JP2002361565A - Fixed abrasive grain structural body for precision polishing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deep scratches though abrasive grains are fixed grains, and to provide an excellent polishing performance compared to loose abrasive grains. SOLUTION: In this fixed abrasive grain structural body 1A, an abrasive grain layer formed by mixing abrasive grains 2 of 0.01 to 9 μm in average particle diameter with resin 3 of 0.98 to 19.6 MPa in 100%M, 19.6 to 88.2 MPa in tensile strength, and 250 to 1000% in elongation is put on the surface of a flexible and thin resin film 1 of 10 to 200 μm in thickness, 98 to 19.6 MPa in 100%M, 19.6 to 88.2 MPa in tensile strength, and 250 to 1000% in elongation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planar or curved lens and a fixed abrasive structure suitable for polishing the surface of a glass substrate for an optical disk or a magnetic disk.

[0002]

2. Description of the Related Art In general, in polishing the surface of lenses and glass substrates for optical disks and magnetic disks, a very high-quality polished surface with small surface roughness and average waviness is required.

For this reason, at present, such polishing is performed, for example, in JP-A-2001-72962 and JP-A-2000-2000.
The mainstream is based on loose abrasives disclosed in, for example, Japanese Patent No.

For example, polishing of a lens includes three steps of (1) roughing, (2) sanding, and (3) polishing. The roughing step (1) is a step of processing a glass material of a cut and pressed lens into a shape having a target size in the first step of precision processing of the lens. (2) The sanding step is a step of removing a crack layer in a roughing step as a previous step and determining the curvature of the lens, and is a step of sufficiently finishing the surface accuracy, curvature, and dimensions. The polishing step (3) is a step of removing a fine crack layer generated inside the surface in the sanding step which is a preceding step, and at the same time, obtaining a mirror surface free from scratches and having no optical problem. This polishing step is usually performed by pouring loose abrasive grains (slurry in which cerium abrasive is suspended in water) onto a polishing dish and pressing the sanded glass material against the polishing dish and sliding. I have.

Conventionally, loose abrasive grains have been used in all of the roughing, sanding, and polishing steps. At present, however, the roughing and sanding steps are performed using diamond metal bond or resin bond. Processing is performed with fixed fixed abrasive grains, and high speed and automation are realized.

In the polishing step, polishing pellets in which a cerium abrasive is fixed with a resin or fixed abrasive grains in which a cerium abrasive is formed on a polyethylene terephthalate film (hereinafter referred to as a PET film) have been studied.
It is not widely used because the scratches in the previous process cannot be completely removed, the fixed abrasive grains themselves cause scratches, and it is difficult to polish in accordance with the curvature of the lens.

[0007] Therefore, the polishing step is still performed with loose abrasive grains.

[0008] Similarly, in the surface finish polishing of glass substrates for optical disks and magnetic disks, polishing with loose abrasive grains is also the mainstream.

[0009]

However, in general, there is a problem in that polishing using loose abrasive grains has a good finish but requires a long time for polishing. In general, polishing with loose abrasive grains is inferior in polishing power to polishing with fixed abrasive grains, and it takes more time to finish. Under such circumstances, the polishing process usually requires 20 to 60 minutes to finish one polishing process.

An object of the present invention is to provide a fixed abrasive structure which can solve the problems of the prior art using fixed abrasive grains in the polishing step and can shorten the time of the polishing step.

[0011]

SUMMARY OF THE INVENTION A fixed abrasive structure according to the present invention has a thickness of 10 to 200 .mu.m, a 100% M of 0.98 MPa to 19.6 MPa and a tensile strength of 1%.
Abrasive particles having an average particle diameter of 0.01 to 9 μm are coated on a surface of a flexible thin resin film having a mean particle size of 0.01 to 9 μm in a range of 9.6 to 88.2 MPa and an elongation of 250 to 1000% by 100% M.
Is 0.98MPa to 19.6MPa and tensile strength is 1
It is characterized in that an abrasive layer formed by kneading with a resin of 9.6 MPa to 88.2 MPa and elongation of 250 to 1000% is provided.

According to one embodiment of the present invention, with respect to the 100% M, the tensile strength and the elongation,
The resin film and the resin have the same characteristics.

According to another embodiment of the present invention, the abrasive grains are cerium oxide abrasive grains having an average particle diameter of 1.5 to 3.0 μm.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described in more detail with reference to the accompanying drawings according to embodiments and examples of the present invention.

Before describing the embodiments and examples of the present invention, the process by which the present inventors arrived at the present invention will be described. The present inventors have previously described in Japanese Patent Application No. 7-28.
The present invention is also an inventor of a polishing sheet and a method for producing the same, which were filed as No. 2677 and patented as Patent No. 2808261. The polishing sheet of the invention according to Japanese Patent No. 2808261 was developed mainly for use in repairing an outer plate such as a hood or a door of a damaged automobile in the automobile repair industry. It is used in place of buff polishing including adjustment and the like, and has succeeded in greatly reducing the time required for polishing and finishing. And this polishing sheet,
An abrasive layer is formed on the surface of a flexible thin resin film, and the resin film has a thickness of 10 to 100 μm.
m, 100% M is 0.98 to 19.6 MPa, tensile strength is 19.6 to 88.2 MPa, and elongation is 25.
0 to 1000%, and the abrasive of the abrasive layer is 400%.
It is the number 4000 from (P400). In this polishing sheet, the abrasive layer is formed by bonding abrasive particles to a thin adhesive layer provided on a resin film, and a flexible resin is coated on the bonded abrasive particles. are doing.

The present inventors have found that such a polishing sheet can be used in place of buff polishing, including skin conditioning by a compound in the automobile repair industry, to greatly reduce the time required for polishing and finishing. In view of the above, it is considered that the same effect can be achieved by using it for surface finishing polishing of lenses and glass substrates for optical disks and magnetic disks.
Therefore, various kinds of such polishing sheets were prepared and tested. However, it was found that the experimental results did not provide a significant effect, as shown in the measurement results of Comparative Example 3 described later.

Therefore, the present inventors have utilized the basic structure of such an abrasive sheet, and have investigated the particle size of the abrasive grains used.
Various types and the like are selected, and further, a method and a structure of forming the abrasive layer are variously selected to prepare various fixed abrasive structures, and lenses, optical disks and magnetic disks are formed using the fixed abrasive structures. The present invention has been accomplished by repeatedly performing an experiment in which the surface finish polishing of the glass substrate for use is performed and the polishing state is measured.

The fixed abrasive structure of the present invention is obtained by forming an abrasive layer in which an extremely flexible resin and abrasive grains are kneaded on the surface of an extremely flexible thin resin film. . Normally, an adhesive layer is provided on the surface of the resin film on the opposite side of the fixed abrasive structure from the abrasive layer, and is adhered to the upper surface of an appropriate release base paper.

FIG. 1 shows an enlarged cross section of one embodiment of such a fixed abrasive structure of the present invention. As is well shown in FIG. 1, the fixed abrasive structure 1A of the present invention comprises:
A resin film 1 is coated with a mixture of abrasive grains 2 and resin 3 to form an abrasive layer 2A. In the above-described polishing sheet of Japanese Patent No. 2808261, a thin adhesive layer is provided on a resin film to bond the abrasive grains to the resin film, and a flexible resin is further coated thereon.

In the embodiment shown in FIG. 1, for ease of use, as shown in FIG. 1, an adhesive layer 4 is provided on a surface of the resin film opposite to the abrasive layer 2A, and a release base paper 5 is attached. This is the same as the case of the polishing sheet of the aforementioned Japanese Patent No. 2808261.

According to a preferred embodiment of the present invention, the resin film 1 has a thickness of 10 to 200 μm and a thickness of 100% M
Is 0.98MPa to 19.6MPa and tensile strength is 1
From 9.6 MPa to 88.2 MPa, elongation is from 250 to 1000%. The abrasive grains 2 of the abrasive grain layer 2A have an average particle diameter of 0.01 μm to 9 μm, and the resin 3 of the abrasive grain layer 2A has a 100% M content of 0.98 MPa to 19.6 MPa.
a, tensile strength from 19.6 MPa to 88.2 MPa
And the elongation is from 250 to 1000%.

Here, 100% M means 100% elongation (2
Tensile strength).

When it is desired to grind a lens or the like using such a fixed abrasive structure of the present invention, as shown in the sectional view of FIG.
Prepare 0. A thickness of 0.5 mm
A 5 mm elastic pad 11 is pasted. Then, the fixed abrasive structure 1A is attached to the pad 11 so that wrinkles do not enter.

On the other hand, the lens 12 is fixed to a fixed holder 13 supported by a screw 14, and is pressed against the dish 10 to which the fixed abrasive structure 1A is attached.

Then, the plate 10 is rotated in the direction of the arrow a, the lens 12 is subordinately rotated in the same direction, and the lens 12 is oscillated in the direction of the arrow b through the wrench 14 to perform polishing.

At this time, since the fixed abrasive structure of the present invention is formed of a resin film and a resin layer which are extremely flexible and have a very easy expansion property, not only a flat surface but also a lens Even curved surfaces can be attached without wrinkling.

In a fixed abrasive structure in which an abrasive layer is formed on a resin film having a property that does not easily elongate, such as a PET film, it can be attached to a planar shape, but can be applied to a curved surface such as a lens. If you do not make a cut in the petal pattern, it will wrinkle and uniform polishing is not possible.

Examples of the present invention and comparative examples will be described below. Example 1 The polishing apparatus and polishing conditions by the polishing apparatus were as follows, and the results of measuring the surface roughness (Ra) for each polishing elapsed time by polishing with the fixed abrasive structure of the present invention were shown in the table of FIG. Example 1 ". Polishing device: PH10 / 10V (Nippon Engis Co., Ltd.) Polishing pad: PORON LE-20 (Inoac Corporation) Polishing conditions Surface plate rotation speed: 150 rpm Glass rotation speed: 63 rpm Processing pressure: 200 KPa Polishing object: white glass 60φ, thickness 8 mm planar shape Fixed abrasive structure Thickness: 55 μm Abrasive: cerium oxide (average particle diameter: 1.5 μm to 2.2)
μm) Resin film: thickness: 40 μm 100% M: 2.16 MPa Tensile strength: 44.1 MPa Elongation: 700% Resin of abrasive layer: thickness: 15 μm 100% M: 2.16 MPa Tensile strength: 44. 1MPa elongation: 700%

Example 2 The abrasive used was cerium oxide (average particle size: 2.5 μm).
m to 3.0 μm) (grain size is coarser than that of Examples, almost 40
The result of measuring the surface roughness (Ra) for each polishing elapsed time by polishing under the same conditions as in Example 1 with the same sample as in Example 1 except that the surface roughness was closer to No. 00) is shown in the table of FIG. Example 2 "
Column. Comparative Example 1 FIG. 3 shows the result of polishing under the same conditions as in Example 1 on a sample in which the same abrasive layer as in Example 1 was formed on a PET film and measuring the surface roughness (Ra) for each elapsed polishing time. The results are collectively shown in the column of “Comparative Example 1” in the table. Comparative Example 2 Free abrasive grains were prepared by dispersing the abrasive grains used in Example 1 in water, and the glass was polished with ordinary free abrasive grains, and the surface roughness (Ra) was measured for each elapsed polishing time. The results are summarized in the column of “Comparative Example 2” in the table shown in FIG. Polishing device: Oscar-type polishing device Polishing pad: Cerium pad LP-66 Polishing conditions Platen rotation speed: 83 rpm Stroke: 60 mm Load: 3.3 kg Polished object: white glass 60φ, thickness 8 mm Comparative example 3 No. 2808261 Abrasive sheet (Buflex Co., Ltd.)
Black (trade name): abrasive grains used Silicon carbide polished under the same conditions as in Example 1 using an average particle diameter of 12 μm (which is considerably coarser than Examples 1 and 2), and the surface roughness (Ra) for each elapsed polishing time Are collectively shown in the column of "Comparative Example 3" in the table shown in FIG.

FIG. 4 is a graph showing the unevenness of the glass surface of the first embodiment. FIG. 4A shows an uneven state before polishing, FIG. 4B shows an uneven state after polishing for 5 minutes, FIG. 4C shows an uneven state after polishing for 10 minutes,
(D) shows an uneven state after polishing for 20 minutes, and (E) shows
The unevenness after polishing for 40 minutes is shown, and (F) shows the unevenness after polishing for 60 minutes.

Similarly, FIG. 5 is a graph showing the unevenness of the glass surface of the second embodiment. FIG. 5 (A)
Indicates an uneven state before polishing, (B) indicates an uneven state after polishing for 5 minutes, (C) indicates an uneven state after polishing for 10 minutes, and (D) indicates an uneven state after polishing for 20 minutes. Indicates the uneven state,
(E) shows the uneven state after polishing for 40 minutes, and (F) shows
This shows an uneven state after polishing for 60 minutes.

FIG. 6 is a graph showing the unevenness of the glass surface of Comparative Example 1. 6A shows an uneven state before polishing, FIG. 6B shows an uneven state after polishing for 5 minutes, FIG. 6C shows an uneven state after polishing for 10 minutes, and FIG.
Shows an uneven state after polishing for 20 minutes, (E) shows an uneven state after polishing for 40 minutes, and (F) shows an uneven state after polishing for 60 minutes.

FIG. 7 is a graph showing the unevenness of the glass surface of Comparative Example 2. 7A shows an uneven state before polishing, FIG. 7B shows an uneven state after polishing for 5 minutes, FIG. 7C shows an uneven state after polishing for 10 minutes, and FIG.
Shows an uneven state after polishing for 20 minutes, (E) shows an uneven state after polishing for 40 minutes, and (F) shows an uneven state after polishing for 60 minutes.

FIG. 8 is a graph showing the unevenness of the glass surface of Comparative Example 3. 8A shows an uneven state before polishing, FIG. 8B shows an uneven state after polishing for 5 minutes, FIG. 8C shows an uneven state after polishing for 10 minutes, and FIG.
Shows an uneven state after polishing for 20 minutes, (E) shows an uneven state after polishing for 40 minutes, and (F) shows an uneven state after polishing for 60 minutes.

As can be seen by comparing the measured values and graphs in these tables, in Comparative Example 2, which is a loose abrasive, it took 20 minutes for Ra to reach 0.02 μm. In Example 1, Ra was 0.02 μm in half of the 10 minutes.

In Comparative Example 1 in which the same abrasive layer was formed on a PET film, Ra was 0.10 even after polishing for 60 minutes.
μm.

Comparative Example 1 (fixed abrasive) and Comparative Example 2
Comparing (free abrasive grains), it can not be said that the fixed abrasive grains always have higher grinding power than the free abrasive grains. Furthermore,
From the measurement results of Comparative Example 3, it can be said that even if the fixed abrasive layer is simply formed on a flexible resin film, the grinding power is not higher than that of the free abrasive.

From the above measurement results, it can be said that cerium oxide having an average particle diameter of 1.5 μm to 3.0 μm was used as the abrasive used in the fixed abrasive structure of the present invention, and 100% M, A predetermined effect is obtained by using a resin of the resin film and the resin of the abrasive grain layer having the same characteristics in terms of tensile strength and elongation.

The reason why the fixed abrasive structure according to the present invention has considerably improved the grinding force with respect to the free abrasive grains is that the abrasive grains of the abrasive layer are made finer and the resin film and the resin of the abrasive layer are made of resin. It is considered that the selection of the characteristics in the specific range can increase the contact area where the abrasive grains hit the surface of the glass to be polished.

[0040]

According to the present invention, deep scratches do not occur despite the use of fixed abrasive grains, and the polishing efficiency is higher than that of free abrasive grains.

Therefore, the fixed abrasive structure of the present invention
When used in place of the conventional surface polishing of glass with loose abrasives, the polishing time can be greatly reduced.

Therefore, the fixed abrasive grain structure of the present invention can be used for polishing a planar or curved lens surface, polishing a glass substrate for an optical disk or a magnetic disk, polishing a silicon wafer surface, polishing a magnetic head surface, and polishing an optical fiber. It is useful in the field where precise finishing of the surface is required, such as surface polishing of a ferrule and surface finishing of a precision mold.

[Brief description of the drawings]

FIG. 1 is an enlarged view showing a cross-sectional structure of one embodiment of a fixed abrasive structure of the present invention.

FIG. 2 is a cross-sectional view schematically showing an example of an apparatus for polishing a lens surface using the fixed abrasive structure of the present invention.

FIG. 3 is a diagram showing a table summarizing measurement results in Examples and Comparative Examples.

FIG. 4 is a graph showing a state of irregularities on the glass surface of Example 1.

FIG. 5 is a graph showing a state of irregularities on a glass surface in Example 2.

FIG. 6 is a graph showing a state of irregularities on the glass surface of Comparative Example 1.

FIG. 7 is a graph showing a state of irregularities on the glass surface of Comparative Example 2.

FIG. 8 is a graph showing a state of irregularities on the glass surface of Comparative Example 3.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Resin film 1A Fixed abrasive structure 2 Abrasive 2A Abrasive layer 3 Resin 4 Adhesive layer 5 Release base paper 10 Plate 11 Pat 12 Lens 13 Fixed holder 14 Kanzashi

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3C063 AA03 AB07 BB01 BB07 BC03 BG01 BG08 BG22 EE01 EE02 FF23 FF30

Claims (3)

[Claims] 1. The thickness is 10 to 200 μm, and 100%
M has a mean particle size of 0.01 to 9 μm on the surface of a flexible thin resin film having a M of 0.98 MPa to 19.6 MPa, a tensile strength of 19.6 MPa to 88.2 MPa, and an elongation of 250 to 1000%. 100% abrasive
An anchor layer characterized in that an abrasive layer formed by kneading with a resin having a M of 0.98 MPa to 19.6 MPa, a tensile strength of 19.6 MPa to 88.2 MPa, and an elongation of 250 to 1000% is provided. Abrasive structure. 2. The fixed abrasive structure according to claim 1, wherein the resin film and the resin have the same characteristics with respect to the 100% M, the tensile strength, and the elongation. 3. The abrasive grains have an average particle diameter of 1.5 to 3.
The fixed abrasive structure according to claim 1, which is a 0 μm cerium oxide abrasive.