TW202039743A - Adhesive sheet and layered product - Google Patents

Abstract

Provided are: an adhesive sheet having excellent outgas resistance; and a layered product comprising the adhesive sheet. This adhesive sheet comprises an adhesive agent layer. The adhesive agent layer contains a crosslinked (meth)acrylic copolymer, a polymerizable monomer having a polymerizable double bond in the molecule, and a photopolymerization initiator. The crosslinked (meth)acrylic copolymer has a structure in which a crosslinkable (meth)acrylic copolymer is crosslinked by a crosslinking agent. The polymerizable monomer includes a monofunctional monomer having a cyclic ether structure and/or a monofunctional monomer having a chain ether structure.

Description

Adhesive sheet and laminate

Invention field

The present invention relates to an adhesive sheet and a laminate provided with the adhesive sheet.

Background of the invention

Adhesive sheets are used, for example, in applications for bonding members to each other, and are widely used in various fields. In recent years, such adhesive sheets have also been used in display devices such as liquid crystal displays (LCD), or input devices such as touch panels. The adhesive sheet is used for bonding each member such as an optical display that constitutes a display device or an input device, and various devices can be manufactured with high precision and ease.

For display devices or input devices, for example, a resin cover panel and a layer composed of a touch panel sensor are bonded by an adhesive sheet, and there are various adhesive sheets suitable for this purpose. The proposal is presented. For example, Patent Document 1 has proposed an adhesive sheet which is composed of an alkyl (meth)acrylate, a reactive functional group-containing monomer having a reactive functional group in the molecule, and an N-ethyl amide containing carboxylate. The adhesive sheet formed by the adhesive composition of the (meth)acrylate polymer and the crosslinking agent (B). The adhesive sheet based on the acrylic polymer with such a specific structure is used in input devices such as touch panels, thereby improving the foaming resistance and the resistance to damp heat whitening. In addition, Patent Document 2 discloses an optical adhesive sheet with an adhesive layer formed of an adhesive composition containing an acrylic polymer of a specific structure and having a specific shear storage elastic modulus . Advanced technical literature Patent literature

[Patent Document 1] JP 2018-172537 A [Patent Document 2] JP 2012-87240 A

Summary of the invention Problems to be solved by the invention

However, when a resin-made cover panel and other components are attached with an adhesive sheet, the gas generated from the cover panel and other components (so-called outgassing) may cause problems such as bubbles, floating and peeling at the interface. For example, protecting the cover panel used for bonding with a hard coat can suppress outgassing. However, at this time, there is a problem that the types of members used for bonding are limited. That is, for members that are prone to outgassing and have no hard coat layer or the like as protection, there is a problem that it is difficult to use conventional adhesive sheets because of poor outgas resistance. In the technique disclosed in Patent Document 1, although a certain degree of improvement in blistering resistance (outgassing resistance) can be expected, however, when polycarbonate without a hard coat layer is used, for example, the blistering resistance is insufficient, so it is still There is room for further improvement.

The present invention has been completed in view of the above-mentioned knowledge, and its object is to provide an adhesive sheet having excellent outgassing resistance and a laminate provided with the adhesive sheet. Means to solve the problem

In order to achieve the above-mentioned object, the inventors have conducted intensive research and found that the above-mentioned object can be achieved by using a monofunctional monomer having a specific ether structure, and thus completed the present invention.

That is, the present invention includes, for example, the subjects described in the following items. Item 1. An adhesive sheet is an adhesive sheet with an adhesive layer, Wherein the aforementioned adhesive layer contains a crosslinked (meth)acrylic copolymer, a polymerizable monomer with polymerizable double bonds in the molecule, and a photopolymerization initiator; The aforementioned crosslinked (meth)acrylic copolymer has a structure in which a crosslinkable (meth)acrylic copolymer is crosslinked by a crosslinking agent; The aforementioned polymerizable monomer includes at least one of a monofunctional monomer having a cyclic ether structure and a monofunctional monomer having a chain ether structure. Item 2. The adhesive sheet according to item 1, wherein the monofunctional monomer having a cyclic ether structure contains 5 to 30 parts by mass relative to 100 parts by mass of the crosslinkable (meth)acrylic copolymer. Item 3. The adhesive sheet of item 1 or 2, wherein the aforementioned cyclic ether structure is a 4- to 6-membered ring. Item 4. The adhesive sheet according to Item 1, wherein the monofunctional monomer having a chain ether structure contains 5 to 50 parts by mass relative to 100 parts by mass of the crosslinkable (meth)acrylic copolymer. Item 5. The adhesive sheet according to any one of items 1 to 4, wherein the polymerizable monomer contains a multifunctional monomer having two or more polymerizable double bonds in the molecule. Item 6. The adhesive sheet of item 5, wherein the aforementioned multifunctional monomer has a bisphenol skeleton in the molecule. Item 7. The adhesive sheet according to Item 5 or 6, wherein the polyfunctional monomer contains 1 to 15 parts by mass relative to 100 parts by mass of the crosslinkable (meth)acrylic copolymer. Item 8. The adhesive sheet according to any one of items 1 to 7, which is used for bonding with one type of first member selected from the group consisting of a resin plate, a resin sheet, and a resin film. Item 9. The adhesive sheet according to Item 8, which is used for bonding the aforementioned first member and one type of second member selected from the group consisting of a glass plate, a resin film, and a resin plate. Item 10. A laminate comprising the adhesive sheet of any one of items 1 to 9 or a cured product thereof. Item 11. The layered body according to Item 10, which further includes the first member, and has a structure in which the first member and the adhesive sheet or hardened product are laminated. Invention effect

The adhesive sheet of the present invention is excellent in outgassing resistance, and is not easy to generate bubbles, float and peel off after bonding.

The form used to implement the invention

The following is a detailed description of the implementation of the present invention. In addition, in this manual, the expressions of "contains" and "contains" include the concepts of "contains", "contains", "substantially constituted by" and "constituted only by".

1. Adhesive sheet The adhesive sheet of the present invention includes an adhesive layer. The aforementioned adhesive layer contains a crosslinked (meth)acrylic copolymer, a polymerizable monomer having a polymerizable double bond in the molecule, and a photopolymerization initiator; the aforementioned crosslinked (meth)acrylic copolymer has crosslinkability (a (Base) A structure formed by crosslinking of acrylic copolymer with a crosslinking agent; the aforementioned polymerizable monomer includes at least one of a monofunctional monomer having a cyclic ether structure and a monofunctional monomer having a chain ether structure.

In addition, in this specification, "(meth)acrylic acid" means "acrylic acid" or "methacrylic acid", and "(meth)acrylate" means "acrylate" or "methacrylate".

<Crosslinked (meth)acrylic copolymer> The crosslinked (meth)acrylic copolymer is a polymer having a crosslinked structure formed by the reaction between a crosslinkable (meth)acrylic copolymer and a crosslinking agent. As such a crosslinked (meth)acrylic copolymer, for example, a well-known crosslinked (meth)acrylic copolymer used for adhesive sheets can be widely used.

(Crosslinkable (meth)acrylic copolymer) The crosslinkable (meth)acrylic copolymer may have a structure in which a functional group exhibiting crosslinking reactivity is bonded to the (meth)acrylic copolymer backbone. It does not specifically limit as a functional group which shows crosslinking reactivity, For example, a hydroxyl group, a carboxyl group, an amino group, an amido group, an epoxy group, a sulfhydryl group, an isocyanate group, etc. are mentioned. From the viewpoint of preventing yellowing and corrosion, the adhesive layer is preferably acid-free, so the crosslinkable (meth)acrylic copolymer is also preferably acid-free. Therefore, the functional group exhibiting crosslinking reactivity preferably does not contain a carboxyl group. A particularly preferred functional group exhibiting crosslinking reactivity is a hydroxyl group. If so, it is easier to form a crosslinked (meth)acrylic copolymer.

As a crosslinkable (meth)acrylic copolymer, for example, it may have a monomer unit having a functional group exhibiting crosslinking reactivity and a monomer unit having no functional group exhibiting crosslinking reactivity. If so, for example, the crosslinkable (meth)acrylic copolymer can be copolymerized with a monomer having a functional group showing crosslinking reactivity and a monomer having no functional group showing crosslinking reactivity. Obtained by polymerization. Hereinafter, a monomer having a functional group exhibiting crosslinking reactivity is referred to as "monomer A", and a monomer having no functional group exhibiting crosslinking reactivity is referred to as "monomer B".

Examples of the monomer A include a hydroxyl group-containing (meth)acrylic monomer and a carboxyl group-containing (meth)acrylic monomer.

Regarding the hydroxyl group-containing (meth)acrylic monomer, as long as it has one or more hydroxyl groups in the molecule, its kind is not particularly limited. Examples of hydroxyl-containing (meth)acrylic monomers include 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 5 -Hydroxypentyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 2-hydroxy 3-phenoxypropyl (meth)acrylate, 2,2-dimethyl 2-hydroxy Ethyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, 2-hydroxy3-phenoxypropyl (meth)acrylate, 8-hydroxyoctyl (meth) Hydroxyalkyl (meth)acrylates such as acrylic esters; hydroxyalkyl (meth)acrylamides such as N-hydroxypropyl (meth)acrylamide; etc.

Among them, the hydroxyl-containing (meth) acrylic monomer is selected from 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 6-hydroxyhexyl (meth)acrylate. One or more of the group consisting of (base) acrylate is preferable. If so, it is easy to obtain an adhesive sheet excellent in outgassing resistance. The hydroxyl-containing (meth)acrylic monomer can be used alone or in combination of two or more different types.

Regarding the carboxyl group-containing (meth)acrylic monomer, as long as it has one or more carboxyl groups in the molecule, its kind is not particularly limited. Examples of carboxyl group-containing (meth)acrylic monomers include (meth)acrylic acid, maleic acid, maleic anhydride, itaconic acid, fumaric acid, pyrocitric acid, 2-(methyl) Oxyethyl phthalic acid, 2-(meth)acryloxyethyl succinic acid, 2-(meth)acryloxyethyl maleic acid, carboxyethyl (methyl) ) Acrylate, carboxyl polycaprolactone mono(meth)acrylate, etc.

As mentioned above, the adhesive sheet is preferably acid-free, so the monomer A is preferably a hydroxyl-containing (meth)acrylic monomer. In addition, the monomer A may be a (meth)acrylic monomer having any one or more functional groups such as an amino group, an amide group, an epoxy group, a thio group, and an isocyanate group. Assuming that the adhesive sheet contains acid, for example, relative to the total mass of the monomers used to form the crosslinkable (meth)acrylic copolymer, the content of the monomer having an acid group may be 5% by mass or less. It is preferably 3% by mass or less, more preferably 1% by mass or less, and particularly preferably 0.1% by mass or less.

Examples of the monomer B include (meth)acrylates having a linear, branched, or cyclic alkyl group; or (meth)acrylates having an aromatic ring. Specific examples of monomer B include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, tertiary butyl (meth) acrylate, Isopropyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl, (meth)acrylic acid Ester etc. Monomer B is based on methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, tertiary butyl (meth) acrylate, isopropyl (methyl) ) Alkyl (meth)acrylates such as acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate and the like are preferred. If so, it is easy to obtain an adhesive sheet excellent in outgassing resistance. Monomer B can be used alone or in combination of two or more different types.

The crosslinkable (meth)acrylic copolymer can be produced by, for example, polymerizing the monomer A and the monomer B by a known polymerization method. As the polymerization method, for example, solution polymerization, bulk polymerization, suspension polymerization, emulsion polymerization, etc. can be used.

Regarding the polymerization to obtain the crosslinkable (meth)acrylic copolymer, the ratio of monomer A to monomer B is not particularly limited, and it can be made according to the purpose of the crosslinkable (meth)acrylic copolymer Set appropriately. For example, in 100 parts by mass of the total amount of monomer A and monomer B, monomer A (monomer with crosslinkable functional group) may contain 0.5-60 parts by mass. If so, the adhesive sheet can have the desired adhesive force, and it is not easy to cause a decrease in outgassing resistance. Among the total 100 parts by mass of monomer A and monomer B, monomer A preferably contains 1 to 55 parts by mass.

Regarding polymerization to obtain a crosslinkable (meth)acrylic copolymer, a polymerizable monomer other than monomer A and monomer B may be used in combination as needed. Examples of such polymerizable monomers include radical polymerizable monomers other than (meth)acrylate compounds and copolymerizable with monomer A and monomer B. As the specific example, vinyl acetate, styrene, etc. are mentioned. The usage amount of the radical polymerizable monomer that can be copolymerized with monomer A and monomer B, for example, in 100 parts by mass of the total amount of monomer A and monomer B, 20 parts by mass or less is preferable.

In addition, in the production of crosslinkable (meth)acrylic copolymers, the ratio (mass ratio) of monomer A and monomer B will correspond to the crosslinkability (meth) obtained by polymerization of monomers A and B The mass ratio of the monomer unit having the functional group exhibiting crosslinking reactivity and the monomer unit having no functional group exhibiting the crosslinking reactivity contained in the acrylic copolymer.

In the polymerization method used to obtain the crosslinkable (meth)acrylic copolymer, a solvent can be used as needed. The type of the solvent is not particularly limited, and it can be widely used, for example, well-known organic solvents that can be used in polymerization. Examples include ester compounds such as ethyl acetate and butyl acetate; ketones such as acetone and methyl ethyl ketone; hydrocarbons such as hexane; aromatic compounds such as toluene, xylene, and benzene. The amount of the solvent used in the aforementioned polymerization reaction is not particularly limited.

In the polymerization method for obtaining the crosslinkable (meth)acrylic copolymer, a polymerization initiator can be used as needed, and it can be widely used, for example, well-known polymerization initiators that are used in general polymerization. As the polymerization initiator, azobisisobutyronitrile, 2,2'-azobis[2-(2-imidazoline-2-yl)propane] dihydrochloride, 1,1'- Azobis(cyclohexanecarbonitrile), di-tertiary butyl peroxide, tertiary butyl hydroperoxide, benzyl peroxide, ammonium persulfate, photopolymerization initiator (Irgacure or Omnirad ( Registered trademark) series, etc.) etc.

The concentration of the polymerization initiator is not particularly limited. For example, it can be appropriately adjusted within a range where the polymer of the obtained crosslinkable (meth)acrylic copolymer has a desired molecular weight. For example, in 100 parts by mass of the total amount of monomer A and monomer B, the polymerization initiator can be used from 0.01 to 5 parts by mass.

The polymerization to obtain the crosslinkable (meth)acrylic copolymer can be carried out in an inert gas environment such as nitrogen.

The polymerization time and polymerization temperature for obtaining the crosslinkable (meth)acrylic copolymer are also not limited, and can be appropriately set according to the types, usage, and polymerization reactivity of monomer A and monomer B used. For example, the polymerization reaction can be carried out at 20~100°C for 1~24 hours.

The weight average molecular weight of the crosslinkable (meth)acrylic copolymer is not particularly limited. For example, from the viewpoint of not easily reducing the adhesive force of the adhesive sheet, it can be 100,000 to 2 million, and 400,000 to 100 Wan is better.

Here, the so-called weight average molecular weight in the present invention is a polystyrene conversion weight average molecular weight measured by gel permeation chromatography (GPC). The GPC device used in the GPC method is not particularly limited. Commercially available GPC measuring machines can be used, such as the LC-2000Plus series manufactured by JASCO Corporation; the measuring machines can be RI-2031Plus, UV-2075Plus, etc. At this time, you can use a GPC string made up of 4 connected GPC columns made by Showa Denko Corporation (Shodex KF801", "Shodex KF803L", "Shodex KF800L" and "Shodex KF800D". The column temperature can be set to 40°C. Tetrahydrofuran was used as the eluent, and the measurement was performed at a flow rate of 1.0 ml/min. Usually, standard polystyrene is used to make the calibration curve, and the weight average molecular weight (Mw) can be obtained by polystyrene conversion.

The crosslinkable (meth)acrylic copolymer can be formed by randomly arranging monomer units having functional groups that exhibit crosslinking reactivity and monomer units that do not exhibit functional groups that exhibit crosslinking reactivity. Random copolymer. Alternatively, the crosslinkable (meth)acrylic copolymer may have another structure such as a block polymer.

(Crosslinking agent) The crosslinking agent is a component used to advance the crosslinking of the crosslinkable (meth)acrylic copolymer. In particular, the crosslinking agent can react with the functional groups that exhibit crosslinking reactivity in the crosslinkable (meth)acrylic copolymer.

The type of crosslinking agent is not particularly limited, and well-known crosslinking agents can be widely used. As a crosslinking agent, an isocyanate crosslinking agent, an epoxy crosslinking agent, etc. are mentioned, for example.

The type of isocyanate crosslinking agent is not particularly limited, and well-known compounds can be widely used. Examples of the isocyanate crosslinking agent include benzylidene diisocyanate, phenylchlorophenyl diisocyanate, benzhydryl diisocyanate, butenyl diisocyanate, hexamethylene diisocyanate, tetramethylene diisocyanate, Polyisocyanates such as hydrogenated benzhydryl diisocyanate and diisocyanate; alicyclic isocyanates such as cyclopentenyl diisocyanate and cyclohexenyl diisocyanate, 2,4-benzylidene diisocyanate, Aromatic isocyanates such as 2,6-benzylidene diisocyanate and 4,4'-diphenylmethyl diisocyanate. The isocyanate crosslinking agent can be used alone or in a mixture of two or more different types. In addition, trifunctional derivatives such as adducts, urates, and biurets obtained from the above-mentioned diisocyanates are preferably used as isocyanate crosslinking agents.

As the epoxy crosslinking agent, for example, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, glycerol diglycidyl ether, Glycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, N,N,N',N'-tetraglycidyl diglycidyl ether Amine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexanone, trimethylolpropane polyglycidyl ether, diglycerol polyglycidyl ether, polyglycerol polyepoxy Propyl ether, sorbitol polyglycidyl ether, etc.

When the crosslinkable (meth)acrylic copolymer is crosslinked by a crosslinking agent to obtain a crosslinked (meth)acrylic copolymer, the ratio of the crosslinkable (meth)acrylic copolymer to the crosslinking agent There is no particular limitation. For example, the crosslinking (meth)acrylic copolymer may use 0.01 to 5 parts by mass of the crosslinking agent per 100 parts by mass. If so, the adhesive sheet can have the desired adhesive force. The crosslinkable (meth)acrylic copolymer is preferably 0.05 to 1 part by mass per 100 parts by mass of the crosslinking agent.

When the crosslinkable (meth)acrylic copolymer is crosslinked by a crosslinking agent, other components can be used in combination as needed. Examples of other components include silane coupling agents. If silane coupling agent is used together, the adhesive strength of the adhesive sheet can be easily improved.

The type of silane coupling agent is not particularly limited, and, for example, well-known compounds can be widely used. Examples of the silane coupling agent include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyldialkoxysilane, γ-aminopropyltriethoxysilane, and γ-glycidoxypropyltrimethoxysilane. Aminopropyltrimethoxysilane, γ-glycidoxypropyltrialkoxysilane, γ-methacryloxypropyltrialkoxysilane, γ-chloropropyltrialkoxysilane, γ-methacryloxypropyl dialkoxysilane, γ-mercaptopropyl trialkoxysilane, vinyl trialkoxysilane, etc.

When the crosslinkable (meth)acrylic copolymer is crosslinked by a crosslinking agent, if a silane coupling agent is used in combination, the amount of the crosslinkable (meth)acrylic copolymer may contain 0.1 per 100 parts by mass ~5 parts by mass.

＜Polymerizable monomer with polymerizable double bond in the molecule＞ In the adhesive sheet, the polymerizable monomer having a polymerizable double bond in the molecule includes at least one of a monofunctional monomer having a cyclic ether structure and a monofunctional monomer having a chain ether structure. That is, the polymerizable monomer having a polymerizable double bond in the molecule may include any one of a monofunctional monomer having a cyclic ether structure and a monofunctional monomer having a chain ether structure, or it may include The situation of both.

(With cyclic ether monomer) A monofunctional monomer having a cyclic ether structure is a monomer having both a polymerizable double bond and a cyclic ether structure in the molecule. Hereinafter, the polymerizable monomer having a polymerizable double bond in the molecule will be referred to as "polymerizable monomer M". In addition, a monomer having both a polymerizable double bond and a cyclic ether structure in the molecule will be referred to as a "cyclic ether monomer".

The type of cyclic ether monomer contained in the polymerizable monomer M is not particularly limited as long as it is a radical polymerizable monomer having a cyclic ether structure in the molecule, and well-known cyclic ether monomers can be widely used . For example, the cyclic ether monomer may have a group containing a cyclic ether structure on the side chain.

The cyclic ether structure is not particularly limited as long as it is a three-membered ring or more. However, from the viewpoint that the outgassing resistance is easily improved, the cyclic ether structure is preferably a four-membered ring or more. That is, the cyclic ether structure is preferably other than a 3-membered ring. Among them, the cyclic ether structure is preferably a 4- to 6-membered ring, that is, at least one of 4-membered ring, 5-membered ring, and 6-membered ring.

Among the atoms constituting the ring of the cyclic ether structure, the number of oxygen atoms is not particularly limited as long as it is one or more. For example, the number of oxygen atoms may be one or two. Among the atoms constituting the ring of the cyclic ether structure, atoms other than oxygen atoms are usually carbon atoms.

The cyclic ether structure is preferably a tetrahydrofuran structure. If so, the outgassing resistance of the adhesive sheet will be particularly improved.

In the cyclic ether structure, atoms other than the oxygen atoms (for example, carbon atoms) constituting the ring may have one or more substituents. The type of the substituent is not particularly limited, and examples thereof include an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, and an alkynyl group having 2 to 10 carbon atoms. More specifically, there are methyl, ethyl, n-propyl, isopropyl and the like.

If the cyclic ether structure has the aforementioned substituents, the number of substituents and bonding positions are not particularly limited, and the effects of the present invention will not be affected in any way. Generally speaking, the number of the aforementioned substituents in the cyclic ether structure is one or two.

Examples of the monomer having a cyclic ether include (meth)acrylate having a cyclic ether structure. In this case, for example, a cyclic ether structure is directly or indirectly bonded to the oxygen atom of the (meth)acrylate ester. If it has a structure in which a cyclic ether structure is indirectly bonded to the oxygen atom of the (meth)acrylate, for example, the group represented by the following general formula (1) or general formula (2) exists in the oxygen atom of the ester and Between cyclic ether structures. -(CH ₂ ) _m- (1) (In formula (1), m represents an integer from 1 to 5)

(式(2)中，n表示0~5的整數)[化1]

(In formula (2), n represents an integer from 0 to 5)

In formula (1), m is preferably 1~2. In formula (2), n is preferably 0~4.

As a further specific example of the monomer having a cyclic ether, the following compounds (3-1) to (3-6) can be given.

[化2]

The cyclic ether monomer contained in the polymerizable monomer M may be one type alone, or may include two or more different cyclic ether monomers.

The content of the cyclic ether monomer in the adhesive sheet is not particularly limited. From the viewpoint of making the adhesive sheet more excellent in outgassing resistance, in the adhesive sheet, the cyclic ether monomer (monofunctional monomer with a cyclic ether structure) is compared with the aforementioned crosslinkability (methyl ) 100 parts by mass of acrylic copolymer, preferably 5-50 parts by mass.

In further detail, in the adhesive sheet, the monomer having cyclic ether is preferably 7 parts by mass or more, and 10 parts by mass or more relative to 100 parts by mass of the aforementioned crosslinkable (meth)acrylic copolymer It is especially good. In addition, in the adhesive sheet, the cyclic ether monomer is preferably 40 parts by mass or less, and more preferably 30 parts by mass or less relative to 100 parts by mass of the aforementioned crosslinkable (meth)acrylic copolymer. It is particularly preferable to contain 25 parts by mass or less.

The polymerizable monomer M may contain a monofunctional polymerizable monomer other than the cyclic ether monomer within a range that does not inhibit the effect of the present invention. As such a monofunctional polymerizable monomer, for example, a well-known monofunctional polymerizable monomer can be widely used. The monofunctional polymerizable monomer other than the cyclic ether monomer may be the chain ether monomer described later. If the polymerizable monomer M contains a monofunctional polymerizable monomer other than a cyclic ether monomer, its content may be, for example, 10% by mass or less, preferably 5% by mass, relative to the total mass of the polymerizable monomer M. It is more preferably 1% by mass or less, and particularly preferably 0.1% by mass or less.

(Chain ether monomer) A monofunctional monomer having a chain ether structure is a monomer having both a polymerizable double bond and a chain ether structure in the molecule. Hereinafter, a monomer having both a polymerizable double bond and a chain ether structure in the molecule will be referred to as a "chain ether monomer".

The chain ether monomer contained in the polymerizable monomer M is not particularly limited as long as it is a radical polymerizable monomer with a chain ether structure in the molecule. Well-known chain ether monomers can be widely used . For example, the chain ether monomer may have a chain ether structure-containing group on the side chain.

Among chain ether monomers, the chain ether structure is not particularly limited. As a chain ether structure, the structure which has a structural unit represented by the following general formula (5) is mentioned, for example.

[化3]

In formula (5), m represents an integer of 1 to 4, k represents an integer of 1 to 15, and R ¹ represents an alkyl group or a group having an aromatic hydrocarbon.

In the aforementioned formula (5), from the viewpoint that the outgassing resistance of the adhesive sheet is particularly easy to improve, m is particularly preferably 1 to 2.

In the aforementioned formula (5), from the viewpoint that the outgassing resistance of the adhesive sheet is particularly easy to improve, k is particularly preferably 1 to 5.

In the aforementioned formula (5), if R ¹ is an alkyl group, its kind is not particularly limited. The alkyl group may have any structure of linear, branched, and cyclic. For example, if the alkyl group is linear or branched, examples of the alkyl group include an alkyl group with 1 to 10 carbon atoms, preferably an alkyl group with 1 to 5 carbon atoms, and an alkyl group with 1 to 4 carbon atoms. The alkyl group is more preferable. From the viewpoint that the outgassing resistance of the adhesive sheet is particularly easy to improve, when R ¹ is an alkyl group, the particularly suitable alkyl group is a methyl group or an ethyl group.

If the alkyl group is cyclic, the carbon number of the alkyl group can be 3 or more, preferably 4 or more, and particularly preferably 5 or more. When the alkyl group is cyclic, the number of carbon atoms in the alkyl group may be 20 or less, preferably 15 or less, and particularly preferably 10 or less.

In the aforementioned formula (5), if R ¹ is a group having an aromatic hydrocarbon, the type is not particularly limited, and examples thereof include a phenyl group and a benzyl group. The group having an aromatic hydrocarbon may have a substituent on the aromatic ring. If so, examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a halogen atom, a hydroxyl group, a carboxyl group, and an amino group. The number of substituents and bonding positions are not particularly limited. From the viewpoint that the outgassing resistance of the adhesive sheet is particularly easy to improve, if R ¹ has an aromatic hydrocarbon group, a phenyl group is particularly suitable.

As a chain ether monomer, the (meth)acrylate which has a chain ether structure is mentioned, for example. In this case, for example, a chain ether structure is directly or indirectly bonded to the oxygen atom of the (meth)acrylate ester. If it has a chain ether structure indirectly bonded to the oxygen atom structure of the (meth)acrylate, for example, the group represented by the aforementioned general formula (1) or general formula (2) exists in the oxygen atom of the ester and the chain ether Structure between.

Among chain ether monomers, a in formula (1) is preferably 1~2. Among chain ether monomers, n in formula (2) is preferably 0~4.

As a further specific example of the chain ether monomer, the following compounds (4-1) to (4-6) can be given.

[化4]

The chain ether monomer contained in the polymerizable monomer M may be a single type, or may include two or more different chain ether monomers.

The content of the chain ether monomer in the adhesive sheet is not particularly limited. From the standpoint of making the adhesive sheet more excellent in outgassing resistance, in the adhesive sheet, the chain ether monomer (monofunctional monomer with a chain ether structure) is compared with the aforementioned crosslinking property (methyl ) 100 parts by mass of acrylic copolymer, preferably 5-50 parts by mass.

In further detail, in the adhesive sheet, the chain-like ether monomer is preferably 7 parts by mass or more, and 10 parts by mass or more relative to 100 parts by mass of the aforementioned crosslinkable (meth)acrylic copolymer It is especially good. In addition, in the adhesive sheet, the chain ether monomer is preferably 40 parts by mass or less, and more preferably 30 parts by mass or less with respect to 100 parts by mass of the aforementioned crosslinkable (meth)acrylic copolymer. It is particularly preferable to contain 25 parts by mass or less.

The polymerizable monomer M may contain a monofunctional polymerizable monomer other than the chain ether monomer within a range that does not inhibit the effect of the present invention. As such a monofunctional polymerizable monomer, for example, a well-known monofunctional polymerizable monomer can be widely used. The monofunctional polymerizable monomer other than the chain ether monomer may be the aforementioned cyclic ether monomer. If the polymerizable monomer M contains a monofunctional polymerizable monomer other than the chain-like ether monomer, its content may be, for example, 10% by mass or less, preferably 5% by mass or less, relative to the total mass of the polymerizable monomer M. It is more preferably 1% by mass or less, and particularly preferably 0.1% by mass or less.

(Multifunctional monomer) The polymerizable monomer M is also preferably a multifunctional monomer containing two or more polymerizable double bonds in the molecule. If so, in addition to easily improving the outgassing resistance of the adhesive sheet, the shrinkage when the adhesive sheet is hardened can be suppressed. Hereinafter, the multifunctional monomer having two or more polymerizable double bonds in the molecule will only be referred to as "multifunctional monomer".

The type of the multifunctional monomer is not particularly limited. For example, well-known multifunctional monomers used in adhesive sheets can be widely used. Among them, from the viewpoint that it is easier to suppress the shrinkage of the adhesive sheet when it is cured, the multifunctional monomer preferably has a bisphenol skeleton in the molecule. More specifically, an alkylene oxide modified (meth)acrylate having a bisphenol skeleton in the molecule can be used as a multifunctional monomer. If so, the alkylene oxide may be, for example, ethylene oxide, propylene oxide, or the like. The number of alkylene oxide units may be, for example, 1 to 5.

Examples of multifunctional monomers include ethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, and di(meth)acrylic acid. 1,4-Butanediol, 1,9-nonanediol di(meth)acrylate, 1,6-hexanediol diacrylate, polybutylene glycol di(meth)acrylate, new di(meth)acrylate Pentylene glycol, tetraethylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, bisphenol A diglycidyl ether diacrylate, tris(meth)acrylate (Meth)acrylates of polyols such as trimethylolpropane acrylate, neopentylerythritol tri(meth)acrylate, neopentylerythritol tetra(meth)acrylate, vinyl methacrylate, etc.

As the aforementioned multifunctional monomer having a bisphenol skeleton in the molecule, for example, the diacrylate of bisphenol A diglycidyl ether, the diacrylate of propoxylated bisphenol A, and the bisphenol F diepoxy Diacrylate of propyl ether, etc.

Multifunctional monomers can also use commercially available products, such as the trifunctional monomer M310 (trimethylolpropane PO modified triacrylate) or the trifunctional monomer M321 (trimethylolpropane propylene oxide) manufactured by Toagosei Co., Ltd. Modified triacrylate), Toagosei's bifunctional monomer M211B (bisphenol A EO modified diacrylate), Toagosyn's bifunctional monomer "ARONIX M208" (bisphenol F EO modified 2 Acrylate), the bifunctional monomer "Viscoat#700HV" (bisphenol A EO (3.8) adduct diacrylate) manufactured by Osaka Organic Chemical Industry Co., Ltd., etc.

Among the polyfunctional monomers, the number of polymerizable double bonds in one molecule is not particularly limited as long as it is 2 or more. For example, in a polyfunctional monomer, the number of polymerizable double bonds in one molecule can be set to two.

The content of the multifunctional monomer in the adhesive sheet is not particularly limited. From the viewpoint of outgassing resistance of the adhesive sheet and further suppression of shrinkage after curing, in the adhesive sheet, the multifunctional monomer is based on 100 parts by mass of the aforementioned crosslinkable (meth)acrylic copolymer. It is better to contain 1 to 15 parts by mass.

In the adhesive sheet, the polyfunctional monomer is preferably 3 parts by mass or more, and particularly preferably 5 parts by mass or more, relative to 100 parts by mass of the aforementioned crosslinkable (meth)acrylic copolymer. In addition, in the adhesive sheet, the polyfunctional monomer is preferably 12 parts by mass or less based on 100 parts by mass of the aforementioned crosslinkable (meth)acrylic copolymer.

The polymerizable monomer M may be composed of only a monofunctional monomer and a polyfunctional monomer. In addition, the polymerizable monomer M may be composed only of a cyclic ether monomer and a polyfunctional monomer, or the polymerizable monomer M may be composed only of a chain ether monomer and a polyfunctional monomer.

＜Photopolymerization initiator＞ The photopolymerization initiator is a component for irradiating the aforementioned polymerizable monomer M with light to cause polymerization reaction (photopolymerization) to proceed. The type of the photopolymerization initiator is not particularly limited as long as it can photopolymerize the polymerizable monomer M. For example, well-known photopolymerization initiators can be widely used.

The photopolymerization initiator is not particularly limited, and for example, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexyl-phenylketone, 2-hydroxy-2-methyl- 1-Phenylacetone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-methylacetone, 2-hydroxy-1-(4-(4-(2-hydroxy-2 -Methylpropanyl)benzyl)phenyl)-2-methyl-1-acetone and other phenalkyl ketone photopolymerization initiators; 2,4,6-trimethylbenzyl- Diphenylphosphine oxide, and 2,4,6-trimethylbenzyl) phenylphosphine oxide and other phosphine oxide-based polymerization initiators; benzyl carboxylic acid methyl or 4 methyl Intramolecular hydrogen abstraction type photopolymerization initiators such as benzophenone; in addition, there are oxime ester photopolymerization initiators or cationic photopolymerization initiators. Only one type of photopolymerization initiator may be used, or two or more types may be used in combination.

In the adhesive sheet, the content of the photopolymerization initiator is, for example, 0.1-10 parts by mass per 100 parts by mass of the aforementioned polymerizable monomer M. Regarding the content of the photopolymerization initiator, based on the crosslinkable (meth)acrylic copolymer, the content of the photopolymerization initiator per 100 parts by mass of the crosslinkable (meth)acrylic copolymer can be set as 0.05 to 5 parts by mass.

＜Adhesive layer＞ As described above, the adhesive layer constituting the adhesive sheet contains the crosslinked (meth)acrylic copolymer, the polymerizable monomer M, and the photopolymerization initiator. As long as the effect of the present invention is not hindered, the adhesive layer may contain other ingredients, such as antistatic agents, antioxidants, preservatives, and the like. If the adhesive layer contains other components, the content can be, for example, 10% by mass or less, preferably 5% by mass or less, more preferably 1% by mass or less, especially 0.1% by mass or less relative to the total mass of the adhesive layer Better.

(Method of forming adhesive layer) The method of forming the adhesive layer is not particularly limited, and widely known methods can be used, for example. For example, the adhesive layer can be formed using an adhesive composition. The adhesive composition used here may contain the aforementioned crosslinkable (meth)acrylic copolymer, the aforementioned crosslinking agent, the aforementioned polymerizable monomer M, and a photopolymerization initiator.

Specifically, the method of forming an adhesive layer may include a step of coating the aforementioned adhesive composition on a substrate to form a coating film of the adhesive composition, and drying (curing) the coating film, Then the step of forming an adhesive layer.

The preparation method of the adhesive composition is not particularly limited. The crosslinkable (meth)acrylic copolymer, the crosslinking agent, the polymerizable monomer M, and the photopolymerization initiator can be added in a specific proportion Made by mixing. The mixing method is also not particularly limited, and for example, a commercially available mixer can be used.

In the aforementioned adhesive composition, the content of each of the cross-linkable (meth)acrylic copolymer, the cross-linking agent, the aforementioned polymerizable monomer M, and the photopolymerization initiator can be appropriately adjusted according to the intended adhesive sheet. set up. Specifically, the aforementioned adhesive can be adjusted so that the contents of the aforementioned cross-linked (meth)acrylic copolymer, polymerizable monomer M, and photopolymerization initiator contained in the adhesive sheet are within the aforementioned ranges, respectively. The content of each ingredient contained in the composition.

In the aforementioned adhesive composition, in order to improve coatability, for example, a solvent may be contained as needed. The solvent is not particularly limited, and examples thereof include ester compounds such as methyl acetate and ethyl acetate; ether compounds such as diethyl ether; ketone compounds such as acetone and methyl ethyl ketone; aliphatic hydrocarbons such as hexane and heptane; Alicyclic hydrocarbons such as cyclohexane; aromatic hydrocarbons such as benzene, toluene and xylene; chlorinated hydrocarbons such as chloroform and 1,2-dichloroethane; alcohols such as methanol, ethanol, isopropanol and tertiary butanol Class etc. The solvent can be used alone or in a mixture of two or more kinds.

When the aforementioned adhesive composition contains a solvent, it is preferable to use the solvent so that the solid content concentration of the adhesive composition is in the range of 10-60% by mass, and more preferably 15~ The solvent is used in the range of 50% by mass.

The method for applying the aforementioned adhesive composition to the substrate is not particularly limited, and a widely known method can be used, for example. For example, knife coater, air knife coater, roll coater, bar coater, gravure coater, micro-gravure coater, bar and leaf coater, lip coater, die coating can be used Commercially available coating devices, such as a machine, curtain coater, etc., apply the aforementioned adhesive composition.

The coating amount of the adhesive composition is not particularly limited, and can be appropriately set according to the thickness of the adhesive layer of the adhesive sheet for the purpose. For example, the coating amount of the adhesive composition can be adjusted such that the thickness of the adhesive layer formed after the drying treatment described later becomes 5 to 1000 μm.

The type of the substrate used for coating the adhesive composition is also not particularly limited, and the substrate used for forming the adhesive layer can be widely used. For example, as a base material for coating the adhesive composition, a release sheet can be cited.

Examples of the release sheet include so-called separators used for protecting the adhesive layer in the adhesive sheet. More specifically, as a release sheet, a resin film provided with a release layer, etc. are mentioned.

Among the release sheets, examples of the resin film include a polyethylene terephthalate film.

The release layer means a layer formed on at least one side of the aforementioned resin film, and has a peeling force smaller than the adhesive force of the adhesive layer, and is formed in such a way that the peeling sheet is easily peeled. Such a release layer can be widely used, for example, as a well-known component of the release layer of an adhesive sheet. For example, a well-known polysilicon oxide material can be used to form the release layer.

When the aforementioned release sheet is used as a substrate, the adhesive composition is coated on the release surface of the release sheet to form a coating film of the adhesive composition.

After applying the adhesive composition on the base material such as the release sheet to form a coating film, a drying process is performed to form an adhesive layer on the base material. Through this drying treatment, the reaction between the crosslinkable (meth)acrylic copolymer contained in the adhesive composition and the crosslinking agent proceeds, and the crosslinkable (meth)acrylic copolymer is performed by the crosslinking agent Crosslinking to form the aforementioned crosslinked (meth)acrylic copolymer.

The conditions of the drying treatment are not particularly limited, and, for example, the conventional drying method of the adhesive composition coating film can be widely used. Such a drying process can be performed using a well-known heating device etc., for example. The heating temperature can be set to, for example, 50 to 200°C, preferably 60 to 150°C. The heating time can be set in such a way that the solvent volatilizes the residual solvent concentration of the adhesive layer to be, for example, 1000 ppm or less. It is preferably within the above temperature range according to the concentration of the adhesive composition, the desired thickness of the adhesive layer, etc. Set it appropriately within 1~30 minutes.

Through the above drying treatment, an adhesive layer containing the crosslinked (meth)acrylic copolymer, the polymerizable monomer M, and a photopolymerization initiator is formed. That is, during the drying process, the crosslinking reaction of the crosslinkable (meth)acrylic copolymer mainly progresses and the curing proceeds, but the aforementioned polymerizable monomer M is still in a state where polymerization has not yet started. In other words, the aforementioned adhesive composition of the adhesive layer can be said to be in a semi-hardened state. In order to avoid misunderstanding, it is noted here that the crosslinking reaction of the crosslinkable (meth)acrylic copolymer is not necessarily completed by the drying treatment, and the crosslinking reaction can still be carried out by the aging treatment described later.

A protective layer for protecting the adhesive layer can also be attached to the adhesive layer formed in this way. At this time, the protective layer is attached to the surface opposite to the base material of the adhesive layer. As the protective layer, as described above, for example, a release sheet can be mentioned. This release sheet as a protective layer is also the same as the above-mentioned base material, and a resin film provided with a release layer is mentioned. As the resin film, in the same manner as described above, for example, a polyethylene terephthalate film and the like can be mentioned, and the release layer can be formed of, for example, a well-known silicone material.

When the base material and the protective layer formed on each surface of the adhesive layer are release sheets (the first release sheet and the second release sheet respectively), the release sheet as the base material (the first release sheet) ) The peeling force of the release layer is preferably different from the adhesive force of the release layer of the release sheet (second release sheet) used to form the protective layer. That is, when both the base material and the protective layer are release sheets, the release forces of the individual release sheets are preferably different. If this is the case, it is easier to selectively remove only one side of the release sheet when peeling off the release sheet, and it is easier to suppress the so-called indiscriminate phenomenon.

After the adhesive layer is formed, and the protective layer is formed as described above according to the needs, the appropriate aging treatment can be performed to obtain the desired adhesive sheet. By this aging treatment, as described above, the crosslinking reaction of the crosslinkable (meth)acrylic copolymer proceeds, and the curing further continues.

The method of aging treatment is not particularly limited, and for example, a method of leaving the adhesive sheet in a gas environment at 15-50°C can be mentioned. The aging time can be appropriately set according to the temperature, for example, it can be from 1 day to 10 days.

＜The composition of the adhesive sheet＞ In the adhesive sheet, the thickness of the adhesive layer is not particularly limited, and can be appropriately set according to the intended use. For example, when the adhesive sheet is used for bonding members such as a resin cover panel such as an input device, the thickness of the adhesive layer can be 5 to 1000 μm. The adhesive sheet may be either a single-sided adhesive sheet or a double-sided adhesive sheet, and is usually a double-sided adhesive sheet.

The adhesive sheet may be formed of only the adhesive layer, or may have other layers as needed. Other layers can be formed on one side or both sides of the adhesive layer. As other layers, the aforementioned release sheet can be mentioned. When a release sheet is formed on both sides of the adhesive layer, as described above, the release force of the two release sheets (the first release sheet and the second release sheet) can be different. If the peeling forces of the two peeling sheets are different, for example, it is easier to selectively peel off only one peeling sheet when peeling the peeling sheet, and it is easier to suppress the so-called indiscriminate phenomenon.

For example, in the aforementioned method for forming the adhesive layer, when the release sheet is used as the base material and the release sheet is also used as the protective layer, an adhesive sheet with release sheets on both sides of the adhesive layer can be directly obtained ( Adhesive sheet with release layer). In addition, after the adhesive layer is formed, a release sheet is additionally provided on both sides of the adhesive layer to obtain an adhesive sheet with a release layer.

If the adhesive sheet has a release sheet, the release sheet has the function of a so-called separator in the adhesive sheet.

When the adhesive sheet includes a release sheet, the thickness of the release sheet is not particularly limited. For example, the thickness of the release sheet can be set to 20 to 300 μm, preferably 30 to 150 μm. The release sheets on both sides of the adhesive layer may have different thicknesses.

<How to use the adhesive sheet> Adhesive sheets can be widely used for the purpose of bonding and adhering components such as substrates and films (adhesive bodies) to each other.

For example, the adhesive sheet is spaced between a pair of adherends so that the adherends are adhered to each other by the adhesive sheet to form a laminate, and the adherends can be adhered to each other by the adhesive sheet. In particular, it is possible to maximize durability by irradiating active energy rays to the laminate after the adherends are bonded by the adhesive sheet. In addition, when the adhesive sheet is provided with a release sheet, the adhesive sheet is spaced between a pair of adherends in a state where the release sheet is peeled off.

As mentioned above, the adhesive layer in the adhesive sheet is present in a semi-hardened state. Therefore, when the active energy ray irradiates the adhesive layer, the polymerizable monomer M present in the adhesive layer is polymerized The reaction is initiated by the photopolymerization initiator. As a result, the hardening of the adhesive layer will continue, and by the hardening of the adhesive layer, the adherends will adhere to each other more strongly.

Because the adhesive layer is hardened, a polymer of polymerizable monomer M (hereinafter referred to as "polymer M") will be formed in the adhesive layer. The polymer M has a constitutional unit derived from a cyclic ether monomer and/or a chain ether monomer in its constitutional unit, and because of this constitutional unit, the adhesive sheet can exhibit excellent outgassing resistance. As a result, even if gas components (outgassing) are generated from the adherend before, during and after the polymerization reaction of the polymerizable monomer M, the adhesive layer is not easily affected by the outgassing, so the adhesive layer It is not easy to generate bubbles, float and peel off after hardening.

In addition, examples of the active energy rays include ultraviolet rays, electron beams, visible light, X-rays, ion beams, and the like. Among them, from the viewpoint of high versatility, ultraviolet light or electron beam is preferable, and ultraviolet light is particularly preferable. As the light source of ultraviolet light, for example, a high-pressure mercury lamp, a low-pressure mercury lamp, an ultra-high pressure mercury lamp, a metal halide lamp, a carbon arc, a xenon arc, an electrodeless ultraviolet lamp, etc. can be used. The electron beam can be released from various electron beam accelerators such as Kirklauf-Walton type, Van de Graaff type, resonance transformer type, insulated core transformer type, linear type, high-frequency high-voltage type, high-frequency type, etc. Out of the electron beam.

The cumulative light quantity of the active energy ray irradiation can be, for example, 500-5000 mJ/cm ² , preferably 1000-4000 mJ/cm ² , and more preferably 1500-3000 mJ/cm ² .

The irradiation method of the active energy ray is not particularly limited, and for example, the entire surface of the laminate may be irradiated with active energy ray. From this point of view, at least one of the adherends is preferably transparent. Regarding the irradiation of active energy rays, for example, a well-known active energy ray irradiation device can be used.

Since the adhesive sheet has excellent resistance to outgassing, it is particularly suitable for applications where bubbles are easily generated due to the outgassing of the adherend in the past.

The adhesive sheet is used for bonding with a first member selected from the group consisting of a resin plate, a resin sheet, and a resin film. The first member can be obtained, for example, by a well-known manufacturing method, or it can be obtained from a commercially available product. When the first member is a resin plate, it can be obtained by various molding methods such as injection molding in addition to the casting method. In addition, in accordance with the purpose of use of the adhesive sheet, the first member can also be formed into various shapes other than plates, sheets, and films.

The thickness of the first member is not particularly limited, and can be appropriately set according to the application of the adhesive sheet. For example, when the first member is a resin plate, its thickness can usually be set to 1 mm or more.

The resin used for forming the first member such as the resin plate is not particularly limited, and examples thereof include acrylic resins such as polymethyl methacrylate, polycarbonate resins, and styrene resins such as polystyrene. The resin may contain two or more different types, for example, a composite material containing acrylic resin and polycarbonate resin. Among them, the adhesive sheet is preferably used for bonding of polymethyl methacrylate resin plates and polycarbonate resin plates, and particularly preferably used for bonding of polycarbonate resin plates. That is, when bonding using an adhesive sheet, one of the adherends may be a resin plate such as polycarbonate resin.

It is known that polycarbonate resin is a material that is prone to outgassing compared to acrylic resin. Therefore, in order to suppress the problem of outgassing, many efforts have been made in the prior art, such as providing a hard coating on the polycarbonate resin sheet. However, when the adhesive sheet of the present invention is used, even if it is a polycarbonate without a hard coating Ester resin board can also suppress the influence caused by outgassing. Outgassing may occur when, for example, the active energy rays are irradiated during bonding, or it may be gradually generated over time after bonding.

The adhesive sheet is preferably used for bonding the aforementioned first member and second member. The second member is not particularly limited, and is preferably used for bonding of one kind of second member selected from the group consisting of a glass plate, a resin film, and a resin plate, for example.

The adhesive sheet has excellent resistance to outgassing and is particularly suitable for bonding polycarbonate resin plates as the adherend, so it is particularly suitable for use in liquid crystal displays (LCD) and other display devices, touch panels and other input devices, etc. . As a constituent member of the touch panel, for example, an ITO film with an ITO film on a transparent resin film, an ITO glass with an ITO film on the surface of a glass plate, and a transparent resin film made by coating a conductive polymer on a transparent resin film Conductive film, hard coat film, fingerprint resistant film, etc. Examples of constituent members of the image display device include anti-reflection films, oriented films, polarizing films, retardation films, and brightness enhancement films used in liquid crystal display devices.

2. Laminated body The laminate of the present invention includes the aforementioned adhesive sheet or its cured product. More precisely, the laminate of the present invention is provided with an adhesive layer or its hardened product. In addition, when the adhesive sheet includes a release sheet, the release sheet is present in the laminate in a peeled state. That is, the laminate includes the aforementioned adhesive layer.

In the laminate, if the adhesive layer is in a semi-hardened state as described above (that is, when the polymerizable monomer M is present in the adhesive layer), the laminate includes an adhesive sheet. On the other hand, in the laminated body, if the adhesive layer is in a state of being further cured by the irradiation of active energy rays as described above, the laminated body is provided with a cured product of the adhesive sheet.

The laminate may be provided with other layers in addition to the adhesive layer, and examples thereof include the aforementioned first member. If the laminated body is equipped with the said 1st member, the laminated body has the structure which laminated|stacked the said 1st member and the layer of the said adhesive sheet or its hardened|cured material. As the first member, it is the same as the first member described in the item <How to use the adhesive sheet>. Accordingly, as the first member, for example, a polycarbonate resin plate can be cited.

In addition to the first member such as a polycarbonate resin plate, the laminate may be provided with other layers, such as a base material layer composed of the aforementioned second member. If so, the laminated body has a structure in which a base material layer, an adhesive sheet or a cured product thereof, and a first member are laminated in this order.

Examples of the base layer include ITO substrates, glass substrates, metal substrates, resin substrates, paper, cloth, non-woven fabrics, and the like.

If the laminate has a cured product of the adhesive sheet, for example, a laminate having an adhesive sheet before curing (ie, an adhesive layer in a semi-cured state) is produced, and the laminate is irradiated with active energy rays to obtain Laminated body with hardened material of adhesive sheet.

The laminate has excellent resistance to outgassing, so it is particularly suitable for applications such as display devices such as liquid crystal displays (LCD) and input devices such as touch panels.

The manufacturing method of the laminate is not particularly limited, and may include, for example, the step of bonding the adhesive layer of the adhesive sheet to the adherend in a semi-cured state, and then irradiating the adhesive layer with active energy rays to harden the adhesive layer. Specifically, the manufacturing method of the laminate sequentially includes: step 1 of laminating an adherend on at least one side of an adhesive sheet; and irradiating the adhesive layer of the adhesive sheet with active energy rays, thereby making the adhesive Step 2 of hardening after layer. That is, the manufacturing method of the laminated body may include the step of forming the adhesive layer by the same method as the aforementioned adhesive layer forming method. [Example]

Hereinafter, the present invention will be described in more detail based on the embodiments, but the present invention is not limited by the aspects of these embodiments.

(Synthesis example 1) <Production of crosslinkable (meth)acrylic copolymer (a-1)> Prepare butyl acrylate (BA) as monomer B (a monomer without functional groups that exhibit crosslinking reactivity), and 2-hydroxyethyl acrylate (2HEA) as monomer A (with exhibiting crosslinking reactivity) The functional group monomer), prepare a monomer mixture with BA of 75% by mass and 2HEA of 25% by mass. After mixing the monomer mixture with an ethyl acetate solution of 2,2'-azobis(2,4-dimethylvaleronitrile) as a radical polymerization initiator to obtain a mixture, the mixture was heated to 60 It was subjected to random copolymerization at °C to obtain a crosslinkable (meth)acrylic copolymer (a-1). The weight average molecular weight of the crosslinkable (meth)acrylic copolymer (a-1) is 580,000.

Here, the weight average molecular weight is measured using a gel permeation chromatography (GPC) method and calculated in terms of polystyrene. The measurement conditions of gel permeation chromatography (GPC) are as follows. Solvent: Tetrahydrofuran Pillars: Shodex KF801, KF803L, KF800L, KF800D (Used with 4 connections made by Showa Denko Corporation) Column temperature: 40℃ Sample concentration: 0.5% by mass Checker: RI-2031plus (made by JASCO) Pump: RI-2080plus (made by JASCO) Flow rate (flow rate): 0.8ml/min Injection volume: 10μL Calibration curve: A calibration curve obtained from 10 samples of standard polystyrene Shodex standard polystyrene (manufactured by Showa Denko) Mw=1320-2,500,000

(Synthesis example 2-1) With reference to the aforementioned Patent Document 1, 60% by mass of 2-ethylhexyl acrylate (2EHA), 5% by mass of 4-propenyl mopholine, 15% by mass of isobornyl acrylate, and 5% by mass of N-vinylacetamide The mass% and 15 mass% of 2-hydroxyethyl acrylate were copolymerized by a solution polymerization method to prepare a crosslinkable (meth)acrylic copolymer (b-1). The molecular weight of this crosslinkable (meth)acrylic copolymer (b-1) was a weight average molecular weight (Mw) of 510,000.

(Synthesis example 2-2) According to the method described in Example 1 of the aforementioned Patent Document 2, a crosslinkable acrylic copolymer was prepared as follows. Mix 63 parts by mass of 2-ethylhexyl acrylate (2EHA), 15 parts by mass of N-vinyl-2-pyrrolidone (NVP), 9 parts by mass of methyl methacrylate (MMA), and 2-hydroxyethyl acrylic acid 13 parts by mass of ester (2HEA) and 2,2'-azobis(2,4-dimethylvaleronitrile) as a radical polymerization initiator were dissolved in ethyl acetate. The solution was heated to 65°C to perform random copolymerization to obtain a crosslinkable acrylic copolymer (b-2). The weight average molecular weight of the crosslinkable acrylic copolymer (b-2) is 780,000.

(Example 1) ＜Production of adhesive composition (A-1)＞ With respect to 100 parts by mass of the crosslinkable acrylic copolymer (a-1) produced in Synthesis Example 1, 0.2 parts by mass of a benzylidene diisocyanate compound (manufactured by TOSOH, Coronate L-55E) as a crosslinking agent was added, 3-glycidoxypropyltrimethoxysilane (KBM-403 manufactured by Shin-Etsu Chemical Co., Ltd.) as a silane coupling agent 0.30 parts by mass, 3-ethyl-3-oxa as a cyclic ether monomer Cyclobutanyl methacrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., OXE-10) 25 parts by mass, as a multifunctional monomer, bisphenol A ethylene oxide modified diacrylate (manufactured by Toagosei Co., Ltd., ARONIX M211B) ) 12 parts by mass and 1.0 part by mass of bis(2,4,6-trimethylbenzyl)phenylphosphine oxide (manufactured by BASF JAPAN, IRGACURE 819) as a photopolymerization initiator to make the solid content Add ethyl acetate as a solvent so that the concentration becomes 35% by mass to obtain a semi-cured adhesive composition (A-1).

＜Making of Adhesive Layer (A-1)＞ Next, prepare a polyethylene terephthalate film with a thickness of 100μm (re-separator film, manufactured by Teijin DuPont Films Co., Ltd., and release-processed polyethylene terephthalate) with an easy-adhesive layer treated with a silicone release agent Ethylene glycol film) as the first release sheet. The adhesive composition (A-1) was uniformly coated with an applicator on the surface on the side of the easy-adhesive layer of the first release sheet so that the coating thickness after drying became 150 μm. After the coating film of the adhesive composition (A-1) is produced, it is dried in an air-circulating constant temperature oven at 90°C for 3 minutes to form an adhesive layer (A-1) on the surface of the first release sheet .

Next, prepare a second release sheet (light separator film, manufactured by Teijin DuPont Films Co., Ltd., and release process polyethylene terephthalate) with a thickness of 75 μm after a release process with higher release properties than the first release sheet. Ester film). This second release sheet was bonded to the adhesive layer (A-1) formed on the surface of the first release sheet. Thereby, a first release sheet/adhesive layer (A-1)/second release sheet structure in which the adhesive layer (A-1) is held by a pair of release sheets with poor peeling force is obtained. Peel off the adhesive sheet of the sheet. The adhesive sheet with the release sheet was allowed to stand for 7 days under conditions of 23° C. and a relative humidity of 50% to perform an aging treatment.

(Example 2) As a cyclic ether monomer, 3-ethyl-3-oxetanyl methacrylate is used as 3-ethyl-3-oxetanyl methacrylate (Osaka Organic Chemical Kogyo Co., Ltd., OXE-30) was substituted, except that the adhesive sheet with the release sheet was obtained in the same manner as in Example 1.

(Example 3) As a cyclic ether monomer, 25 parts by mass of 3-ethyl-3-oxetanyl methacrylate was substituted with 20 parts by mass of tetrahydrofuran acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., Viscoat #150); As a multifunctional monomer, 12 parts by mass of bisphenol A ethylene oxide modified diacrylate was substituted with 6 parts by mass of bisphenol F EO modified diacrylate (manufactured by Toagosei Co., Ltd., ARONIX M208). In the same manner as in Example 1, an adhesive sheet with a release sheet was obtained.

(Example 4) As the cyclic ether monomer, tetrahydrofuran acrylate was substituted with acrylate having a tetrahydrofuran structure (manufactured by Osaka Organic Chemical Industry Co., Ltd., Viscoat#150D), except that the same method as in Example 3 was used to obtain a release sheet Adhesive sheet of material.

(Example 5) As a cyclic ether monomer, 25 parts by mass of 3-ethyl-3-oxetanyl methacrylate was added to (2-methyl-2-ethyl-1,3-dioxolane- 4-yl) methacrylate (Osaka Organic Chemical Industry Co., Ltd., MEDOL-10) 10 parts by mass substitution; as a multifunctional monomer, bisphenol A ethylene oxide was modified to diacrylate 12 parts by mass bisphenol A EO(3.8) adduct diacrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., Viscoat#700HV) was substituted by 10 parts by mass, except that the adhesive sheet with the release sheet was obtained by the same method as in Example 1. .

(Example 6) 10 parts by mass of (2-methyl-2-ethyl-1,3-dioxolane-4-yl)methacrylate was used as cyclotrimethylolpropane methylal acrylate (Osaka Organic Chemical Industry Co., Ltd. Manufactured, Viscoat #200) was substituted by 10 parts by mass, except that the adhesive sheet with the release sheet was obtained in the same manner as in Example 5.

(Example 7) ＜Production of adhesive composition (A-2)＞ With respect to 100 parts by mass of the crosslinkable acrylic copolymer (a-1) produced in Synthesis Example 1, 0.2 parts by mass of a benzylidene diisocyanate compound (manufactured by TOSOH, Coronate L-55E) as a crosslinking agent was added, As a silane coupling agent, 3-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-403) 0.30 parts by mass, as a chain ether monomer, phenoxyethyl acrylate (Osaka Organic Chemical Industry Co., Ltd., Viscoat#192) 25 parts by mass, bisphenol A ethylene oxide modified diacrylate (Toagosei Co., Ltd., ARONIX M211B) as a multifunctional monomer, 12 parts by mass, and 1.0 parts by mass of bis(2,4,6-trimethylbenzyl)phenylphosphine oxide (manufactured by BASF JAPAN, IRGACURE 819) as a photopolymerization initiator, so that the solid content concentration is 35% by mass Add ethyl acetate as a solvent to obtain a semi-hardened adhesive composition (A-2).

＜Making of Adhesive Layer (A-2)＞ Next, prepare a polyethylene terephthalate film with a thickness of 100μm (re-separator film, manufactured by Teijin DuPont Films Co., Ltd., and release-treated polyethylene terephthalate) with an easy-adhesive layer treated with a silicone release agent. An ethylene glycol film) was used as the first release sheet. The adhesive composition (A-2) was uniformly coated with an applicator on the surface on the side of the easy-adhesive layer of the first release sheet so that the coating thickness after drying became 150 μm. After the coating film of the adhesive composition (A-2) is produced, it is dried in an air-circulating constant temperature oven at 90°C for 3 minutes to form an adhesive layer (A-2) on the surface of the first release sheet .

Next, prepare a second release sheet (light separator film, manufactured by Teijin DuPont Films Co., Ltd., and release process polyethylene terephthalate) with a thickness of 75 μm after a release process with higher release properties than the first release sheet. Ester film). This second release sheet was stuck on the adhesive layer (A-2) formed on the surface of the first release sheet. Thereby, a first peeling sheet/adhesive layer (A-2)/second peeling sheet structure with the adhesive layer (A-2) clamped by a pair of peeling sheets with poor peeling force is obtained. Peel off the adhesive sheet of the sheet. The adhesive sheet with the release sheet was allowed to stand for 7 days under conditions of 23° C. and a relative humidity of 50% to perform an aging treatment.

(Example 8) As a chain ether monomer, phenoxyethyl acrylate was replaced with 2-methoxyethyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., 2-MTA), and other than that In the same manner as in Example 7, an adhesive sheet with a release sheet was obtained.

(Example 9) As a chain ether monomer, 25 parts by mass of phenoxyethyl acrylate was used as 2-[2-(ethoxy)ethoxy]ethyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., Viscoat#190) 20 Substitution by mass parts; as a multifunctional monomer, 12 parts by mass of bisphenol A ethylene oxide modified diacrylate was substituted with 6 parts by mass of bisphenol F EO modified diacrylate (manufactured by Toagosei Co., Ltd., ARONIX M208), Otherwise, in the same manner as in Example 7, an adhesive sheet with a release sheet was obtained.

(Example 10) As a chain ether monomer, 2-[2-(ethoxy)ethoxy]ethyl acrylate is used as an acrylate with 2-[2-(ethoxy)ethoxy]ethyl structure (Osaka Organic The product made by Chemical Industry Co., Ltd., Viscoat #190D) was substituted, except that the adhesive sheet with the release sheet was obtained by the same method as in Example 9.

(Example 11) As a chain ether monomer, 25 parts by mass of phenoxyethyl acrylate was substituted with 10 parts by mass of methoxytriethylene glycol acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., Viscoat MTG); Functional monomer, 12 parts by mass of bisphenol A ethylene oxide modified diacrylate was replaced by 10 parts by mass of bisphenol A EO (3.8) adduct diacrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., Viscoat #700HV) Except for this, an adhesive sheet with a release sheet was obtained in the same manner as in Example 7.

(Example 12) 10 parts by mass of methoxy triethylene glycol acrylate was replaced by 10 parts by mass of methoxy polyethylene glycol acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., Viscoat MPE400A), and the same as in Example 11 except that The method obtains an adhesive sheet with a release sheet attached.

(Comparative example 1) Except not using the monofunctional monomer, the multifunctional monomer and the photopolymerization initiator having a cyclic ether structure, the adhesive sheet with the release sheet was obtained in the same manner as in Example 1.

(Comparative example 2) As a monofunctional monomer, 3-ethyl-3-oxetanyl methacrylate was used as isostearic acid acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., ISTA). Other than that, the same as the examples 1 The same method is used to obtain an adhesive sheet with a release sheet attached.

(Comparative example 3) With respect to 100 parts by mass of the crosslinkable (meth)acrylic copolymer (b-1) produced in Synthesis Example 2-1, trimethylolpropane was added as a crosslinking agent to modify benzylidene diisocyanate (TOYOCHEM) BHS8515) 0.15 parts by mass, and 0.30 parts by mass of 3-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Industry Co., Ltd., KBM-403) as a silane coupling agent, so that the solid content concentration becomes 35% by mass In this way, methyl ethyl ketone is added as a solvent to obtain an adhesive composition (B-1). Next, in the manufacturing method of the adhesive layer (A-1) of Example 1, the adhesive composition (A-1) was changed to the adhesive composition (B-1), otherwise the same as the example The same steps as the production method of the adhesive layer (A-1) of 1 were performed to obtain an adhesive sheet with a release sheet attached. The adhesive sheet with the release sheet has an adhesive layer (B-1).

(Comparative Example 4) With respect to 100 parts by mass of the crosslinkable (meth)acrylic copolymer (b-2) produced in Synthesis Example 2-2, an isocyanate-based crosslinking agent (manufactured by Mitsui Chemicals Co., Ltd., Takenate D110N) 0.3 was added as a crosslinking agent Parts by mass, ethylenediamine plus propylene oxide polyol (made by ADEKA, EDP-300) as a crosslinking accelerator 0.2 parts by mass, 3-glycidoxypropyltrimethoxy as a silane coupling agent Silane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-403) 0.15 weight, ethyl acetate as a solvent was added so that the solid content concentration became 30% by mass, to obtain an adhesive composition (B-2). Next, in the manufacturing method of the adhesive layer (A-1) of Example 1, the adhesive composition (A-1) was changed to the adhesive composition (B-2), and the drying process was changed to 60 The condition of drying for 1 minute in an air-circulating constant temperature oven at ℃ and then drying at 155℃ for 1 minute. At the same time, the aging treatment was changed to a treatment at 23℃ for 120 hours. In addition, it was based on the adhesive of Example 1 The same steps as the production method of the layer (A-1) were performed to obtain an adhesive sheet with a release sheet. The adhesive sheet with the release sheet has an adhesive layer (B-2).

<Evaluation of Outgassing Resistance> (Test Example 1-1) Using the adhesive sheets with release sheets produced in Examples 1 to 12 and Comparative Example 2, the outgassing resistance was evaluated as follows. Among the adhesive sheets with the release sheet, the second release sheet belonging to the light separator film is peeled off and the adhesive layer is exposed. The first member is a polycarbonate resin sheet with a thickness of 1 mm (Teijin Co., Ltd. The manufactured Panlite-Sheet PC-1151) is attached to the adhesive layer. Next, the first release sheet belonging to the re-separator film was peeled off, and the entire surface of a glass plate with a size of 100 mm×200 mm as the second member was attached to the exposed adhesive layer. In this way, a laminate sample composed of polycarbonate resin plate/adhesive layer/glass plate was obtained. After treating the laminate sample in an autoclave at 40°C and 0.5 MPa for 30 minutes, the glass plate was irradiated with ultraviolet rays from the side of the glass plate so that the cumulative light amount became 3000 mJ/cm ^{2 to} obtain a test sample with a size of 100 mm×200 mm. Place the test sample in an environment of 85°C and 85% relative humidity, visually observe the test sample after 2 hours and 100 hours, and evaluate bubbles, floating, and peeling based on the following three criteria. ⊚: No bubbles, floating, and peeling were found after 2 hours and after 100 hours. ○: Fine bubbles were observed after 2 hours, and no bubbles, floating, and peeling were observed after 100 hours. ×: Bubbles, floating, and peeling were found both after 2 hours and after 100 hours.

(Test Example 1-2) Except that the adhesive sheet with release sheet produced in Comparative Examples 1, 3, and 4 was used as the adhesive sheet with release sheet, and the laminate sample was not irradiated with ultraviolet rays, it was the same as Test Example 1-1 Method to obtain test samples. The test sample was visually observed, and bubbles, floating, and peeling were evaluated using the same criteria as in Test Example 1-1.

(Test Example 2-1) Using the adhesive sheets with release sheets produced in Examples 1 to 12 and Comparative Example 2, the outgassing resistance was evaluated as follows. Among the adhesive sheets with the release sheet, the second release sheet belonging to the light separator film is peeled off and the adhesive layer is exposed. As the first member, a polycarbonate with a hard coat of 1mm thickness is used. An ester resin board (Iupilon Sheet MR-58U manufactured by Mitsubishi Gas Chemical Co., Ltd.) is attached to the adhesive layer on the side without the hard coat layer. Next, the first release sheet belonging to the re-separator film was peeled off, and the entire surface of a glass plate with a size of 100 mm×200 mm as the second member was attached to the exposed adhesive layer. In this way, a laminate sample composed of polycarbonate resin plate/adhesive layer/glass plate was obtained. After treating the laminate sample in an autoclave at 40°C and 0.5 MPa for 30 minutes, the glass plate was irradiated with ultraviolet rays from the side of the glass plate so that the cumulative light amount became 3000 mJ/cm ^{2 to} obtain a test sample with a size of 100 mm×200 mm. Place the test sample in an environment of 85°C and 85% relative humidity, visually observe the test sample after 2 hours and 100 hours, and evaluate bubbles, floating, and peeling based on the following three criteria. ⊚: No bubbles, floating, and peeling were found after 2 hours and after 100 hours. ○: Fine bubbles were observed after 2 hours, and no bubbles, floating, and peeling were observed after 100 hours. ×: Bubbles, floating, and peeling were found both after 2 hours and after 100 hours.

(Test Example 2-2) Except that the adhesive sheet with release sheet produced in Comparative Examples 1, 3, and 4 was used as the adhesive sheet with release sheet, and the laminate sample was not irradiated with ultraviolet rays, it was the same as Test Example 2-1 Method to obtain test samples. The test sample was visually observed, and bubbles, floating, and peeling were evaluated using the same criteria as in Test Example 2-1.

(Test Example 3-1) Using the adhesive sheet with release sheet produced in Examples 1 to 12 and Comparative Example 2, the outgassing resistance was evaluated as follows. Among the adhesive sheets with the release sheet, the second release sheet belonging to the light separator film is peeled off and the adhesive layer is exposed. As the second member, an ITO film with a thickness of 125 μm (manufactured by Oike Industry Co., Ltd. KB300) is attached to the adhesive layer. Next, peel off the first release sheet that belongs to the re-separator film, and put the acrylic resin board (Mitsubishi) made of polymethacrylate (PMMA) with a size of 100mm×200mm and a thickness of 1mm as the first member. RAYON Corporation, ACRYLITE MR-200) is attached to the exposed adhesive layer on the entire surface. Thereby, a laminate sample composed of polymethacrylate resin board/adhesive layer/ITO film was obtained. After treating the laminate sample in an autoclave at 40°C and 0.5 MPa for 30 minutes, the glass plate was irradiated with ultraviolet rays from the side of the glass plate so that the cumulative light amount became 3000 mJ/cm ^{2 to} obtain a test sample with a size of 100 mm×200 mm. Place the test sample in an environment of 85°C and 85% relative humidity, visually observe the test sample after 2 hours and 100 hours, and evaluate bubbles, floating, and peeling based on the following three criteria. ⊚: No bubbles, floating, and peeling were found after 2 hours and after 100 hours. ○: Fine bubbles were observed after 2 hours, and no bubbles, floating, and peeling were observed after 100 hours. ×: Bubbles, floating, and peeling were found both after 2 hours and after 100 hours.

(Test Example 3-2) Except that the adhesive sheets with release sheets produced in Comparative Examples 1, 3, and 4 were used as the adhesive sheets with release sheets, and the laminate sample was not irradiated with ultraviolet rays, it was the same as Test Example 3-1 Method to obtain test samples. The test sample was visually observed, and the bubble, floating, and peeling were evaluated using the same criteria as in Test Example 3-1.

(Evaluation results) Table 1 and Table 2 show the evaluation results of outgassing resistance. From the comparison of the adhesive sheets obtained in Examples 1 to 6 and the adhesive sheets obtained in Comparative Examples 1 to 4, it can be seen that the adhesive sheets obtained in Examples 1 to 6 have excellent outgassing resistance, especially It also has excellent resistance to outgassing for polycarbonate films without hard coating (Table 1). Similarly, from the comparison of the adhesive sheets obtained in Examples 7 to 12 and the adhesive sheets obtained in Comparative Examples 1 to 4, it can be seen that the adhesive sheets obtained in Examples 7 to 12 are excellent in outgassing resistance , Especially for polycarbonate films that do not have a hard coat layer also has excellent outgassing resistance (Table 2).

[Table 1]

[Table 2]

(no)

Claims (11)

An adhesive sheet is provided with an adhesive layer, and the adhesive sheet is characterized by: The aforementioned adhesive layer contains a crosslinked (meth)acrylic copolymer, a polymerizable monomer having a polymerizable double bond in the molecule, and a photopolymerization initiator; The aforementioned crosslinked (meth)acrylic copolymer has a structure in which a crosslinkable (meth)acrylic copolymer is crosslinked by a crosslinking agent; The aforementioned polymerizable monomer includes at least one of a monofunctional monomer having a cyclic ether structure and a monofunctional monomer having a chain ether structure. The adhesive sheet of claim 1, wherein the monofunctional monomer having a cyclic ether structure contains 5-30 parts by mass relative to 100 parts by mass of the aforementioned crosslinkable (meth)acrylic copolymer. Such as the adhesive sheet of claim 1 or 2, wherein the aforementioned cyclic ether structure is a 4-6 membered ring. The adhesive sheet of claim 1, wherein the monofunctional monomer having a chain ether structure contains 5-50 parts by mass relative to 100 parts by mass of the aforementioned crosslinkable (meth)acrylic copolymer. The adhesive sheet according to any one of claims 1 to 4, wherein the aforementioned polymerizable monomer contains a multifunctional monomer having two or more polymerizable double bonds in the molecule. Such as the adhesive sheet of claim 5, wherein the aforementioned multifunctional monomer has a bisphenol skeleton in the molecule. The adhesive sheet of claim 5 or 6, wherein the multifunctional monomer contains 1 to 15 parts by mass relative to 100 parts by mass of the crosslinkable (meth)acrylic copolymer. The adhesive sheet according to any one of claims 1 to 7, which is used for bonding with a first member selected from the group consisting of a resin plate, a resin sheet, and a resin film. The adhesive sheet according to claim 8, which is used for bonding the aforementioned first member and one second member selected from the group consisting of a glass plate, a resin film, and a resin plate. A laminated body provided with an adhesive sheet or a hardened product thereof according to any one of claims 1 to 9. The laminate according to claim 10, which further includes the first member, and has a structure in which the first member and the adhesive sheet or the cured product are laminated.