Abrasive tape and method for manufacturing magnetic recording medium

Abstract

Provided is an abrasive belt capable of improving the productivity of a magnetic recording medium. The polishing tape according to the present disclosure is a polishing tape wound on one surface of a support in a long tape roll shape in which abrasive grains, which are abrasive materials, are adhered, and the polishing tape is provided with an adhesive layer on the other surface of the support.

Description

Technical Field

[0001] This disclosure relates to a method for manufacturing a grinding belt and a magnetic recording medium. Background Technology

[0002] In recent years, magnetic storage devices have become increasingly important in various products such as personal computers, motion picture recorders, and data servers. A magnetic storage device is a device that uses a magnetic recording medium to store electronic data through magnetic recording; for example, a hard disk drive (HDD) device.

[0003] Typical magnetic recording media, for example, consist of a base layer, an intermediate layer, a magnetic recording layer, and a protective layer sequentially formed on a non-magnetic substrate, and have a multilayer film with a lubricating layer formed on the surface of the protective layer.

[0004] During the manufacturing of magnetic recording media, a polishing process using an abrasive belt is performed to remove foreign matter and protrusions from the surface of the protective layer.

[0005] For example, Patent Document 1 discloses a method for smoothing the surface of a disk substrate by polishing a lubricating protective film formed on the surface of the disk substrate with a strip polishing film processed into a strip shape.

[0006] In addition, to prevent foreign matter from adhering to the abrasive belt, for example, Patent Document 2 discloses an abrasive belt in which an abrasive layer formed on the surface of a plastic film is covered with a peelable protective film.

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent Publication No. 2-10486

[0010] Patent Document 2: Japanese Patent Application Publication No. 2008-264914 Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] Here, in the polishing process... Figure 1 As shown, an abrasive belt 100 is used, on which abrasive grains 102 such as alumina are bonded to a resin film 101 using resin 103. The abrasive belt 100 is a long strip with a width of several centimeters and a length of about 100m, and is supplied in a roll-like state wound on a core material 110.

[0013] If foreign matter or free abrasive particles are mixed into the polishing belt 100, circumferential damage will occur on the surface of the multilayer film during the polishing process, and contamination will easily adhere. Therefore, the polishing belt 100 is manufactured with quality control in a way that prevents the introduction of foreign matter or free abrasive particles. However, in the manufacture of magnetic recording media, problems such as damage or contamination sometimes occur due to the polishing process. Magnetic recording media with damage and contamination on the surface of the multilayer film are treated as defective products, reducing the productivity of magnetic recording media.

[0014] The purpose of this disclosure is to provide a grinding belt that can improve the productivity of magnetic recording media.

[0015] Methods for solving problems

[0016] The inventors of this disclosure focused on the correlation between the incidence of defects caused by circumferential damage and contamination on the surface of the magnetic recording medium and the position of the rollers of the polishing belt used in the polishing process. They discovered that the incidence of defects caused by the polishing process is higher on the outer side of the roller than on the inner side (core material side). The inventors investigated this cause and found that free abrasive particles are generated due to the pressure caused by the tight winding of the polishing belt, and these free abrasive particles are a cause of defects. The pressure caused by the tight winding differs between the inner and outer sides of the roller, resulting in different amounts of free abrasive particles generated on the inner and outer sides. Therefore, the inventors discovered that by providing an adhesive layer on the back side of the polishing belt, i.e., on the side of the support body constituting the polishing belt where no abrasive particles adhere, the adhesive layer can capture the free abrasive particles generated by the pressure during winding, thereby improving the productivity of the magnetic recording medium.

[0017] This disclosure provides the following structure.

[0018] [1] An abrasive belt is a long strip of abrasive grains, which are used as abrasive materials, and is wound in a roll shape on one side of a support.

[0019] The aforementioned abrasive belt has an adhesive layer on the other side of the aforementioned support.

[0020] [2] According to the grinding belt of [1], the adhesive layer comprises one or more adhesives selected from the group consisting of rubber-based adhesives, acrylic adhesives, urethane adhesives and silicone adhesives as adhesives.

[0021] [3] According to the abrasive belt described in [1] or [2], the support body comprises one or more resins selected from the group consisting of polyester resins, polyolefin resins, acrylic resins and polycarbonates.

[0022] [4] The abrasive belt according to any one of [1] to [3] further comprises an undercoating layer between the support and the adhesive layer.

[0023] [5] The abrasive belt according to [4], the above-mentioned base coating comprises an adhesive selected from the group consisting of rubber resin, epoxy resin, polyurethane resin, acrylic resin, polyester resin, silicone resin, silane coupling agent, polyolefin resin, polycarbonate resin and polyurethane resin.

[0024] [6] A method for manufacturing a magnetic recording medium, comprising the following steps:

[0025] A polishing process is performed on a substrate by polishing the surface of a laminate in which a magnetic recording layer and a protective layer are sequentially stacked, using an abrasive material.

[0026] The polishing process described above includes the following steps: on one side of the support, abrasive grains are adhered as abrasive material; on the other side of the support, a long strip of abrasive tape with an adhesive layer is wound in a coiled state; and the abrasive tape supplied from the coiled state is pressed against the surface of the laminate and rubbed.

[0027] [7] The method for manufacturing a magnetic recording medium according to [6] includes a step of forming a lubricating layer on the surface of the above-mentioned laminate.

[0028] The polishing process described above involves polishing the surface of the laminate with the lubricating layer formed thereon using the abrasive material described above.

[0029] The effects of the invention

[0030] According to one aspect of this disclosure, the productivity of magnetic recording media can be improved. Attached Figure Description

[0031] Figure 1 A perspective view showing an example of a grinding belt wound in a coil.

[0032] Figure 2 This is a cross-sectional view showing an example of a magnetic recording medium that is polished using the polishing belt according to an embodiment of the present disclosure.

[0033] Figure 3 A diagram illustrating the polishing process.

[0034] Figure 4 This is an enlarged cross-sectional view showing an example of the abrasive belt used during polishing.

[0035] Figure 5 This figure shows an example of a polishing apparatus used in the process of polishing a laminated body by passing it over an abrasive belt. Detailed Implementation

[0036] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Furthermore, for ease of understanding, the same symbols are used to denote the same constituent elements in each drawing, and repeated descriptions are omitted where appropriate. Additionally, the scale of each component in the drawings may sometimes differ from the actual scale. In this specification, the tilde “~” indicating a numerical range means that, unless otherwise stated, the values ​​described before and after it include both the lower and upper limits. In a numerical range indicated by “~”, if only the unit of the upper limit is described, the lower limit is also in the same unit. Hereinafter, before describing the polishing tape involved in the embodiments of this disclosure (hereinafter, sometimes simply referred to as this embodiment), a magnetic recording medium polished using the polishing tape involved in this embodiment will be described.

[0037] [Magnetic recording media]

[0038] Figure 2 This is a cross-sectional view showing an example of a magnetic recording medium that is polished using the polishing belt according to an embodiment of the present disclosure. Figure 2 As shown, the magnetic recording medium 1 has a laminate 11 and a lubricating layer 12 disposed on both sides of the laminate 11.

[0039] The laminate 11 is stacked on both sides of the substrate 111, and has a magnetic recording layer 112 and a protective layer 113 stacked sequentially from the substrate 111 side.

[0040] The substrate 111 is formed of a non-magnetic material. For example, the substrate 111 can be a metal substrate formed of a metallic material such as aluminum alloy, or a non-metallic substrate formed of a non-metallic material such as glass. Furthermore, a NiP alloy layer can be formed on the surface of these metal and non-metallic substrates, for example, using a plating method or a sputtering method (sometimes referred to as "sputtering").

[0041] The magnetic recording layer 112 is a layer provided for recording and reproducing information, for example, by using magnetic energy supplied by the magnetic head of the HDD to reverse the direction of magnetization and maintain its magnetized state, thereby being provided for storing data.

[0042] In the magnetic recording layer 112, FePt alloys with an L10 structure, CoPt alloys with an L10 structure, or CoCrPt alloys with an hcp structure can be used.

[0043] The magnetic recording layer 112 can be formed using common film formation methods such as sputtering or ion beam deposition.

[0044] The protective layer 113 is configured to suppress corrosion of the magnetic recording layer 112, and at the same time, suppress damage to the surface of the magnetic recording medium 1 and protect the magnetic recording medium 1 when the magnetic head comes into contact with the magnetic recording medium 1, thereby improving the corrosion resistance of the magnetic recording medium 1.

[0045] The protective layer 113 can be formed from commonly used materials as a protective layer for the magnetic recording medium, such as hard carbon film or diamond-like carbon (DLC).

[0046] The protective layer 113 can be formed using common film formation methods such as sputtering or ion beam deposition.

[0047] The protective layer 113 may have its surface hydrogenated or nitrided. By hydrogenating or nitriding its surface, the protective layer 113 can improve its adhesion to the lubricating layer 12 formed on its surface.

[0048] The lubrication layer 12 is provided to suppress the wear of the magnetic head and the surface of the magnetic recording medium 1 when the magnetic head contacts the magnetic recording medium 1, and to improve the corrosion resistance of the magnetic recording medium 1.

[0049] The lubricating layer 12 is formed using a lubricant. As a lubricant, a lubricant generally used in the manufacture of magnetic recording media can be used.

[0050] The thickness of the lubricating layer 12 is preferably 5 to 10 mm. By making the thickness of the lubricating layer 12 5-10 mm... This allows for the suppression of surface wear of the magnetic recording medium 1, improving the corrosion resistance of the magnetic recording medium 1, while simultaneously reducing the distance between the magnetic head and the magnetic recording medium 1 in the HDD to achieve high recording density.

[0051] [Method for manufacturing magnetic recording media]

[0052] The method for manufacturing a magnetic recording medium according to this embodiment includes: a process of forming a laminate 11 on the surfaces of two main surfaces of a substrate 111, wherein a magnetic recording layer 112 and a protective layer 113 are sequentially stacked (laminate forming process); a process of applying a lubricant to the surface of the laminate 11 (coating process); and a process of polishing the surface of the laminate 11 coated with lubricant using an abrasive material (polishing process).

[0053] In addition, in the method for manufacturing magnetic recording media according to this embodiment, the polishing process can be performed before the coating process, and the surface of the laminate 11 without lubricant coating is polished by an abrasive.

[0054] Furthermore, in the method for manufacturing the magnetic recording medium according to this embodiment, the laminate formation process may include other processes such as forming an adhesive layer, a soft magnetic substrate layer, a seed layer, or an orientation control layer between the substrate 111 and the magnetic recording layer 112.

[0055] Furthermore, in the method for manufacturing a magnetic recording medium according to this embodiment, when multiple magnetic recording layers 112 are stacked on the laminate 11, the laminate forming process may include a process of forming non-magnetic layers between the magnetic recording layers 112.

[0056] In the method for manufacturing a magnetic recording medium according to this embodiment, firstly, a laminate 11, on which a magnetic recording layer 112 and a protective layer 113 are sequentially stacked, is formed on the surfaces of the two main surfaces of a prepared substrate 111 (laminate formation process).

[0057] The laminate 11 can be formed using conventional film-forming methods for the magnetic recording layer 112 and the protective layer 113.

[0058] First, a magnetic recording layer 112 is formed on the surfaces of the two main surfaces of the substrate 111. As a method for forming the magnetic recording layer 112, a general film deposition method such as sputtering can be used.

[0059] In sputtering, a target containing a material that forms the magnetic recording layer 112 can be used.

[0060] As a target containing the material forming the magnetic recording layer 112, for example, FePt alloys, CoPt alloys, or CoCrPt alloys can be used.

[0061] As a sputtering method, DC sputtering, DC magnetron sputtering, or RF sputtering can be used.

[0062] When forming the magnetic recording layer 112, RF (Radio Frequency), DC bias, or pulsed DC bias can be used as needed.

[0063] As a reactive gas, O2, H2O, or N2 can be used.

[0064] The sputtering gas pressure is adjusted appropriately to optimize the properties of each layer, typically within the range of approximately 0.1 to 30 Pa.

[0065] Next, a protective layer 113 is formed on the magnetic recording layer 112. The method for forming the protective layer 113 is not particularly limited, and general film formation methods can be used. Examples of methods for forming the protective layer 113 include RF-CVD (Radio Frequency-Chemical Vapor Deposition), which involves decomposing a hydrocarbon-containing feed gas using high-frequency plasma to form a film; IBD (Ion Beam Deposition), which involves ionizing the feed gas using electrons emitted from a filament to form a film; and FCVA (Filtered Cathodic Vacuum Arc), which involves forming a film using a solid carbon target without using a feed gas.

[0066] In addition, in this embodiment, the laminate formation process may form an adhesive layer, a soft magnetic substrate layer, a seed layer or an orientation control layer between the substrate 111 and the magnetic recording layer 112.

[0067] In this embodiment, when the laminate 11 is provided with a plurality of stacked magnetic recording layers 112, the laminate forming process may include a process of forming non-magnetic layers between the magnetic recording layers 112.

[0068] Next, a lubricant is applied to the surface of the laminate 11 to form a lubricant layer 12 containing the lubricant (lubricant forming process). Thus, a magnetic recording medium 1 is obtained as a multilayer body with a lubricant layer 12 formed on the surface of the laminate 11.

[0069] Lubricants can be applied using common coating methods such as dip coating, spin coating, or vapor coating.

[0070] Next, Figure 3 As shown, the surfaces of the lubricating layers 12 formed on both sides of the laminate 11 are polished (polishing process) by passing a belt containing abrasive material (hereinafter, sometimes also called an abrasive belt) 20.

[0071] The polishing process includes: using the polishing belt 20 in a rolled state, pressing the polishing belt 20 supplied in a rolled state onto the surface of the laminate 11 and rubbing it.

[0072] The grinding belt 20 is a long strip, therefore, as Figure 1 As shown, it is supplied in a coiled state and used on the spool of the polishing device in a coiled state.

[0073] Polishing can be performed using a rolled abrasive belt 20, which is pressed against the surface of the lubricating layer 12 formed on the surface of the laminate 11 and rubbed. As a result, a polished laminate 11 can be formed on both sides of the laminate 11.

[0074] Figure 4 An enlarged cross-sectional view showing an example of the abrasive belt 20 used during polishing. Figure 4 As shown, the abrasive belt 20 can abrade the surface of the lubricating layer 12 by sliding the abrasive surface S relative to the surface of the lubricating layer 12 formed by the surface of the laminate 11.

[0075] The polishing belt 20 has an abrasive layer 22 on one side of the support 21 and an adhesive layer 24 on the other side of the support 21. This structure allows the adhesive layer 24 to capture any loose abrasive particles that occur during the winding process. Therefore, circumferential damage is generated on the surface of the lubricating layer 12 during the polishing process, inhibiting contamination adhesion and improving the productivity of the magnetic recording medium 1. Furthermore, the adhesive layer 24 is easily elastically deformable, thus mitigating the tightness during the winding of the polishing belt 20. This further suppresses abrasive particle detachment, thereby improving the productivity of the magnetic recording medium.

[0076] In the adhesive layer 24, the adhesive preferably comprises one or more adhesives selected from the group consisting of rubber-based adhesives, acrylic adhesives, urethane adhesives, and silicone adhesives. The adhesive layer 24 contains such an adhesive that it easily captures free abrasive particles while readily deforming elastically, thereby suppressing particle detachment and improving the productivity of the magnetic recording medium.

[0077] The thickness of the adhesive layer 24 is appropriately selected based on the particle size of the captured abrasive grains, and is preferably several times or more the particle size of the captured abrasive grains. For example, the thickness of the adhesive layer 24 is preferably about 0.1 to 50 μm, and more preferably 0.5 to 20 μm.

[0078] The support 21 preferably comprises one or more resins selected from the group consisting of polyester resins, polyolefin resins, acrylic resins, and polycarbonate resins. By using such a resin to form the support 21, the abrasive belt 20 can ensure mechanical properties, namely, strength, heat resistance, and flexibility.

[0079] As polyester-based resins, resins with polyethylene terephthalate, polybutylene terephthalate, or polyethylene naphthalate as main components are suitable for use, for example. As polyolefin-based resins, resins with polyethylene or polypropylene as main components are suitable for use, for example. As acrylic-based resins, resins with polystyrene, polyvinyl chloride, polyvinyl alcohol, or methacryl alcohol as main components are suitable for use, for example.

[0080] The thickness of the support 21 ensures the mechanical properties of the abrasive belt 20, for example, preferably in the range of 5 to 100 μm, more preferably in the range of 10 to 75 μm.

[0081] The abrasive layer 22 can be composed of abrasive grains 221 and an adhesive 222 that adheres the abrasive grains 221 to the support 21.

[0082] Examples of abrasive particles 221 include particles containing chromium oxide, α-alumina, silicon carbide, nonmagnetic iron oxide, diamond, γ-alumina, α,γ-alumina, fused alumina, corundum, or synthetic diamond. Abrasive particles 221 can be particles containing these materials. They can be used alone or in appropriate combinations of two or more.

[0083] The adhesive 222 is not particularly limited; for example, thermosetting resins, thermoplastic resins, or photosensitive resins can be used. One type of resin can be used alone, or two or more types can be used in combination as the adhesive 222.

[0084] The abrasive belt 20 preferably has a base coating 23 between the support 21 and the adhesive layer 24. By providing the base coating 23 between the support 21 and the adhesive layer 24, the adhesion between the support 21 and the adhesive layer 24 is improved, and the adhesive of the adhesive layer 24 is transferred to the abrasive surface S, preventing contamination of the abrasive surface S.

[0085] As the base layer 23, it preferably comprises an adhesive selected from the group consisting of rubber-based resins, epoxy resins, polyurethane resins, acrylic resins, polyester resins, silicone resins, silane coupling agents, polyolefin resins, polycarbonate resins, and polyurethane resins.

[0086] The thickness of the base coating 23 is not particularly limited, but is generally in the range of 0.1 to 6 μm, and more preferably in the range of 0.5 to 3 μm.

[0087] In addition, when selecting the materials constituting the support 21, the base coating 23 and the adhesive layer 24, it is preferable to consider their compatibility.

[0088] For example, when using a rubber-based adhesive to form the adhesive layer 24, the base layer 23 can be formed using rubber-based resins such as chloroprene rubber, polyisoprene, or polybutadiene, epoxy resin, or polyurethane resin. When using an acrylic adhesive, the base layer 23 can be formed using acrylic resin, polyester resin, epoxy resin, or polyurethane resin. When using a urethane-based adhesive, the base layer can be formed using polyurethane resin, epoxy resin, or acrylic resin. When using a silicone-based adhesive, the base layer 23 can be formed using silicone resin, silane coupling agent, or epoxy resin.

[0089] When the support 21 is formed using a polyester resin, the base layer 23 can be formed using a polyester resin, epoxy resin, or acrylic resin, etc. When the support 21 is formed using a polyolefin resin, the base layer 23 can be formed using a polyolefin resin, epoxy resin, or neoprene rubber, etc. When the support 21 is formed using an acrylic resin, the base layer 23 can be formed using an acrylic resin, polyester resin, or epoxy resin, etc. When the support 21 is formed using polycarbonate, the base layer 23 can be formed using polycarbonate resin, epoxy resin, or polyurethane resin, etc.

[0090] As described above, the grinding belt 20 is a long strip, thus... Figure 1 As shown, it is supplied in a coiled state and used on the spool of the polishing device in a coiled state.

[0091] If the grinding belt 20 is rolled up, free abrasive grains are generated inside the rollers under the pressure of winding. Here, under very high winding pressure, the abrasive grains 221 strongly attached to the support 21 become free. It is generally believed that the abrasive grains 221 weakly attached to the support 21 and the abrasive grains 221 attached to the attached abrasive grains become free. Such free abrasive grains 221 are difficult to completely remove during the manufacturing process of the grinding belt 20, and it is believed that most of them occur after the manufacturing of the grinding belt 20, that is, after the grinding belt 20 is wound up in a roll.

[0092] While reducing the ionization of abrasive particles, the abrasive belt 20 can capture the ionized abrasive particles using the back side of the abrasive belt 20. Thus, even if the abrasive particles become ionized, the ionized abrasive particles can be suppressed from having an adverse effect on the magnetic recording medium 1 during the polishing process.

[0093] In the polishing process, a method can be used to press the abrasive belt 20 onto the surface of the lubricating layer 12 formed on the surface of the laminate 11 and rub it. An example of a polishing apparatus is illustrated in detail with reference to the figures.

[0094] Figure 5 This figure shows an example of a polishing apparatus used in the process of polishing the laminate 11 by passing it over an abrasive belt 20. Figure 5 As shown, the polishing apparatus 50 includes: a set of polishing belts 20 (hereinafter also referred to as "a set of polishing belts 20A and 20B") arranged opposite each other, which sandwich a laminate 11 with a lubricating layer 12 formed on its surface, a rotary support means 51, and a belt moving means 52.

[0095] A set of grinding belts 20A and 20B are each supplied in a rolled state from the first grinding belt supply spool 53A and the second grinding belt supply spool 53B, and are wound in a rolled state by the first grinding belt winding spool 54A and the second grinding belt winding spool 54B.

[0096] In the polishing apparatus 50, a set of abrasive belts 20A and 20B are arranged opposite each other to sandwich a laminate 11 with a lubricating layer 12 formed on its surface from both sides, so that the laminate 11 can be polished efficiently at the same time.

[0097] The rotation support means 51 is used to support the central opening of the laminate 11 on which the lubricating layer 12 is formed, so that the laminate 11 on which the lubricating layer 12 is formed rotates in the circumferential direction (arrow r direction).

[0098] The moving means 52 is used to press a set of abrasive belts 20A and 20B relative to each other along the radial direction of the laminate 11 while pressing the lubricating layer 12 formed on both sides of the rotating laminate 11 in the direction of arrow F.

[0099] In addition, the belt moving means 52 includes a pair of grinding belt pushing means 521 and a pair of grinding belt moving systems 522, which are arranged opposite each other by a set of grinding belts 20A and 20B to sandwich the laminate 11 with the lubricating layer 12 formed on its surface from both sides.

[0100] A pair of grinding belt pushing means 521 includes a first grinding belt pushing means 521A and a second grinding belt pushing means 521B. A pair of grinding belt moving systems 522 includes a first grinding belt moving system 522A and a second grinding belt moving system 522B.

[0101] That is, the belt moving means 52 has: a first grinding belt pushing means 521A and a first grinding belt moving system 522A disposed on one side of a laminate 11 with a lubricating layer 12 formed on its surface, and a second grinding belt pushing means 521B and a second grinding belt moving system 522B disposed on the other side.

[0102] The first grinding belt pushing means 521A is a grinding belt 20A supplied from the first grinding belt supply spool 53A toward the laminate 11. Figure 5 The pushing component is used to push the material in the F direction (on the left side).

[0103] The second grinding belt pushing means 521B is a grinding belt 20B supplied from the second grinding belt supply reel 53B toward the laminate 11. Figure 5 The pushing component (in the F direction on the right side) is used for pushing.

[0104] The first grinding belt moving system 522A has first guide rollers 523A-1 to 523A-6, which move the grinding belt 20A in the direction of arrow Ra.

[0105] The second grinding belt moving system 522B has second guide rollers 523B-1 to 523B-6, which move the grinding belt 20B in the direction of arrow Rb.

[0106] As described above, the magnetic recording medium 1 manufactured using the manufacturing method of the magnetic recording medium according to this embodiment has fewer circumferential damages and contaminations on its surface, thus improving the reliability of its quality. The magnetic recording medium 1 can suppress defects in reading and reading out of the recording, and can maintain a high recording density, thereby making it suitable for use in magnetic recording playback devices. Since the magnetic recording playback device includes the magnetic recording medium manufactured using the manufacturing method of the magnetic recording medium according to this embodiment, its form is not particularly limited, and it can be a magnetic recording playback device that records magnetic information on the magnetic recording medium using a heat-assisted recording method, etc.

[0107] As described above, the embodiments have been illustrated, but these embodiments are merely examples and do not limit the present invention. The embodiments described above can be implemented in various other ways, and various combinations, omissions, substitutions, and modifications can be made without departing from the spirit of the invention. The embodiments described above and their variations are included within the scope and spirit of the invention, and are included within the same scope as the invention described in the claims.

[0108] Example

[0109] The following describes this embodiment in detail based on the examples, but this embodiment is not limited to these examples.

[0110] <Manufacturing of Grinding Belts>

[0111] [Example 1]

[0112] On one side of a 24 μm thick polyethylene terephthalate (PET) strip, abrasive grains of 0.2 μm Al₂O₃ bonded with a thermosetting resin are prepared as the abrasive material. The strip is 12.6 mm wide and 100 m long. On the back side of the strip, as a base coating, an acrylic resin is applied to achieve a dry thickness of 1 μm. Then, as an adhesive layer, a solvent solution of an adhesive composition containing 80% natural rubber and 20% liquid isoprene rubber as the main components is applied to achieve a dry thickness of 3 μm. This process is repeated to produce the abrasive strip.

[0113] [Comparative Example 1]

[0114] On the back side of the belt, no base coating or adhesive layer is formed. Otherwise, the grinding belt is manufactured in the same manner as in Example 1.

[0115] <Confirmation of the capture of abrasive particles during desulfurization>

[0116] The polishing tapes of Example 1 and Comparative Example 1 were wound onto the core material with a tension of 10 N and left to stand for one week. After one week, the polishing tapes were unwound and the back side of the polishing tapes were observed using SEM.

[0117] In the grinding belt of Example 1, it was confirmed that detached abrasive grains were captured in the adhesive layer. Furthermore, it was confirmed that the amount of detached abrasive grains captured by the adhesive layer of the grinding belt in Example 1 was less than the amount of detached abrasive grains captured by the grinding belt in Comparative Example 1. This is believed to be because in the grinding belt of Example 1, the pressure caused by tightening was alleviated, resulting in fewer detached abrasive grains.

[0118] Therefore, compared with the polishing belt of Comparative Example 1, the polishing belt of Example 1 can suppress the amount of abrasive grains that are de-granulated, and can suppress circumferential damage and contamination on the surface of the magnetic recording medium 1, thereby improving the productivity of the magnetic recording medium.

[0119] Explanation of symbols

[0120] 1 Magnetic recording medium

[0121] 11-layer stack

[0122] 12 lubrication layers

[0123] 20, 20A, 20B grinding belts

[0124] 21 Supporters

[0125] 22 abrasive layers

[0126] 50 Polishing Equipment

[0127] 53A No. 1 grinding belt supply reel

[0128] 53B No. 2 grinding belt supply reel

[0129] 54A No. 1 Grinding Belt Winding Reel

[0130] 54B No. 2 grinding belt winding reel

[0131] 111 substrate

[0132] 112 magnetic recording layers

[0133] 113 protective layer

[0134] 221 abrasive grains

[0135] 222 adhesive

[0136] 521 A pair of grinding belts pushing means

[0137] 522 A pair of grinding belt moving systems

[0138] 521A First Grinding Belt Pushing Method

[0139] 521B No. 2 Grinding Belt Pushing Method

[0140] 522A First Grinding Belt Moving System

[0141] 522B Second Grinding Belt Moving System

[0142] S-grinding surface

Claims

1. An abrasive belt, which is an abrasive belt wound in a roll shape as a long strip, having: Support body On one side of the support, abrasive grains are adhered as abrasive material, and An adhesive layer on the other side of the support.

2. The grinding belt according to claim 1, The adhesive layer comprises one or more adhesives selected from the group consisting of rubber-based adhesives, acrylic adhesives, urethane adhesives and silicone adhesives.

3. The grinding belt according to claim 1 or 2, The support comprises one or more resins selected from the group consisting of polyester resins, polyolefin resins, acrylic resins and polycarbonates.

4. The grinding belt according to claim 1 or 2, An undercoat layer is further provided between the support and the adhesive layer.

5. The grinding belt according to claim 4, The base coating comprises an adhesive selected from one or more of the group consisting of rubber-based resins, epoxy resins, polyurethane resins, acrylic resins, polyester resins, silicone resins, silane coupling agents, polyolefin resins, polycarbonate resins, and polyurethane resins.

6. A method for manufacturing a magnetic recording medium, comprising the following steps: A polishing process is performed on a substrate by polishing the surface of a laminate in which a magnetic recording layer and a protective layer are sequentially stacked, using an abrasive material. The polishing process includes the following steps: on one side of the support, abrasive grains are adhered as the abrasive material, and on the other side of the support, a long strip of abrasive tape with an adhesive layer is used in a rolled state, and the abrasive tape supplied from the rolled state is pressed against the surface of the laminate and rubbed.

7. The method for manufacturing a magnetic recording medium according to claim 6, It includes the process of forming a lubricating layer on the surface of the laminate. The polishing process involves polishing the surface of the laminate with the lubricating layer using the abrasive material.

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