Surfactant for electronic materials and detergent for electronic materials including the same

Abstract

To provide a surfactant for electronic materials, containing a compound with surface activity, which can significantly reduce metal ion concentrations using a simple treatment process.SOLUTION: A surfactant for electronic materials comprises a compound represented by chemical formula 1, where R is a C6 or more linear or branched alkyl group, AO is a C2-4 linear or branched oxyalkylene group, and n is an integer of 1 or greater, with a boiling point of 500°C or less at 760 mmHg, wherein the total content of metal ions is 1000 mass ppb or less.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a surfactant for electronic materials and a cleaning agent for electronic materials using the same. [Background technology]

[0002] Surfactants are compounds that have hydrophobic and hydrophilic groups in one molecule, and the compounds form micelles in a solution, allowing polar and non-polar substances to be mixed uniformly. Due to their properties, surfactants are used as cleaning agents in a wide variety of applications. Among these applications, when surfactants are used for electronic materials in the fields of electronics, semiconductors, and precision processing, metal contamination of the surfactant may adversely affect the shape and electrical properties of the electronic materials. In order to prevent such adverse effects, it is necessary to reduce the concentration of metal ions contained in the surfactant as much as possible.

[0003] As treatment methods for reducing the metal ion concentration in a surfactant, for example, a method using electrodialysis with an ion exchange membrane (see Patent Document 1), general methods using concentration, crystallization, and extraction, as well as methods using reverse osmosis membranes and ultrafiltration membranes (see Patent Document 2), a method using a combination of an ion exchange resin and a functional filter (see Patent Document 3), and an ion exchange method in which a diluted aqueous surfactant solution is treated with a mixed resin of a strongly acidic cation exchange resin and a strongly alkaline anion exchange resin (see Patent Document 4) have been proposed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 62-63555 [Patent Document 2] Japanese Patent Application Publication No. 5-317654 [Patent Document 3] JP 2005-213200 A [Patent Document 4] JP 2017-132700 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the above-mentioned treatment methods, in order to reduce the metal ion concentration to the ppb level required for surfactants for electronic materials, special treatment equipment and complicated pretreatment are required.

[0006] On the other hand, purification by distillation can be mentioned as a method for treating organic compounds. By using distillation, compounds with different boiling points can be easily separated, and a high purity compound can be obtained in a few steps. From this, it seems that the metal ion concentration of the compounds constituting the surfactant can be reduced by purifying them by distillation. However, the surfactants for electronic materials that have been used so far have high boiling points due to their large molecular weights and the presence of hydrophilic groups, making purification by distillation difficult. In other words, it has not yet been achieved to use compounds purified by the simple treatment method of distillation as surfactants for electronic materials. Conversely, it has also been found that all compounds previously known to be capable of purification by distillation do not exhibit sufficient surface activity.

[0007] Therefore, an object of the present invention is to provide a surfactant for electronic materials which can sufficiently reduce the metal ion concentration using a simple treatment method and which contains a compound having surface activity. [Means for solving the problem]

[0008] The present inventors have conducted extensive research to solve the above problems. In the process, they have found that compounds having a smaller molecular weight of the hydrophobic group and / or hydrophilic group than compounds that have been conventionally used as surfactants for electronic materials have surface activity. They have also found that these compounds can be purified by distillation under commonly available distillation conditions, and have completed the present invention.

[0009] That is, the present invention has the following configuration. (1) Chemical formula 1 below:

[0010] [ka]

[0011] In the formula, R represents a linear or branched alkyl group having 6 or more carbon atoms. AO represents a linear or branched oxyalkylene group having 2 to 4 carbon atoms; n is an integer equal to or greater than 1; and a compound having a boiling point of 500° C. or less at 760 mmHg, and a total content of metal ions of 1000 ppb or less by mass. (2) The surfactant according to (1), wherein R is a linear or branched alkyl group having 13 or less carbon atoms. (3) The surfactant according to (1) or (2), wherein n is an integer of 4 or less. (4) The surfactant according to any one of (1) to (3), wherein the total content of the metal ions is 20 ppb by mass or less. (5) The surfactant according to any one of (1) to (4), wherein the content of the compound is 90% by mass or more. (6) The surfactant according to any one of (1) to (5), wherein the compound is a fraction itself purified by distillation. (7) A cleaning agent for electronic materials, comprising the surfactant according to any one of (1) to (6). Effect of the Invention

[0012] According to the present invention, a surfactant for electronic materials is provided which can sufficiently reduce the metal ion concentration using a simple treatment method and which contains a compound having surface activity. [Brief description of the drawings]

[0013] [Figure 1]1 is an image showing cleaning results obtained using a cleaning solution of the present invention and a comparative cleaning solution. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, the embodiments for carrying out the present invention will be described in detail. The embodiments shown here are merely examples for embodying the technical idea of ​​the present invention, and do not limit the present invention. Therefore, all other possible embodiments, methods of use, and operating techniques that can be conceived by those skilled in the art without departing from the gist of the present invention are included in the scope and gist of the present invention, and are included in the invention described in the claims and their equivalents. The embodiments described in this specification can be combined in any manner to form other embodiments. In addition, in this specification, the range "X to Y" means "X or more and Y or less". In addition, unless otherwise specified, the operation and measurement of physical properties are performed under the conditions of room temperature (20 to 25°C) and relative humidity of 40 to 60%.

[0015] [Surfactants] The present invention provides a surfactant for electronic materials, which contains a compound represented by the above chemical formula 1 and having a boiling point of 500° C. or less at 760 mmHg, and has a total metal ion content of 1000 ppb or less by mass.

[0016] (Compound represented by chemical formula 1) The surface active compound contained in the surfactant of the present invention is represented by the following chemical formula 1:

[0017] [ka]

[0018] In the above chemical formula 1, R represents a linear or branched alkyl group having 6 or more carbon atoms, AO represents a linear or branched oxyalkylene group having 2 to 4 carbon atoms, and n is an integer of 1 or more. In chemical formula 1, R represents a hydrophobic group, (AO) nacts as a hydrophilic group. Therefore, the compound having the above structure has both a hydrophobic group and a hydrophilic group in one molecule, and therefore has surface activity. Furthermore, the boiling point of the compound represented by Chemical Formula 1 included in the surfactant according to the present invention is 500°C or less at 760 mmHg.

[0019] In the above chemical formula 1, R acts as a hydrophobic group and represents a linear or branched alkyl group having 6 or more carbon atoms. When the number of carbon atoms in R is 6 or more, R can have sufficient hydrophobicity. In the above chemical formula 1, R represents a linear or branched alkyl group having preferably 6 to 13 carbon atoms, more preferably 6 to 9 carbon atoms, and even more preferably 6 to 8 carbon atoms. In one embodiment, in the above chemical formula 1, R represents a linear alkyl group having 6 to 12 carbon atoms, 6 to 10 carbon atoms, 6 to 9 carbon atoms, or 6 to 8 carbon atoms. In one embodiment, in the above chemical formula 1, R represents a branched alkyl group having 6 to 12 carbon atoms, 7 to 12 carbon atoms, 7 to 10 carbon atoms, 7 to 9 carbon atoms, or 7 to 8 carbon atoms. The length of the main skeleton (the skeleton having the longest carbon chain) of R in the above chemical formula 1 can be 5 or more, 6 or more, 7 or more, or 8 or more carbon atoms.

[0020] Examples of linear or branched alkyl groups having 6 or more carbon atoms as R include n-hexyl, n-heptyl, 1-methylhexyl, 2-methylhexyl, 3-methylhexyl, 4-methylhexyl, 5-methylhexyl, n-octyl, 1-methylheptyl, 2-methylheptyl, 3-methylheptyl, 4-methylheptyl, 5-methylheptyl, 6-methylheptyl, 1-ethylhexyl, 2-ethylhexyl, 3-ethylhexyl, 4-ethyl ...ethylhexyl, 3-ethylhexyl, 4-ethylhexyl, nyl, 1-methyloctyl, 2-methyloctyl, 3-methyloctyl, 4-methyloctyl, 5-methyloctyl, 6-methyloctyl, 7-methyloctyl, 1-ethylheptyl, 2-ethylheptyl, 3-ethylheptyl, 4-ethylheptyl, 5-ethylheptyl, n-decyl, 1-methylnonyl, 2-methylnonyl, 3-methylnonyl, 4-methylnonyl, 5-methylnonyl, 6-methylnonyl, 7-methylnonyl, 8-methylnonyl, 1-ethyl Octyl, 2-ethyloctyl, 3-ethyloctyl, 4-ethyloctyl, 5-ethyloctyl, 6-ethyloctyl, n-undecyl, 1-methyldecyl, 2-methyldecyl, 3-methyldecyl, 4-methyldecyl, 5-methyldecyl, 6-methyldecyl, 7-methyldecyl, 8-methyldecyl, 9-methyldecyl, 1-ethylnonyl, 2-ethylnonyl, 3-ethylnonyl, 4-ethylnonyl, 5-ethylnonyl, 6-ethylnonyl, 7-ethylnonyl Examples of ethyldecyl groups include, but are not limited to, n-dodecyl, 1-methylundecyl, 2-methylundecyl, 3-methylundecyl, 4-methylundecyl, 5-methylundecyl, 6-methylundecyl, 7-methylundecyl, 8-methylundecyl, 9-methylundecyl, 10-methylundecyl, 1-ethyldecyl, 2-ethyldecyl, 3-ethyldecyl, 4-ethyldecyl, 5-ethyldecyl, 6-ethyldecyl, 7-ethyldecyl, and 8-ethyldecyl groups.

[0021] In the above formula 1, (AO) nacts as a hydrophilic group, AO represents a linear or branched oxyalkylene group having 2 to 4 carbon atoms, and n is an integer of 1 or more. (AO) n is within the above range, (AO) n may have sufficient hydrophilicity.

[0022] In the above chemical formula 1, AO is preferably a linear or branched oxyalkylene group having 2 to 3 carbon atoms. Examples of AO in the above chemical formula 1 include, but are not limited to, an oxyethylene group, an oxypropylene group, an oxytrimethylene group, or an oxytetramethylene group. Among these, from the viewpoint of obtaining sufficient hydrophilicity, AO is preferably an oxyethylene group or an oxypropylene group, and more preferably an oxyethylene group.

[0023] In the above Chemical Formula 1, n is preferably an integer of 1 to 5, more preferably an integer of 2 to 4, and even more preferably an integer of 3 to 4. In one embodiment, in the above Chemical Formula 1, n can be 5 or less, 4 or less, or 3 or less. In one embodiment, in the above Chemical Formula 1, n can be 2 or more, or 3 or more.

[0024] Examples of the compound represented by chemical formula 1 contained in the surfactant of the present invention include, but are not limited to, monoethylene glycol monoalkyl ether, diethylene glycol monoalkyl ether, triethylene glycol monoalkyl ether, tetraethylene glycol monoalkyl ether, pentaethylene glycol monoalkyl ether, monopropylene glycol monoalkyl ether, dipropylene glycol monoalkyl ether, tripropylene glycol monoalkyl ether, and tetrapropylene glycol monoalkyl ether. Among them, from the viewpoint of having excellent surface activity, monoethylene glycol monoalkyl ether, diethylene glycol monoalkyl ether, triethylene glycol monoalkyl ether, tetraethylene glycol monoalkyl ether, or pentaethylene glycol monoalkyl ether is preferred, triethylene glycol monoalkyl ether, tetraethylene glycol monoalkyl ether, or pentaethylene glycol monoalkyl ether is more preferred, and triethylene glycol monoalkyl ether, tetraethylene glycol monoalkyl ether, or pentaethylene glycol monoalkyl ether is even more preferred. In addition, from the viewpoint of easy purification by distillation, monoethylene glycol monoalkyl ether, diethylene glycol monoalkyl ether, triethylene glycol monoalkyl ether, or tetraethylene glycol monoalkyl ether is preferred. Furthermore, from the viewpoint of combining excellent surface activity with ease of purification by distillation, triethylene glycol monoalkyl ether or tetraethylene glycol monoalkyl ether is preferred.

[0025] Examples of monoethylene glycol monoalkyl ethers include monoethylene glycol mono-n-hexyl ether, monoethylene glycol mono-n-heptyl ether, monoethylene glycol mono-1-methylhexyl ether, monoethylene glycol mono-2-methylhexyl ether, monoethylene glycol mono-3-methylhexyl ether, monoethylene glycol mono-4-methylhexyl ether, monoethylene glycol mono-5-methylhexyl ether, monoethylene glycol mono-n-octyl ether, monoethylene glycol mono-1-methylheptyl ether, monoethylene glycol mono-2-methylheptyl ether, monoethylene glycol mono-3-methylheptyl ether, monoethylene glycol mono-4-methylheptyl ether, monoethylene glycol mono-5-methylheptyl ether, monoethylene glycol mono-6-methylheptyl ether, monoethylene glycol mono-1-ethylhexyl ether, monoethylene glycol mono-2-ethylhexyl ether, monoethylene glycol mono-3-ethylhexyl ether, monoethylene glycol mono monoethylene glycol mono-4-ethylhexyl ether, monoethylene glycol mono-n-nonyl ether, monoethylene glycol mono-1-methyloctyl ether, monoethylene glycol mono-2-methyloctyl ether, monoethylene glycol mono-3-methyloctyl ether, monoethylene glycol mono-4-methyloctyl ether, monoethylene glycol mono-5-methyloctyl ether, monoethylene glycol mono-6-methyloctyl ether, monoethylene glycol mono-7-methyloctyl ether, monoethylene glycol mono-1-ethylheptyl ether, monoethylene glycol mono-2-ethylheptyl ether, monoethylene glycol mono-3-ethylheptyl ether, monoethylene glycol mono-4-ethylheptyl ether, monoethylene glycol mono-5-ethylheptyl ether, monoethylene glycol mono-n-decyl ether, monoethylene glycol mono-1-methylnonyl ether, monoethylene glycol mono-2-methylnonyl ether, monoethylene glycol mono-3-methylnonyl ether, monoethylene glycol mono-4-methylnonyl ether,Monoethylene glycol mono 5-methylnonyl ether, monoethylene glycol mono 6-methylnonyl ether, monoethylene glycol mono 7-methylnonyl ether, monoethylene glycol mono 8-methylnonyl ether, monoethylene glycol mono 1-ethyloctyl ether, monoethylene glycol mono 2-ethyloctyl ether, monoethylene glycol mono 3-ethyloctyl ether, monoethylene glycol mono 4-ethyloctyl ether, monoethylene glycol mono 5-ethyloctyl ether, monoethylene glycol mono 6-ethyloctyl ether, monoethylene glycol mono n-undecyl ether, monoethylene glycol mono 1-methyldecyl ether, monoethylene glycol mono 2-methyldecyl ether, monoethylene glycol mono 3-methyldecyl ether, monoethylene glycol mono 4-methyldecyl ether, monoethylene glycol mono 5-methyldecyl ether, monoethylene glycol mono 6-methyldecyl ether, monoethylene glycol mono 7-methyldecyl ether, monoethylene glycol mono 8-methyl Decyl ether, monoethylene glycol mono 9-methyldecyl ether, monoethylene glycol mono 1-ethylnonyl ether, monoethylene glycol mono 2-ethylnonyl ether, monoethylene glycol mono 3-ethylnonyl ether, monoethylene glycol mono 4-ethylnonyl ether, monoethylene glycol mono 5-ethylnonyl ether, monoethylene glycol mono 6-ethylnonyl ether, monoethylene glycol mono 7-ethylnonyl ether, monoethylene glycol mono n-dodecyl ether, monoethylene glycol mono 1-methylundecyl ether, monoethylene glycol mono 2-methylundecyl ether, monoethylene glycol mono 3-methylundecyl ether, monoethylene glycol mono 4-methylundecyl ether, monoethylene glycol mono 5-methylundecyl ether, monoethylene glycol mono 6-methylundecyl ether, monoethylene glycol mono 7-methylundecyl ether, monoethylene glycol mono 8-methylundecyl ether, monoethylene glycol mono 9-methylundecyl ether,Examples of the ethyl decyl ether include, but are not limited to, monoethylene glycol mono 10-methylundecyl ether, monoethylene glycol mono 1-ethyldecyl ether, monoethylene glycol mono 2-ethyldecyl ether, monoethylene glycol mono 3-ethyldecyl ether, monoethylene glycol mono 4-ethyldecyl ether, monoethylene glycol mono 5-ethyldecyl ether, monoethylene glycol mono 6-ethyldecyl ether, monoethylene glycol mono 7-ethyldecyl ether, and monoethylene glycol mono 8-ethyldecyl ether.

[0026] Examples of diethylene glycol monoalkyl ethers include diethylene glycol mono n-hexyl ether, diethylene glycol mono n-heptyl ether, diethylene glycol mono 1-methylhexyl ether, diethylene glycol mono 2-methylhexyl ether, diethylene glycol mono 3-methylhexyl ether, diethylene glycol mono 4-methylhexyl ether, diethylene glycol mono 5-methylhexyl ether, diethylene glycol mono n-octyl ether, diethylene glycol mono 1-methylheptyl ether, diethylene glycol mono 2-methylheptyl ether, diethylene glycol mono 3-methylheptyl ether, diethylene glycol mono 4-methylheptyl ether, diethylene glycol mono 5-methylheptyl ether, diethylene glycol mono 6-methylheptyl ether, diethylene glycol mono 1-ethylhexyl ether, diethylene glycol mono 2-ethylhexyl ether, diethylene glycol mono 3-ethylhexyl ether, diethylene glycol mono 4-ethylhexyl ether, diethylene glycol mono non-nonyl ether, diethylene glycol mono 1-methyloctyl ether, diethylene glycol mono 2-methyloctyl ether, diethylene glycol mono 3-methyloctyl ether, diethylene glycol mono 4-methyloctyl ether, diethylene glycol mono 5-methyloctyl ether, diethylene glycol mono 6-methyloctyl ether, diethylene glycol mono 7-methyloctyl ether, diethylene glycol mono 1-ethylheptyl ether, diethylene glycol mono 2-ethylheptyl ether, diethylene glycol mono 3-ethylheptyl ether, diethylene glycol mono 4-ethylheptyl ether, diethylene glycol mono 5-ethylheptyl ether, diethylene glycol mono n-decyl ether, diethylene glycol mono 1-methylnonyl ether, diethylene glycol mono 2-methylnonyl ether, diethylene glycol mono 3-methylnonyl ether, diethylene glycol mono 4-methylnonyl ether, diethylene glycol mono 5-methylnonyl ether, diethylene glycol mono 6-methylnonyl ether,Diethylene glycol mono 7-methylnonyl ether, diethylene glycol mono 8-methylnonyl ether, diethylene glycol mono 1-ethyloctyl ether, diethylene glycol mono 2-ethyloctyl ether, diethylene glycol mono 3-ethyloctyl ether, diethylene glycol mono 4-ethyloctyl ether, diethylene glycol mono 5-ethyloctyl ether, diethylene glycol mono 6-ethyloctyl ether, diethylene glycol mono n-undecyl ether, diethylene glycol mono 1-methyldecyl ether, diethylene glycol mono 2-methyldecyl ether, diethylene glycol mono 3-methyldecyl ether, diethylene glycol mono 4-methyldecyl ether, diethylene glycol mono 5-methyldecyl ether, diethylene glycol mono 6-methyldecyl ether, diethylene glycol mono 7-methyldecyl ether, diethylene glycol mono 8-methyldecyl ether, diethylene glycol mono 9-methyldecyl ether, diethylene glycol mono 1-ethylnonyl ether, diethylene glycol mono 2-ethylnonyl diethylene glycol mono 3-ethylnonyl ether, diethylene glycol mono 4-ethylnonyl ether, diethylene glycol mono 5-ethylnonyl ether, diethylene glycol mono 6-ethylnonyl ether, diethylene glycol mono 7-ethylnonyl ether, diethylene glycol mono n-dodecyl ether, diethylene glycol mono 1-methylundecyl ether, diethylene glycol mono 2-methylundecyl ether, diethylene glycol mono 3-methylundecyl ether, diethylene glycol mono 4-methylundecyl ether, diethylene glycol mono 5-methylundecyl ether, diethylene glycol mono 6-methylundecyl ether, diethylene glycol mono 7-methylundecyl ether, diethylene glycol mono 8-methylundecyl ether, diethylene glycol mono 9-methylundecyl ether, diethylene glycol mono 10-methylundecyl ether, diethylene glycol mono 1-ethyldecyl ether, diethylene glycol mono 2-ethyldecyl ether, diethylene glycol mono 3-ethyldecyl ether,Examples of the ethyl decyl ether include, but are not limited to, diethylene glycol mono 4-ethyl decyl ether, diethylene glycol mono 5-ethyl decyl ether, diethylene glycol mono 6-ethyl decyl ether, diethylene glycol mono 7-ethyl decyl ether, and diethylene glycol mono 8-ethyl decyl ether.

[0027] Examples of triethylene glycol monoalkyl ethers include triethylene glycol mono n-hexyl ether, triethylene glycol mono n-heptyl ether, triethylene glycol mono 1-methylhexyl ether, triethylene glycol mono 2-methylhexyl ether, triethylene glycol mono 3-methylhexyl ether, triethylene glycol mono 4-methylhexyl ether, triethylene glycol mono 5-methylhexyl ether, triethylene glycol mono n-octyl ether, triethylene glycol mono 1-methylheptyl ether, triethylene glycol mono 2-methylheptyl ether, triethylene glycol mono 3-methylheptyl ether, triethylene glycol mono 4-methylheptyl ether, triethylene glycol mono 5-methylheptyl ether, triethylene glycol mono 6-methylheptyl ether, triethylene glycol mono 1-ethylhexyl ether, triethylene glycol mono 2-ethylhexyl ether, triethylene glycol mono 3-ethylhexyl ether, triethylene glycol mono triethylene glycol mono-4-ethylhexyl ether, triethylene glycol mono-n-nonyl ether, triethylene glycol mono-1-methyloctyl ether, triethylene glycol mono-2-methyloctyl ether, triethylene glycol mono-3-methyloctyl ether, triethylene glycol mono-4-methyloctyl ether, triethylene glycol mono-5-methyloctyl ether, triethylene glycol mono-6-methyloctyl ether, triethylene glycol mono-7-methyloctyl ether, triethylene glycol mono-1-ethylheptyl ether, triethylene glycol mono-2-ethylheptyl ether, triethylene glycol mono-3-ethylheptyl ether, triethylene glycol mono-4-ethylheptyl ether, triethylene glycol mono-5-ethylheptyl ether, triethylene glycol mono-n-decyl ether, triethylene glycol mono-1-methylnonyl ether, triethylene glycol mono-2-methylnonyl ether, triethylene glycol mono-3-methylnonyl ether, triethylene glycol mono-4-methylnonyl ether,Triethylene glycol mono 5-methylnonyl ether, triethylene glycol mono 6-methylnonyl ether, triethylene glycol mono 7-methylnonyl ether, triethylene glycol mono 8-methylnonyl ether, triethylene glycol mono 1-ethyloctyl ether, triethylene glycol mono 2-ethyloctyl ether, triethylene glycol mono 3-ethyloctyl ether, triethylene glycol mono 4-ethyloctyl ether, triethylene glycol mono 5-ethyloctyl ether, triethylene glycol mono 6-ethyloctyl ether, triethylene glycol mono n-undecyl ether, triethylene glycol mono 1-methyldecyl ether, triethylene glycol mono 2-methyldecyl ether, triethylene glycol mono 3-methyldecyl ether, triethylene glycol mono 4-methyldecyl ether, triethylene glycol mono 5-methyldecyl ether, triethylene glycol mono 6-methyldecyl ether, triethylene glycol mono 7-methyldecyl ether, triethylene glycol mono 8-methyl Decyl ether, triethylene glycol mono 9-methyldecyl ether, triethylene glycol mono 1-ethylnonyl ether, triethylene glycol mono 2-ethylnonyl ether, triethylene glycol mono 3-ethylnonyl ether, triethylene glycol mono 4-ethylnonyl ether, triethylene glycol mono 5-ethylnonyl ether, triethylene glycol mono 6-ethylnonyl ether, triethylene glycol mono 7-ethylnonyl ether, triethylene glycol mono n-dodecyl ether, triethylene glycol mono 1-methylundecyl ether, triethylene glycol mono 2-methylundecyl ether, triethylene glycol mono 3-methylundecyl ether, triethylene glycol mono 4-methylundecyl ether, triethylene glycol mono 5-methylundecyl ether, triethylene glycol mono 6-methylundecyl ether, triethylene glycol mono 7-methylundecyl ether, triethylene glycol mono 8-methylundecyl ether, triethylene glycol mono 9-methylundecyl ether,Examples of the ethyl decyl ether include, but are not limited to, triethylene glycol mono 10-methylundecyl ether, triethylene glycol mono 1-ethyldecyl ether, triethylene glycol mono 2-ethyldecyl ether, triethylene glycol mono 3-ethyldecyl ether, triethylene glycol mono 4-ethyldecyl ether, triethylene glycol mono 5-ethyldecyl ether, triethylene glycol mono 6-ethyldecyl ether, triethylene glycol mono 7-ethyldecyl ether, and triethylene glycol mono 8-ethyldecyl ether.

[0028] Examples of tetraethylene glycol monoalkyl ethers include tetraethylene glycol mono n-hexyl ether, tetraethylene glycol mono n-heptyl ether, tetraethylene glycol mono 1-methylhexyl ether, tetraethylene glycol mono 2-methylhexyl ether, tetraethylene glycol mono 3-methylhexyl ether, tetraethylene glycol mono 4-methylhexyl ether, tetraethylene glycol mono 5-methylhexyl ether, tetraethylene glycol mono n-octyl ether, tetraethylene glycol mono 1-methylheptyl ether, tetraethylene glycol mono 2-methylheptyl ether, tetraethylene glycol mono 3-methylheptyl ether, tetraethylene glycol mono 4-methylheptyl ether, tetraethylene glycol mono 5-methylheptyl ether, tetraethylene glycol mono 6-methylheptyl ether, tetraethylene glycol mono 1-ethylhexyl ether, tetraethylene glycol mono 2-ethylhexyl ether, and tetraethylene glycol mono 3-ethylhexyl ether. , tetraethylene glycol mono 4-ethylhexyl ether, tetraethylene glycol mono n-nonyl ether, tetraethylene glycol mono 1-methyloctyl ether, tetraethylene glycol mono 2-methyloctyl ether, tetraethylene glycol mono 3-methyloctyl ether, tetraethylene glycol mono 4-methyloctyl ether, tetraethylene glycol mono 5-methyloctyl ether, tetraethylene glycol mono 6-methyloctyl ether, tetraethylene glycol mono 7-methyloctyl ether, tetraethylene glycol mono 1-ethylheptyl ether, tetraethylene glycol mono 2-ethylheptyl ether, tetraethylene glycol mono 3-ethylheptyl ether, tetraethylene glycol mono 4-ethylheptyl ether, tetraethylene glycol mono 5-ethylheptyl ether, tetraethylene glycol mono n-decyl ether, tetraethylene glycol mono 1-methylnonyl ether, tetraethylene glycol mono 2-methylnonyl ether, tetraethylene glycol mono 3-methylnonyl ether,Tetraethylene glycol mono 4-methylnonyl ether, tetraethylene glycol mono 5-methylnonyl ether, tetraethylene glycol mono 6-methylnonyl ether, tetraethylene glycol mono 7-methylnonyl ether, tetraethylene glycol mono 8-methylnonyl ether, tetraethylene glycol mono 1-ethyloctyl ether, tetraethylene glycol mono 2-ethyloctyl ether, tetraethylene glycol mono 3-ethyloctyl ether, tetraethylene glycol mono 4-ethyloctyl ether, tetraethylene glycol mono 5-ethyloctyl ether, tetraethylene glycol mono 6-ethyloctyl ether, tetraethylene glycol mono n-undecyl ether, tetraethylene glycol mono 1-methyldecyl ether, tetraethylene glycol mono 2-methyldecyl ether, tetraethylene glycol mono 3-methyldecyl ether, tetraethylene glycol mono 4-methyldecyl ether, tetraethylene glycol mono 5-methyldecyl ether, tetraethylene glycol mono 6-methyldecyl ether, tetra Ethylene glycol mono 7-methyldecyl ether, tetraethylene glycol mono 8-methyldecyl ether, tetraethylene glycol mono 9-methyldecyl ether, tetraethylene glycol mono 1-ethylnonyl ether, tetraethylene glycol mono 2-ethylnonyl ether, tetraethylene glycol mono 3-ethylnonyl ether, tetraethylene glycol mono 4-ethylnonyl ether, tetraethylene glycol mono 5-ethylnonyl ether, tetraethylene glycol mono 6-ethylnonyl ether, tetraethylene glycol mono 7-ethylnonyl ether, tetraethylene glycol mono n-dodecyl ether, tetraethylene glycol mono 1-methylundecyl ether, tetraethylene glycol mono 2-methylundecyl ether, tetraethylene glycol mono 3-methylundecyl ether, tetraethylene glycol mono 4-methylundecyl ether, tetraethylene glycol mono 5-methylundecyl ether, tetraethylene glycol mono 6-methylundecyl ether, tetraethylene glycol mono 7-methylundecyl ether,Examples of the ethyl ether include, but are not limited to, tetraethylene glycol mono 8-methylundecyl ether, tetraethylene glycol mono 9-methylundecyl ether, tetraethylene glycol mono 10-methylundecyl ether, tetraethylene glycol mono 1-ethyldecyl ether, tetraethylene glycol mono 2-ethyldecyl ether, tetraethylene glycol mono 3-ethyldecyl ether, tetraethylene glycol mono 4-ethyldecyl ether, tetraethylene glycol mono 5-ethyldecyl ether, tetraethylene glycol mono 6-ethyldecyl ether, tetraethylene glycol mono 7-ethyldecyl ether, and tetraethylene glycol mono 8-ethyldecyl ether.

[0029] Examples of pentaethylene glycol monoalkyl ethers include pentaethylene glycol mono n-hexyl ether, pentaethylene glycol mono n-heptyl ether, pentaethylene glycol mono 1-methylhexyl ether, pentaethylene glycol mono 2-methylhexyl ether, pentaethylene glycol mono 3-methylhexyl ether, pentaethylene glycol mono 4-methylhexyl ether, pentaethylene glycol mono 5-methylhexyl ether, pentaethylene glycol mono n-octyl ether, pentaethylene glycol mono 1-methylheptyl ether, pentaethylene glycol mono 2-methylheptyl ether, pentaethylene glycol mono 3-methylheptyl ether, pentaethylene glycol mono 4-methylheptyl ether, pentaethylene glycol mono 5-methylheptyl ether, pentaethylene glycol mono 6-methylheptyl ether, pentaethylene glycol mono 1-ethylhexyl ether, pentaethylene glycol mono 2-ethylhexyl ether, and pentaethylene glycol mono 3-ethylhexyl ether. , pentaethylene glycol mono 4-ethylhexyl ether, pentaethylene glycol mono n-nonyl ether, pentaethylene glycol mono 1-methyloctyl ether, pentaethylene glycol mono 2-methyloctyl ether, pentaethylene glycol mono 3-methyloctyl ether, pentaethylene glycol mono 4-methyloctyl ether, pentaethylene glycol mono 5-methyloctyl ether, pentaethylene glycol mono 6-methyloctyl ether, pentaethylene glycol mono 7-methyloctyl ether, pentaethylene glycol mono 1-ethylheptyl ether, pentaethylene glycol mono 2-ethylheptyl ether, pentaethylene glycol mono 3-ethylheptyl ether, pentaethylene glycol mono 4-ethylheptyl ether, pentaethylene glycol mono 5-ethylheptyl ether, pentaethylene glycol mono n-decyl ether, pentaethylene glycol mono 1-methylnonyl ether, pentaethylene glycol mono 2-methylnonyl ether, pentaethylene glycol mono 3-methylnonyl ether,Pentaethylene glycol mono 4-methylnonyl ether, pentaethylene glycol mono 5-methylnonyl ether, pentaethylene glycol mono 6-methylnonyl ether, pentaethylene glycol mono 7-methylnonyl ether, pentaethylene glycol mono 8-methylnonyl ether, pentaethylene glycol mono 1-ethyloctyl ether, pentaethylene glycol mono 2-ethyloctyl ether, pentaethylene glycol mono 3-ethyloctyl ether, pentaethylene glycol mono 4-ethyloctyl ether, pentaethylene glycol mono 5-ethyloctyl ether, pentaethylene glycol mono 6-ethyloctyl ether, pentaethylene glycol mono n-undecyl ether, pentaethylene glycol mono 1-methyldecyl ether, pentaethylene glycol mono 2-methyldecyl ether, pentaethylene glycol mono 3-methyldecyl ether, pentaethylene glycol mono 4-methyldecyl ether, pentaethylene glycol mono 5-methyldecyl ether, pentaethylene glycol mono 6-methyldecyl ether, penta Ethylene glycol mono 7-methyldecyl ether, pentaethylene glycol mono 8-methyldecyl ether, pentaethylene glycol mono 9-methyldecyl ether, pentaethylene glycol mono 1-ethylnonyl ether, pentaethylene glycol mono 2-ethylnonyl ether, pentaethylene glycol mono 3-ethylnonyl ether, pentaethylene glycol mono 4-ethylnonyl ether, pentaethylene glycol mono 5-ethylnonyl ether, pentaethylene glycol mono 6-ethylnonyl ether, pentaethylene glycol mono 7-ethylnonyl ether, pentaethylene glycol mono n-dodecyl ether, pentaethylene glycol mono 1-methylundecyl ether, pentaethylene glycol mono 2-methylundecyl ether, pentaethylene glycol mono 3-methylundecyl ether, pentaethylene glycol mono 4-methylundecyl ether, pentaethylene glycol mono 5-methylundecyl ether, pentaethylene glycol mono 6-methylundecyl ether, pentaethylene glycol mono 7-methylundecyl ether,Examples of the ethyl ether include, but are not limited to, pentaethylene glycol mono 8-methylundecyl ether, pentaethylene glycol mono 9-methylundecyl ether, pentaethylene glycol mono 10-methylundecyl ether, pentaethylene glycol mono 1-ethyldecyl ether, pentaethylene glycol mono 2-ethyldecyl ether, pentaethylene glycol mono 3-ethyldecyl ether, pentaethylene glycol mono 4-ethyldecyl ether, pentaethylene glycol mono 5-ethyldecyl ether, pentaethylene glycol mono 6-ethyldecyl ether, pentaethylene glycol mono 7-ethyldecyl ether, and pentaethylene glycol mono 8-ethyldecyl ether.

[0030] Among them, from the viewpoint of having good surface activity and being easily distillable, triethylene glycol mono 2-ethylhexyl ether or tetraethylene glycol mono 2-ethylhexyl ether is preferred, and triethylene glycol mono 2-ethylhexyl ether is more preferred. The above compounds may be contained alone or in combination of two or more in the surfactant.

[0031] The boiling point of the compound represented by Chemical Formula 1 contained in the surfactant according to the present invention is 500° C. or less at 760 mmHg. When the boiling point of the compound is within the above range, the compound represented by Chemical Formula 1 can be distilled by a commonly available and available distillation apparatus without decomposition of the molecule, and the metal ion concentration can be easily reduced. The boiling point of the compound represented by Chemical Formula 1 is preferably 200 to 450° C., more preferably 250 to 400° C., and even more preferably 300 to 400° C. at 760 mmHg. In one embodiment, the boiling point of the compound represented by Chemical Formula 1 is 50° C. or more, 100° C. or more, 150° C. or more, 200° C. or more, 250° C. or more, or 300° C. or more at 760 mmHg. In one embodiment, the boiling point of the compound represented by Chemical Formula 1 is 450° C. or less, 400° C. or less, 350° C. or less, or 300° C. or less at 760 mmHg.

[0032] The content of the compound represented by Chemical Formula 1 in the surfactant is preferably 90% by mass or more, more preferably 95% by mass or more, even more preferably 99% by mass or more, still more preferably 99.5% by mass or more, and particularly preferably 99.9% by mass or more, based on the total surfactant. The content of the compound represented by Chemical Formula 1 may be 100% by mass based on the total surfactant. When two or more compounds represented by Chemical Formula 1 are used in combination, the content is calculated as the total value of these compounds.

[0033] (Metal ion concentration) In addition, the content of all metal ions contained in the compound represented by Chemical Formula 1 in the surfactant (total of all metal ions) is 1000 mass ppb or less with respect to the entire compound. When the total concentration of all metal ions is 1000 mass ppb or less, the above compound can be used as a surfactant for electronic materials with almost no influence of metal contamination. The metal ions that can be contained in the above compound are not particularly limited, but may be at least one metal ion selected from the group consisting of Li, Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Sr, Ag, Cd, Sn, Ba, W, Au, and Pb. In one embodiment, the total content of metal ions contained in the surfactant is preferably 500 mass ppb or less, more preferably 100 mass ppb or less, even more preferably 50 mass ppb or less, and particularly preferably 20 mass ppb or less. In another embodiment, the total content of metal ions contained (contaminated) in the compound represented by Chemical Formula 1 in the surfactant is also 1000 mass ppb or less, preferably 500 mass ppb or less, more preferably 100 mass ppb or less, even more preferably 50 mass ppb or less, and particularly preferably 20 mass ppb or less. The total content of metal ions contained in the surfactant is 1000 mass ppb or less. Note that the content of metal ions in the surfactant or in the compound represented by Chemical Formula 1 in the surfactant is the value measured (quantified) by ICP mass spectrometry (ICP-MS) described in the Examples section below.

[0034] The surface activity of the surfactants according to the present invention may be evaluated by the tests listed below, but are not limited thereto.

[0035] ·Contact angle The contact angle (25°C, 50% RH) of the surfactant according to the present invention is measured by a method using a contact angle meter described in the Examples section below. When the compound has good surface activity, the contact angle is more than 0° and preferably 70° or less, more preferably 60° or less, even more preferably 50° or less, and particularly preferably 40° or less.

[0036] ·Dynamic surface tension As the surfactant concentration increases, the surface tension decreases. When the surface is completely covered with surfactant molecules, micelles start to form. This point represents the critical micelle concentration (CMC) and thus the minimum surface tension. Adding more surfactant does not further affect the surface tension. The CMC can therefore be measured by observing the change in surface tension as a function of surfactant concentration. One such method for measuring this value is the Wilhelmy plate method. A Wilhelmy plate is usually a thin iridium-platinum plate attached to a balance by wires and positioned perpendicular to the air-liquid interface. The balance is used to measure the force exerted on the plate by wetting. This value is then used to calculate the surface tension (γ) according to equation 1:

[0037]

number

[0038] where l is equal to the wetted perimeter (2w+2d, where w and d are the thickness and width of the plate, respectively), and for cosθ, the contact angle between the liquid and the plate is assumed to be 0 in the absence of existing literature values.

[0039] Dynamic surface tension is the value of surface tension over time for a particular surface or interface. For liquids with added surfactants, this may differ from the equilibrium value. Immediately after the surface is created, the surface tension is equal to that of the pure liquid. As mentioned above, surfactants reduce surface tension, so the surface tension decreases until it reaches an equilibrium value. The time it takes to reach equilibrium depends on the diffusion and adsorption rates of the surfactant.

[0040] The dynamic surface tension value of the surfactant according to the present invention is measured by a method using a bubble pressure dynamic surface tensiometer based on the maximum bubble pressure method, which is described in the Examples section below. This device measures the maximum internal pressure of bubbles formed in a liquid by a capillary. The measured value corresponds to the surface tension at a certain surface elapsed time, which is the time from the start of bubble formation to the maximum pressure. The dependency of the surface tension on the surface elapsed time can be measured by varying the speed at which bubbles are generated. When the compound has good surface activity, at 25°C, 50% RH, 1% by mass aqueous solution, at 15 Hz, it is preferably 38 mN / m or less, more preferably 35 mN / m or less. Also, when the compound has good surface activity, at 25°C, 50% RH, 1% by mass aqueous solution, at 0.08 Hz, it is preferably 38 mN / m or less, more preferably 35 mN / m or less.

[0041] The method for producing the compound represented by Chemical Formula 1 included in the surfactant of the present invention is not particularly limited, but a conventionally known method can be appropriately adopted. For example, the compound is synthesized by heating the corresponding alcohol (ROH) and alkylene oxide as raw materials in the presence of a base catalyst. Examples of the base catalyst include, but are not limited to, metal hydroxides (e.g., lithium hydroxide, sodium hydroxide, potassium hydroxide, calcium hydroxide, etc.) and carbonates (e.g., sodium bicarbonate, sodium carbonate, potassium bicarbonate, potassium carbonate, calcium carbonate, etc.). Among them, from the viewpoint of efficiently proceeding with the reaction, metal hydroxides are preferred, and potassium hydroxide is more preferred. A reaction solvent may or may not be used, but from the viewpoint of efficiently proceeding with the reaction, it is preferable to use no solvent. The reaction temperature is not limited to these, but may be 25°C to 300°C, 50°C to 250°C, 80°C to 200°C, 100°C to 200°C, or 150°C to 180°C.

[0042] In addition, the compound represented by Chemical Formula 1 contained in the surfactant of the present invention is not particularly limited in terms of its specific operation as long as it can purify the target product, and can be purified by distillation using a conventionally known method. The apparatus and distillation conditions for such distillation purification are not particularly limited, and a method such as normal pressure distillation or reduced pressure distillation may be selected depending on the target compound represented by Chemical Formula 1 (polyoxyalkylene monoalkyl ether). For example, the operating pressure is appropriately determined depending on the composition of the mixture, the temperature of the heating source and the cooling source, and is not particularly limited, but from the viewpoint of suppressing side reactions, it is preferable to perform the distillation under conditions of, for example, 1 mmHg, 10 mmHg, 20 mmHg, 50 mmHg, 100 mmHg, 200 mmHg, or 760 mmHg. In addition, the distillation purification step may be performed two or more times. As described above, the compound represented by Chemical Formula 1 contained in the surfactant of the present invention can be purified by such distillation, and therefore the metal ion concentration contained in the compound can be sufficiently reduced. As a result, the metal ion concentration in the surfactant for electronic materials containing the compound can also be reduced in the same manner. In one embodiment, the compound is the fraction itself purified by distillation. When the compound is the fraction obtained by distillation itself, there is no need to carry out further purification by filtering after the distillation, and the intended metal treatment can be achieved by distillation alone.

[0043] (Application) The surfactant according to the present invention has surface activity and a sufficiently low metal ion concentration, and is therefore useful as a surfactant for electronic materials. This surfactant for electronic materials can also be used in a cleaning agent for electronic materials, which will be described later. Here, examples of electronic materials include, but are not limited to, substrates for semiconductor devices such as silicon wafers (for semiconductor elements and display devices, etc.), and substrate surfaces of semiconductors, glass, metals, ceramics, resins, magnetic materials, superconductors, etc., where metal contamination is a problem.

[0044] Furthermore, the electronic material surfactant according to the present invention can also be used for applications such as, but not limited to, chemical liquids for semiconductor processes (surface treatment liquids, etc.); chemical liquids for photoresist processes (treatment liquids, stripping liquids, developing liquids, coating agents, etc.); electrolytes and electrode manufacturing compositions for batteries, condensers, capacitors, etc.; dispersants for pigments and carbon black in inks and paints for electronic materials; dispersants for carbon nanotubes, fullerenes, and metal nanoparticles used in electronic materials; dispersants for titanium oxide in dye-sensitized solar cells; materials related to semiconductor devices (insulating films, abrasives, cleaning agents, adhesives, films, tapes, etc.); and resist-related materials (compositions for forming protective films, pre-wetting liquids, developing liquids, etc.).

[0045] [Cleaning agent] According to the present invention, there is also provided a cleaning agent for electronic materials, comprising the above-mentioned surfactant. The cleaning agent for electronic materials may comprise the above-mentioned surfactant, a basic compound, an organic solvent, and water.

[0046] The content of the surfactant in the cleaning agent is preferably 0.1% by mass to 10% by mass, and more preferably 0.2% by mass to 5% by mass, based on the total amount of the cleaning agent. When the content of the surfactant is 0.1% by mass to 10% by mass, the cleaning agent has a sufficient cleaning effect.

[0047] (Basic compounds) The basic compound that can be contained in the above-mentioned cleaning agent is a compound that adjusts the above-mentioned cleaning agent to basicity among compounds that do not contain metal ions (excluding the organic solvent described below). The above-mentioned basic compound is contained in the above-mentioned cleaning agent, and the cleaning effect of the above-mentioned cleaning agent is improved due to the effect that the decomposition of the dirt components is easily caused. The above-mentioned basic compound includes, but is not limited to, alkylamines and their salts, aromatic amines and their salts, and nitrogen-containing heterocyclic compounds and their salts. Among them, alkylamine salts can be preferably used, more preferably tetraalkylammonium salts, and even more preferably tetramethylammonium salts can be used. The above-mentioned salts include, but are not limited to, halides, hydroxides, nitrates, carbonates, or sulfates. Specific examples of the above-mentioned basic compounds include, but are not limited to, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, trimethyl-2-hydroxyethylammonium hydroxide (choline), triethyl(hydroxyethyl)ammonium hydroxide, ammonium carbonate, ammonium hydrogen carbonate, and ammonium carbamate. Among these, tetramethylammonium hydroxide, tetraethylammonium hydroxide, and tetrapropylammonium hydroxide are preferred, and tetramethylammonium hydroxide is more preferred. The above basic compounds may be used alone or in combination of two or more.

[0048] The content of the basic compound may be 0.5% by mass to 20% by mass or 1% by mass to 15% by mass based on the total amount of the cleaning agent. When the content of the basic compound is 0.5% by mass to 20% by mass, the cleaning agent has a sufficient cleaning effect. When two or more kinds of basic compounds are contained, the content of the basic compound indicates the total content of all the basic compounds.

[0049] (Organic solvent) The organic solvent that can be contained in the cleaning agent is an organic solvent that can be mixed with the basic compound and water, and is liquid at 25°C under standard atmospheric pressure (1013.25hPa). By containing the organic solvent in the cleaning agent, the cleaning effect of the oil-soluble dirt components is improved, and as a result, the overall cleaning effect of the cleaning agent is improved. The organic solvent includes, but is not limited to, alcohol-based solvents, ketone-based solvents, amine-based solvents, and amide-based solvents. Examples of the organic solvent include, but are not limited to, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monoethyl ether, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, ethylenediamine, N,N-diisopropylethylamine, tetramethylethylenediamine, hexamethylenediamine, aniline, toluidi, pyrrole, pyridine, picoline, or lutidine. In particular, from the viewpoint of easy mixing with the basic compound and water, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, monoethanolamine, or diethanolamine is preferred, propylene glycol monomethyl ether or monoethanolamine is more preferred, and propylene glycol monomethyl ether is even more preferred. The organic solvents may be used alone or in combination of two or more.

[0050] The content of the organic solvent may be 1% by mass to 70% by mass or 5% by mass to 60% by mass based on the total amount of the cleaning agent. When the content of the organic solvent is 1% by mass to 70% by mass, the cleaning agent has a sufficient cleaning effect. When two or more kinds of organic solvents are contained, the content of the organic solvents refers to the total content of all the organic solvents.

[0051] (water) The cleaning agent may also contain water. When water is contained in the cleaning agent, the cleaning effect of water-soluble dirt components is improved, and further, the components contained in the cleaning agent are dissolved, thereby improving the overall cleaning effect of the cleaning agent. The water is not particularly limited, but it is preferable to use water that has been distilled or treated with an ion exchange membrane.

[0052] The content of the organic solvent may be 20% by mass to 95% by mass or 25% by mass to 95% by mass based on the total amount of the cleaning agent. When the content of the organic solvent is 20% by mass to 95% by mass, the cleaning agent has a sufficient cleaning effect.

[0053] (Other Ingredients) The cleaning agent according to the present invention may or may not contain a chelating agent, an antioxidant, a rust inhibitor, and / or an antifoaming agent as other components. The other components may be used alone or in combination of two or more. When the other components are added, they may each be contained in an amount of 0.01 to 10 mass% based on the total amount of the cleaning agent.

[0054] (Cleaning method) The cleaning method using the cleaning agent according to the present invention is not limited, and any conventionally known method can be appropriately used. For example, immersion cleaning, ultrasonic cleaning, brush cleaning, scrub cleaning, jet cleaning, spray cleaning, microbubble cleaning, hand wiping cleaning, and combinations thereof can be mentioned. After cleaning, depending on the purpose of use, it can be dried as it is, or it can be rinsed with water or the like and then dried.

[0055] The cleaning agent according to the present invention is used for cleaning electronic materials, including, but not limited to, substrates for semiconductor devices such as silicon wafers (for semiconductor elements and display devices, etc.), and substrate surfaces of semiconductors, glasses, metals, ceramics, resins, magnetic materials, superconductors, etc., where metal contamination is a problem.

[0056] These cleaning agents are used to remove stains from the above-mentioned electronic materials, such as, but not limited to, resist materials (such as a composition for forming a photosensitive photoresist film used in a patterning step) and resist underlayer film materials (such as a composition for forming an organic resist underlayer film, a composition for forming a silicon-containing resist underlayer film, and a composition for forming an organic planarizing film). EXAMPLES

[0057] The present invention will be described in more detail below by way of examples, but the present invention is not limited to the following examples in any way.

[0058] [Synthesis and purification of compounds] Example 1 0.03 parts by mass of potassium hydroxide was added to 100 parts by mass of n-hexanol, and the mixture was heated to 170°C. Then, 43 parts by mass of ethylene oxide was injected under conditions of 1.0 MPa or less and reacted for 10 hours to obtain 143 parts by mass of monoethylene glycol mono-n-hexyl ether crude product.

[0059] Next, the obtained crude product (monoethylene glycol mono-n-hexyl ether) was charged into a glass flask equipped with a packed tower, a thermometer, and a condenser, and purification was carried out under the following distillation conditions. Specifically, the distillation temperature and pressure were set to 110-120°C and 170-200mmHg, respectively, to obtain a first distillate. Next, the distillation temperature was set to 100-110°C, and the pressure was set to 20-40mmHg, to obtain a fraction containing monoethylene glycol mono-n-hexyl ether (C6EO1).

[0060] Example 2 Diethylene glycol mono-n-hexyl ether (C6EO2) was synthesized in the same manner as in Example 1, except that the amount of ethylene oxide used was changed to 86 parts by mass and the distillation temperature was changed to 130 to 150°C.

[0061] Example 3 Monoethylene glycol mono-2-ethylhexyl ether (C8EO1) was synthesized in the same manner as in Example 1, except that 2-ethylhexanol was used instead of n-hexanol, the amount of ethylene oxide used was changed to 34 parts by mass, and the distillation temperature was changed to 110 to 130°C.

[0062] Example 4 Diethylene glycol mono 2-ethylhexyl ether (CEO) was synthesized in the same manner as in Example 1, except that 2-ethylhexanol was used instead of n-hexanol, the amount of ethylene oxide used was changed to 68 parts by mass, and the distillation temperature was changed to 140 to 160°C.

[0063] Example 5 Triethylene glycol mono 2-ethylhexyl ether (CEO) was synthesized in the same manner as in Example 1, except that 2-ethylhexanol was used instead of n-hexanol, the amount of ethylene oxide used was changed to 101 parts by mass, and the distillation temperature was changed to 130 to 140°C.

[0064] Example 6 Tetraethylene glycol mono 2-ethylhexyl ether (CEO) was synthesized in the same manner as in Example 1, except that 2-ethylhexanol was used instead of n-hexanol, the amount of ethylene oxide used was changed to 135 parts by mass, and the distillation temperature was changed to 240 to 260°C.

[0065] Example 7 Pentaethylene glycol mono 8-ethyldecyl ether (C12EO5) was synthesized in the same manner as in Example 1, except that n-dodecanol was used instead of n-hexanol, the amount of ethylene oxide used was changed to 118 parts by mass, and the distillation temperature was changed to 290 to 310°C.

[0066] Comparative Example 1 Triethylene glycol mono-n-butyl ether (C4EO3) was synthesized in the same manner as in Example 1, except that n-butanol was used instead of n-hexanol, the amount of ethylene oxide used was changed to 178 parts by mass, and the distillation temperature was changed to 150 to 170°C.

[0067] Comparative Example 2 Tetraethylene glycol mono-n-butyl ether (C4EO4) was synthesized in the same manner as in Example 1, except that n-butanol was used instead of n-hexanol, the amount of ethylene oxide used was changed to 278 parts by mass, and the distillation temperature was changed to 300 to 330°C.

[0068] Comparative Example 3 n-Hexanol (CEO) was distilled in the same manner as described in Example 1, except that the distillation temperature was 70°C.

[0069] Comparative Example 4 Heptaethylene glycol monostearyl ether (C18EO7) was synthesized in the same manner as in Example 1, except that stearyl alcohol was used instead of n-hexanol, the amount of ethylene oxide used was changed to 114 parts by mass, and purification was performed by filtration through a paper filter.

[0070] [Evaluation of purity and surface activity] (purity) The compounds of Examples 1 to 7 and Comparative Examples 1 to 4 obtained by the above synthesis and purification were confirmed to have a purity of 99% or more by gas chromatography (GC) or the like, and the concentrations of metal ions contained therein were confirmed by inductively coupled plasma mass spectrometry (ICP-MS).

[0071] <ICP-MS conditions> The conditions for inductively coupled plasma mass spectrometry were as follows: Equipment: Agilent 8900ICP-QQQ Calibration curve: 0, 1, 2, 5 ppb.

[0072] <Evaluation criteria> ○: The total metal ion concentration after purification is 1000 mass ppb or less ×: The total metal ion concentration after purification exceeds 1000 ppb by mass.

[0073] (contact angle) In Examples 1 to 7 and Comparative Examples 1 to 4, the contact angle of a 1% by mass aqueous solution was measured. Specifically, a contact angle meter (manufactured by Kyowa Interface Science Co., Ltd., model number: CA-XP) was used in a dry state (25°C / 50% RH) to create a droplet of about 5 μL on the tip of a needle using each 1% by mass aqueous solution as the liquid, and this was brought into contact with a parafilm (manufactured by Bemis) surface to create a droplet. The contact angle was the angle on the side containing the liquid among the angle formed by the tangent to the liquid surface and the parafilm surface at the point where the parafilm and the liquid contact each other.

[0074] <Evaluation criteria> Preferably 60° or less, more preferably 50° or less.

[0075] (dynamic surface tension) Aqueous solutions of 1% by mass of each of Examples 1 to 7 and Comparative Examples 1 to 4 were prepared, and the dynamic surface tension was measured at 25°C (50% RH) using a bubble pressure dynamic surface tensiometer (KRUSS, BP100) by the maximum bubble pressure method. Specifically, the values ​​of the 1% by mass aqueous solutions of each compound were measured at 15 Hz and 0.08 Hz.

[0076] <Evaluation criteria> At 15Hz, 38mN / m or less is preferable, and 35mN / m or less is more preferable. At 0.08Hz, 38mN / m or less is preferable, and 35mN / m or less is more preferable.

[0077] [Cleaning test] (Preparation of cleaning agent samples) Cleaning agent samples were prepared by mixing 0.3% of each of the compounds of Examples 1 to 7 and Comparative Examples 1 to 4, 1.0% of tetramethylammonium hydroxide, 5.7% of propylene glycol monomethyl ether, and 93.0% of pure water.

[0078] (Cleaning test method) The glass substrate with the fingerprints was cleaned by running a cleaning agent heated to 40°C for 1 minute, then running pure water for 1 minute to remove the cleaning agent, and then drying the glass substrate with an air blower. The cleaning effect was confirmed by visually checking the fingerprint stain residue on the glass substrate after drying.

[0079] <Evaluation criteria> ○: No residue ×: Residue present.

[0080] The boiling points at 760 mmHg obtained for Examples 1 to 7 and Comparative Examples 1 to 4 are shown in Table 1. Furthermore, the measurement results of the contact angle, dynamic surface tension, and metal ion concentration for Examples 1 to 7 and Comparative Examples 1 to 4, as well as the results of the cleaning test, are shown in Table 2.

[0081] [Table 1]

[0082] [Table 2]

[0083] From the results shown in Table 2, it was shown that the compounds of Examples 1 to 7 have sufficient surface activity and good cleaning effect. Also, FIG. 1 shows a glass substrate with fingerprints before cleaning, a glass substrate obtained as a result of cleaning using the cleaning solution of Example 5, and a glass substrate obtained as a result of cleaning using a cleaning solution not containing the compound of Example 5 (tetramethylammonium hydroxide 1.0%, propylene glycol monomethyl ether 5.7%, pure water 93.3%). From the results of FIG. 1, it was confirmed that the cleaning solution using the compound of the present invention has excellent cleaning effect. Also, it can be seen that these compounds can sufficiently reduce the metal ion concentration by distillation. In contrast, it was shown that Comparative Examples 1 to 4 do not have sufficient surface activity and have low cleaning effect. Also, in Comparative Example 4, purification by distillation is difficult due to the high boiling point, and the metal ion concentration could not be sufficiently reduced. The values ​​of each metal ion concentration in Example 5 are shown in Table 3.

[0084] [Table 3]

[0085] The results in Table 3 show that the concentration of the above metal ions was 12.7 mass ppb in total, and the metal ion concentration was sufficiently reduced.

Claims

1. The following chemical formula 1: 【Chemistry 1】 In the formula, R represents a linear or branched alkyl group having 6 or more carbon atoms. AO represents a linear or branched oxyalkylene group having 2 to 4 carbon atoms; n is an integer of 1 or more; and a compound having a boiling point of 500° C. or less at 760 mmHg, and a total content of metal ions of 1000 ppb or less by mass.

2. 2. The surfactant according to claim 1, wherein R is a linear or branched alkyl group having up to 13 carbon atoms.

3. The surfactant according to claim 1 , wherein n is an integer of 4 or less.

4. The surfactant according to claim 1 , wherein the total content of the metal ions is 20 ppb by mass or less.

5. The surfactant according to claim 1 , wherein the content of the compound is 90% by mass or more.

6. The surfactant according to claim 1 , wherein the compound is a fraction purified by distillation.

7. A cleaning agent for electronic materials, comprising the surfactant according to any one of claims 1 to 6.

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