JP3314154B2 - Polishing sheet and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to polishing of metals, minerals, etc.
From rough polishing to ultra-precision polishing, such as grinding, finishing polishing of the surface of the body, etc., or mirror polishing of the surface of the magnetic hard disk substrate, or precision finishing polishing of the surface of the magnetic head, lens, etc. The present invention relates to a polishing sheet cut into a tape shape, a disk shape, and the like for use in polishing, and a method for producing the same.

[0002]

2. Description of the Related Art Generally, a polishing sheet is formed by forming a polishing layer containing abrasive particles on the surface of a flexible substrate sheet such as a plastic sheet, a woven fabric, a nonwoven fabric, and a paper. And is appropriately cut into a tape shape, a disk shape, or another shape according to the purpose and form of polishing.

[0003] The material, particle size and hardness of the abrasive particles used, and the thickness and planar shape of the polishing layer (for example, diagonal lines,
The lattice shape, the polka dot shape, and the like are appropriately selected according to the purpose of use of polishing.

[0004] The polishing layer is formed by applying a slurry, which is a mixture of abrasive particles and a binder adhesive, to the surface of the substrate sheet and drying it, or applying a binder adhesive to the surface of the substrate sheet to compress the abrasive particles with compressed air. And dried.

The method for forming a polishing layer by applying a slurry to the surface of a substrate sheet has the advantage that abrasive particles are uniformly and uniformly distributed in the formed polishing layer.

However, in this polishing layer forming method, abrasive particles are arranged in the formed polishing layer so as to overlap one another (hereinafter, referred to as a multilayer arrangement). Since only the abrasive particles distributed in the upper layer contribute to polishing, the abrasive particles distributed in the lower layer of the polishing layer are wasteful and uneconomical.

As abrasive particles, aluminum oxide,
Fine powder such as green silicon carbide is used. In particular, when materials such as diamond, boron nitride, and titanium carbon are used, these materials are very expensive, and the use of materials must be reduced in order to reduce material costs.

On the other hand, in a method of forming a polishing layer by spraying abrasive particles on the surface of a substrate sheet coated with a binder adhesive, the abrasive particles are arranged side by side without overlapping vertically on the surface of the substrate sheet (hereinafter referred to as a single layer arrangement). That)
As a result, only abrasive particles that substantially contribute to polishing can be fixed to the surface of the substrate sheet.

However, in this polishing layer forming method, the classification of the abrasive particles is strict because the distance between the surface of the substrate sheet and the top of the abrasive particles protruding from the surface of the substrate sheet is constant over the entire polishing layer. However, it is extremely difficult to eliminate the variation in the particle diameter, and abnormally protruding abrasive particles are mixed on the surface of the substrate sheet.

Further, after the abrasive particles are sprayed on the surface of the substrate sheet, the excessively sprayed abrasive particles are removed by compressed air or brushing. At this time, the abrasive particles adhered to the surface of the substrate sheet are removed. Is also removed, resulting in uneven distribution of the abrasive particles adhering to the surface of the substrate sheet.

As described above, when polishing is performed using a polishing sheet having a variation in particle size and a distribution of abrasive particles on the surface of the substrate sheet, abnormally protruding abrasive particles unnecessarily damage the surface of the object to be polished, There arises a problem that desired polishing cannot be performed precisely.

[0012] In addition to the above-mentioned demands for reducing the amount of abrasive particles used and the problem of forming unnecessary scratches on the surface of the object to be polished, especially in ultra-precision polishing, the pressing of the abrasive particles on the surface of the object to be polished is performed. The pressure may be locally different depending on the shape of the surface of the object to be polished or the like, causing a problem that the surface of the object to be polished is excessively polished.

It is therefore an object of the present invention to provide a polishing sheet which is economical and free of abnormally protruding abrasive particles and a method for producing the same.

Another object of the present invention is to provide the above-mentioned polishing sheet which can uniformly press the surface of the object to be polished during polishing, and a method for producing the same.

[0015]

A polishing sheet according to the present invention for solving the above-mentioned problems comprises a substrate sheet and a polishing layer formed on the surface of the substrate sheet.

Here, the polishing layer is composed of abrasive particles and a fixed layer in which the abrasive particles are fixed in a single layer arrangement via the lower part of each of the abrasive particles. The distance between the layer and the top of the abrasive particles is constant across the polishing layer. Here, the fixing layer is formed by drying the layer of the binder adhesive applied to the surface of the substrate sheet and fixing it to the surface of the substrate sheet.

The substrate sheet is composed of a flexible sheet and an elastic layer formed on the surface of the flexible sheet (where the surface of the substrate sheet is the surface of the elastic layer,
The polishing layer is formed on the surface of the elastic layer), and the elastic sheet may be provided with elasticity by interposing the elastic layer between the flexible sheet and the polishing layer.

According to the method for producing a polishing sheet of the present invention thus constituted, a low-viscosity slurry in which abrasive particles are uniformly mixed with a binder adhesive is prepared, and the low-viscosity slurry is applied to the surface of the holding member. Then, the abrasive particles are arranged in a single layer on the surface of the holding member. Here, the holding member has a surface having good releasability from a dried product of the binder adhesive of the low viscosity slurry.

Next, the low-viscosity slurry is dried to temporarily hold the abrasive particles on the surface of the holding member. Here, the abrasive particles are temporarily held in a single layer arrangement on the surface of the holding member via the lower part of each of the abrasive particles by a dried binder adhesive of a low viscosity slurry. The edge of the lower portion of each of the abrasive particles is arranged along the surface of the holding member. The other portion of each of the abrasive particles protrudes from the dried binder adhesive (hereinafter, the protruding portion is referred to as a protruding portion).

Next, a high-viscosity binder adhesive is applied to the surface of the substrate sheet to form a layer of the high-viscosity binder adhesive on the surface of the substrate sheet. Pressing the abrasive particles of the single-layer arrangement temporarily held on the surface of the holding member, pushing the protruding portions of the abrasive particles into the layer of the high-viscosity binder adhesive, and drying the layer of the high-viscosity binder adhesive, The abrasive particles are fixed to a fixed layer which is a dried product of the layer of the viscosity binder adhesive.

Here, when giving elasticity to the polishing sheet, a substrate sheet having an elastic layer formed on the surface of a flexible sheet is used. At this time, as described above, the surface of the substrate sheet is the surface of the elastic layer, and the polishing layer is formed on the surface of the elastic layer. Thereafter, the holding member is moved away from the substrate sheet, and the abrasive particles fixed to the fixing layer on the surface of the substrate sheet are separated from the holding member, whereby the polishing sheet of the present invention configured as described above is manufactured. .

Here, the viscosity of the low-viscosity slurry and the viscosity of the high-viscosity binder adhesive are respectively determined when the holding member is moved away from the substrate sheet by temporarily drying the low-viscosity slurry binder adhesive on the surface of the holding member. The viscosity of the abrasive particles should be such that the high-viscosity binder adhesive is dried and adhered to the surface of the substrate sheet to follow the adhered layer formed.

The elastic layer formed on the surface of the flexible sheet is made of soft urethane, foamed urethane or rubber, and has a thickness in the range of 10 μm to 200 μm.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1A, a polishing sheet 10 of the present invention comprises a substrate sheet 11 and a substrate sheet 1.
1 and a polishing layer 12 formed on the surface.

The polishing layer 12 is composed of abrasive particles 13 and a fixed layer 14 ′ formed by applying a binder adhesive to the surface of the substrate sheet 11 and drying the binder.

The binder adhesive includes a urethane type,
A resin such as a polyester resin is used and is applied to the surface of the substrate sheet 11 to a thickness of 1.5 times or more the average particle size of the abrasive particles 13.

As the substrate sheet 11, a plastic sheet, a nonwoven fabric, a woven fabric, paper, or the like can be used.

When giving elasticity to the polishing sheet 10,
As shown in FIG. 1B, a substrate sheet 11 having an elastic layer 11 ″ formed on the surface of a flexible sheet 11 ′ can be used (here, the substrate sheet 11 having the elastic layer 11 ″). Is used, the surface of the substrate sheet 11 is
This is the surface of the elastic layer 11 ″.)

As the flexible sheet 11 ', a plastic sheet, a non-woven fabric, a woven fabric, paper, or the like can be used as in the case of the substrate sheet 11 shown in FIG.

The elastic layer 11 "is made of soft urethane, foamed urethane, rubber, or the like.
The thickness is in the range of m to 200 μm.

Each of the abrasive particles 13 is, as shown,
It is fixed in a single layer arrangement to the fixing layer 14 ′ through the lower part thereof, and is fixed to the distance between the surface of the substrate sheet 11 and the top of the abrasive particles 13 of the polishing layer 12 (in FIG. H) is constant over the polishing layer 12.

The production of the abrasive sheet of the present invention shown in FIG. 1 will be described using the apparatus shown in FIG.

In the production of the abrasive sheet of the present invention, first, abrasive particles are uniformly mixed with a binder adhesive to prepare a low-viscosity slurry, and the low-viscosity slurry is applied to the surface of the holding member by kiss roll coating or the like. After coating and arranging the abrasive particles in a single layer on the surface of the holding member, the low viscosity slurry is dried by a dryer using infrared rays or the like (not shown).

In the apparatus shown in FIG. 2A, a sheet (hereinafter, referred to as a holding sheet) 21 is used as a holding member.

The holding sheet 21 is releasable from a sheet of a polymer of tetrafluoroethylene (for example, Teflon (trademark)), polypropylene, polyethylene, or the like, or a dried low-viscosity slurry binder adhesive. Plastic film sheets are used.

The low viscosity slurry applied to the holding member is 1
It has a viscosity in the range of 0 cp to 60 cp.

The weight ratio of the abrasive particles constituting the low viscosity slurry to the binder adhesive is such that the abrasive particles are 85% by weight.
To 95% by weight, and the binder adhesive is 15%.
% By weight to 5% by weight.

The low viscosity slurry binder adhesive includes:
A polyester-based, urethane-based, acrylic-based resin, or nitrocellulose is used.

Since the low-viscosity slurry has the low viscosity as described above and the weight ratio of the abrasive particles is significantly larger than the binder adhesive as described above, the low-viscosity slurry is applied to the surface of the holding sheet 21. When the abrasive particles 13 are arranged in a single layer, each of the abrasive particles 13 is densely arranged uniformly and uniformly along the surface of the holding sheet 21.
When the low-viscosity slurry on the surface of the holding sheet 21 is dried, as shown in FIG. 3, the abrasive particles 13 are held by the dry matter 22 'of the binder adhesive through each lower part of the abrasive particles 13. It is temporarily held on the surface of the sheet 21.

Next, a high-viscosity binder adhesive is applied to the surface of the substrate sheet 11 by kiss-roll coating or the like (not shown) to form a layer 14 of the high-viscosity binder adhesive on the surface of the substrate sheet.

Here, when giving elasticity to the polishing sheet, as described with reference to FIG. 1B, a substrate sheet in which an elastic layer 11 ″ is previously formed on the surface of a flexible sheet 11 ′ is used. In the following, a substrate sheet composed of a flexible sheet 11 'and an elastic layer 11 "as shown in FIG. Note that FIG.
Reference numeral 11 (11 ′, 11 ″) of (a) denotes the substrate sheet 1
1 or a substrate sheet 11 comprising a flexible sheet 11 'and an elastic layer 11 ".

The high-viscosity binder adhesive applied to the surface of the substrate sheet has a viscosity of 100 cp or more.

As the high-viscosity binder adhesive, a resin such as urethane or polyester is used.

Preferably, the high viscosity binder adhesive layer 14
Is applied so as to have a thickness of 1.5 times or more the average particle size of the abrasive particles 13 of the above low viscosity slurry.

As shown in FIG. 2A, the substrate sheet 11 having the surface of the high-viscosity binder adhesive layer 14 formed thereon is run in the direction of arrow T. Further, as described above, the holding sheet 2 temporarily holding the abrasive particles 13 in a single layer arrangement on the surface.
1 is run in the direction of arrow t, and the layer 14 of the high-viscosity binder adhesive on the surface of the substrate sheet 11 is superimposed on the abrasive particles 13 in a single-layer arrangement on the surface of the holding sheet 21 via the roller 33, Pressure roller 3 arranged facing up and down
The substrate sheet 11 and the holding sheet 21 are sandwiched between 1 and 32 in a sandwich shape.

Thus, the protruding portion of the abrasive particles 13 temporarily held on the holding sheet 21 (the abrasive particles 13 shown in FIG. 3).
Of the binder adhesive protruding from the dried binder adhesive 22) is pressed into the binder adhesive layer 14 of the substrate sheet 11.

At this time, the axial pressure of the pressure roller 31 or 32 is in the range of 1 kg / cm to 10 kg / cm.

Next, with the protruding portions of the abrasive particles 13 temporarily held by the holding sheet 21 being pushed into the binder adhesive layer 14 of the substrate sheet, the abrasive particles 13 are passed through a dryer 34,
The binder adhesive layer 14 is dried to form a fixed layer 14 '.

Thus, the abrasive particles 13 are fixed to the fixing layer 14 ′ on the surface of the substrate sheet 11.

Thereafter, the holding sheet 2 is
1 is separated from the substrate sheet 11, and the abrasive particles 13 fixed to the fixing layer 14 ′ on the surface of the substrate sheet 11 are separated from the holding sheet 21.

At this time, the holding sheet 2 as a holding member
As described above, a material having good releasability from the dried product 22 ′ of the binder adhesive of the low-viscosity slurry is used in Part 1, so that a part of the dried product 22 ′ adheres to the abrasive particles 13. It can be peeled off from the holding sheet 21 as it is.

For this reason, the abrasive particles 13 are applied to the holding sheet 2
1 after peeling from the fixing layer 1 on the surface of the substrate sheet 11.
The surface of the abrasive particles 13 fixed to 4 ′ is wiped off with a brush or the like (not shown) containing an organic solvent.
3 can be removed.

As described above, the polishing sheet 10 of the present invention shown in FIG. 1 is manufactured using the apparatus shown in FIG.

The present invention includes a polishing sheet in which the polishing layer 12 shown in FIG. 1 is formed on the surface of the substrate sheet 11 so as to draw oblique lines, lattices, polka dots, or other patterns.

The polishing sheet of the present invention is shown in FIG.
In the manufacturing method described above in relation to (a), a high-viscosity binder adhesive is applied to the surface of the substrate sheet 11 using a gravure roller or the like having a desired pattern on the surface,
It can be manufactured by forming a layer 14 of a high-viscosity binder adhesive on the surface of the substrate sheet 11 so as to draw a desired pattern.

The polishing sheet of the present invention is
In the apparatus shown in FIG. 2A, instead of the pressure roller 32 having a flat surface disposed on the side of the holding sheet 21, a pressure roller having a convex portion having a desired pattern on the surface is used.
It can be manufactured according to the manufacturing method described above in relation to (a).

For example, the pressure roller 32 shown in FIG.
Instead of using a pressing roller having convex portions 32 'arranged in a substantially C shape as shown in FIG. 2B, a polishing layer arranged in a substantially C shape as shown in FIG. 12 is the substrate sheet 1
1 (or a substrate sheet 11 having an elastic layer 11 ″)
Can be formed on the surface of the elastic layer 11 ″).

Next, the production of the polishing sheet 10 of the present invention shown in FIG. 1 will be described using the apparatus shown in FIG.

Here, as described above with reference to FIG. 2A, in order to give elasticity to the polishing sheet, FIG.
Since the substrate sheet 11 having the elastic layer 11 ″ as shown in FIG. 1 can be used, the flexible sheet 11 ′ and the elastic layer 11 ″ can be used.
Is also denoted by reference numeral 11. Note that reference numeral 11 (11 ', 11 ") in FIG.
As in (a), a substrate sheet 11 or a substrate sheet 11 comprising a flexible sheet 11 'and an elastic layer 11 "is shown.

As shown in FIG. 4, a holding roller 21 'is used as a holding member, and a lower portion of the holding roller 21' is immersed in a low viscosity slurry 22.

The holding roller 21 ′ is a binder adhesive of the low viscosity slurry 22 such as a glass surface, a mirror-polished metal surface, or a surface coated with a polymer of ethylene tetrafluoride (for example, Teflon (trademark)). Dried product 2
2 'has a surface with good peelability.

The low viscosity slurry 22 used here is the same as the low viscosity slurry described with reference to FIG.

When the holding roller 21 ′ rotates (in the direction of arrow R in FIG. 4), the low-viscosity slurry 22 applied to the surface of the holding roller 21 ′ is turned by the blade 41 into a single layer of abrasive particles of the low-viscosity slurry 22. It is arranged so as to be arranged and passes through a dryer 42 using infrared rays or the like, and the binder adhesive is dried, and as shown in FIG.
3 is temporarily held on the surface of the holding roller 21 ′ by the dried matter 22 ′ of the binder adhesive through the lower part of the abrasive particles 13.

Next, as described above with reference to FIG. 2A, the substrate sheet 11 having the surface of the high-viscosity binder adhesive layer 14 formed thereon is run in the direction of arrow T to
The high-viscosity binder adhesive layer 14 on the surface 1 is superimposed on the abrasive particles 13 in a single-layer arrangement on the surface of the holding roller 21 ′ via the roller 43, and the heat is disposed opposite the holding roller 21 ′. The substrate sheet 11 and the holding sheet 21 are sandwiched between the rollers 44 in a sandwich shape.

As a result, the protruding portions of the abrasive particles 13 temporarily held by the holding roller 21 ′ are pushed into the high-viscosity binder adhesive layer 14 of the substrate sheet 11, and the binder adhesive layer 14 is dried. Fixed layer 14 '
Is formed, and the abrasive particles 13 are fixed to the fixing layer 14 ′ on the surface of the substrate sheet 11.

At this time, the axial pressure of the heat roller 44 is
It is in the same range as the axial pressure of the pressure roller 31 or 32 described in relation to (a).

The temperature of the heat roller 44 is set so that the substrate sheet 11 used is not deformed by the heat of the heat roller 44 and the fixing layer 14 ′ of the high-viscosity binder adhesive layer 14 can be formed in a short time. Is set.

The high-viscosity binder adhesive used here is the same as the high-viscosity binder adhesive described above with reference to FIG.

Thereafter, when the substrate sheet 11 is moved in the direction of arrow T shown in FIG. 4, the substrate sheet 11 moves away from the holding roller 21 ′ rotating in the direction of arrow R, and the fixing layer 14 on the surface of the substrate sheet 11. Abrasive particles fixed to '
3 is peeled off from the holding roller 21 '.

At this time, the holding roller 2 as a holding member
As described above, since the material 1 ′ has a good releasability with respect to the dried product 22 ′ of the binder adhesive of the low-viscosity slurry, a part of the dried product 22 ′ is a part of the abrasive particles 13 ′.
Can be peeled off from the holding roller 21 ′ while being adhered.

Therefore, as described above with reference to FIG. 2A, after the abrasive particles 13 are separated from the holding roller 21 ', the abrasive particles fixed to the fixing layer 14' on the surface of the substrate sheet 11 are removed. The surface of the particles 13 can be wiped off with a brush or the like (not shown) containing an organic solvent to remove the dried matter 22 ′ attached to the abrasive particles 13.

The dried material 22 'remaining on the surface of the holding roller 21' is removed by the blade 41 '.

As described above, the polishing sheet 10 of the present invention shown in FIG. 1 is manufactured using the apparatus shown in FIG.

Next, the production of the polishing sheet 10 of the present invention shown in FIG. 1 will be described using the apparatus shown in FIG.

Here, as described above with reference to FIG. 2A, in order to give elasticity to the polishing sheet, FIG.
Since the substrate sheet 11 having the elastic layer 11 ″ as shown in FIG. 1 can be used, the flexible sheet 11 ′ and the elastic layer 11 ″ can be used.
Is also denoted by reference numeral 11. Note that reference numeral 11 (11 ′, 11 ″) in FIG.
As in (a), a substrate sheet 11 or a substrate sheet 11 comprising a flexible sheet 11 'and an elastic layer 11 "is shown.

As shown in FIG. 5, as a holding member, FIG.
A holding sheet 21 identical to the holding sheet 21 described above in connection with (a) is used, and the holding sheet 21 is wrapped around a rotating roller 45 arranged such that the lower part is immersed in the low viscosity slurry 22. ing.

The low viscosity slurry 22 used here is the same as the low viscosity slurry described above with reference to FIG.

When the rotating roller 45 rotates (in the direction of arrow R in FIG. 5), the holding sheet 21 runs following the rotation of the rotating roller 45 (in the direction of arrow t in FIG. 5), and the holding sheet 2 moves.
The low viscosity slurry 22 is applied to the surface of the first.

The low-viscosity slurry 22 applied to the holding sheet 21 is arranged by a blade 41 so that the abrasive particles of the low-viscosity slurry 22 are arranged in a single layer, and passes through a dryer 42 using infrared rays or the like. The binder adhesive is dried, and as shown in FIG. 3, the abrasive particles 13 are temporarily held on the surface of the holding sheet 21 by the dried binder adhesive 22 ′ through the lower part of the abrasive particles 13. Is done.

Next, as described above with reference to FIG. 2A, the substrate sheet 11 having the surface of the high-viscosity binder adhesive layer 14 formed thereon is run in the direction of arrow T to
The high-viscosity binder adhesive layer 14 on the first surface is superimposed on the single-layer array of abrasive particles 13 on the surface of the holding sheet 21 via a roller 43, and a heat roller 44 disposed opposite to a rotating roller 45. And the substrate sheet 11 and the holding sheet 21
And sandwich them in a sandwich.

As a result, the projecting portion of the abrasive particles 13 temporarily held on the surface of the holding sheet 21 is
Is pressed into the high-viscosity binder adhesive layer 14 and the binder adhesive layer 14 is dried to form the fixing layer 1.
4 'is formed, and the abrasive particles 13 are fixed to the fixing layer 14' on the surface of the substrate sheet 11.

At this time, the axial pressure of the heat roller 44 is
The temperature of the heat roller 44 is in the same range as the axial pressure of the pressure roller 31 or 32 described in relation to (a),
Is set to the temperature of the heat roller 44 described above in relation to.

The high-viscosity binder adhesive used here is the same as the high-viscosity binder adhesive described above with reference to FIG.

Thereafter, the substrate sheet 11 is caused to travel in the direction of arrow T shown in FIG. 5, and the holding sheet 21 is caused to travel in the direction of arrow t shown in FIG.
1 away from the fixing layer 14 ′ on the surface of the substrate sheet 11.
The abrasive particles 13 adhered to the support roller 21 'are separated from the holding roller 21'.

At this time, the holding sheet 2 as a holding member
As described above with reference to FIG. 2 (a), a material 1 having good releasability is used for the dried material 22 ′ of the binder adhesive of the low-viscosity slurry. Can be peeled off from the holding sheet 21 with some or all of them adhered to the abrasive particles 13.

For this reason, as described above with reference to FIG. 2A, after the abrasive particles 13 are peeled from the holding sheet 21, the abrasive particles fixed to the fixing layer 14 'on the surface of the substrate sheet 11 are removed. The surface of 13 can be wiped with a brush or the like (not shown) containing an organic solvent to remove the dried matter 22 ′ attached to the abrasive particles 13.

As described above, the polishing sheet 10 of the present invention shown in FIG. 1 is manufactured using the apparatus shown in FIG.

Using the apparatus shown in FIG. 4 or 5, the polishing sheet of the present invention in which the polishing layer 12 shown in FIG. 1 was formed on the surface of the substrate sheet 11 so as to draw a pattern such as diagonal lines, grids, and polka dots. Can be manufactured.

The polishing sheet of the present invention as shown in FIG.
As described above in connection with (a), a high-viscosity binder adhesive is applied to the surface of the substrate sheet 11 using a gravure roller or the like having a desired pattern on the surface, and the high-viscosity binder adhesive is applied to draw the desired pattern. A layer 14 of the viscosity binder adhesive is formed on the surface of the substrate sheet 11 and can be manufactured according to the manufacturing method described in connection with FIG.

[0090]

EXAMPLE A polishing sheet of the present invention was manufactured using the apparatus shown in FIG.

Abrasive particles having an average particle diameter of 3 μm (95% by weight)
And nitrocellulose (5% by weight) are uniformly mixed,
A low viscosity slurry having a viscosity of 10 cp was prepared.

This low-viscosity slurry was applied to one side of a polypropylene sheet having a thickness of 20 μm as a holding sheet by kiss roll coating and dried, and the abrasive particles were temporarily arranged in a single layer on the sheet surface and temporarily held. Was.

A polyester resin and an isocyanate-based curing agent were mixed to prepare a high-viscosity binder adhesive having a viscosity of 100 cp. The high-viscosity binder adhesive was applied to a 20 μm-thick polyester sheet as a substrate sheet by kiss roll coating. The composition was uniformly applied to the surface of the sheet to form a layer of a high-viscosity binder adhesive having a thickness of 10 μm.

The substrate sheet and the holding sheet are passed between pressure rollers (axial pressure: 10 kgf / cm) arranged vertically, and the abrasive particles arranged in a single layer are formed into a layer of a high-viscosity binder adhesive. Push, pass through a dryer to dry the layer of high-viscosity binder adhesive, and after fixing the abrasive particles to the fixing layer, which is a dried product of the high-viscosity binder adhesive,
The abrasive particles fixed to the fixing layer were peeled off from the holding sheet.

Next, the dried binder adhesive of the low-viscosity slurry adhered to the abrasive particles was removed with an organic solvent and a brush to produce a polishing sheet according to the present invention.

A polishing tape manufactured by cutting this polishing sheet into a tape shape, and the same high-viscosity binder adhesive as in the above embodiment on the same substrate sheet surface as the substrate sheet used for the polishing sheet of the present invention in the above embodiment. The surface of an aluminum disk is polished using a conventional polishing tape manufactured by applying an agent and spraying aluminum oxide having an average particle diameter of 1 μm with compressed air, and the surface roughness and grinding force of the disk are determined. Upon examination, it was confirmed that the roughness of the disk surface polished with the polishing tape according to the present invention was very small, and that the grinding power was almost the same.

[0097]

According to the present invention, since the abrasive particles of the abrasive layer of the abrasive sheet are arranged in a single layer, the amount of the abrasive particles used can be reduced, which is economical.

According to the present invention, since the distance between the top of each of the abrasive particles arranged in a single layer of the polishing layer of the polishing sheet and the surface of the substrate sheet is constant over the polishing layer, the polishing layer protrudes abnormally. There is an effect that the abrasive particles can be polished without unnecessary damage to the surface of the object to be polished during polishing.

According to the present invention, by providing an elastic layer between the flexible sheet and the polishing layer to give elasticity to the polishing sheet, the abrasive particles uniformly polish the surface of the object to be polished during polishing. This has the effect of being able to be pressed.

[Brief description of the drawings]

FIG. 1 is a partially enlarged cross-sectional view of a polishing sheet of the present invention.

FIG. 2 (a) is a schematic view of an apparatus for producing the polishing sheet of the present invention, and FIG. 2 (b) is a partially enlarged view of the surface of a pressure roller of the apparatus of FIG. 2 (a). FIG. 2 (c)
FIG. 2 is a partially enlarged view of the surface of the polishing sheet of the present invention manufactured using the pressure roller having the surface of FIG. 2 (b).

FIG. 3 shows a state in which abrasive particles are held on the surface of a holding member.

FIG. 4 is a schematic view of another apparatus for producing the abrasive sheet of the present invention.

FIG. 5 is a schematic view of another apparatus for producing the polishing sheet of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Abrasive sheet 11 ... Substrate sheet 11 '... Flexible sheet 11 "... Elastic layer 12 ... Abrasive layer 13 ... Abrasive particles 14 ... High viscosity binder adhesion Agent layer 14 ': fixed layer 15: elastic layer 21: holding sheet 21': holding roller 22: low viscosity slurry 22 ': drying of binder adhesive of low viscosity slurry Object 31, 32 ... Pressure roller 32 '... Convex part 33, 35, 43 ... Roller 34, 42 ... Dryer 41, 41' ... Blade 44 ... Heat roller 45 ..Rotating roller H: distance between substrate sheet surface and top of abrasive particles R: rotating direction T, t: running direction

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B24D 11/00

Claims (11)

(57) [Claims] 1. A method for manufacturing a polishing sheet, comprising: (1) applying a low-viscosity slurry in which abrasive particles are uniformly mixed with a binder adhesive to a surface of a holding member; (2) drying the low-viscosity slurry and temporarily holding the abrasive particles on the surface of the holding member, wherein the abrasive particles have a low viscosity. An end of the lower portion of each of the abrasive particles is temporarily held in a single layer arrangement on the surface of the holding member through a lower portion of each of the abrasive particles by a dried product of the binder adhesive of the slurry. A portion is arranged along the surface of the holding member, and each of the abrasive particles has a protruding portion protruding from the dried material. (3) High-viscosity binder bonding to the surface of the substrate sheet Agent Forming a layer of the high-viscosity binder adhesive on the surface of the substrate sheet by applying, (4) pressing the abrasive particles arranged in a single layer against the layer of the high-viscosity binder adhesive; Pushing the protruding portions of the abrasive particles into the layer of the high viscosity binder adhesive; (5) drying the layer of the high viscosity binder adhesive to form a fixed layer on the surface of the substrate sheet; Fixing the abrasive particles to the fixing layer; and (6) separating the abrasive particles fixed to the fixing layer from the holding member by moving the holding member away from the substrate sheet. . 2. The method according to claim 1, wherein the viscosity of the low viscosity slurry is in a range of 10 cp to 60 cp, and the viscosity of the high viscosity binder adhesive is 1 cp.
The production method according to any one of the preceding claims, wherein 3. The production method according to claim 1, wherein the weight ratio of the abrasive particles to the binder adhesive in the low viscosity slurry is such that the abrasive particles have a weight ratio of 85% to 95% by weight. Wherein the binder adhesive is in the range of 15% to 5% by weight. 4. The production method according to claim 1, wherein a urethane-based resin or a polyester-based resin is used for the high-viscosity binder adhesive . 5. The method according to claim 1, wherein the thickness of the layer of the high-viscosity binder adhesive is at least 1.5 times the average particle size of the abrasive particles. Production method. 6. The manufacturing method according to claim 1, wherein the holding member is a plastic film sheet that is releasable from the dried binder adhesive. . 7. The production method according to claim 6, wherein the plastic film sheet is a sheet of a polymer of tetrafluoroethylene, polypropylene, or polyethylene. 8. The manufacturing method according to claim 1, wherein the surface of the holding member is a glass surface, a mirror-polished metal surface, or a polymer surface of ethylene tetrafluoride. Production method. 9. The manufacturing method according to claim 1, wherein the substrate sheet is a flexible sheet, and gives elasticity to the polishing sheet formed on the surface of the flexible sheet. The manufacturing method according to claim 1, wherein the surface of the substrate sheet is a surface of the elastic layer, and the polishing layer is formed on the surface of the elastic layer. 10. The method according to claim 9, wherein the elastic layer is made of soft urethane, foamed urethane, or rubber. 11. The method according to claim 9, wherein the thickness of the elastic layer is in a range of 10 μm to 200 μm.