JP2002254324A - Abrasive sheet and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new abrasive sheet that is manufacturable inexpensively and excels in handleability. SOLUTION: The abrasive sheet has a primer layer on one surface of a flexible substrate, and has a diamond-like carbon layer on the surface of the primer layer. The diamond-like carbon layer is formed into a film on the primer layer in a continuous-winding CVD device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an abrasive sheet and a method for producing the same. More specifically, the present invention relates to a polishing sheet using diamond-like carbon (DLC) as a polishing layer for polishing glass and quartz products, and a method for producing the same.

[0002]

2. Description of the Related Art With the development of the information society, the communication mechanism has been shifting from metal conductor telephone lines to optical fiber cables. In optical communication, demand for optical fiber connector components such as ferrules is expected to increase rapidly in the future.

[0003] Materials such as glass and quartz are used for optical communication components, and these materials must be precisely mirror-polished in order to produce a product. For this reason, diamond polishing sheets having a uniform particle size have been used for polishing optical communication components. Although this diamond polishing sheet has excellent polishing properties, it is very expensive at $ 10,000 in A4 size. Further, there is a problem that the abrasive grains drop off from the sheet during polishing, and the dropped particles cause polishing scratches.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a novel polishing sheet which can be manufactured at a low cost and has excellent handleability.

[0005]

An object of the present invention is to provide a polishing sheet characterized in that an underlayer is provided on one surface of a flexible substrate, and a diamond-like carbon (DLC) layer is provided on the surface of the underlayer. Is solved by

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The polishing sheet of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a schematic sectional view of an example of the polishing sheet 1 of the present invention. The polishing sheet 1 has a base layer 5 on one surface of a flexible substrate 3. It has a diamond-like carbon (DLC) layer 7 formed similar to the shape of the surface of the underlayer 5.

The flexible substrate 3 of the polishing sheet 1 shown in FIG. 1 is, for example, a plastic sheet, cloth, paper or the like.
The thickness of the flexible substrate 3 is generally 25 μm to 100 μm.
Is within the range. When the thickness of the flexible substrate 3 is less than 25 μm, the mechanical strength as a polishing sheet becomes insufficient,
It is easy to tear, torn, and cut. On the other hand, when the thickness of the flexible substrate 3 is more than 100 μm, the flexibility is reduced, and the handleability becomes poor.

The underlayer 5 is made of, for example, Si, SiC, Al ₂
It can be formed from inorganic compound particles such as O ₃ , Cr ₂ O ₃ , and CeO ₂ . Other particles can be used. The underlayer 5 can be formed by dispersing such inorganic compound particles in a binder and applying the dispersion to the surface of the flexible substrate 3. The particle size of the inorganic compound particles used for forming the underlayer 5 is generally 0.2 μm.
５０50 μm. When the particle size is less than 0.2 μm, the polishing property of the DLC layer formed on the underlayer becomes insufficient. On the other hand, if the particle size is more than 50 μm, the polishing flaw becomes too deep, which is not preferable. The density of the inorganic compound particles used for forming the underlayer 5 is preferably in the range of 5 to 100 particles / μm ² . When the density is less than 5 / μm ² , the polishing property of the DLC layer formed on the underlayer is insufficient. On the other hand, when the density is more than 100 pieces / μm ² , the polishing property is saturated, which is not preferable in terms of economy.

As an alternative, the count is 400 (particle size 40 μm).
Since polishing tapes having a particle size distribution from No. m) to No. 20000 (particle size 0.2 μm) are commercially available, a DLC layer can be provided on the polishing layer of this commercially available polishing tape. In addition, slippery particles having a particle size of about 10 nm to 50 μm are provided on a flexible substrate at a density of 5 to 100 particles / μm ² ,
A DLC layer may be provided thereon by a CVD method. The presence of the lubricious particles makes it possible to produce a polishing sheet having irregularities on the surface.

The thickness of the underlayer 5 is preferably in the range of 0.1 μm to 50 μm. The thickness of the underlayer 5 is 0.1
If it is less than μm, the DLC layer 7 cannot be sufficiently supported. On the other hand, if the thickness of the underlayer 5 is more than 50 μm, the flexibility is undesirably reduced.

Although DLC is not as hard as diamond, it is a material having a high hardness of 20 to 100 GPa.
Various cutting parts and mold surfaces are coated as wear-resistant materials. However, there is no example in which the material is deposited and used on the surface of a flexible substrate such as a polishing sheet.

The surface of the underlayer 5 has irregularities due to the particles formed. That is, the surface of the underlayer 5 is a rough surface, not a smooth surface. Actually, it was confirmed that even if the DLC layer was provided directly on the surface of the flexible substrate without providing the base layer 5, a smooth DLC layer was formed and the function as a polishing sheet was not performed at all. On the other hand, when the DLC layer 7 is laminated on the surface of the underlayer 5 having a rough surface, the DLC layer 7 having uniform and sharp irregularities can be provided.

The DLC layer 7 is preferably formed by a vapor deposition method such as vapor deposition. According to this method, it is possible to easily form a DLC layer having a uniform thickness and a shape similar to the shape of the surface of the underlying layer below. Therefore,
The thickness of the DLC layer 7 is preferably in the range of 10 nm to 1 μm. If the thickness of the DLC layer 7 is less than 10 nm, not only the polishing property is lost in a short time, but also sufficient polishing property cannot be obtained. On the other hand, when the thickness of the DLC layer 7 is 1 μm
If it is more than that, the flexibility is undesirably reduced.

From the viewpoint of mass productivity for reducing the cost, it is preferable to form the DLC layer with a continuous winding type CVD apparatus. Although there are various types of CVD equipment, DL
In order to form C, it is necessary to apply a negative bias to the substrate side. In the continuous winding type CVD apparatus used for manufacturing the polishing sheet of the present invention, a high frequency of 100 kHz to 1 MHz is applied to the main drum to generate a negative bias on the substrate side. The applied high frequency is 100k
If the frequency is lower than 1 Hz, a sufficient negative bias does not occur, while 1
If the frequency exceeds MHz, the high-frequency current increases even in the insulator, and thermal damage occurs to the flexible substrate. In the present invention, a microwave of 2.45 GHz is used for the main plasma power supply. This is because the density of microwave plasma is higher than that of RF plasma.

[0015] In the film formation of DLC, as a monomer gas,
Ethylene, acetylene, and hydrocarbons including aromatics can be used. Generally, hydrogen gas can be used as the carrier gas. By forming a nitrogen-containing DLC layer by coexisting with a nitrogen-containing gas at the time of forming the DLC, it is possible to obtain higher hardness than ordinary DLC.

[0016]

EXAMPLES The production of the abrasive sheet of the present invention will be described below in detail. Example 1 W of polishing tape MIPOX manufactured by Nihon Micro Coating Co., Ltd.
A series (polishing abrasive is fused alumina, substrate thickness 25μm
No. 600, 2000, 3000, 4000, 8
No. 000), a DLC film was formed thereon by a continuous winding type CVD apparatus to a thickness of 0.15 μm to prepare a DLC-coated polishing sheet. The DLC film formation conditions were substrate RF bias-2.
50V (RF: 250kHz) microwave power 1.2
kW, ethylene flow rate 240sccm, hydrogen flow rate 300sccm,
The degree of vacuum was 0.3 Torr, and the polishing feed rate was 2 m / min.

Comparative Example 1 W of polishing tape MIPOX manufactured by Nihon Micro Coating Co., Ltd.
A series (polishing abrasive is fused alumina, substrate thickness 25μm
No. 600, 2000, 3000, 4000, 8
No. 000) was used directly as a polishing sheet.

Comparative Example 2 D of polishing tape MIPOX manufactured by Nihon Micro Coating Co., Ltd.
Series (Abrasive grains are diamond, substrate thickness 25μm, 600th, 2000th, 3000th, 4000th, 80th
No. 00) was used as it was as a polishing sheet.

The polishing sheets of Example 1, Comparative Examples 1 and 2 were adhered to rubber, and a fused silica ball having a diameter of 5 mm was used. A sliding test was performed under the conditions. For the sliding test, the number of each abrasive sheet was 600, 2000, 300
Nos. 0, 4000 and 8000 were used consecutively.
The sliding time for each tape was 30 minutes. The surface roughness of the fused quartz sphere after the sliding test was measured by AFM. The results are summarized in Table 1 below.

[0020]

Table 1 Ra (nm) Rmax (nm) Example 1 0.45 1.35 Comparative Example 1 0.95 4.02 Comparative Example 2 0.44 1.34

As is clear from the results shown in Table 1,
In comparison with Comparative Example 1 having no DLC layer, it can be understood that in Example 1 having the DLC layer, the smoothness of the fused quartz surface was higher after the sliding test, and the polishing property of quartz was excellent. Further, when comparing Example 1 with a polishing sheet (Comparative Example 2) using diamond abrasive grains, it can be understood that the smoothness obtained in Example 1 is equivalent to Comparative Example 2.

The cost of the DLC-coated polishing sheet obtained in Example 1 was $ 2000 in A4 size, which was about 1/5 that of a polishing sheet using conventional diamond abrasive grains.

[0023]

As described above, according to the present invention,
By manufacturing a polishing sheet having a DLC layer on the outermost surface with a continuous winding type CVD device, polishing is significantly less expensive while maintaining the same abrasiveness of quartz as compared to a polishing sheet using conventional diamond abrasive grains. You can get a sheet.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an example of a polishing sheet of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Polishing sheet of this invention 3 Substrate 5 Underlayer 7 DLC layer

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Tetsuo Mizumura 1-1-88 Ushitora, Ibaraki City, Osaka Prefecture Inside Hitachi Maxell Co., Ltd. (72) Inventor Yoichi Ogawa 1-188 Ushitora, Ibaraki City, Osaka Prefecture F-term in Hitachi Maxell, Ltd. (reference) 3C063 AA03 AB07 BB01 BG08 BG22 BG24 CC11 EE01 EE26

Claims (4)

[Claims] 1. A polishing sheet comprising: a base layer on one surface of a flexible substrate; and a diamond-like carbon layer on the surface of the base layer. 2. The method according to claim 1, wherein the underlayer is made of Si, SiC, Al.
Abrasive sheet according to claim _{1, 2} O _{3, Cr} 2 _{O 3} and is formed from inorganic particles selected from the group consisting of CeO _2, it is characterized. 3. The polishing sheet according to claim 1, wherein the diamond-like carbon layer is formed by chemical vapor deposition (CVD). 4. A polishing sheet according to claim 1, wherein a diamond-like carbon layer is formed on a surface of an underlayer provided on one surface of the flexible substrate by a continuous winding type CVD apparatus. Production method.