process chemicals. Although metal materials have a place in the manufacturing process, such as in the formation of interconnect structures, metal contamination in many processes may cause serious problems to the formed devices, such as low device yield and poor device yield caused by changes in electrical characteristics efficacy. Therefore, it would be desirable to allow the level of metal contaminants in process chemicals to decrease.

Therefore, there is a need in the art for improved ionic resins, purification media, and purification methods that solve one or more problems related to the current advanced level.

According to the first aspect of the present invention, an ion exchange resin is provided. The ion exchange resin includes a cross-linked resin and a salt covalently bonded to the carbon of the resin, wherein the salt includes a first non-metal cation and a first counter anion, wherein the first counter anion includes a second non-metal cation and a thiosulfate counter Anion, and the ion exchange resin is essentially free of metal.

According to another aspect of the present invention, an ion exchange medium is provided. The ion exchange medium includes the ion exchange resin as described herein, and may take the form of, for example, beads, membranes, filters, ion exchange columns, or combinations thereof.

According to another aspect of the present invention, a purification method is provided. The purification method includes contacting a composition including a solvent and impurities with an ion exchange resin as described herein, thereby reducing the content of impurities in the composition.

According to another aspect of the present invention, a method of preparing an ion exchange resin is provided. The method includes: (a) providing an ionic resin, which includes a cross-linked resin and a salt covalently bonded to the carbon of the cross-linked resin, wherein the salt includes a first cation and a first counter anion; and (b) making the ionic resin Contact with a salt including a second cation and a second counter anion including a thiosulfate group to exchange the first counter anion and the second counter anion.

The terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. Unless the context dictates otherwise, the singular forms "一 (a/an)" and "the" are intended to include the singular and plural forms.

In order to solve one or more problems related to the current advanced level, new ion exchange resins have been developed, which can purify the composition by reducing the content of impurities included in the composition. Ion exchange resins include crosslinked resins and salts covalently bonded to the carbon of the resin. The salt includes a first non-metal cation and a first counter anion. The first counter anion includes a second non-metal cation and a thiosulfate counter anion.

The crosslinked resin is usually crosslinked poly(styrene) or other crosslinked vinyl aromatic polymers, such as poly(vinyl furan), poly(vinylpyridine), poly(vinylpyrrole) or poly(vinyl Thiophene). Resins generally contain units formed from one or more polyvinyl (ie containing two or more vinyl) monomers selected from, for example, polyvinylbenzene, polyvinylfuran, polyvinylpyridine, Polyvinylpyrrole or polyvinylthiophene monomer to provide crosslinking function. The ion exchange resin may be, for example, macroporous or gel type, and is preferably macroporous, with a typical pore diameter of 1 nanometer to 100 micrometers, preferably 1 micrometer to 10 micrometers.

Ion exchange resins of the present invention is typically a derivative of a precursor of an anionic cross-linked resin, which can be via a counter anion-exchange resin precursor (typically Cl ^- or OH ^-) thiophosphate sulfate for a first counter anion to Anion exchange. The precursor anionic crosslinked resin from which the ionic resin of the present invention can be derived generally includes a first non-metallic cation covalently bonded to the carbon of the crosslinked resin. This first non-metallic cation is usually retained as part of the derivative resin. The resin carbon bonded to the first non-metal cation is not particularly limited, but in the case of a styrenic polymer, it is usually located at the para position on the aromatic ring with respect to the resin main chain.

其中：R₁ 獨立地選自氫、經取代或未經取代的直鏈或支鏈C1-C20烷基、經取代或未經取代的單環或多環C3-C20烷基、或經取代或未經取代的單環或多環C5-C20芳基，其中一或多個芳環碳視情況經例如N、O或S的雜原子置換，一或多個R₁ 基團視情況藉由單鍵與相鄰的R₁ 基團連接，且兩個或更多個R₁ 基團一起視情況形成環；R₂ 獨立地選自經取代或未經取代的直鏈或支鏈C1-C20烷基、經取代或未經取代的單環或多環C3-C20烷基，或經取代或未經取代的單環或多環C5-C20芳基，其中一或多個芳環碳視情況經例如N、O或S的雜原子置換，且一或多個R₂ 基團視情況藉由單鍵或藉由鍵聯基團，如經取代或未經取代的C1-C4亞烷基鍵聯基團與相鄰的R₂ 基團連接，其中鍵聯基團的一或多個碳原子視情況經例如NR、O或S的雜原子置換，其中R為氫或經取代或未經取代的C1-C5烷基；且R₃ 選自經取代或未經取代的直鏈或支鏈C1-C20烷基、經取代或未經取代的單環或多環C3-C20烷基、或經取代或未經取代的單環或多環C5-C20芳基，其中一或多個芳基環碳視情況經例如N、O或S的雜原子置換。如本文所用，術語「經取代的」意指一或多個氫原子經非氫取代基取代，例如羥基、鹵素（例如氟、氯、碘或溴）、C1-C10烷基、C5-C12芳基、C6-C14芳烷基、C1-C10烷氧基、C6-C12烷氧基或烷基氨基。Suitable first non-metal cations include, for example, one or more cations selected from the group consisting of onium cations, such as ammonium, sulfonium, phosphonium, phosphonium, and arsonium cations, and imine cations. Among these cations, ammonium cations are preferred. Such cations suitable for the first non-metallic cation include cations of the following general formula:

Wherein: R _{1 is} independently selected from hydrogen, substituted or unsubstituted linear or branched C1-C20 alkyl, substituted or unsubstituted monocyclic or polycyclic C3-C20 alkyl, or substituted or Unsubstituted monocyclic or polycyclic C5-C20 aryl groups, in which one or more aromatic ring carbons are optionally replaced by heteroatoms such as N, O, or S, and one or more R ₁ groups are optionally replaced by a single The bond is connected to the adjacent R ₁ group, and two or more R ₁ groups together form a ring as appropriate; R _{2 is} independently selected from substituted or unsubstituted linear or branched C1-C20 alkane Group, substituted or unsubstituted monocyclic or polycyclic C3-C20 alkyl group, or substituted or unsubstituted monocyclic or polycyclic C5-C20 aryl group, in which one or more aromatic ring carbons may be For example, heteroatom replacement of N, O or S, and one or more R ₂ groups are optionally linked by a single bond or by a linking group, such as substituted or unsubstituted C1-C4 alkylene The group is connected to the adjacent R ₂ group, where one or more carbon atoms of the linking group are optionally replaced by heteroatoms such as NR, O or S, where R is hydrogen or substituted or unsubstituted C1-C5 alkyl; and R _{3 is} selected from substituted or unsubstituted linear or branched C1-C20 alkyl, substituted or unsubstituted monocyclic or polycyclic C3-C20 alkyl, or substituted Or unsubstituted monocyclic or polycyclic C5-C20 aryl groups, in which one or more aryl ring carbons are replaced by heteroatoms such as N, O or S as appropriate. As used herein, the term "substituted" means that one or more hydrogen atoms are replaced by non-hydrogen substituents, such as hydroxyl, halogen (such as fluorine, chlorine, iodine, or bromine), C1-C10 alkyl, C5-C12 aromatic Group, C6-C14 aralkyl, C1-C10 alkoxy, C6-C12 alkoxy or alkylamino.

。 其中波狀鍵表示與樹脂的碳的共價鍵。Exemplary cations used as the first non-metallic cation include the following:

. Here, the wavy bond means a covalent bond with the carbon of the resin.

Suitable precursor anionic crosslinked resins from which the ionic resin of the present invention can be derived are commercially available or can be prepared by known techniques. Suitable commercial resins include, for example, Dowex™ Marathon™ MSA Chloride Form, Dowex™ Marathon™ 11 and Dowex™ Marathon™ A (The Dow Chemical Company), Amberlite™ IRA-400 (Cl), Amberlite™ IRA -402 (Cl), Amberlite™ IRA-410 (Cl), Amberlite™ IRA-900 (Cl) and Amberlite™ IRA-4200 (Cl) (Rohm and Haas Company). Methods for preparing suitable precursor anionic crosslinked resins are also known in the literature, for example, as described in U.S. Patent No. 6,756,462B2.

其中：R₄ 獨立地選自氫、經取代或未經取代的直鏈或支鏈C1-C20烷基、經取代或未經取代的單環或多環C3-C20烷基、或經取代或未經取代的單環或多環C5-C20芳基，其中一或多個芳環碳視情況經例如N、O或S的雜原子置換，一或多個R₄ 基團視情況藉由單鍵或藉由鍵聯基團，如經取代或未經取代的C1-C4亞烷基鍵聯基團與相鄰的R₄ 基團連接，其中鍵聯基團的一或多個碳原子視情況經例如NR、O或S的雜原子置換，其中R為氫或經取代或未經取代的C1-C5烷基，且兩個或更多個R₄ 基團一起視情況形成環；R₅ 獨立地選自經取代或未經取代的直鏈或支鏈C1-C20烷基、經取代或未經取代的單環或多環C3-C20烷基，或經取代或未經取代的單環或多環C5-C20芳基，其中一或多個芳環碳視情況經例如N、O或S的雜原子置換，且一或多個R₅ 基團視情況藉由單鍵或藉由鍵聯基團，如經取代或未經取代的C1-C4亞烷基鍵聯基團與相鄰的R₅ 基團連接，其中鍵聯基團的一或多個碳原子視情況經例如NR、O或S的雜原子置換，其中R為氫或經取代或未經取代的C1-C5烷基；且R₆ 選自氫、經取代或未經取代的直鏈或支鏈C1-C20烷基、經取代或未經取代的單環或多環C3-C20烷基、或經取代或未經取代的單環或多環C5-C20芳基。如本文所用，術語「經取代的」意指一或多個氫原子經非氫取代基取代，例如羥基、鹵素（例如氟、氯、碘或溴）、C1-C10烷基、C5-C12芳基、C6-C14芳烷基、C1-C10烷氧基、C6-C12烷氧基或烷基氨基。The first counter anion includes a second non-metal cation and a thiosulfate counter anion. The first and second non-metal cation types can be selected independently of each other. Suitable second non-metal cations include, for example, one or more cations selected from the group consisting of onium cations, such as ammonium, sulfonium, phosphonium, phosphonium, and arsonium cations, and imine cations. Among these cations, ammonium cations are preferred. Such cations suitable for the second non-metallic cation include cations of the following general formula:

Wherein: R _{4 is} independently selected from hydrogen, substituted or unsubstituted linear or branched C1-C20 alkyl, substituted or unsubstituted monocyclic or polycyclic C3-C20 alkyl, or substituted or Unsubstituted monocyclic or polycyclic C5-C20 aryl groups, in which one or more aromatic ring carbons are optionally replaced by heteroatoms such as N, O or S, and one or more R ₄ groups are optionally replaced by a single Bond or by a linking group, such as a substituted or unsubstituted C1-C4 alkylene linking group to the adjacent R ₄ group, wherein one or more carbon atoms of the linking group depend on substituted with heteroatoms such as NR, O or S substitution, wherein R is hydrogen or a substituted or unsubstituted C1-C5 alkyl, and two or more R ₄ groups optionally form a ring together; _{R. 5} Independently selected from substituted or unsubstituted linear or branched C1-C20 alkyl, substituted or unsubstituted monocyclic or polycyclic C3-C20 alkyl, or substituted or unsubstituted monocyclic Or polycyclic C5-C20 aryl groups, in which one or more aromatic ring carbons are optionally replaced by heteroatoms such as N, O, or S, and one or more R ₅ groups are optionally by single bonds or by bonds A linking group, such as a substituted or unsubstituted C1-C4 alkylene linking group, is connected to the adjacent R ₅ group, wherein one or more carbon atoms of the linking group are optionally connected to, for example, NR, O or S heteroatom replacement, wherein R is hydrogen or substituted or unsubstituted C1-C5 alkyl; and R _{6 is} selected from hydrogen, substituted or unsubstituted linear or branched C1-C20 alkyl , A substituted or unsubstituted monocyclic or polycyclic C3-C20 alkyl group, or a substituted or unsubstituted monocyclic or polycyclic C5-C20 aryl group. As used herein, the term "substituted" means that one or more hydrogen atoms are replaced with non-hydrogen substituents, such as hydroxyl, halogen (such as fluorine, chlorine, iodine, or bromine), C1-C10 alkyl, C5-C12 aryl Group, C6-C14 aralkyl, C1-C10 alkoxy, C6-C12 alkoxy or alkylamino.

。Exemplary cations used as the second non-metallic cation include the following:

.

In the manufacture of electronic devices, especially in the manufacture of advanced semiconductor devices, metal impurities may adversely affect the manufacturing process and the resulting devices. Since the presence of metals in the ion exchange resin may contaminate the purified composition, the ion exchange resin is substantially free of metal. As used herein, the term "substantially free of metal" means that the total metal content of the ion exchange resin is less than 500 ppm, preferably less than 400 ppm, more preferably less than 300 ppm and most preferably less than 200 based on the total mass of the ion exchange resin. ppm or less than 100 ppm. Such metal analysis can be performed by inductively coupled plasma mass spectrometry ICP-MS. Preferably, the ionic resin is completely free of metals other than unintended trace metals that may be caused by pollution during resin manufacturing or environmental pollution.

。Hereinafter, an exemplary method for preparing the anion exchange resin according to the present invention is described. The ion exchange resin of the present invention can be prepared by first providing the precursor anion crosslinking resin as described above. The precursor anion exchange resin can be modified as follows: by using an aqueous solvent, a thiosulfate (first counter anion) including non-metal cations and thiosulfate counter anions, and one or more additional groups as appropriate. Treated with separated aqueous salt solution to replace the anions on the precursor anion exchange resin with thiosulfate. The thiosulfate is as described above with respect to the first counter anion. Suitable thiosulfate salts are commercially available or can be easily prepared by those skilled in the art. An exemplary reaction process for preparing the preferred ion exchange resin according to the present invention is as follows:

.

The aqueous solvent may be water (100% by volume) or may be mainly water, such as water greater than 50% by volume, greater than 80% by volume, or greater than 90% by volume. When one or more solvents other than water are used, such solvents are preferably selected from, for example, water-soluble organic solvents, such as alcohols, such as methanol, ethanol or isopropanol; acetone; tetrahydrofuran; 1,4-dioxin Alkane; PGME; glycol ethers such as ethylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol and tripropylene glycol; monomethyl ethers such as dipropylene glycol monomethyl ether and tripropylene glycol monomethyl ether; esters such as lactic acid Ethyl; and combinations thereof. Based on the total thiosulfate composition, the concentration of the thiosulfate in the solution is usually 10 to 30% by weight, preferably 20 to 25% by weight.

As an optional component of the saline solution, it may be necessary to use a surfactant. Suitable surfactants include non-ionic surfactants, such as octylphenol and nonylphenol ethoxylates, such as TRITON® X-114, X-100, X-45, X-15, and branched secondary Alcohol ethoxylates, such as TERGITOL™ TMN-6 (The Dow Chemical Company, Midland, Michigan USA). Other exemplary nonionic surfactants include alcohol (primary alcohol and secondary alcohol) ethoxylates, amine ethoxylates, glucosides, reduced glucosamine, polyethylene glycol, poly(ethylene glycol-co- Propylene Glycol), or the North American edition of "McCutcheon's Emulsifier and Cleaner ( McCutcheon ' s Emulsifiers and Detergents )" other non-ionic surfactants. Nonionic surfactants of acetylenic diol derivatives are also suitable. Such surfactants can be purchased from Air Products and Chemicals, Inc. of Allentown, PA and sold under the trade names SURFYNOL® and DYNOL®. Other suitable surfactants include other polymeric compounds, such as triblock EO-PO-EO copolymer PLURONIC® 25R2, L121, L123, L31, L81, L101, and P123 (BASF, Inc.). If used, such surfactants and other optional additives are usually present in the composition in small amounts, such as 0.01 to 5% by weight based on the total thiosulfate composition.

The thiosulfate salt can be prepared by mixing the solvent, thiosulfate salt, and additional optional components together to dissolve the salt and optional solid components in the solvent.

The ion exchange resin can be prepared by slurrying the precursor cross-linking resin with an aqueous solution of thiosulfate for a period of time that effectively exchanges the anion of the thiosulfate with the precursor resin. The treatment of the precursor resin is usually carried out in air or in an inert gas atmosphere, such as nitrogen or an atmosphere. The treatment time is usually 2 to 30 hours, more usually 4 to 10 hours. Thereafter, the resin is usually washed with water to remove the unbound thiosulfate composition and reaction products. Washing with water is usually carried out several times under stirring, preferably 10 to 50 times. The ratio of water to resin is usually 200:1 to 400:1. The treated resin is preferably dehydrated by washing the resin with a water-miscible organic solvent, the organic solvent being selected from, for example, alcohols such as methanol, ethanol or isopropanol; acetone; tetrahydrofuran; 1,4-dioxane; PGME; glycol ethers such as ethylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol and tripropylene glycol; monomethyl ethers such as dipropylene glycol monomethyl ether and tripropylene glycol monomethyl ether; esters such as ethyl lactate ; And its combination. Washing and/or dehydration can be performed at room temperature or high temperature, for example, at a temperature of 25 to 90°C. Alternatively or additionally, the resin may be subjected to a vacuum drying process, usually at a temperature of 25 to 90 deg.] C and 10 ^- at a pressure of ³ Torr ^- A ^9-10.

The ion exchange resin of the present invention can be used as an ion exchange medium for removing impurities from a solvent. Suitable ion exchange media include, for example, beads, such as beads typically produced by precursor resin polymerization methods, membranes, filter ion exchange columns, or combinations thereof. Ion exchange media and purification methods are generally known in the art, and are described in, for example, US6756462B2, US3207708B1 and WO1999009091A1.

The ion exchange resin of the present invention can be used for the purification of chemicals, and is particularly suitable for the purification of materials used in the electronics industry. The purification method includes contacting a composition including a solvent and impurities with an ion exchange resin as described herein, thereby reducing the content of impurities in the composition. Ion exchange resins can be used to remove impurities, such as peroxides, such as organic peroxides or hydrogen peroxide, or metals, from chemical compositions containing solvents.

The solvent can be, for example, water or an organic solvent, such as diisopropylbenzene, triisopropylbenzene, methanol, isopropanol, methyl isobutyl methanol, propylene glycol, tripropylene glycol, methyl tert-butyl ether, isoamyl Base ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, tripropylene glycol monomethyl ether, tetrahydrofuran, acetone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, 3-ethoxy Ethyl propionate, propylene glycol monomethyl ether acetate, γ-butyrolactone, ethyl lactate, butyl cellosolve, and combinations thereof.

The composition is slurried with the resin, the solution is passed through an ion exchange resin column, or the composition is contacted with a purification medium (such as a membrane or filter including the ion exchange resin of the present invention) to be treated The composition is contacted with the ion exchange resin described herein. The purification process conditions will depend on the type of medium and are within the technical level of the art. For example, in the case of a resin-containing ion exchange column, the rate at which the composition passes through the column is generally about 2 and 20 bed volumes per hour, and can be performed under ambient conditions.

The composition to be treated is preferably a non-acidic material (that is, a material substantially free of free acid), and preferably not a highly polar water-based formulation. Suitable electronic materials include, for example, organic solvents, photoresist compositions, topcoat compositions, organic solvent developers, and non-acidic spin-on carbon (SOC) compositions. The composition to be treated may contain resin or may not contain resin. Such resins may contain acid labile groups, such as third alkyl esters, as is typical in the case of photoresist compositions and certain topcoat compositions. According to the present invention, the composition or one or more individual components of the composition can be treated by contacting the composition or component with an ion exchange resin to remove contaminants such as peroxides and/or metals.

The following non-limiting examples illustrate the invention. Example Synthesis of thiosulfate resin Example 1

Combine 10.712 g Dowex™ Marathon™ MSA ion exchange resin (The Dow Chemical Company) and 19.7 g ammonium thiosulfate (in 70 ml deionized water) in a 100 ml glass bottle and shake for about 2 days. The resulting mixture was decanted, and the resin was washed 10 times with 100 ml of deionized water. Shake the resin for 12-24 hours with 100 ml of deionized water, and repeat the process three times. After decantation, the resin is subjected to high vacuum treatment (20-100 mtorr) for 12-24 hours. Example 2

Combine 78.196 g Dowex™ Marathon™ MSA ion exchange resin (The Dow Chemical Company) and 122.606 g ammonium thiosulfate (in 500 ml deionized water) in a 1 L glass bottle and shake for about 24 hours. The resulting supernatant was decanted, and the resin was washed 40 times with 500 ml of deionized water. A portion of the resin was rinsed with acetone to remove water, and then dried in air for 12-24 hours. Removal of peroxide from the solvent Example 3

1.863 g of the resin of Example 1 and 79.8 g of DOWANOL™ TPM glycol ether (tripropylene glycol methyl ether) (Dow Chemical Company) were mixed in a 100 ml glass bottle, and the mixture was shaken for about one day. A sample of the resin-treated TPM was taken from the bottle by a pipette, and the total peroxide content was analyzed by redox potentiometric titration. The untreated TPM samples were similarly analyzed for total peroxide content. The results are shown in Table 1.

Example 4

1.0 g of the resin of Example 1 and 77.7 g of ethyl lactate were mixed in a 100 ml glass bottle, and the mixture was shaken for about one day. A sample of resin-treated ethyl lactate was taken out of the bottle by a pipette, and the total peroxide content was analyzed by redox potential titration. The total peroxide content of the untreated ethyl lactate sample is similarly analyzed. The results are shown in Table 1.

Example 5

1.033 g of the dry resin of Example 2 was mixed with 100 g of DOWANOL ^™ TPM glycol ether (tripropylene glycol methyl ether) (Dow Chemical Company) in a 100 ml glass bottle, and the mixture was shaken for about one day. A sample of the resin-treated TPM was taken out of the bottle by a pipette, and the total peroxide content was analyzed by oxidation-reduction potential titration. The untreated TPM samples were similarly analyzed for total peroxide content. The results are shown in Table 1.

Example 6

3.677 g of the dry resin of Example 2 and 100 g of ethyl lactate were mixed in a 100 ml glass bottle, and the mixture was shaken for about one day. The ethyl lactate sample was removed from the bottle by pipette and analyzed for peroxide content. The results are shown in Table 1.

The average peroxide content and σ (standard deviation) apply to two samples; n/a=there is no difference in the peroxide content of the two samples.

Example 7

The TPM samples without resin treatment and resin treatment as described in Examples 3 and 5 were analyzed by gas chromatography-mass spectrometry (GC-MS) for fingerprint analysis of TPM before and after resin treatment. The resulting spectrum is shown in Figure 1. The spectra are basically the same, indicating that the resin treatment does not significantly affect the chemical composition of the TPM. Example 8

Analyze the samples of ethyl lactate without resin treatment and after resin treatment as described in Examples 4 and 6 by gas chromatography-mass spectrometry (GC-MS) for the analysis of ethyl lactate before and after resin treatment Perform fingerprint analysis. The resulting spectrum is shown in Figure 2. The spectra are basically the same, indicating that the resin treatment does not significantly affect the chemical composition of ethyl lactate.

The present invention will be described with reference to the following drawings, in which the same element symbols represent the same features, and in which: FIG. 1 illustrates the GC-MS of tripropylene glycol methyl ether (TPM) before and after treatment with the ion exchange resin according to the present invention And Figure 2 illustrates the GC-MS spectrum of ethyl lactate before and after treatment with the ion exchange resin according to the present invention.

Claims (10)

An ion exchange resin comprising a crosslinked resin and a salt covalently bonded to the carbon of the crosslinked resin, wherein the salt includes a first non-metal cation and a first counter anion, wherein the first counter anion includes The second non-metal cation and the thiosulfate counter anion, and wherein the ion exchange resin is substantially free of metal. Such as the ion exchange resin of item 1 of the scope of patent application, wherein the second non-metal cation is optionally substituted ammonium cation. An ion exchange medium, which includes the ion exchange resin as claimed in item 1 or item 2 of the scope of patent application. Such as the ion exchange medium of item 3 in the scope of patent application, wherein the medium is beads, membranes, filters, ion exchange columns or combinations thereof. A purification method includes contacting a composition including a solvent and impurities with an ion exchange resin as in the first or second item of the scope of the patent application, thereby reducing the content of the impurities in the composition. Such as the purification method of item 5 in the scope of patent application, wherein the impurity is hydrogen peroxide or organic peroxide. Such as the purification method of item 5 in the scope of patent application, wherein the impurities are metals. Such as the purification method of any one of items 5 to 7 in the scope of patent application, wherein the solvent is an organic solvent. For example, the purification method of item 8 of the scope of patent application, wherein the organic solvent is selected from the group consisting of diisopropylbenzene, triisopropylbenzene, methanol, isopropanol, methyl isobutyl methanol, propylene glycol, tripropylene glycol, methyl Tertiary butyl ether, isoamyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, tripropylene glycol monomethyl ether, tetrahydrofuran, acetone, methyl isobutyl ketone, cyclopentanone, ring Hexanone, 3-ethoxy Ethyl propionate, propylene glycol monomethyl ether acetate, γ-butyrolactone, ethyl lactate, butyl cellosolve, and combinations thereof. A method for preparing an ion exchange resin, comprising: (a) providing an ion resin, which includes a crosslinked resin and a salt covalently bonded to the carbon of the crosslinked resin, wherein the salt includes a first cation and a first A counter anion; and (b) contacting the ionic resin with a salt including a second cation and a second counter anion including a thiosulfate group, thereby exchanging the first counter anion and the second counter anion.

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