Adhesive film

Abstract

To provide an adhesive film capable of achieving both excellent heat resistance and excellent peelability after high-temperature processing even when having a base material.SOLUTION: An adhesive film comprising a base material and an adhesive layer on at least one surface of the base material, wherein the adhesive layer contains a reactive carbon-carbon double bond-containing compound, the adhesive film has a light transmission of 1.0% or more and 72.0% or less at 436nm wavelengths when the adhesive layer is in an uncured state, and the adhesive film has a 5% weight reduction temperature of 400 °C. or higher after the adhesive layer is cured.SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] During processing of electronic components such as semiconductors, in order to facilitate handling of the electronic components and prevent breakage, the electronic components are protected by being fixed to a support plate via a pressure-sensitive adhesive composition or by being attached with a pressure-sensitive adhesive tape. For example, when a thick-film wafer cut from a high-purity silicon single crystal or the like is ground to a predetermined thickness to obtain a thin-film wafer, the thick-film wafer is adhered to a support plate via a pressure-sensitive adhesive composition.

[0003] Thus, pressure-sensitive adhesive compositions and pressure-sensitive adhesive tapes used for electronic components are required to have high enough adhesion to firmly fix the electronic components during the processing step, and also to be able to be peeled off without damaging the electronic components after the processing step (hereinafter also referred to as "high adhesion and easy peeling"). As a means for achieving high adhesion and easy peeling, for example, Patent Document 1 discloses a pressure-sensitive adhesive sheet that uses a pressure-sensitive adhesive containing an adhesive polymer in which a polyfunctional monomer or oligomer having a radiation-polymerizable functional group is bonded to the side chain or main chain of the polymer. By utilizing the fact that the polymer has a radiation-polymerizable functional group, which hardens when exposed to ultraviolet light, the adhesive strength is reduced by exposure to ultraviolet light during peeling, allowing the sheet to be peeled off without leaving any adhesive residue. [Prior art documents] [Patent documents]

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

[0005] In recent years, in order to respond to the increasing integration density of semiconductors, the TBDB (Temporary Bonding / De-bonding) process has been adopted to manufacture semiconductors by supporting a thin wafer with a support and a temporary fixing material. In the TBDB process, the support and the temporary fixing material must be removed after the process is completed. Examples of the process for removing the support include a process in which the entire surface of the support is irradiated with laser light to peel off the support.

[0006] In the process of removing the temporary fixing material, if the temporary fixing material is in the form of a tape, such as an adhesive film, the adhesive film is often removed by peeling, and since the surfaces of the electronic components, such as semiconductors, that are manufactured have irregularities called bumps, excellent peeling performance is required for electronic components with irregularities. Furthermore, since semiconductor manufacturing, such as the TBDB process, involves high-temperature processing such as heating and processing that generates heat, adhesive films used in semiconductor manufacturing are required to suppress adhesion enhancement due to heat and to be easily peelable from the adherend after the high-temperature processing. Typically, the adhesive film is irradiated with ultraviolet light before the high-temperature processing to harden the adhesive layer of the adhesive film and reduce the adhesive strength of the adhesive layer.

[0007] On the other hand, in order to improve the handleability of the adhesive film, an adhesive film having a substrate is sometimes used, and the substrate for the adhesive film used in the production of semiconductors needs to be a heat-resistant substrate that can also be used for high-temperature processing. However, when an adhesive film having a heat-resistant substrate is used in the manufacture of semiconductors, the heat-resistant substrate is poorly transparent to ultraviolet light, making it difficult to irradiate the adhesive layer with ultraviolet light through the heat-resistant substrate, resulting in insufficient suppression of increased adhesion during high-temperature processing, and the adhesive film may not be easily peeled off from the adherend after high-temperature processing.

[0008] An object of the present invention is to provide an adhesive film that, even when having a substrate, can achieve both excellent heat resistance and excellent releasability after high-temperature processing.

[0009] Disclosure 1 relates to an adhesive film having a substrate and an adhesive layer on at least one surface of the substrate, wherein the adhesive layer contains a curable resin, and the curable resin contains a compound having a reactive carbon-carbon double bond; the adhesive film has a light transmittance of 1.0% or more and 72.0% or less at a wavelength of 436 nm when the adhesive layer is uncured; and the adhesive film has a 5% weight loss temperature of 400°C or more after the adhesive layer is cured. Disclosure 2 is an adhesive film according to Disclosure 1, wherein the compound having a reactive carbon-carbon double bond includes a compound having at least one group selected from the group consisting of a maleimide group and a (meth)acryloyl group. Disclosure 3 is the adhesive film according to Disclosure 2, wherein the compound having a reactive carbon-carbon double bond includes a bismaleimide compound. Disclosure 4 is an adhesive film according to Disclosure 1, 2, or 3, wherein the adhesive layer further contains a non-curable resin, and the non-curable resin contains a resin that does not have a reactive carbon-carbon double bond and has an imide skeleton in the repeating unit of the main chain. Disclosure 5 is the adhesive film of Disclosure 4, in which the resin having no reactive carbon-carbon double bond and an imide skeleton in the repeating unit of the main chain has a silicone skeleton in the repeating unit of the main chain. The present disclosure 6 is an adhesive film of the present disclosure 1, 2, 3, 4, or 5, wherein the adhesive layer further contains a non-curable resin, and the content of the curable resin is 10 parts by mass or more and 90 parts by mass or less out of a total of 100 parts by mass of the curable resin and the non-curable resin. Disclosure 7 is the adhesive film according to Disclosure 1, 2, 3, 4, 5, or 6, wherein the adhesive layer contains a polymerization initiator. Disclosure 8 is the adhesive film of Disclosure 7, wherein the polymerization initiator includes a photopolymerization initiator. Disclosure 9 is the adhesive film of Disclosure 8, wherein the photopolymerization initiator has a molar absorption coefficient of 100 ml / (g·cm) or more for light with a wavelength of 436 nm. Disclosure 10 is the adhesive film according to Disclosure 8 or 9, wherein the photopolymerization initiator contains an oxime ester compound. Disclosure 11 is the adhesive film according to Disclosure 8, 9, or 10, wherein the photopolymerization initiator includes a compound having a carbazole group. Disclosure 12 is the adhesive film according to Disclosure 8, 9, 10, or 11, wherein the photopolymerization initiator contains an oxime ester compound having a carbazole group. Disclosure 13 is the adhesive film of Disclosures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12, wherein the adhesive layer is photocurable. Disclosure 14 uses an ultra-high pressure mercury lamp on the adhesive layer, with a wavelength of 405 nm and an irradiation intensity of 100 mW / cm 2 14. The adhesive film of Disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, or 13, wherein the adhesive layer has a gel fraction of 50 mass % or more after being irradiated with light of 1000 nm through the substrate for 300 seconds. Disclosure 15 is the adhesive film of Disclosures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, or 14, wherein the thickness of the adhesive layer is 5 μm or more and 550 μm or less. Disclosure 16 is an adhesive film according to Disclosures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15, wherein the substrate contains a resin having in its main chain skeleton a repeating unit containing at least one type selected from the group consisting of an ether bond, a ketone group, an ester bond, an amide bond, and an imide bond. Disclosure 17 is the adhesive film of Disclosures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or 16, wherein the thickness of the substrate is 5 μm or more and 150 μm or less. Disclosure 18 is an adhesive film according to Disclosures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, or 17, wherein the adhesive film has a weight loss rate of 1.0% or less after heating at 250°C for 30 minutes after the adhesive layer has hardened. Disclosure 19 is the adhesive film of Disclosures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, or 18, wherein the adhesive film has a 180° peel strength from a silicon wafer of 2.0 N / inch or less after the adhesive layer is cured. Disclosure 20 is an adhesive film according to Disclosures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, or 19, used as a temporary fixing material. Disclosure 21 is the adhesive film of Disclosure 20 used as a temporary fixing material for manufacturing electronic components. The present invention will be described in detail below. [Means for solving the problem]

[0010] The present inventors focused on the fact that heat-resistant substrates transmit light (such as visible light) with wavelengths longer than ultraviolet light, and investigated ways to sufficiently cure the adhesive layer using an adhesive film having a substrate and an adhesive layer with light with wavelengths longer than ultraviolet light. As a result, they found that by adjusting the composition of the adhesive layer and the light transmittance of the adhesive film, it is possible to obtain an adhesive layer and an adhesive film that sufficiently cure even with light with wavelengths longer than ultraviolet light. Furthermore, they investigated adjusting the 5% weight loss temperature after curing of the adhesive layer of such an adhesive film to a specific range. As a result, they found that an adhesive film that has both excellent heat resistance and excellent releasability after high-temperature processing can be obtained, even when it has a substrate, and thus completed the present invention.

[0011] The adhesive film of the present invention has a substrate and an adhesive layer on at least one surface of the substrate. That is, the adhesive film of the present invention may be an adhesive film having an adhesive layer on one surface of the substrate, or an adhesive film having adhesive layers on both surfaces of the substrate. The adhesive layer contains a curable resin. By containing the curable resin, the adhesive layer has curability. The adhesive layer may be curable, for example, by photocuring or thermosetting. From the viewpoint of storage stability, the adhesive layer is preferably photocurable.

[0012] The curable resin contains a compound having a reactive carbon-carbon double bond. By including a compound having a reactive carbon-carbon double bond in the curable resin, the curable resin is efficiently three-dimensionally reticulated by light irradiation or heating, thereby accelerating the curing of the adhesive layer. This prevents the adhesive film of the present invention from experiencing increased adhesion during high-temperature processing or from leaving adhesive residue when peeling the adhesive film after high-temperature processing. Furthermore, the adhesive film of the present invention has excellent heat resistance. It should be noted that the silicone compounds or fluorine compounds used as surface conditioners, which will be described later, are not considered to be the curable resins.

[0013] Examples of the compound having a reactive carbon-carbon double bond include a compound having a maleimide group, a compound having a citraconic group, a compound having a vinyl ether group, a compound having an allyl group, a compound having a (meth)acryloyl group, etc. Among these, from the viewpoint of the heat resistance of the adhesive film of the present invention, a compound having at least one group selected from the group consisting of a maleimide group and a (meth)acryloyl group is preferred, and a compound having a maleimide group is more preferred. In this specification, a carbon-carbon double bond contained in an aromatic ring is not considered to be the above-mentioned "reactive carbon-carbon double bond". In addition, in this specification, "(meth)acryloyl" means acryloyl or methacryloyl.

[0014] The compound having a maleimide group is preferably a monomer or oligomer having a maleimide group, which is a monomer having a maleimide group and a molecular weight of less than 1,000 or an oligomer having a maleimide group and a weight-average molecular weight of less than 1,000.

[0015] The maleimide group-containing monomer or oligomer preferably has a group derived from a diamine compound. As the diamine compound, either an aliphatic diamine compound or an aromatic diamine compound can be used, but an aliphatic diamine compound is preferred. That is, the maleimide group-containing monomer or oligomer more preferably has an aliphatic group derived from a diamine compound. By using an aliphatic diamine compound as the diamine compound (i.e., the maleimide group-containing monomer or oligomer has an aliphatic group derived from a diamine compound), the adhesive layer has better light transmittance, making it easier to adjust the light transmittance at a wavelength of 436 nm of the adhesive layer of the adhesive film of the present invention in an uncured state to a suitable range. Furthermore, the adhesive layer has better flexibility, allowing the adhesive film of the present invention to exhibit high conformability to an adherend having irregularities and to be more easily peeled off.

[0016] In the above-mentioned monomer or oligomer having a maleimide group, the aliphatic diamine compound is preferably a dimer diamine from the viewpoints of the light transmittance and flexibility of the adhesive layer, and the compatibility of the above-mentioned compound having a maleimide group with the solvent and other components. The dimer diamine is a diamine compound obtained by reducing and amminating cyclic and acyclic dimer acids obtained as dimers of unsaturated fatty acids, and examples thereof include linear, monocyclic, and polycyclic dimer diamines. The dimer diamine may contain a carbon-carbon double bond or may be a hydrogenated product to which hydrogen has been added.

[0017] The aliphatic group derived from the dimer diamine is preferably at least one group selected from the group consisting of a group represented by the following formula (1-1), a group represented by the following formula (1-2), a group represented by the following formula (1-3), and a group represented by the following formula (1-4). Among these, the group represented by the following formula (1-2) is more preferred.

[0018] [ka]

[0019] In formulas (1-1) to (1-4), R 1 ~R 16 are each independently a linear or branched hydrocarbon group, and * represents a bond. The bond * is bonded to a nitrogen atom.

[0020] In the above formulas (1-1) to (1-4), R 1 ~R 16 The hydrocarbon group represented by R may be a saturated hydrocarbon group or an unsaturated hydrocarbon group. 1 and R 2 , R 3 and R 4 , R 5 and R 6 , R 7 and R 8 , R 9 and R 10 , R 11 and R 12 , R 13 and R 14 , and R 15 and R 16 The total number of carbon atoms preferably has a lower limit of 7 and an upper limit of 50. When the total number of carbon atoms is within the above range, the adhesive layer has better light transparency and flexibility, and the maleimide group-containing monomer or oligomer has better compatibility with the solvent and other components in the adhesive layer. The total number of carbon atoms is more preferably 9 at the lower limit, 35 at the upper limit, 12 at the even more preferred upper limit, 25 at the even more preferred upper limit, 14 at the even more preferred upper limit, and 18 at the even more preferred upper limit.

[0021] The optical isomerism of the group represented by the above formula (1-1), the group represented by the above formula (1-2), the group represented by the above formula (1-3), and the group represented by the above formula (1-4) is not particularly limited, and includes any optical isomerism.

[0022] From the viewpoint of heat resistance, the above-mentioned monomer or oligomer having a maleimide group preferably contains a bismaleimide compound (that is, the above-mentioned compound having a reactive carbon-carbon double bond preferably contains a bismaleimide compound). Examples of the bismaleimide compound include BMI-689 (manufactured by Designer Molecules).

[0023] As the compound having a reactive carbon-carbon double bond, a resin having a functional group having a reactive carbon-carbon double bond and an imide skeleton in the repeating unit of the main chain can also be used. Examples of the resin having a functional group having a reactive carbon-carbon double bond and an imide skeleton in the repeating unit of the main chain include a resin having a maleimide group and an imide skeleton in the repeating unit of the main chain. Note that the resin having a maleimide group and an imide skeleton in the repeating unit of the main chain has a maleimide group as the functional group having a reactive carbon-carbon double bond. When the adhesive layer does not contain the non-curable resin described below, the compound having the reactive carbon-carbon double bond preferably has a functional group having the carbon-carbon double bond and contains a resin having an imide skeleton in the repeating unit of the main chain, and more preferably contains a resin having the maleimide group and containing an imide skeleton in the repeating unit of the main chain.

[0024] In the resin having the functional group having a reactive carbon-carbon double bond and an imide skeleton in the repeating unit of the main chain, the functional group equivalent weight (weight average molecular weight / number of functional groups having reactive carbon-carbon double bonds) of the functional group having a reactive carbon-carbon double bond is preferably 4000. When the functional group equivalent weight of the functional group having a reactive carbon-carbon double bond is 4000 or less, the adhesive film of the present invention has better heat resistance. This is thought to be because the presence of functional groups having reactive carbon-carbon double bonds at a density above a certain level in the resin molecule shortens the inter-crosslink distance, thereby further suppressing adhesion enhancement during high-temperature processing. A more preferred upper limit of the functional group equivalent weight of the functional group having a reactive carbon-carbon double bond is 3000, and an even more preferred upper limit is 2000. There is no particular preferred lower limit to the functional group equivalent weight of the functional group having the reactive carbon-carbon double bond, but the substantial lower limit is about 600.

[0025] The weight-average molecular weight of the resin having a functional group with a reactive carbon-carbon double bond and an imide skeleton in the repeating unit of its main chain is preferably 1,000 at the lower limit and 100,000 at the upper limit. When the weight-average molecular weight of the resin having a functional group with a reactive carbon-carbon double bond and an imide skeleton in the repeating unit of its main chain is 1,000 or more, the adhesive layer can be easily formed, and the formed adhesive layer exhibits a certain degree of flexibility. Therefore, the adhesive film of the present invention can exhibit higher conformability to an adherend having unevenness and can be more easily peeled off. When the weight-average molecular weight of the resin having a functional group with a reactive carbon-carbon double bond and an imide skeleton in the repeating unit of its main chain is 100,000 or less, the solubility of the resin having a functional group with a reactive carbon-carbon double bond and an imide skeleton in the repeating unit of its main chain in a solvent can be prevented from becoming too low. The weight-average molecular weight of the resin having a functional group with a reactive carbon-carbon double bond and an imide skeleton in the repeating unit of the main chain is more preferably 1,500 in lower limit and 50,000 in upper limit, and even more preferably 2,000 or more but less than 20,000. In this specification, the weight average molecular weight is measured as a polystyrene equivalent molecular weight by gel permeation chromatography (GPC). As a column, for example, HR-MB-M (manufactured by Waters Corporation) can be used.

[0026] In the resin having the functional group having a reactive carbon-carbon double bond and having an imide skeleton in the repeating unit of the main chain, the functional group having a reactive carbon-carbon double bond may be present either in a side chain or at a terminal, but is preferably present at both terminals, and more preferably present in the side chain in addition to both terminals. The functional groups having a reactive carbon-carbon double bond at both ends of the resin having the functional group having a reactive carbon-carbon double bond and having an imide skeleton in the repeating unit of the main chain are highly reactive, and can more fully cure the adhesive layer by irradiation with light, heating, etc. As a result, the adhesive film of the present invention can be more effectively prevented from increasing adhesion during high-temperature processing, and from leaving adhesive residue when peeling the adhesive film after high-temperature processing. Furthermore, the presence of a functional group having a reactive carbon-carbon double bond in the side chain of the resin having the reactive carbon-carbon double bond and an imide skeleton in the repeating unit of its main chain results in superior peelability of the adhesive film of the present invention. This is thought to be due to the fact that the shorter inter-crosslink distance further suppresses adhesion enhancement. Furthermore, the presence of a functional group having a reactive carbon-carbon double bond in the side chain of the resin having the reactive carbon-carbon double bond and an imide skeleton in the repeating unit of its main chain makes it easy to adjust the functional group equivalent of the resin having the functional group having a reactive carbon-carbon double bond and an imide skeleton in the repeating unit of its main chain to 4000 or less, while maintaining the weight-average molecular weight of the resin having the functional group having a reactive carbon-carbon double bond and an imide skeleton in the repeating unit of its main chain to 1000 or more. This allows the adhesive layer to have sufficient initial adhesive strength, while simultaneously preventing the adhesive film of the present invention from undergoing adhesion enhancement during high-temperature processing and from leaving adhesive residue when peeling the adhesive film after high-temperature processing.

[0027] As described above, in a resin having the reactive carbon-carbon double bond and an imide skeleton in the repeating unit of its main chain, the functional group having the reactive carbon-carbon double bond may be located in either a side chain or at a terminal, and the resin may further have a functional group without a carbon-carbon double bond. When a resin having the functional group having a reactive carbon-carbon double bond and an imide skeleton in the repeating unit of its main chain further has a functional group without a carbon-carbon double bond, examples of the functional group without a reactive carbon-carbon double bond include an aliphatic group, an alicyclic group, an aromatic group, an acid anhydride group, and an amino group. Specific examples include an unreacted terminal group of an acid anhydride or a diamine compound that is a raw material for a resin having the functional group having a reactive carbon-carbon double bond and an imide skeleton in the repeating unit of its main chain. When a resin having the functional group having the reactive carbon-carbon double bond and having an imide skeleton in a repeating unit of its main chain has two or more functional groups not having a carbon-carbon double bond in a side chain or at a terminal, the respective functional groups not having a carbon-carbon double bond may be the same or different.

[0028] Specific examples of the resin having a functional group having a reactive carbon-carbon double bond and an imide skeleton in the repeating unit of the main chain include a resin having a constitutional unit represented by the following formula (2) and having a functional group having a reactive carbon-carbon double bond at least in either the terminal or the side chain:

[0029] [ka]

[0030] In formula (2), P 1 represents an aromatic group, and Q 1 represents a linear, branched, or cyclic substituted or unsubstituted aliphatic group.

[0031] In the above formula (2), P 1 is preferably an aromatic group having 5 to 50 carbon atoms. 1is an aromatic group having from 5 to 50 carbon atoms, the adhesive film of the present invention has better heat resistance. That is, the adhesive film of the present invention can further suppress outgassing, voids between the film and the adherend, and lifting during high-temperature processing, and can further prevent increased adhesion to the adherend during high-temperature processing and adhesive residue on the adherend when peeled off after high-temperature processing.

[0032] In the above formula (2), Q 1 is preferably a linear, branched, or cyclic substituted or unsubstituted aliphatic group having from 2 to 100 carbon atoms. 1 is a linear, branched, or cyclic, substituted or unsubstituted aliphatic group having from 2 to 100 carbon atoms, the adhesive layer has superior light transmittance, making it easier to adjust the light transmittance at a wavelength of 436 nm of the adhesive layer of the adhesive film of the present invention in an uncured state to a suitable range. In addition, the adhesive layer has superior flexibility, allowing the adhesive film of the present invention to exhibit high conformability to an adherend having irregularities and to be more easily peeled off. Also, the above Q 1 In particular, from the viewpoints of the optical transparency and flexibility of the adhesive layer, and the compatibility with the solvent and other components of the resin having the reactive carbon-carbon double bond and the imide skeleton in the repeating unit of the main chain, it is preferable that Q 1 is preferably an aliphatic group derived from dimer diamine. The aliphatic group derived from the dimer diamine is preferably at least one group selected from the group consisting of the group represented by the above formula (1-1), the group represented by the above formula (1-2), the group represented by the above formula (1-3), and the group represented by the above formula (1-4). Among these, the group represented by the above formula (1-2) is more preferred.

[0033] The resin having a structural unit represented by the above formula (2) and a functional group having a reactive carbon-carbon double bond at least at the end or in the side chain may further have a structural unit represented by the following formula (3):

[0034] [ka]

[0035] In formula (3), P 2 represents an aromatic group, and Q 2 represents a group having a substituted or unsubstituted aromatic structure.

[0036] P in the above formula (3) 2 is preferably an aromatic group having 5 to 50 carbon atoms. 2 is an aromatic group having from 5 to 50 carbon atoms, the adhesive film of the present invention has better heat resistance. That is, the adhesive film of the present invention can further suppress outgassing during high-temperature processing, voids between the film and the adherend, and lifting, and can further prevent increased adhesion to the adherend and adhesive residue when peeled from the adherend.

[0037] In the above formula (3), Q 2 is preferably a substituted or unsubstituted group having an aromatic structure having 5 to 50 carbon atoms. 2 is a substituted or unsubstituted group having an aromatic structure having from 5 to 50 carbon atoms, the adhesive film of the present invention has better heat resistance. That is, the adhesive film of the present invention can further suppress outgassing, voids between the film and the adherend, and lifting during high-temperature processing, and can further prevent increased adhesion to the adherend during high-temperature processing and adhesive residue on the adherend when peeled off after high-temperature processing.

[0038] In the above formula (3), Q 2is an aromatic group having an aromatic ester group or an aromatic ether group, 2 The aromatic ester group or aromatic ether group in the formula (I) is preferably bonded to the functional group having a reactive carbon-carbon double bond. Here, "aromatic ester group" means a group in which an ester group is directly bonded to an aromatic ring, and "aromatic ether group" means a group in which an ether group is directly bonded to an aromatic ring. By converting the moiety bonded to the ester group or ether group into an aromatic group, the adhesive film of the present invention has superior heat resistance. That is, the adhesive film of the present invention can further suppress outgassing, voids between the film and the adherend, and lifting during high-temperature processing. It can also further prevent increased adhesion to the adherend during high-temperature processing and adhesive residue on the adherend when peeled off after high-temperature processing. Meanwhile, since the functional group having a reactive carbon-carbon double bond is bonded via an aromatic ester group or aromatic ether group, the carbon-carbon double bond in the functional group having a reactive carbon-carbon double bond does not interfere with polymerization and crosslinking upon heating or light irradiation.

[0039] The content of the structural unit represented by formula (2) in a resin having a functional group with a reactive carbon-carbon double bond at at least one of an end and a side chain is preferably 30 mol% at the lower limit, 90 mol% at the upper limit, 50 mol% at the more preferred lower limit, and 80 mol% at the more preferred upper limit. When a resin having a structural unit represented by the above formula (2) and a functional group having a reactive carbon-carbon double bond at least at either the terminal or the side chain contains a structural unit represented by the above formula (3), the content of the structural unit represented by the above formula (3) is preferably 5 mol% at the lower limit, 50 mol% at the upper limit, 10 mol% at the more preferred lower limit, 30 mol% at the more preferred upper limit, and 20 mol% at the most preferred upper limit. By ensuring that the content ratio of each of the constituent units represented by the above formula (2) and the above formula (3) is within the above range, the adhesive film of the present invention can further suppress outgassing, voids between the film and the adherend, and lifting during high-temperature processing, and can be more easily peeled from the adherend when peeled off after high-temperature processing. The structural unit represented by the above formula (2) and the structural unit represented by the above formula (3) may have a block structure consisting of block components in which the respective structural units are arranged consecutively, or may have a random structure in which the respective structural units are arranged randomly.

[0040] Examples of methods for producing a resin having a functional group with a reactive carbon-carbon double bond and an imide skeleton in the repeating unit of the main chain include the following methods. That is, first, a diamine compound is reacted with an aromatic acid anhydride to prepare an imide compound, and then a compound having a functional group reactive with the functional group of the imide compound and a functional group having a carbon-carbon double bond (hereinafter also referred to as a "functional group-containing unsaturated compound") is reacted with the functional group of the imide compound to obtain a resin having the functional group having the reactive carbon-carbon double bond and an imide skeleton in the repeating unit of the main chain. Alternatively, a resin having a functional group with a reactive carbon-carbon double bond and an imide skeleton in the repeating unit of the main chain can be obtained by reacting a diamine compound with an aromatic acid anhydride to prepare an imide compound, and then reacting the end of the imide compound with, for example, maleic anhydride.

[0041] In the production of the resin having a functional group with a reactive carbon-carbon double bond and an imide skeleton in the repeating unit of the main chain, either an aliphatic diamine compound or an aromatic diamine compound can be used as the diamine compound. By using an aliphatic diamine compound as the diamine compound in the production of the resin having a functional group with a reactive carbon-carbon double bond and an imide skeleton in the repeating unit of the main chain, the adhesive film of the present invention has better light transmittance, making it easier to adjust the light transmittance of the adhesive layer of the adhesive film of the present invention in an uncured state at a wavelength of 436 nm to a suitable range. In addition, the adhesive film of the present invention has better flexibility, can exhibit better conformability to an adherend having irregularities, and can be more easily peeled off. Furthermore, by using an aromatic diamine compound as the diamine compound, the adhesive film of the present invention becomes more excellent in heat resistance. The diamine compounds may be used alone or in combination of two or more.

[0042] Examples of the aliphatic diamine compound used in the production of the resin having a functional group with a reactive carbon-carbon double bond and an imide skeleton in the repeating unit of the main chain include 1,10-diaminodecane, 1,12-diaminododecane, dimer diamine, 1,2-diamino-2-methylpropane, 1,2-diaminocyclohexane, 1,2-diaminopropane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,7-diamino-2-methylpropane, 1,8-diamino-2-methylpropane, 1,9-diamino-2-methylpropane, 1,10-diamino-2-methylpropane, 1,12 ... Examples of suitable bis(aminomethyl)cyclohexane include 1,8-diaminoheptane, 1,8-diaminomenthane, 1,8-diaminooctane, 1,9-diaminononane, 3,3'-diamino-N-methyldipropylamine, diaminomaleonitrile, 1,3-diaminopentane, bis(4-amino-3-methylcyclohexyl)methane, 1,2-bis(2-aminoethoxy)ethane, 1,3-bisaminomethylcyclohexane, and 3(4),8(9)-bis(aminomethyl)tricyclo(5.2.1.02,6)decane.

[0043] In the production of the resin having a functional group with a reactive carbon-carbon double bond and an imide skeleton in the repeating unit of its main chain, the aliphatic diamine compound is preferably a dimer diamine from the viewpoints of the optical transparency and flexibility of the adhesive layer and the compatibility of the resin having a functional group with a reactive carbon-carbon double bond and an imide skeleton in the repeating unit of its main chain with solvents and other components. Specific examples of the dimer diamine include dimer diamines capable of constituting at least one group selected from the group consisting of the group represented by the above formula (1-1), the group represented by the above formula (1-2), the group represented by the above formula (1-3), and the group represented by the above formula (1-4).

[0044] Examples of the aromatic diamine compound used in the production of a resin having a functional group with a reactive carbon-carbon double bond and an imide skeleton in the repeating unit of the main chain include 9,10-diaminophenanthrene, 4,4'-diaminooctafluorobiphenyl, 3,7-diamino-2-methoxyfluorene, 4,4'-diaminobenzophenone, 3,4-diaminobenzophenone, 3,4-diaminotoluene, 2,6-diaminoanthraquinone, 2,6-diaminotoluene, 2,3-diaminotoluene, and 1,8-diaminonaphthalene. , 2,4-diaminotoluene, 2,5-diaminotoluene, 1,4-diaminoanthraquinone, 1,5-diaminoanthraquinone, 1,5-diaminonaphthalene, 1,2-diaminoanthraquinone, 2,4-cumenediamine, 1,3-bisaminomethylbenzene, 2-chloro-1,4-diaminobenzene, 1,4-diamino-2,5-dichlorobenzene, 1,4-diamino-2,5-dimethylbenzene, 4,4'-diamino-2,2'-bistrifluoromethylbiphenyl, bis(amino-3-chlorophenyl)ethane, bis(4- Bis(4-amino-3,5-dimethylphenyl)methane, bis(4-amino-3,5-diethylphenyl)methane, 9,9'-bis(4-amino-3-ethylphenyl)fluorene, 2,3-diaminonaphthalene, 2,3-diaminophenol, bis(4-amino-5-methylphenyl)methane, bis(4-amino-3-methylphenyl)methane, bis(4-amino-3-ethylphenyl)methane, 4,4'-diaminophenyl sulfone, 3,3'-diaminophenyl sulfone, bis(4-(4-aminophenoxy)phenyl)sulfone, bis (4-(3-aminophenoxy)phenyl)sulfone, 4,4'-oxydianiline, 4,4'-diaminodiphenyl sulfide, 3,4'-oxydianiline, 2,2-bis(4-(4-aminophenoxy)phenyl)propane, 1,3-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-diamino-3,3'-dihydroxybiphenyl, 4,4'-diamino-3,3'-dimethylbiphenyl, 4,4'-diamino-3,3'-dimethoxybiphenyl, Bisaniline M, Bisaniline P, 9,9-bis(4-aminophenyl)fluorene, o-tolidine sulfone, 5,5'-methylenebis(anthranilic acid), 1,3-bis(4-aminophenoxy)-2,2-dimethylpropane, 1,3-bis(4-aminophenoxy)propane, 1,4-bis(4-aminophenoxy)butane, 1,5-bis(4-aminophenoxy)butane, 2,3,5,6-tetramethyl-1,4-phenylenediamine, 3,3',5,5'-tetramethylbenzidine, 4,4'-diaminobenzanilide, 2,2-bis(4-aminophenyl)hexafluoropropane, polyoxyalkylenediamines (e.g., Jeffamine manufactured by Huntsman), Examples include cyclohexanebis(methylamine), m-xylylenediamine, and p-xylylenediamine.

[0045] Examples of the aromatic acid anhydride used in the production of the resin having a functional group with a reactive carbon-carbon double bond and an imide skeleton in the repeating unit of the main chain include pyromellitic acid, 1,2,5,6-naphthalenetetracarboxylic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 1,2,4,5-naphthalenetetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, 3,3',4,4'-benzophenonetetracarboxylic acid, and 3,3',4,4'-biphenylethertetracarboxylic acid. tetracarboxylic acid, 3,3',4,4'-biphenyltetracarboxylic acid, 2,3,5,6-pyridinetetracarboxylic acid, 3,4,9,10-perylenetetracarboxylic acid, 4,4'-sulfonyldiphthalic acid, 1-trifluoromethyl-2,3,5,6-benzenetetracarboxylic acid, 2,2',3,3'-biphenyltetracarboxylic acid, 2,2-bis(3,4-dicarboxyphenyl)propane, 2,2-bis(2,3-dicarboxyphenyl)propane, 1,1-bis(2,3-dicarboxyphenyl)propane phenyl)ethane, 1,1-bis(3,4-dicarboxyphenyl)ethane, bis(2,3-dicarboxyphenyl)methane, bis(3,4-dicarboxyphenyl)methane, bis(3,4-dicarboxyphenyl)sulfone, bis(3,4-dicarboxyphenyl)ether, benzene-1,2,3,4-tetracarboxylic acid, 2,3,2',3'-benzophenonetetracarboxylic acid, 2,3,3',4'-benzophenonetetracarboxylic acid, phenanthrene-1,8,9,10-tetracarboxylic acid Examples of the anhydrides of carboxylic acids include carboxylic acid, pyrazine-2,3,5,6-tetracarboxylic acid, thiophene-2,3,4,5-tetracarboxylic acid, 2,3,3',4'-biphenyltetracarboxylic acid, 3,4'-oxydiphthalic acid, 4,4'-oxydiphthalic acid, 2,3',3,4'-tetracarboxydiphenyloxide, 4,4'-bis(3,4-dicarboxyphenoxy)diphenyl sulfide, and 4,4'-(4,4'-isopropylidenediphenoxy)-bis(phthalic acid).

[0046] The functional group-containing unsaturated compound is selected depending on the functional group at the end or side chain of the imide compound.

[0047] For example, when the functional group at the end or side chain of the imide compound is a hydroxyl group, examples of the functional group-containing unsaturated compound include maleimide compounds having a carboxyl group, vinyl compounds having an ether group, allyl compounds having a glycidyl group, allyl ether compounds having a glycidyl group, vinyl ether compounds having a glycidyl group, allyl compounds having an isocyanate group, and (meth)acryloyl compounds having an isocyanate group. Examples of the maleimide compound having a carboxy group include maleimide acetate, maleimidopropionic acid, maleimidobutyric acid, maleimidohexanoic acid, trans-4-(N-maleimidomethyl)cyclohexane-1-carboxylic acid, and 19-maleimido-17-oxo-4,7,10,13-tetraoxa-16-azanonadecanoic acid. Examples of the vinyl compound having an ether group include butyl vinyl ether. The allyl compound having a glycidyl group includes, for example, diallyl monoglycidyl isocyanurate. Examples of the allyl ether compound having a glycidyl group include allyl glycidyl ether and glycerin diallyl monoglycidyl ether. Examples of the vinyl ether compound having a glycidyl group include glycidyloxyethyl vinyl ether, glycidyloxybutyl vinyl ether, glycidyloxyhexyl vinyl ether, glycidyl diethylene glycol vinyl ether, and glycidyl cyclohexanedimethanol monovinyl ether. The allyl compound having an isocyanate group includes, for example, allyl isocyanate. Examples of the (meth)acryloyl compound having an isocyanate group include 2-(meth)acryloyloxyethyl isocyanate.

[0048] Furthermore, for example, when the functional group at the end or side chain of the imide compound is a carboxy group, examples of the functional group-containing unsaturated compound include an allyl compound having a hydroxyl group, an allyl compound having a glycidyl group, an allyl ether compound having a glycidyl group, and a vinyl ether compound having a glycidyl group. Examples of the allyl compound having a hydroxyl group include trimethylolpropane diallyl ether and pentaerythritol triallyl ether.

[0049] The content of the maleimide group-containing compound per 100 parts by mass of the curable resin is preferably 10 parts by mass or more at a lower limit and 90 parts by mass or more at a higher limit. When the content of the maleimide group-containing compound is 10 parts by mass or more, the adhesive film of the present invention can further suppress adhesion enhancement during high-temperature processing. When the content of the maleimide group-containing compound is 90 parts by mass or less, the adhesive film of the present invention can further improve releasability from an adherend having irregularities after high-temperature processing. The content of the maleimide group-containing compound is more preferably 20 parts by mass or more at a lower limit and 80 parts by mass or more at a higher limit, and even more preferably 30 parts by mass or more at a higher limit and 70 parts by mass or more at a higher limit.

[0050] Examples of the compound having a (meth)acryloyl group include monomers having a (meth)acryloyl group, etc. Among these, from the viewpoint of releasability, monomers having a (meth)acryloyl group are preferred.

[0051] The monomer having a (meth)acryloyl group preferably does not have an imide bond. When the monomer having a (meth)acryloyl group does not have an imide bond, the adhesive film of the present invention can be easily peeled from an adherend having unevenness during peeling.

[0052] The monomer having a (meth)acryloyl group preferably has two or more (meth)acryloyl groups in one molecule. When the monomer having a (meth)acryloyl group has two or more (meth)acryloyl groups in one molecule, a uniform and sufficient crosslinked body is formed throughout the adhesive layer, and the elastic modulus increases, resulting in a significant decrease in adhesive strength. Therefore, the adhesive film of the present invention can prevent increased adhesion during high-temperature processing and the occurrence of adhesive residue when peeled off after high-temperature processing.

[0053] Examples of monomers having two or more (meth)acryloyl groups in one molecule include ABE-300 (total number of (meth)acryloyl groups: 2), A-BPE-4 (total number of (meth)acryloyl groups: 2), A-BPE-10 (total number of (meth)acryloyl groups: 2), A-BPE-30 (total number of (meth)acryloyl groups: 2), A-DCP (total number of (meth)acryloyl groups: 2), and A-9300S (total number of (meth)acryloyl groups: 2 or 3) (all manufactured by Shin-Nakamura Chemical Co., Ltd.).

[0054] The content of the compound having a (meth)acryloyl group in 100 parts by mass of the curable resin is preferably 2 parts by mass or more at the lower limit and 70 parts by mass or more at the upper limit. When the content of the compound having a (meth)acryloyl group is 2 parts by mass or more, the adhesive film of the present invention can further suppress adhesion enhancement during high-temperature processing. When the content of the compound having a (meth)acryloyl group is 70 parts by mass or less, the adhesive film of the present invention can further improve releasability from an adherend having irregularities after high-temperature processing. The content of the compound having a (meth)acryloyl group is more preferably 3 parts by mass or more at the lower limit and 60 parts by mass or more at the upper limit, and even more preferably 5 parts by mass or more at the upper limit.

[0055] When the adhesive layer contains the curable resin and the non-curable resin described later, the preferred lower limit of the content of the curable resin is 10 parts by mass, and the preferred upper limit is 90 parts by mass, based on 100 parts by mass of the total of the curable resin and the non-curable resin described later. When the content of the curable resin is within this range, the adhesive film of the present invention can be more easily peeled off. From the viewpoint of further improving the peelability of the adhesive film of the present invention, the more preferred lower limit of the content of the curable resin is 20 parts by mass, more preferably 80 parts by mass, even more preferably 30 parts by mass, even more preferably 70 parts by mass, even more preferably 40 parts by mass, and even more preferably 60 parts by mass.

[0056] The adhesive layer preferably further contains a non-curable resin, which allows the adhesive layer to exhibit a certain degree of flexibility even after curing, thereby enabling the adhesive film of the present invention to exhibit higher conformability to an adherend having irregularities and to be more easily peeled off. It should be noted that silicone compounds or fluorine compounds used as surface conditioners, which will be described later, are not considered to be the non-curable resins.

[0057] The non-curable resin preferably contains a resin that does not have a reactive carbon-carbon double bond and has an imide skeleton in the repeating unit of its main chain. The resin that does not have a reactive carbon-carbon double bond and has an imide skeleton in the repeating unit of its main chain has excellent heat resistance due to the imide skeleton, and the main chain is less likely to decompose even when subjected to high-temperature processing at 300°C or higher. Therefore, by including a resin that does not have a reactive carbon-carbon double bond and has an imide skeleton in the repeating unit of its main chain as the non-curable resin, the adhesive film of the present invention can suppress the occurrence of voids and lifting between the film and the support during high-temperature processing, and can prevent increased adhesion to the adherend during high-temperature processing and the occurrence of adhesive residue on the adherend when peeled off after high-temperature processing.

[0058] The weight-average molecular weight of the resin having no reactive carbon-carbon double bond and an imide skeleton in the repeating unit of its main chain is preferably 20,000 (lower limit) and 2,000,000 (upper limit). When the weight-average molecular weight of the resin having no reactive carbon-carbon double bond and an imide skeleton in the repeating unit of its main chain is 20,000 or more, the adhesive film of the present invention has better heat resistance. That is, the adhesive film of the present invention can further suppress outgassing, voids between the film and the adherend, and lifting during high-temperature processing. It can also further prevent increased adhesion to the adherend during high-temperature processing and adhesive residue on the adherend when peeled off after high-temperature processing. When the weight-average molecular weight of the resin having no reactive carbon-carbon double bond and an imide skeleton in the repeating unit of its main chain is 2,000,000 or less, the resin having no carbon-carbon double bond and an imide skeleton in the repeating unit of its main chain has better compatibility with solvents and other components. The weight-average molecular weight of the resin that does not have a polymerizable functional group having a reactive carbon-carbon double bond and has an imide skeleton in the repeating unit of the main chain is more preferably 40,000 in lower limit and 600,000 in upper limit, still more preferably 50,000 in lower limit and still more preferably 300,000 in upper limit.

[0059] Specific examples of resins that do not have the above-mentioned reactive carbon-carbon double bond and have an imide skeleton in the repeating unit of the main chain include resins that have a structural unit represented by the above formula (2) and have a functional group that does not have a reactive carbon-carbon double bond in a side chain or at an end, and resins that have a structural unit represented by the above formula (2) and have functional groups that do not have a reactive carbon-carbon double bond at both ends.From the viewpoint of further improving the heat resistance and flexibility of the adhesive film of the present invention, resins that have a structural unit represented by the above formula (2) and have functional groups that do not have a reactive carbon-carbon double bond at both ends are preferred.

[0060] The resin having no reactive carbon-carbon double bond and having an imide skeleton in the repeating unit of its main chain preferably has a silicone skeleton in the repeating unit of its main chain. By having the silicone skeleton in the repeating unit of its main chain, the resin having no reactive carbon-carbon double bond and having an imide skeleton in the repeating unit of its main chain has more excellent flexibility, and the adhesive film of the present invention can exhibit high conformability to an adherend having irregularities and can be more easily peeled off. Among the resins that do not have the above-mentioned reactive carbon-carbon double bond and have an imide skeleton in the repeating unit of the main chain, examples of those that have the above-mentioned silicone skeleton in the repeating unit of the main chain include resins having a constituent unit represented by the following formula (4):

[0061] [ka]

[0062] In formula (4), P 4 represents an aromatic group, and Q 3 represents a silicone chain.

[0063] In the above formula (4), P 4 is preferably an aromatic group having 5 to 50 carbon atoms. 4 is an aromatic group having 5 to 50 carbon atoms, the adhesive film of the present invention can exhibit particularly high heat resistance. 4 is preferably a structure derived from the above-mentioned aromatic acid anhydride.

[0064] In the above formula (4), Q 3 The silicone chain represented by the formula Q is not particularly limited, and examples thereof include silicone chains having a siloxane unit (a repeating unit having a siloxane skeleton). 3 is preferably a structure derived from a silicone compound having amino groups at both ends, as described below.

[0065] The number of repetitions of the siloxane unit (repeating unit having a siloxane skeleton) in the silicone chain is not particularly limited, but a preferred lower limit is 10 and a preferred upper limit is 100. When the number of repetitions of the siloxane unit is 10 or more, the adhesive film of the present invention can exhibit better releasability and also have improved heat resistance. When the number of repetitions of the siloxane unit is 100 or less, the compatibility of the resin having no reactive carbon-carbon double bond and an imide skeleton in the main chain repeating unit with solvents and other components is further improved. A more preferred lower limit of the number of repetitions of the siloxane unit is 20, a more preferred upper limit is 80, an even more preferred lower limit is 30, and an even more preferred upper limit is 60.

[0066] The resin having a structural unit represented by the above formula (2) and a functional group having no reactive carbon-carbon double bond at both ends may have a structural unit represented by the following formula (5).

[0067] [ka]

[0068] In formula (5), P 5 represents an aromatic group, and Q 4 represents a group having a substituted or unsubstituted aromatic structure.

[0069] In the above formula (5), P 5 is preferably an aromatic group having 5 to 50 carbon atoms. 5 is an aromatic group having from 5 to 50 carbon atoms, the adhesive film of the present invention has better heat resistance. That is, the adhesive film of the present invention can further suppress the occurrence of outgassing, voids, and lifting between the adhesive film and the support during high-temperature processing, and can further prevent the occurrence of increased adhesion to the adherend during high-temperature processing and the occurrence of adhesive residue on the adherend when peeled off after high-temperature processing.

[0070] In the above formula (5), Q 4is preferably a substituted or unsubstituted group having an aromatic structure having 5 to 50 carbon atoms. 4 is a substituted or unsubstituted group having an aromatic structure having from 5 to 50 carbon atoms, the adhesive film of the present invention has better heat resistance. That is, the adhesive film of the present invention can further suppress outgassing and the formation of voids between the film and the adherend during high-temperature processing, and can further prevent increased adhesion to the adherend during high-temperature processing and the generation of adhesive residue from the adherend when peeled off after high-temperature processing.

[0071] In the resin having no reactive carbon-carbon double bond and having an imide skeleton in the repeating unit of the main chain, examples of the functional group having no reactive carbon-carbon double bond include an aliphatic group, an alicyclic group, an aromatic group, an acid anhydride group, an amino group, etc. Specific examples include an unreacted one-terminal constituent group of an acid anhydride or a diamine compound that is a raw material for the resin having no reactive carbon-carbon double bond and having an imide skeleton in the repeating unit of the main chain. The functional groups having no reactive carbon-carbon double bond at both ends of the resin having no reactive carbon-carbon double bond and having an imide skeleton in the repeating unit of the main chain may be the same or different.

[0072] The content of the structural unit represented by formula (2) in a resin having a structural unit represented by formula (2) above and having no reactive carbon-carbon double bonds at both ends is preferably 30 mol% at the lower limit, 90 mol% at the upper limit, 50 mol% at the more preferred lower limit, and 80 mol% at the more preferred upper limit. When a resin having a structural unit represented by the above formula (2) and having no reactive carbon-carbon double bonds at both ends also has a structural unit represented by the above formula (4), the content of the structural unit represented by the above formula (4) is preferably 30 mol% at the lower limit, 90 mol% at the upper limit, 50 mol% at the more preferred lower limit, and 70 mol% at the more preferred upper limit. When a resin having a structural unit represented by the above formula (2) and having no reactive carbon-carbon double bonds at both ends has a structural unit represented by the above formula (5), the content of the structural unit represented by the above formula (5) is preferably 5 mol% at the lower limit, 50 mol% at the upper limit, 10 mol% at the more preferred lower limit, 30 mol% at the more preferred upper limit, and 20 mol% at the even more preferred lower limit. By ensuring that the content ratio of each of the structural units represented by the above formula (2), the structural unit represented by the above formula (4), and the structural unit represented by the above formula (5) is within the above range, the adhesive film of the present invention can further suppress the occurrence of outgassing, voids, and lifting between the film and the support during high-temperature processing, and can be more easily peeled from the adherend when peeled after high-temperature processing. The structural unit represented by the formula (2), the structural unit represented by the formula (4), and the structural unit represented by the formula (5) may have a block structure consisting of block components in which the respective structural units are arranged consecutively, or may have a random structure in which the respective structural units are arranged randomly.

[0073] Examples of a method for producing a resin that does not have a polymerizable functional group having a reactive carbon-carbon double bond and has an imide skeleton in the repeating unit of the main chain include a method of reacting a diamine compound with an aromatic acid anhydride.

[0074] The diamine compound and aromatic acid anhydride used in the method for producing a resin that does not have a polymerizable functional group having a reactive carbon-carbon double bond and has an imide skeleton in the repeating unit of its main chain can be the same as those used in the method for producing a resin that has a reactive carbon-carbon double bond and has an imide skeleton in the repeating unit of its main chain, but does not have a reactive carbon-carbon double bond.

[0075] Furthermore, when the resin that does not have a polymerizable functional group having a reactive carbon-carbon double bond and has an imide skeleton in the repeating unit of its main chain has a silicone skeleton, it can be produced by reacting the above-mentioned silicone compound having amino groups at both ends with the above-mentioned aromatic acid anhydride and, if necessary, the above-mentioned diamine compound to obtain an imide compound.

[0076] Examples of the silicone compound having amino groups at both ends include silicone compounds having amino groups at both ends and having a siloxane unit (a repeating unit having a siloxane skeleton) with a repeat number within the above range. Commercially available silicone compounds include KF-8010, X-22-161A, X-22-161B, KF-8012, and PAM-E (all manufactured by Shin-Etsu Chemical Co., Ltd.).

[0077] The preferred lower limit of the content of the resin that does not have a polymerizable functional group having a reactive carbon-carbon double bond and has an imide skeleton in the repeating unit of its main chain per 100 parts by mass of the curable resin is 10 parts by mass, and the preferred upper limit is 90 parts by mass. When the content of the resin that does not have a polymerizable functional group having a reactive carbon-carbon double bond and has an imide skeleton in the repeating unit of its main chain is within this range, the adhesive film of the present invention can be more easily peeled from an adherend. From the viewpoint of further improving the peelability of the adhesive film of the present invention, the more preferred lower limit of the content of the resin that does not have a polymerizable functional group having a reactive carbon-carbon double bond and has an imide skeleton in the repeating unit of its main chain is 20 parts by mass, and the more preferred upper limit is 80 parts by mass.

[0078] The adhesive layer preferably contains a polymerization initiator, which makes the adhesive layer more likely to harden, and therefore the adhesive film of the present invention can more effectively prevent the adhesive layer from adhering to the adherend during high-temperature processing, and can be more easily peeled from the adherend after high-temperature processing.

[0079] The polymerization initiator may be a photopolymerization initiator or a thermal polymerization initiator, but from the viewpoint of storage stability, a photopolymerization initiator is preferred.

[0080] Examples of the photopolymerization initiator include those that are activated by irradiation with light having a wavelength of 250 to 800 nm. In particular, the photopolymerization initiator has a molar absorption coefficient of 100 ml / (g·cm) for light having a wavelength of 436 nm, which is less likely to overlap with the absorption wavelengths of the curable resin and the non-curable resin, and is sufficiently activated when the adhesive layer is irradiated with light having a long wavelength such as visible light. A more preferable lower limit of the molar absorption coefficient of the photopolymerization initiator for light having a wavelength of 436 nm is 250 ml / (g·cm), and an even more preferable lower limit is 400 ml / (g·cm). There is no particular upper limit to the molar absorption coefficient for light with a wavelength of 436 nm, but it is 1.0 × 10 5 The practical upper limit is about ml / (g·cm).

[0081] Examples of the photopolymerization initiator include acetophenone-based compounds, benzoin ether-based compounds, ketal-based compounds, phosphine oxide-based compounds, oxime ester-based compounds, etc. Among these, it is preferable that the photopolymerization initiator contains an oxime ester-based compound, since it is sufficiently activated even by light with a long wavelength such as visible light. Examples of the acetophenone compounds include methoxyacetophenone, 2-benzyl-2-(dimethylamino)-4'-morpholinobutyrophenone, 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one, and the like. Examples of the benzoin ether compounds include benzoin propyl ether and benzoin isobutyl ether. Examples of the ketal compounds include benzyl dimethyl ketal and acetophenone diethyl ketal. Examples of the phosphine oxide compound include bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (molar absorption coefficient for light with a wavelength of 436 nm: 107 ml / (g·cm)), 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, and the like. Examples of the oxime ester compounds include 1-(O-acetyloxime)-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone, 1-[4-(phenylthio)phenyl]-2-(O-benzoyloxime)-1,2-octadione, Irgacure OXE03 (manufactured by BASF), Irgacure OXE04 (manufactured by BASF), and Nikkacure TKG-01 (manufactured by Nippon Chemical Industry Co., Ltd.). Further, examples of the photopolymerization initiator include bis(η5-cyclopentadienyl)titanocene derivative compounds, benzophenone, Michler's ketone, chlorothioxanthone, dodecylthioxanthone, dimethylthioxanthone, diethylthioxanthone, α-hydroxycyclohexylphenyl ketone, and 2-hydroxymethylphenylpropane. These photopolymerization initiators may be used alone or in combination of two or more.

[0082] The photopolymerization initiator preferably contains a compound having a carbazole group. By containing a compound having a carbazole group, the photopolymerization initiator can be sufficiently activated even by long-wavelength light such as visible light. In addition, the heat resistance of the photopolymerization initiator is further improved, and the adhesive film of the present invention can further suppress outgassing, voids between the film and the adherend, and lifting during high-temperature processing.

[0083] The photopolymerization initiator more preferably contains an oxime ester compound having a carbazole group (i.e., a compound having a carbazole group and an oxime ester group). By containing the oxime ester compound having a carbazole group, the photopolymerization initiator can have a wide π-conjugated system in each structure, shifting the wavelength of light absorbed by the photopolymerization initiator to the longer wavelength side, and providing excellent photoactivity even in the longer wavelength region.

[0084] Examples of the compound having a carbazole group include 1-(O-acetyloxime)-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone, Nikkacure IW-15 (manufactured by Nippon Chemical Industry Co., Ltd., molar absorption coefficient at 436 nm light: 2000 ml / (g cm)), Nikkacure TG-05 (manufactured by Nippon Chemical Industry Co., Ltd.), Nikkacure TG-10 (manufactured by Nippon Chemical Industry Co., Ltd.), and Nikkacure YJ-04(T) (manufactured by Nippon Chemical Industry Co., Ltd., molar absorption coefficient at 436 nm light: 3000 ml / (g cm)).

[0085] Examples of the thermal polymerization initiator include organic peroxide-based thermal polymerization initiators. Among the organic peroxide-based thermal polymerization initiators, commercially available ones include, for example, Perbutyl O, Perbutyl H, and Percumyl H (all manufactured by NOF Corporation).

[0086] The content of the polymerization initiator is preferably 0.1 parts by mass or less and 10 parts by mass or less, relative to 100 parts by mass of the total of the curable resin and the non-curable resin. When the content of the polymerization initiator is within this range, the entire adhesive layer undergoes uniform and rapid polymerization and crosslinking, increasing the elastic modulus and significantly reducing the adhesive strength. Therefore, the adhesive film of the present invention can prevent increased adhesion during high-temperature processing and the occurrence of adhesive residue when peeled off after high-temperature processing. The lower limit of the content of the polymerization initiator is more preferably 0.3 parts by mass, and the upper limit is more preferably 5.0 parts by mass. In this specification, the content per 100 parts by mass of the total of the curable resin and the non-curable resin means the content per 100 parts by mass of the curable resin when the adhesive layer does not contain the non-curable resin.

[0087] The adhesive layer preferably further contains a surface conditioner, which bleeds out to the adherend interface when the adhesive film of the present invention is peeled off, making peeling easier. Examples of the surface conditioner include silicone compounds, fluorine compounds, etc. The silicone compounds or fluorine compounds used as the surface conditioner can prevent the adhesive layer from burning even after high-temperature processing, and furthermore, when the adhesive film of the present invention is peeled off, they bleed out to the interface with the adherend, making peeling easier. Among these, silicone compounds are preferred from the viewpoint of being environmentally friendly and easy to dispose of.

[0088] The surface conditioner may have a functional group crosslinkable with the curable resin and the non-curable resin. When the surface conditioner has a functional group crosslinkable with the curable resin and the non-curable resin, the surface conditioner chemically reacts with the curable resin and the non-curable resin upon irradiation with light or reaction with a crosslinking agent, etc., and is incorporated into the curable resin and the non-curable resin. This prevents silicone compounds or fluorine compounds from adhering to and contaminating the adherend. Examples of functional groups crosslinkable with the curable resin and the non-curable resin include carboxy groups, functional groups having radically polymerizable unsaturated bonds (e.g., vinyl groups, (meth)acryloyl groups, and optionally substituted maleimide groups), hydroxyl groups, amide groups, isocyanate groups, and epoxy groups. In this specification, the silicone compound having a functional group containing a carbon-carbon double bond as a functional group crosslinkable with the curable resin and the non-curable resin is not included in the compound having a reactive carbon-carbon double bond. Furthermore, the carbon-carbon double bond in the silicone compound having a functional group containing a carbon-carbon double bond does not include aromatic carbon-carbon double bonds.

[0089] Examples of the silicone compound include silicone oil, silicone diacrylate, silicone graft copolymer, etc. Specifically, a silicone compound having a siloxane skeleton in the main chain and a functional group having a carbon-carbon double bond in the side chain or at the terminal is preferred. The silicone compound having a siloxane skeleton in its main chain and a functional group having a carbon-carbon double bond in its side chain or at its terminal is preferably at least one selected from the group consisting of silicone compounds represented by the following formula (6-1), silicone compounds represented by the following formula (6-2), and silicone compounds represented by the following formula (6-3): These silicone compounds are particularly excellent in heat resistance and, due to their high polarity, tend to bleed out easily from the adhesive layer.

[0090] [ka]

[0091] X in the above formulas (6-1) to (6-3) and Y in the above formulas (6-1) and (6-3) each independently represent an integer of 0 or more and 1200 or less, and R in the above formulas (6-1) to (6-3) represents a functional group having a carbon-carbon double bond.

[0092] In the above formulas (6-1) to (6-3), examples of the functional group having a carbon-carbon double bond represented by R include an optionally substituted maleimide group, a citraconic imide group, a vinyl ether group, an allyl group, and a (meth)acryloyl group. Among these, an optionally substituted maleimide group is preferred because it provides the adhesive film of the present invention with superior heat resistance. In addition, when there are multiple R in the above formulas (6-1) to (6-3), each R may be the same or different.

[0093] Among the silicone compounds represented by the above formulas (6-1) to (6-3), commercially available examples include EBECRYL350 and EBECRYL1360 (both manufactured by Daicel-Allnex Co., Ltd.), BYK-UV3500 (manufactured by BYK-Chemie Co., Ltd.) and TEGO RAD2250 (manufactured by Evonik Co., Ltd.) (in both cases, R is an acryloyl group).

[0094] Examples of the fluorine compound include hydrocarbon compounds having fluorine atoms.

[0095] The content of the surface conditioner is preferably 0.1 parts by mass at its lower limit and 20 parts by mass at its upper limit, relative to 100 parts by mass of the total of the curable resin and the non-curable resin. By having the content of the surface conditioner within this range, the adhesive film of the present invention has excellent releasability without contaminating the adherend. From the viewpoint of further improving the releasability of the adhesive film of the present invention while suppressing contamination of the adherend, the lower limit of the content of the surface conditioner is more preferably 0.3 parts by mass, and the upper limit is more preferably 10 parts by mass. Since the adhesive layer has excellent heat resistance, it can exert a sufficient effect even if the content of the surface conditioner is relatively small, which further reduces the possibility of contamination by the surface conditioner.

[0096] The adhesive layer preferably further contains an inorganic filler, which can prevent the adhesive film of the present invention from decreasing in elastic modulus at high temperatures and can further prevent peeling during high-temperature processing, even when the adhesive film is subjected to high-temperature processing.

[0097] Examples of the inorganic filler include inorganic fillers consisting of at least one selected from the group consisting of oxides of silicon, titanium, aluminum, calcium, boron, magnesium, and zirconia, and composites thereof. Among these, silica and talc are preferred because they are commercially available at low cost and easily available.

[0098] The inorganic filler may be surface-modified. Examples of the functional group that may be used to modify the surface of the inorganic filler include an alkylsilane group, a methacryloyl group, and a dimethylsiloxane group. Among these, a dimethylsiloxane group is preferred because it has appropriate hydrophobicity.

[0099] The preferred lower limit of the average particle size of the inorganic filler is 5 nm, and the preferred upper limit is 30 μm. By having the average particle size of the inorganic filler within this range, the adhesive film of the present invention can be more effectively prevented from peeling during high-temperature processing, and can be easily peeled by peel treatment when peeled. The more preferred lower limit of the average particle size of the inorganic filler is 10 nm, and the more preferred upper limit is 20 μm, and the even more preferred lower limit is 15 nm, and the even more preferred upper limit is 15 μm. The average particle size can be determined, for example, by observing 50 particles of any inorganic filler under an electron microscope or an optical microscope and calculating the average particle size of each inorganic filler, or by performing laser diffraction particle size distribution measurement.

[0100] The content of the inorganic filler is preferably 1.0 part by mass at the lower limit and 20 parts by mass at the upper limit, relative to 100 parts by mass of the total of the curable resin and the non-curable resin. By having the content of the inorganic filler within this range, peeling of the adhesive film of the present invention can be further suppressed during high-temperature processing, and the adhesive film can be easily peeled by peeling after the high-temperature processing. The lower limit of the content of the inorganic filler is more preferably 3.0 parts by mass, and the upper limit is more preferably 15 parts by mass, even more preferably 5.0 parts by mass, and even more preferably 10 parts by mass.

[0101] The adhesive layer may further contain a gas-generating agent. By containing the gas-generating agent, even after high-temperature processing, gas generated by irradiation with light or heating is released at the interface with the adherend, making it possible to peel the adhesive film from the adherend more easily and without leaving any adhesive residue. Furthermore, even when peeling the adhesive film from a thin adherend after high-temperature processing, damage to the adherend can be prevented.

[0102] The gas generating agent preferably has a weight loss rate of 5% or less at 300°C when heated from 30°C to 300°C at a temperature increase rate of 10°C / min in a nitrogen atmosphere as measured by TG-DTA (thermogravimetry-differential thermal analysis). If the weight loss rate of the gas generating agent is 5% or less, decomposition of the gas generating agent is unlikely to occur even when subjected to high-temperature processing at 300°C or higher, and the adhesive film of the present invention has better heat resistance. In other words, the adhesive film of the present invention can be more effectively prevented from peeling during high-temperature processing, and can be more effectively prevented from causing increased adhesion or leaving adhesive residue upon peeling. The TG-DTA (thermogravimetry-differential thermal analysis) measurement can be carried out using, for example, a TG-DTA device (manufactured by Hitachi High-Tech Science Corporation, "STA7200RV") or the like.

[0103] Examples of the gas generating agent include a gas generating agent that generates gas when heated and a gas generating agent that generates gas when irradiated with light. These gas generating agents may be used alone or in combination of two or more. Among them, from the viewpoint of preventing decomposition of the gas generating agent during high-temperature processing, a gas generating agent that generates gas when irradiated with light is preferred, and a gas generating agent that generates gas when irradiated with ultraviolet light is more preferred. Examples of the gas generating agent include tetrazole compounds or salts thereof, triazole compounds or salts thereof, azo compounds, azide compounds, xanthone acetate, carbonates, etc. These gas generating agents may be used alone or in combination of two or more. Among them, tetrazole compounds or salts thereof are preferred because of their excellent heat resistance.

[0104] The content of the gas generating agent is preferably 5.0 parts by mass at its lower limit and 50 parts by mass at its upper limit, relative to 100 parts by mass of the total of the curable resin and the non-curable resin. By having the content of the gas generating agent within this range, the adhesive film of the present invention has better releasability. The more preferred lower limit of the content of the gas generating agent is 8.0 parts by mass, and the more preferred upper limit is 30 parts by mass.

[0105] The adhesive layer may contain known additives such as photosensitizers, heat stabilizers, antioxidants, antistatic agents, plasticizers, surfactants, waxes, etc., as long as the effects of the present invention are not impaired.

[0106] The adhesive layer was irradiated with an ultra-high pressure mercury lamp at a wavelength of 405 nm and an irradiation intensity of 100 mW / cm. 2The gel fraction of the adhesive layer after irradiation with light through the substrate for 300 seconds (hereinafter sometimes simply referred to as "gel fraction of the adhesive layer after irradiation with light") has a preferred lower limit of 50% by mass. When the gel fraction of the adhesive layer after irradiation with light is 50% by mass or more, the adhesive film of the present invention can further suppress the occurrence of voids and lifting during high-temperature processing, and can be more easily peeled from the adherend. A more preferred lower limit of the gel fraction of the adhesive layer after irradiation with light is 60% by mass, and an even more preferred lower limit is 70% by mass. Furthermore, the preferred upper limit of the gel fraction of the adhesive layer after irradiation with light is not particularly limited, but taking into account the leaching of additives and the like that are not incorporated into the three-dimensional network structure of the crosslinking component, it is essentially 98 mass% or less. When the adhesive film of the present invention has adhesive layers on both sides of the substrate, it is more preferable that the gel fraction of the adhesive layers on both sides after irradiation with light falls within the above range.

[0107] The gel fraction of the adhesive layer after irradiation with light can be measured by the following method. The adhesive film thus obtained was cut into a size of 50 mm wide x 100 mm long, and then irradiated with an ultra-high pressure mercury lamp at a wavelength of 405 nm and an irradiation intensity of 100 mW / cm. 2 The adhesive layer of the cut adhesive film is irradiated with light of wavelength 405 nm and irradiation intensity 100 mW / cm for 300 seconds through the substrate. If the adhesive film has adhesive layers on both sides of the substrate, the light is irradiated from the adhesive layer side where the gel fraction is not measured. 2 The adhesive layer for measuring the gel fraction is irradiated with light. For the adhesive film after light irradiation, a sample consisting of only the adhesive layer W0(g) is prepared by separating the substrate (if the adhesive film has adhesive layers on both sides of the substrate, the substrate and the adhesive layer for which the gel fraction is not measured). The resulting measurement sample is immersed in 50 mL of toluene and shaken in a shaker at 23°C and 200 rpm for 24 hours. After shaking, a metal mesh (opening #200 mesh, W1(g)) is used to separate the toluene from the adhesive layer that has absorbed the toluene and swollen, and the separated adhesive layer is dried at 110°C for 1 hour. The mass W2(g) of the adhesive layer including the dried metal mesh is measured, and the gel fraction (mass%) of the adhesive layer after light irradiation is measured using the following formula: Gel fraction (mass%) = 100 × (W2 - W1) / W0 (W0: initial mass of adhesive layer, W1: initial mass of metal mesh, W2: mass of adhesive layer including metal mesh after drying)

[0108] The method for separating the adhesive layer from the substrate in measuring the gel fraction after irradiating the adhesive layer with light is not particularly limited, as long as treatment with a solvent, treatment involving a chemical reaction, treatment at high temperature, etc., is avoided to avoid denaturation of the adhesive layer. Specific methods include, for example, a method using a tensile tester to select an appropriate temperature and peeling rate to remove the substrate by peeling the adhesive layer from the substrate, and a method of physically grinding the substrate. Alternatively, a sample may be prepared by scraping off W0 (g) from the adhesive layer after irradiating light.

[0109] Methods for adjusting the gel fraction of the adhesive layer after irradiation with light include, for example, increasing the content of polymerization initiator in the resin (the curable resin and the non-curable resin) that constitutes the adhesive layer, changing to a substrate type with better light transmittance, and increasing light transmittance by reducing the thickness of the substrate or adhesive layer.

[0110] The thickness of the adhesive layer is preferably 5 μm at its lower limit and 550 μm at its upper limit. When the thickness of the adhesive layer is 5 μm or more, the adhesive film of the present invention can have sufficient pressure-sensitive or heat-sensitive adhesive strength at the time of initial attachment. When the thickness of the adhesive layer is 550 μm or less, the adhesive layer can exhibit high flexibility, and the adhesive film of the present invention can exhibit high conformability to an adherend having irregularities and can be more easily peeled off. The thickness of the adhesive layer is more preferably 10 μm at its lower limit and 400 μm at its upper limit, and even more preferably 20 μm at its lower limit and 300 μm at its upper limit.

[0111] The adhesive film of the present invention has a substrate. When the adhesive film of the present invention has a substrate, it has excellent handleability. Examples of the substrate include resin films such as acrylic, polyolefin, polycarbonate, polyvinyl chloride, ABS, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), nylon, polyurethane, polyimide, polyether ether ketone (PEEK), and polyamide (PA). Among these, from the viewpoint of high heat resistance, films containing a resin having in the main chain skeleton a repeating unit containing at least one selected from the group consisting of an ether bond, a ketone group, an ester bond, an amide bond, and an imide bond are preferred. More preferred are films containing at least one selected from the group consisting of polyether ether ketone (PEEK) film, polyamide film, and polyimide film. Furthermore, from the viewpoint of ensuring that the light transmittance of the substrate at a wavelength of 436 nm falls within an appropriate range, as described below, polyether ether ketone (PEEK) film is preferred. Furthermore, the substrate may be a film having a mesh structure, a film having holes, glass, or the like.

[0112] The substrate's light transmittance at a wavelength of 436 nm is preferably 3.0% at its lower limit and 75.0% at its upper limit. By ensuring that the substrate's light transmittance at a wavelength of 436 nm falls within the above range, it becomes easier to adjust the light transmittance at a wavelength of 436 nm of the adhesive film of the present invention in an uncured state, as described below, to an appropriate range. The substrate's light transmittance at a wavelength of 436 nm is more preferably 5.0% at its lower limit and 73.0% at its upper limit, and even more preferably 7.0% at its lower limit and 71.0% at its upper limit.

[0113] Methods for adjusting the light transmittance of the substrate at a wavelength of 436 nm include changing the substrate type so that the light transmittance falls within the appropriate range, and changing the thickness of the substrate to fall within the appropriate range described below.

[0114] The thickness of the substrate is preferably 5 μm at its lower limit and 150 μm at its upper limit. By setting the thickness of the substrate within the above range, it becomes easier to adjust the light transmittance at a wavelength of 436 nm in the uncured state of the adhesive film of the present invention, which will be described later, and the flexibility of the adhesive film of the present invention to appropriate values. The thickness of the substrate is more preferably 10 μm at its lower limit and 100 μm at its upper limit.

[0115] The method for producing the adhesive film of the present invention is not particularly limited, and for example, first, the curable resin and, if necessary, the non-curable resin and additives are mixed using a bead mill, ultrasonic dispersion, homogenizer, high-power disperser, roll mill, etc. to obtain an adhesive solution. Next, the obtained adhesive solution is applied to the release-treated surface of a PET film that has been subjected to a release treatment on one side with an applicator, etc., and dried to form an adhesive layer, and then the substrate and the adhesive layer are stacked so that they face each other, thereby obtaining an adhesive film having a substrate and an adhesive layer on one side of the substrate. In addition, after forming two types of adhesive layers using a method similar to that described above, one type of adhesive layer can be stacked on one side of the substrate and the other type of adhesive layer on the other side of the substrate so that they face each other, thereby obtaining an adhesive film having a substrate and adhesive layers on both sides of the substrate.

[0116] In the adhesive film of the present invention, the light transmittance at a wavelength of 436 nm when the adhesive layer is in an uncured state (hereinafter sometimes simply referred to as "the light transmittance at a wavelength of 436 nm of the adhesive film in an uncured state") has a lower limit of 1.0% and an upper limit of 72.0%. When the light transmittance at a wavelength of 436 nm of the adhesive film in an uncured state is within the above range, the adhesive layer in the adhesive film of the present invention can be cured even with light of a long wavelength such as visible light. The preferred lower limit of the light transmittance at a wavelength of 436 nm of the adhesive film in an uncured state is 5.0%, and the preferred upper limit is 65.0%, more preferably 10.0%, and more preferably 60.0%. The light transmittance of the adhesive film in an uncured state at a wavelength of 436 nm can be measured using a spectrophotometer (manufactured by Hitachi High-Tech Science Corporation, "U-3900") or the like in accordance with JIS K7136.

[0117] Methods for adjusting the light transmittance at a wavelength of 436 nm of the adhesive film of the present invention in an uncured state include, for example, changing the substrate to a substrate type with better light transmittance at a wavelength of 436 nm, increasing the light transmittance by reducing the thickness of the substrate or adhesive layer, and adding a polymerization initiator or resin that absorbs light at a wavelength of 436 nm to the adhesive layer.

[0118] The adhesive film of the present invention has a lower limit of 400°C for the 5% weight loss temperature after curing of the adhesive layer (hereinafter, sometimes simply referred to as "5% weight loss temperature after curing of the adhesive film"). When the 5% weight loss temperature after curing of the adhesive film is 400°C or higher, the adhesive film of the present invention has excellent heat resistance. That is, the adhesive film of the present invention can suppress the occurrence of voids and lifting between the adhesive film and the support during high-temperature processing, and can also prevent increased adhesion to the adherend during high-temperature processing and the occurrence of adhesive residue on the adherend when peeled off after high-temperature processing. The preferred lower limit of the 5% weight loss temperature after curing of the adhesive film is 410°C, and more preferably 420°C. Furthermore, the upper limit of the temperature at which the adhesive film of the present invention undergoes a 5% weight loss after curing is not particularly limited, but is substantially about 600°C. The 5% weight loss temperature of the adhesive film after curing can be measured by the following method. That is, a measurement sample obtained by curing the adhesive layer of the adhesive film of the present invention is weighed into an aluminum pan, and the aluminum pan is set in a thermogravimetric analyzer (e.g., "STA7200" manufactured by Hitachi High-Tech Science Corporation). The measurement sample is heated from 25°C at a temperature increase rate of 10°C / min in a nitrogen atmosphere, and the temperature at which the adhesive film loses 5% weight is measured.

[0119] When measuring the 5% weight loss temperature after curing of the adhesive film of the present invention, the adhesive layer of the adhesive film of the present invention can be cured by, for example, photocuring or heat curing. When photocuring is performed, the adhesive layer is irradiated with light through the substrate (from one of the adhesive layer sides when the adhesive film has adhesive layers on both sides of the substrate). Specifically, an ultra-high pressure mercury lamp is used for photocuring, with a wavelength of 405 nm and an irradiation intensity of 100 mW / cm. 2 For heat curing, the resin is cured by heating it in a heated environment such as an oven for 30 minutes.

[0120] Methods for adjusting the 5% weight loss temperature after curing of the adhesive film include, for example, adjusting the content of polymerization initiator relative to the resin constituting the adhesive layer, changing the type of substrate, or changing the thickness of the substrate or adhesive layer.

[0121] The adhesive film of the present invention preferably has a weight loss rate of 1.0% or less when heated at 250°C for 30 minutes after the adhesive layer has been cured (hereinafter, sometimes simply referred to as "weight loss rate of the adhesive film after curing"). When the adhesive film has a weight loss rate of 1.0% or less after curing, the adhesive film of the present invention has superior heat resistance. That is, the adhesive film of the present invention can more effectively prevent voids and lifting from forming between the adhesive film and the support during high-temperature processing, and can also more effectively prevent increased adhesion to the adherend during high-temperature processing and adhesive residue from remaining on the adherend when peeled off after high-temperature processing. The upper limit of the weight loss rate of the adhesive film after curing is more preferably 0.8%, and even more preferably 0.7%. The lower limit of the weight loss rate of the adhesive film after curing is not particularly limited, and the smaller the lower limit, the better, with 0% being the most preferable. The weight loss rate of the adhesive film after curing can be measured by the following method. That is, a measurement sample obtained by curing the adhesive layer of the adhesive film of the present invention is weighed into an aluminum pan, and the aluminum pan is set in a thermogravimetric analyzer (e.g., "STA7200" manufactured by Hitachi High-Tech Science Corporation). The measurement sample is heated from 25°C at a temperature increase rate of 10°C / min in a nitrogen atmosphere, and the weight loss rate after heating at 250°C for 30 minutes is measured.

[0122] When measuring the weight loss rate after curing of the adhesive film, the adhesive layer of the adhesive film of the present invention can be cured by, for example, photocuring or heat curing. When photocuring is performed, the adhesive layer is irradiated with light through the substrate (from one of the adhesive layer sides when the adhesive film has adhesive layers on both sides of the substrate). Specifically, an ultra-high pressure mercury lamp is used for photocuring, with a wavelength of 405 nm and an irradiation intensity of 100 mW / cm. 2 For heat curing, methods include using an oven or the like to cure the film by heating it in a 250°C heating environment for 30 minutes, or by heating it in a 150°C heating environment for 10 minutes.

[0123] Methods for adjusting the weight loss rate after curing of the adhesive film of the present invention include, for example, a method for adjusting the content of polymerization initiator relative to the resin constituting the adhesive layer, a method for changing the type of substrate, a method for changing the thickness of the substrate or adhesive layer, etc.

[0124] The adhesive film of the present invention has a preferred upper limit of 2.0 N / inch for the 180° peel strength from a silicon wafer after the adhesive layer has been cured (hereinafter sometimes simply referred to as "the 180° peel strength from a silicon wafer after the adhesive film has been cured"). When the 180° peel strength from a silicon wafer after the adhesive film has been cured is 2.0 N / inch or less, the adhesive film of the present invention can be easily peeled off after curing. A more preferred upper limit for the 180° peel strength from a silicon wafer after the adhesive film has been cured is 1.0 N / inch, and an even more preferred upper limit is 0.3 N / inch. From the viewpoint of heat resistance of the adhesive film of the present invention, the lower limit of the 180° peel strength from the silicon wafer after the adhesive film has cured is preferably 0.01 N / inch, and more preferably 0.05 N / inch. The 180° peel strength of the adhesive film from the silicon wafer after curing can be measured, for example, by the following method. That is, first, the adhesive film of the present invention is cut into a size of 25 mm wide x 100 mm long, and then, if necessary, a separator such as a release PET film is peeled off from one side (the side to be measured), and the film is laminated to a silicon wafer using a laminator ("Leon13DX" manufactured by Lamy Corporation, speed 3) at 40°C to obtain a laminate. Next, the obtained laminate is irradiated from the adhesive film side with an ultra-high pressure mercury lamp at a wavelength of 405 nm and an irradiation intensity of 100 mW / cm. 2 of light for 300 seconds (accumulated light intensity: 30,000 mJ / cm 2 ) The adhesive layer of the adhesive film is cured by irradiation or the like to prepare a measurement sample. The adhesive film is peeled from the obtained measurement sample under conditions of 25°C, a tensile speed of 300 mm / min, and a peel angle of 180°, thereby measuring the 180° peel strength (N / inch) of the adhesive film against the silicon wafer after it has hardened.

[0125] When measuring the 180° peel strength of the adhesive film of the present invention from a silicon wafer after curing, the adhesive layer of the adhesive film of the present invention can be cured by, for example, photocuring or heat curing. When photocuring is performed, the adhesive layer is irradiated with light through the substrate. Specifically, an ultra-high pressure mercury lamp is used for photocuring, with a wavelength of 405 nm and an irradiation intensity of 100 mW / cm. 2 For heat curing, methods include using an oven or the like to cure the film by heating it in a 250°C heating environment for 30 minutes, or by heating it in a 150°C heating environment for 10 minutes.

[0126] Methods for adjusting the 180° peel strength of the adhesive film of the present invention against a silicon wafer after curing include, for example, irradiating the adhesive layer with a greater amount of light when curing the adhesive layer, increasing the content of polymerization initiator in the resins (the above-mentioned curable resin and the above-mentioned non-curable resin) that make up the adhesive layer, changing to a substrate type with better light transmittance, and increasing light transmittance by reducing the thickness of the substrate or adhesive layer.

[0127] The preferred lower limit of the total thickness of the adhesive film of the present invention is 5 μm, and the preferred upper limit is 550 μm. When the total thickness of the adhesive film of the present invention is 5 μm or more, the entire adhesive film of the present invention can initially have sufficient pressure-sensitive or heat-sensitive adhesive strength. When the total thickness of the adhesive film of the present invention is 550 μm or less, the adhesive film of the present invention can exhibit high flexibility, can exhibit high conformability to an adherend having unevenness, and can be more easily peeled off. The more preferred lower limit of the total thickness of the adhesive film of the present invention is 10 μm, and the more preferred upper limit is 400 μm, and even more preferred lower limit is 20 μm, and even more preferred upper limit is 300 μm.

[0128] The adhesive film of the present invention can be used for any purpose, but due to its excellent releasability, it can be suitably used as a temporary fixing material. Furthermore, the adhesive film of the present invention has excellent heat resistance, preventing increased adhesion to the adherend during high-temperature processing and preventing adhesive residue when peeled off after high-temperature processing, allowing for easy peeling from the adherend. Therefore, the adhesive film of the present invention can be suitably used for temporary fixing of adherends that undergo high-temperature heat treatment. For example, during processing of electronic components such as semiconductors, the adhesive film of the present invention can be used to fix electronic components to a support plate or to protect electronic components by attaching the adhesive film of the present invention to them, in order to facilitate handling and prevent damage to the electronic components. That is, the adhesive film of the present invention can be suitably used as a temporary fixing material for the manufacture of electronic components. [Effects of the Invention]

[0129] According to the present invention, it is possible to provide an adhesive film that has both excellent heat resistance and excellent releasability after high-temperature processing, even when it has a substrate. DETAILED DESCRIPTION OF THE INVENTION

[0130] The following examples will explain the present invention in more detail, but the present invention is not limited to these examples.

[0131] (Synthesis of Polyimide Compound A) A 500 mL round-bottom flask equipped with a Teflon (registered trademark) stirrer was charged with 250 mL of toluene. 39.9 g (0.075 mol) of dimer diamine (Croda, "Priamine 1075") and 23.3 g (0.075 mol) of 4,4'-oxydiphthalic anhydride were added, in that order. A Dean-Stark tube and a condenser were attached to the flask, and the resulting mixture was refluxed for 6 hours and cooled to room temperature. A brown solid toluene solution of a resin (polyimide compound A) having a structural unit represented by the following formula (7), no reactive carbon-carbon double bond, and an imide skeleton in the main chain repeating unit was obtained. The weight-average molecular weight of the obtained polyimide compound A was measured by gel permeation chromatography (GPC, apparatus name: Acquity APC system (manufactured by Waters Corporation)) using THF as an eluent and an HR-MB-M 6.0 × 150 mm (manufactured by Waters Corporation) as a column, and was found to be 70,000.

[0132] [ka]

[0133] (Synthesis of Polyimide Compound B) 250 mL of toluene was placed in a 500 mL round-bottom flask equipped with a Teflon (registered trademark) stirrer. Next, 88 g (0.02 mol) of a silicone compound having amino groups at both ends (KF-8012, manufactured by Shin-Etsu Chemical Co., Ltd., siloxane unit repeat number = 60, weight-average molecular weight 4400) was added. Furthermore, 16 g (0.03 mol) of dimer diamine (Priamine 1075, manufactured by Croda) and 26 g (0.05 mol) of 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride were added, in this order. A Dean-Stark tube and a condenser were attached to the flask, and the mixture was refluxed for 2 hours to obtain a toluene solution of polyimide compound B having the structural units represented by the following formula (8-1), the structural units represented by the following formula (8-2), and the structural units shown in Table 1. The weight average molecular weight of the obtained polyimide compound B was measured by gel permeation chromatography (GPC) using THF as an eluent and an HR-MB-M (manufactured by Waters Corporation) as a column, and was found to be 100,000.

[0134] [ka]

[0135] [Table 1]

[0136] (Synthesis of polyimide compound C) A 500 mL round-bottom flask equipped with a Teflon (registered trademark) stirrer was charged with 250 mL of toluene. 39.9 g (0.075 mol) of dimer diamine (Croda, "Priamine 1075") and 39 g (0.075 mol) of 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride were added, in this order. A Dean-Stark tube and a condenser were attached to the flask, and the resulting mixture was refluxed for 6 hours and cooled to room temperature. A brown solid toluene solution of a resin (polyimide compound C) having a structural unit represented by the following formula (9), no reactive carbon-carbon double bond, and an imide skeleton in the main chain repeating unit was obtained. The weight-average molecular weight of the obtained polyimide compound C was measured by gel permeation chromatography (GPC, apparatus name: Acquity APC system (manufactured by Waters Corporation)) using THF as an eluent and an HR-MB-M 6.0 × 150 mm (manufactured by Waters Corporation) as a column, and was found to be 90,000.

[0137] [ka]

[0138] (Preparation of Acrylic Copolymer E) A reactor equipped with a thermometer, stirrer, and cooling tube was prepared. 94 parts by weight of 2-ethylhexyl acrylate as an alkyl acrylate ester, 6.0 parts by weight of 2-hydroxyethyl methacrylate as a functional group-containing monomer, 0.01 parts by weight of lauryl mercaptan, and 80 parts by weight of ethyl acetate were added to the reactor, and the reactor was heated to initiate reflux. Subsequently, 0.01 parts by weight of 1,1-bis(t-hexylperoxy)-3,3,5-trimethylcyclohexane as a polymerization initiator was added to the reactor, and polymerization was initiated under reflux. Next, 0.01 parts by weight of 1,1-bis(t-hexylperoxy)-3,3,5-trimethylcyclohexane was added 1 hour and 2 hours after the start of polymerization, and 0.05 parts by weight of t-hexylperoxypivalate was added 4 hours after the start of polymerization to continue the polymerization reaction. Then, 8 hours after the start of polymerization, an ethyl acetate solution of a functional group-containing acrylic polymer with a solid content of 55% by mass and a weight-average molecular weight of 600,000 was obtained. 3.5 parts by mass of 2-isocyanatoethyl methacrylate as a functional group-containing unsaturated compound was added to 100 parts by mass of the resin solid content of the obtained ethyl acetate solution containing the functional group-containing acrylic polymer, and the mixture was reacted to obtain acrylic copolymer E. The weight average molecular weight of the obtained acrylic copolymer E was measured by gel permeation chromatography (GPC) using THF as an eluent and HR-MB-M (trade name, manufactured by Waters Corporation) as a column, and was found to be 600,000.

[0139] Example 1 (1) Manufacturing of adhesive films To 150 mL of toluene, 70 parts by weight of polyimide compound A, 30 parts by weight of bismaleimide compound D, 0.1 parts by weight of Nikkacure YJ-04 (T) (manufactured by Nippon Chemical Industry Co., Ltd.) as a photopolymerization initiator, and 1.0 parts by weight of BYK-UV3500 (manufactured by BYK-Chemie Co., Ltd.) as a surface conditioner were added and mixed to prepare a toluene solution of adhesive (a). The obtained toluene solution of adhesive (a) was applied with a doctor knife to the release-treated surface of a 50 μm-thick PET film that had been subjected to one-side release treatment so that the thickness of the dried film was 50 μm, and the coating solution was dried by heating at 110 ° C. for 5 minutes to form an adhesive layer (a). In addition, 70 parts by mass of polyimide compound C, 30 parts by mass of bismaleimide compound D, 0.5 parts by mass of Omnirad 379EG (manufactured by IGM Resins) as a photopolymerization initiator, 20 parts by mass of Tinuvin 1600 (manufactured by BASF) as an ultraviolet absorber, and 0.1 parts by mass of BYK-UV3500 (manufactured by BYK-Chemie) as a surface conditioner were added and mixed to prepare a toluene solution of adhesive (b). The toluene solution was applied to the release-treated surface of a 50 μm-thick PET film that had been subjected to one-sided release treatment so that the thickness of the dried film was 20 μm, and the coating solution was dried by heating at 110 ° C. for 5 minutes to form an adhesive layer (b). An adhesive layer (a) was laminated on one side of a polyether ether ketone (PEEK) film ("EXPEEK" manufactured by Kurabo Industries, Ltd.) and an adhesive layer (b) was laminated on the other side to form an adhesive film having adhesive layers on both sides of the substrate. The bismaleimide compound D is a bismaleimide compound represented by the following formula (10) (manufactured by Designer Molecules, "BMI-689"). The photopolymerization initiator used was Nikkacure YJ-04(T) (manufactured by Nippon Chemical Industry Co., Ltd.), which is an oxime ester compound having a carbazole group.

[0140] [ka]

[0141] (2) Measurement of gel fraction after light irradiation of adhesive layer (a) The obtained adhesive film was cut into a size of 50 mm wide x 100 mm long, and then the cut adhesive film was irradiated with a super-high pressure mercury lamp at a wavelength of 405 nm and an irradiation intensity of 100 mW / cm. 2 Light was irradiated from the adhesive layer (b) side through the substrate toward the adhesive layer (a) for 300 seconds. After the light irradiation, the adhesive film was peeled off from the substrate using a tensile tester at an appropriate temperature and peeling speed, and a sample consisting of only the adhesive layer (a) W0(g) was prepared by separating the substrate from the adhesive layer (b). The obtained measurement sample was immersed in 50 mL of toluene and shaken in a shaker at 23°C and 200 rpm for 24 hours. After shaking, a metal mesh (opening #200 mesh, W1 (g)) was used to separate the toluene from the adhesive layer that had absorbed the toluene and swollen, and the separated adhesive layer was dried at 110°C for 1 hour. The mass W2 (g) of the adhesive layer including the dried metal mesh was measured, and the gel fraction (mass%) of the adhesive layer (a) after light irradiation was measured using the following formula. The results are shown in Table 2. Gel fraction (mass%) = 100 × (W2 - W1) / W0 (W0: initial mass of adhesive layer, W1: initial mass of metal mesh, W2: mass of adhesive layer including metal mesh after drying)

[0142] (3) Measurement of light transmittance at a wavelength of 436 nm when the adhesive film is uncured The light transmittance (%) of the resulting adhesive film in an uncured state at a wavelength of 436 nm was measured using a spectrophotometer (Hitachi High-Tech Science Corporation, "U-3900") in accordance with JIS K 7136. The measurement was performed after peeling off the release PET film protecting the adhesive layer of the adhesive film. The results are shown in Table 2.

[0143] (4) Measurement of the 5% weight loss temperature after curing of the adhesive film The adhesive film thus obtained was irradiated with an ultra-high pressure mercury lamp at a wavelength of 405 nm and an irradiation intensity of 100 mW / cm.2 The adhesive layer was cured by irradiating it with light from the adhesive layer (b) side through the substrate onto the adhesive layer (a) for 300 seconds, and the resulting measurement sample was weighed into an aluminum pan. The aluminum pan was then placed in a thermogravimetric analyzer (Hitachi High-Tech Science Corporation, "STA7200") and heated from 25°C at a heating rate of 10°C / min under a nitrogen atmosphere to measure the temperature (°C) at which the adhesive film lost 5% of its weight. The results are shown in Table 2. The adhesive film is irradiated with light after peeling off the release PET films protecting the adhesive layers on both sides, and the measurement sample does not have any release PET films laminated thereon to protect the adhesive layers.

[0144] (5) Measurement of weight loss rate after adhesive film hardening The adhesive film thus obtained was irradiated with an ultra-high pressure mercury lamp at a wavelength of 405 nm and an irradiation intensity of 100 mW / cm. 2 The adhesive layer was cured by irradiating it with light from the adhesive layer (b) side through the substrate onto the adhesive layer (a) for 300 seconds, and the resulting measurement sample was weighed into an aluminum pan. The aluminum pan was then placed in a thermogravimetric analyzer (Hitachi High-Tech Science Corporation, "STA7200") and heated from 25°C at a heating rate of 10°C / min under a nitrogen atmosphere. After heating to 250°C for 30 minutes, the weight loss rate was measured. The results are shown in Table 2. The adhesive film is irradiated with light after peeling off the release PET films protecting the adhesive layers on both sides, and the measurement sample does not have any release PET films laminated thereon to protect the adhesive layers.

[0145] (6) Measurement of 180° peel strength from a silicon wafer after the adhesive film has hardened The obtained adhesive film was cut into a size of 25 mm wide x 100 mm long, and then the release PET film on the adhesive layer (a) side was peeled off. The film was then laminated onto a silicon wafer using a laminator (Leon 13DX, manufactured by Lamy Corporation, speed 3) at 40°C to obtain a laminate. The obtained laminate was irradiated from the adhesive film side with an ultra-high pressure mercury lamp at a wavelength of 405 nm and an irradiation intensity of 100 mW / cm. 2of light for 300 seconds (accumulated light intensity: 30,000 mJ / cm 2 ) to cure the adhesive layer of the adhesive film, thereby preparing a measurement sample. The adhesive film was peeled from the obtained measurement sample at 25°C, a pulling speed of 300 mm / min, and a peel angle of 180°, to measure the 180° peel strength (N / inch) of the cured adhesive film against the silicon wafer. The results are shown in Table 2.

[0146] (Examples 2 to 27, Comparative Examples 1 to 5) Adhesive films were produced and measurements were carried out in the same manner as in Example 1, except that in the above "(1) Production of adhesive film", the composition and thickness of the adhesive layer and the type and thickness of the substrate were as shown in Tables 2 to 5. The results are shown in Tables 2 to 5.

[0147] (Comparative Example 6) Using the same method as in "(1) Production of adhesive film" above, adhesive layers (a) and (b) having the compositions and thicknesses shown in Table 5 were formed, and adhesive layers (a) and (b) were stacked so that they faced each other, thereby obtaining an adhesive film without a substrate. Other than that, measurements were carried out using the same method as in Example 1. The results are shown in Table 5. In the above-mentioned "(6) Measurement of the 180° peel force from the silicon wafer after the adhesive film has hardened," the adhesive layer stretched and the adhesive film could not be peeled off, so the 180° peel force from the silicon wafer after the adhesive film has hardened could not be measured.

[0148] The types of substrates used in the examples and comparative examples shown in Tables 2 to 5 are as follows: The light transmittance at a wavelength of 436 nm for each thickness of each substrate is also shown. PEEK film (manufactured by Kurabo Industries, Ltd., "EXPEEK") Light transmittance at 436 nm wavelength: 81.5% (thickness 12 μm), 77.7% (thickness 25 μm), 61.3% (thickness 50 μm) Polyamide film (manufactured by Unitika, "Uniamide") Light transmittance at wavelength 436 nm: 83.5% (thickness 25 μm) PEN film (Teijin, "Teonex Q83C") Light transmittance at wavelength 436 nm: 71.2% (thickness 25 μm) Polyimide film 1 (UBE Corporation, "Upilex") Light transmittance at 436 nm wavelength: 27.2% (thickness 12.5 μm), 5.7% (thickness 25 μm) Polyimide film 2 (Toray Industries, Inc., "Kapton") Light transmittance at wavelength 436 nm: 3.2% (thickness 12.5 μm) PET film (manufactured by Toyo Cross Co., Ltd., "LS-PET") Light transmittance at wavelength 436 nm: 77.3% (thickness 25 μm)

[0149] <Evaluation> The adhesive films obtained in the examples and comparative examples were evaluated by the following methods, and the results are shown in Tables 2 to 5.

[0150] (1) Heat resistance evaluation The release PET film on the adhesive layer (b) side of the obtained adhesive film was peeled off, and the film was attached to a 200 mm diameter, 600 μm thick glass (manufactured by SCHOTT, "Tempax") under vacuum and at a temperature of 40°C, and then cut to the shape of the silicon wafer to which the adhesive film was to be attached. Next, the release PET film on the adhesive layer (a) side of the adhesive film attached to the glass was peeled off, and a 200 mm diameter, 700 μm thick silicon wafer was attached under vacuum and at 90°C using a pressure lamination device (manufactured by Takatori, "GWSM-300M") to produce a laminate. An ultra-high pressure mercury lamp was used to irradiate the glass side of the obtained laminate with a wavelength of 405 nm and an irradiation intensity of 100 mW / cm. 2 of light for 300 seconds (accumulated light intensity: 30,000 mJ / cm 2) to obtain a measurement sample. The obtained measurement sample was placed on a hot plate (MSA Factory, "PH224 / 225") with the silicon wafer side in contact with the hot plate, and the laminate was heated at 250 ° C for 30 minutes. After heating, the laminate was visually observed for voids and peeling at the adhesive interface between the adhesive layer (a) and the silicon wafer, as well as for the presence of wrinkles in the adhesive layer (a) after heating. In addition, the heating temperature was changed to 270 ° C as a severe condition, and the observation was performed under the same conditions as above. Based on the observation results, the heat resistance of the adhesive film was evaluated according to the following criteria. ·◎: Even after heating at 250°C for 30 minutes and after heating at 270°C for 30 minutes, no voids or peeling were observed at the adhesive interface with the silicon wafer, and no wrinkles were observed in the adhesive layer (a) attached to the silicon wafer. ○: After heating at 250°C for 30 minutes, no voids or peeling were observed at the adhesive interface with the silicon wafer, and no wrinkles were observed in the adhesive layer (a) attached to the silicon wafer. However, after heating at 270°C for 30 minutes, voids or peeling were observed at the adhesive interface with the silicon wafer, or wrinkles were observed in the adhesive layer (a) attached to the silicon wafer. · △: After heating at 250°C for 30 minutes, no voids or peeling were observed at the adhesive interface with the silicon wafer, but wrinkles were observed in the adhesive layer (a) attached to the silicon wafer. ·×: After heating at 250°C for 30 minutes, voids or peeling were observed at the adhesive interface with the silicon wafer.

[0151] (2) Evaluation of peelability Measurement samples were prepared in the same manner as in "(1) Evaluation of heat resistance" above. The obtained measurement samples were placed in an oven heated to 250°C and left to stand in an environment of 250°C for 30 minutes, thereby carrying out a heat treatment. The obtained measurement samples were irradiated from the glass side with a wavelength of 355 nm and an irradiation energy density of 700 mJ / cm. 2The entire glass surface was irradiated with a pulsed laser having a frequency of 60 kHz, and the glass was peeled from the adhesive film. After that, a 180° peel test was performed at 25°C and a pulling speed of 300 mm / min to measure the 180° peel strength (N / inch). Using the obtained 180° peel strength, the releasability of the adhesive film was evaluated according to the following criteria. · ⊚: The 180° peel force was less than 0.3 N / inch. ·◯: The 180° peel force was 0.3 N / inch or more and less than 1.0 N / inch. · △: The 180° peel force was 1.0 N / inch or more and 2.0 N / inch or less. ·×: The 180° peel force was greater than 2.0 N / inch, or the adhesive film could not be peeled from the silicon wafer. In addition, for Comparative Example 5, the evaluation of heat resistance was "x", so the evaluation of releasability was not carried out. In addition, in Comparative Example 6, the adhesive layer stretched during the 180° peel test, and the adhesive film could not be peeled off.

[0152] [Table 2]

[0153] [Table 3]

[0154] [Table 4]

[0155] [Table 5] [Industrial Applicability]

[0156] According to the present invention, it is possible to provide an adhesive film that has both excellent heat resistance and excellent releasability after high-temperature processing, even when it has a substrate.

Claims

1. An adhesive film having a substrate and an adhesive layer on at least one surface of the substrate, the adhesive layer contains a curable resin, the curable resin includes a compound having a reactive carbon-carbon double bond, The adhesive film has a light transmittance at a wavelength of 436 nm of 1.0% or more and 72.0% or less when the adhesive layer is in an uncured state, The adhesive film has a 5% weight loss temperature of 400° C. or higher after the adhesive layer is cured. An adhesive film characterized by:

2. The adhesive film according to claim 1, wherein the compound having a reactive carbon-carbon double bond includes a compound having at least one group selected from the group consisting of a maleimide group and a (meth)acryloyl group.

3. 3. The adhesive film according to claim 2, wherein the compound having a reactive carbon-carbon double bond includes a bismaleimide compound.

4. The adhesive layer further contains a non-curable resin, 4. The adhesive film according to claim 1, wherein the non-curable resin contains a resin that does not have a reactive carbon-carbon double bond and has an imide skeleton in the repeating unit of the main chain.

5. 5. An adhesive film according to claim 4, wherein the resin having no reactive carbon-carbon double bond and an imide skeleton in the repeating unit of the main chain has a silicone skeleton in the repeating unit of the main chain.

6. the adhesive layer further contains a non-curable resin, The content of the curable resin is 10 parts by mass or more and 90 parts by mass or less in 100 parts by mass of the total of the curable resin and the non-curable resin.

4. The adhesive film according to claim 1, 2 or 3.

7. 4. The adhesive film according to claim 1, wherein the adhesive layer contains a polymerization initiator.

8. The adhesive film according to claim 7 , wherein the polymerization initiator includes a photopolymerization initiator.

9. 9. The adhesive film according to claim 8, wherein the photopolymerization initiator has a molar absorption coefficient of 100 ml / (g·cm) or more for light having a wavelength of 436 nm.

10. The adhesive film according to claim 8 , wherein the photopolymerization initiator comprises an oxime ester compound.

11. The adhesive film according to claim 8 , wherein the photopolymerization initiator comprises a compound having a carbazole group.

12. The adhesive film according to claim 8 , wherein the photopolymerization initiator comprises an oxime ester compound having a carbazole group.

13. 4. An adhesive film according to claim 1, wherein the adhesive layer is photocurable.

14. The adhesive layer was irradiated with an ultra-high pressure mercury lamp at a wavelength of 405 nm and an irradiation intensity of 100 mW / cm ２ 4. The adhesive film according to claim 1, wherein the adhesive layer has a gel fraction of 50% by mass or more after being irradiated with light of 1000 nm through the substrate for 300 seconds.

15. 4. The adhesive film according to claim 1, wherein the adhesive layer has a thickness of 5 μm or more and 550 μm or less.

16. The adhesive film according to claim 1, 2 or 3, wherein the substrate contains a resin having in its main chain skeleton a repeating unit containing at least one selected from the group consisting of an ether bond, a ketone group, an ester bond, an amide bond and an imide bond.

17. 4. The adhesive film according to claim 1, wherein the thickness of the substrate is 5 μm or more and 150 μm or less.

18. 4. The adhesive film according to claim 1, wherein the adhesive film has a weight loss of 1.0% or less when heated at 250°C for 30 minutes after the adhesive layer is cured.

19. 4. The adhesive film according to claim 1, wherein the adhesive film has a 180° peel strength from a silicon wafer of 2.0 N / inch or less after the adhesive layer is cured.

20. 4. The adhesive film according to claim 1, 2 or 3, which is used as a temporary fixing material.

21. The adhesive film according to claim 20, which is used as a temporary fixing material for manufacturing electronic parts.

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