Adhesive composition, adhesive sheet, method for manufacturing the same, and adhesive composition kit

Abstract

The present invention provides an adhesive that exhibits good durability and an adhesive composition suitable for forming the same. [Solution] The adhesive composition comprises an acrylic polymer and an acid component (excluding a carboxylic acid). The adhesive composition contains an alkoxysilane compound, or the acrylic polymer has an alkoxysilyl group.

Description

[Technical Field]

[0001] The present invention relates to adhesive compositions, adhesive sheets, methods for manufacturing the same, and adhesive composition kits, and more particularly to adhesive compositions used for bonding optical components such as optical films. [Background technology]

[0002] Adhesives are used to bond optical components. For example, liquid crystal displays and organic light-emitting diode (EL) displays are used as display devices in electronic equipment. The various optical components that make up such display devices are generally fixed with adhesives. In particular, there is a growing trend towards lighter and thinner display devices for vehicles, outdoor instruments, and personal computers. In such display devices, optical films, such as surface protection films or polarizing films, may be attached to and fixed to the display using adhesives.

[0003] Such adhesive layers require durability. In particular, it is desirable that peeling or foaming does not occur at the edges of the adhesive layer in high-temperature environments. Patent Document 1 discloses that the strength of the adhesive layer is improved and peeling at the edges is suppressed by increasing the amount of isocyanate curing agent and increasing the degree of crosslinking. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2011-37927 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] Reference 1 also discloses that increasing the amount of isocyanate curing agent too much to improve the strength of the adhesive layer can lead to peeling, especially in high-temperature environments. Thus, there was a need for approaches other than simply increasing the amount of curing agent to improve the durability of the adhesive.

[0006] One embodiment of the present invention provides an adhesive that exhibits good durability and an adhesive composition suitable for forming the same. [Means for solving the problem]

[0007] The adhesive composition according to one embodiment of the present invention has the following configuration: An adhesive composition comprising an acrylic polymer and an acid component (excluding a carboxylic acid), wherein the adhesive composition contains an alkoxysilane compound, or the acrylic polymer has an alkoxysilyl group. [Effects of the Invention]

[0008] This invention provides an adhesive that exhibits good durability and an adhesive composition suitable for forming the same. [Modes for carrying out the invention]

[0009] The embodiments will be described in detail below. Note that the following embodiments do not limit the invention as defined in the claims, and not all combinations of features described in the embodiments are essential to the invention. Two or more of the features described in the embodiments may be combined in any way. Furthermore, identical or similar configurations will be given the same reference numeral, and redundant descriptions will be omitted.

[0010] An adhesive composition according to one embodiment of the present invention comprises an acrylic polymer (A) and an acid component (excluding carboxylic acid) (C). Furthermore, this adhesive composition may contain an alkoxysilane compound (B), or the acrylic polymer (A) may have an alkoxysilyl group. The adhesive composition may also be in a mixed form of the acrylic polymer (A), the acid component (C), the alkoxysilane compound (B) if necessary, and a solvent if necessary. Alternatively, the adhesive composition may be a combination of multiple unmixed compositions. For example, the adhesive composition may be a combination of a separate first composition and a second composition. An adhesive composition kit according to one embodiment of the present invention may comprise multiple compositions, such as a first composition and a second composition. In one embodiment, the first composition may contain an acrylic polymer (A) and an acid component (excluding carboxylic acid) (C). The second composition may contain an alkoxysilane compound (B), or an acrylic polymer (A1) having an alkoxysilyl group.

[0011] In one embodiment, the first composition may be, for example, a composition comprising an acrylic polymer (A), an acid component (C), and optionally a solvent. The second composition may be a composition comprising an alkoxysilane compound (B), optionally a crosslinking agent (D), and optionally a solvent.

[0012] In another embodiment, the first composition may be, for example, a composition comprising an acrylic polymer (A), an acid component (C), and optionally a solvent. The second composition may be a composition comprising an alkoxysilane compound (B) and optionally a solvent. Furthermore, the adhesive composition may have a third composition comprising a crosslinking agent (D) and optionally a solvent.

[0013] In one embodiment, the first composition may be, for example, an acrylic polymer (A2) that does not have an alkoxysilyl group, as described later, an acid component (C), and optionally a solvent. The second composition may be an acrylic polymer (A1) that has an alkoxysilyl group, as described later, and optionally an alkoxysilane compound (B), optionally a crosslinking agent (D), and optionally a solvent.

[0014] These multiple compositions can be mixed and used before forming an adhesive layer. That is, the adhesive composition according to one embodiment may be a kit comprising the first composition, the second composition, and optionally a third composition.

[0015] <Acrylic polymer (A)> Acrylic polymer (A) is a homopolymer or copolymer of unsaturated carboxylic acids. In this specification, unsaturated carboxylic acids include unsaturated carboxylic acids and dehydration condensates of unsaturated carboxylic acids with other components. For example, unsaturated carboxylic acids include unsaturated carboxylic acid esters and unsaturated carboxylic acid amides. Furthermore, acrylic polymer (A) may be a polymer of two or more monomers. That is, acrylic polymer (A) may be an oligomer or a polymer.

[0016] In one embodiment, the acrylic polymer (A) is a homopolymer or copolymer of (meth)acrylic acids. That is, the acrylic polymer (A) may have one or more repeating units derived from (meth)acrylic acids (hereinafter referred to as "(meth)acrylic acid repeating units"). In this specification, (meth)acrylic acid refers to acrylic acid and methacrylic acid. Also, (meth)acrylate refers to acrylate and methacrylate.

[0017] As described above, the acrylic polymer (A) may contain (meth)acrylic acid repeating units. For example, the acrylic polymer (A) may contain one or both of the first repeating units and the second repeating units described later.

[0018] The first repeating unit is an example of a (meth)acrylic acid repeating unit. The first repeating unit is distinguished from the second repeating unit described below. The first repeating unit is, for example, a (meth)acrylic acid repeating unit that does not have the functional group included in the second repeating unit described below. A specific example of the first repeating unit is a repeating unit derived from a hydrocarbon group (meth)acrylate or a hydrocarbon group (meth)acrylate having an internal ether bond. Here, the number of carbon atoms of the hydrocarbon group and the number of carbon atoms of the hydrocarbon group having an internal ether bond are, for example, 1 or more and 14 or less.

[0019] Examples of the hydrocarbon group (meth)acrylate include alkyl (meth)acrylates, aralkyl (meth)acrylates, and aryl (meth)acrylates.

[0020] Examples of alkyl (meth)acrylate include alkyl (meth)acrylates having a linear or branched alkyl group, such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, sec-butyl (meth)acrylate, n-pentyl (meth)acrylate, isopentyl (meth)acrylate, n-hexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 1-methylheptyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, n-undecyl (meth)acrylate, n-dodecyl (meth)acrylate, n-tridecyl (meth)acrylate, n-tetradecyl (meth)acrylate; and alkyl (meth)acrylates having an alicyclic alkyl group, such as cyclohexyl (meth)acrylate, 4-tert-butylcyclohexyl (meth)acrylate, isobornyl (meth)acrylate, and dicyclopentanyl (meth)acrylate.

[0021] Examples of aralkyl (meth)acrylate include benzyl (meth)acrylate, 2-phenylethyl (meth)acrylate, and naphthylmethyl (meth)acrylate.

[0022] Examples of aryl (meth)acrylate include phenyl (meth)acrylate, tolyl (meth)acrylate, and naphthyl (meth)acrylate.

[0023] Examples of (meth)acrylate having a hydrocarbon group containing an internal ether bond include alkoxyalkyl (meth)acrylate, aryloxyalkyl (meth)acrylate, alkyl polyoxyalkylene (meth)acrylate, and aryl polyoxyalkylene (meth)acrylate.

[0024] Examples of alkoxyalkyl (meth)acrylates include 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, and 2-butoxyethyl (meth)acrylate.

[0025] Examples of aryloxyalkyl (meth)acrylates include 2-phenoxyethyl (meth)acrylate and 3-phenoxypropyl (meth)acrylate.

[0026] Examples of alkyl polyoxyalkylene (meth)acrylates include 2-(2-ethoxyethoxy)ethyl (meth)acrylate and methoxypolyethylene glycol (meth)acrylate.

[0027] Examples of aryl polyoxyalkylene (meth)acrylates include phenoxydiethylene glycol (meth)acrylate, phenoxytriethylene glycol (meth)acrylate, and nonylphenoxypolyethylene glycol (meth)acrylate.

[0028] The second repeating unit is another example of a (meth)acrylic acid repeating unit. The second repeating unit is a (meth)acrylic acid repeating unit having a functional group.

[0029] In one embodiment, the functional group of the second repeating unit is a functional group that has bonding properties with an alkoxysilane compound (B) or its polymer. For example, the functional group of the second repeating unit is a functional group that has bonding properties with an alkoxysilyl group, a silanol group, or a siloxane bond. The functional group of the second repeating unit can bond with an alkoxysilyl group, a silanol group, or a siloxane bond via a bond-forming reaction, or can interact with an alkoxysilyl group, a silanol group, or a siloxane bond via hydrogen bonding. The presence of such a functional group in the second repeating unit can further improve the strength and durability of the adhesive layer. On the other hand, alkoxysilane compounds, such as silane coupling agents, can generally interact with organic components such as acrylic polymers (A). Therefore, it is not essential that the acrylic polymer (A) has repeating units with functional groups, such as the second repeating unit.

[0030] In one embodiment, the functional group of the second repeating unit is an active hydrogen-containing group or a substituent that is a precursor of an active hydrogen-containing group. Examples of active hydrogen-containing groups include substituents having -OH, -NH, or -SH. Examples of substituents having -OH include hydroxyl groups and carboxyl groups. Examples of substituents having -NH include amino groups. In this specification, amino groups include amide groups. Examples of substituents having -SH include thiol groups. Examples of substituents that are precursors of active hydrogen-containing groups include epoxy groups and alkoxysilyl groups.

[0031] In one embodiment, the functional group of the second repeating unit is at least one of a hydroxyl group, an alkoxysilyl group, an epoxy group, a carboxyl group, and an amino group. In this specification, an alkoxysilyl group refers to a silyl group having at least one alkoxy group. An alkoxysilyl group may be, for example, a trialkoxysilyl group, a dialkoxyalkylsilyl group, an alkoxydialkylsilyl group, or a tri(alkoxyalkoxy)silyl group. In one embodiment, the amino group is a primary or secondary amino group, or a primary or secondary amide group.

[0032] The functional groups of the second repeating unit may be directly bonded to the main chain of the acrylic polymer (A) as side chains. Alternatively, the functional groups of the second repeating unit may be bonded to the main chain of the acrylic polymer (A) via hydrocarbon groups or hydrocarbon groups having internal ether bonds. The number of carbon atoms in the hydrocarbon group is, for example, 1 to 14, preferably 1 to 6. An example of such a hydrocarbon group is an alkylene group. The number of carbon atoms in the hydrocarbon group having internal ether bonds is, for example, 1 to 20, preferably 1 to 14. An example of such a hydrocarbon group having internal ether bonds is an alkylene oxyalkylene group.

[0033] The second repeating unit may be, for example, a repeating unit derived from a (meth)acrylate having a hydroxyl group, a (meth)acrylate having an alkoxysilyl group, a (meth)acrylate having an epoxy group, (meth)acrylic acid, or (meth)acrylamides. Alternatively, the second repeating unit may be, for example, an alkyl (meth)acrylate or an alkoxyalkyl (meth)acrylate, where the alkyl group or alkoxy group is substituted with the functional group described above.

[0034] Examples of (meth)acrylates having a hydroxyl group include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate.

[0035] Examples of (meth)acrylates having an alkoxysilyl group include alkoxysilylalkyl (meth)acrylates such as 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 3-(meth)acryloxypropyldimethylmethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, and 3-(meth)acryloxyoctyltrimethoxysilane.

[0036] Examples of (meth)acrylates having an epoxy group include epoxyalkyl (meth)acrylates such as glycidyl (meth)acrylate, 2-methylglycidyl (meth)acrylate, and 3,4-epoxycyclohexylmethyl (meth)acrylate, as well as epoxyalkoxyalkyl (meth)acrylates such as 4-hydroxybutyl (meth)acrylate glycidyl ether.

[0037] Examples of (meth)acrylamides include (meth)acrylamide, isopropyl(meth)acrylamide, dimethylaminopropyl(meth)acrylamide, and hydroxyethyl(meth)acrylamide.

[0038] The acrylic polymer (A) may further contain repeating units other than (meth)acrylic acid repeating units. For example, the acrylic polymer (A) may contain repeating units derived from vinyl monomers such as styrene, α-methylstyrene, vinyltoluene, vinylpyridine, vinylpyrrolidone, vinyl acetate, and acrylonitrile.

[0039] Furthermore, the acrylic polymer (A) may contain repeating units having the above-mentioned functional groups, but not (meth)acrylic acid repeating units. For example, the acrylic polymer (A) may contain repeating units having the above-mentioned functional groups, derived from vinyl monomers such as vinyltrimethoxysilane, vinyltriethoxysilane, or vinyltris(β-methoxyethoxy)silane.

[0040] In one embodiment, the acrylic polymer (A) contains repeating units having functional groups. For example, the acrylic polymer (A) may contain the above-mentioned second repeating unit, or repeating units having functional groups that are not (meth)acrylic acid repeating units. The repeating units having functional groups may have two or more or two or more types of functional groups. Furthermore, the acrylic polymer (A) may contain two or more types of repeating units having functional groups. Thus, the acrylic polymer (A) can have two or more types of functional groups in its side chains.

[0041] In one embodiment, the acrylic polymer (A) includes a repeating unit having a functional group in addition to the first repeating unit.

[0042] The proportion of (meth)acrylic acid repeating units in 100 parts by mass of acrylic polymer (A) is, from the viewpoint of obtaining appropriate adhesion, for example, 50 parts by mass or more, preferably 70 parts by mass or more, more preferably 90 parts by mass or more, while on the other hand, 100 parts by mass or less.

[0043] The proportion of repeating units having functional groups, or second repeating units, in 100 parts by mass of acrylic polymer (A) is, from the viewpoint of obtaining an appropriate storage modulus, for example, 0.1 parts by mass or more and 50 parts by mass or less, preferably 0.2 parts by mass or more and 20 parts by mass or less, more preferably 0.5 parts by mass or more and 15 parts by mass or less, and even more preferably 1 part by mass or more and 10 parts by mass or less.

[0044] From the viewpoint of obtaining an appropriate storage modulus, the proportion of the first repeating unit in 100 parts by mass of the acrylic polymer (A) is, for example, 80 parts by mass or more and 99.9 parts by mass or less, preferably 85 parts by mass or more and 99.8 parts by mass or less, more preferably 87 parts by mass or more and 99.5 parts by mass or less, and even more preferably 90 parts by mass or more and 99 parts by mass or less.

[0045] In one embodiment, the acrylic polymer (A) contains either or both repeating units derived from butyl acrylate and repeating units derived from methyl acrylate. From the viewpoint of obtaining an appropriate storage modulus, the proportion of repeating units derived from butyl acrylate in 100 parts by mass of the acrylic polymer (A) is, for example, 35 parts by mass or more and 90 parts by mass or less, preferably 50 parts by mass or more and 85 parts by mass or less. From the viewpoint of obtaining an appropriate storage modulus, the proportion of repeating units derived from methyl acrylate in 100 parts by mass of the acrylic polymer (A) is, for example, 0 parts by mass or more and 60 parts by mass or less, preferably 5 parts by mass or more and 45 parts by mass or less, and more preferably 10 parts by mass or more and 30 parts by mass or less.

[0046] The molecular weight of the acrylic polymer (A) is not particularly limited. The acrylic polymer (A) may be an oligomer having a weight-average molecular weight of, for example, less than 100,000. Alternatively, the acrylic polymer (A) may be a polymer having a weight-average molecular weight of 100,000 or more. The weight-average molecular weight of the oligomer acrylic polymer (A) is, for example, 500 or more and less than 100,000, preferably 1,000 or more and less than 100,000, and more preferably 10,000 or more and less than 100,000. The weight-average molecular weight of the polymer acrylic polymer (A) is, for example, 100,000 or more and 10,000,000 or less, preferably 100,000 or more and 5,000,000 or less, and more preferably 1,000,000 or more and 3,000,000 or less. In this specification, the weight-average molecular weight is the polystyrene-equivalent molecular weight measured by gel permeation chromatography.

[0047] In one embodiment, the acrylic polymer (A) may have two or more first repeating units, or two or more second repeating units. Alternatively, the acrylic polymer (A) may have only the first repeating units, or only the second repeating units. Furthermore, the adhesive composition may contain one or more acrylic polymers (A).

[0048] As described above, in one embodiment, the acrylic polymer (A) has an alkoxysilyl group. The acrylic polymer (A1) having an alkoxysilyl group may be an acrylic polymer containing repeating units having an alkoxysilyl group as a functional group. For example, the acrylic polymer (A1) having an alkoxysilyl group may contain side chains having an alkoxysilyl group. In one embodiment, the acrylic polymer (A1) having an alkoxysilyl group is an acrylic polymer containing the above-mentioned second repeating unit having an alkoxysilyl group as a functional group. Furthermore, in one embodiment, the acrylic polymer (A1) having an alkoxysilyl group is an acrylic polymer containing the above-mentioned first repeating unit and the above-mentioned second repeating unit having an alkoxysilyl group as a functional group. In one embodiment, the weight-average molecular weight of the acrylic polymer (A1) is, for example, 5 million or more and less than 10 million, preferably 10 million or more and less than 5 million, and more preferably 10,000 or more and less than 100,000.

[0049] In one embodiment, the adhesive composition containing an acrylic polymer (A1) having an alkoxysilyl group does not contain an alkoxysilane compound (B). In this case, the proportion of repeating units having an alkoxysilyl group, or second repeating units having an alkoxysilyl group, in 100 parts by mass of the acrylic polymer (A1) is, from the viewpoint of obtaining an appropriate storage modulus, for example, 5 parts by mass or more and 80 parts by mass or less, preferably 10 parts by mass or more and 70 parts by mass or less, more preferably 20 parts by mass or more and 60 parts by mass or less, and even more preferably 30 parts by mass or more and 50 parts by mass or less. On the other hand, in one embodiment, the adhesive composition containing an acrylic polymer (A1) having an alkoxysilyl group may contain an alkoxysilane compound (B).

[0050] In one embodiment, the adhesive composition contains, in addition to the acrylic polymer (A1) having alkoxysilyl groups, an acrylic polymer (A2) that is different from the acrylic polymer (A1) having alkoxysilyl groups and does not have alkoxysilyl groups. The acrylic polymer (A2) may be, for example, an acrylic polymer containing the first repeating unit described above. The acrylic polymer (A2) may also be an acrylic polymer containing the second repeating unit described above, which has a functional group other than an alkoxysilyl group as a functional group. Furthermore, the acrylic polymer (A2) may also be an acrylic polymer containing the first repeating unit described above and the second repeating unit described above, which has a functional group other than an alkoxysilyl group as a functional group. The further acrylic polymer (A2) is distinguished from the acrylic polymer (A1) having alkoxysilyl groups in that it does not have alkoxysilyl groups.

[0051] In one embodiment, the amount of acrylic polymer (A1) having alkoxysilyl groups relative to 100 parts by mass of acrylic polymer (A) (total amount of acrylic polymer (A1) having alkoxysilyl groups and acrylic polymer (A2) not having alkoxysilyl groups) is, for example, 1 part by mass or more and 1000 parts by mass or less, preferably 2 parts by mass or more and 200 parts by mass or less, more preferably 5 parts by mass or more and 100 parts by mass or less.

[0052] <Alkoxysilane compound (B)> Alkoxysilane compound (B) is a compound having an alkoxysilyl group or an oligomer thereof. Oligomers of compounds having an alkoxysilyl group are oligomers linked via siloxane bonds and are generally called silicone oligomers or silicone alkoxy oligomers. Alkoxysilane compound (B) may be, for example, an organoalkoxysilane or organopolysiloxane. In one embodiment, alkoxysilane compound (B) is a silane coupling agent. On the other hand, alkoxysilane compound (B) is distinguished from acrylic polymers (A1) having alkoxysilyl groups in which (meth)acrylic acids are linked via carbon chains.

[0053] The molecular weight of the alkoxysilane compound (B), which is a compound having an alkoxysilyl group, is not particularly limited and may be, for example, 500 or less. Furthermore, the molecular weight of the monomer of the oligomer alkoxysilane compound (B) is not particularly limited and may be, for example, 500 or less.

[0054] Organoalkoxysilanes can be hydrocarbons having an alkoxysilyl group, for example. The number of carbon atoms in the hydrocarbon is, for example, 1 to 14, preferably 1 to 6. Organoalkoxysilanes can be, for example, alkylalkoxysilanes, alkenylalkoxysilanes, or arylalkoxysilanes. Furthermore, hydrocarbons having an alkoxysilyl group may have further substituents. Examples of further substituents include (meth)acryloxy groups, epoxy groups, mercapto groups, or amino groups.

[0055] Specific examples of organoalkoxysilanes include methyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(β-methoxyethoxy)silane, 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 3-(meth)acryloxypropyldimethylmethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, 3-(meth)acryloxyoctyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-glycidoxypropyltrimethoxysilane.

[0056] Organopolysiloxanes are compounds having a siloxane skeleton. Organopolysiloxanes can be oligomers of the organoalkoxysilanes mentioned above.

[0057] The adhesive composition may contain one or more alkoxysilane compounds (B).

[0058] From the viewpoint of improving the strength of the adhesive layer, the amount of alkoxysilane compound (B) contained in the adhesive composition according to one embodiment is preferably 0.01 parts by mass or more and 25 parts by mass or less, more preferably 0.02 parts by mass or more and 20 parts by mass or less, and even more preferably 0.05 parts by mass or more and 15 parts by mass or less, per 100 parts by mass of acrylic polymer (A).

[0059] <Acid component (C)> The type of acid component (C) is not particularly limited. On the other hand, from the viewpoint of improving the durability of the adhesive layer, it is preferable that the acid component (C) is something other than a carboxylic acid.

[0060] In one embodiment, the acid component (C) is a protonic acid. The acid component (C) may be, for example, an inorganic acid or a partial ester of an inorganic acid. Alternatively, the acid component (C) may be an organic sulfonic acid or an organic phosphoric acid, or a partial ester of an organic phosphoric acid. The acid component (C) may also be an anhydride of such a protonic acid.

[0061] Examples of inorganic acids include hydrochloric acid, hydrobromic acid, hydroiodic acid, sulfuric acid, sulfurous acid, persulfuric acid, disulfuric acid, disulfite, dithionic acid, dithionic acid, thiosulfuric acid, thiosulfite, nitric acid, phosphoric acid, phosphorous acid, phosphonic acid, phosphonic acid, carbonic acid, silicic acid, and boric acid. Partial esters of inorganic acids may be esters of inorganic acids with alcohol having 1 to 14 carbon atoms, preferably 1 to 6 carbon atoms. Examples of partial esters of inorganic acids include dibutyl phosphate, diethyl phosphate, ethyl sulfate, and dodecyl sulfate.

[0062] Organic sulfonic acids may be, for example, alkyl sulfonic acids having 1 to 14 carbon atoms, preferably 1 to 6 carbon atoms, or aryl sulfonic acids having 6 to 20 carbon atoms, preferably 6 to 14 carbon atoms. Specific examples of organic sulfonic acids include methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, and dodecylbenzenesulfonic acid. Organic phosphoric acids may be, for example, alkyl phosphoric acids having 1 to 14 carbon atoms, preferably 1 to 6 carbon atoms, or aryl phosphoric acids having 6 to 20 carbon atoms, preferably 6 to 14 carbon atoms. Specific examples of organic phosphoric acids include methylphosphonic acid and dimethylphosphinic acid. Partial esters of organic phosphoric acids may be esters of organic phosphoric acids with alcohols having 1 to 14 carbon atoms, preferably 1 to 6 carbon atoms.

[0063] From the viewpoint of improving the durability of the adhesive layer, the amount of acid component (C) contained in the adhesive composition according to one embodiment is preferably 0.001 parts by mass or more and 25 parts by mass or less, more preferably 0.02 parts by mass or more and 20 parts by mass or less, and even more preferably 0.05 parts by mass or more and 15 parts by mass or less, per 100 parts by mass of the acrylic polymer (A).

[0064] The adhesive composition may contain one or more acidic components (C).

[0065] <Crosslinking agent (D)> The crosslinking agent (D) has the effect of curing the adhesive composition by crosslinking the acrylic polymer (A). However, in one embodiment, the alkoxysilyl groups or siloxane bonds of the acrylic polymer (A) or alkoxysilane compound (B) also have the effect of curing the adhesive composition, so it is not essential that the adhesive composition contains the crosslinking agent (D).

[0066] The type of crosslinking agent (D) is not particularly limited. Examples of crosslinking agents (D) include isocyanate-based curing agents, epoxy-based curing agents, metal chelate-based curing agents, and aziridine-based curing agents. The crosslinking agent (D) can be selected according to the type of acrylic polymer (A). For example, a crosslinking agent (D) that reacts with the functional groups in the side chains of the acrylic polymer (A) can be selected. Specifically, if the acrylic polymer (A) has a hydroxyl group, epoxy group, carboxyl group, or amino group, an isocyanate-based curing agent can be selected as the curing agent (B).

[0067] Examples of isocyanate-based curing agents include polyfunctional isocyanate compounds such as tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, tetramethyl xylylene diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate, and polymethylene polyphenyl isocyanate. Another example of isocyanate-based curing agents is an adduct compound of an isocyanate compound and a polyol compound such as trimethylolpropane. Yet another example of isocyanate-based curing agents is the burette, allophanate, and isocyanurate forms of isocyanate compounds.

[0068] Examples of epoxy curing agents include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, N,N-diglycidylaniline, N,N,N',N'-tetraglycidyl-m-xylylenediamine, 1,3-bis(N,N'-diglycidylaminomethyl)cyclohexane, and N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane.

[0069] Examples of metal chelating curing agents include coordination compounds of polyvalent metals such as aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium, or zirconium with acetylacetone or ethyl acetoethyl acetate.

[0070] Examples of aziridine-based curing agents include N,N'-(4,4'-methylenediphenyl)bis(aziridine-1-carboxamide), 1,1'-isophthaloylbis(2-methylaziridine), tris(1-aziridinyl)phosphine oxide, 1,1'-hexamethylenebis(iminocarbonyl)bisaziridine, trimethylolpropane-tris(2-aziridinylpropionate), and 2,4,6-tris(1-aziridinyl)-1,3,5-triazine.

[0071] From the viewpoint of improving the strength of the adhesive layer, the amount of crosslinking agent (D) contained in the adhesive composition according to one embodiment is preferably 0 parts by mass or more and 10 parts by mass or less, more preferably 0.05 parts by mass or more and 2.0 parts by mass or less, even more preferably 0.1 parts by mass or more and 1.0 part by mass or less, and particularly preferably 0.15 parts by mass or more and 0.8 parts by mass or less, per 100 parts by mass of acrylic polymer (A).

[0072] The adhesive composition may contain one or more crosslinking agents (D).

[0073] <Other additives> The adhesive composition may contain other resins or additives. Examples of additives include curing retarders, antistatic agents, tackifiers, antioxidants, heat stabilizers, light stabilizers, UV absorbers, leveling agents, defoamers, antibacterial agents, humectants, pigments, dyes, and fragrances. The adhesive composition may contain one or more of these additives.

[0074] <Manufacturing method> The adhesive composition according to this embodiment can be prepared by known methods. For example, an adhesive composition can be prepared by mixing an acrylic polymer (A) and an acid component (C), and optionally an alkoxysilane compound (B), a crosslinking agent (D), a solvent, and an additive.

[0075] Acrylic polymer (A) can be prepared by known methods. For example, acrylic polymer (A) can be prepared by solution polymerization. Specifically, acrylic polymer (A) can be prepared by polymerizing a mixture of a solvent, monomer, and polymerization initiator in an inert gas atmosphere such as nitrogen gas at a temperature of about 50 to 90°C for 4 to 12 hours.

[0076] As solvents, for example, ester-based solvents such as methyl acetate, ethyl acetate, or butyl acetate; ketone-based solvents such as acetone, methyl ethyl ketone, or methyl isobutyl ketone; or hydrocarbon-based solvents such as toluene, xylene, hexane, or heptane can be used.

[0077] Radical polymerization initiators can be used as polymerization initiators. Specific examples of polymerization initiators include persulfates such as potassium persulfate, sodium persulfate, or ammonium persulfate; oil-soluble azo compounds such as 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis(isobutyric acid)dimethyl, or 1,1'-azobis(cyclohexane-1-carbonitride); and 2,2'-azobis[2-methyl-N- Examples include water-soluble azo compounds such as (2-hydroxyethyl)propionamide, 2,2'-azobis[2-(2-imidazolin-2-yl)propane] or its salts, 2,2'-azobis(2-methylpropionamidine) or its salts, or 4,4'-azobis(4-cyanovaleric acid) or its salts; or organic peroxides such as benzoyl peroxide, cumene hydroperoxide, t-butyl hydroperoxide, t-butylperoxy-2-ethylhexanoate, or t-butylperoxyisobutyrate.

[0078] <How to use> An adhesive layer can be prepared using the adhesive composition according to this embodiment. For example, an adhesive layer can be prepared by applying the adhesive composition and drying it. The resulting adhesive layer can be used to bond optical components such as surface protection films or polarizing films.

[0079] The method of applying the adhesive composition is not particularly limited. For application, for example, a Meyer bar, applicator, brush, spray, roller, gravure coater, die coater, lip coater, comma coater, knife coater, reverse coater, or spin coater can be used. The drying method is also not particularly limited. Examples of drying methods include hot air drying, infrared drying, and reduced pressure drying. Drying conditions can be selected according to the composition of the adhesive composition, film thickness, and type of solvent. In one embodiment, drying is performed at 80°C to 150°C, preferably 100°C to 140°C.

[0080] The thickness of the resulting adhesive layer is not particularly limited. For example, the thickness of the adhesive layer is 1 μm to 200 μm, preferably 3 μm to 100 μm.

[0081] Thus, the method for manufacturing an adhesive sheet according to one embodiment includes a step of forming an adhesive layer from an adhesive composition. For example, by forming an adhesive layer on a base sheet, an adhesive sheet comprising a base sheet and an adhesive layer can be manufactured. Alternatively, by forming an adhesive layer on a release sheet and peeling the adhesive layer from the release sheet, an adhesive sheet consisting only of an adhesive layer can be manufactured. In this way, the adhesive sheet according to one embodiment comprises an adhesive layer formed from an adhesive composition.

[0082] Furthermore, the adhesive sheet according to one embodiment includes an adhesive layer. This adhesive layer contains an acrylic polymer (A) and an acid component (C) excluding a carboxylic acid, and the adhesive layer contains an alkoxysilane compound (B), or the acrylic polymer (A) has an alkoxysilyl group.

[0083] An adhesive layer obtained using the adhesive composition according to one embodiment has high strength. In one embodiment, the storage modulus of the obtained adhesive layer at 23°C is 8.0 × 10⁻⁶. 4 Pa or higher, preferably 10 × 10 4 Pa or higher, more preferably 12 × 10 4 Pa or higher, and more preferably 15 × 10 4 It is Pa or higher. On the other hand, the storage modulus is, for example, 30 × 10⁻⁶. 4 It could be Pa or lower.

[0084] An adhesive layer obtained using the adhesive composition according to one embodiment has high strength even at high temperatures. In one embodiment, the storage modulus of the obtained adhesive layer at 200°C is 4.0 × 10⁻⁶. 4 The pressure is Pa or higher, preferably 5.5 × 10⁻⁶ 4 Pa or higher, more preferably 7.0 × 104 Pa or higher, more preferably 8.0×10 4 Pa or higher. On the other hand, the storage modulus may be, for example, 15×10 4 Pa or less.

[0085] The pressure-sensitive adhesive layer obtained using the pressure-sensitive adhesive composition according to one embodiment exhibits a small decrease in strength at high temperatures. For example, in one embodiment, the storage modulus ratio (storage modulus at 23°C / storage modulus at 200°C) of the obtained pressure-sensitive adhesive layer is less than 3.0, preferably less than 2.5, and more preferably less than 2.0. On the other hand, the storage modulus ratio may be, for example, 1.5 or higher.

[0086] The pressure-sensitive adhesive layer obtained using the pressure-sensitive adhesive composition according to one embodiment has high holding power at high temperatures. For example, in one embodiment, the loss tangent tanδ (loss modulus / storage modulus) at 200°C of the obtained pressure-sensitive adhesive layer is less than 0.2, preferably less than 0.15, and more preferably less than 0.10. On the other hand, tanδ may be, for example, 0.005 or higher.

[0087] In the present specification, the storage modulus refers to shear storage modulus. Further, the storage modulus and tanδ are measured as described in the Examples, with the thickness of the pressure-sensitive adhesive film set to 25 µm, using a solid shear jig, at a frequency of 1 Hz and a temperature increase rate of 3°C / min.

[0088] As described above, the pressure-sensitive adhesive layer obtained using the pressure-sensitive adhesive composition according to one embodiment has high strength and holding power particularly at high temperatures. On the other hand, according to the pressure-sensitive adhesive composition according to one embodiment, peeling between the obtained pressure-sensitive adhesive layer and an adherend such as an optical member can also be suppressed. Therefore, in one embodiment, a pressure-sensitive adhesive exhibiting good durability can be achieved.

[0089] According to the inventors' research, a durable adhesive can be realized by adding an acid component (C) to an adhesive composition in addition to an alkoxysilane compound (B) or an acrylic polymer (A1) having an alkoxysilyl group. Although the reason is not clear, the inventors consider that the acid component (C) promotes the hydrolysis of the alkoxysilyl group or alkoxysilane compound (B) of the acrylic polymer (A1), forming a strong crosslinked structure via the silyl group, and that this crosslinked structure brings about a bond between the adherend and the adhesive, or that the acid component brings about a strong covalent bond between the adherend and the adhesive. [Examples]

[0090] [Production of acrylic polymers containing alkoxysilyl groups (A1) (A1-1 to A1-3)] A reaction apparatus equipped with a stirrer, thermometer, sequential dropper, reflux condenser, and nitrogen inlet tube was filled with nitrogen gas, and then 80 parts toluene, 20 parts methyl ethyl ketone, and 0.3 parts polymerization initiator (2,2'-azobisisobutyronitrile) were added. Meanwhile, a monomer mixture containing the amounts of monomer components shown in Table 1 was prepared in a separate container. The reaction apparatus was heated to 90°C in a nitrogen gas stream, and the monomer mixture measured in the separate container was added dropwise over 120 minutes, and the polymerization reaction was carried out at 90°C for 7 hours. After the reaction was completed, the mixture was cooled and diluted with toluene to obtain acrylic polymers (A1) (A1-1 to A1-3) having alkoxysilyl groups and a solid content of 50% by mass. The weight-average molecular weight of the obtained acrylic polymer (A1) was 60,000.

[0091] [Production of acrylic polymers (A2) (A2-1 to A2-9) that do not contain alkoxysilyl groups] In a reaction apparatus equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet tube, nitrogen gas was sealed in, and the monomer components, 70 parts by mass of ethyl acetate, and 0.05 parts by mass of polymerization initiator (2,2'-azobisisobutyronitrile) in the amounts shown in Table 1 were added. The mixture was reacted at 60°C for 5 hours while stirring in a nitrogen gas stream to obtain acrylic polymers (A2) (A2-1 to A2-9) that do not contain alkoxysilyl groups. The weight-average molecular weight of the obtained acrylic polymer (A2) was 2.2 million.

[0092] [Examples and Comparative Examples] An adhesive composition was obtained by adding the types and amounts of acrylic polymers (A1), acrylic polymers (A2), alkoxysilane compounds (B), acid components (C), and crosslinking agents (D) shown in Table 2, and mixing them thoroughly. Table 2 shows the solid content in parts by mass of each component.

[0093] An adhesive layer was prepared by applying the obtained adhesive composition onto a release film. This adhesive layer contains reaction products between an acrylic polymer and a crosslinking agent.

[0094] [Measurement of storage modulus] Adhesive layers were prepared using the adhesive compositions obtained in each example and comparative example, and the storage modulus of the obtained adhesive layers was measured. Specifically, an adhesive layer with a thickness of 25 μm was prepared by first applying the adhesive composition to a release film and drying it at 120°C.

[0095] The shear storage modulus of the obtained adhesive layer was measured. Specifically, the fabricated adhesive layer was clamped in a solid shearing jig, and the storage modulus (G') and loss modulus (G'') were measured at a frequency of 1 Hz using a Rheogel-E4000 (product name) manufactured by UBM. Measurements were performed at 23°C and 200°C. In addition, the storage modulus ratio (storage modulus (G') at 23°C / storage modulus (G') at 200°C) was calculated. Furthermore, the loss tangent tanδ (loss modulus (G'') / storage modulus (G')) at 200°C was calculated. The measurement results are shown in Table 1.

[0096] The storage modulus (G') at 23°C is 8.0 × 10⁻⁶. 4 The strength is high when it is Pa or higher, 8.0 × 10 4 We evaluated the strength as low if it was less than Pa. Furthermore, the storage modulus (G') at 200°C was 4.0 × 10⁻⁶. 4 The strength is high when it is Pa or higher, 4.0 × 10 4 A value of less than Pa was considered to indicate low strength. Furthermore, a storage modulus ratio of 3.0 or higher was considered to indicate a small decrease in temperature at high temperatures, while a value less than 3.0 was considered to indicate a large decrease in strength at high temperatures. Additionally, a tanδ of less than 0.2 at 200°C was considered to indicate high holding power, while a tanδ of 0.2 or higher was considered to indicate low holding power.

[0097] [Durability evaluation] The adhesive compositions obtained in each example and comparative example were used to bond optical components, and the durability of the adhesion was evaluated. Specifically, the adhesive composition was first applied to a silicone resin-coated PET film (release substrate). The solvent was removed by drying the coating film at 120°C to create an adhesive layer with a thickness of 25 μm. A 110 μm thick polarizing film (TAC) was bonded to the adhesive layer side of the PET film, and then stored in an atmosphere of 23°C and 50% RH for 7 days. In this way, an evaluation sample with a size of 80 mm × 150 mm was prepared.

[0098] After attaching the evaluation samples to glass, they were left in a dry atmosphere at 105°C for 1000 hours. Afterward, foaming and peeling of the evaluation samples were visually inspected. The measurement results are shown in Table 1. In Table 1, ○ indicates that the area of ​​peeling or foaming at the edge of the polarizing film is less than 1 mm from the edge. × indicates that the area of ​​peeling or foaming at the edge of the polarizing film is 1 mm or more from the edge.

[0099] [Table 1]

[0100] [Table 2-1]

[0101] [Table 2-2]

[0102] The abbreviations shown in Tables 1 and 2 represent the following components. BA: Butyl acrylate MA: Methyl acrylate PHEA: 2-Phenoxyethyl acrylate VAC: Vinyl acetate HEA: 2-hydroxyethyl acrylate GMA: Glycidyl methacrylate AM: Acrylamide AAC: Acrylic acid KBM-503: Silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., 3-methacryloxypropyltrimethoxysilane) KR-519: Silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., methyl mercapto-based alkoxy oligomer) KR-516: Silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., epoxy-based alkoxy oligomer) PTSA: p-toluenesulfonic acid D-262: Isocyanurate derivative of tolylene diisocyanate (manufactured by Mitsui Chemicals Polyurethane Co., Ltd., product name: Takenate D-262) D-101E: Adduct of tolylene diisocyanate and polyol compound (manufactured by Mitsui Chemicals, Inc., product name: Takenate D-101E (45EA))

[0103] As shown in Table 2, adhesive layers prepared using the adhesive compositions of Examples 1-2, 4-30, and 33, which contain an acrylic polymer (A), an alkoxysilane compound (B), and an acid component (C), exhibited good durability and strength at high temperatures. Furthermore, as shown in Table 2, adhesive layers prepared using the adhesive compositions of Examples 1-3 and 31-34, which contain an acrylic polymer (A2) having an alkoxysilyl group and an acid component (C), also exhibited good durability and strength at high temperatures. For example, as shown in Examples 3 and 4, adhesive layers exhibiting good durability and strength at high temperatures were obtained by including an alkoxysilane compound (B) in the adhesive composition or by having an alkoxysilyl group in the acrylic polymer (A2). Even when the adhesive composition contained both an acrylic polymer (A1) without an alkoxysilyl group and an acrylic polymer (A2) having an alkoxysilyl group, adhesive layers exhibiting good durability and strength at high temperatures were obtained. Furthermore, these adhesive layers exhibited high storage modulus at both room temperature and high temperatures. Additionally, the decrease in storage modulus with increasing temperature was small. Moreover, these adhesive layers showed low loss tangent at high temperatures.

[0104] In particular, as shown in Examples 28-30, the adhesive layer showed good durability even when the adhesive composition did not contain a crosslinking agent (D). Also, as shown in Examples 1-3 and 6-14, the adhesive layer showed good durability regardless of the composition of the acrylic polymer (A). Furthermore, as shown in Examples 6, 18, and 19, the adhesive layer showed good durability regardless of the composition of the alkoxysilane compound (B). From these results, it can be understood that various compounds containing various silane coupling agents, not limited to the compounds used in the examples, can be used as the alkoxysilane compound (B). In addition, as shown in Examples 24-27, the adhesive layer showed good durability when various acid components (C) other than carboxylic acids were used.

[0105] On the other hand, as shown in the comparison between Example 6 and Comparative Example 1, adhesive layers prepared using adhesive compositions that did not contain the acid component (C) did not exhibit good durability. Furthermore, as shown in the comparison between Example 6 and Comparative Example 4, adhesive layers prepared using adhesive compositions containing a carboxylic acid as the acid component (C) did not exhibit good durability. In addition, as shown in the comparison between Example 6 and Comparative Example 2, when the acrylic polymer (A) did not have an alkoxysilyl group and the adhesive composition did not contain an alkoxysilane compound (B), the adhesive layer did not exhibit good durability. These adhesive layers exhibited low storage modulus at both room temperature and high temperature. Moreover, these adhesive layers showed a large decrease in storage modulus with increasing temperature. Furthermore, these adhesive layers showed a high loss tangent at high temperature.

[0106] Furthermore, as shown in the comparison between Comparative Example 1 and Comparative Example 3, it can be understood that increasing the amount of crosslinking agent increased the elastic modulus of the adhesive layer, i.e., improved the strength of the adhesive layer. However, even though the strength of the adhesive layer was improved by increasing the amount of crosslinking agent, peeling or foaming could not be suppressed. This result demonstrates the effectiveness of the method of adding an acid component (C) to the adhesive composition, as shown in Examples 10 and 28.

[0107] Furthermore, according to one embodiment of the present invention, by improving the durability of the adhesive, it is possible to reduce the disposal of adherends such as optical components, thereby contributing to Goal 12 of the United Nations Sustainable Development Goals (SDGs), "Responsible Consumption and Production."

[0108] The invention is not limited to the embodiments described above, and various modifications and changes are possible within the scope of the gist of the invention.

Claims

1. Acrylic polymers and The acid component, which is boric acid or a partial ester thereof, hydrochloric acid, or an organic sulfonic acid, is present in an amount of 0.001 parts by mass or more and 15 parts by mass or less per 100 parts by mass of the acrylic polymer. An adhesive composition comprising, The acrylic polymer comprises a repeating unit having at least one of a hydroxyl group, an alkoxysilyl group, an epoxy group, a carboxyl group, and an amino group. The adhesive composition comprises 0.1 to 15 parts by mass of an alkoxysilane compound per 100 parts by mass of the acrylic polymer, or the acrylic polymer comprises 0.1 to 50 parts by mass of repeating units having alkoxysilyl groups per 100 parts by mass of the acrylic polymer.

2. The adhesive composition according to claim 1, wherein the adhesive composition comprises an alkoxysilane compound, and the alkoxysilane compound is an organoalkoxysilane or an organopolysiloxane.

3. The acrylic polymer includes side chains having functional groups. The functional group of the side chain is at least one of a hydroxyl group, an alkoxysilyl group, an epoxy group, a carboxyl group, and an amino group. The adhesive composition according to claim 1, wherein the functional group of the side chain has bonding properties with the alkoxysilane compound or polymer thereof contained in the adhesive composition.

4. The adhesive composition according to claim 1, wherein the acrylic polymer includes a side chain having an alkoxysilyl group.

5. The aforementioned acrylic polymer has an alkoxysilyl group, The adhesive composition according to claim 1, wherein the adhesive composition comprises a further acrylic polymer different from the acrylic polymer having the alkoxysilyl group.

6. The acrylic polymer comprises repeating units derived from hydrocarbon groups (meth)acrylate or hydrocarbon groups (meth)acrylate having internal ether bonds, and repeating units having functional groups, wherein the functional group is at least one of a hydroxyl group, an alkoxysilyl group, an epoxy group, a carboxyl group, and an amino group, and the number of carbon atoms in the hydrocarbon groups and hydrocarbon groups having internal ether bonds is 1 to 14, the adhesive composition according to any one of claims 1 to 4.

7. The acrylic polymer comprises, in 100 parts by mass of the acrylic polymer, 80 parts by mass or more and 99.9 parts by mass of repeating units derived from hydrocarbon groups (meth)acrylate or hydrocarbon groups (meth)acrylate having internal ether bonds, and 0.1 parts by mass or more and 20 parts by mass of repeating units having functional groups, wherein the functional group is at least one of a hydroxyl group, an alkoxysilyl group, an epoxy group, a carboxyl group, and an amino group, according to any one of claims 1 to 4.

8. The adhesive composition according to any one of claims 1 to 4, further comprising a crosslinking agent.

9. The shear storage modulus of the adhesive layer formed from the adhesive composition is 8.0 × 10 at a frequency of 1 Hz and 23°C. ４ The adhesive composition according to any one of claims 1 to 5, wherein the pressure is Pa or higher.

10. The shear storage modulus of the adhesive layer formed from the adhesive composition is 4.0 × 10 at a frequency of 1 Hz and 200°C. ４ The adhesive composition according to any one of claims 1 to 4, wherein the pressure is Pa or higher.

11. The adhesive composition according to any one of claims 1 to 4, wherein the ratio of the shear storage modulus of the adhesive layer formed from the adhesive composition to the shear storage modulus at a frequency of 1 Hz and 23°C to the shear storage modulus at a frequency of 1 Hz and 200°C is less than 3.

0.

12. The adhesive composition according to any one of claims 1 to 4, wherein the tanδ of the adhesive layer formed from the adhesive composition is less than 0.2 at a frequency of 1 Hz and 200°C.

13. An adhesive sheet comprising an adhesive layer formed from the adhesive composition according to any one of claims 1 to 4.

14. An adhesive sheet comprising an adhesive layer, The adhesive layer is Acrylic polymers and The acid component, which is boric acid or a partial ester thereof, hydrochloric acid, or an organic sulfonic acid, is present in an amount of 0.001 parts by mass or more and 15 parts by mass or less per 100 parts by mass of the acrylic polymer. Includes, The acrylic polymer comprises a repeating unit having at least one of a hydroxyl group, an alkoxysilyl group, an epoxy group, a carboxyl group, and an amino group. An adhesive sheet wherein the adhesive layer contains 0.1 to 15 parts by mass of an alkoxysilane compound per 100 parts by mass of the acrylic polymer, or the acrylic polymer contains 0.1 to 50 parts by mass of repeating units having alkoxysilyl groups per 100 parts by mass of the acrylic polymer.

15. A method for manufacturing an adhesive sheet, comprising the step of forming an adhesive layer from an adhesive composition according to any one of claims 1 to 4.

16. A first composition comprising an acrylic polymer and an acid component, which is boric acid or a partial ester thereof, hydrochloric acid, or an organic sulfonic acid, in an amount of 0.001 parts by mass to 15 parts by mass per 100 parts by mass of the acrylic polymer, wherein the acrylic polymer includes repeating units having at least one of a hydroxyl group, an alkoxysilyl group, an epoxy group, a carboxyl group, and an amino group. An adhesive composition kit comprising a second composition containing 0.1 to 15 parts by mass of an alkoxysilane compound per 100 parts by mass of the acrylic polymer.

17. A first composition comprising a first acrylic polymer and an acid component which is boric acid or a partial ester thereof, hydrochloric acid, or an organic sulfonic acid, wherein the first acrylic polymer comprises repeating units having at least one of a hydroxyl group, an epoxy group, a carboxyl group, and an amino group, A second composition comprising a second acrylic polymer containing repeating units having alkoxysilyl groups, The first composition contains 0.001 parts by mass or more and 15 parts by mass or less of the acid component with respect to 100 parts by mass of the total of the first acrylic polymer and the second acrylic polymer. The second acrylic polymer comprises 0.1 to 50 parts by mass of repeating units having alkoxysilyl groups per 100 parts by mass of the second acrylic polymer, in an adhesive composition kit.

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