WO2020262340A1

WO2020262340A1 - Adhesive sheet and use of same

Info

Publication number: WO2020262340A1
Application number: PCT/JP2020/024499
Authority: WO
Inventors: あゆみ西丸; 普史形見; 崇弘野中
Original assignee: 日東電工株式会社
Priority date: 2019-06-28
Filing date: 2020-06-23
Publication date: 2020-12-30
Also published as: KR20220024977A; CN114051521A

Abstract

The present invention provides an adhesive sheet which has an adhesive layer. This adhesive sheet has the characteristic (a) and the characteristic (b) described below.　(a) The elastic modulus as determined by a tensile test is 3.0 MPa or more.　(b) The impact resistance as determined by a shear impact test is 2.0 J/(10 mm)² or more.

Description

Adhesive sheet and its use

The present invention relates to an adhesive sheet, a film member with an adhesive sheet, and a method for producing a laminate.
This application claims priority based on Japanese Patent Application No. 2019-122284 filed on June 28, 2019 and Japanese Patent Application No. 2020-107125 filed on June 22, 2020. The entire contents of those applications are incorporated herein by reference.

Generally, an adhesive (also referred to as a pressure-sensitive adhesive; the same applies hereinafter) exhibits a soft solid state (viscoelastic body) in a temperature range near room temperature, and has a property of easily adhering to an adherend by pressure. Taking advantage of these properties, the pressure-sensitive adhesive is widely used in various fields, typically in the form of a pressure-sensitive adhesive sheet containing a pressure-sensitive adhesive layer. Patent Document 1 is mentioned as a technical document relating to the adhesive sheet.

Japanese Patent Application Publication No. 2016-017113

Adhesives are required to have various properties depending on the application. Among these characteristics, there are some that are difficult to achieve at a high level, for example, when trying to improve one characteristic, the other characteristic tends to decrease. As an example of such properties that are difficult to achieve at the same time, a property that is not easily deformed by stress (hereinafter, also referred to as “deformation resistance”) and a property that can withstand impact and maintain a bond with an adherend. (Hereinafter, it is also referred to as "impact resistance").

Therefore, an object of the present invention is to provide an adhesive sheet capable of forming a joint having high deformation resistance and high impact resistance. Another object of the present invention is to provide a film member with an adhesive sheet, which is configured to include the adhesive sheet. Still another object of the present invention is to provide a method for producing a laminate using the pressure-sensitive adhesive sheet.

According to this specification, a pressure-sensitive adhesive sheet containing a pressure-sensitive adhesive layer and having the following characteristics (a) and (b) is provided.
(A) The elastic modulus measured by the following tensile test is 3.0 MPa or more.
(B) The impact resistance measured by the following shear impact test is 2.0 J / (10 mm) ² or more.
[Tensile test]
The pressure-sensitive adhesive layer was irradiated with ultraviolet rays under the conditions of an illuminance of 300 mW / cm ² and an integrated light intensity of 3000 mJ / cm ² , and after aging at 50 ° C. for 48 hours, the pressure-sensitive adhesive layer was 10 mm wide and 150 mm long. Cut to size to make a test piece. In an environment of 23 ° C. and 50% RH, a tensile test was performed on the test piece under the conditions of a chuck distance of 120 mm and a tensile speed of 50 mm / min using a tensile tester, and a stress-displacement curve (hereinafter, “SS”). (Also referred to as “curve”) is obtained, and the elastic coefficient [MPa] (hereinafter, also referred to as tensile elastic coefficient) is calculated from the initial inclination thereof.
[Shear impact test]
A shear impact test is performed using a pendulum type adhesive shear impact tester based on JIS K6855. As a measurement sample, the first surface of the 10 mm square adhesive layer is bonded to the central portion of a chemically strengthened glass plate having a thickness of 25 mm square and 1.7 mm thick, and then the second surface of the adhesive layer is 40 mm square. Attached to the central part of the stainless steel plate (SUS304BA plate) of No. 1 and crimped with a load of 5N for 10 seconds, then autoclaved (50 ° C, 0.5 MPa, 15 minutes), and the illuminance was 300 mW / cm ² from the glass plate side. After irradiating with ultraviolet rays under the condition of an integrated light amount of 3000 mJ / cm ² , aged glass at 50 ° C. for 48 hours is used.
The measurement sample is fixed so that the stainless steel plate is on the lower side, and in an environment of 23 ° C. and 50% RH, a hammer energy of 2.75 J and a hammer speed (impact speed) of 3.5 m are applied to the outer peripheral side surface of the glass plate. The impact resistance [J / (10 mm) ² ] is obtained by measuring the absorbed energy [J] when a hammer is applied under the condition of / sec.

By satisfying the above property (a), for example, the pressure-sensitive adhesive layer can exhibit high deformation resistance in the state of use of the pressure-sensitive adhesive sheet. The pressure-sensitive adhesive sheet satisfying the above characteristics (a) and (b) can form a joint having high deformation resistance and high impact resistance, and thus can be preferably used for the purpose of joining or fixing members, for example.

Further, according to this specification, there is provided a pressure-sensitive adhesive sheet containing a pressure-sensitive adhesive layer, wherein the pressure-sensitive adhesive layer contains a polymer (A) and a photoreactive monomer (B). In some aspects of the pressure-sensitive adhesive sheet, the photoreactive monomer (B) comprises compound B1 having a ring structure and two or more ethylenically unsaturated groups in the molecule. The compound B1 preferably has a molecular weight of 100 g / mol or more per ethylenically unsaturated group. According to the pressure-sensitive adhesive sheet having such a pressure-sensitive adhesive layer, a bond having high deformation resistance and high impact resistance can be preferably formed.

The pressure-sensitive adhesive sheet according to any of the embodiments disclosed herein may satisfy the following property (c). The pressure-sensitive adhesive sheet satisfying the characteristic (c) can be preferably used for the purpose of joining or fixing members, for example.
(C) The peel strength measured by the following peel test is 1.0 N / 10 mm or more.
[Peeling test]
The first surface of the adhesive layer is pressure-bonded to a glass plate by reciprocating a 2 kg rubber roller once, autoclaving (50 ° C., 0.5 MPa, 15 minutes), and then illuminance 300 mW from the glass plate side. Irradiate with ultraviolet rays under the conditions of / cm ² and integrated light intensity of 3000 mJ / cm ² . After aging this at 50 ° C. for 48 hours, the test piece is pulled from the glass plate under the conditions of a peeling angle of 180 degrees and a tensile speed of 60 mm / min in an environment of 23 ° C. and 50% RH. Measure the peeling strength at the time of peeling.

According to this specification, a film member with an adhesive sheet is provided, which includes any of the adhesive sheets disclosed herein and a film member bonded to the adhesive layer of the adhesive sheet. According to the film member with an adhesive sheet, a bond having high deformation resistance and high impact resistance can be suitably formed.

According to this specification, one of the pressure-sensitive adhesive sheets disclosed herein is attached to an adherend, and the pressure-sensitive adhesive sheet is irradiated with ultraviolet rays to photo-cure the pressure-sensitive adhesive layer in this order. A method for producing a laminate including the above is provided. According to such a method, a laminate having both impact resistance and high deformation resistance can be produced.

It should be noted that an appropriate combination of the above-mentioned elements may be included in the scope of the invention for which protection by the patent is sought by the present patent application.

FIG. 1 is a cross-sectional view schematically showing the configuration of the pressure-sensitive adhesive sheet according to the embodiment. FIG. 2 is a cross-sectional view schematically showing the configuration of the pressure-sensitive adhesive sheet according to another embodiment. FIG. 3 is a cross-sectional view schematically showing a film member with an adhesive sheet to which the adhesive sheet according to the embodiment is attached to the film member.

Hereinafter, preferred embodiments of the present invention will be described. Matters other than those specifically mentioned in the present specification and necessary for the implementation of the present invention are based on the teachings regarding the implementation of the invention described in the present specification and the common general knowledge at the time of filing. Can be understood by those skilled in the art. The present invention can be carried out based on the contents disclosed in the present specification and common general technical knowledge in the art. Further, in the following drawings, members / parts having the same action may be described with the same reference numerals, and duplicate description may be omitted or simplified. In addition, the embodiments described in the drawings are schematicized for clearly explaining the present invention, and do not necessarily accurately represent the size and scale of the actually provided product.

In the present specification, the "acrylic polymer" refers to a polymer derived from a monomer component containing an acrylic monomer in an amount of 50% by weight or more, and is also referred to as an acrylic polymer. The acrylic monomer refers to a monomer having at least one (meth) acryloyl group in one molecule. Moreover, in this specification, "(meth) acryloyl" means a comprehensively referring to acryloyl and methacryloyl. Similarly, "(meth) acrylate" means acrylate and methacrylate, and "(meth) acrylic" means acrylic and methacrylic, respectively.
In this specification, "mass" and "weight" are synonymous.

In the present specification, the "photoreactive monomer" is a compound having at least one functional group (photoreactive functional group) in which the reaction can proceed by light irradiation, and is typically the above-mentioned photoreactivity. It is a compound having at least one ethylenically unsaturated group in the molecule as a functional group. The photoreactive monomer referred to here may be any one capable of causing a reaction as a monomer, and for example, it itself has a polymer such as an oligomer or a polymer (for example, at least one ethylenically unsaturated group in the molecule). It may be a polymer).

<Structure example of adhesive sheet>
An example of the configuration of the pressure-sensitive adhesive sheet disclosed herein is shown in FIG. The adhesive sheet 1 includes an adhesive layer 10 in which one surface 10A is a surface (adhesive surface) to be attached to an adherend, and a support 20 laminated on the other surface 10B of the adhesive layer 10. It is configured as a single-sided adhesive sheet (single-sided adhesive sheet with a support) including. The pressure-sensitive adhesive layer 10 is bonded to one surface 20A of the support 20. As the support 20, a resin film such as a polyester film can be used. The support 20 may be an optical film such as a polarizing plate. In the example shown in FIG. 1, the pressure-sensitive adhesive layer 10 has a single-layer structure. As shown in FIG. 1, for example, the adhesive sheet 1 before use (before being attached to the adherend) has an adhesive surface 10A having a release liner 30 having at least the adhesive layer side as a release surface (release surface). It may be in the form of an adhesive sheet 50 with a release liner protected by. Alternatively, the second surface 20B of the support 20 (the surface opposite to the first surface 20A, also referred to as the back surface) is a peeling surface, and the adhesive surface 10A is on the second surface 20B of the support 20. The adhesive surface 10A may be protected by being wound or laminated so as to be in contact with each other.

The release liner is not particularly limited, and for example, a release liner in which the surface of a liner base material such as a resin film or paper is peeled off, a fluoropolymer (polytetrafluoroethylene, etc.), a polyolefin resin (polyethylene, polypropylene, etc.), etc. ), A release liner made of a low-adhesive material or the like can be used. For the peeling treatment, for example, a silicone-based or long-chain alkyl-based peeling agent can be used. In some embodiments, the stripped resin film can be preferably used as the strip liner.

The pressure-sensitive adhesive sheet disclosed herein may be in the form of a supportless double-sided pressure-sensitive adhesive sheet composed of a pressure-sensitive adhesive layer. As shown in FIG. 2, in the supportless double-sided pressure-sensitive adhesive sheet 2, before use, each

side surface

10A, 10B of the pressure-sensitive adhesive layer 10 has at least a peelable surface (peeling surface) on the pressure-sensitive adhesive layer side. It may be in the form protected by the

liners

31 and 32. Alternatively, the back surface of the release liner 31 (the surface opposite to the adhesive side) is the release surface, and the adhesive surface is wound or laminated so that the adhesive surface 10B abuts on the back surface of the release liner 31. 10A and 10B may be in a protected form. Such a support-less double-sided pressure-sensitive adhesive sheet can be used, for example, by bonding a support to the surface of any one of the pressure-sensitive adhesive layers.
Further, the pressure-sensitive adhesive sheet disclosed herein may be in the form of a double-sided pressure-sensitive adhesive sheet with a support in which a pressure-sensitive adhesive layer is laminated on each of one surface and the other surface of the sheet-shaped support. The support in the pressure-sensitive adhesive sheet of this form may be a resin film such as a polyester film or an optical film such as a polarizing plate.

The pressure-sensitive adhesive sheet disclosed here may be a component of a film member with a pressure-sensitive adhesive sheet to which a film member is bonded to one surface of a pressure-sensitive adhesive layer. For example, the pressure-sensitive adhesive sheet 1 shown in FIG. 1 can be a component of the film member 100 with a pressure-sensitive adhesive sheet in which the film member 70 is bonded to one surface 10A of the pressure-sensitive adhesive layer 10, as shown in FIG. The film member may be, for example, an electromagnetic wave transmitting metallic luster member as described in Japanese Patent Application Publication No. 2018-69462, a polarizing plate or other optical film.

<Characteristics of adhesive sheet>
(Tensile modulus)
The pressure-sensitive adhesive sheet disclosed herein has a tensile elastic modulus of 3.0 MPa or more in the pressure-sensitive adhesive layer (which may be a pressure-sensitive adhesive layer formed by using any of the pressure-sensitive adhesive compositions disclosed herein). Is preferable. The tensile elastic modulus is measured by the above-mentioned tensile test, and more specifically, it is measured by the method described in Examples described later. Adhesive layers with higher tensile modulus tend to exhibit better deformation resistance. The pressure-sensitive adhesive sheet having a high tensile elastic modulus can be preferably used for the purpose of joining or fixing members, for example. For example, in a laminated body in which a member and an adherend are bonded via an adhesive layer, the high deformation resistance of the adhesive layer is to maintain the relative position of the member with respect to the adherend with high accuracy. Can help. Further, for example, in a laminated body in which a film member and an adherend are bonded via an adhesive layer, the high deformation resistance of the adhesive layer means that the laminated body is locally from the film member side. It can be useful for suppressing an event in which the appearance of the laminate is changed by being pressed. In a laminated body in which the adherend is a transparent rigid member (for example, a glass member), it is particularly meaningful to suppress a change in appearance visible from the adherend side.

In the pressure-sensitive adhesive sheet according to some preferred embodiments, the tensile elastic modulus may be, for example, 5.0 MPa or more, 7.0 MPa or more, 10.0 MPa or more, 15.0 MPa or more, 20. It may be 0 MPa or more. Deformation resistance tends to improve due to the increase in tensile elastic modulus. The upper limit of the tensile elastic modulus is not particularly limited. The tensile elastic modulus is usually 150 MPa or less from the viewpoint of facilitating balance with other characteristics (for example, one or more characteristics selected from impact resistance, peel strength, haze value, etc.). It is advantageous, preferably 120 MPa or less, 100 MPa or less, 80 MPa or less, or 60 MPa or less. The tensile elastic modulus can be adjusted by selecting the composition of the pressure-sensitive adhesive layer and the like.

In the tensile test, the treatment of irradiating the pressure-sensitive adhesive layer with ultraviolet rays is preferably performed with the pressure-sensitive adhesive layer sandwiched between transparent release liners. As the release liner, a polyester resin film having at least one side peeled (for example, a peeled polyethylene terephthalate resin (PET) film) can be preferably used from the viewpoint of transparency. Although not particularly limited, the thickness of the release liner may be, for example, about 10 μm or more and 125 μm or less, 10 μm or more and 75 μm or less, or 20 μm or more and 50 μm or less.

The thickness of the test piece used in the above tensile test may be about the same as or different from the thickness of the pressure-sensitive adhesive layer constituting the pressure-sensitive adhesive sheet disclosed herein. For example, when the thickness of the pressure-sensitive adhesive layer constituting the pressure-sensitive adhesive sheet is relatively small, a test piece prepared to have a thickness of 5 μm or more (for example, about 5 μm to 200 μm) is used for the purpose of improving operability. The result obtained by performing the tensile test can be adopted as the tensile elastic modulus of the pressure-sensitive adhesive layer. The thickness of the test piece can be adjusted, for example, by appropriately superimposing the pressure-sensitive adhesive layers before irradiation with ultraviolet rays. Further, using the same pressure-sensitive adhesive composition used for forming the pressure-sensitive adhesive layer to be measured, a test piece having a thickness that facilitates a tensile test is prepared, and the above-mentioned tensile test is performed on the test piece. The obtained result can be adopted as the tensile elastic modulus of the pressure-sensitive adhesive layer. The tensile test can be performed using, for example, a test piece having a thickness of about 10 μm to 50 μm (preferably about 15 μm to 25 μm).

(Impact resistance)
The pressure-sensitive adhesive sheet disclosed herein preferably has an impact resistance of 2.0 J / (10 mm) ² or more. The impact resistance is measured by the shear impact test described above, and more specifically, by the method described in Examples described later. According to the pressure-resistant adhesive sheet, a highly reliable bond can be formed. This can be an advantageous feature in, for example, an adhesive sheet used for joining or fixing members. Even if the adhesive sheet receives an impact due to, for example, dropping or collision, the adhesive sheet can withstand the impact and maintain good adhesion between the member and the adherend.

In the pressure-sensitive adhesive sheet according to some preferred embodiments, the impact resistance may be, for example, 2.1 J / (10 mm) ² or more, 2.3 J / (10 mm) ² or more, and 2.5 J / (10 mm). may be ^two or more, may be 2.7 J / (10 ^{mm) 2} or more, may be 3.0 J / (10 ^{mm) 2} or more. PSA sheet disclosed herein, the impact resistance may be preferably implemented in embodiments is 3.3J / ^{(10mm) 2} or more, or 3.5J / ^{(10mm) 2} or more. The upper limit of the impact resistance is not particularly limited. From the viewpoint of easily taking the balance with other characteristics, the impact resistance, for example 20 J / (10 ^mm) may be ^two or less, 15 J / (10 ^mm) may be ^two or less, may be 10J / (10 ^{mm) 2} or less , 8.0J / (10mm) ² may be used, and 6.0J / (10mm) ² or less may be used. The impact resistance can be adjusted by selecting the composition and thickness of the pressure-sensitive adhesive layer.

The pressure-sensitive adhesive sheet disclosed in the present specification includes an aspect in which the tensile elastic modulus is not limited, and in such an aspect, the pressure-sensitive adhesive sheet is not limited to one satisfying the tensile elastic modulus. Similarly, the pressure-sensitive adhesive sheet disclosed herein includes an unrestricted aspect of impact resistance, in which aspect the pressure-sensitive adhesive sheet is not limited to those that satisfy the impact resistance.

(Peeling strength)
The peel strength of the pressure-sensitive adhesive sheet disclosed herein is not particularly limited and can be set according to the purpose. The peel strength is measured by the peel test described above, and more specifically, it is measured by the method described in Examples described later. In some embodiments, the peel strength may be, for example, 0.5 N / 10 mm or more, preferably 1.0 N / 10 mm or more, and 1.5 N / 10 mm or more from the viewpoint of bonding reliability. Is more preferable, and it may be 2.0 N / 10 mm or more, 2.2 N / 10 mm or more, or 2.3 N / 10 mm or more. Further, from the viewpoint of facilitating the balance with other characteristics, the peel strength may be, for example, 10 N / 10 mm or less, 8.0 N / 10 mm or less, 6.0 N / 10 mm or less. It may be 0N / 10mm or less, or 4.0N / 10mm or less. The peel strength can be adjusted by selecting the composition and thickness of the pressure-sensitive adhesive layer.

(Haze value)
In the pressure-sensitive adhesive sheet disclosed herein, the haze value of the pressure-sensitive adhesive layer is not particularly limited. When transparency is required for the pressure-sensitive adhesive layer, the haze value of the pressure-sensitive adhesive layer may be, for example, 10% or less, 5.0% or less, 3.0% or less, 1.0% or less. It may be. As a non-limiting example of a usage mode in which the pressure-sensitive adhesive layer is required to be transparent, a member is bonded to a transparent adherend via a pressure-sensitive adhesive layer, and the above-mentioned is described from the adherend side through the pressure-sensitive adhesive layer. Examples of the usage mode in which the member is visually recognized, the usage mode in which the pressure-sensitive adhesive sheet having the support is joined to the transparent adherend, and the support is visually recognized from the adherend side through the pressure-sensitive adhesive layer. Be done. In some embodiments, the haze value of the pressure-sensitive adhesive layer may be less than 1.0%, less than 0.7%, 0.5% or less (eg 0-0.5%). There may be.

Here, the "haze value" refers to the ratio of diffuse transmitted light to total transmitted light when the measurement target is irradiated with visible light. Also called cloudy value. The haze value can be expressed by the following equation.
Th [%] = Td / Tt × 100
In the above formula, Th is a haze value [%], Td is a scattered light transmittance, and Tt is a total light transmittance.

The haze value is measured by irradiating ultraviolet rays under the conditions of an illuminance of 300 mW / cm ² and an integrated light intensity of 3000 mJ / cm ² , and aging at 50 ° C. for 48 hours, using the adhesive layer as a measurement sample as a haze meter (for example). , "MR-100" manufactured by Murakami Color Technology Research Institute) can be used for measurement. The haze value can be adjusted by selecting, for example, the composition and thickness of the pressure-sensitive adhesive layer. In the treatment of irradiating the pressure-sensitive adhesive layer with ultraviolet rays, the pressure-sensitive adhesive layer is sandwiched between transparent release liners (for example, a PET film that has been peeled off), as in the tensile test in the above-mentioned tensile elastic modulus measurement. It is preferable to carry out in a state of being.

<Adhesive layer>
The pressure-sensitive adhesive sheet in the techniques disclosed herein (including a pressure-sensitive adhesive sheet, a film member with a pressure-sensitive adhesive sheet, and a method for producing a laminate; the same applies hereinafter) includes a pressure-sensitive adhesive layer. The composition of the pressure-sensitive adhesive layer can be selected so that a bond having high deformation resistance and high impact resistance can be formed.

(Polymer (A))
In some embodiments, the pressure-sensitive adhesive layer contains a polymer (A). Examples of materials that can be used as the polymer (A) include acrylic polymers, rubber-based polymers, polyester-based polymers, urethane-based polymers, polyether-based polymers, silicone-based polymers, and polyamide-based polymers known in the field of pressure-sensitive adhesives. Examples thereof include polymers that exhibit rubber elasticity in the room temperature range, such as fluoropolymers. These can be used alone or in combination of two or more.

From the viewpoint of impact resistance and the like, the weight ratio of the polymer (A) to the total weight of the pressure-sensitive adhesive layer is usually preferably 40% by weight or more, preferably 50% by weight or more, preferably 60% by weight. % Or more, and 70% by weight or more. The weight ratio of the polymer (A) to the total weight of the pressure-sensitive adhesive layer is typically less than 100% by weight, and is usually 95% by weight or less from the viewpoint of facilitating the balance of characteristics. Is advantageous, and is preferably 92% by weight or less, 90% by weight or less, or 87% by weight or less.

An acrylic polymer is mentioned as a preferable example of the polymer (A). The pressure-sensitive adhesive layer in the technique disclosed herein may be an acrylic pressure-sensitive adhesive layer containing an acrylic polymer as a base polymer (a main component in the polymer component, that is, a component accounting for more than 50% by weight). The acrylic polymer as the polymer (A) (hereinafter, may be referred to as “acrylic polymer (A)”) is a linear or branched alkyl group having 1 to 20 carbon atoms at the ester terminal. It is preferable that the acrylic polymer is composed of a monomer component containing 40% by weight or more of the (meth) acrylic acid alkyl ester having. Hereinafter, a (meth) acrylic acid alkyl ester having an alkyl group having an number of carbon atoms of X or more and Y or less at the ester terminal may be referred to as "(meth) acrylic acid _CXY alkyl ester".

In some embodiments, the proportion of (meth) acrylic acid C _1-20 alkyl ester in the total monomer component of the acrylic polymer (A) is preferably greater than 40% by weight because it is easy to balance the properties. For example, it may be 45% by weight or more, 50% by weight or more, 55% by weight or more, or 60% by weight or more. The proportion of the (meth) acrylic acid C _1-20 alkyl ester in the monomer component can be 100% by weight, but it is usually suitable to be 98% by weight or less because it is easy to balance the characteristics. For example, it may be 95% by weight or less, or 90% by weight or less. In some embodiments, the proportion of C _1-20 (meth) acrylic acid alkyl ester in the total monomer component of the acrylic polymer (A) is, for example, 85% by weight or less from the viewpoint of improving the cohesiveness of the pressure-sensitive adhesive layer. It may be 80% by weight or less, 75% by weight or less, 70% by weight or less, 65% by weight or less, or 60% by weight or less.

Non-limiting specific examples of (meth) acrylic acid C _1-20 alkyl ester include methyl (meth) acrylic acid, ethyl (meth) acrylic acid, propyl (meth) acrylic acid, isopropyl (meth) acrylic acid, ( N-butyl acrylate, isobutyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isopentyl (meth) acrylate, (meth) Hexyl acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, (meth) ) Decyl acrylate, Isodecyl (meth) acrylate, Undecyl (meth) acrylate, Dodecyl (meth) acrylate, Tridecyl (meth) acrylate, Tetradecyl (meth) acrylate, Pentadecyl (meth) acrylate, (meth) Examples thereof include hexadecyl acrylate, heptadecyl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, nonadecil (meth) acrylate, and eicocil (meth) acrylate.

Of these, it is preferable to use at least (meth) acrylic acid C _4-20 alkyl ester, and it is more preferable to use at least (meth) acrylic acid C _4-18 alkyl ester. Particularly preferred (meth) acrylic acid C _4-18 alkyl esters include n-butyl acrylate (BA) and 2-ethylhexyl acrylate (2EHA). Other specific examples of (meth) acrylic acid C _4-20 alkyl esters that may be preferably used include isononyl acrylate, n-butyl methacrylate (BMA), 2-ethylhexyl methacrylate (2EHMA), isostearyl acrylate ( iSTA) and the like. These (meth) acrylic acid C _4-20 alkyl esters can be used alone or in combination of two or more.

The monomer component preferably contains, for example, either one or both of n-butyl acrylate (BA) and 2-ethylhexyl acrylate (2EHA). In some embodiments, the monomer component preferably comprises at least BA. Here, at least the example of the monomer component containing BA includes a monomer component having a composition containing BA and not containing 2EHA, BA and 2EHA, and the content of 2EHA is less than the content of BA (for example, the content of 2EHA). Contains monomer components of composition (the amount is less than 0.5 times or less than 0.3 times the content of BA).

In some embodiments, the monomer component constituting the acrylic polymer (A) may contain (meth) acrylic acid C _4-18 alkyl ester in a proportion of 40% by weight or more. The ratio of the (meth) acrylic acid C _4-18 alkyl ester to the monomer component may be, for example, 50% by weight or more, 60% by weight or more, or 65% by weight or more.
Further, from the viewpoint of enhancing the cohesiveness of the pressure-sensitive adhesive layer, it is usually appropriate that the ratio of the (meth) acrylic acid C _4-18 alkyl ester to the monomer component is 99.5% by weight or less, and 95% by weight. It may be% or less, 85% by weight or less, and 75% by weight or less.

The monomer component constituting the acrylic polymer (A) contains a (meth) acrylic acid alkyl ester and, if necessary, another monomer (copolymerizable monomer) copolymerizable with the (meth) acrylic acid alkyl ester. You may be. As the copolymerizable monomer, a monomer having a polar group (for example, a carboxy group, a hydroxyl group, a nitrogen atom-containing ring, etc.) or a monomer having a relatively high glass transition temperature of a homopolymer (for example, 10 ° C. or higher) is preferably used. can do. The monomer having a polar group can be useful for introducing a cross-linking point in the acrylic polymer (A) and increasing the cohesive force of the pressure-sensitive adhesive. The copolymerizable monomer may be used alone or in combination of two or more.

Non-limiting specific examples of the copolymerizable monomer include the following.
Carboxylic group-containing monomer: For example, acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, isocrotonic acid and the like.
Acid anhydride group-containing monomer: For example, maleic anhydride, itaconic anhydride.
Hydroxyl group-containing monomers: for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, (meth) acrylic. 4-Hydroxybutyl acid, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, (4-hydroxy) Hydroxyalkyl (meth) acrylates such as methylcyclohexyl) methyl (meth) acrylate.
Monomer containing sulfonic acid group or phosphoric acid group: For example, styrene sulfonic acid, allyl sulfonic acid, sodium vinyl sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfonic acid, (meth) acrylamide propane sulfonic acid, sulfo Propyl (meth) acrylate, (meth) acryloyloxynaphthalene sulfonic acid, 2-hydroxyethylacryloyl phosphate, etc.
Epoxy group-containing monomer: For example, an epoxy group-containing acrylate such as glycidyl (meth) acrylate or -2-ethylglycidyl ether (meth) acrylate, allyl glycidyl ether, glycidyl ether (meth) acrylate and the like.
Cyano group-containing monomer: For example, acrylonitrile, methacrylonitrile, etc.
Isocyanate group-containing monomer: For example, 2-isocyanate ethyl (meth) acrylate and the like.
Amide group-containing monomers: (meth) acrylamide; for example, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N, N-dipropyl (meth) acrylamide, N, N-diisopropyl (meth) N, N-dialkyl (meth) acrylamide such as acrylamide, N, N-di (n-butyl) (meth) acrylamide, N, N-di (t-butyl) (meth) acrylamide; N-ethyl (meth) acrylamide , N-alkyl (meth) acrylamide such as N-isopropyl (meth) acrylamide, N-butyl (meth) acrylamide, Nn-butyl (meth) acrylamide; N-vinylcarboxylic acid amides such as N-vinylacetamide; Monomers having a hydroxyl group and an amide group, for example, N- (2-hydroxyethyl) (meth) acrylamide, N- (2-hydroxypropyl) (meth) acrylamide, N- (1-hydroxypropyl) (meth) acrylamide, N- (3-Hydroxypropyl) (meth) acrylamide, N- (2-hydroxybutyl) (meth) acrylamide, N- (3-hydroxybutyl) (meth) acrylamide, N- (4-hydroxybutyl) (meth) N-Hydroxyalkyl (meth) acrylamide such as acrylamide; monomers having an alkoxy group and an amide group, for example, N-methoxymethyl (meth) acrylamide, N-methoxyethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide. N-alkoxyalkyl (meth) acrylamide such as N, N-dimethylaminopropyl (meth) acrylamide, N- (meth) acryloylmorpholine and the like.
Amino group-containing monomer: For example, aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, t-butylaminoethyl (meth) acrylate.
Monomers having an epoxy group: for example, glycidyl (meth) acrylate, methyl glycidyl (meth) acrylate, allyl glycidyl ether.
Monomers having a nitrogen atom-containing ring: for example, N-vinyl-2-pyrrolidone, N-methylvinylpyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperazine, N-vinylpyrazine, N- Vinylpyrrole, N-vinylimidazole, N-vinyloxazole, N- (meth) acryloyl-2-pyrrolidone, N- (meth) acryloyl piperidine, N- (meth) acryloyl pyrrolidine, N- (meth) acryloyl morpholine, N- Vinyl morpholin, N-vinyl-3-morpholinone, N-vinyl-2-caprolactam, N-vinyl-1,3-oxadin-2-one, N-vinyl-3,5-morpholindione, N-vinylpyrazole, N -Vinyl isoxazole, N-vinylthyazole, N-vinylisothyazole, N-vinylpyridazine and the like (for example, lactams such as N-vinyl-2-caprolactam).
Monomers having a succinimide skeleton: for example, N- (meth) acryloyloxymethylene succinimide, N- (meth) acryloyl-6-oxyhexamethylene succinimide, N- (meth) acryloyl-8-oxyhexamethylene succinimide and the like.
Maleimides: For example, N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, N-phenylmaleimide and the like.
Itaconimides: For example, N-methylitaconimide, N-ethylitaconimide, N-butylitaconimide, N-octylitaconimide, N-2-ethylhexylitaconimide, N-cyclohexylitaconimide, N-lauryl. Itaconimide, etc.
Aminoalkyl (meth) acrylates: For example, aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, t (meth) acrylate. -Butylaminoethyl.
Alkoxy group-containing monomers: for example, 2-methoxyethyl (meth) acrylate, 3-methoxypropyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, propoxyethyl (meth) acrylate, (meth) acrylate. (Meta) Alkoxyalkyl (alkoxyalkyl (meth) acrylate) such as butoxyethyl, ethoxypropyl (meth) acrylate; (meth) methoxyethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, (meth) (Meta) Alkoxyalkylene glycol acrylate (for example, alkoxypolyalkylene glycol (meth) acrylate) such as methoxypolypropylene glycol acrylate.
Alkoxysilyl group-containing monomers: for example 3- (meth) acryloxipropyltrimethoxysilane, 3- (meth) acryloxipropyltriethoxysilane, 3- (meth) acryloxipropylmethyldimethoxysilane, 3- (meth) acryloxy Alkoxysilyl group-containing (meth) acrylates such as propylmethyldiethoxysilane, alkoxysilyl group-containing vinyl compounds such as vinyltrimethoxysilane and vinyltriethoxysilane, and the like.
Vinyl esters: For example, vinyl acetate, vinyl propionate and the like.
Vinyl ethers: For example, vinyl alkyl ethers such as methyl vinyl ether and ethyl vinyl ether.
Aromatic vinyl compounds: for example, styrene, α-methylstyrene, vinyltoluene and the like.
Olefins: For example, ethylene, butadiene, isoprene, isobutylene and the like.
(Meta) acrylic acid ester having an alicyclic hydrocarbon group: For example, cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, adamantyl (meth) acrylate and the like. Acrylate-type hydrocarbon group-containing (meth) acrylate.
(Meta) acrylic acid ester having an aromatic hydrocarbon group: For example, an aromatic hydrocarbon group-containing (meth) acrylate such as phenyl (meth) acrylate, phenoxyethyl (meth) acrylate, and benzyl (meth) acrylate.
In addition, heterocyclic (meth) acrylates such as tetrahydrofurfuryl (meth) acrylate, halogen atom-containing (meth) acrylates such as vinyl chloride and fluorine atom-containing (meth) acrylates, and silicon atom-containing silicone (meth) acrylates. (Meta) acrylate, (meth) acrylic acid ester obtained from terpene compound derivative alcohol, etc.

When such a copolymerizable monomer is used, the amount used is not particularly limited, but it is usually appropriate to use 0.01% by weight or more of the total monomer component. From the viewpoint of better exerting the effect of using the copolymerizable monomer, the amount of the copolymerizable monomer used may be 0.1% by weight or more of the total monomer component, or 0.5% by weight or more. Further, from the viewpoint of facilitating the balance of the adhesive properties, the amount of the copolymerizable monomer used is usually preferably 50% by weight or less of the total monomer component, and preferably 40% by weight or less.

In some embodiments, the monomer component constituting the acrylic polymer (A) may include a monomer having a nitrogen atom. By using a monomer having a nitrogen atom, the cohesive force of the pressure-sensitive adhesive can be increased, and the peel strength after photocuring can be preferably improved. A preferred example of a monomer having a nitrogen atom is a monomer having a nitrogen atom-containing ring. As the monomer having a nitrogen atom-containing ring, those exemplified above can be used, and for example, the general formula (1):

The N-vinyl cyclic amide represented by is used. Here, in the general formula (1), R ¹ is a divalent organic group, and specific examples thereof include − (CH ₂ ) _n −. Here, n is an integer of 2 to 7 (preferably 2, 3 or 4). Of these, N-vinyl-2-pyrrolidone can be preferably adopted. Other preferred examples of monomers having a nitrogen atom include amide group-containing monomers such as (meth) acrylamide.

The amount of the monomer having a nitrogen atom (preferably the monomer having a nitrogen atom-containing ring) is not particularly limited, and may be, for example, 1% by weight or more of the total monomer component, or 3% by weight or more. Further, it can be 5% by weight or more or 7% by weight or more. In one aspect, the amount of the monomer having a nitrogen atom used may be 10% by weight or more, 15% by weight or more, or 20% by weight or more of the total monomer component. Further, the amount of the monomer having a nitrogen atom to be used is appropriately set to, for example, 40% by weight or less of the total monomer component, 35% by weight or less, 30% by weight or less, or 25% by weight or less. May be good. In another aspect, the amount of the monomer having a nitrogen atom used may be, for example, 20% by weight or less of the total monomer component, or 15% by weight or less.

In some embodiments, the monomer component constituting the acrylic polymer (A) may contain a hydroxyl group-containing monomer. By using the hydroxyl group-containing monomer, the cohesive force of the pressure-sensitive adhesive and the degree of cross-linking (for example, cross-linking with an isocyanate cross-linking agent) can be suitably adjusted. When a hydroxyl group-containing monomer is used, the amount used is not particularly limited, and may be, for example, 0.01% by weight or more, 0.1% by weight or more, or 0.5% by weight or more of the entire monomer component. It may be 1% by weight or more, 5% by weight or more, or 10% by weight or more. Further, from the viewpoint of suppressing the water absorption of the pressure-sensitive adhesive layer, in some embodiments, the amount of the hydroxyl group-containing monomer used is preferably, for example, 40% by weight or less of the total monomer component, and is 30% by weight or less. It may be 25% by weight or less, or 20% by weight or less. In another aspect, the amount of the hydroxyl group-containing monomer used may be, for example, 15% by weight or less of the total monomer component, 10% by weight or less, or 5% by weight or less.

In some embodiments, the proportion of the carboxy group-containing monomer in the monomer component of the acrylic polymer (A) may be, for example, 2% by weight or less, 1% by weight or less, and 0.5% by weight or less (for example). It may be less than 0.1% by weight). It is not necessary to substantially use a carboxy group-containing monomer as the monomer component of the acrylic polymer (A). Here, the fact that the carboxy group-containing monomer is not substantially used means that the carboxy group-containing monomer is not used at least intentionally. The pressure-sensitive adhesive layer containing the acrylic polymer (A) in which the amount of the carboxy group-containing monomer used is limited as described above is preferable from the viewpoint of preventing metal corrosion. The pressure-sensitive adhesive sheet having such a pressure-sensitive adhesive layer is also preferably in an embodiment in which the pressure-sensitive adhesive layer is in contact with an adherend and / or a support (which may be a metal foil or a support film containing a metal material) having a metal material. Can be used.

In some embodiments, the monomer component constituting the acrylic polymer (A) may contain an alicyclic hydrocarbon group-containing (meth) acrylate. As a result, the cohesive force of the pressure-sensitive adhesive can be increased, and the peel strength after photo-curing can be improved. As the alicyclic hydrocarbon group-containing (meth) acrylate, those exemplified above can be used, and for example, cyclohexyl acrylate and isobornyl acrylate can be preferably adopted. When the alicyclic hydrocarbon group-containing (meth) acrylate is used, the amount used is not particularly limited, and may be, for example, 1% by weight or more, 3% by weight or more, or 5% by weight or more of the total monomer component. In one aspect, the amount of the alicyclic hydrocarbon group-containing (meth) acrylate used may be 10% by weight or more of the total monomer component, or 15% by weight or more. The upper limit of the amount of the alicyclic hydrocarbon group-containing (meth) acrylate used is appropriately about 40% by weight or less, for example, 30% by weight or less, and 25% by weight or less (for example, 15% by weight). % Or less, and even 10% by weight or less).

The polymerization method for forming (synthesizing) the polymer (A) from the monomer component is not particularly limited, and various conventionally known polymerization methods can be appropriately adopted. For example, thermal polymerization such as solution polymerization, emulsion polymerization, bulk polymerization (typically performed in the presence of a thermal polymerization initiator); photopolymerization performed by irradiating light such as ultraviolet rays (typically). A polymerization method such as radiation polymerization carried out by irradiating radiation such as β-ray or γ-ray; which is carried out in the presence of a photopolymerization initiator; can be appropriately adopted. Two or more polymerization methods may be combined (eg, stepwise).

Examples of the solvent for solution polymerization (polymerization solvent) include aromatic compounds such as toluene (typically aromatic hydrocarbons); esters such as ethyl acetate and butyl acetate; aliphatic compounds such as hexane and cyclohexane or Aromatic hydrocarbons; Alkane halides such as 1,2-dichloroethane; Lower alcohols such as isopropyl alcohol (for example, monovalent alcohols having 1 to 4 carbon atoms); Ethers such as tert-butylmethyl ether Class; Ketones such as methyl ethyl ketone; Any one solvent selected from the above, or a mixed solvent of two or more kinds can be used.

In the polymerization, a known or commonly used thermal polymerization initiator or photopolymerization initiator can be used depending on the polymerization method, polymerization mode, and the like. Such a polymerization initiator may be used alone or in combination of two or more.

The thermal polymerization initiator is not particularly limited, but is, for example, an azo-based polymerization initiator, a peroxide-based initiator, a redox-based initiator by a combination of a peroxide and a reducing agent, and a substituted ethane-based initiator. Etc. can be used. More specifically, for example, 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis (2-methylpropionamidine) disulfate, 2,2'-azobis (2-amidinopropane). ) Dihydrochloride, 2,2'-azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis (N, N'-dimethyleneisobutyramidine), 2 , 2'-Azobis [N- (2-carboxyethyl) -2-methylpropionamidine] Azo-based initiators such as hydrate; persulfates such as potassium persulfate and ammonium persulfate; benzoyl peroxide, t-butyl Peroxide-based initiators such as hydroperoxide and hydrogen peroxide; for example, substituted ethane-based initiators such as phenyl-substituted ethane; for example, a combination of persulfate and sodium hydrogen sulfite, and a combination of peroxide and sodium ascorbate. Redox-based initiators such as; etc., but are not limited thereto. Thermal polymerization can be preferably carried out at a temperature of, for example, about 20 to 100 ° C. (typically 40 to 80 ° C.), but is not limited thereto.

The photopolymerization initiator is not particularly limited, but for example, a ketal-based photopolymerization initiator, an acetophenone-based photopolymerization initiator, a benzoin ether-based photopolymerization initiator, an acylphosphine oxide-based photopolymerization initiator, α- Ketol-based photopolymerization initiator, aromatic sulfonyl chloride-based photopolymerization initiator, photoactive oxime-based photopolymerization initiator, benzoin-based photopolymerization initiator, benzyl-based photopolymerization initiator, benzophenone-based photopolymerization initiator, thioxanthone-based light A polymerization initiator or the like can be used.

The amount of the polymerization initiator used can be a normal amount according to the polymerization method, polymerization mode, etc., and is not particularly limited. For example, about 0.001 to 5 parts by weight of the polymerization initiator (typically about 0.01 to 2 parts by weight, for example, about 0.01 to 1 part by weight) is used with respect to 100 parts by weight of the monomer to be polymerized. Can be done.

For the above polymerization, various conventionally known chain transfer agents (which can also be grasped as a molecular weight adjusting agent or a degree of polymerization adjusting agent) can be used, if necessary. As the chain transfer agent, mercaptans such as n-dodecyl mercaptan, t-dodecyl mercaptan, thioglycolic acid, and α-thioglycerol can be used. Alternatively, a chain transfer agent containing no sulfur atom (non-sulfur chain transfer agent) may be used. Specific examples of the non-sulfur chain transfer agent include anilins such as N, N-dimethylaniline and N, N-diethylaniline; terpenoids such as α-pinene and turpinolene; α-methylstyrene and α-methylstyrene dimer. Such as styrenes; compounds having a benzylidenyl group such as dibenzylidene acetone, cinnamyl alcohol, cinnamyl aldehyde; hydroquinones such as hydroquinone and naphthohydroquinone; quinones such as benzoquinone and naphthoquinone; 2,3-dimethyl-2-butene , 1,5-Cyclooctadiene and the like; alcohols such as phenol, benzyl alcohol and allyl alcohol; benzyl hydrogens such as diphenylbenzene and triphenylbenzene; and the like. The chain transfer agent may be used alone or in combination of two or more. It should be noted that the technique disclosed herein can be preferably implemented even in an embodiment in which a chain transfer agent is not used.

When the chain transfer agent is used, the amount used can be, for example, about 0.005 part by weight to 1 part by weight with respect to 100 parts by weight of the monomer component. In some embodiments, from the standpoint of impact resistance, the amount of the chain transfer agent used per 100 parts by weight of the monomer component can be, for example, 0.01 parts by weight or more, 0.03 parts by weight or more, and 0. It may be 0.05 parts by weight or more, or 0.07 parts by weight or more. Further, in some embodiments, from the viewpoint of deformation resistance, the amount of the chain transfer agent used with respect to 100 parts by weight of the monomer component may be, for example, 0.5 parts by weight or less, or 0.2 parts by weight or less. It may be 0.1 parts by weight or less, or less than 0.1 parts by weight (for example, 0.09 parts by weight or less).

In the technique disclosed herein, the glass transition temperature (Tg) of the polymer (A) is not particularly limited, but is usually preferably less than 0 ° C, preferably less than -10 ° C, and -20. It is preferably less than ° C. The impact resistance tends to be improved by reducing the Tg of the polymer (A). In some embodiments, the Tg of the polymer (A) may be less than -25 ° C or less than -30 ° C. The Tg of the polymer (A) is typically −80 ° C. or higher, for example, −70 ° C. or higher, −60 ° C. or higher, or −55 ° C. or higher. From the viewpoint of increasing the tensile elastic modulus, in some embodiments, the Tg of the polymer (A) is preferably −50 ° C. or higher, more preferably −45 ° C. or higher, and may be −40 ° C. or higher, or −38 ° C. It may be more than that, and it may be more than -35 ° C.

Here, in the present specification, the Tg of the polymer means the Tg obtained by the Fox formula based on the composition of the monomer component used for the preparation of the polymer. As shown below, the Fox formula is a relational expression between the Tg of the copolymer and the glass transition temperature Tgi of the homopolymer in which each of the monomers constituting the copolymer is homopolymerized.
1 / Tg = Σ (Wi / Tgi)

In the above Fox formula, Tg is the glass transition temperature (unit: K) of the copolymer, Wi is the weight fraction of the monomer i in the copolymer (copolymerization ratio based on the weight), and Tgi is the homopolymer of the monomer i. Represents the glass transition temperature (unit: K) of. When the target polymer for specifying Tg is a homopolymer, the Tg of the homopolymer and the Tg of the target polymer match.

As the glass transition temperature of the homopolymer used for calculating Tg, the value described in the publicly known material shall be used. For example, for the monomers listed below, the following values are used as the glass transition temperature of the homopolymer of the monomer.
n-Butyl acrylate-55 ° C
Isostearyl acrylate -18 ° C
Cyclohexyl acrylate 15 ° C
N-Vinyl-2-pyrrolidone 54 ° C
4-Hydroxybutyl acrylate-40 ° C

For the glass transition temperature of homopolymers of monomers other than those exemplified above, the values described in the "Polymer Handbook" (3rd edition, John Wiley & Sons, Inc., 1989) shall be used. When multiple types of values are described in this document, the highest value is adopted.

The weight average molecular weight (Mw) of the polymer (A) is not particularly limited. A resistance to deformation and impact resistance in terms of achieving both good balance, in some embodiments, the Mw of the polymer (A), for example, suitably be at about 10 × 10 ⁴ or more, with 20 × 10 ⁴ than It may be more than 30 × 10 ^4, more than 40 × 10 ^{4 and} more than 50 × 10 ⁴ . The upper limit of Mw of the polymer (A) may be normally be about 500 × 10 ⁴ or less. From the viewpoint of adhesion to the adherend and peel strength, in some embodiments, the Mw of the polymer (A) may be, for example, 150 × 10 ⁴ or less, 100 × 10 ⁴ or less, or 90 × 10 ⁴ it may be below or at 75 × 10 ⁴ or less. Here, Mw refers to a standard polystyrene-equivalent value obtained by gel permeation chromatography (GPC). As the GPC apparatus, for example, the model name "HLC-8320GPC" (column: TSKgelGMH-H (S), manufactured by Tosoh Corporation) may be used. The same applies to the examples described later. The above-mentioned example of Mw may be applied to the Mw of the polymer (A) in the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet disclosed herein, and the polymer (A) in the pressure-sensitive adhesive composition used for forming the pressure-sensitive adhesive layer. ) May be applied to Mw.

(Photoreactive monomer (B))
The pressure-sensitive adhesive layer in the technique disclosed herein may include a photoreactive monomer (B) in addition to the polymer (A) as described above (eg, acrylic polymer (A)). As the photoreactive monomer (B), a compound having two or more ethylenically unsaturated groups contained in the molecule (hereinafter, also referred to as “functional group number”) can be used. The upper limit of the number of functional groups of the compound used as the photoreactive monomer (B) is not particularly limited. The number of functional groups may be, for example, 50 or less, 40 or less, 30 or less, 20 or less, or 15 or less. In some embodiments, a compound having an ethylenically unsaturated group having, for example, 2 to 10 functional groups can be used, preferably a compound having 2 to 8 functional groups, and a compound having 2 to 6 functional groups. Is more preferable to use. The photoreactive monomer (B) may be used alone or in combination of two or more.

The photoreactive monomer (B) contained in the pressure-sensitive adhesive layer can form a crosslinked structure by reacting the ethylenically unsaturated group with light (for example, ultraviolet rays) irradiation after being attached to the adherend. The pressure-sensitive adhesive sheet containing the photoreactive monomer (B) in the pressure-sensitive adhesive layer is subjected to ultraviolet irradiation or the like after being attached to the adherend to cure the pressure-sensitive adhesive layer, thereby enhancing the deformation resistance of the pressure-sensitive adhesive layer. Can be done. As a result, it is possible to suitably achieve both good followability to the surface shape of the adherend at the time of sticking to the adherend and high deformation resistance after sticking.

Examples of the ethylenically unsaturated group include, but are not limited to, an acryloyl group, a methacryloyl group, a vinyl group and an allyl group. The two or more ethylene unsaturated groups that the photoreactive monomer (B) has in the molecule may be the same group or two or more different groups. Preferred ethylenically unsaturated groups from the viewpoint of photoreactivity include acryloyl group and methacryloyl group. Of these, the acryloyl group is preferable.

The functional group equivalent of the compound used as the photoreactive monomer (B) is not particularly limited. The functional group equivalent may be, for example, about 50 to 10000 g / mol, about 50 to 8000 g / mol, about 50 to 5000 g / mol, about 50 to 3000 g / mol, or about 50 to 2000 g / mol. It may be about. In some embodiments, as the photoreactive monomer (B), a compound having a functional group equivalent of about 60 to 800 g / mol (more preferably about 80 to 600 g / mol) is preferably used from the viewpoint of photocurability. Can be done.

The functional group equivalent of the photoreactive monomer (B) is obtained by dividing the molecular weight [g / mol] of the photoreactive monomer (B) by the number of ethylene unsaturated functional groups of the photoreactive monomer (B). It is calculated by. The molecular weight of the photoreactive monomer (B) can be obtained, for example, by a gel permeation chromatography (GPC) method as a weight average molecular weight in terms of standard polystyrene. Further, as the molecular weight [g / mol] of the photoreactive monomer (B), the molecular weight calculated from the manufacturer's nominal value or the molecular structure may be adopted.

The molecular weight of the photoreactive monomer (B) is not particularly limited and can be selected so as to preferably exert the desired effect. For example, as the photoreactive monomer (B), one having a molecular weight of about 20000 or less can be used. From the viewpoint of ease of preparation, coatability, etc. of the pressure-sensitive adhesive composition, the molecular weight of the photoreactive monomer (B) may be, for example, 16000 or less, 10,000 or less, or 4000 or less in some embodiments. Well, it may be 1500 or less, or 1000 or less. The molecular weight of the photoreactive monomer (B) is, for example, 100 or more, and typically 120 or more. From the viewpoint of processability and handleability of the pressure-sensitive adhesive sheet, in some embodiments, the molecular weight of the photoreactive monomer (B) may be, for example, 150 or more, 200 or more, 280 or more, 350 or more. However, it may be 420 or more, 480 or more, or 550 or more.

In the pressure-sensitive adhesive sheet disclosed herein, the amount of the photoreactive monomer (B) contained in the pressure-sensitive adhesive layer is not particularly limited, and depends on the target performance (for example, the tensile elastic modulus of the pressure-sensitive adhesive layer after photo-curing). It can be set appropriately. In some embodiments where the pressure-sensitive adhesive layer comprises a polymer (A) and a photoreactive monomer (B), the amount of photoreactive monomer (B) relative to 100 parts by weight of the polymer (A) contained in the pressure-sensitive adhesive layer is For example, it may be 1 part by weight or more, and usually 3 parts by weight or more is suitable. From the viewpoint of facilitating the increase in the tensile elastic modulus of the pressure-sensitive adhesive layer after photocuring, the amount of the photoreactive monomer (B) with respect to 100 parts by weight of the polymer (A) may be 5 parts by weight or more, or 10 parts by weight or more. , 15 parts by weight or more, or 20 parts by weight or more. Further, from the viewpoint of cohesiveness of the pressure-sensitive adhesive layer before photocuring and handleability of the pressure-sensitive adhesive sheet (for example, processability), the amount of the photoreactive monomer (B) with respect to 100 parts by weight of the polymer (A) is usually 80% by weight. It is appropriate that the amount is 60 parts by weight or less, preferably 50 parts by weight or less, 40 parts by weight or less, and 35 parts by weight or less.

In some embodiments, the pressure-sensitive adhesive layer preferably contains, as the photoreactive monomer (B), at least compound B1 having a ring structure and two or more ethylenically unsaturated groups in the molecule. According to the pressure-sensitive adhesive layer containing the compound B1 having such a structure, the deformation resistance of the pressure-sensitive adhesive layer can be effectively enhanced by light irradiation. The ring in the above ring structure may be an aliphatic ring or an aromatic ring. Further, the ring may be a carbon ring or a heterocycle. The number of rings contained in one molecule of compound B1 may be 1, or may be 2 or more. The upper limit of the number of rings contained in compound B1 is not particularly limited, and may be, for example, 100 or less, 70 or less, 50 or less, 30 or less, 15 or less, 8 or less, 6 It may be less than or equal to, 5 or less, or 4 or less. When compound B1 contains two or more rings, those rings may form fused rings of one or more rings (typically bicyclic or tricyclic fused rings). It does not have to be formed. The ring is preferably contained in the main chain of compound B1. That is, it is preferable that one ethylenically unsaturated group of compound B1 and at least one other ethylenically unsaturated group are linked via the ring structure. Compound B1 may be used alone or in combination of two or more.

As the compound B1, a compound having a ring structure and two or more ethylenically unsaturated groups in the molecule and having a functional group equivalent of 100 g / mol or more can be preferably used. According to the pressure-sensitive adhesive sheet containing the compound B1 satisfying the functional group equivalent in the pressure-sensitive adhesive layer, a bond having high deformation resistance and high impact resistance can be suitably formed. The reason why such an effect is obtained is not particularly limited, but according to Compound B1, the tensile elastic modulus of the pressure-sensitive adhesive layer after light irradiation is effectively increased by the rigidity of the ring structure. It is considered that while the deformation resistance can be imparted, the distance between the cross-linking points can be maintained and a cross-linked structure having high impact resistance can be formed when the functional group equivalent of the compound B1 is a predetermined value or more. In some embodiments, the functional group equivalent of compound B1 may be, for example, 120 g / mol or more, 150 g / mol or more, 180 g / mol or more, 230 g / mol or more, or 280 g / mol or more. It may be 320 g / mol or more, or 350 g / mol or more. Impact resistance tends to improve as the functional group equivalent of compound B1 increases. The functional group equivalent of compound B1 may be, for example, 10000 g / mol or less, 8000 g / mol or less, 5000 g / mol or less, 3000 g / mol or 2000 g / mol or less. In some embodiments, the functional group equivalent of compound B1 is preferably 800 g / mol or less, more preferably 600 g / mol or less, from the viewpoint of photocurability and the like. In some embodiments, the functional group equivalent of compound B1 may be 500 g / mol or less, 400 g / mol or less, or 300 g / mol or less.

In some embodiments, the number of functional groups of compound B1 (ie, the number of ethylenically unsaturated groups contained in the molecule) may be, for example, 2 to 50, 2 to 40, or 2 to 30. It may be 2 to 10, for example, 2 to 6, preferably 2 to 4, or 2 to 3. In some embodiments, compound B1 having 2 functional groups may be preferably employed.

Compound B1 may have a functional group other than the ethylenically unsaturated group. Examples of functional groups other than ethylenically unsaturated groups include hydroxyl groups, carboxy groups, amino groups and the like. Preferable examples of functional groups other than ethylenically unsaturated groups include hydroxyl groups and amino groups.

Examples of compound B1 include bisphenol A glycidyl ether (meth) acrylic acid adduct, bisphenol A glycidylamine (meth) acrylic acid adduct, bisphenol A glycidyl ester (meth) acrylic acid adduct, and the like. Meta) acrylate; alkylene oxide-modified bisphenol A (meth) acrylate such as ethylene oxide (EO) -modified bisphenol A di (meth) acrylate, propylene oxide (PO) -modified bisphenol A di (meth) acrylate; bisphenol F glycidyl ether (meth) ) Bisphenol F type epoxy (meth) acrylate such as acrylic acid adduct, bisphenol F glycidylamine (meth) acrylic acid adduct, bisphenol F glycidyl ester (meth) acrylic acid adduct; EO-modified bisphenol F di (meth) acrylate , PO-modified bisphenol F di (meth) acrylate, alkylene oxide-modified bisphenol F (meth) acrylate; bisphenol E glycidyl ether (meth) acrylic acid adduct, bisphenol E glycidylamine (meth) acrylic acid adduct, bisphenol E glycidyl Bisphenol E-type epoxy (meth) acrylate such as ester (meth) acrylic acid adduct; alkylene oxide-modified bisphenol E (meth) such as EO-modified bisphenol E di (meth) acrylate and PO-modified bisphenol E di (meth) acrylate. Acrylates; containing fluorene skeletons such as 9,9-bis (4-hydroxyphenyl) full orange (meth) acrylate, 9,9-bis [4- (2-hydroxyethoxy) phenyl] full orange (meth) acrylate ( Meta) acrylate; tricyclodecanedimethanol di (meth) acrylate, hydrogenated bisphenol A type epoxy (meth) acrylate, hydrogenated bisphenol F type epoxy (meth) acrylate, hydrogenated bisphenol E type epoxy (meth) acrylate, hydrogenated An aliphatic ring (which may be an alicyclic condensed ring) such as phthalic acid type epoxy (meth) acrylate, hydrogenated terpenephenol (meth) acrylate, and 1,4-cyclohexanedimethanol diglycidyl ether (meth) acrylate. Having (meth) acrylate; (meth) acrylic acid adduct of novolak type epoxy resin; (meth) acrylic acid adduct of thioether type epoxy resin Naphthalene-type epoxy resin (meth) acrylic acid adduct; dicyclopentadiene-type epoxy resin (meth) acrylic acid adduct; alkyldiphenol-type epoxy resin (meth) acrylic acid adduct; biphenyl-type epoxy resin ( Meta) Acrylic acid adduct; Terpenphenol resin (meth) Acrylic acid adduct; Tris (2-hydroxyethyl) isocyanurate di (meth) acrylate, Tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, etc. , Isocyanurate-type (meth) acrylate; divinylbenzene; hydroquinone di (meth) acrylate; resorcindi (meth) acrylate; modified products of any of the above-mentioned materials (for example, amine-modified products, acid-modified products, halogen-modified products); etc. However, the present invention is not limited to these. In some embodiments, compound B1 having an aromatic carbocycle may be preferably employed. Preferable examples of the compound B1 include compounds containing a bisphenol A structure, such as a bisphenol A type epoxy (meth) acrylate, an alkylene oxide-modified bisphenol A (meth) acrylate, and a modified product thereof (for example, an amine-modified product).

Commercially available products that can be used as compound B1 include the product names "A-DCP" and "A-BPE-4" manufactured by Shin-Nakamura Chemical Industry, and the product names "Viscoat # 540" and "Viscoat #" manufactured by Osaka Organic Chemical Industry. 700HV ", Nippon Kayaku's" R-114F ", Kyoeisha Chemical's product name" Epoxy Ester 3000A "," Epoxy Ester 80MFA ", Daicel Ornex's product name" EBECRYL 3700 "," EBECRYL 3703 "," EBECRYL 3603 ”and the like, but are not limited thereto.

The amount of compound B1 with respect to 100 parts by weight of the polymer (A) contained in the pressure-sensitive adhesive layer is not particularly limited, and may be, for example, 0.5 parts by weight or more. From the viewpoint of facilitating the acquisition of a pressure-sensitive adhesive layer having both deformation resistance and impact resistance in a well-balanced manner, in some embodiments, the amount of compound B1 with respect to 100 parts by weight of the polymer (A) is, for example, 1 part by weight or more. It may be 3 parts by weight or more, 5 parts by weight or more, 7 parts by weight or more, 10 parts by weight or more, or 15 parts by weight or more. Further, from the viewpoint of the cohesiveness of the pressure-sensitive adhesive layer before photo-curing and the handleability of the pressure-sensitive adhesive sheet, the amount of the compound B1 with respect to 100 parts by weight of the polymer (A) is usually preferably 80 parts by weight or less. It is preferably 60 parts by weight or less, 50 parts by weight or less, 40 parts by weight or less, and 35 parts by weight or less.

In some embodiments, the pressure-sensitive adhesive layer may contain, as the photoreactive monomer (B), compound B2 having two or more functional groups and having no intramolecular ring structure. Compound B2 is preferably used in combination with compound B1. Thereby, the crosslinked structure of the pressure-sensitive adhesive layer can be adjusted, and a bond having both deformation resistance and impact resistance can be formed more preferably. Compound B2 can be used alone or in combination of two or more.

The number of functional groups of compound B2 may be, for example, 50 or less, 40 or less, 30 or less, 20 or less, or 15 or less. The number of functional groups of compound B2 used in some embodiments may be, for example, 2-10, preferably 3-10, 3-8, or 4-6. .. For example, in an embodiment in which a compound having 2 functional groups is used as compound B1, it may be advantageous to use compound B2 having 3 or more functional groups (preferably 4 or more, more preferably 5 or more, still more preferably 6 or more). ..

The functional group equivalent of compound B2 is not particularly limited, and may be, for example, 5000 g / mol or less, 2000 g / mol or less, or 1000 g / mol or less. In some embodiments, the functional group equivalent of compound B2 may be, for example, 600 g / mol or less, 400 g / mol or less, or 300 g / mol or less from the viewpoint of improving photocurability and hardness of the cured product. , 200 g / mol or less, 150 g / mol or less, 100 g / mol or less. The functional group equivalent of compound B2 is typically 50 g / mol or more, preferably 60 g / mol or more, 70 g / mol or more, 80 g / mol or more, or 90 g / mol or more.

Examples of compounds that can be used as compound B2 include pentaerythritol trimethylolpropane (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, and dipentaerythritol hexa. (Meta) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane tetra (meth) acrylate, trimethylolethanetri (meth) acrylate, tetramethylolmethanetri (meth) acrylate, neopentyl glycol di (meth) acrylate, Includes neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, allyl (meth) acrylate, vinyl (meth) acrylate, EO-modified or PO-modified products of any of the above-mentioned materials, etc. However, it is not limited to these.

In the embodiment using the compound B2, the amount of the compound B2 with respect to 100 parts by weight of the polymer (A) contained in the pressure-sensitive adhesive layer is not particularly limited and may be, for example, 0.1 part by weight or more. From the viewpoint of facilitating the acquisition of a pressure-sensitive adhesive layer having both deformation resistance and impact resistance in a well-balanced manner, in some embodiments, the amount of compound B2 with respect to 100 parts by weight of the polymer (A) is, for example, 1 part by weight or more. It may be 2 parts by weight or more, 4 parts by weight or more, 6 parts by weight or more, 10 parts by weight or more, or 12 parts by weight or more. Further, from the viewpoint of suppressing a decrease in adhesion to the adherend due to excessive cross-linking, in some embodiments, the amount of compound B2 with respect to 100 parts by weight of the polymer (A) may be, for example, 25 parts by weight or less. It is suitable, preferably 17 parts by weight or less, 15 parts by weight or less, 13 parts by weight or less, and 9 parts by weight or less.

In the embodiment in which the compound B1 and the compound B2 are used in combination, the compound B2 is a compound having 3 or more functional groups and having a functional group equivalent smaller than the functional group equivalent of the compound B1 used in combination thereof. It can be preferably adopted. In some embodiments, the ratio of the functional group equivalent FE ₂ of compound B2 to the functional group equivalent FE ₁ of compound B1 (FE ₂ / FE ₁ ) may be, for example, 0.9 or less, or 0.7 or less. , 0.5 or less, or 0.4 or less. According to this aspect, the effect of improving the tensile elastic modulus by the photoreactive monomer (B) can be efficiently exhibited. The lower limit of the above ratio (FE ₂ / FE ₁ ) is not particularly limited, and may be, for example, 0.01 or more, 0.1 or more, or 0.2 or more.

In the embodiment in which the compound B1 and the compound B2 are used in combination, the weight ratio (W ₂ / W ₁ ) of the usage amount W ₂ of the compound B2 to the usage amount W ₁ of the compound B1 is not particularly limited. In some embodiments, the weight ratio (W ₂ / W ₁ ) may be, for example, 0.05-10, 0.1-5, 0.2-3, 0.3-2. It may be. By setting the weight ratio (W ₂ / W ₁ ) to any of the above ranges, the effect of using the compound B1 and the compound B2 in combination tends to be preferably exhibited.

In some aspects of the pressure-sensitive adhesive sheet disclosed herein, the photoreactive monomer (B) can be included in the pressure-sensitive adhesive layer in free form. Such a pressure-sensitive adhesive layer can be suitably formed by using a pressure-sensitive adhesive composition containing the photoreactive monomer (B) in a free form. Here, the "free form" means that the photoreactive monomer (B) is not chemically bonded to another component (for example, the polymer (A)) contained in the pressure-sensitive adhesive layer or the pressure-sensitive adhesive composition. .. The pressure-sensitive adhesive composition containing the photoreactive monomer (B) in a free form can be advantageous from the viewpoint of ease of preparation and suppression of gelation.

In some other form of the pressure-sensitive adhesive sheet disclosed herein, at least a part of the photoreactive monomer (B) is contained in the pressure-sensitive adhesive layer or the pressure-sensitive adhesive composition from the viewpoint of improving the processability of the pressure-sensitive adhesive sheet. It can be contained in the pressure-sensitive adhesive layer in the form of being chemically bonded to other components (for example, polymer (A), cross-linking agent described later, etc.). The chemical bond is, for example, a functional group F1 other than the ethylenically unsaturated group that the photoreactive monomer (B) has in the molecule, and a functional group that the other component has in the molecule and is the functional group F1. It can be a bond formed by reaction with a reactive functional group F2. The other component may be a cross-linking agent, and the photoreactive monomer (B) may be bonded to the polymer (A) via the cross-linking agent.

(Acrylic oligomer)
The pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet disclosed herein includes improved cohesive force, a surface adjacent to the pressure-sensitive adhesive layer (for example, the surface of a support on the pressure-sensitive adhesive sheet, the surface of an adherend to which the pressure-sensitive adhesive sheet is attached, and the like. From the viewpoint of improving the adhesiveness with (), an acrylic oligomer can be contained. The pressure-sensitive adhesive layer containing the acrylic oligomer can be preferably formed by using the pressure-sensitive adhesive composition containing the acrylic oligomer. As the acrylic oligomer, those having a higher Tg than the Tg of the polymer (A) described above can be preferably adopted.

The Tg of the acrylic oligomer is not particularly limited, and may be, for example, about 20 ° C. or higher and 300 ° C. or lower. The Tg may be, for example, about 30 ° C. or higher, about 40 ° C. or higher, about 60 ° C. or higher, about 80 ° C. or higher, or about 100 ° C. or higher. As the Tg of the acrylic oligomer increases, the effect of improving the cohesive force tends to increase in general. Further, from the viewpoint of anchoring property to the support, shock absorption, etc., the Tg of the acrylic oligomer may be, for example, about 250 ° C. or lower, about 200 ° C. or lower, about 180 ° C. or lower, or about 150 ° C. or lower. But it may be. The Tg of the acrylic oligomer is a value calculated based on the Fox formula, like the Tg of the polymer (A).

The Mw of the acrylic oligomer is not particularly limited, and may be, for example, about 1000 or more, usually about 1500 or more, about 2000 or more, or about 3000 or more. Further, the Mw of the acrylic oligomer may be, for example, less than about 30,000, usually less than about 10,000, may be less than about 7,000, and may be less than about 5,000. When Mw is within the above range, the effect of improving the cohesiveness of the pressure-sensitive adhesive layer and the adhesiveness with the adjacent surface is likely to be suitably exhibited. The Mw of the acrylic oligomer can be measured by gel permeation chromatography (GPC) and determined as a standard polystyrene-equivalent value. Specifically, for example, it can be measured in a tetrahydrofuran solvent at a flow rate of about 0.5 mL / min using TSKgelGMH-H (20) × 2 as a column on HPLC8020 manufactured by Tosoh Corporation.

Examples of the monomer components constituting the acrylic oligomer include the various (meth) acrylic acid C _1-20 alkyl esters described above; the various alicyclic hydrocarbon group-containing (meth) acrylates described above; and the various fragrances described above. Examples thereof include (meth) acrylate monomers containing a group hydrocarbon group; (meth) acrylate obtained from a terpene compound derivative alcohol; and the like. These can be used alone or in combination of two or more.

Acrylic oligomers include alkyl (meth) acrylates in which alkyl groups such as isobutyl (meth) acrylate and t-butyl (meth) acrylate have a branched structure; alicyclic hydrocarbon group-containing (meth) acrylate and aromatic hydrocarbons. It is preferable to contain an acrylic monomer having a relatively bulky structure as a monomer unit, such as a group-containing (meth) acrylate; from the viewpoint of improving adhesiveness. Further, when ultraviolet rays are used when synthesizing an acrylic oligomer or when producing an adhesive layer, a monomer having a saturated hydrocarbon group at the ester terminal is preferable because it is unlikely to cause polymerization inhibition, for example, alkyl. Alkyl (meth) acrylates having a branched group or saturated alicyclic hydrocarbon group-containing (meth) acrylates can be preferably used.

The ratio of the (meth) acrylate monomer to all the monomer components constituting the acrylic oligomer is typically more than 50% by weight, preferably 60% by weight or more, and more preferably 70% by weight or more (for example, 80% by weight). And more, 90% by weight or more). In a preferred embodiment, the acrylic oligomer has a monomer composition consisting substantially of only one or more (meth) acrylate monomers. For example, when the monomer component constituting the acrylic oligomer contains an alicyclic hydrocarbon group-containing (meth) acrylate and a (meth) acrylic acid C _1-20 alkyl ester, their weight ratios are not particularly limited. In some embodiments, the weight ratio of the alicyclic hydrocarbon group-containing (meth) acrylate / (meth) acrylic acid C _1-20 alkyl ester is, for example, 10/90 or higher, 20/80 or higher, or 30/70 or higher. It can also be 90/10 or less, 80/20 or less, or 70/30 or less.

As the constituent monomer component of the acrylic oligomer, in addition to the above (meth) acrylate monomer, a functional group-containing monomer can be used if necessary. Examples of the functional group-containing monomer include a monomer having a nitrogen atom-containing heterocycle such as N-vinyl-2-pyrrolidone and N-acryloylmorpholin; an amino group-containing monomer such as N, N-dimethylaminoethyl (meth) acrylate; N, Examples thereof include an amide group-containing monomer such as N-diethyl (meth) acrylamide; a carboxy group-containing monomer such as acrylic acid (AA) and methacrylic acid (MAA); and a hydroxyl group-containing monomer such as 2-hydroxyethyl (meth) acrylate. These functional group-containing monomers may be used alone or in combination of two or more. When a functional group-containing monomer is used, the ratio of the functional group-containing monomer to all the monomer components constituting the acrylic oligomer can be, for example, 1% by weight or more, 2% by weight or more, or 3% by weight or more, and also. For example, it can be 15% by weight or less, 10% by weight or less, or 7% by weight or less. The acrylic oligomer may be one in which a functional group-containing monomer is not used.

Suitable acrylic oligomers include, for example, dicyclopentanyl methacrylate (DCPMA), cyclohexyl methacrylate (CHMA), isobornyl methacrylate (IBXMA), isobornyl acrylate (IBXA), dicyclopentanyl acrylate (DCPA), and the like. In addition to 1-adamantyl methacrylate (ADAM) and 1-adamantyl acrylate (ADA) homopolymers, DCPMA and MMA copolymers, DCPMA and IBXMA copolymers, and ADA and methyl methacrylate (MMA) copolymer weights. Combined, a polymer of CHMA and isobutyl methacrylate (IBMA), a polymer of CHMA and IBXMA, a polymer of CHMA and acryloylmorpholin (ACMO), a polymer of CHMA and diethylacrylamide (DEAA), Examples thereof include a copolymer of CHMA and AA.

Acrylic oligomers can be formed by polymerizing their constituent monomer components. The polymerization method and the polymerization mode are not particularly limited, and various conventionally known polymerization methods (for example, solution polymerization, emulsion polymerization, bulk polymerization, photopolymerization, radiation polymerization, etc.) can be adopted in an appropriate manner. The types of polymerization initiators (for example, azo-based polymerization initiators) that can be used as needed are generally as illustrated for the synthesis of the acrylic polymer (A), and the amount of the polymerization initiator and the chain that is arbitrarily used. Since the amount of the transfer agent (for example, mercaptans) is appropriately set based on the common general knowledge so as to have a desired molecular weight, detailed description thereof will be omitted.

When the pressure-sensitive adhesive layer or the pressure-sensitive adhesive composition contains an acrylic oligomer, the content thereof can be, for example, 0.01 part by weight or more with respect to 100 parts by weight of the polymer (A), and a higher effect can be obtained. From the viewpoint of obtaining, it may be 0.05 parts by weight or more, 0.1 parts by weight or more, or 0.2 parts by weight or more. From the viewpoint of compatibility with the polymer (A), the content of the acrylic oligomer with respect to 100 parts by weight of the polymer (A) is usually preferably less than 50 parts by weight, preferably 30 parts by weight. Less than, more preferably 25 parts by weight or less, for example, 10 parts by weight or less, 5 parts by weight or less, or 1 part by weight or less. It may be a pressure-sensitive adhesive layer or a pressure-sensitive adhesive composition that does not contain an acrylic oligomer.

The pressure-sensitive adhesive layer or pressure-sensitive adhesive composition of the pressure-sensitive adhesive sheet disclosed herein includes, if necessary, a pressure-imparting resin (for example, a rosin-based, petroleum-based, terpene-based, phenol-based, ketone-based, or other tack-imparting resin). Various additions common in the field of adhesives such as viscosity modifiers (for example, thickeners), leveling agents, plasticizers, fillers, colorants such as pigments and dyes, stabilizers, preservatives, anti-aging agents, etc. The agent may be included as any other optional ingredient. As for such various additives, conventionally known ones can be used by a conventional method and do not particularly characterize the present invention, and thus detailed description thereof will be omitted.
It should be noted that the technique disclosed herein can exhibit good adhesive strength without using the above-mentioned tackifier resin. Therefore, in some embodiments, the content of the tackifier resin in the pressure-sensitive adhesive layer or the pressure-sensitive adhesive composition is, for example, less than 10 parts by weight, or even 5 parts by weight, based on 100 parts by weight of the polymer (A). Can be less than. The content of the tackifier resin may be less than 1 part by weight (for example, less than 0.5 parts by weight) or less than 0.1 parts by weight (0 parts by weight or more and less than 0.1 parts by weight). Good. The pressure-sensitive adhesive layer or pressure-sensitive adhesive composition may not contain a tackifier resin.

When the pressure-sensitive adhesive sheet disclosed herein is used for optical purposes, the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet may have predetermined optical properties (for example, transparency). From the viewpoint of such optical properties, other than the polymer (A) occupying the pressure-sensitive adhesive layer (and thus the pressure-sensitive adhesive composition used for forming the pressure-sensitive adhesive layer) and the above-mentioned photoreactive monomer (B) used as necessary. The amount of the component of is preferably limited. In the techniques disclosed herein, the amount of components other than the polymer (A) and the photoreactive monomer (B) in the pressure-sensitive adhesive layer is usually about 30% by weight or less, and about 15% by weight or less. It is suitable, preferably about 12% by weight or less (for example, about 10% by weight or less). In the pressure-sensitive adhesive sheet according to one embodiment, the amount of the components other than the polymer (A) and the photoreactive monomer (B) in the pressure-sensitive adhesive layer may be about 5% by weight or less, and may be about 3% by weight or less. It may be about 1.5% by weight or less (for example, about 1% by weight or less).

(Crosslinking agent)
A cross-linking agent may be used for the pressure-sensitive adhesive layer, if necessary. In the pressure-sensitive adhesive sheets disclosed herein, the cross-linking agent is typically included in the pressure-sensitive adhesive layer in the form after the cross-linking reaction. By using a cross-linking agent, the cohesive force of the pressure-sensitive adhesive layer and the like can be appropriately adjusted. Further, in a pressure-sensitive adhesive sheet containing a photoreactive monomer (B) in the pressure-sensitive adhesive layer, by using a cross-linking agent and a photoreactive monomer (B) in combination, the pressure-sensitive adhesive before photocuring of the photoreactive monomer. The flexibility of the layer and the deformation resistance of the pressure-sensitive adhesive layer after photocuring can be suitably compatible with each other.

The type of the cross-linking agent is not particularly limited, and is selected from the conventionally known cross-linking agents so that the cross-linking agent exhibits an appropriate cross-linking function in the pressure-sensitive adhesive layer, for example, depending on the composition of the pressure-sensitive adhesive composition. be able to. Examples of the cross-linking agent that can be used include isocyanate-based cross-linking agents, epoxy-based cross-linking agents, oxazoline-based cross-linking agents, aziridine-based cross-linking agents, carbodiimide-based cross-linking agents, melamine-based cross-linking agents, urea-based cross-linking agents, metal alkoxide-based cross-linking agents, and metals. Examples thereof include a chelate-based cross-linking agent, a metal salt-based cross-linking agent, a hydrazine-based cross-linking agent, and an amine-based cross-linking agent. These can be used alone or in combination of two or more.

As the isocyanate-based cross-linking agent, a polyfunctional isocyanate compound having two or more functions can be used. For example, aromatic isocyanates such as tolylene diisocyanate, xylene diisocyanate, polymethylene polyphenyl diisocyanate, tris (p-isocyanatophenyl) thiophosphate, diphenylmethane diisocyanate; alicyclic isocyanates such as isophorone diisocyanate; aliphatic isocyanates such as hexamethylene diisocyanate. Isocyanate; etc. Commercially available products include trimethylolpropane / tolylene diisocyanate trimer adduct (manufactured by Toso Co., Ltd., trade name "Coronate L") and trimethylolpropane / hexamethylene diisocyanate trimer adduct (manufactured by Toso Co., Ltd., trade name "Coronate L"). Coronate HL "), isocyanurate of hexamethylene diisocyanate (manufactured by Toso Co., Ltd., trade name" Coronate HX "), trimethylolpropane / xylylene diisocyanate adduct (manufactured by Mitsui Chemicals Co., Ltd., trade name" Takenate D-110N "), etc. Isocyanate adducts and the like can be exemplified.

As the epoxy-based cross-linking agent, one having two or more epoxy groups in one molecule can be used without particular limitation. An epoxy-based cross-linking agent having 3 to 5 epoxy groups in one molecule is preferable. Specific examples of the epoxy-based cross-linking agent include N, N, N', N'-tetraglycidyl-m-xylene diamine, 1,3-bis (N, N-diglycidyl aminomethyl) cyclohexane, and 1,6-hexane. Examples thereof include diol diglycidyl ether, polyethylene glycol diglycidyl ether, and polyglycerol polyglycidyl ether. Commercially available epoxy cross-linking agents include Mitsubishi Gas Chemical's product names "TETRAD-X" and "TETRAD-C", DIC's product name "Epicron CR-5L", and Nagase ChemteX's products. Examples thereof include the name "Denacol EX-512" and the product name "TEPIC-G" manufactured by Nissan Chemical Industries, Ltd.

As the oxazoline-based cross-linking agent, those having one or more oxazoline groups in one molecule can be used without particular limitation.
Examples of aziridine-based cross-linking agents include trimethylolpropane tris [3- (1-aziridinyl) propionate], trimethylolpropane tris [3- (1- (2-methyl) aziridinyl propionate)], and the like. Be done.
As the carbodiimide-based cross-linking agent, a low molecular weight compound or a high molecular weight compound having two or more carbodiimide groups can be used.

Peroxide may be used as the cross-linking agent in some embodiments. Peroxides include di (2-ethylhexyl) peroxydicarbonate, di (4-t-butylcyclohexyl) peroxydicarbonate, di-sec-butylperoxydicarbonate, and t-butylperoxyneodecanoate. , T-hexyl peroxypivalate, t-butylperoxypivalate, dilauroyl peroxide, di-n-octanoyl peroxide, 1,1,3,3-tetramethylbutylperoxyisobutyrate, di Examples thereof include benzoyl peroxide. Among these, examples of peroxides having particularly excellent cross-linking reaction efficiency include di (4-t-butylcyclohexyl) peroxydicarbonate, dilauroyl peroxide, and dibenzoyl peroxide. When a peroxide is used as the polymerization initiator, the peroxide remaining without being used in the polymerization reaction can be used in the crosslinking reaction. In that case, the residual amount of peroxide may be quantified, and if the ratio of peroxide is less than a predetermined amount, the peroxide may be added so as to be a predetermined amount, if necessary. The amount of peroxide can be quantified by the method described in Japanese Patent No. 4971517.

The amount used when a cross-linking agent is used (when two or more kinds of cross-linking agents are used, the total amount thereof) is not particularly limited. From the viewpoint of realizing a pressure-sensitive adhesive that exhibits a well-balanced adhesive property such as adhesive strength and cohesive power, the amount of the cross-linking agent used should be about 5 parts by weight or less with respect to 100 parts by weight of the polymer (A). It may be 3 parts by weight or less, 2 parts by weight or less, 1 part by weight or less, or less than 1 part by weight. In the embodiment in which the cross-linking agent and the photoreactive monomer (B) are used in combination, the amount of the cross-linking agent used with respect to 100 parts by weight of the polymer (A) is, for example, from the viewpoint of facilitating the effect of the combined use. It may be 0.80 parts by weight or less, 0.60 parts by weight or less, 0.30 parts by weight or less, or 0.10 parts by weight or less. The lower limit of the amount of the cross-linking agent used is not particularly limited, and it can be used in an amount larger than 0 parts by weight with respect to 100 parts by weight of the polymer (A). In some embodiments, the amount of the cross-linking agent used may be, for example, 0.001 part by weight or more, 0.01 parts by weight or more, and 0.03 parts by weight, based on 100 parts by weight of the polymer (A). It may be more than a part by weight.

The technique disclosed herein can be preferably carried out in a mode in which at least an isocyanate-based cross-linking agent is used as the cross-linking agent. An isocyanate-based cross-linking agent and another cross-linking agent may be used in combination. In the embodiment using the isocyanate-based cross-linking agent, the amount of the isocyanate-based cross-linking agent used with respect to 100 parts by weight of the polymer (A) may be, for example, 0.005 parts by weight or more, 0.01 parts by weight or more, and 0.03. It may be more than a part by weight. The amount of the isocyanate-based cross-linking agent used with respect to 100 parts by weight of the polymer (A) may be, for example, 10 parts by weight or less, 5 parts by weight or less, 3 parts by weight or less, or less than 2 parts by weight. It may be less than 1 part by weight, less than 0.80 parts by weight, less than 0.60 parts by weight, less than 0.30 parts by weight, less than 0.10 parts by weight, less than 0.08 parts by weight. Good.

A cross-linking catalyst may be used to allow the cross-linking reaction to proceed more effectively. Examples of the cross-linking catalyst include metal-based cross-linking catalysts such as tetra-n-butyl titanate, tetraisopropyl titanate, ferric nasem, butyl tin oxide, and dioctyl tin dilaurate. Of these, tin-based cross-linking catalysts such as dioctyl tin dilaurate are preferable. The amount of the cross-linking catalyst used is not particularly limited. The amount of the cross-linking catalyst used can be, for example, about 0.0001 parts by weight or more, about 0.001 parts by weight or more, about 0.005 parts by weight or more, etc. with respect to 100 parts by weight of the polymer (A). It can be about 1 part by weight or less, about 0.1 part by weight or less, about 0.05 part by weight or less, and the like.

The pressure-sensitive adhesive composition used to form the pressure-sensitive adhesive layer can optionally contain a compound that causes keto-enol tautomerism as a cross-linking retarder. For example, in a pressure-sensitive adhesive composition containing an isocyanate-based cross-linking agent or a pressure-sensitive adhesive composition that can be used by blending an isocyanate-based cross-linking agent, a compound that causes keto-enol tautomerism can be preferably used. As a result, the effect of extending the pot life of the pressure-sensitive adhesive composition can be exhibited.
Various β-dicarbonyl compounds can be used as the compound that causes keto-enol tvariability. Specific examples include β-diketones such as acetylacetone and 2,4-hexanedione; acetoacetate esters such as methyl acetoacetate and ethyl acetoacetate; propionyl acetates such as ethyl propionyl acetate; isobutylyl such as ethyl isobutylyl acetate. Acetic acid esters; malonic acid esters such as methyl malonate and ethyl malonate; and the like. Among them, acetylacetone and acetoacetic ester are preferable compounds. The compounds that cause keto-enol tautomerism can be used alone or in combination of two or more.
The amount of the compound that causes keto-enol tvariability may be, for example, 0.1 part by weight or more and 20 parts by weight or less, and usually 0.5 parts by weight or more and 15 parts by weight, based on 100 parts by weight of the polymer (A). It is appropriate that the weight is 1 part by weight or less, for example, 1 part by weight or more and 10 parts by weight or less, and 1 part by weight or more and 5 parts by weight or less.

(Silane coupling agent)
The pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet disclosed herein may contain a silane coupling agent, if desired. By using a silane coupling agent, the peel strength of the pressure-sensitive adhesive sheet from an adherend (for example, a glass plate) can be improved. The pressure-sensitive adhesive layer containing the silane coupling agent can be suitably formed by using the pressure-sensitive adhesive composition containing the silane coupling agent. In such a pressure-sensitive adhesive composition, the silane coupling agent is preferably contained in the pressure-sensitive adhesive composition in a free form from the viewpoint of suppressing gelation and the like. Further, in some embodiments, the silane coupling agent is preferably contained in the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet disclosed herein in a free form. The silane coupling agent contained in the pressure-sensitive adhesive layer in such a form can effectively contribute to the improvement of the peeling force. The term "free form" as used herein means that the silane coupling agent is not chemically bonded to the pressure-sensitive adhesive composition or other components contained in the pressure-sensitive adhesive layer.

Examples of the silane coupling agent include silicon compounds having an epoxy structure such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane; Amino group-containing silicon compounds such as 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) 3-aminopropylmethyldimethoxysilane; 3-chloro Propyltrimethoxysilane; acetoacetyl group-containing trimethoxysilane; (meth) acrylic group-containing silane coupling agent such as 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane; 3-isocyanatepropyltriethoxysilane Such as isocyanate group-containing silane coupling agent; and the like. In some embodiments, the above effects can be more preferably exerted by adopting a silane coupling agent having a trialkoxysilyl group. Among them, 3-glycidoxypropyltrimethoxysilane and acetoacetyl group-containing trimethoxysilane are exemplified as preferable silane coupling agents.

The amount of the silane coupling agent used can be set so as to obtain the desired effect, and is not particularly limited. In some embodiments, the amount of the silane coupling agent used may be, for example, 0.001 part by weight or more with respect to 100 parts by weight of the polymer (A), and 0.01 part by weight from the viewpoint of obtaining a higher effect. It may be more than 0.05 parts by weight, or 0.1 parts by weight or more. Further, from the viewpoint of suppressing gelation of the pressure-sensitive adhesive composition, it is usually appropriate that the amount of the silane coupling agent used with respect to 100 parts by weight of the polymer (A) is 3 parts by weight or less, and 1 part by weight or less. It may be 0.5 parts by weight or less.

(Photopolymerization initiator)
The pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet disclosed herein may contain a photopolymerization initiator, if necessary, for the purpose of improving or imparting photocurability. Examples of the photopolymerization initiator include a ketal-based photopolymerization initiator, an acetophenone-based photopolymerization initiator, and a benzoin ether-based photopolymerization initiator, as in the case of the photopolymerization initiator exemplified as being usable for the synthesis of the polymer (A). Acylphosphine oxide-based photopolymerization initiator, α-ketol-based photopolymerization initiator, aromatic sulfonyl chloride-based photopolymerization initiator, photoactive oxime-based photopolymerization initiator, benzoin-based photopolymerization initiator, benzyl-based photopolymerization initiator , Benzophenone-based photopolymerization initiator, thioxanthone-based photopolymerization initiator and the like can be used. The photopolymerization initiator may be used alone or in combination of two or more.

Specific examples of the ketal-based photopolymerization initiator include 2,2-dimethoxy-1,2-diphenylethane-1-one and the like.
Specific examples of the acetophenone-based photopolymerization initiator include 1-hydroxycyclohexyl-phenyl-ketone, 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, 1- [4- (2-hydroxyethoxy) -phenyl]. -2-Hydroxy-2-methyl-1-propane-1-one, 2-hydroxy-2-methyl-1-phenyl-propane-1-one, methoxyacetophenone and the like are included.
Specific examples of the benzoin ether-based photopolymerization initiator include benzoin ethers such as benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether and benzoin isobutyl ether, and substituted benzoin ethers such as anisole methyl ether.
Specific examples of the acylphosphine oxide-based photopolymerization initiator include bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide and bis (2,4,6-trimethylbenzoyl) -2,4-di-n-butoxy. Includes phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide and the like.
Specific examples of the α-ketol-based photopolymerization initiator include 2-methyl-2-hydroxypropiophenone, 1- [4- (2-hydroxyethyl) phenyl] -2-methylpropan-1-one, and the like. Is done. Specific examples of the aromatic sulfonyl chloride-based photopolymerization initiator include 2-naphthalene sulfonyl chloride and the like. Specific examples of the photoactive oxime-based photopolymerization initiator include 1-phenyl-1,1-propanedione-2- (o-ethoxycarbonyl) -oxime and the like. Specific examples of the benzoin-based photopolymerization initiator include benzoin and the like. Specific examples of the benzyl-based photopolymerization initiator include benzyl and the like.
Specific examples of the benzophenone-based photopolymerization initiator include benzophenone, benzoylbenzoic acid, 3,3'-dimethyl-4-methoxybenzophenone, polyvinylbenzophenone, α-hydroxycyclohexylphenyl ketone and the like.
Specific examples of the thioxanthone-based photopolymerization initiator include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, and isopropylthioxanthone. , 2,4-Diisopropylthioxanthone, dodecylthioxanthone and the like.

The content of the photopolymerization initiator in the pressure-sensitive adhesive layer is not particularly limited, and can be set so that the desired effect is appropriately exhibited. In some embodiments, the content of the photopolymerization initiator can be, for example, approximately 0.005 parts by weight or more with respect to 100 parts by weight of the polymer (A) contained in the pressure-sensitive adhesive layer, and is usually 0. It is appropriate to have 0.01 parts by weight or more, preferably 0.05 parts by weight or more, 0.10 parts by weight or more, 0.15 parts by weight or more, and 0.20 parts by weight. The above may be applied. As the content of the photopolymerization initiator increases, the photocurability of the pressure-sensitive adhesive layer tends to improve. The content of the photopolymerization initiator with respect to 100 parts by weight of the polymer (A) is usually preferably 10 parts by weight or less, preferably 7 parts by weight or less, and may be 5 parts by weight or less. It may be 3 parts by weight or less, 2 parts by weight or less, or 1 part by weight or less. Not too much content of the photopolymerization initiator can be advantageous from the viewpoint of improving the storage stability (for example, stability against photodegradation) of the pressure-sensitive adhesive sheet.

The pressure-sensitive adhesive layer containing the photopolymerization initiator can be typically formed by using a pressure-sensitive adhesive composition containing the photopolymerization initiator (for example, a solvent-type pressure-sensitive adhesive composition). The pressure-sensitive adhesive composition containing the photopolymerization initiator can be prepared, for example, by mixing other components used in the composition with the photopolymerization initiator. When a pressure-sensitive adhesive composition is prepared using a polymer (A) synthesized (photopolymerized) in the presence of a photopolymerization initiator (for example, an acrylic polymer (A)), the polymer (A) The residue (unreacted product) of the photopolymerization initiator used in synthesizing the above may be used as a part or all of the photopolymerization initiator contained in the pressure-sensitive adhesive layer. The same applies to the case where an acrylic oligomer synthesized in the presence of a photopolymerization initiator is used as an acrylic oligomer used as needed. From the viewpoint of ease of production control, the pressure-sensitive adhesive layer disclosed herein is preferably formed by using a pressure-sensitive adhesive composition prepared by newly adding the above-mentioned amount of the photopolymerization initiator to other components. Can be done.

In addition, the pressure-sensitive adhesive layer in the technique disclosed herein is a leveling agent, a plasticizer, a softening agent, a colorant (dye, pigment, etc.), a filler, and an antioxidant, as long as the effects of the present invention are not significantly impaired. , Antioxidants, UV absorbers, Antioxidants, Light Stabilizers, Preservatives, and other known additives that can be used in adhesives may be included, if necessary. It is desirable to avoid the use of silicone-based additives (for example, silicone-based leveling agents and defoaming agents) in pressure-sensitive adhesive sheets for applications that dislike the inclusion of siloxane (for example, applications for manufacturing electronic devices).

<Formation of adhesive layer>
The pressure-sensitive adhesive layer constituting the pressure-sensitive adhesive sheet disclosed herein can be a cured layer of a pressure-sensitive adhesive composition containing the corresponding component. That is, the pressure-sensitive adhesive layer is subjected to drying (for example, heat-drying), cross-linking (for example, cross-linking by the reaction of the above-mentioned cross-linking agent), cooling, etc. after applying (for example, coating) the pressure-sensitive adhesive composition to an appropriate surface. It can be formed by appropriately performing a curing treatment. When performing two or more types of curing treatments, these can be performed simultaneously or in stages.

In some embodiments, the pressure-sensitive adhesive composition contains at least one of the polymers (A) described above. The pressure-sensitive adhesive composition according to a preferred embodiment contains an acrylic polymer (A) as the polymer (A). The pressure-sensitive adhesive composition may contain the polymer (A) in the form of a precursor thereof. The pressure-sensitive adhesive composition preferably contains any of the above-mentioned polymers (A) and any of the above-mentioned photoreactive monomers (B). The photoreactive monomer (B) preferably contains a compound B1 having a ring structure and two or more ethylenically unsaturated groups in the molecule. The compound B1 preferably has a molecular weight of 100 g / mol or more per ethylenically unsaturated group.

The form of the pressure-sensitive adhesive composition is not particularly limited. For example, a water-dispersed pressure-sensitive adhesive composition in which a pressure-sensitive adhesive (adhesive component) is dispersed in water, or a solvent-type pressure-sensitive adhesive in which the pressure-sensitive adhesive is contained in an organic solvent. The composition may be in various conventionally known forms such as a hot melt type pressure-sensitive adhesive composition which is coated in a heat-melted state and forms a pressure-sensitive adhesive when cooled to around room temperature. From the viewpoint of ease of preparation of the pressure-sensitive adhesive composition, ease of formation of the pressure-sensitive adhesive layer, and the like, the solvent-type pressure-sensitive adhesive composition can be preferably adopted in some embodiments. The solvent-based pressure-sensitive adhesive composition can be preferably prepared using the polymer (A), which is a polymer obtained by solution polymerization of the monomer components.

The pressure-sensitive adhesive composition can be applied using, for example, a conventional coater such as a gravure roll coater, a reverse roll coater, a kiss roll coater, a dip roll coater, a bar coater, a knife coater, or a spray coater. In the pressure-sensitive adhesive sheet having a support, as a method of providing the pressure-sensitive adhesive layer on the support, a direct method of directly applying the pressure-sensitive adhesive composition to the support to form the pressure-sensitive adhesive layer may be used, and peeling may be used. A transfer method may be used in which the pressure-sensitive adhesive layer formed on the surface is transferred to the support.

The thickness of the pressure-sensitive adhesive layer is not particularly limited, and may be, for example, about 3 μm to 500 μm. From the viewpoint of impact resistance, in some embodiments, the thickness of the pressure-sensitive adhesive layer is preferably 5 μm or more, preferably 10 μm or more, and more preferably 15 μm or more. Further, in some embodiments, the thickness of the pressure-sensitive adhesive layer may be, for example, 200 μm or less, preferably 120 μm or less from the viewpoint of suppressing deformation of the pressure-sensitive adhesive layer, and may be 100 μm or less, or 70 μm or less. , 50 μm or less, or 35 μm or less. According to the pressure-sensitive adhesive sheet disclosed herein, a bond having high deformation resistance and high impact resistance can be formed in an embodiment including a pressure-sensitive adhesive layer having a thickness of, for example, 70 μm or less.

<Support>
The pressure-sensitive adhesive sheet according to some aspects may be in the form of a pressure-sensitive adhesive sheet with a support including a support bonded to the pressure-sensitive adhesive layer. The material of the support is not particularly limited, and can be appropriately selected depending on the purpose and mode of use of the adhesive sheet. Non-limiting examples of supports that can be used include a polyolefin film containing a polyolefin such as polypropylene or an ethylene-propylene copolymer as a main component, a polyester film containing a polyester such as polyethylene terephthalate or polybutylene terephthalate as a main component, and the like. Resin film such as polyvinyl chloride film containing polyvinyl chloride as the main component; foam sheet made of foam such as polyurethane foam, polyethylene foam, polychloroprene foam; various fibrous substances (natural fibers such as hemp and cotton, Woven fabrics and non-woven fabrics made of synthetic fibers such as polyester and vinylon, semi-synthetic fibers such as acetate, etc.) alone or by blending; papers such as Japanese paper, high-quality paper, kraft paper, crepe paper; aluminum foil, copper Metal foils such as foils; and the like. The support may be a composite structure of these. Examples of a support having such a composite structure include a metal layer (for example, a metal foil, a continuous or discontinuous metal sputter layer, a metal vapor deposition layer, a metal plating layer, etc.), a metal oxide layer, and the above resin film. Examples thereof include a support having a structure in which and is laminated, and a resin sheet reinforced with an inorganic fiber such as a glass cloth. The support may correspond to an optical member (for example, an optical film) described later, or may be a transparent member formed of a transparent material (for example, a transparent resin material or glass). Good.

As the support of the adhesive sheet disclosed here, various films (hereinafter, also referred to as support films) can be preferably used. The support film may be a porous film such as a foam film or a non-woven fabric sheet, or may be a non-porous film, and the porous layer and the non-porous layer are laminated. It may be a film having a structure. In some embodiments, as the support film, a film containing an independently shape-maintainable (self-supporting or independent) resin film as a base film can be preferably used. As used herein, the term "resin film" means a resin film (of voidless) having a non-porous structure and typically containing substantially no bubbles. Therefore, the resin film is a concept that is distinguished from foam films and non-woven fabrics. The resin film may have a single-layer structure or a multi-layer structure having two or more layers (for example, a three-layer structure).

Examples of the resin material constituting the resin film include polycycloolefin derived from a monomer having an aliphatic ring structure such as polyester, polyolefin, and norbornene structure, nylon 6, nylon 66, and polyamide (PA) such as partially aromatic polyamide. , Polyamide (PI), Polyamideimide (PAI), Polyetheretherketone (PEEK), Polyethersulfone (PES), Polyphenylene sulfide (PPS), Polycarbonate (PC), Polyurethane (PU), Ethylene-vinyl acetate copolymer (EVA), polystyrene, polyvinyl chloride, polyvinylidene chloride, fluororesin such as polytetrafluoroethylene (PTFE), acrylic resin such as polymethylmethacrylate, cellulose-based polymer such as diacetylcellulose and triacetylcellulose, vinyl butyral polymer. , Arilate-based polymer, polyoxymethylene-based polymer, epoxy-based polymer and other resins can be used. The resin film may be formed by using a resin material containing one kind of such a resin alone, or may be formed by using a resin material in which two or more kinds are blended. May be good. The resin film may be unstretched or stretched (for example, uniaxially stretched or biaxially stretched).

Preferable examples of the resin material constituting the resin film include polyester resin, PPS resin and polyolefin resin. Here, the polyester-based resin refers to a resin containing polyester in a proportion of more than 50% by weight. Similarly, the PPS resin refers to a resin containing PPS in a proportion of more than 50% by weight, and the polyolefin-based resin refers to a resin containing polyolefin in a proportion of more than 50% by weight.

As the polyester resin, a polyester resin containing polyester obtained by polycondensing a dicarboxylic acid and a diol as a main component is typically used. Specific examples of the polyester resin include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polybutylene naphthalate and the like.

As the polyolefin resin, one kind of polyolefin can be used alone, or two or more kinds of polyolefins can be used in combination. The polyolefin can be, for example, a homopolymer of α-olefin, a copolymer of two or more kinds of α-olefins, a copolymer of one kind or two or more kinds of α-olefins and another vinyl monomer, and the like. Specific examples include ethylene-propylene copolymers such as polyethylene (PE), polypropylene (PP), poly-1-butene, poly-4-methyl-1-pentene, and ethylene propylene rubber (EPR), and ethylene-propylene-. Examples thereof include butene copolymers, ethylene-butene copolymers, ethylene-vinyl alcohol copolymers and ethylene-ethyl acrylate copolymers. Both low density (LD) polyolefins and high density (HD) polyolefins can be used. Examples of polyolefin resin films include unstretched polypropylene (CPP) film, biaxially stretched polypropylene (OPP) film, low density polyethylene (LDPE) film, linear low density polyethylene (LLDPE) film, medium density polyethylene (MDPE). Examples thereof include a film, a high-density polyethylene (HDPE) film, a polyethylene (PE) film in which two or more types of polyethylene (PE) are blended, and a PP / PE blend film in which polypropylene (PP) and polyethylene (PE) are blended.

Specific examples of the resin film that can be preferably used as the support include PET film, PEN film, PPS film, PEEK film, CPP film and OPP film. Preferred examples from the viewpoint of strength include PET film, PEN film, PPS film and PEEK film. A PET film is mentioned as a preferable example from the viewpoint of availability, dimensional stability, optical characteristics and the like.

Known additives such as light stabilizers, antioxidants, antistatic agents, colorants (dye, pigment, etc.), fillers, slip agents, antiblocking agents, etc. shall be added to the resin film, if necessary. Can be done. The blending amount of the additive is not particularly limited, and can be appropriately set according to the use of the pressure-sensitive adhesive sheet and the like.

The manufacturing method of the resin film is not particularly limited. For example, conventionally known general resin film molding methods such as extrusion molding, inflation molding, T-die casting molding, and calender roll molding can be appropriately adopted.

The support can be a support film substantially composed of such a resin film. Further, the support may be a support film including an auxiliary layer in addition to the resin film. The auxiliary layer may be arranged on the pressure-sensitive adhesive layer side of the resin film, may be arranged on the side opposite to the pressure-sensitive adhesive layer, or may be arranged on both sides of the resin film. Examples of the auxiliary layers include an optical property adjusting layer (eg, a tinted layer, an antireflection layer), a decorative layer that imparts the desired appearance to the support or adhesive sheet (eg, a printed layer, a laminated layer, continuous or non-continuous). (Continuous metal layer, continuous or discontinuous metal oxide layer, etc.), conductive layer, antistatic layer, undercoat layer, release layer, and the like.

The thickness of the support is not particularly limited and can be selected according to the purpose and mode of use of the adhesive sheet. The thickness of the support may be, for example, 1000 μm or less, 500 μm or less, 100 μm or less, 70 μm or less, 50 μm or less, 25 μm or less, 10 μm or less, or 5 μm or less. As the thickness of the support becomes smaller, the flexibility of the adhesive sheet and the ability to follow the surface shape of the adherend tend to improve. Further, from the viewpoint of handleability, workability and the like, the thickness of the support may be, for example, 2 μm or more, and may be 5 μm or more or 10 μm or more. In some embodiments, the thickness of the support may be, for example, 20 μm or greater, 35 μm or greater, or 55 μm or greater.

Corona discharge treatment, plasma treatment, ultraviolet irradiation treatment, acid treatment, alkali treatment, undercoating agent (primer) application, antistatic treatment, if necessary, on the surface of the support on the side bonded to the adhesive layer. Such as, conventionally known surface treatment may be applied. Such a surface treatment may be a treatment for improving the adhesion between the support and the pressure-sensitive adhesive layer, in other words, the anchoring property of the pressure-sensitive adhesive layer on the support. The composition of the primer is not particularly limited and can be appropriately selected from known ones. The thickness of the undercoat layer is not particularly limited, but is usually about 0.01 μm to 1 μm, preferably about 0.1 μm to 1 μm.

In a single-sided pressure-sensitive adhesive sheet with a support, the side surface of the support opposite to the side bonded to the pressure-sensitive adhesive layer (hereinafter, also referred to as the back surface) is peeled, adhesively or adhesively applied as necessary. Conventionally known surface treatments such as improvement treatment and antistatic treatment may be applied. For example, by surface-treating the back surface of the support with a release treatment agent, the rewinding force of the adhesive sheet in the form of being wound in a roll shape can be reduced. As the stripping agent, a silicone-based stripping agent, a long-chain alkyl-based stripping agent, an olefin-based stripping agent, a fluorine-based stripping agent, a fatty acid amide-based stripping agent, molybdenum sulfide, silica powder, or the like can be used. ..

<Manufacturing method of laminate>
The pressure-sensitive adhesive sheet disclosed herein can be preferably used in an embodiment in which the pressure-sensitive adhesive layer is photo-cured after being bonded to the adherend and then adhered to the adherend. By adhering the adhesive sheet to the adherend, an adherend on which the adhesive sheets are laminated is formed. By photocuring the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet, a laminate containing the pressure-sensitive adhesive sheet with the cured pressure-sensitive adhesive layer and the adherend can be obtained. Therefore, according to this specification, one of the pressure-sensitive adhesive sheets disclosed herein is attached to an adherend, and the pressure-sensitive adhesive sheet is irradiated with ultraviolet rays to photo-cure the pressure-sensitive adhesive layer. A method for producing a laminate including the above is provided.

<Use>
The pressure-sensitive adhesive sheet disclosed herein can be used for fixing, joining, molding, decorating, protecting, supporting and the like of members constituting various products. The material constituting at least the surface of the member is, for example, glass such as alkaline glass or non-alkali glass; metal material such as stainless steel (SUS) and aluminum; resin material such as acrylic resin, ABS resin, polycarbonate resin and polystyrene resin. It can be; etc. The member may be, for example, a member constituting various portable devices (portable devices), automobiles, home appliances, and the like. Further, in the above member, the surface to which the adhesive sheet is attached is acrylic, polyester, alkyd, melamine, urethane, acid-epoxy crosslinked, or a composite of these (for example, acrylic melamine, alkyd melamine). ) And the like, or a plated surface such as a zinc-plated steel plate. Further, the member is any support film exemplified as a material that can be used for the support (for example, a resin film or a continuous or discontinuous inorganic layer (metal layer, metal oxide layer, etc.) on the resin film. It may be a support film) having. The pressure-sensitive adhesive sheet disclosed herein can be, for example, a component of a member with a pressure-sensitive adhesive sheet in which the member is bonded to at least one surface of the pressure-sensitive adhesive layer constituting the pressure-sensitive adhesive layer.

An example of a preferable application is an optical application. More specifically, it is disclosed here as, for example, an optical adhesive sheet used for bonding optical members (for bonding optical members), manufacturing products using the above optical members (optical products), and the like. The adhesive sheet to be used can be preferably used.

The optical member is a member having optical characteristics (for example, polarization, light refraction, light scattering, light reflectivity, light transmission, light absorption, light diffractivity, light turning property, visibility, etc.). Say. The optical member is not particularly limited as long as it has optical characteristics, but is used, for example, as a member constituting a device (optical device) such as a display device (image display device) or an input device, or a member thereof. Members include, for example, polarizing plates, wavelength plates, retardation plates, optical compensation films, brightness improving films, light guide plates, reflective films, antireflection films, hard coat (HC) films, shock absorbing films, antifouling films, etc. Photochromic film, light control film, transparent conductive film (ITO film), design film, decorative film, surface protection plate, prism, lens, color filter, transparent substrate, and members in which these are laminated (collectively referred to as these). (Sometimes referred to as "functional film") and the like. The above-mentioned "plate" and "film" shall include a plate-like, a film-like, a sheet-like form, respectively, and for example, the "polarizing film" shall include a "polarizing plate", a "polarizing sheet" and the like. ..

Examples of the display device include a liquid crystal display device, an organic EL (electroluminescence) display device, a PDP (plasma display panel), electronic paper, and the like. Further, examples of the input device include a touch panel and the like.

The optical member is not particularly limited, and examples thereof include members made of glass, acrylic resin, polycarbonate, polyethylene terephthalate, a metal thin film, and the like (for example, sheet-shaped, film-shaped, and plate-shaped members). The "optical member" in this specification also includes a member (design film, decorative film, surface protective film, etc.) that plays a role of decoration and protection while maintaining the visibility of the display device and the input device.

The mode in which the optical members are bonded using the pressure-sensitive adhesive sheet disclosed herein is not particularly limited, and examples thereof include (1) a mode in which the optical members are bonded to each other via the pressure-sensitive adhesive sheet disclosed here, and (2). ) The optical member may be attached to a member other than the optical member via the pressure-sensitive adhesive sheet disclosed herein, or (3) the pressure-sensitive adhesive sheet disclosed here includes the optical member. The adhesive sheet may be attached to an optical member or a member other than the optical member. In the aspect of (3) above, the pressure-sensitive adhesive sheet including the optical member may be, for example, a pressure-sensitive adhesive sheet in which the support is an optical member (for example, an optical film). As described above, the pressure-sensitive adhesive sheet including the optical member as the support can be grasped as the pressure-sensitive optical member (for example, the pressure-sensitive optical film). Further, when the pressure-sensitive adhesive sheet disclosed here is a type of pressure-sensitive adhesive sheet having a support and the above-mentioned functional film is used as the above-mentioned support, the pressure-sensitive adhesive sheet disclosed here is a functional film. It can also be grasped as a "adhesive type functional film" having an adhesive layer disclosed here on at least one side.

The matters disclosed in this specification include the following.
(1) An adhesive sheet containing an adhesive layer.
The pressure-sensitive adhesive layer contains the polymer (A) and the photoreactive monomer (B).
The photoreactive monomer (B) contains compound B1 having two or more ethylenically unsaturated groups.
The compound B1 is an adhesive sheet having a molecular weight (functional group equivalent) of 100 g / mol or more per ethylenically unsaturated group.
(2) The pressure-sensitive adhesive sheet according to (1) above, wherein the compound B1 contains a ring structure in the molecule.
(3) The pressure-sensitive adhesive sheet according to (2) above, wherein the compound B1 contains at least one structure selected from the group consisting of a bisphenol A structure, a bisphenol F structure and a bisphenol E structure in the molecule.
(4) The pressure-sensitive adhesive sheet according to (2) or (3) above, wherein the compound B1 contains an aliphatic ring structure as the ring structure.
(5) The pressure-sensitive adhesive sheet according to any one of (1) to (4) above, wherein the compound B1 contains at least one structure selected from the group consisting of a hydroxyl group and an amino group in the molecule.
(6) Any of the above (1) to (5), wherein the content of the compound B1 in the pressure-sensitive adhesive layer is 0.5 parts by weight or more and 60 parts by weight or less with respect to 100 parts by weight of the polymer (A). Adhesive sheet described in Crab.
(7) The pressure-sensitive adhesive layer contains the compound B1 as the photoreactive monomer (B) and the compound B2 having two or more functional groups and having no intramolecular ring structure (2). The adhesive sheet according to any one of (5).
(8) The pressure-sensitive adhesive sheet according to (7) above, wherein the functional group equivalent of the compound B2 is smaller than the functional group equivalent of the compound B1.
(9) The pressure-sensitive adhesive sheet according to (7) or (8) above, wherein the functional group equivalent of the compound B2 is 400 g / mol or less.
(10) The pressure-sensitive adhesive sheet according to any one of (7) to (9) above, wherein the content of the compound B2 in the pressure-sensitive adhesive layer is 25 parts by weight or less with respect to 100 parts by weight of the polymer (A). ..
(11) The content of the photoreactive monomer (B) in the pressure-sensitive adhesive layer is 1 part by weight or more and 80 parts by weight or less with respect to 100 parts by weight of the polymer (A). ) The adhesive sheet described in any of.
(12) The pressure-sensitive adhesive sheet according to any one of (1) to (11) above, wherein the polymer (A) is an acrylic polymer.
(13) The pressure-sensitive adhesive sheet according to (12) above, wherein the monomer component constituting the acrylic polymer contains a monomer having a nitrogen atom-containing ring.
(14) The pressure-sensitive adhesive sheet according to any one of (1) to (13) above, wherein the glass transition temperature of the polymer (A) is −45 ° C. or higher and lower than 0 ° C.
(15) The pressure-sensitive adhesive sheet according to any one of (1) to (14) above, wherein the pressure-sensitive adhesive layer is crosslinked with a cross-linking agent.
(16) The pressure-sensitive adhesive sheet according to any one of (1) to (15) above, wherein the pressure-sensitive adhesive layer contains a photopolymerization initiator.
(17) The pressure-sensitive adhesive sheet according to any one of (1) to (14) above, wherein the pressure-sensitive adhesive layer contains a silane coupling agent.
(18) The pressure-sensitive adhesive sheet according to any one of (1) to (17) above, wherein the tensile elastic modulus measured by the tensile test is 3.0 MPa or more.
(19) The adhesive sheet according to any one of (1) to (18) above, wherein the impact resistance measured by the shear impact test is 2.0 J / (10 mm) ² or more.
(20) The adhesive sheet according to any one of (1) to (19) above, wherein the peel strength measured by the peel test is 1.0 N / 10 mm or more.

(21) Containing the polymer (A) and the photoreactive monomer (B),
The photoreactive monomer (B) contains compound B1 having two or more ethylenically unsaturated groups.
The compound B1 is a pressure-sensitive adhesive composition having a molecular weight (functional group equivalent) of 100 g / mol or more per ethylenically unsaturated group.
(22) The pressure-sensitive adhesive sheet according to (21) above, wherein the compound B1 contains a ring structure in the molecule.
(23) The pressure-sensitive adhesive composition according to (22) above, wherein the compound B1 contains at least one structure selected from the group consisting of a bisphenol A structure, a bisphenol F structure and a bisphenol E structure in the molecule.
(24) The pressure-sensitive adhesive composition according to (2) or (23) above, wherein the compound B1 contains an aliphatic ring structure as the ring structure.
(25) The pressure-sensitive adhesive composition according to any one of (21) to (24) above, wherein the compound B1 contains at least one structure selected from the group consisting of a hydroxyl group and an amino group in the molecule.
(26) Any of the above (21) to (25), wherein the content of the compound B1 in the pressure-sensitive adhesive layer is 0.5 parts by weight or more and 60 parts by weight or less with respect to 100 parts by weight of the polymer (A). The pressure-sensitive adhesive composition described in Crab.
(27) The pressure-sensitive adhesive layer contains the compound B1 as the photoreactive monomer (B) and the compound B2 having two or more functional groups and having no intramolecular ring structure (22). The pressure-sensitive adhesive composition according to any one of (25).
(28) The pressure-sensitive adhesive composition according to (27), wherein the functional group equivalent of the compound B2 is smaller than the functional group equivalent of the compound B1.
(29) The pressure-sensitive adhesive composition according to (27) or (28) above, wherein the functional group equivalent of the compound B2 is 400 g / mol or less.
(30) The pressure-sensitive adhesive according to any one of (27) to (29) above, wherein the content of the compound B2 in the pressure-sensitive adhesive layer is 25 parts by weight or less with respect to 100 parts by weight of the polymer (A). Composition.
(31) The content of the photoreactive monomer (B) in the pressure-sensitive adhesive layer is 1 part by weight or more and 80 parts by weight or less with respect to 100 parts by weight of the polymer (A). ). The pressure-sensitive adhesive composition according to any one of.
(32) The pressure-sensitive adhesive composition according to any one of (21) to (31) above, wherein the polymer (A) is an acrylic polymer.
(33) The pressure-sensitive adhesive composition according to (32) above, wherein the monomer component constituting the acrylic polymer contains a monomer having a nitrogen atom-containing ring.
(34) The pressure-sensitive adhesive composition according to any one of (21) to (33) above, wherein the glass transition temperature of the polymer (A) is −45 ° C. or higher and lower than 0 ° C.
(35) The pressure-sensitive adhesive composition according to any one of (21) to (34) above, wherein the pressure-sensitive adhesive composition contains a cross-linking agent.
(36) The pressure-sensitive adhesive composition according to any one of (21) to (35) above, wherein the pressure-sensitive adhesive composition contains a photopolymerization initiator.
(37) The pressure-sensitive adhesive composition according to any one of (21) to (36) above, wherein the pressure-sensitive adhesive composition contains a silane coupling agent.
(38) The pressure-sensitive adhesive composition according to any one of (21) to (37) above, which is used for forming the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet according to any one of (1) to (20).
(39) A pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer composed of the pressure-sensitive adhesive composition according to any one of (21) to (37) above.

(40) An adhesive sheet containing an adhesive layer.
An adhesive sheet having a tensile elastic modulus of 3.0 MPa or more measured by the tensile test and an impact resistance of 2.0 J / (10 mm) ² or more measured by the shear impact test.
(41) The adhesive sheet according to (40) above, wherein the peel strength measured by the peeling test is 1.0 N / 10 mm or more.
(42) The pressure-sensitive adhesive sheet according to any one of (40) to (41) above, wherein the pressure-sensitive adhesive layer is the pressure-sensitive adhesive layer according to any one of (1) to (17).
(43) The pressure-sensitive adhesive layer according to any one of (21) to (37) above, wherein the pressure-sensitive adhesive layer is a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition according to any one of (21) to (37). Adhesive sheet.

(44) The pressure-sensitive adhesive composition is formed from the pressure-sensitive adhesive composition and has a thickness selected from the range of 5 μm to 200 μm (preferably in the range of 15 μm to 25 μm) (for example, a pressure-sensitive adhesive layer having a thickness of 20 μm). The pressure-sensitive adhesive composition according to any one of (21) to (37) above, wherein the tensile elastic modulus measured by the tensile test for the pressure-sensitive adhesive layer) is 3.0 MPa or more.
(45) The pressure-sensitive adhesive composition has an impact resistance of 2.0 J / (10 mm) ² or more measured by the shear impact test for a pressure-sensitive adhesive layer having the thickness formed from the pressure-sensitive adhesive composition. The pressure-sensitive adhesive composition according to (44) above.
(46) The pressure-sensitive adhesive composition has a peel strength of 1.0 N / 10 mm or more measured by the peel-off test for a pressure-sensitive adhesive layer having the thickness formed from the pressure-sensitive adhesive composition (44). Alternatively, the pressure-sensitive adhesive composition according to (45).
(47) A film member with an adhesive sheet, which comprises the adhesive sheet according to any one of (1) to (20) and (40) to (43), and a film member bonded to the adhesive layer.
(48) Attaching the adhesive sheet according to any one of (1) to (20) and (40) to (43) above to the adherend, and
By irradiating the adhesive sheet with ultraviolet rays to photo-curing the adhesive layer,
A method for producing a laminate, which comprises in this order.

Hereinafter, some examples of the present invention will be described, but the present invention is not intended to be limited to those shown in such examples. In the following description, "part" and "%" are based on weight unless otherwise specified.

<Synthesis of polymer (A)>
(Polymer P1)
60 parts of n-butyl acrylate (BA), 6 parts of cyclohexyl acrylate (CHA), N-vinyl-2-pyrrolidone (NVP) as monomer components in a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer and a stirrer. 18 parts, 1 part of isostearyl acrylate (iSTA) and 15 parts of 4-hydroxybutyl acrylate (4HBA), 0.085 parts of α-thioglycerol as a chain transfer agent, 122 parts of ethyl acetate as a polymerization solvent were charged, and a thermal polymerization initiator was charged. As a result, 0.2 part of 2,2'-azobisisobutyronitrile (AIBN) was added and solution polymerization was carried out in a nitrogen atmosphere to obtain a solution of the polymer P1. The weight average molecular weight (Mw) of the polymer P1 was 300,000. The Tg of the polymer P1 calculated from the composition of the monomer component is −33 ° C.

(Polymer P2)
In a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer and a stirrer, 64.5 parts of BA, 6 parts of CHA, 9.6 parts of NVP, 5 parts of iSTA and 14.9 parts of 4HBA as monomer components, and α-thio as a chain transfer agent. A solution of the polymer P2 was obtained by charging 0.07 part of glycerol and 122 parts of ethyl acetate as a polymerization solvent and adding 0.2 part of AIBN as a thermal polymerization initiator and performing solution polymerization in a nitrogen atmosphere. The Mw of the polymer P2 was 600,000. The Tg of the polymer P2 calculated from the composition of the monomer component is −39 ° C.

<Preparation of adhesive composition>
(Example 1)
In the solution of the polymer P1 obtained above, per 100 parts of the monomer component used for preparing the solution, an isocyanate-based cross-linking agent X1 (trimethylolpropane / xylylene diisocyanate adduct (manufactured by Mitsui Chemicals, Inc., trade name: Takenate D)) -110N, solid content concentration 75%)) is 0.05 parts based on solid content, dioctyltin dilaurate (manufactured by Tokyo Fine Chemicals, trade name: Envirizer OL-1) 0.01 parts as a cross-linking accelerator, cross-linking retarder 4 parts of acetylacetone, 0.3 part of 3-glycidoxypropyltrimethoxysilane (trade name: KBM-403, manufactured by Shinetsu Chemical Industry Co., Ltd.) as a silane coupling agent, and dipentaerythritol hexaacrylate (new) as a photoreactive monomer. Nakamura Chemical Industry, trade name "A-DPH") 8 parts and tricyclodecanedimethanol diacrylate (New Nakamura Chemical Industry, trade name "A-DCP") 12 parts, and 1-hydroxycyclohexyl as a photopolymerization initiator 0.72 parts of phenyl-ketone (manufactured by IGM Regins, trade name: Omnirad 184) was added and mixed uniformly to prepare a solvent-type pressure-sensitive adhesive composition according to Example 1.

(Examples 2-3, 5-12)
The types and amounts of the photoreactive monomers, the amount of the cross-linking agent, and the amount of the photopolymerization initiator are as shown in Tables 1 and 2, and the same as in the preparation of the solvent-based pressure-sensitive adhesive composition according to Example 1, respectively. A solvent-based pressure-sensitive adhesive composition according to an example was prepared.

(Example 4)
The solvent-based adhesive according to Example 3 except that the isocyanate-based cross-linking agent X2 (trimethylolpropane / tolylene diisocyanate trimer adduct (manufactured by Tosoh Corporation, trade name: Coronate L)) was used instead of the isocyanate-based cross-linking agent X1. The solvent-based pressure-sensitive adhesive composition according to this example was prepared in the same manner as in the preparation of the agent composition.

(Example 13)
The solvent-type pressure-sensitive adhesive composition according to this example was prepared in the same manner as in the preparation of the solvent-type pressure-sensitive adhesive composition according to Example 10 except that the solution of polymer P2 was used instead of the solution of polymer P1.

<Making an adhesive sheet>
The solvent-based pressure-sensitive adhesive composition according to each example prepared above is applied to the peeling surface of a release film R1 (MRF # 38 manufactured by Mitsubishi Resin Co., Ltd.) having a thickness of 38 μm in which one side of the polyester film is a peeling surface. , It was dried at 130 ° C. for 3 minutes to form a photocurable pressure-sensitive adhesive layer (supportless double-sided pressure-sensitive adhesive sheet) having a thickness of 20 μm. A peeling surface of a 38 μm-thick peeling film R2 (MRE # 38 manufactured by Mitsubishi Plastics Co., Ltd.) having one side of the polyester film as a peeling surface was attached to the surface of the pressure-sensitive adhesive layer to protect it. In this way, a laminated sheet having a structure in which the release film R1, the supportless double-sided adhesive sheet, and the release film R2 are laminated in this order was obtained.

<Measurement and evaluation>
The obtained adhesive sheet was measured and evaluated as follows.
(1) Measurement of tensile elastic modulus A high-pressure mercury lamp is used on a laminated sheet (a laminated sheet having a support-less adhesive layer sandwiched between two transparent release films) according to each example, and an illuminance of 300 mW. After irradiating with ultraviolet rays under the conditions of / cm ² and an integrated light intensity of 3000 mJ / cm ² and aging at 50 ° C. for 48 hours, the laminated sheet was cut into a size of 10 mm in width and 150 mm in length. In an environment of 23 ° C. and 50% RH, the release films R1 and R2 are peeled off to expose the adhesive layer, and a tensile tester (manufactured by Minebea, universal tensile compression tester, device name "tensile compression tester, TCM-" Using 1 kNB ”), a tensile test was performed on the test piece under the conditions of a chuck distance of 120 mm and a tensile speed of 50 mm / min to obtain an SS curve, and its initial inclination (elastic deformation region of the SS curve, concretely. Specifically, the tensile elastic modulus [MPa] was calculated from the slope) in the range where the displacement is less than about 5%. The measurements were performed 3 times (ie n = 3) and Tables 1 and 2 show their arithmetic mean values.

(2) Measurement of impact resistance A shear impact test was performed using a pendulum type adhesive shear impact tester based on JIS K6855. As a measurement sample, the laminated sheet according to each example was cut into a 10 mm square, the release film R1 was peeled off to expose the first surface of the pressure-sensitive adhesive layer, and the first surface was 25 mm square and 1.7 mm thick. After being attached to the central part of the tempered glass plate (manufactured by Corning Inc.), the release film R2 is peeled off and the second surface of the adhesive layer is attached to the central part of a 40 mm square stainless steel plate (SUS304BA plate) to form 5N. It is crimped for 10 seconds under load, then autoclaved (50 ° C, 0.5 MPa, 15 minutes) under the conditions of an illuminance of 300 mW / cm ² and an integrated light amount of 3000 mJ / cm ² using a high-pressure mercury lamp from the glass plate side. After irradiating with ultraviolet rays, the one aged at 50 ° C. for 48 hours was used.
The measurement sample was fixed so that the stainless steel plate was on the lower side, and in an environment of 23 ° C. and 50% RH, a hammer energy of 2.75 J and a hammer speed (impact speed) were applied to the outer peripheral side surface of the glass plate. The impact resistance [J / (10 mm) ² ] was determined by measuring the absorbed energy [J] when a hammer was applied under the condition of 5 m / sec. The measurements were performed three times, and Tables 1 and 2 show their arithmetic mean values.

(3) Peeling strength A test piece is prepared by cutting the laminated sheet according to each example into a size of 10 mm in width and 150 mm in length, and the first surface of the pressure-sensitive adhesive layer in the test piece is reciprocated once with a 2 kg rubber roller. Then, it is pressure-bonded to a glass plate (alkaline glass plate manufactured by Matsunami Glass Industry Co., Ltd., manufactured by the float method, thickness 1.35 mm, blue plate edge polished product), and autoclaved (50 ° C, 0.5 MPa, 15 minutes). After that, ultraviolet rays were irradiated from the glass plate side using a high-pressure mercury lamp under the conditions of an illuminance of 300 mW / cm ² and an integrated light amount of 3000 mJ / cm ² . After aging this at 50 ° C. for 48 hours, a tensile tester (manufactured by Minebea, universal tensile compression tester, device name "tensile compression tester, TCM-1kNB") was installed in an environment of 23 ° C. and 50% RH. The peel strength at the time of peeling the test piece from the glass plate was measured under the conditions of a peeling angle of 180 degrees and a tensile speed of 60 mm / min. The measurements were performed three times, and Tables 1 and 2 show their arithmetic mean values.

The haze value of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet according to Examples 1, 6, 8 and 11 was measured by the above-mentioned method and found to be 0.5% or less. The pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheets of Examples 6 and 8 showed particularly good transparency.

The photoreactive monomers used in Examples 1 to 13 are as follows. In Tables 1 and 2, each photoreactive monomer is indicated by an abbreviation.
DPHA: Dipentaerythritol hexaacrylate (Shin Nakamura Chemical Industry, trade name "A-DPH", functional group equivalent 96)
A-DCP: Tricyclodecanedimethanol diacrylate (Shin Nakamura Chemical Industry Co., Ltd., trade name "A-DCP", functional group equivalent 152)
# 540: Bisphenol A diglycidyl ether acrylic acid adduct (Osaka Organic Chemical Industry Co., Ltd., trade name "Viscoat # 540", functional group equivalent 250)
R115F: Bisphenol A diglycidyl ether acrylic adduct (Nippon Kayaku, trade name "KAYARAD R-115F", functional group equivalent 450)
# 700HV: bisphenol A ethylene oxide 3.8 mol adduct diacrylate (Osaka Organic Chemical Industry, trade name "Viscoat # 700HV", functional group equivalent 350)
E3703: Amine-modified bisphenol A type epoxy diacrylate (Dycel Ornex, trade name "EBECRYL 3703", functional group equivalent 425)
APG400: Polypropylene glycol # 400 diacrylate (Shin Nakamura Chemical Industry, trade name "APG-400", functional group equivalent 268)

The adhesive sheets of Examples 1 to 9 shown in Table 1 were excellent in deformation resistance due to their high tensile elastic modulus and exhibited high impact resistance. On the other hand, the pressure-sensitive adhesive sheets of Examples 10, 12, and 13 shown in Table 2 had low deformation resistance, and the pressure-sensitive adhesive sheets of Example 11 had low peel strength.

Although specific examples of the present invention have been described in detail above, these are merely examples and do not limit the scope of claims. The techniques described in the claims include various modifications and modifications of the specific examples illustrated above.

1, 2 Adhesive sheet 10 Adhesive layer 10A One surface (adhesive surface)
10B Other surface 20 Support 20A First surface 20B Second surface (back surface)
30, 31, 32 Release liner 50 Adhesive sheet with release liner 70 Film member 100 Member with adhesive sheet

Claims

An adhesive sheet containing an adhesive layer,
An adhesive sheet having an elastic modulus of 3.0 MPa or more measured by the following tensile test and an impact resistance of 2.0 J / (10 mm) 2 or more measured by the following shear impact test.
[Tensile test]
The pressure-sensitive adhesive layer was irradiated with ultraviolet rays under the conditions of an illuminance of 300 mW / cm 2 and an integrated light intensity of 3000 mJ / cm 2 , and after aging at 50 ° C. for 48 hours, the pressure-sensitive adhesive layer was 10 mm wide and 150 mm long. Cut to size and prepare test pieces. In an environment of 23 ° C. and 50% RH, a tensile test was performed on the test piece under the conditions of a chuck distance of 120 mm and a tensile speed of 50 mm / min using a tensile tester to obtain a stress-displacement curve, and from the initial inclination thereof. Calculate the elastic modulus [MPa].
[Shear impact test]
A shear impact test is performed using a pendulum type adhesive shear impact tester based on JIS K6855. As a measurement sample, the first surface of the 10 mm square adhesive layer is attached to the central portion of a 25 mm square, 1.7 mm thick chemically strengthened glass plate, and then the second surface of the adhesive layer is 40 mm. It is attached to the center of a square stainless steel plate (SUS304BA plate), crimped for 10 seconds under a load of 5N, then autoclaved (50 ° C, 0.5 MPa, 15 minutes), and the illuminance is 300 mW / cm from the glass plate side. 2. Use a glass that has been irradiated with ultraviolet rays under the condition of an integrated light amount of 3000 mJ / cm 2 and then aged at 50 ° C. for 48 hours.
The measurement sample was fixed so that the stainless steel plate was on the lower side, and the conditions were that the hammer energy was 2.75 J and the hammer speed was 3.5 m / sec on the outer peripheral side surface of the glass plate in an environment of 23 ° C. and 50% RH. The impact resistance [J / (10 mm) 2 ] is obtained by measuring the absorbed energy [J] when the hammer is applied.
The pressure-sensitive adhesive sheet according to claim 1, wherein the peel strength measured by the following peel test is 1.0 N / 10 mm or more.
[Peeling test]
A test piece prepared by cutting the adhesive sheet into a size of 10 mm in width and 150 mm in length is pressure-bonded to a glass plate by reciprocating a 2 kg rubber roller once and autoclaved (50 ° C., 0.5 MPa, 15 minutes). After that, ultraviolet rays are irradiated from the glass plate side under the conditions of an illuminance of 300 mW / cm 2 and an integrated light intensity of 3000 mJ / cm 2 . After aging this at 50 ° C. for 48 hours, the test piece is pulled from the glass plate under the conditions of a peeling angle of 180 degrees and a tensile speed of 60 mm / min using a tensile tester in an environment of 23 ° C. and 50% RH. Measure the peeling strength at the time of peeling.
The pressure-sensitive adhesive sheet according to claim 1 or 2, wherein the pressure-sensitive adhesive layer contains a polymer (A) and a photoreactive monomer (B).
The pressure-sensitive adhesive sheet according to claim 3, wherein the photoreactive monomer (B) contains a compound B1 having a ring structure and two or more ethylenically unsaturated groups in the molecule.
The pressure-sensitive adhesive sheet according to claim 4, wherein the compound B1 has a molecular weight of 100 g / mol or more per ethylenically unsaturated group.
An adhesive sheet containing an adhesive layer,
The pressure-sensitive adhesive layer contains the polymer (A) and the photoreactive monomer (B).
The photoreactive monomer (B) contains compound B1 having a ring structure and two or more ethylenically unsaturated groups in the molecule.
The compound B1 is an adhesive sheet having a molecular weight of 100 g / mol or more per ethylenically unsaturated group.
The pressure-sensitive adhesive sheet according to claim 6, wherein the elastic modulus measured by the following tensile test is 3.0 MPa or more.
[Tensile test]
The pressure-sensitive adhesive layer was irradiated with ultraviolet rays under the conditions of an illuminance of 300 mW / cm 2 and an integrated light intensity of 3000 mJ / cm 2 , and after aging at 50 ° C. for 48 hours, the pressure-sensitive adhesive layer was 10 mm wide and 150 mm long. Cut to size to make a test piece. In an environment of 23 ° C. and 50% RH, a tensile test was performed on the test piece under the conditions of a chuck distance of 120 mm and a tensile speed of 50 mm / min using a tensile tester to obtain a stress-displacement curve, and from the initial inclination thereof. Calculate the elastic modulus.
The adhesive sheet according to claim 6 or 7, wherein the impact resistance measured by the following shear impact test is 2.0 J / (10 mm) 2 or more.
[Shear impact test]
A shear impact test is performed using a pendulum type adhesive shear impact tester based on JIS K6855. As a measurement sample, the first surface of the 10 mm square adhesive layer is attached to the central portion of a 25 mm square, 1.7 mm thick chemically strengthened glass plate, and then the second surface of the adhesive layer is 40 mm. It is attached to the center of a square stainless steel plate (SUS304BA plate), crimped for 10 seconds under a load of 5N, then autoclaved (50 ° C, 0.5 MPa, 15 minutes), and the illuminance is 300 mW / cm from the glass plate side. 2. Use a glass that has been irradiated with ultraviolet rays under the condition of an integrated light amount of 3000 mJ / cm 2 and then aged at 50 ° C. for 48 hours.
The measurement sample was fixed so that the stainless steel plate was on the lower side, and the conditions were that the hammer energy was 2.75 J and the hammer speed was 3.5 m / sec on the outer peripheral side surface of the glass plate in an environment of 23 ° C. and 50% RH. The impact resistance [J / (10 mm) 2 ] is obtained by measuring the absorbed energy [J] when the hammer is applied.
A film member with an adhesive sheet, which comprises the adhesive sheet according to any one of claims 1 to 8 and a film member bonded to the adhesive layer.
Attaching the adhesive sheet according to any one of claims 1 to 8 to the adherend,
By irradiating the adhesive sheet with ultraviolet rays to photo-curing the adhesive layer,
A method for producing a laminate, which comprises in this order.