Adsorption tape, article, adsorption tape peeling method, and part manufacturing method

Abstract

The purpose of the present disclosure is to provide a tape that can be peeled off at low elongation without requiring excessive stress when being stretched and peeled off, an article using the tape, a method for peeling off the tape and a method for manufacturing a processed article.　An adsorption tape of the present invention comprises a base material having elongation properties and an adsorption layer formed on at least one side of the base material and provided with a plurality of recessed portions on the surface opposite to the base material.

Description

[Technical Field]

[0001] The present invention relates to an adhesive tape that can fix or join adherends and can be stretched and peeled from the adherends. The present invention also relates to an article using the adhesive tape, a method for peeling the tape, and a method for manufacturing a part (e.g., a processed product) using the adhesive tape. [Background technology]

[0002] Adhesive tapes that adhere to an adherend via an adhesive layer are fixing or joining means that are excellent in workability and have high adhesive reliability, and are generally widely used for joining components that constitute electronic devices, etc. For example, adhesive tapes are used for joining metal sheets that constitute relatively large electronic devices such as flat-screen televisions, home appliances, and office automation equipment, or joining exterior parts to housings, and for joining exterior parts and rigid parts such as batteries to relatively small electronic devices such as mobile electronic terminals, cameras, and personal computers. In recent years, from the perspective of environmental protection, there has been an increasing demand for the recycling and reuse of used products or products scheduled for disposal. Accordingly, adhesive tapes used for joining or fastening parts are required to be easily peeled and removed without leaving adhesive residue on the adherend when various products are disassembled and each part in the product is removed.

[0003] Adhesive tapes are also used in various processing steps for manufacturing microelectronic components such as semiconductor wafers, multilayer ceramic capacitors (hereinafter sometimes referred to as MLCCs), and inductors. For example, adhesive tapes are used to temporarily fix raw substrates when grinding, cutting, or dividing the substrates. Adhesive tapes used in such processing steps must have sufficient adhesion to prevent peeling during processing, but they must also be able to be peeled off after processing is complete without contaminating the electronic components.

[0004] To meet the demand for easy peelability in each of these applications, for example, heat-foaming adhesive tapes are used, which contain heat-foamable balloons in the adhesive layer, and the balloons foam when heated, reducing the adhesive strength, and active energy ray-curing adhesive tapes, in which the adhesive layer hardens when irradiated with active energy rays such as ultraviolet (UV) light, reducing the adhesive strength (Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-229399 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-121511 [Patent Document 3] International Publication No. 2021 / 149569 Summary of the Invention [Problem to be solved by the invention]

[0006] Heat-expandable pressure-sensitive adhesive tapes and active energy ray-curable pressure-sensitive adhesive tapes have the problem that if they are not heated or irradiated with active energy rays sufficiently, the adhesive will remain on the surface of the adherend upon peeling, resulting in so-called adhesive residue and contaminating the adherend. Furthermore, because these pressure-sensitive adhesive tapes require heating or irradiation with active energy rays in order to be peeled, the adherend must have physical properties such as heat resistance and light transmittance, which limits the types of adherends that can be used.

[0007] On the other hand, as an adhesive tape that does not use heat or light for the peeling operation, there is a stretch-release type adhesive tape that can be peeled by stretching and elongating in at least one direction (Patent Document 3). Stretch-release type adhesive tapes are peeled from the adherends by joining two adherends together and stretching the end of the tape at a desired angle, for example, horizontally or perpendicularly, to the adhesive surface. More specifically, stretch-release type adhesive tapes reduce the adhesive area between the adhesive layer and the adherend during the stretching process, and peel when the adhesive reaches a critical area at which the adherend can no longer follow the adhesive layer of the adhesive tape.

[0008] Conventional stretch-release adhesive tapes use an adhesive layer, which requires a large force when stretching. Furthermore, the adhesive strength of the adhesive layer tends to increase over time, so a larger force may be required when peeling. Furthermore, depending on the size of the adherend, the amount of stretching (stretching distance) required to peel can become large, and there are cases where the tape cannot be easily peeled due to low elongation. In particular, when the surface area of ​​the surface that comes into contact with the tape is 1 cm², 2 When a pressure-sensitive adhesive tape attached to a small adherend such as the one described above is stretched, the amount of stretching (stretching distance) required before peeling tends to be large, making peeling at a low elongation even more difficult.

[0009] The present invention has been made in view of the above circumstances, and has as its object to provide an adhesive tape that can be peeled off with low elongation without requiring excessive stress when stretched and peeled off. Another object of the present invention is to provide an article using the above-mentioned suction tape, a method for peeling off the above-mentioned suction tape, and a method for manufacturing a part (for example, a processed product) using the above-mentioned suction tape. [Means for solving the problem]

[0010] The present invention has the following aspects. [1] An adsorption tape having an extensible substrate and an adsorption layer provided on at least one side of the substrate and having a plurality of recesses on the surface opposite the substrate. [2] The adsorption tape according to [1] above, wherein the base material has a breaking elongation of 200% or more. [3] The adsorption tape according to [1] or [2] above, wherein the average opening diameter of the recesses is 300 μm or less. [4] The apparent density of the adsorption layer is 0.1 g / cm 3 More than 1.0g / cm 3 The adsorption tape according to any one of the above [1] to [3], which is as follows: [5] The adsorption tape according to any one of the above [1] to [4], wherein the adsorption layer has an open-cell structure. [6] The adsorption tape according to any one of [1] to [5] above, wherein the opening ratio of the recesses in a plan view of the surface of the adsorption layer opposite to the substrate is 1% or more and 99% or less. [7] The adsorption tape according to any one of the above [1] to [6], wherein the thickness of the adsorption layer is within the range of 10 μm to 1000 μm. [8] The adsorption tape according to any one of the above [1] to [7], further comprising an intermediate layer between the substrate and the adsorption layer. [9] The adsorption tape according to any one of the above [1] to [8], which has a breaking elongation in the range of 200% to 3000% and a breaking strength in the range of 5 MPa to 100 MPa.

[10] The adsorption tape according to any one of the above [1] to [9], which has an elongation at peeling in the range of 101% to 400%.

[11] The adhesive tape according to any one of the above [1] to

[10] , which can be stretched and peeled off.

[12] The suction tape according to any one of [1] to

[11] above, which is used for temporarily fixing parts.

[13] The suction tape according to any one of [1] to

[11] above, which is used for joining two or more parts.

[14] An article comprising a component on the surface of the suction layer of the suction tape according to any one of [1] to

[13] above.

[15] The above-mentioned adhesive tape is a single-sided tape having the above-mentioned adhesive layer on one side of the above-mentioned substrate, The article according to

[14] above, wherein a component is provided on the surface of the adsorption layer.

[16] The article according to

[14] above, wherein the suction tape is double-sided, with the suction layer on each side of the substrate, and has component A on the surface of one suction layer A of the suction tape, and component B on the surface of the other suction layer B of the suction tape.

[17] A method for peeling off the adsorption tape according to any one of [1] to

[13] above that has been attached to an adherend, the method comprising stretching the adsorption tape in at least one direction to peel it off from the adherend.

[18] The method for peeling off an adsorption tape according to

[17] above, wherein the adherend is a small electronic component.

[19] The surface area of ​​the adherend that comes into contact with the suction tape is 100 mm 2 The method for peeling off an adsorption tape according to the above

[17] or

[18] , which is as follows:

[20] A method for manufacturing a component, comprising at least a peeling step of stretching the suction tape according to any one of [1] to

[13] above in at least one direction to peel off a component fixed on the suction layer of the suction tape.

[21] The method for manufacturing a part described in

[20] above, wherein the peeling step includes a transfer step of placing a transfer object on the surface of the part opposite to the suction tape side, and stretching the suction tape in at least one direction from a composite having the suction tape, the part, and the transfer object in this order to peel it off from the part and simultaneously transfer the part to the transfer object.

[22] The method for manufacturing a component according to

[20] or

[21] above, wherein the component is a small electronic component.

[23] The surface area of ​​the part that comes into contact with the adhesive tape is 100 mm 2 The method for manufacturing a part according to any one of the above items

[20] to

[22] , which is as follows:

[24] A method for manufacturing a processed product, comprising the steps of: processing an adherend (workpiece) provided on the surface of the adsorption layer of the adsorption tape described in any one of [1] to

[13] above; and stretching the adsorption tape in at least one direction and peeling the processed adherend (workpiece) from the adsorption layer.

[25] The method for manufacturing a workpiece according to

[24] above, wherein the workpiece is a small electronic component.

[26] The surface area of ​​the workpiece in contact with the suction tape is 1 cm 2 A method for manufacturing a processed product according to the above

[24] or

[25] , which is as follows: [Effects of the Invention]

[0011] According to the present invention, it is possible to provide an adhesive tape that can adsorb and temporarily fix an adherend, and that can be peeled off with low elongation without requiring excessive stress when stretched and peeled off. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic cross-sectional view showing an example of the suction tape of the present invention. [Figure 2] 1 is a schematic diagram showing an adherend adhered (temporarily fixed) to the adsorption tape of the present invention, viewed from above the adherend. [Figure 3] FIG. 2 is a cross-sectional view taken along line AA in FIG. [Figure 4] 1A and 1B are schematic top and cross-sectional views of an adsorption layer. [Figure 5] 1 is a schematic diagram showing a method for measuring the surface adhesive strength of the suction tape of the present invention. [Figure 6] 1A to 1C are process diagrams showing an example of a method for manufacturing a part according to the present invention. [Figure 7] 1A to 1C are process diagrams showing an example of a method for manufacturing a part according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] 1. Adsorption tape The adsorption tape of the present invention (hereinafter also referred to as "this tape") has an extensible substrate and an adsorption layer provided on at least one side of the substrate and having a plurality of recesses on the surface opposite the substrate.

[0014] FIG. 1(a) is a schematic cross-sectional view showing an example of an adsorption tape of the present invention, and FIG. 1(b) is an enlarged view of the dotted line region X in FIG. 1(a). The adsorption tape 1 of the present invention has an adsorption layer 3 provided on one surface of an extensible substrate 2. The adsorption layer 3 has a plurality of recesses 4 on at least the surface 6 opposite the substrate 2 (surface 6 of the adsorption layer). In the tape 1 illustrated in FIG. 1, the surface 6 of the adsorption layer 3 opposite the substrate 2 constitutes one surface of the tape 1, and the surface of the substrate 2 opposite the adsorption layer 3 constitutes the other surface of the tape 1. The surface 6 of the adsorption layer 3 includes the imaginary surface 7 of the recesses 4 (the surface when it is assumed that no recesses are formed). Note that FIG. 4(a), which will be described later, shows a top view of the adsorption layer 3.

[0015] 2 and 3 are schematic diagrams showing a state in which an adherend has been temporarily fixed to the adsorption tape of the present invention, with Fig. 2 being a top view of the adsorption tape as seen from the side on which the adherend is placed, and Fig. 3 being a cross-sectional view taken along line AA in Fig. 2. Note that the multiple recesses 4 on the surfaces of the substrate 2 and the adsorption layer 3 have been omitted from Fig. 2. As illustrated in Figs. 2 and 3, in this tape 1, multiple recesses 4 are formed on the surface 6 of the adsorption layer 3 opposite the substrate 2, and these recesses 4 enable an adherend 5, such as a part, to be fixed on the surface 6. In other words, the surface 6 of the adsorption layer 3 opposite the substrate 2 is the fixing surface (placement surface) for the adherend 5.

[0016] When an adherend is pressed against the surface of the adsorption layer opposite the substrate, the depressions on the surface of the adsorption layer deform, releasing air between the adherend and the adsorption layer and forming an enclosed space. At this time, the pressure difference between the enclosed space and the outside causes the depressions to act as suction cups, adhering to the adherend, allowing the tape to adhere to the adherend and maintaining a fixed state of the adherend. On the other hand, when the tape is stretched (extended), the stress of the stretching deforms the depressions on the surface of the adsorption layer, increasing distortion, and allowing air to enter between the adherend and the depressions, releasing the enclosed space. This eliminates the suction cup function of the depressions in the adsorption layer, allowing the tape to be quickly peeled off from the adherend.

[0017] In the case of a tape that can be stretched and peeled from an adherend, peeling occurs when the adhesive area between the tape and the adherend is reduced during the stretching process. However, in the case of a tape having a conventional adhesive layer, the amount of stretching required to reach the adhesive area at which peeling occurs tends to be large due to the tackiness and adhesive strength of the adhesive layer. In particular, when the contact area with the tape (the surface area of ​​the surface of the adherend in contact with the tape) of the adherend is less than 500 mm 2 Below, further 100mm 2 For the following adherends, it is difficult to achieve a reduction in the adhesive area between the tape and the adherend relative to the tape's elongation rate, and the adherend can adhere to the tape even if the adhesive area between the adherend and the tape is small. Therefore, even if the adhesive area decreases as the tape is stretched, the adherend can be held with a small adhesive area, and as a result, the amount of stretching required to reach an adhesive area large enough to cause the small adherend to peel off tends to be even greater. In contrast, with the present tape, the suction function of the adhesive layer allows it to be attached to and detached from the adherend, particularly small adherends, so it can be peeled off with a small amount of stretching (low elongation) even when peeling from the adherend.

[0018] Furthermore, stretch-peelable tapes using conventional adhesives fix or bond adherends by utilizing the tackiness of the adhesive layer, which can require excessive stress when stretching and peeling, and can easily leave adhesive residue on the adherend. Furthermore, as the tackiness of the adhesive layer increases over time, the stress required for stretching increases, making adhesive residue more likely to occur. In contrast, the present tape utilizes the adhesive force of the recesses in the adhesive layer, so does not require excessive stress when stretching and peeling, and adhesive residue is less likely to occur. Furthermore, because the adhesive force of the present tape is less likely to change over time, it can be peeled with low stress and a small amount of stretching, even over time. This effect is particularly pronounced when the adherend is small and lightweight.

[0019] [Base material] The tape has a substrate having extensibility (hereinafter also referred to as "the substrate"). The substrate needs to be extensible in at least one direction, and preferably has extensibility (stretchability) in all directions within the plane.

[0020] The substrate at least has extensibility that allows it to stretch under tension, but may also have stretchability that allows it to stretch under tension and then shrink to return to its original shape when the tension is released, or it may not necessarily return to its original shape. From the viewpoint of having extensibility, the substrate preferably has at least one of the following physical properties, and more preferably has at least a desired breaking elongation.

[0021] The breaking elongation of the substrate is preferably 200% or more, more preferably 300% or more, more preferably 400% or more, and even more preferably 500% or more, from the viewpoint of exhibiting good extensibility. By making the breaking elongation of the substrate 200% or more, the substrate can exhibit better extensibility, and even when the tape is firmly attached to the adherend, it is possible to prevent excessive stress when stretching and peeling the tape. Furthermore, the breaking elongation of the substrate is not particularly limited as long as the effects of the present invention can be achieved, but since the tape can be peeled from the adherend with a short stretching distance, it can be, for example, 2000% or less, preferably 1800% or less, more preferably 1700% or less, and even more preferably 1500% or less.

[0022] The 50% modulus of the substrate can be 120 MPa or less, preferably 100 MPa or less, and from the viewpoint of superior elongation, more preferably 50 MPa or less, more preferably 30 MPa or less, and particularly preferably 15 MPa or less. Specifically, the 50% modulus of the substrate can be in the range of 0.1 MPa to 120 MPa, preferably 0.3 MPa to 100 MPa, more preferably 0.5 MPa to 50 MPa, even more preferably 1.0 MPa to 25 MPa, even more preferably 1.5 MPa to 15 MPa, and particularly preferably 3.0 MPa to 10 MPa. When the 50% modulus of the substrate is in the above range, the tape can be peeled from the adherend without tearing even when pulled at a relatively high speed when stretched and peeled from the adherend, and the tensile stress when stretching the tape is not too large, making the substrate and the tape easy to elongate.

[0023] The breaking elongation of the substrate refers to the tensile elongation measured when the substrate is punched into a dumbbell shape with a gauge length of 20 mm and a width of 5 mm, and pulled lengthwise at a rate of 500 mm / min using a Tensilon tensile tester (model: RTF-1210, manufactured by A&D Co., Ltd.) at 23°C and 50% RH until breakage. The 50% modulus of the substrate refers to the stress value of the substrate when it is pulled to 50% elongation using the same method as used to measure the breaking elongation of the substrate. In this specification, the "elongation" in the breaking elongation and the "elongation" in the modulus refer to the ratio of the elongated length to the gauge length before elongation [{(gauge length after elongation - gauge length before elongation) / gauge length before elongation} × 100(%)]. The same applies hereinafter.

[0024] The breaking strength of the substrate is not particularly limited as long as the tape can be stretched and peeled off without breaking, but is preferably in the range of 1 MPa to 100 MPa, more preferably 5 MPa to 90 MPa, even more preferably 10 MPa to 90 MPa, more preferably 20 MPa to 90 MPa, and even more preferably 30 MPa to 90 MPa. If the breaking strength of the substrate is within the above range, breaking when the tape is stretched and peeled off can be suppressed, and the stress of stretching the tape can be suppressed from becoming too great.

[0025] The breaking strength per unit width of the substrate is preferably in the range of 1.0 N / mm to 20 N / mm, preferably in the range of 1.5 N / mm to 18 N / mm, preferably in the range of 2.0 N / mm to 15 N / mm, preferably in the range of 2.5 N / mm to 12 N / mm, and preferably in the range of 3.0 N / mm to 10.0 N / mm. By setting the breaking strength per unit width of the substrate within the above range, the tape is less likely to break even when pulled at a high speed when stretched, and the stress when stretching the tape can be prevented from becoming too large. In particular, when the tape is used as a temporary fixing tape for temporarily fixing an adherend, the breaking strength per unit width of the substrate is preferably within the above range.

[0026] The breaking strength of this substrate is measured by punching out a dumbbell shape with a gauge length of 20 mm and a width of 5 mm (initial width) from the substrate, and pulling it lengthwise at a tensile speed of 500 mm / min using a Tensilon tensile tester (model: RTF-1210, manufactured by A&D Co., Ltd.) under conditions of 23°C and 50% RH. The breaking strength per unit width of this substrate is the stress value obtained by dividing the above stress value by the initial width.

[0027] The breaking elongation, 50% modulus, breaking stress, and breaking stress per unit width of the substrate can be adjusted by appropriately selecting the material of the substrate, applying stretching during the manufacturing process of the substrate, etc.

[0028] <Base material composition> The material of the substrate is not particularly limited as long as it has extensibility, but it is usually composed of a substrate composition containing a resin as its main component. A resin layer such as a resin film or resin sheet can be used as the substrate. The substrate may be composed solely of a resin, or may contain a resin as its main component and any other component in addition to the resin. The main component refers to the component that is contained in the largest amount in the total mass of the substrate. The resin content of the total mass of the substrate is preferably 50% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, particularly preferably 95% by mass or more, and may be substantially 100% by mass.

[0029] The substrate may be a single layer or a multilayer containing the above resin, and each layer may contain the same resin as a main component or different resins as main components.

[0030] Examples of resins constituting the substrate include styrene-based resins, urethane-based resins, polyolefin resins, polyester resins, polystyrene, polycarbonate, polymethylpentene, polysulfone, polyether ether ketone, polyether sulfone, polyetherimide, polyimide, fluororesin, nylon, acrylic resin, etc. These resins may be used alone or in combination of two or more.

[0031] The resin preferably has hard segments X and soft segments Y, and the soft segments Y are block copolymers composed of a random copolymer of linear structural units and structural units having side chains. The random presence of linear structural units that contribute to crystallinity and structural units having side chains that contribute to extensibility within the soft segments Y constituting the block copolymer facilitates both improved extensibility and strength at break. This means that the loss of extensibility due to steric hindrance from the structural units having side chains in the soft segments Y can be suppressed, and the extensibility provided by the soft segments Y can be maintained. Meanwhile, the presence of linear structural units in the soft segments Y allows the soft segments Y to form a crystalline structure between molecules when stretched, thereby increasing cohesive force and strength at break. The block copolymer is preferably a triblock or higher copolymer, with a triblock copolymer being preferred, as this facilitates the exertion of the effects of the hard segments X and the soft segments Y. Examples of such resins include styrene-based resins which are styrene-based block copolymers having a hard segment X and a soft segment Y and / or hydrogenated products thereof, urethane-based resins which are urethane-based block copolymers having a hard segment X and a soft segment Y and / or hydrogenated products thereof, and acrylic-based resins which are acrylic-based block copolymers having a hard segment X and a soft segment Y and / or hydrogenated products thereof. Among these, it is more preferable that the block copolymer is a triblock copolymer, since this can achieve both excellent breaking strength and extensibility due to excellent cohesive force.

[0032] The resin is preferably a thermoplastic resin, and among the above-mentioned resins, styrene-based resins, urethane-based resins, and acrylic-based resins are preferred from the viewpoint of being easily adjustable to a suitable breaking stress and breaking elongation. The present substrate is preferably composed primarily of a resin selected from the group consisting of styrene-based resins, urethane-based resins, and acrylic-based resins, as this facilitates the production of a substrate with excellent moldability and excellent breaking elongation and breaking stress. The content of the resin selected from the above group contained in 100% by mass of all resin components constituting the substrate is preferably within the range of 50% to 100% by mass, more preferably within the range of 70% to 100% by mass, more preferably within the range of 80% to 100% by mass, and even more preferably within the range of 90% to 100% by mass. It is particularly preferred that the content be substantially 100% by mass, i.e., that the present substrate is composed of a resin selected from the above group.

[0033] (styrene resin) The styrene-based resin may have a single structure, such as a linear structure, a branched structure, or a multi-branched structure, or may have different structures. A styrene-based resin rich in linear structures can provide excellent elongation at break to the substrate. On the other hand, a styrene-based resin having a branched or multi-branched structure but with styrene blocks at the molecular end can form a pseudo-crosslinked structure and provide excellent cohesive strength. Therefore, it is preferable to use a mixture of styrene-based resins having two or more structures according to the required mechanical properties.

[0034] The styrene-based resin may be any resin containing a structural unit derived from an aromatic vinyl compound, and is preferably a resin containing a structural unit derived from styrene represented by the following general formula (1).

[0035] [ka]

[0036] The styrene-based resin preferably contains structural units derived from aromatic vinyl compounds, particularly structural units derived from styrene represented by the general formula (1) above, in the range of 5% to 75% by mass, more preferably 5% to 50% by mass, even more preferably 10% to 45% by mass, and particularly preferably 10% to 40% by mass, because this makes it easier to obtain the elongation at break and stress at break of the substrate in suitable ranges.

[0037] The styrene resin may have one or more functional groups, such as a carboxyl group, a hydroxyl group, an acid anhydride group, an amino group, or an epoxy group, in the molecular chain and / or at the molecular terminal, or may have no functional groups, as long as the purpose and effects of the invention are not impaired. For example, hydrogen atoms on the benzene ring of the styrene resin may be substituted with alkyl groups, such as methyl and ethyl, and the number of alkyl groups to be substituted may be any number from 1 to 5.

[0038] Among the styrene-based resins, styrene-based block copolymers are preferred because they have a low modulus of elasticity in the low elongation range and can be used as a substrate with high strength and excellent elongation at break. The styrene-based resin may be composed of one type of styrene-based block copolymer or a mixture of two or more types of styrene-based block copolymers.

[0039] The styrene-based block copolymer is a copolymer of an aromatic vinyl compound and a conjugated diene compound, and is a copolymer containing a block mainly composed of aromatic vinyl compound units (hereinafter also referred to as polymer block (A)) and a block mainly composed of conjugated diene compound units (hereinafter also referred to as polymer block (B)), and / or a hydrogenated product thereof. The term "mainly composed of" means that, with the total mass of all polymer blocks being 100% by mass, the structural unit contained in each polymer block accounts for 50% by mass or more, preferably 70% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and may even be substantially 100% by mass.

[0040] The preferred range of the proportion of aromatic vinyl compound units in the styrene-based block copolymer (particularly, the preferred range of the proportion of styrene-derived structural units represented by the general formula (1) or the like) can be the same as the preferred range of the proportion of aromatic vinyl compound units described above (particularly, the preferred range of the styrene-derived structural units represented by the general formula (1) or the like), because this makes it easier to obtain the elongation at break and stress at break of the substrate within a suitable range.

[0041] Specific compounds constituting the polymer block (A) and polymer block (B) of the styrene-based block copolymer include, for example, aromatic vinyl compounds and conjugated diene compounds disclosed in JP 2022-094735 A. Examples of aromatic vinyl compounds constituting the aromatic vinyl compound unit of polymer block (A) include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 1,3-dimethylstyrene, diphenylethylene, 1-vinylnaphthalene, 4-propylstyrene, 4-cyclohexylstyrene, 4-dodecylstyrene, 2-ethyl-4-benzylstyrene, and 4-(phenylbutyl)styrene. Aromatic vinyl compounds may be used alone or in combination. Among these, aromatic vinyl compounds (styrene) represented by the above general formula (1) are preferred. Examples of conjugated dienes constituting the conjugated diene compound units of the polymer block (B) include 1,3-butadiene, 2-methyl-1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, and 1,3-hexadiene. Among these, 1,3-butadiene and 2-methyl-1,3-butadiene (isoprene) are preferred from the viewpoint of versatility. The conjugated diene compounds may be used alone or in combination of two or more.

[0042] The styrene-based block copolymer may be a styrene-based diblock copolymer, a styrene-based triblock copolymer, or a tetrablock or higher styrene-based block copolymer. The styrene-based block copolymer may also be a mixture of a diblock copolymer and a triblock copolymer. Among these, it is more preferable that the styrene-based resin contains at least a styrene-based triblock copolymer, from the viewpoint of achieving both excellent cohesion and extensibility of the substrate. When the styrene-based resin is a mixture of a styrene-based diblock copolymer and a styrene-based triblock copolymer, the content of the styrene-based triblock copolymer in the styrene-based resin is preferably 30% by mass or more, more preferably 40% by mass or more, even more preferably 50% by mass or more, and particularly preferably 60% by mass or more.

[0043] Specific examples of styrene-based block copolymers include styrene-isoprene block copolymers, styrene-isoprene-styrene block copolymers, styrene-isoprene-butadiene-styrene block copolymers, styrene-butadiene-styrene block copolymers, styrene-ethylene-butylene block copolymers, and styrene-ethylene-propylene block copolymers. These may be used alone or in combination of two or more. Examples of the above mixtures include a mixture of a styrene-isoprene block copolymer and a styrene-isoprene-styrene block copolymer.

[0044] The styrene-based block copolymer may also be a hydrogenated styrene-based block copolymer. A hydrogenated styrene-based block copolymer is a copolymer in which the double bonds in the main chain of the styrene-based block copolymer are hydrogenated. Among these, a hydrogenated styrene-based block copolymer composed of a polymer block A mainly composed of styrene compound units and a polymer block B, which is a block composed of a random copolymer of units in which a linear butadiene structure is hydrogenated and units in which an isoprene structure is hydrogenated, is preferred. The polymer block B contains linear structural units that contribute to crystallinity and structural units having side chains that contribute to extensibility, which are present randomly, making it easier to achieve both improved extensibility and breaking strength of the tape.

[0045] Examples of the hydrogenated styrene-based block copolymer include hydrogenated products of the block copolymers listed above as specific examples of the styrene-based block copolymer. Specific examples include styrene-ethylene / butylene-styrene block copolymer (SEBS) and styrene-ethylene-ethylene / propylene-styrene block copolymer (SEEPS). The styrene-ethylene-ethylene / propylene-styrene block copolymer is a hydrogenated product of a block copolymer formed from styrene-butadiene-isoprene-styrene. The styrene-ethylene / butylene-styrene block copolymer is a hydrogenated product of a styrene-isoprene / butadiene-styrene block copolymer. Among these, the hydrogenated product of a styrene-isoprene-butadiene-styrene block copolymer is particularly preferred.

[0046] The content of the styrene-based block copolymer in the substrate is preferably in the range of 100% to 50% by mass, more preferably in the range of 100% to 60% by mass, more preferably in the range of 100% to 70% by mass, even more preferably in the range of 100% to 80% by mass, particularly preferably in the range of 100% to 90% by mass, and may even be substantially 100% by mass, where the total amount of resin in the substrate is 100% by mass. The resulting substrate has a low elastic modulus in the low elongation range, high strength, and excellent elongation at break.

[0047] The weight-average molecular weight (hereinafter also referred to as "Mw") of the styrene-based resin, as measured by gel permeation chromatography (GPC) in terms of standard polystyrene, is preferably in the range of 10,000 to 800,000, more preferably in the range of 30,000 to 500,000, and even more preferably in the range of 50,000 to 300,000. Having the Mw of the styrene-based resin within the above preferred range ensures thermal flowability and compatibility when diluted with a solvent, which is preferable because it allows for the production of a substrate that is heat-resistant while maintaining good workability in the manufacturing process. When the styrene-based resin is a hydrogenated styrene-based block copolymer, the weight-average molecular weight can be set within the above range, but is preferably in the range of 50,000 to 500,000, more preferably in the range of 60,000 to 400,000, even more preferably in the range of 65,000 to 300,000, and particularly preferably in the range of 70,000 to 115,000.

[0048] In this specification, the weight average molecular weight is a value measured using gel permeation chromatography (GPC) in terms of standard polystyrene, and the measurement conditions for the GPC method are as follows. [Measurement conditions] Sample concentration: 0.5% by mass (tetrahydrofuran (THF) solution) Sample injection volume: 100 μL · Eluent: THF · Flow rate: 1.0mL / min · Measurement temperature: 40℃ Column: TSKgel GMHHR-H(20) x 2 Guard column: TSKgel HXL-H Detector: Differential refractometer Standard polystyrene molecular weight: 10,000 to 20 million (Tosoh Corporation)

[0049] Styrenic resins can be produced using known methods, and the production method can be appropriately selected depending on the type of styrene-based resin. For example, known methods can be used to produce styrene-based block copolymers, such as a method of sequentially polymerizing blocks using an anionic living polymerization method, or a method of producing a block copolymer having a living active terminal and then reacting it with a coupling agent to produce a coupled block copolymer. In addition, when the styrene-based resin is a mixture of two or more types of styrene-based block copolymers, they can also be produced as a mixture simultaneously in a single polymerization process. For more specific production methods of various styrene-based resins, methods disclosed in, for example, International Publication No. 2019-003933 and JP 2022-094735 A can be used.

[0050] (urethane resin) As the urethane-based resin, a reaction product of polyol and polyisocyanate can be suitably used. Specific examples of the reaction product include ester-based polyurethane, ether-based polyurethane, polycarbonate-based polyurethane, etc. The urethane-based resins may be used alone or in combination of two or more.

[0051] The polyol can be appropriately selected depending on the purpose, and examples thereof include polyester polyol, polyether polyol, polycarbonate polyol, and acrylic polyol. One type of polyol may be used, or two or more types may be used in combination. Among these, polyester polyol and polyether polyol are preferred as polyols from the viewpoint of obtaining the mechanical properties of the substrate. When heat resistance is required for the substrate, it is preferable to use polyester polyol, and when water resistance and biodegradability resistance are required, it is preferable to use polyether polyol.

[0052] Examples of the polyester polyol include polyesters obtained by an esterification reaction between a low-molecular-weight polyol and a polycarboxylic acid, polyesters obtained by a ring-opening polymerization reaction of a cyclic ester compound such as ε-caprolactone, and copolymer polyesters thereof.

[0053] Examples of the low molecular weight polyols include aliphatic alkylene glycols having a Mw of approximately 60 to 280, such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, neopentyl glycol, and 1,3-butanediol, and cyclohexanedimethanol.

[0054] Examples of the polycarboxylic acid include aliphatic dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, and dodecanedicarboxylic acid; aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, and naphthalenedicarboxylic acid; and anhydrides or esters thereof.

[0055] Examples of the polyether polyol include those obtained by addition polymerization of alkylene oxide using one or more compounds having two or more active hydrogen atoms as an initiator.

[0056] Examples of the polycarbonate polyol include polycarbonate polyols obtained by reacting a carbonate ester and / or phosgene with a low-molecular-weight polyol described below.

[0057] Examples of the carbonate ester include methyl carbonate, dimethyl carbonate, ethyl carbonate, diethyl carbonate, cyclocarbonate, and diphenyl carbonate.

[0058] Examples of low-molecular-weight polyols that can be used to produce the polycarbonate polyols and that can react with carbonate esters and / or phosgene include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, tripropylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,5-hexanediol, 1,6-hexanediol, and 2,5-hexanediol. , 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 2-butyl-2-ethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 2-methyl-1,8-octanediol, 1,4-cyclohexanedimethanol, hydroquinone, resorcinol, bisphenol A, bisphenol F, 4,4'-biphenol, and the like.

[0059] The polyisocyanate can be appropriately selected depending on the purpose, and examples thereof include alicyclic polyisocyanates, aliphatic polyisocyanates, aromatic polyisocyanates, etc. Examples of the polyisocyanate include alicyclic polyisocyanates, etc. One type of polyisocyanate may be used, or two or more types may be used in combination.

[0060] Examples of the alicyclic polyisocyanate include isophorone diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, 4,4'-dicyclohexylmethane diisocyanate, 2,4-methylcyclohexane diisocyanate, 2,6-methylcyclohexane diisocyanate, cyclohexylene diisocyanate, methylcyclohexylene diisocyanate, bis(2-isocyanatoethyl)-4-cyclohexylene-1,2-dicarboxylate, 2,5-norbornane diisocyanate, 2,6-norbornane diisocyanate, dimer acid diisocyanate, bicycloheptane triisocyanate, etc. Alicyclic polyisocyanates may be used alone or in combination of two or more.

[0061] In the urethane resin, the equivalent ratio (NCO / OH equivalent ratio) of the isocyanate group (NCO) of the polyisocyanate to the hydroxyl group (OH) of the polyol is preferably within the range of 1 to 20, more preferably within the range of 1.1 to 13, even more preferably within the range of 1.2 to 5, and particularly preferably within the range of 1.5 to 3.

[0062] Known methods can be used to produce a urethane resin by reacting a polyol with a polyisocyanate. For example, a method can be used in which a polyol charged in a reaction vessel is heated under normal or reduced pressure to remove moisture, and then the polyisocyanate is supplied all at once or in portions to cause the reaction. The reaction conditions for the polyol and polyisocyanate can be, for example, the conditions disclosed in JP 2022-094735 A. When reacting a polyol with a polyisocyanate, a catalyst may be used as needed. The reaction may be carried out in a solvent-free environment or in the presence of an organic solvent. For example, the catalyst and organic solvent disclosed in JP 2022-094735 A can be used.

[0063] (acrylic polymer) The acrylic polymer constituting the substrate may be a random polymer or a block polymer, and the type of polymer is not particularly limited. In particular, the acrylic substrate preferably contains an acrylic block polymer. The acrylic block copolymer may be a diblock copolymer, a triblock copolymer, or a tetrablock or higher block copolymer. Two or more acrylic block copolymers with different block structures may be used in combination. Among these, acrylic triblock copolymers are more preferred because they can achieve both excellent breaking strength and extensibility due to their excellent cohesive force.

[0064] As the acrylic block copolymer, a triblock copolymer having a repeating unit represented by general formula (2) can be used.

[0065] [ka]

[0066] (In the above general formula (2), A, B, and C each independently represent a repeating unit, A and C each independently represent a methacrylic acid alkyl ester monomer unit, B represents an acrylic acid alkyl ester monomer unit, p, q, and r each independently represent the degree of polymerization of each monomer unit. A and C may be methacrylic acid alkyl ester monomer units having the same chemical structure or may be methacrylic acid alkyl ester monomer units having different chemical structures. In the above general formula (2), * represents a bond to another atom, and the same applies hereinafter.)

[0067] In the above general formula (2), A and C each independently represent a methacrylic acid alkyl ester monomer unit. The term "methacrylic acid alkyl ester monomer unit" refers to a structural unit derived from a methacrylic acid alkyl ester monomer when the methacrylic acid alkyl ester monomer is (co)polymerized or graft polymerized, i.e., a repeating unit derived from a methacrylic acid ester monomer. The methacrylic acid alkyl ester monomer unit in the present invention is preferably a methacrylic acid alkyl ester monomer unit represented by the following general formula (3):

[0068] [ka]

[0069] (In the above general formula (3), R 1 represents an alkyl group having 1 to 12 carbon atoms, and one or more hydrogen atoms in the alkyl group are substituted by a substituent R 2 The substituent R 2 is, for example, a halogen atom, an amino group, or a cyano group.

[0070] In the above general formula (3), R 1 is preferably an alkyl group having 1 to 12 carbon atoms, and from the viewpoint of improving the cohesiveness and breaking strength of the substrate, an alkyl group having 1 to 4 carbon atoms is more preferred, and an alkyl group having 1 or 2 carbon atoms is even more preferred. In addition, in the above general formula (3), the alkyl group having 1 to 12 carbon atoms may be linear, branched, or cyclic, but from the viewpoint of improving the cohesiveness and obtaining a substrate with high breaking strength, a linear or branched group is preferred, and a linear group is more preferred.

[0071] In the general formula (3), examples of the alkyl group having 1 to 12 carbon atoms include linear or branched alkyl groups such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl, n-pentyl, isopentyl, hexyl, octyl, nonyl, decyl, undecyl, and dodecyl, as well as cyclic alkyl groups such as cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, dicyclopentanyl, and adamantyl. Among these, from the viewpoint of forming a substrate with high breaking strength, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl, or cyclobutyl is preferred, with methyl, ethyl, and propyl being more preferred. One or more hydrogen atoms in the alkyl group may be substituted with a halogen atom, an amino group, or a cyano group.

[0072] Examples of the alkyl methacrylate monomer include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, t-butyl methacrylate, n-pentyl methacrylate, isopentyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, pentadecyl methacrylate, cyclohexyl methacrylate, lauryl methacrylate, tridecyl methacrylate, 2-hexyldecyl methacrylate, etc. Of these, methyl methacrylate is preferred.

[0073] In the general formula (2), B represents an acrylate alkyl ester monomer unit. In this specification, the term "acrylate alkyl ester monomer unit" refers to a structural unit derived from an acrylate alkyl ester monomer when the acrylate alkyl ester monomer is (co)polymerized or graft polymerized, i.e., a repeating unit derived from an acrylate ester monomer. The acrylate alkyl ester monomer unit is preferably an acrylate alkyl ester monomer unit represented by the following general formula (4):

[0074] [ka]

[0075] (In the above general formula (4), R 3 represents an alkyl group having 1 to 12 carbon atoms, and one or more hydrogen atoms in the alkyl group are substituted by a substituent R 4 The substituent R 4 is, for example, a halogen atom, an amino group, or a cyano group.

[0076] In the above general formula (4), R 3 is more preferably an alkyl group having 1 to 12 carbon atoms, and even more preferably an alkyl group having 4 to 8 carbon atoms. In the above general formula (4), the alkyl group having 1 to 12 carbon atoms may be linear, branched, or cyclic, but is preferably linear or branched. In addition, the alkyl group having 1 to 12 carbon atoms is the same as the alkyl group exemplified in the above general formula (3).

[0077] Preferred R in the above general formula (4) 3 is a linear or branched alkyl group such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl, n-pentyl, isopentyl, hexyl, octyl, nonyl, decyl, undecyl, or dodecyl, or a cyclic alkyl group such as cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, dicyclopentanyl, or adamantyl. One or more hydrogen atoms in the alkyl group may be substituted with a halogen atom, an amino group, or a cyano group.

[0078] Examples of the alkyl acrylate monomer include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, sec-butyl acrylate, t-butyl acrylate, amyl acrylate, isoamyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, etc. Among these, from the viewpoint of imparting extensibility to the substrate, n-butyl acrylate, 2-ethylhexyl acrylate, and copolymers thereof are preferred.

[0079] In the general formula (2), p, q, and r each independently represent the degree of polymerization of each monomer unit. The values ​​of p, q, and r relate to molecular weight, etc. p / (p+q+r) is preferably in the range of 0.02 to 0.40, more preferably in the range of 0.05 to 0.37. q / (p+q+r) is preferably in the range of 0.20 to 0.95, more preferably in the range of 0.25 to 0.90. r / (p+q+r) is preferably in the range of 0.02 to 0.40, more preferably in the range of 0.05 to 0.37.

[0080] The acrylic block copolymer is preferably an acrylic block copolymer having a repeating unit represented by the following general formula (5).

[0081] [ka]

[0082] (In the above general formula (5), R 1 and R 5 each independently represents an alkyl group having 1 to 12 carbon atoms, and one or more hydrogen atoms in the alkyl group are substituted by a substituent R 2 The substituent R 2 is, for example, a halogen atom, an amino group, or a cyano group. 3 represents an alkyl group having 1 to 12 carbon atoms, and one or more hydrogen atoms in the alkyl group are substituted by a substituent R 4 The substituent R4 is a halogen atom, an amino group, or a cyano group.

[0083] In the above general formula (5), R 1 is R in the above general formula (3). 1 In the above general formula (5), R 3 is R in the above general formula (4). 3 In the general formula (5), R 5 is R in the above general formula (3). 1 In the general formula (5), p, q, and r are the same as p, q, and r in the general formula (2). 1 and R 5 may be the same or different.

[0084] When the acrylic triblock copolymer is represented by the general formula (5), R 1 From the viewpoint of enabling the substrate to exhibit high breaking strength, R is preferably selected from the group consisting of linear or branched alkyl groups such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, and t-butyl groups, and cyclobutyl groups. 3 From the viewpoint of enabling the substrate to exhibit high elongation at break, R is preferably selected from the group consisting of a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, an n-pentyl group, an isopentyl group, a hexyl group, an octyl group, a nonyl group, a decyl group, or an undecyl group. 5 is preferably selected from the group consisting of a linear or branched alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, and the like, and a cyclobutyl group, from the viewpoint of enabling the substrate to exhibit high breaking strength.

[0085] Preferred forms of the acrylic triblock copolymer include polymethyl methacrylate block-polyn-butyl acrylate block-polymethyl methacrylate block, polyethyl methacrylate block-polyn-butyl acrylate block-polyethyl methacrylate block, polypropyl methacrylate block-polyn-butyl acrylate block-polypropyl methacrylate block, polymethyl methacrylate block-polyt-butyl acrylate block-polymethyl methacrylate block, and polymethyl methacrylate block-polypropyl acrylate block-polymethyl methacrylate block.

[0086] The acrylic block copolymer may contain only one or more of the triblock copolymers, or may contain only one or more of the diblock copolymers. Furthermore, a mixture of the triblock copolymer and the diblock copolymer can be used as the acrylic block copolymer, and the content of the diblock copolymer in the mixture can be appropriately selected depending on the purpose.

[0087] The weight-average molecular weight (hereinafter also referred to as "Mw") of the acrylic block copolymer is preferably in the range of 50,000 to 300,000, more preferably in the range of 100,000 to 250,000, and even more preferably in the range of 130,000 to 230,000. The number-average molecular weight (hereinafter also referred to as "Mn") of the acrylic block copolymer is preferably in the range of 50,000 to 300,000, more preferably in the range of 100,000 to 250,000, and even more preferably in the range of 130,000 to 230,000. It is more preferable that the Mw of the block copolymer is in the range of 100,000 to 250,000 and the Mn is in the range of 100,000 to 250,000, and even more preferably that the Mw of the block copolymer is in the range of 130,000 to 230,000 and the Mn is in the range of 130,000 to 230,000. The preferred ranges of Mw and Mn of the acrylic triblock copolymers represented by general formula (2) and general formula (5) are the same as those described above.

[0088] The Mw and / or Mn of the acrylic block copolymer are preferably within the above ranges from the viewpoint of achieving both excellent elongation and strength at break while also achieving formability and solubility in solvents for obtaining a substrate of uniform thickness, and it is particularly preferred that Mw and Mn simultaneously satisfy the above ranges. If the Mw or Mn of the acrylic block copolymer is too small, it is difficult to obtain the elongation and strength at break of the substrate, while if the Mw or Mn is too large, it is difficult to dissolve in a solvent, making molding such as heat melting difficult, and making it difficult to obtain the desired substrate.

[0089] The Mw and Mn of the acrylic block copolymer are measured by GPC using a GPC device (HLC-8329GPC, manufactured by Tosoh Corporation). Mw and Mn are values ​​converted into standard polystyrene, and the measurement conditions by GPC are the same as those described above.

[0090] The acrylic block copolymer may be modified, if necessary, with a functional group such as a hydroxyl group, a carboxyl group, an acid anhydride group, an amino group, or a trimethoxysilyl group in the molecular side chain or at the molecular main chain terminal.

[0091] The method for producing the acrylic block copolymer can be appropriately selected from conventionally known production methods, and examples thereof include a method for sequentially polymerizing a block copolymer by an anionic living polymerization method, a cationic living polymerization method, etc. Furthermore, when the block copolymer has stereoregularity such as syndiotacticity, a known method using an organometallic complex may be used.

[0092] When the resin constituting the present substrate is an acrylic polymer, the acrylic polymer may be a cured product of the acrylic block copolymer. The cured product of the acrylic block copolymer can be formed, for example, by irradiating a composition containing the acrylic block copolymer, a polymerizable monomer, and a photopolymerization initiator with active energy rays such as ultraviolet rays.

[0093] The polymerizable monomer is not particularly limited as long as it can be polymerized by irradiation with active energy rays, but polyfunctional (meth)acrylates are preferred. The polyfunctional (meth)acrylate is not particularly limited, and known ones can be used. Examples include polyfunctional (meth)acrylates having two or more polymerizable double bonds in one molecule, such as 1,2-ethanediol diacrylate, 1,2-propanediol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, dipropylene glycol diacrylate, neopentyl glycol diacrylate, tripropylene glycol diacrylate, trimethylolpropane diacrylate, trimethylolpropane triacrylate, tris(2-acryloyloxy)isocyanurate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, di(trimethylolpropane)tetraacrylate, di(pentaerythritol)pentaacrylate, and di(pentaerythritol)hexaacrylate. Other examples of polyfunctional acrylates include urethane acrylate, polyester acrylate, and epoxy acrylate. These may be used alone or in combination of two or more. The polymerizable monomer is preferably used in an amount of 0.5 to 50 parts by mass, more preferably 1 to 40 parts by mass, 1.5 to 30 parts by mass, or 2 to 25 parts by mass, per 100 parts by mass of the acrylic block copolymer.

[0094] Examples of the photopolymerization initiator include carbonyl compounds such as acetophenones, benzophenones, Michler's ketones, and benzoins; sulfur compounds such as tetramethylthiuram monosulfide and thioxanthones; phosphorus compounds such as acylphosphine oxides; titanium compounds such as titanocenes; and azo compounds. One or more photopolymerization initiators may be used alone or in combination. Among these, acetophenones and benzophenones are preferred. The content of the photopolymerization initiator is preferably within a range of 0.1 to 10 parts by mass, more preferably within a range of 0.1 to 7 parts by mass, and even more preferably within a range of 0.1 to 5 parts by mass, per 100 parts by mass of the acrylic block copolymer.

[0095] (Other ingredients) In addition to the various resins described above, the substrate may contain other components as needed. Examples of other components include the tackifier resin, crosslinking agent, antioxidant, UV absorber, filler, polymerization inhibitor, surface conditioner, antistatic agent, defoamer, viscosity modifier, light stabilizer, weather stabilizer, heat stabilizer, antioxidant, leveling agent, additives such as organic pigment, inorganic pigment, pigment dispersant, silica beads, and organic beads, as well as inorganic fillers. Examples of inorganic fillers include silicon oxide, aluminum oxide, titanium oxide, zirconia, and antimony pentoxide. These may be used alone or in combination. The content of other components contained in the substrate can be appropriately selected as long as they do not impair the properties of the tape.

[0096] <Properties> The average thickness of the substrate is not particularly limited as long as the tape can exhibit the desired functions, but is preferably 10 μm or more, more preferably 20 μm or more, more preferably 30 μm or more, and even more preferably 40 μm or more. Having an average thickness of 10 μm or more can prevent operational defects due to wrinkles when handling the tape. Furthermore, the average thickness of the substrate is preferably 500 μm or less, more preferably 450 μm or less. Having an average thickness of 500 μm or less can prevent the tape from being too thick and making it difficult to stretch. The average thickness of the substrate is measured by the method described in the Examples below.

[0097] At least the surface of the substrate facing the adsorption layer may be subjected to a surface treatment, which can enhance adhesion between the substrate and the adsorption layer and prevent delamination. Examples of surface treatments include corona treatment, ozone treatment, plasma treatment, ionizing radiation treatment, dichromate treatment, anchor or primer treatment, etc.

[0098] [Adsorption layer] This tape has an adsorption layer (hereinafter also referred to as "this adsorption layer") on at least one surface of the above-mentioned substrate, the adsorption layer having a plurality of recesses on the surface opposite to the substrate. As shown in Figures 1 and 3, in this tape 1, a plurality of recesses 4 of the adsorption layer 3 are formed at least on the surface 6 opposite to the substrate 2 (surface 6 of the adsorption layer). Note that Figure 3 is a cross-sectional view taken along line AA in Figure 2.

[0099] <Properties> This adhesive layer has numerous recesses (micropores) on at least the surface opposite the substrate, allowing the recesses to function as suction cups and adhere to the adherend. This allows the adhesive layer to adhere to the adherend with sufficient adhesive force. Meanwhile, when the tape adhered to the adherend is stretched, the shape of the recesses is deformed by the stretching force, and the adhesive function of the recesses is released. As a result, this tape can be easily peeled from the adherend and can prevent adhesive residue from being left on the adherend during peeling.

[0100] The present adsorption layer is sufficient as long as it has at least the adsorption properties due to the recesses on the surface opposite the substrate. It is typically a layer that does not have tack (adhesiveness) at room temperature (23°C), i.e., a non-adhesive layer, but it may have tack at room temperature. When the present adsorption layer is a non-adhesive layer that does not have tack at room temperature, contamination of the adherend due to adhesive residue on the adherend when peeling it off can be suppressed. On the other hand, when the present adsorption layer is an adhesive layer that has tack at room temperature, in addition to the adsorption force due to the recesses on the surface, the adhesive strength to the adherend due to the tack can be enhanced. The room temperature tackiness of the present adsorption layer can be adjusted depending on the composition forming the adsorption layer, for example, by adding a tackifier resin to the composition forming the adsorption layer.

[0101] The average opening diameter of the recesses formed on the surface of the adsorption layer may be the same or different. The average opening diameter of the recesses is not particularly limited as long as the recesses can exhibit a suction cup function on the surface of the adsorption layer. However, from the viewpoint of the adsorption force of the recesses to the adherend and the strength of the adsorption layer, it can be, for example, 300 μm or less, preferably 250 μm or less, 200 μm or less, 150 μm or less, 120 μm or less, 100 μm or less, 80 μm or less, or 50 μm or less. Furthermore, the average opening diameter of the recesses is not particularly limited as long as it can exhibit a suction cup function, and can be, for example, 0.1 μm or more, preferably 0.5 μm or more, particularly preferably 1.0 μm or more, more preferably 5.0 μm or more, and even more preferably 10 μm or more.

[0102] The average opening diameter of the recesses can be suitably adjusted depending on the size of the adherend. 2 Below, among others, 100mm 2 or less), the average opening diameter of the recesses can be 300 μm or less, preferably 250 μm or less, more preferably 200 μm or less, even more preferably 150 μm or less, and even more preferably 100 μm or less.

[0103] The average opening diameter of recesses refers to the average opening diameter of the recesses when the adsorption layer is viewed in plan from the surface of the adsorption layer side of the tape, and is a value obtained by taking an enlarged photograph of the surface of the adsorption layer at 100x magnification using a tabletop low-vacuum scanning electron microscope (SEM, Hitachi High-Technologies Corporation, "MiniscopeTM3030Plus"), measuring the opening diameter of an arbitrary recess located in the center of the photograph and all 30 recesses located nearby, and calculating the average value. If the planar shape of the recess is not an approximately perfect circle, the opening diameter is taken as the longest distance between any two points on the periphery of the planar shape of the recess.

[0104] The average opening diameter of the recesses in the adsorption layer can be adjusted, as will be described in detail below, by, for example, adjusting the formulation of the composition that forms the adsorption layer (hereinafter also referred to as the adsorption layer-forming resin composition) by adding a surfactant, thickener, etc.; when forming recesses using the method described below, adjusting the foaming method, foaming conditions, and bubble formation conditions, such as the degree of crushing of the generated bubbles, when foaming the adsorption layer-forming resin composition by mechanical foaming; or adjusting the thickness of the adsorption layer. For example, when generating bubbles using the stirring and mixing method described below, the degree of crushing of the bubbles can be adjusted by increasing the number of beaters in the mixer of the foaming device or by lengthening the stirring time. Furthermore, when generating bubbles using a method such as fine bubbles or microbubbles described below, the degree of crushing can be adjusted by selecting an appropriate generation principle from the generation principles described below, adjusting the swirl speed and flow rate of the fluid containing the adsorption layer-forming resin composition in the bubble generator, or adjusting the gas flow rate injected into the adsorption layer-forming resin composition.

[0105] The present adsorption layer has a plurality of the recesses on at least the surface opposite to the substrate. The number of recesses present on one surface of the present adsorption layer is, for example, 300 recesses / cm per unit area from the viewpoint of the strength of the adhesive force with the adherend. 2 More preferably, 500 particles / cm 2 More preferably, 1000 particles / cm per unit area 2 More preferably, 10,000 particles / cm per unit area 2 Although there is no particular upper limit to the number of recesses present on one surface of the present adsorption layer, the number of recesses per unit area is preferably 1,000,000 / cm from the viewpoint of the mechanical strength of the adsorption layer. 2 Preferably less than 500,000 particles / cm 2 Preferably less than 200,000 particles / cm 2 Preferably less than 100,000 particles / cm 2 Preferably, the number is less than 50,000 / cm2 per unit area, and more preferably, 50,000 / cm2 per unit area. 2 The following is the result.

[0106] The present adsorption layer has a plurality of the recesses on at least the surface opposite the substrate side, but it is more preferable to have a plurality of the recesses on the surface facing the substrate side as well, as this also improves adhesion between the adsorption layer and the substrate. That is, it is more preferable that the present adsorption layer has a plurality of recesses formed on both sides. When recesses are formed on both sides of the present adsorption layer, it is preferable that the number of recesses per unit area on each surface of the adsorption layer is within the above range.

[0107] The number of recesses per unit area on the adsorption layer surface was determined by taking a magnified photograph (100x magnification) of the adsorption layer surface using a tabletop low-vacuum scanning electron microscope (SEM, Hitachi High-Technologies Corporation, "MiniscopeTM3030Plus") and counting the number of recesses present in any 0.5mm x 0.5mm square area. The unit is cm. 2 However, any missing recesses near the periphery of the area where the number of recesses is to be counted are also counted as one.

[0108] The shape of the recesses is not particularly limited, and the planar shape of the recesses as viewed from the surface of the adhesive layer of the present tape may be, for example, a circle, an ellipse, or any other irregular shape surrounded by curves.

[0109] From the viewpoint of suppressing positional variation in the adsorption force of the adsorption layer, the recesses preferably have an opening ratio of 1% or more in a plan view of the surface of the adsorption layer opposite the substrate (the surface of the adsorption layer facing the substrate side) of 3% or more, more preferably 5% or more, and particularly preferably 10% or more. There is no particular upper limit to the opening ratio of the recesses, but the opening ratio of the recesses is, for example, 99% or less. From the viewpoint of the mechanical strength of the adsorption layer, the opening ratio of the recesses is preferably 90% or less, more preferably 80% or less, even more preferably 70% or less, even more preferably 60% or less, and particularly preferably 50% or less.

[0110] The opening ratio of the recesses refers to the ratio of the projected area of ​​the recesses to the area of ​​the surface of the adsorbent layer when viewed in plan from the surface of the adsorbent layer side of the tape. Figure 4(a) is a top view of the adsorbent layer from the side opposite the substrate, and Figure 4(b) is a cross-sectional view along line X-X' in Figure 4(a). The "plan view of the surface of the adsorbent layer opposite the substrate" refers to the adsorbent layer viewed from the top of the page, as shown in Figure 4(a), and the "projected area of ​​the recesses" refers to the total area of ​​the recesses formed on the surface 6 of the adsorbent layer 3 opposite the substrate when viewed in plan. In Figure 4, all recesses are depicted as oval as one embodiment of the present invention, but as mentioned above, the shape of the recesses is not limited to this in the present invention. Furthermore, multiple recesses may have the same or different shapes, and the projected areas may be the same or different. In Figure 4(b), the surface of the adsorbent layer 3 opposite the substrate is designated by the symbol 6, and the surface of the adsorbent layer 3 facing the substrate is designated by the symbol 6'.

[0111] The ratio of the projected area of ​​the recesses can be defined as the ratio of the total area of ​​the recesses present per unit area in a plan view of the adsorption layer. For example, in Fig. 4(a), when the width of the adsorption layer is defined as the direction perpendicular to the longitudinal direction of the adsorption layer 3, the ratio is the total area of ​​all recesses 4 on the surface of the adsorption layer 3 present within a longitudinal length L (not shown) divided by the area of ​​the adsorption layer 3 corresponding to the length L, and is expressed by the following formula: Ratio of the projected area of ​​the recess (%) = S / (L × t) × 100 (In the above formula, S represents the total area of ​​the projected areas of all the recesses of the adsorption layer present within the length L, L represents the longitudinal length, and t represents the width.)

[0112] The aperture ratio of the recesses was measured by photographing the surface of the adsorption layer at 200x magnification (auto-brightness adjustment, 1.27mm x 1.7mm) using an electron microscope (Keyence Corporation, Digital Microscope VHX6000), calculating the area of ​​the black portions in the image and the total area of ​​the image using software analysis, and then dividing the projected area of ​​the black portions by the total area to obtain the aperture ratio. Note that in the image, the black portions represent recesses formed on the surface of the adsorption layer, and the area of ​​the black portions corresponds to the projected area of ​​the recesses.

[0113] The opening ratio of the recesses in the adsorption layer and the number of recesses per unit area on the surface of the adsorption layer will be described in detail below. For example, they can be adjusted by adjusting the blending ratio of surfactants, thickeners, etc. in the adsorption layer-forming resin composition; when forming recesses using the method described below, adjusting the foaming conditions when foaming the adsorption layer-forming resin composition and the bubble formation conditions, such as the degree of crushing of the generated bubbles; or adjusting the thickness of the adsorption layer. For example, when generating bubbles using the stirring and mixing method described below, the degree of crushing of bubbles can be adjusted by increasing the number of beaters in the mixer of the foaming device or lengthening the stirring time. Furthermore, when generating bubbles using a method such as fine bubbles or microbubbles described below, the degree of crushing can be adjusted by selecting an appropriate generation principle from the generation principles described below, adjusting the swirl speed or flow rate of the fluid containing the adsorption layer-forming resin composition in the bubble generator, or adjusting the gas flow rate injected into the adsorption layer-forming resin composition.

[0114] The adsorption layer has a large number of the above-described minute recesses (micropores) formed on at least the surface opposite the substrate, and these recesses (micropores) on the surface exert a suction function, and is therefore sometimes referred to as a micro-suction layer. As long as the adsorption layer has a large number of the above-described recesses formed on at least the surface, it may be a porous body in which a large number of micropores (also called voids or bubbles) are formed inside the adsorption layer, or a non-porous body in which no micropores are formed inside the adsorption layer. Among these, it is preferable that the adsorption layer has a large number of micropores formed on both the surface and the inside. That is, the adsorption layer is preferably a porous body layer having a large number of recesses on one or both sides and a large number of micropores formed inside the layer. The micropores in the adsorption layer are exposed to the surface of the adsorption layer, forming recesses, and further enabling the adsorption layer to be lightweight. Furthermore, air gaps at the interface that occur when the adsorption layer and the adherend are bonded are pushed out and eliminated, making it easier to obtain favorable adhesive strength for the adsorption layer.

[0115] When numerous micropores (also called voids or bubbles) are formed on the surface and inside of the adsorption layer, the adsorption layer may have either a closed-cell structure or an open-cell structure. An open-cell structure is preferred because it provides better bubble release properties. An open-cell structure means that adjacent bubbles have through-holes between them, connecting the bubbles to each other. An adsorption layer with an open-cell structure provides better bubble release properties and facilitates the expulsion of air gaps at the interface with the adherend, allowing for high adhesion to the adherend without trapping bubbles. Furthermore, when peeling from the adherend, gas also penetrates into the adsorption layer, allowing for easier peeling without leaving adhesive residue. The bubble structure within the adsorption layer can be confirmed by observing a magnified image of the cross-section of the adsorption layer using, for example, a tabletop low-vacuum scanning electron microscope (SEM, Hitachi High-Technologies Corporation, "Miniscope™3030Plus"), for example. FIG. 4(b) is a cross-sectional view of the adsorption layer 3, showing an example of an adsorption layer having an open-cell structure in which micropores 8 are formed inside the layer and the micropores communicate with each other.

[0116] When the adsorption layer has micropores inside, the degree of formation of the micropores inside can be evaluated, for example, by the specific gravity or apparent density of the adsorption layer. 3 More than 1.0g / cm 3 and above 0.15 g / cm 3 More than 0.95g / cm 3 Preferably less than 0.2 g / cm 3 More than 0.9g / cm 3 Less than 0.3 g / cm is preferred 3 More than 0.8g / cm 3 The apparent density of the adsorption layer is preferably 0.1 g / cm or less. 3 More than 1.0g / cm 3 and above 0.15 g / cm 3 More than 0.95g / cm 3 Preferably less than 0.2 g / cm 3 More than 0.9g / cm 3 Less than 0.3 g / cm is more preferable.3 More than 0.85g / cm 3 The following is even more preferred:

[0117] By keeping the specific gravity and / or apparent density of the adsorption layer within the above range, air bubbles are less likely to become trapped when the layer is attached to the adherend, allowing the recesses formed on the surface of the adsorption layer to be effectively utilized, thereby improving initial and long-term surface adhesion. Furthermore, since the recesses are not excessive, the strength of the adsorption layer can be ensured, making it easier to prevent the adsorption layer from remaining on the adherend due to cohesive failure of the adsorption layer, or the adhesive from remaining if the adsorption layer has tackiness.

[0118] The specific gravity of the adsorption layer can be calculated by the following method. (Measurement method) A specific gravity cup (Allgood Co., Ltd., 066 series) and the above-mentioned resin composition for forming an adsorption layer were kept at 23°C ± 2°C, and the mass of the empty specific gravity cup was measured. The specific gravity cup was filled with the resin composition for forming an adsorption layer, and the lid was gently placed on the cup to prevent air bubbles from remaining inside the specific gravity cup due to imperfect filling of the resin composition for forming an adsorption layer. The resin composition for forming an adsorption layer that overflowed from the overflow orifice in the center of the lid was wiped off with a rag. The mass of the specific gravity cup filled with the resin composition for forming an adsorption layer was measured, and the specific gravity of the resin composition for forming an adsorption layer was calculated using the following formula. The resin composition for forming an adsorption layer used to measure the specific gravity of the adsorption layer refers to a resin composition for forming an adsorption layer that contains air bubbles. For example, when the adsorption layer is formed by mechanical foaming of a resin emulsion, the resin composition for forming an adsorption layer (foamed resin emulsion) is referred to. Specific gravity of the adsorption layer [g / cm 3 ] = {(Mass [g] of the specific gravity cup filled with the resin composition for forming an adsorption layer) - (Mass [g] of the empty specific gravity cup)} / Volume of the specific gravity cup [cm 3 ]

[0119] The apparent density of the adsorption layer is a value calculated in accordance with JIS K6767. A test piece of the adsorption layer cut into a rectangle of 4 cm length x 5 cm width was prepared, the mass [g] of the test piece was measured, and the apparent volume (length x width x thickness) [cm3 ] and then divide the mass by the apparent volume.

[0120] The specific gravity and apparent density of the adsorption layer, as will be described in detail below, can be adjusted, for example, by adjusting the blending of surfactants, thickeners, etc. in the adsorption layer-forming resin composition; when forming recesses using the method described below, by adjusting the foaming conditions when foaming the adsorption layer-forming resin composition and the bubble formation conditions, such as the degree of crushing of the generated bubbles; or by adjusting the thickness of the adsorption layer. For example, when generating bubbles using the stirring and mixing method described below, the degree of crushing of the bubbles can be adjusted by increasing the number of beaters in the mixer of the foaming device or lengthening the stirring time. Furthermore, when generating bubbles using a method such as fine bubbles or microbubbles described below, the degree of crushing can be adjusted by selecting an appropriate generation principle from the generation principles described below, adjusting the swirl speed or flow rate of the fluid containing the adsorption layer-forming resin composition in the bubble generator, or adjusting the gas flow rate injected into the adsorption layer-forming resin composition.

[0121] The adsorption layer preferably has flexibility and pliability. The adsorption layer preferably has elasticity. The elastic recovery rate of the adsorption layer is not particularly limited and can be the same as that of conventional micro-suction cup layers, but can be, for example, within the range of 50% to 100%, preferably within the range of 70% to 100%, more preferably within the range of 80% to 100%, even more preferably within the range of 90% to 100%, and particularly preferably within the range of 95% to 100%. Here, "elastic recovery rate" refers to the ratio of the restored thickness to the initial thickness, calculated by applying pressure to the adsorption layer in the thickness direction to compress it to 60% or less of its initial thickness (thickness before pressure), releasing the pressure, and measuring the thickness (restored thickness) 10 minutes later.

[0122] The thickness of the adsorption layer is not particularly limited as long as it is thick enough to exhibit suction cup function. For example, it can be 1 μm or more. From the viewpoint of excellent surface adhesion, it is preferably 10 μm or more, more preferably 30 μm or more, even more preferably 40 μm or more, even more preferably 50 μm or more, and particularly preferably 60 μm or more. Furthermore, the thickness of the adsorption layer can be 1000 μm or less, preferably 500 μm or less, and even more preferably 300 μm or less. From the viewpoint of excellent holding power in addition to surface adhesion, the thickness of the adsorption layer is preferably less than 300 μm, more preferably 250 μm or less, and particularly preferably 200 μm or less. More specifically, from the viewpoint of fixing the adherend, the thickness of the adsorption layer can be in the range of 1 μm to 1000 μm, preferably in the range of 10 μm to 1000 μm, more preferably in the range of 10 μm to 500 μm, and even more preferably in the range of 10 μm to 300 μm. In particular, when the present tape is used for bonding two or more adherends, and high holding power is required in addition to surface adhesion, the thickness of the adsorption layer is more preferably in the range of 10 μm to 250 μm in order to achieve excellent surface adhesion and holding power.

[0123] The "thickness of the adsorbent layer" refers to the average thickness of the adsorbent layer on one side of the substrate in the tape. When the tape has an adsorbent layer on both sides, the thickness of the adsorbent layer on one side of the substrate may be the same as or different from the thickness of the adsorbent layer on the other side of the substrate.

[0124] The thickness of the adsorption layer was measured by the method described in the Examples below. Specifically, the thickness of the adsorption layer was measured at five locations at 10 mm intervals along the length and at five locations at 10 mm intervals across the width using a dial thickness gauge (Ozaki Seisakusho Co., Ltd., Model G-0.4N or Model G-2.4N). The thicknesses at these 10 locations were averaged to obtain the average value. In this measurement method, the adsorption layer was formed on a release liner, the combined thickness of the adsorption layer and the release liner was measured, and the average thickness was calculated by subtracting the thickness of the release liner. The thickness of the adsorption layer, as shown by symbol d in Figures 3 and 4, refers to the length between two opposing surfaces of the adsorption layer, between planes where no recesses are formed. Note that the portions of the surface of the adsorption layer where recesses are formed have a virtual surface (the surface assumed to have no recesses; symbol 7 in Figure 1) that is located in the same plane as the plane where no recesses are formed in the cross section of the adsorption layer.

[0125] <Composition of the adsorption layer> The adsorption layer is composed mainly of a resin. The adsorption layer may be formed solely of a resin, or may contain the resin and any other component. The main component of the adsorption layer refers to the component that is most abundant in the total mass of the adsorption layer, and the resin is contained in the adsorption layer at 50% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. The resin that is the main component of the adsorption layer may be referred to as the main polymer.

[0126] (resin) The resin constituting the adsorption layer is not particularly limited as long as it can exhibit the function of an adsorption layer, and examples thereof include acrylic resins such as acrylic polymers (including acrylic rubber), urethane resins (including urethane rubber), silicone resins (including silicone rubber), butadiene rubber (polybutadiene, acrylonitrile butadiene rubber, styrene butadiene rubber, methyl methacrylate butadiene rubber, etc.), polyisoprene, ethylene propylene rubber (EPR), ethylene propylene diene terpolymer rubber (EPDM), polynorbornene, nitrile rubber, chloroprene rubber, butyl rubber, halogenated butyl rubber, ethylene-vinyl acetate rubber (EVA), fluororubber, ethylene acrylic rubber, polyester elastomer, epichlorohydrin rubber, polysulfide rubber, and other synthetic rubbers; natural rubber, chlorinated polyethylene, polyolefin (polyethylene), polystyrene, polyimide, polyvinyl chloride, polypropylene, polyester, phenolic resin, polyacetal resin, silicone resin; and polyolefin-based, polyurethane-based, polyester-based, polyamide-based, and polystyrene-based thermoplastic elastomers. The above resins may be used alone or in combination of two or more. Furthermore, the resin constituting the adsorption layer may be a resin other than the resins exemplified above, as long as it can form the adsorption layer into the desired structure. In particular, from the viewpoint of exhibiting good flexibility and deformability and easily fulfilling the suction cup function, the resin constituting the adsorption layer is preferably one or more resins selected from the group consisting of acrylic resins (acrylic polymers), butadiene rubber, and urethane resins. The resin constituting the adsorption layer preferably contains one or more resins selected from this group as its main component, and the resin selected from this group preferably accounts for 50% by mass or more of the total amount of the resin constituting the adsorption layer, more preferably 80% by mass or more, even more preferably 90% by mass or more, and particularly preferably 100% by mass. When the resin constituting the adsorption layer contains two or more resins selected from the above group, the total content of the two or more resins is preferably within the above range. Furthermore, from the viewpoint of exhibiting good flexibility and deformability and easily fulfilling the suction cup function, the resin constituting the adsorption layer is preferably rubber or elastomer.

[0127] (acrylic polymer) Examples of acrylic polymers include (meth)acrylic acid ester polymers containing structural units derived from one or more (meth)acrylic acid esters. The acrylic polymers are polymers of one or more (meth)acrylic acid alkyl esters and, if necessary, other monomers other than the (meth)acrylic acid alkyl esters. Note that (meth)acrylic refers to acrylic and methacrylic. The acrylic polymers are not particularly limited as long as the adsorption layer can exhibit the desired functions, but acrylic rubber is preferred.

[0128] The (meth)acrylic acid alkyl ester is preferably a (meth)acrylic acid alkyl ester having 1 or more and 14 or less carbon atoms in the alkyl group, and specific examples thereof include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate such as n-butyl (meth)acrylate and sec-butyl (meth)acrylate, isobutyl (meth)acrylate, n-amyl (meth)acrylate, isoamyl (meth)acrylate, n-heptyl acrylate, n-hexyl (meth)acrylate, and n-octyl acrylate. Examples include (meth)acrylic acid ester monomers having a linear or cyclic saturated hydrocarbon group, such as methyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and cyclohexyl (meth)acrylate; and (meth)acrylic acid ester monomers having an alkoxyalkyl group, such as methoxymethyl (meth)acrylate, ethoxymethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-butoxyethyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-propoxyethyl (meth)acrylate, 3-methoxypropyl (meth)acrylate, and 4-methoxybutyl (meth)acrylate. These may be used alone or in combination of two or more. Among these, (meth)acrylic acid alkyl esters having an alkyl group with 4 to 14 carbon atoms are preferred, and (meth)acrylic acid alkyl esters having an alkyl group with 4 to 8 carbon atoms are more preferred, and even more preferred are those containing one or more selected from the group consisting of methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate.

[0129] The proportion of the (meth)acrylic acid alkyl ester in the acrylic polymer is not particularly limited, but is preferably 70 to 99.9 mass % of the total amount of the acrylic polymer, and more preferably 90 to 99.5 mass %.

[0130] The acrylic polymer preferably contains one or more functional group-containing (meth)acrylic acid ester monomers in addition to the (meth)acrylic acid alkyl ester. Examples of functional group-containing (meth)acrylic acid ester monomers include (meth)acrylic acid, crotonic acid, maleic acid and their anhydrides, fumaric acid, itaconic acid, monomethyl maleate, monoethyl fumarate, mono-n-butyl itaconate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, glycidyl (meth)acrylate, N-methylol (meth)acrylamide, N-butoxymethyl acrylamide, and diacetone acrylamide.

[0131] The acrylic polymer preferably contains one or more (meth)acrylic acid derivative monomers, such as (meth)acrylonitrile and (meth)acrylamide, in addition to the (meth)acrylic acid alkyl ester and functional group-containing (meth)acrylic acid ester monomer.

[0132] In addition to the above-mentioned monomers, the acrylic polymer preferably contains one or more vinyl monomers other than (meth)acrylic acid derivative monomers. Examples of vinyl monomers other than (meth)acrylic acid derivative monomers include vinyl acetate, vinyl propionate, vinylidene chloride, vinylidene bromide, styrene, α-methylstyrene, vinyltoluene, chlorostyrene, 2,4-dibromostyrene, vinyl chloride, and ethylene.

[0133] The acrylic polymer can be produced by polymerizing a composition containing a (meth)acrylic acid alkyl ester and, if necessary, a monomer, and further containing, if necessary, a polymerization initiator, an emulsifier, a dispersant, etc. Polymerization methods include, for example, solution polymerization, emulsion polymerization, suspension polymerization, bulk polymerization, etc., but other methods are also acceptable. Among these, in producing the present adsorption layer, it is preferable to use an emulsion polymerization method from the viewpoint of forming desired recesses on the surface of the layer by mechanical foaming.

[0134] (urethane resin) The urethane resin is not particularly limited, and examples thereof include urethane polymers obtained by at least reacting a polyol, a polyisocyanate, and a compound having an active hydrogen group and a hydrophilic group in the molecule.

[0135] The polyol is not particularly limited as long as it has two or more hydroxyl groups, and examples thereof include polyether polyol, polyester polyol, polycaprolactone polyol, polybutadiene polyol, polycarbonate polyol, polythioether polyol, etc. The above polyol compounds may be used alone or in combination of two or more.

[0136] Examples of compounds having an active hydrogen group and a hydrophilic group in the molecule include compounds containing active hydrogen and an anionic group, compounds having active hydrogen and a cationic group in the molecule, and compounds having active hydrogen and a nonionic hydrophilic group in the molecule. Examples of compounds having active hydrogen and an anionic group include dimethylolalkanoic acids such as α,α-dimethylolpropionic acid, α,α-dimethylolbutyric acid, and dimethylolacetic acid. Examples of compounds having an active hydrogen and a nonionic hydrophilic group in the molecule include polyethylene glycol, alkyl alcohol alkylene oxide adducts, and the like.

[0137] The polyisocyanate is not particularly limited as long as it has two or more isocyanate groups in the molecule, and examples thereof include aliphatic polyisocyanates, alicyclic polyisocyanates, aromatic polyisocyanates, triisocyanates, etc. Other examples include dimers and trimers (isocyanurate bonds) of these polyisocyanate compounds, and biuret compounds obtained by reacting these polyisocyanates with amines. Furthermore, polyisocyanates having urethane bonds obtained by reacting these polyisocyanates with polyols can also be used.

[0138] The urethane resin can be formed from a composition containing at least a polyol, a polyisocyanate, and a compound having an active hydrogen group and a hydrophilic group in the molecule, and optionally further containing a low molecular weight polyol, a chain extender, a polymerization terminator, other additives, etc. Examples of the chain extender include the chain extenders disclosed in WO 2019 / 092984.

[0139] (butadiene rubber) The butadiene rubber is preferably a copolymer having, as a constituent unit, an aliphatic conjugated diene monomer and one or more vinyl monomers copolymerizable with the aliphatic conjugated diene monomer.

[0140] Examples of the aliphatic conjugated diene monomer include 1,3-butadiene, 2-methyl-1,3-butadiene, and 2,3-dimethyl-1,3-butadiene.

[0141] The vinyl monomer can be appropriately selected depending on the type of butadiene rubber, and examples thereof include aromatic vinyls such as styrene and α-methylstyrene; alkyl methacrylates such as methyl methacrylate and ethyl methacrylate; alkyl acrylates such as ethyl acrylate and n-butyl acrylate; unsaturated nitriles such as acrylonitrile and methacrylonitrile; vinyl ethers such as methyl vinyl ether and butyl vinyl ether; vinyl halides such as vinyl chloride and vinyl bromide; vinylidene halides such as vinylidene chloride and vinylidene bromide; and vinyl monomers having a glycidyl group such as glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, and ethylene glycol glycidyl ether.

[0142] Examples of such butadiene rubber include styrene butadiene rubber, acrylonitrile butadiene rubber, and (meth)acrylic ester acid butadiene rubber.

[0143] The butadiene rubber may contain other monomers as constituent units, if necessary, in addition to the aliphatic conjugated diene monomer and vinyl monomer described above, such as (meth)acrylamide, styrene, α-methylstyrene, chlorostyrene, vinyltoluene, vinyl acetate, (meth)acrylic acid, and (meth)acrylic acid esters.

[0144] The butadiene rubber can be prepared by mixing the above-mentioned aliphatic conjugated diene monomer and vinyl monomer, and optionally other monomers, and emulsion polymerizing the mixture in the presence of a polymerization initiator.

[0145] (Crosslinking agent) The adsorption layer may contain a crosslinking agent in addition to the resin. That is, the adsorption layer may be a crosslinked product of the resin. The resin in the adsorption layer can form a crosslinked structure. The type of crosslinking agent can be appropriately selected depending on the type of resin, and examples include melamine-based compounds; amine compounds; epoxy-based compounds; carbodiimide-based compounds; oxazoline-based crosslinking agents; polyfunctional isocyanate-based compounds such as tolylene diisocyanate, trimethylolpropane tolylene diisocyanate, and diphenylmethane triisocyanate; metal salts; metal chelate compounds; and peroxides.

[0146] (plasticizer) The adsorption layer may contain a plasticizer. Examples of plasticizers include phthalates, adipates, trimellitates, azelates, sebacates, phosphates, acetyl citrates, triacetin, epoxidized soybean oil, polyesters, and chlorinated paraffins. These may be used alone or in combination.

[0147] (tackifying resin) The adsorption layer may contain a tackifying resin as needed. This can impart tackiness to the adsorption layer at room temperature, further improving adhesion to the adherend and surface adhesive strength in addition to the adsorption power provided by the recesses. The type of tackifying resin is not particularly limited, and general-purpose tackifying resins can be used. Specific examples of tackifying resins include rosin-based tackifying resins, polymerized rosin-based tackifying resins, polymerized rosin ester-based tackifying resins, rosin phenol-based tackifying resins, stabilized rosin ester-based tackifying resins, disproportionated rosin ester-based tackifying resins, hydrogenated rosin ester-based tackifying resins, terpene-based tackifying resins, terpene phenol-based tackifying resins, petroleum resin-based tackifying resins, and (meth)acrylate-based tackifying resins. These may be used alone or in combination of two or more.

[0148] (filler) The adsorption layer may contain a filler. The filler may be one type or two or more types. When the tape is stretched, the filler is exposed from the surface of the adsorption layer, which further reduces the adhesive area between the adsorption layer and the adherend, allowing the tape to be peeled off more easily and quickly.

[0149] The filler material can be selected appropriately, and examples thereof include inorganic fillers such as metals, metal oxides, metal hydroxides, carbides, nitrides, ceramics, glass, silica, carbon, and graphite, organic fillers such as resins, and composite materials thereof. Examples of resins include acrylic resins, polystyrene resins, phenolic resins, nylon, polyester resins, polyurethane resins, polyolefin resins, polyamide resins, polyimide resins, vinylidene chloride resins, and silicone resins. These may be used alone or in combination of two or more. The filler may be a solid filler or a hollow filler. The filler may also be a core-shell filler having a multilayer structure in which a core particle is coated with a substance of a different composition.

[0150] The shape of the filler may be regular or irregular. Specific examples of the shape of the filler include polygonal, cubic, elliptical, spherical, needle-like, flat, and scale-like shapes. Among these, elliptical, spherical, and polygonal shapes are preferred because they improve the sliding of the adsorption layer against the adherend when the tape is stretched, thereby improving the tape's releasability. Fillers of these shapes may be used alone or in combination of two or more.

[0151] The average particle size of the filler is preferably 0.1 μm or more. The average particle size of the filler is preferably 40 μm or less, more preferably 35 μm or less, even more preferably 33 μm or less, even more preferably 20 μm or less, and particularly preferably 10 μm or less. When the tape is stretched and peeled from the adherend, it can be peeled with low elongation. The average particle size of the particles refers to the volume average particle size, and is the particle size at the point where the cumulative curve reaches 50% as measured using a measuring device (Microtrac) that uses a laser diffraction scattering method.

[0152] (additives) In addition to the materials described above, the adsorption layer may contain any additives as long as they do not impair the adsorption properties. Examples of additives include crosslinkers, curing agents, surfactants, thickeners, antioxidants, UV absorbers, fillers, polymerization inhibitors, surface conditioners, antistatic agents, antifoaming agents, viscosity modifiers, light stabilizers, weather stabilizers, heat stabilizers, antioxidants, leveling agents, foaming agents, foaming assistants, foaming agents, foam stabilizers, organic pigments, inorganic pigments, pigment dispersants, plasticizers, softeners, flame retardants, metal deactivators, and silicone compounds. These additives may be used alone or in combination. The content of the additives in the adsorption layer may be appropriately determined as long as they do not impair the properties of the adsorption layer.

[0153] <Method for forming an adsorption layer> The method for producing the adsorption layer is not particularly limited as long as it can form numerous depressions capable of exhibiting adsorption function on at least the surface. Examples include (Method 1) a method in which an adsorption layer-forming resin composition is applied and dried to form a layer and then the surface is roughened; (Method 2) a method in which an adsorption layer is formed using an adsorption layer-forming resin composition containing a filler mixed with a resin component, and then tension is applied to the adsorption layer in at least one direction to create depressions originating from the filler; (Method 3) a method in which a mechanically foamed adsorption layer-forming resin composition is applied and then heat-dried; and (Method 4) a method in which the adsorption layer-forming resin composition is formed into a sheet and then foamed using a foaming agent such as high-pressure inert gas. Among these, Methods 3 and 4 are preferred because they can form the desired depressions on the surface and also form an adsorption layer with a closed-cell or open-cell structure, with bubbles formed within the layer. Method 3, which involves mechanically foaming an adsorption layer-forming resin composition and then heat-drying, is more preferred. The adsorption layer may also be produced by combining several of Methods 1 to 4.

[0154] The resin composition for forming the adsorption layer used to form the adsorption layer may be any composition containing at least the resin (polymer) that is the main component of the adsorption layer, and can be appropriately selected depending on the method for forming the adsorption layer. When the method for forming the adsorption layer is the method of forming a sheet of the mechanically foamed resin composition for forming an adsorption layer (method 3) and then heating and drying it, the resin composition for forming an adsorption layer is preferably a resin emulsion. For example, when the resin constituting the adsorption layer is an acrylic polymer, an adsorption layer containing an acrylic polymer can be formed by mechanically foaming a (meth)acrylic acid ester polymer emulsion and then heating and drying it. The resin composition for forming an adsorption layer before mechanical foaming is referred to as a "resin emulsion," and the mechanically foamed resin composition for forming an adsorption layer is referred to as a "foamed resin emulsion."

[0155] The resin emulsion contains at least the polymer and dispersion medium for forming the adsorption layer described above, and may contain other components as needed. For example, a resin emulsion containing an acrylic polymer can be obtained by emulsion polymerization of one or more (meth)acrylic acid esters, and, if necessary, other monomers other than the (meth)acrylic acid esters, in a dispersion medium in the presence of a polymerization initiator, an emulsifier, a dispersion stabilizer, etc. Furthermore, a resin emulsion containing a urethane resin can be prepared, for example, by a forced emulsification method using an emulsifier and mechanical shear force on a composition containing the above-mentioned polyol and polyisocyanate, or by a self-emulsification method using an ionic or nonionic hydrophilic component linked to the urethane resin skeleton.

[0156] Examples of the dispersion medium include water, organic solvents such as alcohols such as ethanol, ketones such as acetone, esters such as ethyl acetate, ethers such as dipropyl ether, and glycol ethers such as ethylene glycol monomethyl ether.

[0157] The resin emulsion may contain the components described in the above <Composition of Adsorption Layer> section under (Plasticizer), (Tackifying Resin), and (Filler), as well as optional components such as surfactants, silicone compounds, foam stabilizers, thickeners, foaming agents, crosslinking agents, curing agents, and foaming aids in (Additives).

[0158] The resin emulsion can be mechanically processed to disperse and incorporate air bubbles into the resin emulsion, i.e., mechanically foam the resin emulsion, thereby forming a foamed resin emulsion. Known methods can be used for mechanically processing the resin emulsion, including known bubble-generating methods (stirring and mixing methods) such as stirring and mixing the emulsion, and known methods for generating fine bubbles or microbubbles. Known methods for generating fine bubbles or microbubbles include methods that use generation principles such as fluidizing a liquid to entrain gas or blowing gas into a stationary liquid. Examples of methods for fluidizing a liquid include swirling liquid flow, static mixer, ejector, Venturi, and pressurized dissolution. Examples of methods for blowing gas into a stationary liquid include pore, rotary, ultrasonic, vapor condensation, and electrolysis. The equipment used for mechanical foaming of the resin emulsion is not particularly limited, but examples include batch-type foaming machines, continuous foaming machines, and fine bubble generators. An example of a fine bubble generator is a device that generates bubbles from the pores of porous ceramic. Examples of gases that can be introduced in mechanical foaming include air, nitrogen, and oxygen.

[0159] The size, number, and shape of the recesses on the surface of the adsorption layer, the micropores on the surface and in the layer, and the opening diameter and opening ratio of the recesses can be adjusted by the amount of pressurized air fed in the preparation of the foamed resin emulsion, the type and conditions of the selected mechanical foaming method and foaming machine, etc. Specifically, it is preferable to select a mechanical foaming method or adjust the bubble generation conditions in various mechanical generation methods so that the density, flow rate, etc. of the resulting foamed resin emulsion are the desired values. Examples of bubble generation conditions include conditions such as the foaming time and mixer rotation speed in a batch-type foaming machine, and the liquid flow rate, gas flow rate, mixer rotation speed, and foaming time in a continuous foaming machine, the selection of the generation principle in the microbubble generator, and adjustment of the rotation speed, liquid flow rate, and gas flow rate in the microbubble generator.

[0160] The solids concentration of the foam resin emulsion is not particularly limited as long as the desired adsorption layer can be formed, and can be set appropriately, for example, preferably 30 to 60% by mass, where the total amount of the foam resin emulsion is 100% by mass. By setting the solids concentration of the foam resin emulsion within the above range, the foam state formed in the emulsion can be easily reproduced even after drying, and the bubble structure of the adsorption layer can be easily adjusted.

[0161] The expansion ratio of the foam resin emulsion can be, for example, 1.2 to 4 times, preferably 1.5 to 3.5 times, and more preferably 1.8 to 3 times. If the expansion ratio is too low, the adsorption force of the adsorption layer will be weak, making it difficult to adequately fix and / or bond the adherend. On the other hand, if the expansion ratio is too high, the adsorption force of the adsorption layer will be too strong, making the adsorption layer prone to partial destruction or breakage when the tape is stretched and peeled. The expansion ratio is defined as the ratio of the mass per unit volume of the foam resin emulsion after mechanical foaming when it is heat-dried to the mass per unit volume of the resin emulsion before mechanical foaming when it is heat-dried.

[0162] The expansion ratio of the foam resin emulsion can be expressed as the expansion ratio of the adsorption layer. Furthermore, the manufacturing method of the adsorption layer is not limited to when a foam resin emulsion is used, and it is also preferable that the adsorption layer exhibits the above expansion ratio when the adsorption layer is formed by the various methods described above. The specific gravity and apparent density of the adsorption layer can be adjusted to the desired values ​​by adjusting the expansion ratio of the foam resin emulsion.

[0163] The method for applying the foam resin emulsion to the surface of an object to be coated, such as a release liner or a substrate, is not particularly limited, and examples thereof include the casting head method, roll coating method, comma coating method, die coating method, air knife coating method, gravure roll coating method, doctor roll coating method, doctor knife coating method, curtain flow coating method, spraying method, brush coating method, etc. The thickness of the coating layer formed by applying the foam resin emulsion is appropriately selected so that the thickness of the adsorption layer formed by heat drying will be the desired value.

[0164] A coating layer formed from a foam resin emulsion is heated and dried to evaporate and remove the dispersion medium in the emulsion, thereby forming an adsorption layer, which is a heat-dried product of the foam resin emulsion, on the substrate. Examples of devices for heating and drying the coating layer include ovens, hot plates, hot air dryers, and hot air circulation ovens. The temperature, time, and other conditions for the heat drying are appropriately selected depending on the composition of the foam resin emulsion so that the dispersion medium is substantially eliminated from the adsorption layer. The heat drying temperature is, for example, 80°C to 200°C, with 90°C to 150°C being preferred. The heat drying time is not particularly limited, but is preferably 70 minutes or less, more preferably 50 minutes or less, even more preferably 40 minutes or less, and particularly preferably 10 minutes or less, from the perspective of improving productivity. The lower limit of the time is not particularly limited as long as the dispersion medium can be sufficiently removed, and is, for example, 1 minute or more, and preferably 3 minutes or more.

[0165] The resulting adsorption layer contains a resin and micropores (also called voids or bubbles) present in the resin. For example, if the foam resin emulsion is a foam acrylic copolymer emulsion, the resulting adsorption layer will have micropores formed in the acrylic copolymer, resulting in a layer with an open-cell structure or a closed-cell structure.

[0166] Another method for forming the adsorption layer may involve foaming a resin composition for forming an adsorption layer, which is a mixture of a resin and a foaming agent, by in-mold foaming, extrusion foaming, or the like, as in Method 4. Examples of foaming agents include known foaming agents such as sodium bicarbonate, ammonium carbonate, diazoaminobenzene, and N,N'-dinitrosopentamethylenetetramine. A foaming aid may be added to the resin composition for forming an adsorption layer to enhance foaming efficiency. Examples of foaming aids include urea compounds and zinc compounds. The size and number of micropores formed in the adsorption layer can be adjusted by appropriately selecting the amount of foaming agent or foaming aid, foaming conditions, and the like. Adjusting the size and shape of the micropores formed on the surface of the adsorption layer, as well as the opening diameter and opening ratio of the micropores, can be controlled. Furthermore, the specific gravity and apparent density of the adsorption layer can be adjusted to desired values ​​by appropriately selecting the amount of foaming agent and, if necessary, foaming aid.

[0167] Other methods for forming the adsorption layer include, as in Method 1, a method in which the adsorption layer-forming resin composition is applied and dried to form a layer and then the surface is roughened. For example, when the adsorption layer-forming resin composition is extruded into a sheet and the surface is roughened to form recesses, the roughening method includes, for example, pressing a roughened metal roll or press plate against the surface of the sheet to roughen the surface of the sheet, or forming a sheet of the adsorption layer-forming resin composition containing a filler in the same manner as above and applying tension to the sheet to expose the filler on the surface of the sheet to roughen it. By appropriately selecting the roughening conditions, the size and number of micropores in the adsorption layer, as well as the opening diameter and opening ratio of the recesses, can be controlled. Furthermore, by appropriately selecting the degree of roughening, the specific gravity and apparent density of the adsorption layer can be adjusted to the desired values. When applying the adsorption layer-forming resin composition, a coating method similar to Method 3 above can be used. When a filler is used, examples of the filler include fillers similar to the inorganic and organic fillers described above. The amount of filler in the resin composition for forming an adsorption layer is appropriately determined depending on the desired number of recesses to be formed in the adsorption layer, etc. The average particle size, shape, etc. of the filler used are also the same as above, and are appropriately determined depending on the shape, size, etc. of the recesses to be formed in the adsorption layer.

[0168] As in Method 2, a method for applying tension to the adsorption layer in at least one direction to form recesses originating from the filler can be used, for example, by forming the adsorption layer-forming resin composition into a sheet by extrusion molding or the like, and stretching the sheet in at least one direction during extrusion molding to form micropores and recesses on the surface originating from the filler. The filler may be removed by washing or the like, or may remain in the adsorption layer. By appropriately selecting the amount of filler, the stretching conditions, etc., it is possible to control the size and number of micropores in the adsorption layer, the size, shape, and form of the recesses formed on the surface of the adsorption layer, as well as the opening diameter and opening ratio of the recesses. Furthermore, by appropriately selecting the amount of filler, it is possible to adjust the specific gravity and apparent density of the adsorption layer to desired values. The filler may be the same as the inorganic filler and organic filler described above. The amount of filler in the resin composition for forming an adsorption layer is appropriately determined depending on the desired number of recesses to be formed in the adsorption layer.

[0169] When stretching as described above, it is sufficient to stretch to the extent that recesses are formed starting from the filler, or the stretching ratio is appropriately set depending on the desired size of the recesses to be formed, etc. Furthermore, if the stretching ratio is too high, the adsorption layer formed starting from the filler will break, so the stretching ratio does not need to be too high. The stretching ratio is about 1.05 to several times, with 1.1 to 1.5 times being more preferable from the viewpoint of the size of the recesses to be formed and the strength of the adsorption layer.

[0170] [Middle layer] The tape may have an adsorption layer provided directly on the surface of the substrate, but may also have an intermediate layer between the substrate and the adsorption layer to further enhance adhesion between the substrate and the adsorption layer.

[0171] That is, the present tape may be a laminate having a substrate, an intermediate layer adjacent to at least one side of the substrate, and an adsorbent layer adjacent to the intermediate layer. Furthermore, when the present tape has an adsorbent layer on each side of the substrate, the present tape may be a laminate having a substrate, an intermediate layer adjacent to one side of the substrate, an adsorbent layer adjacent to the intermediate layer on the opposite side of the substrate, and an intermediate layer adjacent to the other side of the substrate, and an adsorbent layer adjacent to the intermediate layer on the opposite side of the substrate. The adsorbent layers provided on both sides of the substrate may have the same or different compositions and physical properties.

[0172] The intermediate layer is not particularly limited as long as it is a layer that can bond the substrate and the adsorption layer, and examples thereof include an adhesive layer and a primer layer.

[0173] <Composition of intermediate layer> The intermediate layer contains a polymer as a main component. Examples of the polymer include acrylic polymers, urethane polymers, epoxy polymers, polyester polymers, polyvinyl polymers (e.g., polyvinyl alcohol, vinyl chloride-vinyl acetate copolymers, ethylene-vinyl acetate copolymers, urethane-vinyl chloride acetate copolymers, etc.), rubber polymers (e.g., styrene block copolymers, etc.), and thermoplastic elastomers. These may be used alone or in combination. The polymer content in the intermediate layer may be the largest in the intermediate layer, and the polymer content in the intermediate layer, based on the total amount of the intermediate layer being 100% by mass, may be, for example, 30% by mass or more, preferably 40% by mass or more, more preferably 50% by mass or more, even more preferably 60% by mass or more, and particularly preferably 80% by mass.

[0174] When the intermediate layer is a pressure-sensitive adhesive layer, the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer can be, for example, a pressure-sensitive adhesive containing the above-mentioned polymer as a main component, and specific examples thereof include acrylic pressure-sensitive adhesives, urethane pressure-sensitive adhesives, rubber pressure-sensitive adhesives, polyester pressure-sensitive adhesives, etc. These may be used alone or in combination. Among these, acrylic pressure-sensitive adhesives, urethane pressure-sensitive adhesives, and rubber pressure-sensitive adhesives are preferred because they make it easier to adjust the storage modulus (described later) within a desired range.

[0175] Furthermore, when the intermediate layer is a primer layer, the primer agent constituting the primer layer may be, for example, a primer agent containing as a main component the polymer described above in <Composition of intermediate layer>.

[0176] In addition to the polymer described in <Composition of Intermediate Layer> above, the intermediate layer may contain additives such as a tackifying resin, an antifoaming agent, a coatability improver, a thickener, an organic lubricant, an ultraviolet absorber, an antioxidant, a foaming agent, a dye, a pigment, or particles, as necessary.

[0177] <Properties> The thickness of the intermediate layer is not particularly limited, but from the viewpoint of making it easier for distortion of the adsorption layer to occur when the tape is stretched and peeled off and achieving high adhesion between the substrate and the adsorption layer, it is preferably in the range of 0.01 μm to 100 μm, more preferably in the range of 0.1 μm to 50 μm, and even more preferably in the range of 0.5 μm to 20 μm.

[0178] The intermediate layer has a storage modulus (G'23) of 1.0 x 10 at 23°C. 4 Pa~1.0×10 8 Pa, and preferably in the range of 3.0 × 10 4 Pa ~ 5.0 × 10 7 More preferably, it is in the range of 6.0×10 Pa. 4 Pa~8.0×10 6 It is more preferable that the storage modulus (G'23) of the intermediate layer is within the above range. By setting the storage modulus (G'23) of the intermediate layer within the above range, the intermediate layer becomes a relatively hard layer, so that when the tape is stretched, the intermediate layer does not inhibit the distortion that occurs in the recesses of the adsorption layer, and deterioration of easy releasability due to stretching can be suppressed. Furthermore, when the tape is stretched and peeled, the elongation at peeling can be reduced, and the laminated state (adhesion state) with the adherend can be released with even lower elongation.

[0179] The storage modulus (G'23) of the intermediate layer can be adjusted by changing the gel fraction of the intermediate layer through the structure of the polymer that makes up the intermediate layer, the molecular weight of the polymer, and the amount of crosslinking agent. The polymer structure can be controlled by the type and amount of monomer.

[0180] The storage modulus of the intermediate layer at 23°C (G'23) is determined by stacking the intermediate layers to a thickness of approximately 2 mm to form a test piece, attaching 7.9 mm diameter parallel plates to a Rheometrics Ares 2kSTD viscoelasticity testing machine, and clamping the test piece between them.The test piece is measured in a tensile-sine wave vibration mode at a frequency of 1 Hz and a heating rate of 2°C / min.The storage modulus G' at 23°C is determined by the following conditions:

[0181] [Release liner] The present tape may have a release liner on the surface of the adsorption layer opposite the substrate. By providing a release liner, the surface of the adsorption layer can be protected until the tape is used, and handling before use can be improved. The release liner is peeled off and removed when the tape is used, for example, when it is attached to an adherend. Known release liners can be used, such as paper, plastic film, polytetrafluoroethylene (PTFE) film, and plastic film whose surface has been subjected to a release treatment such as silicone treatment or silicone fluoride treatment.

[0182] [Adhesive tape] The present tape may have an adsorption layer on at least one side of the substrate, but may also have an adsorption layer on each side of the substrate. The adsorption layers on both sides of the substrate may be the same, or may differ in composition, opening diameter of the recesses, opening ratio, and other properties. In the present tape, the adsorption layer may be adjacent to the substrate, or may be provided on the substrate via the above-mentioned intermediate layer.

[0183] The present tape may have an adsorption layer on at least one side of the substrate, either directly or via another layer, and may be a single-sided tape having an adsorption layer on one side of the substrate, a double-sided tape having an adsorption layer on each side of the substrate, or a double-sided tape having an adsorption layer on one side of the substrate and a pressure-sensitive adhesive layer on the other side.

[0184] The total thickness of the tape is not particularly limited as long as it can perform the desired function, but is preferably in the range of 10 μm to 1500 μm, more preferably 30 μm to 1000 μm, and even more preferably 50 μm to 500 μm. By keeping the total thickness of the tape within the above range, it is less likely to fold or wrinkle when used for temporary fixation, and workability is less likely to be impaired. The total thickness of the tape can be measured in the same manner as the thickness of the adsorption layer, intermediate layer, and substrate. When the tape has a release liner on the surface of the adsorption layer, the total thickness of the tape refers to the thickness excluding the release liner.

[0185] The thickness ratio between the adsorption layer and the substrate can be appropriately selected depending on the purpose. The thickness ratio between the adsorption layer and the substrate is the value obtained by dividing the thickness of the adsorption layer by the thickness of the substrate. The ratio of the thickness of the adsorption layer to the thickness of the substrate (= thickness of the adsorption layer / thickness of the substrate) is preferably 1 / 500 or more, more preferably 1 / 400 or more, even more preferably 1 / 200 or more, even more preferably 1 / 100 or more, and particularly preferably 1 / 50 or more. Furthermore, the ratio can be 10 / 1 or less, preferably 5 / 1 or less, and particularly preferably 3 / 1 or less, more preferably 2 / 1 or less, and even more preferably 1 / 1 or less. By keeping the thickness ratio between the adsorption layer and the substrate within the above range, the temporarily fixed adherend can be firmly held when the tape and the adherend are attached, and folding and wrinkling of the tape can be easily suppressed. In addition, when an adsorption layer is provided on both sides of the substrate, the "thickness of the adsorption layer" when calculating the ratio of the thickness of the adsorption layer to the substrate refers to the thickness of the adsorption layer provided on one side of the substrate.

[0186] The breaking elongation of the present tape is not particularly limited as long as the tape can be peeled off without breaking during the stretching process, but is preferably 200% or more, more preferably 300% or more, even more preferably 400% or more, and particularly preferably 500% or more. There is no particular upper limit to the breaking elongation of the present tape, and the breaking elongation of the present tape is preferably 3000% or less, more preferably 2500% or less, even more preferably 2000% or less, even more preferably 1500% or less, particularly preferably 1300% or less, and even particularly preferably 1000% or less. By keeping the breaking elongation of the present tape within the above range, excessive stress when stretching the present tape can be suppressed, and the stretching distance required for the adherend to peel off from the present tape can be shortened.

[0187] The breaking strength of the present tape is not particularly limited as long as the tape can be peeled off without breaking during the stretching process, but is preferably in the range of 5 MPa to 100 MPa, more preferably in the range of 10 MPa to 90 MPa, even more preferably in the range of 15 MPa to 80 MPa, and particularly preferably in the range of 20 MPa to 70 MPa. When the breaking strength of the present tape is within the above range, the tape can be prevented from tearing during the stretching process, and excessive stress when the tape is stretched can be prevented.

[0188] The breaking elongation and breaking strength of this tape refer to the tensile elongation and stress measured when the tape was punched into a dumbbell shape with a gauge length of 20 mm and a width of 5 mm, and pulled lengthwise at a rate of 500 mm / min using a Tensilon tensile testing machine (model: RTF-1210, manufactured by A&D Co., Ltd.) at an ambient temperature of 23°C and 50% RH until breaking.

[0189] The breaking elongation and breaking strength of the present tape can be adjusted by, for example, appropriately selecting the materials of each layer constituting the present tape, particularly the material of the substrate, or by stretching the substrate during the manufacturing process.

[0190] The 50% modulus of the present tape is preferably in the range of 0.1 MPa to 55 MPa, more preferably in the range of 0.2 MPa to 30 MPa, even more preferably in the range of 0.4 MPa to 15 MPa, and particularly preferably in the range of 0.6 MPa to 5 MPa. When the 50% modulus of the present tape is within the above range, the tape can be stretched with a light force in the initial stage of stretching when peeling the tape from an adherend, reducing the stress required for the entire stretching operation and facilitating the operation. Furthermore, when the tape is stretched and peeled, it is easily peeled at a relatively low elongation.

[0191] The 50% modulus of this tape is the stress measured when the tape is punched into a dumbbell shape with a gauge length of 20 mm and a width of 5 mm, and pulled in the lengthwise direction at a rate of 500 mm / min using a Tensilon tensile testing machine (model: RTF-1210, manufactured by A&D Co., Ltd.) under conditions of 23°C and 50% RH, and the elongation reaches 50%.

[0192] The 50% modulus of the present tape can be adjusted by, for example, appropriately selecting the materials of each layer constituting the tape, particularly the material of the substrate, or by stretching the substrate during the manufacturing process.

[0193] The 180° peel strength of the present tape is preferably 0.05 N / mm or more, more preferably 0.06 N / mm or more, and even more preferably 0.07 N / mm or more. The 180° peel strength of the present tape is preferably 1 N / mm or less, more preferably 0.8 N / mm or less, even more preferably 0.5 N / mm or less, even more preferably 0.3 N / mm or less, and particularly preferably 0.2 N / mm or less. By keeping the 180° peel strength of the present tape within the above range, the adherend can be sufficiently fixed, and the tape can be stretched and peeled off with low elongation without the peel strength becoming too high, resulting in good removability.

[0194] The 180° peel strength of this tape can be measured by attaching a 20 mm wide piece of tape to a stainless steel plate at 23°C with the adhesive layer facing up, applying pressure once with a 2 kg roller, leaving it to stand for 1 hour at 23°C, and then pulling it in the 180° direction at a pulling speed of 300 mm / min using a Tensilon tensile tester.

[0195] The surface adhesion strength of this tape 1 hour after application to an adherend is preferably in the range of 10 N / 20 mm to 300 N / 20 mm, more preferably in the range of 20 N / 20 mm to 200 N / 20 mm, and more preferably in the range of 30 N / 20 mm to 100 N / 20 mm. Furthermore, the surface adhesion strength of this tape 24 hours after application to an adherend is preferably in the range of 10 N / 20 mm to 300 N / 20 mm, more preferably in the range of 20 N / 20 mm to 200 N / 20 mm, and more preferably in the range of 30 N / 20 mm to 100 N / 20 mm. By having the surface adhesion strengths 1 hour and 24 hours after application to an adherend within the above ranges, the tape can firmly hold the adherend and can be peeled off with low elongation and low stress without excessive stress required for peeling by elongation and stretching.

[0196] Furthermore, it is preferable that the change in surface adhesive strength over time of this tape be small. When the surface adhesive strength of this tape 1 hour after application to the adherend is defined as P1 and the surface adhesive strength 24 hours after application to the adherend is defined as P2, the rate of change in surface adhesive strength P2 relative to surface adhesive strength P1 (=P2 / P1×100) is preferably 50% or more, more preferably 60% or more, even more preferably 70% or more, and particularly preferably 80% or more. Meanwhile, the rate of change in surface adhesive strength P2 relative to surface adhesive strength P1 is preferably 210% or less, more preferably 200% or less, even more preferably 180% or less, even more preferably 160% or less, particularly preferably 140% or less, and particularly preferably 120% or less. By keeping the rate of change in surface adhesive strength P2 relative to surface adhesive strength P1 within the above range, the change in surface adhesive strength over time is suppressed, and the stress required for peeling by elongation and stretching is not excessive, enabling peeling with low elongation and low stress. In addition, the surface adhesive strength increases over time, which can prevent adhesive residue from being left on the adherend.

[0197] The surface adhesive strengths P1 and P2 1 hour and 24 hours after the tape is applied to the adherend can be measured by the method described in the section "(10) Surface adhesive strength of tape" in the Examples below.

[0198] The smaller the elongation at peeling, the better the stretch-release property of the tape, as the fixed state of the adherend can be released with low elongation. Specifically, the elongation at peeling of the tape is preferably in the range of 101% to 400%, more preferably in the range of 105% to 300%, and even more preferably in the range of 110% to 250%. By setting the elongation at peeling of the tape in the above range, the tape can be peeled from the adherend with low elongation. In particular, when the adherend is a small part (for example, the surface area of ​​the surface in contact with the tape is 500 mm 2 Below, among others, 100mm 2 Below, further 50mm 2 Below, especially 1mm 2 In the case of a part (such as a part described below), the tape can be peeled from the adherend without the need for excessive stretching.

[0199] The stretch releasability (elongation at peeling) of this tape can be measured by the method described in the section "(9) Stretch releasability of tape (elongation at peeling)" in the Examples section described later. In this specification, the "elongation" in the stretch releasability at peeling refers to the ratio of the gauge length of the tape after stretching when the tape is stretched and peeled off the adherend (initial gauge length + length of the stretched portion of the tape) to the initial length of the tape (initial gauge length), calculated by the following formula: {(initial gauge length + length of stretched tape) / initial gauge length} x 100 = elongation at peeling [%]

[0200] [Manufacturing method of this tape] The method for manufacturing this tape is not particularly limited, and examples include a method in which an adsorption layer is formed on a release liner using a resin composition for forming an adsorption layer, for example, by the method described above, and the adsorption layer is then attached to the surface of a substrate, or a method in which an adsorption layer is formed directly on a substrate using a resin composition for forming an adsorption layer.

[0201] In an embodiment in which the present tape has an intermediate layer between the substrate and the adsorption layer, the method for producing the present tape can include, for example, the steps of forming an intermediate layer on a release liner using a composition for forming an intermediate layer, forming an adsorption layer on the release liner using a resin composition for forming an adsorption layer, laminating the intermediate layer to the surface of the substrate to form a laminated intermediate body, and peeling off the release liner from the surface of the intermediate layer to laminate the adsorption layer. Another example of a method for producing the present tape in the above embodiment can include a method in which an intermediate layer is formed directly on the substrate using a composition for forming an intermediate layer, and then forming an adsorption layer on the intermediate layer using a resin composition for forming an adsorption layer.

[0202] In the step of forming an adsorption layer on a release liner, the adsorption layer may be formed by applying a resin composition for forming an adsorption layer (a foam resin emulsion) containing bubbles by mechanical foaming to the release liner and drying it, or by applying a resin composition for forming an adsorption layer that does not contain bubbles, such as a resin emulsion, to the release liner and then foaming it. The methods for forming the adsorption layer and the intermediate layer have already been described.

[0203] From the viewpoint of productivity, this tape is preferably manufactured by forming an adsorption layer on the substrate in the manner described above while unwinding the roll-shaped substrate, and then rewinding it to form a roll, or by forming an adsorption layer on a release liner in the same manner as described above, transferring it to the substrate, and then rewinding it to form a roll, using a roll-to-roll method.

[0204] [Use of this tape] When pressure is applied to the tape, the recesses on the surface of the adhesive layer are crushed, and the adherend is fixed to the adhesive layer by the suction cup effect, making the tape attachable to and fixed to the adherend. On the other hand, when the tape is to be peeled off from the adherend, the tape is stretched in at least one direction. During this stretching, the tape is subjected to stress, causing the recesses on the surface of the adhesive layer to deform, and the adhesive layer is also stretched, creating a gap between the tape and the adherend. This releases the adhesive state (bonded state) between the tape and the adherend due to the suction cup function of the adhesive layer, and the tape is detached from the adherend. As a result, the adhesive tape of the present disclosure is a tape that can be peeled off by stretching.

[0205] The present tape can be used, for example, as a temporary fixing tape for temporarily fixing a component (adherend) on an adsorption layer in a component manufacturing process. The temporary fixing tape can be used, for example, as a process tape for temporarily fixing a component (workpiece and / or processed product) before and after processing during the component (processed product) manufacturing process, as described below. More specific examples of process tapes include tapes for electronic component manufacturing processes, such as manufacturing multilayer ceramic capacitors from green sheets, tapes for semiconductor manufacturing processes, and process tapes used for masking purposes such as solder reflow processes and sputtering processes in the manufacturing processes of various electronic components.

[0206] Furthermore, when the present tape has an adhesive layer on both sides of the substrate, the present tape can also be used as a bonding tape for bonding two or more parts (adherends).

[0207] 2. Items [Items using this tape] The article of the present disclosure comprises one or more components on the adsorption layer of the adsorption tape (the present tape) described above in the section "1. Adsorption Tape." Figure 2, which has already been described, corresponds to a schematic top view showing an example of the article of the present disclosure.

[0208] An article using this tape includes a component on the surface of the adhesive layer of the tape. When the tape is single-sided, having an adhesive layer on one side of the substrate, the article of the present disclosure can be configured as having a component on the surface of the adhesive layer on one side of the substrate. When the tape is double-sided, having adhesive layers on both sides of the substrate, an article using this tape can include a component only on the surface of the adhesive layer on one side of the tape, or can include a component A on the surface of adhesive layer A on one side of the substrate and a component B on the surface of adhesive layer B on the other side of the substrate. The tape can also be double-sided, having an adhesive layer on one side of the substrate and an adhesive layer on the other side. The component temporarily fixed to the tape can be a component before processing (a workpiece) or a component after processing (a processed product), and is not particularly limited. Specific examples of such components include electronic components such as semiconductor wafers, semiconductor elements, packages, green sheets, multilayer ceramic capacitors, inductors, and various chips, and optical components such as optical glass and polarizing plates.

[0209] 3. How to remove the adhesive tape [How to remove this tape] The method for peeling off an adsorption tape according to the present disclosure is a method for peeling off the adsorption tape from the adherend by stretching the adsorption tape described in the above section "1. Adsorption tape" that has been attached to the adherend in at least one direction.

[0210] The method for peeling the present tape from an adherend preferably involves stretching the present tape in at least one direction to peel it from the adherend to which the adsorbent layer is attached. Stretching the present tape in at least one direction creates a gap between the adherend and the adsorbent layer, reducing the suction cup effect of the recesses on the surface of the adsorbent layer, allowing the adherend to detach, making it easier to peel the present tape.

[0211] The tape may be stretched (drawn) in a direction horizontal, vertical, or oblique to the adhesive surface between the tape and the adherend, or in a combination of these directions. The tape may be stretched simultaneously or sequentially in two or more different directions. The tape can be peeled by stretching it in at least one direction at the contact surface (adhesive surface) between the tape and the adherend. Two or more directions are preferred, and stretching in all directions is even more preferred, since this allows for uniform stretching and allows multiple adherends bonded or temporarily fixed to the tape to be peeled simultaneously. Specifically, the tape is stretched (drawn) in a direction such that the angle θ between the contact surface (adhesive surface) between the tape and the adherend and the axis is within the range of -90° to 90°, with the direction in which the tape end is pulled as the axis. When the angle θ is 0°, the axis is horizontal to the adhesive surface; when the angle θ is 90°, the axis is positioned vertically on the adhesive surface side of the tape and the adherend; and when the angle θ is -90°, the axis is positioned vertically on the opposite side of the adhesive surface.

[0212] The method for stretching and elongating the present tape is not particularly limited, and examples include a method of gripping the end of the tape and stretching it, a method of clamping the tape with a jig or the like and pulling it in a certain direction, a method of pulling it while winding it up on a roll, a method of pulling the present tape by utilizing the difference in peripheral speed between two rolls, and a method of attaching a jig having a space that surrounds the adherend to the side of the present tape that will be attached to the adherend, and pushing the present tape from the side opposite the adherend side toward the adherend side with a convex jig to pull the present tape.

[0213] After the adherend is peeled off from the tape, the adherend is removed from the tape. The removal method may involve the adherend dropping under its own weight, or it may be removed from the tape by mechanical operation. Examples of mechanical removal methods include suction, clamping, sweeping, etc. In removal methods by suction, suction means include a suction cup, a suction machine, a suction collet, etc. In removal methods by clamping, clamping means include tweezers, a clamp, etc. In removal methods by sweeping, sweeping methods include a swinging plate, air pressure, a brush, etc.

[0214] When removing an adherend from this tape, the direction of the adhesive surface between the adhesive layer of this tape and the adherend is selected appropriately depending on the manufacturing equipment and method of the part in which this tape is used, such as a vertically upward direction with the adherend facing upward, a vertically downward direction with the adherend facing downward, a direction in which the adhesive surface is parallel to the vertical direction, etc. Furthermore, when the adherend is removed from the tape by falling under its own weight, it is preferable to install this tape so that the adhesive surface is parallel to the vertical direction or vertically downward.

[0215] The adherend in the tape peeling method of the present invention is not particularly limited, and when the tape peeling method of the present invention is used in a part (processed product) manufacturing process, it may be a part before processing or a part after processing. More specific examples of the adherend include the parts (small electronic parts) and examples of adherends explained in the above sections "1. Adsorption tape" to "2. Articles", as well as examples of parts and / or processed products described below.

[0216] The size of the adherend in the present tape peeling method is not particularly limited and can be appropriately selected from the size of the adherend described below. However, in particular, the effect of the present tape peeling method is most pronounced when the surface area of ​​the surface that comes into contact with the adhesive tape is 500 mm 2 (5cm 2 ) below, among which the above surface area is 100 mm 2 (1cm 2 ) or less is particularly preferable. 2 (1cm 2The preferred size of the surface area of ​​the adherend that comes into contact with the tape is the same as that explained in "4. Manufacturing method of components" below.

[0217] 4. Parts manufacturing method The method for manufacturing a component according to the present disclosure includes at least a peeling step of stretching the suction tape described in the above section "1. Adsorption tape" in at least one direction to peel off the component fixed on the adsorption layer of the suction tape.

[0218] 6 is a process diagram showing an example of a method for manufacturing a component according to the present disclosure, which includes a peeling step in which a component 5 is fixed on an adsorption layer 3 of an adsorption tape 1, and the adsorption tape 1 is stretched in one direction (stretching direction D) to peel the component 5 from the adsorption tape 1 (FIGS. 6(a) and (b)). Note that the stretching direction D in FIG. 6 is bidirectional.

[0219] According to the component manufacturing method disclosed herein, a large number of components can be peeled off from the suction tape at once simply by stretching the suction tape while the components are fixed to the suction tape. This eliminates the need for heating or irradiation with energy rays when peeling the components, making the peeling process in component manufacturing simple and easy to carry out and further suppressing the occurrence of component contamination such as glue residue.

[0220] The suction tape used in the component manufacturing method of the present disclosure and the peeling method therefrom are similar to the contents already explained in the above sections "1. Suction Tape" to "3. Method for Peeling Off Suction Tape," and therefore will not be explained here. Furthermore, there are no particular limitations on the components that can be manufactured by the component manufacturing method of the present disclosure, and the contents already explained in the above sections "1. Suction Tape" to "3. Method for Peeling Off Suction Tape" can be applied. The component peeled off from the suction tape in the peeling step may be processed (may be a processed product) or unprocessed (may be a workpiece). Specific examples of components before and after processing include the components already exemplified, such as those explained in the above section "2. Article," and processed products described below.

[0221] The size of the component to be peeled off from the suction tape in the peeling step is not particularly limited, but the surface area of ​​the component in contact with the suction tape is 500 mm 2 It is preferable that the thickness is less than 100 mm. 2 Less than 50mm is preferable 2 Less than 30mm is more preferable. 2 Less than 10mm is preferable 2 Less than 1mm is even more preferable. 2 The following is particularly preferred: A component having the surface area of ​​the surface that comes into contact with the tape can be called a small component. 2 The surface area of ​​the surface that comes into contact with the tape is preferably 0.5 mm or less. 2 It is more preferable that it is 0.2 mm or less. 2 Less than 0.1 mm is more preferable. 2 The following is particularly preferable. The lower limit of the size of the part is not particularly limited, but for example, it is 0.001 mm. 2 More than 0.005mm, preferably 0.005mm 2 More than 0.01 mm, preferably 0.01 mm 2 More than 0.05mm, preferably 0.05mm 2 It can be more than that.

[0222] In the peeling step, the suction tape is stretched in at least one direction. The stretching direction can be set arbitrarily in a plan view of the suction tape. For example, if the suction tape has a longitudinal direction and a transverse direction, the stretching direction may be the longitudinal direction, the transverse direction, a direction generally perpendicular to the longitudinal direction, or another direction, such as a direction inclined at a desired angle relative to the longitudinal direction. Regardless of the longitudinal and transverse directions of the tape, one or more stretching directions may be set based on any point within the tape plane. When one stretching direction and the other stretching direction are 180° opposite, the stretching directions are considered to be bidirectional and the same direction. The stretching direction D shown in Figure 6(a) shows an example of bidirectional stretching from both sides of the tape. The stretching direction may also be unidirectional (for example, only one of the two arrow directions D in Figure 6(a)). Note that "roughly perpendicular" does not have to be exactly 90° to the stretching direction; it is sufficient if it is approximately 90°, and directions that form an angle of 85° to 95°, and even directions that form an angle of 88° to 92° to the stretching direction are acceptable.

[0223] The method for stretching the adsorption tape in one direction (stretching direction) in the peeling step is not particularly limited, and examples include a method of gripping and pulling the adsorption tape with a stretching means such as an expansion member, a method of pulling the adsorption tape while winding it up with a stretching means such as a roll, a method of pressing (pressing) a movable stage or movable pin or the like against the adsorption tape as a stretching means to protrude (push up or down) the adsorption tape, etc. The stretching means may apply tension horizontally to the adhesive surface between the component and the adsorption layer of the adsorption tape, or may apply tension in the direction opposite to the side of the temporary fixing tape on which the component is placed.

[0224] The peeling step may include a transfer step in which a transferee is placed on the surface of the component opposite to the suction tape, and the component is transferred to the transferee by stretching the suction tape in at least one direction from a composite having the suction tape, component, and transferee in this order, to peel the component from the transferee and simultaneously transfer the component to the transferee. FIG. 7 is a process diagram showing another example of a component manufacturing method according to the present disclosure, illustrating an example in which the peeling step includes a transfer step. Note that the substrate 2 and suction layer 3 constituting the suction tape 1 are not shown in FIG. 7. As illustrated in FIG. 7, a transferee 200 is placed on the surface of the component 5 opposite to the contact surface with the suction tape 1 ( FIG. 7(a)), and the component 5 is transferred to the transferee 200 by stretching the suction tape 1 in one or more directions from a composite having the suction tape 1, component 5, and transferee 200 in this order, to peel the component 5 and simultaneously transfer the component 5 to the transferee 200 ( FIGS. 7(b) and 7(c)).

[0225] The transfer object onto which the component is transferred is not particularly limited as long as it can directly or indirectly fix the transferred component, and examples thereof include adhesive tape, sticky tape, and other components coated with adhesive.

[0226] The component manufacturing method of the present disclosure may include at least the peeling step described above, but may also include other steps. For example, it may include a processing step of processing the component (also referred to as the workpiece or the member before processing) temporarily fixed on the suction tape before the peeling step. A method for manufacturing a processed product, which is an example of the component manufacturing method of the present disclosure, will be described later. The component manufacturing method of the present disclosure may also include other steps, such as a cleaning step, a curing step, and a removal step of removing the peeled component from the tape. The processing step and other steps will be described in the section "Method for Manufacturing a Processed Product" below.

[0227] [Manufacturing method for processed products] The method for manufacturing a processed product of the present disclosure includes the steps of processing a workpiece provided on the surface of the adhesive layer of the present tape, and stretching the present tape in at least one direction to peel the processed product from the present tape (the adhesive layer of the present tape). That is, the method for manufacturing a processed product using the present tape includes at least the steps of fixing one or more pre-processed parts (workpieces) on the adhesive layer of the present tape and processing the pre-processed parts (workpieces) on the present tape (processing step), and stretching the tape in at least one direction to peel the tape from the processed parts (workpieces) (peeling step).

[0228] According to the method for manufacturing a processed product disclosed herein, the adhesive function of the adhesive layer surface of the tape sufficiently temporarily fixes the component (workpiece) before processing, making it easy to process the component on the tape. After processing the component, the adhesive layer is released by stretching the tape, allowing the processed component (processed component) to be peeled off from the tape. This prevents contamination of the component by adhesives, etc., and makes it easy to peel the component without the need for a heating device, UV irradiation device, or other peeling equipment.

[0229] In the above-mentioned processing step, the number of pre-processed parts (workpieces) placed on the adhesive layer of the present tape is not particularly limited and can be one or more. The processing method of the pre-processed parts (workpieces) in the above-mentioned processing step is not particularly limited and includes, for example, cutting, polishing, cutting, etching, etc., and the desired processed product is obtained by processing the workpiece. In addition, in the processing step, the parts to be processed in this step may already have undergone a pre-processing step.

[0230] The processed product is not particularly limited, but examples thereof include electronic components such as semiconductor chips, multilayer ceramic capacitors, various chips, and inductors. Among these, small electronic components are preferred. Examples of the workpiece that is the precursor of the processed product include semiconductor wafers and green sheets.

[0231] The size of the workpiece is not particularly limited, but the smaller the workpiece, the smaller the surface area of ​​the surface that contacts the tape per workpiece, which is preferable because the effect of using this tape, especially the effect of the peeling process, is more pronounced. This is because when the size of each workpiece is small, the surface area of ​​the surface that contacts the tape (adhesion area) becomes smaller. However, when a stretch-release tape having an adhesive layer is used, it is difficult to obtain the effect of reducing the adhesive area between the tape and the workpiece relative to the elongation of the tape when stretched, and the workpiece may not be sufficiently peeled unless the tape is stretched excessively. In contrast, in the present disclosure, by using the above-mentioned tape, the adsorption state by the adsorption layer is released even when the elongation of the tape is small, so the workpiece can be easily peeled and detached from the tape. The size of the workpiece is such that the surface area of ​​the surface that contacts the tape (the contact area of ​​each workpiece with this tape before stretching) is 500 mm 2 It is preferable that the contact area (the surface area of ​​the workpiece that comes into contact with the tape) is 100 mm 2 Less than 50mm is preferable 2 Less than 30mm is more preferable. 2 Less than 10mm is preferable 2 Less than 1mm is even more preferable. 2 The following is particularly preferred. A processed product (a processed part) having a surface area in contact with the tape can be called a small part. Among the processed products, a small part having a surface area in contact with the tape of 1 mm 2 Particularly, micro-components with a surface area of ​​0.5 mm or less are preferred. 2 It is more preferable that it is 0.2 mm or less. 2 Less than 0.1 mm is more preferable. 2 The following is particularly preferred. The lower limit of the size of the workpiece is not particularly limited, but for example, it is 0.001 mm. 2 More than 0.005mm, preferably 0.005mm 2 More than 0.01 mm, preferably 0.01 mm 2 More than 0.05mm, preferably 0.05mm 2 It can be more than that.

[0232] In the peeling step, the workpiece is peeled from the tape by stretching the tape in at least one direction. The peeling method can be any of the methods already described. From the viewpoint of uniformly peeling the workpiece from the tape and preventing the workpiece from remaining on the tape, the tape is preferably stretched in two or more different directions, and is preferably stretched uniformly in all directions within the adhesive surface between the adsorption layer and the workpiece (adherend).

[0233] The method for manufacturing a processed product of the present disclosure is sufficient to include at least the processing step and the peeling step, and may also include other steps, such as a cleaning step, a curing step, and a removal step for removing the peeled processed product from the tape. The method for removing the processed product in the removal step may be the same as the method for removing the adherend described above. Furthermore, the resulting processed product may be sent to other steps, such as further processing, assembly of processed products, or joining with other processed products. Depending on the type of process, the other steps may be performed before the processing step, between the processing step and the peeling step, or after the peeling step.

[0234] Although the present tape, the method for peeling the present tape, and the manufacturing method using the present tape have been described above, the present invention is not limited to the configurations of the above-described embodiments. In the configuration of the present tape according to the above embodiment, any other configuration may be added, or any configuration that exhibits the same function may be substituted. Furthermore, in the configuration of the above embodiment, the peeling method of this tape and the manufacturing method using this tape may have any other process added to it, or may be replaced with any process that performs the same function. [Example]

[0235] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

[0236] [evaluation] (1) Measurement of the thickness of the adsorption layer, intermediate layer, and substrate The sample was cut to an arbitrary size, and the thickness was measured at five locations at 10 mm intervals in the lengthwise direction and at five locations at 10 mm intervals in the widthwise direction using a dial thickness gauge (manufactured by Ozaki Manufacturing Co., Ltd., model G-0.4N or model G-2.4N). The value obtained by averaging the thicknesses at these 10 locations was used as the thickness of the target object. For layers that become brittle when isolated, such as adsorption layers and intermediate layers, the release liner used in forming each layer in the following examples was used as a support to measure the total thickness, and the value obtained by subtracting the thickness of the support was used as the thickness.

[0237] (2) Specific gravity of the adsorption layer A specific gravity cup (066 series manufactured by Allgood Co.) and a resin composition for forming an adsorption layer (foam acrylic resin emulsion) were kept at 23°C ± 2°C, and the mass of the empty specific gravity cup was measured. The resin composition for forming an adsorption layer was filled into the specific gravity cup, and the lid was gently placed on the cup to prevent air bubbles from remaining inside the specific gravity cup due to imperfect filling of the resin composition for forming an adsorption layer. The resin composition for forming an adsorption layer that had overflowed from the overflow orifice in the center of the lid was wiped off with a rag, and the mass of the specific gravity cup filled with the resin composition for forming an adsorption layer was measured. The specific gravity of the resin composition for forming an adsorption layer was calculated using the following formula, and the obtained value was taken as the specific gravity of the adsorption layer formed using the resin composition for forming an adsorption layer. Specific gravity [g / cm 3 ]={(mass of the specific gravity cup filled with the resin composition for forming an adsorption layer)−(mass of the empty specific gravity cup)} / volume of the specific gravity cup

[0238] (3) Apparent density of the adsorption layer In accordance with JIS K6767, a test piece of the adsorption layer was cut into a rectangle measuring 4 cm in length and 5 cm in width, and the apparent volume (length x width x thickness) [cm ] of the test piece was calculated from the length, width, and thickness of the test piece. 3 The mass [g] of the test piece was measured, and the mass was divided by the apparent volume to obtain the apparent density.

[0239] (4) Average opening diameter on the surface of the adsorption layer: The adsorption layer was observed in plan view using a tabletop low-vacuum scanning electron microscope (SEM, Hitachi High-Technologies Corporation, "MiniscopeTM3030Plus"), and a magnified photograph of the adsorption layer surface was taken at 100x magnification.The opening diameters of an arbitrary depression located in the center of the photograph and 30 depressions located nearby were then measured, and the average value was taken as the average opening diameter.

[0240] (5) Opening ratio at the surface of the adsorption layer: Using an electron microscope (Keyence Corporation, Digital Microscope VHX6000), the surface of the adsorption layer was photographed at 200x magnification (automatic brightness adjustment, 1.27mm x 1.7mm). The area of ​​the black areas in the image and the total area were calculated using software analysis, and the aperture ratio was calculated by dividing the area of ​​the black areas by the total area. Note that in the above image, the black areas are recesses formed on the surface of the adsorption layer, and the area of ​​the black areas corresponds to the projected area of ​​the recesses.

[0241] (6) Storage modulus G' of the intermediate layer: The intermediate layers were stacked to a thickness of approximately 2 mm to form a test specimen, and parallel plates with a diameter of 7.9 mm were attached to a viscoelasticity tester (Rheometrics Ares 2kSTD) to clamp the test specimen and measure the storage modulus G' at a frequency of 1 Hz and 23°C.

[0242] (7) 50% modulus, breaking strength, breaking elongation Dumbbell-shaped test specimens (substrate and tape) with a gauge length of 20 mm and width of 5 mm were punched out and measured using a Tensilon tensile tester (model: RTF-1210, manufactured by A&D Co., Ltd.) at 23°C and 50% RH. The test specimens were stretched longitudinally at a rate of 500 mm / min. The 50% modulus was calculated by dividing the stress value (unit: N) obtained at 50% elongation by the thickness (unit: mm) and width (unit: mm) of the test specimen. The breaking strength was calculated by dividing the stress value (unit: N) at break by the thickness (unit: mm) and width (unit: mm) of the test specimen, and the elongation at break was calculated as the breaking elongation. The formulas for calculating the elongation and breaking elongation in the modulus are as described above.

[0243] (8) Tape holding power To prevent stretching and peeling of the substrate, the tapes obtained in the Examples and Comparative Examples were lined with a PET single-sided adhesive tape (DIC #8625S) and cut to a 20 mm wide x 100 mm long piece. The tape was placed on the surface of a clean, smooth stainless steel plate (hairline polished with #360 waterproof abrasive paper) at 23°C and 50% RH, with a 20 mm x 20 mm adhesive area. A 2 kg roller was rolled back and forth across the top surface of the tape, and the tape was then left for 1 hour at 23°C to prepare a test specimen. With the stainless steel plate constituting the test specimen fixed, a 1 kg load was applied to the tape in a 70°C environment, and the time from when the tape fell off the stainless steel plate was measured.

[0244] (9) Stretchability of tape (elongation at peeling) The tapes obtained in the Examples and Comparative Examples were cut to a length of 200 mm x width of 20 mm, and both ends (50 mm x 20 mm) were laminated with 50 μm-thick PET film to form gripping tabs for longitudinal stretching of the tape. Three aluminum blocks, each 10 mm long, 10 mm wide, and 4 mm thick, with their bottom surfaces in contact with the adhesive layer were prepared and aligned in series along the length of the tape at the center of the adhesive layer surface of the tape (the adhesive layer surface in Comparative Examples 1 and 2). The test specimens were then pressed together with a load of 1 kg per three blocks for 10 seconds to form test pieces. The tab at one end of the tape was placed in a fixture with the aluminum blocks of the test piece facing downwards. The tab on the opposite side of the tape was then gripped and stretched horizontally at a rate of 300 mm / min. The elongation of the tape (elongation at peeling) when all three aluminum blocks had dropped from the tape was reported as the elongation at peeling. The elongation (elongation at peeling) was calculated using the following formula. In the formula, "initial gauge length + elongated length of the tape" refers to the gauge length of the tape after elongation when all the aluminum blocks have fallen. The gauge length refers to the length of the tape excluding the tab regions on both sides (tape length 200 mm - tab region length 50 mm x 2 = 100 mm). {(initial gauge length + stretched length of tape) / initial gauge length} x 100 = elongation (elongation at peeling) [%]

[0245] (10) Surface adhesive strength of the tape 5, a test stage was prepared by attaching strong adhesive double-sided tape 52 (#8625ER-140 manufactured by DIC Corporation) to the surface of a 2 mm thick stainless steel plate 51a, and the surface of substrate 2 of tape 1 cut to a size of 20 mm × 20 mm opposite to adsorption layer 3 (the surface opposite to the adhesive layer in Comparative Examples 1 and 2) was attached to strong adhesive double-sided tape 52 of the test stage to prepare test piece 55. Next, stainless steel plate 51b measuring 2 mm thick × 50 mm long × 40 mm wide was attached to the surface of adsorption layer 3 of tape 1 (the adhesive layer surface in Comparative Examples 1 and 2) and pressed with 1 kg for 10 seconds. After leaving the plate in an atmosphere of 23°C and 50% RH for 1 hour or 24 hours, test piece 55 was peeled from stainless steel plate 51b at a speed of 300 mm / min in the vertical direction N, and the strength [N / 20 mm] was measured. The surface adhesive strength of Tape 1 measured after being left for 1 hour after being pressed was designated as P1, and the surface adhesive strength of Tape 1 measured after being left for 24 hours after being pressed was designated as P2.

[0246] [material] The materials used in the examples and comparative examples are described below.

[0247] <Base material> ·Base material (1) An ester-based polyurethane resin film (Esmer URS, manufactured by Nihon Matai Co., Ltd., thickness 100 μm) was used as the substrate (1). The composition of the substrate (1) is referred to as substrate material (1).

[0248] ·Base material (2) A mixture of styrene-isoprene copolymer and styrene-isoprene-styrene copolymer was used as the substrate material (2). The mixture contained 25 wt% of styrene-derived structural units represented by the following chemical formula (1), and the proportion of styrene-isoprene copolymer in the total amount of the mixture was 17 wt%.

[0249] [ka]

[0250] Toluene was added to the above substrate material (2) and stirred to make it uniform, and the mixture was applied using an applicator to a release liner (Film Vina 75E-0010GT, manufactured by Fujimori Kogyo Co., Ltd.) so that the thickness after drying would be 100 μm. Four sheets were prepared by drying at 60°C for 5 minutes, and then laminated under pressure of 0.2 MPa to produce a substrate (2) with a thickness of 400 μm.

[0251] ·Base material (3) As the substrate material (3), a hydrogenated styrene-isoprene-styrene triblock copolymer (SEPS, "Septon 2063", manufactured by Kuraray Co., Ltd.) was used. Toluene was added to the substrate material (3) and stirred to make it uniform. The mixture was then applied to a release liner (Film Vina 75E-0010GT, manufactured by Fujimori Kogyo Co., Ltd.) with an applicator so that the thickness after drying would be 100 μm, and the mixture was dried at 60° C. for 5 minutes to obtain the substrate (3).

[0252] ·Base material (4) A 3L three-neck flask was fitted with a three-way stopcock and the inside of the flask was purged with nitrogen. Then, 1861 g of toluene and 14.3 g of 1,2-dimethoxyethane were added with stirring at room temperature. Subsequently, 44.3 g of a toluene solution containing 22.3 mmol of isobutylbis(2,6-di-t-butyl-4-methylphenoxy)aluminum was added, followed by 1.04 g of a cyclohexane solution of sec-butyllithium containing 1.78 mmol of sec-butyllithium. Subsequently, 21.9 g of methyl methacrylate was added. The reaction mixture was initially yellow, but after stirring for 60 minutes at room temperature, it became colorless. The internal temperature of the polymerization mixture was then cooled to -30°C, and 249 g of n-butyl acrylate was added dropwise over 2 hours. After the dropwise addition, the mixture was stirred at -30°C for 5 minutes. 21.9 g of methyl methacrylate was then added and stirred overnight at room temperature. 24 g of methanol was added to terminate the polymerization reaction, and the resulting reaction solution was poured into 15 kg of methanol to precipitate. The precipitate was then collected and dried to yield 296 g of acrylic triblock copolymer (1). The weight-average molecular weight (Mw) and molecular weight distribution (Mw / Mn) of the resulting acrylic triblock copolymer (1) were determined by GPC measurement using the method described above. The weight-average molecular weight (Mw) was 100,000, and the molecular weight distribution (Mw / Mn) was 1.2.

[0253] To 100 parts by mass (solid content) of the acrylic triblock copolymer (1), 2.5 parts by mass of a polyfunctional polymerizable monomer (pentaerythritol triacrylate, manufactured by Toa Gosei Co., Ltd., Aronix M305, molecular weight 298, trifunctional) and 0.4 parts by mass of a photopolymerization initiator (Irgacure 184, manufactured by IGM Resins BV) were added, and ethyl acetate was further added and stirred to obtain a substrate material (4) with a solid content of 40% by mass.

[0254] The obtained substrate material (4) was applied to a release liner (PET38×1, A3, manufactured by Nippa) with an applicator so that the average thickness after drying would be 100 μm, and then dried in a dryer at 80° C. for 2 minutes. Next, after bonding to the release liner (PET38×1, A3, manufactured by Nippa), an electrodeless UV lamp system manufactured by Heraeus was used to apply an integrated light dose of 1,000 mJ / cm. 2 The substrate (4) was prepared by irradiating the substrate with ultraviolet light so that the substrate (4) was

[0255] ·Base material (5) A polyester film (Lumirror S10, Toray Industries, Inc., thickness 100 μm) was used as the non-extensible substrate (5). The composition of the substrate (5) is referred to as substrate material (5).

[0256] The breaking strengths of the substrates 1 to 4 are as shown in the table below, and the breaking strengths per unit width of the substrates 1 to 4 are as follows: Base material 1 (thickness 100 μm): 7.75 N / mm Base material 2 (thickness 400 μm): 7.52 N / mm Base material 3 (thickness 100 μm): 3.21 N / mm Base material 4 (thickness 100 μm): 5.64 N / mm

[0257] <Resin composition for forming intermediate layer> ·Resin composition for forming intermediate layer (1) A reaction vessel equipped with a stirrer, reflux condenser, nitrogen inlet, thermometer, and dropping funnel was charged with 75.94 parts by weight of n-butyl acrylate, 5 parts by weight of 2-ethylhexyl acrylate, 15 parts by weight of cyclohexyl acrylate, 4 parts by weight of acrylic acid, 0.06 parts by weight of 4-hydroxybutyl acrylate, and 200 parts by weight of ethyl acetate. The mixture was stirred and heated to 65°C while blowing in nitrogen to obtain mixture (1). Next, 4 parts by weight of 2,2'-azobisisobutyronitrile solution (2.5% solids) dissolved in ethyl acetate was added to the mixture (1), and the mixture was stirred and held at 65°C for 10 hours to obtain mixture (2). Next, mixture (2) was diluted with ethyl acetate to a solids content of 30% by weight and filtered through a 200-mesh wire mesh to obtain a solution of acrylic copolymer (1) with a weight-average molecular weight of 1.6 million (polystyrene equivalent).

[0258] To 100 parts by mass (solid content) of the acrylic copolymer (1), 2.0 parts by mass of an epoxy-based crosslinking agent (a solution with a solid content of 5% by mass obtained by mixing Tetrad X manufactured by Mitsubishi Gas Chemical Company, Inc. and ethyl acetate) was added, and the mixture was stirred and mixed uniformly to obtain a resin composition (1) for forming an intermediate layer, which is an acrylic adhesive 1.

[0259] ·Resin composition for forming intermediate layer (2) In a reaction vessel equipped with a stirrer, a reflux condenser, a thermometer, a dropping funnel, and a nitrogen gas inlet, 100 parts by mass of monomers consisting of 93.4 parts by mass of butyl acrylate, 3.0 parts by mass of vinyl acetate, 2.5 parts by mass of acrylic acid, 1.0 part by mass of N-vinylpyrrolidone, and 0.1 part by mass of β-hydroxyethyl acrylate, and 0.2 parts by mass of 2,2'-azobisisobutylnitrile as a polymerization initiator were dissolved in 100 parts by mass of ethyl acetate, and the mixture was polymerized at 80°C for 8 hours to obtain a solution of acrylic copolymer (2) having a weight-average molecular weight of 700,000.

[0260] To 100 parts by mass (solid content) of the above acrylic copolymer (2), 15 parts of rosin ester resin A-100 (manufactured by Arakawa Chemical Industries, Ltd.) and 15 parts of polymerized rosin ester resin D-135 (manufactured by Arakawa Chemical Industries, Ltd.) were added, and the mixture was diluted and mixed with toluene to obtain an adhesive solution with a solid content of 40%. Next, 0.9 parts by mass of Burnock D-40 (manufactured by DIC Corporation, trimethylolpropane adduct of tolylene diisocyanate, isocyanate group content 7% by mass, non-volatile content 40% by mass) was added as a crosslinking agent to 100 parts by mass of the above adhesive solution, and the mixture was stirred and mixed to make a homogeneous mixture. After that, the mixture was filtered through a 100-mesh wire mesh to obtain a resin composition (2) for forming an intermediate layer, which is an acrylic adhesive 2.

[0261] ·Resin composition for forming intermediate layer (3) A mixture of styrene-isoprene diblock copolymer (SI) and styrene-isoprene-styrene triblock copolymer (SIS) (the styrene-derived structural unit represented by the above chemical formula (1) is 24% by mass, and the proportion of the styrene-isoprene diblock copolymer in the total amount of the mixture is 67% by mass) was used in an amount of 100 parts by mass, Quinton G115 (a C5 / C9 petroleum resin manufactured by Nippon Zeon Co., Ltd., softening point 115°C), 40 parts by mass, Pencel D-160 (a heavy oil resin manufactured by Arakawa Chemical Industries, Ltd.), and A resin composition for forming an intermediate layer (3), which is a styrene-based adhesive, was obtained by mixing 30 parts by mass of a synthetic rosin ester resin (softening point 150°C to 165°C), 5 parts by mass of Nippon Oil Polybutene HV-50 (polybutene manufactured by JX Nippon Oil & Energy Corporation, pour point -12.5°C), and 1 part by mass of an antioxidant (tetrakis-[methylene-3-(3'5'-di-t-butyl-4-hydroxyphenyl)propionate]methane), and dissolving the mixture in 100 parts by mass of toluene as a solvent.

[0262] <Resin composition for forming adsorption layer (1)> In a 2 L reaction vessel equipped with a stirrer, a thermometer, and a cooler, 200 parts by mass of ion-exchanged water was charged and heated to 80°C, and 225 parts by mass of ethyl acrylate (hereinafter abbreviated as "EA"), 225 parts by mass of n-butyl acrylate (hereinafter abbreviated as "BA"), 70 parts by mass of acrylonitrile (hereinafter abbreviated as "AN"), and 15 parts by mass of N-methylolacrylamide (hereinafter abbreviated as "N-MAM") were added. An emulsion prepared by emulsifying 15 parts by weight of sodium dodecylbenzenesulfonate, 6 parts by weight of acrylic acid (hereinafter abbreviated as "AA") in a solution of 15 parts by weight of sodium dodecylbenzenesulfonate, 5 parts by weight of ammonium persulfate, and 200 parts by weight of ion-exchanged water was added dropwise over two hours to allow emulsion polymerization. After holding for two hours, the mixture was cooled to below 40°C, and the pH was adjusted to 7-8 with aqueous ammonia and the non-volatile content to 54% to 56% with ion-exchanged water to obtain acrylic emulsion (1). The resulting acrylic emulsion (1) had a non-volatile content of 55% and a pH of 7.4. The specific gravity of acrylic emulsion (1) (the resin composition for forming an adsorption layer before mechanical foaming) was 1.01.

[0263] To 100 parts by mass of the above acrylic emulsion (1), 5 parts by mass of Amidair M-3 (a melamine crosslinking agent manufactured by DIC Corporation) was added, followed by 6 parts by mass of Sunspearl RA-33 (a surfactant manufactured by San Nopco Ltd.) and 5 parts by mass of RHEOBYK-H 7625-VF (a thickener manufactured by BYK Japan KK) and stirring uniformly. The mixture was then mechanically foamed for approximately 2 minutes using a household electric hand mixer (THM1300 manufactured by TESCOM Corporation, 600 to 1300 revolutions per minute, speed adjustment set to "1" out of 5 levels) to obtain a resin composition (1) for forming an adsorption layer (a foam acrylic resin emulsion) having a specific gravity of 0.51.

[0264] <Resin composition for forming adsorption layer (2)> Resin composition (2) for forming an adsorption layer (foam acrylic resin emulsion) with a specific gravity of 0.81 was obtained in the same manner as the preparation method for resin composition (1) for forming an adsorption layer, except that the stirring time was changed to approximately 30 seconds and mechanical foaming was performed.

[0265] <Resin composition for forming adsorption layer (3)> Resin composition (3) for forming an adsorption layer (foam-like acrylic resin emulsion) having a specific gravity of 0.18 was obtained in the same manner as the preparation method for resin composition (1) for forming an adsorption layer, except that the stirring time for mechanical foaming was changed to approximately 5 minutes.

[0266] [Example 1] The resin composition (1) for forming an intermediate layer was applied to a release liner (1) (Film Vina 75E-0010GT, manufactured by Fujimori Kogyo Co., Ltd.) with an applicator so that the thickness after drying would be 10 μm, and an intermediate layer was prepared by drying for 3 minutes at 80° C. Subsequently, the intermediate layer was attached to a substrate (1) that had been corona-treated so that the wet tension would be 56 mN / m, and laminated under a pressure of 0.2 MPa to prepare a laminated intermediate. Next, the resin composition (1) for forming the adsorption layer was applied to a release liner (2) (Film Bina 50E-0010NSD, manufactured by Fujimori Kogyo Co., Ltd.) using an applicator so that the thickness after drying was 110 μm, and then dried at 100° C. for 5 minutes to create an adsorption layer having an open-cell structure with numerous recesses formed on its surface. Furthermore, the release liner (1) of the laminated intermediate was peeled off, and the adsorption layer was attached to the exposed surface of the intermediate layer, followed by lamination under a pressure of 0.2 MPa to create the tape of Example 1.

[0267] [Examples 2 to 3] Tapes were produced in the same manner as in Example 1, except that the thickness of the adsorption layer (thickness after drying) was changed to the thickness shown in Table 1.

[0268] [Example 4] Tapes were produced in the same manner as in Example 1, except that the thickness of the intermediate layer (thickness after drying) was changed to the thickness shown in Table 1.

[0269] [Examples 5 to 6] A tape was produced in the same manner as in Example 1, except that the resin composition for forming an intermediate layer (1) was changed to a resin composition for forming an intermediate layer shown in Table 2.

[0270] [Examples 7 to 9] Tapes were prepared in the same manner as in Example 1, except that the substrates shown in Table 2 were used instead of Substrate 1.

[0271] [Example 10] A tape was produced in the same manner as in Example 1, except that the resin composition for forming an adsorbent layer (2) was used instead of the resin composition for forming an adsorbent layer (1).

[0272] [Example 11] A tape was produced in the same manner as in Example 1, except that the resin composition for forming an adsorbent layer (3) was used instead of the resin composition for forming an adsorbent layer (1).

[0273] [Examples 12 to 14] Tapes were prepared in the same manner as in Example 1, except that the thickness of the adsorption layer (thickness after drying) was changed to the thickness shown in Table 1.

[0274] [Comparative Example 1] A tape was prepared in the same manner as in Example 4, except that no adsorption layer was provided.

[0275] Comparative Example 2 A tape was prepared in the same manner as in Example 4, except that no adhesive layer was provided and the thickness (thickness after drying) of the intermediate layer (adhesive layer) was changed to the thickness shown in Table 4.

[0276] Comparative Example 3 An intermediate layer (adhesive layer) was formed on a release liner (1) using the same procedure as in Example 1. An adsorption layer (1) was formed on a release liner (2) using the same procedure as in Example 1. The adsorption layer was attached to the surface of the intermediate layer, and the layers were laminated under a pressure of 0.2 MPa to produce a tape.

[0277] Comparative Example 4 Tapes were prepared in the same manner as in Example 1, except that the substrates shown in Table 4 were used instead of Substrate 1.

[0278] The tapes obtained in the examples and comparative examples were evaluated by the methods described above, and the results are shown in Tables 1 to 4.

[0279] [Table 1]

[0280] [Table 2]

[0281] [Table 3]

[0282] [Table 4]

[0283] As is clear from the above results, this stretch-releasable tape having an adhesive layer was suggested to be able to be peeled from an adherend with less elongation than tapes having conventional adhesive layers (Comparative Examples 1 and 2). For example, the tape of Example 7 and Comparative Example 2 had similar 180° peel strengths (180° peel strength of the tape of Example 7: 1 N / mm, 180° peel strength of the tape of Comparative Example 2: 1.1 N / mm). However, compared with the tape of Example 7, which uses an adhesive layer, the tape of Comparative Example 2, which uses an adhesive layer, required more than twice the elongation required for stretching and peeling (elongation at peeling) as the tape of Example 7. The 180° peel strengths of the tapes of Example 7 and Comparative Example 2 were measured using the method described above in the section on "Tapes" in this specification.

[0284] Furthermore, a comparison of the initial surface adhesive strength P1 of the tape with the surface adhesive strength P2 over time showed that the change in surface adhesive strength (P2 / P1) over time for this tape was smaller than for the comparative tape. This suggests that the deterioration of stretch-peelability over time is suppressed for this tape, and adhesive residue is less likely to remain on the adherend.

[0285] The above trends suggest that this tape can achieve both temporary fixation and easy peeling of parts when used for temporary fixation. Furthermore, tapes with thinner adhesive layers tend to have higher holding power, suggesting that this tape can be used not only for temporary fixation but also for joining applications (tapes for joining two or more adherends) where holding power is required. [Explanation of symbols]

[0286] 1: Adsorption tape 2: Base material 3: Adsorption layer 4: Recess 5: Adherent (parts) 6, 6': Surface of the adsorption layer 7: Virtual surface of the recess 8: Micropores (voids or bubbles) 51a: Stainless steel plate 51b: Stainless steel plate 52: Strong adhesive double-sided tape 55: Test piece 200: Transferee D: Stretching direction of the suction tape (extension direction)

Claims

1. A base material having extensibility; an adsorption layer provided on at least one surface of the substrate and having a plurality of recesses on a surface opposite to the substrate; an intermediate layer between the substrate and the adsorption layer, The base material has a breaking elongation of 200% or more, The average opening diameter of the recesses is 300 μm or less, An adsorption tape in which the resin constituting the adsorption layer is at least one selected from the group consisting of acrylic resins (including acrylic rubber), urethane resins (including urethane rubber), silicone resins (including silicone rubber), polyolefins, polyurethane-based thermoplastic elastomers, polyester-based thermoplastic elastomers, polyamide-based thermoplastic elastomers, and polystyrene-based thermoplastic elastomers.

2. An adsorption tape as described in claim 1, wherein the intermediate layer is at least one selected from the group consisting of acrylic polymers, urethane polymers, rubber polymers, and thermoplastic elastomers.

3. 2. The suction tape according to claim 1, wherein the base material has a breaking elongation of 300% or more and 2000% or less.

4. The apparent density of the adsorption layer is 0.1 g / cm ３ 1.0g / cm or more ３ 2. The adsorption tape of claim 1, wherein:

5. The adsorption tape according to claim 1 , wherein the adsorption layer has an open-cell structure.

6. The suction tape according to claim 1 , wherein the opening ratio of the recesses in a plan view of the surface of the suction layer opposite to the substrate is 1% or more and 99% or less.

7. The adsorption tape according to claim 1, wherein the thickness of the adsorption layer is in the range of 10 μm to 1000 μm.

8. 2. The adsorption tape according to claim 1, wherein the breaking elongation is in the range of 200% to 3000% and the breaking strength is in the range of 5 MPa to 100 MPa.

9. 2. The adsorption tape according to claim 1, wherein the elongation at peeling is in the range of 101% to 400%.

10. 10. The adhesive tape of claim 1 which is stretch releasable.

11. The suction tape according to claim 1, which is used for temporarily fixing components.

12. The adhesive tape according to claim 1, which is used to bond two or more parts together.

13. An article comprising a component on the surface of the adsorption layer of the adsorption tape according to claim 1.

14. the adsorption tape is a single-sided tape having the adsorption layer on one side of the substrate, The article of claim 13 comprising a component on a surface of the adsorbent layer.

15. the adsorption tape is double-sided, having the adsorption layer on each side of the base material, a component A is provided on a surface of one of the suction layers A of the suction tape; The article according to claim 13, further comprising a component B on the other surface of the adsorbent layer B of the adsorbent tape.

16. A method for removing the adhesive tape according to any one of claims 1 to 12 attached to an adherend, comprising: A peeling method in which the adsorption tape is stretched in at least one direction and peeled off from the adherend.

17. The method for peeling off an adsorption tape according to claim 16, wherein the adherend is a small electronic component.

18. The surface area of ​​the adherend that comes into contact with the adsorption tape is 100 mm ２ The method for peeling off an adsorption tape according to claim 16, wherein the method is as follows:

19. The suction tape according to any one of claims 1 to 12 is stretched in at least one direction, The method for manufacturing a component includes at least a peeling step of peeling off the component fixed on the suction layer of the suction tape.

20. 20. The method for manufacturing a component according to claim 19, wherein the peeling step includes a transfer step of placing a transfer target on a surface of the component opposite to the suction tape side, and stretching the suction tape in at least one direction from a composite having the suction tape, the component, and the transfer target in this order to peel the suction tape from the component and simultaneously transfer the component to the transfer target.

21. The method of claim 19, wherein the component is a miniature electronic component.

22. The surface area of ​​the part that comes into contact with the suction tape is 100 mm ２ 20. The method of claim 19, wherein:

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