TW202237778A - Adhesive sheet curable by active energy rays, adhesive sheet laminate that includes release film, adhesive sheet, laminate for configuring image display device, and image display device - Google Patents

Abstract

An adhesive sheet curable by active energy rays that does not readily soften or swell even when penetrated by an oily component such as sebum, that moreover can exhibit exceptional fluidity when affixed to an adherend, and that furthermore can exhibit reliable foaming resistance after having been laminated on an adherend and cured. Proposed by the present invention as said adhesive sheet is an adhesive sheet curable by active energy rays that comprises an adhesive agent layer containing a (meth)acrylic polymer (A) and that satisfies requirements (1) and (2). (1) The thickness is 0.8-1.5 m, and the strain (creep strain) after a pressure of 1,000 Pa has been applied for 1,200 seconds at a temperature of 50 DEG C is 150-1,500%. (2) The oil and fat swelling rate derived according to formula (i) is 30% or less, where So is the initial surface area of the adhesive sheet, and St is the surface area after the adhesive sheet has been immersed in an artificial sebum liquid (a mixture in which squalene/oleic acid = 1/1) for four days at 25 DEG C. Formula (i): (Oil and fat swelling rate (%))=(St-So)/So*100.

Description

Active energy ray curable adhesive sheet, adhesive sheet laminate with release film, adhesive sheet, laminate for constituting image display device, and image display device

The present invention relates to an active energy ray-curable adhesive sheet having a property of being cured by active energy rays, an adhesive sheet laminate with a release film formed using the same, an adhesive sheet, and an image display device. A laminate, and an image display device.

In recent years, in order to improve the visibility of image display devices, operations such as liquid crystal displays (LCDs), plasma displays (PDPs), and electroluminescent displays (ELDs) have been performed with adhesive sheets or liquid adhesives. Fill the gap between the image display panel and the protective panel or touch panel components arranged on the front side (viewing side) to suppress the reflection of incident light or outgoing light from the displayed image on the air layer interface.

As a method of filling the gap between constituent members of such an image display device with an adhesive, for example, Patent Document 1 discloses a method of filling the gap with a liquid adhesive composition containing an ultraviolet curable resin. , to harden by irradiating ultraviolet rays.

Moreover, the method of filling the space|gap between the constituent members for image display devices using an adhesive sheet is also known. For example, Patent Document 2 discloses a method for manufacturing an image display device constituting laminate having at least one side of a transparent double-sided adhesive sheet laminating image display device constituent members. A method in which the primary cross-linked adhesive sheet is bonded to the constituent members of the image display device, and then irradiated with ultraviolet rays through the constituent members of the image display device to make the adhesive sheet harden for the second time.

Patent Document 3 discloses a method of bonding image display device components using an adhesive sheet containing an adhesive composition, irradiating active energy rays through the image display device components, and exchanging the adhesive composition. Combining Image Display Device Constituent Member Next, the above-mentioned adhesive composition contains: an acrylic copolymer including a graft copolymer having a macromonomer as a branch component, a crosslinking agent, and a photopolymerization initiator.

In Patent Document 4, a photocurable adhesive sheet is disclosed, which is characterized in that it is used for laminating a resin with a light transmittance of 10% or less at a wavelength of 365 nm and a light transmittance of at least 60% at a wavelength of 405 nm. The member (X) has an adhesive layer (Y) having all the characteristics of the following (1) to (3). (1) The gel fraction (referred to as "gel fraction X1 before light irradiation") is in the range of 0 to 60%. (2) The light transmittance at a wavelength of 390 nm is 89% or less, and the light transmittance at a wavelength of 410 nm is above 80%. (3) It has photocurability that can be cured by irradiating light with a wavelength of 405 nm.

Also, in recent years, the following problems have arisen when using a notebook computer, a tablet, or a smart phone. That is, there are many chances that people's fingers touch the casing or the image display screen, and there are oily components such as sebum or cosmetics on the surface of the skin in addition to sweat. The end of the joint between the panel and the casing is slowly immersed until it reaches the adhesive layer of the double-sided tape. Moreover, the oily component has the effect of softening and swelling the adhesive, so problems such as overflow of the adhesive composition for adhering the sheet from the edge of the adherend may arise.

In view of this problem, as a double-sided adhesive tape whose adhesive is not easy to soften and swell even when oily components such as sebum are infiltrated, Patent Document 5 discloses an oil-resistant double-sided adhesive tape, which is one of the above-mentioned double-sided adhesive tapes. The adhesive layer comprises an acrylic adhesive composition containing an acrylic copolymer having n-butyl acrylate and a vinyl monomer having a polar group as a monomer component, and acrylic acid in the monomer component forming the above acrylic copolymer The content of n-butyl ester is 70% by mass or more. prior art literature patent documents

Patent Document 1: International Publication No. 2010/027041 Patent Document 2: Japanese Patent No. 4971529 Patent Document 3: International Publication No. 2015/137178 Patent Document 4: Japanese Patent Laid-Open No. 2019-210445 Patent Document 5: Japanese Patent Laid-Open No. 2009-215355

[Problem to be solved by the invention]

Although in the above-mentioned Patent Documents 1 to 4, it is possible to fill the gaps between members constituting the image display device (also referred to as "image display device constituent members"), and to obtain step absorption, etc., further work is required. For the step difference absorption of the components of the image display device with concave and convex steps. That is, the surface of an image display device constituent member may be roughened by wiring, printing, pattern development, etching, drilling, surface treatment, and the like. In recent years, in image display devices such as mobile phones, there has been a trend of displaying almost the entire area of the image display panel in its design, followed by disposing cameras in the display area. In order to arrange cameras in the display, On the functional layer such as polarizing film or reflective film laminated on the surface of the image display panel, holes are provided according to the position and size of the camera. The adhesive sheet used for bonding the constituent members of the image display device having the hole requires the property (high fluidity) that the adhesive can flow into the hole and be filled to every corner. In addition, in the above-mentioned Patent Documents 1 to 4, penetration of oily components such as sebum has not been improved, and high fluidity and oil resistance have not been sufficiently achieved at the same time. Furthermore, in the above-mentioned Patent Document 5, although it has a certain degree of oil resistance effect, it is not yet satisfactory in terms of compatibility with high fluidity. If the adhesive sheet used to bond the components of the image display device having such a step portion cannot follow the unevenness and fill to every corner, air bubbles will be generated inside the adhesive layer, or strain will be generated in the components of the image display device. Or deformation, so the adhesive sheet requires higher fluidity. However, it is difficult to suppress softening and swelling caused by penetration of oily components, and exhibits high fluidity at the time of bonding.

In view of this, the present invention provides an excellent oil resistance that does not soften, swell and overflow from the edge of the adherend even when oily components such as sebum are infiltrated, and even if the adherend exists on the adherend surface The active energy ray-curable adhesive sheet having irregularities such as bottomed holes that can flow into the irregularities, and a laminate for constituting an image display device and an image display device using the same. [Technical means to solve the problem]

The present invention proposes an active energy ray-curable adhesive sheet, which has an adhesive layer comprising a (meth)acrylic polymer (A), and satisfies the following requirements (1) and (2). (1) The thickness is 0.8 to 1.5 mm, and the strain (creep strain) after applying a pressure of 1000 Pa at a temperature of 50°C for 1200 seconds is 150% or more and 1500% or less. (2) Assuming that the initial area of the adhesive sheet is So, the area of the above-mentioned adhesive sheet immersed in artificial sebum solution (squalene: oleic acid = 1:1 mixture) at 25°C for 4 days is At St, the oil swelling rate obtained by the following formula (i) is 30% or less. Grease swelling rate (%)＝[(St－So)/So]×100・・・(i)

Furthermore, the present invention proposes an adhesive sheet laminate with a release film, which is formed by laminating the active energy ray-curable adhesive sheet proposed in the present invention and a release film.

Also, the present invention proposes a laminate for image display device construction, which is provided with an active energy ray hardening between two image display device constituent members with a fat swelling ratio of 30% or less obtained by the following formula (i). It is composed of laminated adhesive sheets, and The above-mentioned adhesive sheet has an adhesive layer formed of an adhesive resin composition containing a (meth)acrylic polymer (A), and has a thickness of 0.8 to 1.5 mm, and a pressure of 1000 Pa is applied at a temperature of 50°C for 1200 seconds The subsequent strain (creep strain) is not less than 150% and not more than 1500%. Grease swelling rate (%)＝[(St－So)/So]×100・・・(i) In formula (i), So is the initial area of the adhesive sheet, and St is the area after immersing the adhesive sheet in artificial sebum solution (squalene: oleic acid = 1:1 mixture) at 25°C for 4 days.

Furthermore, the present invention proposes a laminate for constituting an image display device, which is provided with two constituting members of an image display device having an active energy ray hardening property with a grease swelling ratio of 30% or less obtained by the following formula (i). Adhesive sheets hardened by lamination of hardened adhesive sheets, and The above-mentioned adhesive sheet has an adhesive layer formed of an adhesive composition containing a (meth)acrylic polymer (A), and has a thickness of 0.8 to 1.5 mm, after applying a pressure of 1000 Pa at a temperature of 80°C for 180 seconds The strain (creep strain) is not less than 5% and not more than 220%. Grease swelling rate (%)＝[(St－So)/So]×100・・・(i) In formula (i), So is the initial area of the adhesive sheet, and St is the area after immersing the adhesive sheet in artificial sebum solution (squalene: oleic acid = 1:1 mixture) at 25°C for 4 days.

Furthermore, the present invention proposes an image display device constructed using the above-mentioned laminate for constituting an image display device. [Effect of Invention]

The active energy ray-curable adhesive sheet proposed by the present invention is excellent in oil resistance. For example, even in the presence of oily components such as sebum, it does not soften, swell, and overflow from the edge of the adherend. Moreover, the active energy ray-curable adhesive sheet proposed by the present invention can exhibit excellent fluidity when attached to an adherend by heating, even if there are irregularities such as bottomed holes on the adherend surface of the adherend, It can also flow into unevenness and absorb unevenness.

Next, the present invention will be described based on an embodiment example. However, the present invention is not limited to the embodiments described below.

＜This adhesive sheet＞ An adhesive sheet (referred to as "this adhesive sheet") which is an example of an embodiment of the present invention has an adhesive layer (referred to as "this adhesive") containing a (meth)acrylic polymer (A) as a main component resin. layer") active energy ray curable adhesive sheet.

＜This adhesive layer＞ The present adhesive layer in the present adhesive sheet includes, for example, a (meth)acrylic polymer (A), a crosslinking agent (B) and/or a polymerization initiator (C) if necessary, and other The adhesive composition of the ingredients (referred to as "this adhesive composition") is formed. In this adhesive composition, it is preferable to contain the above-mentioned (meth)acrylic polymer (A) as a main component resin.

The above-mentioned "active energy ray-curable adhesive sheet" means an adhesive sheet having the property of being curable by active energy ray, in other words, an adhesive sheet having active energy ray-curable properties that leaves room for curing by active energy ray Sheet. This adhesive sheet may be cured in a state where there is still room for curing by active energy rays (also referred to as "temporarily cured"), or it may not have been cured at all (referred to as "uncured") and can be cured by Active Energy Ray Hardener. As long as this adhesive sheet is temporarily hardened or not hardened, before or after attaching this adhesive sheet to the adherend, this adhesive sheet can be hardened by active energy rays (also called "Formally hardened"), as a result, cohesion can be improved to improve adhesion.

In addition, the above-mentioned "main component resin" means the resin having the highest mass ratio among the resins constituting the present adhesive layer or the present adhesive composition. The content of the main component resin may account for more than 50% by mass, 60% by mass or more, 70% by mass or more, and 75% by mass or more (including 100% by mass) of the resin constituting the adhesive layer or the adhesive composition of the present adhesive. .

(gel fraction) Before the adhesive sheet is cured by active energy rays, it is in an uncrosslinked state or a slightly crosslinked state, that is, a state in which the gel fraction is 0% to 20%. From the viewpoint of followability to unevenness on the surface to be adhered, the gel fraction is preferably 10% or less, more preferably 8% or less, more preferably 5% or less.

Also, when this adhesive sheet is cured by irradiating active energy rays with a wavelength of 365 nm with a cumulative light intensity of 4000 mJ/cm ² , the gel fraction will increase compared to before hardening, and the gel fraction is preferably 10. % above 80%. By setting the gel fraction to 10% or more after active energy ray curing, it is possible to impart shape stability to the adhesive sheet, or shape stability or durability when it is formed into a laminate. From this viewpoint, the gel fraction after active energy ray hardening is preferably 10% or more, more preferably 30% or more, more preferably 40% or more, and more preferably 50% or more. On the other hand, the gel fraction after active energy ray hardening is preferably 80% or less. With a gel fraction of 80% or less, it has moderate flexibility even after being cured by active energy rays, and can follow the structure of an image display device when the laminate for image display device construction is stored in a high-temperature or low-temperature environment Dimensions of components change without foaming. From this viewpoint, it is more preferably 75% or less, especially preferably 70% or less.

In this adhesive sheet, in order to adjust the gel fraction after hardening to the above range, it is preferable to adjust the composition or molecular weight of the (meth)acrylic polymer (A) as the base polymer, or to adjust the The addition amount of the crosslinking agent (B) is adjusted, or the intensity of the irradiated active energy rays or the integrated light amount is adjusted. However, it is not limited to this method.

＜Laminated structure＞ This adhesive sheet may be composed of a single layer composed of this adhesive layer, or may be composed of multiple layers including two or more layers of this adhesive layer. When the present adhesive sheet is composed of two or more layers, it is preferable that at least the outermost layer or the innermost layer or these two layers are layers corresponding to the present adhesive layer. All layers may be equivalent to the present adhesive layer.

＜Thickness＞ The thickness of the adhesive sheet is preferably from 10 μm to 500 μm, more preferably from 15 μm to 400 μm, and even more preferably from 20 μm to 350 μm.

When the adhesive sheet is composed of two or more layers, the thickness of the layer corresponding to the adhesive layer is preferably 20 to 100% of the thickness of the entire adhesive sheet, and more preferably It is 30% or more or 95% or less, and more preferably 40% or more or 90% or less.

＜Creep characteristics＞ The adhesive sheet preferably has a thickness of 0.8 to 1.5 mm, and the strain (creep strain) after applying a pressure of 1000 Pa at a temperature of 50°C for 1200 seconds is not less than 150% and not more than 1500%. In this adhesive sheet, the above-mentioned creep strain at 50°C is 150% or more, indicating that it is easy to deform under heating. Therefore, it is relatively good in terms of the fact that the adhesive resin can flow and fill concave-convex parts such as bottomed holes by heating. good. From this point of view, the above-mentioned strain is more preferably 160% or more, especially preferably 180% or more, and even more preferably 200% or more. On the other hand, it is preferable at the point which the said creep strain at 50 degreeC is 1500 % or less is excellent in the dimensional stability of an adhesive sheet. From this point of view, the aforementioned strain is more preferably 1400% or less, especially preferably 1300% or less, and still more preferably 1200% or less.

As mentioned above, the above-mentioned creep strain of the adhesive sheet is the value when the thickness is 0.8 mm to 1.5 mm. To accurately measure the creep strain of the adhesive sheet, it is necessary to avoid the problem caused by insufficient thickness of the adhesive sheet. However, due to the influence of the measurement fixture, the measurement results will change. Therefore, it is necessary to adjust the adhesive sheet to a certain thickness range before performing the measurement. By pre-adjusting the thickness of the adhesive sheet within the above range and then measuring the creep strain, the creep strain of the adhesive sheet can be accurately grasped without being affected by the measuring fixture.

Furthermore, the above-mentioned "thickness is 0.8 ~ 1.5 mm" means that when the thickness of the adhesive sheet used as the measurement sample does not meet this range, the thickness of the measurement sample is adjusted to the thickness of the measurement sample by overlapping several adhesive sheets, etc. scope. In other tests, the same is true when the thickness of the sample is determined.

In this adhesive sheet, in order to adjust the creep strain to the above-mentioned range, it is preferable to adjust the composition or molecular weight of the following (meth)acrylic polymer (A) as the base polymer, or to adjust the crosslinking Adjust the amount of agent (B) added. However, it is not limited to this method.

In addition, this adhesive sheet is preferably irradiated with active energy rays with a wavelength of 365 nm and a cumulative light intensity of 4000 mJ/cm ² to harden it. The strain (creep strain) after applying a pressure of 1000 Pa for 180 seconds is not less than 5% and not more than 220%. In this adhesive sheet, the above-mentioned strain (creep strain) after hardening and applying a pressure of 1,000 Pa at a temperature of 80°C for 180 seconds is 5% or more, which means that even after hardening, it is easy to deform and stress at high temperatures. Since it is excellent in relaxation, it is preferable in that even if the size of the adherend changes due to temperature changes after bonding with the adherend, it can follow without occurrence of a fracture at the interface with the adherend. Excellent durability can be obtained without blistering or peeling. From this point of view, the creep strain after active energy ray hardening is more preferably 7% or more, more preferably 10% or more, and even more preferably 15% or more. On the other hand, if the upper limit of the above-mentioned strain (creep strain) after hardening is too high, the adhesive sheet may protrude from the end face of the laminate under high temperature environment and the end face may become sticky. The aforementioned creep strain after energy ray hardening is preferably 220% or less, more preferably 100% or less, still more preferably 80% or less, and more preferably 60% or less, 40% or less, and 30% or less. Among the above-mentioned upper limit values of strain (creep strain) after hardening, in particular, by being 80% or less, durability in a higher temperature environment or in a lower temperature environment can be obtained, and paste overflow at the end of the adhesive sheet can be suppressed Or the generation of air bubbles in the surface. From this point of view, the upper limit is preferably 70% or less, more preferably 60% or less, further preferably 40% or less, particularly preferably 30% or less.

In addition, regarding the creep strain after active energy ray hardening of the above-mentioned adhesive sheet, it is measured after adjusting the thickness of the adhesive sheet to 0.8 mm to 1.5 mm in the same manner as above. However, as described above, The reason for this is that the influence of the measuring jig is considered, and it is not intended that the thickness of the adhesive sheet should be within the above-mentioned range.

In this adhesive sheet, in order to adjust the creep strain after active energy ray curing to the above range, it is preferable to adjust the composition or molecular weight of the (meth)acrylic polymer (A) as the main component resin, Either adjust the type or addition amount of the crosslinking agent (B), or adjust the irradiation amount of active energy rays. However, it is not limited to this method.

＜Oil swelling rate＞ This adhesive sheet is preferably the area after its initial area is set as So, and this adhesive sheet is immersed in artificial sebum solution (squalene: oleic acid = 1:1 mixture) at 25°C for 4 days. When it is St, the fat swelling rate obtained by the following formula (i) is 30% or less. Grease swelling rate (%)＝[(St－So)/So]×100・・・(i)

The shape of the adhesive sheet used in the measurement of fat swelling rate is arbitrary. As a method of measuring the area, for example, if the adhesive sheet is polygonal or circular, it can be calculated from the outer peripheral dimensions. In addition, it can also be obtained by performing image processing and analysis on the measured adhesive sheet.

If the above-mentioned oil swelling rate of the adhesive sheet is 30% or less, even if oily components such as sebum permeate, it is difficult to soften and swell, and excellent oil resistance can be exhibited. From this point of view, the above-mentioned fat swelling rate of the adhesive sheet is more preferably 25% or less, especially preferably 20% or less, still more preferably 15% or less, and still more preferably 10% or less.

In addition, this adhesive sheet is preferably irradiated with active energy rays with a wavelength of 365 nm and a cumulative light quantity of 4000 mJ/cm ² to harden, and the oil swelling rate after hardening is 30% or less. If the oil swelling rate after hardening is 30% or less, even if oily components such as sebum penetrate, it will not be easy to soften and swell, and can exhibit excellent oil resistance. From this point of view, the above-mentioned fat swelling ratio after curing of the adhesive sheet is preferably 30% or less, more preferably 28% or less, and still more preferably 25% or less.

In this adhesive sheet, in order to adjust the oil swelling ratio to the above range, for example, only the composition of the following (meth)acrylic polymer (A) as the base polymer, such as a vinyl monomer having a polar group , and butyl acrylate and other alkyl (meth)acrylates with relatively short carbon numbers (for example, less than 6) to adjust the composition ratio of the alkyl (meth)acrylate, or to adjust the structure or amount of the crosslinking agent (B), Alternatively, it is sufficient to adjust the irradiation dose of active energy rays, etc. However, it is not limited to these methods.

＜Adhesion＞ This adhesive sheet preferably has an adhesive force of more than 2 N/cm to soda-lime glass, that is, the roll of this adhesive sheet is pressed against soda-lime glass by making the roller reciprocate once, and after curing at 60°C for 30 minutes, At 23°C and 40%RH, peel the adhesive sheet from the above-mentioned soda-lime glass at a peeling angle of 180° and a peeling speed of 60 mm/min. At this time, the 180° peeling force against the glass is more than 2 N/cm. When the peeling force is 2 N/cm, positioning or temporary fixation at the time of laminating constituent members of an image display device described below becomes easy. Also, the effect of suppressing penetration of oily components such as sebum can be obtained. From this point of view, the 180° peel force is preferably 2 N/cm or higher, more preferably 4 N/cm or higher, more preferably 5 N or higher, and still more preferably 10 N/cm or higher. In addition, although the upper limit of peeling force is not specifically limited, Usually, it is 20 N/cm.

In addition, the adhesive sheet is preferably bonded to the soda-lime glass, and the adhesive force when hardened is 2 N/cm or more, that is, the adhesive sheet is pressed against the soda-lime glass by making the roller reciprocate once, and then After curing at 60°C for 30 minutes, the adhesive sheet was cured by irradiating active energy rays with a wavelength of 365 nm so that the cumulative light intensity became 4000 mJ/cm ² , and cured at 23°C for 15 hours. , peel the adhesive sheet from the above-mentioned soda-lime glass at a peeling angle of 180° and a peeling speed of 60 mm/min. At this time, the 180° peeling force against the glass is 2 N/cm or more. When the peeling force is 2 N/cm, it is preferable to suppress penetration of oily components such as sebum when it is bonded to the image display device constituents described below to form a laminate, and durability becomes good. From this point of view, after bonding to soda-lime glass, the above-mentioned peeling force when irradiated with active energy rays is preferably 2 N/cm or more, more preferably 3 N/cm or more, more preferably 5 N/cm or more, and more preferably 10 N/cm or more. In addition, although the upper limit of peeling force is not specifically limited, Usually, it is 20 N/cm.

＜This adhesive composition＞ In addition to the (meth)acrylic polymer (A), the adhesive composition preferably also includes a crosslinking agent (B) and/or a polymerization initiator (C), and optionally a silane coupling agent (D), the composition of other components.

((meth)acrylic polymer (A)) In this pressure-sensitive adhesive composition, a (meth)acrylic polymer (A) is contained, and a (meth)acrylic polymer (A) is contained especially as a main component resin. That is, the resin with the highest mass ratio among the resins constituting the present adhesive composition. In this case, the mass ratio of the (meth)acrylic polymer (A) in the resin constituting the adhesive composition may be 50% by mass or more, of which 70% by mass or more, of which 80% by mass or more, Of these, 90% by mass or more (including 100% by mass) may be used.

As the above-mentioned (meth)acrylic polymer (A), it is derived from the following formula 1 (wherein, R ₁ represents a hydrogen atom or a methyl group, and R ₂ represents a straight chain or branched chain having 1 to 18 carbon atoms. The structural unit of a compound represented by an alkyl group or an alicyclic hydrocarbon group) is preferably obtained by polymerizing a polymer component containing 35% by mass or more of the monomer component.

Among them, the (meth)acrylic polymer (A) is more preferably obtained by polymerizing the above-mentioned monomer component as a polymerization component containing 40% by mass or more, especially preferably obtained by polymerizing containing 50% by mass or more. , especially preferably one obtained by polymerization containing 60% by mass or more.

Furthermore, in the present invention, "(meth)acrylic acid" means to include acrylic acid and methacrylic acid respectively, "(meth)acryl" means to include acryl and methacryl respectively, "( "Meth)acrylate" means to include acrylate and methacrylate, respectively, and "(co)polymer" means to include polymers and copolymers.

As the monomer represented by the above formula 1, for example, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, ( n-butyl methacrylate, isobutyl (meth)acrylate, second butyl (meth)acrylate, third butyl (meth)acrylate, amyl (meth)acrylate, (meth)acrylic acid Isopentyl, Neopentyl (meth)acrylate, Hexyl (meth)acrylate, Cyclohexyl (meth)acrylate, Heptyl (meth)acrylate, 2-Ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, tertiary butylcyclohexyl (meth)acrylate, (meth)acrylate Base) decyl acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, (meth)acrylic acid Myristyl ester, Cetyl (meth)acrylate, Stearyl (meth)acrylate, Isostearyl (meth)acrylate, Isostearyl (meth)acrylate, (Meth) 3,5,5-trimethylcyclohexyl acrylate, dicyclopentyl (meth)acrylate, dicyclopentenyl (meth)acrylate, and the like. These can be used 1 type or in combination of 2 or more types. These can be used 1 type or in combination of 2 or more types.

Among these, from the viewpoint of imparting durability to the oily component to the adhesive, for example, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate are preferable. Esters, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, second butyl (meth)acrylate, third butyl (meth)acrylate, ( Amyl methacrylate, isopentyl (meth)acrylate, neopentyl (meth)acrylate, hexyl (meth)acrylate, cyclohexyl (meth)acrylate, etc., the carbon number of the alkyl group is 6 or less Alkyl (meth)acrylate, and more preferably methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, ( n-butyl methacrylate, isobutyl (meth)acrylate, second butyl (meth)acrylate, third butyl (meth)acrylate, amyl (meth)acrylate, (meth)acrylic acid Alkyl (meth)acrylates such as isopentyl (meth)acrylate and neopentyl (meth)acrylate whose alkyl group has 5 or less carbon atoms, and more preferably ethyl (meth)acrylate, n-(meth)acrylate Propyl ester, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, second butyl (meth)acrylate, third butyl (meth)acrylate, etc. Alkyl (meth)acrylates having an alkyl group having 2 or more and 4 or less carbon atoms, among which n-butyl (meth)acrylate is preferred.

The above-mentioned (meth)acrylic polymer (A) is preferably a copolymer having "other copolymerizable monomers" other than the above-mentioned monomer components as copolymerization components.

The above-mentioned "other copolymerizable monomers" are contained in the (meth)acrylic polymer (A), preferably in a ratio of 1 to 60% by mass, more preferably in a ratio of 2% by mass or more and 50% by mass or less, Among these, it is more preferable to contain it in the ratio of 3 mass % or more or 40 mass % or less.

Examples of the "other copolymerizable monomers" include (a) carboxyl group-containing monomers (hereinafter also referred to as "copolymerizable monomers a1"), (b) hydroxyl-containing monomers (hereinafter also referred to as "copolymerizable monomers a1"), monomer a2"), (c) amine-containing monomer (hereinafter also referred to as "copolymerizable monomer a3"), (d) epoxy group-containing monomer (hereinafter also referred to as "copolymerizable monomer a4") ), (e) amide group-containing monomer (hereinafter also referred to as "copolymerizable monomer a5"), (f) vinyl monomer (hereinafter also referred to as "copolymerizable monomer a6"), (g) macromonomer monomer (hereinafter also referred to as "copolymerizable monomer a7"), (h) aromatic-containing monomer (hereinafter referred to as "copolymerizable monomer a8"), or (i) monomer containing other functional groups ( Hereafter referred to as "copolymerizable monomer a9"). These can be used 1 type or in combination of 2 or more types.

Examples of the above-mentioned copolymerizable monomer a1 include: (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypropyl (meth)acrylate, carboxybutyl (meth)acrylate, ω-carboxy- Polycaprolactone mono(meth)acrylate, 2-(meth)acryloxyethyl hexahydrophthalate, 2-(meth)acryloxypropyl hexahydrophthalate, 2-(Meth)acryloxyethylphthalic acid, 2-(meth)acryloxypropylphthalic acid, 2-(meth)acryloxyethylmaleic acid, 2-(Meth)acryloxypropylmaleic acid, 2-(meth)acryloxyethylsuccinic acid, 2-(meth)acryloxypropylsuccinic acid, crotonic acid, Fumaric acid, maleic acid, itaconic acid. These may be used 1 type or in combination of 2 or more types.

Examples of the above-mentioned copolymerizable monomer a2 include: 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxy-1-methylethyl (meth)acrylate , 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, glycerol mono(meth)acrylate, polyethylene glycol mono(meth)acrylate base) acrylate, polypropylene glycol mono(meth)acrylate, polyethylene glycol polypropylene glycol mono(meth)acrylate, polyethylene glycol polybutylene glycol mono(meth)acrylate, polypropylene glycol polybutylene Hydroxyl-containing (meth)acrylates such as alcohol mono(meth)acrylate and hydroxyphenyl (meth)acrylate. These may be used 1 type or in combination of 2 or more types.

As the above-mentioned copolymerizable monomer a3, for example, aminomethyl (meth)acrylate, aminoethyl (meth)acrylate, aminopropyl (meth)acrylate, amino (meth)acrylate Aminoalkyl (meth)acrylates such as isopropyl esters; N-alkylaminoalkyl (meth)acrylates, N,N-dimethylaminoethyl (meth)acrylates, (methyl) N,N-dialkylaminoalkyl (meth)acrylates such as N,N-dimethylaminopropyl acrylate. These may be used 1 type or in combination of 2 or more types.

Examples of the above-mentioned copolymerizable monomer a4 include: glycidyl (meth)acrylate, methylglycidyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, 4 - Hydroxybutyl (meth)acrylate glycidyl ether. These may be used 1 type or in combination of 2 or more types.

Examples of the above-mentioned copolymerizable monomer a5 include (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-butyl(meth)acrylamide, N- Methylol(meth)acrylamide, N-methylolpropane(meth)acrylamide, N-methoxymethyl(meth)acrylamide, N-butoxymethyl(methyl)acrylamide ) acrylamide, diacetone (meth)acrylamide, maleimide, maleimide. These may be used 1 type or in combination of 2 or more types.

As said copolymerizable monomer a6, the compound which has a vinyl group in a molecule|numerator is mentioned. As such compounds, for example, ethoxy diethylene glycol acrylate, methoxy triethylene glycol acrylate, methoxy polyethylene glycol acrylate, methoxy dipropylene glycol acrylate, methoxy Polypropylene glycol acrylate and other functional monomers with functional groups such as alkoxyalkyl groups, polyalkylene glycol di(meth)acrylates, vinyl acetate, N-vinyl-2-pyrrolidone Vinyl monomers such as vinyl propionate and vinyl laurate, and aromatic vinyl monomers such as styrene, chlorostyrene, chloromethylstyrene, α-methylstyrene and other substituted styrenes. These may be used 1 type or in combination of 2 or more types.

The macromonomer system as the above-mentioned copolymerizable monomer a7 is a polymer monomer having a free radical polymerizable unsaturated group at the terminal and a high molecular weight skeleton component. The number average molecular weight of the macromonomer is preferably at least 1000, more preferably at least 1500, and still more preferably at least 2000. In addition, the upper limit of the number average molecular weight is 10000 normally.

By using the copolymerizable monomer a7, a macromonomer can be introduced as a branch component of the graft copolymer, and the (meth)acrylate copolymer can be made into a graft copolymer. For example, a (meth)acrylic polymer (A) comprising a graft copolymer having a macromonomer as a branch component can be prepared. Therefore, the characteristics of the graft copolymer can be changed by the selection or compounding ratio of the copolymerizable monomer a7 and other monomers. In particular, in the present invention, the copolymerization ratio of the macromonomer in the (meth)acrylic polymer (A) is preferably 100 parts by mass relative to 100 parts by mass of the copolymer from the point of view of imparting fluidity at the time of hot-melting. It is 10 mass parts or less, more preferably 3 mass parts or more or 9 mass parts or less, especially preferably 4 mass parts or more or 8 mass parts or less.

The skeleton component of the macromonomer is preferably composed of (meth)acrylate polymer or vinyl polymer. For example, linear or branched alkyl (meth)acrylates, alicyclic (meth)acrylates, the above-mentioned copolymerizable monomer a1, the above-mentioned copolymerizable monomer Those exemplified in the body a2, the above-mentioned copolymerizable monomer a6, the following copolymerizable monomer a8, and the like can be used alone or in combination of two or more kinds.

Examples of the above-mentioned copolymerizable monomer a8 include: benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, nonyl Phenol EO modified (meth)acrylate, etc. These may be used 1 type or in combination of 2 or more types.

As the above-mentioned copolymerizable monomer a9, for example, (meth)acrylic acid-modified silicone, 2-acryloxyethyl acid phosphate, (meth)acrylic acid 2,2,2-trifluoroethyl 2,2,3,3-tetrafluoropropyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, 1H,1H (meth)acrylate, Fluorinated monomers such as 5H-octafluoropentyl ester, (meth)acrylic acid 1H, 1H, 2H, 2H-tridecafluoro-n-octyl ester, etc. These may be used 1 type or in combination of 2 or more types.

It is preferable that the said (meth)acrylic polymer (A) does not contain or substantially does not contain the said "copolymerizable monomer a1" from viewpoints, such as metal corrosion resistance and yellowing resistance. In addition, the term "does not contain or substantially does not contain the copolymerizable monomer a1" means not only completely excluding it, but also allowing the (meth)acrylate (co)polymer to contain less than 0.5% by mass, It is preferably less than 0.1% by mass of the copolymerizable monomer a1.

From the viewpoint of imparting durability to the oily component, adhesive force, and cohesion to the adhesive, the above-mentioned (meth)acrylic polymer (A) preferably contains a vinyl monomer having a polar group, Among them, those containing a hydroxyl group-containing monomer and/or a nitrogen atom-containing monomer are preferred. That is, the above-mentioned (meth)acrylic polymer (A) preferably has the above-mentioned "copolymerizable monomer a2", "copolymerizable monomer a3" or "copolymerizable monomer a5", especially "copolymerizable monomer a2 "As a copolymer component.

The (meth)acrylic polymer (A) is preferably a block copolymer and/or a graft copolymer from the viewpoint of imparting hot-melt property to the adhesive. Here, the block copolymer refers to a block copolymer having a plurality of polymer chains containing repeating units derived from (meth)acrylate, and the plurality of polymer chains with different chemical structures are linearly bonded. things. Here, the graft copolymer is preferably a copolymer containing a repeating unit derived from (meth)acrylate as a backbone component and a repeating unit derived from a macromonomer as a branch component of the graft copolymer, wherein Those containing a graft copolymer are preferred.

In the present invention, since it affects the flexibility of the adhesive sheet at room temperature, or the wettability of the adhesive resin composition to the adherend, that is, the adhesiveness, the adhesive resin composition in the It has moderate adhesiveness (tackiness) at room temperature, and the glass transition temperature of (meth)acrylic polymer (A) is preferably -70°C to 0°C, especially preferably -65°C or above or - 5°C or lower, particularly preferably -60°C or higher or -10°C or lower.

In this case, the glass transition temperature of the copolymer component means a value calculated by Fox's calculation formula based on the glass transition temperature and composition ratio of the polymer obtained from the homopolymer of the respective copolymer components.

In addition, the calculation formula of Fox is a calculated value obtained by the following formula, and can be obtained using the value recorded in the polymer handbook [Polymer Handbook, J. Brandrup, Interscience, 1989]. 1/(273+Tg)=Σ(Wi/(273+Tgi)) [Where, Wi represents the weight fraction of monomer i, and Tgi represents the Tg (°C) of the homopolymer of monomer i]

When the (meth)acrylic copolymer (A) is obtained, the glass transition temperature of at least one of the repeating units derived from (meth)acrylate in the acrylic polymer (A) is preferably It is -70～0℃. Examples of (meth)acrylate constituting such a repeating unit include n-butyl acrylate, n-hexyl acrylate, n-octyl acrylate, n-nonyl acrylate, n-decyl acrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, 2-methylhexyl acrylate, isooctyl acrylate, isononyl acrylate, isodecyl acrylate, isodecyl methacrylate, isostearyl acrylate, isooctyl methacrylate Stearyl ester, highly branched stearyl acrylate, highly branched stearyl methacrylate, etc., but not limited thereto.

Moreover, it is preferable that the glass transition temperature of at least 1 repeating unit among the repeating units derived from the (meth)acrylate which an acryl-type copolymer (A) has is 5-140 degreeC. Specifically, since it will affect the melting temperature of the adhesive sheet, the glass transition temperature (Tg) is preferably 5 to 140°C, more preferably 30°C to 130°C, and more preferably 40°C or higher or 120°C or lower, more preferably 50°C or higher or 110°C or lower. If there is a repeating unit having such a glass transition temperature (Tg), by adjusting the molecular weight, excellent processability or storage stability can be maintained, and it can be adjusted to heat-melt at a specific temperature, such as around 20 to 80°C .

Examples of (meth)acrylate constituting such a repeating unit include methyl (meth)acrylate, ethyl methacrylate, n-propyl (meth)acrylate, and isopropyl (meth)acrylate. , n-butyl methacrylate, tertiary butyl (meth)acrylate, isobutyl (meth)acrylate, iso-(meth)acrylate, cyclohexyl (meth)acrylate, 1,4- Cyclohexanedimethanol mono(meth)acrylate, tetrahydrofurylmethyl methacrylate, benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, the above-mentioned copolymerizable monomer a7, and the like.

In the present invention, when the (meth)acrylic polymer (A) is a block copolymer or a graft copolymer, an adhesive sheet excellent in shape stability and heat-melt property can be obtained. Block copolymers and graft copolymers can be produced by known methods, and especially graft copolymers can be produced by using a macromonomer as a copolymerization component as described above.

Here, the block copolymer refers to a copolymer having a plurality of polymer chains containing repeating units derived from (meth)acrylate, and the plurality of polymer chains having different chemical structures are linearly bonded. Part of the blocks of the block copolymer preferably contain repeating units derived from macromonomers. On the other hand, a graft copolymer is a copolymer containing a repeating unit derived from (meth)acrylate as a main component, and refers to a copolymer having a comb-like polymer, a brush-like polymer, a star-shaped Structurers such as polymers, coconut polymers, dumbbell polymers, etc. Copolymers containing repeating units derived from macromonomers as branch components of the graft copolymer are preferred.

When the above-mentioned (meth)acrylic polymer (A) is a copolymer containing a structural unit derived from a macromonomer as described above, it is preferable to 100 parts by mass of the product contains 3 to 10 parts by mass of macromonomer. If the copolymerization ratio of the macromonomer is 3 parts by mass or more with respect to 100 parts by mass of the copolymer, it is preferable in terms of suppressing excessive flow during storage or hot-melt; on the other hand, if it is 10 parts by mass Hereinafter, it is preferable in terms of providing fluidity at the time of hot-melting. From this viewpoint, the copolymerization ratio of the macromonomer is preferably 3 parts by mass or more, and more preferably 4 parts by mass or more. On the other hand, it is preferably 10 parts by mass or less, preferably 9 parts by mass or less, preferably 8 parts by mass or less, and preferably less than 7 parts by mass.

The glass transition temperature of the repeating unit derived from the macromonomer is preferably 20 to 150°C, more preferably 40°C or higher or 130°C or lower, and even more preferably 60°C or higher or 120°C or lower. In addition, when the above-mentioned (meth)acrylic polymer (A) is a block copolymer and/or a graft copolymer, the content of the copolymer component whose glass transition temperature is in the above-mentioned range is relatively low for the same reason as above. Preferably, it is 3 mass parts or more with respect to 100 mass parts of said (meth)acryl-type polymers (A), More preferably, it is 4 mass parts or more. On the other hand, it is preferably 10 parts by mass or less, preferably 9 parts by mass or less, preferably 8 parts by mass or less, and preferably less than 7 parts by mass.

The above-mentioned (meth)acrylic polymer (A) preferably contains "an alkyl (meth)acrylate having an alkyl group having 6 or less carbon atoms" and "a vinyl monomer having a polar group" as monomers ingredients. In this case, the content of "alkyl (meth)acrylate having an alkyl group having 6 or less carbon atoms" in the monomer components forming the acrylic polymer (A) is preferably 40% by mass or more, and "having a polar group The content of "vinyl monomer" is preferably not less than 10% by mass and not more than 50% by mass. For oil resistance, that is, in order to suppress penetration of oily components and swelling caused by oily components, it is preferable to contain a "polar group-containing vinyl monomer" as a monomer component forming the acrylic copolymer (A). On the other hand, as the polar group in the (meth)acrylic polymer (A) increases, the cohesive force of the adhesive sheet tends to increase and the heat-melt property tends to decrease. In addition, the polar groups or the polar groups and other components react due to heating or the like, and gelation proceeds slowly, which may impair the quality stability of the adhesive sheet. Thus, it is difficult to achieve both oil resistance and hot melt properties at a high quality level. However, if the above-mentioned (meth)acrylic polymer (A) has such a composition, it is possible to suppress the penetration of the oily component of the adhesive sheet and the swelling of the adhesive sheet caused by the oily component, and also It is hot-melt, so it is preferable. From this point of view, the content of the "alkyl (meth)acrylate having an alkyl group having 6 or less carbon atoms" in the monomer component forming the (meth)acrylic polymer (A) is preferably 40% by mass % or more, more preferably 90% by mass or less, and more preferably 45% by mass or more or 85% by mass or less. Also, the content of the "vinyl monomer having a polar group" is preferably at least 2 parts by mass, more preferably at least 3 parts by mass, and even more preferably It is preferably at least 5 parts by mass, and particularly preferably at least 10 parts by mass. On the other hand, it is preferably less than 50 parts by mass, more preferably less than 45 parts by mass, especially preferably less than 40 parts by mass, especially preferably less than 35 parts by mass, especially preferably less than 30 parts by mass, and especially preferably less than 30 parts by mass. It is 25 mass parts or less.

(Crosslinking agent (B)) The crosslinking agent (B) is a compound or a composition that can cause a polymerization reaction or a crosslinking reaction by a radical reaction using active energy rays, and is bonded to a (meth)acrylic polymer. The crosslinking agent (B) is a compound having two or more crosslinkable functional groups. By including the crosslinking agent (B), the adhesive composition can form a crosslinked structure and improve the durability or oil resistance of the adhesive sheet.

The crosslinking agent (B) is preferably a polyfunctional (meth)acrylate having a cyclic structure from the viewpoint of suppressing swelling caused by an oily component after forming a crosslinked structure.

From the viewpoint of securing the properties of the adhesive sheet that is hardened by irradiation with active energy rays, the crosslinking agent (B) preferably contains a polyfunctional (meth)acryloyl group having two or more (meth)acryloyl groups. Acrylate component (b-1). Also, from the viewpoint of improving the followability to thermal dimensional changes of the adherend, it is preferable to further include a monofunctional (meth)acrylate component (b-2) having one (meth)acryl group. .

This adhesive composition can form The cross-linking structure promotes the cross-linking reaction of the (meth)acrylic polymer (A), which can accelerate the hardening of the adhesive composition. Furthermore, by including the monofunctional (meth)acrylate component (b-2) having one (meth)acryl group, the molecular weight between the crosslinking points of the cured product can be increased, so the degree of freedom of molecular chain movement In addition, when the adherend is laminated through this adhesive sheet, even when the size of the adherend is deformed due to repeated operations such as heating and cooling, the adhesive sheet containing this adhesive composition can also follow it. And deformation.

From this viewpoint, it is preferable to contain a polyfunctional (meth)acrylate component (b-1) and a monofunctional (meth)acrylate component (b-2). In this case, the content mass ratio is preferably (b-1):(b-2)=1:0.1 to 1:9, more preferably 1:1 to 1:9, and still more preferably 1:2 ~1:9. By being within this range, the monofunctional (meth)acrylate component (b-2) does not become too much, and there is no possibility that the sensitivity to light may fall and productivity may fall, and it can fully follow a to-be-adhered body.

Also, the content of the crosslinking agent (B) is preferably 0.2 parts by mass or more, more preferably 0.5 parts by mass or more, and more preferably 1 part by mass relative to 100 parts by mass of the (meth)acrylic polymer (A). parts by mass or more. The upper limit is preferably at most 30 parts by mass, more preferably at most 25 parts by mass, and even more preferably at most 20 parts by mass. Also, from the viewpoint of forming a cross-linked structure and imparting swelling resistance and cohesive force to the oily component after hardening, the content of the polyfunctional (meth)acrylate component (b-1) is preferably at a level relative to ( 100 parts by mass of the meth)acrylic polymer (A) is at least 0.5 parts by mass, preferably at least 1 part by mass, especially preferably at least 1.5 parts by mass, particularly preferably at least 6 parts by mass. The upper limit is preferably not more than 20 parts by mass, especially preferably not more than 15 parts by mass, particularly preferably not more than 10 parts by mass. From the viewpoint of adjusting the crosslink density and imparting moderate flexibility to the cured product, the content of the monofunctional (meth)acrylate component (b-2) is preferably 100% relative to the (meth)acrylic polymer (A ) 100 parts by mass is 2 parts by mass or more, preferably 4 parts by mass or more, particularly preferably 6 parts by mass or more. The upper limit is preferably not more than 20 parts by mass, especially preferably not more than 18 parts by mass, particularly preferably not more than 15 parts by mass.

The polyfunctional (meth)acrylate component (b-1) is preferably a component having a glass transition temperature higher than 0°C when made into a homopolymer, more preferably 5°C or higher, and even more preferably 10°C above. In addition, the upper limit is usually 250°C. On the other hand, the monofunctional (meth)acrylate component (b-2) is preferably a component having a glass transition temperature of 0°C or lower when made into a homopolymer, more preferably -10°C or lower, and further preferably It is preferably below -20°C. Note that the lower limit is usually -80°C. By containing the monofunctional (meth)acrylate component (b-2) with a low glass transition temperature, it hardens gradually even when hardened, so it deforms following the dimensional change of the adherend, so, for example, it is easy to repeat In the durability test of heating and cooling, etc., it is also possible to suppress the occurrence of peeling and air bubbles. Here, the glass transition temperature means the maximum value of loss tangent (tan δ) obtainable by dynamic viscoelasticity measurement at a frequency of 1 Hz.

Examples of the polyfunctional (meth)acrylate component (b-1) include: 1,4-butanediol di(meth)acrylate, glycerin di(meth)acrylate, neopentyl glycol di (meth)acrylate, glyceryl glycidyl ether di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, tri Cyclodecane dimethanol di(meth)acrylate, Dihydroxyadamantane di(meth)acrylate, Adamantane dimethanol di(meth)acrylate, Dicyclopentadiene di(meth)acrylate, Adamantanetriol tri(meth)acrylate, adamantanetrimethanol tri(meth)acrylate, cyclohexanedimethanol di(meth)acrylate, dioxanediol di(meth)acrylate, Spirodiol di(meth)acrylate, fennel di(meth)acrylate, bisphenol A polyethoxy di(meth)acrylate, bisphenol A polypropoxy di(meth)acrylate, bisphenol A polyethoxy di(meth)acrylate, Phenol F polyethoxy di(meth)acrylate, ethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, trimethylolpropane trioxyethyl(methyl) ) acrylate, ε-caprolactone modified tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate, pentaerythritol tri(meth)acrylate, propoxylated pentaerythritol tri(meth)acrylate, Ethoxylated pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, propoxylated pentaerythritol tetra(meth)acrylate, ethoxylated pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate ester, polyethylene glycol di(meth)acrylate, tris(acryloxyethyl)isocyanurate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol penta(meth)acrylate, tripentaerythritol Hexa(meth)acrylate, tripentaerythritol penta(meth)acrylate, hydroxypivalate neopentyl glycol di(meth)acrylate, ε-caprolactone addition of hydroxypivalate neopentyl glycol Two (meth)acrylates, trimethylolpropane tri(meth)acrylates, trimethylolpropane polyethoxy tri(meth)acrylates, two-trimethylolpropane tetra( UV-curable polyfunctional (meth)acrylic monomers such as methacrylates; other than the above, polyester (meth)acrylates, epoxy (meth)acrylates, aminomethacrylates, etc. Polyfunctional (meth)acrylic oligomers such as ester (meth)acrylate and polyether (meth)acrylate. These can be used 1 type or in combination of 2 or more types.

Among these, from the viewpoint of preventing swelling caused by oily components, tricyclodecane dimethanol di(meth)acrylate, dihydroxyadamantane di(meth)acrylate, adamantane Alkanedimethanol di(meth)acrylate, dicyclopentadiene di(meth)acrylate, adamantanetriol tri(meth)acrylate, adamantanetrimethanol tri(meth)acrylate, cyclohexane Alkanedimethanol di(meth)acrylate, dioxanediol di(meth)acrylate, spirodiol di(meth)acrylate, fennel di(meth)acrylate, bisphenol A polyethoxylate Di(meth)acrylate, bisphenol A polypropoxy di(meth)acrylate, bisphenol F polyethoxy di(meth)acrylate, ε-caprolactone modified tris(2-hydroxy Ethyl) isocyanuric acid tri(meth)acrylate, isocyanuric acid tris(acryloxyethyl) ester and other (meth)acrylic acid esters having a cyclic structure, among which it is more preferable to have an alicyclic structure or Heterocyclic structure tricyclodecane dimethanol di(meth)acrylate, dihydroxyadamantane di(meth)acrylate, adamantane dimethanol di(meth)acrylate, dicyclopentadiene di(meth)acrylate base) acrylate, adamantanetriol tri(meth)acrylate, adamantanetrimethanol tri(meth)acrylate, cyclohexanedimethanol di(meth)acrylate, dioxanediol di(meth)acrylate base) acrylate, spirodiol di(meth)acrylate, among which tricyclodecane dimethanol di(meth)acrylate and dihydroxyadamantane di(meth)acrylate with alicyclic structure are more preferred , Adamantanedimethanol di(meth)acrylate, dicyclopentadiene di(meth)acrylate.

Examples of the monofunctional (meth)acrylate component (b-2) include ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, (meth)acrylate Butyl acrylate, isobutyl (meth)acrylate, tertiary butyl (meth)acrylate, amino (meth)acrylate, isoamino (meth)acrylate, 2-ethyl (meth)acrylate Hexyl (meth)acrylate, lauryl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, (meth) Lauryl acrylate, Isododecyl (meth)acrylate, Myristyl (meth)acrylate, Stearyl (meth)acrylate, Isostearyl (meth)acrylate, ( Behenyl methacrylate, Cyclopropyl (meth)acrylate, Cyclobutyl (meth)acrylate, Cyclopentyl (meth)acrylate, Cyclohexyl (meth)acrylate, Cyclo(meth)acrylate Heptyl, Cyclooctyl (meth)acrylate, Cyclononyl (meth)acrylate, Cyclodecyl (meth)acrylate, Iso(meth)acrylate, Noryl (meth)acrylate, Adamantyl (meth)acrylate, tricyclodecane dimethanol acrylate, ethoxylated-o-phenylphenol acrylate, 2-hydroxy-o-phenylphenol propyl acrylate, methoxypolyethylene glycol ( Meth)acrylate, Methoxypolypropylene Glycol (Meth)acrylate, Polyethylene Glycol (Meth)acrylate, Polypropylene Glycol (Meth)acrylate, Phenoxyethylene Glycol (Meth)acrylate , Phenoxydiethylene glycol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, 2-hydroxy-o-phenylphenol propyl acrylate, 2-(meth)acryl Oxyethylsuccinic acid, 2-(meth)acryloxyethyl tetrahydrophthalic acid, 2-(meth)acryloxyethyl hexahydrophthalic acid, 2-(methyl) ) acryloxypropyl phthalic acid, 2-(meth)acryloxypropyl phthalic acid, 2-(meth)acryloxypropyl hexahydrophthalic acid, etc. (form base) benzyl acrylate, benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxyethylene glycol (meth)acrylate, 2-naphthyl (meth)acrylate, (meth) ) 9-anthracene acrylate, 1-pyrenylmethyl (meth)acrylate, benzyl (meth)acrylate, tricyclodecane dimethanol monoacrylate monocarboxylic acid, dicyclopentanyl acrylate, (meth)acrylic acid 2-Hydroxyethyl ester, 2-Hydroxypropyl (meth)acrylate, 3-Hydroxypropyl (meth)acrylate, 2-Hydroxybutyl (meth)acrylate, 4-Hydroxybutyl (meth)acrylate, Trimethylolpropane mono(meth)acrylate, glycerol mono(meth)acrylate, pentaerythritol mono(meth)acrylate, diglycerol mono(meth)acrylate, di-trimethylolpropane mono( Meth)acrylate, Dipentaerythritol Mono(meth)acrylate, Ethoxylated Trimethylolpropane Mono(meth)acrylate, Propoxylated Trimethylolpropane Mono(meth)acrylate, Ethoxylated Glycerol Mono (meth)acrylates, propoxylated glycerol mono( Meth)acrylate, ethoxylated pentaerythritol mono(meth)acrylate, propoxylated pentaerythritol mono(meth)acrylate, ethoxylated di-trimethylolpropane mono(meth)acrylate, ethoxylated di-trimethylolpropane mono(meth)acrylate, Methylolpropane mono(meth)acrylate, alkylene oxide modified diglycerin mono(meth)acrylate and alkylene oxide modified dipentaerythritol mono(meth)acrylate, etc.; : Monofunctional oligomers such as monofunctional urethane (meth)acrylate, monofunctional epoxy (meth)acrylate, and monofunctional polyester (meth)acrylate. These can be used 1 type or in combination of 2 or more types.

＜Polymerization initiator (C)＞ The polymerization initiator (C) should just be a compound which generate|occur|produces a radical by an active energy ray. Polymerization initiators (C) are roughly divided into two types according to the mechanism of free radical generation. They are roughly divided into cleavage-type photoinitiators that can cleavage and decompose the single bond of the initiator itself to generate free radicals, and excited initiators. A hydrogen abstraction type photoinitiator that forms an excited complex with the hydrogen donor in the system and can transfer the hydrogen of the hydrogen donor.

As the polymerization initiator (C), it may be any one of a cracking type photoinitiator and a hydrogen abstraction type photoinitiator, and may be used alone or in combination. Furthermore, one of each may be used Or use 2 or more types together.

As the cleavage-type photoinitiator, for example, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2- Methyl-1-phenyl-propan-1-one, 1-(4-(2-hydroxyethoxy)phenyl)-2-hydroxy-2-methyl-1-propan-1-one, 2- Hydroxy-1-[4-{4-(2-hydroxy-2-methyl-propionyl)benzyl}phenyl]-2-methyl-propan-1-one, oligo(2-hydroxy-2 -Methyl-1-(4-(1-methylvinyl)phenyl)acetone), methyl phenylglyoxylate, 2-benzyl-2-dimethylamino-1-(4-𠰌 Linylphenyl) butan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-𠰌linylpropan-1-one, 2-(dimethylamino )-2-[(4-methylphenyl)methyl]-1-[4-(4-𠰌linyl)phenyl]-1-butanone, bis(2,4,6-trimethylbenzene Formyl)-phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, (2,4,6-trimethylbenzoyl)ethoxyphenylphosphine oxide Phosphine, bis(2,6-dimethoxybenzoyl) 2,4,4-trimethylpentylphosphine oxide, or derivatives thereof.

、2-氯9-氧硫𠮿

、3-甲基9-氧硫𠮿

、2,4-二甲基9-氧硫𠮿

、、2-甲基蒽醌、2-乙基蒽醌、2-第三丁基蒽醌、2-胺基蒽醌或其衍生物等。Examples of hydrogen abstraction photoinitiators include: benzophenone, 4-methyl-benzophenone, 2,4,6-trimethylbenzophenone, 4-phenylbenzophenone Ketone, 3,3'-dimethyl-4-methoxybenzophenone, 4-(meth)acryloxybenzophenone, methyl 2-benzoylbenzoate, benzoylformic acid Methyl ester, bis(2-phenyl-2-oxoacetic acid)oxybisethylene, 4-(1,3-acryloyl-1,4,7,10,13-pentaoxotridecyl) Benzophenone, 9-oxosulfur

, 2-Chloro9-oxosulfur 𠮿

, 3-methyl 9-oxosulfur 𠮿

, 2,4-Dimethyl 9-oxosulfur 𠮿

,, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2-aminoanthraquinone or its derivatives, etc.

The content of the above-mentioned polymerization initiator (C) is not particularly limited. As a standard, it is preferably contained in a ratio of 0.1 to 10 parts by mass, including 0.5 to 5 parts by mass, and 1 to 3 parts by mass relative to 100 parts by mass of the (meth)acrylic polymer (A).

＜Silane coupling agent (D)＞ The silane coupling agent (D) can improve adhesion, especially the adhesion to glass materials.

Examples of silane coupling agents include unsaturated groups such as vinyl, acryloxy, and methacryloxy groups, amino groups, epoxy groups, etc., and hydrolyzable functions such as alkoxy groups. base compound. Specific examples of silane coupling agents include N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyl Methyldimethoxysilane, γ-Aminopropyltriethoxysilane, γ-Glycidoxypropyltrimethoxysilane, γ-Methacryloxypropyltrimethoxysilane, etc. Among them, in this adhesive layer, γ-glycidoxypropyltrimethoxysilane or γ-methacryloxysilane can be preferably used from the viewpoint of good adhesion and less discoloration such as yellowing. Propyltrimethoxysilane. The said silane coupling agent can be used individually by 1 type or in combination of 2 or more types.

It is preferable that content of the said silane coupling agent (D) is 0.1-5 mass parts with respect to 100 mass parts of (meth)acryl-type polymers (A), More preferably, it is 0.2-3 mass parts or less. Furthermore, similarly to the silane coupling agent, coupling agents such as organic titanate compounds can also be effectively used.

＜Other ingredients＞ As "other components" other than the above contained in this adhesive composition, for example, if necessary, an adhesion-imparting resin, an antioxidant, a light stabilizer, a metal deactivator, an anti-aging agent, a moisture absorbing agent, a polymer Various additives such as inhibitors, UV absorbers, rust inhibitors, inorganic particles, etc. Moreover, reaction catalysts, such as a tertiary amine type compound, a quaternary ammonium type compound, and a tin laurate compound, may be contained suitably as needed.

(block copolymer or graft copolymer) The present adhesive composition may contain a block copolymer and/or a graft copolymer as a polymer other than the (meth)acrylic polymer (A) in order to impart heat-fusibility to the present adhesive sheet. These copolymers preferably have at least one rubbery segment and at least one glassy segment.

Here, the block copolymer refers to a block copolymer having a plurality of polymer chains containing a repeating unit derived from a certain monomer, and the plurality of polymer chains having different chemical structures are linearly bonded. Also, the graft copolymer refers to a copolymer containing a repeating unit derived from a monomer as a main component, and a repeating unit derived from a monomer different from the main component as a branch component of the graft copolymer.

The rubber-like segment is a portion showing a glass transition temperature (Tg) that has not reached room temperature, and the Tg of the rubber-like segment is preferably less than 0°C, more preferably less than -10°C, and more preferably less than -10°C. -20°C. The monomer constituting the rubbery segment may, for example, be a conjugated diene or a hydrogenated derivative of a conjugated diene. Here, the conjugated diene preferably contains 4 to 12 carbon atoms. Examples of conjugated dienes include butadiene, isoprene, ethylbutadiene, phenylbutadiene, 1,3-pentadiene, pentadiene, hexadiene, ethylene Hexadiene, and dimethylbutadiene. The polymeric conjugated dienes can be used individually or mutually as copolymers. In one embodiment, the conjugated diene is selected from the group consisting of isoprene, butadiene, ethylene-butadiene copolymer, and combinations thereof.

Glassy segments are those that exhibit a Tg above room temperature. The Tg of the glassy segment is 40°C or higher, preferably 60°C or higher, more preferably 80°C or higher. As a monomer which comprises a glassy segment, a monovinyl aromatic monomer is mentioned, for example, but it is not limited to these. For example, examples of monovinyl aromatic monomers include styrene, vinylpyridine, vinyltoluene, α-methylstyrene, methylstyrene, dimethylstyrene, ethylstyrene, diethylstyrene, butylstyrene, tert-butylstyrene, di-n-butylstyrene, isopropylstyrene, other alkylated styrenes, styrene analogs, and styrene homologues.

The content of block copolymers and/or graft copolymers other than the (meth)acrylic polymer (A) is preferably 1 part by mass relative to 100 parts by mass of the (meth)acrylic polymer (A) Above, more preferably at least 2 parts by mass, especially at least 5 parts by mass. The upper limit is preferably 100 parts by mass or less, more preferably 95 parts by mass or less, and more preferably 90 parts by mass or less.

(Plasticizer) The present adhesive composition may contain a plasticizer to impart hot-melt property to the present adhesive sheet.

It does not specifically limit as an example of a plasticizer. For example, it may be selected from polyisobutylene, polyisoprene, polybutadiene, amorphous polyolefin and its copolymer, silicone, polyacrylate, oligomer polyurethane, ethylene propylene copolymer substances, any combination or mixture thereof. Among them, the plasticizer is preferably polyisobutylene. As an example of the polyisobutylene plasticizer which can be used in this specification, what is marketed by BASF (BASF) under the trade name OPPANOL, especially the thing selected from OPPANOLB series can be mentioned.

From the point of view of environmental protection, the value of the volatile organic compound (VOC) of the plasticizer used is preferably smaller, and in the case of measurement by thermogravimetric analysis, it is preferably less than 1000 ppm , more preferably less than 800 ppm, more preferably less than 600 ppm, most preferably less than 400 ppm.

The content quality of the plasticizer is not particularly limited. Preferably, it is 0.1-20 mass parts with respect to 100 mass parts of (meth)acryl-type polymers (A), More preferably, it is 0.5-15 mass parts.

(Hydrocarbon-based adhesion imparting agent) The present adhesive composition may contain a hydrocarbon-based adhesive imparting agent to impart hot-melt property to the present adhesive sheet. Examples of hydrocarbon-based tackifiers include polyterpenes (such as α-pinene-based resins, β-pinene-based resins, and limonene-based resins) and aromatic-modified polyterpene resins (such as phenol-modified polyterpene-based resins). resin) and other terpene resins, 2,3-dihydrobenzofuran-indene resins, petroleum-based resins such as C5-based hydrocarbon resins, C9-based hydrocarbon resins, C5/C9-based hydrocarbon resins, and dicyclopentadiene-based resins, Rosins such as modified rosin or hydrogenated rosin, polymerized rosin, and rosin ester. The hydrocarbon-based adhesive agent is preferably compatible with the adhesive composition.

The content of the hydrocarbon-based adhesion imparting agent is not particularly limited. Preferably, it is 0.1-40 mass parts with respect to 100 mass parts of (meth)acryl-type polymers (A), More preferably, it is 0.5-20 mass parts or less.

By including these plasticizers and hydrocarbon-based adhesive imparting agents, it is possible to suitably produce a hot-melt adhesive composition having adhesive properties.

＜Preparation method of this adhesive composition＞ The present adhesive composition can be obtained by mixing a crosslinking agent (B) and/or a polymerization initiator (C) preferably in a specific amount in addition to the (meth)acrylic polymer (A), and then Obtained as necessary silane coupling agent (D) and other components. The mixing method is not particularly limited, and the order of mixing the components is also not particularly limited. In addition, a heat treatment step may be added when producing the present adhesive composition. In this case, it is desirable to heat-process after mixing each component of this adhesive composition in advance. Those obtained by concentrating and masterbatching various mixing components can be used.

Also, the mixing device is not particularly limited, for example, a universal kneader, a planetary mixer, a Banbury mixer, a kneader, a frame mixer, a pressurized kneader, a three-roll mill, and a two-roll mill can be used. . If necessary, a solvent can be used for mixing. Furthermore, the present adhesive composition can be used as a solvent-free system that does not contain a solvent. By using it as a solvent-free system, there is an advantage of improving heat resistance and light resistance without leaving a solvent.

＜Layers other than this adhesive layer＞ In the present invention, if the adhesive sheet is composed of two or more layers, it is preferable from the viewpoint of making the storage stability, workability, and adhesive properties of the adhesive sheet good, and in this case, it is preferable It is preferable to have an intermediate layer as a layer other than this adhesive layer, for example, the composition of an intermediate layer is arbitrary. However, from the viewpoint of further improving interlayer adhesion, it is preferable that the adhesive composition forming a layer other than the present adhesive layer also contains (meth)acrylic polymer (A) as a main component resin, and preferably It contains the same (meth)acrylic-type polymer (A) as this adhesive layer as a main component resin. Furthermore, it is preferable that the layer other than this adhesive agent layer also contains a crosslinking agent (B) and a polymerization initiator (C). In this case, the crosslinking agent (B) further preferably contains a polyfunctional (meth)acrylate component (b-1) and a monofunctional (meth)acrylate component (b-2).

＜How to make or use this adhesive sheet＞ The adhesive sheet can also be used in the form of a single adhesive sheet. For example, the adhesive composition can be directly coated on the adherend to form a sheet, or the adhesive composition can be directly extruded or injected into a mold to produce the adhesive sheet. Furthermore, this adhesive sheet can also be produced by directly filling this adhesive composition between members, such as a conductive member.

On the other hand, this adhesive sheet can also be produced as an adhesive sheet laminate with an adhesive layer formed from this adhesive composition and a release film with a release film. For example, the form of an adhesive sheet with a release film formed by forming the present adhesive composition on a release film in the form of a single-layer or multi-layer sheet can also be used.

As a material of the said release film, a polyester film, a polyolefin film, a polycarbonate film, a polystyrene film, an acrylic film, a triacetyl cellulose film, a fluororesin film etc. are mentioned, for example. Among these, polyester films and polyolefin films are particularly preferred.

The thickness of the release film is not particularly limited. Among them, for example, from the standpoint of workability and handleability, it is preferably 25 μm to 500 μm, more preferably 38 μm or more or 250 μm or less, and even more preferably 50 μm or more or 200 μm or less.

＜This laminate＞ A laminate for an image display device (referred to as "this laminate") as an example of an embodiment of the present invention includes this adhesive sheet interposed between two constituent members for an image display device. A laminate for forming an image display device in which constituent members for a display device are laminated through this adhesive sheet. This laminate can be bonded to two image display devices by irradiating active energy rays to this adhesive sheet to harden this adhesive sheet (this hardened adhesive sheet is referred to as "this hardened adhesive sheet") Use components.

In this case, the above-mentioned two components of the image display device can be, for example, at least one of which is a member of the group consisting of a touch sensor, an image display panel, a surface protection panel, a polarizing film, and a retardation film. A laminate of any one type or a combination of two or more types.

When at least one of the above-mentioned two image display device constituent members has unevenness on the contact surface with this adhesive sheet, as long as the ratio of depth (mm)/bottom area (mm ² ) is 1.0 ×10 ^-5 ~ 3.0×10 ^-1 , of which 5.0×10 ^-5 or more or 2.0×10 ^-1 or less, of which 1.0×10 ^-4 or more or 1.0×10 ^-1 or less bottomed holes are acceptable Further enjoy the effect of this adhesive sheet. At this time, the adhesive composition of the adhesive sheet can be filled in the bottomed hole, and at this time, the bottomed hole can be filled so that there are no voids with a diameter of at least 1 mm or more. In addition, the above-mentioned "diameter of the void" means the longest diameter when the void is non-spherical.

Specific examples of this laminate include release film/this adhesive sheet or this hardened adhesive sheet/touch panel, image display panel/this adhesive sheet or this hardened adhesive sheet/touch panel. Control panel, image display panel/adhesive sheet or adhesive sheet after hardening/touch panel/adhesive sheet or adhesive sheet after hardening/protective panel, polarizing film/adhesive sheet or adhesive sheet after hardening Adhesive sheet/touch panel, polarizing film/adhesive sheet or adhesive sheet after hardening/touch panel/adhesive sheet or adhesive sheet after hardening/protection panel.

The above-mentioned touch panel also includes a structure in which a protective panel internalizes a touch panel function, or a structure in which an image display panel internalizes a touch panel function. Therefore, the present laminate may be, for example, release film/present adhesive sheet or present cured adhesive sheet/protective panel, release film/present adhesive sheet or present cured adhesive sheet/image display panel, image display panel, etc. Such as display panel/this adhesive sheet or this hardened adhesive sheet/protective panel etc. In addition, in the above-mentioned structure, the present adhesive sheet or the cured adhesive sheet, and members such as a touch panel, a surface protection panel, an image display panel, a polarizing film, and a retardation film adjacent thereto can be mentioned. All the components of the above-mentioned conductive layer are interposed therebetween. However, it is not limited to these lamination examples.

In addition, as said touch panel, the thing of the system, such as a resistive film system, an electrostatic capacitance system, and an electromagnetic induction system, is mentioned. Among them, the electrostatic capacitance method is preferable.

As the material of the above-mentioned protective panel, in addition to glass, alicyclic polyolefin resins such as acrylic resins, polycarbonate resins, and cycloolefin polymers, styrene resins, polyvinyl chloride resins, polyamide resins, etc. Plastics such as imide resins, phenol resins, melamine resins, and epoxy resins.

The image display panel is composed of polarizing film, other optical films such as retardation film, liquid crystal material and backlight system (generally, the adhesive composition or the adhered surface of the adhesive article facing the image display panel is an optical film ), according to the control method of the liquid crystal material, there are STN (Super Twisted Nematic, super twisted nematic) method or VA (vertical alignment) method or IPS (In-Plane Switching, transverse electric field effect) method, etc., which can be any method .

This laminate can be used, for example, as a component of image display devices such as liquid crystal displays, organic EL (Electroluminescence) displays, inorganic EL displays, electronic paper, plasma displays, and microelectromechanical systems (MEMS) displays.

<Manufacturing method of laminated body for constituting image display device> Next, an example of the manufacturing method of this laminated body is demonstrated. However, the manufacturing method of this laminated body is not limited to the method demonstrated below.

In this laminated system, this adhesive sheet is bonded to one side of the first image display device component to form a bonded body, and the bonded surface of the second image display device component and the above-mentioned Adhesive sheets for the laminated body to form a laminated body. As the bonding method, known methods such as roll bonding, pressure bonding using a parallel plate, and separator bonding can be used. As the bonding environment, there are atmospheric bonding method of bonding under normal pressure, and vacuum bonding method of bonding under reduced pressure. From the viewpoint of preventing air bubbles during bonding, a method of bonding on parallel plates under a reduced pressure environment is preferable.

Next, the above-mentioned laminate is heated to melt the adhesive sheet. That is, heating the above-mentioned laminate at 40°C to 80°C to melt the above-mentioned adhesive sheet, and adapt the adhesive composition to the surface of the adherend, in the case where the above-mentioned second image display device constituent member has concave-convex portions When, the adhesive composition is flowed into the concavo-convex part. The heating temperature at this time is preferably from 40°C to 80°C, more preferably from 45°C to 75°C, and even more preferably from 50°C to 70°C. In addition, pressure treatment may be performed together with heat treatment, and an air pressure of 0.2 MPa or more and 0.8 MPa or less may be applied to this laminate. The air pressure at this time is preferably from 0.2 MPa to 0.8 MPa, more preferably from 0.25 MPa to 0.75 MPa, and particularly preferably from 0.30 MPa to 0.70 MPa. Moreover, the above-mentioned treatment time is preferably 5 minutes or more, more preferably 5 minutes or more or 60 minutes or less, and even more preferably 10 minutes or more or 45 minutes or less.

Next, the present adhesive sheet sandwiched between the first and second image display constituent members is irradiated with active energy rays to harden the present adhesive sheet to manufacture the present laminate. Furthermore, in the above, the second image display device constituent member may have concavo-convex portions, such as bottomed holes, on the contact surface with the adhesive sheet. According to the present invention, the adhesive composition can be sufficiently flowed into the second image display device. 2 Inside the bottomed hole of the components of the image display device.

In the present invention, ultraviolet rays and visible rays are suitable as the active energy rays at the time of irradiating the above-mentioned active energy rays. Regarding the light source when irradiating active energy rays, for example, high-pressure mercury lamps, metal halide lamps, xenon lamps, halogen lamps, LED (light-emitting diode, light-emitting diode) lamps, fluorescent lamps, etc., among them, It can be used separately according to the wavelength of the irradiated light or the amount of irradiation. Also, there is no particular limitation on the irradiation time or irradiation method. For example, in the case of ultraviolet irradiation, the cumulative light amount at a wavelength of 365 nm is preferably 100 mJ/cm ² to 10000 mJ/cm ² , more preferably 500 mJ/cm ² to 8000 mJ/cm ² , more preferably 1000 mJ/cm ² to 6000 mJ/cm ² , especially preferably 1500 mJ/cm ² to 4000 mJ/cm ² .

As a preferable example of this laminated body, a laminated body for constituting an image display device having a structure in which two image display device constituent members are laminated via a hardened adhesive sheet, and the hardened adhesive sheet is exemplified Under specific hardening conditions, the creep strain at 80°C for 180 seconds at a thickness of 0.8-1.5 mm after hardening is more than 10%. The hardened adhesive sheet is a sheet obtained by photohardening the original adhesive sheet. In this case, for example, at least one of the constituent members of the image display device has unevenness, for example, the surface in contact with the above-mentioned adhesive sheet has a depth (mm)/bottom area (mm ² ) of 1.0×10 ^-5 to 3.0×10 ^-1 bottomed hole. At this time, it is preferable that the above-mentioned cured adhesive sheet is filled in the bottomed hole, and the bottomed hole is filled in a state where there are no voids having a diameter of at least 1 mm or more. In addition, the above-mentioned "diameter of the void" means the longest diameter when the void is non-spherical.

<This image display device> An image display device (also referred to as "the present image display device") as an example of an embodiment of the present invention is an image display device including the laminate for constituting the present image display device. Specific examples of the present image display device include, for example, liquid crystal displays, organic EL displays, inorganic EL displays, electronic paper, plasma displays, and microelectromechanical system (MEMS) displays.

＜Description of sentences＞ In the present invention, when expressed as "X~Y" (X, Y are arbitrary numbers), unless otherwise specified, it includes the meaning of "more than X but less than Y" and also includes "preferably greater than X". ” or “preferably less than Y”. In addition, when expressed as "more than X" (X is any number) or "below Y" (Y is any number), it also includes the intention of "preferably greater than X" or "preferably less than Y". . In addition, in the present invention, a "sheet" conceptually includes a sheet, a film, and a tape. [Example]

The invention is further illustrated by the following examples. However, the present invention should not be construed limitedly by the Examples shown below.

First, the details of the raw materials of the adhesive composition prepared in the examples will be described.

＜(Meth)acrylic polymer (A)＞ ・(Meth)acrylic polymer (A-1): 6 parts by mass of polymethyl methacrylate macromonomer (Tg105°C) with a number average molecular weight of 2800, 74 parts by mass of butyl acrylate (Tg-55°C), Acrylic graft copolymer (mass average molecular weight: 330,000, Tg-42°C) obtained by random copolymerization of 20 parts by mass of 2-hydroxyethyl acrylate (Tg-15°C) ・(Meth)acrylic polymer (A-2): 15 parts by mass of polymethyl methacrylate macromonomer (Tg105°C) with a number average molecular weight of 2800, 81 parts by mass of butyl acrylate (Tg-50°C), Acrylic graft copolymer (mass average molecular weight: 160,000, Tg-36°C) obtained by random copolymerization of 4 parts by mass of acrylic acid (Tg106°C)

The glass transition temperature of each copolymerized component in the above-mentioned (meth)acrylic polymer is a literature value based on the glass transition temperature obtained by the homopolymer of the component. Regarding the macromonomer, literature values of glass transition temperatures obtained from homopolymers of components forming the high-molecular-weight skeleton in the macromonomer are described. The glass transition temperature of the acrylic copolymer describes the theoretical Tg calculated by Fox's calculation formula based on the glass transition temperature and composition ratio of the above-mentioned copolymerization components.

＜Crosslinking agent (B)＞ ・Crosslinking agent (B-1): Tricyclodecane dimethanol dimethacrylate ・Crosslinking agent (B-2): propoxylated pentaerythritol triacrylate

＜Polymerization initiator (C)＞ ・Initiator (C-1): Mixture of 2,4,6-trimethylbenzophenone and 4-methylbenzophenone ("Esacure TZT" manufactured by IGM Corporation)

[Example 1] 100 parts by mass of (meth)acrylic polymer (A-1), 5 parts by mass of crosslinking agent (B-1), and 1.5 parts by mass of initiator (C-1) were uniformly mixed to prepare an adhesive composition . On a 100 μm-thick release film (PET (polyethylene terephthalate, polyethylene terephthalate) film manufactured by Mitsubishi Chemical Corporation) that has been treated with silicone release, the thickness of the above-mentioned adhesive composition is 100 μm The way to make it unfold into a sheet.

Next, a release film (PET film manufactured by Mitsubishi Chemical Corporation) with a thickness of 75 μm treated with silicone release was laminated on the sheet-shaped adhesive composition to form a laminate, and a release film/adhesive sheet was obtained. 1/ Adhesive sheet with release film 1. In addition, the adhesive sheet 1 is an active energy ray-curable adhesive sheet having active energy ray-curable properties cured by irradiation with active energy rays.

[Examples 2-5, Comparative Examples 1-2] Adhesive sheets 2 to 7 were produced in the same manner as in Example 1 except that the composition shown in Table 1 was changed.

[Comparative example 3] As shown in the composition shown in Table 2, the (meth)acrylic polymer (A), crosslinking agent (B), and initiator (C) are uniformly mixed to obtain an adhesive composition, which is then coated with silicon A release film (PET film manufactured by Mitsubishi Chemical Corporation) having a thickness of 100 μm treated with ketone release was spread into a sheet shape so that the thickness of the above-mentioned adhesive composition became 100 μm. Next, a release film (PET film manufactured by Mitsubishi Chemical Corporation) with a thickness of 75 μm treated with silicone release was laminated on the sheet-shaped adhesive composition to form a laminate, and a release film/adhesive sheet was obtained. α1/Adhesive sheet for the middle layer of the release film attached to the release film α1 (thickness: 100 μm). Also, in the same manner as above, an adhesive sheet β1 (thickness: 25 μm) for the surface layer with a release film comprising a release film/adhesive sheet β1/release film, and a release film/adhesive sheet were obtained. Material β'1/Adhesive sheet β'1 (thickness: 25 μm) for the inner layer of the release film attached to the release film. Peel and remove the release film on both sides of the adhesive sheet α1 with the release film in sequence, and separate the adhesive sheet β1 for the surface layer with the release film and the adhesive sheet β'1 for the inner layer with the release film The release film of the former is peeled off and removed in turn, and the adhesive sheet β1 for the surface layer and the adhesive sheet β'1 for the inner layer are sequentially pasted on the surface and the inside of the adhesive sheet α1 to obtain '1) Adhesive sheet 8 with a thickness of 150 μm including release film/adhesive sheet 8/adhesive sheet 8 with release film. In addition, the adhesive sheet 8 is an active energy ray-curable adhesive sheet having active energy ray-curable properties cured by irradiation with active energy rays.

[Physical property measurement and evaluation] The following various measurements and evaluations were performed on the adhesive sheets 1 to 8 produced in the above-mentioned Examples and Comparative Examples. The evaluation results are summarized in Table 1 and Table 2.

＜Creep test＞ Using a plurality of adhesive sheets produced in the examples and comparative examples, the adhesive sheets with the release film peeled off are laminated so that the thickness becomes about 0.9 mm, and the release film is included/overlapped to a thickness of about 0.9 mm. Adhesive sheet/adhesive sheet with release film, which is produced by punching out a circular shape with a diameter of 8 mm using a punching machine. Using a rheometer ("DHR-2" manufactured by TA Instruments), the strain (%) after application for 1200 seconds with a measuring jig: 8 mm diameter parallel plate, temperature: 50° C., and pressure: 1000 Pa was measured.

<Creep test (after hardening)> For the adhesive sheets with release film produced in Examples and Comparative Examples, a high-pressure mercury lamp was used to pass the peeling treatment so that the cumulative light intensity at 365 nm became 4000 mJ/cm ² The polyethylene terephthalate film irradiates ultraviolet rays to the adhesive sheet to harden the adhesive sheet. The hardened adhesive sheets were laminated so that the thickness became about 0.9 mm, and punched out into a circular shape with a diameter of 8 mm. Using a rheometer ("DHR-2" manufactured by TA Instruments), the strain (%) after application for 180 seconds with a measuring jig: 8 mm diameter parallel plate, temperature: 80° C., and pressure: 1000 Pa was measured.

＜Gel fraction＞ About 0.1 g of adhesive sheet pieces were collected from each adhesive sheet produced in Examples and Comparative Examples. Wrap the collected adhesive sheet in a SUS (Steel Use Stainless, Japanese Stainless Steel Standard) wire mesh (#150) of quality (X) made into a bag in advance, close the mouth of the bag to make a sample, and measure the sample The quality (Y). After the above sample was immersed in ethyl acetate and stored in the dark at 23°C for 24 hours, the ethyl acetate was evaporated by taking out the above sample and heating at 70°C for 4.5 hours. The mass of the dried sample (Z) To measure. The measured mass of each of them was used to calculate the gel fraction by the following formula. Gel fraction (%)=[(Z－X)/(Y－X)]×100

For the adhesive sheet with release film produced in Examples and Comparative Examples, ultraviolet rays were irradiated to the adhesive sheet through the release film so that the cumulative light intensity at 365 nm became 4000 mJ/ ^cm2 using a high-pressure mercury lamp, and the adhesive sheet wood hardening. Regarding the adhesive sheet after hardening, the gel fraction after active energy ray hardening was determined in the same manner as the evaluation procedure of the above-mentioned gel fraction.

＜Adhesion＞ One of the release films of the adhesive sheets prepared in Examples and Comparative Examples was peeled off, and a polyethylene terephthalate film ("COSMOSHINE A4300" manufactured by Toyobo Co., Ltd.) with a thickness of 100 μm was attached as a backing film. laminated products. After cutting the above-mentioned laminated product to a length of 150 mm and a width of 10 mm, peel off the remaining release film and expose the adhesive surface on the soda-lime glass, and make the roller reciprocate once to carry out roll-bonding on the above-mentioned adhesive sheet. Cure at 60°C for 30 minutes for final attachment. The adhesion measurement sample was peeled at a peeling angle of 180° and a peeling speed of 60 mm/min in an environment of 23°C and 40%RH, and the peeling force (N/cm) to glass at this time was measured.

<Adhesive force (after hardening)> Peel off one of the release film of the adhesive sheet with release film produced in Examples and Comparative Examples, and stick a polyethylene terephthalate film (Toyobo "COSMOSHINE A4300" manufactured by the company) was used as a base film to prepare laminated products. After the above-mentioned laminate was cut to a length of 150 mm and a width of 10 mm, the adhesive surface exposed by peeling off the remaining release film was rolled on the soda-lime glass and the roller was reciprocated once to bond the above-mentioned adhesive sheet. After curing the bonded product at 60°C for 30 minutes for the final attachment, irradiate the adhesive sheet with ultraviolet light through the substrate film so that the cumulative light intensity at 365 nm becomes 4000 mJ/ ^cm2 to harden the adhesive sheet, and then cure at 23°C After 15 hours, a sample for measuring adhesion was prepared. The adhesion test sample was peeled at 23°C 40%RH at a peeling angle of 180° and a peeling speed of 60 mm/min, and the peeling force (N/cm) to glass at this time was measured to obtain the adhesion after hardening force.

＜Oil resistance＞ The adhesive sheet with release film produced in the examples and comparative examples was cut into a 10 mm×10 mm square, and a release film was peeled off to expose the surface of the adhesive sheet to prepare a sample for measuring the swelling rate of oil. The above test sample for oil swelling rate was immersed in artificial sebum solution (oleic acid: squalene = 1:1) for 4 days in an environment of 25°C. Let the area of the sample for measuring the oil swelling rate before being immersed in the artificial sebum solution be So, and the area of the sample for measuring the oil swelling rate after being immersed in the artificial sebum solution be set as St, and calculate the oil swelling rate according to the following formula (i): Rate. Grease swelling rate (%)＝[(St－So)/So]×100・・・(i)

＜Hot Fusibility＞ A double-sided adhesive sheet with a thickness of 20 μm was laminated on one side of a polyethylene terephthalate film with a thickness of 50 μm (“S-100, thickness 50 μm” manufactured by Mitsubishi Chemical Corporation) with a hand roller, Make a polyethylene terephthalate film with an adhesive layer (total thickness 120 μm). The aforementioned polyethylene terephthalate film with the adhesive layer was cut to 54 mm×82 mm, and a bottomed hole with a diameter of 4 mm was opened at the four corners of the cut film so that the distance from the end surface to the center of the hole was 6 mm. The above-mentioned film was rolled onto a soda-lime glass of 54 mm×82 mm and thickness 0.55 mm to prepare a substrate for evaluation of plugging properties having four bottomed holes with a diameter of 4 mm and a depth of 120 μm.

The adhesive surface exposed by peeling off one of the release film-attached adhesive sheets produced in Examples and Comparative Examples was roll-bonded on soda-lime glass (82 mm×54 mm×0.55 mm thick). Then peel off the remaining release film, make the exposed adhesive surface face the surface with bottomed holes of the above-mentioned base material for plugging property evaluation, and apply it under reduced pressure (absolute pressure 2 kPa) using a vacuum laminating machine. Press fit. Heating and pressurization processing (65 degreeC, gauge pressure 0.45 MPa, 20 minutes) were performed using an autoclave, and the laminated body for hot-melt property evaluation was produced.

Visually observe the above-mentioned laminated body, and if a void with a diameter of 1 mm or more is seen inside one or more bottomed holes, it is judged as "× (poor)", otherwise it is judged as "○ (good) )". Furthermore, the diameter of the void is judged to be the longest diameter when the void is non-spherical.

＜Storability＞ Peel off one of the release films of the adhesive sheets with release film produced in Examples and Comparative Examples, cut the adhesive sheet into a 30 mm × 30 mm square, and overlap the release film on it. Form film, cut out (half cut) the size of the adhesive sheet (30 mm × 30 mm square) of the cut marking line. In this state, it was stored in an environment of 40° C. for 200 hours. For each side of the adhesive sheet, the maximum value of the portion where the paste overflowed from the above-mentioned marking line was measured, and the average value of the four sides was set as the paste overflow distance (mm). A paste overflow distance of less than 0.3 mm was judged as "○ (good)", and a paste overflow distance of 0.3 mm or more was judged as "× (poor)".

＜Durability＞ Adhesive surface roll of a polarizing plate with an adhesive layer (70 mm×150 mm) with a thickness of 87 μm is attached to a soda-lime glass with a thickness of 75 mm×155 mm and a thickness of 0.55 mm to produce a polarizer with an adhesive layer/soda-lime Base material for durability evaluation of glass.

The adhesive surface roll exposed by peeling off one of the release film-attached adhesive sheets produced in Examples and Comparative Examples was pressure-bonded to soda-lime glass (75 mm×155 mm×0.55 mm thick). Then, the remaining release film was peeled off, and the exposed adhesive surface faced the surface of the polarizing plate of the above-mentioned durability evaluation substrate, and it was pressed and bonded under reduced pressure (absolute pressure 2 kPa) using a vacuum laminating machine. After heating and pressurizing in an autoclave (65°C, gauge pressure 0.45 MPa, 20 minutes), the adhesive sheet was cured by irradiating ultraviolet rays through soda-lime glass so that the cumulative light intensity at 365 nm became 4000 mJ/ ^cm2 . A sample for durability evaluation was produced.

Put this reliability evaluation sample into a thermal cycle tester, and perform 100 cycles of high temperature and low temperature cycles (high temperature: 80°C, low temperature: -40°C, exposure time: 30 minutes for each temperature, temperature change rate: within 5 minutes) And keep.

Visually observe the samples for reliability evaluation after storage, judge as "○ (good)" if no paste overflow on the end surface and air bubbles in the surface are seen, and judge as "○ (good)" if paste overflow on the end surface and/or air bubbles in the surface are seen The judgment is "×(poor)".

[Table 1] Example 1 Example 2 Example 3 Example 4 Example 5 Comparative example 1 Comparative example 2 Adhesive sheet 1 Adhesive sheet 2 Adhesive sheet 3 Adhesive sheet 4 Adhesive sheet 5 Adhesive sheet 6 Adhesive sheet 7 composition (Meth)acrylic polymer (A) A-1 parts by mass 100 100 100 100 100 A-2 100 100 Cross-linking agent (B) B-1 5 2.5 7.5 5 B-2 2.5 10 Initiator (C) C-1 1.5 1,5 1.5 1.5 1.5 1.5 1.5 Evaluation creep strain Strain after 1200 seconds at 50°C % 559 657 756 328 431 4959 53 Strain after 180 seconds at 80°C (after hardening) % 12 26 8 17 211 2 12 gel fraction - % 0 0 0 0 0 0 0 After hardening % 67 65 67 68 48 81 45 Adhesion - N/cm 11 14.0 12.0 10.9 15.4 3 5 After hardening N/cm 14.5 18.7 18.8 11.3 16.5 15 8 oil resistance - % 1% 3% 5% 8% 4% 51% 125% After hardening % 11% 11% twenty three% twenty two% 3% 65% 85% hot melt Appearance after 65°C, 0.45 MPa, 20 minutes - 〇 〇 〇 〇 〇 〇 x Custody Paste spillage mm 0.2 0.2 0.2 0.1 0.1 0.3 0.1 determination 〇 〇 〇 〇 〇 x 〇 Durability Appearance after thermal cycle test 〇 〇 〇 〇 〇 〇 〇 Overview 〇 〇 〇 〇 〇 x x

[Table 2] Comparative example 3 Adhesive sheet 8 Composition for middle layer (α1) (Meth)acrylic polymer (A) A-1 parts by mass A-2 100 Cross-linking agent (B) B-1 B-2 4 Initiator (C) C-1 1.5 Composition for inner and outer layers (β1)(β'1) (Meth)acrylic polymer (A) A-1 parts by mass A-2 100 Cross-linking agent (B) B-1 B-2 15 Initiator (C) C-1 1.5 Evaluation creep strain Strain after 1200 seconds at 50°C % 196 Strain after 180 seconds at 80°C (after hardening) % 11 gel fraction - % 0 After hardening % 49 Adhesion - N/cm 3 After hardening N/cm 18 oil resistance - % 57% After hardening % 37% hot melt Appearance at 65°C, 0.45 MPa, 20 minutes - x Custody Paste spillage mm - determination - - Durability Appearance after thermal cycle test 〇 Overview x

The adhesive sheet of the example has creep characteristics and oil swelling ratio in a specific range, and is excellent in hot melt property, oil resistance, storage stability and durability. Furthermore, the adhesive sheets of Examples 1 to 4 were prepared with a cross-linking agent, and the creep strain after hardening at 80°C for 180 seconds was 80% or less, so it was comparable to that of Example 5 without a cross-linking agent. Compared with other adhesive sheets, the durability in high temperature and low temperature environments is more excellent. On the other hand, the adhesive sheet 6 of Comparative Example 1 has a high oil expansion rate and poor oil resistance. Also, the creep strain after 1200 seconds at 50°C is large, and the storage property is poor. The adhesive sheet 7 of Comparative Example 2 has a higher oil expansion rate and poor oil resistance. Also, the amount of creep strain after 1200 seconds at 50°C was small, and the hot melt property was not sufficient. Although the adhesive sheet 8 of Comparative Example 3 satisfies the creep strain after 1200 seconds at 50°C, it has a high oil expansion rate and poor oil resistance. From the above, it can be seen that it is difficult to have oil resistance, fluidity, and hot melt properties at the same time.

Claims (18)

An active energy ray-curable adhesive sheet comprising an adhesive layer comprising a (meth)acrylic polymer (A) and satisfying the following requirements (1) and (2), (1) The thickness is 0.8 to 1.5 mm, and the strain (creep strain) after applying a pressure of 1,000 Pa at a temperature of 50°C for 1,200 seconds is 150% or more and 1,500% or less; (2) Assuming that the initial area of the adhesive sheet is So, the area of the above-mentioned adhesive sheet immersed in artificial sebum solution (squalene: oleic acid = 1:1 mixture) at 25°C for 4 days is At St, the oil swelling rate calculated by the following formula (i) is 30% or less; Grease swelling rate (%)=[(St－So)/So]×100・・・(i). The active energy ray-curable adhesive sheet according to claim 1, wherein the (meth)acrylic polymer (A) is a block copolymer and/or a graft copolymer. The active energy ray-curable adhesive sheet according to claim 2, wherein the above-mentioned (meth)acrylic polymer (A) is a copolymer comprising a structural unit derived from a macromonomer, and 100% of the polymer (A) parts by mass, the copolymerization ratio of the macromonomer is 3-10 parts by mass. The active energy ray-curable adhesive sheet according to any one of claims 1 to 3, wherein the (meth)acrylic polymer (A) has a (meth)acrylic alkyl group having an alkyl group having 6 or less carbon atoms Esters and vinyl monomers having polar groups are used as monomer components, and the content of alkyl (meth)acrylates in which the carbon number of the alkyl group in the monomer components of the acrylic polymer (A) is 6 or less 40% by mass or more, and the content of the vinyl monomer having a polar group is 10% by mass or more and 50% by mass or less. The active energy ray-curable adhesive sheet according to any one of Claims 1 to 4, wherein the above-mentioned adhesive layer is composed of a (meth)acrylic polymer (A), a crosslinking agent (B) and/or a polymer The layer formed by the adhesive composition of the initiator (C). The active energy ray-curable adhesive sheet according to claim 5, wherein the crosslinking agent (B) is a multifunctional (meth)acrylate (b-1) having a ring structure. The active energy ray-curable adhesive sheet according to claim 5 or 6, wherein the polyfunctional (meth)acrylate (b-1) is The content is not less than 0.5 parts by mass and not more than 20 parts by mass. The active energy ray-curable adhesive sheet according to any one of claims 1 to 7, wherein the gel fraction is not less than 0% and not more than 20%. The active energy ray-curable adhesive sheet according to any one of Claims 1 to 8, wherein if the active energy ray with a wavelength of 365 nm and a cumulative light quantity of 4000 ^mJ /c is irradiated to make it harden, the gel fraction is the same as that before hardening Relatively high, the gel fraction is 10% or more and 80% or less. The active energy ray-curable adhesive sheet according to any one of claims 1 to 9, wherein the thickness when cured by irradiating active energy rays with a wavelength of 365 nm and a cumulative light quantity of 4000 mJ/ ^cm2 is set to 0.8 to 1.5 mm , and the strain (creep strain) after applying a pressure of 1000 Pa at a temperature of 80°C for 180 seconds is not less than 5% and not more than 80%. An adhesive sheet laminate with a release film, comprising a laminate of the active energy ray-curable adhesive sheet and a release film according to any one of Claims 1 to 10. An adhesive sheet obtained by hardening the active energy ray-curable adhesive sheet according to any one of Claims 1 to 10. A laminate for constituting an image display device comprising two image display device constituting members interposed via an active energy ray-curable adhesive sheet having a fat swelling ratio of 30% or less as determined by the following formula (i) constituted by layering, and The above-mentioned adhesive sheet has an adhesive layer formed of an adhesive resin composition containing a (meth)acrylic polymer (A), and has a thickness of 0.8 to 1.5 mm, and a pressure of 1000 Pa is applied at a temperature of 50°C for 1200 seconds The subsequent strain (creep strain) is not less than 150% and not more than 1500%, Grease swelling rate (%)＝[(St－So)/So]×100・・・(i) In formula (i), So is the initial area of the adhesive sheet, and St is the area after immersing the adhesive sheet in artificial sebum solution (squalene: oleic acid = 1:1 mixture) at 25°C for 4 days. A laminate for constituting an image display device comprising two constituting members of an image display device and hardened by an active energy ray-curable adhesive sheet having a fat swelling rate of 30% or less obtained by the following formula (i) A composition formed by laminating adhesive sheets after hardening, and The above-mentioned adhesive sheet has an adhesive layer formed of an adhesive composition containing a (meth)acrylic polymer (A), and has a thickness of 0.8 to 1.5 mm, after applying a pressure of 1000 Pa at a temperature of 80°C for 180 seconds The strain (creep strain) is not less than 5% and not more than 220%, Grease swelling rate (%)＝[(St－So)/So]×100・・・(i) In formula (i), So is the initial area of the adhesive sheet, and St is the area after immersing the adhesive sheet in artificial sebum solution (squalene: oleic acid = 1:1 mixture) at 25°C for 4 days. The laminate for image display device construction according to Claim 13 or 14, wherein the above-mentioned adhesive sheet is composed of multiple layers of 2 or more layers. The laminate for forming an image display device according to any one of Claims 13 to 15, wherein at least one of the constituent members of the image display device has a depth (mm)/bottom area ( mm ² ) is a bottomed hole of 1.0×10 ^-5 ~ 3.0×10 ^-1 . The laminated body for constituting an image display device according to any one of claims 13 to 16, wherein the constituting member of the image display device includes a touch panel, an image display panel, a surface protection panel, a polarizing film and a retardation film A laminate of any one or a combination of two or more of the groups formed. An image display device constituted by using the laminate for constituting an image display device according to any one of Claims 13 to 17.