JP7406693B1 - Double-sided adhesive tape for fixing polishing members, multi-layer polishing pad, method for fixing top pad to surface plate, and method for fixing multi-layer polishing pad to surface plate - Google Patents

Abstract

[Problem] To provide a double-sided adhesive tape that is difficult to shift or peel off even at high temperatures during polishing, and has the properties of being easy to peel off after polishing. [Solution] A film base material, an acrylic-based first adhesive layer, and a natural rubber-based second adhesive layer, (1) for fixing a top pad to a cushion layer, or (2) for fixing a top pad to a cushion layer. A double-sided adhesive tape for fixing a polishing member to a surface plate or for fixing a cushion layer of a multilayer polishing pad to a surface plate, the tape having a thickness of a first adhesive layer and a second adhesive layer. The difference is 25 μm or less, the thickness of the film base material is 20 μm or more and less than 75 μm, and in the case of (1) above, the first adhesive layer is in contact with the top pad, the second adhesive layer is in contact with the cushion layer, and the In the case of (2), the first adhesive layer is in contact with the top pad and the second adhesive layer is in contact with the surface plate, and in the case of (3), the first adhesive layer is in contact with the cushion layer and the second adhesive layer is in contact with the top pad. Touches the surface plate. [Selection diagram] None

Description

The present invention relates to a double-sided adhesive tape for fixing a polishing member, which is used when polishing objects such as silicon wafers, glass (for liquid crystals, reinforced), and hard disks. Specifically, the present invention fixes a top pad to a cushion layer, fixes a top pad to a surface plate, or fixes a cushion layer of a multilayer type polishing pad having a top pad and a cushion layer to a surface plate. Related to double-sided adhesive tape for
The present invention also relates to a multilayer type polishing pad in which a top pad is fixed to a cushion layer using a double-sided adhesive tape for fixing a polishing member.
Furthermore, the present invention relates to a method of fixing a top pad to a surface plate and a method of fixing a cushion layer of a multilayer polishing pad to a surface plate.

2. Description of the Related Art A polishing method and apparatus is known in which a top pad or a multilayer polishing pad is bonded to a polishing machine surface plate using double-sided adhesive tape when polishing a surface to be polished. It is also known to bond a top pad and a cushion layer together using double-sided adhesive tape to form a multilayer polishing pad.
Patent Document 1 describes a double-sided adhesive tape that includes an acrylic adhesive layer on one side of a base material and a rubber adhesive layer on the other side of the base material.
Patent Document 2 discloses that a thermal adhesive layer containing 40 to 100% by mass of a thermoplastic elastomer is provided on one side of a base material, and an acrylic adhesive layer or a rubber adhesive layer is provided on the other side of the base material. Double-sided adhesive tape is listed.

Japanese Patent Application Publication No. 2012-057135 Japanese Patent Application Publication No. 2013-213192

During polishing, the top pad, multilayer polishing pad, double-sided adhesive tape used for attachment, and surface plate may become hot. In recent years, from the viewpoint of reducing costs and improving efficiency, polishing pads are being used for longer periods of time than before in order to reduce the time it takes to replace polishing pads. Furthermore, the polishing time may be shortened by increasing the temperature or pressure during polishing.
The double-sided adhesive tape used for attachment is subjected to shearing force during polishing. Double-sided adhesive tapes are required to have the ability to prevent the adhesive from shifting or peeling off during polishing.
On the other hand, after polishing is completed, when the top pad or multilayer polishing pad is removed from the surface plate together with the double-sided adhesive tape, it is required that no adhesive layer remains on the surface of the surface plate. That is, double-sided adhesive tapes are required to have performance that is difficult to shift or peel off, and performance that is easy to peel off.

An object of the present invention is to provide a double-sided adhesive tape that is difficult to shift or peel off even at high temperatures during polishing, and has the properties of being easy to peel off after polishing.

The present inventors have conducted extensive research to solve the above problems, and as a result, have arrived at the following invention.
[1]
A double-sided adhesive tape for fixing an abrasive member, comprising a film base material, a first adhesive layer located on one surface of the film base material, and a second adhesive layer located on the other surface of the film base material. hand,
The difference in thickness between the first adhesive layer and the second adhesive layer is 25 μm or less,
The thickness of the film base material is 20 μm or more and less than 75 μm,
The first adhesive layer is an acrylic adhesive layer formed from an acrylic adhesive containing a tackifying resin and an acrylic copolymer formed from an acrylic monomer containing 60% by weight of butyl (meth)acrylate. and
The second adhesive layer is a natural rubber adhesive layer formed from a natural rubber adhesive containing natural rubber, an inorganic oxide, and a tackifying resin,
A double-sided adhesive tape for fixing an abrasive member according to any of the following (1) to (3),
(1) Double-sided adhesive tape for fixing the polishing member to fix the top pad to the cushion layer (2) Double-sided adhesive tape for fixing the polishing member to fix the top pad to the surface plate (3) The top pad and the cushion layer A double-sided adhesive tape for fixing a polishing member for fixing a cushion layer of a multilayer type polishing pad to a surface plate.In the case of (1) above, the first adhesive layer is in contact with the top pad, and the second adhesive layer is in contact with the cushion layer. in contact with
In the case of (2) above, the first adhesive layer is in contact with the top pad, the second adhesive layer is in contact with the surface plate,
In the case of (3) above, the first adhesive layer is in contact with the cushion layer, and the second adhesive layer is in contact with the surface plate.
Double-sided adhesive tape for fixing polishing parts.

[2] The double-sided adhesive tape for fixing an abrasive member according to [1] above, wherein the second adhesive layer is thinner than the first adhesive layer.

The double-sided adhesive tape for fixing an abrasive member according to [1] or [2] above, wherein the natural rubber adhesive contains 3 to 80 parts by mass of an inorganic oxide based on 100 parts by mass of natural rubber.

[4] Any one of [1] to [3] above, wherein the natural rubber adhesive contains 30 to 180 parts by mass of a tackifying resin based on a total of 100 parts by mass of natural rubber and inorganic oxide. The double-sided adhesive tape for fixing an abrasive member described in .

[5] The double-sided adhesive tape for fixing an abrasive member according to any one of [1] to [4] above, wherein the natural rubber adhesive contains a polyterpene resin as a tackifying resin.

[6] The double-sided adhesive for fixing an abrasive member according to any one of [1] to [5] above, wherein the acrylic adhesive contains 40 to 100% by mass of terpene phenol resin in 100% by mass of tackifier resin. tape.

[7] The abrasive member fixing according to any one of [1] to [6] above, wherein the acrylic adhesive contains 40 to 70 parts by mass of a tackifier resin based on 100 parts by mass of the acrylic copolymer. double-sided adhesive tape.

[8] A multilayer polishing pad, the top pad of which is fixed to a cushion layer using the double-sided adhesive tape for fixing a polishing member according to any one of [1] to [7] above.

[9] A method for fixing a top pad to a surface plate using the double-sided adhesive tape for fixing an abrasive member according to any one of [1] to [7] above.

[10] A method for fixing a multilayer type polishing pad having a top pad and a cushion layer to a surface plate using the double-sided adhesive tape for fixing a polishing member according to any one of [1] to [7] above.

The double-sided adhesive tape for fixing an abrasive member of the present invention includes a double-sided adhesive tape for fixing a top pad to a cushion layer, a double-sided adhesive tape for fixing a top pad to a surface plate, and a multi-layered adhesive tape having a top pad and a cushion layer. When used as a double-sided adhesive tape to fix the cushion layer of a type of polishing pad to a surface plate, the shearing force applied during polishing will not be unilaterally biased towards the adhesive layer, which has weaker cohesive force, so it will not shift or peel off. After polishing is completed, the top pad or multi-layer polishing pad can be removed without leaving any adhesive layer on the surface plate.

The double-sided adhesive tape for fixing an abrasive member of the present invention includes a film base material, a first adhesive layer located on one surface of the film base material, and a second adhesive layer located on the other surface of the film base material. Equipped with.
The double-sided adhesive tape for fixing an abrasive member of the present invention is also referred to as a double-sided adhesive sheet for polishing or a double-sided adhesive film for polishing.

[First adhesive layer (acrylic adhesive layer)]
The first adhesive layer will be explained.
The first adhesive layer is an acrylic adhesive layer formed from an acrylic adhesive containing a tackifying resin and an acrylic copolymer formed from an acrylic monomer containing 60 parts by weight or more of butyl (meth)acrylate. be.

<Acrylic monomer>
Acrylic monomers include (meth)acrylic acid alkyl esters as so-called "non-functional" acrylic monomers. Here, "having no functional group" means having no functional group other than the (meth)acryloyl group. The acrylic monomer contains 60% by weight or more of butyl acrylate, which is an acrylic monomer that does not have a functional group, and contains alkyl (meth)acrylates other than butyl (meth)acrylate that does not have a functional group. , may further contain other monomers having functional groups such as carboxy groups and hydroxy groups.
In the present invention, the proportion of butyl (meth)acrylate in 100% by weight of the acrylic monomer for forming the acrylic copolymer is 60% by weight or more, more preferably 80% by weight or more. By being within the above range, it becomes possible to have a well-balanced combination of adhesive force and cohesive force suitable for a double-sided adhesive tape for fixing an abrasive member.
As butyl (meth)acrylate, butyl acrylate is preferred, and n-butyl acrylate is more preferred.

<(Meth)acrylic acid alkyl ester (other than butyl (meth)acrylate) that does not have a functional group>
As (meth)acrylic acid alkyl esters other than butyl (meth)acrylate that do not have a functional group,
For example, methyl (meth)acrylate, ethyl (meth)acrylate, isobutyl (meth)acrylate, propyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, (meth)acrylate 2 - Ethylhexyl, octyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, lauryl (meth)acrylate, and the like.

<Monomer having a carboxy group>
Moreover, it is preferable that the acrylic copolymer in the present invention has a carboxyl group. By using an acrylic copolymer with carboxyl groups and adding a curing agent as described below, it becomes easier to introduce a structure in which the crosslinking density can be easily controlled into the acrylic adhesive layer, thereby achieving a balance between adhesive force and cohesive force. easy.
From the above point of view, the monomer having a carboxy group is preferably used in an amount of 1 to 9% by weight, more preferably 2 to 8% by weight, in 100% by weight of the acrylic monomer. Examples of the monomer having a carboxyl group include (meth)acrylic acid, itaconic acid, maleic acid, etc., with (meth)acrylic acid being preferred and acrylic acid being preferred. These monomers are not limited to these monomers, and may be used alone or in combination of two or more.

<Monomer having hydroxy group>
Further, in the present invention, the acrylic copolymer may have a hydroxy group within a range that satisfies the required performance. Acrylic copolymers having hydroxy groups can be formed, for example, by copolymerizing 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, etc. can. The monomer having a hydroxy group is not limited to these monomers, and may be used alone or in combination of two or more types.
Furthermore, by not copolymerizing a monomer with a hydroxy group with butyl (meth)acrylate, it is possible to reduce dense crosslinking between polymers and increase the adhesive strength to adherends such as top pads. .

<Other monomers>
Further, in the present invention, an acrylic copolymer obtained by copolymerizing (meth)acrylamide, vinyl acetate, acrylonitrile, etc. can also be used within a range that satisfies the required performance.

<Acrylic copolymer>
The acrylic copolymer used in the present invention can be polymerized by solution polymerization, emulsion polymerization, bulk polymerization, or polymerization by ultraviolet irradiation. It is preferable to use

In the present invention, conventionally known polymerization initiators such as peroxide-based polymerization initiators and azobis-based polymerization initiators can be used for copolymerization.
Examples of organic peroxide polymerization initiators include benzoyl peroxide, di-t-butyl peroxide, cumene hydroperoxide, t-butyl peroxybenzoate, t-butyl peroxyneodecanoate, and t-butyl peroxide. Examples include peroxy 2-ethylhexanoate.
Examples of azobis-based polymerization initiators include 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-amidinopropane) dihydrochloride, 2,2'-azobis[2-(5-methyl- Examples include 2-imidazolin-2-yl)propane] dihydrochloride, 2,2'-azobis(2-methylpropionamidine) disulfate, 2,2'-azobis(N,N'-dimethyleneisobutyramidine), etc. It will be done.
These polymerization initiators may be used alone or in combination of two or more.

The polymerization average molecular weight of the acrylic copolymer used in the present invention is preferably 300,000 to 1,500,000, more preferably 400,000 to 1,200,000. By setting it within the above range, it becomes possible to have a well-balanced combination of adhesive force and cohesive force suitable for a double-sided adhesive sheet for polishing.
In the present invention, the weight average molecular weight is a polystyrene equivalent weight average molecular weight determined by GPC measurement, and the GPC measurement conditions are as follows. Apparatus: SHIMADZU Prominence (manufactured by Shimadzu Corporation) Column: TOSOH TSK-GEL GMHXL (manufactured by Tosoh Corporation) was used. Solvent: tetrahydrofuran, flow rate: 0.5 ml/min, temperature: 40°C, sample concentration: 0.1 wt%, sample injection amount: 100 μl

<Tackifier resin contained in first adhesive layer>
As described above, the first adhesive layer is formed from an acrylic adhesive containing an acrylic copolymer and a tackifying resin. From the viewpoint of improving the cohesive force of the acrylic adhesive layer formed, the acrylic adhesive preferably contains 40 to 70 parts by mass, and 40 to 60 parts by mass, of a tackifying resin based on 100 parts by mass of the acrylic copolymer. It is more preferable to include. When the double-sided adhesive tape for fixing polishing members of the present invention is used to fix the top pad to the cushion layer, the acrylic adhesive layer with high cohesive force should be used on the top pad side, which is more likely to be exposed to high temperatures during polishing. is important. Furthermore, when using the double-sided adhesive tape for fixing abrasive members of the present invention to fix the top pad to the surface plate, it is important to use the acrylic adhesive layer with high cohesive force on the top pad side, not on the surface plate side. It is. In addition, when the double-sided adhesive tape for fixing polishing members of the present invention is used to fix a multilayer type polishing pad to a surface plate, the acrylic adhesive layer with high cohesive force is placed on the cushion layer side, not on the surface plate side. It is important to use it.
Note that the cohesive force of the adhesive layer is generally measured and evaluated as holding force.

Examples of tackifying resins include rosin-based resins such as rosin ester, polymerized rosin, hydrogenated rosin, disproportionated rosin, maleic acid-modified rosin, fumaric acid-modified rosin, and rosin phenolic resin;
Terpene resins such as α-pinene resin, β-pinene resin, dipentene resin, polyterpene resin, aromatic terpene resin (terpene phenol resin, styrenated terpene resin), hydrogenated terpene resin, acid-modified terpene resin;
Petroleum-based hydrocarbon resins such as C5 aliphatic hydrocarbon resins, C9 aromatic hydrocarbon resins, hydrogenated C9 hydrocarbon resins, C5-C9 copolymer resins, dicyclopentadiene hydrocarbon resins,
Examples include coumaron-indene resin, styrene resin, alkylphenol resin, and xylene resin.
As long as it is a tackifier resin, it is not limited to these and may be used alone or in combination of two or more types, but from the viewpoint of the balance between tackiness and heat resistance, terpene type resins are preferred, and terpene phenol resins are more preferred.
The terpene phenol resin preferably contains 40 to 100% by mass, more preferably 60 to 100% by mass, and even more preferably 80 to 100% by mass, based on 100% by mass of the tackifying resin.

Examples of terpene phenol resins include:
Clayton's SylVares series TP95 (softening point 95 ± 5 °C, same hereinafter), TP105 (105 ± 5 °C), TP115 (115 ± 5 °C),
Yasuhara Chemical's YS polyster series U115 (softening point 115±5℃, the same applies hereinafter), T80 (80±5℃), T100 (100±5℃), T115 (115±5℃), T130 (130±5℃) ℃), T145 (145±5℃), etc.

The acrylic adhesive for forming the first adhesive layer can further contain a curing agent that can react with the functional group of the acrylic copolymer. From the viewpoint of improving the cohesive force of the first adhesive layer, it is preferable to introduce a crosslinked structure into the first adhesive layer by the reaction between the acrylic copolymer and the curing agent.
Examples of the curing agent include isocyanate compounds, epoxy compounds, aziridinyl compounds, and organic metal compounds, with isocyanate compounds being preferred.
The curing agent is preferably used in an amount of 1 part by weight or more and 5 parts by weight or less, more preferably 1 part by weight or more and 3 parts by weight or less, based on 100 parts by weight of the acrylic copolymer.

Furthermore, in the present invention, the acrylic adhesive for forming the first adhesive layer may contain fillers, pigments, dyes, diluents, polymerization inhibitors, and ultraviolet absorbers that are incorporated into known adhesives as necessary. , an ultraviolet stabilizer, a coupling agent, and the like, or two or more kinds thereof may be used. Further, the amount of the additive to be added is not particularly limited as long as it is sufficient to obtain the necessary physical properties.

[Second adhesive layer (natural rubber adhesive layer)]
The second adhesive layer will be explained.
The second adhesive layer is a natural rubber adhesive layer formed from a natural rubber adhesive containing natural rubber, an inorganic oxide, and a tackifying resin. In the natural rubber pressure-sensitive adhesive of the present invention, synthetic rubber can be used in combination with natural rubber, if necessary, within a range that does not impair the desired performance.

<Natural rubber>
Examples of natural rubber include natural rubber such as RSS (Ribbed Smoked Sheet) and TSR (Technically Specified Rubber). Examples of RSS include RSS1, RSS2, RSS3, RSS4, and RSS5, and examples of TSR include TSRCV, TSRL, TSR5, TSR10, TSR20, and TSR50, but natural rubber is limited to these. They can be used as needed within a range that does not impair the required performance, and two or more types may be used in combination.
Moreover, natural rubber can be used after being masticated with a masticating roll depending on the required performance.

<Inorganic oxide>
The inorganic oxide has a function of imparting cohesive force to the natural rubber adhesive layer. Examples of the inorganic oxide include zinc oxide, magnesium oxide, titanium oxide, silicon oxide, and lead oxide, with zinc oxide being preferred.
The natural rubber adhesive preferably contains 3 to 80 parts by mass, more preferably 5 to 70 parts by mass, and even more preferably 10 to 50 parts by mass of an inorganic oxide based on 100 parts by mass of natural rubber. .
Natural rubber adhesives are produced by adding an inorganic oxide to natural rubber and kneading the mixture to obtain an intermediate having a ML (1+4) and a Mooney viscosity of about 30,000 to 100,000 at 100°C. It is preferable to mix and obtain a coating resin.

<Tackifier resin contained in second adhesive layer>
As described above, the second adhesive layer is formed from a natural rubber adhesive containing natural rubber, an inorganic oxide, and a tackifying resin. In order to improve the cohesive force of the natural rubber adhesive layer to be formed, the natural rubber adhesive preferably contains 30 to 180 parts by mass of a tackifier resin per 100 parts by mass of the natural rubber and inorganic oxide in total. , more preferably 50 to 150 parts by mass.
Examples of tackifying resins include rosin-based resins such as rosin ester, polymerized rosin, hydrogenated rosin, disproportionated rosin, maleic acid-modified rosin, fumaric acid-modified rosin, and rosin phenolic resin;
Terpene resins such as α-pinene resin, β-pinene resin, dipentene resin, polyterpene resin, aromatic terpene resin (terpene phenol resin, styrenated terpene resin), hydrogenated terpene resin, acid-modified terpene resin;
Petroleum-based hydrocarbon resins such as C5 aliphatic hydrocarbon resins, C9 aromatic hydrocarbon resins, hydrogenated C9 hydrocarbon resins, C5-C9 copolymer resins, dicyclopentadiene hydrocarbon resins,
Examples include coumaron-indene resin, styrene resin, alkylphenol resin, and xylene resin.
As long as it is a tackifier resin, it is not limited to these, and it may be used alone or in combination of two or more types. As the tackifier resin, a terpene resin is preferable, and a polyterpene resin is more preferable, from the viewpoint of improving adhesion to a low-polar adherend and improving chemical resistance to an aqueous polishing slurry solution containing water as a main component. Further, from the viewpoint of adhesion to polishing members and the like, it is preferable to use a rosin resin in combination, and as the rosin resin, hydrogenated rosin ester is preferable. The polyterpene resin is preferably contained in an amount of 40 to 100% by weight, more preferably 50 to 90% by weight, and even more preferably 60 to 80% by weight based on 100% by weight of the tackifying resin.

Examples of polyterpene resins include:
Clayton's SylVares series TRB115 (softening point 115°C, same applies below), TRB1115T (115°C), TR7115 (115°C), TRM1115 (115°C), TR7125 (softening point 125°C), TRB125 (softening point 125°C) ), TRB1135 (135°C), TR90 (90°C), TR105 (softening point 105°C),
Examples include PX1250 (softening point 125°C, hereinafter the same), PX1150 (115°C), PX1000 (100°C), and PX800 (80°C) of the YS resin series manufactured by Yasuhara Chemical Co., Ltd.
These tackifying resins may be used alone or in combination of two or more.

Since natural rubber often has functional groups such as carboxy groups, hydroxyl groups, and amino groups, the natural rubber adhesive for forming the second adhesive layer contains a curing agent that can react with the functional groups. It can further include: From the viewpoint of improving the cohesive force of the second adhesive layer, it is preferable to introduce a crosslinked structure into the second adhesive layer through a reaction between natural rubber and a curing agent.
Examples of the curing agent include isocyanate compounds, epoxy compounds, aziridinyl compounds, and organic metal compounds, with isocyanate compounds being preferred.
The curing agent is preferably used in an amount of 1 part by weight or more and 30 parts by weight or less, more preferably 5 parts by weight or more and 25 parts by weight or less, based on 100 parts by weight of natural rubber.

Furthermore, in the present invention, the natural rubber adhesive for forming the second adhesive layer may contain fillers, pigments, dyes, diluents, polymerization inhibitors, and ultraviolet absorbers that are blended into known adhesives as necessary. It may contain various additives such as UV stabilizers, UV stabilizers, and coupling agents, and two or more types may be used. Further, the amount of the additive to be added is not particularly limited as long as it is sufficient to obtain the necessary physical properties.

When using the double-sided adhesive tape for fixing polishing members of the present invention to fix the top pad to the cushion layer, it is important to use the natural rubber adhesive layer on the side of the cushion layer that is less likely to be exposed to high temperatures during polishing. . In addition, when the double-sided adhesive tape for fixing polishing members of the present invention is used to fix a top pad to a surface plate or a multilayer type polishing pad to a surface plate, natural rubber is attached to the surface plate side. By using the adhesive layer, the top pad can be peeled off from the surface plate along with the double-sided adhesive tape without leaving any adhesive layer after polishing.

[Double-sided adhesive tape for fixing polishing members]
As described above, the double-sided adhesive tape for fixing an abrasive member of the present invention includes a film base material, a first adhesive layer located on one surface of the film base material, and a first adhesive layer located on the other surface of the film base material. A double-sided adhesive tape comprising two adhesive layers, wherein the difference in thickness between the first adhesive layer and the second adhesive layer is 25 μm or less, preferably 20 μm or less, more preferably 15 μm or less. . By setting the difference in thickness between the first adhesive layer and the second adhesive layer within the above range, excellent cohesive force (holding force) for polishing can be obtained.
Further, the thickness of the first adhesive layer and the second adhesive layer is preferably 10 to 100 μm, more preferably 20 to 80 μm, and even more preferably 30 to 70 μm, and in particular, the thickness of the second adhesive layer is more than that of the first adhesive layer. Preferably it is thin. By making the second adhesive layer thinner than the first adhesive layer, the cohesive force (holding force) of the second adhesive layer can be increased.

<Film base material>
The film base material located between the first adhesive layer and the second adhesive layer and used as a support for both adhesive layers includes a plastic film.
Examples of the plastic film include films made of polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate, PPS (polyphenylene sulfide), nylon, triacetylcellulose, cycloolefin, polyimide, and polyamide.
Further, the surface of the film base material may be subjected to adhesion-facilitating treatment in order to improve the adhesion with the adhesive layer. For the adhesion-facilitating treatment, known methods such as a dry method using corona discharge and a wet method using an anchor coating agent can be used. Among the film base materials, it is more preferable to use a film that has been treated to facilitate adhesion on both sides. By using a film with an easily adhesive treated surface, the adhesion with the adhesive layer is improved, and it is possible to obtain a double-sided adhesive tape that does not easily leave adhesive residue on the surface plate.
Moreover, an antistatic layer can be formed on the film base material. The antistatic layer is formed by applying a composition containing conductive carbon particles, conductive metal particles, conductive polymers, etc. to the surface of the film base material, or by applying metal vapor deposition or metal plating to the surface of the film base material. It can be formed by

As the film base material becomes thinner, the adhesive force (peel force) to the cushion layer increases.
It is better to fix the top pad to the cushion layer using double-sided adhesive tape for fixing polishing members with a thin film base material to form a multilayer type polishing pad than to use a thick film base material. It is expected that gender will be utilized. Similarly, when the cushion layer of a multi-layer polishing pad having a top pad and a cushion layer is fixed to a surface plate using a double-sided adhesive tape for fixing a polishing member with a thin film base, the multi-layer polishing pad It can be expected to be used for cushioning properties.
On the other hand, as the film base material becomes thicker, the adhesion force (peel force) to the surface plate increases, but on the other hand, when removing the top pad or multi-layer type polishing pad from the surface plate after polishing, it will stick to the surface plate. Since the layer (hereinafter sometimes abbreviated as "glue") is likely to remain, the thinner the film base material is, the more preferable it is from the viewpoint of preventing the adhesive from remaining.
Therefore, in the present invention, it is important that the thickness of the film base material is 20 μm or more and less than 75 μm, and preferably 20 μm or more and 50 μm or less.

The double-sided adhesive tape for fixing an abrasive member of the present invention can be manufactured, for example, by the following methods (A) and (B).
(A) After coating a release liner with an acrylic adhesive and a natural rubber adhesive to form a first adhesive layer and a second adhesive layer, the first adhesive layer is applied to each side of the film base material. and a second adhesive layer is bonded together.
(B) Either an acrylic adhesive or a natural rubber adhesive is coated on one side of the film base material to form a first adhesive layer or a second adhesive layer. Separately, the release liner is coated with the other adhesive, either an acrylic adhesive or a natural rubber adhesive, to form the other adhesive layer, and on the side of the film base material on which the adhesive layer is not formed, Apply the other adhesive layer formed on the release liner.
Note that the adhesive layer is usually protected with a release liner until just before the adhesive tape is used.

The release liner has a release layer formed by coating a release agent on a base material such as paper, plastic film, or synthetic paper. Examples of the release agent include silicone, alkyd resin, melamine resin, fluororesin, and acrylic resin. The removable pressure-sensitive adhesive of the present invention has the effect that the peeling force is hardly dependent on the type of release agent. Note that the thickness of the release liner is not particularly limited, but is approximately 10 to 200 μm.

For coating the adhesive, known methods such as a roll coater method, a comma coater method, a lip coater method, a die coater method, a reverse coater method, a silk screen method, and a gravure coater method can be used. After coating, it can be dried using a hot air oven, an infrared heater, etc.

As described above, the double-sided adhesive tape for fixing an abrasive member of the present invention can be used in three major ways.
That is,
(1) Used to fix the top pad to the cushion layer to form a multi-layer polishing pad,
(2) Used to fix the top pad to the surface plate,
(3) It is used to fix the cushion layer of a multilayer polishing pad having a top pad and a cushion layer to a surface plate.

The top pad, also called a polishing cloth, is a member that comes into direct contact with the object to be polished during polishing, and includes hard polyurethane sheets, synthetic leather, suede, velor, and the like. The top pad may be used as a single layer fixed to a surface plate as in the case (2) above, or it may be bonded to a cushion layer to form the outermost surface of a multilayer polishing pad. be.
Examples of the cushion layer include foam and nonwoven fabric. Examples of the foam include urethane foam, polyethylene foam, and polypropylene foam. Examples of the nonwoven fabric include those manufactured from polyester and the like, and those manufactured from natural products such as wool.
In the case of (3) above, the multilayer polishing pad used may be one formed using the double-sided adhesive tape for fixing polishing members of the present invention, or may be formed using another double-sided adhesive tape. It may be formed using.

EXAMPLES The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to the following examples. In the examples, "parts" means "parts by weight" and "%" means "% by weight."

<Synthesis Example 1: Acrylic copolymer (A-1)>
In a 4-necked flask equipped with a stirrer, thermometer, reflux condenser, dropping device, and nitrogen inlet tube, under a nitrogen atmosphere, add 47.5 parts by weight of butyl acrylate, 2.5 parts by weight of acrylic acid, ethyl acetate as a solvent, and start. An appropriate amount of azobisisobutyronitrile was added as an agent.
Separately, a dropping tube was charged with 47.5 parts by weight of butyl acrylate, 2.5 parts by weight of acrylic acid, ethyl acetate as a solvent, and appropriate amounts of azobisisobutyronitrile as an initiator.
Next, the flask was gradually heated, and after confirming the start of the reaction, the solution was added dropwise from the dropping tube over a period of 1 hour. The reaction was further continued for 8 hours at an internal temperature of about 80°C. After the reaction was completed, the mixture was cooled and an appropriate amount of ethyl acetate was added to obtain an acrylic copolymer (A-1) having a weight average molecular weight of 600,000.

<Synthesis Examples 2 to 3: Acrylic copolymer (A-2), (A-3)>
Acrylic copolymers (A-2) and (A-3) were obtained in the same manner as Synthesis Example 1 except that the monomer composition was as shown in Table 1. The monomer composition shown in Table 1 is the total of the amount put into the flask and the amount put into the dropping tube.

<Formulation example 1: Acrylic adhesive>
For 100 parts by mass of acrylic copolymer (A-1), 40 parts by mass of YS Polystar T130 (manufactured by Yasuhara Chemical Co., Ltd., terpene phenol resin, softening point 130 ° C.) as a tackifying resin, and an isocyanate compound as a curing agent. 1.5 parts by mass of a certain TDI-TMP adduct (1 mole of trimethylolpropane added to 3 moles of tolylene diisocyanate) was blended to obtain an acrylic adhesive.

<Formulation Examples 2 to 4: Acrylic adhesive>
According to the formulation shown in Table 2, an acrylic pressure-sensitive adhesive was obtained in the same manner as in Formulation Example 1.

<Formulation example 11: Natural rubber adhesive>
While masticating 100 parts by mass of natural rubber SSR1 several times with a masticating roller, 15 parts by mass of zinc oxide was mixed to obtain an intermediate having a Mooney viscosity of 45,000.
Thereafter, in a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a dropping device, and a nitrogen introduction tube, appropriate amounts of methyl ethyl ketone, toluene, and Gomuki G were charged as a solvent to the intermediate under a nitrogen atmosphere. The flask was then gradually heated to an internal temperature of about 50° C. for 3 hours to obtain a uniform dispersion.
The obtained dispersion was cooled, and at an internal temperature of about 40°C or less, 60 parts by mass of YS Resin PX1150 (manufactured by Yasuhara Chemical Co., Ltd., polyterpene resin, softening point 115°C) was added as a tackifying resin, and Ester Gum H (Arakawa Chemical Co., Ltd.) was added as a tackifying resin. 25 parts by weight of hydrogenated rosin ester (softening point: 68-75°C) manufactured by BASF Japan, 2 parts by weight of Irgafos 168 (manufactured by BASF Japan) as an anti-aging agent, diluted with methyl ethyl ketone and toluene, and the tackifying resin was dissolved. Stirring was continued until the mixture was mixed, to obtain a base material for a natural rubber adhesive having a nonvolatile content of 23% and a viscosity of 17,000 mPa·s.
To 100 parts by mass of natural rubber contained in the base material, 20 parts by mass of TDI-TMP adduct, which is an isocyanate compound, was blended as a curing agent to obtain a natural rubber pressure-sensitive adhesive.

<Formulation Examples 12 to 13: Natural rubber adhesive>
According to the formulation shown in Table 3, a natural rubber adhesive was obtained in the same manner as in Formulation Example 11.

<Formulation example 14: Natural rubber adhesive>
As shown in Table 3, a natural rubber pressure-sensitive adhesive was obtained in the same manner as in Formulation Example 11, except that 100 parts by mass of natural rubber SSR1 was masticated without adding zinc oxide.

The abbreviations in Tables 1 to 3 are as follows.
BA: n-butyl acrylate 2EHA: 2-ethylhexyl acrylate AA: acrylic acid

YS Polyster T130 (manufactured by Yasuhara Chemical Co., Ltd., terpene phenol resin, softening point 130°C)
YS resin PX1150 (manufactured by Yasuhara Chemical Co., Ltd., polyterpene resin, softening point 115°C)
Ester Gum H (manufactured by Arakawa Chemical Industries, hydrogenated rosin ester, softening point 68-75°C)
Pencel D125 (manufactured by Arakawa Chemical Industries, polymerized rosin ester, softening point 120-130°C)

TDI-TMP adduct: isocyanate compound with trimethylolpropane added to toluene diisocyanate

<Creation of adhesive sheet>
The acrylic adhesive of Formulation Example 1 was coated on a 25 μm polyethylene terephthalate (hereinafter referred to as PET) film base material so that the thickness after drying was 50 μm, and dried at 100 ° C. for 2 minutes. After that, a release liner was attached.
Separately, the natural rubber adhesive of Formulation Example 11 was coated on another release liner so that the thickness after drying was 50 μm, and dried at 100° C. for 2 minutes.
Next, the obtained natural rubber adhesive layer was attached to the side of the PET film on which the acrylic adhesive layer was not provided, and was left at 23° C.-50% for one week to obtain the double-sided adhesive sheet of Example 1. The adhesive strength, holding power, and adhesive residue after the water immersion test were evaluated using the methods described below. The results are shown in Table 4.

[Example 2 ], [Reference Example 3] , [Comparative Example 1]
A double-sided adhesive sheet was obtained in the same manner as in Example 1, except that the natural rubber adhesives of Formulation Examples 12 to 14 were used instead of the natural rubber adhesive of Formulation Example 11, as shown in Table 4. evaluated. Note that Example 3 in Table 4 refers to Reference Example 3.

[Example 4], [Comparative Examples 2-3]
A double-sided adhesive sheet was obtained in the same manner as in Example 1, except that the acrylic adhesives of Formulation Examples 2 to 4 were used instead of the acrylic adhesive of Formulation Example 1, as shown in Table 5, and evaluated in the same manner. . Note that Table 5 also shows Example 1.

[Examples 5-6] , [Reference Example 7]
A double-sided adhesive sheet was obtained in the same manner as in Example 1, except that the thicknesses of the acrylic adhesive layer and the natural rubber adhesive layer were changed as shown in Table 6, and evaluated in the same manner. Note that Table 6 also shows Example 1. Example 7 in Table 6 means Reference Example 7.

[Examples 8-9], [Comparative example 4]
A double-sided adhesive sheet was obtained in the same manner as in Example 1, except that the thicknesses of the acrylic adhesive layer and the natural rubber adhesive layer were as shown in Table 7, respectively, and evaluated in the same manner. Note that Table 7 also shows Example 1.

[Examples 10-11], [Comparative Example 5]
A double-sided adhesive sheet was obtained in the same manner as in Example 1, except that the thicknesses of the acrylic adhesive layer and the natural rubber adhesive layer were as shown in Table 8, respectively, and evaluated in the same manner. Note that Table 8 also shows Example 2.

[Example 12], [Comparative Examples 6-7]
A double-sided adhesive sheet was obtained in the same manner as in Example 1, except that the thickness of the film base material was changed as shown in Table 9, and evaluated in the same manner. Note that Table 9 also shows Example 1.

[Evaluation method]
<Adhesive force of first adhesive layer to top pad>
The release liner on the second adhesive layer side of the obtained adhesive sheet was peeled off, a 25 μm thick PET film for backing was attached, and the sheet was cut into a size of 25 mm in width and 100 mm in length to prepare a sample.
Next, in an atmosphere of 23° C. and 50% RH, the release liner covering the first adhesive layer, which is the opposite side to the side to which the backing PET film was attached, was peeled off from the obtained sample, and the exposed first adhesive layer was peeled off. 1 adhesive layer was placed on the top pad, and a 2 kg roller was moved back and forth once to temporarily press it, and then the layers were bonded together using a pressure roller at a temperature of 90°C, a speed of 3.0 M/min, and a pressure of 0.3 MPa. The sample was left for 24 hours in an atmosphere of 23° C. and 50% RH to form a test piece. The adhesive force of the test piece was measured under the same environment using a tensile tester under the conditions of a peeling angle of 180 degrees and a peeling speed of 300 mm/min. Note that a hard polyurethane sheet was used as the top pad.

<Adhesive strength of the first adhesive layer and the second adhesive layer to the cushion layer>
The release liner on the second adhesive layer side of the obtained adhesive sheet was peeled off, a 25 μm thick PET film for backing was attached, and the sheet was cut into a size of 25 mm in width and 100 mm in length to prepare a sample.
Next, in an atmosphere of 23° C. and 50% RH, the release liner covering the first adhesive layer, which is the opposite side to the side to which the backing PET film was attached, was peeled off from the obtained sample, and the exposed first adhesive layer was peeled off. 1 adhesive layer was placed on the cushion layer, and a 2 kg roller was moved back and forth once to temporarily press the layers, and then the layers were bonded using a pressure roller at a temperature of 90°C, a speed of 3.0 M/min, and a pressure of 0.3 MPa. It was left for 24 hours in an atmosphere of 23° C. and 50% RH to form a test piece. The adhesive force of the test piece was measured under the same environment using a tensile tester under the conditions of a peeling angle of 180 degrees and a peeling speed of 300 mm/min.
The adhesive strength of the second adhesive layer was also measured in the same manner. Note that a urethane foam sheet was used as the cushion layer.

<Adhesive force of second adhesive layer to stainless steel plate>
The release liner on the first adhesive layer side of the obtained adhesive sheet was peeled off, a 25 μm thick PET film for backing was attached, and the sheet was cut into a size of 25 mm in width and 100 mm in length to prepare a sample.
Next, in an atmosphere of 23°C and 50% RH, the release liner covering the second adhesive layer, which is the opposite side to the side to which the backing PET film was bonded, was peeled off from the obtained sample, and the exposed second adhesive layer was peeled off. Two adhesive layers were placed on a stainless steel plate, and a 2 kg roller was moved back and forth once to press them together, and then left in the same environment for 24 hours to prepare a test piece. The adhesive force of the test piece was measured under the same environment using a tensile tester under the conditions of a peeling angle of 180 degrees and a peeling speed of 300 mm/min.

Note that the adhesive force of the first adhesive layer and the second adhesive layer is practically required to be at least 20 N or more with respect to the top pad and the cushion layer.
Furthermore, in Tables 4 to 9, the top pad, cushion layer, and stainless steel plate that are adherends are described as PAD, cushion, and SUS, respectively.

<Holding power>
Prepare the same sample as in the case of the adhesive force measurement, peel off 25 mm of the release liner from the 100 mm long end, place the 25 mm long x 25 mm wide area on the top pad, cushion layer, and stainless steel plate, respectively. After pressing a 2 kg roller back and forth once, it was left for 20 minutes in an atmosphere of 23° C.-50%.
Then, in an atmosphere of 80°C, a 1kg weight was attached to the lower end of the 100mm long sample and set so that a force was applied in a 180 degree direction, and after 24 hours the adhesion position was measured by how many millimeters from the adherend. , or the number of seconds for the film to completely slip off was measured for each of the first adhesive layer and the second adhesive layer, and evaluated based on the following criteria.
・1st adhesive layer vs. top pad ○: less than 1.0 mm ×: 1.0 mm or less ・(1st adhesive layer or 2nd adhesive layer) vs. cushion layer ◎: 20,000 seconds or more Excellent ○: 10,000 seconds or more, Less than 20,000 seconds Good △: 5,000 seconds or more, less than 10,000 seconds Possible ×: Less than 5,000 seconds Not possible/Second adhesive layer vs. stainless steel plate 〇: 10,000 seconds or more ×: Less than 10,000 seconds

<Glue residue after water immersion test>
A sample was prepared in the same manner as in the adhesive force measurement above, and immediately after the second adhesive layer was pressed onto a stainless steel plate, the test piece was immersed together with the stainless steel plate in warm water at 40°C, and after 24 hours, the test piece was immersed in hot water. After taking it out and washing with water, the second adhesive layer was peeled off from the stainless steel plate under the same conditions as in the case of measuring the adhesive strength, and the surface of the stainless steel plate was observed to confirm the presence or absence of adhesive layer residue.
○: There was no residue at all (good)
△: There was a slight residue (no practical problem) ×: There was a residue (unusable)

As shown in Tables 4 to 9, the first adhesive layer of the double-sided adhesive tapes of each example exhibited excellent adhesion to the top pad and cushion layer, and the second adhesive layer exhibited excellent adhesion to the cushion layer and stainless steel plate. Show power. In addition, the first adhesive layer in the double-sided adhesive tape of each example showed excellent holding power against the top pad and cushion layer at high temperatures, and the second adhesive layer showed excellent holding power against the cushion layer and stainless steel plate at high temperatures. Indicates holding power. Furthermore, the second adhesive layer in the double-sided adhesive tape of each example can be peeled off without leaving any residue of the adhesive layer on the stainless steel plate after the water immersion test.
On the other hand, the double-sided adhesive tapes of the comparative examples were inferior in either the performance of the first adhesive layer with respect to the top pad and the cushion layer, or the performance of the second adhesive layer with respect to the cushion layer and the stainless steel plate.

Claims (10)

A double-sided adhesive tape for fixing an abrasive member, comprising a film base material, a first adhesive layer located on one surface of the film base material, and a second adhesive layer located on the other surface of the film base material. hand,
The difference in thickness between the first adhesive layer and the second adhesive layer is 25 μm or less,
The thickness of the film base material is 20 μm or more and less than 75 μm,
The first adhesive layer is made of an acrylic adhesive containing an acrylic copolymer having a thickness of 30 to 70 μm and a tackifier resin, which is formed from an acrylic monomer containing 60% by weight of butyl (meth)acrylate. It is an acrylic adhesive layer formed,
The second adhesive layer is a natural rubber adhesive layer with a thickness of 30 to 70 μm, which is formed from a natural rubber adhesive containing natural rubber, an inorganic oxide, and a polyterpene resin as a tackifier resin ,
A double-sided adhesive tape for fixing an abrasive member according to any of the following (1) to (3),
(1) Double-sided adhesive tape for fixing the polishing member to fix the top pad to the cushion layer (2) Double-sided adhesive tape for fixing the polishing member to fix the top pad to the surface plate (3) The top pad and the cushion layer A double-sided adhesive tape for fixing a polishing member for fixing a cushion layer of a multilayer type polishing pad to a surface plate.In the case of (1) above, the first adhesive layer is in contact with the top pad, and the second adhesive layer is in contact with the cushion layer. in contact with
In the case of (2) above, the first adhesive layer is in contact with the top pad, the second adhesive layer is in contact with the surface plate,
In the case of (3) above, the first adhesive layer is in contact with the cushion layer, and the second adhesive layer is in contact with the surface plate.
Double-sided adhesive tape for fixing polishing parts. The double-sided adhesive tape for fixing an abrasive member according to claim 1, wherein the second adhesive layer is thinner than the first adhesive layer. The double-sided adhesive tape for fixing an abrasive member according to claim 1 or 2, wherein the natural rubber adhesive contains 3 to 80 parts by mass of an inorganic oxide based on 100 parts by mass of natural rubber. 4. The double-sided adhesive tape for fixing an abrasive member according to claim 3, wherein the natural rubber adhesive contains 30 to 180 parts by mass of a tackifying resin based on 100 parts by mass of the natural rubber and inorganic oxide. The double-sided adhesive tape for fixing an abrasive member according to claim 3 , wherein the natural rubber adhesive contains 40 to 100% by mass of polyterpene resin based on 100% by mass of tackifying resin. The double-sided adhesive tape for fixing an abrasive member according to claim 1 or 2, wherein the acrylic adhesive contains 40 to 100% by mass of a terpene phenol resin based on 100% by mass of the tackifying resin. The double-sided adhesive tape for fixing an abrasive member according to claim 6, wherein the acrylic adhesive contains 40 to 70 parts by mass of a tackifier resin based on 100 parts by mass of the acrylic copolymer. A multilayer polishing pad, wherein the top pad is fixed to the cushion layer using the double-sided adhesive tape for fixing a polishing member according to claim 1. A method for fixing a top pad to a surface plate using the double-sided adhesive tape for fixing an abrasive member according to claim 1. A method for fixing a multilayer type polishing pad having a top pad and a cushion layer to a surface plate using the double-sided adhesive tape for fixing a polishing member according to claim 1.