TW202113009A - Adhesive sheet, adhesive sheet with release sheet, laminate, and method for producing laminate - Google Patents

Abstract

The present invention addresses the problem of providing an adhesive sheet that has weak initial adhesive strength, allowing for excellent positioning functionality (reworkability), while also exhibiting excellent adhesive strength after being heated. The present invention pertains to an adhesive sheet satisfying physical properties (1) and (2). Physical property (1): a glass adhesive strength of 0.05 to 3 N/25mm, one minute after pasting, as measured in conformance with the adhesive strength measuring method set forth in JIS Z 0237. Physical property (2): a glass adhesive strength of 10 N/25mm or greater, after the adhesive sheet has been pasted onto a glass plate and has undergone heat treatment for 30 minutes under the conditions of 100 DEG C and 0.5 MPa, as measured in conformance with the adhesive strength measuring method set forth in JIS Z 0237.

Description

Adhesive sheet, adhesive sheet with release sheet, laminate, and method for manufacturing laminate

The present invention relates to an adhesive sheet, an adhesive sheet with a release sheet, a laminate, and a method for manufacturing the laminate.

Previously, display devices such as liquid crystal displays (LCD), or input devices used in combination with display devices, such as touch panels, have been widely used. In the manufacture of these display devices or input devices, a transparent adhesive sheet is used for bonding optical members, and a transparent adhesive sheet is also used for bonding the display device and the input device.

In various display devices, adhesive sheets are used for bonding optical members. However, optical members are often more expensive than adhesive sheets. In the manufacturing steps of display devices, it is necessary to reattach optical members, etc. In this case, it is also required to reprocess (re-peel) the adhesive sheet. For example, Patent Document 1 discloses an adhesive sheet comprising a support and an adhesive layer laminated on at least one side of the support, and the research has the following contents: by comparing the elastic coefficient of the adhesive sheet or the relative resistance to the stainless steel plate The adhesive force is set in the specified range to make an adhesive sheet suitable for both initial low adhesiveness and strong adhesiveness during use.

In addition, Patent Document 2 discloses an adhesive composition containing: a (meth)acrylic copolymer (A) as a copolymer of monomer components, the monomer component containing 61% by mass to 93% by mass (Meth)acrylic acid alkoxyalkyl ester, 6% to 19% by mass of tertiary nitrogen-containing monomers, 1% to 20% by mass of crosslinkable functional group-containing monomers; and crosslinking Agent (B). [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 6355874 [Patent Document 2] Japanese Patent Laid-Open No. 2018-159018

[The problem to be solved by the invention] However, since the pressure-sensitive adhesive sheet of Patent Document 1 has a support, it may not be suitable for bonding applications of optical members, which are being thinned in recent years. In addition, in the adhesive sheet in the previous literature, the difference between the initial adhesive force and the adhesive force after heating cannot be said to be sufficiently large, and sometimes the opposite characteristics of good reworkability and high adhesive force after heating cannot be exhibited.

Therefore, the inventors of the present invention, in order to solve the problems of the prior art, aim to provide an adhesive sheet with weak initial adhesive force and excellent position adjustment ability (reworkability), and on the other hand, exhibits excellent adhesive force after heating. the study. [Means to solve the problem]

Specifically, the present invention has the following structure.

[1] An adhesive sheet that satisfies the following physical properties (1) and physical properties (2); Physical properties (1): The relative adhesive force of the glass measured in accordance with the Japanese Industrial Standards (Japanese Industrial Standards, JIS) Z 0237, the relative adhesive force of the glass after one minute of bonding is 0.05 N/25 mm to 3 N/25 mm; Physical properties (2): The relative adhesive strength of the glass measured in accordance with the measurement method of adhesive strength described in JIS Z 0237 after the adhesive sheet was attached to a glass plate and heated at 100°C and 0.5 MPa for 30 minutes was 10 N/25 mm or more. [2] The adhesive sheet according to [1], wherein the adhesive sheet is an adhesive sheet obtained by curing an adhesive composition containing a crosslinkable (meth)acrylic copolymer and a crosslinking agent, The crosslinkable (meth)acrylic copolymer contains a unit derived from an alkoxyalkyl group-containing (meth)acrylate, a unit derived from a crosslinkable functional group-containing (meth)acrylate, and is derived from Nitrogen monomer units and units derived from methyl methacrylate, Relative to the total mass of the crosslinkable (meth)acrylic copolymer, the content of the unit derived from the alkoxyalkyl group-containing (meth)acrylate is 40% by mass to 90% by mass, which is derived from the crosslinkability The content of the functional group (meth)acrylate unit is 4% by mass to 20% by mass, and the content of the unit derived from the nitrogen-containing monomer is 3% by mass to 20% by mass, which is derived from methyl methacrylate The content of the unit is 3% by mass to 20% by mass. [3] The adhesive sheet according to [1] or [2], wherein the relative adhesive force of glass in the physical property (2) is more than 100 times the relative adhesive force of glass in the physical property (1). [4] The pressure-sensitive adhesive sheet according to [2] or [3], wherein the crosslinkable functional group of the crosslinkable functional group-containing (meth)acrylate is a hydroxyl group or a carboxyl group. [5] The pressure-sensitive adhesive sheet as described in any one of [2] to [4], wherein the crosslinkable (meth)acrylic copolymer has an intercalation consisting of three or more consecutive units derived from methyl methacrylate. Segmented branch chain. [6] The adhesive sheet according to any one of [2] to [5], wherein the crosslinking agent contains at least one selected from the group consisting of isocyanate compounds, epoxy compounds, and metal chelate compounds. [7] An adhesive sheet with a release sheet, comprising a pair of release sheets with different peeling forces on both surfaces of the adhesive sheet as described in any one of [1] to [6]. [8] A laminated body comprising the adhesive sheet described in any one of [1] to [6] and an adherend. [9] The laminate according to [8], wherein the adhesive sheet is a heat-hardened sheet. [10] The laminate according to [8] or [9], wherein the adherend is an optical member. [11] The laminated body according to any one of [8] to [10], wherein the laminated body is used for an optical element or used for an image display device. [12] A method for manufacturing a laminate, comprising: bonding the adhesive sheet as described in any one of [1] to [6] to an adherend and temporarily bonding; and performing heat treatment or heating The step of pressing and bonding the adhesive sheet and the adherend completely. [13] The method for producing a laminate according to [12], wherein in the step of complete bonding, heat treatment is performed at 50°C to 120°C for 1 minute to 120 minutes. [14] The method of manufacturing a laminate according to [12] or [13], wherein the adherend is an optical member. [Effects of the invention]

According to the present invention, it is possible to obtain an adhesive sheet having a weak initial adhesive force and excellent position adjustment ability (reworkability), and on the other hand, an adhesive sheet exhibiting an excellent adhesive force after heating.

Hereinafter, the present invention will be described in detail. The description of the structural requirements described below may be performed based on representative embodiments or specific examples, but the present invention is not limited to such embodiments. In addition, the numerical range indicated by "~" in this specification means the range which includes the numerical value described before and after "~" as the lower limit and the upper limit.

In addition, in this specification, "(meth)acrylic acid" means both or either of acrylic acid and methacrylic acid. In addition, in this specification, "single body" and "monomer" have the same meaning, and "polymer" and "polymer" have the same meaning.

＜Adhesive sheet＞ The present invention relates to an adhesive sheet satisfying the following physical properties (1) and physical properties (2). Physical properties (1): The relative adhesive force of the glass measured in accordance with the adhesive force measurement method described in JIS Z 0237, one minute after bonding, is 0.05 N/25 mm to 3 N/25 mm. Physical properties (2): The relative adhesive strength of the glass measured in accordance with the measurement method of adhesive strength described in JIS Z 0237 after the adhesive sheet was attached to a glass plate and heated at 100°C and 0.5 MPa for 30 minutes was 10 N/25 mm or more.

When measuring the relative adhesive force of glass in physical properties (1), the relative adhesive force of glass after one minute after bonding to the glass was measured in accordance with the measurement method of adhesive force described in JIS Z 0237. More specifically, a 100 μm PET (manufactured by Toyobo Co., Ltd./product number: Cosmoshine A4300) was attached to one side of the adhesive sheet, and treated in an autoclave at 100° C. and 0.5 MPa for 30 minutes. Then, the adhesive sheet of the single-sided PET substrate obtained in the above manner was bonded to soda glass (Hiraoka Special Glass Manufacturing (strand), the pressure-bonding surface is the opposite surface of the tin float method). At this time, in accordance with the 180° peel adhesion measurement method described in JIS Z 0237, except that soda glass was used for the test plate, a sample for measurement was produced. Then, one minute after crimping, the adhesive force was measured at a peeling speed of 300 mm/min. The adhesive force is regarded as the relative adhesive force of glass in the physical properties (1). The relative adhesion of glass in the physical properties (1) may be 0.05 N/25 mm or more, preferably 0.10 N/25 mm or more, and more preferably 0.15 N/25 mm or more. In addition, the relative adhesion of the glass in the physical properties (1) may be 3 N/25 mm or less, preferably 2 N/25 mm or less, more preferably 1.5 N/25 mm or less, and still more preferably 1 N/25 mm or less.

When measuring the relative adhesive force of the glass in the physical property (2), a sample for measurement is prepared in the same manner as the method of the physical property (1). After that, the sample for measurement was processed for 30 minutes under the conditions of 100° C. and 0.5 MPa using an autoclave, and then allowed to stand for 2 hours in an environment of 23° C. and a relative humidity of 50%. Then, the adhesive force was measured at a peeling speed of 300 mm/min using the same method as the physical property (1). The adhesive force is regarded as the relative adhesive force of glass in the physical properties (2). In physical properties (2), the relative adhesion of the glass should be 10 N/25 mm or more, preferably 15 N/25 mm or more, more preferably 20 N/25 mm or more, and more preferably 30 N/25 mm or more . In addition, the relative adhesion of the glass in the physical properties (2) is preferably 50 N/25 mm or less.

The pressure-sensitive adhesive sheet of the present invention has such a structure, and therefore, the initial adhesive force is weak, and the position adjustment ability (reworkability) is excellent. Therefore, when the adhesive sheet of the present invention is used for, for example, an optical member bonding application and reattachment is required, the adhesive sheet can be easily peeled from the optical member. Specifically, the pressure-sensitive adhesive sheet can be easily peeled from the optical member, thereby suppressing the generation of residual glue originating from the pressure-sensitive adhesive sheet. Furthermore, in the adhesive sheet of the present invention, an excellent adhesive force can be exhibited after heating. Therefore, by heating the adhesive sheet of the present invention after bonding to the optical member, the adhesive sheet can exhibit excellent adhesive force. Thereby, the adherends can be firmly attached to each other. In this way, the adhesive sheet of the present invention successfully suppresses the initial adhesive force to a low level, improves the adhesive force after heating, and has two opposite adhesive properties.

In the adhesive sheet of the present invention, the relative adhesive force of the glass in the physical property (2) is preferably 100 times or more than the relative adhesive force of the glass in the physical property (1), more preferably 120 times or more, and more preferably 130 times or more, Especially preferred is 150 times or more. In this way, in the adhesive sheet of the present invention, it is preferable that the relative adhesive force of glass in the physical property (2) is greatly different from the relative adhesive force of the glass in the physical property (1). This can more effectively improve the position adjustment ability (reworkability), and in turn can make the adhesive force stronger after heating.

＜Structure of Adhesive Sheet＞ The adhesive sheet of the present invention has an adhesive layer. The adhesive sheet is preferably an adhesive sheet including only an adhesive layer, more preferably a double-sided adhesive sheet. In this case, the adhesive sheet may be a single-layer adhesive sheet including an adhesive layer, or a multilayer adhesive sheet in which a plurality of adhesive layers are laminated.

The present invention may also relate to an adhesive sheet with a release sheet including a release sheet on both surfaces of the adhesive sheet. When the adhesive sheet of the present invention includes release sheets on both surfaces, the adhesive sheet 10 with a release sheet as shown in FIG. 1 preferably has a release sheet 12a and a release sheet 12b on both surfaces of the adhesive layer 11.

Examples of the release sheet include: a release laminate sheet having a base material for a release sheet and a release agent layer provided on one side of the base material for a release sheet, or a polyethylene film or polypropylene film as a low-polarity base material. Polyolefin film. As the base material for the release sheet in the release laminated sheet, paper or polymer film can be used. As the release agent constituting the release agent layer, for example, a general addition type or condensation type silicone release agent or a long-chain alkyl group-containing compound can be used. In particular, an addition type silicone release agent with high reactivity can be preferably used. Specific examples of silicone-based release agents include BY24-4527 and SD-7220 manufactured by Toray Dow Corning Silicone, or KS-3600 and KS-774 manufactured by Shin-Etsu Chemical Co., Ltd. , X62-2600, etc. In addition, it is preferable that the silicone release agent contains an _{organosilicon compound having SiO 2} units and (CH ₃ ) ₃ SiO _1/2 units or CH ₂ =CH(CH ₃ )SiO _1/2 units, that is, silicone resins. . Specific examples of silicone resins include BY24-843, SD-7292, SHR-1404 manufactured by Toray Dow Corning Silicone, etc., or KS-3800, X92 manufactured by Shin-Etsu Chemical Co., Ltd. -183 and so on. As a peelable laminated sheet, you may use a commercial item. For example, a heavy release film made by Teijin Dupont Film (stock) as a release-treated polyethylene terephthalate film, or a polyethylene terephthalate film made by Teijin Dupont Film (stock) As a light release film of polyethylene terephthalate film with release treatment.

The adhesive sheet with a release sheet preferably has a pair of release sheets with different peeling forces on both surfaces of the adhesive sheet. That is, in order to make it easy to peel, it is preferable to set the peelability of the peeling sheet 12a and the peeling sheet 12b differently. If the releasability from one is different from the releasability from the other, it is easy to peel only the peeling sheet with high releasability first. In this case, what is necessary is just to adjust the peelability of the peeling sheet 12a and the peeling sheet 12b according to the bonding method or bonding order.

＜Adhesive layer＞ The adhesive sheet of the present invention is preferably one obtained by curing an adhesive composition containing a crosslinkable (meth)acrylic copolymer and a crosslinking agent. Furthermore, the adhesive sheet preferably includes an adhesive layer.

Here, the crosslinkable (meth)acrylic copolymer preferably contains a unit derived from an alkoxyalkyl group-containing (meth)acrylate and is derived from a crosslinkable functional group-containing (meth)acrylate. The units of, the units derived from the nitrogen-containing monomer and the units derived from methyl methacrylate, relative to the total mass of the crosslinkable (meth)acrylic copolymer, are derived from the alkoxyalkyl-containing (meth) The content of the acrylate unit is 40% to 90% by mass, and the content of the unit derived from the crosslinkable functional group-containing (meth)acrylate is 4% to 20% by mass, which is derived from the nitrogen-containing monomer The content of the unit of the weight body is 3% by mass to 20% by mass, and the content of the unit derived from methyl methacrylate is 3% by mass to 20% by mass.

The gel fraction of the adhesive layer is preferably 40% by mass or more, more preferably 45% by mass or more, and still more preferably 50% by mass or more. In addition, the gel fraction of the adhesive layer is preferably 100% by mass or less, more preferably 95% by mass or less, and still more preferably 90% by mass or less. Furthermore, the gel fraction is the gel fraction before heating the adhesive sheet, but in the adhesive sheet, since the change in the gel fraction before and after heating is small, it is preferably at 100°C and 0.5 MPa The gel fraction of the adhesive sheet after heat treatment for 30 minutes under the conditions of is also within the above range.

The gel fraction of the adhesive layer is a value measured by the following method. First, collect about 0.1 g of the adhesive sheet (adhesive layer) into a sample bottle, add 30 ml of ethyl acetate and shake for 24 hours. After that, the contents of the sample bottle were separated by filtration with a 150-mesh stainless steel metal mesh, and the residue on the metal mesh was dried at 100° C. for 1 hour, and the dry mass (g) was measured. Based on the obtained dry mass, the gel fraction was calculated using the following formula 1. Gel fraction (mass%)=(dry mass/collection quality of adhesive sheet)×100···Formula 1

The thickness of the adhesive layer can be appropriately set according to the application and is not particularly limited, and is preferably 5 μm to 300 μm, more preferably 8 μm to 200 μm, particularly preferably 10 μm to 150 μm. By setting the thickness of the adhesive layer within the above range, the overflow or blocking of the adhesive can be suppressed, and therefore the workability can be improved. Furthermore, by setting the thickness of the adhesive layer within the above range, the production of the double-sided adhesive sheet becomes easy.

＜Adhesive composition＞ The adhesive composition preferably contains a crosslinkable (meth)acrylic copolymer and a crosslinking agent.

<Crosslinkable (meth)acrylic copolymer> The crosslinkable (meth)acrylic copolymer contains a unit derived from an alkoxyalkyl group-containing (meth)acrylate, a unit derived from a crosslinkable functional group-containing (meth)acrylate, and is derived from Nitrogen monomer units and units derived from methyl methacrylate. Furthermore, in this specification and the scope of the patent application, "unit" is a repeating unit (monomeric unit) constituting a polymer.

The crosslinkable (meth)acrylic copolymer contains a unit derived from an alkoxyalkyl group-containing (meth)acrylate. The (meth)acrylate containing an alkoxyalkyl group is an alkoxyalkyl (meth)acrylate. As the (meth)acrylic acid alkoxyalkyl ester, for example, it is preferable that the alkoxy group has 1 to 12 carbon atoms and the alkylene group bonded to the alkoxy group has 1 to 18 carbon atoms (methyl ) Alkoxyalkyl acrylate. The carbon number of the alkoxy group is preferably 1-8, more preferably 1-4, and particularly preferably 1 or 2. In addition, the number of carbon atoms of the alkylene group bonded to the alkoxy group is preferably 1-12, more preferably 1-8, still more preferably 1-4, and particularly preferably 1-3.

Examples of such alkoxyalkyl (meth)acrylates include: 2-methoxymethyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, (meth) 2-ethoxymethyl acrylate, 2-ethoxyethyl (meth)acrylate, 3-methoxypropyl (meth)acrylate, 3-ethoxypropyl (meth)acrylate, (former Base) 4-methoxybutyl acrylate, 4-ethoxybutyl (meth)acrylate and the like. Among these, 2-methoxyethyl (meth)acrylate is particularly preferred.

Relative to the total mass of the crosslinkable (meth)acrylic copolymer, the content of the unit derived from the alkoxyalkyl group-containing (meth)acrylate is preferably 40% by mass or more, more preferably 45% by mass or more , More preferably 50% by mass or more, further preferably 55% by mass or more, and particularly preferably 60% by mass or more. In addition, the content of the unit derived from the alkoxyalkyl group-containing (meth)acrylate is preferably 90% by mass or less with respect to the total mass of the crosslinkable (meth)acrylic copolymer. By setting the content of the unit derived from the alkoxyalkyl group-containing (meth)acrylate within the above range, it is easy to suppress the initial adhesive force of the adhesive sheet to be low, and on the other hand, the adhesive force after heating is improved.

The crosslinkable (meth)acrylic copolymer contains a unit derived from a (meth)acrylate having a crosslinkable functional group. The unit derived from the crosslinkable functional group-containing (meth)acrylate is preferably a unit derived from a carboxyl group-containing (meth)acrylate, a unit derived from a hydroxyl group-containing (meth)acrylate, and The unit of the amino group-containing (meth)acrylate is derived from the unit of the glycidyl group-containing (meth)acrylate. Among them, the crosslinkable functional group is particularly preferably a hydroxyl group or a carboxyl group. That is, the unit derived from the crosslinkable functional group-containing (meth)acrylate is particularly preferably a unit derived from a carboxyl group-containing (meth)acrylate or a unit derived from a hydroxyl group-containing (meth)acrylate.

Examples of the unit derived from the carboxyl group-containing (meth)acrylate include acrylic acid and methacrylic acid. Examples of the unit derived from the hydroxyl group-containing (meth)acrylate include: 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate Ester, 3-chloro-2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, Polyalkylene glycol mono(meth)acrylate and the like. As a unit derived from an amino group-containing (meth)acrylate, (meth)acrylamide, allylamine, etc. are mentioned, for example. As a unit derived from glycidyl group-containing (meth)acrylate, glycidyl (meth)acrylate etc. are mentioned.

Relative to the total mass of the crosslinkable (meth)acrylic copolymer, the content of the unit derived from the crosslinkable functional group-containing (meth)acrylate is preferably 4% by mass or more, more preferably 4.5% by mass or more , And more preferably 5% by mass or more. In addition, relative to the total mass of the crosslinkable (meth)acrylic copolymer, the content of the unit derived from the crosslinkable functional group-containing (meth)acrylate is preferably 20% by mass or less, more preferably 15% by mass %the following. By setting the content of the unit derived from the crosslinkable functional group-containing (meth)acrylate within the above range, it is easy to suppress the initial adhesive force of the adhesive sheet to be low, and on the other hand, the adhesive force after heating is improved.

The crosslinkable (meth)acrylic copolymer contains a unit derived from a nitrogen-containing monomer. The nitrogen-containing monomer is a monomer containing nitrogen in one molecule. As the nitrogen-containing monomer, for example, dimethyl acrylamide, diethyl acrylamide, acryl morpholine, hydroxyethyl acrylamide, hydroxymethyl acrylamide, methoxymethyl Acrylamide, ethoxymethacrylamide, dimethylaminoethacrylamide, N-vinylcaprolactam, N-vinyl-2-pyrrolidone, (meth)acrylic acid two Methylaminoethyl, N-vinylformamide, etc. Among them, the nitrogen-containing monomer is preferably at least one selected from acrylamide derivatives, amine group-containing monomers, and nitrogen-containing heterocyclic ring-containing monomers, and more preferably acrylamide derivatives. The acrylamide derivative is more preferably at least one selected from the group consisting of dimethylacrylamide, diethylacrylamide, and acrylmorpholine, and particularly preferably dimethylacrylamide. Since the crosslinkable (meth)acrylic copolymer contains the unit derived from the nitrogen-containing monomer as described above, it is easy to suppress the initial adhesive force of the adhesive sheet to a low level, and on the other hand, the adhesive force after heating is improved.

The content of the unit derived from the nitrogen-containing monomer relative to the total mass of the crosslinkable (meth)acrylic copolymer is preferably 3.0% by mass or more, more preferably 3.5% by mass or more, and still more preferably 4.0% by mass or more . In addition, the content of the unit derived from the nitrogen-containing monomer relative to the total mass of the crosslinkable (meth)acrylic copolymer is preferably 20% by mass or less, and more preferably 15% by mass or less. By setting the content of the unit derived from the nitrogen-containing monomer within the above range, it is easy to suppress the initial adhesive force of the adhesive sheet to be low, and on the other hand, the adhesive force after heating is improved.

The crosslinkable (meth)acrylic copolymer contains units derived from methyl methacrylate. The content of units derived from methyl methacrylate relative to the total mass of the crosslinkable acrylic polymer is preferably 3% by mass or more, more preferably 3.5% by mass or more, still more preferably 4% by mass or more, and still more preferably 4.5% by mass or more, particularly preferably 5% by mass or more. In addition, the content of units derived from methyl methacrylate relative to the total mass of the crosslinkable acrylic polymer is preferably 20% by mass or less, and more preferably 15% by mass or less. By setting the content of the methyl methacrylate-derived unit within the above range, it is easy to suppress the initial adhesive force of the adhesive sheet to be low, and on the other hand, the adhesive force after heating is improved.

The crosslinkable (meth)acrylic copolymer preferably has a block-like branched chain in which three or more units derived from methyl methacrylate are continuous. The crosslinkable (meth)acrylic copolymer preferably has a block polymerized part composed of three or more consecutive units derived from methyl methacrylate, and it is preferred that the block polymerized part constitutes a crosslinkable (a Base) Branched chain of acrylic copolymer. Since the cross-linkable (meth)acrylic copolymer has a block-like branched chain composed of three or more consecutive units derived from methyl methacrylate, it is easy to effectively suppress the initial adhesion of the adhesive sheet to a low level. , On the other hand, improve the adhesion after heating.

In the case of introducing a block-like branched chain composed of three or more consecutive units derived from methyl methacrylate into the crosslinkable (meth)acrylic copolymer, it is preferable to synthesize a crosslinkable (meth)acrylic acid copolymer. In the case of acrylic copolymer, a macromonomer of methyl methacrylate is formulated. Furthermore, the macromonomer is an oligomer or polymer having a polymerizable reactive group at the end. At this time, the macromonomer is preferably one in which 3 to 500 methyl methacrylate are polymerized. In addition, a polymerizable functional group is introduced into the terminal of the macromonomer, and a polymerizable functional group such as an acrylic group or a methacrylic group is preferably introduced as the polymerizable functional group. Among them, it can be preferably used for macromonomers in which 3 to 500 polymer chains are polymerized with methyl methacrylate and methacrylic acid groups are bonded to the ends. In addition, a commercially available product can also be used for such a macromonomer, for example, AA-6 manufactured by Toagosei Co., Ltd. can be used.

In addition to the monomer unit, the crosslinkable (meth)acrylic copolymer may further have a repeating unit derived from an alkyl (meth)acrylate. Examples of the alkyl (meth)acrylate include ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, (meth) ) Tertiary butyl acrylate, isobutyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, (meth)acrylic acid N-octyl ester, isooctyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, ( N-undecyl (meth)acrylate, n-dodecyl (meth)acrylate, stearyl (meth)acrylate, methoxyethyl (meth)acrylate, ethoxy (meth)acrylate Ethyl ester, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, etc. Among the alkyl (meth)acrylates, at least one selected from the group consisting of n-butyl (meth)acrylate and 2-ethylhexyl (meth)acrylate is preferable in terms of increasing adhesiveness.

In addition, the crosslinkable (meth)acrylic copolymer may have other monomer units as necessary. Other monomers may be copolymerized with the acrylic monomers, and examples thereof include (meth)acrylonitrile, vinyl acetate, styrene, vinyl chloride, vinylpyrrolidone, vinylpyridine, and the like.

<Weight average molecular weight of crosslinkable (meth)acrylic copolymer> The weight average molecular weight of the crosslinkable (meth)acrylic copolymer is preferably 100,000 to 2 million, more preferably 200,000 to 1.5 million. If the weight average molecular weight is within the above range, it is easy to suppress the initial adhesive force of the adhesive sheet to be low, and on the other hand, the adhesive force after heating is improved. In addition, the weight average molecular weight of a crosslinkable (meth)acrylic copolymer is the value before crosslinking by the crosslinking agent mentioned later. The weight average molecular weight is a value obtained by measuring by size exclusion chromatography (SEC) on the basis of polystyrene. As the crosslinkable (meth)acrylic copolymer, a commercially available one can be used, or one synthesized by a known method can also be used.

＜Crosslinking agent＞ The adhesive composition preferably contains a crosslinking agent. The crosslinking agent can be appropriately selected in consideration of the reactivity with the crosslinkable functional group possessed by the crosslinkable (meth)acrylic copolymer. For example, it can be selected from known crosslinking agents such as isocyanate compounds, epoxy compounds, oxazoline compounds, aziridine compounds, metal chelate compounds, and butylated melamine compounds. Among them, the crosslinking agent preferably contains at least one selected from the group consisting of isocyanate compounds, epoxy compounds, and metal chelate compounds.

As an isocyanate compound, toluene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, etc. are mentioned, for example. As examples of commercially available products, toluene diisocyanate compounds (manufactured by Japan Polyurethane Industry Co., Ltd., Coronate L), xylylene diisocyanate compounds (Mitsui Chemicals Co., Ltd.) Manufacturing, Takenate (D-110N), etc. As the epoxy compound, for example, TETRAD-C (manufactured by Mitsubishi Gas Chemical Co., Ltd.), TETRAD-X manufactured by Mitsubishi Gas Chemical Co., Ltd.) Wait. Examples of the metal chelate compound include Alumichelate A (manufactured by Kawaken Fine Chemicals Co., Ltd.) and the like.

The content of the crosslinking agent in the adhesive composition can be appropriately selected according to the desired adhesiveness, etc., relative to 100 parts by mass of the crosslinkable (meth)acrylic copolymer, it is preferably 0.01 to 5 parts by mass, and more Preferably, it is 0.1 parts by mass to 3 parts by mass. By setting the content of the crosslinking agent within the above range, processability can be further improved. Furthermore, as the crosslinking agent, one type may be used alone or two or more types may be used in combination, and when two or more types are used in combination, it is preferable that the total mass is within the above-mentioned range.

＜Solvent＞ The adhesive composition may also include a solvent. In this case, the solvent is used to improve the applicability of the adhesive composition. Examples of solvents include hydrocarbons such as hexane, heptane, octane, toluene, xylene, ethylbenzene, cyclohexane, and methylcyclohexane; dichloromethane, trichloroethane, and trichloroethylene. , Tetrachloroethylene, dichloropropane and other halogenated hydrocarbons; methanol, ethanol, propanol, isopropanol, butanol, isobutanol, diacetone alcohol and other alcohols; diethyl ether, diisopropyl ether, dioxane, Ethers such as tetrahydrofuran; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, isophorone, cyclohexanone; methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, acetic acid Esters such as amyl ester and ethyl butyrate; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monomethyl ether acetate And other polyols and their derivatives.

The content of the solvent in the adhesive composition is not particularly limited. With respect to 100 parts by mass of the crosslinkable (meth)acrylic copolymer, it is preferably 25 parts by mass to 500 parts by mass, and more preferably 30 parts by mass to 400 parts by mass. Copies. In addition, the content of the solvent relative to the total mass of the adhesive composition is preferably 10% by mass to 90% by mass, and more preferably 20% by mass to 80% by mass. One type of solvent may be used alone, or two or more types may be used in combination. When two or more types are used in combination, the total mass is preferably within the above range.

＜Other ingredients＞ The adhesive composition may contain other components other than the above within a range that does not impair the effects of the present invention. Examples of other components include components known as additives for adhesives. For example, light stabilizers such as plasticizers, antioxidants, metal corrosion inhibitors, adhesion imparting agents, silane coupling agents, ultraviolet absorbers, hindered amine compounds, etc. can be selected as needed. In addition, dyes or pigments may be added for the purpose of coloring.

As the plasticizer, for example, a non-functional acrylic polymer can be used. Examples of non-functional acrylic polymers include polymers containing only acrylic monomer units that do not have functional groups other than acrylate groups, or polymers containing acrylic monomer units that do not have functional groups other than acrylate groups. A polymer of non-acrylic monomer units with functional groups. Since the non-functional acrylic polymer is not cross-linked, it can improve the step followability without affecting the adhesion. Examples of antioxidants include phenol-based antioxidants, amine-based antioxidants, lactone-based antioxidants, phosphorus-based antioxidants, and sulfur-based antioxidants. These antioxidants may be used individually by 1 type, and may use 2 or more types together. As a metal corrosion inhibitor, a benzotriazole-based resin can be cited as a preferable example in terms of the compatibility of the adhesive or the height of the effect. Examples of the adhesion imparting agent include rosin resins, terpene resins, terpene phenol resins, coumarone-indene resins, styrene resins, xylene resins, phenol resins, petroleum resins, and the like. As the silane coupling agent, for example, mercaptoalkoxysilane compounds (for example, mercapto-substituted alkoxy oligomers, etc.) and the like can be cited. Examples of ultraviolet absorbers include benzotriazole-based compounds, benzophenone-based compounds, and triazine-based compounds.

＜Manufacturing method of adhesive sheet＞ The manufacturing method of the adhesive sheet of the present invention preferably includes a step of applying the adhesive composition on the release sheet to form a coating film, and a step of heating the coating film. When a solvent is included in the adhesive composition, the solvent is removed by this heating step, and the coating film is heated to cause a reaction between the crosslinkable (meth)acrylic copolymer and the crosslinking agent to form a cured product ( Adhesive layer).

In the step of heating the coating film, it is preferable to set the heating temperature to 50°C to 150°C, and the heating time depends on the thickness of the coating film or the content of the solvent of the adhesive composition, and it is preferably set to 1 minute ~60 minutes. For heating the coating film, a known heating device such as a heating furnace and an infrared lamp can be used. In addition, it is preferable to implement an aging treatment in which the adhesive sheet is allowed to stand at a certain temperature for a certain period of time after heating. The aging treatment can be performed by standing still at 23°C for 7 days, for example.

The application of the adhesive composition can be carried out using a known coating device. Examples of coating devices include: blade coaters, air knife coaters, roll coaters, bar coaters, gravure coaters, micro gravure coaters, bar blade coaters, and lip coaters. Cloth machine, die coater, curtain coater, etc.

<How to use the adhesive sheet> When using the adhesive sheet of the present invention, it is preferable to include a step of contacting the adhesive sheet with the surface of the adherend, and a step of heating the adhesive sheet after contacting the adhesive layer with the surface of the adherend. Since the adhesive sheet of the present invention has low initial adhesive force, it can be easily peeled off soon after being attached to the adherend, and has excellent reworkability. However, by heating the adhesive sheet after attaching the adhesive sheet to the adherend, the adhesive sheet is The adhesion of stickies is improved. In the method of using the adhesive sheet, when heating the adhesive sheet after being attached to the adherend, the heating temperature is preferably 50°C to 120°C, and the heating time is preferably 1 minute to 120 minutes. In addition, pressure may be applied during the heat treatment, and for example, a pressure of 0.2 MPa to 0.9 MPa is preferably applied. By carrying out this kind of heating treatment, the adhesive force of the adhesive sheet is significantly improved, and it adheres more firmly to the adherend.

＜Use of Adhesive Sheets＞ The pressure-sensitive adhesive sheet of the present invention is preferably used for bonding optical members. As an optical member, each structural member in optical products, such as a touch panel and an image display device, is mentioned. As the structural member of the touch panel, for example, an ITO film provided with an ITO film on a transparent resin film, an ITO glass provided with an ITO film on the surface of a glass plate, and a transparent resin film coated with a conductive polymer Transparent conductive film, hard coat film, fingerprint resistant film, etc. As a structural member of an image display device, for example, an anti-reflection film, an alignment film, a polarizing film, a retardation film, and a brightness enhancement film used in a liquid crystal display device can be cited. In addition, the adhesive sheet of the present invention can also be used for bonding liquid crystal modules and touch panel modules to each other. Examples of materials used in these members include: glass, polycarbonate, polyethylene terephthalate, polymethyl methacrylate, polyethylene naphthalate, cycloolefin polymer, triethyl Cellulose, polyimide, acylated cellulose, etc.

＜Laminated body＞ The present invention also relates to a laminate having the adhesive sheet and adherend. The laminated body is preferably a manufacturer in the method of producing a laminated body described later. Furthermore, the adherend is preferably arranged on both sides of the adhesive sheet. That is, the laminate of the present invention preferably has an adherend 50/adhesive layer 11/adhesive 50 laminated in this order as shown in FIG. 2. The adherend is preferably an optical member, and as the optical member, the above-mentioned general member can be exemplified.

The adhesive sheet in the present invention is preferably a heat-hardened sheet obtained by bonding to an adherend and then performing heat treatment. More specifically, the adhesive sheet of the present invention is preferably attached to the adherend in a state of primary heating, and is preferably attached to the adherend and then subjected to secondary heating. The heat treatment is performed after bonding to the adherend in the manner described above, whereby the adhesion between the adhesive sheet and the adherend is significantly improved. For example, when the adhesive sheet is attached to the adherend, the adhesive force before the heat treatment is set to P, and the adhesive force after the heat treatment is set to Q, the value of Q/P is preferably 100 or more, and more It is preferably 120 or more, more preferably 130 or more, and particularly preferably 150 or more.

The laminated body is preferably used for optical elements or for image display devices. That is, in the laminate, the adherend is preferably an optical member or an image display device. As an image display device, a liquid crystal display, an organic EL display, etc. are mentioned. As an optical member, each structural member in optical products, such as a touch panel and an image display device, is mentioned. As the structural member of the touch panel, for example, an ITO film provided with an ITO film on a transparent resin film, an ITO glass provided with an ITO film on the surface of a glass plate, and a transparent resin film coated with a conductive polymer Transparent conductive film, hard coat film, fingerprint resistant film, etc. As a structural member of an image display device, for example, an anti-reflection film, an alignment film, a polarizing film, a retardation film, and a brightness enhancement film used in a liquid crystal display device can be cited. In addition, the adhesive sheet of the present invention can also be used for bonding liquid crystal modules and touch panel modules to each other. Examples of materials used in these members include: glass, polycarbonate, polyethylene terephthalate, polymethyl methacrylate, polyethylene naphthalate, cycloolefin polymer, triethyl Cellulose, polyimide, acylated cellulose, etc.

＜Manufacturing method of laminated body＞ The present invention also relates to a method for manufacturing a laminate, which includes: bonding an adhesive sheet satisfying the following physical properties (1) and physical properties (2) to an adherend to temporarily bond them; and performing heat treatment or heating The step of pressure treatment to completely bond the adhesive sheet and the adherend. Physical properties (1): The relative adhesive force of the glass measured in accordance with the adhesive force measurement method described in JIS Z 0237, one minute after bonding, is 0.05 N/25 mm to 3 N/25 mm. Physical properties (2): The relative adhesive strength of the glass measured in accordance with the measurement method of adhesive strength described in JIS Z 0237 after the adhesive sheet was attached to a glass plate and heated at 100°C and 0.5 MPa for 30 minutes was 10 N/25 mm or more.

According to the manufacturing method of the present invention, position adjustment (reprocessing) can be performed in the bonding step of the adhesive sheet, and at the same time, a laminate in which each layer is firmly adhered after heating can be manufactured. Since the pressure-sensitive adhesive sheet used in the manufacturing method of the present invention satisfies the condition of the above-mentioned physical property (1), it is excellent in position adjustment ability (reworkability). Therefore, when the pressure-sensitive adhesive sheet used in the manufacturing method of the present invention is used for, for example, an optical member bonding application and reattachment is required, the pressure-sensitive adhesive sheet can be easily peeled off from the optical member. Specifically, the pressure-sensitive adhesive sheet can be easily peeled from the optical member, thereby suppressing the generation of residual glue originating from the pressure-sensitive adhesive sheet. Furthermore, according to the manufacturing method of this invention, the laminated body which the adhesive sheet and the to-be-adhered body adhere firmly after heating, and each layer adhere|attaches firmly can be obtained. In this way, the manufacturing method of the present invention can successfully perform position adjustment (reprocessing) in the bonding step of the adhesive sheet, and at the same time improve the adhesion after heating, and can manufacture a laminated body with two opposite adhesive properties.

In the manufacturing method of the present invention, the relative adhesion of the glass in the physical property (2) is preferably 100 times or more than the relative adhesion of the glass in the physical property (1), more preferably 120 times or more, and more preferably 130 times or more, Especially preferred is 150 times or more. In this way, in the adhesive sheet, it is preferable that the relative adhesive force of the glass in the physical property (2) is greatly different from the relative adhesive force of the glass in the physical property (1). This enables position adjustment (reprocessing) in the bonding step of the adhesive sheet, and at the same time, the adhesion after heating can be made stronger.

In the step of temporarily bonding the adhesive sheet and the adherend, the adhesive sheet is brought into contact with the adherend, and pressure is applied as necessary. For example, it is preferable to bond the adhesive sheet and the adherend using a manual roller, a laminator, or the like. Furthermore, in the step of temporarily adhering, it is also possible not to pressurize but to place the adherend only on the adhesive surface of the adhesive sheet.

In the step of completely bonding the adhesive sheet and the adherend, the temporarily bonded laminate obtained in the temporarily bonding step is subjected to heat treatment or heat and pressure treatment. The heating temperature in the complete bonding step is preferably 50°C or higher, more preferably 80°C or higher. In addition, the heating temperature in the complete bonding step is preferably 120°C or lower, more preferably 110°C or lower. The heating time in the complete bonding step is preferably 1 minute or more, more preferably 5 minutes or more, and still more preferably 10 minutes or more. In addition, the heating time in the complete bonding step is preferably 120 minutes or less, more preferably 100 minutes or less, and still more preferably 90 minutes or less.

In the complete bonding step, when heat and pressure is applied to the temporarily bonded laminate, the pressure conditions are preferably, for example, to apply a pressure of 0.2 MPa to 0.9 MPa.

Furthermore, the complete subsequent steps can be set multiple times. For example, after the step of attaching the adhesive sheet to one of the adherends for complete bonding, the step of attaching the adhesive sheet to the other adherend to further complete bonding may be provided. In this way, the adherend can also be attached to both sides of the adhesive sheet. [Example]

Examples and comparative examples are listed below to more specifically illustrate the characteristics of the present invention. The materials, usage amount, ratio, processing content, processing order, etc. shown in the following examples can be appropriately changed as long as they do not deviate from the gist of the present invention. Therefore, the scope of the present invention should not be limitedly interpreted by the specific examples shown below.

(Example 1) (Synthesis of crosslinkable (meth)acrylic copolymer A-1) Blending methyl methacrylate (MMA), 2-methoxyethyl acrylate monomer (MEA), dimethyl acrylamide (DMAA), acrylic acid 2 in a mass ratio of 10:75:5:10 -Hydroxyethyl monomer (2HEA), dissolving azobisisobutyronitrile (AIBN) as a radical polymerization initiator in the solution. The solution was heated to 60° C. for random copolymerization to obtain an acrylic copolymer solution (A-1) having a solid content concentration of 40% by mass.

＜Making of Adhesive Sheet＞ With respect to 100 parts by mass of the solid content of the crosslinkable (meth)acrylic copolymer A-1, 0.8 parts by mass of an isocyanate-based crosslinking agent (manufactured by Mitsui Chemicals Co., Ltd., Takenate D-110N) is added and used The ethyl acetate was diluted and stirred so as to become a solution with a solid content concentration of 34% by mass, thereby preparing an adhesive composition. The adhesive composition prepared as described above was uniformly applied to a thickness of 38 including a release agent layer treated with a silicone-based release agent using an applicator so that the coating thickness after drying became 25 μm μm polyethylene terephthalate film (first release sheet) (manufactured by F-Tex Co., 38RL-07(2)) on the surface, and air circulation constant temperature oven at 100°C Dry for 3 minutes to form an adhesive layer on the surface of the first release sheet. Then, a second release sheet (manufactured by F-Tex Co., Ltd., 38RL-07(L)) having a thickness of 38 μm was attached to the surface of the adhesive layer. In this way, a double-sided adhesive sheet with a release sheet including a structure of a first release sheet/adhesive layer/second release sheet in which an adhesive layer is sandwiched by a pair of release sheets having a poor release force is obtained. The double-sided adhesive sheet was cured for 7 days under the conditions of 23° C. and relative humidity of 50%.

(Example 2) (Synthesis of crosslinkable (meth)acrylic copolymer A-2) Blending methyl methacrylate (MMA) macromonomers (manufactured by Toagosei Co., Ltd., AA-6), n-butyl acrylate (BA), and acrylic acid in a mass ratio of 10:5:70:5:10 2-Methoxyethyl (MEA), Dimethacrylamide (DMAA), 2-Hydroxyethyl acrylate monomer (2HEA), in addition to cross-linkable (meth)acrylic copolymer A-1 Similarly, an acrylic copolymer solution (A-2) with a solid content concentration of 40% by mass was obtained. Furthermore, the methyl methacrylate (MMA)-based macromonomer is one having a methacrylic acid group at the end of the oligomer of methyl methacrylate (MMA). The degree of polymerization of oligomers of methyl methacrylate (MMA) is about 60.

＜Making of Adhesive Sheet＞ A-2 was used instead of the cross-linkable (meth)acrylic copolymer A-1, and the addition amount of the cross-linking agent was changed to 0.5 parts by mass, except that it was the same as in Example 1 to obtain a double-sided adhesive with a release sheet sheet.

(Example 3) (Synthesis of crosslinkable (meth)acrylic copolymer A-3) Blending methyl methacrylate (MMA), 2-methoxyethyl acrylate (MEA), dimethyl acrylamide (DMAA), acrylic acid (AA) in a mass ratio of 10:75:10:5 Except for this, in the same manner as the synthesis of the crosslinkable (meth)acrylic copolymer A-1, an acrylic copolymer solution (A-3) having a solid content concentration of 40% by mass was obtained.

＜Making of Adhesive Sheet＞ A-3 was used instead of the crosslinkable (meth)acrylic copolymer A-1, and 0.3 parts by mass of epoxy crosslinking agent (manufactured by Mitsubishi Gas Chemical Co., Ltd., TETRAD) was added instead of the isocyanate crosslinking agent. ) X) Except for that, in the same manner as in Example 1, a double-sided pressure-sensitive adhesive sheet with a release sheet was obtained.

(Example 4) (Synthesis of crosslinkable (meth)acrylic copolymer A-4) Blending methyl methacrylate (MMA) macromonomer (manufactured by Toagosei Co., Ltd., AA-6), n-butyl acrylate (BA), and acrylic acid in a mass ratio of 10:5:7:10:5 2-Methoxyethyl (MEA), dimethylacrylamide (DMAA), acrylic acid (AA), except for the synthesis of the crosslinkable (meth)acrylic copolymer A-1, to obtain a solid An acrylic copolymer solution (A-4) with a component concentration of 40% by mass.

＜Making of Adhesive Sheet＞ A-4 was used instead of the crosslinkable (meth)acrylic copolymer A-1, and 0.8 parts by mass of a metal chelate crosslinking agent (Kawaken Fine Chemicals, Kawaken Fine Chemicals) was added instead of the isocyanate crosslinking agent. Except aluminum chelate (Alumichelate) A), in the same manner as in Example 1, a double-sided pressure-sensitive adhesive sheet with a release sheet was obtained.

(Comparative example 1) (Synthesis of crosslinkable (meth)acrylic copolymer B-1) Blending n-butyl acrylate (BA), dimethyl acrylamide (DMAA), and 2-hydroxyethyl acrylate monomer (2HEA) in a mass ratio of 80:10:10. In addition, it is cross-linkable In the same manner as in the synthesis of (meth)acrylic copolymer A-1, an acrylic copolymer solution (B-1) having a solid content concentration of 40% by mass was obtained.

＜Making of Adhesive Sheet＞ Except having used B-1 instead of the crosslinkable (meth)acrylic copolymer A-1, it carried out similarly to Example 1, and obtained the double-sided pressure-sensitive adhesive sheet with a release sheet.

(Comparative example 2) (Synthesis of crosslinkable (meth)acrylic copolymer B-2) Except that 2-ethylhexyl acrylate (2EHA) and acrylic acid (AA) were blended so that the mass ratio was 95:5, it was obtained in the same manner as the synthesis of the crosslinkable (meth)acrylic copolymer A-1. An acrylic copolymer solution (B-2) having a solid content concentration of 40% by mass.

＜Making of Adhesive Sheet＞ Use B-2 instead of the crosslinkable (meth)acrylic copolymer A-1, change the isocyanate-based crosslinking agent to Tosoh's Coronate L-55 and add 1.2 parts by mass Except for this, in the same manner as in Example 1, a double-sided pressure-sensitive adhesive sheet with a release sheet was obtained.

(Comparative example 3) Mix the 2-methoxyethyl acrylate monomer (MEA), dimethyl acrylamide (DMAA), and 2-hydroxyethyl acrylate monomer (2HEA) so that the mass ratio becomes 85:10:5. Azobisisobutyronitrile (AIBN) as a radical polymerization initiator is dissolved in the solution. The solution was heated to 60°C for random copolymerization to obtain an acrylic copolymer solution (B-3) having a solid content concentration of 40% by mass.

＜Making of Adhesive Sheet＞ The crosslinkable (meth)acrylic copolymer A-1 was replaced by B-3, and the isocyanate-based crosslinking agent was changed to Y-75 manufactured by Soken Chemical Co., Ltd. and 0.6 parts by mass was added. The same as Example 1 except that A double-sided adhesive sheet with a release sheet was obtained.

(Measurement) ＜Relative adhesion of glass＞ Physical properties (1) Peel off the peeling sheet on the lightly peeling side of the double-sided adhesive sheet with peeling sheet of the Examples and Comparative Examples. After bonding with 100 μm PET (manufactured by Toyobo Co., Ltd./Product No.: Cosmoshine A4300), use an autoclave at 100°C And treated for 30 minutes under the condition of 0.5 MPa to obtain an adhesive sheet with a PET substrate on one side. The peeling sheet on the heavy peeling side of the adhesive sheet of the single-sided PET substrate obtained in the above manner was peeled off, and the peeling sheet was attached to the soda glass (Hiraoka special glass production (strand) pressure bonding surface is the opposite surface of the tin float method). At this time, in accordance with the 180° peel adhesion measurement method described in JIS Z 0237, except that soda glass was used for the test plate, a sample for measurement was produced. Then, one minute after crimping, the adhesive force was measured at a peeling speed of 300 mm/min. Let this adhesive force be the physical property (1).

Physical properties (2) Before the pressure bonding to the test plate, a sample for measurement was prepared in the same manner as in the method of physical property (1). After that, the sample for measurement was processed for 30 minutes under the conditions of 100° C. and 0.5 MPa using an autoclave, and then allowed to stand for 2 hours in an environment of 23° C. and a relative humidity of 50%. Then, the adhesive force was measured at a peeling speed of 300 mm/min using the same method as the physical property (1). Let this adhesive force be the physical property (2).

(Evaluation) ＜Position adjustment ability (reworkability)＞ Cut the adhesive sheet of the single-sided PET substrate produced by the method of physical properties (1) into a size of 50 mm × 60 mm, and use a manual roller to cut a 30 mm × 40 mm (thickness 10 mm) float flat glass (Japan (Made by Sheet Glass Co., Ltd.) and the adhesive sheet are crimped so that the center points are overlapped to make a laminate. The laminate produced in the manner described above was placed on a horizontal stage in an environment of 23° C. and a relative humidity of 50% with the adhesive sheet side positioned below. Within one minute after crimping, gently press the adhesive sheet on the part exposed from the glass plate with one hand, and hold the glass plate with the other hand to peel the glass plate from the adhesive sheet upward. The peelability at this time was evaluated by the following criteria. ○: Easy to peel off ×: It cannot be peeled off, or it cannot be peeled off if it is not peeled off so that the side of the adhesive sheet is up and the adhesive sheet is pulled up from the end

＜Adhesion after heating＞ Using an oven at 80°C (relative humidity less than 10%), the laminate produced in the same way as the evaluation method of position adjustment ability (reworkability) was treated for 30 minutes, and then it was allowed to stand at 23°C and 50% relative humidity. Leave it for 60 minutes. After that, the peelability of the glass plate was evaluated by the following criteria in the same manner as the evaluation method of the position adjustment ability (reworkability). ○: It cannot be peeled off, or if it is not peeled off with the adhesive sheet side up and the adhesive sheet is pulled up from the end, it cannot be peeled off ×: easy to peel off

[Table 1] Example 1 Example 2 Example 3 Example 4 Comparative example 1 Comparative example 2 Comparative example 3 Crosslinkable (meth)acrylic polymer species A-1 A-2 A-3 A-4 B-1 B-2 B-3 (Meth) alkylene acrylate MMA MMA/BA MMA MMA/BA BA 2EHA - Allocation amount [mass%] 10 10/5 10 10/5 80 95 - Alkoxyalkyl (meth)acrylate MEA MEA MEA MEA - - MEA Allocation amount [mass%] 75 70 75 70 - - 85 Nitrogen-containing monomer DMAA DMAA DMAA DMAA DMAA - DMAA Allocation amount [mass%] 5 5 10 10 10 - 10 Monomers containing crosslinkable functional groups 2HEA 2HEA AA AA 2HEA AA 2HEA Allocation amount [mass%] 10 10 5 5 10 5 5 Crosslinking agent Product name Takenate D-110N Takenate D-110N TETRAD X Alumichelate A Takenate D-110N Coronate L-55 Y-75 species Isocyanate Isocyanate Epoxy Metal chelate Isocyanate Isocyanate Isocyanate Allocation amount [parts by mass] 0.8 0.5 0.3 0.8 0.8 1.2 0.6 Relative adhesion of glass Physical properties (1) One minute after crimping [N/25 mm] 0.21 0.29 0.15 0.25 twenty three 0.12 4 Physical properties (2) 100℃ and 0.5 MPa×30 minutes after treatment [N/25 mm] 40 39 42 45 41 0.54 30 Adhesion of physical properties (2) / Adhesive power of physical properties (1) 190 134 280 180 1.8 4.5 7.5 Position adjustment performance (reworkability) One minute after crimping ○ ○ ○ ○ X ○ X Adhesion after heating 80℃ and 30 minutes after crimping ○ ○ ○ ○ ○ X ○

The adhesive sheet of the example has a weak initial adhesive force and is excellent in position adjustment ability (reworkability). On the other hand, it exhibits an excellent adhesive force after heating.

(Example 11) (Synthesis of crosslinkable (meth)acrylic copolymer A-1) Blending methyl methacrylate (MMA), 2-methoxyethyl acrylate monomer (MEA), dimethyl acrylamide (DMAA), acrylic acid 2 in a mass ratio of 10:75:5:10 -Hydroxyethyl monomer (2HEA), dissolving azobisisobutyronitrile (AIBN) as a radical polymerization initiator in the solution. The solution was heated to 60° C. for random copolymerization to obtain an acrylic copolymer solution (A-1) having a solid content concentration of 40% by mass.

＜Making of Adhesive Sheet＞ With respect to 100 parts by mass of the solid content of the crosslinkable (meth)acrylic copolymer A-1, 0.8 parts by mass of an isocyanate-based crosslinking agent (manufactured by Mitsui Chemicals Co., Ltd., Takenate D-110N) is added and used The ethyl acetate was diluted and stirred so as to become a solution with a solid content concentration of 34% by mass, thereby preparing an adhesive composition. The adhesive composition prepared as described above was uniformly applied to a thickness of 38 including a release agent layer treated with a silicone-based release agent using an applicator so that the coating thickness after drying became 25 μm μm polyethylene terephthalate film (first release sheet) (manufactured by F-Tex, 38RL-07(2)) surface, and air circulation constant temperature oven at 100°C Dry for 3 minutes to form an adhesive layer on the surface of the first release sheet. Then, a second release sheet (manufactured by F-Tex Co., Ltd., 38RL-07(L)) having a thickness of 38 μm was attached to the surface of the adhesive layer. In this way, a double-sided adhesive sheet with a release sheet including a structure of a first release sheet/adhesive layer/second release sheet in which an adhesive layer is sandwiched by a pair of release sheets having a poor release force is obtained. The double-sided adhesive sheet was cured for 7 days under the conditions of 23° C. and relative humidity of 50%.

＜Production of laminated body＞ Peel off the peeling sheet on the lightly peeling side of the double-sided adhesive sheet obtained in the above manner, and bond it with 100 μm PET (manufactured by Toyobo Co., Ltd./Product No.: Cosmoshine A4300), and then use an autoclave at 100°C and 0.5 MPa Treated under the conditions for 30 minutes, thereby obtaining a single-sided PET substrate adhesive sheet. Then the single-sided PET substrate adhesive sheet was cut into a size of 50 mm × 60 mm, and the center point of the adhesive sheet was overlapped with a manual roller to crimp it on a float plate glass of 30 mm × 40 mm (thickness 10 mm). (Manufactured by Nippon Sheet Glass Co., Ltd.) to produce a laminated body in a temporarily bonded state The laminate obtained in this manner was processed in an oven at 60° C. for 60 minutes to complete the laminate in a completely bonded state.

(Example 12) The laminated body in the temporarily bonded state obtained in Example 11 was processed in an oven at 100° C. for 60 minutes, and except that the laminated body in a completely bonded state was completed in the same manner as in Example 11.

(Example 13) (Synthesis of crosslinkable (meth)acrylic copolymer A-2) Mixing methyl methacrylate (MMA) macromonomer (manufactured by Toagosei Co., Ltd., AA-6) and 2-methoxyethyl acrylate (MEA) in a mass ratio of 10:75:10:5 , Dimethacrylamide (DMAA), acrylic acid (AA), except for the synthesis of the crosslinkable (meth)acrylic copolymer A-1, to obtain an acrylic copolymer with a solid content of 40% by mass Solution (A-2). Furthermore, the methyl methacrylate (MMA)-based macromonomer is one having a methacrylic acid group at the end of the oligomer of methyl methacrylate (MMA). The degree of polymerization of oligomers of methyl methacrylate (MMA) is about 60.

＜Making of Adhesive Sheet＞ A-2 was used instead of the crosslinkable (meth)acrylic copolymer A-1, and the isocyanate-based crosslinking agent was replaced with an epoxy-based crosslinking agent (manufactured by Mitsubishi Gas Chemical Co., Ltd., TETRAD X) ) Except for 0.3 parts by mass, in the same manner as in Example 11, a double-sided pressure-sensitive adhesive sheet with a release sheet was obtained.

＜Production of laminated body＞ Except having used the obtained double-sided adhesive sheet, it carried out similarly to Example 11, and obtained the laminated body.

(Example 14) The laminated body in the temporarily bonded state obtained in Example 13 was processed in an oven at 100° C. for 60 minutes, and except that the laminated body in a completely bonded state was completed in the same manner as in Example 13.

(Comparative Example 11) (Synthesis of crosslinkable (meth)acrylic copolymer B-1) Blending n-butyl acrylate (BA), dimethyl acrylamide (DMAA), and 2-hydroxyethyl acrylate monomer (2HEA) in a mass ratio of 80:10:10. In addition, it is cross-linkable In the same manner as in the synthesis of (meth)acrylic copolymer A-1, an acrylic copolymer solution (B-1) having a solid content concentration of 40% by mass was obtained.

＜Making of Adhesive Sheet＞ Except having used B-1 instead of the crosslinkable (meth)acrylic copolymer A-1, it carried out similarly to Example 11, and obtained the double-sided pressure-sensitive adhesive sheet with a release sheet.

＜Production of laminated body＞ Peel off the peeling sheet on the lightly peeling side of the double-sided adhesive sheet obtained in the above manner, and bond it with 100 μm PET (manufactured by Toyobo Co., Ltd./Product No.: Cosmoshine A4300), and then use an autoclave at 100°C and 0.5 MPa Treated under the conditions for 30 minutes, thereby obtaining a single-sided PET substrate adhesive sheet. Then the single-sided PET substrate adhesive sheet was cut into a size of 50 mm × 60 mm, and the center point of the adhesive sheet was overlapped with a manual roller to crimp it on a float plate glass of 30 mm × 40 mm (thickness 10 mm). (Manufactured by Nippon Sheet Glass Co., Ltd.) to produce a laminated body in a temporarily bonded state. The layered body obtained in this manner was left to stand for 3 hours in an environment of 23° C. and a relative humidity of 50% to complete the layered body.

(Comparative Example 12) (Synthesis of crosslinkable (meth)acrylic copolymer B-2) Except that 2-ethylhexyl acrylate (2EHA) and acrylic acid (AA) were blended so that the mass ratio was 95:5, it was obtained in the same manner as the synthesis of the crosslinkable (meth)acrylic copolymer A-1. An acrylic copolymer solution (B-2) having a solid content concentration of 40% by mass.

＜Making of Adhesive Sheet＞ Use B-2 instead of the crosslinkable (meth)acrylic copolymer A-1, change the isocyanate-based crosslinking agent to Tosoh's Coronate L-55 and add 1.2 parts by mass Except for this, it carried out similarly to Example 11, and obtained the double-sided adhesive sheet with a peeling sheet.

＜Production of laminated body＞ Peel off the peeling sheet on the lightly peeling side of the double-sided adhesive sheet obtained in the above manner, and bond it with 100 μm PET (manufactured by Toyobo Co., Ltd./Product No.: Cosmoshine A4300), and then use an autoclave at 100°C and 0.5 MPa Treated under the conditions for 30 minutes, thereby obtaining a single-sided PET substrate adhesive sheet. Then the single-sided PET substrate adhesive sheet was cut into a size of 50 mm × 60 mm, and the center point of the adhesive sheet was overlapped with a manual roller to crimp it on a 30 mm × 40 mm (thickness 10 mm) float flat glass. (Manufactured by Nippon Sheet Glass Co., Ltd.) to produce a laminated body in a temporarily bonded state. The layered body obtained in the manner was treated in an oven at 100° C. for 60 minutes to complete the layered body.

(Comparative Example 13) Mix the 2-methoxyethyl acrylate monomer (MEA), dimethyl acrylamide (DMAA), and 2-hydroxyethyl acrylate monomer (2HEA) so that the mass ratio becomes 85:10:5. Azobisisobutyronitrile (AIBN) as a radical polymerization initiator is dissolved in the solution. The solution was heated to 60°C for random copolymerization to obtain an acrylic copolymer solution (B-3) having a solid content concentration of 40% by mass.

＜Making of Adhesive Sheet＞ The crosslinkable (meth)acrylic copolymer A-1 was replaced with B-3, and the isocyanate-based crosslinking agent was changed to Y-75 manufactured by Soken Chemical Co., and 0.6 parts by mass was added. The same as Example 11 except that A double-sided adhesive sheet with a release sheet was obtained.

＜Production of laminated body＞ Peel off the peeling sheet on the lightly peeling side of the double-sided adhesive sheet obtained in the above manner, and bond it with 100 μm PET (manufactured by Toyobo Co., Ltd./Product No.: Cosmoshine A4300), and then use an autoclave at 100°C and 0.5 MPa Treated under the conditions for 30 minutes, thereby obtaining a single-sided PET substrate adhesive sheet. Then the single-sided PET substrate adhesive sheet was cut into a size of 50 mm × 60 mm, and the center point of the adhesive sheet was overlapped with a manual roller to crimp it on a float plate glass of 30 mm × 40 mm (thickness 10 mm). (Manufactured by Nippon Sheet Glass Co., Ltd.) to produce a laminated body in a temporarily bonded state. The layered body obtained in the manner was treated in an oven at 100° C. for 60 minutes to complete the layered body.

(Measurement) ＜Relative adhesion of glass＞ Physical properties (1) The peeling sheet of the adhesive sheet of the single-sided PET substrate prepared in the examples and comparative examples was peeled off, and the soda glass was attached to the soda glass (made by Hiraoka Special Glass (strand), the pressure-bonding surface was the opposite surface of the tin float method). At this time, except for using soda glass for the test plate, a sample for measurement was produced in accordance with the 180° peel adhesion measurement method described in JIS Z 0237. Then, one minute after crimping, the adhesive force was measured at a peeling speed of 300 mm/min. Let this adhesive force be the physical property (1).

Physical properties (2) Before the pressure bonding to the test plate, a sample for measurement was prepared in the same manner as in the method of physical property (1). After that, the sample for measurement was processed for 30 minutes under the conditions of 100° C. and 0.5 MPa using an autoclave, and then allowed to stand for 2 hours in an environment of 23° C. and a relative humidity of 50%. Then, the adhesive force was measured at a peeling speed of 300 mm/min using the same method as the physical property (1). Let this adhesive force be the physical property (2).

(Evaluation) ＜Position adjustment ability (reworkability)＞ The laminated body in the temporarily bonded state produced in the Examples and Comparative Examples was placed on a horizontal stage in an environment of 23° C. and a relative humidity of 50% with the adhesive sheet side positioned downward. Within one minute after crimping, gently press the adhesive sheet on the part exposed from the glass plate with one hand, and hold the glass plate with the other hand to peel the glass plate from the adhesive sheet upward. The peelability at this time was evaluated by the following criteria. ○: Easy to peel off ×: It cannot be peeled off, or it cannot be peeled off if it is not peeled off so that the side of the adhesive sheet is up and the adhesive sheet is pulled up from the end

＜Adhesion after heating＞ Regarding the laminates (in a completely bonded state) produced in the Examples and Comparative Examples, the peelability of the glass plate was evaluated by the following criteria in the same manner as the evaluation method of the position adjustment ability (reworkability). ○: It cannot be peeled off, or if it is not peeled off with the adhesive sheet side up and the adhesive sheet is pulled up from the end, it cannot be peeled off ×: easy to peel off

[Table 2] Example 11 Example 12 Example 13 Example 14 Comparative example 11 Comparative example 12 Comparative example 13 Crosslinkable (meth)acrylic polymer species A-1 A-1 A-2 A-2 A-1 B-2 B-3 (Meth) alkylene acrylate MMA MMA MMA MMA MMA 2EHA - Allocation amount [mass%] 10 10 10 10 10 95 - Alkoxyalkyl (meth)acrylate MEA MEA MEA MEA MEA - MEA Allocation amount [mass%] 75 75 75 75 75 - 85 Nitrogen-containing monomer DMAA DMAA DMAA DMAA DMAA - DMAA Allocation amount [mass%] 5 5 10 10 5 - 10 Monomers containing crosslinkable functional groups 2HEA 2HEA AA AA 2HEA AA 2HEA Allocation amount [mass%] 10 10 5 5 10 5 5 Crosslinking agent Product name Takenate D-110N Takenate D-110N TETRAD X TETRAD X Takenate D-110N Coronate L-55 Y-75 species Isocyanate Isocyanate Epoxy Epoxy Isocyanate Isocyanate Isocyanate Allocation amount [parts by mass] 0.8 0.8 0.3 0.3 0.8 1.2 0.6 Relative adhesion of glass Physical properties (1) One minute after crimping [N/25 mm] 0.21 0.29 0.15 0.25 twenty three 0.12 4 Physical properties (2) 100℃ and 0.5 MPa×30 minutes after treatment [N/25 mm] 40 39 42 45 41 0.54 30 Adhesion of physical properties (2) / Adhesive power of physical properties (1) 190 134 280 180 1.8 4.5 7.5 Bonding conditions for the complete next step (treatment temperature after bonding) 60℃ 100°C 60℃ 100°C 23℃ 100°C 100°C Position adjustment performance (reworkability) One minute after crimping ○ ○ ○ ○ ○ ○ X Adhesion after heating 80℃ and 30 minutes after crimping ○ ○ ○ ○ X X ○

By using the manufacturing method of the laminated body of an Example, the position adjustment (reprocessing) can be performed at the initial stage of lamination, and at the same time, the laminated body which each layer adhered firmly after heating can be obtained.

10: Adhesive sheet with peeling sheet 11: Adhesive layer 12a: Peel off sheet 12b: Peel off sheet 50: Stickies 100: layered body

Fig. 1 is a schematic view showing a cross section of an adhesive sheet having a release sheet or a base material. Fig. 2 is a schematic diagram illustrating the structure of a laminated body manufactured in a method of manufacturing a laminated body.

10: Adhesive sheet with peeling sheet

11: Adhesive layer

12a: Peel off sheet

12b: Peel off sheet

Claims (14)

An adhesive sheet that satisfies the following physical properties (1) and physical properties (2); Physical properties (1): The relative adhesive force of the glass measured in accordance with the measurement method of adhesive force described in the Japanese Industrial Standard Z 0237, after one minute of bonding, is 0.05 N/25 mm～3 N/25 mm; Physical properties (2): The pressure-sensitive adhesive sheet is attached to a glass plate and heated at 100°C and 0.5 MPa for 30 minutes. The glass is measured in accordance with the method of measuring the adhesive force described in the Japanese Industrial Standard Z 0237. The adhesive force is 10 N/25 mm or more. The adhesive sheet according to claim 1, wherein the adhesive sheet is an adhesive sheet obtained by curing an adhesive composition containing a crosslinkable (meth)acrylic copolymer and a crosslinking agent, The crosslinkable (meth)acrylic copolymer contains a unit derived from an alkoxyalkyl group-containing (meth)acrylate, a unit derived from a crosslinkable functional group-containing (meth)acrylate, and a source Units in nitrogen-containing monomers and units derived from methyl methacrylate, Relative to the total mass of the crosslinkable (meth)acrylic copolymer, the content of the unit derived from the alkoxyalkyl group-containing (meth)acrylate is 40% by mass to 90% by mass, which is derived from the crosslinking The content of the unit of the (meth)acrylate of the linkable functional group is 4% by mass to 20% by mass, and the content of the unit derived from the nitrogen-containing monomer is 3% by mass to 20% by mass, which is derived from methyl methacrylate The content of the ester unit is 3% by mass to 20% by mass. The adhesive sheet according to claim 1 or 2, wherein the relative adhesive force of the glass in the physical property (2) is more than 100 times the relative adhesive force of the glass in the physical property (1). The pressure-sensitive adhesive sheet according to claim 2, wherein the crosslinkable functional group of the crosslinkable functional group-containing (meth)acrylate is a hydroxyl group or a carboxyl group. The pressure-sensitive adhesive sheet according to claim 2, wherein the crosslinkable (meth)acrylic copolymer has a block-like branched chain in which the methyl methacrylate-derived unit is continuously three or more units. The adhesive sheet according to claim 2, wherein the crosslinking agent contains at least one selected from the group consisting of isocyanate compounds, epoxy compounds, and metal chelate compounds. An adhesive sheet with a peeling sheet, comprising a pair of peeling sheets with different peeling forces on both surfaces of the adhesive sheet according to any one of claims 1 to 6. A laminated body comprising the adhesive sheet according to any one of claims 1 to 6 and an adherend. The laminate according to claim 8, wherein the adhesive sheet is a heat-hardened sheet. The laminate according to claim 8 or 9, wherein the adherend is an optical member. The laminated body according to claim 8 or 9, wherein the laminated body is used in an optical element or in an image display device. A method for manufacturing a laminate has: The step of attaching the adhesive sheet according to any one of claims 1 to 6 to the adherend and temporarily adhering; and A step of performing heat treatment or heat and pressure treatment to completely bond the adhesive sheet and the adherend. The method of manufacturing a laminate according to claim 12, wherein in the step of complete bonding, heat treatment is performed at 50°C to 120°C for 1 minute to 120 minutes. The method of manufacturing a laminate according to claim 12 or 13, wherein the adherend is an optical member.

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