JP6624825B2 - Heat release type adhesive sheet - Google Patents

Description

  The present invention relates to a heat-peelable pressure-sensitive adhesive sheet.

  BACKGROUND ART Conventionally, when cutting a material of an electronic component, an adhesive sheet is used to fix the material. At the time of this cutting, a so-called chip fly may occur in which the fragmented electronic material falls off the adhesive sheet and flies. In recent years, when processing electronic components such as module components and sensors, an adhesive sheet may be attached to an uneven surface (for example, a sealing resin surface, an electrode pattern surface, or the like), and the above-described problem of chip skipping has become significant. .

  On the other hand, as an adhesive sheet used for cutting a material of an electronic component, an adhesive sheet whose adhesive force is reduced by heating (for example, Patent Document 1) is known. When such an adhesive sheet is used, it is possible to improve the adhesive strength and to obtain a releasability enough to peel off the workpiece after cutting. However, such an adhesive sheet has a problem that although it exhibits a predetermined fixability to a flat adherend, it does not exhibit sufficient fixability to an uneven surface adherend.

JP-A-2002-121510

  The adhesive strength of the pressure-sensitive adhesive sheet can be improved, for example, by adding a tackifier resin to the pressure-sensitive adhesive layer. When the tackifier resin is added, the adhesive strength of the adhesive layer itself is improved, and a pressure-sensitive adhesive sheet having sufficient fixability to an adherend having a flat adherend surface can be obtained. However, for an adherend having a fine uneven surface such as an electrode pattern surface, even if such an adhesive sheet is used, sufficient fixability cannot be obtained, and the problem of chip flying can be solved. Can not.

  The present invention has been made in order to solve the above-mentioned conventional problems, and an object of the present invention is to provide a pressure-sensitive adhesive sheet which can be suitably used at the time of processing a material for an electronic component, and a surface to be adhered is flat. It is an object of the present invention to provide a heat-peelable pressure-sensitive adhesive sheet exhibiting sufficient fixability not only on an adherend but also on an adherend having an uneven surface.

The heat-peelable pressure-sensitive adhesive sheet of the present invention is a heat-peelable pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer, wherein the heat-peelable pressure-sensitive adhesive sheet contains an antistatic material, and the pressure-sensitive adhesive layer has a pressure-sensitive adhesive and a heat-expandable material. The base polymer comprising the microspheres and constituting the pressure-sensitive adhesive comprises a structural unit A derived from a (meth) acrylic acid alkyl ester having a side chain having a branched structure, and the content of the structural unit A is determined by the base polymer. Medium, 20% by weight or more.
In one embodiment, the pressure-sensitive adhesive layer contains the antistatic material.
In one embodiment, the heat-peelable pressure-sensitive adhesive sheet of the present invention further includes a substrate, and the substrate includes the antistatic material.
In one embodiment, the heat-peelable pressure-sensitive adhesive sheet of the present invention further includes an antistatic layer provided on a side of the substrate opposite to the pressure-sensitive adhesive layer, wherein the antistatic layer is formed of the antistatic layer. Including materials.
In one embodiment, the heat-peelable pressure-sensitive adhesive sheet of the present invention further includes an antistatic layer provided between the base material and the pressure-sensitive adhesive layer, wherein the antistatic layer is formed of the antistatic material. including.
In one embodiment, the side chain having the branched structure of the structural unit A has 5 or more carbon atoms.
In one embodiment, the pressure-sensitive adhesive layer further includes a tackifier resin, and the content of the tackifier resin is 1 part by weight to 80 parts by weight based on 100 parts by weight of the base polymer.
In one embodiment, the heat-peelable pressure-sensitive adhesive sheet of the present invention has a pressure-sensitive adhesive strength to a PET film of 2 N / 20 mm or more.
According to another aspect of the present invention, a method for manufacturing an electronic component is provided. This method of manufacturing an electronic component includes, after attaching the electronic component material on the heat-peelable pressure-sensitive adhesive sheet, cutting the electronic component material.
According to still another aspect of the present invention, an electronic component is provided. This electronic component is manufactured by the above manufacturing method.

  According to the present invention, by using a base polymer containing a structural unit A derived from an acrylic monomer having a side chain having a branched structure as the base polymer of the pressure-sensitive adhesive layer, excellent conformability to an uneven surface, and An adhesive sheet having a sufficient adhesive strength can be obtained. Such a pressure-sensitive adhesive sheet is suitably used as a pressure-sensitive adhesive sheet for fixing a material of an electronic component in a step of cutting the material, and can contribute to prevention of chip fly when cutting the material.

  Further, the pressure-sensitive adhesive sheet of the present invention is a heat-peelable pressure-sensitive adhesive sheet containing heat-expandable microspheres in a pressure-sensitive adhesive layer. The heat-peelable pressure-sensitive adhesive sheet of the present invention exhibits sufficient adhesive strength to fix the material of the electronic component when processing (for example, cutting) the material of the electronic component, and after processing, provides appropriate peelability by heating. Show.

1 is a schematic sectional view of a heat-peelable pressure-sensitive adhesive sheet according to one embodiment of the present invention. (A) And (b) is a schematic sectional drawing of the heat peelable adhesive sheet by another embodiment of this invention. FIG. 6 is a schematic sectional view of a heat-peelable pressure-sensitive adhesive sheet according to still another embodiment of the present invention.

A. Overall configuration diagram 1 of a heat-peelable pressure-sensitive adhesive sheet is a schematic cross-sectional view of the heat-peelable pressure-sensitive adhesive sheet according to one embodiment of the present invention. The heat-peelable pressure-sensitive adhesive sheet 100 includes a pressure-sensitive adhesive layer 10. The pressure-sensitive adhesive layer 10 includes a pressure-sensitive adhesive and a plurality of heat-expandable microspheres. In the heat-peelable pressure-sensitive adhesive sheet of the present invention, the heat-expandable microspheres expand or foam due to heating, resulting in unevenness on the surface. Expresses sex. The heat-peelable pressure-sensitive adhesive sheet of the present invention, in which both adhesive strength and peelability are compatible, is suitably used, for example, as a pressure-sensitive adhesive sheet for temporarily fixing the processed product when processing an electronic component material. In this embodiment, the heat-peelable pressure-sensitive adhesive sheet 100 further includes a base material 20. In the illustrated example, an example is shown in which the pressure-sensitive adhesive layer 10 is disposed on one side of the substrate 20, but the pressure-sensitive adhesive layer may be disposed on both sides of the substrate.

  The heat-peelable pressure-sensitive adhesive sheet contains an antistatic material. In one embodiment, the antistatic material is contained in the pressure-sensitive adhesive layer. In another embodiment, the antistatic material is contained in a substrate. The antistatic material may be contained in both the pressure-sensitive adhesive layer and the substrate. Details of the antistatic material will be described later.

  FIGS. 2A and 2B are schematic sectional views of a heat-peelable pressure-sensitive adhesive sheet according to still another embodiment of the present invention. These heat-peelable pressure-sensitive adhesive sheets 200 and 200 ′ further include an antistatic layer 30. The antistatic layer 30 includes an antistatic material. The antistatic layer 30 may be provided on the opposite side of the base material 20 from the pressure-sensitive adhesive layer 10 (FIG. 2A), or may be provided between the pressure-sensitive adhesive layer 10 and the base material 20. Good (FIG. 2B). Preferably, the antistatic layer is provided on the side of the substrate opposite to the pressure-sensitive adhesive layer. When the pressure-sensitive adhesive layers are disposed on both sides of the substrate, the antistatic layer may be disposed between the substrate and the pressure-sensitive adhesive layer.

  In the heat-peelable pressure-sensitive adhesive sheet of the present invention, the pressure-sensitive adhesive layer contains a base polymer containing a structural unit A derived from an alkyl (meth) acrylate having a side chain having a branched structure (hereinafter, also referred to as a branched structure side chain). By using as a base polymer, a pressure-sensitive adhesive sheet excellent in followability to an uneven surface and having sufficient pressure-sensitive adhesive strength can be obtained. On the other hand, the inventors of the present application have found that when an electronic component material is attached to a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer composed of a base polymer containing a predetermined amount of the structural unit A, the electronic component material is easily damaged. I found an issue. The present invention is an invention that can solve such a new problem. That is, the present invention improves the followability to an uneven surface and damages an electronic component material as an adherend by including an antistatic material. It is an invention to provide a heat-peelable pressure-sensitive adhesive sheet which can prevent the occurrence of the heat-peeling. The heat-peelable pressure-sensitive adhesive sheet of the present invention has excellent fixability to not only electronic component materials having a flat adhered surface but also electronic component materials having various irregularities, and cuts the electronic component material. It is possible to prevent chip fly when subjected to the process. Further, the heat-peelable pressure-sensitive adhesive sheet of the present invention can prevent damage (for example, short-circuit) of an electronic component material as an adherend.

  FIG. 3 is a schematic sectional view of a heat-peelable pressure-sensitive adhesive sheet according to still another embodiment of the present invention. The heat-peelable pressure-sensitive adhesive sheet 300 further includes an elastic layer 40. The elastic layer 40 may be provided adjacent to the pressure-sensitive adhesive layer, and in one embodiment, is provided between the pressure-sensitive adhesive layer 10 and the base material 20 as in the illustrated example. Further, the elastic layer may be provided on the opposite side of the base material from the pressure-sensitive adhesive layer, or may be provided on both sides of the base material. By providing the elastic layer, followability to an adherend having an uneven surface is improved. Further, when the pressure-sensitive adhesive sheet provided with the elastic layer is heated at the time of peeling, the deformation (expansion) in the surface direction of the pressure-sensitive adhesive layer is restricted, and the deformation in the thickness direction is prioritized. As a result, the releasability is improved. Note that the antistatic material may be contained in the elastic layer.

  Although not shown, the heat-peelable pressure-sensitive adhesive sheet of the present invention may be provided with a release liner outside the pressure-sensitive adhesive layer for the purpose of protecting the pressure-sensitive adhesive surface until use. The heat-peelable pressure-sensitive adhesive sheet of the present invention has little peeling electrification generated when the release liner is peeled off, and thus can prevent damage (for example, short circuit) of the electronic component material as the adherend.

  The adhesive force a1 at 23 ° C. when the heat-peelable pressure-sensitive adhesive sheet of the present invention is adhered to a polyethylene terephthalate (PET) film is preferably 2 N / 20 mm or more, more preferably 3 N / 20 mm to 20 N / 20 mm. And more preferably 4 N / 20 mm to 10 N / 20 mm. Within such a range, a heat-peelable pressure-sensitive adhesive sheet useful as a sheet for temporary fixing when cutting electronic component materials or the like can be obtained. In the present specification, the adhesive force refers to an adhesive force measured by a method according to JIS Z 0237: 2000. A specific measuring method will be described later. The heat-peelable pressure-sensitive adhesive sheet of the present invention is a pressure-sensitive adhesive sheet whose adhesive strength is reduced by heating. The “adhesive strength at 23 ° C.” refers to the adhesive strength before the adhesive strength is reduced.

  The adhesive force a2 after sticking the adhesive surface of the heat-peelable pressure-sensitive adhesive sheet of the present invention to a polyethylene terephthalate film and heating is preferably 0.2 N / 20 mm or less, more preferably 0.1 N / 20 mm or less. is there. In the present specification, the heating of the heat-peelable pressure-sensitive adhesive sheet refers to heating at a temperature and time at which the heat-expandable microspheres expand or foam to reduce the adhesive force. The heating is, for example, heating at 70 ° C. to 270 ° C. for 1 minute to 10 minutes.

  The ratio (a2) between the adhesive strength when the adhesive surface of the heat-peelable adhesive sheet of the present invention is adhered to the polyethylene terephthalate film (that is, the adhesive strength before heating (a1)) and the adhesive strength after heating (a2). / A1) is preferably 0.5 or less, more preferably 0.1 or less. The lower limit of (a2 / a1) is preferably 0.0001, and more preferably 0.0005.

  As described above, the heat-peelable pressure-sensitive adhesive sheet of the present invention has irregularities on the pressure-sensitive adhesive surface when heated at a predetermined temperature. The surface roughness Ra of the pressure-sensitive adhesive surface after heating the heat-peelable pressure-sensitive adhesive sheet of the present invention is preferably 3 μm or more, more preferably 5 μm or more. Within such a range, it is possible to obtain a pressure-sensitive adhesive sheet in which the pressure-sensitive adhesive strength is reduced or disappears after heating, and the adherend can be easily peeled off. The surface roughness Ra of the pressure-sensitive adhesive surface refers to the surface roughness Ra of the pressure-sensitive adhesive surface of the pressure-sensitive adhesive sheet after heating without an adherend. The surface roughness Ra can be measured according to JIS B 0601: 1994.

B. The content form of the antistatic material of the antistatic material, for example, (1) the form contained in the pressure-sensitive adhesive layer as an additive in the form contained in the substrate as a (2) additives, (3) pressure-sensitive adhesive layer Alternatively, a form contained in a layer (antistatic layer) different from the substrate may be used. Examples of the antistatic layer in the form (3) include an antistatic layer containing a resin (form (3a)) and an antistatic layer composed of a metal or a metal oxide (form (3b)). . Preferably, it is in the form (2) or (3), and more preferably in the form (3a). Further, from the viewpoint of transparency, the form (2) or (3a) can be preferably selected, and more preferably (3a). When the antistatic material is contained as in the mode (2) or (3a), a heat-peelable pressure-sensitive adhesive sheet having excellent transparency (for example, light transmittance of 70% to 90%) can be obtained. In such a heat-peelable pressure-sensitive adhesive sheet, it is easy to identify the adherend through the pressure-sensitive adhesive sheet. In the heat-peelable pressure-sensitive adhesive sheet of the present invention, since the pressure-sensitive adhesive layer containing the heat-expandable microspheres has optical turbidity, the transparency of other members is increased, and the transparency of the heat-peelable pressure-sensitive adhesive sheet as a whole is increased. Is preferred. Further, if the form (1) or (3) is selected, that is, if the antistatic material is used without being included in the base material, it is possible to prevent bleeding of the antistatic material due to aging and to improve the quality. A heat-peelable pressure-sensitive adhesive sheet having excellent stability can be obtained. Therefore, it is particularly preferable that the antistatic material is contained as in the form (3a). According to this form, a heat-peelable pressure-sensitive adhesive sheet excellent in transparency, stability in quality, and the like can be obtained. In still another embodiment, a mode in which an antistatic material is contained in the elastic layer, a mode in which the base material itself functions as an antistatic material such as using a metal foil as the base material, and the like are exemplified.

  The content ratio of the antistatic material can be adjusted according to the form of the antistatic material. The content ratio of the antistatic material is preferably from 0.00001% by weight to 10% by weight, more preferably from 0.0001% by weight to 5% by weight, based on the weight of the heat-peelable pressure-sensitive adhesive sheet.

B-1. Form in which the antistatic material is contained in the pressure-sensitive adhesive layer as an additive (form (1))
In the embodiment (1), the antistatic material is contained in the pressure-sensitive adhesive layer forming composition, and the pressure-sensitive adhesive layer containing the antistatic material is formed by forming the pressure-sensitive adhesive layer with the pressure-sensitive adhesive layer forming composition. Is formed. In such a case, the content ratio of the antistatic material in the pressure-sensitive adhesive layer is preferably 0.01 parts by weight to 10 parts by weight, more preferably 100 parts by weight, based on 100 parts by weight of the base polymer constituting the pressure-sensitive adhesive layer. 0.05 to 5 parts by weight. Within such a range, when the electronic component material is adhered to the electronic component material, damage to the electronic component material can be prevented.

  Examples of the antistatic material contained in the composition for forming a pressure-sensitive adhesive layer include a conductive polymer and an ionic liquid. These antistatic materials may be used alone or in combination of two or more.

(Ionic liquid)
The ionic liquid is a liquid organic compound and refers to a molten salt (ionic compound) that is liquid at room temperature and has good compatibility with the base polymer in the pressure-sensitive adhesive composition. Thereby, segregation of the ionic liquid on the surface of the pressure-sensitive adhesive layer can be suppressed, and a decrease in the adhesive force over time and a contamination due to transfer to the adherend can be prevented. Here, the term "compatible" means that when the ionic liquid and the base polymer are mixed by an appropriate mixing method (melt blending, solution blending), they are uniformly mixed and hardly phase-separated.

  In addition, when an ionic liquid is used, a pressure-sensitive adhesive layer exhibiting excellent antistatic properties can be formed. The reason why the excellent antistatic property is obtained by using the ionic liquid is not clear, but is presumed as follows. That is, since the ionic liquid is in a liquid state, molecular movement is easier than that of a commonly used surfactant, and the rearrangement of molecules is easily caused by generation of electric charge. Therefore, when an ionic liquid is used, a charge neutralization mechanism by molecular rearrangement works, so that it is considered that an excellent antistatic effect is obtained. In addition, since the ionic liquid is in a liquid state at room temperature, it can be easily added to the adhesive and dispersed or dissolved as compared with a solid salt. Further, since the ionic liquid has no vapor pressure (non-volatile), it does not disappear over time and has a characteristic of continuously obtaining antistatic properties.

  The content of the ionic liquid is preferably 0.01 to 10 parts by weight, more preferably 0.01 to 8 parts by weight, based on 100 parts by weight of the base polymer constituting the pressure-sensitive adhesive layer. And more preferably 0.1 to 5 parts by weight. Within such a range, a sufficient antistatic effect can be obtained.

式（Ａ）中、のＲａは、炭素数４から２０の炭化水素基を表し、ＲｂおよびＲｃはそれぞれ独立して、水素または炭素数１から１６の炭化水素基を表す。なお、Ｒａ、ＲｂおよびＲｃはヘテロ原子を含んでいてもよい。また、窒素原子が２重結合により結合している場合、Ｒｃはない。
式（Ｂ）中、Ｒｄは、炭素数２から２０の炭化水素基を表し、Ｒｅ、ＲｆおよびＲｇはそれぞれ独立して、水素または炭素数１から１６の炭化水素基を表す。Ｒｄ、Ｒｅ、ＲｆおよびＲｇはヘテロ原子を含んでもよい。
式（Ｃ）中、Ｒｈは、炭素数２から２０の炭化水素基を表し、Ｒｉ、ＲｊおよびＲｋはそれぞれ独立して、水素または炭素数１から１６の炭化水素基を表す。Ｒｈ、Ｒｉ、ＲｊおよびＲｋはヘテロ原子を含んでもよい。
式（Ｄ）中、Ｚは、窒素、硫黄、またはリン原子を表し、Ｒｌ、Ｒｍ、ＲｎおよびＲｏはそれぞれ独立して、炭素数１から２０の炭化水素基を表し、ヘテロ原子を含んでもよい。ただし、Ｚが硫黄原子の場合、Ｒｏはない。
式（Ｅ）中、Ｒｐは、炭素数１から１８の炭化水素基を表し、ヘテロ原子を含んでもよい。 As the ionic liquid, any appropriate ionic liquid can be used as long as the effects of the present invention can be obtained. The ionic liquid is preferably a nitrogen-containing onium salt, a sulfur-containing onium salt or a phosphorus-containing onium salt, and more preferably a salt comprising an organic cation component and an anion component represented by the following general formulas (A) to (E). It is preferably used. This is because they exhibit excellent antistatic ability.

In the formula (A), Ra represents a hydrocarbon group having 4 to 20 carbon atoms, and Rb and Rc each independently represent hydrogen or a hydrocarbon group having 1 to 16 carbon atoms. In addition, Ra, Rb, and Rc may include a hetero atom. When the nitrogen atom is bonded by a double bond, there is no Rc.
In the formula (B), Rd represents a hydrocarbon group having 2 to 20 carbon atoms, and Re, Rf and Rg each independently represent hydrogen or a hydrocarbon group having 1 to 16 carbon atoms. Rd, Re, Rf and Rg may contain heteroatoms.
In the formula (C), Rh represents a hydrocarbon group having 2 to 20 carbon atoms, and Ri, Rj and Rk each independently represent hydrogen or a hydrocarbon group having 1 to 16 carbon atoms. Rh, Ri, Rj and Rk may include heteroatoms.
In the formula (D), Z represents a nitrogen, sulfur, or phosphorus atom, and R1, Rm, Rn, and Ro each independently represent a hydrocarbon group having 1 to 20 carbon atoms, and may include a hetero atom. . However, when Z is a sulfur atom, there is no Ro.
In the formula (E), Rp represents a hydrocarbon group having 1 to 18 carbon atoms and may include a hetero atom.

  Examples of the cation represented by the formula (A) include a pyridinium cation, a piperidinium cation, a pyrrolidinium cation, a cation having a pyrroline skeleton, and a cation having a pyrrole skeleton. Examples thereof include a pyridinium cation, a piperidinium cation, a pyrrolidinium cation, a cation having a pyrroline skeleton, and a cation having a pyrrole skeleton. Specific examples include, for example, 1-ethylpyridinium cation, 1-butylpyridinium cation, 1-hexylpyridinium cation, 1-butyl-3-methylpyridinium cation, 1-butyl-4-methylpyridinium cation, 1-hexyl-3 Pyridinium cations such as -methylpyridinium cation, 1-butyl-3,4-dimethylpyridinium cation; 1-propylpyridinium cation, 1-pentylpyridinium cation, 1,1-dimethylpyridinium cation, 1-methyl -1-ethylpiperidinium cation, 1-methyl-1-propylpiperidinium cation, 1-methyl-1-butylpiperidinium cation, 1-methyl-1-pentylpiperidinium cation, 1-methyl-1 -Hexylpiridinium Cation, 1-methyl-1-heptylpyridinium cation, 1-ethyl-1-propylpyridinium cation, 1-ethyl-1-butylpyridinium cation, 1-ethyl-1-pentylpyridinium cation, 1-ethyl-1-hexylpyridinium cation, 1-ethyl-1-heptylpyridinium cation, 1,1-dipropylpyridinium cation, 1-propyl-1-butylpyridinium cation, 1,1- Piperidinium cations such as dibutylpiperidinium cation; 1,1-dimethylpyrrolidinium cation, 1-methyl-1-ethylpyrrolidinium cation, 1-methyl-1-propylpyrrolidinium cation, 1-methyl- 1-butyl pyrrolidinium cation, 1-methyl-1-pentyl pyrrolidi Cation, 1-methyl-1-hexylpyrrolidinium cation, 1-methyl-1-heptylpyrrolidinium cation, 1-ethyl-1-propylpyrrolidinium cation, 1-ethyl-1-butylpyrrolidinium cation, 1-ethyl-1-pentylpyrrolidinium cation, 1-ethyl-1-hexylpyrrolidinium cation, 1-ethyl-1-heptylpyrrolidinium cation, 1,1-dipropylpyrrolidinium cation, 1-propyl Pyrrolidinium cations such as -1-butylpyrrolidinium cation and 1,1-dibutylpyrrolidinium cation; 2-methyl-1-pyrroline cation, 1-ethyl-2-phenylindole cation, 1,2-dimethylindole And a 1-ethylcarbazole cation.

  Examples of the cation represented by the formula (B) include an imidazolium cation, a tetrahydropyrimidinium cation, and a dihydropyrimidinium cation. For example, imidazolium cation, tetrahydropyrimidinium cation, dihydropyrimidinium cation and the like can be mentioned. Specific examples include, for example, 1,3-dimethylimidazolium cation, 1,3-diethylimidazolium cation, 1-ethyl-3-methylimidazolium cation, 1-butyl-3-methylimidazolium cation, 1-hexyl -3-methylimidazolium cation, 1-octyl-3-methylimidazolium cation, 1-decyl-3-methylimidazolium cation, 1-dodecyl-3-methylimidazolium cation, 1-tetradecyl-3-methylimidazolium Cation, 1,2-dimethyl-3-propylimidazolium cation, 1-ethyl-2,3-dimethylimidazolium cation, 1-butyl-2,3-dimethylimidazolium cation, 1-hexyl-2,3-dimethyl Imidazolium such as imidazolium cation Thione; 1,3-dimethyl-1,4,5,6-tetrahydropyrimidinium cation, 1,2,3-trimethyl-1,4,5,6-tetrahydropyrimidinium cation, 1,2,3 Tetrahydropyrimidinium cations such as 4-tetramethyl-1,4,5,6-tetrahydropyrimidinium cation and 1,2,3,5-tetramethyl-1,4,5,6-tetrahydropyrimidinium cation 1,3-dimethyl-1,4-dihydropyrimidinium cation, 1,3-dimethyl-1,6-dihydropyrimidinium cation, 1,2,3-trimethyl-1,4-dihydropyrimidinium cation 1,2,3-trimethyl-1,6-dihydropyrimidinium cation, 1,2,3,4-tetramethyl-1,4-dihydropyrimidinium cation Dihydropyrimidinium cations such as 1,2,3,4-tetramethyl-1,6-dihydropyrimidinium cation and 1-butyl-3-methyl such as 1-butyl-3-methylpyridinium bisimide A pyridinium cation.

  Examples of the cation represented by the formula (C) include a pyrazolium cation and a pyrazolinium cation. For example, a pyrazolium cation, a pyrazolinium cation and the like can be mentioned. Specific examples include, for example, a 1-methylpyrazolium cation, a 3-methylpyrazolium cation, and a 1-ethyl-2-methylpyrazolinium cation.

  Examples of the cation represented by the formula (D) include a tetraalkylammonium cation, a trialkylsulfonium cation, and a tetraalkylphosphonium cation. Further, a cation in which part of the alkyl group of these cations is substituted with an alkenyl group, an alkoxyl group, or an epoxy group may be used. Further, as described above, R1, Rm, Rn and Ro are a hydrocarbon group having 1 to 20 carbon atoms, and are preferably an alkyl group having 1 to 20 carbon atoms. Further, R1, Rm, Rn and Ro may be an aromatic ring group or an aliphatic ring group. Specific examples of the cation represented by the formula (D) include a tetraalkylammonium cation, a trialkylsulfonium cation, and a tetraalkylphosphonium cation, and a part of the alkyl group is substituted with an alkenyl group or an alkoxyl group, and further, an epoxy group. And the like. As specific examples, for example, N, N-dimethyl-N-ethyl-N-propylammonium cation, N, N-dimethyl-N-ethyl-N-butylammonium cation, N, N-dimethyl-N-ethyl-N -Pentyl ammonium cation, N, N-dimethyl-N-ethyl-N-hexyl ammonium cation, N, N-dimethyl-N-ethyl-N-heptyl ammonium cation, N, N-dimethyl-N-ethyl-N-nonyl Ammonium cation, N, N-dimethyl-N, N-dipropylammonium cation, N, N-dimethyl-N-propyl-N-butylammonium cation, N, N-dimethyl-N-propyl-N-pentylammonium cation, N, N-dimethyl-N-propyl-N-hexylammonium cation, N, N- Methyl-N-propyl-N-heptyl ammonium cation, N, N-dimethyl-N-butyl-N-hexylammonium cation, N, N-dimethyl-N-butyl-N-heptyl ammonium cation, N, N-dimethyl- N-pentyl-N-hexylammonium cation, N, N-dimethyl-N, N-dihexylammonium cation, trimethylheptylammonium cation, N, N-diethyl-N-methyl-N-propylammonium cation, N, N-diethyl -N-methyl-N-pentylammonium cation, N, N-diethyl-N-methyl-N-heptylammonium cation, N, N-diethyl-N-propyl-N-pentylammonium cation, triethylmethylammonium cation, triethylpropyl A Monium cation, triethylpentylammonium cation, triethylheptylammonium cation, N, N-dipropyl-N-methyl-N-ethylammonium cation, N, N-dipropyl-N-methyl-N-pentylammonium cation, N, N-dipropyl -N-butyl-N-hexylammonium cation, N, N-dipropyl-N, N-dihexylammonium cation, N, N-dibutyl-N-methyl-N-pentylammonium cation, N, N-dibutyl-N-methyl -N-hexylammonium cation, trioctylmethylammonium cation, N-methyl-N-ethyl-N-propyl-N-pentylammonium cation, tetramethylammonium cation, tetraethylammonium cation, tet Labutylammonium cation, tetrahexylammonium cation, tributylethylammonium cation, trimethyldecylammonium cation, N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium cation, glycidyltrimethylammonium cation, diallyldimethylammonium cation Trialkylsulfonium cations, such as trimethylsulfonium cation, triethylsulfonium cation, tributylsulfonium cation, trihexylsulfonium cation, diethylmethylsulfonium cation, dibutylethylsulfonium cation, dimethyldecylsulfonium cation; tetramethylphosphonium cation; Tetraethylphosphoni Mukachion, tetrabutylphosphonium cation, tetra hexyl phosphonium cation, phosphonium cation, triethyl methyl phosphonium cation, tributyl ethyl phosphonium cation, tetraalkylphosphonium cations such as trimethyl decyl phosphonium cation.

  In the present invention, among the above cation components, cations represented by the formula (A) (particularly, 1-ethylpyridinium cation, 1-butylpyridinium cation, 1-hexylpyridinium cation, 1-butyl-3-methylpyridinium) Cations, pyridium cations such as 1-butyl-4-methylpyridinium cation, 1-hexyl-3-methylpyridinium cation, 1-butyl-3,4-dimethylpyridinium cation), and cations represented by the formula (D) (particularly, , Triethylmethylammonium cation, tributylethylammonium cation, trimethyldecylammonium cation, diethylmethylsulfonium cation, dibutylethylsulfonium cation, dimethyldecylsulfonium cation, triethylmethylphospho Asymmetric tetraalkylammonium cations such as cations, tributylethylphosphonium, and trimethyldecylphosphonium cations, trialkylsulfonium cations, tetraalkylphosphonium cations, and N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium cations , Diallyldimethylammonium cation, glycidyltrimethylammonium cation, etc.) are preferably used in that particularly excellent antistatic properties can be obtained.

  Specific examples of the cation represented by the formula (E) include, as Rp, for example, methyl group, ethyl group, propyl group, butyl group, hexyl group, octyl group, nonyl group, decyl group, dodecyl group, tridecyl group, Sulfonium salts having an alkyl group having 1 to 18 carbon atoms such as a tetradecyl group and an octadecyl group are exemplified.

As the anion component, any appropriate anion component can be used as long as it can form an ionic liquid together with the cation component. For example, Cl ⁻ , Br ⁻ , I ⁻ , AlCl ₄ ⁻ , Al ₂ Cl ₇ ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , ClO ₄ ⁻ , NO ₃ ⁻ , CH ₃ COO ⁻ , CF ₃ COO ⁻ , CH ₃ SO _{^{3 -, CF 3 SO 3 -}} , (CF 3 SO 2) 2 n -, (CF 3 SO 2) 3 C -, AsF 6 -, SbF 6 -, NbF 6 -, TaF 6 -, F (HF) n _{^{-, (CN) 2 N -}} , C 4 F 9 SO 3 -, (C 2 F 5 SO 2) 2 N -, C 3 F 7 COO -, is _{(CF 3 SO 2) (CF} 3 CO) N and the like No. The hydrophobic anion component tends to hardly bleed on the surface of the pressure-sensitive adhesive, and is preferably used from the viewpoint of low contamination. Further, an anion component containing a fluorine atom is particularly preferably used because an ionic compound having a low melting point can be obtained.

The ionic liquid in the present invention is appropriately selected and used from the combination of the cation component and the anion component. For example, 1-butylpyridinium tetrafluoroborate, 1-butylpyridinium hexafluorophosphate, 1-butyl-3-methylpyridinium Tetrafluoroborate, 1-butyl-3-methylpyridinium trifluoromethanesulfonate, 1-butyl-3-methylpyridinium bis (trifluoromethanesulfonyl) imide, 1-butyl-3-methylpyridinium bis (pentafluoroethanesulfonyl) imide, 1 -Hexylpyridinium tetrafluoroborate, 1,1-dimethylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1-methyl-1-ethylpyrrolidinium bis (trifluoromethane 1-methyl-1-propylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1-methyl-1-butylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1-methyl-1-pentylpyrrolidinium Bis (trifluoromethanesulfonyl) imide, 1-methyl-1-hexylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1-methyl-1-heptylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1-ethyl-1- Propylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1-ethyl-1-butylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1-ethyl-1-pentylpyrrolidinium bis (trifluoromethanesulfonyl) imide 1-ethyl-1-hexylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1-ethyl-1-heptylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1,1-dipropylpyrrolidinium bis (trifluoro 1-propyl-1-butylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1,1-dibutylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1-propylpiperidinium bis (trifluoromethanesulfonyl) imide , 1-pentylpiridinium bis (trifluoromethanesulfonyl) imide, 1,1-dimethylpiridinium bis (trifluoromethanesulfonyl) imide, 1-methyl-1-ethylpiperidinium bis (trifluoro) 1-methyl-1-propylpiperidinium bis (trifluoromethanesulfonyl) imide, 1-methyl-1-butylpiridinium bis (trifluoromethanesulfonyl) imide, 1-methyl-1-pentylpiperidinium bis (trifluoromethanesulfonyl) ) Imide, 1-methyl-1-hexylpiperidinium bis (trifluoromethanesulfonyl) imide, 1-methyl-1-heptylpiperidinium bis (trifluoromethanesulfonyl) imide, 1-ethyl-1-propylpiperidinium bis (trifluoromethanesulfonyl) imide , 1-ethyl-1-butylpyridinium bis (trifluoromethanesulfonyl) imide, 1-ethyl-1-pentylpiridinium bis (trifluoromethanesulfonyl) imide Imide), 1-ethyl-1-hexylpiridinium bis (trifluoromethanesulfonyl) imide, 1-ethyl-1-heptylpiridinium bis (trifluoromethanesulfonyl) imide, 1,1-dipropylpiridinium bis (trifluoromethanesulfonyl) imide, 1-propyl-1-butylpiperidinium bis (trifluoromethanesulfonyl) imide, 1,1-dibutylperidinium bis (trifluoromethanesulfonyl) imide, 1,1-dimethylpyrrolidinium bis (pentafluoroethanesulfonyl) imide, 1-methyl -1-ethylpyrrolidinium bis (pentafluoroethanesulfonyl) imide, 1-methyl-1-propylpyrrolidinium bis (pentafluoroethanesulfonyl) imide, 1-methyl-1 Butylpyrrolidinium bis (pentafluoroethanesulfonyl) imide, 1-methyl-1-pentylpyrrolidinium bis (pentafluoroethanesulfonyl) imide, 1-methyl-1-hexylpyrrolidinium bis (pentafluoroethanesulfonyl) imide , 1-methyl-1-heptylpyrrolidinium bis (pentafluoroethanesulfonyl) imide, 1-ethyl-1-propylpyrrolidinium bis (pentafluoroethanesulfonyl) imide, 1-ethyl-1-butylpyrrolidinium bis (Pentafluoroethanesulfonyl) imide, 1-ethyl-1-pentylpyrrolidinium bis (pentafluoroethanesulfonyl) imide, 1-ethyl-1-hexylpyrrolidinium bis (pentafluoroethanesulfonyl) imide, 1-ethyl- 1 -Heptylpyrrolidinium bis (pentafluoroethanesulfonyl) imide, 1,1-dipropylpyrrolidinium bis (pentafluoroethanesulfonyl) imide, 1-propyl-1-butylpyrrolidinium bis (pentafluoroethanesulfonyl) imide 1,1-dibutylpyrrolidinium bis (pentafluoroethanesulfonyl) imide, 1-propylpiridinium bis (pentafluoroethanesulfonyl) imide, 1-pentylpiridinium bis (pentafluoroethanesulfonyl) imide, 1,1-dimethylpi Lyidinium bis (pentafluoroethanesulfonyl) imide, 1-methyl-1-ethylpiperidinium bis (pentafluoroethanesulfonyl) imide, 1-methyl-1-propylpiperidinium bis (pentafluoro (Ethanesulfonyl) imide, 1-methyl-1-butylpiperidinium bis (pentafluoroethanesulfonyl) imide, 1-methyl-1-pentylpiridinium bis (pentafluoroethanesulfonyl) imide, 1-methyl-1-hexylpiperidinium bis (pentane Fluoroethanesulfonyl) imide, 1-methyl-1-heptylpiridinium bis (pentafluoroethanesulfonyl) imide, 1-ethyl-1-propylpiridinium bis (pentafluoroethanesulfonyl) imide, 1-ethyl-1-butylpyridinium bis ( Pentafluoroethanesulfonyl) imide, 1-ethyl-1-pentylpiperidinium bis (pentafluoroethanesulfonyl) imide, 1-ethyl-1-hexylpiperidinium bis (pentaflu (Loethanesulfonyl) imide, 1-ethyl-1-heptylpiridinium bis (pentafluoroethanesulfonyl) imide, 1,1-dipropylpiridinium bis (pentafluoroethanesulfonyl) imide, 1-propyl-1-butylpyridinium bis (pentafluoro Ethanesulfonyl) imide, 1,1-dibutylpiridinium bis (pentafluoroethanesulfonyl) imide, 2-methyl-1-pyrroline tetrafluoroborate, 1-ethyl-2-phenylindole tetrafluoroborate, 1,2-dimethylindoletetra Fluoroborate, 1-ethylcarbazole tetrafluoroborate, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium acetate, 1-E Tyl-3-methylimidazolium trifluoroacetate, 1-ethyl-3-methylimidazolium heptafluorobutyrate, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, 1-ethyl-3-methylimidazolium perfluorobutanesulfonate 1-ethyl-3-methylimidazolium dicyanamide, 1-ethyl-3-methylimidazolium bis (trifluoromethanesulfonyl) imide, 1-ethyl-3-methylimidazolium bis (pentafluoroethanesulfonyl) imide, Ethyl-3-methylimidazolium tris (trifluoromethanesulfonyl) methide, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium hexafluorophosphate , 1-butyl-3-methylimidazolium trifluoroacetate, 1-butyl-3-methylimidazolium heptafluorobutyrate, 1-butyl-3-methylimidazolium trifluoromethanesulfonate, 1-butyl-3-methylimidazolium Perfluorobutanesulfonate, 1-butyl-3-methylimidazolium bis (trifluoromethanesulfonyl) imide, 1-hexyl-3-methylimidazolium bromide, 1-hexyl-3-methylimidazolium chloride, 1-hexyl-3-methyl Imidazolium tetrafluoroborate, 1-hexyl-3-methylimidazolium hexafluorophosphate, 1-hexyl-3-methylimidazolium trifluoromethanesulfonate, 1-octyl-3-methylimi Zolium tetrafluoroborate, 1-octyl-3-methylimidazolium hexafluorophosphate, 1-hexyl-2,3-dimethylimidazolium tetrafluoroborate, 1,2-dimethyl-3-propylimidazolium bis (trifluoromethanesulfonyl ) Imide, 1-methylpyrazolium tetrafluoroborate, 3-methylpyrazolium tetrafluoroborate, N, N-dimethyl-N-ethyl-N-propylammoniumbis (trifluoromethanesulfonyl) imide, N, N-dimethyl -N-ethyl-N-butylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-ethyl-N-pentylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-ethyl -N-hexylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-ethyl-N-heptylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-ethyl-N-nonylammonium bis (Trifluoromethanesulfonyl) imide, N, N-dimethyl-N, N-dipropylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-propyl-N-butylammoniumbis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-propyl-N-pentylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-propyl-N-hexylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl Ru-N-propyl-N-heptylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-butyl-N-hexylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-butyl- N-heptyl ammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-pentyl-N-hexylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N, N-dihexylammonium bis (trifluoromethane Sulfonyl) imide, trimethylheptylammonium bis (trifluoromethanesulfonyl) imide, N, N-diethyl-N-methyl-N-propylammoniumbis (trifluoromethanesulfonyl) imide, N, N-diethyl- -Methyl-N-pentylammonium bis (trifluoromethanesulfonyl) imide, N, N-diethyl-N-methyl-N-heptylammoniumbis (trifluoromethanesulfonyl) imide, N, N-diethyl-N-propyl-N-pentyl Ammonium bis (trifluoromethanesulfonyl) imide, triethylpropylammonium bis (trifluoromethanesulfonyl) imide, triethylpentylammonium bis (trifluoromethanesulfonyl) imide, triethylheptylammonium bis (trifluoromethanesulfonyl) imide, N, N-dipropyl-N- Methyl-N-ethylammonium bis (trifluoromethanesulfonyl) imide, N, N-dipropyl-N-methyl-N-pentylammonium bis (trifluoro Olomethanesulfonyl) imide, N, N-dipropyl-N-butyl-N-hexylammoniumbis (trifluoromethanesulfonyl) imide, N, N-dipropyl-N, N-dihexylammoniumbis (trifluoromethanesulfonyl) imide, N-dibutyl-N-methyl-N-pentylammonium bis (trifluoromethanesulfonyl) imide, N, N-dibutyl-N-methyl-N-hexylammoniumbis (trifluoromethanesulfonyl) imide, trioctylmethylammonium bis (trifluoromethane Sulfonyl) imide, N-methyl-N-ethyl-N-propyl-N-pentylammonium bis (trifluoromethanesulfonyl) imide, 1-butylpyridinium (trifluoromethanesulfonyl) trifluoro Cetamide, 1-butyl-3-methylpyridinium (trifluoromethanesulfonyl) trifluoroacetamide, 1-ethyl-3-methylimidazolium (trifluoromethanesulfonyl) trifluoroacetamide, tetrahexylammonium bis (trifluoromethanesulfonyl) imide, diallyldimethyl Ammonium tetrafluoroborate, diallyldimethylammonium trifluoromethanesulfonate, diallyldimethylammoniumbis (trifluoromethanesulfonyl) imide, diallyldimethylammoniumbis (pentafluoroethanesulfonyl) imide, N, N-diethyl-N-methyl-N- (2- Methoxyethyl) ammonium tetrafluoroborate, N, N-diethyl-N-methyl-N- (2-methoxy Ethyl) ammonium trifluoromethanesulfonate, N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium bis (trifluoromethanesulfonyl) imide, N, N-diethyl-N-methyl-N- (2-methoxy Ethyl) ammonium bis (pentafluoroethanesulfonyl) imide, glycidyltrimethylammonium trifluoromethanesulfonate, glycidyltrimethylammoniumbis (trifluoromethanesulfonyl) imide, glycidyltrimethylammoniumbis (pentafluoroethanesulfonyl) imide, diallyldimethylbis (pentafluoroethane) Sulfonyl) imide and the like.

  The method of synthesizing the ionic liquid is not particularly limited as long as the desired ionic liquid can be obtained. In general, the literature “Ionic liquids—the forefront of development and the future—” [CMC Co., Ltd.] Published and published]], a halide method, a hydroxide method, an acid ester method, a complex forming method, a neutralization method and the like are used. Also, a commercially available ionic liquid can be employed.

(Conductive polymer)
Any appropriate polymer can be used as the conductive polymer as long as the effects of the present invention can be obtained. For example, polythiophene, polyaniline, polypyrrole and the like can be mentioned.

B-2. Form in which the antistatic material is contained in the base material as an additive (form (2))
As the antistatic material used in the embodiment (2), any suitable antistatic material can be used as long as the effects of the present invention can be obtained. For example, the conductive polymer described in the section B-1 and the antistatic agent described in the section B-3 described below can be used.

  In the embodiment (2), the content ratio of the antistatic material is preferably 20% by weight or less, more preferably 0.05% by weight to 10% by weight, based on the total weight of the substrate.

  The method for incorporating the antistatic material into the base material is not particularly limited as long as the antistatic material can be uniformly mixed with the resin used for the base material, for example, a heating roll, a Banbury mixer, a pressure kneader, A method of using a twin-screw kneader or the like to cause the base material to be included.

B-3. A form in which the antistatic material is contained in a layer (antistatic layer) different from the pressure-sensitive adhesive layer or the substrate (form (3))
As described above, examples of the antistatic layer in the form (3) include an antistatic layer containing a resin (form (3a)) and an antistatic layer composed of a metal or a metal oxide (form (3b)). No.

The surface resistivity of the antistatic layer is preferably 1.0 × 10 ¹³ Ω / □ or less, more preferably 1.0 × 10 ¹² Ω / □ or less, and still more preferably 1.0 × 10 ^11. Ω / □ or less. Within such a range, when the electronic component material is adhered to the electronic component material, damage to the electronic component material can be prevented. The surface resistivity can be measured according to JIS K 6911 (under 23 ° C./50% atmosphere, electrode area: 20 cm ² , applied voltage: 500 V, applied time: 30 seconds, using concentric electrodes (probes)). .

<Antistatic layer containing resin (form (3a))>
In one embodiment, the antistatic layer contains an antistatic material and a binder resin (form (3a-1)).

  In this embodiment (form (3a-1)), examples of the antistatic material contained in the antistatic layer include quaternary ammonium salts, pyridinium salts, primary, secondary, and tertiary amino groups. A cationic antistatic agent having a cationic functional group; an anionic antistatic agent having an anionic functional group such as a sulfonate, a sulfate, a phosphonate, and a phosphate; an alkylbetaine and its derivatives, imidazoline and Zwitterionic antistatic agents such as derivatives thereof, alanine and derivatives thereof; Nonionic antistatic agents such as aminoalcohols and derivatives thereof, glycerin and derivatives thereof, polyethylene glycol and derivatives thereof; cation-type, anion-type and zwitterion-type Polymerized or copolymerized with a monomer having an ion conductive group Ion-conductive polymer and the like was like. These compounds may be used alone or as a mixture of two or more.

  Specific examples of the cationic antistatic agent include, for example, quaternary ammonium groups such as alkyltrimethylammonium salt, acyloylamidopropyltrimethylammonium methosulfate, alkylbenzylmethylammonium salt, acyl choline chloride, and polydimethylaminoethyl methacrylate. (Meth) acrylate copolymers having a quaternary ammonium group such as polyvinylbenzyltrimethylammonium chloride, and diallylamine copolymers having a quaternary ammonium group such as polydiallyldimethylammonium chloride. These compounds may be used alone or as a mixture of two or more.

  Specific examples of the anionic antistatic agent include, for example, alkyl sulfonates, alkyl benzene sulfonates, alkyl sulfates, alkyl ethoxy sulfates, alkyl phosphates, sulfonic acid group-containing styrene copolymers And the like. These compounds may be used alone or as a mixture of two or more.

  Specific examples of the zwitterionic antistatic agent include, for example, alkyl betaine, alkyl imidazolium betaine, and carbobetaine graft copolymer. These compounds may be used alone or as a mixture of two or more.

  Specific examples of the nonionic antistatic agent include, for example, fatty acid alkylolamide, di (2-hydroxyethyl) alkylamine, polyoxyethylene alkylamine, fatty acid glycerin ester, polyoxyethylene glycol fatty acid ester, sorbitan fatty acid ester , Polyoxysorbitan fatty acid esters, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl ether, polyethylene glycol, polyoxyethylene diamine, copolymers of polyether, polyester and polyamide, methoxypolyethylene glycol (meth) acrylate and the like. . These compounds may be used alone or as a mixture of two or more.

  Any appropriate resin can be used as the binder resin constituting the antistatic layer. For example, a polyester resin, an acrylic resin, a polyvinyl resin, a urethane resin, a melamine resin, an epoxy resin, and the like can be given. Further, a crosslinking agent may be used in combination. Examples of the crosslinking agent include methylolated or alkylolated melamine compounds, urea compounds, glyoxal compounds, acrylamide compounds, epoxy compounds, isocyanate compounds, and the like.

  In another embodiment, the antistatic layer is formed from a conductive polymer (form (3a-2)). Any appropriate polymer can be used as the conductive polymer as long as the effects of the present invention can be obtained. For example, polythiophene, polyaniline, polypyrrole and the like can be mentioned.

  As a method for forming an antistatic layer containing a resin (a binder resin or a conductive polymer), for example, a composition for forming an antistatic layer prepared by diluting the above antistatic material and a binder resin with any appropriate solvent, Alternatively, a method in which the composition for forming an antistatic layer prepared by diluting the conductive polymer with an appropriate solvent is applied to a substrate, an adhesive layer or an elastic layer, and dried.

  Examples of the solvent used in the coating solution include water; organic solvents such as methyl ethyl ketone, acetone, ethyl acetate, tetrahydrofuran, dioxane, cyclohexanone, n-hexane, toluene, xylene, methanol, ethanol, n-propanol, and isopropanol. And the like. These solvents may be used alone or as a mixture of two or more.

  Any appropriate method can be adopted as a method of applying the coating liquid. For example, a roll coating method, a gravure coating method, a reverse coating method, a roll brushing method, a spray coating method, an air knife coating method, an impregnation method, a curtain coating method and the like can be mentioned.

  The thickness of the antistatic layer containing a resin is preferably 0.01 μm to 5 μm, and more preferably 0.03 μm to 1 μm. If the thickness of the antistatic layer is less than 0.01 μm, the antistatic function may not be stably exhibited. When the thickness of the antistatic layer is larger than 5 μm, there is a possibility that poor appearance due to coating unevenness or the like may occur.

<Antistatic layer composed of metal or metal oxide (form (3b))>
In the embodiment (3b), the antistatic layer is formed of any appropriate metal or metal oxide as long as the effects of the present invention can be obtained. Examples of the metal include indium, tin, antimony, gold, silver, copper, aluminum, nickel, chromium, titanium, iron, cobalt, copper iodide, and alloys or mixtures thereof. Among them, aluminum is preferable. Examples of the metal oxide include indium tin oxide, indium zinc oxide, tin oxide, antimony oxide, and indium oxide.

  Examples of the method for forming the antistatic layer composed of a metal or a metal oxide include a vacuum deposition method, a sputtering method, an ion plating method, a chemical vapor deposition method, a spray pyrolysis method, a chemical plating method, and an electroplating method. No. Further, a metal film or a metal oxide film may be laminated on a substrate, an adhesive layer or an elastic layer to form an antistatic layer.

  The thickness of the antistatic layer composed of a metal or a metal oxide is preferably from 2 nm to 1000 nm, more preferably from 5 nm to 500 nm.

C. Pressure-sensitive adhesive layer The pressure-sensitive adhesive layer preferably contains a pressure-sensitive adhesive and thermally expandable microspheres. The pressure-sensitive adhesive layer may include an antistatic material as described in the section B.

  The thickness of the pressure-sensitive adhesive layer is preferably 300 μm or less, more preferably 5 μm to 150 μm, and still more preferably 10 μm to 100 μm. When the thickness of the pressure-sensitive adhesive layer is larger than 300 μm, the equipment used is restricted, productivity is significantly reduced, and processing accuracy (linearity of cut surface, chip chipping, etc.) when subjected to a cutting process such as dicing is reduced. There is a possibility that troubles such as running may occur.

  The elastic modulus of the pressure-sensitive adhesive layer at 25 ° C. by the nanoindentation method is preferably 0.1 MPa to 100 MPa, more preferably 0.5 MPa to 50 MPa, and further preferably 0.8 MPa to 30 MPa. The elastic modulus by the nanoindentation method refers to the load obtained by continuously measuring the load applied to the indenter and the depth of indentation when the indenter is pressed into the sample (adhesive surface) during loading and unloading. It refers to the elastic modulus determined from the load-indentation depth curve. In the present specification, the elastic modulus by the nanoindentation method refers to the elastic modulus measured as described above under the conditions of a load of 1 mN, a load / unload speed of 0.1 mN / s, and a holding time of 1 s. The elastic modulus of the pressure-sensitive adhesive layer by the nanoindentation method refers to the elastic modulus measured by the above-described measuring method by selecting a portion where no heat-expandable microspheres exist, that is, the elastic modulus of the pressure-sensitive adhesive.

When the pressure-sensitive adhesive layer contains an antistatic material, the surface resistivity of the pressure-sensitive adhesive layer is preferably 1.0 × 10 ¹³ Ω / □ or less, more preferably 1.0 × 10 ¹² Ω / □ or less. And more preferably 1.0 × 10 ¹¹ Ω / □ or less. Within such a range, when the electronic component material is adhered to the electronic component material, damage to the electronic component material can be prevented.

(Adhesive)
As the pressure-sensitive adhesive, an acrylic pressure-sensitive adhesive is preferably used. Examples of the acrylic pressure-sensitive adhesive include, for example, an acrylic pressure-sensitive adhesive having, as a base polymer, an acrylic polymer (homopolymer or copolymer) using one or more alkyl (meth) acrylates as a monomer component. Is mentioned.

  The base polymer constituting the pressure-sensitive adhesive contains a structural unit A derived from an alkyl (meth) acrylate having a branched side chain. By using a polymer containing the structural unit A as the base polymer, it is possible to obtain a heat-peelable pressure-sensitive adhesive sheet having excellent adhesive strength and excellent irregularity followability. If such a heat-peelable pressure-sensitive adhesive sheet is used for temporary fixing in a cutting step of an electronic component material, chip flying of the material can be prevented.

  In the base polymer, the content ratio of the structural unit A is preferably 20% by weight or more, more preferably 25% by weight to 99% by weight, and further preferably 55% by weight to 99% by weight. Within such a range, the above-described effects (high adhesive strength and good irregularity followability) become remarkable.

  The number of carbon atoms in the side chain of the branched structure of the structural unit A is preferably 5 or more, more preferably 6 to 18, and still more preferably 8 to 18. Within such a range, the above-described effects (high adhesive strength and good irregularity followability) become remarkable.

  Examples of the alkyl (meth) acrylate constituting the structural unit A include, for example, isobutyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, and (meth) acrylic acid 2 -Ethylhexyl, isooctyl (meth) acrylate, isononyl (meth) acrylate, isodecyl (meth) acrylate, 2-ethylbutyl (meth) acrylate, 2-methylbutyl (meth) acrylate and the like.

  In the structural unit A, the alkyl group constituting the branched side chain preferably has 5 or more carbon atoms, more preferably has 6 to 18 carbon atoms, and still more preferably has 8 to 18 carbon atoms. Within such a range, the above-described effects (high adhesive strength and good irregularity followability) become remarkable.

  Examples of the alkyl (meth) acrylate other than the alkyl (meth) acrylate constituting the structural unit A include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and ( Butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, (meth) ) Eicosyl acrylate and the like. Preferably, a (meth) acrylic acid alkyl ester having a linear alkyl group having 1 to 18 carbon atoms can be used.

  The above-mentioned base polymer (acrylic polymer) is used for the purpose of modifying the cohesive strength, heat resistance, crosslinkability, etc., and if necessary, other monomer components copolymerizable with the above-mentioned (meth) acrylic acid alkyl ester. May be included. Such monomer components include, for example, carboxyl group-containing monomers such as acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid; maleic anhydride, icotanic anhydride Acid anhydride monomers such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, hydroxyhexyl (meth) acrylate, hydroxyoctyl (meth) acrylate, (meth) Hydroxyl group-containing monomers such as hydroxydecyl acrylate, hydroxylauryl (meth) acrylate, (4-hydroxymethylcyclohexyl) methyl methacrylate; styrene sulfonic acid, allyl sulfonic acid, 2- (meth) acrylamide Sulfonic acid group-containing monomers such as 2-methylpropanesulfonic acid, (meth) acrylamidopropanesulfonic acid, sulfopropyl (meth) acrylate, (meth) acryloyloxynaphthalenesulfonic acid; (meth) acrylamide, N, N-dimethyl (meth) ) (N-substituted) amide monomers such as acrylamide, N-butyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methylolpropane (meth) acrylamide; aminoethyl (meth) acrylate, (meth) acryl Aminoalkyl (meth) acrylate-based monomers such as N, N-dimethylaminoethyl acid and t-butylaminoethyl (meth) acrylate; (meth) methyl such as methoxyethyl (meth) acrylate and ethoxyethyl (meth) acrylate ) Alkoxy acrylate Alkyl monomers; Maleimide monomers such as N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, N-phenylmaleimide; N-methylitaconimide, N-ethylitaconimide, N-butylitaconimide, N-octyl Itaconimide monomers such as itaconimide, N-2-ethylhexylitaconimide, N-cyclohexylitaconimide, N-laurylitaconimide; N- (meth) acryloyloxymethylene succinimide; N- (meth) acryloyl-6-oxyhexamethylene Succinimide-based monomers such as succinimide and N- (meth) acryloyl-8-oxyoctamethylene succinimide; vinyl acetate, vinyl propionate, N-vinylpyrrolidone, methylvinylpyro Vinyls such as lidone, vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazine, vinylpyrazine, vinylpyrrole, vinylimidazole, vinyloxazole, vinylmorpholine, N-vinylcarboxylic acid amides, styrene, α-methylstyrene, N-vinylcaprolactam -Based monomers; cyanoacrylate monomers such as acrylonitrile and methacrylonitrile; epoxy-containing acrylic monomers such as glycidyl (meth) acrylate; polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, and (meth) acrylic acid Glycol-based acrylic ester monomers such as methoxyethylene glycol and methoxypolypropylene glycol (meth) acrylate; tetrahydrofur (meth) acrylate Acrylic ester-based monomers having a heterocycle such as ril, fluorine (meth) acrylate, silicone (meth) acrylate, a halogen atom, a silicon atom, etc .; hexanediol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate , (Poly) propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa Polyfunctional monomers such as (meth) acrylate, epoxy acrylate, polyester acrylate and urethane acrylate; olefin-based monomers such as isoprene, butadiene and isobutylene; And vinyl ether monomers such as vinyl ether. These monomer components may be used alone or in combination of two or more.

  The content ratio of the unit corresponding to the other monomer component is preferably 1 to 20 parts by weight, more preferably 2 to 15 parts by weight, based on 100 parts by weight of the base polymer, More preferably, it is 2 to 10 parts by weight. Within such a range, it is possible to achieve both the conformability to irregularities on the adherend, the adhesive strength, and the properties of heat releasability.

  The pressure-sensitive adhesive may include any appropriate additive as needed. Examples of the additive include a cross-linking agent, a tackifier, a plasticizer (for example, trimellitate plasticizer, pyromellitic ester plasticizer), a pigment, a dye, a filler, an antioxidant, and a conductive material. , An ultraviolet absorber, a light stabilizer, a release adjuster, a softener, a surfactant, a flame retardant, an antioxidant and the like.

  Any appropriate tackifier is used as the tackifier. As the tackifier, for example, a tackifier resin is used. Specific examples of the tackifying resin include rosin-based tackifying resins (eg, unmodified rosin, modified rosin, rosin phenol-based resin, rosin ester-based resin, etc.), terpene-based tackifying resins (eg, terpene-based resin, terpene phenol) Resin, styrene-modified terpene resin, aromatic-modified terpene resin, hydrogenated terpene resin), hydrocarbon-based tackifying resin (eg, aliphatic hydrocarbon resin, aliphatic cyclic hydrocarbon resin, aromatic resin) Hydrocarbon resin (for example, styrene resin, xylene resin, etc.), aliphatic / aromatic petroleum resin, aliphatic / alicyclic petroleum resin, hydrogenated hydrocarbon resin, cumarone resin, cumarone indene resin Phenolic tackifying resins (eg, alkylphenolic resins, xylene formaldehyde resins, resols, Novo Tsu, etc. h), ketone-based tackifying resins, polyamide-based tackifying resins, epoxy-based tackifying resins, such as an elastomer-based tackifying resins. Among them, a rosin-based tackifying resin, a terpene-based tackifying resin or a phenol-based tackifying resin is preferred. Particularly preferred are rosin phenol-based tackifying resins and terpene phenol-based tackifying resins. Since these tackifiers and the base polymer exhibit relatively good compatibility, according to the pressure-sensitive adhesive obtained using the tackifier, stable irregularity followability is possible. As a result, it is possible to obtain a heat-peelable pressure-sensitive adhesive sheet excellent in suppressing chip fly. The tackifiers may be used alone or in combination of two or more.

  A commercially available product may be used as the tackifier. Specific examples of commercially available tackifiers include terpene phenolic resins such as "YS Polystar S145" and "Mighty Ace K140" manufactured by Yashara Chemical Co., Ltd., and "Tamanol 901" manufactured by Arakawa Chemical; Sumitomo Bakelite Co., Ltd. Rosin phenolic resin such as trade name "Sumilite Resin PR-12603" manufactured by Arakawa Chemical Co., Ltd .; alkyl phenolic resin such as "Tamanol 1010R" and "Tamanol 200N" manufactured by Arakawa Chemical Co. An alicyclic saturated hydrocarbon resin such as Arukawa Chemical's trade name "Alcon P-140";

  The content of the tackifier is preferably 1 part by weight to 80 parts by weight, more preferably 5 parts by weight to 70 parts by weight, and still more preferably 10 parts by weight to 100 parts by weight of the base polymer. It is 50 parts by weight, particularly preferably 10 to 40 parts by weight. By adding a tackifier, the adhesive strength can be increased. On the other hand, the addition of the tackifier is a factor that hinders the conformability of the pressure-sensitive adhesive sheet, and in the present invention, the pressure-sensitive adhesive layer is converted from the base polymer having the structural unit A derived from a specific monomer as described above. By forming, it is possible to achieve both conformability to irregularities and high adhesive strength.

  Examples of the crosslinking agent include an isocyanate crosslinking agent, an epoxy crosslinking agent, a melamine crosslinking agent, a peroxide crosslinking agent, a urea crosslinking agent, a metal alkoxide crosslinking agent, a metal chelate crosslinking agent, and a metal. Salt-based crosslinking agents, carbodiimide-based crosslinking agents, oxazoline-based crosslinking agents, aziridine-based crosslinking agents, amine-based crosslinking agents, and the like. Among them, an isocyanate-based crosslinking agent or an epoxy-based crosslinking agent is preferred.

  Specific examples of the isocyanate-based crosslinking agent include lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate; alicyclic isocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate, and isophorone diisocyanate; Aromatic isocyanates such as tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate and xylylene diisocyanate; trimethylolpropane / tolylene diisocyanate trimer adduct (trade name "Coronate L", manufactured by Nippon Polyurethane Industry Co., Ltd.); Methylolpropane / hexamethylene diisocyanate trimer adduct (trade name "Coronate HL", manufactured by Nippon Polyurethane Industry Co., Ltd.), isocyanate of hexamethylene diisocyanate Rate bodies (Nippon Polyurethane Industry Co., Ltd. under the trade name "Coronate HX") isocyanate adducts of the like; and the like. The content of the isocyanate-based crosslinking agent can be set to any appropriate amount depending on the desired adhesive strength, and is typically 0.1 to 20 parts by weight based on 100 parts by weight of the base polymer. And more preferably 0.5 to 10 parts by weight.

  Examples of the epoxy crosslinking agent include N, N, N ', N'-tetraglycidyl-m-xylenediamine, diglycidylaniline, 1,3-bis (N, N-glycidylaminomethyl) cyclohexane (Mitsubishi Gas Chemical brand, trade name "Tetrad C"), 1,6-hexanediol diglycidyl ether (Kyoeisha Chemical Co., trade name "Epolite 1600"), neopentyl glycol diglycidyl ether (Kyoeisha Chemical Co., trade name " Epolite 1500NP "), ethylene glycol diglycidyl ether (Kyoeisha Chemical Co., trade name" Epolite 40E "), propylene glycol diglycidyl ether (Kyoeisha Chemical Co., trade name" Epolite 70P "), polyethylene glycol diglycidyl ether (Japan The product name "Epiol" manufactured by Yushi -400 "), polypropylene glycol diglycidyl ether (manufactured by NOF Corporation, trade name" Epiol P-200 "), sorbitol polyglycidyl ether (manufactured by Nagase ChemteX Corporation, trade name" Denacol EX-611 "), glycerol polyglycidyl Ether (manufactured by Nagase ChemteX Corporation, trade name "Denacol EX-314"), pentaerythritol polyglycidyl ether, polyglycerol polyglycidyl ether (manufactured by Nagase ChemteX Corporation, trade name "Denacol EX-512"), sorbitan polyglycidyl ether Trimethylolpropane polyglycidyl ether, diglycidyl adipate, diglycidyl o-phthalate, triglycidyl-tris (2-hydroxyethyl) isocyanurate, resor Emissions diglycidyl ether, bisphenol -S- diglycidyl ether, epoxy resins having two or more epoxy groups in the molecule. The content of the epoxy-based crosslinking agent can be set to any appropriate amount depending on the desired adhesive strength, and is typically 0.01 to 10 parts by weight based on 100 parts by weight of the base polymer. And more preferably 0.03 to 5 parts by weight.

(Thermal expansion microspheres)
As the above-mentioned heat-expandable microsphere, any appropriate heat-expandable microsphere can be used as long as it is a microsphere that can be expanded or foamed by heating. As the heat-expandable microsphere, for example, a microsphere in which a substance that easily expands by heating is included in an elastic shell can be used. Such heat-expandable microspheres can be produced by any appropriate method, for example, a coacervation method, an interfacial polymerization method, or the like.

  Examples of substances that easily expand upon heating include propane, propylene, butene, normal butane, isobutane, isopentane, neopentane, normal pentane, normal hexane, isohexane, heptane, octane, petroleum ether, halides of methane, tetraalkylsilanes And azodicarbonamide which is gasified by thermal decomposition.

  Examples of the material constituting the shell include, for example, acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, α-ethoxyacrylonitrile, nitrile monomers such as fumaronitrile; acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, Carboxylic acid monomers such as citraconic acid; vinylidene chloride; vinyl acetate; methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, (Meth) acrylic acid esters such as isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, and β-carboxyethyl acrylate; styrene monomers such as styrene, α-methylstyrene, and chlorostyrene ; It includes polymer composed like; acrylamides, substituted acrylamides, methacrylamide, amide monomers such as substituted methacrylamide. The polymer composed of these monomers may be a homopolymer or a copolymer. Examples of the copolymer include vinylidene chloride-methyl methacrylate-acrylonitrile copolymer, methyl methacrylate-acrylonitrile-methacrylonitrile copolymer, methyl methacrylate-acrylonitrile copolymer, and acrylonitrile-methacrylonitrile-itaconic acid copolymer. Polymers.

  As the heat-expandable microspheres, an inorganic or organic foaming agent may be used. Examples of the inorganic foaming agent include ammonium carbonate, ammonium hydrogen carbonate, sodium hydrogen carbonate, ammonium nitrite, sodium borohydride, various azides, and the like. Examples of the organic blowing agent include chloroalkane compounds such as trichloromonofluoromethane and dichloromonofluoromethane; azo compounds such as azobisisobutyronitrile, azodicarbonamide, and barium azodicarboxylate. Hydrazine compounds such as paratoluenesulfonylhydrazide, diphenylsulfone-3,3'-disulfonylhydrazide, 4,4'-oxybis (benzenesulfonylhydrazide), allylbis (sulfonylhydrazide); p-toluylenesulfonyl semicarbazide, 4, Semicarbazide compounds such as 4'-oxybis (benzenesulfonyl semicarbazide); triazole compounds such as 5-morpholyl-1,2,3,4-thiatriazole; N, N'-dinitrosopentamethylenetetramine; '- dimethyl -N, N'-dinitrosoterephthalamide; etc. N- nitroso compounds, and the like.

  A commercially available product may be used as the thermally expandable microsphere. Specific examples of commercially available heat-expandable microspheres include “Matsumoto Microsphere” (trade name, manufactured by Matsumoto Yushi Seiyaku Co., Ltd. (grades: F-30, F-30D, F-36D, F-36LV, F-50). , F-50D, F-65, F-65D, FN-100SS, FN-100SSD, FN-180SS, FN-180SSD, F-190D, F-260D, F-2800D); EXPANCEL "(grades: 053-40, 031-40, 920-40, 909-80, 930-120), and" Dieform "(grades: H750, H850, H1100, S2320D, S2640D, manufactured by Kureha Chemical Industry Co., Ltd.) M330, M430, M520), "ADVANCEL" manufactured by Sekisui Chemical Co., Ltd. (grade: EML101, EMH204, EHM3) 1, EHM302, EHM303, EM304, EHM401, EM403, EM501) and the like.

  The particle diameter of the heat-expandable microspheres before heating is preferably 0.5 μm to 80 μm, more preferably 5 μm to 45 μm, still more preferably 10 μm to 20 μm, and particularly preferably 10 μm to 15 μm. . Therefore, the particle size of the above-mentioned heat-expandable microspheres before heating is preferably 6 μm to 45 μm, more preferably 10 μm to 35 μm, in terms of the average particle diameter. The above particle diameter and average particle diameter are values determined by a particle size distribution measuring method in a laser scattering method.

  It is preferable that the heat-expandable microspheres have appropriate strength so that they do not burst until the volume expansion coefficient becomes preferably 5 times or more, more preferably 7 times or more, and still more preferably 10 times or more. When using such heat-expandable microspheres, the adhesive force can be efficiently reduced by heat treatment.

  The content ratio of the heat-expandable microspheres in the pressure-sensitive adhesive layer can be appropriately set according to the desired decrease in the adhesive strength. The content of the heat-expandable microspheres is, for example, 1 part by weight to 150 parts by weight, preferably 10 parts by weight to 130 parts by weight, and more preferably 25 parts by weight, based on 100 parts by weight of the base polymer forming the pressure-sensitive adhesive layer. １００100 parts by weight.

D. Substrate Examples of the substrate include a resin sheet, nonwoven fabric, paper, metal foil, woven fabric, rubber sheet, foam sheet, and a laminate thereof (particularly, a laminate including a resin sheet). Examples of the resin constituting the resin sheet include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), polyethylene (PE), polypropylene (PP), ethylene-propylene copolymer, and ethylene-propylene. Vinyl acetate copolymer (EVA), polyamide (nylon), wholly aromatic polyamide (aramid), polyimide (PI), polyvinyl chloride (PVC), polyphenylene sulfide (PPS), fluororesin, polyetheretherketone (PEEK) ) And the like. Examples of the nonwoven fabric include nonwoven fabrics made of heat-resistant natural fibers such as nonwoven fabrics containing Manila hemp; and synthetic resin nonwoven fabrics such as polypropylene resin nonwoven fabric, polyethylene resin nonwoven fabric, and ester-based resin nonwoven fabric.

  In one embodiment, as described in section B, the base material may include an antistatic material. As the base material including the antistatic material, for example, a resin sheet into which the antistatic material is kneaded can be used. The resin sheet can be formed from a composition for forming a base material including a resin and an antistatic material. In another embodiment, a metal foil or the like may be used as the base material, and the base material itself may be an antistatic material.

  The thickness of the base material can be set to any appropriate thickness depending on the desired strength or flexibility, the purpose of use, and the like. The thickness of the substrate is preferably 1000 μm or less, more preferably 1 μm to 1000 μm, further preferably 1 μm to 500 μm, particularly preferably 3 μm to 300 μm, and most preferably 5 μm to 250 μm.

  The substrate may be subjected to a surface treatment. Examples of the surface treatment include corona treatment, chromic acid treatment, ozone exposure, flame exposure, high-voltage impact exposure, ionizing radiation treatment, and coating treatment with a primer. By performing such a surface treatment, the adhesiveness between the pressure-sensitive adhesive layer and the substrate can be increased.

  Examples of the organic coating material include materials described in Plastic Hard Coat Material II (CMC Publishing, (2004)). Preferably, a urethane-based polymer, more preferably, polyacrylurethane, polyesterurethane or a precursor thereof is used. This is because application and application to the base material are simple, and various types can be selected industrially and can be obtained at low cost. The urethane polymer is, for example, a polymer composed of a reaction mixture of an isocyanate monomer and an alcoholic hydroxyl group-containing monomer (for example, a hydroxyl group-containing acrylic compound or a hydroxyl group-containing ester compound). The organic coating material may contain, as optional additives, a chain extender such as a polyamine, an antioxidant, an oxidation stabilizer and the like. Although the thickness of the organic coating layer is not particularly limited, for example, about 0.1 μm to 10 μm is suitable, about 0.1 μm to 5 μm is preferable, and about 0.5 μm to 5 μm is more preferable.

E. FIG. Elastic layer As described above, the heat-peelable pressure-sensitive adhesive sheet of the present invention may further include an elastic layer.

  The elastic layer includes a base polymer, and a sticky polymer may be used as the base polymer. Examples of the base polymer constituting the elastic layer include acrylic polymers: rubber polymers such as natural rubber and synthetic rubber (for example, nitrile, diene, and acrylic); thermoplastic elastomers such as polyolefin and polyester; Vinyl alkyl ether polymer; silicone polymer; polyester polymer; polyamide polymer; urethane polymer; styrene-diene block copolymer; ethylene-vinyl acetate copolymer; polyurethane polymer; polybutadiene; soft polyvinyl chloride; Curable polymers and the like can be mentioned. The base polymer forming the elastic layer may be the same as or different from the base polymer forming the pressure-sensitive adhesive layer. The elastic layer may be a foamed film formed from the base polymer. The foamed film can be obtained by any appropriate method. The elastic layer and the pressure-sensitive adhesive layer can be distinguished by the presence or absence of the heat-expandable microspheres (the elastic layer does not include the heat-expandable microspheres).

  The acrylic polymer as a base polymer constituting the elastic layer is, for example, an acrylic polymer (homopolymer or copolymer) using one or more alkyl (meth) acrylates as a monomer component. . Specific examples of the alkyl (meth) acrylate include alkyl (meth) acrylates having a linear or branched alkyl group having 20 or less carbon atoms. Further, the acrylic polymer may include a unit corresponding to another monomer component copolymerizable with the alkyl (meth) acrylate. Examples of such monomer components include acrylic acid, methacrylic acid, icotanic acid, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, N-methylolacrylamide, acrylonitrile, and methacrylic acid. Examples include lonitrile, glycidyl acrylate, glycidyl methacrylate, vinyl acetate, styrene, isoprene, butadiene, isobutylene, and vinyl ether.

  The elastic layer may include any appropriate additive as needed. Examples of the additive include a crosslinking agent, a vulcanizing agent, a tackifier, a plasticizer, a softener, a filler, an antioxidant, and the like. When a hard resin such as polyvinyl chloride is used as the base polymer, it is preferable to form an elastic layer having desired elasticity by using a plasticizer and / or a softener in combination.

  The thickness of the elastic layer is preferably 3 μm to 200 μm, and more preferably 5 μm to 100 μm. Within such a range, the above-mentioned function of the elastic layer can be sufficiently exhibited.

  The elastic modulus of the elastic layer at 25 ° C. is preferably less than 100 MPa, more preferably 0.1 MPa to 50 MPa, and further preferably 0.1 MPa to 10 MPa. Within such a range, the above-mentioned function of the elastic layer can be sufficiently exhibited.

F. Manufacturing method of heat-peelable pressure-sensitive adhesive sheet The heat-peelable pressure-sensitive adhesive sheet of the present invention can be manufactured by any appropriate method. The heat-peelable pressure-sensitive adhesive sheet of the present invention is, for example, a method of directly applying a pressure-sensitive adhesive layer-forming composition on a substrate, or a method of coating the pressure-sensitive adhesive layer-forming composition on any appropriate substrate. A method of transferring the formed coating layer to a substrate, and the like can be given.

  The composition for forming a pressure-sensitive adhesive layer includes the pressure-sensitive adhesive and the heat-expandable microspheres, and further includes an antistatic material as needed. Further, the composition for forming an adhesive layer may include any appropriate solvent.

  When the heat-peelable pressure-sensitive adhesive sheet has an antistatic layer containing a resin, the antistatic layer is formed by mixing the antistatic material and the binder resin with any appropriate solvent, as described in the section B-3. The composition for forming an antistatic layer prepared by dilution, or the composition for forming an antistatic layer prepared by diluting the conductive polymer with any appropriate solvent is applied to a substrate, an adhesive layer or an elastic layer. It can be formed by coating.

  When the antistatic layer is formed from a metal layer or a metal oxide layer, the metal layer or the metal oxide layer may be formed by, for example, a vacuum deposition method, a sputtering method, or an ion plating method as described in the section B-3. , A chemical vapor deposition method, a spray pyrolysis method, a chemical plating method, an electroplating method and the like. Further, a metal film or a metal oxide film may be laminated on a substrate, an adhesive layer or an elastic layer to form an antistatic layer.

  The timing of forming the antistatic layer is not particularly limited, and the antistatic layer can be formed at any appropriate timing according to the configuration of the heat-peelable pressure-sensitive adhesive sheet. For example, the antistatic layer can be formed after forming a laminate of the base material and the pressure-sensitive adhesive layer. Further, after forming the antistatic layer on the substrate, the pressure-sensitive adhesive layer (or the elastic layer) may be formed on the substrate having the antistatic layer, and the antistatic layer may be formed on the pressure-sensitive adhesive layer (or the elastic layer). May be transferred to the substrate after forming the pressure-sensitive adhesive layer (or the elastic layer) with the antistatic layer.

  When the pressure-sensitive adhesive layer has the above-mentioned elastic layer, the elastic layer can be formed by, for example, applying a composition for forming an elastic layer on a substrate or a pressure-sensitive adhesive layer. Further, the elastic layer may be formed by applying the composition for forming an elastic layer on any appropriate substrate and transferring the formed coating layer.

  Any appropriate application method can be adopted as a method for applying each of the above compositions. For example, each layer can be formed by drying after coating. Examples of the coating method include a coating method using a multi coater, a die coater, a gravure coater, an applicator, and the like. Examples of the drying method include natural drying and heat drying. The heating temperature in the case of heating and drying can be set to any appropriate temperature depending on the characteristics of the substance to be dried.

G. FIG. How to use heat-peelable pressure-sensitive adhesive sheet (method of manufacturing electronic components)
According to another aspect of the present invention, a method for manufacturing an electronic component is provided. The method for manufacturing an electronic component of the present invention includes attaching the electronic component material obtained in a large area on the heat-peelable pressure-sensitive adhesive sheet, and cutting the electronic component material.

  Examples of the electronic component include a component for a semiconductor device such as a silicon wafer; a multilayer capacitor; an inductor; a resistor; a piezoelectric element; a vibrator; an LED;

  In the above manufacturing method, first, the heat-peelable pressure-sensitive adhesive sheet is placed on a worktable, and the electronic component material obtained in a large area is adhered onto the heat-peelable pressure-sensitive adhesive sheet.

  Thereafter, the electronic component material can be obtained by cutting the electronic component material by any appropriate method. Examples of the cutting method include a method using a blade such as a rotary blade and a flat blade, a method using a laser beam, and the like.

  In the cutting process, the cutting may be performed under heating. For example, the processing table may be heated to 30 ° C. to 150 ° C. to perform cutting.

  Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples. The evaluation method in the example is as follows. In the examples, “parts” and “%” are based on weight unless otherwise specified.

(1) Cutting processability A QFN lead frame (size: 125 mm x 65 mm; adhesive; sealed on a pressure-sensitive adhesive layer of a heat-peelable pressure-sensitive adhesive sheet with an epoxy resin (trade name "CEL-9200HF9" manufactured by Hitachi Chemical Co., Ltd.) A resin surface (surface roughness Ra: 3 μm) is attached to the surface to be bonded to the sheet, and the resin surface is attached and fixed to a 6-inch dicing ring, and is fully filled into 250 chips of 5 mm × 5 mm size through a dicer. Cutting was performed (cutting processing was performed by dicing). In this cutting, the number of chip jumps was calculated and evaluated as cutting workability.
As a dicing blade, ZH05-SD2000-N1-110-DD manufactured by DISCO was used. The feed speed of the dicing blade was 70 mm / S, and the number of revolutions of the dicing blade was 50,000 / s.

(2) Heat-peeling property After the cutting process of the above (1), a heat treatment was performed at 130 ° C. for 10 minutes using a hot-air dryer (trade name “SPH-201” manufactured by Espec Corporation). After the heat treatment, the heat-peelable pressure-sensitive adhesive sheet was inverted so that the chips were naturally dropped such that the chips were on the lower side. At this time, the heat-peelability was evaluated based on the number of chips remaining on the heat-peelable pressure-sensitive adhesive sheet without falling naturally.

(3) Adhesive force measuring method A heat-peelable pressure-sensitive adhesive sheet is cut into a size having a width of 20 mm and a length of 140 mm, and a polyethylene terephthalate film (trade name “Lumirror S-10”) as an adherend is formed on the pressure-sensitive adhesive layer. Toray Co., Ltd .; thickness: 25 μm, width: 20 mm) in accordance with JIS Z 0237 (2000), under a temperature of 23 ± 2 ° C. and a humidity of 65 ± 5% RH, reciprocating a 2 kg roller once. Then, they were pressed and bonded. Next, the heat-peelable pressure-sensitive adhesive sheet with the adherend was set on a tensile tester equipped with a thermostat (manufactured by Shimadzu Corporation, trade name “Shimadzu Autograph AG-120 kN”) set at 23 ° C., and left for 30 minutes. I do. After standing, the load when the adherend was peeled off from the heat-peelable pressure-sensitive adhesive tape at a temperature of 23 ° C. under the conditions of a peeling angle of 180 ° and a peeling speed (tensile speed) of 300 mm / min was measured. The maximum load at that time (the maximum value of the load excluding the peak top at the beginning of the measurement) was determined, and this maximum load was defined as the adhesive force (N / 20 mm) of the thermally expandable adhesive layer.

(4) Total light transmittance The total light transmittance of the heat-peelable pressure-sensitive adhesive sheet was measured in accordance with JIS-6714, using an integrating sphere light transmittance measurement device (trade name “Haze Meter HM-150, manufactured by Murakami Color Research Laboratory Co., Ltd.). ".

(5) Peeling charge (measurement of peeling voltage)
On the adhesive surface of the heat-peelable pressure-sensitive adhesive sheet (width 70 mm × length 130 mm), a silicone-treated surface of a charge-removed release liner (silicone-treated PET film, manufactured by Toray Co., Ltd., trade name: “Therapyel”, thickness: 38 μm) is applied. The sample for evaluation was produced by bonding. At this time, the end of the release liner in the length direction of 30 mm protruded from the heat-peelable pressure-sensitive adhesive sheet. The heat-peelable pressure-sensitive adhesive sheet and the release liner were bonded together with a hand roller under the conditions (temperature: 23 ° C., humidity 50% RH) according to JIS Z 0237 (2000).
After the evaluation sample was left in an environment of 23 ° C. and 50% RH for one day, the protruding portion of the release liner was grasped, and the release liner was peeled in the length direction at a peel angle of 150 ° and a peel speed of 10 m / min. . At a position 100 mm vertically away from the surface of the pressure-sensitive adhesive from the point where the release liner and the heat-peelable pressure-sensitive adhesive sheet are separated, measure the voltage on the surface of the pressure-sensitive adhesive layer generated during peeling, and peel off the maximum value. Voltage. In addition, as the measuring device, a potential measuring device (trade name “KSD-0103” manufactured by Kasuga Denki Co., Ltd.) was used. The measurement environment was 23 ° C. and 50% RH.

(6) Stability over time of adhesive properties The heat-peelable adhesive sheet is stored for 2 months in an atmosphere of a temperature of 23 ° C. and a humidity of 50%, and the adhesive strength (A0) measured in the above (2) and 2 months From the adhesive force (A1) after the lapse of time, a change rate X% of the adhesive force was calculated by the following formula (I). In Table 3, the case where the rate of change X% was less than 50% was evaluated as ○, and the case where it was 50% or more was evaluated as ×.
X (%) = (A1 / A0) × 100

[Production Example 1] Preparation of pressure-sensitive adhesive layer-forming composition I Acrylic polymer as base polymer (2 ethylhexyl acrylate: ethyl acrylate: methyl methacrylate: hydroxyethyl acrylate (weight ratio) = 30: 70: 5) : 5) 100 parts by weight, 10 parts by weight of a terpene phenol-based tackifying resin (trade name "YS Polystar S145", manufactured by Yasuhara Chemical Co., Ltd.), and an isocyanate-based crosslinking agent (trade name, "Coronate L", manufactured by Nippon Polyurethane Co., Ltd.) Parts by weight, a crosslinking accelerator (manufactured by Tokyo Fine Chemical Company, trade name "Envirizer OL-1") 0.03 parts by weight, and heat-expandable microspheres (manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd., trade name "Matsumoto Microsphere" F-65 "; 150 ° C. foam expansion type) 30 parts by weight and toluene were mixed to prepare a resin solution, and this was The composition I was used for forming an adhesive layer.
When the pressure-sensitive adhesive layer is formed from the pressure-sensitive adhesive layer-forming composition I, the content of the structural unit A in the pressure-sensitive adhesive layer is 27 parts by weight with respect to 100 parts by weight of the base polymer.

[Production Examples 2 to 12] Preparation of pressure-sensitive adhesive layer forming compositions II to XII Types and weight ratios of monomers constituting acrylic polymer, types and amounts of crosslinking agent, and types and amounts of tackifying resin Was obtained in the same manner as in Production Example 1 except that the compositions shown in Table 1 were used, to obtain compositions II to XII for forming an adhesive layer. In Production Example 9, 10 parts by weight of an ionic liquid (ionic conductivity imparting agent, manufactured by Nippon Carlit Co., Ltd., trade name "PEL20A") was blended to prepare a composition IX for forming an adhesive layer. In Production Example 10, 3 parts by weight of an ionic liquid (manufactured by Nippon Carlit Co., Ltd., trade name “CIL-312”, 1-butyl-3-methylpyridinium bis (trifluoromethanesulfonyl) imide) was compounded, A composition X for forming an agent layer was prepared.
Details of the crosslinking agent and tackifier resin described in Table 1 are as follows.
<Crosslinking agent>
Tetrad C: manufactured by Mitsubishi Gas Chemical Company, trade name "Tetrad C", epoxy crosslinking agent <tackifying resin>
Mighty Ace G125: manufactured by Yashara Chemical Co., Ltd., trade name “Mighty Ace G125”, terpene phenol-based tackifying resin Tamanoru 901: manufactured by Arakawa Chemical Industries, Ltd., trade name “Tamanol 901”, terpene phenol-based tackifying resin Tamanoru 200N: Arakawa Chemical Industries Company name, “Tamanol 200N”, alkylphenol-based tackifying resin Superester A125: Arakawa Chemical Industries, Ltd., product name “Superester A125”, rosin-based tackifying resin

[Production Example 13] Preparation of composition I for forming an elastic layer Acrylic polymer (2 ethylhexyl acrylate: ethyl acrylate: methyl methacrylate: hydroxyethyl acrylate (weight ratio) = 30: 70: 5: 5) 100 weight And 3 parts by weight of an isocyanate-based crosslinking agent (trade name: "Coronate L", manufactured by Nippon Polyurethane Co., Ltd.) and toluene were mixed to prepare a resin solution, which was used as composition I for forming an elastic layer.

[Production Examples 14 to 20] Preparation of elastic layer-forming compositions II to VIII Except that the types and weight ratios of the monomers constituting the acrylic pressure-sensitive adhesive and the amount of the crosslinking agent were as shown in Table 2, In the same manner as in Production Example 12, compositions II to VIII for forming an elastic layer were obtained.

[Example 1]
An aqueous dispersion containing 1.2% by weight of polythiophene (polyethylene dioxythiophene polystyrene sulfonate) as an antistatic material (manufactured by Heraeus, trade name "Clebios P") and a polyester resin solution (manufactured by Toyobo, The trade name “Vylonal MD1200”, solid content concentration: 1.2% by weight) was mixed so that the solid content weight ratio (aqueous dispersion: resin solution) was 6: 4. The mixture was diluted with a water mixed solvent (isopropyl alcohol: pure water = 6: 4 (weight ratio)) so that the solid content concentration was 1% by weight, to prepare a composition I for forming an antistatic layer.
The obtained antistatic layer-forming composition I is applied to a PET substrate (trade name “Lumirror S10”, manufactured by Toray Industries, Inc., thickness: 100 μm), dried, and dried to a thickness of 50 nm on the substrate. Was formed.
Next, the composition I for forming an elastic layer obtained in Production Example 13 is applied to the surface of the PET substrate opposite to the antistatic layer and dried, and an elastic layer having a thickness of 15 μm is formed on the surface. Formed.
Separately, the pressure-sensitive adhesive layer-forming composition I obtained in Production Example 1 was applied on a Si-treated surface of a PET separator (thickness: 38 μm) and dried to form a pressure-sensitive adhesive layer precursor having a thickness of 35 μm. . The precursor is transferred to the surface of the elastic layer opposite to the PET substrate, and the heat-peelable pressure-sensitive adhesive sheet (antistatic layer (50 nm) / substrate (100 μm) / elastic layer (15 μm) / adhesive Layer (35 μm)).
The obtained heat-peelable pressure-sensitive adhesive sheet was subjected to the above evaluations (1) to (6). Table 3 shows the results.

[Example 2]
Example 1 was repeated except that the composition I for forming the elastic layer was used in place of the composition I for forming the elastic layer, and the composition II for forming the pressure-sensitive adhesive layer was used instead of the composition I for forming the pressure-sensitive adhesive layer. Similarly, a heat-peelable pressure-sensitive adhesive sheet (antistatic layer (50 nm) / substrate (100 μm) / elastic layer (15 μm) / pressure-sensitive adhesive layer (35 μm)) was obtained. The obtained heat-peelable pressure-sensitive adhesive sheet was subjected to the above evaluations (1) to (6). Table 3 shows the results.

[Example 3]
Poly (3,4-ethylenedioxythiophene) is mixed with an alcohol dispersion of poly (3,4-ethylenedioxythiophene) (trade name "Enocoat BP105", manufactured by Kaken Sangyo Co., Ltd.) and propanol as an antistatic material. ) Was prepared to contain 1% by weight of an antistatic layer-forming composition II.
A composition for forming an adhesive layer using a composition II for forming an antistatic layer instead of the composition I for forming an antistatic layer, and a composition III for forming an elastic layer instead of the composition I for forming an elastic layer. A heat-peelable pressure-sensitive adhesive sheet (antistatic layer (50 nm) / substrate (100 μm) / elastic layer (15 μm) in the same manner as in Example 1 except that the composition III for forming a pressure-sensitive adhesive layer was used instead of I. / Pressure-sensitive adhesive layer (35 μm)). The obtained heat-peelable pressure-sensitive adhesive sheet was subjected to the above evaluations (1) to (6). Table 3 shows the results.

[Example 4]
Example 3 was repeated except that the composition IV for forming an elastic layer was used instead of the composition III for forming an elastic layer, and the composition IV for forming an adhesive layer was used instead of the composition III for forming an adhesive layer. Similarly, a heat-peelable pressure-sensitive adhesive sheet (antistatic layer (50 nm) / substrate (100 μm) / elastic layer (15 μm) / pressure-sensitive adhesive layer (35 μm)) was obtained. The obtained heat-peelable pressure-sensitive adhesive sheet was subjected to the above evaluations (1) to (6). Table 3 shows the results.

[Example 5]
Example 1 was repeated except that the composition V for forming an elastic layer was used in place of the composition I for forming an elastic layer, and the composition V for forming a pressure-sensitive adhesive layer was used instead of the composition I for forming an adhesive layer. Similarly, a heat-peelable pressure-sensitive adhesive sheet (antistatic layer (50 nm) / substrate (100 μm) / elastic layer (15 μm) / pressure-sensitive adhesive layer (35 μm)) was obtained. The obtained heat-peelable pressure-sensitive adhesive sheet was subjected to the above evaluations (1) to (6). Table 3 shows the results.

[Example 6]
Example 1 was repeated except that the composition VI for forming an elastic layer was used instead of the composition I for forming an elastic layer, and the composition VI for forming an adhesive layer was used instead of the composition I for forming an adhesive layer. Similarly, a heat-peelable pressure-sensitive adhesive sheet (antistatic layer (50 nm) / substrate (100 μm) / elastic layer (15 μm) / pressure-sensitive adhesive layer (35 μm)) was obtained. The obtained heat-peelable pressure-sensitive adhesive sheet was subjected to the above evaluations (1) to (6). Table 3 shows the results.

[Example 7]
Except for using the pressure-sensitive adhesive layer forming composition VII in place of the pressure-sensitive adhesive layer forming composition I, in the same manner as in Example 1, a heat-peelable pressure-sensitive adhesive sheet (antistatic layer (50 nm) / substrate (100 μm ) / Elastic layer (15 μm) / adhesive layer (35 μm)). The obtained heat-peelable pressure-sensitive adhesive sheet was subjected to the above evaluations (1) to (6). Table 3 shows the results.

Example 8
As a base material, a PET base material (trade name “X53 Lumirror # 100”, manufactured by Toray Industries, Inc., thickness: 100 μm, surface resistivity: 1 × 10 ¹⁰ Ω / □) containing an antistatic material was prepared.
The composition I for forming an elastic layer obtained in Production Example 13 was applied to the PET base material containing the antistatic material, and dried to form an elastic layer having a thickness of 15 μm on the surface.
Separately, the pressure-sensitive adhesive layer-forming composition I obtained in Production Example 1 was applied on a Si-treated surface of a PET separator (thickness: 38 μm) and dried to form a pressure-sensitive adhesive layer precursor having a thickness of 35 μm. . The precursor is transferred to the surface of the elastic layer opposite to the PET substrate to obtain a heat-peelable pressure-sensitive adhesive sheet (substrate (100 μm) / elastic layer (15 μm) / pressure-sensitive adhesive layer (35 μm)). Was.
The obtained heat-peelable pressure-sensitive adhesive sheet was subjected to the above evaluations (1) to (6). Table 3 shows the results.

[Example 9]
Except that the pressure-sensitive adhesive layer forming composition VIII was used instead of the pressure-sensitive adhesive layer forming composition I, a heat-peelable pressure-sensitive adhesive sheet (antistatic layer (50 nm) / substrate (100 μm ) / Elastic layer (15 μm) / adhesive layer (35 μm)). The obtained heat-peelable pressure-sensitive adhesive sheet was subjected to the above evaluations (1) to (6). Table 3 shows the results.

[Example 10]
In the same manner as in Example 1, a composition I for forming an antistatic layer was prepared.
The composition I for forming an antistatic layer is applied to a PET substrate (trade name “Lumirror S10”, manufactured by Toray Industries, Inc., thickness: 100 μm) and dried to form an antistatic layer having a thickness of 50 nm on the substrate. did.
Next, the composition I for forming an elastic layer obtained in Production Example 13 was applied on the antistatic layer and dried to form an elastic layer having a thickness of 15 μm.
Separately, the pressure-sensitive adhesive layer forming composition I obtained in Production Example 1 was applied on a PET film (thickness: 38 μm) and dried to form a pressure-sensitive adhesive layer precursor having a thickness of 35 μm. The precursor was transferred onto the elastic layer to obtain a heat-peelable pressure-sensitive adhesive sheet (base material (100 μm) / antistatic layer (50 nm) / elastic layer (15 μm) / pressure-sensitive adhesive layer (35 μm)). .
The obtained heat-peelable pressure-sensitive adhesive sheet was subjected to the above evaluations (1) to (6). Table 3 shows the results.

[Example 11]
As a laminate of the antistatic layer and the base material, a PET film having an antistatic layer formed by vapor deposition (trade name “Half-deposited FB-15”, manufactured by Toray Industries, Inc., thickness: 50 μm, total light transmittance: 15%) Got ready.
Next, the composition I for forming an elastic layer obtained in Production Example 13 is applied to the substrate side of the laminate (that is, the surface of the PET film on which the deposition is not performed), and dried, and the surface is dried. To form an elastic layer having a thickness of 15 μm.
Separately, the pressure-sensitive adhesive layer-forming composition I obtained in Production Example 1 was applied on a Si-treated surface of a PET separator (thickness: 38 μm) and dried to form a pressure-sensitive adhesive layer precursor having a thickness of 35 μm. . The precursor is transferred to the surface of the elastic layer opposite to the substrate, and the heat-peelable pressure-sensitive adhesive sheet (antistatic layer / substrate / elastic layer (15 μm) / pressure-sensitive adhesive layer (35 μm)) is formed. Obtained.
The obtained heat-peelable pressure-sensitive adhesive sheet was subjected to the above evaluations (1) to (6). Table 3 shows the results.

[Example 12]
The elastic layer forming composition I obtained in Production Example 13 was applied to a PET substrate (trade name “Lumirror S10”, manufactured by Toray Industries, Inc., thickness: 100 μm), dried, and dried to a thickness of 15 μm on the surface. An elastic layer was formed.
Separately, the pressure-sensitive adhesive layer forming composition IX obtained in Production Example 9 was applied on a Si-treated surface of a PET separator (thickness: 38 μm), and dried to form a pressure-sensitive adhesive layer precursor having a thickness of 35 μm. . The precursor is transferred to the surface of the elastic layer opposite to the PET substrate to obtain a heat-peelable pressure-sensitive adhesive sheet (substrate (100 μm) / elastic layer (15 μm) / pressure-sensitive adhesive layer (35 μm)). Was. The present embodiment is an experimental example in which an ionic liquid as an antistatic material is included in the pressure-sensitive adhesive layer.
The obtained heat-peelable pressure-sensitive adhesive sheet was subjected to the above evaluations (1) to (6). Table 3 shows the results.

Example 13
(Antistatic layer (50 nm) / base material (100 μm) / adhesive layer (35 μm)) was obtained in the same manner as in Example 1 except that the elastic layer was not formed. The obtained heat-peelable pressure-sensitive adhesive sheet was subjected to the above evaluations (1) to (6). Table 3 shows the results.

[Example 14]
A film was prepared by the method described in Example 12 of JP-A-4-348161, and this film (thickness: 50 nm) was used as an antistatic layer as a PET substrate (trade name "Lumirror S10" manufactured by Toray Industries, Inc.). (Thickness: 100 μm). The film contains polyaniline as an antistatic material and has a surface resistivity of 2.5 × 10 ⁵ Ω / □.
Next, the composition I for forming an elastic layer obtained in Production Example 13 is applied to the surface of the PET substrate opposite to the antistatic layer and dried, and an elastic layer having a thickness of 15 μm is formed on the surface. Formed.
Separately, the pressure-sensitive adhesive layer-forming composition I obtained in Production Example 1 was applied on a Si-treated surface of a PET separator (thickness: 38 μm) and dried to form a pressure-sensitive adhesive layer precursor having a thickness of 35 μm. . The precursor is transferred to the surface of the elastic layer opposite to the PET substrate, and the heat-peelable pressure-sensitive adhesive sheet (antistatic layer (50 nm) / substrate (100 μm) / elastic layer (15 μm) / adhesive Layer (35 μm)).
The obtained heat-peelable pressure-sensitive adhesive sheet was subjected to the above evaluations (1) to (6). Table 3 shows the results.

[Example 15]
The elastic layer forming composition I obtained in Production Example 13 was applied to a PET substrate (trade name “Lumirror S10”, manufactured by Toray Industries, Inc., thickness: 100 μm), dried, and dried to a thickness of 15 μm on the surface. An elastic layer was formed.
Separately, the pressure-sensitive adhesive layer forming composition X obtained in Production Example 10 was applied on a Si-treated surface of a PET separator (thickness: 38 μm) and dried to form a pressure-sensitive adhesive layer precursor having a thickness of 35 μm. . The precursor is transferred to the surface of the elastic layer opposite to the PET substrate to obtain a heat-peelable pressure-sensitive adhesive sheet (substrate (100 μm) / elastic layer (15 μm) / pressure-sensitive adhesive layer (35 μm)). Was. The present embodiment is an experimental example in which an ionic liquid as an antistatic material is included in the pressure-sensitive adhesive layer.
The obtained heat-peelable pressure-sensitive adhesive sheet was subjected to the above evaluations (1) to (6). Table 3 shows the results.

[Comparative Example 1]
Example 1 was repeated except that the composition for forming an elastic layer VII was used instead of the composition for forming an elastic layer I and the composition XI for forming an adhesive layer was used instead of the composition I for forming an adhesive layer. Similarly, a heat-peelable pressure-sensitive adhesive sheet (antistatic layer (50 nm) / substrate (100 μm) / elastic layer (15 μm) / pressure-sensitive adhesive layer (35 μm)) was obtained. The obtained heat-peelable pressure-sensitive adhesive sheet was subjected to the above evaluations (1) to (6). Table 3 shows the results.

[Comparative Example 2]
Example 1 was repeated except that the composition for forming an elastic layer VIII was used instead of the composition for forming an elastic layer I and the composition XII for forming an adhesive layer was used instead of the composition I for forming an adhesive layer. Similarly, a heat-peelable pressure-sensitive adhesive sheet (antistatic layer (50 nm) / substrate (100 μm) / elastic layer (15 μm) / pressure-sensitive adhesive layer (35 μm)) was obtained. The obtained heat-peelable pressure-sensitive adhesive sheet was subjected to the above evaluations (1) to (6). Table 3 shows the results.

[Comparative Example 3]
A heat-peelable pressure-sensitive adhesive sheet (substrate (100 μm) / elastic layer (15 μm) / pressure-sensitive adhesive layer (35 μm)) was obtained in the same manner as in Example 1 except that the antistatic layer was not formed. The obtained heat-peelable pressure-sensitive adhesive sheet was subjected to the above evaluations (1) to (6). Table 3 shows the results.

  As is evident from Table 3, when the heat-peelable pressure-sensitive adhesive sheet of the present invention is used as a temporary fixing sheet in a cutting step of an electronic component material, chip flying can be prevented. Further, the heat-peelable pressure-sensitive adhesive sheet of the present invention has a small peeling charge amount. The pressure-sensitive adhesive sheet having a large amount of peeling charge as in Comparative Example 3 may damage the attached electronic component material.

  The production method and the pressure-sensitive adhesive sheet of the present invention can be suitably used for producing chip-shaped electronic components such as semiconductor chips.

DESCRIPTION OF SYMBOLS 10 Adhesive layer 20 Substrate 30 Antistatic layer 40 Elastic layer 100, 200, 300 Adhesive sheet

Claims (9)

A heat-peelable pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer,
The heat-peelable pressure-sensitive adhesive sheet contains an antistatic material,
The pressure-sensitive adhesive layer includes a pressure-sensitive adhesive and heat-expandable microspheres,
The base polymer constituting the pressure-sensitive adhesive includes a structural unit A derived from an alkyl (meth) acrylate,
The structural unit A has a side chain having a branched structure ,
The content of the structural unit A is 55% by weight or more in the base polymer;
Thermal peeling type adhesive sheet.   The heat-peelable pressure-sensitive adhesive sheet according to claim 1, wherein the pressure-sensitive adhesive layer contains the antistatic material. Further comprising a substrate,
The heat-peelable pressure-sensitive adhesive sheet according to claim 1, wherein the base material contains the antistatic material. Substrate, and
Further comprising an antistatic layer is provided on the side opposite to the pressure-sensitive adhesive layer of the substrate,
The antistatic layer contains the antistatic material,
The heat-peelable pressure-sensitive adhesive sheet according to claim 1 . A substrate, and
Further comprising an antistatic layer is provided between the said substrate the pressure-sensitive adhesive layer,
The antistatic layer contains the antistatic material,
The heat-peelable pressure-sensitive adhesive sheet according to claim 1 .   The heat-peelable pressure-sensitive adhesive sheet according to any one of claims 1 to 5, wherein the side chain having a branched structure of the structural unit A has 5 or more carbon atoms. The pressure-sensitive adhesive layer further includes a tackifier resin,
The heat-peelable pressure-sensitive adhesive sheet according to any one of claims 1 to 6, wherein the content of the tackifier resin is 1 part by weight to 80 parts by weight based on 100 parts by weight of the base polymer.   The heat-peelable pressure-sensitive adhesive sheet according to any one of claims 1 to 7, wherein the pressure-sensitive adhesive strength to the PET film is 2 N / 20 mm or more. After sticking an electronic component material on the heat-peelable pressure-sensitive adhesive sheet according to any one of claims 1 to 8,
Cutting the electronic component material,
Manufacturing method of electronic components.

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