Method for recovering dimethyl sulfoxide from recovered resist remover

Abstract

A method for recovering dimethyl sulfoxide, including a step of contacting a recovered resist remover containing at least one compound selected from the group consisting of glycol ether, glycol and triol, and dimethyl sulfoxide with water and performing distillation.

Claims

1. A method for recovering dimethyl sulfoxide from a composition, the method comprising: contacting the composition with water, where the composition comprises at least one compound selected from a group consisting of glycol ethers, glycols, and triols, and dimethyl sulfoxide; and performing distillation on the composition contacted with water to recover a purified dimethyl sulfoxide product, wherein an amount of the water contacted with the composition is from 0.1 to 100 parts by mass with respect to 1 part by mass of the composition.

2. The method according to claim 1, wherein the at least one compound is selected from a group consisting of 3-methoxy-3-methyl-1-butanol, diethylene glycol, propylene glycol, glycerin and 2-(2-methoxyethoxy)ethanol.

3. The method according to claim 1, wherein the at least one compound is 3-methoxy-3-methyl-1-butanol.

4. The method according to claim 1, wherein the composition is a resist remover that has been used to wash and remove an unnecessary resist film in photolithography.

5. The method according to claim 1, wherein the composition further comprises a quaternary ammonium hydroxide, a resist component, or both.

6. The method according to claim 5, wherein the composition further comprises at least one other component selected from a group consisting of water, alkanolamines, amino acids, surfactants, and antifoaming agents.

7. The method according to claim 1, wherein the distillation is performed such that the purified dimethyl sulfoxide product has a purity of 99.9%.

8. The method according to claim 1, wherein a purity of the purified dimethyl sulfoxide product obtained by the distillation is higher than a purity of a dimethyl sulfoxide product obtained by distilling the composition without contacting with water.

9. The method according to claim 1, wherein the distillation is performed at a temperature of from 104 to 250° C.

Description

DESCRIPTION OF EMBODIMENTS

(1) The method of the present invention will be described in detail below.

(2) In the present invention, the “recovered resist remover” as a target for recovering DMSO typically refers to a used resist remover after washing and removing an unnecessary resist film or the like in photolithography, and includes at least one compound selected from the group consisting of glycol ether, glycol and triol, and DMSO.

(3) Usually, the recovered resist remover also includes a quaternary ammonium hydroxide, a resist component, and the like.

(4) Examples of the glycol ether include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, 3-methoxy-3-methyl-1-butanol (MMB), dipropylene glycol monomethyl ether, and 2-(2-methoxyethoxy)ethanol.

(5) Examples of the glycol include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, and triethylene glycol.

(6) Examples of the triol include glycerin.

(7) Among these, the compound is preferably at least one selected from the group consisting of MMB, diethylene glycol, propylene glycol, glycerin and 2-(2-methoxyethoxy)ethanol, and more preferably MMB.

(8) Examples of the quaternary ammonium hydroxide include tetramethylammonium hydroxide (TMAH), tetraethyl ammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, trimethylethylammonium hydroxide, dimethyldiethylammonium hydroxide, trimethyl (2-hydroxyethyl) ammonium hydroxide, triethyl (2-hydroxyethyl) ammonium hydroxide, and spiro-[1,1′]-bipyrrolidinium hydroxide.

(9) Among these, the quaternary ammonium hydroxide is preferably at least one selected from the group consisting of TMAH, tetrapropylammonium hydroxide, and spiro-[1,1′]-bipyrrolidinium hydroxide, and more preferably TMAH.

(10) The recovered resist remover may contain water, alkanolamines, an amino acid, a surfactant, an antifoaming agent, or the like as the other components.

(11) In the method for recovering DMSO of the present invention, the recovered resist remover is brought into contact with water and then distillation is performed. Thus, at least one compound selected from the group consisting of glycol ether, glycol and triol can be first distilled out, and then high purity DMSO can be distilled out.

(12) The contact between the recovered resist remover and water can be carried out by, for example, mixing the recovered resist remover and water. As a specific method when the recovered resist remover is brought into contact with water to perform distillation, for example, a method of adding water to the recovered resist remover and performing distillation can be exemplified. In carrying out such a method of adding water to the recovered resist remover and performing distillation, water may be added to the recovered resist remover at once, followed by distillation, or distillation may be performed while adding water intermittently or at a constant rate.

(13) The temperature at the time of distillation is preferably in the range of 30 to 250° C., and more preferably in the range of 50 to 230° C. The distillation may be carried out under normal pressure or under reduced pressure.

(14) The amount of water added is preferably in the range of 0.1 to 100 parts by mass, and more preferably in the range of 0.1 to 10 parts by mass, with respect to 1 part by mass of the recovered resist remover.

EXAMPLES

(15) Hereinafter, the present invention will be described in detail by examples and the like, but the present invention is not limited by these examples.

Example

(16) To a 500 mL three-necked flask equipped with a Helipack 50 cm distillation column (distillation stage number: 7 stages), a mixture of 70 g DMSO and 30 g MMB was added as a recovered resist remover. 300 g of water was added thereto, and distillation was carried out under conditions of an internal temperature of 104 to 140° C., and normal pressure. When the distillate disappeared, DMSO was distilled out under conditions of an internal temperature of 120 to 130° C. and 2 to 10 mmHg to obtain 62.2 g of DMSO having a purity of 99.9% (yield 88.9%).

Comparative Example

(17) A similar operation was carried out as in Example, except that water was not added. As a result, 22.3 g of DMSO having a purity of 82.3% was obtained.

(18) Although the above Example and Comparative Example are the tests on the conditions which do not contain quaternary ammonium hydroxide and resist components that are considered to be normally contained in the actual recovered resist remover, these components are considered not to be distilled by distillation, so that the above Example and Comparative Example function sufficiently as model tests.

(19) From the results of Example and Comparative Example, it can be seen that in accordance with the method of the present invention, high purity DMSO can be efficiently recovered from a recovered resist remover at a low cost.

INDUSTRIAL APPLICABILITY

(20) According to the method of the present invention, high purity DMSO can be efficiently recovered from a recovered resist remover at a low cost, which is useful in that DMSO which has been conventionally discarded can be reused.