JP2001334473A - Abrasive sheet and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an abrasive sheet having good abrasive efficiency, with abrasive grains exposed from the surface of an abrasive layer in the state of being firmly fixed to the abrasive layer, without causing the deposition of an abrasive grain fixing resin binder on a workpiece surface or the removal of the abrasive grains, and its manufacturing method. SOLUTION: The abrasive sheet 11 is produced by forming the abrasive layer 13 in which the abrasive grains 14 are fixed with the resin binder 15, on the surface of a flexible substrate sheet 12 and then removing a surface region 15' of the abrasive layer 13 with plasma etching until parts of the abrasive grains 14 are exposed from the surface of the abrasive layer 12. The abrasive layer 13 is preferably formed in single-layer arrangement with the abrasive grains 14 laterally lined, not vertically overlapped with one another. The surface resin 15' of the abrasive layer 13 is removed with plasma etching so that the abrasive grains 14 are exposed 1/20-1/2 of an average grain size from the surface of the abrasive layer 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to finish polishing of the surface of a vehicle body or the like, mirror polishing of the surface of a hard disk substrate for a magnetic recording medium, rough polishing of metal or nonmetal such as a magnetic head, a lens, an end face of an optical fiber, etc. The present invention relates to a polishing sheet that is appropriately cut into a tape shape, a disk shape, or the like for use in polishing over polishing, and a method for producing the same.

[0002]

2. Description of the Related Art A polishing sheet has a polishing layer in which abrasive particles are fixed on the surface of a flexible substrate sheet such as a plastic sheet, woven fabric, nonwoven fabric, paper or the like. What is, depending on the polishing application, tape, disk-shaped or other shapes are appropriately cut,
Be commercialized.

The polishing layer is formed by applying a slurry-like polishing coating obtained by mixing abrasive particles to a mixed solution of a polyester-based or urethane-based resin binder and a solvent such as methyl ethyl ketone on the surface of a substrate sheet, followed by drying. . Such a slurry-like polishing paint is widely used because it can uniformly and uniformly distribute abrasive particles in a polishing layer formed on the surface of a substrate sheet.

However, when the coating film of the abrasive coating applied on the substrate sheet is dried to evaporate the solvent component in the coating material, the temperature difference between the surface and the bottom surface of the coating film, the surface tension of the coating film, etc. As a result, a convection phenomenon occurs in the coating film, so that irregularities are formed on the surface of the polishing layer after the coating film is dried, and abnormal projections are locally formed.

In order to solve this problem, Japanese Patent Laid-Open No.
As disclosed in Japanese Patent Application Laid-Open No. 1-207640, a slurry-like polishing paint is applied to the surface of a shaping member (plastic sheet), and the polishing paint applied to the surface of the shaping member is dried to form a slurry. After forming a polishing layer on the surface, a substrate sheet coated with an adhesive is adhered to the surface of the polishing layer formed on the surface of the forming member, and the polishing sheet is applied while the polishing layer is adhered to the surface of the substrate sheet. Only the shaped member was peeled from the polishing layer to produce a polishing sheet.

[0006] When the polishing layer is formed on the surface of the substrate sheet in this manner, the surface of the polishing layer has a shape following the surface of the shaping member, so that a surface free from local abnormal projections can be obtained. However, in the polishing layer formed in this way, most of the abrasive particles distributed on the surface are coated with a resin binder, and during polishing, the abrasive particles are sufficiently pressed against the surface of the workpiece. It is not disclosed in Japanese Patent Application Laid-Open No. H11-207640, because the polishing efficiency is reduced, and a resin binder component adheres to the surface of the workpiece during polishing, thereby deteriorating the surface accuracy of the workpiece. As described above, the surface resin of the polishing layer was wiped off with a brush or the like containing an organic solvent.

However, when an organic solvent is used, it is difficult to evenly wipe the surface resin of the polishing layer, and the surface resin is unevenly wiped. There arises a problem that the abrasive particles are shed from the polishing layer and scratches are formed on the surface of the workpiece.

[0008] Accordingly, an object of the present invention is to allow the abrasive particles to be exposed from the surface of the polishing layer while being firmly fixed to the polishing layer, and a resin for fixing the abrasive particles during polishing. An object of the present invention is to provide a polishing sheet having a high polishing efficiency, in which a binder does not adhere to a surface of a workpiece and does not fall off, and a method for producing the same.

[0009]

According to the present invention, there is provided a polishing sheet comprising: a polishing layer in which abrasive particles are fixed with a resin binder;
It is manufactured by removing the surface resin of the polishing layer by plasma etching and exposing a part of the abrasive particles from the surface of the polishing layer.

The polishing layer preferably has a single-layer arrangement structure in which the abrasive particles are arranged side by side without overlapping one another.

[0011] The surface resin of the polishing layer is subjected to plasma etching so that the abrasive particles are separated from the surface of the polishing layer by 1 / of the average particle size.
It is removed so as to expose 20 to 1/2.

[0012]

FIG. 1 (b) shows a polishing sheet according to the present invention.
Is indicated by reference numeral 11. The polishing sheet 11 of the present invention is shown in FIG.
As shown in FIG. 1A, a polishing layer 13 in which abrasive particles 14 are fixed with a resin binder 15 is formed on the surface of a flexible substrate sheet 12, and then, as shown in FIG. 13 is manufactured by removing the surface resin 15 ′ by plasma etching and exposing a part of the abrasive particles 14 from the surface of the polishing layer 13.

The polishing layer 13 is made of a slurry-like polishing coating obtained by mixing abrasive particles 14 in a mixed solution of a resin binder 15 such as polyester or urethane and a solvent such as methyl ethyl ketone. The abrasive particles 14 are applied to the surface and dried to evaporate the solvent. The abrasive particles 14 are uniformly and uniformly distributed on the abrasive layer 13 and fixed by the resin binder 15. The abrasive particles 14 have an average particle size of 0.01 to
Particles such as aluminum oxide, green silicon carbide, silicon oxide, cerium oxide, chromium oxide, iron oxide, diamond, boron carbide, cerium oxide, or silicon oxide, such as 50 μm crushed (irregular shape), spherical, needle-like, or plate-like Is used, and the size, material and shape of the particles to be used are appropriately selected according to the polishing application.

The polishing layer 13 may have a multilayer arrangement structure (not shown) in which the abrasive particles 14 are arranged so as to overlap one another, but are arranged side by side so that the abrasive particles 14 do not overlap one another. An aligned single-layer array structure (see FIG. 1) is preferred. This is because the polishing layer having a single-layer arrangement structure can reduce the amount of abrasive particles and resin binder used, and can reduce the thickness of the polishing sheet, as compared with the polishing layer having a multilayer arrangement structure. This is because there is an advantage in that the storage space can be saved when the is made into a roll shape.

FIG. 2A shows a single-layer structure of the polishing layer.
As shown in (c), the slurry-like polishing paint is applied to the surface of the shaping member 16 so that the abrasive particles 14 have a single-layer arrangement structure side by side so that the abrasive particles 14 do not overlap each other. The polishing paint applied to the surface of the shaping member 16 is dried, and the polishing layer 13 having a single-layer arrangement structure is formed on the surface of the shaping member 16.
Is formed on the polishing layer 13 formed on the surface of the shaping member 16 and the adhesive layer 1 formed on the surface of the substrate sheet 12.
7 on the surface of the substrate sheet 12 and an adhesive layer 17
This is achieved by peeling off the shaping member 16 from the polishing layer 13 while the polishing layer 13 is adhered via the.

As shown in FIG. 2C, after the polishing paint is dried, most of the abrasive particles 14 on the surface of the polishing layer 13 of the polishing sheet 10 are covered with the resin binder 15, The resin binder 15 (that is, the surface resin 15 'covering the abrasive particles 14) adheres to the surface of the workpiece during polishing.

The polishing sheet 11 of the present invention shown in FIG.
Is manufactured by removing the surface resin 15 'by plasma etching. As shown in FIG. 3, an apparatus 20 used for this plasma etching includes an electrode 24 connected to a high-frequency power supply 26 inside a reaction tank 21 provided with a gas inlet 22 and an exhaust port 23, and an electrode 24 facing the electrode 24. And ground electrodes 25 arranged in
And a feed portion 27 for feeding the polishing sheet 10 formed on the surface of the substrate sheet 12, and sent from the feed portion 27 and passed between the electrodes 24 and 25 to remove the surface resin 15 ′. And a winding section 28 for winding the.

The removal of the surface resin 15 ′ from the polishing layer 13 is performed by adding
Oxygen or argon gas is introduced as a reaction gas under a vacuum environment of not more than mmHg, high frequency power is applied between the electrodes 24 and 25 to generate plasma of gas molecules, and this plasma is caused to collide with the surface of the polishing layer 13. It is done by doing.

The removal of the surface resin 15 ′ is performed by the polishing layer 13.
Is performed so that the exposed portion of the abrasive particles 14 in the above step is 1/20 to 1/2 of the average particle diameter of the abrasive particles 14.
This is because if the exposed portion of the abrasive particles 14 is less than 1/20, the polishing efficiency is reduced, and the resin adheres to the surface of the workpiece during polishing.
This is because if the exposed portion of No. 4 is more than 1/2, the abrasive particles are shed during polishing and cause scratch formation.

Example 1 A mixed solution of a polyester resin binder and a solvent such as methyl ethyl ketone was prepared.
A slurry-like abrasive paint produced by mixing alumina oxide particles (abrasive particles) having an average particle diameter of 1 μm was coated with a 16 μm-thick
About 1μm on the surface of polypropylene sheet (shape member)
And dried, to form a polishing layer having a single-layer arrangement structure on the surface of the polypropylene sheet.

Next, an adhesive is applied to the surface of a polyester sheet (substrate sheet) having a thickness of 25 μm to form an adhesive layer having a thickness of 3 μm. This adhesive layer is used as a polishing layer on the surface of the polypropylene sheet. After sticking, the polypropylene sheet was peeled off from the polishing layer while the polishing layer was stuck on the polyester sheet surface. The surface of the polishing layer thus obtained is a polypropylene sheet (shaping member)
The surface was shaped like the surface of.

The sheet thus obtained was formed into a roll, which was attached to the feed section of the plasma etching apparatus shown in FIG. 3, the reaction tank was set in a vacuum environment of 0.12 mmHg, and the feed rate of the sheet was 1 At a rate of 0.5 m / min, oxygen gas was introduced into the reaction tank at a flow rate of 50 ml / min, high-frequency power of 100 w was applied, and the surface resin covering the polishing layer was uniformly removed.

The condition of the surface of the polishing layer of the polishing tape of Example 1 is as shown in the electron microscope (SEM) photograph shown in FIG. 4, and the abrasive particles were exposed by about 0.1 μm.

<Example 2> A slurry-like polishing paint produced by mixing alumina oxide particles (abrasive particles) having an average particle size of 3 µm with a mixed solution of a polyester resin binder and a solvent such as methyl ethyl ketone was used to form a slurry. A polishing layer having a single-layer array structure was formed on the surface of the polypropylene sheet by applying a thickness of about 3 μm to the surface of a 16 μm polypropylene sheet (shaping member) and drying.

Next, an adhesive is applied to the surface of a polyester sheet (substrate sheet) having a thickness of 25 μm, an adhesive layer having a thickness of 5 μm is formed on the surface of the polyester sheet, and the adhesive layer is used as a polishing layer. After attaching, the polypropylene sheet was peeled off from the polishing layer. The surface of the polishing layer obtained in this manner had a shape conforming to the surface of the polypropylene sheet (shaping member).

The sheet thus obtained was attached to the unwinding portion of the etching apparatus shown in FIG.
A vacuum environment of 12 mmHg was set, the sheet feeding speed was set to 0.4 m / min, oxygen gas was supplied into the reaction tank at a flow rate of 50 ml / min, and high-frequency power of 100 w was applied to the polishing layer. The covered surface resin was uniformly removed.

The state of the surface of the polishing tape of Example 2 is as shown in the electron microscope (SEM) photograph shown in FIG. 5, and the abrasive particles were exposed by about 0.5 μm.

[0028]

As the present invention is configured as described above,
Not only in the polishing sheet having the multilayer arrangement structure but also in the polishing sheet having the single layer arrangement structure, the surface of the polishing layer can be exposed in a state where the abrasive particles are firmly fixed, so that the abrasive particles during polishing are degranulated. In addition, not only the surface resin does not adhere to the surface of the workpiece, but also the polishing efficiency can be improved.

[Brief description of the drawings]

FIG. 1 (a) is a cross-sectional view of a polishing sheet before plasma etching, and FIG. 1 (b) is a cross-sectional view of the polishing sheet after plasma etching.

FIGS. 2A to 2D are cross-sectional views of a polishing sheet in respective manufacturing steps for explaining an example.

FIG. 3 is a schematic diagram of a plasma etching apparatus used in the method of the present invention.

FIG. 4 is an electron micrograph of a polishing layer surface of a polishing sheet manufactured according to the method of the present invention (Example 1).

FIG. 5 is an electron micrograph of a polishing layer surface of a polishing sheet manufactured according to the method of the present invention (Example 2).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Abrasive sheet before plasma etching 11 ... Abrasive sheet after plasma etching 12 ... Substrate sheet 13 ... Abrasive layer 14 ... Abrasive particles 15 ... Resin binder 15 '... Surface resin 16 ... Shaping member 17 ... Adhesive layer 20 ... Plasma etching device 21 ... Reaction tank 22 ... Gas inlet 23 ... Exhaust outlet 24,25 ... Electrode 26 ... High frequency power supply 27 ... Sending unit 28 ... Winding unit

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) B24D 3/28 B24D 3/28 (72) Inventor Mitsuru Saito 3-4-1 Musashino Nihon Micro Coating, Akishima-shi, Tokyo Incorporated F term (reference) 3C058 AA05 AA09 CB03 3C063 AA03 AB07 BB03 BB24 BC05 BG01 BG08 BG22 EE01 EE02 EE26

Claims (4)

[Claims] After a polishing layer in which abrasive particles are fixed with a resin binder is formed on the surface of a flexible substrate sheet, the resin on the surface of the polishing layer is removed by plasma etching, and the surface of the polishing layer is removed from the surface of the polishing layer. A method for producing a polishing sheet, which exposes a part of abrasive particles. 2. The method of manufacturing a polishing sheet according to claim 1, wherein the polishing layer has a single-layer arrangement structure in which abrasive particles are arranged side by side without overlapping vertically. 3. The method for producing a polishing sheet according to claim 1, wherein said abrasive particles are exposed from the surface of said polishing layer by 1/20 to 1/2 of an average particle diameter. 4. A polishing sheet produced by the method according to claim 1.