Adhesive composition, adhesive sheet, optical member, and display device

Abstract

The adhesive composition contains (A) a (meth) acrylic copolymer, (B) a polyisocyanate compound, (C) a silane compound having a mercapto group and an alkoxysilyl group, and (D) a silane compound having an amino group and not having an alkoxysilyl group, the (meth) acrylic copolymer (A) contains monomer units having carboxyl groups in an amount of 0.5-3.0% by mass relative to the total constituent units, and has an Mw of 500,000-1,200,000; the content of the compound (B) is 0.1-0.6 parts by mass with respect to 100 parts by mass of the copolymer (A), and when the number of moles of mercapto groups in the compound (C) is Pmmol, the number of moles of amino groups in the compound (D) is Qmmol, and the number of moles of carboxyl groups in the copolymer (A) is Rmmol, the functional group ratio as determined by formula (X) is 2.5 * 10 <-4 > or more and less than 3.5 * 10 <-3 >. Functional group ratio = P * (Q / R)... (X).

Description

Technical Field

[0001] The present disclosure relates to an adhesive composition, an adhesive sheet, an optical component, and a display device. Background Art

[0002] A liquid crystal display device generally includes a liquid crystal cell having a liquid crystal layer sandwiched between two support substrates, and optical films such as a polarizing plate, a retardation film, and a brightness enhancement film. When manufacturing a liquid crystal display device by laminating the liquid crystal cell with the optical films and the optical films with each other, these components are bonded via an adhesive layer formed using an adhesive composition. In a liquid crystal display device, from the viewpoint of ensuring visibility, a (meth)acrylic-based adhesive composition is mostly used.

[0003] For example, Japanese Patent Application Laid-Open No. 2011-178903 discloses an adhesive composition containing: an acrylic copolymer (A) having a weight average molecular weight of 400,000 or more and less than 900,000 and containing 1% by weight to 4% by weight of a carboxyl group-containing monomer as a copolymer component, an acrylic copolymer (B) having a weight average molecular weight of 400,000 or more and less than 900,000 and containing 0.1% by weight to 4% by weight of a carboxyl group-containing monomer and 0.05% by weight to 5% by weight of a hydroxyl group-containing monomer as copolymer components, and 5 parts by weight to 30 parts by weight of an isocyanate compound (C) added with respect to 100 parts by weight of the mixture of the acrylic copolymer (A) and the acrylic copolymer (B).

[0004] In addition, International Publication No. 2016 / 072197 discloses an adhesive composition for a polarizing plate for forming an adhesive layer in direct contact with a polarizer, containing a (meth)acrylic copolymer (A) and an isocyanate-based crosslinking agent (B), and containing 10 to 40 parts by weight of the crosslinking agent (B) with respect to 100 parts by mass of the copolymer (A). The above (meth)acrylic copolymer (A) is obtained by copolymerizing a monomer component containing 10 to 30% by mass of a (meth)acrylic alkyl ester (a1) having a glass transition temperature of 0°C or higher of the homopolymer, and 0.1 to 5% by mass of a crosslinkable functional group-containing monomer (a2) containing a hydroxyl group-containing monomer and a carboxyl group-containing monomer, and has a weight average molecular weight of 600,000 or less and a glass transition temperature of -80 to 0°C as measured by gel permeation chromatography. Summary of the Invention

[0005] Optical films such as polarizing films are usually composed of multiple components with different shrinkage rates when laminated, so they are prone to dimensional changes with changes in temperature and / or humidity. Therefore, when an adherend to which an optical film is adhered via an adhesive layer is placed in a high-temperature environment (for example, a high-temperature and low-humidity environment), there may be problems such as shrinkage of the optical film, wrinkling of the adhesive layer and / or the optical film, and peeling of the adhesive layer from the adherend. In addition, when an adherend to which an optical film is adhered via an adhesive layer is placed in a high-temperature environment, volatile components such as moisture remaining in the optical film may volatilize, causing foaming at the interface between the adhesive layer and the optical film and / or the adherend. Therefore, the adhesive composition used in the optical film is required to be able to form an adhesive layer that can suppress the above-mentioned foaming, wrinkling, and peeling generated in a high-temperature environment (so-called adhesive layer with excellent high-temperature durability).

[0006] However, when attaching a polarizing film to a liquid crystal cell, a polarizing film with an adhesive layer is generally used. When attaching a polarizing film to a liquid crystal cell, if foreign matter is caught between the adhesive layer provided on the polarizing film and the liquid crystal cell or if there is a positional deviation due to an incorrect attachment position, the polarizing film with the adhesive layer needs to be peeled off from the liquid crystal cell and reattached. In order to reuse the liquid crystal cell after peeling, when peeling the adhesive layer from the liquid crystal cell, it is required to have the property of being easily peeled off without damaging the liquid crystal cell or leaving paste residue on the attachment surface with the liquid crystal cell (so-called reprocessability). In addition, as described above, the peeling operation is not limited to the operation immediately after attachment, and sometimes it is carried out a long time after attachment. Therefore, the adhesive layer is required to have excellent reprocessability that can be easily peeled off without problems even after a long time has passed since the polarizing film was attached to the liquid crystal cell. In recent years, with the increase in the size of optical displays, the area of optical films such as polarizing films has become larger, so it has become more difficult to peel the optical film from the display, and there is a trend to require more excellent reprocessability for the adhesive layer than in the past.

[0007] In order to improve the reprocessability of the adhesive layer, it is necessary to reduce the wettability of the interface between the adhesive layer and the adherend (hereinafter also referred to as "the interface of the adhesive layer"). However, if the wettability of the interface of the adhesive layer is reduced, the durability of the adhesive layer against the stress generated by the shrinkage of the optical film in a high-temperature environment will be insufficient, and problems such as peeling of the adhesive layer from the adherend are likely to occur.

[0008] In addition, in recent years, in the context of increasing concern for the environment, there has been a demand to reduce the amount of organic solvents used. If the content of the organic solvent in the adhesive composition becomes small, the viscosity of the adhesive composition becomes high, which impairs the coatability. In order to reduce the content of the organic solvent in the adhesive composition without increasing the viscosity of the adhesive composition, it is considered to reduce the weight-average molecular weight of the base resin used in the adhesive composition. If the weight-average molecular weight of the base resin is low, a large amount of organic solvent is not required to adjust the viscosity of the adhesive composition. However, if the weight-average molecular weight of the base resin is reduced, the cohesive force of the formed adhesive layer is insufficient, and the high-temperature durability may decrease.

[0009] As described above, in the past, it has been difficult to form an adhesive layer that exhibits both high-temperature durability and reprocessability at a high level using an adhesive composition containing a base resin with a low weight-average molecular weight in order to reduce the amount of organic solvent used.

[0010] On the other hand, the adhesive compositions described in JP-A-2011-178903 and WO 2016 / 072197 both use a base resin with a low weight-average molecular weight, but a large amount of crosslinking agent is used to achieve excellent high-temperature durability. Therefore, it is considered that the adhesive force of the adhesive layer is high and the reprocessability is poor.

[0011] The present disclosure has been made in view of the above circumstances.

[0012] A problem to be solved by one embodiment of the present disclosure is to provide an adhesive composition capable of forming an adhesive layer having excellent high-temperature durability and reprocessability.

[0013] Another problem to be solved by another embodiment of the present disclosure is to provide an adhesive sheet, an optical component, and a display device including an adhesive layer formed from the above adhesive composition.

[0014] Specific methods for solving the problems include the following aspects.

[0015] <1> An adhesive composition comprising a (meth)acrylic copolymer (A), a polyisocyanate compound (B), a silane compound (C) having a mercapto group and an alkoxysilyl group, and a silane compound (D) having an amino group and not having an alkoxysilyl group.

[0016] The above (meth)acrylic copolymer (A) contains a structural unit derived from a monomer having a carboxyl group in a proportion of 0.5% by mass to 3.0% by mass based on all the structural units, and has a weight-average molecular weight in the range of 500,000 to 1,200,000.

[0017] With respect to 100 parts by mass of the above-mentioned (meth)acrylic copolymer (A), the content of the above-mentioned polyisocyanate compound (B) is in the range of 0.1 part by mass to 0.6 part by mass.

[0018] When the number of moles of the mercapto group in the above-mentioned silane compound (C) is P mmol, the number of moles of the amino group in the above-mentioned silane compound (D) is Q mmol, and the number of moles of the carboxyl group in the above-mentioned (meth)acrylic copolymer (A) is R mmol, the functional group ratio calculated by the following formula (X) is 2.5×10 -4 or more and less than 3.5×10 -3 in the range.

[0019] Functional group ratio = P×(Q / R) ··· (X)

[0020] <2> The adhesive composition according to <1>, wherein the above-mentioned silane compound (C) has a siloxane bond.

[0021] <3> The adhesive composition according to <1> or <2>, wherein with respect to 100 parts by mass of the above-mentioned (meth)acrylic copolymer (A), the content of the above-mentioned silane compound (C) is in the range of 0.1 part by mass to 0.6 part by mass.

[0022] <4> The adhesive composition according to any one of <1> to <3>, wherein the above-mentioned (meth)acrylic copolymer (A) further contains a structural unit derived from a monomer having a hydroxyl group.

[0023] <5> The adhesive composition according to any one of <1> to <4>, further comprising a polyfunctional alicyclic epoxy compound.

[0024] <6> An adhesive sheet comprising an adhesive layer formed from the adhesive composition according to any one of <1> to <5>.

[0025] <7> An adhesive sheet comprising an optical film and an adhesive layer,

[0026] the above-mentioned adhesive layer is provided on at least one surface of the above-mentioned optical film and is formed from the adhesive composition according to any one of <1> to <5>.

[0027] <8> The adhesive sheet according to <7>, wherein the above-mentioned optical film is a polarizing plate.

[0028] <9> An optical component comprising, in order:

[0029] a glass substrate,

[0030] an adhesive layer formed from the adhesive composition according to any one of <1> to <5>, and

[0031] Optical film.

[0032] <10>A display device includes the optical component described in <9>.

[0033] According to one embodiment of the present disclosure, an adhesive composition capable of forming an adhesive layer excellent in high-temperature durability and reprocessability can be provided.

[0034] According to another embodiment of the present disclosure, an adhesive sheet, an optical component, and a display device including an adhesive layer formed of the above adhesive composition can be provided. Detailed Description

[0035] Hereinafter, the adhesive composition, adhesive sheet, optical component, and display device of the present disclosure will be described in detail. The description of the requirements described below is sometimes made based on representative embodiments of the present disclosure. The present disclosure is not limited to such embodiments and can be appropriately modified and implemented within the scope of the object of the present disclosure.

[0036] In the present disclosure, a numerical range indicated by "~" means a range including the numerical values described before and after "~" as the lower limit value and the upper limit value, respectively.

[0037] Within the numerical ranges described stepwise in the present disclosure, the upper limit value or the lower limit value described in a certain numerical range can be replaced with the upper limit value or the lower limit value of another numerically described stepwise range. In addition, within the numerical ranges described in the present disclosure, the upper limit value or the lower limit value described in a certain numerical range can be replaced with the value shown in the examples.

[0038] In the present disclosure, a combination of two or more preferred modes is a more preferred mode.

[0039] In the present disclosure, when there are a plurality of substances belonging to each component in the adhesive composition, unless otherwise specified, the amount of each component in the adhesive composition means the total amount of the above-mentioned plurality of substances present in the adhesive composition.

[0040] In the present disclosure, unless otherwise specified, "solid content" means the components other than the solvent contained in the composition.

[0041] In the present disclosure, "solvent" means water and / or an organic solvent.

[0042] In the present disclosure, "(meth)acrylic monomer" means a monomer having a (meth)acryloyl group.

[0043] In the present disclosure, "(meth)acrylic copolymer" means a copolymer containing structural units derived from (meth)acrylic monomers and having a proportion of structural units derived from (meth)acrylic monomers of 50% by mass or more.

[0044] In the present disclosure, the term “(meth)acrylic acid” is a term encompassing both “acrylic acid” and “methacrylic acid”, the term “(meth)acrylate” is a term encompassing both “acrylate” and “methacrylate”, and the term “(meth)acryloyl” is a term encompassing both “acryloyl” and “methacryloyl”.

[0045] In the present disclosure, “n-” means normal, “i-” means iso, “s-” means secondary, and “t-” means tertiary.

[0046] In the present disclosure, “mass %” has the same meaning as “weight %”, and “parts by mass” has the same meaning as “parts by weight”.

[0047] In the present disclosure, “monomer” has the same meaning as “monomeric unit”, and “polymer” has the same meaning as “polymer” and “copolymer”.

[0048] In the present disclosure, the term “process” not only refers to an independent process, but also includes cases where, even if it cannot be clearly distinguished from other process areas, as long as the desired purpose of the process can be achieved.

[0049] [Adhesive Composition]

[0050] The adhesive composition of the present disclosure contains a (meth)acrylic copolymer (A), a polyisocyanate compound (B), a silane compound (C) having a mercapto group and an alkoxysilyl group, and a silane compound (D) having an amino group and not having an alkoxysilyl group. Among them, the above-mentioned (meth)acrylic copolymer (A) contains a structural unit derived from a monomer having a carboxyl group in a proportion of 0.5 mass % to 3.0 mass % based on all the structural units, and the weight average molecular weight is in the range of 500,000 to 1,200,000. Based on 100 parts by mass of the above-mentioned (meth)acrylic copolymer (A), the content of the above-mentioned polyisocyanate compound (B) is in the range of 0.1 parts by mass to 0.6 parts by mass. When the number of moles of the mercapto group in the above-mentioned silane compound (C) is P mmol, the number of moles of the amino group in the above-mentioned silane compound (D) is Q mmol, and the number of moles of the carboxyl group in the above-mentioned (meth)acrylic copolymer (A) is R mmol, the functional group ratio calculated by the following formula (X) is 2.5×10 -4 or more and less than 3.5×10 -3 in the range.

[0051] Functional group ratio = P × (Q / R) ··· (X)

[0052] With increasing concern for the environment in recent years, there has also been a demand in the field of adhesives to reduce the amount of organic solvents used. However, if the content of organic solvents in the adhesive composition is decreased, the viscosity of the adhesive composition becomes high, which impairs the coatability. In order to reduce the content of organic solvents in the adhesive composition without increasing the viscosity of the adhesive composition, it has been considered to reduce the weight average molecular weight of the base resin used in the adhesive composition. However, if the weight average molecular weight of the base resin is decreased, the cohesive force of the formed adhesive layer becomes insufficient and the high-temperature durability may decrease.

[0053] In contrast, although the adhesive composition of the present disclosure contains a (meth)acrylic copolymer having a low weight average molecular weight as a base resin, it is also capable of forming an adhesive layer having excellent high-temperature durability. In addition, the adhesive layer formed from the adhesive composition of the present disclosure is also excellent in reprocessability, which has been difficult to achieve simultaneously with high-temperature durability in the past. The reason why the adhesive composition of the present disclosure exhibits such an effect is not clear, but the present inventors presume as follows. Herein, the following presumption does not limitatively explain the adhesive composition of the present disclosure, but is merely illustrative as an example.

[0054] The (meth)acrylic copolymer (A) contained in the adhesive composition of the present disclosure contains a structural unit derived from a monomer having a carboxyl group in a specific range. The carboxyl group possessed by the (meth)acrylic copolymer (A) contributes to the crosslinking reaction between the polyisocyanate compound (B) contained in the adhesive composition of the present disclosure in a specific range and the (meth)acrylic copolymer (A), thereby exhibiting the effect of improving the cohesive force of the adhesive layer. In addition, the carboxyl group possessed by the (meth)acrylic copolymer (A) can exhibit the effect of enhancing the interaction at the interface between the adhesive layer and the adherend. If the cohesive force of the adhesive layer is increased and the interaction at the interface between the adhesive layer and the adherend is enhanced, the high-temperature durability of the adhesive layer is good. However, if the interaction at the interface between the adhesive layer and the adherend is too strong, the reprocessability decreases.

[0055] As a method for improving the reprocessability, a method of using a silane compound can be cited. Generally, a silane compound exhibits the effect of improving the reprocessability by appropriately reducing the adhesion between the adhesive layer and the adherend (e.g., glass). However, if the silane compound is excessively concentrated at the interface between the adhesive layer and the adherend, the adhesion between the adhesive layer and the adherend is excessively decreased, so that the adhesive layer cannot withstand the stress generated by the shrinkage of the polarizing plate in a high-temperature environment, and sometimes defects such as peeling occur. In the process of repeated and in-depth research, the present inventors have found a method of using two silane compounds having specific functional groups that interact with the carboxyl group possessed by the (meth)acrylic copolymer (A) as a method for preventing the excessive concentration of the silane compound at the interface between the adhesive layer and the adherend.

[0056] The adhesive composition of the present disclosure contains: a silane compound (C) having a mercapto group and an alkoxysilyl group, and a silane compound (D) having an amino group and not having an alkoxysilyl group. It is considered that the mercapto group of the silane compound (C) interacts with the carboxyl group of the (meth)acrylic copolymer (A), so that the silane compound (C) is appropriately unevenly distributed at the interface between the adhesive layer and the adherend. In addition, it is considered that the alkoxysilyl group of the silane compound (C) reacts with the silanol group on the glass surface in a high-temperature environment, thereby improving the adhesion between the adhesive layer and the adherend and suppressing the decrease in high-temperature durability caused by the uneven distribution of the silane compound (C). On the other hand, since the amino group of the silane compound (D) is a basic functional group, the interaction with the acidic functional group, i.e., the carboxyl group, of the (meth)acrylic copolymer (A) is strong. That is, the amino group of the silane compound (D) has a stronger interaction with the carboxyl group of the (meth)acrylic copolymer (A) than the mercapto group of the silane compound (C). It is considered that the silane compound (D) appropriately reduces the adhesion between the adhesive layer and the adherend and makes the reprocessability of the adhesive layer good. On the other hand, since it is not excessively unevenly distributed at the interface between the adhesive layer and the adherend, it does not hinder the effect of the silane compound (C) in suppressing the decrease in high-temperature durability.

[0057] The adhesive composition of the present disclosure is designed by focusing on the interaction of the functional groups as described above. In the adhesive composition of the present disclosure, as constituent components, a (meth)acrylic copolymer (A) containing a structural unit derived from a monomer having a carboxyl group in a specific range ratio, a polyisocyanate compound (B) in a specific range ratio with respect to the (meth)acrylic copolymer (A), a silane compound (C) having a mercapto group and an alkoxysilyl group, and a silane compound (D) having an amino group and not having an alkoxysilyl group are selected, and the functional group ratios of the mercapto group in the silane compound (C) and the amino group in the silane compound (D) to the carboxyl group in the (meth)acrylic copolymer (A) are adjusted. As a result, the cohesive force of the formed adhesive layer is appropriately increased, and the balance of the interaction between the carboxyl group of the (meth)acrylic copolymer (A) and the mercapto group, alkoxysilyl group of the silane compound (C), and amino group of the silane compound (D) is good. Therefore, it is speculated that although the (meth)acrylic copolymer (A) having a relatively low weight-average molecular weight is contained, the high-temperature durability and reprocessability are also excellent.

[0058] In the present disclosure, the (meth)acrylic copolymer (A) that "contains a structural unit derived from a monomer having a carboxyl group in a proportion of 0.5% by mass to 3.0% by mass based on all the structural units and has a weight-average molecular weight in the range of 500,000 to 1,200,000" is also referred to as "specific (meth)acrylic copolymer (A)". In addition, in the present disclosure, the silane compound (C) having a mercapto group and an alkoxysilyl group is also referred to as "specific silane compound (C)". In addition, in the present disclosure, the silane compound (D) having an amino group and not having an alkoxysilyl group is also referred to as "specific silane compound (D)". In addition, in the present disclosure, the "functional group ratio obtained by formula (X)" is also referred to as "functional group ratio (X)".

[0059] [Specific (meth)acrylic copolymer (A)]

[0060] The adhesive composition of the present disclosure contains a (meth)acrylic copolymer (A) [i.e., specific (meth)acrylic copolymer (A)] that contains a structural unit derived from a monomer having a carboxyl group in a proportion of 0.5% by mass to 3.0% by mass based on all the structural units and has a weight-average molecular weight in the range of 500,000 to 1,200,000.

[0061] The adhesive composition of the present disclosure may contain only one kind of specific (meth)acrylic copolymer (A), or may contain two or more kinds.

[0062] <Structural unit derived from a monomer having a carboxyl group>

[0063] The specific (meth)acrylic copolymer (A) contains a structural unit derived from a monomer having a carboxyl group in a proportion of 0.5% by mass to 3.0% by mass based on all the structural units.

[0064] In the present disclosure, the "structural unit derived from a monomer having a carboxyl group" refers to a structural unit formed by addition polymerization of a monomer having a carboxyl group.

[0065] The type of the monomer having a carboxyl group is not particularly limited.

[0066] Examples of the monomer having a carboxyl group include a monomer having at least one carboxyl group and an ethylenically unsaturated group in one molecule.

[0067] Examples of the ethylenically unsaturated group are not particularly limited, and include, for example, vinyl, allyl, vinylphenyl, (meth)acrylamide group, and (meth)acryloyl group.

[0068] As the ethylenically unsaturated group, (meth)acryloyl group is preferred.

[0069] Specific examples of the monomer having a carboxyl group include (meth)acrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, pentenedioic acid, citraconic acid, ω-carboxy-polycaprolactone mono(meth)acrylate [for example, ω-carboxy-polycaprolactone (n≈2) monoacrylate], and succinic acid derivatives (for example, 2-acryloyloxyethyl succinate).

[0070] As the monomer having a carboxyl group, (meth)acrylic acid is preferred, and acrylic acid is more preferred.

[0071] The specific (meth)acrylic copolymer (A) may contain only one kind of structural unit derived from the monomer having a carboxyl group, or may contain two or more kinds.

[0072] With respect to all the structural units of the specific (meth)acrylic copolymer (A), the content of the structural unit derived from the monomer having a carboxyl group in the specific (meth)acrylic copolymer (A) is 0.5% by mass to 3.0% by mass.

[0073] If the content of the structural unit derived from the monomer having a carboxyl group in the specific (meth)acrylic copolymer (A) is 0.5% by mass or more with respect to all the structural units of the specific (meth)acrylic copolymer (A), the formed adhesive layer tends to exhibit excellent high-temperature durability. For this reason, it is considered that the cohesive force of the adhesive layer is sufficiently increased, and the interaction at the interface between the adhesive layer and the adherend (for example, glass) is sufficiently enhanced.

[0074] With respect to all the structural units of the specific (meth)acrylic copolymer (A), the content of the structural unit derived from the monomer having a carboxyl group in the specific (meth)acrylic copolymer (A) is preferably 1.0% by mass or more, and more preferably 1.5% by mass or more.

[0075] If the content of the structural unit derived from the monomer having a carboxyl group in the specific (meth)acrylic copolymer (A) is 3.0% by mass or less with respect to all the structural units of the specific (meth)acrylic copolymer (A), the formed adhesive layer tends to exhibit excellent reprocessability. For this reason, it is considered that the interaction at the interface between the adhesive layer and the adherend is not excessively enhanced.

[0076] With respect to all the structural units of the specific (meth)acrylic copolymer (A), the content of the structural unit derived from the monomer having a carboxyl group in the specific (meth)acrylic copolymer (A) is preferably 2.5% by mass or less, and more preferably 2.0% by mass or less.

[0077] In a certain mode, with respect to all the constituent units of the specific (meth)acrylic copolymer (A), the content of the constituent units derived from the monomer having a carboxyl group in the specific (meth)acrylic copolymer (A) can be in the range of 0.5% by mass to 2.5% by mass, can be in the range of 0.5% by mass to 2.0% by mass, can be in the range of 1.0% by mass to 3.0% by mass, can be in the range of 1.0% by mass to 2.5% by mass, can be in the range of 1.0% by mass to 2.0% by mass, can be in the range of 1.5% by mass to 2.5% by mass.

[0078] <Constituent units derived from the monomer having a hydroxyl group>

[0079] The specific (meth)acrylic copolymer (A) preferably further contains constituent units derived from the monomer having a hydroxyl group.

[0080] If the specific (meth)acrylic copolymer (A) further contains constituent units derived from the monomer having a hydroxyl group, there is a tendency for the high-temperature durability of the formed adhesive layer to be good.

[0081] In the present disclosure, the "constituent units derived from the monomer having a hydroxyl group" refers to the constituent units formed by addition polymerization of the monomer having a hydroxyl group.

[0082] The type of the monomer having a hydroxyl group is not particularly limited.

[0083] As the monomer having a hydroxyl group, for example, a monomer having at least one hydroxyl group and an ethylenically unsaturated group in one molecule can be cited.

[0084] As the ethylenically unsaturated group, there is no particular limitation, and for example, vinyl, allyl, vinylphenyl, (meth)acrylamide group, and (meth)acryloyl group can be cited.

[0085] As the ethylenically unsaturated group, (meth)acryloyl group is preferred.

[0086] As specific examples of the monomer having a hydroxyl group, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, 3-methyl-3-hydroxybutyl (meth)acrylate, 1,1-dimethyl-3-hydroxybutyl (meth)acrylate, 1,3-dimethyl-3-hydroxybutyl (meth)acrylate, 2,2,4-trimethyl-3-hydroxypentyl (meth)acrylate, 2-ethyl-3-hydroxyhexyl (meth)acrylate, N-hydroxyethyl (meth)acrylamide, glycerol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, polyethylene glycol mono(meth)acrylate, and poly(ethylene glycol-propylene glycol) mono(meth)acrylate can be mentioned.

[0087] As the monomer having a hydroxyl group, a hydroxylalkyl (meth)acrylate is preferred, a hydroxylalkyl (meth)acrylate having a hydroxylalkyl group with 2 to 4 carbon atoms is more preferred, 2-hydroxyethyl acrylate or 4-hydroxybutyl acrylate is further preferred, and 2-hydroxyethyl acrylate is particularly preferred.

[0088] When the specific (meth)acrylic copolymer (A) contains a structural unit derived from a monomer having a hydroxyl group, it may contain only one structural unit derived from a monomer having a hydroxyl group, or may contain two or more.

[0089] When the specific (meth)acrylic copolymer (A) contains a structural unit derived from a monomer having a hydroxyl group, the content ratio of the structural unit derived from the monomer having a hydroxyl group is not particularly limited.

[0090] With respect to all the structural units of the specific (meth)acrylic copolymer (A), the content ratio of the structural unit derived from the monomer having a hydroxyl group in the specific (meth)acrylic copolymer (A) is preferably 0.5% by mass or more, more preferably 1.0% by mass or more, further preferably 1.5% by mass or more, and particularly preferably 2.0% by mass or more, for example.

[0091] With respect to all the structural units of the specific (meth)acrylic copolymer (A), the upper limit of the content ratio of the structural unit derived from the monomer having a hydroxyl group in the specific (meth)acrylic copolymer (A) can be 4.0% by mass or less, for example.

[0092] In a certain mode, relative to all the constituent units of the specific (meth)acrylic acid copolymer (A), the content of the constituent units derived from the monomer having a hydroxyl group in the specific (meth)acrylic acid copolymer (A) can be in the range of 0.5% by mass to 4.0% by mass, can be in the range of 1.0% by mass to 4.0% by mass, can be in the range of 1.5% by mass to 4.0% by mass, and can be in the range of 2.0% by mass to 4.0% by mass.

[0093] <Constituent units derived from (meth)acrylic acid alkyl ester monomers>

[0094] The specific (meth)acrylic acid copolymer (A) preferably contains constituent units derived from (meth)acrylic acid alkyl ester monomers.

[0095] In the present disclosure, the "constituent units derived from (meth)acrylic acid alkyl ester monomers" refers to the constituent units formed by the addition polymerization of (meth)acrylic acid alkyl ester monomers.

[0096] It should be noted that the "(meth)acrylic acid alkyl ester monomers" in the present disclosure do not include monomers belonging to monomers having a carboxyl group and monomers belonging to monomers having a hydroxyl group. That is, the "(meth)acrylic acid alkyl ester monomers" in the present disclosure refer to (meth)acrylic acid alkyl ester monomers having no hydroxyl group and / or carboxyl group. In the present disclosure, for example, (meth)acrylic acid alkyl ester monomers having a carboxyl group are classified as the above-mentioned monomers having a carboxyl group, and (meth)acrylic acid alkyl ester monomers having a hydroxyl group are classified as the above-mentioned monomers having a hydroxyl group.

[0097] The type of (meth)acrylic acid alkyl ester monomers is not particularly limited.

[0098] (Meth)acrylic acid alkyl ester monomers can be acrylic acid alkyl ester monomers or methacrylic acid alkyl ester monomers.

[0099] The alkyl group of the (meth)acrylic acid alkyl ester monomer can be unsubstituted or can have a substituent (excluding carboxyl group and hydroxyl group), but is preferably unsubstituted.

[0100] The alkyl group of the (meth)acrylic acid alkyl ester monomer can be any of linear, branched or cyclic.

[0101] The number of carbon atoms of the alkyl group of the (meth)acrylic acid alkyl ester monomer is preferably, for example, 1 to 18, more preferably 1 to 12, further preferably 1 to 8, and particularly preferably 1 to 4.

[0102] As specific examples of the (meth)acrylic acid alkyl ester monomer, methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, stearyl (meth)acrylate, lauryl (meth)acrylate, cyclohexyl (meth)acrylate, and isobornyl (meth)acrylate can be mentioned.

[0103] As the (meth)acrylic acid alkyl ester monomer, at least one selected from n-butyl acrylate, methyl acrylate, and methyl methacrylate is preferred.

[0104] When the specific (meth)acrylic copolymer (A) contains a structural unit derived from the (meth)acrylic acid alkyl ester monomer, it may contain only one structural unit derived from the (meth)acrylic acid alkyl ester monomer, or may contain two or more.

[0105] When the specific (meth)acrylic copolymer (A) contains a structural unit derived from the (meth)acrylic acid alkyl ester monomer, the content rate of the structural unit derived from the (meth)acrylic acid alkyl ester monomer is not particularly limited. For example, relative to all the structural units of the specific (meth)acrylic copolymer (A), it is preferably 50% by mass or more, more preferably in the range of 50% by mass to 99.5% by mass, further preferably in the range of 60% by mass to 99.0% by mass, and particularly preferably in the range of 70% by mass to 98.5% by mass.

[0106] Here, when the content rate of the structural unit derived from the (meth)acrylic acid alkyl ester monomer in the specific (meth)acrylic copolymer (A) is 50% by mass or more relative to all the structural units of the specific (meth)acrylic copolymer (A), it means that the structural unit derived from the (meth)acrylic acid alkyl ester monomer is included as the main component of the structural units of the specific (meth)acrylic copolymer (A).

[0107] <Structural units from other monomers>

[0108] The specific (meth)acrylic copolymer (A) may contain a structural unit derived from a monomer that does not belong to any of the monomers having a carboxyl group, monomers having a hydroxyl group, and (meth)acrylic acid alkyl ester monomers (so-called other monomers).

[0109] In the present disclosure, the "structural unit derived from other monomers" refers to a structural unit formed by addition polymerization of other monomers.

[0110] As constituent units derived from other monomers, for example, constituent units derived from (meth)acrylate esters having an aromatic ring typified by benzyl (meth)acrylate and phenoxyethyl (meth)acrylate can be mentioned; constituent units derived from alkoxyalkyl (meth)acrylate esters typified by methoxyethyl (meth)acrylate and ethoxyethyl (meth)acrylate; constituent units derived from aromatic monovinyls typified by styrene, α-methylstyrene, tert-butylstyrene, p-chlorostyrene, chloromethylstyrene, and vinyltoluene; constituent units derived from vinyl cyanides typified by acrylonitrile and methacrylonitrile; constituent units derived from vinyl esters typified by vinyl formate, vinyl acetate, vinyl propionate, and vinyl versatate, etc.

[0111] For example, from the viewpoint of suppressing white leakage, the specific (meth)acrylic copolymer (A) preferably contains constituent units derived from (meth)acrylate esters having an aromatic ring, more preferably contains constituent units derived from phenoxyethyl (meth)acrylate, and further preferably contains constituent units derived from phenoxyethyl acrylate as constituent units derived from other monomers. Herein, "white leakage" refers to a phenomenon in which light leaks and the liquid crystal display device turns white, for example.

[0112] When the specific (meth)acrylic copolymer (A) contains constituent units derived from other monomers, it may contain only 1 kind of constituent unit derived from other monomers, or may contain 2 or more kinds.

[0113] When the specific (meth)acrylic copolymer (A) contains constituent units derived from other monomers, the content ratio of the constituent units derived from other monomers can be appropriately set within a range that does not impair the effects of the adhesive composition of the present disclosure.

[0114] <<Weight-average molecular weight of the specific (meth)acrylic copolymer (A)>>

[0115] The weight-average molecular weight (also referred to as "Mw".) of the specific (meth)acrylic copolymer (A) is in the range of 500,000 to 1,200,000, preferably in the range of 600,000 to 1,200,000, more preferably in the range of 700,000 to 1,200,000, and further preferably in the range of 800,000 to 1,200,000.

[0116] If the weight-average molecular weight of the specific (meth)acrylic copolymer (A) is 500,000 or more, the formed adhesive layer tends to exhibit excellent high-temperature durability. For this reason, it is considered that the cohesive force of the adhesive layer is sufficiently increased.

[0117] When the weight average molecular weight of the specific (meth)acrylic copolymer (A) is 1.2 million or less, there is a tendency to be able to sufficiently reduce the amount of the organic solvent for dilution used to adjust the viscosity of the adhesive composition to the viscosity required for coating. The reason for this is considered to be that the viscosity of the solution of the specific (meth)acrylic copolymer (A) incorporated when preparing the adhesive composition becomes low.

[0118] The weight average molecular weight of the specific (meth)acrylic copolymer (A) is a value measured by the following method. Specifically, the measurement is carried out according to the following (1) to (3).

[0119] (1) The solution of the specific (meth)acrylic copolymer (A) is coated on release paper and dried at 100 °C for 1 minute to obtain a film-like specific (meth)acrylic copolymer (A).

[0120] (2) Using the film-like specific (meth)acrylic copolymer (A) obtained in the above (1) and tetrahydrofuran, a sample solution with a solid content concentration of 0.2 mass% is obtained. It should be noted that the so-called "solid content concentration" here refers to the mass ratio of the specific (meth)acrylic copolymer (A) in the sample solution.

[0121] (3) Using gel permeation chromatography (GPC) under the following conditions, the weight average molecular weight of the specific (meth)acrylic copolymer (A) is determined in terms of standard polystyrene conversion value.

[0122] ~Conditions~

[0123] Measurement device: High-speed GPC [Model: HLC-8420GPC, manufactured by Tosoh Corporation]

[0124] Detector: Differential refractive index detector (RI) [installed in HLC-8420, manufactured by Tosoh Corporation]

[0125] Column: Use 2 TSKgel GMH XL 〔manufactured by Tosoh Corporation〕

[0126] Column temperature: 40 °C

[0127] Eluent: Tetrahydrofuran

[0128] Injection volume of the sample solution: 100 μL

[0129] Flow rate: 0.8 mL / minute

[0130] The weight average molecular weight of the specific (meth)acrylic copolymer (A) can be adjusted to a desired value by adjusting the polymerization temperature, polymerization time, amount of the organic solvent used, type of the polymerization initiator, amount of the polymerization initiator used, etc. when polymerizing the monomers.

[0131] <<Content of Specific (Meth)acrylic Acid Copolymer (A)>>

[0132] The content of the specific (meth)acrylic acid copolymer (A) in the adhesive composition of the present disclosure is not particularly limited. For example, relative to the total solid content amount in the adhesive composition, it is preferably 50.0% by mass to 99.8% by mass, more preferably 60.0% by mass to 99.6% by mass, and still more preferably 70.0% by mass to 99.4% by mass.

[0133] In the present disclosure, "the total solid content amount in the adhesive composition" refers to the total mass of the adhesive composition when the adhesive composition does not contain a solvent, and refers to the mass of the residue remaining after removing the solvent from the adhesive composition when the adhesive composition contains a solvent.

[0134] 〔Method for Producing Specific (Meth)acrylic Acid Copolymer (A)〕

[0135] The method for producing the specific (meth)acrylic acid copolymer (A) is not particularly limited.

[0136] The specific (meth)acrylic acid copolymer (A) can be produced by polymerizing the above-mentioned monomers by a known polymerization method represented by, for example, solution polymerization method, emulsion polymerization method, suspension polymerization method, and bulk polymerization method.

[0137] As the polymerization method, from the aspect that the processing steps are relatively simple and can be carried out in a short time when preparing the adhesive composition of the present disclosure after production, the solution polymerization method is preferred.

[0138] In the solution polymerization method, generally, a specified organic solvent, monomer, polymerization initiator, and a chain transfer agent used as needed are put into a polymerization tank. For example, at the reflux temperature of the organic solvent, the reaction is heated with stirring for several hours. In this case, at least a part of the organic solvent, monomer, polymerization initiator, and a chain transfer agent used as needed can be added successively. In addition, the reaction can be carried out in a nitrogen stream.

[0139] Examples of the organic solvent used in the polymerization reaction include aromatic hydrocarbon compounds, aliphatic hydrocarbon compounds, alicyclic hydrocarbon compounds, ester compounds, ketone compounds, diol ether compounds, and alcohol compounds.

[0140] As the organic solvent used during the polymerization reaction, more specifically, for example, aromatic hydrocarbon compounds represented by benzene, toluene, ethylbenzene, n-propylbenzene, tert-butylbenzene, o-xylene, m-xylene, p-xylene, tetralin, decalin, and aromatic naphtha, aliphatic or alicyclic hydrocarbon compounds represented by n-hexane, n-heptane, n-octane, isooctane, n-decane, dipentene, petroleum spirit, naphtha, and turpentine, ester compounds represented by methyl acetate, ethyl acetate, n-butyl acetate, n-pentyl acetate, 2-hydroxyethyl acetate, 2-butoxyethyl acetate, 3-methoxybutyl acetate, and methyl benzoate, ketone compounds represented by acetone, methyl ethyl ketone, methyl isobutyl ketone, isophorone, cyclohexanone, and methylcyclohexanone, ethylene glycol ether compounds represented by ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and diethylene glycol monobutyl ether, and alcohol compounds represented by methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, and tert-butanol can be cited.

[0141] When manufacturing the specific (meth)acrylic copolymer (A), it is preferable to use organic solvents that are less likely to undergo chain transfer during the polymerization reaction, such as aromatic hydrocarbon compounds, ester compounds, and ketone compounds. From the viewpoints of the solubility of the specific (meth)acrylic copolymer (A) and the ease of the polymerization reaction, it is particularly preferable to use methyl acetate and / or ethyl acetate.

[0142] During the polymerization reaction, only one kind of organic solvent can be used, or two or more kinds can be used.

[0143] As the polymerization initiator, for example, organic peroxides and azo compounds used in the usual solution polymerization method can be cited.

[0144] Specific examples of the organic peroxides include tert-butyl peroxy-2-ethylhexanoate, tert-butyl hydroperoxide, cumene hydroperoxide, dicumyl peroxide, benzoyl peroxide, lauroyl peroxide, hexanoyl peroxide, diisopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, tert-butyl peroxyneopentanoate, 2,2-bis(4,4-di-tert-butylperoxycyclohexyl)propane, 2,2-bis(4,4-di-tert-amylperoxycyclohexyl)propane, 2,2-bis(4,4-di-tert-octylperoxycyclohexyl)propane, 2,2-bis(4,4-di-α-cumylperoxycyclohexyl)propane, 2,2-bis(4,4-di-tert-butylperoxycyclohexyl)butane, and 2,2-bis(4,4-di-tert-octylperoxycyclohexyl)butane.

[0145] As specific examples of the azo compound, 2,2'-azobisisobutyronitrile [AIBN], 2,2'-azobis(2,4-dimethylvaleronitrile) [ABVN], 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 1,1'-azobis(cyclohexane-1-carbonitrile), and dimethyl 2,2'-azobis(isobutyrate) can be cited.

[0146] In the polymerization reaction, one kind of polymerization initiator may be used alone, or two or more kinds may be used.

[0147] The amount of the polymerization initiator used is not particularly limited. For example, it can be appropriately set according to the molecular weight of the specific (meth)acrylic acid copolymer (A) as the target.

[0148] When producing the specific (meth)acrylic acid copolymer (A), a chain transfer agent can be used as needed.

[0149] As the chain transfer agent, for example, cyanoacetic acid, an alkyl ester compound of cyanoacetic acid having 1 to 8 carbon atoms, bromoacetic acid, an alkyl ester compound of bromoacetic acid having 1 to 8 carbon atoms, aromatic compounds represented by α-methylstyrene, anthracene, phenanthrene, fluorene, and 9-phenylfluorene, aromatic nitro compounds represented by p-nitroaniline, nitrobenzene, dinitrobenzene, p-nitrobenzoic acid, p-nitrophenol, and p-nitrotoluene, benzoquinone derivatives represented by benzoquinone and 2,3,5,6-tetramethyl-p-benzoquinone, borane derivatives represented by tributylborane, halogenated hydrocarbon compounds represented by carbon tetrabromide, carbon tetrachloride, 1,1,2,2-tetrabromoethane, tribromoethylene, trichloroethylene, bromotrichloromethane, tribromomethane, and 3-chloro-1-propene, aldehyde compounds represented by chloral and furfural, alkyl mercaptan compounds having 1 to 18 carbon atoms, aromatic mercaptan compounds represented by benzenethiol and tolyl mercaptan, mercaptoacetic acid, an alkyl ester compound of mercaptoacetic acid having 1 to 10 carbon atoms, hydroxyalkyl mercaptan compounds having 1 to 12 carbon atoms, and terpene compounds represented by pinene and terpinolene can be cited.

[0150] When producing the specific (meth)acrylic acid copolymer (A), when a chain transfer agent is used, the amount of the chain transfer agent used is not particularly limited. For example, it can be appropriately set according to the molecular weight of the specific (meth)acrylic acid copolymer (A) as the target.

[0151] The polymerization temperature is not particularly limited. For example, it can be appropriately set according to the molecular weight of the specific (meth)acrylic acid copolymer (A) as the target.

[0152] [Polyisocyanate compound (B)]

[0153] The adhesive composition of the present disclosure contains a polyisocyanate compound (B), and the content of the polyisocyanate compound (B) is in the range of 0.1 part by mass to 0.6 part by mass with respect to 100 parts by mass of a specific (meth)acrylic copolymer (A).

[0154] In the present disclosure, the polyisocyanate compound (B) functions as a crosslinking agent.

[0155] Examples of the polyisocyanate compound (B) include aliphatic polyisocyanate compounds, alicyclic polyisocyanate compounds, and aromatic polyisocyanate compounds.

[0156] The "aliphatic polyisocyanate compound" includes, for example, aliphatic polyisocyanate compounds, polymers of aliphatic polyisocyanate compounds, adducts of aliphatic polyisocyanate compounds and polyol compounds [e.g., trimethylolpropane (TMP); the same applies hereinafter], and biuret bodies of aliphatic polyisocyanate compounds. Specific examples of the aliphatic polyisocyanate compound include hexamethylene diisocyanate (HMDI), pentamethylene diisocyanate (PDI), tetramethylene diisocyanate, trimethylhexamethylene diisocyanate, and lysine diisocyanate.

[0157] The "alicyclic polyisocyanate compound" includes, for example, alicyclic polyisocyanate compounds, polymers of alicyclic polyisocyanate compounds, adducts of alicyclic polyisocyanate compounds and polyol compounds, and biuret bodies of alicyclic polyisocyanate compounds. Specific examples of the alicyclic polyisocyanate compound include isophorone diisocyanate (IPDI), hydrogenated toluene diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated 4,4'-diphenylmethane diisocyanate, and 4,4'-dicyclohexylmethane diisocyanate.

[0158] The "aromatic polyisocyanate compound" includes, for example, aromatic polyisocyanate compounds, polymers of aromatic polyisocyanate compounds, adducts of aromatic polyisocyanate compounds and polyol compounds, and biuret bodies of aromatic polyisocyanate compounds. Specific examples of the aromatic polyisocyanate compound include toluene diisocyanate (TDI), xylylene diisocyanate (XDI), and 4,4'-diphenylmethane diisocyanate.

[0159] As the polyisocyanate compound (B), an aromatic polyisocyanate compound is preferred, and at least one selected from toluene diisocyanate compounds and xylylene diisocyanate compounds is more preferred.

[0160] "Toluene diisocyanate compounds" include, for example, TDI, polymers of TDI, adducts of TDI and polyol compounds, and biuret bodies of TDI.

[0161] As the toluene diisocyanate compound, an adduct of TDI and TMP is preferred.

[0162] "Xylylene diisocyanate compounds" include, for example, XDI, polymers of XDI, adducts of XDI and polyol compounds, and biuret bodies of XDI.

[0163] As the xylylene diisocyanate compound, an adduct of XDI and TMP is preferred.

[0164] As the polyisocyanate compound (B), commercially available products can be used.

[0165] Examples of commercially available products of the polyisocyanate compound (B) include "COLONATE (registered trademark) HX", "COLONATE (registered trademark) HL-S", "COLONATE (registered trademark) L", "COLONATE (registered trademark) L-45E", "COLONATE (registered trademark) 2031", "COLONATE (registered trademark) 2037", "COLONATE (registered trademark) 2234", "COLONATE (registered trademark) 2785", "Aquanate (registered trademark) 200", and "Aquanate (registered trademark) 210" [manufactured by Tosoh Corporation above], "Sumidur (registered trademark) N3300", "Desmodur (registered trademark) N3400", and "Sumidur (registered trademark) N75" [manufactured by Sumika Covestro Urethane Co., Ltd. above], "DURANATE (registered trademark) D201", "DURANATE (registered trademark) E405-70B", "DURANATE (registered trademark) E405-80T", "DURANATE (registered trademark) AE700-100", "DURANATE (registered trademark) 24A-100", "DURANATE (registered trademark) TSA-100", and "DURANATE (registered trademark) TSE-100" [manufactured by Asahi Kasei Corporation above], and "TAKENATE (registered trademark) D-110N", "TAKENATE (registered trademark) D-101E", "TAKENATE (registered trademark) D-120N", "TAKENATE (registered trademark) D-140N", "TAKENATE (registered trademark) M-631N", and "MT-OLESTER (registered trademark) NP1200" [manufactured by Mitsui Chemicals, Inc. above].

[0166] The adhesive composition of the present disclosure may contain only one polyisocyanate compound (B), or may contain two or more thereof.

[0167] With respect to 100 parts by mass of the specific (meth)acrylic copolymer (A), the content of the polyisocyanate compound (B) in the adhesive composition of the present disclosure is in the range of 0.1 part by mass to 0.6 part by mass.

[0168] If, with respect to 100 parts by mass of the specific (meth)acrylic copolymer (A), the content of the polyisocyanate compound (B) in the adhesive composition of the present disclosure is within the above range, the formed adhesive layer tends to exhibit excellent high-temperature durability. For this reason, it is considered that the adhesive layer is neither too soft nor too hard and has an appropriate hardness.

[0169] With respect to 100 parts by mass of the specific (meth)acrylic copolymer (A), the content of the polyisocyanate compound (B) in the adhesive composition of the present disclosure is preferably 0.15 part by mass or more, more preferably 0.2 part by mass or more. Further, with respect to 100 parts by mass of the specific (meth)acrylic copolymer (A), the content of the polyisocyanate compound (B) in the adhesive composition of the present disclosure is preferably 0.5 part by mass or less, more preferably 0.3 part by mass or less.

[0170] In a certain mode, with respect to 100 parts by mass of the specific (meth)acrylic copolymer (A), the content of the polyisocyanate compound (B) in the adhesive composition of the present disclosure may be in the range of 0.1 part by mass to 0.5 part by mass, may be in the range of 0.1 part by mass to 0.3 part by mass, may be in the range of 0.15 part by mass to 0.5 part by mass, may be in the range of 0.2 part by mass to 0.5 part by mass, or may be in the range of 0.2 part by mass to 0.3 part by mass.

[0171] 〔Bifunctional or higher epoxy compound〕

[0172] The adhesive composition of the present disclosure preferably further contains a compound having two or more epoxy groups in one molecule (so-called bifunctional or higher epoxy compound).

[0173] In the present disclosure, the bifunctional or higher epoxy compound functions as a crosslinking agent.

[0174] If the adhesive composition of the present disclosure further contains a bifunctional or higher epoxy compound, the formed adhesive layer tends to have good high-temperature durability.

[0175] The number of epoxy groups in a bifunctional or higher epoxy compound in one molecule is not particularly limited as long as it is 2 or more. The bifunctional or higher epoxy compound is preferably, for example, at least one selected from a compound having 2 epoxy groups in one molecule (so-called bifunctional epoxy compound; the same applies hereinafter), a compound having 3 epoxy groups in one molecule (so-called trifunctional epoxy compound), and a compound having 4 epoxy groups in one molecule (so-called tetrafunctional epoxy compound), and more preferably a compound having 2 epoxy groups in one molecule.

[0176] Examples of the bifunctional or higher epoxy compound include ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, polybutylene glycol diglycidyl ether, glycerol diglycidyl ether, glycerol triglycidyl ether, dipropylene glycol polyglycidyl ether, polypropylene glycol polyglycidyl ether, resorcinol diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol polyglycidyl ether, sorbitol polyglycidyl ether, adipic acid diglycidyl ester, phthalic acid diglycidyl ester, tris(glycidyl) isocyanurate, tris(epoxypropoxyethyl) isocyanurate, 1,3-bis(N,N-glycidylaminomethyl) cyclohexane, N,N,N',N'-tetraglycidyl-1,3-benzenedimethanamine, and the like.

[0177] As the bifunctional or higher epoxy compound, for example, from the viewpoint of compatibility with a specific (meth)acrylic copolymer, an alicyclic epoxy compound is preferred.

[0178] If the compatibility between the specific (meth)acrylic copolymer and the bifunctional or higher epoxy compound is high, the high-temperature durability of the adhesive layer formed from the adhesive composition of the present disclosure can be further improved.

[0179] In addition, as the bifunctional or higher epoxy compound, an alicyclic epoxy compound having an ester bond in the molecule or an alicyclic epoxy compound having a siloxane bond in the molecule is more preferred.

[0180] As the alicyclic epoxy compound having an ester bond in the molecule, an alicyclic epoxy compound represented by the following formula (I) is preferred.

[0181]

[0182] In formula (I), R represents a divalent organic linking group having an ester bond.

[0183] The divalent organic linking group having an ester bond is not particularly limited. For example, in addition to the ester bond, a group formed by linking one or more ester bonds with one or more divalent hydrocarbon groups can be cited.

[0184] Examples of the divalent hydrocarbon group linked to the ester bond include linear or branched alkylene groups having 1 to 18 carbon atoms and divalent alicyclic hydrocarbon groups.

[0185] The number of atoms of the divalent organic linking group represented by R in formula (I) is not particularly limited. For example, it is preferably 3 or more, more preferably 3 to 200, further preferably 3 to 100, and particularly preferably 3 to 30.

[0186] In the present disclosure, the "number of atoms of the organic linking group" refers to the number of atoms in the main chain of the organic linking group. The "number of atoms in the main chain" refers to the number of atoms in the atomic chain that connects two alicyclic epoxy groups in formula (I), and does not include the number of atoms of the substituents. For example, when the main chain in the organic linking group contains a "cyclohexane ring", the number of atoms in the cyclohexane ring portion is counted as "6".

[0187] As the alicyclic epoxy compound represented by formula (I), a compound represented by the following formula (II) is preferred.

[0188]

[0189] In formula (II), n represents an integer of 0 to 5, preferably an integer of 0 to 4, more preferably an integer of 0 to 3, further preferably an integer of 0 to 2, and particularly preferably 0 or 1.

[0190] As the epoxy compound having two or more functional groups, commercially available products can be used.

[0191] Examples of commercially available products of epoxy compounds having two or more functional groups include commercially available products of alicyclic epoxy compounds having an ester bond in the molecule, "CELLOXIDE 2021P" and "CELLOXIDE 2081" [manufactured by Daicel Corporation], and commercially available products of alicyclic epoxy compounds having a siloxane bond in the molecule, "X-40-2669", "X-40-2678" and "KR-470" [manufactured by Shin-Etsu Chemical Co., Ltd.]. In addition, examples of commercially available products of epoxy compounds having two or more functional groups also include "TETRAD (registered trademark)-X" and "TETRAD (registered trademark)-C" [manufactured by Mitsubishi Gas Chemical Company, Inc.], and "DENACOL (registered trademark) EX-201" and "DENACOL (registered trademark) EX-931" [manufactured by Nagase Chemtex Corporation].

[0192] When the adhesive composition of the present disclosure contains an epoxy compound having two or more functional groups, it may contain only one epoxy compound having two or more functional groups, or may contain two or more.

[0193] When the adhesive composition of the present disclosure contains an epoxy compound having two or more functional groups, the content of the epoxy compound having two or more functional groups is not particularly limited. For example, relative to 100 parts by mass of a specific (meth)acrylic copolymer (A), it is preferably in the range of 0.05 parts by mass to 0.5 parts by mass, more preferably in the range of 0.1 parts by mass to 0.4 parts by mass, and further preferably in the range of 0.15 parts by mass to 0.3 parts by mass.

[0194] [Specific silane compound (C)]

[0195] The adhesive composition of the present disclosure contains a silane compound (C) having a mercapto group and an alkoxysilyl group [i.e., specific silane compound (C)].

[0196] In the adhesive composition of the present disclosure, the specific silane compound (C) can contribute to improving the high-temperature durability of the formed adhesive layer.

[0197] The number of mercapto groups of the specific silane compound (C) may be 1 or more, and may be 2 or more.

[0198] The mercapto equivalent of the specific silane compound (C) is not particularly limited. For example, from the viewpoint of the strength of the interaction between the silane compound (C) and the (meth)acrylic copolymer, it is preferably 300 g / eq to 1000 g / eq, and more preferably 400 g / eq to 800 g / eq.

[0199] In the present disclosure, the mercapto equivalent of the specific silane compound (C) is a value measured by a titration method using a potassium iodide solution and a sodium thiosulfate solution.

[0200] The type of alkoxysilyl group of the specific silane compound (C) is not particularly limited.

[0201] The alkoxysilyl group of the specific silane compound (C) is preferably an alkoxysilyl group having 1 to 3 carbon atoms in the alkoxy group, more preferably an alkoxysilyl group having 1 to 2 carbon atoms in the alkoxy group, from the viewpoint of reactivity with the silanol group on the glass surface.

[0202] Specific examples of the alkoxysilyl group include methoxysilyl group and ethoxysilyl group.

[0203] The number of alkoxysilyl groups of the specific silane compound (C) may be 1 or more, and may be 2 or more.

[0204] The number of alkoxysilyl groups in the specific silane compound (C) can be in the range of, for example, 1 to 50, and can be in the range of 1 to 30.

[0205] The specific silane compound (C) preferably has a siloxane bond (-Si-O-Si-). If the specific silane compound (C) has a siloxane bond, there is a tendency for the wettability at the interface between the adhesive and the glass to be appropriately reduced and the reprocessability to be good.

[0206] Examples of the specific silane compound (C) that does not have a siloxane bond include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropyl dimethoxymethylsilane, and mercaptomethyltrimethoxysilane.

[0207] Examples of the specific silane compound (C) that has a siloxane bond include an alkoxy oligomer type mercapto group-containing silane coupling agent (so-called mercapto group-containing oligomer type silane coupling agent) having a polysiloxane structure in the main chain.

[0208] As the specific silane compound (C), commercially available products can be used.

[0209] Examples of commercially available products of the specific silane compound (C) that does not have a siloxane structure include "KBM-802", "KBM-803", and "X-12-1307" [manufactured by Shin-Etsu Chemical Co., Ltd.], and "Z-6062" [manufactured by DowTORAY Co., Ltd.].

[0210] Examples of commercially available products of the specific silane compound (C) that has a siloxane bond include "X-41-1805" and "X-41-1810" [manufactured by Shin-Etsu Chemical Co., Ltd.].

[0211] The adhesive composition of the present disclosure may contain only 1 type of specific silane compound (C), or may contain 2 or more types.

[0212] The content of the specific silane compound (C) in the adhesive composition of the present disclosure is not particularly limited as long as it is in the range that makes the functional group ratio (X) described later 2.5×10 -4 or more and less than 3.5×10 -3 . For example, relative to 100 parts by mass of the specific (meth)acrylic copolymer (A), it is preferably in the range of 0.1 part by mass to 0.6 part by mass, more preferably in the range of 0.15 part by mass to 0.5 part by mass, and further preferably in the range of 0.2 part by mass to 0.4 part by mass.

[0213] 〔Specific silane compound (D)〕

[0214] The adhesive composition of the present disclosure contains a silane compound (D) having an amino group and no alkoxysilyl group (i.e., a specific silane compound (D)).

[0215] In the adhesive composition of the present disclosure, the specific silane compound (D) can contribute to improving the reprocessability of the formed adhesive layer.

[0216] The number of amino groups of the specific silane compound (D) may be 1 or more, and may be 2 or more.

[0217] The amino group of the specific silane compound (D) is preferably an amino group derived from a monoamine or an amino group derived from a diamine. For example, from the viewpoint of making the high-temperature durability of the formed adhesive layer better, an amino group derived from a diamine is more preferred.

[0218] The amino equivalent of the specific silane compound (D) is not particularly limited. For example, from the viewpoint of the strength of the interaction between the silane compound (C) and the (meth)acrylic copolymer, it is preferably 1000 g / eq to 8000 g / eq, more preferably 5000 g / eq to 7000 g / eq.

[0219] In the present disclosure, the amino equivalent of the specific silane compound (D) is a value measured by a titration method using an aqueous hydrochloric acid solution.

[0220] Examples of the specific silane compound (D) include a side-chain amino-modified polydimethylsiloxane compound having an amino group in the side chain of the polydimethylsiloxane skeleton, and a both-end amino-modified polydimethylsiloxane compound having an amino group at both ends of the polydimethylsiloxane skeleton.

[0221] As the specific silane compound (D), commercially available products can be used.

[0222] Examples of commercially available products of the specific silane compound (D) include "X-12-161B", "KF-859", "KF-869", "KF-880", "KF-8004", and "KF-8008" [the above are manufactured by Shin-Etsu Chemical Co., Ltd.].

[0223] The adhesive composition of the present disclosure may contain only one kind of specific silane compound (D), or may contain two or more kinds.

[0224] The content of the specific silane compound (D) in the adhesive composition of the present disclosure is such that the following functional group ratio (X) is 2.5×10 -4 or more and less than 3.5×10 -3The content within the range is not particularly limited. For example, relative to 100 parts by mass of the specific (meth)acrylic copolymer (A), it is preferably in the range of 0.01 part by mass to 0.7 part by mass, more preferably in the range of 0.05 part by mass to 0.5 part by mass, and further preferably in the range of 0.1 part by mass to 0.3 part by mass.

[0225] <<Functional group ratio>>

[0226] In the adhesive composition of the present disclosure, when the number of moles of the mercapto group in the specific silane compound (C) is P mmol, the number of moles of the amino group in the specific silane compound (D) is Q mmol, and the number of moles of the carboxyl group in the specific (meth)acrylic copolymer (A) is R mmol, the functional group ratio [i.e., functional group ratio (X)] calculated by the following formula (X) is 2.5×10 -4 or more and less than 3.5×10 -3 range.

[0227] Functional group ratio = P×(Q / R) ··· (X)

[0228] If the functional group ratio (X) is 2.5×10 -4 or more, the formed adhesive layer tends to exhibit excellent reprocessability.

[0229] The functional group ratio (X) is preferably 3.5×10 -4 or more, more preferably 4.5×10 -4 or more, further preferably 5.5×10 -4 or more, and particularly preferably 6.5×10 -4 or more.

[0230] If the functional group ratio (X) is less than 3.5×10 -3 , the formed adhesive layer tends to exhibit excellent high-temperature durability.

[0231] The functional group ratio (X) is preferably 2.5×10 -3 or less, more preferably 1.5×10 -3 or less, further preferably 1.0×10 -3 or less, and particularly preferably 0.5×10 -3 or less.

[0232] In a certain mode, the functional group ratio (X) can be in the range of 3.5×10 -4 to 2.5×10 -3 range, can be in the range of 4.5×10 -4 to 1.5×10 -3 range, can be in the range of 5.5×10 -4 to 0.5×10-3 The range can be 6.5×10 -4 ~9.5×10 -4 range.

[0233] The number of moles P [unit: mmol] of the mercapto group in the specific silane compound (C) is obtained by the following formula (x1).

[0234] The number of moles P [unit: mmol] of the mercapto group in the specific silane compound (C)

[0235] = [The amount of the specific silane compound (C) used [unit: g]] / [The mercapto equivalent of the specific silane compound (C) [unit: g / eq]] × 1000 ··· (x1)

[0236] It should be noted that the mercapto equivalent of the specific silane compound (C) in the formula (x1) is obtained by the following formula (x1-1).

[0237] The mercapto equivalent of the specific silane compound (C) [unit: g / eq]

[0238] = [The molecular weight of the specific silane compound (C) [unit: g / mol]] / [The number of mercapto groups in one molecule of the specific silane compound (C)] ··· (x1-1)

[0239] The number of moles Q [unit: mmol] of the amino group in the specific silane compound (D) is obtained by the following formula (x2).

[0240] The number of moles Q [unit: mmol] of the amino group in the specific silane compound (D)

[0241] = [The amount of the specific silane compound (D) used [unit: g]] / [The amino equivalent of the specific silane compound (D) [unit: g / eq]] × 1000 ··· (x2)

[0242] The amino equivalent of the specific silane compound (D) in the formula (x2) is obtained by the following formula (x2-1).

[0243] The amino equivalent of the specific silane compound (D) [unit: g / eq]

[0244] = [The molecular weight of the specific silane compound (D) [unit: g / mol]] / [The number of amino groups in one molecule of the specific silane compound (D)] ··· (x2-1)

[0245] The number of moles R [unit: mmol] of the carboxyl group in the specific (meth)acrylic acid copolymer (A) is obtained by the following formula (x3).

[0246] It should be noted that the molecular weight of the constituent unit of acrylic acid derived from the monomer having a carboxyl group is 72.06 g / mol.

[0247] The number of moles R [unit: mmol] of the carboxyl group in the specific (meth)acrylic copolymer (A)

[0248] = [Content of the constituent unit derived from the monomer having a carboxyl group in the specific (meth)acrylic copolymer (A) [unit: mass%]] / 100 × [Amount of the specific (meth)acrylic copolymer (A) used [unit: g]] / [Molecular weight of the constituent unit derived from the monomer having a carboxyl group [unit: g / mol]] × [Number of carboxyl groups in the constituent unit derived from the monomer having a carboxyl group] × 1000 ··· (x3)

[0249] 〔Organic solvent〕

[0250] The adhesive composition of the present disclosure may contain an organic solvent.

[0251] If the adhesive composition of the present disclosure contains an organic solvent, the coatability can be improved.

[0252] As the organic solvent, for example, the same solvents as those used in the polymerization reaction of the above-mentioned specific (meth)acrylic copolymer (A) can be cited.

[0253] When the adhesive composition of the present disclosure contains an organic solvent, it may contain only one kind of organic solvent or two or more kinds.

[0254] When the adhesive composition of the present disclosure contains an organic solvent, the content of the organic solvent is not particularly limited and can be appropriately set according to the purpose.

[0255] 〔Other components〕

[0256] Within the range that does not impair its effects, the adhesive composition of the present disclosure may contain components other than the above-mentioned components (so-called other components) as needed.

[0257] As other components, polymers other than the specific (meth)acrylic copolymer (A), compounds that can function as crosslinking agents other than polyisocyanate compounds and bifunctional or higher epoxy compounds, crosslinking catalysts, antioxidants, colorants (such as dyes and pigments), light stabilizers (such as ultraviolet absorbers), antistatic agents, and various other additives can be cited.

[0258] When the adhesive composition of the present disclosure contains other components, the content of the other components can be appropriately set within the range that does not impair the effects of the adhesive composition of the present disclosure.

[0259] <<Use of the adhesive composition>>

[0260] The use of the adhesive composition of the present disclosure is not particularly limited.

[0261] Since the adhesive composition of the present disclosure can form an adhesive layer excellent in high-temperature durability and reprocessability, it is suitable, for example, as an adhesive composition used in an optical film (i.e., an adhesive composition for an optical film). The adhesive composition of the present disclosure is particularly suitable as an adhesive composition used for a polarizing plate in an optical film (i.e., an adhesive composition for a polarizing plate).

[0262] As specific uses of the adhesive composition of the present disclosure, there can be mentioned uses such as bonding a polarizing plate to a glass substrate of a liquid crystal cell and bonding optical films to each other.

[0263] [Adhesive sheet]

[0264] The adhesive sheet of the present disclosure includes an adhesive layer formed from the adhesive composition of the present disclosure.

[0265] The adhesive sheet of the present disclosure also includes the sheet-like adhesive layer itself formed from the adhesive composition of the present disclosure.

[0266] The adhesive layer included in the adhesive sheet of the present disclosure contains a cured product of the adhesive composition of the present disclosure. The cured product contains, for example, a crosslinked product of a specific (meth)acrylic copolymer (A) crosslinked and cured using a polyisocyanate compound (B).

[0267] Since the adhesive sheet of the present disclosure includes an adhesive layer formed from the above-described adhesive composition of the present disclosure, it is less likely to cause defects caused by shrinkage of the optical film in a high-temperature environment (for example, in a high-temperature and low-humidity environment). Specifically, these defects are wrinkles of the adhesive layer and the optical film, and peeling of the adhesive layer from the adherend. In addition, since the adhesive sheet of the present disclosure includes an adhesive layer formed from the above-described adhesive composition of the present disclosure, foaming is less likely to occur at the interface between the adhesive layer and the optical film and / or the adherend in a high-temperature environment (for example, in a high-temperature and low-humidity environment). In addition, since the adhesive sheet of the present disclosure includes an adhesive layer formed from the above-described adhesive composition of the present disclosure, it has excellent reprocessability.

[0268] The thickness of the adhesive layer included in the adhesive sheet of the present disclosure is not particularly limited.

[0269] The thickness of the adhesive layer is generally 1 μm to 100 μm, preferably 5 μm to 50 μm, and more preferably 10 μm to 30 μm.

[0270] The "thickness of the adhesive layer" in the present disclosure refers to the average thickness of the adhesive layer.

[0271] The average thickness of the adhesive layer is a value obtained by the following method.

[0272] Measure the thickness at 10 randomly selected positions in the thickness direction of the adhesive layer using a film thickness gauge. Calculate the arithmetic mean of the measured values, and use the obtained value as the average thickness of the adhesive layer.

[0273] The adhesive sheet of the present disclosure can be a substrate-free type adhesive sheet without a substrate, or a substrate-type adhesive sheet having an adhesive layer on one or both sides of the substrate.

[0274] When the adhesive sheet of the present disclosure is a substrate-free type adhesive sheet without a substrate or a substrate-type adhesive sheet having an adhesive layer on one side of the substrate, in the adhesive sheet of the present disclosure, the exposed surface of the adhesive layer can be protected by a release sheet.

[0275] Generally, before the adhesive sheet is put into practical use, the release sheet protects the surface of the adhesive layer and is peeled off during use.

[0276] The release sheet is not particularly limited as long as it can be easily peeled off from the adhesive layer.

[0277] Examples of the release sheet include resin films, papers, synthetic papers, and composite sheets obtained by laminating two or more of them, which are surface-treated (so-called easy-peeling treatment) on one or both sides with a release treatment agent.

[0278] In the present disclosure, a release sheet in which one or both sides of a resin film are surface-treated (so-called easy-peeling treatment) with a release treatment agent is also referred to as a "release film".

[0279] Examples of the release treatment agent include silicone-based release treatment agents (such as silicone), wax-based release treatment agents (such as paraffin wax), and fluorine-based release treatment agents (such as fluorine-based resins).

[0280] Examples of the resin film include polyester films typified by polyethylene terephthalate (PET) films.

[0281] Examples of the paper include high-quality paper and coated paper.

[0282] The thickness of the release sheet is not particularly limited and is generally 20 μm to 180 μm.

[0283] When the adhesive sheet of the present disclosure has a substrate, the substrate is not particularly limited as long as an adhesive layer can be formed thereon.

[0284] As the base material, for example, films containing polyolefin resins [such as polyethylene (PE) and polypropylene (PP)], polyester resins [such as polyethylene terephthalate (PET)], acetate resins (such as cellulose triacetate), polyethersulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyurethane resins, (meth)acrylic resins, vinyl chloride resins, ABS (Acrylonitrile Butadiene Styrene) resins, fluorine resins and other resins can be cited.

[0285] From the viewpoint of improving the adhesion between the base material and the adhesive layer, surface treatments such as corona discharge treatment and plasma discharge treatment (so-called easy adhesion treatment) can be applied to the surface of the side of the base material where the adhesive layer is provided.

[0286] The base material can contain various additives such as plasticizers, colorants (such as dyes and pigments), heat stabilizers, light stabilizers, antistatic agents, flame retardants, antioxidants, fillers and the like.

[0287] Patterns can be applied to a part or the whole of the base material.

[0288] When the adhesive sheet of the present disclosure includes a base material, the base material is preferably an optical film. In this case, as a mode of the adhesive sheet of the present disclosure, a mode including an optical film and an adhesive layer is preferred, and the adhesive layer is provided on at least one surface of the optical film and is formed of the adhesive composition of the present disclosure.

[0289] The type of the optical film is not particularly limited.

[0290] Specific examples of the optical film include polarizing plates, AG (Anti-Glare) polarizing plates, wavelength plates (such as 1 / 2 wavelength plates and 1 / 4 wavelength plates), retardation films containing the above wavelength plates, viewing angle compensation films, optical compensation films, brightness enhancement films, light guide plates, reflection films, antireflection films, prism sheets, lens sheets, diffusion plates and transparent conductive films.

[0291] As the optical film, a polarizing plate (so-called polarizing film) is preferred.

[0292] The polarizing plate is composed of at least a polarizer, and can be a single polarizer, or a structure in which a polarizer and a protective film are laminated. That is, the polarizing plate can be a single-layer structure of a single polarizer, a two-layer structure having a protective film on one side of the polarizer, or a three-layer structure having protective films on both sides of the polarizer.

[0293] As a layer structure of the adhesive sheet of the present disclosure when the base material is a polarizing plate, for example, there can be mentioned methods such as an adhesive layer / polarizing plate [protective film / polarizer / protective film], an adhesive layer / polarizing plate [phase difference film / polarizer / protective film], an adhesive layer / polarizing plate [phase difference film / protective film / polarizer / protective film], etc.

[0294] As the protective film, a film containing resins such as triacetyl cellulose (TAC), polycycloolefin (COP), polyethylene terephthalate (PET), and polymethyl methacrylate (PMMA) is used, for example.

[0295] As the polarizer, a stretched film impregnated with iodine-containing polyvinyl alcohol (PVA) is used, for example.

[0296] As the phase difference film, a film containing resins such as polycycloolefin (COP) is used, for example.

[0297] The thickness of the base material is not particularly limited, generally 10 μm to 500 μm, preferably 10 μm to 300 μm, more preferably 10 μm to 200 μm, and further preferably 10 μm to 130 μm.

[0298] The "thickness of the base material" in the present disclosure refers to the average thickness of the base material.

[0299] The average thickness of the base material is a value obtained by the following method.

[0300] The thickness of 10 randomly selected parts in the thickness direction of the base material is measured using a film thickness gauge. The arithmetic mean of the measured values is calculated, and the obtained value is used as the average thickness of the base material.

[0301] [Method for manufacturing the adhesive sheet]

[0302] The method for manufacturing the adhesive sheet of the present disclosure is not particularly limited.

[0303] The adhesive sheet of the present disclosure can be manufactured by a known method.

[0304] As a method for manufacturing the adhesive sheet of the present disclosure, for example, the following methods can be mentioned.

[0305] When the adhesive sheet of the present disclosure is a substrate-free adhesive sheet, first, the adhesive composition of the present disclosure is coated on the easily peelable surface of the release sheet, thereby forming a coating film on the release sheet. Then, the formed coating film is dried, thereby forming an adhesive film on the release sheet. Next, the exposed surface of the formed adhesive film is overlapped and adhered to the easily peelable surface of another prepared release sheet, and then cured, whereby the adhesive sheet of the present disclosure having a laminate structure of release sheet / adhesive layer / release sheet can be manufactured.

[0306] When the adhesive sheet of the present disclosure is a substrate-containing adhesive sheet, first, a coating film is formed on the substrate by applying the adhesive composition of the present disclosure to one surface of the substrate (preferably the surface subjected to adhesion treatment). Next, the formed coating film is dried to form an adhesive film on the substrate. Then, the exposed surface of the formed adhesive film is overlapped and adhered to the easily peelable surface of the release sheet, and then cured, whereby the adhesive sheet of the present disclosure having a laminated structure of substrate / adhesive layer / release sheet can be produced.

[0307] When the adhesive sheet of the present disclosure is a substrate-containing adhesive sheet, as another method, for example, the following method can be cited.

[0308] A coating film is formed on the release sheet by applying the adhesive composition of the present disclosure to the easily peelable surface of the release sheet. Next, the formed coating film is dried to form an adhesive film on the release sheet. Then, the exposed surface of the formed adhesive film is overlapped and adhered to one surface of the substrate (preferably the surface subjected to adhesion treatment), and then cured, whereby the adhesive sheet of the present disclosure having a laminated structure of substrate / adhesive layer / release sheet can be produced.

[0309] The coating method of the adhesive composition is not particularly limited.

[0310] As the coating method of the adhesive composition, for example, known methods such as using a gravure roll coater, an inverse roll coater, a kiss roll coater, an impregnating roll coater, a knife coater, a spray coater, a bar coater, an applicator, etc. can be cited.

[0311] The coating amount of the adhesive composition is not particularly limited, and can be appropriately set according to the thickness of the formed adhesive layer, for example.

[0312] The drying method of the coating film is not particularly limited.

[0313] As the drying method of the coating film, for example, methods such as natural drying, heat drying, hot air drying, vacuum drying, etc. can be cited.

[0314] The drying temperature and drying time of the coating film are not particularly limited, and can be appropriately set according to the thickness of the coating film, the amount of organic solvent in the coating film, etc.

[0315] As an example of the drying conditions, conditions such as drying by blowing air at 60°C to 130°C at a wind speed of 3 m / s to 5 m / s for 30 seconds to 300 seconds using a hot air circulation dryer can be cited.

[0316] As the curing method, for example, a method of standing for 2 days to 7 days in an environment of an atmosphere temperature of 20°C to 35°C and a relative humidity of 45% to 55% can be cited.

[0317] [Optical Component]

[0318] The optical component of the present disclosure sequentially includes a glass substrate, an adhesive layer formed of the adhesive composition of the present disclosure, and an optical film.

[0319] Since the optical component of the present disclosure includes an adhesive layer formed of the adhesive composition of the present disclosure, adverse conditions caused by shrinkage of the optical film are less likely to occur in a high-temperature environment (for example, a high-temperature and low-humidity environment). Specifically, wrinkles of the adhesive layer and the optical film, and peeling of the adhesive layer from the glass substrate are less likely to occur. In addition, since the optical component of the present disclosure includes an adhesive layer formed of the adhesive composition of the present disclosure, foaming is less likely to occur at the interface between the adhesive layer and the optical film and / or the glass substrate in a high-temperature environment (for example, a high-temperature and low-humidity environment).

[0320] The thickness of the glass substrate is not particularly limited, and is generally 0.3 mm to 0.7 mm, preferably 0.3 mm to 0.5 mm.

[0321] Examples of the glass substrate include a soda glass plate, a non-alkali glass plate, and a glass plate with an ITO (Indium Tin Oxide) film.

[0322] The adhesive layer and the optical film in the optical component of the present disclosure have the same meaning as the adhesive layer and the optical film in the adhesive sheet of the present disclosure, and the preferred embodiments are the same, so the description is omitted here.

[0323] The optical component of the present disclosure can be applied, for example, as a component of a display device.

[0324] Examples of the display device include a liquid crystal display and an organic EL (Electro-Luminescence) display.

[0325] The manufacturing method of the optical component of the present disclosure is not particularly limited.

[0326] The optical component of the present disclosure can be manufactured, for example, by using an optical film as a base material, manufacturing the adhesive sheet of the present disclosure by the above method, and then bonding the adhesive layer of the adhesive sheet to the glass substrate.

[0327] [Display device]

[0328] The display device of the present disclosure includes the optical component of the present disclosure.

[0329] Since the display device of the present disclosure includes the optical component of the present disclosure, foaming is less likely to occur at the interface between the adhesive layer and the optical film and / or the glass substrate even when placed in a high-temperature environment (for example, a high-temperature and low-humidity environment), peeling is less likely to occur between the adhesive layer and the glass substrate, and wrinkles are less likely to occur in the adhesive layer and / or the optical film.

[0330] Specific examples of the display device are as described above.

[0331] Examples

[0332] Hereinafter, the adhesive composition of the present disclosure will be described in more detail using examples. The present disclosure is not limited to the following examples as long as it does not exceed its gist.

[0333] [Manufacture of (meth)acrylic copolymer (A)]

[0334] [Production Example A-1]

[0335] In a reactor equipped with a thermometer, a stirrer, a nitrogen inlet tube, and a reflux condenser, 78.7 parts by mass of n-butyl acrylate [n-BA; an acrylic acid alkyl ester monomer], 18.0 parts by mass of phenoxyethyl acrylate [PHEA; an acrylate having an aromatic ring], 0.5 parts by mass of acrylic acid [AA; a monomer having a carboxyl group], 2.8 parts by mass of 2-hydroxyethyl acrylate [2HEA; a monomer having a hydroxyl group], 133.3 parts by mass of ethyl acetate [an organic solvent], and 20.0 parts by mass of methyl acetate [an organic solvent] were added and mixed. After obtaining a mixture, the inside of the reactor was purged with nitrogen. Next, while stirring the mixture in the reactor, the temperature was raised to 70°C, and then 0.01 part by mass of 2,2'-azobis(2,4-dimethylvaleronitrile) [ABVN; a polymerization initiator] and 60.0 parts by mass of methyl acetate were successively added to the mixture in the reactor. After the addition was completed, the mixture was maintained for 6 hours for a polymerization reaction to obtain a polymerization product. The obtained polymerization product was diluted with ethyl acetate to a solid content concentration of 25.0 mass%, and then cooled to obtain a solution of (meth)acrylic copolymer A-1.

[0336] Here, the so-called "solid content concentration" refers to the mass ratio of (meth)acrylic copolymer A-1 in the solution of (meth)acrylic copolymer A-1. The same applies to the solutions of (meth)acrylic copolymers A-2 to A-15 manufactured below.

[0337] [Production Examples A-2 and A-13 to A-15]

[0338] In Production Examples A-2 and A-13 to A-15, the monomer components of (meth)acrylic copolymer (A) were changed to the monomer components shown in Table 1, and otherwise, the same operations as in Production Example A-1 were performed to obtain solutions of (meth)acrylic copolymers A-2 and A-13 to A-15 having a solid content concentration of 25.0 mass%.

[0339] [Production Examples A-3 to A-12]

[0340] In Production Examples A-3 to A-12, the monomer components of the (meth)acrylic acid copolymer (A) were changed to the monomer components shown in Table 1, and at least one of the amount of the organic solvent used and the amount of the polymerization initiator used was adjusted so that the weight-average molecular weight of the (meth)acrylic acid copolymer (A) was adjusted to the weight-average molecular weight shown in Table 1. Otherwise, the same operations as in Production Example A-1 were carried out to obtain solutions of the (meth)acrylic acid copolymers A-3 to A-12 having a solid content concentration of 25.0% by mass.

[0341] The monomer components [unit: mass%] and the weight-average molecular weight (expressed as "M w ") of the (meth)acrylic acid copolymers A-1 to A-15 are shown in Table 1.

[0342] The weight-average molecular weights of the (meth)acrylic acid copolymers A-1 to A-15 were measured by the same method as the method for measuring the weight-average molecular weight of the above-mentioned specific (meth)acrylic acid copolymer (A).

[0343] Among the (meth)acrylic acid copolymers A-1 to A-15, the (meth)acrylic acid copolymers A-1 to A-10 and A-12 belong to the specific (meth)acrylic acid copolymer (A) in the present disclosure.

[0344] [Table 1]

[0345]

[0346] The details of each monomer described in Table 1 are as follows.

[0347] <(Meth)acrylic acid alkyl ester monomer>

[0348] "n-BA": n-butyl acrylate

[0349] "MA": methyl acrylate

[0350] "MMA": methyl methacrylate

[0351] <Monomer having a carboxyl group>

[0352] "AA": acrylic acid (molecular weight: 72.06)

[0353] <Monomer having a hydroxyl group>

[0354] "2HEA": 2-hydroxyethyl acrylate

[0355] <Other monomers (monomers having an aromatic ring)>

[0356] "PHEA": phenoxyethyl acrylate

[0357] In Table 1, the "-" recorded in the monomer component column means that the monomer belonging to this column is not used.

[0358] [Preparation of Adhesive Composition]

[0359] [Example 1]

[0360] 400.00 parts by mass of a solution of (meth)acrylic copolymer A-1 (100 parts by mass in terms of solid content), 0.56 parts by mass of TAKENATE D-101E [trade name, an adduct of toluene diisocyanate (TDI) and trimethylolpropane (TMP), solid content concentration: 45% by mass, manufactured by Mitsui Chemicals, Inc.] as the polyisocyanate compound (B) (0.25 parts by mass in terms of solid content), 0.30 parts by mass of X-41-1810 [trade name, a silane compound having a methyl group, a mercapto group and a siloxane bond, solid content concentration: 100% by mass, manufactured by Shin-Etsu Chemical Co., Ltd.] as the silane compound (C) (0.30 parts by mass in terms of solid content), 0.15 parts by mass of KF-859 [trade name, a silane compound having an amino group and no alkoxysilyl group, solid content concentration: 100% by mass, manufactured by Shin-Etsu Chemical Co., Ltd.] as the silane compound (D) (0.15 parts by mass in terms of solid content), and an appropriate amount of ethyl acetate [organic solvent] were thoroughly mixed to obtain the adhesive composition of Example 1.

[0361] [Examples 2 to 20]

[0362] In Examples 2 to 20, the composition of the adhesive composition was changed to the composition shown in Table 2, and except for this, the same operations as in Example 1 were carried out to obtain the respective adhesive compositions of Examples 2 to 20.

[0363] [Examples 21 to 28]

[0364] In Examples 21 to 28, the composition of the adhesive composition was changed to the composition shown in Table 3, and except for this, the same operations as in Example 1 were carried out to obtain the respective adhesive compositions of Examples 21 to 28.

[0365] [Comparative Examples 1 to 15]

[0366] In Comparative Examples 1 to 15, the composition of the adhesive composition was changed to the composition shown in Table 4, and except for this, the same operations as in Example 1 were carried out to obtain the respective adhesive compositions of Comparative Examples 1 to 15.

[0367] The compositions of the respective adhesive compositions of Examples 1 to 28 and Comparative Examples 1 to 15, and the number of moles of carboxyl groups [unit: mmol] in the (meth)acrylic copolymer (A) in the respective adhesive compositions of Examples 1 to 28 and Comparative Examples 1 to 15, the number of moles of mercapto groups [unit: mmol] in the silane compound (C), the number of moles of amino groups [unit: mmol] in the silane compound (D), and the functional group ratio are shown in Tables 2 to 4.

[0368] The number of moles of carboxyl groups [unit: mmol] in the (meth)acrylic copolymer (A), the number of moles of mercapto groups [unit: mmol] in the silane compound (C), the number of moles of amino groups [unit: mmol] in the silane compound (D), and the functional group ratio are determined by the same method as the method for determining the number of moles of carboxyl groups R [unit: mmol] in the specific (meth)acrylic copolymer (A), the number of moles of mercapto groups P [unit: mmol] in the specific silane compound (C), the number of moles of amino groups Q [unit: mmol] in the specific silane compound (D), and the functional group ratio (X) described above, that is, by Formula (x1), Formula (x2), Formula (x3), and Formula (X).

[0369] In Tables 2 to 4, the "number of moles of carboxyl groups in the (meth)acrylic copolymer (A)" is recorded as the "number of moles of carboxyl groups in (A)", the "number of moles of mercapto groups in the silane compound (C)" is recorded as the "number of moles of mercapto groups in (C)", and the "number of moles of amino groups in the silane compound (D)" is recorded as the "number of moles of amino groups in (D)".

[0370]

[0371]

[0372]

[0373] The details of the components described in Tables 2 to 4 are as follows.

[0374] <Polyisocyanate compound>

[0375] “TAKENATE D-101E” [trade name, an adduct of toluene diisocyanate (TDI) and trimethylolpropane (TMP), solid content concentration: 45% by mass, manufactured by Mitsui Chemicals, Inc.]

[0376] “TAKENATE D-110N” [trade name, an adduct of xylylene diisocyanate (XDI) and trimethylolpropane (TMP), solid content concentration: 75% by mass, manufactured by Mitsui Chemicals, Inc.]

[0377] The above "TAKENATE" is a registered trademark.

[0378] <Bifunctional or higher epoxy compounds>

[0379] "CELLOXIDE 2021P" [trade name, chemical name: 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, an alicyclic epoxy compound having an ester bond in the molecule, solid content concentration: 100% by mass, manufactured by Daicel Corporation]

[0380] "X-40-2669" [trade name, an alicyclic epoxy group-containing linear siloxane difunctional oligomer (an alicyclic epoxy compound having a siloxane bond in the molecule), solid content concentration: 100% by mass, manufactured by Shin-Etsu Chemical Co., Ltd.]

[0381] <Silane compound (C)>

[0382] "X-41-1810" [trade name, a silane compound having a methyl group, a mercapto group, and a siloxane bond, mercapto equivalent: 450 g / eq, solid content concentration: 100% by mass, manufactured by Shin-Etsu Chemical Co., Ltd.]]

[0383] "X-41-1805" [trade name, a silane compound having a methyl group, a mercapto group, and a siloxane bond, mercapto equivalent: 800 g / eq, solid content concentration: 100% by mass, manufactured by Shin-Etsu Chemical Co., Ltd.]]

[0384] "X-12-1307" [trade name, a silane compound having a mercapto group, mercapto equivalent: 168 g / eq, solid content concentration: 100% by mass, manufactured by Shin-Etsu Chemical Co., Ltd.]]

[0385] The above "X-41-1810", "X-41-1805" and "X-12-1307" all correspond to the specific silane compound (C) in the present disclosure.

[0386] <Silane compound (D)>

[0387] "KF-859" [trade name, a silane compound having an amino group and no alkoxysilyl group, amino equivalent: 6000 g / eq, solid content concentration: 100% by mass, manufactured by Shin-Etsu Chemical Co., Ltd.]

[0388] "KF-880" [trade name, a silane compound having an amino group and no alkoxysilyl group, amino equivalent: 1800 g / eq, solid content concentration: 100% by mass, manufactured by Shin-Etsu Chemical Co., Ltd.]

[0389] "KF-8004" [Trade name, a silane compound having an amino group and no alkoxysilyl group, amino equivalent: 1500 g / eq, solid content concentration: 100% by mass, manufactured by Shin-Etsu Chemical Co., Ltd.]

[0390] The above "KF-859", "KF-880" and "KF-8004" all correspond to the specific silane compound (D) in the present disclosure.

[0391] <Other silane compounds>

[0392] "SH-8400" [Trade name, side-chain polyether modified silicone oil, solid content concentration: 100% by mass, manufactured by Dow TORAY Co., Ltd.]

[0393] "KBM-403" [Trade name, chemical name: 3-glycidoxypropyltrimethoxysilane, solid content concentration: 100% by mass, manufactured by Dow TORAY Co., Ltd.]

[0394] In Tables 2 to 4, the values recorded in the "Blending amount" column are all values converted to solid components.

[0395] In Tables 2 to 4, the "-" recorded in the composition column of the adhesive composition means that the component belonging to this column is not blended.

[0396] In Tables 2 to 4, the "-" recorded in the columns of "Moles of carboxyl group in (A)", "Moles of mercapto group in (C)", "Moles of amino group in (D)" and "Functional group ratio" means that there is no corresponding value.

[0397] [Manufacture of polarizing plate with adhesive layer]

[0398] The adhesive composition prepared above was coated on the easily peelable surface of a peelable film [type: MRF, thickness: 38 μm, manufactured by Mitsubishi Chemical Corporation] that had been surface-treated (so-called easy peel treatment) with a silicone-based peel treatment agent to form a coated film. It should be noted that the coating amount of the adhesive composition was such that the thickness of the adhesive film described below would be 20 μm. Next, for the formed coated film, hot air was blown at a speed of 3 m / s for 60 seconds at 100 °C using a hot air circulation dryer to dry the coated film and form an adhesive film with a thickness of 20 μm on the peelable film. Next, the exposed surface of the formed adhesive film was overlapped and adhered to one TAC layer surface of a polarizing plate (thickness: 100 μm) having a structure of a cellulose triacetate (TAC) layer / a polyvinyl alcohol (PVA) layer containing a polarizer / a TAC layer. Next, the laminate obtained by adhesion was left standing for 7 days (so-called curing period) in an environment of an atmospheric temperature of 23 °C and 50% RH to cure the adhesive film. Thus, a polarizing plate with an adhesive layer having a structure of a peelable film / an adhesive layer / a polarizing plate (TAC layer / PVA layer / TAC layer) was produced.

[0399] [Evaluation]

[0400] 1. High-temperature durability

[0401] (1) Preparation of evaluation samples

[0402] The polarizing plate with an adhesive layer prepared above was cut so that the long side was 0° with respect to the absorption axis of the polarizing plate to produce a test piece with a size of 130 mm (short side) × 230 mm (long side). Next, the peelable film of the test piece was peeled off. After overlapping it so that the surface of the adhesive layer exposed by peeling contacted one surface of a glass plate [type: soda lime glass, manufactured by Matsunami Glass Industry Co., Ltd.], it was crimped using a laminator to adhere the test piece to the glass plate.

[0403] An evaluation sample having a structure of a glass plate / an adhesive layer / a polarizing plate (TAC layer / PVA layer / TAC layer) was prepared as described above.

[0404] (2) Evaluation test

[0405] The evaluation sample prepared above was subjected to autoclave treatment at a treatment temperature of 50 °C and a treatment pressure of 5 kg / cm 2 for 20 minutes, and then left standing for 24 hours in an environment of an atmospheric temperature of 23 °C and 50% RH. The evaluation sample after standing for 24 hours was left standing for 500 hours in an environment of an atmospheric temperature of 95 °C and 10% RH (so-called high-temperature and low-humidity environment). The state of the evaluation sample after standing for 500 hours was observed visually and evaluated according to the following evaluation criteria. The evaluation results are shown in Tables 5 and 6.

[0406] In the following evaluation criteria, "A", "B", and "C" represent practical levels, and "A" is the most preferred.

[0407] - Evaluation Criteria -

[0408] A: No foaming, wrinkling, or peeling was confirmed in the evaluation sample.

[0409] B: At least one of foaming, wrinkling, or peeling was slightly confirmed in the evaluation sample, but at a level where there are no practical problems.

[0410] C: At least one of foaming, wrinkling, or peeling was confirmed in the evaluation sample, but at a level where it is practically acceptable.

[0411] D: At least one of foaming, wrinkling, or peeling was clearly confirmed in the evaluation sample, at a level where it is not practically acceptable.

[0412] 2. Reprocessability

[0413] (1) Preparation of the evaluation sample

[0414] The polarizing plate with an adhesive layer prepared above was cut to prepare a test piece with a size of 25 mm (short side) × 75 mm (long side). Next, the release film of the test piece was peeled off. After overlapping in such a way that the surface of the adhesive layer exposed by peeling contacted one surface of a glass plate [type: soda lime glass, manufactured by Matsunami Glass Industry Co., Ltd.], it was pressed using a laminator to bond the test piece to the glass plate.

[0415] An evaluation sample having a structure of glass plate / adhesive layer / polarizing plate (TAC layer / PVA layer / TAC layer) was prepared as described above.

[0416] (2) Evaluation test

[0417] The evaluation sample prepared above was subjected to autoclave treatment for 20 minutes under the conditions of a treatment temperature of 50 °C and a treatment pressure of 5 kg / cm 2 and then left standing for 1 day in an environment with an atmospheric temperature of 23 °C and 50% RH. The evaluation sample left standing for 1 day was designated as "Evaluation Sample X".

[0418] In addition, as another system, the evaluation sample prepared above was subjected to autoclave treatment for 20 minutes under the conditions of a treatment temperature of 50 °C and a treatment pressure of 5 kg / cm 2 and then left standing for 15 days in an environment with an atmospheric temperature of 23 °C and 50% RH. The evaluation sample left standing for 15 days was designated as "Evaluation Sample Y".

[0419] For evaluation samples X and Y, a single-column type material testing machine (model: STA-1225) manufactured by A&D Co., Ltd. was used as the measuring device. The adhesive strength (unit: N / 25 mm) was measured under the conditions of an ambient temperature of 23°C, 50% RH, and a peeling speed of 0.3 m / min when the test piece [composition: adhesive layer / polarizer (TAC layer / PVA layer / TAC layer)] was peeled 180° along the long side (75 mm) direction from the glass plate. Based on the adhesive strength of evaluation sample X (so-called initial adhesive strength) and the adhesive strength of evaluation sample Y (so-called adhesive strength over time), the change amount of the adhesive strength (unit: N / 25 mm) of the evaluation sample before and after standing was calculated by the following formula. Change amount of adhesive strength = (adhesive strength of evaluation sample Y) - (adhesive strength of evaluation sample X).

[0420] Then, the evaluation was carried out according to the following evaluation criteria. The adhesive strength of evaluation sample X, the adhesive strength of evaluation sample Y, the change amount of the adhesive strength, and the evaluation results are shown in Tables 5 and 6.

[0421] In the following evaluation criteria, "A", "B", and "C" are practical levels, and "A" is most preferred.

[0422] - Evaluation Criteria -

[0423] A: The change amount of the adhesive strength is less than 2.0 N / 25 mm.

[0424] B: The change amount of the adhesive strength is 2.0 N / 25 mm or more and less than 3.0 N / 25 mm.

[0425] C: The change amount of the adhesive strength is 3.0 N / 25 mm or more and less than 4.0 N / 25 mm.

[0426] D: The change amount of the adhesive strength is 4.0 N / 25 mm or more and / or the adhesive strength over time exceeds 12.0 N / 25 mm.

[0427] [Table 5]

[0428]

[0429] [Table 6]

[0430]

[0431] In Table 6, "Unable to measure ※" means that the adhesive layer is too soft and the adhesive layer is damaged during peeling, making it impossible to measure the adhesive strength and evaluate the reprocessability.

[0432] As shown in Table 5, it was confirmed that the high-temperature durability and reprocessability of the adhesive layer formed from the adhesive compositions of Examples 1 to 28 were excellent.

[0433] On the other hand, as shown in Table 6, it was confirmed that at least one of the high-temperature durability and reprocessability of the adhesive layer formed from the adhesive compositions of Comparative Examples 1 to 15 was inferior to that of the adhesive layer formed from the adhesive composition of the Example.

Claims

1. An adhesive composition comprising a (meth)acrylic copolymer A, a polyisocyanate compound B, a silane compound C having a mercapto group and an alkoxysilyl group, and a silane compound D having an amino group and no alkoxysilyl group, The (meth)acrylic copolymer A contains a structural unit derived from a monomer having a carboxyl group at a ratio of 0.5% to 3.0% by mass relative to all structural units, and has a weight average molecular weight in the range of 500,000 to 1,200,000; The content of the polyisocyanate compound B is in the range of 0.1 to 0.6 parts by mass relative to 100 parts by mass of the (meth)acrylic copolymer A. When the number of moles of mercapto groups in the silane compound C is Pmmol, the number of moles of amino groups in the silane compound D is Qmmol, and the number of moles of carboxyl groups in the (meth)acrylic copolymer A is Rmmol, the functional group ratio calculated by the following formula (X) is 2.5×10 -4 More than and less than 3.5×10 -3 range, Functional group ratio = P × (Q / R)···(X).

2. The adhesive composition according to claim 1, wherein The silane compound C has a siloxane bond.

3. The adhesive composition according to claim 1, wherein The content of the silane compound C is in the range of 0.1 to 0.6 parts by mass based on 100 parts by mass of the (meth)acrylic copolymer A.

4. The adhesive composition according to claim 1, wherein The (meth)acrylic copolymer A further includes a structural unit derived from a monomer having a hydroxyl group.

5. The adhesive composition according to claim 1, wherein Furthermore, difunctional or higher-functional alicyclic epoxy compounds are included. 6 . A pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition according to claim 1 .

7. An adhesive sheet comprising an optical film and an adhesive layer, The pressure-sensitive adhesive layer is provided on at least one surface of the optical film, and is formed from the pressure-sensitive adhesive composition according to any one of claims 1 to 5.

8. The adhesive sheet according to claim 7, wherein The optical film is a polarizing plate.

9. An optical component, comprising: Glass substrate, A pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition according to any one of claims 1 to 5, and an optical film. 10 . A display device comprising the optical component according to claim 9 .

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