JP2013151677A - Detergent for electronic material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a detergent for an electronic material which exhibits extremely high detergent properties for abrasive grains even when used at high temperatures, and a method for producing the electronic material.SOLUTION: A detergent for an electronic material includes: a non-ionic surfactant (A) the cloud point in 2-wt.% aqueous solution of which is 35-95°C; a high-molecular anionic surfactant (B) having an aromatic ring and a sulfonic group in the molecule and having a weight average molecular weight of 1,000-100,000; and water. The cloud point in 2-wt.% aqueous solution of the detergent for the electronic material is 50-95°C.

Description

The present invention relates to a cleaning agent for electronic materials and a method for producing electronic materials.
More specifically, the present invention relates to a cleaning agent suitable for removing abrasive grains after polishing of the surface and polishing debris in the manufacture of an electronic material, and a method for manufacturing an electronic material using this cleaning liquid.

Electronic materials, especially magnetic disks, are becoming smaller and higher capacity year by year, and the flying height of magnetic heads is becoming smaller. For this reason, there is a demand for a substrate in which abrasive grains, polishing scraps, and the like do not remain in the manufacturing process of the magnetic disk substrate.

The magnetic disk manufacturing process includes a substrate process (1) which is a process for producing a flattened substrate and a media process (2) which is a process for sputtering a magnetic layer onto the substrate.
Of these, in the substrate step (1), polishing with a slurry containing abrasive grains is performed to flatten the substrate, and then particles such as the slurry and generated polishing scraps are rinsed and washed, and further removed by rinsing. The missing particles are cleaned and removed completely in a subsequent cleaning process.

On the other hand, in the media step (2), which is a step of sputtering the magnetic layer on the substrate, cleaning is performed before sputtering in order to remove foreign matters adhering during transportation or storage.

As the capacity of magnetic disks has been increasing in recent years, the cleanliness of substrates has been required more than ever, and the conventional cleaning methods cannot cope with them. Therefore, in order to remove the strongly adhered abrasive grains after the polishing process, it is necessary to set the cleaning temperature with the cleaning agent higher than before, and there is a cleaning agent suitable for use under high temperature conditions. It is requested.

Usually, the cleaning agent contains a nonionic surfactant for the purpose of removing organic substances such as coolant used in the polishing process. A cleaning agent containing a nonionic surfactant exhibits a cloud point phenomenon due to the nonionic surfactant, and becomes insoluble in water at a high temperature. Therefore, when it is washed at a high temperature, the insoluble nonionic surfactant adheres to the substrate, and as a result, the detergency with respect to the abrasive grains deteriorates.

In response to the above-described problem of stability at high temperatures, methods for increasing the stability of cleaning agents at high temperatures have been proposed. For example, a method of increasing the cloud point of a nonionic surfactant-containing cleaning agent using benzenesulfonic acid, p-toluenesulfonic acid or the like (Patent Document 1) can be mentioned.

However, the cleaning agent of Patent Document 1 is stable even at a high temperature when the proportion of water is relatively low, such as a cleaning agent stock solution. However, the proportion of water is overwhelming as in the conditions for actually using the cleaning agent. When is high, a part of the nonionic surfactant cannot be dissolved and becomes slightly cloudy. In particular, when the pH of the cleaning agent is alkaline, the solubility of the nonionic surfactant itself decreases, so that insolubilization at high temperatures becomes significant. The cleaning agent containing the insolubilized material cannot be used because it contaminates the substrate and attaches a lot of abrasive grains.
In order to achieve a severely high recording density of a magnetic disk, higher cleaning performance is required for abrasive grains that are difficult to remove.

JP 2009-84565 A

Accordingly, it is an object of the present invention to provide a cleaning agent for electronic materials, which has a very high cleaning ability for abrasive grains even when used at high temperatures, and a method for producing an electronic material.

As a result of investigations to achieve the above-mentioned object, the present inventors have determined that a polymer-type anionic surfactant (B) having a specific functional group in the molecule, a nonionic surfactant (A) and a nonionic surfactant (A) The cleaning agent contained as an essential component together with water has been found to have high detergency for abrasive grains without precipitation of the nonionic surfactant (A) even when washed at a high temperature, leading to the present invention. It was.
That is, the present invention relates to a nonionic surfactant (A) having a cloud point of 35 to 95 ° C. in a 2% by weight aqueous solution, an aromatic ring and a sulfonic acid group in the molecule, and a weight average molecular weight of 1,000 to 100. A cleaning agent for electronic materials, which comprises a polymer type anionic surfactant (B) having a viscosity of 1,000,000 and water, and a cloud point of a 2% by weight aqueous solution of the cleaning agent for electronic materials is 50 to 95 ° C. A method for producing an electronic material using the cleaning agent.

The cleaning material for electronic materials and the method for producing the electronic material according to the present invention include magnetic disk substrates (particularly glass substrates for magnetic disks, aluminum substrates for magnetic disks, and aluminum for magnetic disks plated with nickel-phosphorus (Ni-P)). Excellent cleaning performance for fine abrasive grains, which is a problem in the manufacturing process of the substrate). Particularly when used at high temperatures, it has high detergency.
Therefore, it is possible to provide a magnetic disk substrate having high cleanliness required for increasing the recording density of the magnetic disk substrate.

The detergent for electronic materials of the present invention is a nonionic surfactant (A) having a cloud point of 35 to 95 ° C. in a 2% by weight aqueous solution, an aromatic ring and a sulfonic acid group in the molecule, and a weight average molecular weight of 1. The polymer type anionic surfactant (B) which is 1,000,000 to 100,000 and water, and has high detergency when used at a high temperature.
Here, the high temperature cannot be specified depending on the actual production site conditions, but generally indicates 50 ° C. or higher. The normal cleaning temperature is 20 to 40 ° C., but in order to improve the cleaning property, it is required to warm the cleaning to 50 ° C. or higher for cleaning. As washing at a high temperature, it is preferable to wash at 50 to 80 ° C. from the viewpoint of detergency.

In the present invention, the electronic material is not particularly limited, and includes a magnetic disk substrate (glass substrate, aluminum substrate and aluminum substrate with Ni-P plating), semiconductor substrate (semiconductor element, silicon wafer, etc.), compound Examples include semiconductor substrates (SiC substrates, GaAs substrates, GaN substrates, AlGaAs substrates, etc.), sapphire substrates (LEDs, etc.), optical lenses, printed wiring boards, optical communication cables, micro electromechanical systems (MEMS), and crystal resonators. The magnetic disk substrate is preferable from the viewpoint of cleanability against abrasive grains.

The 1st essential component of the cleaning agent for electronic materials of this invention is a nonionic surfactant (A) whose cloud point in 35 weight% aqueous solution is 35-95 degreeC.
In general, when a 0.5 to 5% by weight aqueous solution of a nonionic surfactant containing a polyoxyethylene chain in the molecule is heated, for example, water molecules bonded to the polyoxyethylene chain by hydrogen bonds in water. It will come off in response to sequential heating. As a result, the hydrophilicity of the polyoxyethylene portion gradually decreases, so that the nonionic surfactant is less soluble in water and the entire aqueous solution becomes cloudy. It is also known that the aqueous solution of nonionic surfactant that becomes cloudy at a temperature higher than the temperature at which it starts to become cloudy improves the hydrophilicity of the polyoxyethylene portion when the temperature decreases, so that the turbidity disappears and the entire aqueous solution becomes transparent. ing.
In the present invention, this clouding temperature is called a cloud point, and a 2% by weight aqueous solution of the nonionic surfactant (A) has a cloud point of 35 to 95 ° C. When the clouding point of the 2% by weight aqueous solution of (A) is less than 35 ° C., the nonionic surfactant is used at the time of dilution washing or rinsing after washing even if the polymer type anionic surfactant (B) is used in combination. Since the agent (A) is precipitated, the substrate is contaminated and the cleaning properties of the abrasive grains are deteriorated.

The cloud point in the present invention is measured by the following operation using a 2% by weight nonionic surfactant (A) aqueous solution as a test solution.
(1) First, 10 cm ³ of the test solution is put into a 30 cm ³ test tube.
(2) Put a test tube in a 25 ° C. hot tub and raise the temperature of the test solution at a rate of 1 ° C./5 seconds while manually stirring the test solution using a glass rod-shaped thermometer.
(3) Read the temperature at which it becomes cloudy even after stirring.
(4) Remove the test tube from the hot tub and gradually lower the temperature while stirring the test solution with a stirring bar in an atmosphere of 25 ° C.
(6) The above (2) to (4) are repeated twice, and the average value of the temperatures read in (3) is taken as the cloud point.

The nonionic surfactant (A) of the present invention includes an alkylene oxide adduct (A1) of an aliphatic alcohol having 8 to 24 carbon atoms, an alkylene oxide adduct (A2) of a fatty acid having 8 to 24 carbon atoms, and a carbon number. An alkylene oxide adduct (A3) of an aliphatic alkylamine having 8 to 24, an alkylene oxide adduct (A4) of a phenolic hydroxyl group-containing compound having 6 to 46 carbon atoms and a polyoxypropylene glycol ethylene oxide adduct (A5). Among the nonionic surfactants selected from the group, a nonionic surfactant having a cloud point of 35 to 95 ° C. in a 2% by weight aqueous solution can be mentioned.

The alkylene oxide adduct (A1) of an aliphatic alcohol having 8 to 24 carbon atoms can be obtained by adding an alkylene oxide to an aliphatic alcohol having 8 to 24 carbon atoms.
Examples of the aliphatic alcohol having 8 to 24 carbon atoms include octyl alcohol, decyl alcohol, dodecyl alcohol, tridecyl alcohol, tetradecyl alcohol, octadecyl alcohol, octadecenyl alcohol and tetracosyl alcohol.

Examples of the alkylene oxide include alkylene oxides having 2 to 4 carbon atoms [ethylene oxide (hereinafter abbreviated as EO), propylene oxide (hereinafter abbreviated as PO) and butylene oxide]. Of these, EO and PO are preferable from the viewpoint of detergency, and EO is more preferable. Two or more types of alkylene oxides may be used in combination, and the addition form in the case of using two or more types may be block addition or random addition, and block addition is preferred.
The average added mole number of alkylene oxide is preferably 1 to 50 moles, more preferably 1 to 20 moles from the viewpoint of detergency.

As (A1), dodecyl alcohol EO adduct (average addition mole number = 4 to 18), isotridecyl alcohol EO adduct (average addition mole number = 4 to 18), isotridecyl alcohol PO (average addition mole number) = 1-5) EO adduct (average added mole number = 4-18), hexadecyl alcohol EO adduct (average added mole number = 4-18), hexadecyl alcohol PO (average added mole number = 1-5) EO adduct (average addition mole number = 4-18), octadecyl alcohol EO adduct (average addition mole number = 4-18), etc. are mentioned.

The fatty acid alkylene oxide adduct (A2) can be obtained by adding alkylene oxide to a fatty acid having 8 to 24 carbon atoms.
Examples of the fatty acid having 8 to 24 carbon atoms include octanoic acid, decanoic acid, dodecanoic acid, tetradecanoic acid, octadecanoic acid, octadecenoic acid, eicosanoic acid, and tetracosanoic acid.

Examples of the alkylene oxide include alkylene oxides in the alkylene oxide adduct (A1), and preferred ranges are also the same.

  As (A2), dodecanoic acid EO adduct (average addition mole number = 4 to 18), octadecanoic acid EO adduct (average addition mole number = 4 to 18) and tetracosanoic acid EO adduct (average addition mole number = 4). To 18) and the like.

The alkylene oxide adduct (A3) of an aliphatic alkylamine having 8 to 24 carbon atoms can be obtained by adding an alkylene oxide to an aliphatic alkylamine having 8 to 24 carbon atoms.
Examples of the aliphatic alkyl amine having 8 to 24 carbon atoms include octylamine, decylamine, dodecylamine, tetradecylamine, hexadecylamine, octadecylamine, octadecenylamine and tetracosylamine.

Examples of the alkylene oxide include alkylene oxides in the alkylene oxide adduct (A1), and preferred ranges are also the same.

As (A3), dodecylamine EO adduct (average added mole number = 4 to 18), dodecylamine PO (average added mole number = 1 to 5) EO adduct (average added mole number = 4 to 18), hexa Decylamine EO adduct (average addition moles = 4-18), octadecylamine EO adduct (average addition moles = 4-18), octadecenylamine EO adduct (average addition moles = 4-18) and Tetracosylamine EO adduct (average number of added moles = 4 to 18) and the like.

The alkylene oxide adduct (A4) of a phenolic hydroxyl group-containing compound having 6 to 46 carbon atoms can be obtained by adding an alkylene oxide to a phenolic hydroxyl group-containing compound having 6 to 46 carbon atoms.
Examples of the phenolic hydroxyl group-containing compound having 6 to 46 carbon atoms include phenol, cresol, cumylphenol, bisphenol A, novolak, benzylated phenol, styrenated phenol, styrenated cresol, styrenated cumylphenol, styrenated novolak, and octylphenol. And nonylphenol.

Examples of (A4) include styrenated phenol (degree of styrenation = 1 to 3) EO adduct (average added mole number = 4 to 18), cumylphenol EO adduct (average added mole number = 4 to 18), and the like. Can be mentioned.

The polyoxypropylene glycol ethylene oxide adduct (A5) can be obtained by adding ethylene oxide to polyoxypropylene glycol. Specifically, polyoxypropylene glycol (average added mole number = 10 to 100) ethylene oxide adduct (average added mole number = 10 to 200) and the like can be mentioned.
Of these, the alkylene oxide adduct (A1) of aliphatic alcohol is preferred from the viewpoint of detergency against abrasive grains at high temperatures.

As is well known, the alkylene oxide adducts of (A1) to (A5) are mixtures of alkylene oxide adducts having different numbers of moles of alkylene oxide addition, and each alkylene oxide that is a component depending on the type and number of moles of alkylene oxide added. The adduct has a different HLB value. That is, the nonionic surfactant (A) of the present invention is a mixture of alkylene oxide adducts having different HLB values.

Here, “HLB” is an index indicating the balance between hydrophilicity and lipophilicity, and is described, for example, in “Introduction to Surfactants” (published by Sanyo Chemical Industries, Ltd., 2007, Takehiko Fujimoto), page 212. By the Oda method, it can be calculated from the ratio between the organic value and the inorganic value of the organic compound.
The organic value and the inorganic value for deriving HLB = 10 × inorganic / organic HLB can be calculated by using the values in the table described in “Introduction of Surfactant” on page 213.

The alkylene oxide adducts of (A1) to (A5) are mixtures in which alkylene oxide adducts having different HLB values are mixed at various contents. In the present invention, each HLB value of the alkylene oxide adduct and its molar content are included. The arithmetic average value considering the rate is defined as the molar average HLB value.
The nonionic surfactant (A) in the electronic material cleaning agent of the present invention is an alkylene oxide adduct of an aliphatic alcohol (A1) from the viewpoint of high-temperature cleaning properties, and the molar average HLB value described above. Is more preferably 12.0 to 16.0.

In (A1), the total molar content of the alkylene oxide adduct having an HLB value of 7.0 or less contained in (A1) is preferably 10 mol% or less from the viewpoint of detergency at high temperatures.

Here, in the alkylene oxide adduct (A1) of the aliphatic alcohol having a molecular weight distribution, the molar content of the alkylene oxide adduct of the aliphatic alcohol of each HLB value is high-performance liquid chromatography even if it is an unknown sample. It can be determined by time-of-flight mass spectrometry (LC-TOF / MS) and high performance liquid chromatography (HPLC).
Specifically, first, the molecular weight of the component contained in the alkylene oxide adduct (A1) is identified by LC-TOF / MS, and converted into the aforementioned HLB value for each alkylene oxide adduct of the identified aliphatic alcohol. To do. Next, the peak area and total peak area of each component are calculated by HPLC.
Therefore, the molar content of the alkylene oxide adduct of the aliphatic alcohol having an HLB of 7.0 or less is the sum of the peak areas and the total peaks of the respective components of the alkylene oxide adduct of the aliphatic alcohol having an HLB of 7.0 or less. It can be calculated from the area ratio.

The content of the nonionic surfactant (A) having a cloud point of 35 to 95 ° C. in a 2% by weight aqueous solution of the electronic material cleaning agent of the present invention is usually 0.01 to 10% by weight, preferably 0.1 to 0.1%. 5% by weight.
Moreover, when using the cleaning agent for electronic materials of the present invention, it may be further diluted with water and used as a cleaning solution. The content of the nonionic active agent (A) at the time of use is 0.001 to 1% by weight based on the weight of the cleaning liquid, and more preferably 0.005 to 0.5% by weight from the viewpoint of detergency. .

The second essential component of the electronic material cleaning agent of the present invention contains both an aromatic ring and a sulfonic acid group in the molecule, and has a weight average molecular weight (hereinafter abbreviated as Mw) of 1,000 to 100,000. This is a polymer type anionic surfactant (B). Mw can be measured by gel permeation chromatography (GPC).

  In the present invention, Mw is measured by GPC at 40 ° C. using polyethylene oxide as a reference substance. [For example, apparatus main body: HLC-8120 (manufactured by Tosoh Corporation), column: TSKgel α6000, G3000 PWXL, manufactured by Tosoh Corporation, detector: differential refractometer detector built in apparatus main body, eluent: 0.5% sodium acetate Water / methanol (volume ratio 70/30), eluent flow rate: 1.0 ml / min, column temperature: 40 ° C., sample: 0.25% eluent solution, injection amount: 200 μl, standard substance: Tosoh Corporation ) TSK STANDARD POLYETHYLENE OXIDE, data processing software: GPC-8020 model II (manufactured by Tosoh Corporation)].

  Examples of the polymer type anionic surfactant (B) in the present invention include naphthalene sulfonic acid formalin condensate, polystyrene sulfonic acid and salts thereof.

Examples of the type of counter cation of the salt (B) include sodium cation, potassium cation and amine cation. These may be used alone or in combination of two or more.

In addition, as the salt of (B), for example, a sodium salt of polystyrene sulfonic acid may be blended from the beginning as the salt, or by further blending polystyrene sulfonic acid in the system with an alkali such as sodium hydroxide. Salts may be formed in the cleaning solution.

The content of (B) in the electronic material cleaning agent of the present invention is 0.01 to 10% by weight, preferably 0.1 to 5% by weight, based on the weight of the cleaning agent.
Further, the electronic material cleaning agent of the present invention may be further diluted with water when used, and the content of (B) at the time of use is 0.001 to 1% by weight based on the weight of the cleaning solution. From the viewpoint of detergency, it is more preferably 0.005 to 0.5% by weight.

  The weight ratio of the content of (B) to the content of (A) in the electronic material cleaning agent of the present invention is 0.01 to 100, preferably 0.5 to 10 from the viewpoint of detergency.

Examples of water that is another essential component of the electronic material cleaning agent of the present invention include ultrapure water, ion-exchanged water, RO water, and distilled water. Ultrapure water is preferable from the viewpoint of cleanliness.

The detergent for electronic materials of the present invention contains a nonionic surfactant (A) and a polymer type anionic surfactant (B), so that a 2% by weight aqueous solution has a cloud point of 50 to 95 ° C. . When using the cleaning agent of the present invention under high temperature conditions, the nonionic surfactant (A) can be cleaned without precipitating, so that it is excellent in abrasive cleaning properties, and particles of nonionic surfactant are derived. Occurrence can be suppressed.

The electronic material cleaning agent of the present invention preferably contains a chelating agent (C) in order to improve cleaning properties.

Examples of the chelating agent (C) include aminopolycarboxylic acids (for example, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, etc.), hydroxycarboxylic acids (for example, tartaric acid, citric acid, gluconic acid, gallic acid, etc.), phosphonic acids (for example, 1 -Hydroxyethylidene-1,1-diphosphonic acid, nitrilotrismethylenephosphonic acid and the like) and condensed phosphoric acid (for example, tripolyphosphoric acid and the like); and salts thereof. Two or more chelating agents of the present invention may be used in combination.
Among these, 1-hydroxyethylidene-1, 1-diphosphonic acid, diethylenetriaminepentaacetic acid and salts thereof are preferable from the viewpoint of detergency.

The content of the chelating agent (C) in the electronic material cleaning agent of the present invention at the time of use is 0.001 to 5% by weight based on the weight of the cleaning liquid at the time of use, and is preferably 0 from the viewpoint of detergency. 0.01 to 0.5% by weight.

The electronic material cleaning agent of the present invention may further contain an alkali component in addition to the above-described (A), (B), and (C).
Examples of the alkali component include inorganic alkalis such as sodium hydroxide and potassium hydroxide; amines such as diethanolamine, isopropanolamine, monoethanolamine and 2-aminoethyl-ethanolamine.
From the viewpoint of detergency, the pH during use of the electronic material cleaner of the present invention is preferably 7 to 12, and more preferably 8 to 11. When the pH of the cleaning liquid is alkaline, there is a problem that the solubility of the nonionic active agent is lowered.

Another embodiment of the present invention is a method for producing an electronic material including a step of cleaning the electronic material after the polishing step under a high temperature condition of 50 to 80 ° C., using the electronic material cleaning agent, Suitable for manufacturing method of magnetic disk substrate.
However, the present invention is not limited to a magnetic disk substrate, and is widely useful in the manufacture of electronic materials as long as it is the manufacture of electronic materials that require the removal of abrasive slurry and polishing debris.

  When the electronic material cleaning agent of the present invention is used in the production of a magnetic disk substrate, it can be used after the first stage polishing or the second stage polishing in the substrate process, or in the media process, and the media process is particularly preferable. .

Hereinafter, although an example and a comparative example explain the present invention further, the present invention is not limited to these. Hereinafter, unless otherwise specified, “%” represents “% by weight” and “parts” represents “parts by weight”.

[Production Example 1]
In a stainless steel pressure-resistant reaction vessel equipped with a stirrer and a temperature controller, 240 parts (1.1 mol parts) of 7-tetradecanol and 10 parts (0.027 mol parts) of a 25% aqueous solution of tetramethylammonium hydroxide And dehydrated for 30 minutes at 100 ° C. under reduced pressure of −0.08 MPaG or less. 630 parts (14.3 mole parts) of ethylene oxide was added dropwise over 3 hours while controlling the reaction temperature at 100 ° C., and then aged at 100 ° C. for 3 hours. Furthermore, the mixture was stirred at 150 ° C. for 2 hours under a reduced pressure of −0.08 MPaG or less, and the remaining tetramethylammonium hydroxide was thermally decomposed and removed under reduced pressure to obtain the nonionic surfactant (A-1) of the present invention. 870 parts were obtained.
(Cloud point: 80 ° C., average HLB value: 14.5, molar content of ethylene oxide adduct of 7-tetradecanol having HLB of 7.0 or less: 2 mol%)

[Production Example 2]
270 parts (1.0 mole part) of oleyl alcohol and 10 parts (0.027 mole part) of a 25% aqueous solution of tetramethylammonium hydroxide are charged into a stainless steel pressure-resistant reaction vessel equipped with a stirrer and a temperature controller. Dehydration was performed at 100 ° C. under a reduced pressure of −0.08 MPaG for 30 minutes. 220 parts (5.0 mole parts) of ethylene oxide was added dropwise over 3 hours while controlling the reaction temperature at 100 ° C., and then aged at 100 ° C. for 3 hours.
Then, 10 parts (0.027 mol part) of a 25% aqueous solution of tetramethylammonium hydroxide was charged and dehydrated for 30 minutes at 100 ° C. under reduced pressure of −0.08 MPaG or less. 90 parts (1.5 mole parts) of propylene oxide was dropped over 3 hours while controlling the reaction temperature at 100 ° C., and then aged at 100 ° C. for 3 hours.
Subsequently, 10 parts (0.027 mol part) of a 25% aqueous solution of tetramethylammonium hydroxide was charged and dehydrated for 30 minutes at 100 ° C. under reduced pressure of 4 kPa or less. 90 parts (5.0 mole parts) of ethylene oxide was added dropwise over 3 hours while controlling the reaction temperature at 100 ° C., and then aged at 100 ° C. for 3 hours. Further, the mixture was stirred at 150 ° C. for 2 hours under a reduced pressure of −0.08 MPaG or less, and the remaining tetramethylammonium hydroxide was thermally decomposed and removed under reduced pressure to obtain the nonionic surfactant (A-2 of the present invention). ) 800 parts were obtained.
(Cloud point: 73 ° C., average HLB value: 13.4, molar content of ethylene oxide adduct of oleyl alcohol having an HLB of 7.0 or less: 8 mol%)

[Production Example 3]
In a stainless steel pressure-resistant reaction vessel equipped with a stirrer and a temperature controller, 240 parts (1.1 mol parts) of 7-tetradecanol and 10 parts (0.027 mol parts) of a 25% aqueous solution of tetramethylammonium hydroxide And dehydrated for 30 minutes at 100 ° C. under reduced pressure of −0.08 MPaG or less. 130 parts (3.0 mole parts) of ethylene oxide was added dropwise over 3 hours while controlling the reaction temperature at 100 ° C., and then aged at 100 ° C. for 3 hours. Further, the mixture was stirred for 2 hours at 150 ° C. under a reduced pressure of −0.08 MPaG or less, and the remaining tetramethylammonium hydroxide was thermally decomposed and removed under reduced pressure to obtain the nonionic surfactant (A-3 of the present invention). ) 370 parts were obtained.
(Cloud point: 35 ° C., average HLB value: 10.5, molar content of ethylene oxide adduct of 7-tetradecanol having an HLB of 7.0 or less: 12 mol%)

[Production Example 4]
In a stainless steel pressure-resistant reaction vessel equipped with a stirrer and a temperature controller, 240 parts (1.1 mol parts) of 7-tetradecanol and 10 parts (0.027 mol parts) of a 25% aqueous solution of tetramethylammonium hydroxide And dehydrated for 30 minutes at 100 ° C. under reduced pressure of −0.08 MPaG or less. 570 parts (13.0 mol parts) of ethylene oxide was added dropwise over 3 hours while controlling the reaction temperature at 100 ° C., and then aged at 100 ° C. for 3 hours. Furthermore, the mixture was stirred at 150 ° C. for 2 hours under a reduced pressure of −0.08 MPaG or less, and the remaining tetramethylammonium hydroxide was thermally decomposed and removed under reduced pressure, whereby the nonionic surfactant (A-4) of the present invention was removed. ) 810 parts were obtained.
(Cloud point: 95 ° C., average HLB value: 16.0, molar content of ethylene oxide adduct of 7-tetradecanol having an HLB of 7.0 or less: 1 mol%)

[Production Example 5]
270 parts (1.0 mole part) of oleyl alcohol and 10 parts (0.027 mole part) of a 25% aqueous solution of tetramethylammonium hydroxide are charged into a stainless steel pressure-resistant reaction vessel equipped with a stirring device and a temperature control device. And dehydration for 30 minutes under a reduced pressure of −0.08 MPaG or less at 100 ° C. 170 parts (3.9 mole parts) of ethylene oxide was added dropwise over 3 hours while controlling the reaction temperature at 100 ° C., and then aged at 100 ° C. for 3 hours. Further, the mixture was stirred at 150 ° C. for 2 hours under a reduced pressure of −0.08 MPaG or less, and the remaining tetramethylammonium hydroxide was thermally decomposed and removed under reduced pressure to obtain the nonionic surfactant (A-5 of the present invention). ) 440 parts were obtained.
(Cloud point: 60 ° C., average HLB value: 12.0, mole content of ethylene oxide adduct of oleyl alcohol having HLB of 7.0 or less: 10 mol%)

[Production Example 6]
A reaction vessel with stirring was charged with 21 parts of naphthalenesulfonic acid and 10 parts of ultrapure water, and 8 parts of 37% formaldehyde was added dropwise over 3 hours while maintaining the temperature in the system at 80 ° C. with stirring.
After completion of the dropwise addition, the temperature was raised to 105 ° C. and reacted for 25 hours, and then cooled to room temperature and sodium hydroxide was gradually added while adjusting to 25 ° C. in a water bath to adjust the pH to 6.5. Ultrapure water was added to adjust the solid content to 40% to obtain a 40% aqueous solution (B-1) of a sodium salt of a naphthalenesulfonic acid formalin condensate which is a polymer type anionic surfactant of the present invention. In addition, the weight average molecular weight of (B-1) was 5,000.

[Production Example 7]
100 parts of ultrapure water was charged into a reaction vessel capable of temperature adjustment and stirring, and after nitrogen substitution, the temperature was raised to 90 ° C. Under stirring, 800 parts of a 25% aqueous solution of sodium styrenesulfonate and 40 parts of a 1% by weight aqueous solution of 4,4′-azobis (4-cyanopentanoic sodium) were simultaneously added dropwise over 3.5 hours. After completion of dropping, the mixture was stirred at 90 ° C. for 5 hours.
By adjusting to a concentration of 40% with ultrapure water, a 40% aqueous solution (B-2) of polystyrene sulfonate sodium salt, which is a polymer type anionic surfactant of the present invention, was obtained. In addition, the weight average molecular weight of (B-2) was 50,000.

[Comparative Production Example 1]
Except changing 220 parts of ethylene oxide to 130 parts (3 mol), it carried out similarly to manufacture example 2, and obtained the nonionic surfactant (A'-1) for a comparison.
(Cloud point: 33 ° C., average HLB value: 12.5, molar content of ethylene oxide adduct of oleyl alcohol having HLB of 7.0 or less: 8 mol%)

[Comparative Production Example 2]
A reaction vessel capable of temperature adjustment and stirring was charged with 300 parts of isopropyl alcohol and 100 parts of ultrapure water, and the temperature was raised to 75 ° C. after purging with nitrogen. Under stirring, 407 parts of a 75% aqueous solution of acrylic acid and 95 parts of a 15% isopropyl alcohol solution of dimethyl-2,2′-azobisisobutyrate were simultaneously added dropwise over 3.5 hours. After completion of the dropwise addition, the mixture was stirred at 75 ° C. for 5 hours, and then ultrapure water was intermittently added so that the system did not solidify, and the mixture of water and isopropyl alcohol was distilled off until isopropyl alcohol could not be detected.
About 120 parts of sodium hydroxide was added to the obtained polyacrylic acid aqueous solution, neutralized until the pH became 7.0, and adjusted to a concentration of 40% with ultrapure water, whereby an anion for comparison was used. A 40% aqueous solution (B′-1) of polycarboxylic acid sodium salt, which is a surfactant, was obtained. The weight average molecular weight of (B′-1) was 10,000.

Commercially available reagents were used for the chelating agent (C) and the alkali component in Table 1.

Examples 1-7 and Comparative Examples 1-4
Each component was blended so as to have the composition shown in Table 1, and stirred at 25 ° C. with a magnetic stirrer at 40 rpm for 20 minutes to obtain the cleaning agent of the present invention and the cleaning agent for comparison.
The cleaning agent was further diluted 50 times with ultrapure water to prepare a sample solution for performance test.

Various performance evaluation tests of the stability of the cleaning agent at high temperatures and the cleaning properties at high temperatures were performed by the following methods.
This evaluation was conducted in a clean room of class 1,000 (FED-STD-209D, US Federal Standard, 1988) to prevent contamination from the atmosphere.

<Stability test at high temperature>
The stability test at a high temperature is a test for confirming whether the sample solution does not generate an insolubilized material under a high temperature condition, and was performed by the following method.
The sample solution was placed in a 100 mL glass bottle and the temperature was adjusted to 80 ° C.
Light was applied to the sample solution after temperature adjustment with a laser pointer, and the way of the light was visually observed.
The light streak is not visible when it is completely dissolved, but when there is an insolubilized material, the light is reflected on the insolubilized material and the Tyndall phenomenon is visible where the light streak is visible. Can be evaluated.
In an actual cleaning tank, the temperature may be locally higher than the set temperature, so the test was evaluated at a temperature higher than the actual cleaning temperature.
The stability test at a high temperature was determined according to the following criteria, and the determination results are shown in Table 1.

[Criteria for stability testing]
3: No Tyndall phenomenon is observed.
2: Tyndall phenomenon is slightly observed.
1: Tyndall phenomenon is clearly seen.

<Detergency test at high temperature>
A commercially available colloidal silica (“COMPOL80” particle size of about 80 nm manufactured by Fujimi Incorporated) as a polishing agent was used to polish a 3.5-inch Ni—P plated aluminum substrate for a magnetic disk under the following conditions.
Polishing device: “NFD-4BL” manufactured by Nano Factor Co., Ltd.
Slurry supply rate: 50 mL / min Load: 30 g / cm ²
Rotation speed: surface plate 30rpm, gear 20rpm
Polishing time: 5 minutes

After polishing the substrate, the surface was washed with running water for 1 minute with ultrapure water, blown with nitrogen and dried to prepare a contaminated substrate.
1,000 parts of each of the prepared sample solutions was put in a glass beaker and temperature-controlled at 60 ° C. The above-mentioned contaminated substrate was immersed in a beaker containing a sample solution, and washed with an ultrasonic cleaner (200 kHz) at 50 ° C. for 5 minutes. After cleaning, the substrate was taken out, rinsed with running water for 1 minute with ultrapure water, then blown with nitrogen gas and dried to obtain an evaluation substrate.
A surface inspection device that illuminates the surface of the Ni-P plated aluminum substrate for a magnetic disk and amplifies and detects the reflected light impinging on a foreign substance of about 10 μm or more (“Micro-Max VMX-” manufactured by Vision Cytec Co., Ltd.) 7100 ") and the number of abrasive grains adhering to a 1 cm square on the substrate was counted using image analysis software" Sigmascan ".
Moreover, it tested similarly with the ultrapure water as a blank instead of a sample liquid.
At that time, the number of adhered foreign matters such as blank abrasive grains was 720.
The cleanability test at a high temperature was determined according to the following criteria, and the determination results are shown in Table 1.

[Judgment criteria for detergency test]
5: Adhesion number is less than 1/100 of blank 4: Adhesion number is 1/100 or more and less than 1/20 of blank 3: Adhesion number is 1/20 or more and less than 1/5 of blank 2: Adhesion number is 1 / of blank 5 or more and less than 1/2: Number of adhesion is 1/2 or more of blank

From Table 1, Example 1 containing both a nonionic surfactant (A) having a cloud point of 35 to 95 ° C. and a polymeric anionic surfactant (B) having an aromatic ring and a sulfonic acid group in the molecule. The cleaning agent of ~ 7 is excellent in stability at high temperature. The cleaning agents of Examples 2 to 7 have a high cloud point although the pH is alkaline. Moreover, the washing | cleaning property in the high temperature of the cleaning agent of Examples 1-7 is high, and especially the cleaning agent of Examples 2-7 whose pH is alkaline is high. Among them, Examples 2 to 4 and 6 to 7 in which the HLB of the nonionic surfactant is 12.0 to 16.0 among the detergents of Examples 2 to 7 having an alkaline pH are evaluated at high temperature. Examples 4 and 6, which are high and have a low distribution of HLB = 7.0 or less, are particularly high.

On the other hand, the cleaning agents of Comparative Examples 1 to 3 that do not contain the polymer anionic surfactant (B) have low stability at high temperatures and low cleaning properties at high temperatures. In particular, the cleaning agents of Comparative Examples 2 and 3 in which the alkaline component is further added and the pH of the cleaning agent is alkaline are further reduced in stability at high temperatures as compared with Comparative Example 1, and the cleaning properties at high temperatures are also low. .
Further, even when (B) is included, the cleaning agent of Comparative Example 4 containing a nonionic surfactant having a nonionic surfactant with a cloud point of less than 35 ° C. is somewhat improved in stability at high temperatures. It turns out that it is sufficient and the cleaning property is also poor.

The cleaning agent for electronic materials of the present invention can reduce the cleaning performance of abrasive grains on a substrate compared to conventional cleaning agents. In particular, it can be greatly reduced when cleaning at high temperatures. Therefore, it can be used as a cleaning agent for a magnetic disk substrate such as a hard disk whose recording density is increasing. In addition, the method for producing an electronic material of the present invention can be used for a magnetic disk substrate such as a hard disk that requires a particularly high cleaning level for residual particles.

Claims (8)

  Nonionic surfactant (A) having a cloud point of 35 to 95 ° C. in a 2% by weight aqueous solution, a polymer having an aromatic ring and a sulfonic acid group in the molecule and a weight average molecular weight of 1,000 to 100,000 An anionic surfactant (B) and water, wherein the clouding point of a 2% by weight aqueous solution of the electronic material cleaner is 50 to 95 ° C.   The nonionic surfactant (A) is an alkylene oxide adduct (A1) of an aliphatic alcohol having 8 to 24 carbon atoms, and its molar average HLB value is 12.0 to 16.0. Cleaning agent for electronic materials. The nonionic surfactant (A) is an alkylene oxide adduct (A1) of an aliphatic alcohol having 8 to 24 carbon atoms, and the total of alkylene oxide adducts having an HLB value of 7.0 or less contained in (A1) The cleaning agent for electronic materials according to claim 1 or 2, wherein the molar content is 10 mol% or less.   The electronic material according to any one of claims 1 to 3, wherein the polymer type anionic surfactant (B) is at least one selected from the group consisting of naphthalene sulfonic acid formalin condensate, polystyrene sulfonic acid and salts thereof. Cleaning agent.   Furthermore, the cleaning agent for electronic materials in any one of Claims 1-4 containing a chelating agent (C).   The electronic material cleaning agent according to any one of claims 1 to 5, wherein the electronic material is a magnetic disk substrate.   The manufacturing method of an electronic material including the process of wash | cleaning an electronic material on 50-80 degreeC conditions using the cleaning agent for electronic materials in any one of Claims 1-6.   The method of manufacturing an electronic material according to claim 7, wherein the electronic material is a magnetic disk substrate.