CN107032603B - Method for manufacturing magnetic disk and glass substrate for information recording medium - Google Patents
Method for manufacturing magnetic disk and glass substrate for information recording medium Download PDFInfo
- Publication number
- CN107032603B CN107032603B CN201710066079.1A CN201710066079A CN107032603B CN 107032603 B CN107032603 B CN 107032603B CN 201710066079 A CN201710066079 A CN 201710066079A CN 107032603 B CN107032603 B CN 107032603B
- Authority
- CN
- China
- Prior art keywords
- glass substrate
- less
- magnetic disk
- glass
- manufacturing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- C03C3/00—Glass compositions
- C03C3/04—Glass compositions containing silica
- C03C3/076—Glass compositions containing silica with 40% to 90% silica, by weight
- C03C3/083—Glass compositions containing silica with 40% to 90% silica, by weight containing aluminium oxide or an iron compound
- C03C3/085—Glass compositions containing silica with 40% to 90% silica, by weight containing aluminium oxide or an iron compound containing an oxide of a divalent metal
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- C03C3/00—Glass compositions
- C03C3/04—Glass compositions containing silica
- C03C3/076—Glass compositions containing silica with 40% to 90% silica, by weight
- C03C3/083—Glass compositions containing silica with 40% to 90% silica, by weight containing aluminium oxide or an iron compound
- C03C3/085—Glass compositions containing silica with 40% to 90% silica, by weight containing aluminium oxide or an iron compound containing an oxide of a divalent metal
- C03C3/087—Glass compositions containing silica with 40% to 90% silica, by weight containing aluminium oxide or an iron compound containing an oxide of a divalent metal containing calcium oxide, e.g. common sheet or container glass
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/84—Processes or apparatus specially adapted for manufacturing record carriers
- G11B5/8404—Processes or apparatus specially adapted for manufacturing record carriers manufacturing base layers
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- C03C3/00—Glass compositions
- C03C3/04—Glass compositions containing silica
- C03C3/076—Glass compositions containing silica with 40% to 90% silica, by weight
- C03C3/089—Glass compositions containing silica with 40% to 90% silica, by weight containing boron
- C03C3/091—Glass compositions containing silica with 40% to 90% silica, by weight containing boron containing aluminium
-
- G11B5/7315—
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/62—Record carriers characterised by the selection of the material
- G11B5/73—Base layers, i.e. all non-magnetic layers lying under a lowermost magnetic recording layer, e.g. including any non-magnetic layer in between a first magnetic recording layer and either an underlying substrate or a soft magnetic underlayer
- G11B5/739—Magnetic recording media substrates
- G11B5/73911—Inorganic substrates
- G11B5/73921—Glass or ceramic substrates
Abstract
The invention relates to a method for manufacturing a magnetic disk and a glass substrate for an information recording medium. The invention provides a method for manufacturing a magnetic disk capable of forming a magnetic recording layer at a high temperature. The present invention relates to a method for manufacturing a magnetic disk, comprising a step of forming a magnetic recording layer on a glass substrate having a temperature of 550 ℃ or higher, wherein the glass substrate contains 60 to 75% by mole of SiO27 to 17% of Al2O30 or more and less than 2% of B2O3And at least one component selected from MgO, CaO, SrO and BaO in a total amount of more than 18% and not more than 26%, wherein the total content of the 7 components is not less than 95%, and the total content of Li is less than 1%2O、Na2O and K2Any one or more of O, or none of the 3 components.
Description
The application is a divisional application of Chinese patent applications with application dates of 2013, 5 and 31, international application numbers of PCT/JP2013/065285 and Chinese application numbers of 201380029770.2.
Technical Field
The present invention relates to a method for manufacturing a magnetic disk and a glass substrate for an information recording medium, and more particularly to a method for manufacturing a magnetic disk in which a magnetic recording layer is formed at a high temperature and a glass substrate suitable for the manufacturing method.
Background
In recent years, with the increase in the recording capacity of hard disk drives, the increase in recording density has been progressing at a high rate. However, as the recording density increases, the thermal stability is impaired by the fine magnetic particles, and the problem arises that the SN ratio of the crosstalk or the reproduction signal decreases.
Therefore, a heat-assisted magnetic recording technique has attracted attention as a technique of combining light and magnetism. This technique is a technique of applying an external magnetic field to record in a state where the coercive force of a portion locally heated by irradiating a magnetic recording layer with laser light or near-field light is lowered, and reading the recording magnetization by a GMR element or the like, and since recording can be performed on a high-retention medium, magnetic particles can be made fine while thermal stability is maintained.
However, in order to form a multilayer film from a high-retention medium, it is necessary to sufficiently heat the substrate, and a high-heat-resistance substrate is required.
In addition, in order to meet the demand for higher recording density in the perpendicular magnetic recording system, a magnetic recording layer different from the conventional one has been proposed, but the formation of such a magnetic recording layer often requires the substrate to be heated to a high temperature.
As a substrate that can cope with the above-described thermally assisted magnetic recording technology, a silicon substrate has been proposed (see patent document 1).
Documents of the prior art
Patent document
Patent document 1: japanese laid-open patent publication No. 2009-199633
Disclosure of Invention
Problems to be solved by the invention
However, in general, a silicon substrate is concerned about strength as compared with a glass substrate. Therefore, in the production of a magnetic disk in which a magnetic recording layer is formed by heating a substrate to a high temperature, a glass substrate is also preferably used.
Accordingly, an object of the present invention is to provide a method for producing such a magnetic disk and a method for producing a glass substrate for an information recording medium suitable for such a production method.
Means for solving the problems
A process for producing a magnetic disk, which comprises the step of forming a magnetic recording layer on a glass substrate having a temperature of 550 ℃ or higher, wherein the glass substrate is a glass substrateThe plate contains 60 to 75 mole percent of SiO27 to 17% of Al2O30 or more and less than 2% of B2O3And at least one component selected from MgO, CaO, SrO and BaO in a total amount of more than 18% and not more than 26%, wherein the total content of the 7 components is not less than 95%, and the total content of Li is less than 1%2O、Na2O and K2Any one or more of O, or none of the 3 components.
The present invention also provides the method for manufacturing a magnetic disk, wherein the glass substrate contains 10.5 to 20% by mole of at least one of MgO and CaO in total.
The present invention also provides the method for manufacturing a magnetic disk, wherein the glass substrate contains 6% or more of MgO in a molar percentage.
The present invention also provides the method for producing a magnetic disk, wherein the glass substrate contains more than 18 mass% of Al2O3。
Further, the present invention provides the method for producing a magnetic disk, wherein the SiO of the glass substrate2A value obtained by dividing the content (molar percentage) of (b) by the total amount RO of the contents (molar percentages) of MgO, CaO, SrO and BaO is 4.3 or less.
Further, the present invention provides the method for manufacturing a magnetic disk, wherein the viscosity of the glass substrate is 102Temperature T at dPa · s2Is below 1710 ℃.
The present invention also provides the method for manufacturing a magnetic disk, wherein the annealing point of the glass substrate is 650 ℃ or higher.
The present invention also provides the method for manufacturing a magnetic disk, wherein the glass substrate has a specific modulus of 32MNm · kg or more.
Further, the present invention provides the method for producing a magnetic disk, wherein the glass substrate has an acid resistance index A of 0.025 nm/hr or less.
The present invention also provides the method for producing a magnetic disk, wherein the alkali resistance index B of the glass substrate is 0.28 nm/hr or less.
The present invention also provides a glass substrate for an information recording medium, which contains 60 to 75% by mole of SiO27 to 17% of Al2O30 or more and less than 2% of B2O3And at least one component selected from MgO, CaO, SrO and BaO in a total amount of more than 18% and not more than 26%, wherein the total content of the 7 components is not less than 95%, and the total content of Li is less than 1%2O、Na2O and K2Any one or more of O, or none of the 3 components.
The present invention also provides the glass substrate for an information recording medium, wherein the glass substrate contains 10.5 to 20% by mole of at least one of MgO and CaO in total.
The present invention also provides the glass substrate for an information recording medium, wherein MgO is contained in a molar percentage of 6% or more.
The present invention also provides the glass substrate for an information recording medium, wherein the glass substrate contains more than 18% by mass of Al2O3。
The present invention also provides the glass substrate for an information recording medium, wherein SiO is2A value obtained by dividing the content (molar percentage) of (b) by the total amount RO of the contents (molar percentages) of MgO, CaO, SrO and BaO is 4.3 or less.
The present invention also provides the glass substrate for an information recording medium, wherein the information recording medium is a magnetic disk.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a glass substrate that can be easily manufactured as described below, while allowing the substrate to be heated to a high temperature in the manufacture of a magnetic disk on which a magnetic recording layer is formed.
International publication No. 2011/136027 discloses a glass composition having excellent heat resistance. However, it was found that the viscosity of the glass having the composition shown in example 14 was 102Temperature T at dPa · s2Therefore, the melting property is poor and defects such as bubbles are not easily removed.
It is also known that the glass having the composition shown in example 14 of international publication No. 2011/136027 has a specific modulus as low as 31.2MNm · kg, and is likely to cause a fluttering phenomenon when the magnetic disk is rotated at high speed, and cannot cope with a high recording density. Further, it is found that the glass having such a composition is insufficient in acid resistance, and is likely to have a rough surface or the like after a polishing step or the like, and cannot cope with a high recording density. Further, it is found that the glass having such a composition is insufficient in alkali resistance, and is likely to have a surface roughness after a cleaning process or the like, and cannot cope with a high recording density.
The present inventors have found the above-described facts, and have completed the invention of the glass substrate of the present invention, and an object thereof is to provide a glass substrate having heat resistance applicable to a heat-assisted magnetic recording technique, having excellent mechanical properties, having excellent chemical durability, and also having excellent meltability.
The present invention also provides a method for manufacturing a glass substrate for an information recording medium, comprising a disk processing step of processing a glass plate into a glass disk, a grinding step of grinding a main surface of the glass disk, a main surface polishing step of polishing the ground main surface of the glass disk, and a cleaning step of cleaning the glass disk between, within, or after the steps, wherein the glass substrate contains 60 to 75% by mole of SiO27 to 17% of Al2O30 or more and less than 2% of B2O3And at least one component selected from MgO, CaO, SrO and BaO in a total amount of more than 18% and not more than 26%, wherein the total content of the 7 components is not less than 95%, and the total content of Li is less than 1%2O、Na2O and K2Any one or more of O, or none of the 3 components.
In the above method for producing a glass substrate for an information recording medium, the glass disk may be a so-called doughnut-shaped glass disk having a hole at the center thereof or a glass disk having no hole. In addition, the end face may be subjected to etching treatment or mirror polishing in addition to normal chamfering.
The present invention also provides the method for producing a glass substrate for an information recording medium, wherein the annealing point of the glass substrate is 650 ℃ or higher.
The present invention also provides a method for producing the glass substrate for an information recording medium, wherein the glass substrate is produced by a float process or a down-draw process. Examples of the down-draw method include a melting method and a slot down-draw method.
The present invention also provides a method for producing the glass substrate for an information recording medium, wherein the information recording medium is a magnetic disk.
Effects of the invention
According to the method for manufacturing a magnetic disk of the present invention, since the magnetic recording layer can be formed on the glass substrate at a high temperature, the magnetic disk can be made to have a high recording density. In addition, according to the method for manufacturing a magnetic disk of the present invention, since the glass substrate on which the magnetic recording layer is formed has a high specific modulus and surface roughness is less likely to occur in the polishing step, the cleaning step, or the like, a magnetic disk that can cope with a high recording density can be obtained.
The glass substrate for an information recording medium of the present invention is a glass substrate capable of forming a magnetic recording layer at a high temperature and realizing high density of a magnetic disk.
Further, the glass substrate for an information recording medium of the present invention is less likely to have surface roughness due to an acidic polishing slurry (hereinafter referred to as an acid solution) in a polishing step of the glass substrate or the like, and by using the glass substrate for an information recording medium of the present invention, an information recording medium having a high recording density can be manufactured with good productivity. When the surface of the glass substrate is easily roughened by the acid solution, the glass substrate needs to be replaced by the acid solution with a high pH value. When the glass substrate is polished using an acid solution having a high pH, the polishing rate decreases, it takes time to achieve a predetermined polishing amount, and the productivity decreases. Alternatively, the polishing time before the surface roughness is generated is shortened, and the predetermined surface roughness cannot be achieved.
Further, the glass substrate for an information recording medium of the present invention is less likely to have surface roughness due to an alkali solution in a cleaning process of the glass substrate or the like, and by using the glass substrate for an information recording medium of the present invention, an information recording medium having a high recording density can be manufactured with good productivity. When the surface of the glass substrate is easily roughened by the alkali solution, the glass substrate needs to be replaced by the alkali solution with a small pH value. When the glass substrate is cleaned with an alkali solution having a small pH, the cleaning power is reduced, it takes time to achieve a predetermined degree of cleanliness, and productivity is reduced. Alternatively, the time until surface roughness occurs is shortened, and the predetermined cleanliness cannot be achieved.
The glass substrate for an information recording medium of the present invention is a glass substrate for an information recording medium which can form a magnetic recording layer at a high temperature and is excellent in melting property, that is, mass productivity.
Detailed Description
The material of the magnetic recording layer used in the method for producing a magnetic disk of the present invention is typically FePt or SmCo5。
The magnetic recording layer is formed on a glass substrate at a temperature typically 550 ℃ or higher. The temperature of the glass substrate is preferably set to 600 ℃ or higher or 650 ℃ or higher, for example, as necessary. The temperature of the glass substrate is usually set to 800 ℃ or lower.
In the method for manufacturing a magnetic disk of the present invention, a layer such as an underlayer is formed between the glass substrate and the magnetic recording layer as necessary, and a layer such as a protective film is formed on the magnetic recording layer as necessary.
Glass constituting a glass substrate used in the method for producing a magnetic disk of the present invention (hereinafter, sometimes referred to as substrate glass or glass of the present invention) and the annealing point T of the glass substrate of the present inventionAPreferably 650 ℃ or higher, so that the deformation of the glass during the formation of the magnetic recording layer can be suppressed and the magnetic disk can be read normally. More preferably 700 ℃ or higher, particularly preferably 750 ℃ or higher, and typically 800 ℃ or lower.
The viscosity of the substrate glass is 10 for good meltability2Temperature T at dPa · s2Preferably 1710 ℃ or lower. More preferably 1700 ℃ or lower, and still more preferably 1680 ℃ or lower.
To stabilize the rotation of a magnetic disk and to reduce the rotationThe glass of the present invention preferably has a density of 2.7g/cm in order to reduce the load on the motor, reduce power consumption, reduce the heat dissipation load due to heat generation of the motor, and make the glass less likely to be damaged3Hereinafter, typically 2.62g/cm3The following.
The substrate glass preferably has a specific modulus of 32MNm/kg or more so as to be resistant to chattering phenomenon at high-speed rotation and to cope with high recording density. More preferably 32.5MNm/kg or more, and still more preferably 33MNm/kg or more.
In order to cope with a high recording density without causing a phenomenon such as surface roughening in a polishing step or the like, the acid resistance index a of the substrate glass is preferably 0.025 nm/hr or less. More preferably 0.02 nm/hr or less.
In order to cope with a high recording density without causing surface roughness or the like in a cleaning step or the like, the alkali resistance index B of the substrate glass is preferably 0.28 nm/hr or less. More preferably 0.27 nm/hr or less.
The acid resistance index a is determined by the following measurement method.
A glass plate having a thickness of 1 to 2mm and a size of 4cm square was mirror-polished on both surfaces with colloidal silica, and the end surfaces were mirror-polished with ceria abrasive grains, to obtain a measurement sample. It was kept at room temperature at pH 2(0.01 mol/l) HNO3The aqueous solution was immersed for 3 hours. The amount of dissolved Si in the aqueous solution was analyzed by ICP mass spectrometry to obtain a measured value. The amount of Si eluted and SiO in the glass are determined by the following formula2The etching rate of the glass was calculated from the content and the density of the glass.
Acid resistance index a 1000 × L1/[ d × P × (atomic weight of Si 28)/(SiO ×)2Molecular weight of (1) ═ 60)]/3
The acid resistance index A was expressed in nm/hr, and L1 was the amount of Si eluted per unit area of the glass plate and expressed in μ g/cm2D is the density of the glass in g/cm3P is SiO in the glass2The content in mass percentage of (b) is in mass%.
The alkali resistance index B is determined by the following measurement method.
A glass plate having a thickness of 1 to 2mm and a size of 4cm square was mirror-polished on both surfaces with colloidal silica, and the end surfaces were mirror-polished with ceria abrasive grains, to obtain a measurement sample. This was immersed in an aqueous NaOH solution at pH 12(0.01 mol/l) maintained at room temperature for 3 hours while applying ultrasonic waves at 100 kHz. The amount of dissolved Si in the aqueous solution was analyzed by ICP mass spectrometry to obtain a measured value. The amount of Si eluted and SiO in the glass are determined by the following formula2The etching rate of the glass was calculated from the content and the density of the glass.
Alkali resistance index B1000 × L2/[ d × P × (atomic weight of Si 28)/(SiO ×)2Molecular weight of (1) ═ 60)]/3
Alkali resistance index B was expressed in nm/hr, and L2 was the amount of Si eluted per unit area of the glass plate and expressed in μ g/cm2D is the density of the glass in g/cm3P is SiO in the glass2The content in mass percentage of (b) is in mass%.
Next, the composition of the glass of the present invention will be described using the content in terms of mole percentage unless otherwise specified.
SiO2Is an essential component. SiO for the purpose of reducing the weight of the substrate, preventing the substrate from being damaged, and maintaining the basic chemical durability2Is more than 60 percent. Preferably 63% or more, more preferably 65% or more, and further preferably 66% or more. On the other hand, in order to reduce the viscosity of glass, improve the meltability, and improve the chemical durability by the composition close to the composition of the present invention, SiO is used2The content is set to 75% or less. Preferably 71% or less, more preferably 70% or less, and still more preferably 69% or less.
Al2O3Is an essential component. In order to improve heat resistance, suppress phase separation, maintain smoothness of the substrate surface after polishing/cleaning of the substrate, and maintain non-marring property, Al is added2O3The content is set to 7% or more. Preferably 9% or more, more preferably 11% or more, and further preferably more than 12%, more preferably more than 12.5%. On the other hand, Al is added to improve the melting property of the glass2O3The content was set to 17% or less. Preferably 16% or less, more preferably 15% or less, and still more preferably 14% or less. In addition, Al2O3The content of (b) is preferably more than 18 mass%.
B2O3It is not essential, but may be contained to improve the melting property and the scratch resistance of the glass. To maintain acid resistance and increase TAA 1 to B2O3Set to less than 2%. Preferably 1.5% or less, more preferably 1.0% or less, and still more preferably 0.5% or less.
MgO, CaO, SrO and BaO are components for improving the melting property of glass and for improving the acid resistance and alkali resistance, and it is necessary to contain any one or more components in an amount of more than 18% in total (RO). Preferably 18.5% or more, more preferably 19% or more. On the other hand, the RO amount is set to 26% or less in order to improve the devitrification property and make the glass less likely to be damaged. Preferably 24% or less, more preferably 22% or less.
Of these 4 components, 10.5% or more of any one or more of MgO and CaO is preferably contained. In order to improve the meltability and to reduce T2To make the glass less susceptible to damage, the total content of MgO and CaO is preferably set to 10.5% or more. More preferably 11% or more, and still more preferably 12% or more. In order to lower the devitrification temperature and facilitate the molding, it is preferable to set the MgO + CaO to 20% or less. More preferably 18% or less.
In order to increase specific modulus, improve acid resistance and alkali resistance and reduce viscosity to 102Temperature T at dPa · s2，SiO2A value obtained by dividing the content (molar percentage) of (c) by the total amount RO of the contents (molar percentages) of MgO, CaO, SrO and BaO is preferably set to 4.3 or less. More preferably 4.1 or less, and still more preferably 3.9 or less.
Further, MgO is a component for increasing young's modulus, and has an effect of increasing the rigidity of the glass, and therefore, it is preferably contained in an amount of 6% or more. More preferably 7% or more.
The glass of the present invention essentially contains the above 7 components, but may contain other components within a range not impairing the object of the present invention. However, in this case, the total content of these components is less than 5% in order to maintain the indelibility, the acid resistance and the alkali resistance, and the specific modulus. Hereinafter, components other than the above 7 components will be exemplarily described.
ZnO is a component which exerts the same effect as MgO, CaO, SrO and BaO, and may be contained in a range of less than 5%. The total content of ZnO and RO is preferably more than 18% and not more than 26%.
Li2O、Na2O and K2O to TATherefore, it is preferable that the total content of these 3 components is less than 1% or these components are not substantially contained.
Since oxides having an atomic number larger than Ti such as V may easily damage glass, when these oxides are contained, the total content of these oxides is preferably 3% or less. More preferably 2% or less, particularly preferably 1% or less, and most preferably 0.3% or less.
SO3、F、Cl、As2O3、Sb2O3And SnO2Etc. are representative components as clarifying agents.
Examples
Preparation of SiO with the composition shown in Table 127 glasses of composition expressed in molar percentage in the column of BaO. In table 1, MgCa represents the total content of MgO and CaO, and RO represents the total content of MgO, CaO, SrO, and BaO. For these glasses, the density d (unit: g/cm) was measured3) Annealing point TA(unit: DEG C), Young's modulus E (unit: GPa), specific modulus E/d (unit: MNm/kg), and viscosity of 104Temperature T at dPa · s4(unit:. degree. C.) and a viscosity of 102Temperature T at dPa · s2The unit is DEG C, the devitrification temperature is in DEG C, the acid resistance index A and the alkali resistance index B.
The above measurement was carried out as follows.
Density: 20-50 g of glass without bubbles was measured by the Archimedes method.
Annealing point: measured according to JIS R3103 (2001).
Young's modulus: a glass plate having a thickness of 5 to 10mm and a size of 3cm × 3cm was measured by an ultrasonic pulse method.
Specific modulus: the Young's modulus obtained above was divided by the density.
T4、T2: the measurement was performed by using a rotational viscometer.
Devitrification temperature: the glass was pulverized into glass pellets of about 2mm with a mortar, the glass pellets were arranged in a platinum boat, and heat-treated in a temperature gradient furnace for 24 hours. The maximum value of the temperature of the crystallized glass particles was defined as the devitrification temperature.
The acid resistance index a is determined by the following measurement method.
A glass plate having a thickness of 1 to 2mm and a size of 4cm square was mirror-polished on both surfaces with colloidal silica, and the end surfaces were mirror-polished with ceria abrasive grains, to obtain a measurement sample. It was kept at room temperature at pH 2(0.01 mol/l) HNO3The aqueous solution was immersed for 3 hours. The amount of dissolved Si in the aqueous solution was analyzed by ICP mass spectrometry to obtain a measured value. The amount of Si eluted and SiO in the glass are determined by the following formula2The etching rate of the glass was calculated from the content and the density of the glass.
Acid resistance index a 1000 × L1/[ d × P × (atomic weight of Si 28)/(SiO ×)2Molecular weight of (1) ═ 60)]/3
The acid resistance index A was expressed in nm/hr, and L1 was the amount of Si eluted per unit area of the glass plate and expressed in μ g/cm2D is the density of the glass in g/cm3P is SiO in the glass2The content in mass percentage of (b) is in mass%.
The alkali resistance index B is determined by the following measurement method.
Polishing both surfaces of a glass plate having a thickness of 1 to 2mm and a size of 4cm square with colloidal silica by mirror polishing and polishing with ceriaThe glass plate obtained by mirror polishing of the end face of each bead was used as a measurement sample. This was immersed in an aqueous NaOH solution at pH 12(0.01 mol/l) maintained at room temperature for 3 hours while applying ultrasonic waves at 100 kHz. The amount of dissolved Si in the aqueous solution was analyzed by ICP mass spectrometry to obtain a measured value. The amount of Si eluted and SiO in the glass are determined by the following formula2The etching rate of the glass was calculated from the content and the density of the glass.
Alkali resistance index B1000 × L2/[ d × P × (atomic weight of Si 28)/(SiO ×)2Molecular weight of (1) ═ 60)]/3
Alkali resistance index B was expressed in nm/hr, and L2 was the amount of Si eluted per unit area of the glass plate and expressed in μ g/cm2D is the density of the glass in g/cm3P is SiO in the glass2The content in mass percentage of (b) is in mass%.
Examples 1 to 6 are examples of the substrate glass used in the present invention. Example 7 is a substrate glass for comparison.
TABLE 1
| (mol%) | Example 1 | Example 2 | Example 3 | Example 4 | Example 5 | Example 6 | Example 7 |
| SiO2 | 69.5 | 67.0 | 67.0 | 66.5 | 68.4 | 66.8 | 70.8 |
| Al2O3 | 12.0 | 13.5 | 13.0 | 13.0 | 13.5 | 13.6 | 12.5 |
| B2O3 | 0.0 | 0.0 | 1.0 | 0.0 | 0.0 | 1.2 | 1.3 |
| MgO | 7.0 | 10.0 | 9.0 | 12.7 | 7.6 | 6.2 | 5.0 |
| CaO | 6.0 | 5.0 | 5.5 | 4.7 | 7.1 | 9.3 | 5.2 |
| SrO | 2.5 | 4.5 | 4.5 | 3.1 | 3.4 | 2.9 | 1.5 |
| BaO | 3.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 3.7 |
| MaO+CaO | 13.O | 15.0 | 14.5 | 17.4 | 14.7 | 15.5 | 10.2 |
| RO | 18.5 | 19.5 | 19.O | 20.5 | 18.1 | 18.4 | 15.4 |
| SiO2/RO | 3.76 | 3.44 | 3.53 | 3.24 | 3.78 | 3.63 | 4.60 |
| d | 2.60 | 2.59 | 2.59 | 2.58 | 2.57 | 2.62 | 2.63 |
| TA | B10 | 785 | 780 | 795 | 795 | 790 | 786 |
| E | 84 | 88 | 87 | 91 | 91 | 85 | 82 |
| E/d | 32.3 | 34.0 | 33.6 | 35.3 | 35.4 | 32.4 | 31.2 |
| T2 | 1700 | 1650 | 1650 | 1650 | 1700 | 1660 | 1720 |
| T4 | 1320 | 1300 | 1300 | 1295 | 1320 | 1300 | 1350 |
| Devitrification temperature | 1220 | 1285 | 1280 | 1310 | 1295 | 1310 | 1215 |
| Index of acid resistance A | 0.018 | 0.029 | |||||
| Alkali resistance index B | 0.26 | 0.29 |
The present invention has been described in detail using the specific embodiments, but it is apparent to those skilled in the art that various changes and modifications can be made without departing from the purpose and scope of the present invention. In addition, the present application is based on japanese patent application (japanese patent application 2012-127872) filed on 6/5/2012, the entire contents of which are incorporated by reference.
Industrial applicability
The present invention can be used for manufacturing a magnetic disk and a glass substrate for an information recording medium.
Claims (10)
1. A method for manufacturing a magnetic disk, comprising a step of forming a magnetic recording layer on a glass substrate having a temperature of 550 ℃ or higher,
the glass substrate contains 63% or more and less than 71% of SiO in terms of mole percentage211 to 14% of Al2O30 or more and less than 2% of B2O3And at least one component selected from MgO, CaO, SrO and BaO in a total amount of more than 18% and not more than 22%, wherein the total content of the 7 components is not less than 95%, and the total content of Li is less than 1%2O、Na2O and K2Any one or more of O or none of the 3 components,
the glass substrate contains more than 18% of Al in percentage by mass2O3And is and
the glass substrate has a specific modulus of 32MNm/kg or more.
2. The method for manufacturing a magnetic disk according to claim 1, wherein the glass substrate contains 10.5 to 20% by mole of at least one of MgO and CaO in total.
3. The method for manufacturing a magnetic disk according to claim 1 or 2, wherein the glass substrate contains 6% or more of MgO in a molar percentage.
4. The method for manufacturing a magnetic disk according to claim 1 or 2, wherein the glass substrate has a specific modulus of 32.5MNm/kg or more.
5. The method for manufacturing a magnetic disk according to claim 1 or 2, wherein an acid resistance index A of the glass substrate is 0.025 nm/hr or less.
6. The method for producing a magnetic disk according to claim 1 or 2, wherein the alkali resistance index B of the glass substrate is 0.28 nm/hr or less.
7. The method for manufacturing a magnetic disk according to claim 1 or 2, wherein the viscosity of said glass substrate is up to 102Temperature T at dPa · s2Is below 1710 ℃.
8. The method for manufacturing a magnetic disk according to claim 1 or 2, wherein the annealing point of the glass substrate is 650 ℃ or higher.
9. A glass substrate for an information recording medium, wherein the glass substrate contains 63% or more and less than 71% of SiO in terms of mole percentage211 to 14% of Al2O30 or more and less than 2% of B2O3And at least one component selected from MgO, CaO, SrO and BaO in a total amount of more than 18% and not more than 22%, wherein the total content of the 7 components is not less than 95%, and the total content of Li is less than 1%2O、Na2O and K2O or any one or more of the above 3 components, and the glass substrate contains no component and is characterized in that the glass substrate contains no component and no component in percentage by massAl content of more than 18% by weight2O3And the specific modulus of the glass substrate is 32MNm/kg or more.
10. The glass substrate for an information recording medium according to claim 9, wherein the information recording medium is a magnetic disk.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2012-127872 | 2012-06-05 | ||
| JP2012127872 | 2012-06-05 | ||
| CN201380029770.2A CN104364212A (en) | 2012-06-05 | 2013-05-31 | Method for producing magnetic disk and glass substrate for information recording media |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201380029770.2A Division CN104364212A (en) | 2012-06-05 | 2013-05-31 | Method for producing magnetic disk and glass substrate for information recording media |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107032603A CN107032603A (en) | 2017-08-11 |
| CN107032603B true CN107032603B (en) | 2020-10-16 |
Family
ID=49711961
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710066079.1A Active CN107032603B (en) | 2012-06-05 | 2013-05-31 | Method for manufacturing magnetic disk and glass substrate for information recording medium |
| CN201380029770.2A Pending CN104364212A (en) | 2012-06-05 | 2013-05-31 | Method for producing magnetic disk and glass substrate for information recording media |
Family Applications After (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201380029770.2A Pending CN104364212A (en) | 2012-06-05 | 2013-05-31 | Method for producing magnetic disk and glass substrate for information recording media |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JP5907259B2 (en) |
| CN (2) | CN107032603B (en) |
| SG (1) | SG11201408098RA (en) |
| WO (1) | WO2013183569A1 (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6379678B2 (en) * | 2014-05-29 | 2018-08-29 | 日本電気硝子株式会社 | Manufacturing method of glass substrate |
| TW202039390A (en) * | 2019-02-07 | 2020-11-01 | 日商Ａｇｃ股份有限公司 | Alkali-free glass |
| CN113412242A (en) * | 2019-02-07 | 2021-09-17 | Ａｇｃ株式会社 | Alkali-free glass |
| CN113412244A (en) * | 2019-02-07 | 2021-09-17 | Ａｇｃ株式会社 | Alkali-free glass |
| US11718553B2 (en) | 2019-03-19 | 2023-08-08 | AGC Inc. | Alkali-free glass substrate |
| WO2021117897A1 (en) * | 2019-12-13 | 2021-06-17 | Hoya株式会社 | Glass for magnetic recording medium substrate or for glass spacer to be used in magnetic recording/reproducing device, magnetic recording medium substrate, magnetic recording medium, glass spacer to be used in magnetic recording/reproducing device, and magnetic recording/reproducing device |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61236631A (en) * | 1985-04-10 | 1986-10-21 | Ohara Inc | Refractory and heat resistant glass |
| JPS61261232A (en) * | 1985-05-13 | 1986-11-19 | Ohara Inc | Fire-resistant and heat-resistant glass |
| JP3804101B2 (en) * | 1995-04-27 | 2006-08-02 | 旭硝子株式会社 | Glass substrate for magnetic disk |
| JP3804112B2 (en) * | 1996-07-29 | 2006-08-02 | 旭硝子株式会社 | Alkali-free glass, alkali-free glass manufacturing method and flat display panel |
| JP5339173B2 (en) * | 2007-09-27 | 2013-11-13 | 日本電気硝子株式会社 | Tempered glass substrate, glass and method for producing tempered glass substrate |
| CN101417861A (en) * | 2007-10-26 | 2009-04-29 | 旭硝子株式会社 | Glass for information recording media substrate, glass substrate for magnetic disk and magnetic disk |
| MY177073A (en) * | 2010-04-27 | 2020-09-04 | Agc Inc | Method for producing magnetic disk, and glass substrate for information recording medium |
| CN102417297A (en) * | 2010-09-27 | 2012-04-18 | 旭硝子株式会社 | Alkali-free glass and flat display panel |
-
2013
- 2013-05-31 JP JP2014519971A patent/JP5907259B2/en active Active
- 2013-05-31 SG SG11201408098RA patent/SG11201408098RA/en unknown
- 2013-05-31 CN CN201710066079.1A patent/CN107032603B/en active Active
- 2013-05-31 WO PCT/JP2013/065285 patent/WO2013183569A1/en active Application Filing
- 2013-05-31 CN CN201380029770.2A patent/CN104364212A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| WO2013183569A1 (en) | 2013-12-12 |
| CN107032603A (en) | 2017-08-11 |
| JP5907259B2 (en) | 2016-04-26 |
| SG11201408098RA (en) | 2015-02-27 |
| JPWO2013183569A1 (en) | 2016-01-28 |
| CN104364212A (en) | 2015-02-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107032603B (en) | Method for manufacturing magnetic disk and glass substrate for information recording medium | |
| US9023421B2 (en) | Method for producing magnetic disk, and glass substrate for information recording medium | |
| JP5393974B2 (en) | Manufacturing method of glass substrate for magnetic disk and magnetic disk | |
| TWI547458B (en) | A magnetic recording medium substrate glass, a magnetic recording medium substrate, a method for manufacturing the same, and a magnetic recording medium | |
| KR100557262B1 (en) | Glass substrate for information recording medium and information recording medium to which the glass substrate is applied | |
| JP5748675B2 (en) | GLASS SUBSTRATE FOR INFORMATION RECORDING MEDIUM, INFORMATION RECORDING MEDIUM, AND METHOD FOR PRODUCING THEM | |
| JP4213077B2 (en) | GLASS SUBSTRATE FOR INFORMATION RECORDING MEDIUM AND ITS MANUFACTURING METHOD, AND INFORMATION RECORDING MEDIUM AND ITS MANUFACTURING METHOD | |
| JP4252956B2 (en) | Glass for chemical strengthening, substrate for information recording medium, information recording medium, and method for producing information recording medium | |
| JPWO2004041740A1 (en) | SUBSTRATE FOR INFORMATION RECORDING MEDIUM, INFORMATION RECORDING MEDIUM, AND ITS MANUFACTURING METHOD | |
| WO2018088563A1 (en) | Glass for magnetic recording medium substrates, magnetic recording medium substrate, magnetic recording medium, and glass spacer for magnetic recording/reproducing apparatuses | |
| JP6308044B2 (en) | Alkali-free glass for magnetic recording media and glass substrate for magnetic recording media using the same | |
| JP4713064B2 (en) | Manufacturing method of glass substrate for information recording medium and glass substrate for information recording medium manufactured by the manufacturing method | |
| JP2015027932A (en) | Alkali-free glass for magnetic recording medium, and glass substrate for magnetic recording medium prepared using the same | |
| CN108137380B (en) | Glass for data storage medium substrate, glass substrate for data storage medium, and magnetic disk | |
| JPH11232627A (en) | Substrate for information record medium | |
| JP2001143246A (en) | Substrate for information recording medium and its manufacturing method as well as information recording medium and information recorder using the same | |
| JP6299472B2 (en) | Alkali-free glass for magnetic recording media and glass substrate for magnetic recording media using the same | |
| JPH10241134A (en) | Glass substrate for information-recording medium and magnetic recording medium using the same | |
| JP2000169184A (en) | Crystallized glass for information recording disk and its production | |
| JP2002288823A (en) | Manufacturing method of substrate for information record medium | |
| WO2017002835A1 (en) | Glass for magnetic recording medium substrate, magnetic recording medium substrate, and magnetic recording medium | |
| WO2014136751A1 (en) | Glass substrate for information recording media, and information recording medium | |
| WO2024053741A1 (en) | Glass for magnetic recording medium substrate, magnetic recording medium substrate, and magnetic recording/reproducing apparatus | |
| WO2024053740A1 (en) | Glass for magnetic recording medium substrate or for glass spacer to be used in magnetic recording/reproducing device, magnetic recording medium substrate, magnetic recording medium, glass spacer to be used in magnetic recording/reproducing device, and magnetic recording/reproducing device | |
| WO2013094451A1 (en) | Glass substrate |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| CB02 | Change of applicant information |
Address after: Tokyo, Japan Applicant after: AGC Corporation Address before: Tokyo, Japan Applicant before: Asahi Glass Co., Ltd. |
|
| CB02 | Change of applicant information | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |