Easy-to-dismantle adhesive composition, adhesive sheet, and laminate

Abstract

To provide an adhesive composition that can achieve both high heat resistance and easy dismantling. [Solution] An easily disassembled adhesive composition containing a thermosetting resin (A) having an ester skeleton and an acid generator (B).

Description

Technical Field

[0001] The present invention relates to a readily disassemblable adhesive composition, an adhesive sheet formed using the readily disassemblable adhesive composition, and a laminate.

Background Art

[0002] A readily disassemblable adhesive composition having a certain adhesive strength and also having the property of reducing the adhesive strength at a desired timing to enable easy peeling (disassembly) is in increasing demand for applications such as the separate recovery of dissimilar materials, the repair and replacement of defective parts, and the improvement of productivity by temporary adhesion in the manufacturing process.

[0003] For example, as in Patent Document 1, a readily disassemblable adhesive composition for temporarily fixing a sheet material or a protective substrate to a product being manufactured in a processing step such as grinding of semiconductor products such as semiconductor wafers or capacitors, optical system products, etc. has been proposed.

[0004] Also, in the recycling field (reuse or separate waste treatment), in order to recycle the adhesive substrate, a readily disassemblable adhesive composition that can be easily peeled (disassembled) when it becomes unnecessary has been proposed as a readily disassemblable adhesive composition that can be easily peeled by irradiating the laminate with energy such as heat or light and the substrate can be reused (Patent Documents 2 to 4).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

[0006] However, conventional easily disassembled adhesive compositions, such as those described in Patent Documents 1 to 4, have not been able to adequately achieve both the maintenance of peel strength under high-temperature conditions (heat resistance) and easy disassembly, and further improvements are needed. In this specification, high-temperature conditions refer to a temperature range of approximately 140°C to 250°C.

[0007] This invention has been made in view of the aforementioned problems, and aims to provide an adhesive composition that can achieve both high heat resistance and easy dismantling. [Means for solving the problem]

[0008] In other words, the present invention is as follows: [1] An easily disassembled adhesive composition containing a thermosetting resin (A) having an ester skeleton and an acid generator (B). [2] The easily disassembled adhesive composition according to [1], further comprising a crosslinking agent (C) that improves the crosslink density by reacting with functional groups of the thermosetting resin (A) having an ester skeleton. [3] The easily disassembled adhesive composition according to [1] or [2], wherein the thermosetting resin (A) having the ester skeleton has a carboxyl group as the functional group. [4] The easily dismantled adhesive composition according to [2], wherein the content of the acid generator (B) is 1% by mass or more and 50% by mass or less when the total solid content of the easily dismantled adhesive composition is 100% by mass. [5] The easily dismantled adhesive composition according to [2] or [4], wherein the equivalent ratio (C equivalent / A equivalent) of the equivalent amount of the crosslinking agent (C) to the equivalent amount of the thermosetting resin (A) having an ester skeleton is 0.5 or more and 6 or less. [6] The easily disassembled adhesive composition according to any one of [1] to [5], wherein the thermosetting resin (A) having an ester skeleton is a polyester resin. [7] The easily dismantled adhesive composition according to any one of [2], [4], [5], or [6], wherein the crosslinking agent (C) is an epoxy resin. [8] An easily dismantled adhesive composition according to any one of [1] to [7], further containing filler (D). [9] The easily dismantled adhesive composition according to [8], wherein the filler (D) is an inorganic filler.

[10] The easily dismantled adhesive composition according to [8] or [9], wherein the content of the filler (D) is 1% by mass or more and 50% by mass or less when the total solid content of the easily dismantled adhesive composition is 100% by mass. An easily disassembled adhesive sheet formed using an easily disassembled adhesive composition described in any of

[11] [1] to

[10] .

[12] The peel strength when peeling the cured product of the easily disassembled adhesive sheet, obtained by heat curing while laminated on a substrate, from the substrate at 23°C, 50%RH, with a tensile speed of 300 mm / min and a peel angle of 180°, where A1 is the peel strength before heat treatment of the cured product at 200°C for 1 hour, and A2 is the peel strength after heat treatment of the cured product at 200°C for 1 hour, The easily dismantled adhesive sheet according to

[11] , wherein A1 and A2 satisfy the range of the following formula (1). (A2 / A1) × 100 ≥ 90 ···(1)

[13] The peel strength when peeling a cured product of the easily disassemblable adhesive sheet, obtained by heat curing the sheet in a laminated state on a substrate, from the substrate at 23°C, 50%RH, with a tensile speed of 300 mm / min and a peel angle of 180°, where A3 is defined as the peel strength after irradiation with energy rays without heat treatment at 200°C on the cured product, and A4 is defined as the peel strength after irradiation with energy rays after heat treatment at 200°C on the cured product, The easily dismantled adhesive sheet according to

[12] , wherein A3 and A4 satisfy at least one of the following formulas (2) and (3). (A3 / A1) × 100 ≤ 10 and (A4 / A2) × 100 ≤ 10 ···(2) A3 ≤ 0.3 N / mm and A4 ≤ 0.3 N / mm...(3)

[14] The easily dismantled adhesive sheet according to any one of

[11] to

[13] , wherein the cured product of the easily dismantled adhesive sheet obtained by thermal curing while laminated on a substrate can be peeled off from the substrate by irradiation with energy rays.

[15] The easily dismantled adhesive sheet according to any one of

[11] to

[14] , wherein when the cured product of the easily dismantled adhesive sheet obtained by thermal curing while laminated on a substrate is peeled off from the substrate, a portion of the easily dismantled adhesive sheet remaining on the substrate can be removed with an organic solvent.

[16] A laminate comprising a base material and an easily disassembled adhesive sheet laminated on the base material, A laminate in which the easily disassembled adhesive sheet is formed using an easily disassembled adhesive composition described in any of [1] to

[10] , and the total light transmittance is 85% or more.

[17] The laminate according to

[16] , wherein the haze value is 0.2% or more and 5.2% or less. A method for producing an easily disassembled adhesive sheet using an easily disassembled adhesive composition described in any of

[18] [1] to

[10] , A method for manufacturing an easily disassembled adhesive sheet, comprising molding and drying an easily disassembled adhesive composition under LED lighting.

[19] A method for manufacturing an article, comprising fixing a workpiece, which is a precursor of the article, with an easily disassembled adhesive sheet, processing the workpiece, and then peeling off the easily disassembled adhesive sheet from the workpiece fixed with the easily disassembled adhesive sheet to obtain the processed article, A method for manufacturing an article, wherein the easily dismantled adhesive sheet is described in any one of the items

[11] to

[14] .

[20] A method for dismantling a cured product, comprising curing an easily dismantled adhesive composition containing a thermosetting resin (A) having an ester skeleton and an acid generator (B), and irradiating the cured product with energy rays to dismantle the cured product. [Effects of the Invention]

[0009] The present invention was completed for the first time by the inventors who have intensively studied to improve the heat resistance and the decomposability of a readily decomposable adhesive composition more than before, and by using a thermosetting resin having an ester skeleton as the main component, it was found that the decomposability by an acid can be improved more than before. According to the present invention, by using a thermosetting resin as the main component, while having higher heat resistance than before, a readily decomposable adhesive composition having sufficiently high decomposability more than before can be provided by containing a resin having an ester skeleton and an acid generator.

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited thereto.

[0011] The readily decomposable adhesive composition according to the present embodiment is used, for example, to obtain an adhesive sheet for temporary fixing used in the manufacturing process of electronic components. The adhesive sheet formed by this readily decomposable adhesive composition can be cured at a desired timing by heat, and the cured product can be decomposed at a desired timing by irradiation with an energy ray, so that the cured adhesive sheet can be easily peeled from the adherend.

[0012] <Readily decomposable adhesive composition> The readily decomposable adhesive composition according to the present embodiment contains, for example, a thermosetting resin (A) having an ester skeleton and an acid generator (B).

[0013] The thermosetting resin (A) having an ester skeleton includes not only resins generally known as thermoplastic resins but also resins having thermosetting functional groups and having properties as thermosetting resins. For example, it is one or more resins selected from the group consisting of polyester resins, polyester urethane resins, thermosetting polycarbonate resins, vinyl ester resins, polyester-modified epoxy resins, and rosin esters.

[0014] Examples of polyester resins include Toyobo's "Byron (registered trademark, hereinafter the same) 200 (Mn: 17000, Tg: 67℃, hydroxyl value: 6mgKOH / g, acid value: <2mgKOH / g)", "Byron 220 (Mn: 3000, Tg: 53℃, hydroxyl value: 50mgKOH / g, acid value: <2mgKOH / g)", "Byron 226 (Mn: 8000, Tg: 65℃, hydroxyl value: 20mgKOH / g, acid value: <2mgKOH / g)", and "Byron 296 (Mn: 14000, Tg: 71℃, hydroxyl value: 7mgKOH / g, acid value: 6mgKOH / g)". )", Byron 550 (Mn: 28000, Tg: -15℃, hydroxyl value: 4mgKOH / g, acid value: <2mgKOH / g)", Byron 560 (Mn: 3000, Tg: 7℃, hydroxyl value: 8mgKOH / g, acid value: <2mgKOH / g)", Byron 822 (Mn: 15000, Tg: 68℃, hydroxyl value: 3mgKOH / g, acid value: 5mgKOH / g)", Byron GK150 (Mn: 13000, Tg: 20℃, hydroxyl value: 7mgKOH / g, acid value: 5mgKOH / g)", Byron GK150 (Mn: 13000, Tg: 20℃, "Byron GK360 (Mn: 16000, Tg: 56℃, hydroxyl value: 7mgKOH / g, acid value: 5mgKOH / g)", "Byron GK570 (Mn: 19000, Tg: 0℃, hydroxyl value: 6mgKOH / g, acid value: <2mgKOH / g)", "Byron GK780 (Mn: 11000, Tg: 36℃, hydroxyl value: 11mgKOH / g, acid value: 3mgKOH / g)", "Byron GK810 (Mn: 6000, Tg: 46℃, hydroxyl value: 19mgKOH / g, acid value: 5mgKOH / g)", Byron BX1001 (Mn: 28000, Tg: -18℃, hydroxyl value: 8mgKOH / g, acid value: 2mgKOH / g) Mitsubishi Chemical Corporation "Nichigo Polyester (registered trademark, same below) TP-217 (Tg: 40℃, hydroxyl value: <7mgKOH / g, acid value: <3mgKOH / g)", Nichigo Polyester TP-220 (Tg: 70℃, hydroxyl value: 3~8mgKOH / g, acid value: <3mgKOH / g)", Nichigo Polyester TP-290 (Tg: 10℃, hydroxyl value: 2~6mgKOH / g, acid value: <4mgKOH / g),Examples include "Nichigo Polyester LP-011 (Tg: 4℃, hydroxyl value: 4-8 mgKOH / g, acid value: <3 mgKOH / g)" and "Nichigo Polyester LP-033 (Tg: 15℃, hydroxyl value: 4-8 mgKOH / g, acid value: <1 mgKOH / g)". In addition to these commercially available polyester resins, polyester resins manufactured by known methods may also be used. For example, polyester resins having any molecular weight, Tg (glass transition temperature), and acid value can be produced by methods such as polycondensation of dicarboxylic acid and glycol, or reaction of polyester polyol and tetracarboxylic dianhydride. The glass transition temperature (Tg) of each resin can be determined by differential scanning calorimetry (DSC) in accordance with JIS K7121. Furthermore, the Mn (number-average molecular weight) of each resin can be measured as a polystyrene equivalent value using gel permeation chromatography (GPC).

[0015] Examples of polyester urethane resins include Toyobo's "Byron UR-1350 (Mn: 30000, Tg: 46℃, hydroxyl value: 3~4 mgKOH / g, acid value: <1 mgKOH / g)", "Byron UR-1700 (Mn: 16000, Tg: 92℃, hydroxyl value: 19 mgKOH / g, acid value: 26 mgKOH / g)", and "Byron UR-3500 (Mn: 40000, Examples include "Byron UR6100 (Mn: 25000, Tg: -30℃, hydroxyl value: 4-6mgKOH / g, acid value: <1mgKOH / g)", and "Byron UR-8300 (Mn: 30000, Tg: 23℃, hydroxyl value: 3-4mgKOH / g, acid value: <1mgKOH / g)".

[0016] Preferably, the thermosetting polycarbonate resin has a thermosetting functional group called a hydroxyl group, and its hydroxyl value is between 1 and 10. Specifically, examples include the Yupizeta® RX-P series (hydroxyl value: 2-8 mgKOH / g) manufactured by Mitsubishi Gas Chemical Company.

[0017] Examples of vinyl ester resins include DIC Corporation's "EPICLON UE-8410," "EPICLON UE-8215," and "EPICLON UE-8071-60BH."

[0018] Examples of polyester-modified epoxy resins include "Epoxy Ester M-600A," "Epoxy Ester M40EM," "Epoxy Ester 70PA," and "Epoxy Ester 3000MK," all manufactured by Kyoeisha Chemical Co., Ltd.

[0019] Examples of rosin esters include "Ester Gum AA-L," "Ester Gum 105," "Pensel GA-100," "Pensel C," and "Pensel D-125," all manufactured by Arakawa Chemical Industries, Ltd.

[0020] In this embodiment, the thermosetting resin (A) having an ester skeleton is preferably a resin having an ester skeleton and containing at least one carboxyl group. Specific examples of such resins include polyester resin, polyester urethane resin, and vinyl ester resin. The thermosetting resin (A) having an ester skeleton is more preferably a polyester resin, and particularly preferably an amorphous polyester resin.

[0021] The content of the thermosetting resin (A) having an ester skeleton is preferably 30% to 99% by mass, more preferably 35% to 95% by mass, and even more preferably 40% to 90% by mass, based on 100% by mass of the solids (solid content) of the easily dismantled adhesive composition. A content of 30% by mass or more of the thermosetting resin (A) having an ester skeleton allows the easily dismantled adhesive composition to exhibit sufficient adhesion (peel strength), and a content of 99% or less ensures reliable dismantling, which is preferable. The solid content of the easily dismantled adhesive composition refers to the solid portion remaining after the solvent has been evaporated and removed, if the easily dismantled adhesive composition contains a solvent. The solid content of the easily dismantled adhesive composition according to this embodiment is considered to have approximately the same mass as the adhesive sheet after drying (or curing), as described later.

[0022] The acid generator (B) is a compound that can generate acid by irradiation with energy rays such as ultraviolet rays, X-rays, or gamma rays, or by heat treatment. The easily disassembled adhesive composition in this embodiment may contain one or more acid generators. The acid generator (B) is not particularly limited, and known ones can be widely used.

[0023] Examples of acid generators (B) include onium salt-based acid generators such as iodonium salts and sulfonium salts, triazine-based acid generators, oxime sulfonate-based acid generators, diazomethane-based acid generators such as bisalkylsulfonyl diazomethanes or bisarylsulfonyl diazomethanes, poly(bissulfonyl) diazomethanes, nitrobenzyl sulfonate-based acid generators, iminosulfonate-based acid generators, and disulfone-based acid generators. Among these acid generators, onium salt-based acid generators are preferred because they have a high decomposition temperature.

[0024] Examples of sulfonium salts include (4-phenylthiophenyl)diphenylsulfonium triflate, (4-phenylthiophenyl)diphenylsulfonium tetrakis(pentafluorophenyl)borate, (4-phenylthiophenyl)diphenylsulfonium hexafluorophosphate, (4-phenylthiophenyl)diphenylsulfonium hexafluoroantimonium, triphenylsulfonium triflate, triphenylsulfonium tetrakis(pentafluorophenyl)borate, triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonium, tris(4-methylphenyl)sulfonium) triflate, tris(4-methylphenyl)sulfonium tetrakis(pentafluorophenyl)borate, tris(4-methylphenyl)sulfonium hexafluorophosphate, and tris(4-methylphenyl)sulfonium hexafluoroantimonium.

[0025] Examples of iodonium salts include p-isopropylphenyl-p-tolylliodonium trifluorotris(perfluoroethyl)phosphate, diphenyliodonium hexafluorophosphate, diphenyliodonium triflate, diphenyliodonium tetrafluoroborate, diphenyliodonium hexafluoroarsenate, and bis(4-tert-butylphenyl)iodonium tetrafluoroborate.

[0026] The content of the acid generator (B) is preferably 1% by mass or more and 50% by mass or less, more preferably 5% by mass or more and 30% by mass or less, and even more preferably 5% by mass or more and 20% by mass or less, based on 100% by mass of the solid content of the easily dismantled adhesive composition. If the proportion of the acid generator (B) is 1% by mass or more, the treatment to generate acid and exhibit easy decomposition properties (e.g., exposure) can be performed in a short time, and if it is 50% by mass or less, swelling due to the decomposition of the acid generator by heating and unexpected decomposition of the cured product of the easily decomposed adhesive composition can be suppressed, which is preferable.

[0027] The material may further contain a crosslinking agent (C) that improves the crosslink density by reacting with the functional groups of the thermosetting resin (A) having the ester skeleton. When the crosslinking agent (C) is included, it is preferable that the thermosetting resin (A) having the ester skeleton has a functional group capable of thermosetting reaction for reacting with the crosslinking agent (C). Examples of functional groups that can react with the crosslinking agent (C) in a thermosetting manner include carboxyl groups, epoxy groups, hydroxyl groups, benzoxazine groups, cyanate ester groups, active ester groups, carbodiimide groups, acid anhydride groups, oxetanyl groups, episulfide groups, isocyanate groups, and amino groups. The thermosetting resin (A) having the ester skeleton may have one of these functional groups alone or two or more. Furthermore, the thermosetting resin (A) having the ester skeleton may further contain, as other functional groups, one or more selected from the group consisting of radical polymerizable functional groups such as acrylic groups, methacrylic groups, styryl groups, allyl groups, vinyl groups, propenyl groups, and maleimide groups.

[0028] The crosslinking agent (C) can be used without particular limitations as long as it reacts with the crosslinkable functional groups of the thermosetting resin (A) having the ester skeleton upon heating to produce crosslinking hardening. Examples of such crosslinking agents (C) include amino resins such as melamine resin, benzoguanamine resin, and urea resin, phenolic resins, polyisocyanate resins, metal chelate compounds, polyaziridine resins, polycarbodiimide resins, unsaturated compounds, polyol resins, and epoxy resins. One of these resins may be used alone as the crosslinking agent (C), or two or more may be used in combination.

[0029] For example, when using a thermosetting resin (A) having an ester skeleton in which the functional group is a carboxyl group, it is preferable to use an epoxy resin as the crosslinking agent (C). When using epoxy resin as the crosslinking agent (C), a wide range of epoxy resins can be used, for example, those having two or more epoxy groups in their molecule. Specifically, examples include biphenyl-type epoxy resins, naphthalene-type epoxy resins, naphthol-type epoxy resins, anthracene-type epoxy resins, bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, bisphenol S-type epoxy resins, bisphenol AF-type epoxy resins, novolac-type epoxy resins, trisphenol-type epoxy resins, alicyclic epoxy resins, dicyclopentadiene-type epoxy resins, aliphatic epoxy resins, glycidylamine-type epoxy resins, glycidyleste-type epoxy resins, heterocyclic epoxy resins, and the like. These may be used individually or in combination of two or more types.

[0030] As mentioned above, commercially available epoxy resins such as those listed below can be used.For example, DIC Corporation's "HP-4032", "HP-4032H", "HP-4032D" (naphthalene-type epoxy resin), "HP-4770" (naphthalene-type bifunctional epoxy resin), "HP-4700", "HP-4710" (naphthalene-type tetrafunctional epoxy resin), "HP-5000", "HP-9900" (naphthalene skeleton-modified polyfunctional epoxy resin), "N-690" (cresol novolac-type epoxy resin), "N-890" (bisphenol A-type polyfunctional epoxy resin), "HP-7200", "HP-7200L", "HP-7200H", "HP-7200HH", "HP-7200HH H" (dicyclopentadiene-type epoxy resin), "EXA-1514" (bisphenol S-type epoxy resin), "EXA-7311", "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", "HP-6000" (naphthylene ether type epoxy resin), Nippon Kayaku Co., Ltd.'s "EPPN-502H" (trisphenol type epoxy resin), "NC-7000L" (naphthol novolac type epoxy resin), "NC-3000H", "NC-3000", "NC-3000L", "NC-3100" (biphenyl type epoxy resin), Nippon Steel Chemical & Material Co., Ltd.'s "ESN475V" (naphthalene type epoxy resin), "ESN485" (naphthol novolac type epoxy resin), Mitsubishi Chemical Corporation's "YX4000H", "YL6121" (biphenyl type epoxy resin), "YX4000 HK" (bixylenol type epoxy resin), "YX8800" (anthracene type epoxy resin), Osaka Gas Chemical Co., Ltd.'s "PG-100", "CG-500", Examples include Mitsubishi Chemical's "YL7800" (fluorene-type epoxy resin), "jER(registered trademark, same hereinafter)1010" (solid bisphenol A type epoxy resin), "jER1031S" (tetraphenylethane-type epoxy resin), "jER1004FS" (bisphenol A type epoxy resin), and "YX7700" (structure undisclosed); Daicel's "Epolid PB-3600" and "Epolid(registered trademark, same hereinafter)PB-4700" (epoxidized polybutadiene); and Mitsubishi Chemical's "jERYX7760" (fluorine-containing epoxy resin). In this embodiment, the case in which the easily dismantled adhesive composition contains a crosslinking agent (C) has been described, but the crosslinking agent (C) is not an essential component.

[0031] When a crosslinking agent (C) is included, its content is preferably such that the equivalent ratio of epoxy group equivalents to carboxyl group equivalents (epoxy group equivalents / carboxyl group equivalents) is 0.5 or more and 6 or less, more preferably 1 or more and 5 or less, even more preferably 1.5 or more and 4 or less, and particularly preferably 2 or more and 3 or less, in order to cause a proper curing reaction with the thermosetting resin (A) having the ester skeleton. By setting the equivalent ratio to 0.5 or more, peeling or blistering does not occur even when heat treatment is performed at 200°C or higher, and sufficient heat resistance can be obtained. Furthermore, setting it to 6 or less is preferable because it prevents the acid generated from the acid generator from being inhibited by the excess epoxy resin, and enables the development of decomposition properties in a short time.

[0032] Furthermore, the carboxyl group equivalent of the thermosetting resin (A) having an ester skeleton, used to determine the equivalent ratio mentioned above, can be determined using the acid value of the thermosetting resin (A) having an ester skeleton, using the following formula. (Formula): Carboxylate group equivalent (g / eq) = 56100 / Acid value (mgKOH / g) Furthermore, the acid value can be calculated by titrating with a 0.1N potassium hydroxide-ethanol solution and phenolphthalein as an indicator, and determining the amount of KOH consumed per gram of resin (mgKOH / g).

[0033] The epoxy equivalent of the crosslinking agent (C) used to determine the aforementioned equivalent ratio is the value obtained by dividing the molecular weight of the epoxy compound by the number of epoxy groups in one molecule, and can be determined by potentiometric measurement using a 0.1 mol / L perchloric acid acetic acid standard solution in accordance with JIS K7236.

[0034] The easily dismantled adhesive composition according to this embodiment may contain filler (D). Insofar as it does not lose its properties as an adhesive composition having thermosetting and easily dismantled properties, it may also contain fillers, elastomers, other additives, etc., in addition to the components described above.

[0035] The filler (D) may be an organic filler or an inorganic filler, but an inorganic filler is more preferable. Including an organic filler can improve flexibility and adhesion to the substrate, while including an inorganic filler can adjust the coefficient of thermal expansion and improve heat resistance. Furthermore, omitting filler (D) can increase transparency and keep haze low.

[0036] Examples of organic fillers include acrylic resins, silicone resins, butadiene rubber, polyester, polyurethane, polyvinyl butyral, polyarylate, polymethyl methacrylate, acrylic rubber, polystyrene, NBR, SBR, silicone-modified resins, and organic fine particles of copolymers containing these as components.

[0037] Examples of inorganic fillers include silicates such as talc, calcined clay, uncalcined clay, mica, and glass; oxides such as titanium dioxide, aluminum oxide (alumina), fused silica (fused spherical silica, fused crushed silica), synthetic silica, crystalline silica, and silica oxide; carbonates such as calcium carbonate, magnesium carbonate, and hydrotalcite; hydroxides such as aluminum hydroxide, magnesium hydroxide, and calcium hydroxide; sulfates such as barium sulfate and calcium sulfate; sulfites such as calcium sulfite; borates such as zinc borate, barium metaborate, aluminum borate, calcium borate, and sodium borate; and nitrides such as aluminum nitride, boron nitride, and silicon nitride.

[0038] The shape of filler (D) is not particularly limited and may be, for example, amorphous, spherical, fibrous, or flake-shaped. These fillers may be used individually or in combination of two or more types.

[0039] The average primary particle diameter of the filler (D) is not particularly limited, but is preferably 0.01 μm or more and 20 μm or less, more preferably 0.1 μm or more and 15 μm or less, and particularly preferably 0.5 μm or more and 10 μm or less. A diameter of 0.01 μm or more may be advantageous in terms of the handling and dispersibility of the filler. Furthermore, if it is 20 μm or less, the transparency and mechanical strength of the cured product of the easily disassembled adhesive composition can be improved. The average primary particle diameter of the filler can be measured by known methods, such as scanning electron microscope (SEM), transmission electron microscope (TEM), dynamic light scattering (DLS), and static light scattering.

[0040] If a filler (D) is included, the filler content is preferably 1% by mass or more and 50% by mass or less, more preferably 5% by mass or more and 45% by mass or less, and even more preferably 10% by mass or more and 40% by mass or less, based on 100% by mass of the solid content of the easily dismantled adhesive composition.

[0041] The easily disassembled adhesive composition according to this embodiment may contain other components besides those mentioned above, as long as they do not lose their properties as an adhesive composition having thermosetting and easily disassembled properties. Examples of other components include thermoplastic resins, tackifiers, flame retardants, curing agents, curing accelerators, foaming agents, photosensitizers, coupling agents, thermal aging inhibitors, leveling agents, defoaming agents, pigments, and organic solvents.

[0042] If thermoplastic resins are included as other components, the content of these other components is preferably 40% by mass or less, for example, based on 100% by mass of the solids (solid content) of the easily disassembled adhesive composition, and may be in the range of 30% by mass or less, 20% by mass or less, 10% by mass or less, 5% by mass or less, 1% by mass or less, etc. Depending on the application and required properties of the easily disassembled adhesive composition, only one of the above-mentioned other components may be included, or two or more may be used in combination.

[0043] Examples of thermoplastic resins include urethane resins such as polyurethane (PU) and thermoplastic polyurethane (TPU); vinyl chloride resins such as polycarbonate (PC), polyvinyl chloride (PVC), and vinyl chloride-vinyl acetate copolymer resins; acrylic resins such as polyacrylic acid, polymethacrylic acid, polymethyl polyacrylate, polymethyl methacrylate (PMMA), and polyethyl methacrylate; polyester resins such as polyethylene terephthalate (PET), polybutylene terephthalate, polytrimethylene terephthalate, polyethylene naphthalate, and polybutylene naphthalate; polyamide resins such as nylon (registered trademark); polystyrene (PS), imide-modified polystyrene, and acrylonitrile butadiene. One or more resins selected from the group consisting of polystyrene resins such as styrene (ABS) resin, imide-modified ABS resin, styrene-acrylonitrile copolymer (SAN) resin, and acrylonitrile-ethylene-propylene-diene-styrene (AES) resin; olefin resins such as polyethylene (PE) resin, polypropylene (PP) resin, and cycloolefin resin; cellulose resins such as nitrocellulose and cellulose acetate; thermoplastic resins such as silicone resins and fluororesins; styrene-based thermoplastic elastomers, olefin-based thermoplastic elastomers, vinyl chloride-based thermoplastic elastomers, urethane-based thermoplastic elastomers, ester-based thermoplastic elastomers, and amide-based thermoplastic elastomers can be used.

[0044] The organic solvent is not particularly limited as long as it uniformly dissolves or disperses each component. Specific examples of organic solvents include aromatic hydrocarbons such as benzene, toluene, and xylene; aliphatic hydrocarbons such as hexane, heptane, octane, and decane; alicyclic hydrocarbons such as cyclohexane, cyclohexene, methylcyclohexane, and ethylcyclohexane; halogenated hydrocarbons such as trichloroethylene, dichloroethylene, chlorobenzene, and chloroform; alcoholic solvents such as methanol, ethanol, isopropyl alcohol, butanol, pentanol, hexanol, propanediol, and phenol; ketone solvents such as acetone, methyl isobutyl ketone, methyl ethyl ketone, pentanone, hexanone, cyclohexanone, isophorone, and acetophenone; and methyl cellsolve and ethyl cellsolve. One or more solvents can be selected from the group consisting of cellosolbs such as methyl acetate, ethyl acetate, butyl acetate, methyl propionate, butyl formate, glycol ether solvents such as ethylene glycol mono-n-butyl ether, ethylene glycol mono-iso-butyl ether, ethylene glycol mono-tert-butyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol mono-iso-butyl ether, triethylene glycol mono-n-butyl ether, and tetraethylene glycol mono-n-butyl ether. If a solvent is included, the amount of organic solvent should be within a range that allows the easily disassembled adhesive composition to be applied to a substrate or support, and can be appropriately selected depending on the desired film thickness to which the easily disassembled adhesive composition is to be applied. As an example, it is preferable to add an organic solvent such that the solid content concentration of the easily disassembled adhesive composition is within the range of 10% by mass or more and 70% by mass or less, more preferably 15% by mass or more and 60% by mass or less, and particularly preferably 20% by mass or more and 50% by mass or less.

[0045] <Method for manufacturing (preparing) easily dismantled adhesive compositions> The easily disassembled adhesive composition according to this embodiment can be manufactured (prepared) as a solution (varnish) or slurry in which the components, such as (A), (B), and (C) described above, are uniformly dissolved in a solvent by adding them to a suitable solvent such as the aforementioned organic solvent and stirring. A method for manufacturing the easily disassembled adhesive composition can be described as thoroughly mixing predetermined amounts of raw materials with a mixer or dissolver, and then kneading them with a mixing roll, kneader, bead mill, ball mill, extruder, etc. A solution or slurry of the easily disassembled adhesive composition can be suitably used in the manufacture of adhesive sheets. Alternatively, the solution or slurry of the easily disassembled adhesive composition can be directly applied to a substrate and used as an adhesive by heat curing.

[0046] <Method for curing easily dismantled adhesive compositions> When the easily dismantled adhesive composition is heated, covalent bonds that form three-dimensional crosslinks (intermolecular crosslinks) occur between the aforementioned components (A) or between component (A) and component (C), forming a crosslinked structure and yielding a cured product. The heating process for curing the easily dismantled adhesive composition may be carried out in a single step, from an unheated (unreacted) state to a fully cured state, or it may be carried out by heating until it reaches a semi-cured state, then cooling it once, and then heating it again until it is fully cured. The temperature, heating time, and other conditions for curing the easily dismantled adhesive composition can be appropriately selected depending on the composition of the easily dismantled adhesive composition. However, if the adhesive composition according to this embodiment is heated at 130°C for 1 hour, for example, a completely cured product can be obtained. The conditions for thermosetting are not particularly limited, but for example, the curing temperature is preferably 70°C to 160°C, more preferably 100°C to 160°C, and particularly preferably 110°C to 140°C. The curing time is preferably 1 minute to 240 minutes, more preferably 1 minute to 180 minutes, and particularly preferably 1 minute to 120 minutes. Whether an easily dismantled adhesive composition has completely cured can be determined, for example, by its solubility when immersed in an organic solvent, the change in its infrared absorption spectrum measured by an infrared spectrophotometer, or the amount of heat generated by differential scanning calorimetry (DSC).

[0047] <Method for dismantling cured products of easily dismantled adhesive compositions> When dismantling a cured product obtained by completely curing an easily dismantled adhesive composition using the curing method described above, acid is generated from the oxygen generating agent contained in the cured product by irradiating the cured product with energy rays or by heat treating the cured product. When acid is generated in this way, the ester skeleton of the thermosetting resin (A) having an ester skeleton is hydrolyzed by this acid, causing the cured product to dismantle and reducing its adhesion. Examples of energy beam irradiation include ultraviolet to visible light (approximately 100 nm to approximately 800 nm) energy beams obtained from high-pressure or ultra-high-pressure mercury lamps, metal halide lamps, xenon lamps, carbon arc lamps, fluorescent lamps, semiconductor solid-state lasers, argon lasers, He-Cd lasers, XeCl excimer lasers, XeF excimer lasers, KrF excimer lasers, ArF excimer lasers, F2 lasers, etc. Among these, it is preferable to use a radiation source with a high photohardness of 200 nm to 400 nm. Furthermore, it is also possible to use high-energy radiation such as electron beams and X-rays. Examples of heat treatment include heating or cooling. These treatments for generating acid from these acid generators may be used individually or in combination of two or more.

[0048] <Method for manufacturing adhesive sheets> When manufacturing an adhesive sheet using the easily disassembled adhesive composition according to this embodiment, for example, the sheet can be manufactured by uniformly applying a solution (varnish) or slurry of the easily disassembled adhesive composition prepared as described above onto a support substrate such as a release film or release paper, molding it into a desired shape, and drying it. Using an adhesive sheet in this way is preferable because it allows for the formation of an adhesive layer with good film thickness uniformity and surface smoothness compared to the case where an easily dismantled adhesive composition is applied directly to the adherend.

[0049] The method for applying the easily disassembled adhesive composition onto the above-mentioned substrate can be any known method as appropriate, depending on the desired film thickness or uniformity of the adhesive sheet, and is not particularly limited. Examples of known methods include roll coating, reverse roll coating, transfer roll coating, gravure coating, gravure reverse coating, comma coating, rod coating, blade coating, bar coating, wire bar coating, die coating, lip coating, dip coating, and the like. One method for drying the easily dismantled adhesive composition applied to the above-mentioned substrate is to heat it in order to volatilize the solvent in the adhesive composition. The temperature at this time should be the temperature at which the solvent evaporates. Preferably, it should be between 60°C and 150°C, more preferably between 80°C and 140°C, and particularly preferably between 80°C and 120°C. The drying time is preferably between 10 seconds and 30 minutes, more preferably between 30 seconds and 20 minutes, and particularly preferably between 30 seconds and 10 minutes. Alternatively, the drying process may be carried out by increasing the temperature, or by drying continuously at multiple temperatures and for different durations (for example, 60°C for 30 seconds, 80°C for 60 seconds, 100°C for 60 seconds, etc.).

[0050] The thickness of the dried adhesive sheet formed on the substrate is preferably 1 μm to 100 μm, more preferably 1 μm to 50 μm, and particularly preferably 5 μm to 30 μm. A thickness of 1 μm or more of the adhesive sheet makes it easier to obtain good adhesion and reactivity to energy rays, while a thickness of 100 μm or less makes it possible to more reliably prevent outgassing and decomposition of the acid generator under high-temperature conditions. Furthermore, it is preferable to handle and manufacture the adhesive sheet according to this embodiment under LED lighting used as indoor lighting. With LED lighting used as indoor lighting, the amount of irradiation in the specific wavelength range (especially the ultraviolet region) that causes many acid generators to decompose and generate acid is extremely small, and it is considered that the generation of acid from acid generators due to ultraviolet light can be suppressed, and the properties of the adhesive sheet will not be affected. Therefore, when manufacturing the adhesive sheet according to this embodiment, it is not necessary to use a yellow room (a room or booth covered with an ultraviolet cut filter to prevent photosensitivity by ultraviolet light) or lighting that cuts out specific wavelength ranges, resulting in excellent productivity. This is also true in the manufacturing process of the easily disassembled resin composition, laminate, and articles using them according to this embodiment.

[0051] The support substrate (also simply called the substrate) is preferably one or more selected from resin films, paper substrates, metal foils, glass substrates, semiconductor wafers, or composites thereof. In particular, when used as a release substrate when manufacturing an adhesive sheet, it is preferable that the film allows the adhesive sheet, which has been formed into a film, to be peeled off the film and that the adhesive sheet can be transferred onto the surface to be processed, such as a workpiece. This substrate may, for example, have an uneven surface. When used as a release substrate, it is preferable that the film thickness of the release substrate is 1 μm or more and 125 μm or less, as this makes it easier to ensure the flexibility of the adhesive sheet.

[0052] Specific examples of the aforementioned resin film include polyester resin, polyamide resin, polyimide resin, polyamide-imide resin, polycarbonate resin, liquid crystal polymer, polyphenylene sulfide, syndiotactic polystyrene, polyolefin resin, fluororesin, or various olefin films such as polyethylene, polypropylene, ethylene-α-olefin copolymer, and propylene-α-olefin copolymer, as well as polyethylene terephthalate. When used as a release substrate, it is preferable to use a resin film that has a release layer formed by applying a release agent such as a silicone-based, fluorine-based, or alkyd-based agent to it.

[0053] Examples of paper substrates include fine paper, kraft paper, roll paper, and glassine paper. A coating layer of a sealant such as clay, polyethylene, or polypropylene may be applied to one or both sides of these paper substrates. When used as a release substrate, it is preferable to use one that further includes the aforementioned release layer on top of the coating layer.

[0054] Examples of metal foils include those made from various metals such as SUS, copper, aluminum, iron, steel, zinc, and nickel, as well as their alloys, plated products, and metals treated with other metals such as zinc or chromium compounds. When used as a release substrate, it is preferable that the release layer described above is formed on one or both sides. Furthermore, this adhesive sheet can also be cured using the same method as the easily dismantled adhesive composition described above.

[0055] <Method for manufacturing laminates> A method for producing a laminate comprising an adhesive sheet made of the easily disassembled adhesive composition according to this embodiment is as follows: For example, from an adhesive sheet prepared as described above, in which release substrates are laminated on both sides thereof, one release substrate is peeled off, and a heating roller is rotated and moved from the other release substrate side to heat-press the adhesive sheet onto the surface of the substrate (e.g., the workpiece) which is the adherend, the remaining release substrate is peeled off, and another substrate is similarly heat-pressed onto the other side of the adhesive sheet to obtain a laminate precursor. The laminate precursor thus obtained is heated and pressed to heat-cur the adhesive sheet and obtain a fully cured product, thereby obtaining a laminate. Another method for obtaining a laminate is to directly apply an easily disassembled adhesive composition to the substrate (e.g., the workpiece) and then heat-cur it. The conditions for heating and pressing are not particularly limited, but one example is a method in which the temperature is 70°C to 180°C, the pressing pressure is 0.5 MPa to 5 MPa, and the pressing time is 1 second to 240 minutes. Furthermore, if air bubbles remain in the adhesive sheet or between layers, it may lead to a decrease in appearance quality and adhesion strength, so it is preferable to heat and press under vacuum conditions. Also, the heat curing may be performed simultaneously with the heating and pressing, or it may be performed in a separate process. If it is performed in a separate process, a hot plate, constant temperature bath, autoclave, etc., can be used for heat curing.

[0056] <Manufacturing method for processed parts that require a temporary fixing step during manufacturing> Examples of methods for manufacturing articles that use the easily dismantled adhesive composition and adhesive sheet obtained in this embodiment for temporary fixing include the following: First, a laminate is manufactured by bonding the workpiece, which is a precursor to the article, to a support material using a cured adhesive sheet in the same procedure as described above for manufacturing the laminate. Next, the workpiece is subjected to processing such as cutting and polishing. After the processing is complete, the cured adhesive sheet in the laminate is irradiated with energy rays or subjected to heat treatment to break down the cured material, thereby peeling the cured material off the workpiece to obtain the article, which is the processed product.

[0057] <Effects of this embodiment> The easily dismantled adhesive composition according to this embodiment can provide the following effects. Since the material contains a thermosetting resin (A) having an ester skeleton and an acid generator (B), it is thought that decomposition (especially hydrolysis of the ester skeleton) occurs due to the acid generated from the acid generator (B) after energy irradiation, reducing adhesion to the substrate and enabling easy decomposition. Furthermore, since it contains a crosslinking agent (C) and uses a thermosetting resin (A) having an ester skeleton with functional groups that can react with the crosslinking agent (C), the density of the three-dimensional crosslinks formed during thermosetting can be improved, further enhancing heat resistance and adhesion (peel strength). In addition, since the equivalent ratio of reactive functional groups of the thermosetting resin (A) having an ester skeleton and the crosslinking agent (C) is within an optimal range, the thermosetting resin (A) having an ester skeleton and the crosslinking agent (C) can react appropriately, and as a result, even higher heat resistance and adhesion (peel strength) can be achieved.

[0058] Specifically, the easily disassembled adhesive composition according to this embodiment contains a thermosetting resin (A) having an ester skeleton and an acid generator (B) as described above, so it is possible to provide an adhesive sheet with the following properties.

[0059] The peel strength when peeling a cured adhesive sheet obtained by heat-curing an adhesive sheet laminated on a substrate from the substrate at 23°C, 50%RH, with a tensile speed of 300 mm / min and a peel angle of 180°, where A1 is the peel strength before heat treatment at 200°C for 1 hour and A2 is the peel strength after heat treatment at 200°C for 1 hour, can be such that A1 and A2 satisfy the range of the following formula (1). (A2 / A1) × 100 ≥ 90 ···(1)

[0060] Thus, the easily disassembled adhesive composition and the adhesive sheet formed using this easily disassembled adhesive composition according to this embodiment provide an adhesive sheet that exhibits sufficient heat resistance, with no decrease in peel strength even after heat treatment at 200°C. Since the material can be dismantled by irradiation with energy rays, for example, even when used in a soldering process for components used in electronic circuits, dismantling will not begin even at high temperatures of around 200°C, which is the melting point of solder, thus further enhancing heat resistance.

[0061] Furthermore, as described above, the easily disassembled adhesive composition according to this embodiment contains a thermosetting resin (A) having an ester skeleton and an acid generator (B), so it is possible to provide an adhesive sheet that exhibits sufficient disassembly properties as follows. The peel strength when peeling a cured adhesive sheet, obtained by heat curing an adhesive sheet laminated on a substrate, from the substrate at 23°C, 50%RH, a tensile speed of 300 mm / min, and a peel angle of 180°, is defined as follows: if the peel strength after irradiation with energy rays without heat treatment at 200°C is A3, and the peel strength after heat treatment at 200°C and then irradiation with energy rays is A4, then A3 and A4 can satisfy at least one of the following equations (2) and (3). (A3 / A1) × 100 ≤ 10 and (A4 / A2) × 100 ≤ 10 ···(2) A3 ≤ 0.3 N / mm and A4 ≤ 0.3 N / mm...(3)

[0062] According to the laminate manufactured using the easily disassembled adhesive composition and adhesive sheet of this embodiment, since a highly light-transmitting resin such as polyester resin is used as the main component of the thermosetting resin (A) having an ester skeleton, if a substrate is used as the base material constituting the laminate whose total light transmittance is equal to or greater than that of the cured product of the easily disassembled adhesive composition, and whose haze value is equal to or less than that of the cured product of the easily disassembled adhesive composition, it is possible to manufacture a laminate with a total light transmittance of 85% to 95%, more preferably 89% to 93%, and a haze value of 5.2% or less. The haze value is more preferably 3% or less, and particularly preferably 1% or less. By setting the total light transmittance of the laminate to 85% or more and the haze value to 5.2% or less, it is not only possible to facilitate the alignment of components in the manufacturing process of the articles described above, but it is also possible to suitably use the laminate according to this embodiment in applications where aesthetic appeal is required or where high transmittance is required (e.g., optical applications). The total light transmittance can be determined by measuring the diffuse transmittance (DT) and the total light transmittance (TT) using a commercially available haze meter. Furthermore, the haze value can be calculated using the following formula (4). As the haze meter, a HazeMeter NDH8000 (manufactured by Nippon Denshoku Industries Co., Ltd.) or an equivalent product conforming to JIS K7361-1 can be used. Haze value (%) = (DT / TT) × 100 ... (4) Furthermore, the substrates whose total light transmittance is equal to or greater than that of the cured product of the easily dismantled adhesive composition, and whose haze value is equal to or less than that of the cured product of the easily dismantled adhesive composition, are not particularly limited, and general substrates such as acrylic plates and glass plates can be used as appropriate.

[0063] The cured product of the easily dismantled adhesive composition or adhesive sheet according to this embodiment is dismantled by the acid generated from the acid generator, which breaks down the three-dimensional crosslinked structure and reduces its molecular weight. Therefore, after dismantling and peeling it off the adherend, any residue remaining on the adherend surface can be easily removed or cleaned. Methods for removing or cleaning the adhesive layer adhering to the substrate after peeling include one or more methods such as ultraviolet laser, infrared laser, ashing, ultrasonic treatment, immersion in water or acid, alkali, or organic solvent, or wiping with a brush or cloth soaked in a solvent. Wiping with an organic solvent is preferable because it allows for easier removal and cleaning of the residue. Specific procedures for wiping with an organic solvent include directly applying the organic solvent to the cured product of the easily dismantled adhesive composition remaining on the surface of the substrate and then wiping it with a cloth, or impregnating a cloth with an organic solvent and then wiping the surface of the substrate with the cloth. Removal and cleaning can be made easier by immersing the cured product remaining on the substrate surface in an organic solvent for a predetermined time before wiping, or by performing ultrasonic treatment before wiping. The organic solvent used is not particularly limited, and any organic solvent used in the production of the easily disassembled adhesive composition according to this embodiment can be used. In particular, it is preferable to use a low-polarity solvent such as acetone or methyl ethyl ketone. As described above, the easily disassembled adhesive composition or adhesive sheet according to this embodiment allows for easy removal of the cured material from the substrate, and any remaining cured material can be easily removed and washed away. This improves the recyclability when recycling substrates used in the manufacture of products or when disassembling and recycling laminates. [Examples]

[0064] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. First, adhesive compositions for Examples 1-15 and Comparative Examples 1-3 were prepared, each containing the components shown in Tables 1 and 2 as solids in the proportions shown in Table 1. Each adhesive composition was obtained by mixing the components and adding methyl ethyl ketone to achieve a solid content concentration of 40%, followed by stirring.

[0065] Next, each resin composition of Examples 1 to 15 and Comparative Examples 1 to 3 described above was applied to a 50 μm thick non-silicone release PET film (second release substrate described later, manufactured by Higashiyama Film Co., Ltd., HYNS70), and dried at 120°C for 5 minutes to produce an adhesive sheet with a thickness of 10 μm. A silicone release PET film (first release substrate described later, manufactured by Higashiyama Film Co., Ltd., HY-US20) was laminated by roll lamination at 120°C, 0.3 MPa, and 1.0 m / min so as to cover the side of the adhesive sheet opposite to the side in contact with the non-silicone release PET film.

[0066] The components in Tables 1 and 2 are as follows. In addition, α in the tables indicates the epoxy equivalent ratio to the carboxyl group equivalent of component A. A-1) Polyester resin (Tg: 15℃, Mn: 16,000, Acid value: 7mgKOH / g) A-2) Polyester resin (Tg: 50℃, Mn: 20,000, Acid value: 19 mg KOH / g) A') Maleic anhydride-modified styrene-diene block copolymer (Product name: ToughTec® M1913, manufactured by Asahi Kasei Corporation, Acid value: 10 mg CH3ONa / g) B) Acid generator: (4-phenylthiophenyl)diphenylsulfonium hexafluorophosphate (manufactured by Tokyo Chemical Industry Co., Ltd.) C-1) Epoxy resin (Product name: YX7700, manufactured by Mitsubishi Chemical Corporation, epoxy equivalent: 260-285 g / eq) C-2) Epoxy resin (Product name: jER1004FS, manufactured by Mitsubishi Chemical Corporation, epoxy equivalent: 770-850 g / eq) C-3) Epoxy resin (Product name: N-890, manufactured by DIC Corporation, epoxy equivalent: 200-220 g / eq) D) Inorganic filler (Product name: CT-76, manufactured by Asada Flour Milling Co., Ltd.)

[0067] As mentioned above, the following evaluation tests were conducted on each adhesive sheet manufactured, and the results are shown in Tables 1 and 2. <Heat resistance evaluation> The first release substrate was peeled off from each adhesive sheet in Examples 1-15 and Comparative Examples 1-3, and roll-laminated with 100 μm thick aluminum foil at 120°C, 0.3 MPa, and 1.0 m / min. The second release substrate was peeled off this laminate, and a 1 mm thick glass substrate (high-grade soda glass manufactured by Muto Chemical Co., Ltd. (76 mm x 26 mm x 1.0 mm)) was heat-pressed onto it under the same conditions. Vacuum heating and pressing was performed at 140°C, 1 MPa for 30 seconds, and then heat curing was performed in a constant temperature bath at 140°C for 1 hour to obtain a sample for evaluating peel strength in which the adhesive sheet was fully cured. In each of the following evaluations, the laminate obtained after heat curing is considered the initial state (initial). Peel strength was measured using a universal tester (product name: Strograph VGS05-E, manufactured by Toyo Seiki Co., Ltd.) at 23°C and 50% RH, with aluminum foil applied, a peel width of 5 mm, and a tensile speed of 300 mm / min to perform a 180° peel test, and the initial peel strength (A1) was measured. Samples for evaluating peel strength, prepared using the same procedure as described above, were heat-treated in a 200°C constant temperature bath for 1 hour. A peel test was then performed under the same conditions as described above, and the peel strength (A2) after heat treatment was measured. Based on the results of these peel tests, the retention rate (heat resistance) of the initial peel strength (A1) and the peel strength after heat treatment (A2) was calculated and evaluated using the following formula 1. (Peel strength after heat treatment A2) / (Initial peel strength A1) × 100 ... (1) The evaluation criteria for the results of Equation 1 are as follows: ◎...Over 100% 〇...90% or more and 100% or less ×···Less than 90%

[0068] <Assessment of dismantlingability> A sample for peel strength evaluation, prepared using the same procedure as that used for heat resistance evaluation, was subjected to exposure testing using an exposure device (HTE-3000NEL-N, manufactured by Fuse Technonet Co., Ltd.) with an integrated exposure dose of 1000 mJ / cm². 2 The material was irradiated with UV energy rays to achieve the desired result. After UV irradiation, a peel test was performed under the same conditions as the heat resistance evaluation, and the peel strength (A3) was measured. The sample for evaluating peel strength, prepared using the same procedure as described above, was heat-treated in a 200°C constant temperature bath for 1 hour. Subsequently, an exposure device (HTE-3000NEL-N, manufactured by Fuse Technonet Co., Ltd.) was used to achieve an integrated exposure of 3000 mJ / cm². 2 UV light was applied to achieve the desired result. After UV irradiation, a peel test was performed under the same conditions as the heat resistance evaluation, and the peel strength (A4) was measured. Based on these A3 and A4 values, the retention rate of peel strength (destructibility) after UV irradiation before and after heat treatment was determined using the following equations 2(2a and 2b). (Peel strength after UV irradiation A3 / Peel strength after UV irradiation A1) × 100 ... (2a) (Peeling strength after UV irradiation A4 / Peeling strength after UV irradiation A2) × 100 ... (2b) The results of Equation 2 and the value of A3 were evaluated according to the following evaluation criteria. Condition A: The values ​​calculated by Equation 2a and Equation 2b are both 10% or less. Condition B: Peel strength A3 and A4 after UV irradiation are both 0.3 N / mm or less. ◎...Meets both condition A or condition B. ○... Either condition A or condition B must be met. ×...Neither condition A nor B is met.

[0069] <Evaluation of total light transmittance and haze value> The first release substrate was peeled off from each adhesive sheet in Examples 1-15 and Comparative Examples 1-3, and roll-laminated with a 125 μm thick polycarbonate substrate (product name: Panlite® PC-2151, manufactured by Teijin Corporation) at 120°C, 0.3 MPa, and 1.0 m / min. The second release substrate was peeled off from this laminate, and the aforementioned polycarbonate substrate was heat-pressed onto it under the same conditions. Vacuum heating and pressing was performed at 140°C, 1 MPa, for 30 seconds, and then thermocuring was performed in a constant temperature bath at 140°C for 1 hour to obtain samples for evaluating total light transmittance and haze. Total light transmittance was measured using a HazeMeter NDH8000 (manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with JIS K7361-1, and diffuse transmittance (DT) and total light transmittance (TT) were measured. The haze value was calculated from the following equation 4. Haze value (%) = (DT / TT) × 100 ... (4)

[0070] <Evaluation of cleanability> In the evaluation of disassembly ease, the cured material remaining on the substrate surface after peeling off the cured adhesive sheet was wiped off with a cotton swab impregnated with methyl ethyl ketone, and the cleanability at that time was evaluated according to the following evaluation items. Evaluation criteria for cleaning performance ◎····Can be wiped off by rubbing with a cotton swab two times or less. ○····Can be wiped away by rubbing with a cotton swab, 3 to 20 times. △····Even after rubbing more than 20 times, some residue remains. ×····Do not wipe off

[0071] [Table 1]

[0072] [Table 2]

[0073] <Consideration> From the results in Table 1, it was found that in Examples 1 to 15, which contained both a thermosetting resin (A) having an ester skeleton and an acid generator (B), the peel strength A2 after heat treatment was equal to or greater than the peel strength before heat treatment in the heat resistance evaluation, indicating very high heat resistance. Furthermore, in the dismantling evaluation, the peel strength after energy ray irradiation was sufficiently low regardless of whether heating was performed, indicating that the adhesive sheet also possessed high dismantling properties. Furthermore, it was confirmed that similar results could be obtained by changing the type of thermosetting resin having an ester skeleton and the type of crosslinking agent, as shown in Examples 1 to 6. The same applies when the content of the acid generator is changed, as in Examples 10-13. In contrast, Comparative Examples 1 and 2, which do not contain an acid generator, show no decrease in peel strength after energy ray irradiation, indicating poor decomposition. Furthermore, in Comparative Example 3, where the thermosetting resin used as the main component does not have an ester skeleton, despite containing an acid generator, the results are as shown in the Examples. Compared to examples 1-15, the disassembly properties were clearly worse, suggesting that in examples 1-15 of the present invention, the ester skeleton of the thermosetting resin used as the main component was hydrolyzed by the acid, resulting in high disassembly properties. Furthermore, while Examples 14 and 15, which contain fillers, appear to have little effect on heat resistance under the heat treatment (200°C) described in Table 1, it is thought that their heat resistance will improve under even higher temperature conditions such as 250°C. In these examples and comparative examples, an acid generator that generates acid by energy ray irradiation (specifically UV irradiation) is used. However, even if an acid generator that generates acid by other types of energy rays or heat treatment is used, the mechanism of hydrolysis of ester bonds remains the same, and similar results are expected to be obtained.

Claims

1. An easily disassembled adhesive composition containing a thermosetting resin (A) having an ester skeleton and an acid generator (B).

2. The easily disassembled adhesive composition according to claim 1, further comprising a crosslinking agent (C) that improves the crosslink density by reacting with functional groups of the thermosetting resin (A) having an ester skeleton.

3. The easily disassembled adhesive composition according to claim 2, wherein the thermosetting resin (A) having the ester skeleton has a carboxyl group as the functional group.

4. The easily dismantled adhesive composition according to claim 1, wherein the content of the acid generating agent (B) is 1% by mass or more and 50% by mass or less when the total solid content of the easily dismantled adhesive composition is 100% by mass.

5. The easily dismantled adhesive composition according to claim 2, wherein the equivalent ratio (C equivalent / A equivalent) of the equivalent amount of the crosslinking agent (C) to the equivalent amount of the thermosetting resin (A) having the ester skeleton is 0.5 or more and 6 or less.

6. The easily disassembled adhesive composition according to claim 1, wherein the thermosetting resin (A) having an ester skeleton is a polyester resin.

7. The easily dismantled adhesive composition according to claim 2, wherein the crosslinking agent (C) is an epoxy resin.

8. The easily dismantled adhesive composition according to claim 1, further comprising filler (D).

9. The easily dismantled adhesive composition according to claim 8, wherein the filler (D) is an inorganic filler.

10. The easily dismantled adhesive composition according to claim 8, wherein the content of the filler (D) is 1% by mass or more and 50% by mass or less when the total solid content of the easily dismantled adhesive composition is 100% by mass.

11. An easily disassembled adhesive sheet formed using the easily disassembled adhesive composition described in any one of claims 1 to 10.

12. The peel strength when peeling a cured product of the easily disassemblable adhesive sheet, obtained by heat curing the laminated adhesive sheet onto a substrate, from the substrate at 23°C, 50% RH, with a tensile speed of 300 mm / min and a peel angle of 180°, where A1 is the peel strength before heat treatment at 200°C for 1 hour and A2 is the peel strength after heat treatment at 200°C for 1 hour, The easily dismantled adhesive sheet according to claim 11, wherein A1 and A2 satisfy the range of the following formula (1). (A2 / A1)×100≧90...(1)

13. The peel strength when peeling a cured product of the easily disassemblable adhesive sheet, obtained by heat curing the sheet in a laminated state on a substrate, from the substrate at 23°C, 50% RH, with a tensile speed of 300 mm / min and a peel angle of 180°, where A3 is defined as the peel strength after irradiation with energy rays without heat treatment at 200°C, and A4 is defined as the peel strength after heat treatment at 200°C followed by irradiation with energy rays, The easily dismantled adhesive sheet according to claim 12, wherein A3 and A4 satisfy at least one of the following formulas (2) and (3). (A3 / A1) × 100 ≤ 10 and (A4 / A2) × 100 ≤ 10 ... (2) A3 ≤ 0.3 N / mm and A4 ≤ 0.3 N / mm ... (3)

14. The easily dismantled adhesive sheet according to claim 11, wherein the cured product of the easily dismantled adhesive sheet, obtained by thermal curing while laminated on a substrate, can be peeled off from the substrate by irradiation with energy rays or heat treatment.

15. The easily dismantled adhesive sheet according to claim 11, wherein when the cured product of the easily dismantled adhesive sheet obtained by heat curing while laminated on a substrate is peeled off from the substrate, a portion of the easily dismantled adhesive sheet remaining on the substrate can be removed with an organic solvent.

16. A laminate comprising a base material and an easily disassembled adhesive sheet laminated on the base material, The aforementioned easily dismantled adhesive sheet A laminate formed using an easily disassembled adhesive composition described in any one of claims 1 to 10, wherein the total light transmittance is 85% or more.

17. The laminate according to claim 16, wherein the haze value is 0.2% or more and 5.2% or less.

18. A method for producing an easily disassembled adhesive sheet using the easily disassembled adhesive composition described in any one of claims 1 to 10, A method for manufacturing an easily disassembled adhesive sheet, comprising molding and drying an easily disassembled adhesive composition under LED lighting.

19. A method for manufacturing an article, comprising fixing a workpiece, which is a precursor to the article, with an easily disassembled adhesive sheet, processing the workpiece, and then peeling off the easily disassembled adhesive sheet from the workpiece that was fixed with the easily disassembled adhesive sheet to obtain the processed article, A method for manufacturing an article, wherein the easily dismantled adhesive sheet is as described in claim 11.

20. A method for dismantling a cured product, comprising curing an easily dismantled adhesive composition containing a thermosetting resin (A) having an ester skeleton and an acid generator (B), and then irradiating the cured product with energy rays or heat-treating the cured product.

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