adhesive tape

Abstract

To provide an adhesive tape which can easily be peeled and removed from an adherend without damaging and contaminating the adherend even when left in a high temperature condition by making the adherend irradiated with an active energy ray and extending it so as to sufficiently lower an adhesive force to the adherend, and to provide a processing method of an electronic member.SOLUTION: In an adhesive tape, an adhesive layer contains an acrylic adhesive polymer having a carbon-carbon double bond and a functional group, a photopolymerization initiator, a thermal polymerization initiator, a cross-linking agent reacting with the functional group, and a filler, in which, when an average particle diameter of the filler is denoted by R(μm) and thickness of the adhesive layer is denoted by D(μm), the rate of R to D (R / D) is in a range of 0.10-1.00, and when the adhesive tape is preserved in a high temperature environment of 200°C for 1 hour, at least one of an elongation rate measured after taken out and left standing in the MD direction or that in the TD direction is 30% or more.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an adhesive tape, particularly to an adhesive tape for adhering electronic components during processing and detaching the adhesive tape after high-temperature processing. The present invention relates to an adhesive tape for temporarily fixing electronic components used for the above-mentioned purposes, and a method for processing electronic components. [Background technology]

[0002] In recent years, adhesive tapes have been frequently used in the manufacturing processes of industrial products. Many of these process adhesive tapes are required to adhere firmly to the adherend (workpiece) during use and be easily removable from the adherend (workpiece) after use. To meet this demand, a technology is known in which heat or active energy rays are applied to the adhesive of the tape after use to cause a chemical reaction, thereby facilitating tape removal. Another technology is known in which the tape is stretched without applying heat or active energy rays to the adhesive of the tape, thereby facilitating tape removal. Generally, active energy rays refer to non-thermal energy such as light and radiation. Furthermore, reaction mechanisms caused by active energy rays are generally distinguished from reaction mechanisms caused by heat.

[0003] Patent Document 1 describes a radiation-curable adhesive tape used to secure semiconductor wafers during dicing. The adhesive layer of this radiation-curable adhesive tape contains spherical particles of an acrylic resin polymer. As a result, the adhesive strength (hereinafter sometimes referred to as "adhesion") is sufficiently reduced by radiation exposure, so that even large elements can be easily picked up without stretching the adhesive tape after radiation exposure.

[0004] Patent Document 2 describes a film for protecting the surfaces of displays, optical components, substrates, etc. The adhesive composition described here exhibits both high levels of adhesion and reworkability. The adhesive composition of the protective film is a mixture of a hydroxyl group-containing urethane prepolymer and a multifunctional (meth) Contains an acrylate, a thermal radical initiator, a crosslinking agent, and a photoradical initiator This prevents excessive adhesive strength, and the adhesive strength at the time of peeling is maintained by light irradiation. The adhesive strength is lower than that of conventional adhesives, so it is possible to achieve a high level of both adhesiveness and reworkability. Furthermore, the occurrence of the adhesive layer falling off can be reduced.

[0005] Patent Document 3 describes a dicing film used to fix an article when cutting (dicing) the article into small pieces. This dicing film has a base film made of an extensible plastic film, and an adhesive layer containing a filler having an average particle size within a predetermined range relative to the thickness of the adhesive layer. As a result, when the extensible base film is pulled, the thickness of the adhesive layer becomes thinner accordingly, so that the filler is exposed or protrudes from the surface of the adhesive layer, reducing the adhesive strength and making it easier to remove the chips. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 9-8109 [Patent Document 2] Japanese Patent Application Publication No. 2019-104870 [Patent Document 3] Japanese Patent Application Publication No. 16543 / 1983 Summary of the Invention [Problem to be solved by the invention]

[0007] The substrates bonded with the above-mentioned process adhesive tapes are often glass, sapphire glass, ceramic, or silicon wafers. In recent years, micro LED displays have attracted attention as next-generation display devices. In the manufacture of such micro LED displays, adhesive tapes and transfer techniques using adhesive tapes are being considered to transport and precisely align LED chips on the surface of display substrates. Furthermore, these electronic components temporarily fixed on the tape may be processed under high-temperature conditions of approximately 160°C or higher. Examples of such processes include the curing process of encapsulation resins in bulk encapsulation (e.g., curing temperature 165°C), high-temperature drying and curing processes after metal dry coating or wet coating of electronic components, and solder mounting. Therefore, there is a need for process adhesive tapes that can be easily removed from the processed substrates without damaging or contaminating them, even when processed under such high-temperature conditions.

[0008] The radiation-curable adhesive tape of Patent Document 1 is once placed under high temperature conditions (for example, 160°C or higher). When the adhesive is applied to the substrate, the adhesive strength of the adhesive layer to the substrate increases, and the adhesive layer remains sufficiently bonded even when irradiated with radiation. There is a risk that the adhesion will not decrease.

[0009] The adhesive composition of Patent Document 2 is a urethane-based adhesive, and has a low initial adhesive strength. When the pressure-sensitive adhesive composition is used for temporarily fixing electronic components, the size and weight of the electronic components to be adhered Depending on the type of product, it may shift from its designated position during processing or transportation, or in the worst case, it may peel off. Furthermore, the pressure-sensitive adhesive composition of Patent Document 2 contains a low-molecular-weight polyfunctional (meth)acrylate. Therefore, there is a risk of contaminating electronic components or subjecting them to high temperature conditions (e.g., 160°C or higher). When placed on the surface, the adhesive strength of the adhesive layer to the adherend increases, and the adhesive remains strong even when exposed to light. There is a risk that the force will not decrease.

[0010] The dicing film of Patent Document 3, once placed under high temperature conditions (e.g., 160°C or higher), increases the adhesive strength of the pressure-sensitive adhesive layer to the adherend, and there is a risk that the adhesive strength will not decrease sufficiently even if the dicing film is stretched. Also, in the examples of Patent Document 3, an ethylene-vinyl acetate copolymer resin film is used as the base film of the dicing film, but this has insufficient heat resistance and may not be able to withstand processing under high temperature conditions.

[0011] The present invention solves the above-mentioned problems, and an object of the present invention is to provide an adhesive tape that suppresses an increase in adhesive strength to an adherend even when placed under high temperature conditions, and that can be easily peeled and detached without damaging or contaminating the adherend by irradiating it with active energy rays and stretching it, thereby preventing an increase in adhesive strength to an adherend, and to provide a method for processing electronic components using the adhesive tape. [Means for solving the problem]

[0012] The pressure-sensitive adhesive tape of the present invention is a pressure-sensitive adhesive tape having a sheet-like substrate that transmits active energy rays and a pressure-sensitive adhesive layer provided on a surface of the sheet-like substrate, The adhesive layer contains an acrylic adhesive polymer having a carbon-carbon double bond and a functional group, a photopolymerization initiator, a thermal polymerization initiator, a crosslinking agent that reacts with the functional group, and a filler. the ratio of R to D (R / D) is in the range of 0.10 or more and 1.00 or less, where R (μm) is the average particle size of the filler and D (μm) is the thickness of the pressure-sensitive adhesive layer; The pressure-sensitive adhesive tape is characterized in that, after being stored in a high-temperature environment at 200°C for 1 hour, it is taken out and left in an environment of 23°C and 50% RH for 2 hours or more, and then at least one of the elongation in the MD direction and the elongation in the TD direction measured according to the method specified in JIS Z 0237 (2009) (with the tensile speed being 100 mm / min) is 30% or more.

[0013] In one embodiment, the sheet-like substrate contains a polyester-based thermoplastic elastomer.

[0014] In one embodiment, the polyester-based thermoplastic elastomer has a Vicat softening point of 125°C or higher.

[0015] In one embodiment, the thermal polymerization initiator is contained in an amount in the range of 0.1 parts by mass or more and 31.0 parts by mass or less relative to 100 parts by mass of the acrylic adhesive polymer having a carbon-carbon double bond and a functional group.

[0016] In one embodiment, the average particle size of the filler is in the range of 2 μm or more and 30 μm or less.

[0017] In one embodiment, the filler is contained in an amount of 0.1 parts by mass or more and 62.0 parts by mass or less relative to 100 parts by mass of the acrylic adhesive polymer having a carbon-carbon double bond and a functional group.

[0018] In one embodiment, the filler has a strength of 8.5 MPa or more at 30% deformation in a microcompression test.

[0019] In one embodiment, the carbon-carbon double bond content of the acrylic adhesive polymer having a carbon-carbon double bond and a functional group is in the range of 0.25 mmol / g or more and 1.67 mmol / g or less.

[0020] In one embodiment, the pressure-sensitive adhesive layer contains an oligomer having a carbon-carbon double bond.

[0021] In one embodiment, the oligomer having a carbon-carbon double bond has two or more carbon-carbon double bonds, a carbon-carbon double bond equivalent weight in the range of 250 or more and 1,400 or less, and a weight average molecular weight in the range of 1,500 or more and 4,900 or less.

[0022] In one embodiment, the oligomer having a carbon-carbon double bond is contained in an amount of up to 120 parts by mass per 100 parts by mass of the acrylic adhesive polymer having a carbon-carbon double bond and a functional group.

[0023] In one embodiment, the pressure-sensitive adhesive tape is stored in a high-temperature environment of 200°C for 1 hour, then taken out and left in a 23°C, 50% RH environment for 2 hours or more, and then stretched 30% in the MD direction or 30% in the TD direction, and the arithmetic surface height (Sa) of the pressure-sensitive adhesive layer surface measured in accordance with ISO 25178 30 However, it is 0.20 μm or more.

[0024] In one embodiment, the pressure-sensitive adhesive tape is stored in a high-temperature environment of 200°C for 1 hour, then taken out and left in a 23°C, 50% RH environment for 2 hours or more, and then stretched 50% in the MD direction or 50% in the TD direction, and the arithmetic surface height (Sa) of the pressure-sensitive adhesive layer surface measured in accordance with ISO 25178 50 However, it is 0.20 μm or more.

[0025] In one embodiment, the pressure-sensitive adhesive tape is used as a pressure-sensitive adhesive tape for temporarily fixing electronic components.

[0026] The method for processing electronic components of the present invention includes the steps of temporarily fixing an electronic component to the adhesive layer of the adhesive tape, processing the electronic component by applying a high temperature of 160°C or more and 200°C or less to the electronic component, irradiating the adhesive tape with active energy rays from the sheet-like substrate film side, stretching the adhesive tape, and peeling / detaching the electronic component from the adhesive layer of the adhesive tape. [Effects of the Invention]

[0027] According to the present invention, there is provided a pressure-sensitive adhesive tape in which an increase in adhesive strength to an adherend is suppressed even when placed under high-temperature conditions, and in which the adhesive strength is sufficiently reduced by irradiating the tape with active energy rays and then stretching it, or by stretching it and then irradiating it with active energy rays. As a result, electronic components such as elements processed under high-temperature conditions using the pressure-sensitive adhesive tape of the present invention can be easily detached from the pressure-sensitive adhesive tape without being damaged by irradiating the pressure-sensitive adhesive tape with active energy rays and then stretching it, or by stretching the pressure-sensitive adhesive tape and then irradiating it with active energy rays. In other words, electronic components processed under high-temperature conditions after being temporarily fixed to the pressure-sensitive adhesive tape can be easily peeled and detached from the pressure-sensitive adhesive tape without ultimately being contaminated or damaged. DETAILED DESCRIPTION OF THE INVENTION

[0028] The adhesive tape of the present invention comprises a sheet-like substrate and an adhesive provided on the surface of the sheet-like substrate. The pressure-sensitive adhesive layer may be provided on one side of the sheet-like substrate, or on both sides. It may be provided on one side, but it is preferable that it is provided on one side.

[0029] [Sheet substrate] The sheet-like substrate may be formed from a material that transmits active energy rays such as electron beams and ultraviolet rays and has strength sufficient to withstand the usage environment, and is not particularly limited. However, from the viewpoint of achieving both heat resistance and extensibility and suppressing necking during extension, examples include films formed from resin materials including polyester-based thermoplastic elastomers, polyamide-based thermoplastic elastomers, polyimide-based thermoplastic elastomers, aramid-based thermoplastic elastomers, silicone-based elastomers, and epoxy-based resins. These materials may be used alone or in combination of two or more. Furthermore, the thermoplastic elastomer may be formed from a block copolymer having hard segments and soft segments, a polymer alloy of a hard polymer and a soft polymer, or a material having both of these properties.

[0030] When the resin material used to form the sheet substrate contains a resin such as the elastomer, the proportion of the elastomer can be, for example, in the range of 50% by mass to 100% by mass of the total resin constituting the sheet substrate. That is, the resin constituting the sheet substrate may be composed solely of the elastomer. The proportion of the elastomer is preferably in the range of 70% by mass to 100% by mass, more preferably 90% by mass to 100% by mass.

[0031] Among the above-mentioned resins such as elastomers, thermoplastic elastomers such as polyester-based thermoplastic elastomers and polyamide-based thermoplastic elastomers are preferred from the viewpoints of ultraviolet transmittance, versatility, and economy, and polyester-based thermoplastic elastomers are more preferred from the viewpoint of improving heat resistance.

[0032] The polyester-based thermoplastic elastomer may have any structure other than the polyester component as the hard segment. The soft segment may be made of polyester, polyether, polyether ester, or the like. These may be used alone or in combination of two or more. That is, the polyester component constituting the hard segment may contain, for example, a structural unit derived from a monomer such as dimethyl terephthalate. On the other hand, the component constituting the soft segment may contain, for example, a structural unit derived from a monomer such as 1,4-butanediol or poly(oxytetramethylene) glycol.

[0033] More specifically, these include (1) so-called polyester-polyether type thermoplastic elastomers, which use aromatic polyesters for the hard segments and polyethers for the soft segments, and (2) so-called polyester-polyester type thermoplastic elastomers, which use aromatic polyesters for the hard segments and aliphatic polyesters for the soft segments. A typical example of the former is a PBT (polybutylene terephthalate)-PTMG [poly(oxytetramethylene) glycol]-PBT type block copolymer, and a typical example of the latter is a PBT-PCL [poly(ε-caprolactone)]-PBT type block copolymer.

[0034] Furthermore, the polyamide-based thermoplastic elastomer may have any structure other than the polyamide component as the hard segment. Polyester, polyether, polyether ester, etc. can be used as the soft segment. These may be used alone or in combination of two or more. For example, polyamide 6, polyamide 11, polyamide 12, etc. can be used as the polyamide component constituting the hard segment. These may be used alone or in combination of two or more. Various lactams, etc. can be used as monomers for these polyamide components. On the other hand, components constituting the soft segment can contain structural units derived from monomers such as dicarboxylic acids or polyether polyols. Among these, polyether diols are preferred as the polyether polyol, and examples thereof include poly(oxytetramethylene) glycol and poly(oxypropylene) glycol. These may be used alone or in combination of two or more.

[0035] More specifically, polyetheramide-type polyamide-based thermoplastic elastomers, polyester Examples include teramide-type polyamide thermoplastic elastomers and polyether-ester amide-type polyamide thermoplastic elastomers.

[0036] When a thermoplastic elastomer such as a polyester-based thermoplastic elastomer or a polyamide-based thermoplastic elastomer is used as the resin constituting the sheet-like substrate, the Vicat softening point of the thermoplastic elastomer is preferably 125°C or higher, more preferably 150°C or higher, depending on the temperature at which the adhesive tape is used to process the adherend (workpiece). When the Vicat softening point of the thermoplastic elastomer is 125°C or higher, for example, even when the adhesive tape is once placed under high-temperature conditions (e.g., 160°C or higher), deformation of the adhesive tape and a decrease in extensibility (elongation rate) can be suppressed. The Vicat softening point can be measured in accordance with the A50 method specified in JIS K7206-1999.

[0037] As the polyester-based thermoplastic elastomer, commercially available products having a Vicat softening point of 125°C or higher can be used, and can be appropriately selected from series such as "TEFABLOC (trade name)" manufactured by Mitsui Chemicals, Inc., "HYTREL (trade name)" manufactured by Toray DuPont Co., Ltd., and "PELPRENE (trade name)" manufactured by Toyobo Co., Ltd. These may be used alone or in combination of two or more types.

[0038] Furthermore, as the polyamide-based thermoplastic elastomer, commercially available products having a Vicat softening point of 125°C or higher can also be used, and can be appropriately selected from series such as "Pebax (trade name)" manufactured by Arkema Co., Ltd., "Daiamid (trade name)" manufactured by Daicel-Evonik Ltd., "Vestamid (trade name)" manufactured by Daicel-Evonik Ltd., and "UBESTA XPA (trade name)" manufactured by Ube Industries, Ltd. These may be used alone or in combination of two or more types.

[0039] Furthermore, when the resin constituting the sheet-like substrate contains a resin other than the elastomer, such a resin may contain the thermoplastic resins exemplified below. Examples of such thermoplastic resins include polyester-based resins, polyamide-based resins, polyolefin-based resins, polycarbonate-based resins, acrylic-based resins, homopolymer and copolymer resins containing components derived from aromatic vinyl monomers, and poly(oxyalkylene) glycols that are not copolymerized with polyester-based thermoplastic elastomer block copolymers. Among these, polyester-based resins and polyamide-based resins are preferred. Examples of the polyester-based resins include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and polybutylene naphthalate. Examples of the polyamide-based resins include nylon 6 and nylon 12.

[0040] Furthermore, the resin constituting the sheet-like substrate may contain various additives such as plasticizers and softeners (mineral oil, etc.), fillers (carbonates, sulfates, titanates, silicates, titanium oxide, magnesium oxide, silica, talc, mica, clay, fibrous fillers, etc.), antioxidants, light stabilizers, antistatic agents, lubricants, and colorants, provided that the effects of the present invention are not impaired. These may be used alone or in combination of two or more. The content of these additives is not particularly limited, but should be within a range that allows the sheet-like substrate to exhibit the desired functions and not lose extensibility.

[0041] Examples of methods for producing the sheet-like substrate (substrate film) include conventional production methods such as the casting method, T-die method, inflation method, and calendar method. Among these, the casting method is preferred because the absence of shear stress during film production of the sheet-like substrate reduces the orientation of polymer molecules and allows the substrate film 1 to be uniformly stretched without fragmentation during stretching. Specifically, for example, resin pellets that form the material for the sheet-like substrate are dried as needed, and then the molten resin is extruded at a temperature of 190 to 300°C using an extruder such as a T-die. The molten resin is then cooled using a pinch-pressure or single-sided touch method on a single or multiple casting drums at a temperature of 30 to 70°C, resulting in a film formed without substantial stretching, producing an unstretched sheet-like substrate (substrate film). During casting, electrostatic adhesion, air knife, or suction chamber methods can be used to obtain a sheet-like substrate (substrate film) with minimal thickness unevenness.

[0042] Furthermore, the sheet-like substrate (substrate film) may have a single layer structure or a laminated structure. When the sheet-like substrate (substrate film) has a laminated structure, the method for producing the sheet-like substrate (substrate film) may be a conventional film lamination method such as co-extrusion or dry lamination.

[0043] The total thickness of the sheet-like substrate is not particularly limited, and is preferably in the range of 10 μm or more and 200 μm or less, and more preferably in the range of 50 μm or more and 150 μm or less, for example.

[0044] The sheet-like substrate has a pressure-sensitive adhesive layer formed on at least one side thereof using an active energy ray-curable pressure-sensitive adhesive (described later) to cure and shrink the pressure-sensitive adhesive layer when a workpiece processed at high temperature is attached or detached from the surface. Therefore, the pressure-sensitive adhesive layer must be irradiated with active energy rays. Specifically, for example, when ultraviolet (UV) rays are used as the active energy rays, the parallel light transmittance of the ultraviolet (UV) rays measured by a spectrophotometer through the sheet-like substrate is preferably 1% or more, more preferably 5% or more, at a wavelength of 365 nm. The sheet-like substrate used for the spectrophotometer measurement is stored in a high-temperature environment at 200°C for 1 hour, then removed and left in a 23°C, 50% RH environment for 2 hours or more. If the parallel light transmittance of ultraviolet (UV) rays through the sheet-like substrate is less than 1%, even if the adhesive layer of the adhesive tape is irradiated with ultraviolet (UV) rays from the sheet-like substrate side after high-temperature processing of the adherend, the ultraviolet (UV) rays may not sufficiently reach the adhesive layer using an active energy ray-curable adhesive, causing the adhesive layer to not sufficiently cure and shrink, and the adhesive strength to the adherend may not be sufficiently reduced. As a result, in the process of peeling and detaching the adherend from the adhesive layer (pickup process), poor pickup of the adherend may occur, i.e., damage to the adherend, contamination due to adhesive residue on the adherend, reduced yield, reduced work efficiency, etc. If the parallel light transmittance of ultraviolet (UV) rays through the sheet-like substrate is 1% or more, the adhesive layer using an active energy ray-curable adhesive can sufficiently cure and shrink after high-temperature processing of the adherend, allowing the adhesive strength to the adherend to be sufficiently reduced. As a result, the pickup ability of the adherend is good.

[0045] [Adhesive layer] The adhesive layer uses an active energy ray curable adhesive. The adhesive has a moderate adhesive strength that can secure the adherend sufficiently under normal conditions, but When exposed to energy rays, a three-dimensional crosslinking reaction occurs, causing the storage modulus of the adhesive to increase. The glass transition temperature also rises and the volume of the adhesive shrinks, This significantly reduces the adhesive force to the object, making it easier to attach and detach the object. When the adhesive is applied, it is difficult for adhesive residue to remain on the adherend. It contains a functional group such as a carbon-carbon double bond that exhibits reactivity upon irradiation with active energy rays.

[0046] The active energy ray curable adhesive used in the present invention is an acrylic adhesive polymer, a photopolymer It generally contains an active energy ray reaction agent, a thermal polymerization initiator, a crosslinking agent, and a filler. The reactive group (carbon-carbon double bond) is contained in the acrylic adhesive polymer.

[0047] The pressure-sensitive adhesive layer is formed on the sheet-like substrate by, for example, a coating method. The adhesive layer coating liquid is obtained by diluting the .lambda.-ray curing adhesive with an organic solvent such as toluene or ethyl acetate. Next, the obtained pressure-sensitive adhesive layer coating liquid is applied to the surface of the sheet-like substrate, dried, and cured. A release-treated sheet-like substrate is attached to the adhesive layer. It is preferable to do this. Alternatively, the pressure-sensitive adhesive layer coating liquid may be first applied to the surface of a release-treated sheet-like substrate, dried, and then transferred to the sheet-like substrate and cured to form the pressure-sensitive adhesive layer. The thickness of the pressure-sensitive adhesive layer is not particularly limited, but is generally in the range of 5 μm to 100 μm, preferably 10 μm to 30 μm.

[0048] In order to increase the adhesive strength between the pressure-sensitive adhesive layer and the sheet-like substrate, a layer of adhesive may be applied to the surface of the sheet-like substrate. After the corona treatment, plasma treatment, or coating of a primer composition, etc. is performed, the pressure-sensitive adhesive layer is The coating liquid may be applied to the surface of a sheet-like substrate.

[0049] (acrylic adhesive polymer) The acrylic adhesive polymer is, for example, an adhesive tape that adheres to electronic components during processing. The adhesive layer of the tape adheres to the electronic components. The acrylic adhesive polymer has carbon- A material having a carbon-carbon double bond is used. When the adhesive layer is irradiated with active energy rays during attachment / detachment of the adherend, the carbon-carbon double bond undergoes a radical addition reaction, and the polymer chains are highly cross-linked, increasing the storage modulus of the adhesive layer and lowering the glass transition temperature. The deformation efficiency when peeling (detaching) the adhesive layer decreases, and the volume also shrinks. Therefore, the effect of reducing the adhesive force of the pressure-sensitive adhesive layer is improved.

[0050] As a method for producing an acrylic adhesive polymer having a carbon-carbon double bond, in particular Although not limited thereto, it is usually a (meth)acrylic acid ester and a functional group-containing unsaturated compound. Copolymerization with a substance to obtain a copolymer, and then addition reaction with the functional groups of that copolymer. Examples of such methods include a method of subjecting a compound having a functional group and a carbon-carbon double bond capable of reacting with the compound. do.

[0051] The functional group referred to here is a thermally reactive functional group that can coexist with a carbon-carbon double bond. Examples of the functional groups include active hydrogen groups such as hydroxyl groups, carboxyl groups, and amino groups, and groups such as hydroxyl groups, carboxyl groups, and amino groups. It is a functional group that reacts thermally with active hydrogen groups such as lysidyl groups. Active hydrogen groups are groups that contain nitrogen atoms other than carbon. A functional group having an element such as oxygen or sulfur and a hydrogen atom directly bonded to it.

[0052] The addition reaction may involve, for example, converting a hydroxyl group in a side chain of the copolymer into a (meth) Isocyanate compounds having an acryloyloxy group (e.g., 2-methacryloyloxy) a method of reacting the carboxyl group in the side chain of the copolymer with dimethyl isocyanate, etc. a method of reacting the glycidyl group in the side chain of the copolymer with glycidyl (meth)acrylate; There are also methods for reacting lysidyl groups with (meth)acrylic acid. In this case, the acrylic adhesive polymer is crosslinked with a crosslinking agent described later to further improve the adhesiveness. In order to achieve polymerization, functional groups such as hydroxyl groups, carboxyl groups, and glycidyl groups remain. In this way, an acrylic adhesive polymer having an active energy ray reactive group (carbon-carbon double bond) such as a (meth)acryloyloxy group and a functional group is obtained. It is possible.

[0053] In the above addition reaction, the reactivity of the carbon-carbon double bond with active energy rays is maintained. For this reason, it is preferable to use a polymerization inhibitor. A quinone-based polymerization inhibitor such as non-monomethyl ether is preferred. The amount of polymerization inhibitor is as follows: Although there is no particular limitation, it is usually 0 to the total amount of the base polymer and the radiation reactive compound. The range is between 0.01% by mass and 0.1% by mass.

[0054] The acrylic adhesive polymer preferably has a weight-average molecular weight in the range of 100,000 to 2,000,000, and more preferably 300,000 to 1,500,000. When the weight-average molecular weight of the acrylic adhesive polymer is less than 100,000, it is difficult to obtain a highly viscous adhesive composition solution with a viscosity of several thousand to several tens of thousands of cP, taking into account factors such as coatability, which is undesirable. Furthermore, the adhesive strength may be reduced, which may result in insufficient adhesion of the adherend during processing, or contamination of the adherend during attachment and detachment. On the other hand, when the weight-average molecular weight exceeds 2,000,000, although there are no particular problems with the properties of the adhesive tape, it is difficult to mass-produce the acrylic adhesive polymer. For example, the acrylic adhesive polymer may gel during synthesis, which is undesirable. Here, the weight-average molecular weight refers to a standard polystyrene equivalent value measured by gel permeation chromatography.

[0055] The acrylic adhesive polymer preferably has a carbon-carbon double bond content in the range of 0.10 mmol / g or more and 2.00 mmol / g or less, more preferably 0.25 mmol / g or more and 1.67 mmol / g or less. When the carbon-carbon double bond content of the acrylic adhesive polymer is less than 0.10 mmol / g, a photoradical crosslinking reaction does not occur sufficiently even when irradiated with active energy rays. As a result, the adhesive strength cannot be sufficiently reduced, making it difficult to detach the adherend. On the other hand, when the carbon-carbon double bond content exceeds 2.00 mmol / g, the pressure-sensitive adhesive layer becomes too hard after irradiating with active energy rays, and there is a risk that the pressure-sensitive adhesive layer will cleave and peel off from the sheet-like substrate when the pressure-sensitive adhesive tape is stretched. Furthermore, from the viewpoint of the storage stability of the pressure-sensitive adhesive tape against light, this is not practically preferable. The carbon-carbon double bond content of the acrylic adhesive polymer can be calculated by measuring the iodine value of the acrylic adhesive polymer.

[0056] The main structure of acrylic adhesive polymers is a (meth)acrylic acid alkyl ester monomer. The copolymer is composed of an active hydrogen group-containing monomer and / or a glycidyl group-containing monomer. can be. Examples of the (meth)acrylic acid alkyl ester monomer include hexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, and octadecyl (meth)acrylate, which are monomers having 5 or less carbon atoms, and pentyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, ethyl (meth)acrylate, and methyl (meth)acrylate. Examples of the active hydrogen group-containing monomer include hydroxyl group-containing monomers such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 6-hydroxyhexyl (meth)acrylate; carboxyl group-containing monomers such as (meth)acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid; acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride; amide monomers such as (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-butyl(meth)acrylamide, N-methylol(meth)acrylamide, N-methylolpropane(meth)acrylamide, N-methoxymethyl(meth)acrylamide, and N-butoxymethyl(meth)acrylamide; and amino group-containing monomers such as aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, and t-butylaminoethyl (meth)acrylate. Examples of the glycidyl group-containing monomer include glycidyl (meth)acrylate, etc. The content of the thermally reactive functional group that can coexist with these carbon-carbon double bonds is not particularly limited, but is preferably in the range of 5% by mass to 50% by mass based on the total amount of the copolymerization monomer components.

[0057] Specifically, copolymers of these copolymers include 2-ethylhexyl acrylate and Copolymer with acrylic acid, 2-ethylhexyl acrylate and 2-hydroxyethyl acrylate Copolymer of 2-ethylhexyl acrylate, 2-ethylhexyl acrylate, methacrylic acid and 2-hydroxy acrylate Examples of copolymers include, but are not limited to, terpolymers with hydroxyethyl. stomach.

[0058] The acrylic adhesive polymer may be used with other adhesives as needed to improve cohesive strength and heat resistance. The other copolymerizable monomer components may include, for example, Specifically, for example, cyano group-containing monomers such as (meth)acrylonitrile, ethylene, propylene Olefin monomers such as ethylene, isoprene, butadiene, and isobutylene, styrene, α- Styrene monomers such as methylstyrene and vinyltoluene, vinyl acetate, vinyl propionate vinyl ester monomers such as vinyl ether, ... halogen atom-containing monomers such as ether monomers, vinyl chloride, vinylidene chloride, etc., (meth ) Alkoxy group-containing compounds such as methoxyethyl acrylate and ethoxyethyl (meth)acrylate Monomer, N-vinyl-2-pyrrolidone, N-methylvinylpyrrolidone, N-vinylpyridine N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperazine, N-vinyl Pyrazine, N-vinylpyrrole, N-vinylimidazole, N-vinyloxazole, N -Vinylmorpholine, N-vinylcaprolactam, N-(meth)acryloylmorpholine These other copolymerizable monomer components include monomers having a nitrogen atom-containing ring such as They may be used alone or in combination of two or more.

[0059] (Crosslinkable oligomer) The pressure-sensitive adhesive layer preferably contains an oligomer having a carbon-carbon double bond. When the pressure-sensitive adhesive layer is irradiated with active energy rays, the oligomer Addition between oligomers or between oligomers and the above-mentioned acrylic adhesive polymer As a result, the adhesive layer does not contain crosslinking oligomers and does not contain crosslinking oligomers. In comparison, the storage modulus and glass transition temperature of the pressure-sensitive adhesive layer are increased, and the volume is increased. The shrinkage improves the effect of reducing the adhesive strength of the adhesive layer when the adherend is attached or detached. The oligomer may include, for example, a photopolymerizable polyfunctional oligomer.

[0060] The crosslinkable oligomer preferably has two or more carbon-carbon double bonds. The crosslinkable oligomer preferably has a weight-average molecular weight of 1,000 to 5,000, more preferably 1,500 to 4,900. If the weight-average molecular weight of the crosslinkable oligomer is less than 1,000, the use of a large amount of the crosslinkable oligomer may result in contamination of the adherend. Furthermore, if the amount of carbon-carbon double bonds in the crosslinkable oligomer is small, the adhesive strength to the adherend may increase excessively when placed under high temperature conditions, and the adhesive strength may not be sufficiently reduced even when irradiated with active energy rays during desorption. On the other hand, if the weight-average molecular weight of the crosslinkable oligomer is greater than 5,000 and the amount of carbon-carbon double bonds in the crosslinkable oligomer is small, the degree of curing and shrinkage of the pressure-sensitive adhesive layer may be small, and further reduction in adhesive strength may not be achieved. Here, the weight-average molecular weight refers to the standard polystyrene equivalent value measured by gel permeation chromatography.

[0061] The double bond equivalent of the crosslinkable oligomer is preferably in the range of 150 to 1,500, more preferably in the range of 250 to 1,400, and even more preferably in the range of 250 to 490. If the double bond equivalent of the crosslinkable oligomer is less than 150, the pressure-sensitive adhesive layer will become hard due to the increased crosslink density upon irradiation with active energy rays, resulting in an excessively high flexural modulus. For example, when the adherend is pushed up through the pressure-sensitive adhesive tape to be peeled off, if the adherend has low mechanical strength (specifically, semiconductor chips or thin glass), the adherend may crack. Furthermore, if the content of the crosslinkable oligomer is high, storage stability against light may be impaired. On the other hand, if the double bond equivalent of the crosslinkable oligomer exceeds 1,500, the degree of curing and shrinkage of the pressure-sensitive adhesive layer may be small, and the effect of further reducing adhesive strength may not be achieved. Here, the double bond equivalent is defined by the formula: double bond equivalent = molecular weight / number of double bonds in the same molecule. The value of the double bond equivalent defined by the above formula can be calculated from the amount of double bonds in a sample quantified based on the iodine value measured in accordance with JIS K0070: 1992 and the mass or molecular weight of the sample. When the sample is likely to contain multiple components, the double bond equivalent may be determined by separating each component as necessary and measuring the iodine value of the separated component.

[0062] Preferred crosslinkable oligomers include polyacrylate oligomers and polyether oligomers. Examples of suitable photopolymerizable polyfunctional oligomers include photopolymerizable oligomers such as polyester oligomers, polyester oligomers, and polyurethane oligomers. Among these, polyurethane oligomers are preferred from the viewpoint of reducing the bleeding of the pressure-sensitive adhesive and providing good adhesion to the adherend at high temperatures, and aliphatic polyester oligomers are preferred from the viewpoint of ease of controlling the reactivity. These photopolymerizable polyfunctional oligomers can be used alone. Alternatively, two or more of them may be used in combination.

[0063] Examples of polyacrylate oligomers include hexanediol di(meth)acrylate. acrylate, neopentyl glycol di(meth)acrylate, trimethylolpropane tri( meth)acrylate, dipentaerythritol hexa(meth)acrylate, epoxy ( Examples of the acrylate include (meth)acrylate and oligoester (meth)acrylate.

[0064] Examples of polyether oligomers include polyethylene glycol and polypropylene. glycol, polybutylene glycol, and those having one or both ends methyl Examples of such blocking agents include acrylate, phenyl, (meth)acrylate, and the like. can be.

[0065] Examples of polyester oligomers include ε-caprolactone and its fragments. End or both ends are blocked with a blocking agent such as methyl, phenyl, or (meth)acrylate. Examples of blockades include:

[0066] Examples of polyurethane oligomers include polyether polyols and polyester polyols. Macropolyols such as polyols, polycarbonate polyols, and polybutadiene polyols urethane polyols such as the reaction product of hydroxybenzoates with polyisocyanate monomers, e.g., hydroxybenzoates Hydroxyethyl (meth)acrylate, phenyl glycidyl ether acrylate, pentaerythritol Hydroxy(meth)acrylates such as taerythritol triacrylate and glycerin dimethacrylate ) Acrylate monomer and methylene diisocyanate, tolylene diisocyanate, Polyisocyanate monomers such as isophorone diisocyanate, or the above-mentioned urethane Examples of the urethane acrylate include a reaction product of a methyl acrylate and a methyl acrylate polyol.

[0067] When the pressure-sensitive adhesive layer contains a crosslinkable oligomer, the blending ratio of the crosslinkable oligomer is The crosslinkable oligomer content is preferably 120 parts by mass or less, more preferably 11 to 100 parts by mass, per 100 parts by mass of the adhesive polymer. If the crosslinkable oligomer content exceeds 120 parts by mass, adhesion to the adherend cannot be maintained when the adherend is processed at high temperatures, which is undesirable. Furthermore, there is a risk of contamination of the adherend surface after detachment.

[0068] (Crosslinking agent) The adhesive layer of the present embodiment is formed by increasing the molecular weight of the acrylic adhesive polymer described above. The crosslinking agent is not particularly limited, and may be any of the above-mentioned acrylic crosslinking agents. The functional groups of the adhesive polymer are hydroxyl, carboxyl, and glycidyl groups. A known crosslinking agent having a functional group capable of reacting with the above can be used. For example, polyisocyanate-based crosslinking agents, epoxy-based crosslinking agents, aziridine-based crosslinking agents, melamine resin crosslinking agents, etc. Fatty crosslinking agents, urea resin crosslinking agents, acid anhydride compound crosslinking agents, polyamine crosslinking agents, carboxylate Among these, from the viewpoint of reactivity and versatility, Therefore, it is preferable to use a polyisocyanate-based crosslinking agent. The amount of the crosslinking agent to be added is determined based on the amount of the acrylic adhesive polymer. The amount of crosslinking agent is preferably in the range of 0.01 parts by mass or more and 5.00 parts by mass or less, more preferably 0.10 parts by mass or more and 3.00 parts by mass or less, relative to 100 parts by mass of the polymer. If the blending amount of the crosslinking agent is too large, depending on the type of acrylic adhesive polymer, there is a risk that the adhesive strength when the pressure-sensitive adhesive tape is affixed to the adherend may decrease, or that the uncrosslinked components may contaminate the adherend.

[0069] (thermal polymerization initiator) Thermal polymerization initiators are particularly sensitive to heat during high-temperature processing after the adherend is attached to the adhesive tape. As a result, some of the carbon-carbon double bonds in acrylic adhesive polymers and crosslinkable oligomers In this case, the thermal radical crosslinking reaction is initiated, so that the crosslinking of the adhesive layer progresses and the adhesive layer is The storage modulus and glass transition temperature increase and the material becomes harder than in the state of the thermal polymerization initiator. The active energy ray-curable adhesive of the present invention containing This phenomenon is typically seen in active energy ray curable adhesives, namely, When the adhesive layer is placed on the surface, it softens and becomes wet with the adherend, increasing the adhesive strength to the adherend. Furthermore, depending on the composition, the phenomenon of excessive increase can be significantly suppressed. The adhesive strength to the adherend is almost completely reduced before the active energy ray irradiation at the time of desorption. In this state, the carbon-carbon bond of the active energy ray curable adhesive Not all of the double bonds are consumed, and some of the carbon-carbon double bonds remain. Therefore, when the active energy rays are irradiated during desorption, the photopolymerization initiator described below This promotes the photoradical crosslinking reaction of the remaining carbon-carbon double bonds, resulting in the formation of a pressure-sensitive adhesive layer. The adhesive is further hardened and shrunk, and finally the adherend is transported to the container without contamination or damage from the adhesive tape. The adhesive layer is made mainly of acrylic adhesive polymer. Therefore, it is assumed that the radical crosslinking reaction proceeds in a part of the adhesive layer as described above. Even when processed under high temperature conditions, the adhesive strength can be maintained to the extent that it is possible to hold the adherend in place.

[0070] The thermal polymerization initiator is preferably a compound that generates radical active species upon heating, e.g. Examples include peroxides, azo compounds, persulfates, etc. Among these, peroxides are preferred because they can be easily selected depending on the processing temperature of the adherend.

[0071] Specifically, the peroxide is t-butyl hydroperoxide (10-hour half-life temperature 167℃), cumene hydroperoxide (same 158℃), diisopropyl benzene Paramenthane hydroperoxide (same 145°C), paramenthane hydroperoxide (same 1 28℃), di-t-butyl peroxide (124℃), di(2-t-butyl peroxide (isopropyl) benzene (same 119°C), dicumyl peroxide (same 117°C), t -Butyl peroxybenzoate (same temperature 104℃), dibenzoyl peroxide (same temperature 74℃) ℃), t-butylperoxy-2-ethylhexanoate (72℃), t-hexylperoxy These may be used alone. Alternatively, two or more of them may be used in combination.

[0072] The azo compound is 1,1-azobis(cyclohexane-1-carbonitrile) (1 0-hour half-life temperature 88℃), 4,4'-azobis(4-cyanovaleric acid) (same 68℃), 2 ,2'-Azobis(2-methylbutyronitrile) (same 67°C), dimethyl 2,2'-azo Bis(2-methylpropionate) (same temperature 66°C), 2,2'-azobis(isobutyronite) 2,2'-azobisdimethylvaleronitrile (same temperature 65°C), 2,2'-azobisdimethylvaleronitrile (same temperature 52°C) 1,1' -Azobis(1-acetoxy-1-phenylethane) (same 61°C), dimethyl 2,2'- Azobisisobutyrate (same as 67°C), azocumene, 2-(tert-butylazo)-2 -cyanopropane, 2,2'-azobis(2,4,4-trimethylpentane), 2,2' -azobis(2-methylpropane) and the like. These may be used alone. Alternatively, two or more types may be used in combination.

[0073] Persulfates include potassium persulfate (10-hour half-life temperature 71°C), ammonium persulfate, Examples of these include sodium persulfate (same temperature 62°C) and sodium persulfate (same temperature 71°C). Alternatively, two or more of them may be used in combination.

[0074] The 10-hour half-life temperature of the thermal polymerization initiator to be used should be selected appropriately depending on the processing temperature of the adherend. However, for example, when the processing temperature is 165°C or higher and 200°C or lower, the 10-hour half-life temperature of the thermal polymerization initiator used is preferably in the range of 60°C or higher and 125°C or lower. If the 10-hour half-life temperature is too low compared to the processing temperature, the adhesive strength to the adherend when exposed to the processing temperature may be excessively reduced, which may affect the processing operation (such as the adherend being displaced or falling off). On the other hand, if the 10-hour half-life temperature is too high compared to the processing temperature, the effect of suppressing the increase in adhesive strength to the adherend when exposed to the processing temperature may be reduced, and the adhesive strength may not be sufficiently reduced even when irradiated with active energy rays during desorption.

[0075] The amount of the thermal polymerization initiator used in the present invention is 0 parts by mass, the content is preferably in the range of 0.1 parts by mass or more and 31.0 parts by mass or less, and more preferably 1.0 parts by mass or more and 20.0 parts by mass or less.

[0076] If the amount of the thermal polymerization initiator added is less than 0.1 parts by mass, the reactivity to heat may be insufficient. As a result, the adhesive does not harden sufficiently, resulting in a loss of adhesive strength when placed under high temperature conditions. The increase cannot be sufficiently suppressed, and the adherend does not peel off even when irradiated with active energy rays afterwards. On the other hand, if the amount of the thermal polymerization initiator added exceeds 31.0 parts by mass, In this case, the adhesive strength to the substrate when placed under high temperature conditions will be too low, making it difficult to carry out processing work. There is also a risk of contamination of the substrate.

[0077] (Photopolymerization initiator) The photopolymerization initiator is sensitive to the irradiation of the adhesive layer with active energy rays when the adherend is attached or detached. The photopolymerization initiator generates radicals, initiating a crosslinking reaction of the carbon-carbon double bonds of the acrylic adhesive polymer or crosslinkable oligomer remaining in the pressure-sensitive adhesive layer after exposure to high temperatures. As a result, the pressure-sensitive adhesive layer further hardens and shrinks under irradiation with active energy rays, thereby reducing the adhesive strength to the adherend. Preferred photopolymerization initiators are compounds that generate radical active species when exposed to ultraviolet light or the like, and examples include alkylphenone radical polymerization initiators, acylphosphine oxide radical polymerization initiators, and oxime ester radical polymerization initiators. These photopolymerization initiators may be used alone or in combination of two or more.

[0078] Examples of the alkylphenone radical polymerization initiator include a benzyl methyl ketal radical polymerization initiator, an α-hydroxyalkylphenone radical polymerization initiator, and an α-aminoalkylphenone radical polymerization initiator.

[0079] Specific examples of the benzyl methyl ketal radical polymerization initiator include 2,2'-dimethoxy-1,2-diphenylethan-1-one (for example, trade name: Omnirad651, manufactured by IGM Resins BV). Specific examples of the α-hydroxyalkylphenone radical polymerization initiator include 2-hydroxy-2-methyl-1-phenylpropan-1-one (trade name: Omnirad1173, manufactured by IGM Resins BV), 1-hydroxycyclohexyl phenyl ketone (trade name: Omnirad184, manufactured by IGM Resins BV), 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one (trade name: Omnirad2959, manufactured by IGM Resins BV), and 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)benzyl]phenyl}-2-methylpropan-1-one (trade name: Omnirad127, manufactured by IGM Resins BV). Specific examples of the α-aminoalkylphenone radical polymerization initiator include 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one (trade name: Omnirad907, manufactured by IGM Resins BV), 2-benzyl-2-(dimethylamino)-4′-morpholinobutyrophenone (trade name: Omnirad369, manufactured by IGM Resins BV), and 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one (trade name: Omnirad379EG, manufactured by IGM Resins BV).

[0080] Specific examples of the acylphosphine oxide radical polymerization initiator include 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (trade name: OmniradTPO, manufactured by IGM Resins BV) and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (trade name: Omnirad819, manufactured by IGM Resins BV).

[0081] Examples of the oxime ester radical polymerization initiator include 1,2-octanedione, 1-[4-(phenylthio)phenyl]-, 2-(O-benzoyloxime) (trade name: OmniradOXE-01, manufactured by IGM Resins BV).

[0082] Among these, from the viewpoint of heat resistance, that is, the ability to sufficiently generate radical active species by ultraviolet irradiation or the like even when placed under high temperature conditions, it is preferable to use an α-aminoalkylphenone radical polymerization initiator such as Omnirad369, Omnirad369E, or Omnirad379EG as the photopolymerization initiator.

[0083] The amount of the photopolymerization initiator to be added is preferably 100 parts by mass of the acrylic adhesive polymer. The range is preferably 0.1 parts by mass or more and 10.0 parts by mass or less, more preferably 0.5 parts by mass or more and 5.0 parts by mass or less, and even more preferably 1.0 parts by mass or more and 2.0 parts by mass or less.

[0084] If the amount of photopolymerization initiator added is less than 0.1 parts by mass, the photopolymerization initiator may not reflect light to the active energy rays. The adhesive does not cure or shrink sufficiently due to insufficient resilience, and when exposed to active energy rays, On the other hand, if the amount of addition is 10.0 parts by mass, it may become difficult to remove the adherend. If the amount exceeds this range, the effect will be saturated and this is not preferable from the viewpoint of economy.

[0085] Furthermore, as a sensitizer for such a photopolymerization initiator, dimethylaminoethyl methacrylate Compounds such as 4-dimethylaminobenzoic acid isoamyl may be added to the adhesive.

[0086] (filler) The filler crosslinks the adhesive layer when irradiated with active energy rays, and when it hardens and shrinks, This reduces the contact area of ​​the pressure-sensitive adhesive layer with the adherend. Furthermore, when the pressure-sensitive adhesive tape is stretched, the thickness of the pressure-sensitive adhesive layer becomes thinner as the tape is stretched, causing the filler to be exposed or protrude from the surface of the pressure-sensitive adhesive layer, thereby reducing the contact area of ​​the pressure-sensitive adhesive layer with the adherend. These synergistic effects further reduce the adhesive strength of the pressure-sensitive adhesive layer with the adherend.

[0087] The size of the filler is determined by the relationship between the average particle diameter of the filler and the thickness of the adhesive layer. (μm) and the thickness of the pressure-sensitive adhesive layer is D (μm), the ratio of R to D (R / D) is preferably in the range of 0.10 or more and 1.00 or less, more preferably 0.40 or more and 0.80 or less, and even more preferably 0.50 or more and 0.80 or less. If the ratio of R to D (R / D) is less than 0.10, the proportion of filler exposed to the surface of the adhesive layer or protruding from the surface of the adhesive layer due to shrinkage of the adhesive layer due to active energy ray irradiation or thinning of the adhesive layer due to stretching of the adhesive tape, i.e., the effect of reducing the contact area of ​​the adhesive layer with the adherend, may be insufficient. As a result, after being placed under high-temperature conditions, for example, even when irradiated with active energy rays and the adhesive tape is stretched, the adhesive strength may not be sufficiently reduced, making it difficult to peel the adherend. On the other hand, if the ratio of R to D (R / D) exceeds 1.00, the adhesion between the adhesive layer and the sheet-like substrate may be poor. Furthermore, the initial adhesive strength to the adherend before irradiation with active energy rays may be reduced, making it impossible to sufficiently hold the adherend, which may affect processing operations (such as displacement or detachment of the adherend).

[0088] When the thickness of the pressure-sensitive adhesive layer is, for example, in the preferred range of 10 μm or more and 30 μm or less, the average particle diameter of the filler is preferably in the range of 1 μm or more and 30 μm or less, more preferably 4 μm or more and 24 μm or less, and even more preferably 5 μm or more and 24 μm or less. If the average particle diameter of the filler is in the above range, the effect of reducing the contact area of ​​the pressure-sensitive adhesive layer with the adherend can be more significantly exhibited. Note that the average particle diameter referred to in the present invention is the 50% diameter value (D ) in the volume-based cumulative fraction when the integral volume is calculated from particles with a small particle size distribution measured after adding the filler and dispersant to a medium that does not dissolve or swell the filler and ultrasonically dispersing the filler using a laser scattering particle size distribution analyzer (for example, a particle size distribution analyzer "Model LA-920" manufactured by Horiba, Ltd.). 50% ), means the median diameter.

[0089] The filler is preferably contained in an amount of 0.1 to 62.0 parts by mass, more preferably 1.5 to 50.0 parts by mass, and even more preferably 2.0 to 10.0 parts by mass relative to 100 parts by mass of the acrylic adhesive polymer, depending on its average particle size. If the filler content is less than 0.1 part by mass, when the pressure-sensitive adhesive layer shrinks due to irradiation with active energy rays or the pressure-sensitive adhesive layer thickness is reduced due to stretching of the adhesive tape, the filler is less exposed to the surface of the pressure-sensitive adhesive layer or protrudes from the surface of the pressure-sensitive adhesive layer, which may result in insufficient reduction in the contact area of ​​the pressure-sensitive adhesive layer with the adherend. As a result, after exposure to high temperatures, for example, even when the pressure-sensitive adhesive tape is irradiated with active energy rays and stretched, it may be difficult to peel the adherend. On the other hand, if the filler content exceeds 62.0 parts by mass, the adhesion between the pressure-sensitive adhesive layer and the sheet-like substrate may be poor. Furthermore, the initial adhesive strength to the adherend before irradiation with active energy rays will decrease, and the adherend may not be held sufficiently, which may affect processing (the adherend may become displaced or fall off). By containing the above filler in this range, the effect of reducing the contact area of ​​the adhesive layer with the adherend can be more significantly achieved.

[0090] The filler preferably has a strength of 8.5 MPa or more at 30% deformation in a microcompression test, more preferably in the range of 20 MPa to 70 MPa, and even more preferably in the range of 29 MPa to 70 MPa. If the filler has a strength of less than 8.5 MPa at 30% deformation, when the thickness of the pressure-sensitive adhesive layer is reduced by stretching the pressure-sensitive adhesive tape, the effect of reducing the contact area of ​​the pressure-sensitive adhesive layer with the adherend may be insufficient. As a result, even if the pressure-sensitive adhesive tape is placed under high-temperature conditions and then irradiated with active energy rays and stretched, the adhesive strength may not be sufficiently reduced, making it difficult to peel the adherend.

[0091] The strength at 30% deformation in the microcompression test of the above filler is measured using the Shimadzu Corporation's MCT-510 microcompression tester. Specifically, the measurement is performed using the following method. First, the filler to be used is dispersed in ethanol, and then the filler dispersion is applied to the sample stage (material: flat SKS plate) of the microcompression tester and dried to prepare the measurement sample. Next, an individual filler particle is selected using the MCT-510's optical microscope, and the particle size (diameter) dn (unit: mm) of the selected filler is measured using the MCT-510's particle size measurement cursor. Next, a pressure indenter (a diamond flat indenter with a diameter of 50 μm) is lowered onto the apex of the selected filler at a constant loading rate (9.6841 mN / sec), gradually applying a load to the filler up to a maximum load of 490 mN. The load Pn (unit: N) at which the filler particle diameter (diameter) measured previously is displaced by 30% is used to calculate the compressive strength Fn (unit: MPa) according to JIS R 1639-5:2007 using the following formula (1). Five measurements are performed for each filler, and the average of the three data points excluding the maximum and minimum values ​​is used as the strength at 30% deformation in the microcompression test. The measurements are performed in an environment of 23±5°C and 50±10% RH. In the present invention, the measurements are performed in an environment of 23°C and 50% RH.

[0092] Fn=2.48×Pn / (π dn 2 ) Formula (1)

[0093] The filler has a predetermined strength (hardness) so that the adhesive layer can withstand irradiation of active energy rays. When cured and shrunk, the contact area of ​​the adhesive layer with the adherend is reduced. This further enhances the effect of reducing the adhesive strength of the pressure-sensitive adhesive layer to the adherend.

[0094] In some embodiments, as a filler, for example, for use as a toner component or as an additive to paint. It is widely used in various applications such as optical materials, cosmetics, and molding resins. Crosslinked particles of acrylic polymers can be used. As a method for producing polymers, a method is used in which a polymer is produced in a homogeneous reaction system, and the polymer is then crushed and classified. The monomer is finely dispersed in a reaction solvent such as an aqueous medium in which the monomer does not substantially dissolve, and the aqueous medium is Examples of such a method include a method of producing an acrylic polymer by polymerizing an acrylic monomer that is finely dispersed in a medium in the form of fine oil droplets, and a method of adding fine acrylic polymer particles (seed particles) of the same type when polymerizing an acrylic monomer in this heterogeneous system, impregnating the acrylic polymer fine particles with the acrylic monomer, and reacting the acrylic monomer on the acrylic polymer fine particles so that the acrylic polymer fine particles grow.

[0095] Specifically, for example, methyl methacrylate, methyl acrylate, butyl acrylate, Acrylic monomers such as butyl methacrylate, etc., can be used alone or in combination. The acrylic resin was polymerized into a three-dimensional structure by emulsion polymerization in the presence of a crosslinking agent. It is produced by synthesizing a polymer, dehydrating it, and then jet-pulverizing it. Nylbenzene, ethylene glycol dimethacrylate, trimethylolpropane triacrylate The acrylic resin thus obtained is a polyfunctional vinyl compound such as acrylate. The polymer is a spherical particle with a weight-average molecular weight of about 20,000 to 1,000,000. In order to more significantly reduce the contact area of ​​the adhesive layer with the filter, The aspect ratio of the color is preferably about 0.8 to 1.2.

[0096] The filler is not particularly limited in terms of material, shape, crosslinked or non-crosslinked, etc., and examples of fillers other than the above-mentioned crosslinked acrylic polymer particles include resin particles such as crosslinked methyl (meth)acrylate-styrene copolymer particles, crosslinked polystyrene particles, crosslinked butyl (meth)acrylate-styrene copolymer particles, silicone resin particles, crosslinked urethane particles, and inorganic particles such as alumina and silica. Although it is usually preferable to use only one of these, two or more of them may be used in combination as long as the effects of the present invention are not impaired.

[0097] [Adhesive tape] The pressure-sensitive adhesive tape of the present embodiment is stored in a high-temperature environment of 200°C for 1 hour, then removed and left in a 23°C, 50% RH environment for 2 hours or more, and thereafter, the pressure-sensitive adhesive tape has at least one of an MD elongation and a TD elongation measured according to the method specified in JIS Z 0237 (2009) (with a tensile speed of 100 mm / min) of 30% or more. The elongation is preferably 40% or more, and more preferably 50% or more. The upper limit of the elongation is not particularly limited, but from the viewpoint of workability, it is preferably, for example, about 200%. Here, an elongation of 30% means that the tape has been stretched to a length 1.30 times its original length. The MD direction refers to the direction of flow of the sheet-like substrate (substrate film) during film formation, and the direction perpendicular to the MD direction is called the TD direction. Since pressure-sensitive adhesive tapes are usually manufactured as rolls, the MD direction of the pressure-sensitive adhesive tape is the same as the MD direction of the sheet-like substrate (substrate film), and the TD direction of the pressure-sensitive adhesive tape is the same as the TD direction of the sheet-like substrate (substrate film). Although the stretching directions in the present invention are defined as the TD and MD directions for convenience, the stretching direction may be in any direction as long as the adhesive tape can maintain an elongation of 30% or more. That is, the stretching may be in any direction over 360°, for example, a direction shifted by 45° from the MD direction. Furthermore, radial stretching is also possible as long as it does not impede the effects of the present invention. The same concept applies to the arithmetic surface height (Sa) of the adhesive layer surface, which will be described later.

[0098] In the adhesive tape that has been placed under the above-mentioned high-temperature conditions, if at least one of the elongation percentages in the MD direction or the TD direction is 30% or more, when the adhesive tape is stretched by 30% or more in a direction in which it can be stretched by 30% or more, the thickness of the adhesive layer becomes sufficiently thin in response to the stretching, so that the filler is likely to be exposed to or protrude from the surface of the adhesive layer, and the contact area of ​​the adhesive layer with the adherend can be effectively reduced by stretching the adhesive tape by 30% or more in a direction in which it can be stretched by 30% or more even after high-temperature processing of the adherend.

[0099] It is preferable that the adhesive tape of this embodiment has an elongation percentage in both the MD direction and the TD direction of 30% or more when the adhesive tape is placed under the high-temperature conditions.

[0100] Furthermore, the pressure-sensitive adhesive tape is stored in a high-temperature environment of 200°C for 1 hour, then removed and left in a 23°C, 50% RH environment for 2 hours or more, and then the arithmetic surface height (Sa) of the pressure-sensitive adhesive layer surface measured in accordance with ISO 25178 in at least one of a state in which the tape is stretched 30% in the MD direction or a state in which the tape is stretched 30% in the TD direction. 30 The arithmetic surface height (Sa) is preferably 0.20 μm or more, more preferably 0.30 μm or more, and even more preferably 0.40 μm or more. 30 Although the upper limit of is not particularly limited, from the viewpoint of ensuring initial adhesive strength, it is preferably, for example, about 1.33 μm. Here, "30% stretched" means a state in which the adhesive is stretched to a length 1.30 times its original length. The arithmetic surface height (Sa) is a value determined in accordance with ISO 25178 using a laser microscope to measure the three-dimensional shape of an arbitrary 200 μm × 200 μm area on the adhesive surface, and represents the average absolute value of the height difference between the average surface of the adhesive surface and each uneven point, and is a parameter for evaluating surface roughness.

[0101] After being placed under the high temperature condition, the pressure-sensitive adhesive tape is stretched by 30% in the MD direction or 30% in the TD direction, and the arithmetic surface height (Sa) 30 When the thickness is 0.20 μm or more, when the adhesive tape is stretched 30% in a direction in which it can be stretched 30%, the filler is exposed to the surface of the adhesive layer or protrudes from the surface of the adhesive layer, thereby effectively reducing the contact area of ​​the adhesive layer with the adherend.

[0102] Furthermore, the pressure-sensitive adhesive tape is stored in a high-temperature environment of 200°C for 1 hour, then taken out and left in a 23°C, 50% RH environment for 2 hours or more, and then the arithmetic surface height (Sa) of the pressure-sensitive adhesive layer surface measured in accordance with ISO 25178 in at least one of a state where the tape is stretched 50% in the MD direction or a state where the tape is stretched 50% in the TD direction is 50 The arithmetic surface height (Sa) is preferably 0.20 μm or more, more preferably 0.30 μm or more, and even more preferably 0.40 μm or more. 50 Although there is no particular upper limit to the thickness, from the viewpoint of ensuring the initial adhesive strength, it is preferably, for example, about 2.00 μm.

[0103] After being placed under the high temperature condition, the pressure-sensitive adhesive tape is stretched by 50% in the MD direction or by 50% in the TD direction, and the arithmetic surface height (Sa) 50 When the thickness is 0.20 μm or more, when the adhesive tape is stretched 50% in a direction in which it can be stretched 50%, the filler is exposed to the surface of the adhesive layer or protrudes from the surface of the adhesive layer, thereby effectively reducing the contact area of ​​the adhesive layer with the adherend.

[0104] Furthermore, the pressure-sensitive adhesive tape preferably has a small difference between the upper and lower yield points in a stress-strain curve measured by the method specified in JIS Z 0237 (2009) (provided that the tensile speed is 100 mm / min), and more preferably has no yield point. Here, "a small difference between the upper and lower yield points" means "the tensile stress at the lower yield point is 0.9 to 1.0 times the tensile stress at the upper yield point." When the pressure-sensitive adhesive tape is stretched, if the difference between the upper and lower yield points is large and there is a clear yield point, for example, an external force applied when stretching the pressure-sensitive adhesive tape in the MD direction is not transmitted to the entire pressure-sensitive adhesive tape, but is likely to be concentrated and transmitted to areas of the pressure-sensitive adhesive tape where no adherend is bonded, or to the edges of the adhesive tape's end-holding portions when the pressure-sensitive adhesive tape is stretched. In this case, necking occurs, and the external force applied during stretching is not sufficiently transmitted to the adhesive tape portion corresponding to the area where the adherend is adhered, particularly at both end edge portions in the stretching direction of the adhesive region, making it difficult for the sheet-like substrate to stretch in the stretching direction, and therefore the adhesive layer and thickness are unlikely to become thin in the above-mentioned portion. As a result, the filler is unlikely to be exposed to or protrude from the adhesive layer surface in the above-mentioned portion, making it difficult to reduce the contact area of ​​the adhesive layer with the adherend, and there is a risk that the promotion of peeling of the adherend is hindered.

[0105] [Electronic component processing method] The pressure-sensitive adhesive tape of the present invention can be used, for example, as a pressure-sensitive adhesive tape for temporarily fixing electronic components when subjecting electronic components to high-temperature processing. A method for processing electronic components of the present invention includes the steps of temporarily fixing electronic components to the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape, processing the electronic components by applying a high temperature of 160°C or more and 200°C or less, irradiating the pressure-sensitive adhesive tape with active energy rays from the sheet-like substrate film side, stretching the pressure-sensitive adhesive tape, and peeling / detaching the electronic components from the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape.

[0106] In the step of temporarily fixing electronic components to the adhesive tape, the method for temporary fixing is not particularly limited, but examples include a method in which multiple electronic components are arranged at regular intervals on the adhesive layer of the adhesive tape and temporarily fixed by pressing, and a method in which electronic components temporarily fixed at regular intervals on a separately prepared low-adhesive tape are transferred onto the adhesive layer of the adhesive tape of the present invention and temporarily fixed thereon.

[0107] In the step of subjecting a plurality of electronic components temporarily fixed on the adhesive layer of the adhesive tape to a processing treatment in which a high temperature of 160°C or more and 200°C or less is applied, the processing treatment is not particularly limited, but examples thereof include a curing treatment of the sealing resin in bulk sealing, a metal-based dry coating treatment on the electronic components, a high-temperature drying and curing treatment after a resin-based wet coating on the electronic components, and a solder mounting treatment.

[0108] In the step of irradiating the sheet-like substrate film side of the pressure-sensitive adhesive tape with active energy rays, the active energy rays are not particularly limited, but examples thereof include ultraviolet rays, visible light, infrared rays, electron beams, β rays, and γ rays. Among these active energy rays, ultraviolet rays (UV) and electron beams (EB) are preferred, and ultraviolet rays (UV) are particularly preferred. The light source for irradiating the ultraviolet rays (UV) is not particularly limited, but examples thereof include black lights, ultraviolet fluorescent lamps, low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, carbon arc lamps, metal halide lamps, and xenon lamps. ArF excimer lasers, KrF excimer lasers, excimer lamps, and synchrotron radiation can also be used. The irradiation dose of the ultraviolet rays (UV) can be appropriately set depending on the ultraviolet transmittance of the sheet-like substrate, and can be, for example, 100 mJ / cm. 2 More than 2,000J / cm 2 The range below is preferable, and 300 mJ / cm 2 More than 1,000J / cm 2 The following range is more preferable:

[0109] In the step of stretching the adhesive tape, the stretching method is not particularly limited, and the adhesive tape may be stretched manually or automatically using a mechanical device. When stretching manually, for example, the adhesive tape may be stretched in one direction by holding both ends by hand, or may be stretched in one direction using a manual uniaxial stretching machine. When stretching automatically using a mechanical device, for example, a device that can chuck and fix both ends of the adhesive tape and stretch it in one direction, such as a tensile tester, may be used, or an expanding device that can stretch it radially, such as that used in manufacturing semiconductor chips, may be used.

[0110] In the step of peeling and detaching the electronic component from the adhesive layer of the adhesive tape, the peeling and detaching method is not particularly limited, and may be manual or automatic using a mechanical device. When peeling and detaching manually, for example, a suction pad or tweezers may be used, or the component may be squeezed from the sheet-like substrate side with a squeegee or the like. When peeling and detaching automatically using a mechanical device, for example, a method of peeling and detaching by vacuum suction using a rubber suction collet or the like may be used. [Example]

[0111] The present invention will be explained in more detail with reference to the following examples, but the present invention is not limited to these examples. It's not that.

[0112] 1. Preparation of Adhesive Tape Example 1 <Sheet-shaped substrate> A 100 μm-thick sheet substrate A was prepared by film formation using a thermoplastic polyether polyester elastomer (TPEE) resin (trade name: Hytrel 4767N, Vicat softening point: 159°C) manufactured by DuPont-Toray Co., Ltd. The surface of sheet substrate A on which the adhesive layer was to be formed was subjected to corona treatment to enhance adhesion. After being hung and stored in a high-temperature environment at 200°C for 1 hour, the sheet substrate A was removed and left in a 23°C, 50% RH environment for at least 2 hours. The parallel light transmittance at a wavelength of 365 nm of the sheet substrate A measured after this was 18.8%. Incidentally, the parallel light transmittance at a wavelength of 365 nm of the sheet substrate A in its normal state was 24.6%.

[0113] <Release film> A release film having a thickness of 50 μm (product name: HY-S06, material: PET) manufactured by Higashiyama Film Co., Ltd. was prepared as the release film.

[0114] <Preparation of acrylic adhesive polymer A> Copolymerization monomer components include 2-ethylhexyl acrylate (2-EHA), acrylic 2-Hydroxyethyl methacrylate (2-HEA) was prepared. These copolymerizable monomer components were mixed at a copolymerization ratio of 75 parts by mass of 2-EHA / 2-HEA / 25 parts by mass, and the base polymer was synthesized by solution radical polymerization using ethyl acetate as the solvent. Next, 15 parts by mass of 2-isocyanatoethyl methacrylate (MOI), an active energy ray-reactive compound, containing an isocyanate group and an active energy ray-reactive carbon-carbon double bond, was blended with 100 parts by mass of the solid content of this base polymer. This was reacted with some of the hydroxyl groups in the 2-HEA to synthesize acrylic adhesive polymer A (solid content: 30% by mass) containing a carbon-carbon double bond in the side chain. During this reaction, 0.05 parts by mass of hydroquinone monomethyl ether was used as a polymerization inhibitor. The weight-average molecular weight of the synthesized acrylic adhesive polymer A was measured by gel permeation chromatography (GPC, solvent: tetrahydrofuran) to be 800,000. The carbon-carbon double bond content was 0.84 mmol / g.

[0115] <Preparation of adhesive solution (adhesive composition)> 333.3 parts by mass (solid content equivalent: 10 10.0 parts by mass of cross-linked acrylic filler A manufactured by Negami Chemical Industrial Co., Ltd. (trade name: Art Pearl J-7PY, average particle size: 6 μm, degree of cross-linking: high, strength at 30% deformation in microcompression test: 69 MPa) was blended with 10.0 parts by mass of the adhesive. After uniformly stirring, 1.0 part by mass of dialkyl peroxide A manufactured by NOF Corporation (trade name: Perbutyl D, solids concentration: 100% by mass, 10-hour half-life temperature: 123.7°C) was blended as a thermal polymerization initiator, 1.5 parts by mass of α-aminoalkylphenone photopolymerization initiator A manufactured by IGM Resins BV (trade name: Omnirad369) was blended as a photopolymerization initiator, and 2.0 parts by mass (1.5 parts by mass of isocyanate cross-linking agent A manufactured by Tosoh Corporation (trade name: Coronate L, solids concentration: 75% by mass) was blended as a cross-linking agent. The mixture was diluted with ethyl acetate and stirred to prepare an adhesive solution with a solids concentration of 30% by mass.

[0116] <Preparation of adhesive tape> Next, the adhesive solution prepared above was applied to the release-treated surface of the release film so that the dry thickness of the adhesive layer was 10 μm, and then dried. The corona-treated surface of the sheet-like substrate A, which had been formed using the thermoplastic polyether polyester elastomer resin (TPEE), was attached to the adhesive layer, and the resulting sheet was wound up to prepare an adhesive tape. After forming an adhesive layer on the sheet-like substrate A in this manner, the adhesive layer was aged for 120 hours in an environment of 40°C to crosslink the acrylic adhesive polymer with the crosslinking agent, thereby thermally curing the polymer, thereby producing an adhesive tape for evaluation.

[0117] Example 2 An adhesive tape was prepared in the same manner as in Example 1, except that in preparing the adhesive solution (adhesive composition), 42.7 parts by mass of urethane acrylate oligomer A manufactured by Negami Chemical Industrial Co., Ltd. (product name: Art Resin UN-3320HA, weight average molecular weight: 1,500, number of functional groups: 6, double bond equivalent: 250) was further added.

[0118] Example 3 An adhesive tape was produced in the same manner as in Example 1, except that the acrylic adhesive polymer and adhesive solution (adhesive composition) were prepared as follows.

[0119] <Preparation of acrylic adhesive polymer B> Copolymerization monomer components include 2-ethylhexyl acrylate (2-EHA), acrylic 2-Hydroxyethyl methacrylate (2-HEA) was prepared. These copolymerizable monomer components were mixed at a copolymerization ratio of 75 parts by mass of 2-EHA / 2-HEA / 25 parts by mass, and the base polymer was synthesized by solution radical polymerization using ethyl acetate as the solvent. Next, 16 parts by mass of 2-isocyanatoethyl methacrylate (MOI), an active energy ray-reactive compound, was added to 100 parts by mass of the base polymer solids. This compound reacted with some of the hydroxyl groups in the 2-HEA to synthesize acrylic adhesive polymer B (solids concentration: 30% by mass) containing carbon-carbon double bonds in the side chain. During this reaction, 0.05 parts by mass of hydroquinone monomethyl ether was used as a polymerization inhibitor. The weight-average molecular weight of the synthesized acrylic adhesive polymer B was measured by gel permeation chromatography (GPC, solvent: tetrahydrofuran) to find a value of 850,000. The carbon-carbon double bond content was 0.89 mmol / g.

[0120] <Preparation of adhesive solution (adhesive composition)> 333.3 parts by mass (solid content equivalent: 10 0 parts by mass) and 0.1 parts by mass of cross-linked acrylic filler A manufactured by Negami Chemical Industrial Co., Ltd. (trade name: Art Pearl J-7PY, average particle size: 6 μm, degree of cross-linking: high, strength at 30% deformation in microcompression test: 69 MPa). After uniform stirring, 1.0 parts by mass of dialkyl peroxide A manufactured by NOF Corporation (trade name: Perbutyl D, solids concentration: 100% by mass, 10-hour half-life temperature: 123.7°C) as a thermal polymerization initiator, 1.5 parts by mass of α-aminoalkylphenone photopolymerization initiator A manufactured by IGM Resins BV (trade name: Omnirad369) as a photopolymerization initiator, and 2.0 parts by mass (1.5 parts by mass of isocyanate cross-linking agent A manufactured by Tosoh Corporation (trade name: Coronate L, solids concentration: 75% by mass) as a cross-linking agent were mixed in the ratio, and the mixture was diluted with ethyl acetate and stirred to prepare a pressure-sensitive adhesive solution with a solids concentration of 30% by mass.

[0121] Example 4 An adhesive tape was produced in the same manner as in Example 3, except that in preparing the adhesive solution (adhesive composition), the amount of dialkyl peroxide-based peroxide A manufactured by NOF Corporation (trade name: Perbutyl D, solid content concentration: 100% by mass, 10-hour half-life temperature: 123.7°C) was changed to 30.0 parts by mass, and the amount of isocyanate-based crosslinking agent A manufactured by Tosoh Corporation (trade name: Coronate L, solid content concentration: 75% by mass) was changed to 1.33 parts by mass (1.0 part by mass in terms of solid content).

[0122] Example 5 An adhesive tape was prepared in the same manner as in Example 3, except that 42.7 parts by mass of urethane acrylate oligomer A (trade name: Art Resin UN-3320HA, weight average molecular weight: 1,500, number of functional groups: 6, double bond equivalent: 250) manufactured by Negami Chemical Industrial Co., Ltd. was further added to the adhesive solution (adhesive composition).

[0123] Example 6 An adhesive tape was prepared in the same manner as in Example 3, except that in preparing the adhesive solution (adhesive composition), 100.0 parts by mass of urethane acrylate oligomer A manufactured by Negami Chemical Industrial Co., Ltd. (product name: Art Resin UN-3320HA, weight average molecular weight: 1,500, number of functional groups: 6, double bond equivalent: 250) was further added.

[0124] Example 7 An adhesive tape was produced in the same manner as in Example 1, except that the acrylic adhesive polymer and adhesive solution (adhesive composition) were prepared as follows.

[0125] <Preparation of acrylic adhesive polymer C> Copolymerization monomer components include 2-ethylhexyl acrylate (2-EHA), acrylic 2-Hydroxyethyl methacrylate (2-HEA) was prepared. These copolymerizable monomer components were mixed at a copolymerization ratio of 75 parts by mass of 2-EHA / 2-HEA / 25 parts by mass, and the base polymer was synthesized by solution radical polymerization using ethyl acetate as the solvent. Next, 17 parts by mass of 2-isocyanatoethyl methacrylate (MOI), which has an isocyanate group and an active energy ray-reactive carbon-carbon double bond, was added to 100 parts by mass of the solid content of this base polymer. This was reacted with some of the hydroxyl groups in the 2-HEA to synthesize acrylic adhesive polymer C (solids concentration: 30% by mass), which has a carbon-carbon double bond in the side chain. During this reaction, 0.05 parts by mass of hydroquinone monomethyl ether was used as a polymerization inhibitor. The weight-average molecular weight of the synthesized acrylic adhesive polymer C was measured by gel permeation chromatography (GPC, solvent: tetrahydrofuran) to be 800,000. The carbon-carbon double bond content was 0.94 mmol / g.

[0126] <Preparation of adhesive solution (adhesive composition)> 333.3 parts by mass (solid content equivalent: 10 0 parts by mass) and 50.0 parts by mass of cross-linked acrylic filler A manufactured by Negami Chemical Industrial Co., Ltd. (trade name: Art Pearl J-7PY, average particle size: 6 μm, degree of cross-linking: high, strength at 30% deformation in microcompression test: 69 MPa). After uniform stirring, 1.0 part by mass of dialkyl peroxide A manufactured by NOF Corporation (trade name: Perbutyl D, solids concentration: 100% by mass, 10-hour half-life temperature: 123.7°C) as a thermal polymerization initiator, 1.5 parts by mass of α-aminoalkylphenone photopolymerization initiator A manufactured by IGM Resins BV (trade name: Omnirad369) as a photopolymerization initiator, and 1.33 parts by mass (1.0 part by mass of isocyanate cross-linking agent A manufactured by Tosoh Corporation (trade name: Coronate L, solids concentration: 75% by mass) as a cross-linking agent were mixed in the following ratios. The mixture was diluted with ethyl acetate and stirred to prepare a pressure-sensitive adhesive solution with a solids concentration of 30% by mass.

[0127] Example 8 An adhesive tape was produced in the same manner as in Example 1, except that in preparing the adhesive solution (adhesive composition), cross-linked acrylic filler A manufactured by Negami Chemical Industrial Co., Ltd. (trade name: Art Pearl J-7PY, average particle size: 6 μm, degree of cross-linking: high, strength at 30% deformation in a micro-compression test: 69 MPa) was replaced with cross-linked urethane filler A manufactured by Negami Chemical Industrial Co., Ltd. (trade name: JB-800T, average particle size: 6 μm, strength at 30% deformation in a micro-compression test: 8.5 MPa) and the blending amount was changed to 0.1 parts by mass.

[0128] Example 9 An adhesive tape was produced in the same manner as in Example 1, except that the acrylic adhesive polymer and adhesive solution (adhesive composition) were prepared as follows.

[0129] <Preparation of acrylic adhesive polymer D> Copolymerization monomer components include 2-ethylhexyl acrylate (2-EHA), acrylic 2-Hydroxyethyl methacrylate (2-HEA) was prepared. These copolymerizable monomer components were mixed at a copolymerization ratio of 75 parts by mass of 2-EHA / 2-HEA / 25 parts by mass, and the base polymer was synthesized by solution radical polymerization using ethyl acetate as the solvent. Next, 4 parts by mass of 2-isocyanatoethyl methacrylate (MOI), an active energy ray-reactive compound, containing an isocyanate group and an active energy ray-reactive carbon-carbon double bond, was added to 100 parts by mass of the solid content of this base polymer. This was reacted with some of the hydroxyl groups in the 2-HEA to synthesize acrylic adhesive polymer D (solid concentration: 30% by mass) containing a carbon-carbon double bond in the side chain. During this reaction, 0.05 parts by mass of hydroquinone monomethyl ether was used as a polymerization inhibitor. The weight-average molecular weight of the synthesized acrylic adhesive polymer D was measured by gel permeation chromatography (GPC, solvent: tetrahydrofuran) to find a value of 820,000. The carbon-carbon double bond content was 0.25 mmol / g.

[0130] <Preparation of adhesive solution (adhesive composition)> 333.3 parts by mass (solid content equivalent: 10 0 parts by mass), 85.4 parts by mass of urethane acrylate oligomer A manufactured by Negami Chemical Industrial Co., Ltd. (trade name: Art Resin UN-3320HA, weight average molecular weight: 1,500, number of functional groups: 6, double bond equivalent: 250) and 10.0 parts by mass of cross-linked acrylic filler A manufactured by Negami Chemical Industrial Co., Ltd. (trade name: Art Pearl J-7PY, average particle size: 6 μm, degree of cross-linking: high, strength at 30% deformation in microcompression test: 69 MPa) were mixed and stirred uniformly, and then 1.0 part by mass of dialkyl peroxide peroxide A manufactured by NOF Corporation (trade name: Perbutyl D, solid content concentration: 100% by mass, 10-hour half-life temperature: 123.7°C) was added as a thermal polymerization initiator and IGM Resins A mixture of 1.5 parts by mass of an α-aminoalkylphenone photopolymerization initiator A (trade name: Omnirad369) manufactured by BV and 2.0 parts by mass (1.5 parts by mass equivalent to solids) of an isocyanate crosslinking agent A (trade name: Coronate L, solids concentration: 75% by mass) manufactured by Tosoh Corporation as a crosslinking agent was diluted with ethyl acetate and stirred to prepare a pressure-sensitive adhesive solution with a solids concentration of 30% by mass.

[0131] Example 10 An adhesive tape was produced in the same manner as in Example 1, except that the acrylic adhesive polymer was prepared as follows.

[0132] <Preparation of acrylic adhesive polymer E> Copolymerization monomer components include 2-ethylhexyl acrylate (2-EHA), acrylic 2-Hydroxyethyl methacrylate (2-HEA) was prepared. These copolymerizable monomer components were mixed at a copolymerization ratio of 70 parts by mass of 2-EHA / 30 parts by mass of 2-HEA, and the base polymer was synthesized by solution radical polymerization using ethyl acetate as the solvent. Next, 35 parts by mass of 2-isocyanatoethyl methacrylate (MOI), which has an isocyanate group and an active energy ray-reactive carbon-carbon double bond, was added to 100 parts by mass of the solid content of this base polymer. This was reacted with some of the hydroxyl groups in the 2-HEA to synthesize acrylic adhesive polymer D (solid concentration: 30% by mass) with a carbon-carbon double bond in the side chain. During this reaction, 0.05 parts by mass of hydroquinone monomethyl ether was used as a polymerization inhibitor. The weight-average molecular weight of the synthesized acrylic adhesive polymer D was measured by gel permeation chromatography (GPC, solvent: tetrahydrofuran) to be 750,000. The carbon-carbon double bond content was 1.67 mmol / g.

[0133] Example 11 An adhesive tape was produced in the same manner as in Example 7, except that an adhesive solution (adhesive composition) was prepared as described below and the thickness of the adhesive layer was changed to 11 μm.

[0134] <Preparation of adhesive solution (adhesive composition)> 333.3 parts by mass (100 parts by mass in terms of solid content) of the solution of acrylic adhesive polymer C prepared above was mixed with 85.4 parts by mass of urethane acrylate oligomer A manufactured by Negami Chemical Industrial Co., Ltd. (trade name: Art Resin UN-3320HA, weight average molecular weight: 1,500, number of functional groups: 6, double bond equivalent: 250) and 10.0 parts by mass of cross-linked acrylic filler B manufactured by Soken Chemical & Engineering Co., Ltd. (trade name: Chemisnow MX-1000, average particle size: 10 μm, degree of cross-linking: standard, strength at 30% deformation in microcompression test: 56 MPa), and the mixture was stirred uniformly. Then, 1.0 part by mass of dialkyl peroxide peroxide A manufactured by NOF Corporation (trade name: Perbutyl D, solid content concentration: 100% by mass, 10-hour half-life temperature: 123.7°C) was added as a thermal polymerization initiator, and IGM Resins A mixture of 1.5 parts by mass of an α-aminoalkylphenone photopolymerization initiator A (trade name: Omnirad369) manufactured by BV and 2.0 parts by mass (1.5 parts by mass equivalent to solids) of an isocyanate crosslinking agent A (trade name: Coronate L, solids concentration: 75% by mass) manufactured by Tosoh Corporation as a crosslinking agent was diluted with ethyl acetate and stirred to prepare a pressure-sensitive adhesive solution with a solids concentration of 30% by mass.

[0135] Example 12 An adhesive tape was produced in the same manner as in Example 11, except that in preparing the adhesive solution (adhesive composition), cross-linked acrylic filler D (trade name: Artpearl J-4P, average particle size: 2.2 μm, degree of cross-linking: low, strength at 30% deformation in a microcompression test: 70 MPa) manufactured by Negami Chemical Industrial Co., Ltd. was used instead of cross-linked acrylic filler B (trade name: Chemisnow MX-1000, average particle size: 10 μm, degree of cross-linking: standard, strength at 30% deformation in a microcompression test: 56 MPa) manufactured by Soken Chemical & Engineering Co., Ltd., the blending amount was changed to 15.0 parts by mass, and the thickness of the adhesive layer was changed to 22 μm.

[0136] Example 13 An adhesive tape was produced in the same manner as in Example 2, except that in preparing the adhesive solution (adhesive composition), cross-linked acrylic filler A manufactured by Negami Chemical Industrial Co., Ltd. (trade name: Artpearl J-7PY, average particle size: 6 μm, degree of cross-linking: high, strength at 30% deformation in a microcompression test: 69 MPa) was replaced with cross-linked acrylic filler B manufactured by Soken Chemical & Engineering Co., Ltd. (trade name: Chemisnow MX-1000, average particle size: 10 μm, degree of cross-linking: standard, strength at 30% deformation in a microcompression test: 56 MPa), and the thickness of the adhesive layer was changed to 20 μm.

[0137] (Comparative Example 1) An adhesive tape was prepared in the same manner as in Example 1, except that in preparing the adhesive solution (adhesive composition), cross-linked acrylic filler A manufactured by Negami Chemical Industrial Co., Ltd. (trade name: Artpearl J-7PY, average particle size: 6 μm, degree of cross-linking: high, strength at 30% deformation in microcompression test: 69 MPa) and dialkyl peroxide peroxide A manufactured by NOF Corporation (trade name: Perbutyl D, solids concentration: 100% by mass, 10-hour half-life temperature: 123.7°C) were not added.

[0138] (Comparative Example 2) An adhesive tape was prepared in the same manner as in Example 2, except that in preparing the adhesive solution (adhesive composition), cross-linked acrylic filler A manufactured by Negami Chemical Industrial Co., Ltd. (trade name: Artpearl J-7PY, average particle size: 6 μm, degree of cross-linking: high, strength at 30% deformation in microcompression test: 69 MPa) and dialkyl peroxide peroxide A manufactured by NOF Corporation (trade name: Perbutyl D, solids concentration: 100% by mass, 10-hour half-life temperature: 123.7°C) were not added.

[0139] (Comparative Example 3) An adhesive tape was prepared in the same manner as in Example 1, except that cross-linked acrylic filler A (product name: Art Pearl J-7PY, average particle size: 6 μm, degree of cross-linking: high, strength at 30% deformation in microcompression test: 69 MPa) manufactured by Negami Chemical Industrial Co., Ltd. was not added when preparing the adhesive solution (adhesive composition).

[0140] Comparative Example 4 An adhesive tape was prepared in the same manner as in Example 2, except that cross-linked acrylic filler A (product name: Art Pearl J-7PY, average particle size: 6 μm, degree of cross-linking: high, strength at 30% deformation in microcompression test: 69 MPa) manufactured by Negami Chemical Industrial Co., Ltd. was not added when preparing the adhesive solution (adhesive composition).

[0141] (Comparative Example 5) An adhesive tape was produced in the same manner as in Example 2, except that the acrylic adhesive polymer was prepared as follows.

[0142] <Preparation of acrylic adhesive polymer F> 2-Ethylhexyl acrylate (2-EHA) and 2-hydroxyethyl acrylate (2-HEA) were prepared as copolymerization monomer components. These copolymerization monomer components were mixed at a copolymerization ratio of 2-EHA / 2-HEA = 75 parts by mass / 25 parts by mass, and acrylic adhesive polymer F (solids concentration: 30% by mass) was synthesized by solution radical polymerization using ethyl acetate as the solvent. In the above reaction, 0.05 parts by mass of hydroquinone monomethyl ether was used as a polymerization inhibitor. The weight-average molecular weight of the synthesized acrylic adhesive polymer F, which does not have an active energy ray-reactive carbon-carbon double bond, was measured by gel permeation chromatography (GPC, solvent: tetrahydrofuran) and was found to be 800,000.

[0143] (Comparative Example 6) An adhesive tape was produced in the same manner as in Example 2, except that a sheet-like substrate B having a laminated structure formed using the following polyolefin (PO)-based resin was used instead of the sheet-like substrate A formed using a thermoplastic polyether polyester elastomer (TPEE) resin.

[0144] <Sheet-shaped substrate> Random copolymer polypropylene (PP·PE) resin (Vicat softening point: 119°C) was used for the first and third layers, and low-density polyethylene (LDPE) resin (Vicat softening point: 102°C) was used for the second layer. A 90 μm-thick PO-based sheet substrate B was produced using a two-type, three-layer T-die coextrusion molding machine. The thicknesses of the layers were 10 μm (PP·PE), 70 μm (LDPE), and 10 μm (PP·PE). The surface of sheet substrate B on which the adhesive layer was to be formed was corona-treated to enhance adhesion. Sheet substrate B melted after being suspended in a high-temperature environment at 200°C for 1 hour, making it impossible to measure the parallel light transmittance at a wavelength of 365 nm. The parallel light transmittance of sheet substrate B at a wavelength of 365 nm in its normal state was 29.0%.

[0145] (Comparative Example 7) <Sheet-shaped substrate> Random copolymer polypropylene (PP·PE) resin (Vicat softening point: 119°C) was used for the first and third layers, and ethylene-vinyl acetate copolymer (EVA) resin (vinyl acetate content: 5% by mass, Vicat softening point: 84°C) was used for the second layer. An 80 μm-thick EVA-based sheet substrate C was produced using a two-type, three-layer T-die coextrusion molding machine. The thicknesses of the layers were 8 μm (1st layer: PP·PE), 64 μm (2nd layer: EVA), and 8 μm (3rd layer: PP·PE). The surface of sheet substrate C on the adhesive layer side was corona-treated to enhance adhesion. Sheet substrate C melted after being suspended in a high-temperature environment at 200°C for 1 hour, making it impossible to measure the parallel light transmittance at a wavelength of 365 nm. The parallel light transmittance of sheet substrate C at a wavelength of 365 nm in its normal state was 13.5%.

[0146] <Preparation of acrylic adhesive polymer G> The acrylic adhesive polymer used was the commercially available acrylic adhesive polymer G (trade name: Polysic 410-SA, a terpolymer of n-butyl acrylate (n-BA), 2-ethylhexyl acrylate (2-EHA), and acrylic acid (AA), solids concentration: 37% by mass, no carbon-carbon double bonds) manufactured by Sanyo Chemical Industries, Ltd. The weight-average molecular weight of the acrylic adhesive polymer G was measured by gel permeation chromatography (GPC, solvent: tetrahydrofuran) and found to be 900,000.

[0147] <Preparation of adhesive solution (adhesive composition)> 270.3 parts by mass (solid content equivalent: 10 10.0 parts by mass of crosslinked acrylic filler B manufactured by Soken Chemical & Engineering Co., Ltd. (trade name: Chemishnow MX-1000, average particle size: 10 μm, degree of crosslinking: standard, strength at 30% deformation in microcompression test: 56 MPa) was blended with 10.0 parts by mass of the adhesive (0.0 ...

[0148] <Preparation of adhesive tape> Next, the adhesive solution prepared above was applied to the release-treated surface of the release film described above so that the dry thickness of the adhesive layer was 20 μm, and then dried.The corona-treated surface of EVA-based sheet-like substrate C, which had a two-resin, three-layer structure formed using random copolymer polypropylene resin as the resin for the first and third layers and ethylene-vinyl acetate copolymer as the resin for the second layer, was bonded to the adhesive layer, and the substrate was taken up to prepare an adhesive tape. After forming an adhesive layer on the sheet-like substrate C in this manner, the adhesive layer was aged for 120 hours in an environment of 40°C to crosslink the acrylic adhesive polymer with the crosslinking agent, thereby thermally curing the polymer, thereby producing an adhesive tape for evaluation.

[0149] (Comparative Example 8) An adhesive tape was produced in the same manner as in the comparative example, except that the EVA-based sheet-like substrate C was replaced with the sheet-like substrate A formed using the thermoplastic polyether polyester elastomer (TPEE) resin.

[0150] (Comparative Example 8) <Sheet-shaped substrate> As the sheet-like substrate D, a polyethylene terephthalate (PET) film (product name: BP21, thickness 100 μm, Vicat softening point: 74°C) manufactured by Nanya Plastics Co., Ltd. was prepared, and the surface of the sheet-like substrate D on which the pressure-sensitive adhesive layer was to be formed was subjected to a corona treatment to enhance adhesion. After being hung and stored in a high-temperature environment at 200°C for 1 hour, the sheet-like substrate D was removed and left in a 23°C, 50% RH environment for 2 hours or more. The parallel light transmittance at a wavelength of 365 nm of the sheet-like substrate D measured after this was 47.7%. Incidentally, the parallel light transmittance at a wavelength of 365 nm of the sheet-like substrate C in its normal state was 74.2%.

[0151] <Preparation of acrylic adhesive polymer H> Copolymerization monomer components include 2-ethylhexyl acrylate (2-EHA), acrylic n-Butyl acrylate (n-BA) and 2-hydroxyethyl acrylate (2-HEA) were prepared. These copolymerization monomer components were mixed in a copolymerization ratio of 2-EHA / n-BA / 2-HEA = 20 parts by mass / 75 parts by mass / 5 parts by mass, and acrylic adhesive polymer H (solids concentration: 35% by mass) was synthesized by solution radical polymerization using ethyl acetate as the solvent. In the above reaction, 0.05 parts by mass of hydroquinone monomethyl ether was used as a polymerization inhibitor. The weight-average molecular weight of the synthesized acrylic adhesive polymer H was measured by gel permeation chromatography (GPC, solvent: tetrahydrofuran) to be 800,000.

[0152] <Preparation of adhesive solution (adhesive composition)> 303.0 parts by mass (solid content equivalent: 10 0 parts by mass), multifunctional acrylate A (ethoxylated isocyanate) manufactured by Shin-Nakamura Chemical Co., Ltd. Nuric acid triacrylate, trade name: A-9300, molecular weight: 423, number of functional groups: 3, double A mixture of 100 parts by weight of a crosslinked acrylic filler D manufactured by Negami Chemical Industrial Co., Ltd. (trade name: Art Pearl GR-600 transparent, average particle size: 10 μm, degree of crosslinking: medium, strength at 30% deformation in microcompression test: 60 MPa) and 60.0 parts by weight of a crosslinked acrylic filler D manufactured by Negami Chemical Industrial Co., Ltd. (trade name: Art Pearl GR-600 transparent, average particle size: 10 μm, degree of crosslinking: medium, strength at 30% deformation in microcompression test: 60 MPa) was mixed and stirred uniformly. Then, 1.0 part by weight of an α-hydroxyalkylphenone photopolymerization initiator B manufactured by IGM Resins BV (trade name: Omnirad184) was mixed as a photopolymerization initiator, and 4.0 parts by weight (3.0 parts by weight in terms of solids content) of an isocyanate crosslinking agent C manufactured by Tosoh Corporation (trade name: Coronate L, solids concentration: 75% by weight) was mixed as a crosslinking agent. The mixture was diluted with ethyl acetate and stirred to prepare a pressure-sensitive adhesive solution with a solids concentration of 33% by weight.

[0153] <Preparation of adhesive tape> Next, the adhesive solution prepared above was applied to the corona-treated surface of the polyethylene terephthalate (PET) film (sheet-like substrate D) so that the dry thickness of the adhesive layer was 30 μm, and then dried.The release-treated surface of the release film described above was attached to the adhesive layer and wound up to prepare an adhesive tape. After forming an adhesive layer on the sheet-like substrate D in this manner, the adhesive layer was aged for 120 hours in an environment of 40°C to crosslink the acrylic adhesive polymer with the crosslinking agent, thereby thermally curing the polymer, thereby producing an adhesive tape for evaluation.

[0154] (Comparative Example 9) <Sheet-shaped substrate> As the sheet-like substrate D, a polyethylene terephthalate (PET) film (product name: BP21, thickness 100 μm, Vicat softening point: 74°C) manufactured by Nanya Plastics Co., Ltd. was prepared, and the surface of the sheet-like substrate D on which the pressure-sensitive adhesive layer was to be formed was subjected to a corona treatment to enhance adhesion. After being hung and stored in a high-temperature environment at 200°C for 1 hour, the sheet-like substrate D was removed and left in a 23°C, 50% RH environment for 2 hours or more. The parallel light transmittance at a wavelength of 365 nm of the sheet-like substrate D measured after this was 47.7%. Incidentally, the parallel light transmittance at a wavelength of 365 nm of the sheet-like substrate C in its normal state was 74.2%.

[0155] <Preparation of adhesive solution> Toyochem urethane prepolymer A (product name: Cyabain SH-101, Hydroxyl value: 18 mg KOH / g, solid content concentration: 60% by mass, 167 parts by mass (solid content equivalent: 1 00 parts by mass), multifunctional acrylate B (dipentaerythritol) manufactured by Shin-Nakamura Chemical Co., Ltd. Tall polyacrylate [mixture of pentafunctional and hexafunctional acrylates], product name: A- 9550, hydroxyl value: 53 mg KOH / g, double bond equivalent [proton per 1 mol of double bond] The mixture was mixed in a ratio of 75 parts by mass of the copolymer (mass of copolymer: 110 g / mol) and stirred uniformly. After that, peroxydicarbonate peroxide B (trade name: Peroxydicarbonate) manufactured by NOF Corporation was used as a thermal polymerization initiator. (O-methyl-TCP, solids concentration: 100% by mass, 10-hour half-life temperature: 40.8°C) 5 parts by mass of acylphosphine (IGM Resins BV) as a photopolymerization initiator; A pressure-sensitive adhesive solution with a solids concentration of 33% by mass was prepared by blending 2.0 parts by mass of an oxide-based photopolymerization initiator C (trade name: OmniradTPO H), 5.0 parts by mass of an ionic liquid-type antistatic agent A (trade name: FC4400) manufactured by 3M Japan as an antistatic agent, and 49.3 parts by mass (22.2 parts by mass equivalent to solids content) of an isocyanate-based crosslinking agent C (trade name: Coronate L-45E, solids concentration: 45% by mass) manufactured by Tosoh Corporation as a crosslinking agent, and diluting with ethyl acetate and stirring.

[0156] <Preparation of adhesive tape> Next, the adhesive solution prepared above was applied to the corona-treated surface of the polyethylene terephthalate (PET) film (sheet-like substrate D) so that the dry thickness of the adhesive layer was 30 μm, and then dried.The release-treated surface of the release film described above was attached to the adhesive layer and wound up to prepare an adhesive tape. After forming an adhesive layer on the sheet-like substrate D in this manner, the adhesive layer was aged for 120 hours in an environment of 40°C to crosslink the acrylic adhesive polymer with the crosslinking agent, thereby thermally curing the polymer, thereby producing an adhesive tape for evaluation.

[0157] 2. Evaluation method for adhesive tapes The adhesive tapes produced in Examples 1 to 13 and Comparative Examples 1 to 9 and the sheet-like substrates used therein were pretreated (heat treated, stretched, etc.) as necessary, and cut to a predetermined size (length x width) to prepare test specimens.

[0158] 2.1 Measurement of UV transmittance of sheet substrate The sheet-like substrates A to D used in the above-mentioned pressure-sensitive adhesive tapes were stored by hanging in a high-temperature environment at 200°C for 1 hour, then removed and left in a 23°C, 50% RH environment for at least 2 hours, and then their ultraviolet (UV) transmittance was measured using a spectrophotometer "V-670DS" (product name) manufactured by JASCO Corporation. Specifically, the transmittance of parallel light at a wavelength of 365 nm was measured. Note that if significant melt deformation occurred when stored by hanging in a high-temperature environment at 200°C for 1 hour, measurement was deemed unacceptable.

[0159] 2.2 Measuring the elongation of adhesive tape The pressure-sensitive adhesive tapes produced in the above Examples and Comparative Examples were stored by hanging in a high-temperature environment at 200°C for 1 hour with the release film removed, then removed and left in a 23°C, 50% RH environment for at least 2 hours, and then cut into a size of 150 mm in length in the MD and 25 mm in width in the TD, and the elongation in the MD and TD directions was measured using a tensile tester "MinebeaTechnoGraph TG-5kN" (product name) manufactured by MinebeaMitsumi Inc. based on the method specified in JIS Z 0237 (2009). The environment during measurement was a temperature of 23°C and a humidity of 50% RH. If significant melt deformation occurred when the tape was stored by hanging in a high-temperature environment at 200°C for 1 hour, the measurement was deemed unsuitable.

[0160] 2.3 Measurement of the arithmetic surface height (Sa) of the adhesive layer surface of adhesive tape For the adhesive tapes produced in the above examples and comparative examples, the arithmetic surface height (Sa) of the adhesive surface was measured using a laser microscope as one of the indicators for measuring the degree of exposure of the filler to the surface of the adhesive layer or protrusion from the adhesive surface when the adhesive tape was stretched.

[0161] Specifically, the adhesive tape, with the release film removed, was hung and stored in a high-temperature environment at 200°C for 1 hour, then removed and left in an environment of 23°C and 50% RH for at least 2 hours, and then cut into pieces 150 mm long in the MD direction and 25 mm wide in the TD direction to prepare measurement samples in which the adhesive tape was stretched 30% and 50% in the MD direction. The adhesive tape was stretched using the above-mentioned tensile tester at a tension speed of 100 mm / min, and the stretched sample was fixed to a glass plate with double-sided tape to maintain the 30% and 50% stretched states, and then subjected to measurement. In accordance with ISO 25178, a laser microscope "VK-X1050" (product name) manufactured by Keyence Corporation was used to measure the three-dimensional shape of an arbitrary 200 μm x 200 μm area on the adhesive surface near the center of these samples, and the arithmetic surface height (Sa) of the adhesive layer surface when the adhesive tape was stretched 30% was measured. 30and the arithmetic surface height (Sa) of the adhesive layer surface when the adhesive tape is stretched 50%. 50 was determined. The measurement was performed at three different random locations on the surface of the adhesive layer near the center of the adhesive tape in the TD direction, and the average value was taken as the arithmetic surface height (Sa) of the adhesive layer surface of the adhesive tape. In measuring the elongation of the adhesive tape described above, the arithmetic surface height (Sa) was not measured for samples that were significantly melt-deformed when stored hanging in a high-temperature environment at 200°C for 1 hour, or samples whose elongation was less than 30%.

[0162] 2.4 Measurement of initial adhesive strength For each test piece of the pressure-sensitive adhesive tape produced in the above Examples and Comparative Examples, an adhesive strength test (peel adhesive strength test) was conducted on a bright annealed stainless steel plate (SUS304BA plate) in its normal state (before heat treatment) in accordance with the method described in Test Methods for Pressure-sensitive Adhesive Tapes and Pressure-sensitive Adhesive Sheets (JIS Z 0237 (2009)).

[0163] Specifically, the release film was peeled off from each test piece of adhesive tape cut to a length of 250 mm in the MD direction and a width of 25 mm in the TD direction. The adhesive surface was then attached to the above-mentioned stainless steel plate, which had been thoroughly cleaned, taking care not to trap air bubbles. After pressing the tape against a 2000 g roller at a speed of 5 mm / s, the tape was left for 20 minutes at 23°C and 50% RH. The tape was then peeled off at a speed of 300 mm / min in a 90° direction relative to the stainless steel plate using a tensile tester, and the initial adhesive strength to the stainless steel plate was measured. The application and measurement were performed in an environment of 23°C and 50% RH.

[0164] There are no particular restrictions on the initial adhesive strength in a normal state, but it is important that the adhesive strength is such that it is easy to attach to the adherend. From the viewpoint of the strength and holding of the adherend during processing, the strength is preferably 0.5 N / 10 mm or more. Furthermore, taking into account the phenomenon of increased adhesive strength when placed under high temperature conditions, the adhesive strength is 0.5N / It is more preferable to keep it in the range of 10 mm to 3.5 N / 10 mm.

[0165] The initial adhesive strength under normal conditions was evaluated according to the following criteria, with a rating of ◯ being considered a pass.

[0166] 〇: 0.5N / 10mm or more ×: Less than 0.5N / 10mm

[0167] 2.5 Measurement of adhesive strength after heat treatment For each test piece of the adhesive tape produced in the above Examples and Comparative Examples, an adhesive strength test (peel adhesive strength test) after heat treatment on a bright annealed stainless steel plate (SUS304BA plate) was carried out in accordance with the method described in Test Methods for Adhesive Tapes and Adhesive Sheets (JIS Z 0237 (2009)), in the same manner as the measurement of initial adhesive strength.

[0168] Specifically, the release film was peeled off from a piece of adhesive tape cut to a length of 250 mm in the MD direction and a width of 25 mm in the TD direction. The adhesive surface was then attached to the above-mentioned stainless steel plate, which had been thoroughly cleaned, taking care not to trap air bubbles. The tape was then pressed against the stainless steel plate by a 2000 g roller, moving back and forth at a speed of 5 mm / s. The stainless steel plate with the adhesive tape attached was then stored in a high-temperature environment at 200°C for 1 hour, then removed and left in an environment at 23°C and 50% RH for at least 2 hours to prepare a measurement sample. The tape was then peeled off at a speed of 300 mm / min in a 90° direction relative to the stainless steel plate using a tensile tester, and the adhesive strength of the heat-treated stainless steel plate was measured. The environment during attachment and measurement was a temperature of 23°C and a humidity of 50% RH.

[0169] The adhesive strength after heat treatment (storing at 200°C for 1 hour, then leaving in an environment of 23°C and 50% RH for 2 hours or more) is not particularly limited, but from the viewpoint of maintaining adherend retention during processing under high temperature conditions, it is preferably 0.5 N / 10 mm or more. Furthermore, considering the effect of reducing adhesive strength due to subsequent irradiation with active energy rays, it is more preferable to keep it in the range of 0.5 N / 10 mm to 2.5 N / 10 mm.

[0170] The adhesive strength after the heat treatment was evaluated according to the following criteria, with a rating of ◯ being considered a pass.

[0171] 〇: 0.5N / 10mm or more ×: Less than 0.5N / 10mm

[0172] 2.6 Measurement of adhesive strength after ultraviolet (UV) irradiation Using the measurement samples prepared in 2.4 above (before heat treatment: normal state) and the measurement samples prepared in 2.5 (after heat treatment: stored at 200°C for 1 hour, then left in an environment of 23°C and 50% RH for 2 hours or more), an adhesive strength test (peel adhesive strength test) after ultraviolet (UV) irradiation on a stainless steel plate was carried out for each test piece of the above adhesive tape in accordance with the method described in Test Method for Adhesive Tapes and Adhesive Sheets (JIS Z 0237 (2009)), in the same way as the measurement of initial adhesive strength.

[0173] Specifically, the measurement sample (before heat treatment) prepared in 2.4 above and the measurement sample (after heat treatment) prepared in 2.5 above were subjected to a high-pressure mercury lamp (lamp model: H04-L21) manufactured by Eye Graphics Co., Ltd., with an accumulated light intensity of 300 mJ / cm 2 The adhesive tape was irradiated with ultraviolet (UV) light from the side where it was attached so that the adhesive tape adhered to the stainless steel plate was uniform. Next, using a tensile tester, the tape was peeled off at a 90° angle to the stainless steel plate at a rate of 300 mm / min, and the adhesive strength after UV irradiation to the stainless steel plate was measured. The environment during attachment and measurement was a temperature of 23°C and a humidity of 50% RH.

[0174] In the normal state before heat treatment, the adhesive strength after ultraviolet (UV) irradiation is Considering the increase in adhesive strength when placed on a surface, the value should be as small as possible. Specifically, it is preferable to set it to 0.10N / 10mm or less, and 0.0 It is more preferable to keep it at 5N / 10mm or less.

[0175] In addition, after heat treatment, the adhesive strength after ultraviolet (UV) irradiation is The level at which it can be easily removed (separated) without damage is 0.25N / 10m It is preferable that the load is 0.10N / 10mm or less (lower limit: 0N / 10mm). It is more preferable to do so.

[0176] 2.7 Evaluation of pick-up properties (ease of peeling and detaching of adherends) Three stainless steel chips, each 0.5 mm thick and 10 mm x 10 mm in size, were attached at equal intervals to the adhesive layer surface of each test piece (cut to a size of 150 mm long in the MD direction and 25 mm wide in the TD direction) of the adhesive tape produced in the above Examples and Comparative Examples, to prepare an evaluation sample in its normal state before heat treatment and an evaluation sample after heat treatment, respectively. Condition (1): After ultraviolet (UV) irradiation from the sheet-like substrate side of the adhesive tape, when the adhesive tape is stretched by 30% in the MD direction, Condition (2): After ultraviolet (UV) irradiation from the sheet-like substrate side of the adhesive tape, when the adhesive tape is stretched by 50% in the MD direction, The pick-up properties of the stainless steel tip were evaluated under the following two conditions.

[0177] Specifically, three of the stainless steel chips, the adhesive surface of which had been thoroughly cleaned, were attached at equal intervals (chip intervals of 5 mm) to the adhesive layer surface at the center in the MD direction of each test piece of adhesive tape from which the release film had been removed, with the aim of minimizing the inclusion of air bubbles. Then, the test piece was subjected to a pressure of 200 g / cm 2The tape was pressed with a pressure of 0.05 MPa for 20 minutes, and then stored in a high-temperature environment at 200°C for 1 hour. Then, evaluation samples were prepared in their normal state before heat treatment, and samples were stored in a high-temperature environment at 200°C for 1 hour, removed, and left in a 23°C, 50% RH environment for at least 2 hours. Then, ultraviolet (UV) irradiation was performed under the same conditions as in 2.6. Then, a test was performed to evaluate the pick-up ability of the stainless steel chip from the adhesive layer using tweezers, centered on the stainless steel chip-attached portion of the evaluation sample, under two conditions: (1) when the adhesive tape was stretched 30% in the MD direction, and (2) when the adhesive tape was stretched 50%. The adhesive tape was stretched using a manual uniaxial stretching machine at a stretching speed of approximately 100 mm / min. The environment during application and measurement was a temperature of 23°C and a humidity of 50%.

[0178] The pick-up property was evaluated according to the following criteria, and a rating of 0 or higher was considered to be acceptable.

[0179] ◎: All three stainless steel tips were easily peeled off and removed without any deformation or damage. ○: There was some resistance when peeling, but all three stainless steel tips were peeled and removed without deformation or damage. △: There was resistance when peeling off, and all three stainless steel chips were able to be peeled off and detached, but at least one of them was deformed or had scratches on the edge. ×: All three stainless steel chips were difficult to peel off and detach.

[0180] 2.8 Evaluation of contamination on the stainless steel tip surface In the evaluation of pickup properties in 2.7 above, the surface of the stainless steel chip (the surface that had been in contact with the adhesive layer) that could be peeled off and detached from the heat-treated evaluation sample was evaluated for contamination.

[0181] Specifically, the surface of the stainless steel chip was observed under a microscope, and the area of ​​the adhesive composition residue relative to the area of ​​the adhesive tape attached was evaluated according to the following criteria. A rating of ⊚ or ◯ was considered to be acceptable.

[0182] ◎: The total area of ​​residue is less than 1% of the adhesive tape area. 〇: The total area of ​​residue relative to the adhesive tape area is 1% or more and less than 5% △: The total area of ​​residue relative to the adhesive tape area is 5% or more but less than 25% ×: The total area of ​​residue relative to the adhesive tape area is 25% or more

[0183] 3. Overall evaluation of adhesive tape The adhesive tape was evaluated comprehensively according to the following criteria. A or B was used to evaluate the electrical conductivity of the adhesive tape. It was judged to be at a level that could be used as an adhesive tape for temporarily fixing sub-components, and was therefore rated as passed.

[0184] A: When the initial adhesive strength is rated as 〇 and the pickup and contamination resistance are rated as ◎. B: When all initial adhesive strength ratings are 0, and pickup and contamination ratings are 0 C: When the initial adhesive strength evaluation is 〇 and the pickup and contamination evaluations include △, or when the initial adhesive strength evaluation includes × and the pickup and contamination evaluations are △ to ◎ D: Regardless of the evaluation of initial adhesive strength, the evaluation of pickup property and contamination property includes "x" If the adhesive tape could not be stretched by 30% or more after the heat treatment, it was evaluated as D.

[0185] Tables 1 to 7 show the configurations and properties of the sheet-like substrates and adhesive layers of the adhesive tapes, and Tables 8 to 14 show the properties and evaluation results of the adhesive tapes.

[0186] [Table 1]

[0187] [Table 2]

[0188]

Table 3

[0189]

Table 4

[0190]

Table 5

[0191]

Table 6

[0192]

Table 7

[0193]

Table 8

[0194]

Table 9

[0195]

Table 10

[0196]

Table 11

[0197]

Table 12

[0198]

Table 13

[0199] [Table 14]

[0200] First, as shown in Tables 1 to 11, it was confirmed that the pressure-sensitive adhesive tapes of Examples 1 to 13, which satisfy the requirements of the present invention, obtained favorable results in evaluations of initial adhesive strength before UV irradiation, pick-up properties, and surface contamination of the picked-up stainless steel chip, even after heat treatment. That is, it was found that the pressure-sensitive adhesive tape of the present invention inhibits an increase in adhesive strength to the adherend even when the adherend held on the pressure-sensitive adhesive tape is processed in a high-temperature environment, and that the adhesive strength to the adherend is sufficiently reduced by irradiation with active energy rays and stretching, allowing the adherend to be easily peeled and detached without damage or contamination. This demonstrates that the pressure-sensitive adhesive tape of the present embodiment is useful, for example, as a temporary adhesive tape for electronic components that require processing under high-temperature conditions of about 200°C.

[0201] In contrast, as shown in Tables 12 to 14, it was confirmed that the adhesive tapes of Comparative Examples 1 to 9, which do not satisfy the requirements of the present invention, had evaluation results that were inferior to those of the adhesive tapes of Examples 1 to 13 in any of the evaluation items of initial adhesive strength before ultraviolet irradiation, pick-up property, and contamination of the surface of the picked-up stainless steel chip.

[0202] Specifically, in the adhesive tapes of Comparative Examples 1 and 2, which did not contain a filler or a thermal polymerization initiator in the adhesive layer, the adhesive strength increased significantly after heat treatment compared to Examples 1 and 2, so that the adhesive strength did not decrease sufficiently even when subsequently irradiated with ultraviolet (UV) light, and the stainless steel chip could not be picked up even when the adhesive tape was stretched.

[0203] In the adhesive tapes of Comparative Examples 3 and 4, which did not contain a filler in the adhesive layer, the adhesive strength did not decrease sufficiently even when irradiated with ultraviolet (UV) light after heat treatment, compared to Examples 1 and 2, and the stainless steel chips were difficult to pick up even when the adhesive tape was stretched.

[0204] The adhesive layer contains an acrylic adhesive polymer that does not have a carbon-carbon double bond. In the adhesive tape of Comparative Example 5, which used an adhesive polymer, the adhesive strength did not decrease sufficiently even when exposed to ultraviolet (UV) light, compared to Example 2, and it was difficult to pick up the stainless steel chips even when the adhesive tape was stretched.

[0205] In the adhesive tape of Comparative Example 6, in which the sheet-like substrate was a PO-based material, the sheet-like substrate melted and deformed during heat treatment, making it unsuitable for processing in a high-temperature environment.

[0206] In the adhesive tape of Comparative Example 7, in which the sheet-like substrate was EVA-based, the sheet-like substrate melted and deformed during heat treatment, making it unsuitable for processing in a high-temperature environment. In addition, because the acrylic adhesive polymer used was an acrylic adhesive polymer that did not have a carbon-carbon double bond, the adhesive strength did not decrease sufficiently even when irradiated with ultraviolet (UV) light.

[0207] In the adhesive tape of Comparative Example 8, which had a PET sheet substrate and contained no thermal polymerization initiator in the adhesive layer, the adhesive strength increased after heat treatment, and the adhesive strength did not decrease sufficiently even after subsequent irradiation with ultraviolet (UV) light. In addition, the sheet substrate could not be stretched by 30% or more.

[0208] The adhesive tape of Comparative Example 9, in which the sheet-like substrate was PET-based, the adhesive layer contained a filler, but the acrylic adhesive polymer used was an acrylic adhesive polymer without a carbon-carbon double bond, a multifunctional acrylate was used instead of a urethane acrylate oligomer, and no thermal polymerization initiator was contained, had low initial adhesive strength. Furthermore, the adhesive strength did not decrease sufficiently even when irradiated with ultraviolet (UV) light after heat treatment. Furthermore, the sheet-like substrate could not be stretched by 30% or more.

Claims

1. A pressure-sensitive adhesive tape having a sheet-like substrate that transmits active energy rays and a pressure-sensitive adhesive layer provided on a surface of the sheet-like substrate, the pressure-sensitive adhesive layer contains an acrylic pressure-sensitive adhesive polymer having a carbon-carbon double bond and a functional group, a photopolymerization initiator, a thermal polymerization initiator, a crosslinking agent reactive with the functional group, and a filler; the carbon-carbon double bond content of the acrylic adhesive polymer having a carbon-carbon double bond and a functional group is 0.25 mmol / g or more and 1.85 mmol / g or less; the filler is contained in an amount of 0.1 parts by mass or more and 62.0 parts by mass or less relative to 100 parts by mass of the acrylic adhesive polymer having a carbon-carbon double bond and a functional group, the ratio of R to D (R / D) is in the range of 0.10 or more and 1.00 or less, where R (μm) is the average particle size of the filler and D (μm) is the thickness of the pressure-sensitive adhesive layer; The pressure-sensitive adhesive tape is stored in a high-temperature environment of 200°C for 1 hour, then taken out and left in an environment of 23°C and 50% RH for 2 hours or more, and thereafter, the pressure-sensitive adhesive tape has an elongation percentage in at least one of the machine direction and the transverse direction of 30% or more, as measured based on the method specified in JIS Z 0237 (2009) (with the proviso that the pulling speed is 100 mm / min).

2. The pressure-sensitive adhesive tape according to claim 1 , wherein the sheet-like substrate contains a polyester-based thermoplastic elastomer.

3. The pressure-sensitive adhesive tape according to claim 2 , wherein the polyester-based thermoplastic elastomer has a Vicat softening point of 125° C. or higher.

4. The pressure-sensitive adhesive tape according to any one of claims 1 to 3, wherein the thermal polymerization initiator is contained in an amount in the range of 0.1 parts by mass or more and 31.0 parts by mass or less relative to 100 parts by mass of the acrylic pressure-sensitive adhesive polymer having a carbon-carbon double bond and a functional group.

5. The pressure-sensitive adhesive tape according to any one of claims 1 to 4, wherein the filler has an average particle size in the range of 2 µm or more and 30 µm or less.

6. The pressure-sensitive adhesive tape according to any one of claims 1 to 5, wherein the filler has a strength of 8.5 MPa or more at 30% deformation in a microcompression test.

7. The pressure-sensitive adhesive tape according to any one of claims 1 to 6, wherein the pressure-sensitive adhesive layer contains an oligomer having a carbon-carbon double bond.

8. The pressure-sensitive adhesive tape according to any one of claims 1 to 7, wherein the oligomer having a carbon-carbon double bond has two or more carbon-carbon double bonds, a carbon-carbon double bond equivalent in the range of 250 or more and 1,400 or less, and a weight average molecular weight in the range of 1,500 or more and 4,900 or less.

9. The pressure-sensitive adhesive tape according to any one of claims 1 to 8, wherein the oligomer having a carbon-carbon double bond is contained in an amount of up to 120 parts by mass per 100 parts by mass of the acrylic pressure-sensitive adhesive polymer having a carbon-carbon double bond and a functional group.

10. The pressure-sensitive adhesive tape is stored in a high-temperature environment of 200°C for 1 hour, and then taken out and left in an environment of 23°C and 50% RH for 2 hours or more. Thereafter, the arithmetic mean height (Sa) of the pressure-sensitive adhesive layer surface measured in accordance with ISO 25178 in at least one of a state in which the pressure-sensitive adhesive tape is stretched 30% in the MD direction and a state in which the pressure-sensitive adhesive tape is stretched 30% in the TD direction is ３０ The pressure-sensitive adhesive tape according to any one of claims 1 to 9, wherein the thickness is 0.20 µm or more.

11. The pressure-sensitive adhesive tape is stored in a high-temperature environment of 200°C for 1 hour, and then taken out and left in an environment of 23°C and 50% RH for 2 hours or more. Thereafter, the arithmetic mean height (Sa) of the pressure-sensitive adhesive layer surface measured in accordance with ISO 25178 in at least one of a state in which the pressure-sensitive adhesive tape is stretched by 50% in the MD direction and a state in which the pressure-sensitive adhesive tape is stretched by 30% in the TD direction is ５０ The pressure-sensitive adhesive tape according to any one of claims 1 to 10, wherein the thickness is 0.20 µm or more.

12. The adhesive tape according to any one of claims 1 to 11, which is an adhesive tape for temporarily fixing electronic components.

13. A step of temporarily fixing an electronic component to the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape according to any one of claims 1 to 12; a step of subjecting the electronic component to a processing treatment in which a high temperature of 160°C or more and 200°C or less is applied; a step of irradiating the pressure-sensitive adhesive tape with active energy rays from the sheet-like substrate film side; stretching the adhesive tape; and peeling and detaching the electronic component from the adhesive layer of the adhesive tape.

14. An adhesive tape having a sheet-like substrate that transmits active energy rays and an adhesive layer provided on a surface of the sheet-like substrate, the pressure-sensitive adhesive layer contains an acrylic pressure-sensitive adhesive polymer having a carbon-carbon double bond and a functional group, a photopolymerization initiator, a thermal polymerization initiator, a crosslinking agent reactive with the functional group, and a filler; The pressure-sensitive adhesive tape according to claim 1 or 2, characterized in that the acrylic pressure-sensitive adhesive polymer contains 2-ethylhexyl acrylate as a monomer component in an amount of 70 parts by mass or more, based on 100 parts by mass of the total amount of copolymer monomer components constituting the (meth)acrylic acid ester copolymer.

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