Frame-type adhesive materials and adhesive sheets

Abstract

To provide a seamless frame-type adhesive material while reducing waste, and an adhesive sheet made using the frame-type adhesive material. [Solution] The frame-type adhesive material 1 comprises two or more adhesive tape pieces 2 and an adhesive resin 3 arranged between the ends of the adhesive tape pieces, and the adhesive resin has a shear storage modulus of 1 MPa or less at 25°C measured at a frequency of 1 Hz in a dynamic viscoelastic measurement, or a probe tack value of 0.05 N / 5 mmφ or more measured under conditions of 25°C, a pressure of 98 gf, a pressure rate of 100 mm / sec, a pressure time of 10 seconds, and a peel rate of 5 mm / sec.

Description

[Technical Field]

[0001] The present invention relates to a frame-type adhesive material and an adhesive sheet. [Background technology]

[0002] BACKGROUND ART Adhesive tapes are used inside electronic devices such as smartphones and PCs to bond electronic components together (see, for example, Patent Documents 1 to 4). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2023-32903 A [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-141374 [Patent Document 3] JP 2015-41072 A [Patent Document 4] Japanese Patent Application Publication No. 2018-173486 Summary of the Invention [Problem to be solved by the invention]

[0004] Adhesive tapes are punched into a wide variety of shapes and are widely used to bond substrates and other materials. However, any portions of the tape that are not the desired shape are discarded as waste. In recent years, reducing waste loss associated with punching has become an issue in the adhesive tape industry in order to reduce CO2 emissions. Because waste tends to be particularly high for shapes with hollows, such as frame shapes, efforts are being made to improve punching shapes to reduce waste loss. For example, to form a square-shaped adhesive material, methods of combining multiple parts have been explored, such as combining four strips of adhesive tape to form a square shape. However, this method is prone to gaps when assembling multiple parts, which can result in insufficient performance, such as dustproofing, waterproofing, and light-blocking properties.

[0005] Patent Document 1 discloses a method for joining a front panel to a frame member, in which adhesive tape is applied to tape joining areas on the joining surface of the frame member and an adhesive is applied to an application area between the tape joining areas. However, Patent Document 1 does not disclose any details of the adhesive used. Furthermore, the method described in this document involves placing the adhesive tape and adhesive directly on the housing, and does not anticipate peeling the adhesive from the housing and transferring it to another member. The same can be said for the methods described in Patent Documents 2 to 4.

[0006] The present invention aims to provide a seamless frame-type adhesive material that reduces waste and also to provide an adhesive sheet that is constructed using the frame-type adhesive material. [Means for solving the problem]

[0007] The present inventors discovered that by disposing an adhesive resin having predetermined physical properties between the ends of two or more adhesive tape pieces so that the pieces form a frame shape (frame type) as a whole, it is possible to reduce waste caused by punching, while also realizing a seamless adhesive material in which the gaps between the adhesive tape pieces are sealed with the adhesive resin and the gaps are sufficiently suppressed, and this discovery led to the completion of the present invention. That is, the present disclosure relates to the following frame-shaped adhesive material and adhesive sheet.

[0008] Disclosure 1 is a frame-type adhesive material comprising two or more adhesive tape pieces and an adhesive resin disposed between the ends of the adhesive tape pieces, wherein the adhesive resin has a shear storage modulus of 1 MPa or less at 25°C measured at a frequency of 1 Hz in a dynamic viscoelastic measurement, or a probe tack value of 0.05 N / 5 mmφ or more measured under conditions of 25°C, a pressure of 98 gf, a pressure rate of 100 mm / sec, a pressure time of 10 seconds, and a peel rate of 5 mm / sec. Disclosure 2 is the frame-type adhesive material of Disclosure 1, wherein the adhesive resin has a Tan δ peak temperature of 25° C. or lower when dynamic viscoelasticity is measured at a frequency of 1 Hz. Disclosure 3 is the frame-type adhesive material of Disclosure 1 or 2, wherein the OD value is 2 or more at at least one joint between the adhesive resin and the adhesive tape piece. A fourth aspect of the present disclosure is the frame-shaped adhesive material according to any one of the first to third aspects of the present disclosure, wherein at least one of the adhesive tape pieces is strip-shaped, L-shaped, or U-shaped. Disclosure 5 is the frame-type adhesive material according to any one of Disclosures 1 to 4, wherein the adhesive resin is a cured product of a photocurable composition containing a monofunctional (meth)acrylate, a photopolymerization initiator, and a filler. A sixth aspect of the present disclosure is the frame-type adhesive material of the fifth aspect of the present disclosure, wherein the photocurable composition further contains a polyfunctional (meth)acrylate. Disclosure 7 is the frame-shaped adhesive material according to any one of Disclosures 1 to 6, wherein the adhesive resin has a gel fraction of 20% by mass or more and 70% by mass or less. Disclosure 8 of the present invention is a pressure-sensitive adhesive sheet comprising a separator and the frame-shaped pressure-sensitive adhesive material of any one of Disclosures 1 to 7 of the present invention arranged on at least one surface of the separator. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to provide a seamless frame-type adhesive material while reducing waste. Furthermore, according to the present disclosure, it is also possible to provide an adhesive sheet using the frame-type adhesive material. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic plan view for explaining the positional relationship between an adhesive tape piece 2 and an adhesive resin 3 that constitute a frame-type adhesive material 1. As shown in FIG. [Figure 2] FIG. 2 is a schematic plan view for explaining the positional relationship between the adhesive tape piece 2 and the adhesive resin 3 that constitute the frame-type adhesive material 1. As shown in FIG. [Figure 3] FIG. 3 is a schematic plan view for explaining the positional relationship between the adhesive tape piece 2 and the adhesive resin 3 that constitute the frame-type adhesive material 1. As shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] [Frame-type adhesive material] The frame-type adhesive material of the present disclosure includes two or more adhesive tape pieces and an adhesive resin disposed between the ends of the adhesive tape pieces. Specifically, the frame-type adhesive material has a shape in which the two or more adhesive tape pieces and the adhesive resin are arranged in a frame shape (also referred to as a frame shape) as a whole in a plan view.

[0012] The frame shape refers to a peripheral shape such as a polygon or a circle. The frame shape may be either a polygon or a circle, but a polygon is preferable, and a rectangle (i.e., a square or a rectangle) is more preferable. The circle here also includes an oval.

[0013] Specific examples of the frame-type adhesive material are shown in Figures 1 to 3. Figures 1 to 3 are planar schematic views for explaining the positional relationship between adhesive tape pieces 2 and adhesive resin 3 constituting a frame-type adhesive material 1. Figure 1 illustrates a rectangular frame-type adhesive material 1 including four strip-shaped (I-shaped) adhesive tape pieces 2 and adhesive resin 3 arranged between the ends of the adhesive tape pieces 2, Figure 2 illustrates a rectangular frame-type adhesive material 1 including two L-shaped adhesive tape pieces 2 and adhesive resin 3 arranged between the ends of the adhesive tape pieces 2, and Figure 3 illustrates a rectangular frame-type adhesive material 1 including two U-shaped adhesive tape pieces 2 and adhesive resin 3 arranged between the ends of the adhesive tape pieces 2.

[0014] The frame size of the frame-type adhesive varies depending on the shape of the frame and the size of the adherend, but for example, when the frame is rectangular, the frame size is preferably 1 cm x 1 cm or more and 50 cm x 50 cm or less, and more preferably 4 cm x 4 cm or more and 21.5 cm x 38.3 cm or less. Here, the "frame size of the frame-type adhesive" refers to the dimensions of the outermost sides of the frame-type adhesive when the frame-type adhesive, which is composed of adhesive tape pieces and adhesive resin, is viewed in plan. When the frame is rectangular, the frame size refers to the vertical length x horizontal length of the outermost sides of the rectangle.

[0015] The line width of the frame-shaped adhesive varies depending on the adherend, the desired application, etc., and is not particularly limited, but may be, for example, 0.1 mm or more and 5 mm or less. In this case, sufficient adhesive performance and excellent design properties can be exhibited. The line width of the frame-shaped adhesive may also be 10 mm or more and 50 mm or less. Here, the "line width of the frame-shaped adhesive" essentially corresponds to the line width of the adhesive tape piece when the frame-shaped adhesive composed of the adhesive tape piece and the adhesive resin is viewed in plan. The line width of the adhesive tape piece refers to the dimension in the width direction perpendicular to the longitudinal direction of the adhesive tape piece when viewed in plan. For reference, in Figures 1 to 3, the portion corresponding to the line width of the frame-shaped adhesive (i.e., the line width of the adhesive tape piece) is indicated by the symbol a.

[0016] The thickness of the frame-shaped adhesive varies depending on the adherend, application, etc., but is preferably 0.01 mm or more and 5 mm or less, and more preferably 0.05 mm or more and 2 mm or less. Here, "thickness of the frame-shaped adhesive" means the maximum dimension in the thickness direction of the frame-shaped adhesive (for example, the direction perpendicular to the paper in Figures 1 to 3). That is, it means the maximum thickness dimension among the thickness of the adhesive tape piece constituting the frame-shaped adhesive, the thickness of the adhesive resin, and, if an adhesive resin is disposed on the adhesive tape piece, the total thickness of both.

[0017] The frame-shaped adhesive preferably has an OD value (optical density) of 2 or more, more preferably 3 or more, and even more preferably 4 or more, at at least one location at the joint between the adhesive resin and the adhesive tape piece. When the OD value at the location is within this range, the frame-shaped adhesive can achieve a high level of both light-blocking properties and adhesiveness. In particular, it is preferable that the OD value be within the above range at all locations on the frame-shaped adhesive. The upper limit of the OD value is not particularly limited, but is, for example, 7 or less.

[0018] In this specification, the OD value of the frame-type adhesive material is the OD value in the width direction of the adhesive tape piece constituting the frame-type adhesive material (i.e., the direction perpendicular to the longitudinal direction of the adhesive tape piece), and can be measured using an optical densitometer (manufactured by X-rite, "Spectrometer").

[0019] Here, "a joint between an adhesive resin and an adhesive tape piece" means a location where one adhesive tape piece and the adhesive resin come into contact. As will be described later, Figures 1 to 3 show a form in which the adhesive resin is disposed in the gap between the ends of the adhesive tape pieces, and in this case, there are at least eight joints between the adhesive resin and the adhesive tape pieces in Figure 1, and at least four joints in each of Figures 2 and 3.

[0020] <Adhesive tape piece> The frame-shaped adhesive material has two or more adhesive tape pieces. At least one of the adhesive tape pieces is preferably strip-shaped, L-shaped, or U-shaped, and it is more preferable that all of the adhesive tape pieces contained in the frame-shaped adhesive material have at least one shape selected from the group consisting of strip-shaped, L-shaped, and U-shaped. The frame-shaped adhesive material may have adhesive tape pieces of two or more of these shapes.

[0021] The adhesive tape piece may be a supported type adhesive tape piece having a substrate, or a non-supported type adhesive tape piece having no substrate. Both adhesive tape pieces having a substrate and adhesive tape pieces having no substrate are included in preferred embodiments of the present disclosure.

[0022] When the above-mentioned adhesive tape piece has a substrate, the adhesive tape piece may be a single-sided adhesive tape piece having an adhesive layer on one side of the substrate, or a double-sided adhesive tape piece having adhesive layers on both sides of the substrate.

[0023] Examples of the substrate include resin sheets made of resins such as acrylic resin, olefin resin, polycarbonate, polyvinyl chloride, ABS resin, polyethylene terephthalate (PET), nylon, polyurethane, polyimide, and polyethylene foam (PE foam). The shape of the substrate is not particularly limited, and it may have a mesh structure or may have holes. In particular, from the viewpoints of strength, flexibility, and the like, it is preferable that the substrate is a foam substrate having a foam structure. Such embodiments in which the adhesive tape piece has a foam structure are included in preferred embodiments of the present disclosure.

[0024] The adhesive tape piece may be transparent, opaque, or translucent, and may be colorless or colored. However, since it is preferable that the OD values ​​of the frame-shaped adhesive material at all positions are within the above range, as described above, it is preferable that the OD value of the adhesive tape piece is also within the above range.

[0025] The adhesive tape piece preferably has a probe tack value of 0.05 N / 5 mmφ or more at 25°C. This makes it easier to peel the frame-shaped adhesive material from the separator and transfer it to another member. A preferred range for the probe tack value of the adhesive tape piece is the same as the preferred range for the probe tack value of the adhesive resin described below. In this specification, "probe tack value at 25°C" means a probe tack value measured under conditions of 25°C, a pressure of 98 gf, a pressure rate of 100 mm / sec, a pressure time of 10 seconds, and a peel rate of 5 mm / sec, and the measurement method will be described later.

[0026] The line width of the adhesive tape piece varies depending on the adherend and application, but like the line width of the frame-type adhesive material, it may be, for example, 0.1 mm or more and 5 mm or less, or 10 mm or more and 50 mm or less.

[0027] The thickness of the frame-type adhesive material varies depending on the adherend, application, etc., but is preferably 0.01 mm or more and 5 mm or less, and more preferably 0.05 mm or more and 2 mm or less.

[0028] The adhesive tape piece can be obtained by cutting a commonly used adhesive tape (which may be a commercially available product) into a predetermined shape or the like.

[0029] <Adhesive resin> An adhesive resin is disposed between the ends of the adhesive tape pieces (i.e., between one end of a first adhesive tape piece and an end of a second adhesive tape piece that is located on the side of the first adhesive tape piece). By disposing the adhesive resin between the ends of two or more adhesive tape pieces, a frame-type adhesive material that is gapless (i.e., seamless) is realized as a whole.

[0030] The ends of the adhesive tape pieces may overlap, may be in contact with each other without overlapping, or may be in contact with each other with a gap therebetween. The adhesive resin is disposed in the overlapping portion, contact portion, or gap so as to connect the ends of the adhesive tape pieces. Figures 1 to 3 show a form in which the adhesive resin is disposed in the gap between the ends of the adhesive tape pieces.

[0031] The adhesive resin has a shear storage modulus at 25°C of 1 MPa or less, or a probe tack value at 25°C of 0.05 N / 5 mmφ or more. By disposing such an adhesive resin between the ends of the adhesive tape pieces, the formation of gaps between the adhesive tape pieces is sufficiently suppressed, resulting in a seamless frame-type adhesive material. Therefore, the frame-type adhesive material has excellent waterproof and dust-proof properties. Furthermore, when the probe tack value is within the above range, the frame-type adhesive material can be easily peeled from the separator and transferred to another member. It is particularly preferable that the adhesive resin have a storage modulus (25°C) of 1 MPa or less and a probe tack value of 0.05 N / 5 mmφ or more.

[0032] The storage modulus (25°C) of the adhesive resin is preferably 0.95 MPa or less from the viewpoint of improving waterproofness, etc. The lower limit of the storage modulus (25°C) of the adhesive resin is not particularly limited, but is preferably 0.001 MPa or more, and more preferably 0.01 MPa or more, from the viewpoint of improving adhesive strength, for example.

[0033] In this specification, "shear storage modulus at 25°C" means the shear storage modulus at 25°C measured at a frequency of 1 Hz in dynamic viscoelasticity measurement, and is also referred to as "storage modulus (25°C)" or "G'(25°C)". The shear storage modulus at 25°C is measured by the following method. First, a measurement sample consisting of only the adhesive resin is prepared. The obtained measurement sample is subjected to a dynamic viscoelasticity spectrum measurement from -50°C to 200°C using a dynamic viscoelasticity measuring device (IT Measurement & Control Co., Ltd., "DVA-200") under conditions of a slow heating rate shear deformation mode of 5°C / min, a measurement frequency of 1 Hz, and a strain of 0.1%, and the storage modulus at 25°C is measured.

[0034] From the viewpoint of facilitating transfer of the frame-shaped adhesive material, the probe tack value of the adhesive resin at 25°C is more preferably 0.08 or more, even more preferably 0.5 or more, and particularly preferably 1.0 or more. There is no particular upper limit to the probe tack value of the adhesive resin, but considering adhesive strength, for example, it is preferably 5 or less.

[0035] In this specification, the probe tack value at 25° C. is measured by the following method. First, a measurement sample consisting of only the adhesive resin is prepared. When measuring the probe tack value of an adhesive tape piece, a measurement sample consisting of only the adhesive tape piece is prepared. A probe tack test is performed on the obtained measurement sample using a probe tack tester (such as "TAC-2" manufactured by RHESCA) under the following conditions: 25°C, pressure of 98 gf, pressure rate of 100 mm / sec, pressure time of 10 seconds, and peel rate of 5 mm / sec.

[0036] Examples of methods for adjusting the storage modulus (25°C) and probe tack value of the adhesive resin include a method of adjusting the type and blending ratio of the polymerizable compound contained in the photocurable composition that forms the adhesive resin, as described below.

[0037] The adhesive resin preferably has a Tan δ peak temperature (also simply referred to as "Tan δ peak") of 25°C or less, obtained when dynamic viscoelasticity is measured at a frequency of 1 Hz. This further improves the waterproofing properties of the frame-type adhesive material. The Tan δ peak of the adhesive resin is more preferably 23°C or less. The lower limit of the Tan δ peak of the adhesive resin is not particularly limited, but is, for example, -10°C. Note that when there are multiple Tan δ peak temperatures, it is preferable that the lowest Tan δ peak temperature is within the above range.

[0038] In this specification, the Tan δ peak is measured by the following method. First, a measurement sample consisting of only the adhesive resin is prepared. The storage modulus G1 and loss modulus G2 of the obtained measurement sample are measured using a dynamic viscoelasticity measuring device ("DVA-200" manufactured by IT Measurement Control Co., Ltd.) under the conditions of a constant temperature rise tensile mode and a frequency of 1 Hz. Then, the following formula (i): Tanδ peak temperature = G2 / G1 (i) Based on this, the Tan δ peak temperature is calculated.

[0039] As a method for adjusting the Tan δ peak temperature of the adhesive resin, for example, a method of adjusting the type and compounding ratio of the polymerizable compound contained in the photocurable composition that provides the adhesive resin can be mentioned.

[0040] The adhesive resin preferably has a gel fraction of 20% by mass or more and 70% by mass or less. A gel fraction within this range allows the frame-type adhesive material to have superior adhesive strength and creep resistance. The lower limit of the gel fraction is more preferably 25% by mass. The upper limit of the gel fraction is preferably 65% ​​by mass, more preferably 60% by mass.

[0041] In this specification, the gel fraction of the adhesive resin can be measured by the following method. First, W0 (g) of adhesive resin is scraped off from the frame-shaped adhesive material, immersed in 50 mL of tetrahydrofuran, and shaken in a shaker at 23°C and 200 rpm for 24 hours. After shaking, a metal mesh (opening #200 mesh) is used to separate the tetrahydrofuran from the adhesive resin that has absorbed the tetrahydrofuran and swollen. The separated adhesive resin is dried at 110°C for 1 hour. The mass of the adhesive resin including the dried metal mesh is measured, and the gel fraction (% by mass) is calculated using the following formula (ii). Gel fraction (mass%) = 100 × (W1 - W2) / W0 (ii) In the formula, W0 represents the initial mass of the adhesive resin, W1 represents the mass of the adhesive resin including the metal mesh after drying, and W2 represents the initial mass of the metal mesh.

[0042] Examples of methods for adjusting the gel fraction of the adhesive resin include a method of adjusting the amount of a crosslinking component (such as a polyfunctional (meth)acrylate) or a photopolymerization initiator in the photocurable composition that forms the adhesive resin.

[0043] The OD value of the adhesive resin is preferably 2 or more, more preferably 2.5 or more, and even more preferably 3 or more. When the OD value of the adhesive resin is within this range, the frame-shaped adhesive material can achieve both light-blocking properties and adhesiveness at a higher level. The upper limit of the OD value is not particularly limited, but is, for example, 7 or less. The OD value of the adhesive resin means the OD value when the thickness of the measurement sample (i.e., the adhesive resin only) is 1 mm, and can be measured using the optical densitometer described above.

[0044] The adhesive resin is preferably a cured product of a photocurable composition containing a monofunctional (meth)acrylate, a photopolymerization initiator, and a filler. The photocurable composition will be further described below. Each component contained in the photocurable composition may be one type or two or more types.

[0045] In this specification, "(meth)acrylate" means acrylate and / or methacrylate, "(meth)acryloyl group" means acryloyl group and / or methacryloyl group, and "(meth)acrylic acid" means acrylic acid and / or methacrylic acid. "Monofunctional" means that one monomer (polymerizable compound) molecule contains one (meth)acryloyl group, and "polyfunctional" means that one monomer molecule contains two or more (meth)acryloyl groups.

[0046] (Monofunctional (meth)acrylate) The photocurable composition contains a monofunctional (meth)acrylate. The monofunctional (meth)acrylate is a polymerizable compound. When the photocurable composition contains the monofunctional (meth)acrylate, the adhesive resin, which is a cured product of the photocurable composition, has superior adhesive strength, and the storage modulus (25°C) and probe tack value of the adhesive resin can be easily adjusted to fall within a predetermined range.

[0047] Examples of the monofunctional (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, n-heptyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, isomyristyl (meth)acrylate, stearyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, cyclohexane ... Dihexyl (meth)acrylate, isobornyl (meth)acrylate, bicyclopentenyl (meth)acrylate, benzyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-butoxyethyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, methoxyethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, tetrahydrofurfuryl alcohol acrylic acid polymer ester, ethyl carbitol (meth)acrylate, 2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, 1H,1H,5H-Octafluoropentyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, 2-(meth)acryloyloxyethyl succinate, 2-(meth)acryloyloxyethyl hexahydrophthalate, 2-(meth)acryloyloxyethyl 2-hydroxypropyl phthalate, 2-(meth)acryloyloxyethyl phosphate, (3-ethyloxetan-3-yl)methyl (meth)acrylate, 2-(((butylamino)carbonyl)oxy)ethyl (meth)acrylate, (3-propyloxetan-3-yl)methyl (meth)acrylate, (3-butyloxetan-3-yl)methyl (meth)acrylate, (3-ethyloxetan-3-yl)ethyl (meth)acrylate, (3-ethyloxetan-3-yl)propyl (meth)acrylate, (3-ethyloxetan-3-yl)butyl (meth)acrylate, (3-ethyloxetan-3-yl)pentyl (meth)acrylate, (3-ethyloxetan-3-yl)hexyl (meth)acrylate, γ-butyrolactone (meth)acrylate, (2,2-dimethyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, (2-methyl-2-isobutyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, (2-cyclohexyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, cyclic trimethylolpropane formal acrylate, N-(meth)acryloyloxyethyl hexahydrophthalimide, and the like. Among these, the monofunctional (meth)acrylate preferably contains a compound that, when made into a homopolymer, has a glass transition temperature of 50°C or less.

[0048] The content of the monofunctional (meth)acrylate in the photocurable composition (100% by mass of the total solids content) is preferably 30% by mass or more, and more preferably 50% by mass or more. The upper limit of the content of the monofunctional (meth)acrylate in the photocurable composition (100% by mass of the total solids content) is preferably 80% by mass or less, and more preferably 70% by mass or less. When the content of the monofunctional (meth)acrylate falls within this range, the storage modulus (25°C) and probe tack value of the adhesive resin can be more easily adjusted to the desired ranges.

[0049] (Multifunctional (meth)acrylate) It is more preferable that the photocurable composition further contains a polyfunctional (meth)acrylate. The polyfunctional (meth)acrylate is a polymerizable compound and serves as a cross-linking component. Therefore, when the photocurable composition further contains a polyfunctional (meth)acrylate in addition to a monofunctional (meth)acrylate, it becomes easy to adjust the gel fraction of the adhesive resin to a suitable range, and therefore the adhesive resin has better adhesive strength and creep retention.

[0050] Examples of the polyfunctional (meth)acrylate include polyfunctional urethane (meth)acrylate, polyfunctional (meth)acrylic acid ester compound, polyfunctional epoxy (meth)acrylate, etc. The term "epoxy (meth)acrylate" refers to a compound in which all epoxy groups in an epoxy compound have reacted with (meth)acrylic acid.

[0051] The polyfunctional urethane (meth)acrylate can be obtained, for example, by reacting an isocyanate compound with a (meth)acrylic acid derivative having a hydroxyl group in the presence of a catalytic amount of a tin compound.

[0052] Examples of the isocyanate compound include isophorone diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, diphenylmethane-4,4'-diisocyanate (MDI), hydrogenated MDI, polymeric MDI, 1,5-naphthalene diisocyanate, norbornane diisocyanate, tolidine diisocyanate, xylylene diisocyanate (XDI), hydrogenated XDI, lysine diisocyanate, triphenylmethane triisocyanate, tris(isocyanatephenyl)thiophosphate, tetramethylxylylene diisocyanate, and 1,6,11-undecane triisocyanate.

[0053] The isocyanate compound may also be a chain-extended isocyanate compound obtained by reacting a polyol with an excess of an isocyanate compound. Examples of polyols include ethylene glycol, propylene glycol, glycerin, sorbitol, trimethylolpropane, carbonate diol, polyether diol, polyester diol, and polycaprolactone diol.

[0054] Examples of the (meth)acrylic acid derivative having a hydroxyl group include hydroxyalkyl mono(meth)acrylate, mono(meth)acrylate of a dihydric alcohol, and mono(meth)acrylate or di(meth)acrylate of a trihydric alcohol.

[0055] Examples of the hydroxyalkyl mono(meth)acrylate include 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate, 2-hydroxybutyl(meth)acrylate, and 4-hydroxybutyl(meth)acrylate. Examples of the dihydric alcohol include ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, and polyethylene glycol. Examples of the trihydric alcohol include trimethylolethane, trimethylolpropane, and glycerin.

[0056] Examples of the polyfunctional (meth)acrylic acid ester compound include 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, 2-n-butyl-2-ethyl-1,3-Propanediol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, ethylene oxide-added bisphenol A di(meth)acrylate, propylene oxide-added bisphenol A di(meth)acrylate, ethylene oxide-added bisphenol F di(meth)acrylate, dimethylol dicyclopentadiene Di(meth)acrylate, ethylene oxide modified isocyanuric acid di(meth)acrylate, 2-hydroxy-3-(meth)acryloyloxypropyl (meth)acrylate, carbonate diol di(meth)acrylate, polyether diol di(meth)acrylate, polyester diol di(meth)acrylate, polycaprolactone diol di(meth)acrylate, polybutadiene diol di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, trimethyl Trimethylolpropane tri(meth)acrylate, ethylene oxide-added trimethylolpropane tri(meth)acrylate, propylene oxide-added trimethylolpropane tri(meth)acrylate, caprolactone-modified trimethylolpropane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, ethylene oxide-added isocyanuric acid tri(meth)acrylate, glycerin tri(meth)acrylate, propylene oxide-added glycerin tri(meth)acrylate , pentaerythritol tri(meth)acrylate, tris(meth)acryloyloxyethyl phosphate, ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol monohydroxypenta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, caprolactone-modified dipentaerythritol hexa(meth)acrylate, etc.

[0057] Examples of the polyfunctional epoxy(meth)acrylate include bisphenol A type epoxy(meth)acrylate, bisphenol F type epoxy(meth)acrylate, bisphenol E type epoxy(meth)acrylate, and caprolactone-modified versions of these.

[0058] Among these, the polyfunctional (meth)acrylate preferably contains a polyfunctional urethane (meth)acrylate, which provides the adhesive resin with even better adhesive strength and creep resistance.

[0059] The mass ratio of the monofunctional (meth)acrylate to the polyfunctional (meth)acrylate in the photocurable composition (monofunctional (meth)acrylate / polyfunctional (meth)acrylate) may be, for example, 50 to 100 / 50 to 0, but from the viewpoint of enabling the adhesive resin to exhibit a better balance of adhesive strength, cohesion, creep retention, and the like, it is more preferably 50 to 95 / 50 to 5, and even more preferably 80 to 99.5 / 20 to 0.5.

[0060] (Photopolymerization initiator) The photocurable composition contains a photopolymerization initiator. When the photocurable composition contains a photopolymerization initiator, the initiation reaction of the photopolymerization initiator serves as a starting point for reaction of a polymerizable compound such as a monofunctional (meth)acrylate or a polyfunctional (meth)acrylate, which makes it easier to produce a high molecular weight compound. As a result, the adhesive resin has better adhesive strength and creep resistance.

[0061] The molecular weight of the photopolymerization initiator is preferably 800 or more, more preferably 1000 or more, and even more preferably 1100 or more. When the molecular weight of the photopolymerization initiator is distributed, the molecular weight of the photopolymerization initiator means the weight average molecular weight. From the viewpoints of solubility and handleability, the molecular weight of the photopolymerization initiator is preferably 10000 or less, and more preferably 5000 or less.

[0062] In this specification, the "weight average molecular weight" can be determined by measuring the molecular weight distribution in terms of polystyrene using, for example, gel permeation chromatography (GPC). Specifically, it can be determined by measuring, for example, using gel permeation chromatography (Waters, "2690 Separations Module" or the like) under the following conditions: Solvent: tetrahydrofuran Sample flow rate: 1 mL / min Detector: Differential refractive index RI Column: GPC KF-806L (Showa Denko) Column temperature (measurement temperature): 40°C Injection volume: 20μL

[0063] The photopolymerization initiator is preferably a Norrish type I photopolymerization initiator. The photopolymerization initiator preferably contains a compound having two or more photopolymerization initiation points. In particular, the photopolymerization initiator preferably has two or more carbonyl groups per molecule that contribute to the Norrish type I cleavage reaction.

[0064] Examples of the Norrish type I photopolymerization initiator include polymers of ethyl (2,4,6-trimethylbenzoyl)-phenylphosphonate, polyethylene glycol di(β-4(4-(2-dimethylamino-2-benzyl)butanoylphenyl)piperazine)propionate, bis(benzophenone-2-carboxylic acid) polyethylene glycol ester, 1-hydroxycyclohexyl phenyl ketone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and 2-benzyl-2-(dimethylamino)-4'-morpholinobutyrophenone.

[0065] Among the above Norrish type I photopolymerization initiators, commercially available ones include, for example, Omnipol TP, Omnipol 910, Omnirad TPO, and Omnirad 369 (all manufactured by IGM Resins).

[0066] When the total amount of the monofunctional (meth)acrylate and polyfunctional (meth)acrylate in the photocurable composition is taken as 100 parts by mass, the content of the photopolymerization initiator is preferably 1 part by mass or more, more preferably 3 parts by mass or more. Furthermore, the content of the photopolymerization initiator is preferably 10 parts by mass or less, more preferably 8 parts by mass or less. Here, "the total amount of the monofunctional (meth)acrylate and polyfunctional (meth)acrylate in the photocurable composition" refers to the total amount of only the monofunctional (meth)acrylate when the photocurable composition contains only monofunctional (meth)acrylate and no polyfunctional (meth)acrylate (the same applies hereinafter).

[0067] (filler) The photocurable composition contains a filler. By containing a filler in the photocurable composition, the viscosity is adjusted to an appropriate range, and printability is further improved.

[0068] Examples of the filler include inorganic fillers such as silica, talc, glass beads, asbestos, gypsum, diatomaceous earth, smectite, bentonite, montmorillonite, sericite, activated clay, alumina, zinc oxide, magnesium oxide, tin oxide, calcium carbonate, magnesium carbonate, magnesium hydroxide, aluminum hydroxide, aluminum nitride, silicon nitride, barium sulfate, and calcium silicate; and organic fillers such as polyester fine particles, polyurethane fine particles, vinyl polymer fine particles, and (meth)acrylic polymer fine particles. Among these, the filler is preferably an inorganic filler, more preferably silica, and even more preferably fumed silica.

[0069] When the total amount of the monofunctional (meth)acrylate and the polyfunctional (meth)acrylate in the photocurable composition is 100 parts by mass, the content of the filler is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, and preferably 10 parts by mass or less, more preferably 5 parts by mass or less.

[0070] (tackifier) The photocurable composition may contain a tackifier. When the photocurable composition contains a tackifier, the adhesive resin has better adhesive strength.

[0071] Examples of the tackifier include rosin-based resins and terpene-based resins.

[0072] Examples of the rosin resin include rosin diol. The rosin diol is not particularly limited as long as it is a rosin-modified diol having two rosin skeletons and two hydroxyl groups in the molecule. Diols having a rosin component in the molecule are called rosin polyols, and these include polyether-type rosin polyols such as polypropylene glycol (PPG) and polyester-type rosin polyols such as condensation polyester polyols, lactone polyester polyols, and polycarbonate diols, in which the skeleton excluding the rosin component is a polyether-type rosin polyol, such as condensation polyester polyols, lactone polyester polyols, and polycarbonate diols. Examples of the rosin component include abietic acid, abietic acid derivatives such as dehydroabietic acid, dihydroabietic acid, tetrahydroabietic acid, diabietic acid, and neoabietic acid, pimaric acid-type resin acids such as levopimaric acid, hydrogenated rosins obtained by hydrogenating these, and disproportionated rosins obtained by disproportionating these.

[0073] Examples of the rosin diol include rosin esters obtained by reacting rosin with polyhydric alcohols, epoxy-modified rosin esters obtained by reacting rosin with epoxy compounds, and modified rosins having hydroxyl groups, such as polyethers having a rosin skeleton, etc. These can be produced by conventionally known methods.

[0074] Commercially available examples of the above rosin-based resins include Pine Crystal KE-100, Pine Crystal KE-311, Pine Crystal KE-359, Pine Crystal KE-604, Pine Crystal KE-615-3, Pine Crystal KR-614, Pine Crystal D-6011, and Pine Crystal D-6250 (all manufactured by Arakawa Chemical Industries, Ltd.).

[0075] Examples of the terpene resin include terpene phenol resins, which are copolymers of phenol and terpene resins, which are essential oil components obtained from natural products such as rosin and orange peel, and include fully hydrogenated terpene phenol resins and partially hydrogenated terpene phenol resins.

[0076] Here, the fully hydrogenated terpene phenolic resin is a terpene resin obtained by substantially completely hydrogenating a terpene phenolic resin, and the partially hydrogenated terpene phenolic resin is a terpene resin obtained by partially hydrogenating a terpene phenolic resin. The terpene phenolic resin has a terpene-derived double bond and an aromatic ring double bond derived from a phenol. Therefore, the fully hydrogenated terpene phenolic resin means a resin in which both the terpene moiety and the phenol moiety are completely or almost hydrogenated, and the partially hydrogenated terpene phenolic resin means a resin in which the degree of hydrogenation of these moieties is partial rather than complete. The hydrogenation method and reaction format are not particularly limited.

[0077] Among the above terpene phenol-based resins, commercially available examples include YS Polystar G150 and YS Polystar NH (fully hydrogenated terpene phenol-based resin) manufactured by Yasuhara Chemical Co., Ltd.

[0078] When the total amount of the monofunctional (meth)acrylate and the polyfunctional (meth)acrylate in the photocurable composition is 100 parts by mass, the amount of the tackifier is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and is preferably 30 parts by mass or less, more preferably 25 parts by mass or less.

[0079] (coloring agent) The photocurable composition may contain a colorant, which makes it easy to adjust the optical density (OD value) within a predetermined range, thereby providing the adhesive resin with excellent light-blocking properties.

[0080] The colorant may be a pigment or a dye, and specific examples include titanium black, zirconium nitride, carbon black, iron oxide, aniline black, cyanine black, etc. Among these, from the viewpoint of further enhancing the light-shielding property, the colorant is preferably a pigment, and more preferably a black pigment.

[0081] When a particulate pigment is used as the colorant, the average primary particle diameter of the pigment is preferably 1 nm or more, more preferably 5 nm or more, and even more preferably 10 nm or more, from the viewpoint of easily adjusting the optical density within a predetermined range. Furthermore, in consideration of the handleability of the photocurable composition, the average primary particle diameter is preferably 700 nm or less, more preferably 500 nm or less, and even more preferably 100 nm or less. The average primary particle diameter can be obtained, for example, by measuring the particle diameters of 50 or more particles using a scanning electron microscope and calculating the average value.

[0082] When the total amount of the monofunctional (meth)acrylate and the polyfunctional (meth)acrylate in the photocurable composition is 100 parts by mass, the content of the colorant is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, and preferably 7 parts by mass or less, more preferably 5 parts by mass or less.

[0083] (Other ingredients) The photocurable composition may further contain, as necessary, one or more of the following: a polymerizable compound other than the monofunctional (meth)acrylate or polyfunctional (meth)acrylate, a thickener, a crosslinking agent, an antifoaming agent, an organic solvent, etc.

[0084] The photocurable composition can be obtained by mixing the above-mentioned components using a mixer such as a homodisper, homomixer, universal mixer, planetary mixer, kneader, or three-roll mixer.

[0085] The photocurable composition can be cured by irradiation with light to give a cured product, and can be cured as a single liquid photocurable composition.

[0086] A method for producing the frame-type adhesive material of the present disclosure preferably includes, for example, step (1) of attaching two or more pieces of adhesive tape to a separator in a frame shape, step (2) of arranging a photocurable composition between the ends of the adhesive tape pieces, step (3) of curing the photocurable composition, and step (4) of peeling off the separator after step (3).The adhesive sheet described below can be obtained by a production method including steps (1), (2), and (3).

[0087] Examples of a method for disposing the photocurable composition between the ends of the adhesive tape piece include printing methods such as screen printing, inkjet printing, flexographic printing, gravure printing, slot die coating, knife coating, spray coating, spin coating, stencil printing, dispensing, jet dispensing, and reverse offset printing. Among these, disposing the photocurable composition between the ends of the adhesive tape piece by dispensing is preferred.

[0088] When the photocurable composition is arranged, it is preferable that the line width of the adhesive resin, which is the cured product of the photocurable composition, is equivalent to the line width of the adhesive tape piece located at the position where the photocurable composition is arranged. The line width of the adhesive resin means the dimension (length) of the adhesive resin in the width direction perpendicular to the longitudinal direction of the adhesive tape piece when the frame-shaped adhesive material composed of the adhesive tape piece and the adhesive resin is viewed in plan.

[0089] The frame-shaped adhesive is preferably formed on a separator and transferable to an adherend. A structure comprising a separator and the frame-shaped adhesive disposed on at least one surface of the separator is referred to as a "pressure-sensitive adhesive sheet." The material of the adherend is not particularly limited, and examples include metals such as stainless steel and aluminum, and resins.

[0090] [Adhesive sheet] The pressure-sensitive adhesive sheet of the present disclosure comprises a separator and the frame-shaped pressure-sensitive adhesive material described above disposed on at least one surface of the separator.

[0091] The separator is not particularly limited as long as it protects the adhesive surface of the frame-type adhesive material and can be peeled off from the frame-type adhesive material. Specifically, the separator preferably has, for example, a separator substrate and a release layer disposed on at least one side of the separator substrate. The release layer is formed by subjecting the separator substrate to a release treatment. The release layer is composed of an organic resin such as a fluorine-based resin, a long-chain alkyl-containing resin, an alkyd-based resin, a polyolefin-based resin, a PET resin, or a rubber-based elastomer. Examples of separator substrates include resin films made of thermoplastic resins, thermosetting resins, elastomer resins, and the like, and paper.

[0092] The separator may also be the substrate of the support-type adhesive tape piece, or may be made of the same material as the substrate.

[0093] The pressure-sensitive adhesive sheet is preferably in a roll form. Forming the pressure-sensitive adhesive sheet in a roll form facilitates the manufacturing process, transportation, and storage of the pressure-sensitive adhesive sheet. Furthermore, the pressure-sensitive adhesive sheet in a roll form is suitable for continuous processing and can be cut to any length depending on the required size, making it flexible for a variety of uses. [Example]

[0094] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, "parts" means "parts by mass."

[0095] 1. Preparation of photocurable composition Compositions A to I were obtained by mixing the materials in a planetary mixer (Thinky Corporation, "Awatori Rentaro") according to the compounding ratios shown in Table 1. The unit in Table 1 is "parts," and the total amount of the monofunctional (meth)acrylate and polyfunctional (meth)acrylate was 100 parts.

[0096] Details of the materials indicated by abbreviations in the table are as follows: <Monofunctional (meth)acrylate> Ethyl carbitol acrylate (Osaka Organic Chemical Industry Co., Ltd., "Viscoat #190, CBA, EEEA") (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl acrylate (Osaka Organic Chemical Industry Co., Ltd., "MEDOL-10") N-Acryloyloxyethylhexahydrophthalimide (Toagosei Co., Ltd., "M-140")

[0097] <Multifunctional (meth)acrylate> Polyether-based multifunctional urethane acrylate (Shin-Nakamura Chemical Co., Ltd., "NK Oligo UA-160TM", number of acryloyl groups per molecule: 2, weight-average molecular weight: 1600)

[0098] <Photoinitiator> Polymer of ethyl (2,4,6-trimethylbenzoyl)-phenylphosphonate (IGM Resins, "Omnipol TP", Norrish type I photoinitiator with a molecular weight of 1200, 3 photoinitiators)

[0099] <Thickener> Elastomer resin without epoxy reactive groups (Kuraray Co., Ltd., "Clarity (registered trademark) LA2140", a block copolymer of methyl methacrylate (MMA) and n-butyl acrylate (nBA))

[0100] <Tackifier> Ultra-light-colored rosin ester (Arakawa Chemical Industries, "KE-359") Rosin-containing diol (Arakawa Chemical Industries, Ltd., "D-6011")

[0101] <Pigments> Highly UV-transmitting black pigment (Mitsubishi Materials Electronic Chemicals Co., Ltd., "NITRBLACK (registered trademark) UB-2")

[0102] <Filler> Fumed silica (Evonic, "AEROSIL® R805")

[0103] [Table 1]

[0104] 2. Prepare adhesive tape pieces <Adhesive tape piece 1> A non-supported transparent adhesive tape (manufactured by Sekisui Chemical Co., Ltd., "SEKISUI SJ Tape", colorless and transparent, 200 μm thick) having no substrate was cut into a strip to prepare adhesive tape piece 1. The line width of the adhesive tape piece was 1 mm.

[0105] <Adhesive tape piece 2> A non-support type black adhesive tape (black, thickness 90 μm) without a substrate was prepared by adding titanium black to "SEKISUI SJ Tape" manufactured by Sekisui Chemical Co., Ltd. Two sheets of this black adhesive tape were prepared, and then the two sheets of black adhesive tape were bonded to both sides of a 19 μm thick PET film substrate to prepare a double-sided adhesive tape (black, total thickness 199 μm). This double-sided adhesive tape was cut into strips to prepare adhesive tape piece 2. The line width of the adhesive tape piece was either 0.1 mm, 1 mm, 5 mm, or 25 mm.

[0106] <Adhesive tape piece 3> The double-sided adhesive tape used to obtain the adhesive tape piece 2 was cut into an L-shape to prepare an adhesive tape piece 3. The line width of the adhesive tape piece was 1 mm.

[0107] <4 pieces of adhesive tape> The double-sided adhesive tape used to obtain the adhesive tape piece 2 was cut into a U-shape to prepare an adhesive tape piece 4. The line width of the adhesive tape piece was 1 mm.

[0108] <Adhesive tape piece 5> The double-sided adhesive tape used to obtain the adhesive tape piece 2 was left uncut to obtain the adhesive tape piece 5.

[0109] 3. Preparation of adhesive sheets, etc. Using the composition obtained in 1 above and the adhesive tape pieces prepared in 2 above, adhesive sheets and the like were produced as follows.

[0110] Example 1 Four pieces of adhesive tape 1 were prepared. These four pieces of adhesive tape were arranged on a release PET film (manufactured by Nippa Corporation, "50E") as shown in Figure 1. However, the longitudinal length of each adhesive tape piece was adjusted appropriately so that the frame size (rectangle) was 10 cm x 10 cm. Thereafter, using a dispenser (manufactured by Musashi Engineering Co., Ltd., "SHOTMASTER300SX"), composition A was applied so as to fill each gap (four locations) between the ends of each adhesive tape piece. Thereafter, a release PET film (manufactured by Nippa Corporation, "38C") was placed facing the adhesive tape pieces and the applied composition, and then the adhesive tape pieces were exposed to light at a wavelength of 365 nm and an illuminance of 2.5 mW / cm. 2 The adhesive sheet was then irradiated with light for 3 minutes, thereby obtaining a frame-shaped adhesive material containing the adhesive tape piece and the cured product of Composition A (adhesive resin) sandwiched between two release PET films. The line width of the cured body (adhesive resin) when the frame-shaped adhesive material is viewed from above is shown in the "Line Width" column of Table 2 (and Table 3).

[0111] <Example 2> An adhesive sheet was obtained in the same manner as in Example 1, except that the adhesive tape piece and photocurable composition shown in Table 2 were used instead of the adhesive tape piece 1 and composition A.

[0112] <Examples 3 to 5> Each adhesive sheet was obtained in the same manner as in Example 2, except that each adhesive tape piece shown in Table 2 was used instead of adhesive tape piece 2.

[0113] Example 6 A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 2, except that the frame size was changed to 4 cm x 4 cm.

[0114] Example 7 A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 2, except that the frame size was changed to 21.5 cm x 38.3 cm.

[0115] Example 8 An adhesive sheet was obtained in the same manner as in Example 2, except that two adhesive tape pieces 3 were used instead of four adhesive tape pieces 2, and the adhesive tape pieces were arranged as shown in Figure 2.

[0116] Example 9 An adhesive sheet was obtained in the same manner as in Example 2, except that two adhesive tape pieces 4 were used instead of four adhesive tape pieces 2, and the adhesive tape pieces were arranged as shown in Figure 3.

[0117] <Examples 10 to 15> Each pressure-sensitive adhesive sheet was obtained in the same manner as in Example 2, except that each photocurable composition shown in Table 3 was used instead of composition B.

[0118] <Comparative Example 1> The adhesive tape piece 5 was punched out so as to form a rectangular opening in the center thereof, and the punched-out portion was discarded. In this way, a square-shaped adhesive tape was obtained.

[0119] <Comparative Example 2> Four pieces of adhesive tape 2 were prepared. These four pieces of adhesive tape were placed on a release PET film (Nippa Corporation, "50E") as shown in Figure 1. However, the longitudinal length of each adhesive tape piece was adjusted appropriately so that the frame size (rectangle) was 10 cm x 10 cm. In this way, an adhesive material consisting of four pieces of adhesive tape was obtained.

[0120] <Comparative Example 3> A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 2, except that composition I was used instead of composition B.

[0121] 4. Evaluation test The following physical property evaluation tests were carried out using the adhesive sheets etc. produced in 3 above. In addition, the adhesive resin (adhesive resin located in one location) was scraped off from each adhesive sheet etc., and the Tan δ peak temperature, shear storage modulus at 25°C, probe tack value at 25°C and gel fraction of the adhesive resin were measured using the measurement methods described above. The results are shown in Tables 2 and 3.

[0122] (1) Spreadability The coatability of the composition used to obtain each PSA sheet was evaluated. Specifically, when the composition was applied to a separator (release PET film) using a dispenser (Musashi Engineering Co., Ltd., "SHOTMASTER300SX"), if the shape immediately after application was maintained for 2 minutes or more, it was evaluated as "Good." If the shape was maintained for 30 seconds or more but less than 2 minutes, it was evaluated as "Acceptable." If the shape was maintained for less than 30 seconds, it was evaluated as "Poor."

[0123] (2) Disposal loss The center was punched out to obtain each adhesive sheet, etc., and if tape waste was generated during this process, it was rated as "×" (Poor), and if punching was not required and no tape waste was generated, it was rated as "◯" (Good).

[0124] (3) Waterproof Each adhesive sheet was attached to a 0.5 mm thick piece of glass and then pressed using a 2 kg roller to prepare a test sample. This test sample was left standing at 23°C for 24 hours. The test sample was then submerged in a water tank and left standing for 5 minutes. The test sample was placed at a depth of 30 cm. The test sample was then removed from the water tank, and the amount of water that had penetrated into the frame was measured and evaluated according to the following criteria. ◎ (Excellent): No water intrusion. ◯ (Good): Water penetration was 1% by volume or less relative to 100% frame volume. △ (Acceptable): Water penetration was more than 1% by volume and 10% by volume or less relative to 100% frame volume. × (Poor): Water intrusion exceeded 10% by volume relative to 100% frame volume.

[0125] (4) Light blocking property For each adhesive material obtained by peeling the release PET film from each adhesive sheet, the OD value in the width direction of the adhesive tape piece (i.e., the direction perpendicular to the longitudinal direction of the adhesive tape piece) was measured using the method described above. The measurement point (measurement location) was the adhesive resin part. For Comparative Example 1, the OD value was measured at an arbitrary point on the square-shaped adhesive tape, and for Comparative Example 2, the OD value was measured at an arbitrary point on adhesive tape piece 2. Each example was evaluated according to the OD value measured using the following criteria. ◎ (Excellent): OD value was 4 or more. ◯ (Good): OD value was 3 or more and less than 4. Δ (Acceptable): OD value was 2 or more and less than 3. × (Poor): OD value was less than 2.

[0126] [Table 2]

[0127] [Table 3] [Explanation of symbols]

[0128] 1: Frame-type adhesive 2: adhesive tape piece 3: Adhesive resin a: Line width of frame-type adhesive material

Claims

1. two or more pieces of adhesive tape; an adhesive resin disposed between the ends of the adhesive tape pieces; The adhesive resin is a frame-type adhesive material having a shear storage modulus of 1 MPa or less at 25°C measured at a frequency of 1 Hz in a dynamic viscoelasticity measurement, or a probe tack value of 0.05 N / 5 mmφ or more measured under conditions of 25°C, a pressure of 98 gf, a pressure rate of 100 mm / sec, a pressure time of 10 seconds, and a peel rate of 5 mm / sec.

2. 2. The frame-type adhesive material according to claim 1, wherein the adhesive resin has a Tan δ peak temperature of 25°C or less when dynamic viscoelasticity is measured at a frequency of 1 Hz.

3. 2. The frame-type adhesive material according to claim 1, wherein the OD value is 2 or more at at least one joint between the adhesive resin and the adhesive tape piece.

4. 2. The frame-shaped adhesive material according to claim 1, wherein at least one of the adhesive tape pieces is in the shape of a strip, an L-shape, or a U-shape.

5. 2. The frame-shaped adhesive material according to claim 1, wherein the adhesive resin is a cured product of a photocurable composition containing a monofunctional (meth)acrylate, a photopolymerization initiator, and a filler.

6. The frame-type adhesive material according to claim 5 , wherein the photocurable composition further contains a polyfunctional (meth)acrylate.

7. The frame-type adhesive material according to claim 1 , wherein the adhesive resin has a gel fraction of 20% by mass or more and 70% by mass or less.

8. A pressure-sensitive adhesive sheet comprising a separator and the frame-shaped pressure-sensitive adhesive material according to any one of claims 1 to 7, disposed on at least one surface of the separator.

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