JP2003013020A - Adhesive sheet for dust removing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive sheet for dust removing, decreasing carried-in dust therewith, so eliminating influence on oriented film on the substrate of TFT and color filter, ITO film, polyimide film and the like and causing no transference of the adhesive for dust removing. SOLUTION: This adhesive sheet for dust removing is characterized by consisting of a substrate, an adhesive layer for dust removing formed on one side of the substrate and an exfoliating layer laminated on the adhesive layer for dust removing.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a glass surface of a liquid crystal panel, an alignment film on a TFT substrate or a color filter substrate,
The present invention relates to a dust-removing pressure-sensitive adhesive sheet that removes dust adhering to ITO films, polyimide films, and the like.

[0002]

2. Description of the Related Art Conventionally, an adhesive sheet for removing water and dust has been used for cleaning a TFT substrate, a color filter substrate and the like, and for cleaning after rubbing. Here, rubbing means rubbing the surface of an alignment film, an ITO film, a polyimide film, etc. on a TFT or a color filter substrate with a special cloth to give unidirectionality to the surface. Since the alignment film, the ITO film, the polyimide film, and the like are rubbed, dust is generated.

[0003]

If water is used to remove dust, it requires a high degree of water purity, requires a long time to dry, and has an orientation on a TFT or a color filter substrate. There is a problem that the physical properties of the film, the ITO film, the polyimide film, etc. are changed.

On the other hand, in removing dust using a dust-removing adhesive sheet, an alignment film on a TFT or a color filter substrate, unless an additive that easily migrates into the adhesive is included,
Problems such as changes in physical properties of the ITO film, the polyimide film, etc. do not occur. However, there are problems such as transfer of the adhesive, peeling of the alignment film, the ITO film, the polyimide film on the TFT or the color filter substrate, and the inability to remove dust depending on the adhesive force of the adhesive. . If the base material of the dust-removing pressure-sensitive adhesive sheet is plastic, it is easily charged, and the dust-removing pressure-sensitive adhesive sheet carries the dust by adsorbing the dust, and on the contrary, the alignment film on the glass surface of the liquid crystal panel, TFT or color filter substrate. There is also a problem in that dust is attached to the ITO film, the polyimide film, and the like.

Therefore, the present invention reduces the amount of dust carried by the dust-removing adhesive sheet, and at the same time, the glass surface of the liquid crystal panel, the alignment film on the TFT or the color filter substrate,
Transfer of the adhesive to the ITO film, polyimide film, etc. does not occur,
Alignment film on the TFT or color filter substrate, ITO film,
Eliminates the effect on physical properties due to contamination of polyimide film, etc.
An object of the present invention is to provide a dust-removing pressure-sensitive adhesive sheet that does not cause peeling of an alignment film, an ITO film, a polyimide film or the like on an FT or a color filter substrate.

[0006]

The present inventors have arrived at the present invention as a result of intensive research to achieve the above object. That is, if the adhesive strength or average molecular weight of the adhesive is within a specific range, transfer of the adhesive does not occur and peeling of the alignment film, ITO film, polyimide film, etc. on the TFT or color filter substrate does not occur. , The surfactant easily migrates, and when the surfactant migrates, it may contaminate the alignment film, the ITO film, the polyimide film, etc. on the TFT or the color filter substrate, and affect the physical properties. , When dust adheres to the adhesive layer, it is used as a dust removing adhesive sheet without being removed.Therefore, dust may transfer to the glass surface of the liquid crystal panel, etc. The present invention has been accomplished by finding that dust adhering to the base material of the pressure-sensitive adhesive sheet for dust removal is easily incorporated into the pressure-sensitive adhesive layer.

The dust-removing pressure-sensitive adhesive sheet according to claim 1 of the present invention comprises a base material, a dust-removing pressure-sensitive adhesive layer formed on one surface of the base material, and a release layer laminated on the dust-removing pressure-sensitive adhesive layer. An adhesive sheet for dust removal, characterized in that The pressure-sensitive adhesive sheet for dust removal according to claim 2 of the present invention is the pressure-sensitive adhesive sheet for dust removal according to claim 1, wherein the base material is a vinyl acetate derivative or an olefin film.
The pressure-sensitive adhesive sheet for dust removal according to claim 3 of the present invention is the pressure-sensitive adhesive sheet for dust removal according to claim 1 or 2, wherein the substrate has a thickness of 25 µm to 300 µm. The pressure-sensitive adhesive sheet for dust removal according to claim 4 of the present invention,
The pressure-sensitive adhesive sheet for dust removal according to any one of claims 1 to 3, wherein the pressure-sensitive adhesive has an adhesive force of 0.1 N to 10 N / 25 mm. In the pressure-sensitive adhesive sheet for dust removal according to claim 5 of the present invention, the thickness of the pressure-sensitive adhesive layer is 5
The pressure-sensitive adhesive sheet for dust removal according to any one of claims 1 to 4, wherein the pressure-sensitive adhesive sheet has a diameter of 30 to 30 μm. The pressure-sensitive adhesive sheet for dust removal according to claim 6 of the present invention,
The dust-removing pressure-sensitive adhesive sheet according to any one of claims 1 to 5, wherein the pressure-sensitive adhesive has an average molecular weight of 500,000 or more and 1.4 million or less. The pressure-sensitive adhesive sheet for dust removal according to claim 7 of the present invention is characterized in that the pressure-sensitive adhesive layer is an acrylic pressure-sensitive adhesive or a rubber-based pressure-sensitive adhesive. This is an adhesive sheet for dust removal. The pressure-sensitive adhesive sheet for dust removal according to claim 8 of the present invention is characterized in that the pressure-sensitive adhesive does not contain a surfactant, and the pressure-sensitive adhesive sheet for dust removal according to any one of claims 1 to 7. Is. The pressure-sensitive adhesive sheet for dust removal according to claim 9 of the present invention is the pressure-sensitive adhesive sheet for dust removal according to any one of claims 1 to 8, wherein the release layer is a polyester film. .

The above-mentioned objects, other objects, features and advantages of the present invention will become more apparent from the detailed description of the embodiments of the invention described below.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention comprises a base material, a pressure-sensitive adhesive layer formed on one side of the base material, and a surface of the dust-removing pressure-sensitive adhesive layer, that is, a surface opposite to the base material. And a release layer, the adhesive film does not transfer to the glass surface of the liquid crystal panel, the alignment film on the TFT or color filter substrate, the ITO film, the polyimide film, etc., and the alignment film on the TFT or color filter substrate, ITO Dust removal that does not affect the physical properties due to contamination of the film, polyimide film, etc., and can efficiently remove dust existing on the glass surface of the liquid crystal panel, the alignment film on the TFT or color filter substrate, the ITO film, the polyimide film, etc. The present invention relates to a pressure-sensitive adhesive sheet laminate.

The substrate used for the dust-removing pressure-sensitive adhesive sheet of the present invention is not particularly limited, but polyolefin films such as polyethylene film and polypropylene film;
Polyester films such as polyethylene terephthalate and polybutylene terephthalate; polyamide films such as hexamethylene adipamide; halogen-containing films such as polyvinyl chloride, polyvinylidene chloride and polyfluoroethylene; polyvinyl acetate, polyvinyl alcohol, ethylene vinyl acetate Plastic films such as polymers such as vinyl acetate and derivative films thereof are preferable because they do not generate fine dust unlike paper. Of these plastic films, vinyl acetate and its derivative films and polyolefin films are preferable. This is because they have flexibility and rubber elasticity, and also have resistance to stress cracking.

The thickness of the base material is not particularly limited, but is 25
Those having a thickness of μm to 300 μm are used. Preferably 40
The thickness is from μm to 150 μm. If the thickness is 25 μm or less, the film is so thin that it is difficult to handle.
If it is 0 μm or more, it becomes hard, so the glass surface of the liquid crystal panel
Alignment film on the TFT or color filter substrate, ITO film,
This is because dust cannot be removed due to insufficient contact with the polyimide film or the like. Although it depends on the type of the film, the ethylene vinyl acetate copolymer film has a thickness of 80 μm to 150 μm.
A polyethylene film or polypropylene film having a thickness of 40 μm to 100 μm is preferable because it has good contact with the glass surface of the liquid crystal panel, the alignment film on the TFT or color filter substrate, the ITO film, the polyimide film, etc. .

The pressure-sensitive adhesive used in the pressure-sensitive adhesive layer of the dust-removing pressure-sensitive adhesive sheet of the present invention has an adhesive force of 0.1 to 10 N / 2.
There is no particular limitation as long as it is 5 mm. For example, rubber type such as natural rubber, styrene-butadiene copolymer, styrene-isoprene copolymer, polyisobutylene, butyl rubber; acrylic type containing acrylic acid ester, 2-ethylhexyl acrylate, butyl acrylate, ethyl acrylate, etc. as main monomers. A vinyl adhesive such as polyvinyl ether or vinyl acetate is used. Preferably, an acrylic-based pressure-sensitive adhesive containing 2-ethylhexyl acrylate or butyl acrylate as a main monomer, and a rubber-based pressure-sensitive adhesive containing polyisobutylene as a main component are used.

The adhesive strength of the adhesive is JIS Z 0237.
Measurement method in accordance with (However, as a test plate SUS430B
Using A, the pressure-sensitive adhesive sheet is pressure-bonded to the test plate and measured 20 minutes later), but is 0.1 N to 10 N / 25 mm, preferably 0.5 N to 5 N / 25 mm. If the adhesive strength of the adhesive layer is 0.1 N / 25 mm or less, a liquid crystal panel,
If the dust on the alignment film on the TFT or color filter substrate cannot be sufficiently removed and it is 10 N / 25 mm or more,
Alignment film on the TFT or color filter substrate, ITO film,
This is because the polyimide film and the like will be peeled off.

Various additives may be added to the pressure-sensitive adhesive layer. For example, a cross-linking agent, a catalyst, a plasticizer, an antioxidant, a colorant, an antistatic agent, a filler, a tackifier, a surfactant, etc. may be added. However, in the present invention, the surfactant is not included. The surfactant migrates,
Alignment film on the TFT or color filter substrate, ITO film,
This is because it may contaminate the polyimide film or the like and affect the physical properties. Here, the surfactant means an additive added to reduce the surface tension, and corresponds to polyoxyethylene nonylphenyl ether, alkylbenzene sulfonate, and the like. The surfactant also has a function of suppressing the adhesive force. Since no surfactant is contained, there is no bleeding of the surfactant from the adhesive layer, and the physical properties of the alignment film, ITO film, polyimide film, etc. on the TFT or color filter substrate due to contamination are not affected.

The thickness of the pressure-sensitive adhesive layer is generally 1 μm to 5 μm.
Although it is 0 μm, in the present invention, it is preferably 5 μm to 30 μm, more preferably 5 μm to 15 μm.
If it is 5 μm or less, it is difficult to remove dust,
This is because if the thickness is more than μm, the alignment film, the ITO film, the polyimide film, etc. on the TFT or the color filter substrate may be peeled off.

The average molecular weight of the adhesive is 500,000 or more and 140
It is desirable that it is less than 10,000. If the average molecular weight is less than 500,000, transfer of the adhesive will occur, and if it is 1.4 million or more, the adhesive strength will decrease, and the glass surface of the liquid crystal panel, the alignment film of the TFT or the color filter substrate, the ITO film, the polyimide film, etc. This is because the dust existing on the surface cannot be removed.

The method used to form the pressure-sensitive adhesive layer is not particularly limited, but a coating method is generally used. The adhesive is coated on the substrate and dried in a dryer. After the adhesive layer is formed on the base material and passed through the drying device, the release film is formed.
Since they are laminated and attached without time, the amount of dust carried by the pressure-sensitive adhesive sheet can be reduced without the dust adhering to the pressure-sensitive adhesive layer. Also, after coating the adhesive on a plastic film that may be coated with a silicone-based release agent, and drying in a dryer,
The base material may be laminated and attached. Also in this case, since the release layer having the adhesive layer formed thereon is passed through the drying device and the base material is laminated and attached without time, the dust does not adhere to the adhesive layer, The amount of dust carried in the adhesive sheet can be reduced.

The material used as the release layer is preferably a plastic film which does not generate dust. The plastic film used for the release layer of the present invention is not particularly limited, but a polyolefin film such as a polyethylene film or a polypropylene film; a polyester film such as polyethylene terephthalate or polybutylene terephthalate; a polyamide film such as hexamethylene adipamide. Films: Halogen-containing films such as polyvinyl chloride, polyvinylidene chloride, polyfluoroethylene, etc .; Vinyl acetate such as polyvinyl acetate, polyvinyl alcohol, ethylene vinyl acetate copolymer, and derivative films thereof are used. A polyester film is preferable, and for example, polyethylene terephthalate is used. This is because it has appropriate elasticity. The plastic film used for the release layer may be coated with a release agent. For example, when using a plastic film coated with a silicone-based release agent.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to these Examples.

[0020]

Example 1 An acrylic pressure-sensitive adhesive (100 parts by weight of a polymer containing butyl acrylate as a main monomer, 4 parts by weight of an isocyanate-based cross-linking agent) on the surface of a 38 μm thick polyethylene terephthalate film coated with a silicone-based release agent, (A molecular weight of 590,000) is applied so that the thickness after drying becomes 10 μm, and is dried at 100 ° C. for 3 minutes by a drying device. Immediately after that, an adhesive layer and an ethylene vinyl acetate copolymer film (group having a thickness of 110 μm) are prepared. Materials) were adhered to each other to produce an adhesive sheet for dust removal.

[0021]

Example 2 An acrylic pressure-sensitive adhesive (100 parts by weight of a polymer containing butyl acrylate as a main monomer, 1.5 parts by weight of an isocyanate-based cross-linking agent) was coated on the surface of a 38 μm-thick polyethylene terephthalate film coated with a silicone-based release agent. , Molecular weight 590,000) so that the thickness after drying is 10 μm, and is dried at 100 ° C. for 3 minutes by a drying device. Immediately after that, an adhesive layer and an ethylene vinyl acetate copolymer film having a thickness of 110 μm ( The base material) was attached to produce a dust-removing pressure-sensitive adhesive sheet.

[0022]

Example 3 An acrylic pressure-sensitive adhesive (100 parts by weight of a polymer having butyl acrylate as a main monomer, 5 parts by weight of an isocyanate-based crosslinking agent, a molecular weight of 38 μm thick polyethylene terephthalate film coated with a silicone-based release agent, a molecular weight 1 million) so as to have a thickness after drying of 10 μm, and dried at 100 ° C. for 3 minutes by a drying device, and immediately thereafter, an adhesive layer and an ethylene vinyl acetate copolymer film (base material) having a thickness of 110 μm (base material). ) Was stuck together to produce a dust-removing pressure-sensitive adhesive sheet.

[0023]

Example 4 A polyisobutylene-based pressure-sensitive adhesive (100 parts by weight of a polymer having polyisobutylene as a main monomer, a molecular weight of 1,200,000) was dried on one surface of an unstretched polypropylene film (base material) having a thickness of 40 μm. To be 10 μm, and dried at 80 ° C. for 3 minutes by a drying device. Immediately after that, the pressure-sensitive adhesive layer and the surface of the polyethylene terephthalate film having a thickness of 38 μm coated with the silicone release agent are attached to remove dust. An adhesive sheet was produced.

[0024]

Example 5 An acrylic pressure-sensitive adhesive (100 parts by weight of a polymer having butyl acrylate as a main monomer, 5 parts by weight of a melamine-based cross-linking agent, a catalyst) was coated on the surface of a 38 μm thick polyethylene terephthalate film coated with a silicone-based release agent. 0.5 parts by weight, molecular weight of 740,000) and a thickness after drying of 10
It is coated so that it becomes μm, and it is dried at 100 ° C for 3
After drying for a minute, immediately after that, the pressure-sensitive adhesive layer and a 110 μm-thick ethylene vinyl acetate copolymer film (base material) were bonded together to produce a dust-removing pressure-sensitive adhesive sheet.

[0025]

Comparative Example 1 An acrylic adhesive (100 parts by weight of a polymer having butyl acrylate as a main monomer, 3 parts by weight of an isocyanate crosslinking agent, and a molecular weight of 380,000) was dried on one surface of a polyethylene film having a thickness of 55 μm. Thickness is 6 μm
And the surface of the polyethylene terephthalate film having a thickness of 38 μm coated with the silicone-based release agent are adhered to each other to remove dust by using a drying device. A sheet was prepared.

[0026]

Comparative Example 2 An acrylic pressure-sensitive adhesive (polymer 100 containing 2-ethylhexyl acrylate as a main monomer) was formed on one surface of an unstretched polypropylene film (base material) having a thickness of 50 μm.
Parts by weight, 5 parts by weight of isocyanate crosslinking agent, molecular weight 42
10,000) to a thickness of 5 μm after drying, and dried at 80 ° C. for 3 minutes with a drying device, and immediately thereafter, an adhesive layer and a silicone-based release agent of a polyethylene terephthalate film having a thickness of 38 μm are applied. The adhered surface was bonded to produce a dust-removing pressure-sensitive adhesive sheet.

[0027]

[Comparative Example 3] An acrylic pressure-sensitive adhesive (100 parts by weight of a polymer containing butyl acrylate as a main monomer, 5 parts by weight of a melamine-based cross-linking agent, and melamine) were coated on the surface of a 38 μm thick polyethylene terephthalate film coated with a silicone-based release agent. 0.5 parts by weight of a system catalyst, 0.5 parts by weight of a surfactant, and a molecular weight of 740,000) are coated by a usual coating method so that the thickness after drying is 10 μm, and dried at 100 ° C. for 3 minutes by a drying device Immediately after that, the pressure-sensitive adhesive layer was laminated with a 110 μm-thick ethylene vinyl acetate copolymer film (base material) to prepare a dust-removing pressure-sensitive adhesive sheet.

With respect to the dust-removing pressure-sensitive adhesive sheets of the above-mentioned Examples and Comparative Examples, the film (polyethylene terephthalate film) constituting the peeling layer was peeled from the pressure-sensitive adhesive layer, and the exposed pressure-sensitive adhesive layer surface was attached to the alignment film on the TFT substrate. After wearing
The adhesive sheet for dust removal was peeled off. The results are shown in Table 1.
As is clear from Table 1, the dust-removing pressure-sensitive adhesive sheet according to the present invention is free from contamination and has good dust-removing efficiency.

[0029]

[Table 1]

[0030]

According to the present invention, the glass surface of the liquid crystal panel,
Alignment film on the TFT or color filter substrate, ITO film,
The transfer of the adhesive to the polyimide film etc. does not occur, the physical properties of the alignment film on the TFT or color filter substrate, the ITO film, the polyimide film, etc. are not affected, and the alignment film on the TFT or color filter substrate, It is possible to provide a dust-removing pressure-sensitive adhesive sheet that does not cause peeling of the ITO film, the polyimide film, or the like and has high dust-removal efficiency.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yoshiaki Igarashi             11-9 Higashitakatsucho, Tennoji Ward, Osaka City Stock Association             Inside Sumilon F term (reference) 4F100 AK03A AK22A AK25B AK41C                       AK42 AK52 AK68 AN00B                       AR00B AR00C AT00A BA03                       BA07 BA10A BA10C GB41                       JA07B JL06 JL13B JL14C                       YY00A YY00B                 4J004 AA04 AA05 AA06 AA07 AA09                       AA10 CA03 CA04 CA05 CA06                       CC02 CE01 DA02 DA03 DB02                       EA01 FA10                 4J040 CA011 CA081 CA091 DA141                       DB051 DD051 DE021 DF021                       JA09 JA12 JB09 LA01 LA06                       MA10 MB03 NA20 NA21

Claims (9)

[Claims] 1. A dust-removing pressure-sensitive adhesive sheet comprising a substrate, a dust-removing pressure-sensitive adhesive layer formed on one surface of the substrate, and a release layer laminated on the dust-removing pressure-sensitive adhesive layer. 2. The pressure-sensitive adhesive sheet for dust removal according to claim 1, wherein the substrate is a vinyl acetate derivative or an olefin film. 3. The dust-removing pressure-sensitive adhesive sheet according to claim 1, wherein the substrate has a thickness of 25 μm to 300 μm. 4. The adhesive strength of the adhesive is 0.1 N to 10 N /
The dust-removing pressure-sensitive adhesive sheet according to any one of claims 1 to 3, which has a length of 25 mm. 5. The dust-removing pressure-sensitive adhesive sheet according to any one of claims 1 to 4, wherein the pressure-sensitive adhesive layer has a thickness of 5 μm to 30 μm. 6. The adhesive has an average molecular weight of 500,000 or more 14
The dust-removing pressure-sensitive adhesive sheet according to any one of claims 1 to 5, wherein the pressure-sensitive adhesive sheet is at most 0,000. 7. The dust-removing pressure-sensitive adhesive sheet according to any one of claims 1 to 6, wherein the pressure-sensitive adhesive is an acrylic pressure-sensitive adhesive or a rubber pressure-sensitive adhesive. 8. The dust-removing pressure-sensitive adhesive sheet according to any one of claims 1 to 7, wherein the pressure-sensitive adhesive does not contain a surfactant. 9. The dust-removing pressure-sensitive adhesive sheet according to claim 1, wherein the release layer is a polyester film.