JP5383000B6 - Double-sided adhesive tape and method for producing the same - Google Patents

Description

  The present invention relates to a double-sided adhesive tape that can be used for fixing polyurethane rubber and silicone rubber used in operation keys of digital cameras, mobile phone terminals, personal computers, portable audio players, and the like.

  Conventionally, polyurethane rubber and silicone rubber can be fixed with adhesives to fix polyurethane rubber and silicone rubber used for operation keys used in digital cameras, mobile phone terminals, personal computers and portable audio players. It has been supported by fixing with a double-sided adhesive tape having a total thickness of 70 μm or more. However, in the case of the said adhesive agent, since curing time (drying time of an adhesive agent) is required and a solvent volatilizes, it was not so preferable. Moreover, in the case of fixing with a double-sided adhesive tape, since the total thickness is 70 μm or more, it is not preferable because it prevents the digital home appliance from being thinned.

Moreover, as a double-sided pressure-sensitive adhesive tape having the same pressure-sensitive adhesive as that of the present invention, that is, an acrylic pressure-sensitive adhesive on one side and a silicone pressure-sensitive adhesive on the other side, the one having improved peelability of the separator for the silicone-based pressure-sensitive adhesive layer ( Patent Document 1), an intermediate resin layer having a glass transition temperature higher than that of an acrylic pressure-sensitive adhesive layer and an elongation at break at 23 ° C. of 0.7 to 70% (Patent Document 2), A synthetic rubber, an acrylic resin, an olefin resin, a silicone resin, and a urethane resin (Patent Document 3), a foamed pressure-sensitive adhesive layer (Patent Document 4), and characterized by impact resistance There is a thing (patent document 5).
JP-A-5-320592 JP 2002-194301 A Japanese Patent Laid-Open No. 10-17201 JP-A-6-212130 Japanese Patent Laid-Open No. 2003-313516

  However, the inventions described in Patent Documents 1 to 5 are all adhesive layers for fixing polyurethane rubber and silicone rubber used for operation keys of digital cameras, mobile phone terminals, personal computers and portable audio players. None of the above-mentioned structures and the substrate thickness and tape thickness are specified.

  SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems, and a polyurethane rubber or silicone rubber and a casing used for operation keys of a digital camera, a mobile phone terminal, a personal computer, a portable audio player, etc. An object of the present invention is to provide a double-sided pressure-sensitive adhesive tape that can be used for fixing to a component and can be thinned.

  In order to achieve the object of the present invention, the present invention is configured as described in the claims.

  That is, the present invention relates to a double-sided pressure-sensitive adhesive tape having pressure-sensitive adhesive layers on both sides of a base material comprising a heat-resistant polymer film, an acrylic pressure-sensitive adhesive layer on one side of the base material, and an addition polymerization type modification on the other side. The total thickness of the double-sided pressure-sensitive adhesive tape is 20 to 60 μm.

  In this case, the thickness of the base material is 4 to 13 μm.

  In the method for producing a double-sided pressure-sensitive adhesive tape of the present invention, a step of applying an acrylic pressure-sensitive adhesive to the release-treated surface of the first release film to form an acrylic pressure-sensitive adhesive layer, and a base material on the acrylic pressure-sensitive adhesive layer A step of bonding, a step of directly applying an easy adhesion treatment agent to the other surface of the acrylic pressure-sensitive adhesive layer through the substrate, and an addition polymerization type modified silicone pressure sensitive adhesive on the surface of the easy adhesion treatment agent coating Directly coating to form an addition polymerization modified silicone pressure-sensitive adhesive layer, and further including a step of bonding the second release film to the addition polymerization modified silicone pressure sensitive adhesive layer.

  The present invention relates to a double-sided pressure-sensitive adhesive tape having pressure-sensitive adhesive layers on both sides of a base material comprising a heat-resistant polymer film, wherein the base material is an acrylic pressure-sensitive adhesive layer on one side and the other side is an addition-polymerization-modified silicone type. Since it has an adhesive layer and the total thickness of the double-sided adhesive tape is 20 to 60 μm, an acrylic adhesive surface is suitable for fixing to a case or part of a mobile phone terminal or a digital camera, polyurethane rubber, A silicone-based adhesive is suitable for fixing to the silicone rubber, and both can be fixed. As a result, it can be used for fixing parts such as digital cameras, mobile phone terminals, personal computers and portable audio players. In addition, it is possible to reduce the thickness of parts used for mobile phone terminals, digital cameras, and the like.

  In this case, since the thickness of the base material is 4 to 13 μm, the workability in the punching process of parts such as a mobile phone terminal and a digital camera is excellent. Moreover, even if it bends 90 degree | times and affixes, generation | occurrence | production of peeling and floating by the repulsion of a base material can be prevented.

  Further, in the method for producing a double-sided pressure-sensitive adhesive tape of the present invention, a step of applying an acrylic pressure-sensitive adhesive to the release-treated surface of the first release film to form an acrylic pressure-sensitive adhesive layer, based on the acrylic pressure-sensitive adhesive layer. A step of laminating materials, a step of directly applying an easy-adhesion treatment agent to the other surface of the acrylic pressure-sensitive adhesive layer through the base material, and an addition-polymerization-modified silicone adhesive on the surface of the easy-adhesion treatment agent-coated surface A step of forming an addition polymerization-modified silicone pressure-sensitive adhesive layer by directly applying an agent, and a step of bonding a second release film to the addition polymerization-type modified silicone pressure-sensitive adhesive layer. The double-sided pressure-sensitive adhesive tape has high tensile strength and tear strength, and can suppress the occurrence of substrate breakage and wrinkles.

  In the double-sided pressure-sensitive adhesive tape having pressure-sensitive adhesive layers on both sides of a base material made of a heat-resistant polymer film, the present inventors have an acrylic pressure-sensitive adhesive layer on one side of the base material and added to the other side. It has a polymerization-type modified silicone pressure-sensitive adhesive layer and the total thickness of the double-sided pressure-sensitive adhesive tape is 20 to 60 μm, so that it can be used for operation keys of digital cameras, mobile phone terminals, personal computers, and portable audio players. It has been found that a double-sided pressure-sensitive adhesive tape that can be used for fixing a polyurethane rubber or silicone rubber to a casing and parts and can be thinned is obtained.

It has an acrylic pressure-sensitive adhesive layer formed of a pressure-sensitive adhesive composition containing an acrylic polymer, a tackifier, and a crosslinking agent on one side of a substrate comprising the heat-resistant polymer film of the present invention, and the other side. An acrylic polymer used in a double-sided pressure-sensitive adhesive tape having an addition-polymerization-modified silicone pressure-sensitive adhesive layer formed from a pressure-sensitive adhesive composition containing a silicone polymer, a catalyst, and a crosslinking agent is an alkyl (meth) acrylate. It consists of a copolymer of a monomer and a polar group-containing monomer and a cross-linking agent, and the solvent (eg, toluene, ethyl acetate, xylene, n-hexane, etc.) or water in the adhesive is dried or the adhesive. (Meth) acrylic acid alkyl ester monomer, polar group-containing monomer and polyfunctional acrylate with a photopolymerization initiator (for example, Irgacure 184, Irgacure 651, Ill Cure 369, Irgacure 1800 (Ciba Specialty Chemicals, Inc.), Chivacure TPO, Chivacure 107, Chivacure
173, Chivacure 1256 (Chaitech) or the like) is added in an amount of 0.001 to 5.0 parts by weight, and ultraviolet (UV) polymerization is performed to form an acrylic pressure-sensitive adhesive layer. Examples of the copolymer of the (meth) acrylic acid alkyl ester monomer and the polar group-containing monomer include, for example, a copolymer of 2-ethylhexyl acrylate and acrylic acid, isooctyl acrylate and 2-hydroxy methacrylate. A copolymer with ethyl, a terpolymer of butyl acrylate, acrylic acid and 2-hydroxyethyl methacrylate, and the like are used, but not particularly limited thereto.

  Examples of the above (meth) acrylic acid alkyl ester monomers include, for example, ethyl group, propyl group, butyl group, pentyl group, hexyl group, 2-ethylhexyl group, octyl group, isooctyl group, nonyl group, isononyl group. In general, an ester of (meth) acrylic acid having an alkyl group having 20 or less carbon atoms, typically represented by a decyl group, and the like. The above (meth) acrylic acid alkyl esters are used alone or in combination of two or more.

  Examples of the polar group-containing monomer include acrylic acid, methacrylic acid, itaconic acid, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, dimethylaminoethyl acrylate, acrylonitrile, and acrylic acid-β. -Polymerizable unsaturated monomers having polar groups such as carboxyl group, hydroxyl group, amino group, etc., represented by carboxyethyl (β-CEA), methacrylonitrile, N-vinyl-2-pyrrolidone, etc. Is mentioned.

  The tackifier for the acrylic adhesive layer is a highly weatherable hydrogenated rosin resin (fully hydrogenated rosin resin), aliphatic fully saturated hydrocarbon resin, hydrogenated terpene resin (fully hydrogenated terpene resin) or Silane coupling agents, specifically, Pine Crystal KE-100, Pine Crystal KE-311, Pine Crystal KE-359, Pine Crystal KE-604 (manufactured by Arakawa Chemical Industries), Archon P-70, Archon P -100, Archon P-115, Archon P-125, Archon P-140 (Arakawa Chemical Industries), Clearon P-85, Clearon P-105, Clearon P-115, Clearon P-125, Clearon M-105, Clearon K-100, Clearon K-110 (manufactured by Yasuhara Chemical) and silane coupling agent -6011, Z-6020, Z-6050, Z-6041, Z-6044, Z-6920, Z-6075, Z-6300, Z-6825, Z-6033, Z-6062, Z-6860 (above, Toray -Dow Corning) is used, but is not particularly limited thereto.

  The crosslinking agent for the acrylic pressure-sensitive adhesive layer is, for example, one having two or more functional groups such as isocyanate group (polyisocyanate) or epoxy group (epoxy resin) in the molecule, or 1,6-hexanediol. A polyfunctional acrylate such as diacrylate or triethylene glycol diacrylate or a metal chelate compound is used, but is not particularly limited thereto.

  Moreover, as a base material which consists of a heat resistant polymer film, a polyester film (PET), a polyethylene naphthalate (PEN), a polyimide film (PI), a polyphenylene sulfide film (PPS), a polycarbonate film (PC), a polyamide film, for example (PA), fluorine-containing high molecular weight film (polyvinyl fluoride (PVF), tetrafluoroethylene-ethylene copolymer (ETFE)), specifically, Toray Lumirror (PET), Teijin Tetron (PET), Unitika's Emblet (PET), Teijin's Teonex (PEN), Pyromellitic acid todiaminodiphenyl ether polyimide (Toray DuPont Kapton H (PI), Kaneka Apical AH (PI), Toray Lina (PPS), Teijin Panlite (PC), Toray Mikutron (PA), DuPont Tedlar (PVF), Asahi Glass Aflex (ETFE), etc. are used. Absent.

  The easy adhesion treatment agent (primer) to be applied before coating the silicone pressure-sensitive adhesive layer comprises a condensation reaction type and addition polymerization type silicone copolymer and a catalyst, and a solvent (for example, Toluene, ethyl acetate, xylene, n-hexane, etc.) or water is dried to form an easy adhesion treatment agent layer. As the condensation reaction type and addition polymerization type silicone copolymer, for example, SRX290, BY24-712, Syl-off23 (manufactured by Toray Dow Corning), X-40-3501 (manufactured by Shin-Etsu Chemical) are used, and the catalyst is: For example, NC-25, SRX242AC, SRX242AD, SRX212 catalyst (manufactured by Toray Dow Corning) are used, but not particularly limited thereto.

  The silicone copolymer comprises an addition polymerization type silicone copolymer having a vinylsilyl group (Si—CH═CH2 group), a hydrosilyl group (Si—H group), a catalyst, and a crosslinking agent. A solvent (for example, toluene, ethyl acetate, xylene, n-hexane, etc.) or water is dried to form a silicone pressure-sensitive adhesive layer. Examples of the silicone copolymer of the addition polymerization type modified silicone pressure-sensitive adhesive layer include SD4560, SD4570, SD4580, SD4584, SD4585, SD4585, SD4592, BY24-740 (manufactured by Toray Dow Corning), X-40-3068, X-40-3102, X-40-3103, and X-40-3104 (manufactured by Shin-Etsu Chemical) are used, but are not particularly limited thereto.

  Examples of the catalyst for the addition polymerization type modified silicone pressure-sensitive adhesive layer include SRX212 catalyst (manufactured by Dow Corning Toray) and CAT-PL-50T (manufactured by Shin-Etsu Chemical). Is not to be done.

  Examples of the crosslinking agent for the addition polymerization type modified silicone pressure-sensitive adhesive layer include BY24-741, RD-1, and RD-2 (manufactured by Toray Dow Corning), but are particularly limited thereto. It is not a thing.

  As the release film, Teijin Burex, Toray Film Processing Therapy, Nipper Nipper Sheet, etc. are used, but not particularly limited thereto. Moreover, as a thickness of a peeling film, it is a thing of 19-100 micrometers.

  Moreover, as a compounding quantity of the crosslinking agent of an acrylic adhesive layer, 0.50-4.0 weight part of the said adhesive composition is preferable. When the blending amount is less than 0.50 parts by weight, the double-sided pressure-sensitive adhesive tape cannot hold 40 ° C. holding power, which is not preferable. Moreover, when a compounding quantity exceeds 4.0 weight part, since a crosslinking density will become high too much and, as a result, cohesion force will increase and 40 degreeC retainability cannot be maintained, it is unpreferable.

  Moreover, as a compounding quantity of the tackifier of an acrylic adhesive layer, 0-50 weight part of the said adhesive composition is preferable. If the blending amount exceeds 50 parts by weight, the tackifier will ooze out on the surface of the double-sided pressure-sensitive adhesive tape and contaminate the adherend (part).

  Moreover, as a compounding quantity of the catalyst of a silicone type adhesive layer, 0.1 weight part or more of the said adhesive composition is preferable. When the amount is less than 0.1 part by weight, the reaction of the silicone polymer is not promoted, which is not preferable.

  Moreover, as a compounding quantity of the crosslinking agent of a silicone type adhesive layer, 0.1-1.5 weight part of the said adhesive composition is preferable. When the blending amount is less than 0.1 parts by weight, the double-sided pressure-sensitive adhesive tape cannot hold 40 ° C. holding power, which is not preferable. On the other hand, if the blending amount exceeds 1.5 parts by weight, the crosslinking density becomes too high, and as a result, the cohesive force increases and the 40 ° C. retention cannot be maintained, which is not preferable.

  Moreover, as thickness of a double-sided adhesive tape, the range of 20-60 micrometers is more preferable, More preferably, the range of 30-50 micrometers is preferable. If the thickness is less than 20 μm, an effect as a force for fixing the component cannot be obtained, which is not preferable. On the other hand, when the thickness exceeds 60 μm, it is not preferable because the material parts used for the digital camera, the mobile phone terminal and the like cannot be thinned.

  Regarding the adhesive strength (to stainless steel) of the acrylic adhesive layer, the adhesive strength is 2.5 N / 10 mm or more, preferably 3.0 N / 10 mm or more. When the adhesive strength is less than 2.5 N / 10 mm, the affixing strength for fixing the component and the housing is low, which is not preferable.

  Further, regarding the adhesive strength (to silicone rubber) of the silicone-based pressure-sensitive adhesive layer, it is desirable that the adhesive strength is 0.8 N / 10 mm or more, preferably 1.0 N / 10 mm or more. When the adhesive strength is less than 0.8 N / 10 mm, the adhesive strength for fixing the silicone rubber component is low, which is not preferable.

  In addition, the holding force of the double-sided adhesive tape that can be used for material parts used in digital cameras and mobile phone terminals is not dropped for 24 hours when the adherend is a stainless steel plate, the test atmosphere is 40 ° C., and the load is 9.8 N. It is desirable. In the case where the holding force is broken between the adherend interface, the cohesive failure in the middle of the pressure-sensitive adhesive layer, and falling between the double-sided pressure-sensitive adhesive tape layers, the holding strength of the component is low, which is not preferable.

  The base material thickness of the double-sided pressure-sensitive adhesive tape is 4 to 13 μm, more preferably 9 to 12 μm. If the substrate thickness is less than 4 μm, the processability in the part punching process is poor, and it is difficult to handle the coatability. When the thickness of the base material exceeds 13 μm, the repulsion of the base material is increased, and this is not preferable for use due to problems such as peeling and floating when the film is bent by 90 ° and attached.

  The thickness of the acrylic pressure-sensitive adhesive layer of the double-sided pressure-sensitive adhesive tape is 8 to 48 μm, more preferably 10 to 28 μm. If the thickness of the acrylic pressure-sensitive adhesive layer is less than 8 μm, the fixing force of the parts is low, which is not preferable. When the thickness of this acrylic pressure-sensitive adhesive layer exceeds 48 μm, the total thickness of the double-sided pressure-sensitive adhesive tape (thickness of acrylic pressure-sensitive adhesive layer + substrate thickness + thickness of addition polymerization type modified silicone pressure-sensitive adhesive layer) is 60 μm. Therefore, it is not suitable for thinning of mobile phone parts and the like, which is not preferable.

The thickness of the easy-adhesion treatment agent layer for the silicone pressure-sensitive adhesive is very thin and it is very difficult to control the thickness, so it is defined by the coating amount before drying. The coating amount before drying is 0.1 to 100 g / m ² , more preferably 5 to 30 g / m ² . When the application amount of the easy-adhesion treatment agent for the silicone pressure-sensitive adhesive is less than 0.1 g / m ² , the adhesion between the base material and the silicone pressure-sensitive adhesive cannot be obtained, which is not preferable. Moreover, when the application amount of the easy-adhesion treatment agent for the silicone pressure-sensitive adhesive exceeds 100 g / m ² , the pressure-sensitive adhesive characteristics are affected, which is not preferable.

  The thickness of the addition polymerization type modified silicone pressure-sensitive adhesive layer of the double-sided pressure-sensitive adhesive tape is preferably 8 to 48 μm, more preferably 10 to 28 μm. When the thickness of the silicone-based pressure-sensitive adhesive layer is less than 8 μm, the fixing force of the silicone rubber part or the like is low, which is not preferable. If the thickness of the silicone-based pressure-sensitive adhesive layer exceeds 48 μm, the total thickness of the double-sided pressure-sensitive adhesive tape exceeds 60 μm, which is not suitable for reducing the thickness of mobile phone parts and the like.

  The silicone polymer used for the silicone-based pressure-sensitive adhesive layer has a drying temperature of 100 to 120 ° C., and an addition polymerization type is desirable because deformation of the release film and the substrate can be suppressed. The condensation polymerization type silicone polymer is not preferable because the drying temperature is 150 to 200 ° C., and the deformation of the release film and the substrate occurs. In addition, an ultraviolet polymerization type silicone polymer is not preferable because its adhesiveness to silicone is less than 0.8 N / 10 mm.

  Hereinafter, the double-sided pressure-sensitive adhesive tape of the present invention and the production method thereof will be specifically described with reference to the drawings.

As shown in FIG. 1, the double-sided pressure-sensitive adhesive tape of the present invention comprises a first release film 1, an acrylic pressure-sensitive adhesive layer 2, a base material 3 made of a heat-resistant polymer film, an easy adhesion treatment agent-coated surface 4, and addition polymerization. It consists of a six-layer structure of a mold-modified silicone pressure-sensitive adhesive layer 5 and a second release film 6.
In the production method, as a first step, an acrylic pressure-sensitive adhesive is applied to the release-treated surface of the first release film 1 (for acrylic pressure-sensitive adhesive), heat-dried, or irradiated with ultraviolet rays (UV) in a nitrogen atmosphere. Then, the acrylic pressure-sensitive adhesive layer 2 is formed, and the base material 3 made of a heat-resistant polymer film is bonded to the acrylic pressure-sensitive adhesive layer 2 and wound up. As the second stage, an easy-adhesion treatment agent for silicone-based pressure-sensitive adhesive is directly applied to the opposite surface of the pressure-sensitive adhesive coated product wound up in the first stage via the substrate 3, and heated and dried. take. Further, as the third stage, the addition polymerization type modified silicone pressure-sensitive adhesive is directly coated on the easy adhesion treatment agent coated surface 4 wound up in the second stage, followed by drying by heating. Layer 5 is formed. Next, the second release film 6 (for silicone pressure sensitive adhesive) is bonded to the addition polymerization modified silicone pressure sensitive adhesive layer 5 and wound up.

  In the present invention, in the production of double-sided pressure-sensitive adhesive tape, the easy adhesion treatment agent and the addition polymerization type modified silicone pressure-sensitive adhesive are directly applied to the opposite surface through the base material of the pressure-sensitive adhesive coated product wound in the first stage. Is desirable. Regarding the easy adhesion treatment, transfer coating is not preferable because the effect of the easy adhesion treatment is not observed. With regard to addition polymerization type modified silicone pressure-sensitive adhesive layer as well, the transfer coating, that is, the method of coating the release film and transferring the coated product to the substrate, cannot maintain the adhesion, resulting in adhesive interlaminar fracture. This is not preferable.

  The double-sided pressure-sensitive adhesive tape of the present invention is not particularly limited as long as its use can be used for fixing parts of digital cameras and mobile phone terminals, and fixing of parts is required. It is suitably used as a terminal component and greatly contributes to its thinning.

  The configuration of the double-sided pressure-sensitive adhesive tape of the present invention will be specifically described with reference to examples. However, the double-sided pressure-sensitive adhesive tape of the present invention is not limited to this. In the description of the examples and specific examples of the present invention, “part” represents part by weight, “μm” represents thickness, and “minute or displacement mm” represents holding force characteristics.

[Example 1]
A pressure-sensitive adhesive composition of 95 parts of a monomer composition of acrylic acid / butyl acrylate = 2/98 and a copolymer of the same composition (weight average molecular weight (hereinafter referred to as Mw): 3 million) was crosslinked to 5 parts. Add 0.50 parts of triethylene glycol diacrylate, 0.20 parts Irgacure 184 made by Ciba Specialty Chemicals, and 5.0 parts of tackifier Pine Crystal KE311 made by Arakawa Chemical Industries The resultant was mixed, applied to a release film having a thickness of 19 μm so that the adhesive layer had a thickness of 8 μm, irradiated with ultraviolet rays, and bonded to a 4 μm PET film manufactured by Toray. Next, 1.0 part of BY24-712 manufactured by Toray Dow Corning, 0.5 part of catalyst SRX212 catalyst manufactured by Toray Dow Corning, and 100 parts of toluene were added and mixed uniformly. On the opposite surface of the coating, 0.1 g / m ^{2 was} applied. Next, 100 parts of addition polymerization type modified silicone pressure-sensitive adhesive X-40-3103 manufactured by Shin-Etsu Chemical Co., Ltd., 1.0 part of catalyst CAT-PL-50T manufactured by Shin-Etsu Chemical Co., Ltd., and RD-2 0.4 part manufactured by Toray Dow Corning And 100 parts of toluene are added, mixed uniformly, coated on the easy-adhesion treated surface so that the pressure-sensitive adhesive layer has a thickness of 8 μm, and a 75 μm-thick release film is further bonded to the double-sided pressure-sensitive adhesive tape with a total thickness of 20 μm. (Sheet) was obtained. As shown in Table 1, this double-sided pressure-sensitive adhesive tape (sheet) had adhesive strength and holding power.

[Example 2]
50 parts of a monomer composition of acrylic acid / acrylic acid-2-ethylhexyl / acrylic acid-β-carboxyethyl = 7/90/3, 50 parts of a copolymer (Mw: 200,000) of the same composition 0.5 part of polyisocyanate having 2 or more isocyanate groups in the molecule (Coronate 55E made by Nippon Polyurethane) was added to the product as a cross-linking agent, and 50 parts of Arakawa Chemical Industries tackifier Alcon P-100 was added. The mixture was uniformly mixed, applied to a release film having a thickness of 38 μm so that the adhesive layer had a thickness of 8 μm, and bonded to a 12 μm PI film (Apical AH manufactured by Kaneka Corporation). Next, 2.5 parts of Toray Dow Corning Silicone Copolymer SRX290, 0.10 parts of Toray Dow Corning Catalyst SRX242AC, 0.05 parts of Toray Dow Corning Catalyst SRX242AD and 100 parts of toluene were added uniformly. Then, 50 g / m ^{2 was} applied to the opposite surface of the PI film as an easy adhesion treating agent. Next, 100 parts of Toray Dow Corning addition polymerization type modified silicone pressure-sensitive adhesive SD4570, 1.0 part of Toray Dow Corning catalyst SRX212 catalyst, 0.1 part of Toray Dow Corning crosslinker BY24-741 and toluene Add 100 parts, mix uniformly, apply to the easy-adhesion treated surface so that the pressure-sensitive adhesive layer has a thickness of 10 μm, and paste a 100 μm-thick release film together, and double-sided pressure-sensitive adhesive tape with a total thickness of 30 μm (sheet ) As shown in Table 1, this double-sided pressure-sensitive adhesive tape (sheet) had adhesive strength and holding power.

[Example 3]
30 parts of a monomer composition of acrylic acid / acrylic acid-2-ethylhexyl = 2/98, 70 parts of a copolymer (Mw: 700,000) of the same composition, 2 epoxy groups in the molecule Add 1.0 parts of epoxy resin (hardening agent E-AX, manufactured by Soken Chemical Co., Ltd.) as a cross-linking agent, and add 0.3 part of Toray Dow Corning tackifier silane coupling agent Z-6062 uniformly The film was applied to a release film having a thickness of 50 μm so that the adhesive layer had a thickness of 8 μm, and a 12 μm PEN film (Teonex manufactured by Teijin) was bonded thereto. Next, 2.0 parts of Toray Dow Corning silicone copolymer SRX290, 0.1 part of Toray Dow Corning catalyst SRX242AC, 0.1 part of Toray Dow Corning catalyst SRX242AD and 100 parts of n-hexane were added. Mix evenly, and as an easy-adhesive treatment agent, 15
g / m ^{2 was} applied. Next, 100 parts of Toray Dow Corning addition polymerization type modified silicone pressure-sensitive adhesive SD4580, 1.0 part of Toray Dow Corning catalyst SRX212 catalyst, 1.5 parts of Toray Dow Corning crosslinker BY24-741 and toluene Add 100 parts, mix evenly, and apply to the easy-adhesion treated surface to an adhesive layer thickness of 20 μm, and then apply a 38 μm-thick release film together to a total thickness of 40 μm double-sided adhesive tape (sheet) Got. As shown in Table 1, this double-sided pressure-sensitive adhesive tape (sheet) had adhesive strength and holding power.

[Example 4]
A pressure-sensitive adhesive composition of 15 parts of a monomer composition of acrylic acid / butyl acrylate / acrylic acid-2-hydroxyethyl = 2/95/3 and 85 parts of a copolymer (Mw: 2 million) of the same composition, 4.0 parts of polyisocyanate having two or more isocyanate groups in the molecule is added as a cross-linking agent (curing agent D-40 manufactured by Dainippon Ink & Chemicals, Inc.), and further, 20 parts of Yashara Chemical tackifier Clearon P-105 And 15 parts of Arakawa Chemical Industries' tackifier Pine Crystal KE604, uniformly mixed, applied to a 50 μm-thick release film to an adhesive layer thickness of 20 μm, and affixed to a 10 μm PC film (Teijin Panlite) Combined. Next, 1.5 parts of Toray-Dow Corning silicone copolymer BY24-712, Toray-Dow Corning catalyst SRX212 catalyst 0.3 part and 100 parts of toluene are added and mixed uniformly, and an easy adhesion treatment agent. As a result, 20 g / m ^{2 was} applied to the opposite surface of the PC film. Next, 100 parts of Toray Dow Corning addition polymerization type modified silicone pressure-sensitive adhesive SD4580, 1.0 part of Toray Dow Corning catalyst SRX212 catalyst, 0.5 part of Toray Dow Corning crosslinker BY24-741 and toluene Add 100 parts, mix uniformly, apply to the easy-adhesion treated surface so that the pressure-sensitive adhesive layer has a thickness of 20 μm, and then attach a 75 μm-thick release film to the double-sided pressure-sensitive adhesive tape (sheet) with a total thickness of 50 μm ) As shown in Table 1, this double-sided pressure-sensitive adhesive tape (sheet) had adhesive strength and holding power.

[Example 5]
20 parts of a monomer composition of acrylic acid / acrylic acid-2-ethylhexyl = 8/92, 80 parts of a copolymer (Mw: 700,000) of the same composition, 2 epoxy groups in the molecule Add 0.8 parts of epoxy resin (TETRAC C, manufactured by Mitsubishi Gas Chemical Co., Ltd.) as a cross-linking agent, mix uniformly, and apply to a 25 μm-thick release film so that the adhesive layer has a thickness of 20 μm. 12 μm PPS film It was pasted together (Torayrina manufactured by Toray). Next, 3.0 parts of Toray / Dow Corning silicone copolymer SRX290, 0.2 parts of Toray / Dow Corning catalyst SRX242AC, 0.1 part of Toray / Dow Corning catalyst SRX242AD and 100 parts of toluene were added uniformly. Then, 10 g / m ^{2 was} applied to the opposite surface of the PPS film as an easy adhesion treatment agent. Next, 100 parts of addition polymerization type modified silicone pressure-sensitive adhesive X-40-3104 manufactured by Shin-Etsu Chemical Co., Ltd., 1.0 part of catalyst CAT-PL-50T manufactured by Shin-Etsu Chemical Co., Ltd., 0.6 part of RD-2 manufactured by Toray Dow Corning And 100 parts of toluene are added, mixed uniformly, coated to an easy-adhesion-treated surface so that the adhesive layer has a thickness of 28 μm, and a 75 μm-thick release film is bonded together, with a total thickness of 60 μm double-sided adhesive tape (Sheet) was obtained. As shown in Table 1, this double-sided pressure-sensitive adhesive tape (sheet) had adhesive strength and holding power.

[Example 6]
A pressure-sensitive adhesive composition of 30 parts of a monomer composition of acrylic acid / acrylic acid-2-ethylhexyl = 6/94 and 70 parts of a copolymer (Mw: 700,000) of the same composition has 2 epoxy groups in the molecule. Add 0.5 parts of epoxy resin (TETRAD X, manufactured by Mitsubishi Gas Chemical Co., Ltd.) as a cross-linking agent, and then uniformly mix 0.1 part of Toray Dow Corning's tackifier silane coupling agent Z-6020. The film was applied to a release film having a thickness of 36 μm so that the adhesive layer had a thickness of 10 μm, and was bonded to a 13 μm PET film (Tetron manufactured by Teijin). Next, 2.0 parts of Toray-Dow Corning silicone copolymer BY24-712, Toray-Dow Corning catalyst SRX212 catalyst 0.4 parts and 100 parts of toluene are added and mixed uniformly, and an easy adhesion treatment agent. As a result, 15 g / m ^{2 was} applied to the opposite surface of the PET film. Next, 100 parts of Toray Dow Corning addition-polymerization-modified silicone adhesive SD4580, 0.8 part of Toray Dow Corning Catalyst SRX212 Catalyst, 0.3 part of Toray Dow Corning Cross-Linker BY24-741 and toluene Add 100 parts, mix evenly, and apply to the easy-adhesion treated surface to a pressure-sensitive adhesive thickness of 27 μm, and then apply a 38 μm-thick release film, and a total thickness of 50 μm double-sided pressure-sensitive adhesive tape (sheet) ) As shown in Table 1, this double-sided pressure-sensitive adhesive tape (sheet) had adhesive strength and holding power.

[Comparative Example 1]
Into the pressure-sensitive adhesive composition of 30 parts of a monomer composition of acrylic acid / acrylic acid-2-ethylhexyl = 10/90 and 70 parts of a copolymer (Mw: 700,000) of the same composition, 2 isocyanate groups were added in the molecule. Add 3.0 parts of polyisocyanate (Nippon Polyurethane Coronate 55E) as a cross-linking agent, mix uniformly, apply to a 38 μm-thick release film so that the adhesive layer has a thickness of 30 μm, and then add a 25 μm PEN film ( Teijin Teonex). Next, 3.0 parts of Toray Dow Corning silicone copolymer SRX290, 0.05 parts of Toray Dow Corning catalyst SRX242AC, 0.05 parts of Toray Dow Corning catalyst SRX242AD and 100 parts of toluene were added uniformly. Then, 10 g / m ^{2 was} applied to the opposite surface of the PEN film as an easy adhesion treatment agent. Next, 100 parts of addition polymerization type modified silicone pressure-sensitive adhesive X-40-3104 manufactured by Shin-Etsu Chemical Co., Ltd. 0.8 part of catalyst CAT-PL-50T manufactured by Shin-Etsu Chemical Co., Ltd. 0.6 part of cross-linking agent RD-2 manufactured by Toray Dow Corning And 100 parts of toluene are added, mixed uniformly, coated on the easy-adhesion treated surface so that the adhesive layer thickness is 35 μm, and then a 50 μm-thick release film is attached, and the total thickness is 90 μm double-sided adhesive tape. (Sheet) was obtained. Since this double-sided pressure-sensitive adhesive tape (sheet) has a total thickness of 70 μm or more, it was not suitable for thinning digital home appliances.

[Comparative Example 2]
A pressure-sensitive adhesive composition containing 50 parts of a monomer composition of acrylic acid / acrylic acid-2-ethylhexyl = 8/92 and 50 parts of a copolymer (Mw: 700,000) of the same composition, 2 epoxy groups in the molecule. Add 1.0 parts of epoxy resin (hardening agent E-AX, manufactured by Soken Chemical Co., Ltd.) as a crosslinking agent, and uniformly add 0.2 parts of Toray Dow Corning tackifier silane coupling agent Z-6041 The mixture was applied to a release film having a thickness of 50 μm so that the adhesive layer had a thickness of 10 μm, and bonded to a 10 μm PET film (Tetron manufactured by Teijin). Next, on the opposite side of the PET film, an acrylic pressure-sensitive adhesive having the same composition is applied so that the thickness of the pressure-sensitive adhesive layer is 10 μm. Further, a 75 μm-thick release film is bonded, and a double-sided pressure-sensitive adhesive tape having a total thickness of 30 μm. (Sheet) was obtained. As shown in Table 1, this double-sided pressure-sensitive adhesive tape (sheet) did not provide a value satisfying the standard value for the adhesive strength of silicone rubber.

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[Thickness] According to JIS-Z-0237 (2000). In addition, the dial gauge prescribed | regulated to JIS-B-7503 is used for the measurement of thickness.

  [Adhesive strength] The adhesive strength of the double-sided adhesive tape was measured according to JIS-Z-1528 (2004). The coated surface coated with acrylic pressure-sensitive adhesive is a polished stainless steel plate (thickness 1.5 mm) as the adherend, and the coated surface coated with addition polymerization type modified silicone pressure-sensitive adhesive is Tigers polymer as the adherend. Using a silicone rubber SR-70 (thickness: 1 mm) manufactured by Co., Ltd., a test piece lined with a 0.019 mm thick polyester (PET) film was pasted and reciprocated once with a roller with a load of 19.6 N. After a minute, it peeled and measured in the 180 degree direction with the peeling speed of 300 mm / min with the Aiko tensile tester.

  [Retention force] According to JIS-Z-1528 (2004), it is backed by a PET film having a thickness of 0.019 mm, dropped (minutes) or displaced width (mm) at a measurement temperature of 40 ° C., a load of 9.8 N, and a test time of 24 hours. Was measured.

The block diagram of the double-sided adhesive tape of this invention is represented.

Explanation of symbols

1: First release film, 2: Acrylic pressure-sensitive adhesive layer, 3: Substrate composed of heat-resistant polymer film, 4: Adhesion treatment surface, 5: Addition-polymerized modified silicone pressure-sensitive adhesive layer, 6 : Second release film

Claims (1)

A process of forming an acrylic pressure-sensitive adhesive layer by applying an acrylic pressure-sensitive adhesive to the release-treated surface of the first release film having a thickness of 19 to 100 μm. From the heat-resistant polymer film to the acrylic pressure-sensitive adhesive layer A step of bonding a substrate having a thickness of 4 to 13 μm , a condensation reaction type or addition polymerization type silicone copolymer on the other surface of the acrylic pressure-sensitive adhesive layer through the substrate, a catalyst, a solvent, A step of directly applying an easy-adhesion treatment agent comprising: a step of directly applying an addition-polymerizable silicone pressure-sensitive adhesive on the surface of the easy-adhesion treatment agent-coated surface to form an addition-polymerization type silicone-based pressure-sensitive adhesive layer; Furthermore, the manufacturing method of the double-sided adhesive tape whose total thickness is 20-60 micrometers characterized by including the process of bonding a 2nd peeling film to the said addition polymerization type silicone type adhesive layer.

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