TW202018038A - Adhesive tape - Google Patents

Abstract

The purpose of the present invention is to provide an adhesive tape that is capable of easily peeled off from an adherend which can react by irradiation with light and leaves less residues on the adherend. The present invention pertains to an adhesive tape comprising an adhesive layer that contains a photocurable adhesive. When the adhesive layers of two of these adhesive tapes are laminated and then photocured, the peeling force between these two tapes is not more than 75 gf/inch. When this adhesive tape is applied to a polymethyl methacrylate plate and photocured, and the adhesive tape is then peeled off, the difference between the contact angle versus water of the region on the polymethyl methacrylate plate where the adhesive tape was applied and the contact angle versus water of the polymethyl methacrylate plate prior to application of the adhesive tape is within ±20%.

Description

Adhesive tape

The present invention relates to an adhesive tape that can easily peel off an "adhered body that may react by light irradiation" and suppress contamination of the adhered body.

The adhesive film can be easily joined, so it is used in various industrial fields. In the construction field, the adhesive film is used for the temporary fixation of the curing sheet, the bonding of the interior materials, etc. In the automotive field, the adhesive film is used for the fixing of the interior parts such as sheets and sensors, side protection strips, window side stops The fixing of rainboards and other external parts is used in the field of electrical and electronic adhesive films for module assembly, module bonding to the housing, etc. More specifically, for example, the adhesive film is also widely used as a surface protective film for protecting the surfaces of optical devices, metal plates, coated metal plates, resin plates, glass plates, and other members (for example, Patent Documents 1 to 3) .

The adhesive tape used for the surface protection film requires high adhesion that does not peel off when protection is required. On the other hand, it also requires light peelability that can be easily peeled off without protection (hereinafter, also referred to as "high adhesion light peeling") ). As an adhesive composition that achieves high adhesion and easy peeling, Patent Document 4 discloses an adhesive tape using a photo-curable adhesive that is cured by irradiation of light such as ultraviolet rays and has reduced adhesive strength. By using a photo-curable adhesive as the adhesive, the adherend can be reliably fixed in the processing step, and can be easily peeled off by irradiating ultraviolet rays or the like. Prior technical literature Patent Literature

Patent Document 1: Japanese Patent Laid-Open No. 1-129085 Patent Document 2: Japanese Patent Laid-Open No. 6-1958 Patent Document 3: Japanese Patent Laid-Open No. 8-12952 Patent Document 4: Japanese Patent Laid-Open No. 5-32946

[Problems to be solved by the invention]

In recent years, due to the advancement of technology, components have been miniaturized and thinned in the field of electronics. If such thinned components are deformed or damaged once the force is peeled off, the adhesive strips require higher light peeling. Sex. The conventional adhesive tape is blended with a release agent such as polysiloxane compound, so that the release agent penetrates the interface between the adhesive tape and the adherend, thereby improving light peelability. In addition, in order to reduce the contamination of the adhesive body caused by the residue of the mold release agent, the mold release agent has a functional group that can bond with the adhesive. The mold release agent has a functional group that can react with the adhesive, thereby suppressing the bonding of the adhesive tape to the adhesive when the adhesive tape is hardened and the release agent remaining in the adherend.

On the other hand, the adherend has a hard coat layer made of transparent resin or the like on the surface. When the conventional adhesive tape is used for such an adherend with a hard coating, there is a release agent that not only reacts with the adhesive but also reacts with the resin of the hard coating when the adhesive tape is hardened, thereby adhering the tape The problem becomes difficult to peel.

The object of the present invention is to provide an adhesive tape in view of the above-mentioned current situation, which can easily peel off the "adherent body that may react by light irradiation" and suppress contamination of the adherend. [Technical means to solve the problem]

The present invention is an adhesive tape having an adhesive layer that contains a photo-curable adhesive. After the two adhesive layers of the adhesive tape are attached to each other and photo-cured, the peeling force of the two adhesive tapes 75 gf/inch or less, attach the adhesive tape to the polymethyl methacrylate board and photo-harden it. After peeling the adhesive tape, the part of the polymethyl methacrylate board pasted the adhesive tape The difference between the contact angle of water and the contact angle of the polymethyl methacrylate board before attaching the above adhesive tape to water is within ±20%. Hereinafter, the present invention will be described in detail.

The adhesive tape of the present invention has an adhesive layer, and the adhesive layer contains a photo-curable adhesive. The adhesive tape has a light-curing adhesive, which can be attached to the adherend with sufficient adhesive force to protect the adherend, and by hardening the adhesive layer after attachment, it can be adhered without damage without protection Peel off the adhesive tape easily.

In the adhesive tape of the present invention, after the two adhesive layers of the adhesive tape are adhered to each other and photo-hardened, the peeling force (hereinafter, referred to as the bonding peeling force) of the two adhesive tapes is 75 gf/inch or less. By making the bonding peeling force 75 gf/inch or less, even when it is used for an adherend that can react by light irradiation, the adherend is difficult to be contaminated and can be easily peeled off. Furthermore, even when used to protect a fragile adherend, the adhesive tape can be peeled without damaging the adherend. In terms of further improving the light peeling performance, the above-mentioned bonding peeling force is preferably 55 gf/inch or less, more preferably 20 gf/inch or less, further preferably 10 gf/inch or less, and particularly preferably 5 gf Below /inch, the best is below 4 gf/inch. The above-mentioned bonding peeling force is usually 0.01 gf/inch or more. The above-mentioned bonding peeling force can be specifically measured by the following method. Attach the double-sided tape (acrylic foam substrate strongly followed by double-sided tape, HYPERJOINT H9004, manufactured by Nitto Denko Corporation) to the entire surface of the polymethyl methacrylate board (PMMA board) with a rubber roller. Remove the peeling paper of the attached double-sided tape, and use a rubber roller to cut and cut the substrate side of the adhesive tape of the same size as the PMMA board, thereby bonding the PMMA board and the substrate side of the adhesive tape with double-sided tape . Using a 2 kg pressure-bonding rubber roller at a speed of 10 mm/sec, the adhesive layer side of the adhesive tape attached to the PMMA board was laminated to the adhesive layer side of the same adhesive tape cut to a width of 25 mm to obtain a test sample. The obtained test sample was irradiated with ultraviolet light at 365 nm for 8 seconds using a high-pressure mercury UV irradiator to adjust the illuminance so that the irradiation intensity on the surface of the adhesive tape became 50 mW/cm ² . Thereafter, for the adhesive tape cut to a width of 25 mm, a tensile tester (angle-free adhesion, film peeling analysis device VPA-2S, manufactured by Kyowa Interface Science Co., Ltd.) was used at a peeling speed of 2400 mm/min according to JIS Z0237 A tensile test in the 180° direction was carried out, and the 180° peel strength (gf/25 mm) was measured to obtain the peeling force.

In the adhesive tape of the present invention, the adhesive tape is attached to a polymethyl methacrylate board (PMMA board) and light-hardened, and after the adhesive tape is peeled off, the polymethyl methacrylate board is pasted through the adhesive tape The difference between the contact angle of the part with water and the contact angle of the polymethyl methacrylate board before attaching the above adhesive tape to water is within ±20%. Attach the adhesive tape to the PMMA board and photo-harden it. After peeling, the difference between the contact angle of the part of the PMMA board pasted with the adhesive tape to water and the contact angle of the PMMA board before the adhesive tape to water is small. Thereby, it is possible to produce an adhesive tape which suppresses the paste remaining on the adherend and is excellent in low pollution. From the same viewpoint, the difference in the contact angle is preferably within ±10%, more preferably within ±4%, and even more preferably within ±2%. The above-mentioned contact angle can be measured by a method according to JIS R3257, and specifically, can be measured by the following method. Use a 2 kg pressure-bonding rubber roller to attach a 25 mm wide adhesive tape to the PMMA board (Delaglas A999, transparent, 2 mm×50 mm×100 mm, manufactured by Asahi Kasei Corporation) at a speed of 10 mm/sec. Thereafter, it was allowed to stand at room temperature 23°C and 50% relative humidity for 1 day to obtain a test sample. The obtained test sample was irradiated with ultraviolet light at 365 nm for 8 seconds by adjusting the illuminance so that the irradiation intensity on the surface of the adhesive tape became 50 mW/cm ² using a high-pressure mercury UV irradiator, and then the adhesive tape was peeled off. According to the JIS R3257 static drop method, a fully automatic handheld contact angle meter/surface free energy analysis MSA manufactured by KRUSS is used to measure the contact angle A of the water on the part of the PMMA board to which the adhesive tape is attached. Next, the contact angle B of the PMMA board to which the adhesive tape has not been attached is measured, and the contact angle change rate is calculated by the following formula (I). In addition, the drop amount of water was set to 3 μL. Change rate of contact angle (%) = ((contact angle A/contact angle B)-1)×100 (I)

Examples of the photo-curable adhesive include photo-curable adhesives containing a polymerizable polymer as a main component and containing an ultraviolet polymerization initiator as a polymerization initiator. The above polymerizable polymer can be obtained, for example, by synthesizing a (meth)acrylic polymer having a functional group in the molecule (hereinafter, referred to as a (meth)acrylic polymer containing a functional group) in advance and making it It reacts with a compound having a functional group that reacts with the above functional group and a radically polymerizable unsaturated bond in the molecule (hereinafter, referred to as a functional group-containing unsaturated compound).

The functional group-containing (meth)acrylic polymer is obtained as follows: alkyl acrylate and/or alkyl methacrylate whose carbon number of the alkyl group is usually in the range of 2 to 18 is The main monomer is copolymerized with the main monomer, the functional group-containing monomer, and, if necessary, other copolymerizable monomers copolymerized with these by conventional methods. The weight average molecular weight of the functional group-containing (meth)acrylic polymer is usually about 200,000 to 2 million. In addition, in this specification, the weight average molecular weight can be determined by the GPC method. For example, THF as an eluent and HSPgel HR MB-M 6.0×150 mm (manufactured by Waters) as a column can be used at 40°C. , Determined by polystyrene standards.

Examples of the functional group-containing monomer include: a carboxyl group-containing monomer, a hydroxyl group-containing monomer, an epoxy group-containing monomer, an isocyanate group-containing monomer, or an amine group-containing monomer Monomer etc. Examples of the carboxyl group-containing monomer include acrylic acid and methacrylic acid. Examples of the hydroxyl group-containing monomer include hydroxyethyl acrylate and hydroxyethyl methacrylate. Examples of the epoxy group-containing monomers include glycidyl acrylate and glycidyl methacrylate. Examples of the isocyanate group-containing monomer include isocyanatoethyl acrylate and isocyanatoethyl methacrylate. Examples of the amine group-containing monomer include amino ethyl acrylate and amino ethyl methacrylate.

Examples of the other copolymerizable monomers for modification include various monomers used in general (meth)acrylic polymers such as vinyl acetate, acrylonitrile, and styrene.

As the functional group-containing unsaturated compound that reacts with the functional group-containing (meth)acrylic polymer, the functional group-containing (meth)acrylic polymer can be used as the functional group-containing unsaturated compound. The same monomer. For example, when the functional group of the functional group-containing (meth)acrylic polymer is a carboxyl group, an epoxy group-containing monomer or an isocyanate group-containing monomer is used. When the functional group is a hydroxyl group, an isocyanate group-containing monomer is used. When the functional group is an epoxy group, a carboxyl group-containing monomer or acrylamide-containing monomer such as acrylamide is used. When the functional group is an amine group, an epoxy group-containing monomer is used.

、十二烷基9-氧硫

、二甲基9-氧硫

、二乙基9-氧硫

、α-羥基環己基苯基酮、2-羥基甲基苯基丙烷等。作為上述苯乙酮衍生物化合物，可列舉甲氧基苯乙酮等。作為上述安息香醚系化合物，可列舉安息香丙醚、安息香異丁醚等。作為上述縮酮衍生物化合物，可列舉二苯乙二酮二甲基縮酮（benzil dimethyl ketal）、苯乙酮二乙基縮酮等。該等紫外線聚合起始劑可單獨使用，亦可併用2種以上。Examples of the above-mentioned ultraviolet polymerization initiator include those activated by irradiation of ultraviolet rays with a wavelength of 200 to 410 nm. Examples of such an ultraviolet polymerization initiator include acetophenone derivative compounds, benzoin ether-based compounds, ketal derivative compounds, phosphine oxide derivative compounds, and bis(η5-cyclopentadienyl)diocene Titanium derivative compounds, benzophenone, Michler's ketone, chlorine 9-oxosulfur

、Dodecyl 9-oxysulfur

Dimethyl 9-oxysulfur

, Diethyl 9-oxysulfur

, Α-hydroxycyclohexyl phenyl ketone, 2-hydroxymethyl phenyl propane, etc. Examples of the acetophenone derivative compounds include methoxyacetophenone and the like. Examples of the benzoin ether-based compound include benzoin propyl ether and benzoin isobutyl ether. Examples of the ketal derivative compounds include benzil dimethyl ketal, acetophenone diethyl ketal, and the like. These ultraviolet polymerization initiators may be used alone or in combination of two or more.

The adhesive layer is preferably a polyfunctional oligomer or monomer containing radical polymerizability. By making the adhesive layer contain a radically polymerizable polyfunctional oligomer or monomer, the ultraviolet curability is improved. The polyfunctional oligomer or monomer is preferably one having a weight average molecular weight of 10,000 or less, and more preferably has a weight average molecular weight of 5000 or less and the number of radically polymerizable unsaturated bonds in the molecule is 2 to 20 In order to use ultraviolet irradiation, the three-dimensional network of the adhesive layer can be efficiently achieved. The weight average molecular weight can be determined using GPC measurement, for example.

Examples of the polyfunctional oligomers or monomers include trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, neopentyl alcohol triacrylate, neopentyl alcohol tetraacrylate, and di neopentyl alcohol. Tetraol monohydroxy pentaacrylate, dipentaerythritol hexaacrylate, or the same methacrylates as described above. In addition, there may be mentioned 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, commercially available oligoester acrylate, and the same methacrylic acid as described above Ester etc. These polyfunctional oligomers or monomers may be used alone or in combination of two or more.

The adhesive layer may also contain a cross-linking agent to improve the cohesion of the light-curing adhesive. Examples of the crosslinking agent include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, aziridine-based crosslinking agents, and metal chelate-based crosslinking agents. Among them, in terms of further improving the cohesive force of the photo-curable adhesive, an isocyanate-based crosslinking agent is preferred.

The cross-linking agent preferably contains 0.1 to 20% by weight in the adhesive layer. By containing the cross-linking agent in the above range, the photo-curing adhesive can be cross-linked moderately, and the cohesion of the photo-curing adhesive can be further improved while maintaining a high adhesive force. From the same viewpoint, the more preferable lower limit of the content of the above-mentioned crosslinking agent is 0.5% by weight, the more preferable lower limit is 1.0% by weight, and the more preferable upper limit is 15% by weight, and the more preferable upper limit is 10% by weight.

The adhesive layer preferably contains "a compound having silicon atoms and/or fluorine atoms", and more preferably contains "a compound having silicon atoms and fluorine atoms". If the adhesive layer contains "a compound having silicon and/or fluorine atoms (more preferably a compound having silicon atoms and fluorine atoms)", the compound having silicon and/or fluorine atoms penetrates the surface of the adhesive layer to suppress and then strengthen Therefore, the above-mentioned peeling force can be easily adjusted to the above range, and the adhesive tape can be peeled off more easily.

Examples of the compound having silicon and/or fluorine atoms include hydrocarbon compounds having silicon and/or fluorine atoms. The hydrocarbon compound may be a saturated hydrocarbon compound or an unsaturated hydrocarbon compound. Among them, in terms of excellent light releasability, a hydrocarbon compound containing a “functional group having silicon and fluorine atoms” and having a molecular weight of the functional group having silicon and fluorine of 100 or more is preferable.

The compound having silicon and/or fluorine atoms preferably has a carbon-carbon double bond. If the above compound with silicon and/or fluorine atoms has a carbon-carbon double bond, by stimulating the adhesive layer, the compound with silicon and/or fluorine atoms can be chemically bonded to the light-curing adhesive, so the number of Contamination by adherends caused by residues of silicon and/or fluorine atoms. In addition, the contamination by the adherend can be reduced, so that the range of the contact angle can be easily adjusted to the above range.

The adhesive layer preferably contains a cross-linking agent, and the compound having silicon atoms and/or fluorine atoms preferably has a functional group that can react with the cross-linking agent. By making the above-mentioned compound having a silicon atom and/or fluorine atom have a functional group that can react with a crosslinking agent, the compound having a silicon atom and/or fluorine atom can be bonded to the light-curing adhesive via the crosslinking agent, so It is possible to reduce the contamination by the adherend and easily adjust the range of the contact angle to the above range. In addition, the reaction between the compound having silicon atoms and/or fluorine atoms and the crosslinking agent is not a reaction that occurs by light irradiation. Therefore, even when applied to an adherend having a surface that can react with light irradiation, such as a hard coat, it is difficult to react with the adherend, and the adhesive tape can be more easily peeled off. The compound having a silicon atom and/or fluorine atom preferably has a functional group that can react with the cross-linking agent, and does not have a carbon-carbon double bond. In this case, even in the case of an adherend having a surface that can react by light irradiation, such as a hard coat, it is more difficult to react with the adherend, and the adhesive tape can be peeled off more easily.

The functional group that can react with the crosslinking agent is appropriately selected according to the functional group of the crosslinking agent, and examples thereof include a hydroxyl group, a carboxyl group, an amine group, and a thiol group. Among them, in terms of making it possible to easily adjust the range of the contact angle to the above range and to provide an adhesive tape excellent in low contamination and light peelability of the adherend, hydroxyl groups are preferred.

From the viewpoint of low contamination and light peelability of the adherend, the compound having silicon and/or fluorine atoms is preferably selected from the group consisting of hydroxyl, carboxyl, amine, and epoxy groups. (Meth)acrylic compound with at least one functional group in the group (also referred to as "(meth)acrylic compound with silicon"). In a preferred embodiment of the present invention, the (meth)acrylic compound having silicon and the like has silicon and/or fluorine in its side chain and is selected from the group consisting of hydroxyl, carboxyl, amine and epoxy groups At least 1 functional group. Among them, in view of the fact that an adhesive tape excellent in low pollution and light peelability of the adherend can be produced, it is preferable to have the following structural formula (1-1), the following structural formula (1-2) and The (meth)acrylic compound of the structure represented by the following structural formula (1-3).

In Structural Formula (1-1), Structural Formula (1-2), and Structural Formula (1-3), R ¹ to R ³ each independently represent hydrogen or methyl. R ⁴ represents at least one kind of hydrocarbon group having 1 to 20 carbon atoms or hydrogen selected from the group consisting of hydroxyl group, carboxyl group, amine group and epoxy group. R ⁵ represents a group having silicon and/or fluorine. R ⁶ represents hydrogen or a hydrocarbon group having 1 to 20 carbon atoms.

The carbon number of the hydrocarbon group in R ⁴ is preferably from 1 to 20, more preferably from 2 to 10, from the viewpoint that the glass transition temperature is set to room temperature or less and the surface of the adhesive during peeling has flexibility. Furthermore, it is preferably 3 to 7.

In R ⁵ , a group having silicon and/or fluorine preferably contains a silicon group having a molecular weight of 100 to 2000 and/or from the viewpoint of suppressing the subsequent enhancement and compatibility with a photocurable adhesive. The hydrocarbon group of 1 to 20 carbon atoms of fluorine. Furthermore, it is more preferable to contain: a silicon group having a molecular weight of 300 to 1000 and/or a hydrocarbon group having a carbon number of 2 to 10, and more preferably a silicon group having a molecular weight of 500 to 800 and/or a carbon number of 3 to 8 Of hydrocarbon. Examples of the group having silicon and/or fluorine in the compound represented by the structural formula (1) include, for example, siloxyalkyl groups and fluoroalkyl groups.

From the viewpoint of the glass transition temperature, the carbon number of the hydrocarbon group in R ⁶ is preferably 1-20, more preferably 3-10, and still more preferably 4-8.

The (meth)acrylic compound having the structure represented by the above structural formula (1-1), the above structural formula (1-2) and the above structural formula (1-3) may be an embedding containing the structure represented by each structural formula The segmented block copolymer may also be a random copolymer that randomly contains the structure represented by each structural formula. Among them, a random copolymer is preferable in that the residue of the paste can be further suppressed and the peelability of the adhesive tape is further improved. In addition, it may have a structure of a monomer unit other than the structures represented by the structural formula (1-1), the structural formula (1-2), and the structural formula (1-3).

Composition of the structural unit represented by each structural formula in the (meth)acrylic compound having the structure represented by the above structural formula (1-1), the above structural formula (1-2) and the above structural formula (1-3) The ratio (integer ratio) is not particularly limited, and from the viewpoint of compatibility with the acrylic polymer, the composition ratio (integer ratio) of each structural unit is preferably an integer of 1 or more. It is more preferably an integer of 10 or more, and further preferably an integer of 20 or more. The composition ratio (integer ratio) of each structural unit is usually preferably an integer of 100 or less. The composition ratio (integer ratio) of each structural unit can be calculated by structural analysis using NMR or the like.

The compound having silicon and/or fluorine atoms preferably has a weight average molecular weight of 500 or more and 200,000 or less. If the weight average molecular weight of the compound having silicon and/or fluorine atoms is within the above range, an adhesive tape with more excellent light peelability and low pollution can be produced. From the same viewpoint, the more preferable lower limit of the weight average molecular weight of the above-mentioned compound having silicon and/or fluorine atoms is 1,000, the more preferable lower limit is 3000, and the more preferable upper limit is 100,000, and the more preferable upper limit is 50,000.

The content of the compound having silicon and/or fluorine atoms in the adhesive layer is preferably a lower limit of 0.1% by weight, more preferably a lower limit of 1% by weight, and a preferable upper limit of 20% by weight, and more preferably an upper limit of 10% by weight %. By making the content of the above-mentioned compound having silicon and/or fluorine atoms within these ranges, the adhesive tape can be peeled off more easily.

The adhesive layer may contain well-known additives such as fumed silica and other inorganic fillers, plasticizers, resins, surfactants, waxes, and particulate fillers.

The thickness of the adhesive layer is not particularly limited, but the lower limit is preferably 5 μm, and the upper limit is 100 μm. If the thickness of the adhesive layer is within the above range, the adherend can be protected with sufficient adhesive force, and the paste residue during peeling can also be suppressed. The more preferable lower limit of the thickness of the adhesive layer is 10 μm, and the more preferable upper limit is 60 μm.

The adhesive tape of the present invention preferably has a substrate on one side of the adhesive layer. The above-mentioned substrate is not particularly limited, and examples thereof include polyolefin-based resin films, polyester-based resin films, ethylene-vinyl acetate copolymers, modified olefin-based resin films, polyvinyl chloride-based resin films, and polyurethanes. Resin film, cycloolefin polymer resin film, acrylic resin film, polycarbonate film, ABS (acrylonitrile-butadiene-styrene) resin film, polyamide film, polyurethane film, polyimide film, etc. Examples of the polyolefin-based resin film include polyethylene films and polypropylene films. Examples of the polyester resin film include polyethylene terephthalate (PET) film, polyethylene naphthalate (PEN) film, and the like. Examples of the modified olefin-based resin film include ethylene-acrylate copolymers. In addition, in order to exert higher releasability, a substrate with a higher elastic modulus is preferable. In addition, when it is desired to check the state of the adherend across the surface protection tape, a substrate with a low haze value (for example, a haze of 2 or less) is preferable.

The above substrate may also contain additives such as antistatic agents, mold release agents, antioxidants, weathering agents, crystal nucleating agents, and resin modifiers such as polyolefins, polyesters, polyamides, and elastomers.

The thickness of the above substrate is not particularly limited, and the lower limit is preferably 25 μm, and the upper limit is preferably 200 μm. By making the thickness of the above-mentioned base material within the above-mentioned range, a surface protective film excellent in operability can be produced. From the same viewpoint, the better lower limit of the thickness of the above-mentioned substrate is 50 μm, and the more preferable upper limit is 188 μm.

The adhesive tape of the present invention preferably has a peeling force of less than 50 gf/inch on the polymethyl methacrylate board after light curing. By making the peeling force on the PMMA board after light curing 50 gf/inch or less, the adhesive tape can be peeled off with a lighter force. From the same viewpoint, the peeling force to the PMMA board after the photo-curing is more preferably 30 gf/inch or less, further preferably 10 gf/inch or less, and usually 0.01 gf/inch or more. The peeling force on the PMMA board after the photo-curing can be measured by the following method. The adhesive tape was cut into short strips with a width of 25 mm to prepare test pieces. Place the test piece on the PMMA board (Delaglas A999, transparent, 2 mm×50 mm×100 mm, manufactured by Asahi Kasei Corporation) in such a manner that the adhesive layer becomes opposed to the PMMA board. Next, a 2 kg rubber roller was made to reciprocate once on the test piece at a speed of 10 mm/sec, thereby bonding the test piece to the PMMA board to make a test sample. The obtained test sample was irradiated with ultraviolet light at 365 nm for 8 seconds using a high-pressure mercury UV irradiator to adjust the illuminance so that the irradiation intensity on the surface of the adhesive tape became 50 mW/cm ² . Thereafter, a tensile tester (angle-free adhesion, film peeling analysis device VPA-2S, manufactured by Kyowa Interface Science Co., Ltd.) was used to perform a tensile test in the direction of 180° at a peeling speed of 2400 mm/min in accordance with JIS Z0237 to measure 180° peel strength (N/25 mm).

The method for manufacturing the adhesive tape of the present invention is not particularly limited. For example, it can be manufactured by the following method: using a solvent to dissolve and mix the above-mentioned photocurable adhesive, crosslinking agent, the above-mentioned compound having silicon and/or fluorine atoms, and optionally additives to make an adhesive solution, and apply the adhesive Method of drying the solution and stacking it on the substrate layer after drying; or directly coating and drying the substrate layer.

The application of the adhesive tape of the present invention is not particularly limited, and even when used in a case where the surface has a hard-coated surface that can react by light irradiation and is fragile, it can be peeled without damaging the adherend The light releasability and the low contamination that the paste is difficult to remain, so it can be particularly suitable for protecting tapes used to protect electronic components such as optical devices or optical films. The adhesive tape of the present invention for manufacturing electronic parts is also one of the present invention. In a preferred embodiment of the present invention, the above-mentioned adhesive tape for protecting a surface that can react by light irradiation is provided. [Effect of invention]

According to the present invention, it is possible to provide an adhesive tape that can easily peel off the "adherent body that may react by light irradiation" and suppress contamination of the adherend.

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

(Manufacture of release agent A) Prepare a reactor equipped with a thermometer, agitator, condenser tube, nitrogen introduction tube, and three-way valve. To this reactor, 30 parts by weight of isobornyl methacrylate as alkyl (meth)acrylate, 30 parts by weight of 2-ethylhexyl methacrylate, as having silicon atoms and/or fluorine atoms are added The terminal methacrylic acid modified polydimethylsiloxane (the weight average molecular weight of the siloxane is 1×10 ³ ) is 20 parts by weight. Furthermore, 20 parts by weight of 2-perfluorohexyl ethyl methacrylate as a monomer having fluorine and 1 part by weight of hydroxyethyl methacrylate as a monomer containing functional groups were added. Furthermore, after 0.01 part by weight of lauryl mercaptan and 80 parts by weight of ethyl acetate were added to the reactor, the reactor was heated to start reflux. Then, 0.01 parts by weight of azobisdimethylvaleronitrile and 0.01 parts by weight of 2-methyl-2-butyltellanyl-ethyl propionate as polymerization initiators were added to the above reactor in The reactor was heated in a hot water bath set at 75°C, thereby starting polymerization. Then, 8 hours after the start of polymerization, an ethyl acetate solution containing 55% by weight of a solid component containing a mold release agent A, which had the following structural formula (2-1) and the following randomly Compound having a silicon atom and a fluorine atom in the structure represented by the structural formula (2-2), the following structural formula (2-3), the following structural formula (2-4) and the following structural formula (2-5) . Among the compounds having silicon atoms and fluorine atoms, the following structural formula (2-1), the following structural formula (2-2), the following structural formula (2-3), the following structural formula (2-4) and The composition ratio (integer ratio) of the structural units represented by the following structural formula (2-5) is 1:20:20:30:1. In addition, the weight average molecular weight of the compound having silicon atoms and fluorine atoms is about 2×10 ⁴ .

(Manufacture of release agent B) The blending amount of 2-perfluorohexyl ethyl methacrylate was 40 parts by weight, and it was the same as the production of the release agent A except that the terminal methacrylic acid modified polydimethylsiloxane was not added. An ethyl acetate solution of a mold release agent B was obtained. The mold release agent B randomly had the following structural formula (3-1), the following structural formula (3-2), and the following structural formula (3-3) And a compound having a fluorine atom of the structure represented by the following structural formula (3-4). The structure represented by the following structural formula (3-1), the following structural formula (3-2), the following structural formula (3-3) and the following structural formula (3-4) in the compound having a fluorine atom The composition ratio (integer ratio) of the units is 1:40:30:30.

(Manufacture of release agent C) The blending amount of the terminal methacrylic acid modified polydimethylsiloxane is 40 parts by weight, and the production of the release agent A is the same except that hexyl ethyl 2-perfluoromethacrylate is not added. An ethyl acetate solution of a mold release agent C was obtained. The mold release agent C randomly had the following structural formula (4-1), the following structural formula (4-2), and the following structural formula (4-3) And a compound having a silicon atom with a structure represented by the following structural formula (4-4). The structure represented by the following structural formula (4-1), the following structural formula (4-2), the following structural formula (4-3) and the following structural formula (4-4) in the compound having a silicon atom The composition ratio (integer ratio) of the units is 1:40:30:30.

(Manufacture of release agent D) To 100 parts by weight of the resin solid content of the ethyl acetate solution of the mold release agent C, 3.5 parts by weight of 2-isocyanatoethyl methacrylate was added and reacted. An ethyl acetate solution of a mold release agent D was obtained. The mold release agent D had the following structural formula (5-1), the following structural formula (5-2), and the following structural formula (5-3) randomly. And the compound represented by the following structural formula (5-4) having a carbon-carbon double bond group and a silicon atom. In the compound having a carbon-carbon double bond group and a silicon atom, the following structural formula (5-1), the following structural formula (5-2), the following structural formula (5-3), and the following structural formula (5 -4) The composition ratio (integer ratio) of the represented structural units is 1:40:30:30.

(Manufacture of release agent E) The blending amount of the terminal methacrylic acid modified polydimethylsiloxane is 40 parts by weight, and the blending amount of hydroxyethyl methacrylate is 2 parts by weight. In the same manner as above, an ethyl acetate solution containing "(meth)acrylic polymer containing functional groups" was obtained. 1.3 parts by weight of 2-isocyanatoethyl methacrylate was added to 100 parts by weight of the resin solid content of the obtained ethyl acetate solution containing "(meth)acrylic polymer containing functional groups" And react. An ethyl acetate solution of a mold release agent E was obtained. The mold release agent E randomly had the following structural formula (6-1), the following structural formula (6-2), and the following structural formula (6-3) , A compound having a carbon-carbon double bond group, a hydroxyl group, and a silicon atom having the structure represented by the following structural formula (6-4) and the following structural formula (6-5). The following structural formula (6-1), the following structural formula (6-2), the following structural formula (6-3), the following structural formula in the compound having a carbon-carbon double bond group, a hydroxyl group and a silicon atom The composition ratio (integer ratio) of structural units represented by (6-4) and the following structural formula (6-5) is 1:1:40:30:30.

(Example 1) (Manufacture of light-curing adhesive) A reactor equipped with a thermometer, a stirrer, and a condenser is prepared, and 94 parts by weight of 2-ethylhexyl acrylate as an alkyl (meth)acrylate and methyl as a functional group-containing monomer are added to the reactor After 6 parts by weight of hydroxyethyl acrylate, 0.01 parts by weight of lauryl mercaptan, and 80 parts by weight of ethyl acetate, the reactor was heated to start reflux. Then, 0.01 parts by weight of 1,1-bis(third hexyl peroxide)-3,3,5-trimethylcyclohexane as a polymerization initiator was added to the above-mentioned reactor, and polymerization was started under reflux. Secondly, after 1 hour and 2 hours after the start of the polymerization, 0.01 parts by weight of 1,1-bis(trihexyl peroxide)-3,3,5-trimethylcyclohexane were also added, and then, the polymerization Four hours after the start, 0.05 parts by weight of trihexyl peroxypivalate was added and the polymerization reaction was continued. Then, 8 hours after the start of polymerization, an ethyl acetate solution of a functional group-containing (meth)acrylic polymer having a solid content of 55% by weight and a weight average molecular weight of 600,000 was obtained. To 100 parts by weight of the resin solid content of the obtained ethyl acetate solution containing "(meth)acrylic polymer containing functional group", 2-isomethacrylic acid, which is an unsaturated compound containing functional group, is added 3.5 parts by weight of ethyl cyanoacetate was reacted to obtain an ethyl acetate solution of a polymerizable polymer. 5 parts by weight of the release agent A, 15.0 parts by weight of the isocyanate-based crosslinking agent, and 2 parts by weight of the photopolymerization initiator were mixed with respect to 100 parts by weight of the resin solid content of the ethyl acetate solution of the obtained polymerizable polymer To obtain an ethyl acetate solution of the light-curing adhesive that constitutes the adhesive layer. In addition, the isocyanate-based crosslinking agent and the photopolymerization initiator system used the following. Isocyanate-based crosslinking agent: Coronate L, manufactured by Nippon Urethane Industry Photopolymerization initiator: Irgacure 369, manufactured by BASF

(Manufacture of adhesive tape) As a base material, a 75 μm polyethylene terephthalate (PET) film was prepared, and the ethyl acetate solution of the obtained photocurable adhesive was applied to the dry film with a doctor blade so that the thickness of the dry film became 75 μm. On the substrate, the coating solution was dried by heating at 110°C for 5 minutes to obtain an adhesive tape.

(Measurement of the peeling force of lamination) The double-sided tape (acrylic foam base material strongly adhered to the double-sided tape, HYPERJOINT H9004, manufactured by Nitto Denko Corporation) is attached to the polymethyl methacrylate board (PMMA board) with a rubber roller The whole face. Remove the peeling paper of the attached double-sided tape, and use a rubber roller to cut and cut the substrate side of the adhesive tape of the same size as the PMMA board, thereby bonding the PMMA board and the substrate side of the adhesive tape with double-sided tape . Using a 2 kg pressure-bonding rubber roller at a speed of 10 mm/sec, the adhesive layer side of the adhesive tape attached to the PMMA board was bonded to the adhesive layer side of the same adhesive tape cut to a width of 25 mm to obtain a test sample. The obtained test sample was irradiated with ultraviolet light at 365 nm for 8 seconds using a high-pressure mercury UV irradiator to adjust the illuminance so that the irradiation intensity on the surface of the adhesive tape became 50 mW/cm ² . Thereafter, for the adhesive tape cut to a width of 25 mm, a tensile tester (angle-free adhesion, film peeling analysis device VPA-2S, manufactured by Kyowa Interface Science Co., Ltd.) was used at a peeling speed of 2400 mm/min according to JIS Z0237 A tensile test in the 180° direction was carried out, and the 180° peel strength (gf/25 mm) was measured to obtain the peeling force.

(Measurement of peeling force after light curing) Cut the adhesive tape into a short strip of 25 mm width to prepare a test piece. Place the test piece on the PMMA board (Delaglas A999, transparent, 2 mm×50 mm×100 mm, manufactured by Asahi Kasei Corporation) in such a manner that the adhesive layer becomes opposed to the PMMA board. Next, a 2 kg rubber roller was made to reciprocate once on the test piece at a speed of 10 mm/sec, thereby bonding the test piece to the PMMA board to make a test sample. The obtained test sample was irradiated with ultraviolet light at 365 nm for 8 seconds using a high-pressure mercury UV irradiator to adjust the illuminance so that the irradiation intensity on the surface of the adhesive tape became 50 mW/cm ² . After that, using a tensile tester (angle-free adhesion, film peeling analysis device VPA-2S, manufactured by Kyowa Interface Science Co., Ltd.), it was allowed to stand at a temperature of 23° C. and a relative humidity of 50% for 24 hours, at a peeling speed according to JIS Z0237 The tensile test at 180° direction was conducted at 2400 mm/min, and the 180° peel strength (N/25 mm) was measured.

(Measurement of contact angle change rate) PMMA board (Delaglas A999, transparent, 2 mm×50 mm×100 mm, manufactured by Asahi Kasei Corporation) was used. Use a 2 kg pressure-bonded rubber roller to attach a 25 mm wide adhesive tape to the PMMA board at a speed of 10 mm/sec. Thereafter, the test sample was obtained by standing at room temperature 23° C. and 50% relative humidity for 1 day. The obtained test sample was irradiated with ultraviolet light at 365 nm for 8 seconds by adjusting the illuminance so that the irradiation intensity on the surface of the adhesive tape became 50 mW/cm ² using a high-pressure mercury UV irradiator, and then the adhesive tape was peeled off. According to the JIS R3257 static drop method, a fully automatic handheld contact angle meter/surface free energy analysis MSA manufactured by KRUSS is used to measure the contact angle A of the water on the part of the PMMA board to which the adhesive tape is attached. Next, the contact angle B of the PMMA board to which the adhesive tape has not been attached is measured, and the contact angle change rate is calculated by the following formula (I). In addition, the drop amount of water was set to 3 μL. Change rate of contact angle (%) = ((contact angle A/contact angle B)-1)×100 (I)

(Examples 2 to 12, Comparative Examples 1, 2) The adhesive tape was obtained in the same manner as in Example 1 except that the types and blending amounts of the mold release agent and crosslinking agent used were as described in Tables 1 and 2. In addition, as the epoxy-based cross-linking agent, E-5XM manufactured by Soken Chemical Co., Ltd. was used.

<Evaluation> The surface protection films obtained in Examples and Comparative Examples were evaluated as follows. The results are shown in Tables 1 and 2.

(Evaluation of peelability) The obtained adhesive tape was cut to a width of 25 mm. Attach the cut adhesive tape to the PMMA board with hard coating (Acrylite MR-200, Mitsubishi Chemical Corporation) at a room temperature of 23°C and a relative humidity of 50% using a 2 kg pressure-bonded rubber roller at a speed of 10 mm/sec manufacture). After being left for 30 minutes, using a high-pressure mercury UV irradiator, the illuminance was adjusted so that the irradiation intensity on the surface of the adhesive tape became 50 mW/cm ² , and 365 nm ultraviolet rays were irradiated from the substrate side for 8 seconds to harden the adhesive layer. Thereafter, in accordance with JIS Z0237, the adhesive tape was peeled at a speed of 2400 mm/min to measure the 180-degree peel strength. Regarding the obtained 180-degree peel strength, the case of 4.5 gf/inch or less is set to "◎", the case of greater than 4.5 gf/inch and less than 9.0 gf/inch is set to "〇", the case of greater than 9.0 gf/inch and 30.0 gf The case of /inch or less is set to "Δ", and the case of more than 30.0 gf/inch is set to "×", and the peelability is evaluated.

(Evaluation of change rate of adhesion) The obtained adhesive tape was cut to a width of 25 mm. Attach the cut adhesive tape to the PMMA board (Delaglas A999, transparent, 2 mm×50 mm×100 mm) at a room temperature of 23° C. and a relative humidity of 50% using a 2 kg crimping rubber roller at a speed of 10 mm/sec , Manufactured by Asahi Kasei Corporation). Thereafter, it was allowed to stand at room temperature 23°C and 50% relative humidity for 1 day, and the adhesive tape was peeled off. Secondly, at a room temperature of 23°C and a relative humidity of 50%, use a 2 kg pressure-bonded rubber roller to attach an 18 mm wide transparent invisible tape (810-3-18, manufactured by 3M) to PMMA at a speed of 10 mm/sec. The part of the board pasted the adhesive tape. Thereafter, in accordance with JIS Z0237, the invisible tape was peeled at a speed of 300 mm/min to measure the 180-degree peel strength A. At a room temperature of 23°C and a relative humidity of 50%, a 2 kg pressure-bonded rubber roller was used to attach the above-mentioned invisible tape to the PMMA board to which no adhesive tape had been attached at a speed of 10 mm/sec. Thereafter, in accordance with JIS Z0237, the invisible tape was peeled at a speed of 300 mm/min to measure the 180-degree peel strength B. The 180-degree peel strength B of the obtained invisible tape was compared with the 180-degree peel strength A of the PMMA board after the above-mentioned adhesive tape was attached to the invisible tape, and the change rate of the adhesive force was evaluated by the following formula (II). Adhesive force change rate (%) = ((180 degree peel strength A/180 degree peel strength B)-1)×100 100 (II) When the difference in peel strength is within ±5% is set to "◎", when it is greater than ±5% and within ±10%, it is set to "〇", and when it is greater than ±10% and within ±30%, it is set to When "Δ" and more than ±30% are set as "×", the change rate of adhesive force is evaluated.

[Table 1]

[產業上之可利用性][Table 2]

[Industry availability]

According to the present invention, it is possible to provide an adhesive tape that can easily peel off the "adherent body that may react by light irradiation" and suppress contamination of the adherend.

no

no

Claims (8)

An adhesive tape having an adhesive layer, the adhesive layer containing a light-curing adhesive, After two adhesive layers of the above-mentioned adhesive tape are attached to each other and photo-hardened, the peeling force of the two above-mentioned adhesive tapes is 75 gf/inch or less, and the above-mentioned adhesive tape is attached to a polymethyl methacrylate board and subjected to light After hardening and peeling the adhesive tape, the contact angle of the part of the polymethyl methacrylate board past the adhesive tape to water and the contact angle of the polymethyl methacrylate board before the adhesive tape to water The difference is within ±20%. The adhesive tape according to claim 1, wherein the adhesive layer contains 0.1 to 20% by weight of a cross-linking agent. The adhesive tape according to claim 1 or 2, wherein the adhesive layer contains a compound having silicon atoms and/or fluorine atoms. The adhesive tape according to claim 3, wherein the compound having a silicon atom and/or a fluorine atom has a carbon-carbon double bond. The adhesive tape according to claim 3, wherein the adhesive layer contains a crosslinking agent, and the compound having a silicon atom and/or a fluorine atom has a functional group that can react with the crosslinking agent. 2. The adhesive tape according to 2, 3, 4 or 5, wherein a substrate is provided on one surface of the adhesive layer. 2. The adhesive tape as described in 2, 3, 4, 5 or 6 has a peeling force of less than 50 gf/inch on the polymethyl methacrylate board after light curing. 2. The adhesive tape as described in 2, 3, 4, 5, 6 or 7 is used to manufacture electronic parts.