WO2006022145A1 - Process for manufacturing glass substrate for magnetic recording medium and glass substrate for magnetic recording medium obtained by the process - Google Patents
Process for manufacturing glass substrate for magnetic recording medium and glass substrate for magnetic recording medium obtained by the process Download PDFInfo
- Publication number
- WO2006022145A1 WO2006022145A1 PCT/JP2005/014703 JP2005014703W WO2006022145A1 WO 2006022145 A1 WO2006022145 A1 WO 2006022145A1 JP 2005014703 W JP2005014703 W JP 2005014703W WO 2006022145 A1 WO2006022145 A1 WO 2006022145A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- glass substrate
- magnetic recording
- recording medium
- substrate
- 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.)
- Ceased
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
- C03C19/00—Surface treatment of glass, not in the form of fibres or filaments, by mechanical means
-
- 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
Definitions
- the present invention relates to a process for manufacturing a glass substrate for a magnetic recording medium, and to a glass substrate for a magnetic recording medium which is obtained by the process. More specifically, the invention relates to a process for manufacturing a glass substrate for a magnetic recording medium wherein a glass substrate is polished and then washed prior to texturing treatment, as well as to a glass substrate for a magnetic recording medium which is obtained by the process.
- Background Art Glass substrates used for magnetic recording media such as hard disks must have a high degree of flatness and smoothness. Glass substrates are therefore subjected to a step for surface polishing and a subsequent step for washing. The glass substrates for magnetic recording media which are obtained by such processes are also subjected to a texturing step for surface treatment.
- abrasive grains such as of cerium oxide or zirconium oxide as a polishing agent, but a problem is encountered when such abrasive grains adhere to the glass surface. As a result, it is necessary to remove the adhering abrasive grains and glass shavings produced during the polishing step by washing prior to the texturing step.
- inorganic acids or organic acids are commonly used for washing after polishing (for example, see Japanese Unexamined Patent Publication No. 2003-212603), but conventional washing methods result in formation of a non-uniform texture in the subsequent texturing step, thereby producing variation between substrates, creating manifest defects in the substrate surface or creating overall waviness in the substrate, and therefore washing methods which avoid these problems have been desired.
- the present invention therefore comprises the following aspects.
- a process for manufacturing a glass substrate for a magnetic recording medium comprising polishing a glass substrate is polished using abrasive grains and then washing the substrate using a 0.02-0.3% aqueous hydrofluoric acid solution.
- glass substrates for magnetic recording media which have no surface defects or overall waviness, and which allow texture to be formed in the subsequent texturing step in a uniform manner without creating variation between substrates.
- the glass substrate is preferably sheet-like glass composed of amorphous glass having a basic composition of aluminosilicate.
- Abrasive grains such as of cerium oxide, zirconium oxide, aluminum oxide, silicon oxide or the like may be used as the polishing agent for polishing of the glass substrate surface.
- abrasive grains composed of cerium oxide are preferred from the viewpoint of polishing efficiency.
- the polishing agent may be used as a suspension of the abrasive grains in water.
- the polished glass substrate is then subjected to a washing step.
- the washing is carried out using an aqueous hydrofluoric acid solution with a concentration of 0.02-0.3% (mass%, hereinafter indicated only by "%") .
- the hydrofluoric acid concentration of the aqueous hydrofluoric acid solution is preferably no greater than 0.15% and more preferably 0.04-0.15%.
- the washing with the aqueous hydrofluoric acid solution will generally involve dipping of the glass substrate in the aqueous hydrofluoric acid solution.
- the dipping temperature is preferably 10-70°C, more preferably 15-60°C, even more preferably 25-50°C and most preferably about 40 0 C, and the dipping time is preferably 1-3 minutes and most preferably about 2 minutes.
- the glass substrate is preferably subjected to mechanical washing such as ordinary brush scrubbing prior to washing with the aqueous hydrofluoric acid solution.
- This process yields a glass substrate for a magnetic recording medium, but for later manufacturing a magnetic recording medium, the glass substrate for a magnetic recording medium is subsequently subjected first to a texturing step and then to a step of forming a magnetic film on the surface by an ordinary procedure, finally yielding a magnetic recording medium. Furthermore, the washing treatment described above results in excellent advantages of the resulting glass substrate for a magnetic recording medium, in that it minimizes manifestation of defects in the substrate surface and overall waviness of the substrate, while allowing texture to be formed in the subsequent texturing step in a uniform manner without creating variation between substrates.
- Substrate for magnetic recording media were manufactured using amorphous glass having a 90 % by mass predominant component composition of B 2 O 3 + AI 2 O3 + SiO 2 and a 7 % by mass remaining composition of Li 2 ⁇ + Na 2 O + K 2 O.
- the raw material glass having the aforementioned composition was melted and press molded to obtain a disk-shaped glass sheet.
- a hole was formed in the glass sheet using a drill.
- the main surface of each panel was subjected to two-stage lapping process comprising loose lapping and tight lapping, for adjustment of the panel thickness.
- the inner edge of the hole and the outer peripheral edge of the panel were each subjected to chamfering to form chamfered edges.
- the polishing agent used was a cerium oxide powder-containing polishing agent (MIREK by Mitsui Kinzoku Co., Ltd.) .
- Each of the obtained panels was then washed by brush scrubbing and then washed by dipping in an aqueous hydrofluoric acid solution for removal of the surface residue to obtain a glass substrate for a magnetic recording medium.
- the hydrofluoric acid concentration (wt%) for dip washing was changed as shown in Table 1 below, and the surface roughness, overall waviness and surface defects of the substrates were evaluated.
- the dipping temperature was approximately 40 0 C and the dipping time was approximately 2 minutes.
- the surface roughness (Ra) was evaluated in a 10 ⁇ m field using an AFM (Atomic Microscope) by Digital Instruments.
- the waviness (Wa) was evaluated as the waviness in a wavelength range with a frequency component of up to 5 mm, using an Opti-flat interferometer by Phase Shift Corp.
- the surface defects were evaluated in a 10 nm slice using an RZ3500 ODT (Optical Defect Tester) by Hitachi Hightechnology.
- each obtained substrate was subjected to texturing treatment using a diamond slurry, and was then mounted in a sputtering apparatus for sputtering to form a base film composed of a chromium alloy and a magnetic film composed of a cobalt alloy, after which a diamond- like carbon film was formed thereover by CVD and the film was coated with Fonblin Z-Tetraol (Solvay Solexis) as a lubricant to manufacture a magnetic recording medium.
- the total thickness of the film formed by sputtering was 90 nm, and the thickness of the film formed by CVD was 10 nm. Twenty-five such magnetic recording media were manufactured in this manner.
- the texture uniformity of each of the magnetic recording media was evaluated by visual inspection under a 100,000 lux condensed beam lamp in a dark room, and the media yield was evaluated by glide (BG) and error testing (ER) . The evaluation was carried out under conditions allowing evaluation of media with a 40 GB recording capacity on a single 65 mm-diameter disk. Table 1
- the present invention provides glass substrates for magnetic recording media which exhibit no surface defects or overall waviness while allowing uniform texture formation in the subsequent texturing step and creating no variation between substrates, and it may therefore be advantageously applied for manufacturing magnetic recording media.
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Manufacturing Of Magnetic Record Carriers (AREA)
- Magnetic Record Carriers (AREA)
- Surface Treatment Of Glass (AREA)
Abstract
A process for manufacturing a glass substrate for a magnetic recording medium, comprising polishing a glass substrate is polished using abrasive grains and then washing the substrate using a 0.02-0.3% aqueous hydrofluoric acid solution, and a glass substrate for a magnetic recording medium which is manufactured by the process. A polished glass substrate for a magnetic recording medium is manufactured, whereby during washing after polishing of the glass substrate, manifestation of substrate surface defects and overall waviness of the substrate can be minimized, and whereby texture formation in the subsequent texturing step can be accomplished in uniform manner without creating variation between substrates.
Description
DESCRIPTION
PROCESS FOR MANUFACTURING GLASS SUBSTRATE FOR MAGNETIC
RECORDING MEDIUM AND GLASS SUBSTRATE FOR MAGNETIC RECORDING MEDIUM OBTAINED BY THE PROCESS
Cross-Reference to Related Application This application is an application filed under 35 U.S.C. § 111 (a) claiming benefit of priority pursuant to 35 U.S.C. § 119 (e) (1) of the filing date of the
Provisional Application 60/606,438 filed September 2, 2004, pursuant to 35 U.S.C. § 111 (b) . Technical Field The present invention relates to a process for manufacturing a glass substrate for a magnetic recording medium, and to a glass substrate for a magnetic recording medium which is obtained by the process. More specifically, the invention relates to a process for manufacturing a glass substrate for a magnetic recording medium wherein a glass substrate is polished and then washed prior to texturing treatment, as well as to a glass substrate for a magnetic recording medium which is obtained by the process. Background Art Glass substrates used for magnetic recording media such as hard disks must have a high degree of flatness and smoothness. Glass substrates are therefore subjected to a step for surface polishing and a subsequent step for washing. The glass substrates for magnetic recording media which are obtained by such processes are also subjected to a texturing step for surface treatment.
Efficient polishing of glass substrate surfaces is accomplished by using abrasive grains such as of cerium oxide or zirconium oxide as a polishing agent, but a problem is encountered when such abrasive grains adhere to the glass surface. As a result, it is necessary to remove the adhering abrasive grains and glass shavings
produced during the polishing step by washing prior to the texturing step.
For amorphous glass substrates, inorganic acids or organic acids are commonly used for washing after polishing (for example, see Japanese Unexamined Patent Publication No. 2003-212603), but conventional washing methods result in formation of a non-uniform texture in the subsequent texturing step, thereby producing variation between substrates, creating manifest defects in the substrate surface or creating overall waviness in the substrate, and therefore washing methods which avoid these problems have been desired.
On the other hand, treatment of polished glass substrates with aqueous hydrofluoric acid solutions is known (see Japanese Unexamined Patent Publication No. 2000-302482), but the purpose of such treatment is removal of the surface layer of the glass substrate by etching with the aqueous hydrofluoric acid solution, and therefore aqueous hydrofluoric acid solutions having a high concentration of 0.5% or greater are used for etching of the glass surface layer. Disclosure of Invention
It is an object of the present invention to provide a process for manufacturing a polished glass substrate for a magnetic recording medium, whereby during washing after polishing of the glass substrate, manifestation of substrate surface defects and overall waviness of the substrate can be minimized, and whereby texture formation in the subsequent texturing step can be accomplished in a uniform manner without creating variation between substrates; it is another object to provide a glass substrate for a magnetic recording medium exhibiting excellent characteristics, which is obtained by the aforementioned process. As a result of much diligent research in light of the circumstances of the prior art described above, the present inventors discovered that the aforementioned
problem can be overcome by using a low-concentration aqueous hydrofluoric acid solution for washing treatment of polished glass substrates.
The present invention therefore comprises the following aspects.
[1] A process for manufacturing a glass substrate for a magnetic recording medium, comprising polishing a glass substrate is polished using abrasive grains and then washing the substrate using a 0.02-0.3% aqueous hydrofluoric acid solution.
[2] A process for manufacturing a glass substrate for a magnetic recording medium according to [1] above, wherein the glass substrate is a substrate composed of amorphous glass. [3] A process for manufacturing a glass substrate for a magnetic recording medium according to [1] or [2] above, wherein the concentration of the aqueous hydrofluoric acid solution is 0.04-0.15%.
[4] A process for manufacturing a glass substrate for a magnetic recording medium according to any one of
[1] to [3] above, wherein the washing is carried out at a temperature of 10-70°C.
[5] A glass substrate for a magnetic recording medium manufactured by a process according to any one of [1] to [4] above.
[6] A magnetic recording medium manufactured using a glass substrate for a magnetic recording medium according to [5] above.
According to the invention, it is possible to provide glass substrates for magnetic recording media which have no surface defects or overall waviness, and which allow texture to be formed in the subsequent texturing step in a uniform manner without creating variation between substrates. Best Mode for Carrying Out the Invention
A preferred embodiment of the invention will now be described. However, the following explanation focuses
- A -
specifically on a preferred example of carrying out the invention and is not intended to place any restrictions whatsoever on the scope of the invention.
According to the invention, the glass substrate is preferably sheet-like glass composed of amorphous glass having a basic composition of aluminosilicate.
Abrasive grains such as of cerium oxide, zirconium oxide, aluminum oxide, silicon oxide or the like may be used as the polishing agent for polishing of the glass substrate surface. Among these, abrasive grains composed of cerium oxide are preferred from the viewpoint of polishing efficiency. The polishing agent may be used as a suspension of the abrasive grains in water.
The polished glass substrate is then subjected to a washing step. According to the invention, the washing is carried out using an aqueous hydrofluoric acid solution with a concentration of 0.02-0.3% (mass%, hereinafter indicated only by "%") . The hydrofluoric acid concentration of the aqueous hydrofluoric acid solution is preferably no greater than 0.15% and more preferably 0.04-0.15%. The washing with the aqueous hydrofluoric acid solution will generally involve dipping of the glass substrate in the aqueous hydrofluoric acid solution. In this case, the dipping temperature is preferably 10-70°C, more preferably 15-60°C, even more preferably 25-50°C and most preferably about 400C, and the dipping time is preferably 1-3 minutes and most preferably about 2 minutes.
According to the invention, the glass substrate is preferably subjected to mechanical washing such as ordinary brush scrubbing prior to washing with the aqueous hydrofluoric acid solution.
This process yields a glass substrate for a magnetic recording medium, but for later manufacturing a magnetic recording medium, the glass substrate for a magnetic recording medium is subsequently subjected first to a
texturing step and then to a step of forming a magnetic film on the surface by an ordinary procedure, finally yielding a magnetic recording medium. Furthermore, the washing treatment described above results in excellent advantages of the resulting glass substrate for a magnetic recording medium, in that it minimizes manifestation of defects in the substrate surface and overall waviness of the substrate, while allowing texture to be formed in the subsequent texturing step in a uniform manner without creating variation between substrates.
The present invention will now be explained in greater detail through the following example.
Substrate for magnetic recording media were manufactured using amorphous glass having a 90 % by mass predominant component composition of B2O3 + AI2O3 + SiO2 and a 7 % by mass remaining composition of Li2θ + Na2O + K2O.
First, the raw material glass having the aforementioned composition was melted and press molded to obtain a disk-shaped glass sheet. A hole was formed in the glass sheet using a drill. Next, the main surface of each panel was subjected to two-stage lapping process comprising loose lapping and tight lapping, for adjustment of the panel thickness. The inner edge of the hole and the outer peripheral edge of the panel were each subjected to chamfering to form chamfered edges.
After polishing the inner edge of the hole and the outer peripheral edge of the processed glass substrate to a mirror surface, the main surface of the panel was also polished to a final mirror surface. The polishing agent used was a cerium oxide powder-containing polishing agent (MIREK by Mitsui Kinzoku Co., Ltd.) .
Each of the obtained panels was then washed by brush scrubbing and then washed by dipping in an aqueous hydrofluoric acid solution for removal of the surface residue to obtain a glass substrate for a magnetic
recording medium.
The hydrofluoric acid concentration (wt%) for dip washing was changed as shown in Table 1 below, and the surface roughness, overall waviness and surface defects of the substrates were evaluated. The dipping temperature was approximately 400C and the dipping time was approximately 2 minutes.
The surface roughness (Ra) was evaluated in a 10 μm field using an AFM (Atomic Microscope) by Digital Instruments. The waviness (Wa) was evaluated as the waviness in a wavelength range with a frequency component of up to 5 mm, using an Opti-flat interferometer by Phase Shift Corp. The surface defects were evaluated in a 10 nm slice using an RZ3500 ODT (Optical Defect Tester) by Hitachi Hightechnology.
Next, each obtained substrate was subjected to texturing treatment using a diamond slurry, and was then mounted in a sputtering apparatus for sputtering to form a base film composed of a chromium alloy and a magnetic film composed of a cobalt alloy, after which a diamond- like carbon film was formed thereover by CVD and the film was coated with Fonblin Z-Tetraol (Solvay Solexis) as a lubricant to manufacture a magnetic recording medium. The total thickness of the film formed by sputtering was 90 nm, and the thickness of the film formed by CVD was 10 nm. Twenty-five such magnetic recording media were manufactured in this manner.
The texture uniformity of each of the magnetic recording media was evaluated by visual inspection under a 100,000 lux condensed beam lamp in a dark room, and the media yield was evaluated by glide (BG) and error testing (ER) . The evaluation was carried out under conditions allowing evaluation of media with a 40 GB recording capacity on a single 65 mm-diameter disk.
Table 1
I
I
Industrial Applicability
The present invention provides glass substrates for magnetic recording media which exhibit no surface defects or overall waviness while allowing uniform texture formation in the subsequent texturing step and creating no variation between substrates, and it may therefore be advantageously applied for manufacturing magnetic recording media.
Claims
1. A process for manufacturing a glass substrate for a magnetic recording medium, comprising polishing a glass substrate is polished using abrasive grains and then washing the substrate using a 0.02-0.3% aqueous hydrofluoric acid solution.
2. A process for manufacturing a glass substrate for a magnetic recording medium according to claim 1, wherein the glass substrate is a substrate composed of amorphous glass.
3. A process for manufacturing a glass substrate for a magnetic recording medium according to claim 1 or 2, wherein the concentration of the aqueous hydrofluoric acid solution is 0.04-0.15%.
4. A process for manufacturing a glass substrate for a magnetic recording medium according to any one of claims 1 to 3, wherein the washing is carried out at a temperature of 10-70°C.
5. A glass substrate for a magnetic recording medium manufactured by a process according to any one of claims 1 to 4.
6. A magnetic recording medium manufactured using a glass substrate for a magnetic recording medium according to claim 5.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US11/660,743 US20080032608A1 (en) | 2004-08-27 | 2005-08-04 | Process for Manufacturing Glass Substrate for Magnetic Recording Medium and Glass Substrate for Magnetic Recording Medium Obtained by the Process |
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2004248068 | 2004-08-27 | ||
| JP2004-248068 | 2004-08-27 | ||
| US60643804P | 2004-09-02 | 2004-09-02 | |
| US60/606,438 | 2004-09-02 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO2006022145A1 true WO2006022145A1 (en) | 2006-03-02 |
Family
ID=38214902
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/JP2005/014703 Ceased WO2006022145A1 (en) | 2004-08-27 | 2005-08-04 | Process for manufacturing glass substrate for magnetic recording medium and glass substrate for magnetic recording medium obtained by the process |
Country Status (4)
| Country | Link |
|---|---|
| US (1) | US20080032608A1 (en) |
| JP (1) | JP2006092718A (en) |
| CN (1) | CN1993298A (en) |
| WO (1) | WO2006022145A1 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8190594B2 (en) | 2008-06-09 | 2012-05-29 | Brightedge Technologies, Inc. | Collecting and scoring online references |
| JP2012064295A (en) * | 2009-11-10 | 2012-03-29 | Showa Denko Kk | Method for manufacturing glass substrate for magnetic recording medium |
| JP5624829B2 (en) * | 2010-08-17 | 2014-11-12 | 昭和電工株式会社 | Method for manufacturing glass substrate for magnetic recording medium |
| JP2012089221A (en) * | 2010-10-22 | 2012-05-10 | Showa Denko Kk | Method for manufacturing glass substrate for magnetic recording medium |
| WO2015099178A1 (en) * | 2013-12-26 | 2015-07-02 | Hoya株式会社 | Substrate for magnetic disk, magnetic disk, and magnetic disk drive device |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000348338A (en) * | 1999-03-30 | 2000-12-15 | Hoya Corp | Production of glassy substrate for information recording medium and information recording medium |
| JP2001026460A (en) * | 1999-05-13 | 2001-01-30 | Nippon Sheet Glass Co Ltd | Glass substrate for information recording medium, its production and information recording medium |
| JP2004086930A (en) * | 2002-07-03 | 2004-03-18 | Hoya Corp | Method of manufacturing magnetic disk glass substrate and magnetic disk |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5045465A (en) * | 1973-08-28 | 1975-04-23 | ||
| US6544893B2 (en) * | 1999-03-30 | 2003-04-08 | Hoya Corporation | Method of manufacturing a glass substrate for an information recording medium, and method of manufacturing an information recording medium |
| JP2001195732A (en) * | 2000-01-05 | 2001-07-19 | Asahi Techno Glass Corp | Method for manufacturing glass substrate for magnetic disk and glass substrate for magnetic disk |
| JP2003141718A (en) * | 2001-10-31 | 2003-05-16 | Nippon Sheet Glass Co Ltd | Method of manufacturing glass substrate for information recording medium |
-
2005
- 2005-08-04 WO PCT/JP2005/014703 patent/WO2006022145A1/en not_active Ceased
- 2005-08-04 US US11/660,743 patent/US20080032608A1/en not_active Abandoned
- 2005-08-04 CN CNA2005800258347A patent/CN1993298A/en active Pending
- 2005-08-22 JP JP2005239696A patent/JP2006092718A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000348338A (en) * | 1999-03-30 | 2000-12-15 | Hoya Corp | Production of glassy substrate for information recording medium and information recording medium |
| JP2001026460A (en) * | 1999-05-13 | 2001-01-30 | Nippon Sheet Glass Co Ltd | Glass substrate for information recording medium, its production and information recording medium |
| JP2004086930A (en) * | 2002-07-03 | 2004-03-18 | Hoya Corp | Method of manufacturing magnetic disk glass substrate and magnetic disk |
Also Published As
| Publication number | Publication date |
|---|---|
| US20080032608A1 (en) | 2008-02-07 |
| JP2006092718A (en) | 2006-04-06 |
| CN1993298A (en) | 2007-07-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103151051B (en) | Glass substrate for magnetic disk and magnetic disk | |
| JP5542989B2 (en) | Manufacturing method of glass substrate for magnetic disk and manufacturing method of magnetic disk | |
| JP5297549B2 (en) | Manufacturing method of glass substrate for magnetic disk and manufacturing method of magnetic disk | |
| JP5297321B2 (en) | Manufacturing method of glass substrate for magnetic disk | |
| JP6089039B2 (en) | Glass substrate for magnetic disk, magnetic disk | |
| CN103456321B (en) | Glass substrate for magnetic recording medium | |
| US20020061603A1 (en) | Method of manufacturing a glass substrate for an information recording medium, and method of manufacturing an information recording medium | |
| JP2001167427A (en) | Glass substrate for information-recording medium, information-recording medium, and their manufacturing methods | |
| JP4785406B2 (en) | Polishing slurry, method for producing glass substrate for information recording medium, and method for producing information recording medium | |
| JP4198607B2 (en) | Manufacturing method of glass substrate for magnetic disk and manufacturing method of magnetic disk | |
| US8317572B2 (en) | Method for manufacturing a glass substrate for a magnetic disc | |
| US7700205B2 (en) | Process for manufacturing glass substrate for magnetic recording medium, glass substrate for magnetic recording medium obtained by the process, and magnetic recording medium obtained using the substrate | |
| US20080032608A1 (en) | Process for Manufacturing Glass Substrate for Magnetic Recording Medium and Glass Substrate for Magnetic Recording Medium Obtained by the Process | |
| JP3801568B2 (en) | Manufacturing method of glass substrate for magnetic disk and manufacturing method of magnetic disk | |
| WO2010041536A1 (en) | Process for producing glass substrate, and process for producing magnetic recording medium | |
| WO2010041537A1 (en) | Process for producing glass substrate, and process for producing magnetic recording medium | |
| JP2003173518A (en) | Method for manufacturing glass substrate for magnetic recording medium, method for manufacturing magnetic recording medium | |
| CN101384517A (en) | Method for producing glass substrate for magnetic recording medium, glass substrate for magnetic recording medium obtained by the method, and magnetic recording medium obtained using the same | |
| JP2007164916A (en) | Substrate for magnetic disk and magnetic recording medium | |
| JP2008262675A (en) | Glass substrate for magnetic disk | |
| JP2012064294A (en) | Manufacturing method of glass substrate for magnetic disk and manufacturing method of magnetic disk | |
| JP2014216043A (en) | Manufacturing method of magnetic disk glass substrate, and manufacturing method of magnetic disk | |
| JP2014216044A (en) | Manufacturing method of magnetic disk glass substrate, and manufacturing method of magnetic disk | |
| SG176884A1 (en) | Manufacturing method of magnetic disk-use glass substrate, and magnetic disk | |
| WO2013146131A1 (en) | Manufacturing method for glass substrate for information recording medium, and information recording medium |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| AK | Designated states |
Kind code of ref document: A1 Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BW BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE EG ES FI GB GD GE GH GM HR HU ID IL IN IS KE KG KM KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NA NG NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SM SY TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW |
|
| AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): BW GH GM KE LS MW MZ NA SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LT LU LV MC NL PL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG |
|
| 121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
| WWE | Wipo information: entry into national phase |
Ref document number: 200580025834.7 Country of ref document: CN |
|
| WWE | Wipo information: entry into national phase |
Ref document number: 11660743 Country of ref document: US |
|
| NENP | Non-entry into the national phase |
Ref country code: DE |
|
| 122 | Ep: pct application non-entry in european phase | ||
| WWP | Wipo information: published in national office |
Ref document number: 11660743 Country of ref document: US |