JP5977606B2 - Surface treatment sheet with abrasive particles for treating the surface of a workpiece - Google Patents

Description

  The present invention relates to a sheet for processing the surface of a work such as a magnetic hard disk, a magnetic head, a semiconductor wafer, a liquid crystal panel, and an optical lens. In particular, it removes unnecessary protrusions (burrs), scratches, foreign particles such as particles adhering to the surface of the workpiece, or contaminants floating on the surface of the workpiece, which are left on the surface of the workpiece that has been processed such as film formation. The present invention also relates to a surface treatment sheet with abrasive particles for smoothing and flattening the surface of a workpiece with higher accuracy.

  Devices such as computers, televisions, cameras, and telephones are always required to have higher performance. That is, it is required to realize higher performance by increasing the recording capacity of sound, images, etc., and improving the smoothness and cleanliness of the screen (liquid crystal panel) and lens. In order to manufacture such a device so as to exhibit the expected performance at the design stage, it is important to manufacture each component constituting the device with high accuracy as designed.

  For example, a magnetic recording medium 1 such as a magnetic hard disk shown in FIG. 1 is made of a substrate 2 (made of glass or an aluminum alloy whose surface has been subjected to Ni-P plating treatment) formed into a disk having a predetermined size. The base layer 3, the magnetic layer 4, the protective layer 5, and the lubricating layer 6 are formed on the substrate. The manufacturing process of such a magnetic recording medium 1 is roughly divided into a substrate pretreatment process, a film forming process, and a post-treatment process. Specifically, each process includes each process as shown in FIG.

  The substrate pretreatment process mainly includes i) substrate formation process, ii) rough polishing process, iii) inner and outer peripheral end face grinding process, iv) inner and outer peripheral end face polishing process, and v) surface finish polishing process. When manufacturing a perpendicular magnetic recording medium, high-precision mirror polishing is performed in the surface finishing polishing step v). When an in-plane magnetic recording medium is manufactured, vi) surface texture processing is further performed after the surface finishing step v), and the substrate surface is appropriately roughened along the circumferential direction.

  In the film forming step, vii) the base layer 3 is formed on the surface of the substrate pretreated as described above by a thin film manufacturing apparatus, and viii) the magnetic layer 4 (perpendicular magnetic recording medium is soft when manufacturing a perpendicular magnetic recording medium). This is a step of forming the recording magnetic layer), ix) the protective layer 5 and x) the lubricating layer 6 on the magnetic layer.

  Further, post-processing is performed to clean the surface of the substrate on which the film has been formed. As shown in FIG. 2, the post-processing step-I is composed of xi) burnishing process and xii) wiping process. Through these steps, the magnetic recording medium 1 is manufactured.

  The xi) burnishing step xi) is performed by lightly polishing the surface of the formed substrate (for example, the lubricating layer 6), thereby removing fine abnormal protrusions (burrs) or fixed matters on the surface of the formed substrate. This is a removal step (Patent Document 1: Japanese Patent Laid-Open No. 2001-66755). For example, the process may be performed by mixing fine alumina abrasive grains and a resin and applying a polishing tape (burnish tape) coated on the surface of the film base with a rubber contact roll or the like. This is done by pressing on.

  The wiping treatment step xii) is a step for removing foreign matters such as particles and oil adhering to the surface of the substrate on which the film has been formed and oil, or dust and dirt floating on the surface after the burnishing treatment. (Patent Document 2: JP-A-10-106229, 3: JP-A-2009-299218, 4: JP-A-2010-97636). In this process, a tape (wiping tape) or a knitted fabric that does not have an abrasive force substantially is used to remove contaminants and floating matters with low adhesion (not fixed) and to flatten and smooth the surface. (Wiping cloth) is used.

  In the burnishing process as described above, foreign matter such as particles generated in the film forming process adheres to the tape and is caught between the surface of the work (object to be processed), or moves on the surface to move the work. The surface could be damaged. For this reason, as in post-processing step-II in FIG. 3, vi-a) wiping processing step a may be performed (Patent Document 5: Japanese Patent Laid-Open No. 2008-135091). The wiping process a is a process for previously wiping off relatively large foreign matters and deposits so as not to cause scratches or the like in the burnish process. After this process, xi) burnishing process and xii) wiping process are performed. Thus, conventionally, the wiping process and the burnish process are performed in combination (multiple times).

  Further, in the burnishing process, the abrasive grains fixed to the polishing tape used fall off, or the surface of the abrasive grains is slightly crushed, so that the degranulated material and the crushed abrasive powder are removed from the surface of the workpiece. In the past, the surface of the abrasive layer of the polishing tape was covered with a solid resin layer having a thickness in the range of 0.5 μm to 10 μm, and the surface of the resin layer was liquid. A polishing tape covered with a lubricating layer was proposed (Patent Document 6: Japanese Patent Laid-Open No. 2010-12530).

  Alternatively, as a polishing tape for mechanically polishing the surface of a workpiece such as a magnetic recording medium, a tape in which a large number of polishing hairs with abrasive grains made of a non-conductive material are provided on the surface of a substrate has been proposed ( Patent Document 7: Japanese Patent No. 3598115).

JP 2001-67655 A Japanese Patent Laid-Open No. 10-106229 JP 2009-299218 A JP 2010-97636 A JP 2008-135091 A JP 2010-12530 A Japanese Patent No. 3598115 JP 2001-162504 A

  As described above, when combining a plurality of wiping treatment steps and burnish treatment steps so as not to cause scratches or the like in the burnish treatment step, there is a problem that the number of steps increases and the manufacturing cost increases. .

  Further, in the burnishing process, when a conventional polishing tape whose abrasive layer is coated with a resin or the like is used, even if the surface contamination of the magnetic recording medium due to degreasing is suppressed, the protrusion generated in the film forming process It has been difficult to remove the sticking matter and the like with high processing accuracy required for high-density recording.

  When the flocked sheet according to Patent Document 7 is used as an abrasive tape, the abrasive particles are fixed to the flocked tip, so that there is a problem that the flocked tip comes into contact with the surface of the work like a toothbrush and generates scratches. . The flocking sheet according to Patent Document 7 is for applying a fine and uniform texture to the surface of a hard disk substrate or the like, and thus is not suitable for a post-processing step (cleaning step).

  In view of the above-described problems, the present invention can accurately remove unnecessary protrusions and fixed objects formed on the surface of the work without causing new fine scratches on the surface of the work such as a substrate. An object of the present invention is to provide a surface treatment sheet with abrasive particles that can be removed and foreign matter and dirt adhering to and floating on the surface can be removed. In other words, the surface of the workpiece is properly polished so as not to scrape too much to remove the adhering matter, and there is no degranulation of the abrasive particles. It aims at providing the sheet | seat with an abrasive particle which has it.

  Another object of the present invention is to perform a shortened and efficient post-treatment (cleaning) step by using the above-mentioned surface treatment sheet with abrasive particles.

  The surface treatment sheet with abrasive particles according to one embodiment of the present invention for achieving the above object is based on a woven fabric composed of long fibers. The coverage of the surface of either the warp or weft constituting the woven fabric is higher than that of the other, and at least the surface of the warp or weft has a high coverage on the surface. Consists of yarn. Abrasive particles are fixed to the surfaces of a plurality of single yarns located in a portion of the base material in contact with the surface of the workpiece by a binder resin. The plurality of single yarns include a single yarn having a recess formed on the surface, and the abrasive particles are fixed to at least the recess. By setting it as such a structure, the surface treatment sheet | seat which has both a burnish effect | action and a wiping effect | action is obtained.

  The surface treatment sheet with abrasive particles according to another embodiment of the present invention is based on a knitted fabric composed of long fibers composed of a plurality of single yarns. Abrasive particles are fixed to the surfaces of a plurality of single yarns located at portions of the base material that are in contact with the surface of the workpiece by a binder resin. The plurality of single yarns includes a single yarn having a recess formed on the surface, and abrasive particles are fixed to at least the recess. The knitted fabric (knit) may be composed of weft knitting (horizontal) or warp knitting (vertical knitting).

  The recess is a polygon having a cross-sectional shape of a single yarn of three or more vertices, or a multi-leaf shape having three or more protrusions, and between each vertex of the polygon or each of the multi-leaf shapes. It may be formed by recessing between the protrusions.

  Preferably, the plurality of single yarns constituting the long fiber includes a modified cross-section fiber having a non-circular cross-sectional shape. The cross-sectional shape may be a 3-10 leaf shape or a star shape.

  It is preferable that the abrasive particles are fixed to the recesses formed on the surface of such a single yarn. This is because the adhesion strength of the abrasive particles is increased, and the abrasive particles can be allowed to act so as not to cause fine scratches on the surface of the workpiece while preventing the particles from falling off.

  The concave portions may be formed continuously along the longitudinal direction of the single yarn by having the single yarn having a predetermined cross-sectional shape. Moreover, a recessed part may be regularly formed surrounding the periphery of the longitudinal axis of a single yarn. Alternatively, the recesses may be irregularly formed around the longitudinal axis.

  The abrasive particles may be fixed only to the concave portions, mainly fixed to the concave portions, or may be fixed to the entire surface of the single yarn including the concave portions.

  The sheet for surface treatment according to the present invention is characterized in that each of the plurality of single yarns to which the abrasive particles are fixed is not fixed to each other and can move independently. By doing so, the surface of the sheet in contact with the workpiece has sufficient cushioning properties, and scratches or the like are not formed on the surface of the workpiece.

  The single yarn fineness of the plurality of single yarns is preferably in the range of 0.01 dtex or more and 4.5 dtex or less. The average particle size of the abrasive particles is preferably 10 μm or less.

  The single yarn fiber diameter of the plurality of single yarns is preferably in the range of 1 μm or more and 20 μm or less. The fiber diameter is an average diameter (circle-converted diameter) of a circle whose cross-sectional area is converted to the same circle when the cross-sectional shape is not circular (an irregular shape such as a triangle or a star).

  The abrasive particles are made of an inorganic material, an organic material, or a mixture of an inorganic material and an organic material, and have an average particle diameter of 10 μm or less and preferably ½ or less of the single yarn fiber diameter. With a configuration in which fine abrasive grains are fixed to the surface of a fine single yarn, a sheet capable of processing the surface of the workpiece with high accuracy is obtained.

  Furthermore, in the sheet for surface treatment according to the present invention, the coverage of the warp or weft on the surface of the woven fabric serving as the substrate is 70% or more, and when the surface of the workpiece is treated, the surface of the substrate in contact with the surface of the workpiece The portion is configured to be either one of the warp and the weft having a high coverage.

  The structure of the woven fabric is a Mihara structure (plain weave, satin weave, or weft weave), and it is particularly preferable that weaving weave or satin weave.

  The part of the base material that contacts the surface of the workpiece is composed of an array of warps or wefts, so that it has an appropriate cushioning property and acts uniformly on the surface of the workpiece to effectively prevent protrusions and deposits. Can be removed and wiped off.

  As described above, the surface treatment sheet with abrasive particles according to the present invention has a structure in which abrasive particles are attached to the surface of each fine single yarn located in a portion in contact with the surface of the workpiece of the base material by a binder resin. It has become. Since the single yarns to which the abrasive particles are fixed are not fixed to each other, the sheet has a cushioning property, and the surface of the workpiece is not scraped excessively or without forming a scratch on the surface of the workpiece. Can be cleaned with high precision. In other words, while acting on the surface of the workpiece with a light polishing force and exerting a burnish action that removes sticking matters and deposits such as unnecessary protrusions, multiple single yarns are stuck to foreign matter and dirt, etc. The wiping action can also be exerted.

  Since the woven or knitted fabric used for the base material is composed of long fibers, the single yarn fiber waste constituting the portion of the base material that contacts the workpiece does not fall off and contaminate the surface of the workpiece. Further, the shape of the surface of the plurality of single yarns in contact with the surface of the work can elastically contact the surface of the work while holding the abrasive particles stably. Occurrence of scratches due to falling off or crushing of abrasive particles is prevented, and highly accurate post-processing can be performed.

  By implementing the surface treatment sheet with abrasive particles according to the present invention, the post-treatment process can be performed efficiently. For example, the surface of a workpiece such as a magnetic recording medium can be flattened and cleaned with high accuracy by a single post-processing step using the sheet according to the present invention, and high density recording as designed can be realized. Further, it is possible to shorten the conventional process of performing the burnish process and / or the wiping process a plurality of times, improve the yield, and improve the reliability of the product.

FIG. 1 is a schematic cross-sectional view of a magnetic recording medium. FIG. 2 is a diagram showing a manufacturing process of the magnetic recording medium. FIG. 3 is a diagram showing another example of the post-processing step in the manufacturing process of the magnetic recording medium. FIG. 4: is the (a) top view of the textile fabric of one aspect used for the base material of the sheet | seat of this invention, (b) Organizational chart, (c) WW sectional drawing. FIG. 5 is an SEM photograph of the surface of the fabric of one embodiment used for the base material of the sheet of the present invention. FIG. 6 shows (a) an enlarged SEM photograph of the XX section in FIG. 5 and (b) an enlarged SEM photograph of the YY section in FIG. 5 of the fabric of one embodiment used for the base material of the sheet of the present invention. It is. Fig.7 (a) is a figure which shows typically one aspect of the several single yarn which comprises the weft of the textile fabric based on this invention, and FIG.7 (b) shows typically one aspect of a single yarn. FIG. FIGS. 8A and 8B are enlarged SEM photographs of 2000 times (left) and 5000 times (right) of the portion of the surface treatment sheet with abrasive particles according to the present invention that is in contact with the surface of the workpiece. FIG. 9 is a view schematically showing a double-sided cleaning device that performs a post-processing step using the surface treatment sheet with abrasive particles according to the present invention. FIG. 10 is a diagram schematically showing a gravure coating apparatus used for manufacturing the surface treatment sheet with abrasive particles according to the present invention.

  In the following, the features of the present invention will be described together with preferred embodiments which are not intended to limit the present invention. The drawings are simplified for the purpose of explanation, and the scales do not necessarily match.

Fabrics used in the base material of the substrate present invention is formed by intersecting vertically arranged the warp and weft yarns consisting of long fibers at right angles. The knitted fabric is formed by repeatedly forming a loop by making a loop with long fibers and passing a thread through the loop.

  The woven fabric used for the base material of the present invention has a structure in which warps and wefts are arranged. The structure may be a Mihara structure, that is, plain weave (plain), oblique weave (twill, twill), satin weave, and preferably weave or satin weave. The texture of the oblique weave is a structure in which two or more warps or wefts are arranged to intersect with the wefts or warps, and has a characteristic that wrinkles appear in an oblique direction. In satin weaving, the points where the warp and weft intersect (intersection points, structure points) are arranged away from each other. Either warp or weft appears on the surface for a long time, and the structure points are almost on the surface. It does not appear.

  The woven fabric according to the present invention preferably has a higher coverage ratio on one surface of warp or weft (ratio of the warp or weft appearing on the surface with respect to the fabric area when the woven fabric is viewed in a plane) than the other. (70% or more, 80% or more, 90% or more, etc., any value between 70% and 100%). Moreover, it is preferable that the arrangement | sequence of the warp or the weft which appears on the surface of a textile fabric is equal to the X direction or the Y direction regarding the orthogonal X-axis Y-axis. The structure of the woven fabric according to the present invention is not limited to the three-primary structure having the above-described characteristics, and may be a changed structure obtained by changing the three-dimensional structure, or a mixed structure obtained by mixing these.

  FIGS. 4A to 4C show one embodiment of the fabric 10 used for the base material of the surface treatment sheet with abrasive particles according to the present invention. As shown in FIG. 4 (a), the woven fabric 10 has a weft 12 that floats and appears on the surface, and has a twill texture as shown in FIG. 4 (b). As shown in a schematic cross section of the fabric 10 in FIG. 4C, the weft 12 swells in the thickness direction rather than the warp 11. The types of single yarns constituting the warp 11 and the weft 12 may be the same or different.

  FIG. 5 shows a scanning electron microscope (SEM) photograph of the surface of the fabric 10. In the surface of the fabric 10 having the texture of the oblique weave shown in FIG. 4B, only a few warps 11 (structure points) appear, and the weft 12 covers almost the entire surface (90 percent). Since the portion of the woven fabric 10 that contacts the work is composed of the wefts 12 uniformly, the abrasive particles can be uniformly dispersed and held.

  6 (a) and 6 (b) show enlarged SEM photographs of the cross section of the fabric 10. The weft 12 swells to the surface side of the warp 11 in both the XX and YY sections. . Each of the warp 11 and the weft 12 is composed of a plurality of single yarns. In this way, the weft 12 is floated for a long time on the surface of the fabric, and the warp 12 is composed of a plurality of single yarns, so the fabric 10 has cushioning properties (elasticity). When processing the surface of the workpiece, the portion of the woven fabric 10 consisting of the wefts 12 (the portion located on the surface side from the warp yarn 11 at the texture point) is elastically in contact with the surface of the workpiece and is suitable for surface treatment. Demonstrate the effect.

  Since the portion of the fabric 10 that is in contact with the surface of the workpiece is composed of only the wefts 12, the total fineness (dtex) of the wefts 12 constituting the fabric 10 is 2 to 10 times the total fineness (dtex) of the warp 11. It is preferable to make it. By doing in this way, the surface of the textile 10 can be made into a state with substantially no gap by the arrangement of the wefts 12. Such a portion of the fabric 10 in contact with the workpiece surface can hold the abrasive particles uniformly and cause the workpiece to act uniformly. Furthermore, since it is composed of the long weft 12 that floats, it has cushioning properties and the abrasive particles can be softly brought into contact with the surface of the workpiece, so that scratches such as scratches can be prevented. In the above description, the warp yarn 11 and the weft yarn 12 can be interchanged.

  FIG. 7 schematically shows a plurality of single yarns 13a and 13b constituting the weft 12 (and / or the warp 11). Various types and shapes of single yarns constituting the weft yarn 12 can be used. Preferably, the weft 12 includes a single yarn 13a having a concave portion formed on the surface. The single yarn 13a is a modified cross-section fiber having a non-circular cross-sectional shape, and may be composed of a split fiber of a composite fiber. For example, the cross-sectional shape of the single yarn 13a is not limited to this, but may be a star shape having an arbitrary number of vertices as shown in FIG. By fixing the abrasive particles to the surface of the single yarn having such a recess with a binder resin, the fixing strength of the abrasive particles can be increased, and detachment can be prevented.

  The single yarn fineness of the single yarn contained in the weft 12 is preferably in the range of 0.01 dtex or more and 4.5 dtex or less. Alternatively, the single yarn fiber diameter is preferably 50 μm or less, preferably 1 μm or more and 20 μm or less. When the single yarn fiber diameter is less than 1 μm, it is difficult to fix the abrasive particles to the surface of a sufficient single yarn, and the abrasive particles are likely to fall off. As a result, scratches may occur on the surface of the workpiece due to the deagglomerated abrasive particles. When the single yarn fiber diameter exceeds 50 μm, the rigidity of the woven fabric sheet is increased and the cushioning property is lowered, and the surface of the woven fabric sheet may not be uniformly contacted with the surface of the workpiece, resulting in uneven cleaning. is there. By setting the single yarn fineness (fiber diameter) within the above range, contaminants on the surface of the workpiece can be removed with high accuracy.

  As the single yarn, for example, a synthetic fiber such as a polyester fiber, a polyamide resin (nylon), or a polypropylene fiber may be used. The weft 12 constituting the fabric 10 may be composed of one type of single yarn (for example, 13a), or may be composed of a plurality of types of single yarn (for example, 13a, 13b, etc.).

  The thickness of the fabric 10 is generally in the range of 50 μm to 550 μm.

Abrasive Particles The surface treatment sheet with abrasive particles of the present invention has abrasive particles on the surface of each single yarn (one, one) located on the surface of the fabric 10 as a substrate that is in contact with the workpiece surface. It is characterized by being fixed by.

FIG. 8 shows an enlarged SEM photograph of the surface treatment sheet according to the present invention in which abrasive particles are fixed to each of the single yarns located in contact with the surface of the workpiece of the base material with a binder resin. FIG. 8A shows an alumina (Al ₂ O ₃ ) abrasive particle fixed. The abrasive particles are crushed particles, and are dispersed and fixed over the entire surface including the concave portion of the single yarn.

FIG. 8B is a diagram in which abrasive particles of silica (SiO ₂ ) are fixed. The abrasive particles are precipitated grains (crystal growth grains), and each abrasive particle has a (true) spherical shape. The abrasive particles are fixed mainly to the recesses on the surface of the single yarn.

As the abrasive particles, particles made of an inorganic material can be used. As the inorganic particles, silicon carbide (SiC), diamond, cubic boron nitride (cBN) and the like can be used in addition to the above-mentioned alumina (Al ₂ O ₃ ) and silica (SiO ₂ ). These inorganic particles may be crushed particles or precipitated particles, and may or may not have a spherical shape. By using such abrasive particles, a sheet having an abrasive power suitable for burnishing can be obtained.

  As the abrasive particles, particles made of an organic material may be used. Such abrasive particles may be made of, for example, polystyrene, polymethyl methacrylate, and the like. Alternatively, the abrasive particles may be composed of an arbitrary mixture of an inorganic material and an organic material.

  The average particle size of the abrasive particles is preferably 10 μm or less, and preferably in the range of 0.05 μm or more and 5.0 μm or less. If the thickness exceeds 10 μm, the polishing action becomes strong, which causes scratches and scratches, which is not preferable. On the other hand, if the particle size is too large, the fixing strength of the abrasive particles to the surface of the fine single yarn having the fineness (fiber diameter) described above becomes weak, which is not preferable because it causes degranulation. Increasing the amount of the binder resin to increase the fixing strength is not preferable because the cushioning property of the surface of the sheet is lowered. By making the average particle size of the abrasive particles 10 μm or less (preferably 0.05 μm or more and 5.0 μm or less), the portion of the sheet that acts on the workpiece surface has sufficient cushioning properties and is suitable for the post-processing step. Sheet.

  The material, shape, and the like of the abrasive particles can be selected depending on the material of the workpiece that is the object to be processed, the contamination state of the surface, and the like. By selecting the material, shape, and the like of the abrasive particles, a desired action can be selectively strengthened or weakened among the burnish action and the wiping action.

  In the portion of the surface treatment sheet with abrasive particles according to the present invention that is in contact with the surface of the workpiece, undulations (waves) are formed by the shape and texture (texture point) of the single yarn. This wave also provides cushioning suitable for cleaning to the sheet, and is effective for wiping away particles and the like by removing the protrusions by causing the abrasive particles fixed to each single yarn to act appropriately on the surface of the workpiece. is there. That is, the portion of the cushioning sheet that contacts the workpiece surface acts on the workpiece surface with an appropriate (weak) polishing force, and protrusions and deposits can be removed without forming scratches. Further, since the single yarns are not fixed to each other, the contaminant that has moved to the sheet side can be taken into the sheet, and the contaminant can be prevented from adhering to the workpiece again. In addition, the base material consists of a woven or knitted fabric composed of long fibers, and the surface is impregnated with a binder resin, so there is no loss of fiber waste or abrasive particles, and there is no contamination of the workpiece derived from the sheet. Cleaning process can be performed.

Production of Surface Treated Sheet with Abrasive Particles The surface treated sheet with abrasive particles according to the present invention is coated with a coating made of abrasive particles and a binder resin on the surface of a woven or knitted fabric as a substrate, dried and wound on a reel. It is manufactured by cutting into a predetermined size. A specific manufacturing method will be described below using a fabric as an example.

-Base material The raw fabric (for example, thickness 50micrometer-550micrometer, width 500mm, length 600m) is prepared. The structure of the woven fabric, the warp, the type of single yarn constituting the weft, and the like can be selected as appropriate.

-Abrasive particles Abrasive particles include (spherical) inorganic particles, such as alumina, silicon carbide, silicon dioxide (silica), zirconia, diamond or cubic boron nitride, acrylic resins, epoxy resins, polyethylene resins, polyurethane-based particles (Spherical) organic particles made of a resin or the like, or (spherical) mixed particles of an inorganic substance and an organic substance can be used. The average particle size of the abrasive particles is in the range of 0.05 μm or more and 10 μm or less.

-Binder resin As the binder resin for fixing the abrasive particles to the surface of the single yarn, one or more resins selected from polyester resin, polyurethane resin, copolymer vinyl resin, epoxy resin, phenol resin, etc. are used as a solvent. The dissolved one is used. As the solvent, toluene, methyl ethyl ketone, xylene, ethyl acetate, cyclohexanone, acetone, alcohol or the like can be used. An isocyanate-based curing agent is added to this.

-Paint A paint is produced by mixing abrasive particles and a binder resin. The viscosity of the paint is preferably in the range of 50 cp to 300 cp. When the viscosity of the paint is less than 50 cp, the paint falls from the surface of the base material to the lower layer side, and a sufficient amount of abrasive particles cannot be fixed on the surface of the single yarn located at the portion in contact with the work. Since the abrasive particles cannot sufficiently act on the surface, the adhered foreign matter or the like cannot be sufficiently removed. When the viscosity of the paint exceeds 300 cp, the paint stagnates on the upper surface of the base material, and the layer in which the binder resin and abrasive particles are fixed to the part in contact with the surface of the work so that the adjacent single yarns are fixed to each other. As a result, the cushioning property of the surface portion of the seat is lowered, which causes a scratch on the surface of the workpiece.

  The blending ratio (weight ratio) of the solid content in the paint is preferably in the range of 30% by weight or more and 90% by weight or less of the abrasive particles. When the proportion of abrasive particles is less than 30% by weight, the blending ratio of the binder resin and the like increases, and the area where the adjacent fine single yarns adhere to each other at the surface portion acting on the surface of the workpiece of the sheet increases. Therefore, it is not preferable. When the proportion of the abrasive particles exceeds 90% by weight, the amount of particles that are not sufficiently bonded to the binder resin increases, and the abrasive particles are separated during cleaning, which causes an increase in scratches. Table 1 below shows the composition of the paint.

Alumina _{(Al 2 O} 3), silica 30 wt% to 90 wt% abrasive particles made of (SiO ₂₎ or the like, toluene saturated polyester resin, methyl ethyl ketone and the resin was dissolved in a mixed solvent of ethyl acetate solution 5% and 40 Add 1 wt% to 10 wt% of an isocyanate-based curing agent just before being applied to the surface of the substrate (woven fabric) after mixing and stirring with wt%, dispersing abrasive particles in the resin solution, and filtering. Thus, a paint having a viscosity adjusted to a range of 50 cp to 300 cp is manufactured.

-Application | coating method Although the gravure coating is used suitably for the method of apply | coating a coating material to a base material, spray coating or electrodeposition coating may be used instead. Gravure coating is a method in which a gravure roller is coated with a paint in which abrasive particles are dispersed, and this is transferred to the surface of a substrate wound around a backup roller. The base material coated with the paint is dried and wound on a reel to obtain an original sheet of a surface treatment sheet with abrasive particles.

  FIG. 10 schematically shows a gravure coating apparatus 30 for producing the surface treatment sheet according to the present invention. The gravure coating apparatus 30 includes a gravure roller 31 and a backup roller 32 disposed in proximity to the gravure roller 31. The raw material B of the base material is disposed on the backup roller 32 with the surface to which the paint is applied facing outward, and is curved in a substantially U-shape as the backup roller 32 rotates in the circumferential direction R2 (counterclockwise). Drive in the R direction. The gravure roller 31 is partially immersed in a paint 33 in which abrasive particles and a binder resin are kneaded and rotated in the direction R1 (clockwise). The paint 33 ′ adhering to the gravure roller 31 is adjusted to a predetermined amount of paint 33 ″ by the doctor blade 34. Such a coating material 33 ″ is applied to the surface of the original fabric B as the original fabric B of the base material is conveyed in the R direction, and abrasive particles adhere to the surface of each single yarn. The thickness of the coating material to be applied may be adjusted by the distance between the gravure roller 31 and the backup roller 32.

  The raw material of the base material coated with the coating material is solidified with a resin binder through a drying furnace, and the abrasive particles are fixed to each surface of the single yarn located in the portion acting on the surface of the workpiece. This is wound up on a reel to obtain the raw sheet of the surface treatment sheet with abrasive particles according to the present invention. The raw sheet of the surface treatment sheet may be cut into a predetermined length and width according to the application and used as a cleaning tape. The width of the cleaning tape may vary depending on the diameter of the magnetic hard disk or the structure of the cleaning device when the work to be processed is a magnetic hard disk. For example, the raw sheet of the surface treatment sheet may be cut into a width of 6.3 mm, 12.6 mm, 38 mm, or the like, and the length may be a unit of 10 to 20 m.

The post-processing (cleaning) process Figure 9 using the sheet of the present invention, the double-sided cleaning device 20 (Patent Document 8: JP 2001-162504) to clean both sides of the disk-shaped workpiece W such as a magnetic hard disk simultaneously schematic Has been shown. In the double-sided cleaning device 20, cleaning tapes T and T ′ (broken lines) with abrasive particles obtained by cutting the original fabric manufactured as described above into a predetermined width (for example, 12.6 mm) are used.

  The double-sided cleaning device 20 includes a cleaning head 22 for cleaning both sides of a disk-shaped workpiece W, and means (not shown) for reciprocating the cleaning head 22 in the direction of arrow X. The cleaning head 22 has a pair of arms 23, 23 arranged to face each other, and elastic backings (elastic pads) 24, 24 made of rubber or the like are opposed to each other at the tips of the arms 23, 23. It is fixed.

  Cleaning of both surfaces (surface A, surface B) of the workpiece W is performed by rotating the workpiece W attached to the spindle 21 and feeding the cleaning tapes T and T ′ onto the backings 24 and 24, and applying the pressurizing means 25 and 25. The cleaning head 22 is reciprocated along the radial direction of the workpiece W (the direction indicated by the arrow X) while driving and pressing the cleaning tapes T and T ′ against both surfaces A and B of the workpiece W via the backings 24 and 24. Is done. During the cleaning, the cleaning tapes T and T ′ may be sent out continuously or intermittently, and may be stopped (that is, the cleaning tapes T and T ′ are not sent out during the cleaning).

  The surface treatment sheet with abrasive particles (cleaning tape with abrasive particles) of the present invention may be implemented by other cleaning devices and cleaning methods. For example, the raw material of the surface treatment sheet with abrasive particles may be cut into a desired shape and used as a cleaning pad with abrasive particles. After affixing the cleaning pad to the surface of the surface plate, supplying the cleaning liquid to the surface of the cleaning pad while rotating the surface plate, and pressing the surface of the work against the surface of the cleaning pad, the surface finish of the work surface Alternatively, processing such as cleaning can be performed.

Example 1
A cleaning sheet with abrasive particles of Example 1 was produced. Twill fabric (manufactured by Toray Industries, Inc., # 14185, see FIGS. 5 and 6) was used as the substrate. The long fibers constituting the woven fabric have a triangular cross-section polyester fiber having a single yarn fineness of about 0.12 dtex (single yarn fiber diameter: about 4 μm), and a single yarn fineness of about 0.55 dtex (single yarn fiber diameter: It was made of a nylon fiber having a star-shaped cross section with a diameter of about 136 / inch and a horizontal density of about 170 / inch. The thickness of the fabric was about 300 μm.

As the abrasive particles, Al ₂ O ₃ (AWA # 10000) and an average particle diameter of 0.5 μm are used, and this is used as a binder (binder) resin A (Toyobo Co., Ltd., Byron 10SS (solution)), a binder. (Binder) Resin B (manufactured by Toyobo Co., Ltd., Byron GK680 (solution)), organic solvent (commercially available methyl ethyl ketone, toluene, ethyl acetate), and curing agent (Dainippon Ink & Chemicals, Vernock D750) A coating solution (paint) was produced by mixing with. Table 2 shows the blending amount of the paint and the solid content blending ratio.

  First, the binder resin A and the binder resin B are weighed, an organic solvent is added to the tank, and while stirring, alumina abrasive particles are added and stirred for about 30 minutes, whereby a mixed solution containing alumina particles is obtained. manufactured. Next, the alumina particles were sufficiently dispersed in the mixed solution using a disperser, and then filtered using a filter to remove foreign matters from the mixed solution. Further, while the mixed solution was stirred, a curing agent was added, and an organic solvent was further added until a predetermined concentration was obtained, whereby a coating solution was produced. The viscosity of the paint thus produced was about 190 cp. The blending ratio of the abrasive particles to the solid binder resin was 76% by weight.

  The above paint was applied to the surface of the woven fabric. Application of the paint was performed by the gravure coating described above with reference to FIG.

  Next, the coating solution applied to the surface of the woven fabric was dried at 100 ° C. through a drying furnace to solidify the coating solution, and the alumina abrasive particles were fixed to the single fibers on the surface of the woven fabric. Finally, it was cut into a predetermined width and length, and the cleaning sheet with abrasive particles of Example 1 was manufactured.

  FIG. 8A is an SEM photograph of the sheet of Example 1. FIG. Alumina particles are fixed to the entire surface including the recesses for each single yarn.

Example 2
A cleaning sheet with abrasive particles of Example 2 was produced. In the cleaning sheet with abrasive particles of Example 2, spherical silica particles having an average particle diameter of 1.0 μm were used as abrasive particles. Moreover, the coating material was manufactured by using the same material as in Example 1 and changing the blending ratio as shown in Table 3 below. Other conditions were the same as in Example 1.

  FIG. 8B is an SEM photograph of the sheet of Example 2. True spherical silica particles are mainly fixed to the recesses on each of the surfaces of the single yarn.

Comparative Example 1
As the cleaning sheet of Comparative Example 1, the same fabric as in Example 1 was used, and the cleaning sheet was used as it was without applying a coating containing abrasive particles.

Comparative Example 2
As a cleaning sheet of Comparative Example 2, a flocked sheet with abrasive particles was produced. In the flocked sheet with abrasive particles of Comparative Example 2, a large number of fibers made of polyester having an average fiber diameter of 10 μm and an average length of 500 μm (500 μm ± 100 μm) are planted on a PET substrate sheet having a thickness of 50 μm. 1 was prepared by applying the same paint using the same application method.

Cleaning test Cut the cleaning sheets of Examples 1 and 2 and Comparative Examples 1 and 2 into cleaning tapes, and use them to clean both sides of the magnetic hard disk and examine the surface condition before and after cleaning. A cleaning test was conducted.

  The magnetic hard disk used in the cleaning test was obtained by mirror-polishing the surface of a 2.5-inch glass substrate and then forming an underlayer, a magnetic layer, a protective layer, and a lubricating layer on the mirror-polished surface. One test hard disk was prepared for each of Examples 1 and 2 and Comparative Examples 1 and 2. A cleaning test on both sides (A side and B side) of the test hard disk was performed using the double side cleaning device described above with reference to FIG. The cleaning conditions were as shown in Table 4 below.

  Under the above-described cleaning conditions, the number of foreign matters (particles), protrusions, and scratches existing on the surface of the test hard disk before and after cleaning, and how the surface roughness (Ra, Rmax) changed were tested. The number of foreign objects (particles) and protrusions and the number of scratches are determined by irradiating the surface of a test hard disk rotating at 5000 rpm in the radial direction with an optical surface analyzer (manufactured by Candela Instruments, OSA5100). It was measured. The average surface roughness (Ra) and the maximum height (Rmax: maximum value of the height difference between the protrusion and the valley) were measured using a white light microscope (Zygo, New View 5020) and the surface of the test hard disk. It was measured in an arbitrary range of 0.87 mm x 0.87 mm.

  The results of cleaning tests conducted using the cleaning sheets (tapes) of Examples 1 and 2 and Comparative Examples 1 and 2 are shown in Tables 5 to 8 below. The left side of the table shows the state of both sides of the test hard disk before cleaning, and the right side of the table shows the state of both sides of the test hard disk after cleaning.

  As shown in Tables 5 and 6, the cleaning sheets (tapes) of Examples 1 and 2 according to the present invention have a highly flat hard disk surface (for example, the average surface roughness after cleaning is 0). .4 nm) particles and protrusions can be removed, and it has both high-precision burnish action and wiping action.

  Since the cleaning sheet (tape) of Comparative Example 1 did not have abrasive particles, as shown in Table 7, the protrusions and deposits could not be sufficiently removed. Further, the cleaning sheet (tape) of Comparative Example 2 decreased the maximum height (Rmax), but increased scratches, and thus was not suitable for the cleaning process (burnishing process, wiping process).

  Those skilled in the art will appreciate that many different modifications are possible without departing from the spirit and aspects of the invention. Accordingly, it goes without saying that the embodiments of the present invention are merely examples, and do not limit the scope of the present invention.

10 Woven fabric 11 Warp yarn 12 Weft yarn 13a Single yarn 1
13b Single yarn 2

Claims (8)

A surface treatment sheet with abrasive particles for treating the surface of a workpiece,
A base material composed of a woven fabric of long fibers, wherein the coverage of the surface of either the warp or the weft constituting the fabric is higher than the other, and the coating on at least the surface of the warp or the weft A base material in which the long fibers constituting the warp or weft having a high rate are composed of a plurality of single yarns;
Abrasive particles fixed by a binder resin to the surface of a plurality of single yarns located in the portion of the base material in contact with the surface of the workpiece,
Consisting of
The plurality of single yarns includes a single yarn having a recess formed on the surface, and the abrasive particles are fixed to at least the recess,
Sheet for surface treatment. A surface treatment sheet with abrasive particles for treating the surface of a workpiece,
A base material composed of a knitted fabric of long fibers, wherein the long fibers are composed of a plurality of single yarns;
Abrasive particles fixed by a binder resin to the surface of a plurality of single yarns located in the portion of the base material in contact with the surface of the workpiece,
Consisting of
The plurality of single yarns includes a single yarn having a recess formed on the surface, and the abrasive particles are fixed to at least the recess,
Sheet for surface treatment. The concave portion is a polygon having a cross-sectional shape of a single yarn included in the plurality of single yarns is a polygon having three or more vertices, or a multileaf shape having three or more protrusions, and each vertex of the polygon is Or formed by recessing between the protrusions of each of the multilobes,
The sheet for surface treatment according to claim 1 or 2. Each of the plurality of single yarns to which the abrasive particles are fixed are not fixed to each other and can move independently.
The surface treatment sheet according to any one of claims 1 to 3. The single yarn fineness of the plurality of single yarns is in the range of 0.01 dtex or more and 4.5 dtex or less,
The average particle size of the abrasive particles is 10 μm or less,
The surface treatment sheet according to any one of claims 1 to 4. The coverage of the warp or the weft on the surface of the fabric is 70% or more,
When the surface of the workpiece is treated, the portion of the base material that is in contact with the surface of the workpiece is configured such that either the warp or the weft has a high coverage.
The surface treatment sheet according to claim 1. The fabric structure is a Mihara structure,
The surface treatment sheet according to claim 1. The texture of the woven fabric is a twill weave or satin weave,
The surface treatment sheet according to claim 1.