JP5575420B2 - Magnetic disk substrate cleaning agent - Google Patents

Description

  The present invention relates to a magnetic disk substrate cleaning agent.

In the magnetic disk substrate cleaning technology, with the recent increase in recording density of magnetic disks, the minute amount of particles and impurities remaining on the substrate at the time of manufacture greatly affect the performance and yield of the magnetic disk. It has become extremely important. In particular, since the particles to be cleaned are becoming finer and more easily adhere to the interface and remain more than before, it is urgently necessary to establish an advanced cleaning technique.
For this reason, as a method for preventing contamination by these particles, a method for improving particle removability using a surfactant has been proposed (Patent Documents 1 and 2).

JP 11-43791 A Japanese Patent Laid-Open No. 2002-212597

However, in recent years, among magnetic disk substrates, particularly aluminum substrates, a step of applying a Ni-P plating, which is a nonmagnetic layer, to a surface of the substrate, followed by polishing with alumina slurry and / or colloidal silica and mirror finishing, and thereafter There is a step of texturing the substrate surface using diamond slurry if necessary, but there is a problem that these abrasives and polishing debris adhere firmly to the substrate surface and cannot be removed sufficiently by the cleaning step. . Since particles such as these abrasives and polishing debris are firmly attached to the substrate surface, in order to remove them sufficiently, the substrate surface is slightly etched, and the particles are dispersed in the liquid. Furthermore, it is necessary to prevent particles dispersed in the liquid from reattaching to the substrate surface. However, in the above-mentioned Patent Document-1, the surface tension of a 10 vol% aqueous solution is 30 dyne / cm, which contains an aggregating agent and a surfactant having an adsorption amount to an abrasive of 5 mg / m ² or more and a number average molecular weight of 100,000 or more. A method for preventing re-adhesion by aggregating and coarsening abrasive fine particles to be cleaned using the following cleaning composition has been proposed, but the coarse particles slightly adhere to the substrate surface. However, there is no possibility that serious problems may be caused, and there is no description about the specific composition of ingredients. Moreover, although the method proposed in the above-mentioned Patent Document-2 can improve the effect of preventing the reattachment of particles to some extent by using an anionic surfactant, there is almost no etching property, so the particle removability is insufficient. There was a problem that the cleaning property was insufficient.

  Therefore, the object of the present invention is to have an appropriate etching property without impairing the flatness of the surface of the magnetic disk substrate and also to have a good dispersibility of particles detached from the substrate surface, realizing an excellent particle removability. Another object of the present invention is to provide a magnetic disk substrate cleaning agent that enables highly efficient high-level cleaning that can improve the yield rate during manufacturing and can be cleaned in a short time.

  As a result of intensive investigations to obtain a magnetic disk substrate cleaning agent that solves the above problems, the present inventors have found that by including a specific chelating agent in the cleaning agent, the particle removability is remarkably improved. The invention has been reached.

  That is, the present invention includes a magnetic disk substrate cleaning agent comprising a chelating agent (A) having at least four phosphonic acid groups in the molecule, the magnetic disk substrate cleaning agent, and an active ingredient concentration of 0. .01-15 wt% cleaning liquid for magnetic disk substrate, magnetic disk substrate cleaning method for cleaning magnetic disk substrate using the cleaning liquid, and manufacturing of magnetic disk substrate including a step of cleaning the magnetic disk substrate by the cleaning method Is the method.

  The cleaning agent of the present invention is excellent in the cleaning performance of fine particles which are a problem in the manufacturing process of the magnetic disk, and has an effect that the cleaning can be efficiently performed in a short time without damaging the substrate.

  As the chelating agent (A) having at least 4 phosphonic acid groups in the molecule used in the cleaning agent of the present invention, a low molecular compound (A-1) {ethylenediaminetetra ( Methylenephosphonic acid) (salt), hexamethylenediaminetetra (methylenephosphonic acid) (salt), propylenediaminetetra (methylenephosphonic acid) (salt), cis-1,2-cyclohexanediaminetetra (methylenephosphonic acid) (salt) , Trans-1,2-cyclohexanediaminetetra (methylenephosphonic acid) (salt) and glycol etherdiaminetetra (methylenephosphonic acid) (salt), etc.}; low molecular weight compounds having five phosphonic acid groups in the molecule (A -2) {Diethylenetriaminepenta (methylenephosphonic acid) (salt), 3,3'-diaminodip Pyramine penta (methylenephosphonic acid) (salt), bis (hexamethylene) triaminepenta (methylenephosphonic acid) (salt), etc.}; low molecular weight compound having six phosphonic acid groups in the molecule (A-3) { Triethylenetetramine hexa (methylenephosphonic acid) (salt), tris (2-aminoethyl) amine hexa (methylenephosphonic acid) (salt), tris (2-aminopropyl) amine hexa (methylenephosphonic acid) (salt), etc.}; molecule Low molecular weight compound having 7 or more phosphonic acid groups (A-4) {tetraethylenepentamine hepta (methylenephosphonic acid) (salt), pentaethylenehexamineocta (methylenephosphonic acid) (salt) and hexamethylenetetramine Octa (methylene phosphonic acid) (salt), etc.}.

  Among these, by having an appropriate etching property without impairing the flatness of the Ni-P plated substrate or glass substrate, it exhibits an excellent effect of preventing the reattachment of fine particles, and is also rinsed From the viewpoint of excellent rinsability at the time, (A-1), (A-2) and (A-3) are preferable, and ethylenediaminetetra (methylenephosphonic acid) (salt), cis-1, 2-cyclohexanediaminetetra (methylenephosphonic acid) (salt), trans-1,2-cyclohexanediaminetetra (methylenephosphonic acid) (salt), diethylenetriaminepenta (methylenephosphonic acid) (salt) and triethylenetetraminehexa (methylenephosphone) Acid) (salt), particularly preferred are ethylenediaminetetra (methylenephosphonic acid) (salt) and di A Chi triamine penta (methylene phosphonic acid) (salt).

  When the chelating agent (A) forms a salt, the salt is not particularly limited. For example, primary amines of acids exemplified as the above (A) (alkylamines such as methylamine, ethylamine and butylamine, mono Ethanolamine and guanidine etc.) salt, secondary amine (dialkylamine such as dimethylamine, diethylamine and dibutylamine and diethanolamine etc.) salt, tertiary amine {trialkylamine such as trimethylamine, triethylamine and tributylamine, triethanolamine, N -Methyldiethanolamine and 1,4-diazabicyclo [2.2.2] octane (hereinafter abbreviated as DABCO) etc.} salt, amidine {1,8-diazabicyclo [5.4.0] -7-undecene (hereinafter DBU) Abbreviation) and 1,5-diazabishi [4.3.0] -5-nonene (hereinafter abbreviated as DBN), 1H-imidazole, 2-methyl-1H-imidazole, 2-ethyl-1H-imidazole, 4,5-dihydro-1H-imidazole, 2-methyl-4,5-dihydro-1H-imidazole, 1,4,5,6-tetrahydro-pyrimidine, 1,6 (4) -dihydropyrimidine etc.} salt, alkali metal (sodium cation and potassium cation etc.) salt , Ammonium salts and quaternary ammonium (tetraalkylammonium etc.) salts.

  The chelating agent (A) of the present invention may be used alone or in combination of two or more. Moreover, (A) has the feature that the rinse property at the time of the rinse after washing | cleaning is very excellent by having four or more phosphonic acid groups in a molecule | numerator.

  From the viewpoint of detergency, the cleaning agent of the present invention preferably contains a surfactant (B) in addition to the chelating agent (A). When (B) is contained, cleaning properties such as particle re-adhesion prevention properties are further improved.

  (B) includes nonionic surfactant (B-1), anionic surfactant (B-2), cationic surfactant (B-3) and amphoteric surfactant (B-4). Can be mentioned.

  Examples of the nonionic surfactant (B-1) include alkylene oxides [ethylene oxide, 1,2- or 1,3-propylene oxide and 1,2-, 1,3-, 2,3- or 1,4. -Butylene oxide and the like: hereinafter abbreviated as AO] addition type nonionic surfactant (B-1a), polyhydric alcohol type nonionic surfactant (B-1b) and the like.

(B-1a) includes higher alcohol (8 to 18 carbon atoms) AO adduct (1 to 30 moles added per active hydrogen), alkyl (1 to 12 carbon atoms) phenol AO adduct (active hydrogen) Addition mole number per 1 to 30), fatty acid (carbon number 8 to 18) AO adduct (addition mole number 1 to 30 per active hydrogen), aliphatic amine (carbon number 6 to 24) AO Adduct (number of moles added per active hydrogen 1-30), polypropylene glycol (average molecular weight 200-6,000 based on hydroxyl value) AO adduct (number of moles added per active hydrogen 1-500; Polyoxyethylene polyoxypropylene glycol), polyoxyethylene (1-30 added moles per active hydrogen) alkyl (1-20 carbon atoms) allyl ether and sorbitan mono Fatty acids of polyhydric (2 to 8 or more) alcohols (2 to 30 carbon atoms) such as urate AO adduct (addition mole number 1 to 30) and sorbitan monooleate AO adduct (addition mole number 1 to 30) (C8-C24) ester AO adduct (addition mole number per active hydrogen 1-30) etc. are mentioned.

  As (B-1b), fatty acid (carbon) of polyvalent (2 to 8 or more) alcohols (2 to 30 or more carbon atoms) such as glycerol monostearate, glycerol monooleate, sorbitan monolaurate and sorbitan monooleate 8-24) Esters and fatty acid alkanolamides such as lauric acid monoethanolamide and lauric acid diethanolamide.

  Of (B-1), from the viewpoint of detergency, (B-1a) is preferred, and more preferred is a higher alcohol (10 to 16 carbon atoms) AO adduct (added mole per active hydrogen). 2-20), alkyl (carbon number 1-12) phenol AO adduct (2-20 added moles per active hydrogen), aliphatic amine (carbon number 8-18) AO adduct (active hydrogen) The number of moles added per unit is 2 to 20) and the polypropylene glycol (average molecular weight based on hydroxyl value 200 to 6,000) ethylene oxide adduct (the number of added moles per active hydrogen 1 to 500).

  Examples of the anionic surfactant (B-2) include a high molecular weight anionic surfactant (B-2a) and a low molecular weight anionic surfactant (B-2b).

Polymeric anionic surfactant (B-2a) includes sulfonic acid (salt) group, sulfate ester (salt) group, phosphonic acid (salt) group, phosphate ester (salt) group and carboxylic acid (salt) Having at least one group selected from the group consisting of groups and one or more repeating units other than methylene groups in the molecule, and a weight average molecular weight (hereinafter abbreviated as Mw) of 300- Examples include an anionic surfactant having 800,000 or a degree of condensation of 2 or more.
Mw in the present invention is measured at 40 ° C. using polyethylene oxide as a reference substance by gel permeation chromatography (hereinafter abbreviated as GPC). For example, apparatus body: HLC-8120 (manufactured by Tosoh Corporation), column: TSKgel α6000, G3000 PWXL, manufactured by Tosoh Corporation, detector: differential refractometer detector built in the apparatus 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 volume: 200 μl, standard substance: Tosoh Corporation It is measured with equipment and conditions such as TSK TANDARD POLYETHYLENE OXIDE, data processing software: GPC-8020 model II (manufactured by Tosoh Corporation).
In the above and the following, unless otherwise specified,% represents% by weight.
Specific examples of (B-2a) include the following.

(B-2a-1) a polymeric anionic surfactant having a sulfonic acid (salt) group:
Polystyrene sulfonic acid, styrene / styrene sulfonic acid copolymer, poly {2- (meth) acryloylamino-2,2-dimethylethanesulfonic acid}, 2- (meth) acryloylamino-2,2-dimethylethanesulfonic acid / Styrene copolymer, 2- (meth) acryloylamino-2,2-dimethylethanesulfonic acid / acrylamide copolymer, 2- (meth) acryloylamino-2,2-dimethylethanesulfonic acid / (meth) acrylic acid co Polymer, 2- (meth) acryloylamino-2,2-dimethylethanesulfonic acid / (meth) acrylic acid / acrylamide copolymer, 2- (meth) acryloylamino-2,2-dimethylethanesulfonic acid / styrene / Acrylamide copolymer and 2- (meth) acryloylamino-2,2-dimethyl ester Polymers such as ethylene sulfonic acid / styrene / (meth) acrylic acid copolymer, naphthalene sulfonic acid formaldehyde condensate, methyl naphthalene sulfonic acid formaldehyde condensate, dimethyl naphthalene sulfonic acid formaldehyde condensate, anthracene sulfonic acid formaldehyde condensate, melamine sulfone Acid formaldehyde condensates and condensates such as aniline sulfonic acid-phenol-formaldehyde condensates and salts thereof;

(B-2a-2) Polymeric anionic surfactant having a sulfate (salt) group:
Poly {2-hydroxyethyl (meth) acrylate sulfate}, 2-hydroxyethyl (meth) acrylate / 2-hydroxyethyl (meth) acrylate sulfate copolymer, sulfuric acid of poly {2-hydroxyethyl (meth) acrylate} Esterified products, polymers such as poly {(meth) acryloyloxypolyoxyalkylene sulfate} and (meth) acryloyloxypolyoxyalkylene sulfate / acrylic acid copolymers, cellulose such as cellulose, methylcellulose or ethylcellulose sulfate esterified products Derivatives and salts thereof;

(B-2a-3) Polymeric anionic surfactant having a phosphonic acid (salt) group:
Polymers such as poly {(meth) acryloyloxyethylphosphonic acid} and 2-hydroxyethyl (meth) acrylate / (meth) acryloyloxyethylphosphonic acid copolymer, naphthalenephosphonic acid formaldehyde condensate, methylnaphthalenephosphonic acid formaldehyde condensation , Dimethyl naphthalene phosphonic acid formaldehyde condensate and anthracene phosphonic acid formaldehyde condensate, condensates such as aniline phosphonic acid-phenol-formaldehyde condensate, and salts thereof;

(B-2a-4) Polymeric anionic surfactant having a phosphate ester (salt) group:
Poly {2-hydroxyethyl (meth) acrylate phosphate}, 2-hydroxyethyl (meth) acrylate / 2-hydroxyethyl (meth) acrylate phosphate copolymer, poly {2-hydroxyethyl (meth) acrylate} Phosphoric acid ester, poly {(meth) acryloyloxypolyoxyalkylene phosphoric acid ester} and (meth) acryloyloxy polyoxyalkylene phosphoric acid ester / acrylic acid copolymer, cellulose, methyl cellulose or ethyl cellulose phosphorus Cellulose derivatives such as acid esterified products and salts thereof;

(B-2a-5) Polymeric anionic surfactant having a carboxylic acid (salt) group:
Poly (meth) acrylic acid, (meth) acrylic acid-maleic acid copolymer, (meth) acrylic acid-itaconic acid copolymer, (meth) acrylic acid-fumaric acid copolymer, (meth) acrylic acid / acetic acid Polymers such as vinyl copolymer, 2-hydroxyethyl methacrylate / (meth) acrylic acid copolymer and poly {2-hydroxyethyl (meth) acrylate} carboxymethylated product, benzoic acid formaldehyde condensate and benzoic acid-phenol -Condensates such as formaldehyde condensates, cellulose derivatives such as carboxymethylcellulose, carboxymethylmethylcellulose and carboxymethylethylcellulose, and salts thereof.

  Although there is no limitation in particular as a salt in case (B-2a) forms a salt, For example, the salt which has the same counter cation as what was illustrated as a salt of the said chelating agent (A) is mentioned. Among these salts, primary amine salts, secondary amine salts, tertiary amine salts, amidine salts, ammonium salts, and quaternary ammonium salts are particularly preferable from the viewpoint of preventing metal contamination of the substrate. Preference is given to tertiary amine salts, amidine salts and quaternary ammonium salts.

When (B-2a) is a polymer or a cellulose derivative, the Mw is usually 300 to 800,000, preferably 600 to 400,000, more preferably from the viewpoint of preventing reattachment of particles and low foaming properties. Is 1,000 to 80,000, particularly preferably 2,000 to 40,000.
In the case where (B-2a) is a condensate, the degree of condensation is usually 2 to 200, more preferably 3 to 100, particularly preferably 3 to 3 from the viewpoint of preventing reattachment of particles and low foaming properties. 50.

  Examples of the low molecular weight anionic surfactant (B-2b) include a sulfonic acid surfactant (B-2b-1) having no repeating unit other than a methylene group in the molecule, and a sulfate ester surfactant (B -2b-2), fatty acid surfactants (B-2b-3), phosphate ester surfactants (B-2b-4), and the like.

  Examples of the sulfonic acid surfactant (B-2b-1) include sulfosuccinic acid mono- or diesters (salts) of alcohols having 6 to 24 carbon atoms, sulfonic oxides (salts) of α-olefins having 8 to 24 carbon atoms, Examples thereof include alkylbenzene sulfonic acid (salt) and petroleum sulfonate (salt) having an alkyl group having 8 to 14 carbon atoms.

  As the sulfate ester surfactant (B-2b-2), sulfuric acid ester (salt) of an aliphatic alcohol having 8 to 18 carbon atoms, sulfuric acid of an AO 1 to 10 mol adduct of an aliphatic alcohol having 8 to 18 carbon atoms Examples include esters (salts), sulfated oils (salts), sulfated fatty acid esters (salts), and sulfated olefins (salts).

  Examples of the fatty acid surfactant (B-2b-3) include fatty acid (salt) having 8 to 18 carbon atoms and ether carboxylic acid (salt) of an aliphatic alcohol having 8 to 18 carbon atoms.

  Examples of the phosphate ester surfactant (B-2b-4) include phosphoric acid mono- or diesters (salts) of higher alcohols having 8 to 24 carbon atoms and phosphoric acid mono- or diesters of higher alcohols having 8 to 24 carbon atoms. Diester (salt) etc. are mentioned.

  The salt when (B-2b-1), (B-2b-2), (B-2b-3) and (B-2b-4) form a salt is not particularly limited. The salt which has the counter cation similar to what was illustrated as a salt of the said chelating agent (A) is mentioned.

  Among the anionic surfactants (B-2), the polymer type anionic surfactant (B-2a) is preferable from the viewpoint of the anti-redeposition property, and the polymer type anionic surfactant (B-) is preferable. When 2a) is used, a low molecular weight sulfonic acid surfactant (B-2b-1), a sulfate ester surfactant (B-2b-2), and a fatty acid surfactant (B-) are further used as necessary. One or more selected from 2b-3) may be used in combination.

  As the cationic surfactant (B-3), a quaternary ammonium salt type surfactant (B-3a) {for example, alkyl (C1-30) trimethylammonium salt, dialkyl (C1-30) Dimethylammonium salt, nitrogen ring-containing quaternary ammonium salt, poly (addition mole number 2 to 15) oxyalkylene (carbon number 2 to 4) chain-containing quaternary ammonium salt and alkyl (carbon number 1 to 30) amidoalkyl ( C1-C10) dialkyl (C1-C4) methylammonium salt} and amine-based surfactant (B-3b) {for example, an aliphatic tertiary amine having 3 to 90 carbon atoms, 3 to 90 carbon atoms Inorganic acid salts or organic acid salts of alicyclic (including nitrogen-containing heterocycles) tertiary amines and C3-90 hydroxyalkyl group-containing tertiary amines.

  As the amphoteric surfactant (B-4), a betaine-type amphoteric surfactant (B-4a) {for example, alkyl (C1-30) dimethylbetaine, alkyl (C1-30) amide alkyl (carbon number) 1-4) Dimethylbetaine, alkyl (C1-30) dihydroxyalkyl (C1-30) betaine and sulfobetaine type}, amino acid type amphoteric surfactant (B-4b) {eg, alanine type [alkyl (C1-30) Aminopropionic acid type and alkyl (C1-30) iminodipropionic acid type] and glycine type [alkyl (C1-30) aminoacetic acid type]} and aminosulfonate type Amphoteric surfactant (B-4c) {for example, alkyl (C1-30) taurine type amphoteric surfactant} and the like.

  Among the surfactants (B), nonionic surfactants (B-1), anionic surfactants (B-2) and (B-1) are preferable from the viewpoint of preventing reattachment of particles. (B-2) is used in combination, and (B-2) is more preferred. In the case of combined use, the weight ratio {(B-1) / (B-2)} of (B-1) and (B-2) is preferably 5 or less, more preferably from the viewpoint of detergency and foamability. Is 0.001-2, particularly preferably 0.01-1.5.

The cleaning agent of the present invention may further contain an alkali component (C).
By containing the alkali component (C), the cleaning properties for particles are further improved.
(C) includes a quaternary ammonium salt (C-1) represented by the general formula (2), ammonia (C-2), an aliphatic amine having 1 to 12 carbon atoms (C-3), an inorganic alkali (C-4) and mixtures thereof are mentioned.

In the formula, R ¹ , R ² , R ³ and R ⁴ are each independently an alkyl group having 1 to 24 carbon atoms or a group represented by — (R ⁵ O) r—H, and R ⁵ is carbon. The alkylene group of number 2-4, r represents the integer of 1-6.
Examples of the alkyl group having 1 to 24 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl , Hexosyl, docosyl, tricosyl, and tetracosyl groups.
Examples of the alkylene group having 2 to 4 carbon atoms include ethylene, 1,2- or 1,3-propylene and 1,2-, 1,3-, 2,3- or 1,4-butylene. From the viewpoint of rinsing properties during rinsing, r is preferably 1 to 3.

  Specific examples of (C-1) include tetramethylammonium hydroxide, ethyltrimethylammonium hydroxide, tetraethylammonium hydroxide, triethylmethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide. Side, tetrapentylammonium hydroxide, tetrahexylammonium hydroxide, hydroxyethyltrimethylammonium hydroxide, triethylhydroxyethylammonium hydroxide, dihydroxyethyldimethylammonium hydroxide, trihydroxyethylmethylammonium hydroxide, etc. Can be mentioned.

  Examples of the aliphatic amine having 1 to 12 carbon atoms (C-3) include an alkylamine having 1 to 6 carbon atoms, an alkanolamine having 2 to 6 carbon atoms, an alkylenediamine having 2 to 5 carbon atoms, a cyclic amine, an amidine compound, and Examples thereof include poly (n = 2 to 6) alkylene (carbon number 2 to 7) poly (n = 3 to 6) amine.

  Examples of the alkylamine having 1 to 6 carbon atoms include monoalkylamines having 1 to 6 carbon atoms {methylamine, ethylamine, propylamine, isopropylamine, butylamine, hexylamine, etc.} and dialkylamines having 2 to 6 carbon atoms {dimethylamine , Ethylmethylamine, methylpropylamine, butylmethylamine, diethylamine, ethylpropylamine, diisopropylamine, etc.}.

  Examples of the alkanolamine having 2 to 6 carbon atoms include monoethanolamine, diethanolamine, triethanolamine, dimethylaminoethanol, diethylaminoethanol, N-methyl-diethanolamine, mono-n-propanolamine, monoisopropanolamine, and di-n-propanol. Amine, diisopropanolamine, tri-n-propanolamine, triisopropanolamine, 2-amino-2-methyl-1-propanol, N- (aminoethyl) ethanolamine, N, N-dimethyl-2-aminoethanol and 2 -(2-aminoethoxy) ethanol and the like.

  Examples of the alkylene diamine having 2 to 5 carbon atoms include ethylene diamine, propylene diamine, propylene diamine, tetramethylene diamine and hexamethylene diamine.

Examples of the cyclic amine include piperidine, piperazine and DABCO.
Examples of amidine compounds include DBU and DBN.
Poly (n = 2-6) alkylene poly (n = 3-7) amines include diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexamethyleneheptamine, iminobispropylamine and bis (hexamethylene). ) Triamine and the like.

  Examples of the inorganic alkali (C-4) include lithium hydroxide, sodium hydroxide and potassium hydroxide.

  Among (C), from the viewpoint of detergency, a quaternary ammonium salt (C-1), an aliphatic amine having 1 to 12 carbon atoms (C-3) and a combination thereof are preferable, and tetramethyl is more preferable. Ammonium hydroxide, ethyltrimethylammonium hydroxide, tetraethylammonium hydroxide, triethylmethylammonium hydroxide, monoethanolamine, diethanolamine, triethanolamine, mono-n-propanolamine, monoisopropanolamine, N-methyl- Diethanolamine, DBU, DBN and combinations thereof.

The cleaning agent of the present invention may further contain a hydrophilic solvent (D). Examples of the hydrophilic solvent (D) include organic solvents having a solubility [(D) / 100 gH ₂ O] in water at 20 ° C. of 3 or more, preferably 10 or more.
Examples of (D) include sulfoxide (dimethylsulfoxide and the like); sulfone {dimethylsulfone, diethylsulfone, bis (2-hydroxyethyl) sulfone, sulfolane, 3-methylsulfolane and 2,4-dimethylsulfolane, etc.}; amide { N, N-dimethylformamide, N-methylformamide and N, N-dimethylacetamide, N, N-dimethylpropionamide and the like}; lactam {N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone and N-hydroxy Methyl-2-pyrrolidone, etc .; Lactone {β-propiolactone, β-butyrolactone, γ-butyrolactone, γ-valerolactone, δ-valerolactone, etc.}; Alcohol {methanol, ethanol, isopropanol, etc. }; Glycols and glycol ethers { Ethylene glycol, ethylene glycol monomethyl ether, triethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, propylene glycol, propylene glycol monomethyl ether, dipropylene Glycol monomethyl ether, 1,3-butylene glycol, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, etc.}; oxazolidinone (N-methyl-2-oxazolidinone) Nitrile (acetonitrile, propionitrile, butyronitrile, acrylonitrile, methacrylonitrile, etc.); carbonate (ethylene carbonate, propion carbonate, etc.); ketone (acetone, diethyl ketone, acetophenone, methyl ethyl ketone) , Cyclohexanone, cyclopentanone, diacetone alcohol, etc.); cyclic ethers (tetrahydrofuran, tetrahydropyran, etc.) and the like. (D) may be used alone or in combination of two or more.

Among (D), glycol and glycol ether are preferable from the viewpoint of detergency, and ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether and diethylene glycol monobutyl ether are more preferable.
When the hydrophilic solvent (D) and the surfactant (B) are used in combination, the weight ratio {(D) / (B)} of (D) and (B) is preferably from the viewpoint of rinsing properties during rinsing. 0.1 to 10, more preferably 0.3 to 5, particularly preferably 0.5 to 3.

  The cleaning agent of the present invention may further contain water. Examples of water used in the cleaning agent of the present invention include tap water, industrial water, ground water, distilled water, ion exchange water, and ultrapure water, and in particular, ion exchange water (electric conductivity 0.2 μS / cm or less) or Ultrapure water (specific resistance value of 18 MΩ · cm or more) is preferable.

  The cleaning agent of the present invention is a chelating agent (E) other than the following (A), a reducing agent (F), a dispersing agent (G), and a trivalent or higher valence, as long as the effects of the cleaning agent of the present invention are not impaired. You may contain 1 or more types of components chosen from the group which consists of a polyhydric alcohol (H) and another additive (I). Among these, one or more selected from the group consisting of (E), (F) and (H) is preferable from the viewpoint of detergency.

As the chelating agent (E) other than (A), aminopolycarboxylic acid (salt) (E-1) {for example, ethylenediaminetetraacetic acid (EDTA) (salt), diethylenetriaminepentaacetic acid (DTPA) (salt), triethylene Tetramine hexaacetic acid (TTHA) (salt), hydroxyethylethylenediaminetriacetic acid (HEDTA) (salt), dihydroxyethylethylenediaminetetraacetic acid (DHEDDA) (salt), nitrilotriacetic acid (NTA) (salt), hydroxyethyliminodiacetic acid (salt) HIDA) (salt), β-alanine diacetate (salt), aspartate diacetate (salt), methylglycine diacetate (salt), iminodisuccinate (salt), serine diacetate (salt), hydroxyiminodisuccinate (salt) , Dihydroxyethylglycine (salt), aspartic acid (salt) and glutamic acid Salt)};
Hydroxycarboxylic acid (salt) (E-2) {eg, hydroxyacetic acid (salt), tartaric acid (salt), citric acid (salt) and gluconic acid (salt)};
Cyclocarboxylic acid (salt) (E-3) {eg, pyromellitic acid (salt), benzopolycarboxylic acid (salt) and cyclopentanetetracarboxylic acid (salt)};
Ether carboxylic acids (salts) (E-4) (eg, carboxymethyl tartronate, carboxymethyloxysuccinate, oxydisuccinate, tartaric acid monosuccinate and tartaric acid disuccinate);
Other carboxylic acids (salts) (E-5) {eg maleic acid derivatives and oxalic acid (salts)};
Condensed phosphoric acid (salt) (E-6) {for example, metaphosphoric acid (salt), tripolyphosphoric acid (salt) and hexametaphosphoric acid (salt)};
In addition, as these salts, what was illustrated by the above-mentioned chelating agent (A) is mentioned. These may be used alone or in combination of two or more.
Of these, (E-1), (E-2) and (E-6) are preferable from the viewpoint of cleaning performance, and (E-1) and (E-6) are more preferable. Particularly preferred are ethylenediaminetetraacetic acid (EDTA) (salt), diethylenetriaminepentaacetic acid (DTPA) (salt), dihydroxyethylethylenediaminetetraacetic acid (DHEDDA) (salt), aspartic acid diacetic acid (salt), aspartic acid (salt), Glutamic acid (salt), metaphosphoric acid (salt) and hexametaphosphoric acid (salt), most preferred are ethylenediaminetetraacetic acid (EDTA) (salt), diethylenetriaminepentaacetic acid (DTPA) (salt) and hexametaphosphoric acid (salt).

  Examples of the reducing agent (F) include an organic reducing agent (F-1) and an inorganic reducing agent (F-2). Examples of the organic reducing agent (F-1) include an aliphatic organic reducing agent (F-1a), an aromatic organic reducing agent (F-1b), and other organic reducing agents (F-1c).

  As the aliphatic organic reducing agent (F-1a), ascorbic acid (salt) having 6 to 9 carbon atoms [L-ascorbic acid, isoascorbic acid, 5,6-alkylidene-L-ascorbic acid {5,6-isopropylidene Liden-L-ascorbic acid, 5,6- (butane-2-ylidene) -L-ascorbic acid and 5,6- (pentane-3-ylidene) -L-ascorbic acid, etc.}, L-ascorbic acid-6 Carboxylic acid esters {L-ascorbic acid-6-acetic acid ester and L-ascorbic acid-6-propanoic acid ester, etc.}, ascorbic acid sulfuric acid ester, ascorbic acid phosphoric acid ester, ascorbic acid glucoside, ascorbic acid isopalmitate and these Salt, etc.].

  Examples of the aromatic organic reducing agent (F-1b) include aromatic amines having 6 to 9 carbon atoms (p-phenylenediamine, p-aminophenol and the like) and phenol compounds having 6 to 30 carbon atoms [3-hydroxyflavone and tocopherol. Monohydric phenols such as (α-, β-, γ-, δ-, ε- or η-tocopherol, etc.) and 3,4,5-trihydroxybenzoic acid, pyrocatechol, resorcinol, hydroquinone, naphthoresorcinol, pyrogallol and Polyphenols such as phloroglucinol].

  Other organic reducing agents (F-1c) include phosphorus-based reducing agents (such as tris-2-carboxyethylphosphine), aldehydes (such as formaldehyde and acetaldehyde), borane complexes (borane-tert-butylamine complex, borane-N). , N-diethylaniline complex and borane-trimethylamine complex), thiol-based reducing agents (such as cysteine and aminoethanethiol) and hydroxylamine-based reducing agents (such as hydroxylamine and diethylhydroxylamine).

As the inorganic reducing agent (F-2), sulfurous acid (salt), thiosulfuric acid (salt), phosphorous acid (salt), hypophosphorous acid (salt), ferrous sulfate, stannic chloride, cyanohydroxide Sodium boron, sodium borohydride and the like are included.
As a salt in case a reducing agent (F) forms a salt, the salt which has the same counter cation as what was illustrated as a salt of the said chelating agent (A) is mentioned.

Of these reducing agents (F), from the viewpoint of controlling the etching property of the cleaning agent, the organic reducing agent (F-1) is preferable, and the aliphatic organic reducing agent (F-1a) and other organic reductions are more preferable. Among the agents (F-1c), thiol reducing agents, particularly preferred are ascorbic acid (salt) and cysteine.
Moreover, (F) may be used independently and may use 2 or more types together.

Examples of the dispersant (G) include those conventionally used as fine particle dispersants, such as polysaccharides and derivatives thereof (hydroxyethylcellulose, cationized cellulose, hydroxymethylcellulose, hydroxypropylcellulose, guar gum, cationized guar gum, xanthan gum). , Alginate and cationized starch, etc.) and poval and phosphate esters {phytic acid, di (polyoxyethylene) alkyl ether phosphate and tri (polyoxyethylene) alkyl ether phosphate, etc.} -2a) also has a dispersing action, but is not included in the dispersant (G) in the present invention.
Moreover, (G) may be used independently and may use 2 or more types together.

As the trihydric or higher polyhydric alcohol (H),
(H-1) aliphatic polyhydric alcohol (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, etc.);
(H-2) dehydrated condensate of (H-1) (diglycerin, triglycerin, tetraglycerin, pentaglycerin, etc.);
(H-3) Saccharides such as monosaccharides {pentose (arabinose, xylose, ribose, xylulose, ribulose etc.), hexose (glucose, mannose, galactose, fructose, sorbose, tagatose etc.), heptose (sedheptulose etc.)}, two Sugars (such as trehalose, saccharose, maltose, cellobiose, gentiobiose and lactose) and trisaccharides (such as raffinose and maltotriose);
(H-4) sugar alcohol (arabitol, adonitol, xylitol, sorbitol, mannitol, dulcitol, etc.);
(H-5) Trisphenol (such as Trisphenol PA);
In addition, these AO adducts (addition mole number 1 to 7 mol) and the like can be mentioned.
(H) may be used alone or in combination of two or more.

  Among (H), (H-1), (H-2), (H-3) and (H-4) are preferable from the viewpoint of the substrate corrosion prevention effect, and glycerin, saccharose and sorbitol are more preferable. It is.

  Examples of other additives (I) include antioxidants, rust inhibitors, pH adjusters, buffers, antifoaming agents, preservatives, and hydrotropes.

  Antioxidants include phenolic antioxidants {2,6-di-t-butylphenol, 2-t-butyl-4-methoxyphenol, 2,4-dimethyl-6-t-butylphenol, etc.}, amine-based oxidation Inhibitors {monoalkyldiphenylamines such as monooctyldiphenylamine and monononyldiphenylamine; dialkyldiphenylamines such as 4,4'-dibutyldiphenylamine and 4,4'-dipentyldiphenylamine; polyalkyldiphenylamines such as tetrabutyldiphenylamine and tetrahexyldiphenylamine; Naphthylamine such as naphthylamine and phenyl-α-naphthylamine}, sulfur compounds {phenothiazine, pentaerythritol-tetrakis- (3-laurylthiopropionate) and bis (3 5-tert-butyl-4-hydroxybenzyl) sulfide etc.} and phosphorus antioxidant {bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite, phenyldiisodecylphosphite, diphenyldiisooctylphos Phyte and triphenyl phosphite etc.}.

  Examples of the rust preventive include benzotriazole, tolyltriazole, benzotriazole having 2 to 10 carbon atoms, benzimidazole, imidazole having 2 to 20 carbon atoms, and 2 to 20 hydrocarbon groups. Nitrogen-containing organic rust preventives such as thiazole and 2-mercaptobenzothiazole; alkyl or alkenyl succinic acids such as dodecenyl succinic acid half ester, octadecenyl succinic anhydride and dodecenyl succinic acid amide; sorbitan monooleate, glycerin monoole And polyhydric alcohol partial esters such as acrylate and pentaerythritol monooleate. These may be used alone or in combination of two or more.

  Examples of the pH adjuster include inorganic acids (hydrochloric acid, sulfuric acid, nitric acid, sulfamic acid and the like) and the inorganic alkalis (C-4) exemplified above, and these may be used alone or in combination of two or more. .

  Examples of the buffer include organic acids, inorganic acids and salts thereof having a buffering action. Examples of the organic acid include acetic acid, formic acid, gluconic acid, glycolic acid, tartaric acid, fumaric acid, levulinic acid, valeric acid, maleic acid, and mandelic acid. Examples of the inorganic acid include phosphoric acid and boric acid. . Moreover, as a salt of these acids, the thing similar to the salt illustrated by the above-mentioned chelating agent (A) is mentioned. These may be used alone or in combination of two or more.

  Examples of the antifoaming agent include silicone antifoaming agents {antifoaming agents containing dimethyl silicone, fluorosilicone, polyether silicone and the like as constituents}. These may be used alone or in combination of two or more.

  Examples of preservatives include triazine derivatives {hexahydro-1,3,5-tris (2-hydroxyethyl) -S-triazine and the like}, isothiazoline derivatives {1,2-benzisothiazolin-3-one, 2-methyl-4- Isothiazolin-3-one and 5-chloro-2-methyl-4-isothiazolin-3-one etc.}, pyridine derivative {pyridine 2-pyridinethiol-1-oxide (salt) etc.}, morpholine derivative {4- (2- Nitrobutyl) morpholine and 4,4- (2-ethyl-2-nitrotrimethylene) -dimorpholine and the like}, benzimidazole derivatives {2- (4-thiazolyl) benzimidazole and the like} and other preservatives [poly {oxyethylene ( Dimethylimino) ethylene (dimethylimino) ethylene} dichloride, p-chloro-m- Silenol, phenoxyethanol, phenoxypropanol, acetoxydimethyldioxane, isopropylmethylphenol, tetrachloroisophthalonitrile, bisbromoacetoxyethane, 3-iodo-2-propynylbutylcarbamate and 2-bromo-2-nitropropane-1,3-diol Etc.]. These may be used alone or in combination of two or more.

  Examples of the hydrotrope include toluene sulfonic acid (salt), xylene sulfonic acid (salt), cumene sulfonic acid (salt), and benzoic acid (salt). These may be used alone or in combination of two or more. As a salt in case a hydrotrope agent forms a salt, the salt which has the same counter cation as what was illustrated as a salt of the said chelating agent (A) is mentioned.

  The pH of the cleaning agent of the present invention (25 ° C.) is an effective component concentration when used as a cleaning liquid, which will be described later, from the viewpoint of cleaning properties and flatness of the substrate after cleaning. For aluminum substrates, it is preferably 2-13, particularly preferably 6-11, most preferably 8-10, and for magnetic disk glass substrates, preferably 2-14, especially Preferably it is 7-13, Most preferably, it is 10-12. When the pH is in this range, it has an appropriate etching property without impairing the flatness of the aluminum substrate or glass substrate subjected to Ni-P plating, and has an excellent effect of preventing the reattachment of fine particles. It becomes easy to demonstrate. In addition, the active ingredient in this invention means components other than water.

  The contents of the chelating agent (A) and the optional components (B) to (I) in the cleaning agent of the present invention based on the weight of the cleaning agent are as follows.

The content of the chelating agent (A) is usually 0.1 to 100%, preferably 0.2 to 50%, more preferably 0.5 to 20%, particularly preferably 1 from the viewpoints of detergency and flatness. -10%.
When the surfactant (B) is contained, its content is preferably from 0.1 to 50%, more preferably from 0.5 to 10%, particularly preferably from 1 to 5%, from the viewpoint of detergency.
When the alkali component (C) is contained, the content is preferably 0.1 to 20%, more preferably 0.2 to 15%, particularly preferably 0.5 to 10% from the viewpoint of detergency. It is.
When the hydrophilic solvent (D) is contained, its content is 0.1 to 80%, more preferably 0.5 to 50%, and particularly preferably 1 to 30%.

When the chelating agent (E) other than (A) is contained, the content thereof is preferably 0.01 to 10%, more preferably 0.05 to 5%, particularly preferably 0.00 from the viewpoint of cleaning performance. 1 to 3%.
When the reducing agent (F) is contained, the content is preferably 0.01 to 10%, more preferably 0.02 to 8%, particularly preferably 0.1 from the viewpoint of controlling the etching property of the substrate. ~ 5%.
When the dispersant (G) is contained, its content is preferably 0.1 to 10%, more preferably 0.5 to 8%, and particularly preferably 1 to 5% from the viewpoint of cleaning performance.
When the trihydric or higher polyhydric alcohol (H) is contained, the content thereof is preferably 0.1 to 30%, more preferably 0.5 to 20%, particularly preferably 1 to 5, from the viewpoint of cleaning performance. 10%.

  When other additives (I) are contained, the amount of each additive added is preferably 0 for antioxidants, chelating agents, rust inhibitors, pH adjusters, buffers, reducing agents, and hydrotropes. 0.1 to 10%, more preferably 0.5 to 8%, and particularly preferably 1 to 5%. The amount of antifoaming agent added is preferably 0.01 to 2%, more preferably 0.02 to 1.5%, particularly preferably 0.1 to 1%. The total content of other additives (I) is 0.01 to 20%, more preferably 0.02 to 10%, and particularly preferably 0.1 to 8%.

  In addition, when composition is the same and overlaps between said arbitrary components (E)-(I), the quantity which shows the addition effect which each arbitrary component shows corresponds regardless of the effect as another arbitrary component In consideration of the fact that effects as other optional components can be obtained at the same time, the amount used is adjusted according to the purpose of use.

  The concentration of the active ingredient of the cleaning agent of the present invention is usually from 0.1 to 100%, preferably from 1 to 90%, more preferably from 2 to 80%, particularly preferably from the viewpoint of workability and transport efficiency during use. 5 to 75%. Therefore, the content of water in the cleaning agent of the present invention is usually 0 to 99.9%, preferably 10 to 99%, more preferably 20 to 98, particularly preferably 25 to 95%.

The metal contents of Na, K, Ca, Fe, Cu, Al, Pb, Ni and Zn atoms in the cleaning agent of the present invention are effective components of the cleaning agent from the viewpoint of preventing metal contamination of the magnetic disk substrate. Is preferably 20 ppm or less, more preferably 10 ppm or less, and particularly preferably 5 ppm or less.
As a method for measuring the content of these metal atoms, a known method such as an atomic absorption method, an ICP emission analysis method, or an ICP mass spectrometry method can be used.

  In the magnetic disk substrate cleaning liquid of the present invention, the above-described cleaning agent is diluted with water, particularly ion-exchanged water (electric conductivity of 0.2 μS / cm or less) or ultrapure water (specific resistance value of 18 MΩ · cm or more) as necessary. The cleaning liquid used in the cleaning process is a magnetic disk substrate cleaning liquid having an active ingredient concentration of 0.01 to 15%, preferably 0.05 to 10%. In addition, when the active ingredient concentration of the cleaning agent is 15% or less, it may be used as a cleaning solution with the same concentration.

  The electric conductivity (mS / cm) of the cleaning liquid is preferably 0.2 to 10.0, more preferably 0.5 to 5.0, and particularly preferably 0, from the viewpoint of preventing re-adhesion of particles and etching properties. .7 to 3.5.

  The contact angle (25 ° C.) of the cleaning liquid with respect to the magnetic disk substrate is usually 30 ° or less, preferably 1 to 15 °, more preferably 1 to 8 °. When the contact angle is within this range, it is preferable from the viewpoint of detergency. In addition, the contact angle in this invention can be measured using a fully automatic contact angle meter [Kyowa Interface Science Co., Ltd. product, PD-W], for example.

  The above-mentioned cleaning liquid obtained by diluting the cleaning agent of the present invention as necessary can be suitably used for cleaning a magnetic disk substrate, and can be suitably used for a magnetic disk aluminum substrate and a glass substrate. In particular, an excellent cleaning property can be exhibited for an aluminum substrate subjected to Ni-P plating.

The magnetic disk substrate cleaning method of the present invention is a cleaning method for cleaning a magnetic disk substrate in the above-described cleaning liquid.
The object to be cleaned (dirt) is oil (coolant, etc.), dirt from the human body (fingerprint, sebum, etc.), plasticizer (dioctyl phthalate, etc.), organic matter such as organic particles, inorganic particles {polishing agent (for example, colloidal silica, Inorganic substances such as alumina, cerium oxide, diamond, etc.), polishing scraps, etc.}.
The cleaning method of the present invention is particularly effective when the magnetic disk substrate is an aluminum substrate plated with Ni-P.

Since the cleaning method of the present invention is extremely excellent in particle removability, the magnetic disk manufacturing process is a process in which particles such as abrasives or polishing scraps are generated or a process requiring a high degree of cleanliness. Preferably, the cleaning process after the grinding process, the cleaning process after the polishing process, the cleaning process after the texturing process, and / or the film forming process (for example, forming the underlayer, the magnetic layer, the protective layer, etc. with a sputtering apparatus) It is preferable to apply as a cleaning method in the previous cleaning step.
When the polishing step is a polishing step using alumina and / or silica as an abrasive or when diamond is used in the texturing step, the effect of the cleaning method of the present invention is particularly easily exhibited.

  The cleaning method in the cleaning method of the present invention includes at least one cleaning method selected from the group consisting of ultrasonic cleaning, shower cleaning, spray cleaning, brush cleaning, immersion cleaning, immersion rocking cleaning, and single wafer cleaning. In any case, the effect of the cleaning method of the present invention is easily exhibited.

  The washing temperature (° C.) when using the washing liquid of the present invention is preferably 10 to 80 ° C., more preferably 15 to 70, and particularly preferably 20 to 60 from the viewpoint of detergency.

  The contact angle (25 ° C.) of water with the magnetic disk substrate cleaned by the cleaning method of the present invention is preferably 20 ° or less, more preferably 1 to 15 °, and particularly preferably 5 to 10 °. When the contact angle is within this range, a uniform film can be formed when a magnetic film or the like is formed by sputtering, which is preferable from the viewpoint of magnetic characteristics.

The surface roughness (Ra) of the magnetic disk substrate surface after being cleaned by the cleaning method of the present invention is preferably 0.5 nm or less, more preferably 0.01 to 0.3 nm, and particularly preferably 0.05 to 0.00. 25 nm. When the surface roughness (Ra) of the substrate is in this range, it is preferable from the viewpoint of improving the recording density of the magnetic disk substrate.
The surface roughness (Ra) of the magnetic disk substrate surface can be measured under the following conditions using E-Sweep manufactured by SII Nano Technology.
Measurement mode: DFM (tapping mode)
Scan area: 1μm × 1μm
Number of scan lines: 256 (Y-direction scan)
Correction: Flat correction in X and Y directions

The method of manufacturing a magnetic disk substrate according to the present invention is a method of manufacturing a magnetic disk substrate including a step of cleaning the magnetic disk substrate by the cleaning method.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to this. Unless otherwise specified, “parts” means “parts by weight” below. The measurement conditions of the molecular weight of the polymer by GPC were measured by the method described above. In the following, ultrapure water having a specific resistance value of 18 MΩ · cm or more was used.

[Production Example 1]
In a stainless steel autoclave equipped with a stirrer and a temperature controller, 200 parts (1.1 mol parts) of lauryl alcohol and 10 parts (0.027) of a 25% aqueous solution of tetramethylammonium hydroxide (hereinafter abbreviated as TMAH). The dehydration was performed at 100 ° C. under a reduced pressure of 4 kPa or less for 30 minutes. 430 parts (9.8 mol parts) of ethylene oxide (hereinafter abbreviated as EO) was dropped 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 2.6 kPa or less to decompose and remove the remaining TMAH, and a nonionic surfactant lauryl alcohol EO 9 mol adduct (B-1-1). ) 630 parts were obtained.

[Production Example 2]
185 parts (1.0 mole part) of laurylamine and 3.6 parts (0.01 mole part) of 25% TMAH aqueous solution were charged into a stainless steel autoclave equipped with a stirrer and a temperature controller, and 100 ° C., 4 kPa or less. For 30 minutes under reduced pressure. 264 parts (6.0 mol parts) of EO 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 2.6 kPa or less to decompose and remove the remaining TMAH, and laurylamine EO 6 mol adduct (B-1-2) which is a nonionic surfactant. 445 parts were obtained.

[Production Example 3]
A stainless steel autoclave equipped with a stirrer and a temperature control device was charged with 212 parts (1.0 mole part) of cumylphenol and 2.9 parts (0.008 mole part) of 25% TMAH aqueous solution at 100 ° C., 4 kPa. It dehydrated for 30 minutes under the following reduced pressure. 352 parts (8.0 mol parts) of EO 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 2.6 kPa or less to decompose and remove the remaining TMAH, and a nonionic surfactant cumylphenol EO 8 mol adduct (B-1-3). ) 560 parts were obtained.

[Production Example 4]
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. The obtained polyacrylic acid aqueous solution is neutralized with DBU (about 450 parts) until the pH becomes 7, and the concentration is adjusted with ultrapure water, thereby allowing polyacrylic acid DBU salt (B-) as an anionic surfactant. A 40% aqueous solution of 2-1) was obtained. In addition, Mw of (B-2-1) was 10,000.

[Production Example 5]
100 parts of ethylene dichloride was charged in a reaction vessel with stirring capable of temperature adjustment and refluxing, and after purging with nitrogen under stirring, the temperature was raised to 90 ° C. to reflux ethylene dichloride. 120 parts of styrene and an initiator solution prepared by previously dissolving 1.7 parts of 2,2′-azobisisobutyronitrile in 20 parts of ethylene dichloride were separately added dropwise to the reaction vessel over 6 hours, and the addition was completed. Thereafter, polymerization was further performed for 1 hour. After the polymerization, the mixture was cooled to 20 ° C. under a nitrogen seal, 105 parts of anhydrous sulfuric acid was added dropwise over 10 hours while controlling the temperature at 20 ° C., and a sulfonation reaction was further carried out for 3 hours after the completion of the addition. After the reaction, the solvent was distilled off and solidified, and then 345 parts of ultrapure water was added and dissolved to obtain a polystyrenesulfonic acid aqueous solution. The resulting polystyrene sulfonic acid aqueous solution is neutralized with 25% TMAH aqueous solution (about 400 parts) until the pH becomes 7, and the concentration is adjusted with ultrapure water, thereby allowing trimethylammonium polystyrene sulfonate, an anionic surfactant. A 40% aqueous solution of salt (B-2-2) was obtained. In addition, Mw of (B-2-2) was 40,000, and the sulfonation rate was 97%.

[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, then cooled to room temperature (about 25 ° C.), DBU was gradually added while adjusting to 25 ° C. in a water bath, and adjusted to pH 6.5 (DBU). Use about 15 parts). Ultrapure water was added to adjust the solid content to 40% to obtain a 40% aqueous solution of a DBU salt (B-2-3) of a naphthalenesulfonic acid formalin condensate as an anionic surfactant. In addition, Mw of (B-2-3) was 5,000.

[Production Example 7]
Production Example except that 407 parts of 70% monomer aqueous solution consisting of 227 parts of acrylamido-2-methylpropanesulfonic acid, 78 parts of acrylic acid and 131 parts of ultrapure water was used instead of 407 parts of 75% aqueous solution of acrylic acid. Polymerization was conducted in the same manner as in Example 4 to obtain an aqueous solution of acrylamide-2-methylpropanesulfonic acid / acrylic acid copolymer. The resulting acrylamide-2-methylpropanesulfonic acid / acrylic acid copolymer aqueous solution was adjusted to pH 6.5 by gradually adding DBU while controlling the temperature to 25 ° C. (using about 280 parts of DBU). By adjusting the concentration with pure water, a 40% aqueous solution of acrylamide-2-methylpropanesulfonic acid / acrylic acid copolymer DBU salt (B-2-4), which is an anionic surfactant, was obtained. In addition, Mw of (B-2-4) was 8,000.

[Production Example 8]
Instead of 407 parts of 75% aqueous solution of acrylic acid, 65% of 50% aqueous solution of sodium methacryloyloxypolyoxyalkylenesulfate (manufactured by Sanyo Chemical Co., Ltd., Eleminol RS-30) and 145 parts of acrylic acid Polymerization was conducted in the same manner as in Production Example 4 except that 465 parts of the monomer aqueous solution was used to obtain a methacryloyloxypolyoxyalkylene sulfate sodium salt / acrylic acid copolymer aqueous solution. After diluting the obtained aqueous copolymer solution with ultrapure water so that the solid content concentration becomes 10%, using a cation exchange resin “Amberlite IR-120B” (manufactured by Organo Corporation), Sodium ions were removed until the concentration became 1 ppm or less. The sodium content was measured using an ICP emission analyzer (Varian730-ES, manufactured by VARIAN). The resulting methacryloyloxypolyoxyalkylene sulfate / acrylic acid copolymer aqueous solution is gradually neutralized until the pH becomes 7 by gradually adding 25% TMAH aqueous solution (about 600 parts) while controlling the temperature at 25 ° C. By adjusting the concentration with ultrapure water, a 10% aqueous solution of methacryloyloxypolyoxyalkylene sulfate / acrylic acid copolymer tetramethylammonium salt (B-2-5), which is an anionic surfactant, was obtained. In addition, Mw of (B-2-5) was 9,000.

[Production Example 9]
136 parts of octylbenzenesulfonic acid and 245 parts of ultrapure water were charged into a beaker and dissolved until uniform. DBN (about 65 parts) is gradually added to the obtained aqueous solution of octylbenzenesulfonic acid to neutralize it until the pH becomes 7, and the concentration is adjusted with ultrapure water, whereby octylbenzenesulfone which is an anionic surfactant is obtained. A 40% aqueous solution of acid DBN salt (B-2-6) was obtained.

[Production Example 10]
144 parts of octanoic acid and 300 parts of ultrapure water were charged into a beaker and dissolved until uniform. Diethanolamine (about 105 parts) is gradually added to the obtained octanoic acid aqueous solution to neutralize it until the pH becomes 7, and the concentration is adjusted with ultrapure water, whereby an octanoic acid diethanolamine salt (anionic surfactant) ( A 40% aqueous solution of B-2-7) was obtained.

[Examples 1 to 16], [Comparative Examples 1 to 7]
Each compounding component described in Table 1 or Table 2 is used at room temperature (about 25 ° C.) in a beaker using the number of mixing components described in Table 1 or Table 2 (however, shown in Table 1 and Table 2 in terms of active ingredients). Under the same stirring and mixing, the cleaning agents of Examples 1 to 16 and Comparative Examples 1 to 7 were prepared.
The obtained cleaning agent was diluted 10 times with ultrapure water as a cleaning solution, and the pH, cleaning property-1, cleaning property-2, surface flatness-1, the eluted Ni content (etching property), and cleaning were as follows. Table 1 or Table 2 shows the results of measurement or evaluation of the contact angle-1 of the rear substrate, the contact angle-1 of the cleaning liquid, and the rinse property evaluation-1.

[Examples 17 to 25], [Comparative Examples 8 to 11]
Each compounding component shown in Table 3 was mixed and stirred uniformly at room temperature (about 25 ° C) in a beaker using the number of parts shown in Table 3 (however, expressed in terms of active ingredients in Table 3). The cleaning agents of Examples 17 to 25 and Comparative Examples 8 to 11 were prepared.
The obtained cleaning agent was diluted 10-fold with ultrapure water to obtain a cleaning solution by the following methods: pH, cleaning property-3, cleaning property-4, surface flatness-2, substrate contact angle-2 after cleaning, cleaning solution Table 3 shows the results of measurement or evaluation of contact angle-2 and rinse property evaluation-2.

In addition, chelating agents (E) other than chelating agents (A), nonionic surfactants (B-1), alkali components (C), hydrophilic solvents (D) and (A) in Tables 1 to 3 Abbreviations are as follows.
EDTMP: ethylenediaminetetra (methylenephosphonic acid)
CDTMP: cis-1,2-cyclohexanediaminetetra (methylenephosphonic acid)
DTPMP: Diethylenetriaminepenta (methylenephosphonic acid)
PE74: polyoxyethylene polyoxypropylene glycol {New Pole PE-74, manufactured by Sanyo Chemical Industries, Ltd.}
TMAH: tetramethylammonium hydroxide TEA: triethanolamine DBU: 1,8-diazabicyclo [5.4.0] -7-undecene DEGM: diethylene glycol monomethyl ether TEGM: triethylene glycol monomethyl ether EDTA: ethylenediaminetetraacetic acid NTA: Nitrilotriacetic acid HEDP: 1-hydroxyethylidene-1,1-diphosphonic acid NTMP: Nitrilotris (methylenephosphonic acid)
Moreover, the quantity of the ultrapure water described in Tables 1 to 3 is the ultrapure water in the aqueous solutions of the surfactants (B-1-1) to (B-2-7) obtained in Production Examples 1 to 10. It is the quantity including.

<Measurement method of pH>
The pH of the cleaning solution was measured at 25 ° C. with a pH meter (H-12, M-12).

<Evaluation method of detergency-1>
After polishing a 3.5-inch Ni-P plated magnetic disk substrate using a commercially available colloidal silica slurry (particle size: about 30 nm) and a polishing cloth as an abrasive, rinse the surface with ultrapure water, nitrogen The contaminated substrate was produced by blowing with 1,000 parts of the cleaning liquid was placed in a glass beaker, the produced contaminated substrate was immersed, and cleaning was performed at 30 ° C. for 5 minutes in an ultrasonic cleaner (200 kHz). After cleaning, the substrate is taken out, thoroughly rinsed with ultrapure water, blown with nitrogen gas and dried, and the surface cleaning device (VMX, manufactured by VISION PSYTEC Co., Ltd.) is used to clean the substrate surface according to the following evaluation criteria. -4100Napier). This evaluation was performed in a class 100 clean room (HED-STD-209D, US Federal Standard, 1988) to prevent contamination from the atmosphere.
A: Almost completely removed.
○: Almost cleaned.
Δ: Some particles remain.
X: Almost no washing

<Evaluation method of washability-2>
Evaluation was conducted in the same manner as in Detergency-1 except that a commercially available alumina slurry (particle size: about 0.4 μm) was used as the abrasive.

<Evaluation method of washability-3>
Evaluation was carried out in the same manner as in Detergency-1 except that a cerium oxide slurry (particle size: about 1 μm) was used as the abrasive and a 2.5-inch glass substrate for the magnetic disk was used as the magnetic disk substrate.

<Evaluation method of detergency-4>
Evaluation was performed in the same manner as in Detergency-1 except that a 2.5-inch glass substrate for magnetic disk was used as the magnetic disk substrate.

<Evaluation method of surface flatness-1>
After taking 10 ml of the cleaning solution in a 20 ml glass container and adjusting the temperature to 30 ° C., a Ni-P plated magnetic disk substrate cut into a size of 2 cm × 2 cm is placed and immersed at 30 ° C. for 20 minutes. Thereafter, the substrate was taken out using tweezers, rinsed thoroughly with ultrapure water to remove the cleaning solution, and then blown with nitrogen at room temperature (25 ° C.) to dry the substrate. The surface roughness (Ra) of the dried substrate surface was measured using an atomic force microscope (S-I Nano Technology Co., Ltd., E-Sweep) to evaluate the surface flatness. The surface roughness (Ra) of the substrate before the test was 0.12 nm.

<Evaluation method of surface flatness-2>
Evaluation was made in the same manner as in the surface flatness-2 except that a magnetic disk glass substrate was used as the substrate. In addition, the surface roughness (Ra) of the substrate before the test was 0.10 nm.

<Evaluation method of eluted Ni content (etching property)>
Put 100 parts of cleaning solution in a polypropylene container, put one 3.5-inch Ni-P plated magnetic disk substrate in it, and wrap the upper part with a thin film made of polyvinylidene chloride to prevent moisture from evaporating. And kept in a room adjusted to 23 ° C. for 12 hours. After standing, the cleaning liquid was collected, and the Ni content in the cleaning liquid was measured with an ICP emission spectrometer (Varian730-ES, manufactured by VARIAN). In addition, the Ni content (ppm) eluted during the test was calculated | required similarly by previously measuring Ni content also about the washing | cleaning liquid before a test, and calculating | requiring the difference. The greater the eluted Ni content, the higher the etching property.

<Measurement Method of Contact Angle-1 of Substrate After Cleaning>
The contact angle (25 ° C., after 1 second) with respect to water was measured using a fully automatic contact angle meter [manufactured by Kyowa Interface Science Co., Ltd., PD-W] for the substrate immediately after the evaluation with the above-described detergency-1. .

<Measuring method of contact angle-2 of substrate after cleaning>
The contact angle (25 ° C., 1 second) with respect to water was measured using a fully automatic contact angle meter (manufactured by Kyowa Interface Science Co., Ltd., PD-W) for the substrate immediately after the evaluation in the above-described cleaning property-3. .

<Measurement Method of Contact Angle-1 of Cleaning Solution>
Fully automatic contact angle meter (PD-W, manufactured by Kyowa Interface Science Co., Ltd.) for each cleaning solution contact angle (25 ° C, after 1 second) to a 3.5-inch Ni-P plated magnetic disk substrate. It measured using.

<Measurement method of cleaning liquid contact angle-2>
The contact angle (at 25 ° C., after 1 second) of each cleaning solution to a 2.5-inch magnetic disk glass substrate was measured using a fully automatic contact angle meter [Kyowa Interface Science Co., Ltd., PD-W]. .

<Evaluation method of rinse property evaluation-1>
100 parts of the cleaning solution was taken in a glass beaker, and one 3.5-inch Ni-P plated magnetic disk substrate was placed therein and allowed to stand for 5 minutes. After standing, the substrate was taken out and naturally dried. The dried substrate was immersed in 1,000 parts of ultrapure water previously collected in a glass beaker for 5 seconds, and then immediately removed and naturally dried. According to the following evaluation criteria, the cleaning agent residue on the substrate surface was evaluated with a surface observation device (manufactured by VISION PSYTEC, VMX-4100Napier). This evaluation was performed in a clean room of class 100 (HED-STD-209D, US Federal Standard, 1988) to prevent contamination from the atmosphere. The cleaning liquid and ultrapure water used were temperature-controlled at 23 ° C. in advance.
A: Almost no residue.
○: Almost no residue, but a slight residue is observed. .
Δ: There is a slight residue.
X: Many residues.

<Evaluation method of rinse property evaluation-2>
Evaluation was performed in the same manner as in the rinse property evaluation-1, except that a 2.5-inch glass substrate for a magnetic disk was used as the substrate.

  From Tables 1 to 3, it can be seen that the cleaning agent of the present invention is extremely excellent in removing particles adhering to the magnetic disk substrate surface after cleaning. In addition, although it has an appropriate etching property, there is almost no change in the flatness of the substrate surface after cleaning, so there is no fear of causing substrate surface roughness during cleaning, and it is very effective for particles that adhere firmly to the substrate surface. It turns out that it is. Furthermore, since the cleaning agent of the present invention can reduce the contact angle of water on the surface of the substrate after cleaning, it is also possible to achieve an effect of realizing an extremely clean substrate surface and an effect of high rinsing properties.

  Since the cleaning agent of the present invention is excellent in the cleaning property of particles on the magnetic disk substrate, it can be effectively used as a cleaning agent in the process of producing a magnetic disk substrate (such as an aluminum substrate and a glass substrate).

Claims (10)

A magnetic disk substrate cleaning agent comprising a chelating agent (A) having at least four phosphonic acid groups in the molecule and a surfactant (B) , wherein (B) is a nonionic surfactant And / or a magnetic disk substrate cleaning agent which is a polymer type anionic surfactant . Furthermore, an alkali component (C) and / or a hydrophilic solvent (D) are contained. The cleaning agent for magnetic disk substrates as described. A magnetic disk substrate cleaning solution comprising the magnetic disk substrate cleaning agent according to claim 1 or 2 and having an active ingredient concentration of 0.01 to 15% by weight. A magnetic disk substrate cleaning method, comprising: cleaning a magnetic disk substrate using the magnetic disk substrate cleaning liquid according to claim 3 . 5. The method of cleaning a magnetic disk substrate according to claim 4 , wherein the magnetic disk substrate is an aluminum substrate or a glass substrate plated with Ni-P. Washing steps after the grinding step, the washing step after the polishing step, cleaning of the magnetic disk substrate according to claim 4 or 5, wherein cleaning the magnetic disc substrate by washing after texturing process step and / or film-forming step prior to the cleaning process Method. 7. The method of cleaning a magnetic disk substrate according to claim 6 , wherein alumina or silica is used as an abrasive in the polishing step, and diamond is used in the texturing step. The method according to any one of claims 4 to 7 , wherein the cleaning is performed using at least one cleaning method selected from the group consisting of ultrasonic cleaning, shower cleaning, spray cleaning, brush cleaning, immersion cleaning, immersion rocking cleaning, and single wafer cleaning. The magnetic disk substrate cleaning method described. The method for cleaning a magnetic disk substrate according to claim 4 , wherein a contact angle of water at 25 ° C. with respect to the substrate after cleaning is 20 ° or less. A method for manufacturing a magnetic disk substrate, comprising the step of cleaning the magnetic disk substrate by the cleaning method according to claim 4 .