Adhesive tape

Abstract

To provide an adhesive tape which can reduce adhesion enhancement due to high temperatures and can also be used for a material which does not transmit light.SOLUTION: There is provided an adhesive tape having an adhesive layer, wherein the adhesive layer has a shear storage modulus of 4.0×104 to 1.0×106 Pa at 25°C as evaluated by dynamic viscoelasticity measurement and the adhesive layer has a contact angle to water of 80 degrees of more after the adhesive layer side of the adhesive tape is attached to glass, heated at 220°C for 120 minutes and peeled off.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an adhesive tape. [Background technology]

[0002] In the manufacturing process of semiconductor chips, adhesive tape is used to facilitate the handling of wafers and semiconductor chips during processing and to prevent breakage. For example, when a thick-film wafer cut from a high-purity silicon single crystal is ground to a predetermined thickness to produce a thin-film wafer, the thick-film wafer is ground after adhesive tape is attached to the wafer.

[0003] Such adhesive tapes are required to have high adhesiveness sufficient to firmly fix adherends such as wafers and semiconductor chips during the processing step, and also to be able to be peeled off without damaging the adherends such as wafers and semiconductor chips after the processing step is completed (hereinafter also referred to as "high adhesion and easy peeling"). As an adhesive tape that achieves high adhesion and easy peeling, Patent Document 1 discloses an adhesive tape that uses a photocurable adhesive that hardens and reduces adhesive strength when irradiated with light such as ultraviolet light. By using a photocurable adhesive as the adhesive, the adherend can be securely fixed during processing, and can also be easily peeled off by irradiating with ultraviolet light or the like. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 5-32946 Summary of the Invention [Problem to be solved by the invention]

[0005] In the manufacturing process of electronic components such as semiconductor chips, high-temperature processing at temperatures of 200°C or higher is sometimes performed. Therefore, adhesive tapes used in such manufacturing processes are required to have heat resistance and adhesion enhancement resistance, i.e., to prevent adhesion enhancement even at high temperatures. Conventionally, photocurable adhesive tapes, such as those described in Patent Document 1, have been used to reduce adhesion enhancement caused by high temperatures. Meanwhile, in the manufacture of electronic components, wafers, substrates, etc., are sometimes fixed to support plates via double-sided adhesive tape, followed by wiring and other processes. However, in recent years, opaque materials such as copper, aluminum, and glass epoxy have increasingly been used as support plates due to cost and ease of handling. However, there is a problem in that adhesive tapes using conventional photocurable adhesives cannot be cured on such opaque support plates.

[0006] An object of the present invention is to provide a pressure-sensitive adhesive tape that can reduce adhesion enhancement due to high temperatures and can be used on materials that do not transmit light. [Means for solving the problem]

[0007] The present invention relates to a pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer, wherein the pressure-sensitive adhesive layer has a shear storage modulus of 4.0×10 at 25° C. as evaluated by dynamic viscoelasticity measurement. 4 ~2.0×10 6 Pa, and the pressure-sensitive adhesive layer has a water contact angle of 80° or more after the pressure-sensitive adhesive layer side of the pressure-sensitive adhesive tape is attached to glass, heated at 220°C for 120 minutes, and peeled off. The present invention will be described in detail below.

[0008] The pressure-sensitive adhesive tape according to one embodiment of the present invention has a pressure-sensitive adhesive layer. The pressure-sensitive adhesive tape of one embodiment of the present invention may have other layers as long as it has a pressure-sensitive adhesive layer. Furthermore, the pressure-sensitive adhesive tape of one embodiment of the present invention may be a supported type having a substrate, or a non-supported type having no substrate. When the pressure-sensitive adhesive tape of one embodiment of the present invention has a substrate, it is sufficient that the pressure-sensitive adhesive layer is present on at least one side of the substrate, and it may be a single-sided pressure-sensitive adhesive tape or a double-sided pressure-sensitive adhesive tape.

[0009] The pressure-sensitive adhesive layer has a shear storage modulus of 4.0×10 at 25°C as evaluated by dynamic viscoelasticity measurement. 4 ~2.0×10 6 It is Pa. The shear storage modulus of the adhesive layer is 4.0×10 4 When the shear storage modulus of the adhesive layer is 2.0×10 Pa or more, the adhesive layer can have a hardness suitable for an adhesive tape. 6 From the same viewpoint as above, the preferable lower limit of the shear storage modulus is 8.0 × 10 Pa or less, so that the pressure-sensitive adhesive layer does not become too hard, and the adhesive tape can be prevented from sticking, thereby suppressing adhesive residue. 4 Pa, a more preferable lower limit is 1.0 × 10 5 The preferred upper limit of the shear storage modulus is 1.5 × 10 6 Pa, and a more preferable upper limit is 1.3 × 10 6 Pa, and a more preferable upper limit is 1.0 × 10 6 Pa, and the particularly preferred upper limit is 7.0 × 10 5 Pa, the most preferred upper limit is 2.0 × 10 5 It is Pa. The shear storage modulus can be determined as the storage modulus at 25°C from the measured values ​​obtained by measuring the shear mode of dynamic viscoelasticity measurement using a dynamic viscoelasticity measuring device (e.g., DVA-200 manufactured by IT Measurement Control Co., Ltd.) at an angular frequency of 10 Hz and a heating rate of 5°C / min from -50°C to 200°C. The shear storage modulus varies little with temperature, so that if the pressure-sensitive adhesive tape according to one embodiment of the present invention has a shear storage modulus within the above range at 25°C, the above-mentioned effects can be achieved even at high temperatures of around 220°C.

[0010] The pressure-sensitive adhesive layer has a water contact angle of 80° or more after the pressure-sensitive adhesive layer side of the pressure-sensitive adhesive tape is attached to glass, heated at 220°C for 120 minutes, and then peeled off (hereinafter simply referred to as water contact angle after heating). When the pressure-sensitive adhesive tape is attached to glass, heated, and peeled off, the pressure-sensitive adhesive layer has a water contact angle within the above range, making the surface hydrophobic and less likely to interact with the adherend, thereby reducing adhesion enhancement due to heating. From the same perspective, the lower limit of the water contact angle after heating is preferably 81°, more preferably 81.5°, and even more preferably 82°. The upper limit of the water contact angle after heating is preferably 110°, more preferably 105°, even more preferably 103°, even more preferably 100°, particularly preferably 97°, especially preferably 95°, very preferably 92°, and even more preferably 91°.

[0011] The water contact angle after heating can be measured by a method in accordance with JIS R 3257:1999, and specifically, can be measured by the following method. The adhesive tape is cut into 25 mm widths. The cut adhesive tape is applied to a glass substrate (e.g., Matsunami Glass Industrial Co., Ltd., large white-edged glass slide No. 2) at a room temperature of 23°C and a relative humidity of 50% using a 2 kg pressure rubber roller at a speed of 10 mm / sec. The tape is then heated at 220°C for 120 minutes. After cooling, the adhesive tape is peeled from the glass substrate, and the water contact angle of the adhesive layer is measured using a contact angle measuring device (e.g., KSV, CAM 200) in accordance with JIS R 3257:1999. Specifically, a 2 μL drop of ultrapure water is dropped onto the adhesive layer surface of a horizontally placed adhesive tape at a room temperature of 25°C and a humidity of 40%. The water contact angle is determined as the angle between the pure water and the adhesive layer surface 5 seconds after the drop.

[0012] In the pressure-sensitive adhesive tape according to one embodiment of the present invention, the pressure-sensitive adhesive layer preferably has a water contact angle at 25° C. of 103° or less. When the pressure-sensitive adhesive layer has a water contact angle of 103° or less at 25°C, it can be attached to an adherend with more appropriate adhesive strength (initial adhesive strength). From the same viewpoint, the upper limit of the water contact angle of the pressure-sensitive adhesive layer at 25°C is more preferably 102°, and even more preferably 100°. There is no particular limitation on the lower limit of the water contact angle of the pressure-sensitive adhesive layer at 25°C, but 80° is preferred. The water contact angle of the pressure-sensitive adhesive layer at 25°C can be measured in the same manner as the water contact angle after heating, except that heat treatment is not performed.

[0013] The pressure-sensitive adhesive layer preferably contains a pressure-sensitive adhesive having a crosslinkable functional group, a silicone-based graft copolymer having a crosslinkable functional group, and a crosslinking agent capable of reacting with the pressure-sensitive adhesive and the silicone-based graft copolymer to crosslink them. By including a crosslinking agent in the pressure-sensitive adhesive layer, the pressure-sensitive adhesive can be crosslinked, making it easier to adjust the shear storage modulus within the above range. Furthermore, by including a silicone-based graft copolymer in the pressure-sensitive adhesive layer, the silicone-based graft copolymer bleeds out onto the surface of the pressure-sensitive adhesive layer upon heating, making the surface of the pressure-sensitive adhesive layer hydrophobic, making it easier to adjust the water contact angle after heating within the above range. Furthermore, by making the surface of the pressure-sensitive adhesive layer hydrophobic, the pressure-sensitive adhesive layer and the adherend are less likely to interact, reducing the adhesive strength, thereby reducing adhesion enhancement. Furthermore, by including a crosslinkable functional group in the silicone-based graft copolymer, the silicone-based graft copolymer can be bonded to the pressure-sensitive adhesive via the crosslinking agent, thereby suppressing contamination of the adherend.

[0014] The adhesive is not particularly limited, and may be either a curable or non-curable type. A curable adhesive is one that has a polymerizable functional group such as a double bond and is cured by stimulation such as heat or light, while a non-curable adhesive is one that does not substantially have a polymerizable functional group. The adhesive is preferably a non-curable adhesive because it can simplify the manufacturing process and can be used on opaque materials that cannot be photocured. Examples of non-curable adhesives include non-photocurable adhesives, non-thermocurable adhesives, and non-energy curable adhesives.

[0015] Examples of the pressure-sensitive adhesive include acrylic pressure-sensitive adhesives, silicone pressure-sensitive adhesives, urethane pressure-sensitive adhesives, rubber pressure-sensitive adhesives, etc. Among these, non-silicone pressure-sensitive adhesives are preferred because they allow for easy adjustment of the water contact angle after heating and the shear storage modulus, and acrylic pressure-sensitive adhesives are more preferred.

[0016] Examples of the crosslinkable functional groups present in the pressure-sensitive adhesive and the silicone graft copolymer include, independently, carboxyl groups, hydroxyl groups, glycidyl groups, amino groups, amide groups, nitrile groups, etc. Among these, carboxyl groups are preferred because they allow for easy adjustment of the shear storage modulus within the above range.

[0017] The pressure-sensitive adhesive is preferably an acrylic polymer having a molecular weight distribution (Mw / Mn) of 1.05 to 2.5, and more preferably an acrylic polymer obtained by living radical polymerization having a molecular weight distribution (Mw / Mn) of 1.05 to 2.5 (hereinafter simply referred to as "living radically polymerized acrylic polymer"). The living radical polymerization acrylic polymer is an acrylic polymer obtained by living radical polymerization, preferably using an organotellurium polymerization initiator, using acrylic monomers such as (meth)acrylic acid esters and (meth)acrylic acid as raw materials. Living radical polymerization is a type of polymerization in which molecular chains grow without being hindered by side reactions such as termination reactions or chain transfer reactions. Living radical polymerization produces polymers with more uniform molecular weights and compositions than, for example, free radical polymerization, and can suppress the generation of low-molecular-weight components, thereby reducing adhesive residue even when high-temperature treatment is performed. Furthermore, the shear storage modulus can be easily adjusted within the above range. From the perspective of further reducing adhesive residue, the lower limit of the molecular weight distribution of the living radical polymerization acrylic polymer is more preferably 1.1, and the upper limit is more preferably 2.0.

[0018] In the living radical polymerization, various polymerization methods may be employed. For example, an iron, ruthenium, or copper catalyst and a halogen-based initiator may be used (ATRP), TEMPO may be used, or an organotellurium polymerization initiator may be used. Among these, the use of an organotellurium polymerization initiator is preferred. Unlike other living radical polymerizations, living radical polymerization using an organotellurium polymerization initiator can polymerize radical polymerizable monomers having polar functional groups such as hydroxyl groups or carboxyl groups using the same initiator without protecting any of them, thereby producing polymers having uniform molecular weights and compositions. Therefore, radical polymerizable monomers having polar functional groups can be easily copolymerized.

[0019] The organotellurium polymerization initiator is not particularly limited as long as it is one that is generally used in living radical polymerization, and examples thereof include organotellurium compounds and organotelluride compounds. Examples of the organotellurium compound include (methyltellanyl-methyl)benzene, (1-methyltellanyl-ethyl)benzene, (2-methyltellanyl-propyl)benzene, 1-chloro-4-(methyltellanyl-methyl)benzene, 1-hydroxy-4-(methyltellanyl-methyl)benzene, 1-methoxy-4-(methyltellanyl-methyl)benzene, 1-amino-4-(methyltellanyl-methyl)benzene, 1-nitro-4-(methyltellanyl-methyl)benzene, 1-cyano-4-(methyltellanyl-methyl)benzene, 1-methylcarbohydrate, 1-methyl-4-(methyltellanyl-methyl)benzene ... 1-phenylcarbonyl-4-(methyltellanyl-methyl)benzene, 1-methoxycarbonyl-4-(methyltellanyl-methyl)benzene, 1-phenoxycarbonyl-4-(methyltellanyl-methyl)benzene, 1-sulfonyl-4-(methyltellanyl-methyl)benzene, 1-trifluoromethyl-4-(methyltellanyl-methyl)benzene, 1-chloro-4-(1-methyltellanyl-ethyl)benzene, 1-hydroxy-4-(1-methyltellanyl-ethyl)benzene, 1-methyl- 1-amino-4-(1-methyltellanyl-ethyl)benzene, 1-nitro-4-(1-methyltellanyl-ethyl)benzene, 1-cyano-4-(1-methyltellanyl-ethyl)benzene, 1-methylcarbonyl-4-(1-methyltellanyl-ethyl)benzene, 1-phenylcarbonyl-4-(1-methyltellanyl-ethyl)benzene, 1-methoxycarbonyl-4-(1-methyltellanyl-ethyl)benzene, 1-phenoxycarbonyl-4-(1-methyltellanyl-ethyl)benzene benzene, 1-sulfonyl-4-(1-methyltellanyl-ethyl)benzene, 1-trifluoromethyl-4-(1-methyltellanyl-ethyl)benzene, 1-chloro-4-(2-methyltellanyl-propyl)benzene, 1-hydroxy-4-(2-methyltellanyl-propyl)benzene, 1-methoxy-4-(2-methyltellanyl-propyl)benzene, 1-amino-4-(2-methyltellanyl-propyl)benzene, 1-nitro-4-(2-methyltellanyl-propyl)benzene, 1-cyano-4-(2-methyltellanyl-propyl)benzene,1-Methylcarbonyl-4-(2-methyltellanyl-propyl)benzene, 1-phenylcarbonyl-4-(2-methyltellanyl-propyl)benzene, 1-methoxycarbonyl-4-(2-methyltellanyl-propyl)benzene, 1-phenoxycarbonyl-4-(2-methyltellanyl-propyl)benzene, 1-sulfonyl-4-(2-methyltellanyl-propyl)benzene, 1-trifluoromethyl-4-(2-methyltellanyl-propyl)benzene, 2-(methyltellanyl-methyl)pyridine, 2-(1- Examples of suitable organotellurium compounds include methyltellanyl-ethyl)pyridine, 2-(2-methyltellanyl-propyl)pyridine, 2-methyltellanyl-methyl ethanoate, 2-methyltellanyl-methyl propionate, 2-methyltellanyl-methyl 2-methylpropionate, 2-methyltellanyl-ethyl ethanoate, 2-methyltellanyl-ethyl propionate, 2-methyltellanyl-ethyl 2-methylpropionate, 2-methyltellanylacetonitrile, 2-methyltellanylpropionitrile, and 2-methyl-2-methyltellanylpropionitrile. The methyltellanyl group in these organotellurium compounds may be an ethyltellanyl group, n-propyltellanyl group, isopropyltellanyl group, n-butyltellanyl group, isobutyltellanyl group, t-butyltellanyl group, phenyltellanyl group, or the like. These organotellurium compounds may be used alone or in combination of two or more.

[0020] Examples of the organic telluride compounds include dimethyl ditelluride, diethyl ditelluride, di-n-propyl ditelluride, diisopropyl ditelluride, dicyclopropyl ditelluride, di-n-butyl ditelluride, di-sec-butyl ditelluride, di-tert-butyl ditelluride, dicyclobutyl ditelluride, diphenyl ditelluride, bis-(p-methoxyphenyl) ditelluride, bis-(p-aminophenyl) ditelluride, bis-(p-nitrophenyl) ditelluride, bis-(p-cyanophenyl) ditelluride, bis-(p-sulfonylphenyl) ditelluride, dinaphthyl ditelluride, and dipyridyl ditelluride. These organic telluride compounds may be used alone or in combination of two or more. Among these, dimethyl ditelluride, diethyl ditelluride, di-n-propyl ditelluride, di-n-butyl ditelluride, and diphenyl ditelluride are preferred.

[0021] In addition to the organotellurium polymerization initiator, an azo compound may be used as a polymerization initiator for the purpose of accelerating the polymerization rate, within the scope of not impairing the effects of the present invention. The azo compound is not particularly limited as long as it is one that is generally used in radical polymerization, and examples thereof include 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 1,1-azobis(cyclohexane-1-carbonitrile), 1-[(1-cyano-1- methylethyl)azo]formamide, 4,4'-azobis(4-cyanovaleric acid), dimethyl-2,2'-azobis(2-methylpropionate), dimethyl-1,1'-azobis(1-cyclohexanecarboxylate), 2,2'-azobis{2-methyl-N-[1,1'-bis(hydroxymethyl)-2-hydroxyethyl]propionamide}, 2,2'-azobis[2-methyl-N-(2-hydroxyethyl )propionamide], 2,2'-azobis[N-(2-propenyl)-2-methylpropionamide], 2,2'-azobis(N-butyl-2-methylpropionamide), 2,2'-azobis(N-cyclohexyl-2-methylpropionamide), 2,2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride, 2,2'-azobis{2-[1-(2-hydroxyethyl)-2-imidazoline-2- Examples of azo compounds include 2,2'-azobis[2-(2-imidazolin-2-yl)propane], 2,2'-azobis(2-amidinopropane) dihydrochloride, 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine] tetrahydrate, 2,2'-azobis(1-imino-1-pyrrolidino-2-methylpropane) dihydrochloride, and 2,2'-azobis(2,4,4-trimethylpentane). These azo compounds may be used alone or in combination of two or more.

[0022] Since the pressure-sensitive adhesive has a crosslinkable functional group, a monomer having a crosslinkable functional group is blended as a polymerizable monomer in the living radical polymerization acrylic polymer. When the crosslinkable functional group is a carboxyl group, examples of the monomer having a carboxyl group include (meth)acrylic acid. When the crosslinkable functional group is a hydroxyl group, examples of the monomer having a hydroxyl group include (meth)acrylic acid esters having a hydroxyl group, such as 4-hydroxybutyl (meth)acrylate and 2-hydroxyethyl (meth)acrylate. When the crosslinkable functional group is a glycidyl group, examples of the monomer having a glycidyl group include glycidyl (meth)acrylate. When the crosslinkable functional group is an amide group, examples of the monomer having an amide group include hydroxyethyl acrylamide, isopropyl acrylamide, and dimethylaminopropyl acrylamide. When the crosslinkable functional group is a nitrile group, examples of the monomer having a nitrile group include acrylonitrile.

[0023] When the acrylic monomer having a carboxyl group is used, its content is not particularly limited, but the preferred lower limit in the radical polymerizable monomer polymerized in the living radical polymerization is 0.1 wt % and the preferred upper limit is 10 wt %. When the content is 0.1 wt % or more, the living radical polymerization acrylic polymer can be sufficiently bonded to the silicone graft copolymer via the crosslinking agent, thereby reducing contamination of the adherend. When the content is 10 wt % or less, the pressure-sensitive adhesive does not become too hard, and adhesive residue on the pressure-sensitive adhesive tape can be suppressed.

[0024] When the (meth)acrylic acid ester having a hydroxyl group is used, its content is not particularly limited, but a preferred upper limit in the radical polymerizable monomer polymerized in the living radical polymerization is 30 wt %. By keeping the content at 30 wt % or less, the heat-resistant adhesion of the pressure-sensitive adhesive can be further improved.

[0025] The acrylic monomer polymerized in the living radical polymerization may be a radical polymerizable monomer other than the acrylic monomer having a crosslinkable functional group. Examples of the other radical polymerizable monomer include other (meth)acrylic acid esters. Also, acrylic monomers having other polar functional groups such as amino groups, amide groups, and nitrile groups may be used. Furthermore, in addition to the acrylic monomers, vinyl compounds may be used as monomers.

[0026] The other (meth)acrylic acid esters are not particularly limited, and examples thereof include (meth)acrylic acid alkyl esters such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, isomyristyl (meth)acrylate, and stearyl (meth)acrylate, as well as cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, benzyl (meth)acrylate, 2-butoxyethyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, glycidyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, and polypropylene glycol mono(meth)acrylate. These (meth)acrylic acid esters may be used alone or in combination of two or more.

[0027] The vinyl compound is not particularly limited, and examples thereof include (meth)acrylamide compounds such as N,N-dimethylacrylamide, N,N-diethylacrylamide, N-isopropylacrylamide, N-hydroxyethylacrylamide, acrylamide, etc., N-vinylpyrrolidone, N-vinylcaprolactam, N-vinylacetamide, N-acryloylmorpholine, acrylonitrile, styrene, vinyl acetate, etc. These vinyl compounds may be used alone or in combination of two or more.

[0028] In the living radical polymerization, a dispersion stabilizer may be used, such as polyvinylpyrrolidone, polyvinyl alcohol, methyl cellulose, ethyl cellulose, poly(meth)acrylic acid, poly(meth)acrylic acid ester, and polyethylene glycol. As the method for the living radical polymerization, a conventionally known method can be used, and examples thereof include solution polymerization (boiling point polymerization or constant temperature polymerization), emulsion polymerization, suspension polymerization, and bulk polymerization. When a polymerization solvent is used in the living radical polymerization, the polymerization solvent is not particularly limited. Examples of the polymerization solvent include nonpolar solvents such as hexane, cyclohexane, octane, toluene, and xylene, and highly polar solvents such as water, methanol, ethanol, propanol, butanol, acetone, methyl ethyl ketone, methyl isobutyl ketone, tetrahydrofuran, dioxane, and N,N-dimethylformamide. These polymerization solvents may be used alone or in combination of two or more. The polymerization temperature is preferably 0 to 110°C from the viewpoint of the polymerization rate.

[0029] The living radical polymerization acrylic polymer has a molecular weight of preferably 500,000 lower limit, more preferably 800,000 lower limit, and preferably 1,500,000 upper limit, more preferably 1,200,000 upper limit. When the molecular weight of the living radical polymerization acrylic polymer is within the above range, it becomes easy to adjust the water contact angle after heating and the shear storage modulus to the above ranges.

[0030] The silicone graft copolymer is not particularly limited as long as it has a crosslinkable functional group, which may be present in the graft chain, the main chain, or both the graft chain and the main chain.

[0031] From the viewpoint of reducing contamination of the adherend, the silicone-based graft copolymer preferably contains a structural unit derived from a polar functional group-containing monomer and a silicone macromonomer. From the viewpoint of reducing contamination of the adherend, the silicone-based graft copolymer is preferably a graft copolymer having a side chain containing silicone. Examples of the polar functional group-containing monomer include a hydroxyl group-containing monomer, an amino group-containing monomer, and a hydroxyl group-containing monomer. Among these, from the viewpoint of easy control of adhesive strength, the polar functional group-containing monomer is preferably a carboxyl group-containing monomer.

[0032] When the polar functional group-containing monomer is a carboxyl group-containing monomer, from the viewpoint of further improving the initial adhesive strength and adhesive strength after heating, the silicone graft copolymer is preferably obtained by copolymerizing a mixed monomer containing preferably 0.1 wt% or more, and preferably 90 wt% or less, of the carboxyl group-containing monomer. The content of the carboxyl group-containing monomer is more preferably 0.5 wt% or more, and even more preferably 1 wt% or more. The content of the carboxyl group-containing monomer is more preferably 80 wt% or less, even more preferably 70 wt% or less, still more preferably 60 wt% or less, particularly preferably 50 wt% or less, especially preferably 40 wt% or less, particularly preferably 30 wt% or less, and very preferably 20 wt% or less.

[0033] In a preferred embodiment of the present invention, the silicone graft copolymer is preferably obtained by copolymerizing a mixed monomer containing 0.1 to 2.5% by weight of a carboxyl group-containing monomer (carboxylic acid-containing monomer) and 1 to 90% by weight of a silicone macromonomer. The carboxyl group-containing monomer is the source of the crosslinkable functional group of the silicone graft copolymer. By incorporating it in the above-mentioned content range, the silicone graft copolymer and the pressure-sensitive adhesive can be bonded via the crosslinker, thereby suppressing contamination of the adherend. The silicone macromonomer imparts bleeding properties to the silicone graft copolymer. By incorporating it in the above-mentioned content range, it is possible to reduce adhesion enhancement due to high temperatures. In particular, by using the above-mentioned pressure-sensitive adhesive, the above-mentioned crosslinker, and a silicone graft copolymer obtained by copolymerizing the above-mentioned mixed monomer, it is possible to further reduce adhesion enhancement due to high temperatures and suppress contamination of the adherend. Note that the content of the carboxyl group-containing monomer is particularly important in adjusting the water contact angle after heating to within the above-mentioned range. When the carboxyl group-containing monomer is 0.1 wt % or more, the resulting silicone graft copolymer can be sufficiently bonded to the pressure-sensitive adhesive. When the carboxyl group-containing monomer content is 2.5 wt% or less, the reduction in carboxyl groups not used to bond with the PSA prevents the PSA layer surface from becoming hydrophilic, making it easier to adjust the water contact angle after heating to the above range and reducing adhesion enhancement. From the above perspectives, a more preferred lower limit for the carboxyl group-containing monomer content is 1.0 wt%, an even more preferred lower limit is 1.5 wt%, a more preferred upper limit is 2.0 wt%, and an even more preferred upper limit is 1.7 wt%. Furthermore, from the perspective of achieving a water contact angle after heating within the above range and further reducing adhesion enhancement, a more preferred lower limit for the silicone macromonomer content is 2 wt%. A more preferred lower limit for the silicone macromonomer content is 2.5 wt%, an even more preferred lower limit is 3 wt%, a particularly preferred lower limit is 3.5 wt%, an especially preferred lower limit is 4 wt%, a very preferred lower limit is 4.5 wt%, and a most preferred lower limit is 5 wt%. A more preferred upper limit of the silicone macromonomer content is 80% by weight, an even more preferred upper limit is 60% by weight, an even more preferred upper limit is 50% by weight, an especially preferred upper limit is 40% by weight, an especially preferred upper limit is 30% by weight, a very preferably upper limit is 25% by weight, and a most preferably upper limit is 20% by weight.

[0034] In a preferred embodiment of the present invention, the silicone graft copolymer may be obtained by copolymerizing a mixed monomer containing a (meth)acrylic acid ester in addition to the polar functional group-containing monomer and the silicone macromonomer. The (meth)acrylic acid ester is not particularly limited, and examples thereof include (meth)acrylic acid alkyl esters such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, isomyristyl (meth)acrylate, and stearyl (meth)acrylate; cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, benzyl (meth)acrylate, 2-butoxyethyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, glycidyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, and polypropylene glycol mono(meth)acrylate. These (meth)acrylic acid esters may be used alone or in combination of two or more kinds. When the mixed monomer contains a (meth)acrylic acid ester, the content of the (meth)acrylic acid ester is preferably 1% by weight or more, and preferably 99% by weight or less. The content of the (meth)acrylic acid ester is more preferably 5% by weight or more, even more preferably 7.5% by weight or more, even more preferably 10% by weight or more, and more preferably 95% by weight or less, even more preferably 90% by weight or less, and even more preferably 80% by weight or less.

[0035] The crosslinkable functional groups of the silicone graft copolymer may be the same as the crosslinkable functional groups of the pressure-sensitive adhesive, and may be the same as or different from the crosslinkable functional groups of the pressure-sensitive adhesive.

[0036] The silicone macromonomer preferably has a weight average molecular weight of 500 or more, and more preferably 1,000 or more. When the weight-average molecular weight of the silicone macromonomer is equal to or greater than the lower limit, the hydrophobic surface layer formed by the silicone graft copolymer becomes thicker, thereby further reducing adhesion enhancement. From the same viewpoint, the upper limit of the weight-average molecular weight of the silicone macromonomer is more preferably 50,000, and is usually 20,000 or less.

[0037] From the viewpoints of preventing contamination of adherends and controlling initial and post-heat adhesive strength, the silicone graft copolymer has an acid value of preferably 0.5 mgKOH / g or more, more preferably 1 mgKOH / g or more, even more preferably 3 mgKOH / g or more, particularly preferably 5 mgKOH / g or more, and most preferably 10 mgKOH / g or more. The acid value is preferably 22 mgKOH / g or less, more preferably 20 mgKOH / g or less, and even more preferably 19 mgKOH / g or less.

[0038] The silicone macromonomer may be any monomer having a siloxane bond-containing group in its side chain, such as a silicone group-containing acrylic monomer or a siloxane bond-containing styrene monomer. Among these, siloxane bond-containing acrylic monomers are preferred because of their excellent heat resistance and weather resistance. Examples of the siloxane bond-containing acrylic monomer include monomers having the structural formula shown in the following general formula (1) or (2).

[0039] [ka]

[0040] Here, R represents a (meth)acryloyl group-containing functional group, and X and Y each independently represent an integer of 0 or more, and usually an integer of 5000 or less, particularly 500 or less.

[0041] The content of the silicone macromonomer in the raw material monomers of the silicone graft copolymer of the present invention is preferably 1% by weight or more and 90% by weight or less. By keeping the silicone macromonomer content within this range, increased adhesion at high temperatures can be further suppressed. From the viewpoint of further suppressing increased adhesion at high temperatures, the lower limit of the silicone macromonomer content is more preferably 5% by weight, even more preferably 10% by weight, and even more preferably 80% by weight, and even more preferably 60% by weight.

[0042] Examples of monomers other than the carboxyl group-containing monomer and the silicone macromonomer include (meth)acrylic esters. Acrylic monomers having other polar functional groups such as hydroxyl groups, amino groups, amide groups, and nitrile groups can also be used. Furthermore, in addition to the acrylic monomers, vinyl compounds may also be used as monomers.

[0043] The silicone graft copolymer preferably has a weight average molecular weight of 400,000 or less. When the weight average molecular weight of the silicone graft copolymer is 400,000 or less, it becomes more mobile within the pressure-sensitive adhesive layer, and the silicone graft copolymer tends to collect on the surface of the pressure-sensitive adhesive layer, thereby further reducing adhesion enhancement. The upper limit of the weight average molecular weight of the silicone graft copolymer is more preferably 300,000, even more preferably 250,000, and particularly preferably 200,000, and is usually 10,000 or more.

[0044] The content of the silicone graft copolymer is preferably 0.1 to 30 parts by weight relative to 100 parts by weight of the pressure-sensitive adhesive. When the content of the silicone-based graft copolymer is 0.1 parts by weight or more, adhesion enhancement can be further reduced. When the content of the silicone-based graft copolymer is 30 parts by weight or less, the silicone-based graft copolymer can be sufficiently bonded to the pressure-sensitive adhesive, and contamination of the adherend can be further suppressed. From the same viewpoint, the lower limit of the content of the silicone-based graft copolymer per 100 parts by weight of the pressure-sensitive adhesive is more preferably 0.5 parts by weight, even more preferably 1 part by weight, and even more preferably 10 parts by weight, and even more preferably 5 parts by weight.

[0045] The crosslinking agent can be appropriately selected from those capable of bonding with the crosslinkable functional groups of the pressure-sensitive adhesive and the silicone-based graft copolymer. Examples of the crosslinking agent include epoxy-based crosslinking agents and isocyanate-based crosslinking agents. Among these, epoxy-based crosslinking agents are preferred because they are easy to adjust to the shear storage modulus range.

[0046] The content of the crosslinking agent relative to 100 parts by weight of the pressure-sensitive adhesive is preferably 0.5 parts by weight, more preferably 1 part by weight, and preferably 5 parts by weight, more preferably 3 parts by weight. When the content of the crosslinking agent is within the above range, the pressure-sensitive adhesive and the silicone graft copolymer can be sufficiently crosslinked, and the water contact angle after heating and the shear storage modulus can be easily adjusted to fall within the above ranges.

[0047] The pressure-sensitive adhesive layer may contain known additives such as inorganic fillers such as fumed silica, plasticizers, resins, surfactants, waxes, particulate fillers, antioxidants, and gas generating agents.

[0048] The thickness of the pressure-sensitive adhesive layer is not particularly limited, but the lower limit is preferably 5 μm and the upper limit is preferably 100 μm. When the thickness of the pressure-sensitive adhesive layer is within the above range, it can be attached to the adherend with sufficient adhesive strength and can also suppress adhesive residue upon peeling. The lower limit of the thickness of the pressure-sensitive adhesive layer is more preferably 10 μm and the upper limit is more preferably 60 μm.

[0049] The method for producing the pressure-sensitive adhesive tape according to one embodiment of the present invention is not particularly limited, and any conventionally known method can be used. For example, the pressure-sensitive adhesive tape can be produced by applying a solution of the pressure-sensitive adhesive components to a film that has been subjected to a release treatment, followed by drying.

[0050] The uses of the adhesive tape according to one embodiment of the present invention are not particularly limited, but examples include the manufacture of electronic components such as semiconductor chips and display devices (OLEDs, liquid crystal display devices, etc.). However, since the adhesive tape can reduce adhesion enhancement due to high temperatures and can be applied to opaque materials, it can be particularly suitably used as a protective tape in the manufacture of electronic components such as semiconductor chips.

[0051] In another embodiment of the present invention, there is also provided use of the above-mentioned pressure-sensitive adhesive tape in the production of electronic components. In particular, in the production of electronic components using opaque materials, such as semiconductor chips, the above-mentioned pressure-sensitive adhesive tape can be advantageously used as a protective tape. [Effects of the Invention]

[0052] According to the present invention, it is possible to provide a pressure-sensitive adhesive tape that can reduce adhesion enhancement due to high temperatures and can be used on materials that do not transmit light. DETAILED DESCRIPTION OF THE INVENTION

[0053] The following examples will explain the present invention in more detail, but the present invention is not limited to these examples.

[0054] (Synthesis of adhesive A) 6.38 g (50 mmol) of tellurium (40 mesh, metallic tellurium, manufactured by Aldrich) was suspended in 50 mL of tetrahydrofuran (THF), and 34.4 mL (55 mmol) of a 1.6 mol / L n-butyllithium / hexane solution (manufactured by Aldrich) was slowly added dropwise at room temperature. The reaction solution was stirred until the metallic tellurium completely disappeared. 10.7 g (55 mmol) of ethyl 2-bromoisobutyrate was added to the reaction solution at room temperature and stirred for 2 hours. After the reaction was completed, the solvent was concentrated under reduced pressure, followed by vacuum distillation to obtain ethyl 2-methyl-2-n-butyltellanylpropionate as a yellow oil.

[0055] In an argon-substituted glove box, 19 μL of the obtained 2-methyl-2-n-butyltellanyl-ethyl propionate, 34 mg of V-60 (2,2'-azobisisobutyronitrile, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and 1 mL of ethyl acetate were added to a reaction vessel, which was then sealed and removed from the glove box. Next, while argon gas was flowing into the reaction vessel, a total of 100 g of the mixed monomers shown in Table 1 and 66.5 g of ethyl acetate as a polymerization solvent were added to the reaction vessel, and the polymerization reaction was carried out at 60 ° C. for 20 hours to obtain a solution containing a living radically polymerized acrylic polymer (adhesive A). The resulting solution containing PSA A was then diluted 50-fold with tetrahydrofuran (THF). The diluted solution was filtered, and the filtrate was fed to a gel permeation chromatograph. GPC measurement was performed at a sample flow rate of 1 mL / min and a column temperature of 40°C to measure the polystyrene-equivalent molecular weight of PSA A, and determine the weight-average molecular weight (Mw) and molecular weight distribution (Mw / Mn). A Waters 2690 Separations Model gel permeation chromatograph was used. A polytetrafluoroethylene filter with a pore diameter of 0.2 μm was used. A GPC KF-806L (Showa Denko KK) column was used, and a differential refractometer was used as the detector.

[0056] (Synthesis of adhesives B, C, and F) Solutions containing adhesives B, C, and F were obtained in the same manner as in the synthesis of adhesive A, except that the composition of the mixed monomers was as shown in Table 1, and the weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn) were determined.

[0057] (Synthesis of adhesive D) A reactor equipped with a thermometer, a stirrer, and a cooling tube was prepared, and 100 parts by weight of 2-ethylhexyl acrylate, 3 parts by weight of acrylic acid, 0.1 parts by weight of hydroxyethyl acrylate, and 80 parts by weight of ethyl acetate were added to the reactor as monomers. The reactor was heated to initiate reflux. Subsequently, 0.01 parts by weight of V-60 (2,2'-azobisisobutyronitrile, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added to the reactor as a polymerization initiator, and a polymerization reaction was carried out at 60°C for 8 hours to obtain an ethyl acetate solution of Pressure-Sensitive Adhesive D. The weight-average molecular weight (Mw) and molecular weight distribution (Mw / Mn) were determined in the same manner as in the synthesis of Pressure-Sensitive Adhesive A.

[0058] (Synthesis of adhesives E and G) Ethyl acetate solutions of adhesives E and G were obtained in the same manner as in the synthesis of adhesive C, except that the monomer compositions were as shown in Table 1, and the weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn) were determined.

[0059] (Synthesis of Bleeding Agent A) A reactor equipped with a thermometer, a stirrer, and a condenser was prepared. 39.9 parts by weight of 2-ethylhexyl acrylate as a monomer, 60 parts by weight of a silicone macromonomer (KF-2012, methacryloyl-modified silicone, weight-average molecular weight 4600, manufactured by Shin-Etsu Chemical Co., Ltd.), 0.1 parts by weight of acrylic acid, 0.2 parts by weight of n-dodecanethiol, and 80 parts by weight of ethyl acetate were added to the reactor. The reactor was heated to initiate reflux. Subsequently, 0.1 parts by weight of 2,2'-azobisisobutyronitrile (V-60, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added as a polymerization initiator to the reactor, and polymerization was initiated under reflux. Next, 1 hour after the start of polymerization, 2,2'-azobisisobutyronitrile (V-60, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added in 0.1 parts by weight increments. Six hours after the start of polymerization, 0.2 parts by weight of 2,2'-azobisisobutyronitrile (V-60, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added to continue the polymerization reaction. Seven hours after the start of polymerization, an ethyl acetate solution of bleed agent A, a silicone graft copolymer, was obtained. The weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn) were determined in the same manner as in the synthesis of Pressure-Sensitive Adhesive A. The acid value was calculated from the amount of monomer charged. The glass transition temperature (Tg) of bleed agent A was also calculated as a theoretical value calculated using the following FOX equation: 1 / Tg=W1 / Tg1+W2 / Tg2++Wn / Tgn (In the formula, Tg is the glass transition temperature (K) of bleeding agent A, W1, W2, ..., Wn are the weight fractions of each monomer, and Tg1, Tg2, ..., Tgn are the glass transition temperatures of the homopolymers of each monomer.) The glass transition temperatures of the homopolymers used in the above calculation can be values ​​listed in the literature.

[0060] (Synthesis of Bleeding Agents B to X) Ethyl acetate solutions of bleed agents B to X, which are silicone graft copolymers, were obtained in the same manner as for the synthesis of bleed agent A, except that the monomer compositions were as shown in Tables 2 and 3, and the weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn) were determined.

[0061] Example 1 Ethyl acetate was added to the obtained adhesive A-containing solution for 100 parts by weight of the nonvolatile content, and the mixture was stirred. Bleeding agent A and an epoxy-based crosslinking agent were then added in the types and amounts shown in Table 4, and the mixture was stirred to obtain an ethyl acetate solution of an adhesive composition with a nonvolatile content of 30% by weight. The resulting ethyl acetate solution of the pressure-sensitive adhesive composition was applied to the corona-treated surface of a 50 μm-thick transparent polyethylene naphthalate film, one side of which had been corona-treated, using a doctor knife to give a dry film thickness of 40 μm, and the coating solution was dried by heating at 110°C for 5 minutes. The film was then left to stand for 3 days at 40°C to obtain a pressure-sensitive adhesive tape. Tetrad C, manufactured by Mitsubishi Gas Chemical Company, Inc., was used as the epoxy-based crosslinking agent.

[0062] (Measurement of water contact angle at 25°C) The water contact angle was measured using a contact angle measuring device (CAM 200, manufactured by KSV) in accordance with JIS R 3257:1999. Specifically, the adhesive tape was cut into a 25 mm width and used for the measurement. A 2 μL drop of ultrapure water was dropped onto the adhesive layer surface of the adhesive tape placed horizontally at room temperature of 25°C and humidity of 40%. The angle between the pure water and the adhesive layer surface 5 seconds after the drop was taken as the water contact angle.

[0063] (Measurement of water contact angle after heating) The adhesive tape was cut into 25 mm widths. The cut adhesive tape was attached to a glass substrate (large glass slide with white edges, No. 2, manufactured by Matsunami Glass Industrial Co., Ltd.) at a room temperature of 23°C and a relative humidity of 50% using a 2 kg pressure rubber roller at a speed of 10 mm / sec. Next, a heat treatment was performed once at 220°C for 120 minutes. After cooling, the adhesive tape was peeled from the glass substrate, and the water contact angle was measured using a contact angle measuring device (manufactured by KSV, CAM 200) in accordance with JIS R 3257:1999. Specifically, a 2 μL drop of ultrapure water was dropped onto the surface of the adhesive layer of an adhesive tape placed horizontally at room temperature of 25°C and humidity of 40%. The angle between the pure water and the adhesive layer surface 5 seconds after the drop was taken as the water contact angle.

[0064] (Measurement of shear storage modulus) Using a dynamic viscoelasticity measuring device (IT Measurement Control, DVA-200), measurements were performed from -50°C to 200°C in shear mode with an angular frequency of 10Hz and a heating rate of 5°C / min. Of the measurements obtained, the storage modulus at 25°C was measured.

[0065] (Examples 2 to 25, Comparative Examples 1 to 12) Pressure-sensitive adhesive tapes were produced in the same manner as in Example 1, except that the types and amounts of pressure-sensitive adhesive, bleeding agent, and crosslinking agent used were as shown in Tables 4 to 6, and the water contact angle before heating, the water contact angle after heating, and the shear storage modulus were measured. The isocyanate crosslinking agent used was Coronate L manufactured by Tosoh Corporation. The epoxy-modified silicone used was X-22-163C manufactured by Shin-Etsu Chemical Co., Ltd. The isocyanate crosslinking agent used was Coronate L45 manufactured by Nippon Polyurethane Industry Co., Ltd.

[0066] <Evaluation> The pressure-sensitive adhesive tapes obtained in the examples and comparative examples were evaluated by the following methods. The results are shown in Tables 4 to 6.

[0067] (Evaluation of initial adhesive strength) The adhesive tape was cut to a width of 25 mm. The cut adhesive tape was attached to a glass substrate (large glass slide with white polished edges, No. 2, manufactured by Matsunami Glass Industrial Co., Ltd.) at a room temperature of 23°C and a relative humidity of 50% using a 2 kg pressure rubber roller at a speed of 10 mm / sec. After leaving it for 30 minutes, the surface protection film was peeled off at a speed of 300 mm / min in accordance with JIS Z0237, and the 180-degree peel strength was measured, which was taken as the initial adhesive strength.

[0068] (Evaluation of adhesive strength after heating) The adhesive tape was cut to a width of 25 mm. The cut adhesive tape was attached to a glass substrate (large glass slide with white edges, No. 2, manufactured by Matsunami Glass Industrial Co., Ltd.) at a room temperature of 23°C and a relative humidity of 50% using a 2 kg pressure rubber roller at a speed of 10 mm / sec. Next, a heat treatment was performed once at 220°C for 120 minutes. After cooling, the surface protection film was peeled off at a speed of 300 mm / min according to JIS Z0237, and the 180-degree peel strength was measured, which was taken as the adhesive strength after heating.

[0069] (Evaluation of contamination) After heating and measuring the adhesive strength, the glass plate was visually inspected and the residue was evaluated according to the following criteria. A: No residue B: Partial residue present (area of ​​residue is less than 10%) C: Residue is present on the entire surface (area with residue exceeds 10%)

[0070] [Table 1]

[0071] [Table 2]

[0072] [Table 3]

[0073] [Table 4]

[0074] [Table 5]

[0075] [Table 6] [Industrial Applicability]

[0076] According to the present invention, it is possible to provide a pressure-sensitive adhesive tape that can reduce adhesion enhancement due to high temperatures and can be used on materials that do not transmit light.

Claims

1. An adhesive tape having an adhesive layer, The pressure-sensitive adhesive layer has a shear storage modulus of 4.0×10 at 25° C. as evaluated by dynamic viscoelasticity measurement. ４ ~2.0 x 10 ６ Pa, The pressure-sensitive adhesive layer has a water contact angle of 80° or more after the pressure-sensitive adhesive layer side of the pressure-sensitive adhesive tape is attached to glass, heated at 220°C for 120 minutes, and peeled off.

2. The adhesive tape according to claim 1, wherein the adhesive layer has a water contact angle of 110° or less after the adhesive layer side of the adhesive tape is attached to glass, heated at 220° C., and peeled off.

3. 3. The pressure-sensitive adhesive tape according to claim 1, wherein the pressure-sensitive adhesive layer has a water contact angle of 103° or less at 25°C.

4. 4. The adhesive tape according to claim 1, wherein the adhesive layer is made of a non-hardening adhesive.

5. 5. The pressure-sensitive adhesive tape according to claim 1, wherein the pressure-sensitive adhesive layer contains a pressure-sensitive adhesive having a crosslinkable functional group, a silicone-based graft copolymer having a crosslinkable functional group, and a crosslinking agent capable of reacting with the pressure-sensitive adhesive and the silicone-based graft copolymer to crosslink them.

6. 6. The pressure-sensitive adhesive tape according to claim 1, wherein the silicone graft copolymer has an acid value of 0.5 mgKOH / g or more and 20 mgKOH / g or less.

7. The pressure-sensitive adhesive tape according to claim 5 or 6, wherein the silicone graft copolymer is obtained by copolymerizing a mixed monomer containing 0.1 to 2.5% by weight of a carboxyl group-containing monomer and 1 to 90% by weight of a silicone macromonomer, and has a weight average molecular weight of 400,000 or less.

8. The adhesive tape according to claim 5 , wherein the crosslinking agent is an epoxy-based crosslinking agent.

9. 8. The pressure-sensitive adhesive tape according to claim 5, wherein the content of said silicone graft copolymer is 0.1 to 30 parts by weight per 100 parts by weight of the pressure-sensitive adhesive.

10. The adhesive tape according to claim 5, 8, or 9, wherein the adhesive is an acrylic polymer having a molecular weight distribution (Mw / Mn) of 1.05 to 2.

5.

11. Use of the adhesive tape according to any one of claims 1 to 10 in the production of electronic components.

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