TW202113008A - Pressure-sensitive adhesive sheet - Google Patents

Abstract

Provided is a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer. The pressure-sensitive adhesive layer has a pressure-sensitive adhesive surface that can be adhered onto an adherend. The pressure-sensitive adhesive sheet is such that, when the pressure-sensitive adhesive surface is adhered onto an alkali glass plate, and 3 hours thereafter, 20 [mu]L of release water is supplied, the wet release force FW0, as measured under the conditions of 300 mm/minute pull speed and 180 degrees release angle, is 1.0 N/10 mm or less. In addition, the pressure-sensitive adhesive sheet is such that, when the pressure-sensitive adhesive surface is adhered onto the alkali glass plate, heat-treated at 60 DEG C for 5 hours, and thereafter, 20 [mu]L of release water is supplied, the wet release force FW2, as measured at room temperature under the conditions of 300 mm/minute pull speed and 180 degree release angle, is 4.0 N/10 mm or greater.

Description

Adhesive sheet

The present invention relates to an adhesive sheet. This application claims priority based on Japanese Patent Application No. 2019-143394 filed on August 2, 2019, and the entire content of this application is incorporated into this specification by reference.

Generally speaking, adhesives (also known as pressure-sensitive adhesives. The same below) have the following properties: they are soft and solid (viscoelastic) in a temperature region near room temperature, and they are simply bonded by pressure. In the adherend. Effective use of this property, the adhesive is widely used in various fields in the form of an adhesive sheet with an adhesive layer on the substrate, or an adhesive sheet without a substrate without a substrate. . As a technical document on the adhesive, Patent Document 1 can be cited. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Application Publication No. 2013-216726

[The problem to be solved by the invention]

For adhesives, various characteristics are required depending on the application. Among these characteristics, there is a tendency that if one characteristic is to be improved, the other characteristic is lowered, and it is difficult to balance them at a high level. As an example of the characteristics that are in such a difficult relationship, the adhesive force to the adherend and the secondary processability can be cited. The above-mentioned secondary processing refers to, for example, a situation in which adhesion failure (positional deviation, wrinkle or bubble generation, foreign matter jamming, etc.) occurs when the adhesive sheet is attached to the adhesive sheet, or after the adhesive sheet is attached When a defect is found in the adherend, the adhesive sheet is peeled from the adherend and re-attached. In particular, when the adherend is brittle or thin, in order to prevent damage or deformation of the adherend due to secondary processing, the peeling force of the adhered sheet from the adherend (ie , The adhesive force to the adherend is suppressed low, so it is not easy to realize an adhesive sheet that has good secondary processability and can form a highly reliable joint.

Patent Document 1 describes that in order to take into account the property of not foaming or peeling under exposure to high temperature or high temperature and high humidity, and after attaching the adherend to high temperature conditions, no adhesion remains on the adherend. The adhesive composition can be peeled off (non-paste residue), so that the adhesive composition contains organopolysiloxane and/or its hydrolysis condensate with a specific structure. However, non-paste residue and low peel strength are different properties. Patent Document 1 does not consider reducing the peeling force during secondary processing in order to prevent damage to the adherend, etc.

Therefore, the object of the present invention is to provide an adhesive sheet that can be easily peeled off using an aqueous liquid such as water and can form a highly reliable joint. Another object of the present invention is to provide a laminate formed using the above-mentioned adhesive sheet. [Technical means to solve the problem]

According to this specification, an adhesive sheet with an adhesive layer is provided. The adhesive layer has an adhesive surface that can be attached to the adherend. The water peeling force FW0 of the above-mentioned adhesive sheet is 1.0 N/10 mm or less. The water peeling force FW0 is that after attaching the above-mentioned adhesive surface to an alkali glass plate for 3 hours, 20 μL of peeling water is supplied and the drawing speed is 300 mm. Measured under the condition of 180° peeling angle per minute. In addition, the water peeling force FW2 of the above-mentioned adhesive sheet is 4.0 N/10 mm or more. The water peeling force FW2 is obtained by attaching the above-mentioned adhesive surface to an alkali glass plate and heat-treating it at 60°C for 5 hours, and then supplying 20 μL of The water was peeled off and measured at room temperature under the conditions of a stretching speed of 300 mm/min and a peeling angle of 180 degrees. Since this adhesive sheet has a low water peeling force FW0, it can be easily peeled off from the adherend using an aqueous liquid such as water. In addition, since the above-mentioned adhesive sheet has a high water peeling force FW2, it can be bonded to an adherend with good water resistance and reliability.

In a preferred aspect of the adhesive sheet disclosed in this specification, the water peeling force FW1 is 1.0 N/10 mm or less, and the water peeling force FW1 is to stick the adhesive surface to the alkali glass plate and pass it at room temperature. After 7 days, 20 μL of peeling water was supplied and the measurement was performed under the conditions of a stretching speed of 300 mm/min and a peeling angle of 180 degrees. Since this adhesive sheet has a low water peeling force FW1 after 7 days at room temperature, it can be easily peeled off using an aqueous liquid such as water even after a certain period of time after being attached to the adherend. Thereby, the productivity and the flexibility of step management of the laminated body produced by attaching the above-mentioned adhesive sheet to the adherend can be improved.

The adhesive layer preferably contains a compound S having an alkoxysilyl group represented by the following general formula (A) and a hydrophobic portion in the molecule as a peeling force enhancer. -Si(CH ₃ ) _n (OR) _3-n (A) (here, n is 0 or 1, R is selected from methyl and ethyl) The compound S has a hydrolyzable alkoxy group (-SiOR group) ), which can improve the peeling force at the interface between the adhesive surface and the adherend, which can contribute to the improvement of bonding reliability. The adhesive sheet disclosed herein can be preferably implemented using compound S.

In some aspects, the adhesive layer includes a compound having an ethoxysilyl group as the compound S. By using the compound S having an ethoxysilyl group, the early increase in water peeling force can be suppressed, and an adhesive sheet with a higher water peeling force FW2 can be better realized.

In some aspects, the adhesive layer includes a compound with a molecular weight of 500 [g/mole] or more as the compound S. By using the compound S, the early increase in water peeling force can be suppressed, and an adhesive sheet with higher water peeling force FW2 can be better realized.

In some aspects of the adhesive sheet, the above-mentioned adhesive layer contains a water affinity agent. By including a water affinity agent in the adhesive layer, the water releasability of the adhesive surface can be improved.

In some types of adhesive sheets, the above-mentioned adhesive layer may be a layer formed of a light-curing or solvent-based adhesive composition. The adhesive layer formed by the adhesive composition is suitable for realizing an adhesive sheet with a lower water peeling force FW0 and a higher water peeling force FW2. The adhesive layer formed from the above-mentioned adhesive composition is also preferable from the viewpoint of the optical properties (for example, transparency) of the adhesive layer.

In some aspects, the above-mentioned adhesive layer is a photo-crosslinkable adhesive layer. The photocrosslinkable adhesive layer can improve the deformation resistance by photocrosslinking the photocrosslinkable adhesive constituting the layer. Thus, according to the adhesive sheet with the photo-crosslinkable adhesive layer, for example, after the adhesive sheet is attached to the adherend, the photo-crosslinkable adhesive layer is photo-crosslinked, thereby being attached to The surface shape of the adherend is good, and it can form a joint with higher deformation resistance after photo-crosslinking.

The peel strength FN1 of the above-mentioned adhesive sheet after heat and humidity in several aspects is 3.0 N/10 mm or more. The peel strength after heat and humidity FN1 is that the adhesive surface is attached to an alkali glass plate in a humid and hot environment at 85℃ and 85%RH. Keep it for 24 hours, then keep it at 23°C and 50%RH for 5 hours, and then measure it under the conditions of a tensile speed of 300 mm/min and a peeling angle of 180 degrees under the same environment. According to the adhesive sheet with higher peel strength FN1 after heat and humidity, a joint with good heat and humidity durability can be formed.

According to this specification, there is provided a laminate including a member and an adhesive sheet layer laminated on the member. The above-mentioned adhesive sheet layer is a layer formed by attaching any one of the adhesive sheets disclosed herein to the above-mentioned member. Thereby, the said laminated body can become a reliable bonding|bonding of the said adhesive sheet layer and the said member.

In some aspects, the contact angle of the surface of the above-mentioned member to which the above-mentioned adhesive sheet is attached to distilled water is 50 degrees or less. The laminated body disclosed herein can be preferably implemented in an aspect including such a member.

Furthermore, the appropriate combination of the above-mentioned elements can also be included in the scope of the invention for which patent protection is sought through this international application.

Hereinafter, preferred embodiments of the present invention will be described. Furthermore, for matters necessary to implement the present invention other than the matters specifically mentioned in this specification, the industry can understand based on the hints on the implementation of the invention described in this specification and the technical common sense at the time of filing the application. The present invention can be implemented based on the content disclosed in this specification and common technical knowledge in the field. In addition, in the following drawings, members and parts that perform the same function may be described with the same reference numerals, and repeated descriptions may be omitted or simplified. In addition, the embodiments described in the drawings are modeled in order to clearly explain the present invention, and may not accurately represent the size or scale of the actual product provided.

In this specification, the so-called "acrylic polymer" refers to a polymer derived from a monomer component containing more than 50% by weight of an acrylic monomer, and is also called an acrylic polymer. The aforementioned acrylic single system refers to a monomer having at least one (meth)acrylic acid group in one molecule. In addition, in this specification, the term "(meth)acryloyl group" means an allyl group and a methacryloyl group. Similarly, the so-called "(meth)acrylate" refers to the meaning including acrylic acid ester and methacrylate, and the so-called "(meth)acrylic acid" refers to the meaning including acrylic acid and methacrylic acid.

＜Example of the composition of the adhesive sheet＞ An example of the configuration of the adhesive sheet disclosed herein is shown in FIG. 1. The adhesive sheet 1 is constituted as a single-sided adhesive sheet. The single-sided adhesive sheet includes an adhesive layer 10 whose surface 10A becomes the sticking surface to the adherend, and the adhesive layered on The substrate 20 of the other surface 10B of the layer 10. The adhesive layer 10 is fixedly bonded to one surface 20A of the substrate 20. As the substrate 20, for example, a plastic film such as a polyester film can be used. In the example shown in FIG. 1, the adhesive layer 10 has a single-layer structure. The adhesive sheet 1 before use (before being attached to the adherend) can be, for example, the adhesive surface 10A as shown in FIG. 1 protected by a release liner 30 whose at least the adhesive layer side becomes a release surface (release surface) The form of the adhesive sheet 50 with a release liner. Alternatively, it may be in a form in which the second surface 20B of the substrate 20 (the surface on the opposite side to the first surface 20A, also referred to as the back surface) becomes the peeling surface, and the adhesive surface 10A abuts against the substrate The second surface 20B of 20 is wound or laminated to protect the adhesive surface 10A.

The release liner is not particularly limited. For example, a release liner with a release treatment on the surface of a liner substrate such as a resin film or paper, or a fluorine-based polymer (polytetrafluoroethylene, etc.) or polyolefin-based resin can be used. (Polyethylene, polypropylene, etc.) release liners of low adhesion materials, etc. In the above-mentioned peeling treatment, for example, a silicone-based, long-chain alkyl-based peeling treatment agent can be used. In some aspects, it is preferable to use a resin film subjected to a release treatment as a release liner.

The adhesive layer of the adhesive sheet disclosed herein is not limited to the single-layer structure as the above-mentioned structural example, and may be in addition to the above-mentioned adhesive layer (typically, the adhesive layer containing compound S), and further have the same or 1 or 2 or more adhesive layers (additional adhesive layers) of different composition. Each layer of the additional one or two or more adhesive layers may or may not contain the above-mentioned compound S. When the additional adhesive layer is arranged on the side of the substrate than the above-mentioned adhesive layer, from the viewpoint of both good secondary processability and higher peeling force, the additional adhesive layer may include an increase in peeling force The agent (for example, compound S) may not be included.

The adhesive sheet disclosed herein may also be in the form of a substrate-free double-sided adhesive sheet including an adhesive layer. As shown in Fig. 2, the double-sided adhesive sheet 2 without a substrate before use can be a release liner in which each surface 10A, 10B of the adhesive layer 10 becomes a release surface (release surface) from at least the adhesive layer side 31, 32 The form of protection. Alternatively, it may be a form in which the back surface of the release liner 31 (the surface on the opposite side to the adhesive side) becomes the release surface, and the adhesive surface 10B abuts against the back surface of the release liner 31 for winding or Laminates so that the adhesive surfaces 10A, 10B are protected. Such a double-sided adhesive sheet without a substrate can be used by bonding a substrate to any surface of the adhesive layer, for example.

The adhesive sheet disclosed herein may be a constituent element of a member attached to the adhesive sheet in which a member (for example, an optical member) is bonded to a surface of an adhesive layer. For example, the adhesive sheet 1 shown in FIG. 1 may be a constituent element of the adhesive sheet-attached optical member 100 in which the optical member 70 is bonded to one surface 10A of the adhesive layer 10 as shown in FIG. 3. As the above-mentioned optical member, it is preferable that the surface on which the adhesive sheet is attached is a non-water-absorbent smooth surface. The adhesive sheet-attached optical member of this structure can be easily subjected to secondary processing by applying the following water peeling method as necessary when attaching the adhesive sheet to the optical member. The above-mentioned optical member may be, for example, a glass substrate, a resin film, a metal plate, a resin film having a surface modification layer (for example, a coating layer, a sputtering layer, etc.) containing glass, and the like. In addition, the above-mentioned member may be subjected to hydrophilization treatment on the surface to be bonded to the adhesive sheet. Examples of the hydrophilization treatment include corona treatment, plasma treatment, or hydrophilic coating treatment in which a hydrophilic coating is provided, and treatments that contribute to the improvement of hydrophilicity (for example, introduction of hydroxyl groups).

＜Characteristics of Adhesive Sheets＞ (Water peeling force FW0) The adhesive sheet disclosed herein preferably has a water peeling force FW0 (hereinafter, also referred to as "initial water peeling force") of 1.0 N/10 mm or less. The above-mentioned water peeling force FW0 is determined by attaching the adhesive surface of the adhesive sheet of the measuring object to the adherend for 3 hours, and then supplying 20 μL of peeling water at a stretching speed of 300 mm/min and a peeling angle of 180 degrees. Determination. After the adhesive sheet having the water peeling force FW0 is attached to the adherend, it can be easily peeled off from the adherend using an aqueous liquid such as water. With this, for example, when defects such as jamming of foreign objects or poor adhesion are confirmed when sticking to an adherend, the adhesive sheet can be easily peeled from the adherend and re-attached. In some aspects, the water peeling force FW0 (initial water peeling force) is preferably less than 1.0 N/mm, or less than 0.8 N/10 mm, or less than 0.7 N/10 mm, or less than 0.6 N/10 mm. The adhesive sheet with lower water peeling force FW0 can further reduce the load applied to the adherend when the adhesive sheet is peeled off by the water peeling method. For example, this characteristic is particularly meaningful for adhesive sheets that are attached to the following adherends: thinner adherends, more brittle adherends, adherends that are easily deformed (elongated, bent, twisted, etc.), on the surface Adhered body with easily damaged film, etc. The lower limit of the water peeling force FW0 is not particularly limited, and it can be substantially 0 N/10 mm, more than 0 N/10 mm, or more than 0.1 N/10 mm.

Furthermore, from the viewpoint of improving the secondary workability, in the measurement of the water peeling force FW0 described above, it is preferable that the adhesive sheet is peeled from the adherend without leaving the adhesive on the adherend. That is, it is preferably an adhesive sheet excellent in non-paste residue. Whether or not the adhesive remains on the adherend can be grasped, for example, by visually observing the adherend after peeling off the adhesive sheet. Similarly, in the measurement of the following water peeling forces FW1 to FW3, it is preferable that the adhesive sheet is peeled from the adherend without leaving the adhesive on the adherend.

The adhesive sheet disclosed herein can improve the bonding reliability (for example, water resistance reliability) by increasing the water peeling force at a desired time point. The improvement of the above-mentioned water peeling force can be promoted by proper heating treatment. The heating temperature in the case of performing the above-mentioned heat treatment may be 40°C or higher, for example, 50°C or higher, or 60°C or higher. The upper limit of the heating temperature is not particularly limited. Generally, it is appropriate to set the heating temperature to 100°C or lower, preferably 80°C or lower, 65°C or lower, or 45°C or lower. The heating time in the case of performing the above-mentioned heating treatment can be set in a manner that can appropriately obtain the promotion effect of water peeling force promotion, and is not particularly limited. The heating time can be selected from, for example, a range of about 5 minutes to 12 hours.

(Water peeling force FW2) The adhesive sheet disclosed herein preferably has a water peeling force FW2 (hereinafter, also referred to as "water peeling force after heat treatment") of 4.0 N/10 mm or more. The above-mentioned water peeling force FW2 is a method of attaching the adhesive surface of the adhesive sheet of the measuring object to the adherend and heat-treating it at 60°C for 5 hours, and then supplying 20 μL of peeling water at a stretching speed of 300 mm/min. Measured at room temperature under the condition of an angle of 180 degrees. According to the adhesive sheet with higher water peeling force FW2, after the water peeling force is increased, a joint with good water resistance and reliability can be formed. In some aspects, the above-mentioned water peeling force FW2 (water peeling force after heat treatment) is preferably 4.5 N/10 mm or more. From the viewpoint of water resistance reliability, it may be 5.0 N/10 mm or more. It is 6.0 N/10 mm or more, or 7.0 N/10 mm or more. The upper limit of the water peeling force FW2 is not particularly limited. From the viewpoint of easy compatibility with the suppression of the following water peeling force FW1, in some aspects, the water peeling force FW2 may be, for example, 20 N/10 mm or less, or 15 N/10 mm or less. It can be 10 N/10 mm or less.

Furthermore, the adhesive sheet disclosed in this specification includes an aspect in which the water peeling force is unlimited. In this aspect, the adhesive sheet is not limited to those that satisfy the above-mentioned water peeling force FW0, FW2. In addition, the above-mentioned heat treatment is not necessary to increase the water peeling force of the adhesive sheet disclosed herein. For example, after sticking to the adherend, keep it in a temperature area of room temperature for a long time (for example, about 30 days or more), which can also increase the water peeling force to the adherend and improve the reliability of water resistance Sex. After the step or period in which it is desired to have good water-peelability (lower water-peeling force) for the adherend, heat treatment is performed at an appropriate time point as necessary to promote the improvement of the water-peeling force.

(Water peeling force FW1) The adhesive sheet disclosed herein preferably has a water peeling force FW1 (hereinafter, also referred to as "water peeling force after 7 days at room temperature") of 1.0 N/10 mm or less. The above-mentioned water peeling force FW1 is based on attaching the adhesive surface of the adhesive sheet of the measurement object to the adherend and after 7 days at room temperature, 20 μL of peeling water is supplied and the tensile speed is 300 mm/min, the peeling angle Measured under the condition of 180 degrees. More specifically, it is measured by the procedure described in the following Examples. The adhesive sheet with low water peeling force FW1 can be easily peeled off using an aqueous liquid such as water even after 7 days have passed at room temperature after being attached. According to this pressure-sensitive adhesive sheet, for example, it is possible to collectively perform secondary processing operations on a laminate produced within a predetermined time (for example, within 7 days). Thereby, it is possible to improve the productivity or the flexibility of the step management of the laminated body produced by attaching the above-mentioned adhesive sheet to the adherend (for example, a member, preferably an optical member). In some aspects, the above-mentioned water peeling force FW1 (water peeling force after 7 days at room temperature) is preferably less than 1.0 N/mm, or less than 0.8 N/10 mm, or less than 0.7 N/mm. 10 mm, or less than 0.6 N/10 mm. According to the adhesive sheet with low water peeling force FW1, even after being attached to the adherend, after a certain amount of time, the pressure on the adherend when the adhesive sheet is peeled off by the water peeling method can be reduced. The applied load. This characteristic is, for example, adhesion to thinner adherends, brittle adherends, adherends that are easily deformed (elongation, bending, twisting, etc.), and adherences with easily damaged films on the surface. The sheet is particularly meaningful. The lower limit of the water peeling force FW1 is not particularly limited, and it may be substantially 0 N/10 mm, may exceed 0 N/10 mm, or may be 0.1 N/10 mm or more.

(Water peeling force FW3) In some preferred aspects, the adhesive sheet preferably has a water peeling force FW3 (hereinafter, also referred to as "water peeling force after 14 days at room temperature") of 1.0 N/10 mm or less. According to the adhesive sheet, the productivity or the flexibility of step management of the laminated body produced by attaching the adhesive sheet to the adherend can be further improved. The above-mentioned water peeling force FW3 is measured by applying 20 μL of peeling water after attaching the adhesive surface to the adherend and 14 days at room temperature under the conditions of a tensile speed of 300 mm/min and a peeling angle of 180 degrees. . More specifically, it is measured by the procedure described in the following Examples. The above-mentioned water peeling force FW3 (water peeling force after 14 days at room temperature) is preferably less than 1.0 N/mm, or less than 0.8 N/10 mm, or less than 0.7 N/10 mm, or Less than 0.6 N/10 mm. The lower limit of the water peeling force FW2 is not particularly limited, and may be substantially 0 N/10 mm, may exceed 0 N/10 mm, or may be 0.1 N/10 mm or more.

(Peel strength after damp heat FN1) Among some aspects of the adhesive sheet disclosed herein, the adhesive sheet preferably has a peel strength after wet heat FN1 of 3.0 N/10 mm or more. The above-mentioned peel strength after damp heat FN1 is to stick the adhesive surface of the adhesive sheet of the measuring object to the adherend and keep it at 85℃ and 85%RH for 24 hours, and then at 23℃ and 50%RH. After keeping it for 5 hours, it is measured under the conditions of a stretching speed of 300 mm/min and a peeling angle of 180 degrees in the same environment (without using water). More specifically, it is measured by the procedure described in the following Examples. An adhesive sheet with a higher peel strength FN1 after damp heat is preferable from the viewpoint of bonding reliability. The wet heat peel strength FN1 is more preferably 5.0 N/10 mm or more, or 7.0 N/10 mm or more, or 10 N/10 mm or more, or 12 N/10 mm or more. The upper limit of the wet heat peel strength FN1 is not particularly limited. From the point of view that it is easily compatible with the suppression of the water peeling force FW1, in some aspects, the water peeling force FW2 may be 25 N/10 mm or less, 20 N/10 mm or less, or 15 N /10 mm or less.

In the measurement of the above-mentioned water peeling force FW1 to FW3 and the peel strength after moist heat FN1, as the adherend, an alkali glass plate with a contact angle of 5 to 10 degrees with respect to distilled water can be used. As such an alkali glass plate, an alkali glass plate (thickness 1.35 mm, green glass edging product) manufactured by Songlang Glass Industry Co., Ltd. can be used. Alternatively, the equivalent of the alkali glass plate manufactured by the above-mentioned Songlang Glass Industry Co., Ltd. can be used. As the tensile testing machine, a universal tensile and compression testing machine (device name "tensile compression testing machine, TCM-1kNB", manufactured by Minebea Corporation) or its equivalent can be used. The measurement of the peeling strength is carried out by peeling off the test piece attached to the adherend from bottom to top. The same measuring method can also be used in the following examples. In addition, in an adhesive sheet that includes a photo-crosslinkable adhesive layer, and is applied to an adhesive sheet in which a part or all of the adhesive layer is photo-crosslinked after being attached to the adherend, it is suitable for attaching to The test piece after the alkali glass of the adherend is irradiated with light through the alkali glass plate in an environment of 23°C and 50% RH. When the measurement object is a double-sided adhesive sheet, the measurement can be performed by attaching a PET film as a backing to one of the adhesive surfaces of the double-sided adhesive sheet in the following manner.

In addition, the contact angle of the said alkali glass plate was measured as follows. That is, in a measurement atmosphere of 23°C and 50%RH, use a contact angle meter (manufactured by Kyowa Interface Science Co., Ltd., trade name "DMo-501", control box "DMC-2", control and analysis software " FAMAS (version 5.0.30)") is measured by the drop method. The dripping amount of distilled water was set to 2 μL, and the contact angle was calculated by the Θ/2 method based on the image 5 seconds after the dripping (implemented with N5).

(Haze value) In the technology disclosed herein, the haze value of the adhesive sheet is suitably about 10% or less, and may be about 5% or less (for example, about 3% or less). The above-mentioned haze value is preferably 1.0% or less. Such a high-transparency adhesive sheet is suitable for optical applications that require high light transmittance. The haze value of the adhesive sheet may be less than 1.0%, or less than 0.7%, or less than 0.5% (for example, 0 to 0.5%). The haze value of the adhesive layer in the technology disclosed herein can also be preferably applied to the haze value of the adhesive sheet.

Here, the "haze value" refers to the ratio of diffuse transmitted light to total transmitted light when visible light is irradiated to the measurement object. Also known as the fog value. The haze value can be expressed by the following formula. Th[%]=Td/Tt×100 In the above formula, Th is the haze value [%], Td is the scattered light transmittance, and Tt is the total light transmittance. The haze value can be measured using a haze meter (for example, "MR-100" manufactured by Murakami Color Research Institute). The haze value can be adjusted by, for example, selecting the composition or thickness of the adhesive layer.

＜Adhesive layer＞ The adhesive layer of the adhesive sheet disclosed herein may be selected from acrylic adhesives, rubber-based adhesives (natural rubber, synthetic rubber, mixed systems of these, etc.), silicone-based adhesives, Polyester-based adhesives, urethane-based adhesives, polyether-based adhesives, polyamide-based adhesives, fluorine-based adhesives, and other well-known adhesives such as one or two or more types of adhesives The adhesive layer of the composition. Here, the acrylic adhesive refers to an adhesive that uses an acrylic polymer as a base polymer. The same applies to rubber-based adhesives and other adhesives. Furthermore, the concept of polymer referred to herein also includes polymers of relatively low degree of polymerization, which are generally sometimes referred to as oligomers. Furthermore, in this specification, the "base polymer" of the adhesive refers to the main component of the polymer contained in the adhesive. In addition, in this specification, the term "principal component" means a component containing more than 50% by weight when there is no special description.

(Acrylic Adhesive) From the viewpoint of transparency or weather resistance, among several aspects, an acrylic adhesive can be preferably used as the constituent material of the adhesive layer. As the acrylic adhesive, for example, it is preferable to contain an acrylic polymer as a base polymer. The acrylic polymer contains a monomer component, and the monomer component contains a carbon atom at the end of the ester at a ratio of 40% by weight or more. Alkyl (meth)acrylate of a linear or branched alkyl group having a number of 1 or more and 20 or less. Hereinafter, the alkyl (meth)acrylate having an alkyl group having a carbon number of X or more and Y or less at the end of the ester may be expressed as "C _XY alkyl (meth)acrylate". _{In terms of easy to obtain the balance of characteristics, the ratio of the C 1-20} alkyl (meth)acrylate in the entire monomer component of the acrylic polymer in one aspect is suitably more than 50% by weight, for example, it can be 55% by weight. % Or more, may be 60% by weight or more, or may be 70% by weight or more. _{For the same reason, the ratio of the C 1-20} alkyl (meth)acrylate in the monomer component may be, for example, 99.9% by weight or less, or 99.5% by weight or less, or 99% by weight or less. _{In another aspect, the ratio of the C 1-20} alkyl (meth)acrylate of the acrylic polymer in the entire monomer component can be, for example, 98% by weight or less, from the viewpoint of improving the cohesiveness of the adhesive layer Specifically, it may be 95% by weight or less, or 85% by weight or less (for example, less than 80% by weight), or 70% by weight or less, or 60% by weight or less.

As _{non-limiting specific examples of C 1-20} alkyl (meth)acrylate, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate Base) isopropyl acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, second butyl (meth)acrylate, third butyl (meth)acrylate, (meth)acrylic acid Amyl ester, isoamyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, (meth)acrylate Base) isooctyl acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate Ester, dodecyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, (meth) Cetyl acrylate, heptadecyl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, nonadecyl (meth)acrylate, (meth)acrylate Base) Eicosyl acrylate and the like.

Among these, it is preferable to use at least C _4-20 alkyl (meth)acrylate, and it is more preferable to use at least C _4-18 alkyl (meth)acrylate. For example, it is preferable to include one or both of n-butyl acrylate (BA) and 2-ethylhexyl acrylate (2EHA) as the aforementioned monomer components, and it is particularly preferable to include an acrylic adhesive containing at least 2EHA. _{As other examples of C 4-20} (meth)acrylate C 4-20 alkyl esters that can be preferably used, examples include: isononyl acrylate, n-butyl methacrylate (BMA), and 2-ethylhexyl methacrylate (2EHMA), Isostearyl Acrylate (iSTA), etc.

In some aspects, the monomer components constituting the acrylic polymer may include C _4-18 alkyl (meth)acrylate at a ratio of 40% by weight or more. _{The ratio of the C 4-18} alkyl (meth)acrylate in the monomer component may be, for example, 50% by weight or more, 60% by weight or more, or 65% by weight or more. It may also be a monomer component containing a _{C 6-18} alkyl (meth)acrylate in a ratio equal to or higher than any of the above-mentioned lower limits. In addition, from the viewpoint of improving the cohesiveness of the adhesive layer, _{the ratio of the C 4-18} alkyl (meth)acrylate in the monomer components is usually appropriately set to 99.5% by weight or less, or 95 The weight% or less may be 85% by weight or less, or may be 75% by weight or less. It may also be a monomer component containing a _{C 6-18} alkyl (meth)acrylate in a ratio below any of the above upper limits.

The monomer component constituting the acrylic polymer may also include an alkyl (meth)acrylate and, if necessary, other monomers (copolymerizable monomers) copolymerizable with the alkyl (meth)acrylate. As a copolymerizable monomer, a monomer having a polar group (for example, a carboxyl group, a hydroxyl group, a ring containing a nitrogen atom, etc.), or a homopolymer whose glass transition temperature is relatively high (for example, a temperature above 10°C) can be preferably used. )monomer. Monomers with polar groups can help introduce cross-linking points to the acrylic polymer, or improve the cohesive force of the adhesive. The copolymerizable monomer can be used individually by 1 type or in combination of 2 or more types.

As non-limiting specific examples of the copolymerizable monomer, the following can be cited. Carboxyl-containing monomers: for example, acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, methacrylic acid, etc. Monomers containing acid anhydride groups: for example, maleic anhydride and itaconic anhydride. Hydroxyl-containing monomers: for example 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate , 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, (meth)acrylic acid Hydroxyalkyl (meth)acrylates such as 12-hydroxylauryl ester, (4-hydroxymethylcyclohexyl)methyl (meth)acrylate and the like. Monomers containing sulfonic or phosphoric acid groups: such as styrene sulfonic acid, allyl sulfonic acid, sodium vinyl sulfonate, 2-(meth)acrylamide-2-methylpropanesulfonic acid, (methyl) ) Acrylic acid propane sulfonic acid, (meth) sulfopropyl acrylate, (meth) acrylic acid oxynaphthalene sulfonic acid, acrylic acid 2-hydroxyethyl phosphate and the like. Epoxy-containing monomers: such as glycidyl (meth)acrylate or 2-ethyl glycidyl (meth)acrylate and other epoxy-containing acrylates, allyl glycidyl ether, (methyl) ) Glycidyl acrylate etc. Cyano group-containing monomers: for example, acrylonitrile, methacrylonitrile, etc. Monomers containing isocyanate groups: for example 2-(meth)acryloyloxyethyl isocyanate, (meth)acryloyl isocyanate, m-isopropenyl-α,α-dimethylbenzyl isocyanate Wait. Monomers containing amide groups: for example (meth)acrylamide; N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N,N -Dipropyl(meth)acrylamide, N,N-diisopropyl(meth)acrylamide, N,N-bis(n-butyl)(meth)acrylamide, N,N- N,N-dialkyl(meth)acrylamide such as di(tertiary butyl)(meth)acrylamide; N-ethyl(meth)acrylamide, N-isopropyl(methyl) ) N-alkyl (meth)acrylamides such as acrylamide, N-butyl(meth)acrylamide, N-n-butyl(meth)acrylamide, etc.; N-vinylacetamide, etc. N-vinyl carboxylic acid amides; monomers with hydroxyl and amide groups, such as N-(2-hydroxyethyl)(meth)acrylamide, N-(2-hydroxypropyl)(methyl )Acrylamide, N-(1-hydroxypropyl)(meth)acrylamide, N-(3-hydroxypropyl)(meth)acrylamide, N-(2-hydroxybutyl)(formaldehyde N-hydroxyalkyl(meth)acrylamide, N-(3-hydroxybutyl)(meth)acrylamide, N-(4-hydroxybutyl)(meth)acrylamide, etc. Amide; monomers with alkoxy and amide groups, such as N-methoxymethyl (meth)acrylamide, N-methoxyethyl (meth)acrylamide, N-butoxy N-alkoxyalkyl (meth)acrylamide such as methyl (meth)acrylamide; and N,N-dimethylaminopropyl (meth)acrylamide, N-(meth)acrylamide, etc. Base) acryloyl 𠰌line and so on. Monomers containing amine groups: for example, aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, and tertiary butylaminoethyl (meth)acrylate. Monomers with epoxy groups: for example, glycidyl (meth)acrylate, methylglycidyl (meth)acrylate, and allyl glycidyl ether. Monomers with a ring containing nitrogen atoms: such as N-vinyl-2-pyrrolidone, N-methylvinylpyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinyl Pyrimidine, N-vinyl piperidine, N-vinylpyridine, N-vinylpyrrole, N-vinylimidazole, N-vinyl azole, N-(meth)acryloyl-2-pyrrolidone , N-(meth)acryloyl piperidine, N-(meth)acryloylpyrrolidine, N-vinyl pyrrolidine, N-(meth) acryloyl pyrrolidine, N-vinyl-3 -𠰌linone, N-vinyl-2-caprolactam, N-vinyl-1,3-㗁𠯤-2-one, N-vinyl-3,5-𠰌linedione, N-ethylene Pyrazole, N-vinylisoxazole, N-vinylthiazole, N-vinylisothiazole, N-vinylisothiazole, etc. (e.g., N-vinyl-2-caprolactam and other internal amines ). Monomers with succinimidyl skeleton: for example, N-(meth)acryloxymethylene succinimidyl, N-(meth)acrylonitrile-6-oxyhexamethylene succinimidyl Amine, N-(meth)acryloyl-8-oxyhexamethylene succinimide, etc. Maleimines: for example, N-cyclohexyl maleimines, N-isopropyl maleimines, N-lauryl maleimines, N-benzene Base maleimide and so on. Ikonimines: such as N-methyl Ikonimines, N-ethyl Ikonimines, N-butyl Ikonimines, N-octyl Ikonimines, N- 2-Ethylhexyl Ikonimines, N-cyclohexyl Ikonimines, N-Lauryl Ikonimines, etc. (Meth)acrylic acid amino alkyl esters: for example (meth)acrylic acid aminoethyl, (meth)acrylic acid N,N-dimethylaminoethyl, (meth)acrylic acid N,N-di Ethylaminoethyl, tert-butylaminoethyl (meth)acrylate. Alkoxy-containing monomers: for example, 2-methoxyethyl (meth)acrylate, 3-methoxypropyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, (meth)acrylate Alkoxyalkyl (meth)acrylic acid such as propoxyethyl (meth)acrylate, butoxyethyl (meth)acrylate, ethoxypropyl (meth)acrylate, etc. (Base) acrylate); methoxy glycol (meth) acrylate, methoxy polyethylene glycol (meth) acrylate, methoxy polypropylene glycol (meth) acrylate and other alkoxy alkylenes Base glycol (meth)acrylate (for example, alkoxy polyalkylene glycol (meth)acrylate). Monomers containing alkoxysilyl groups: for example, 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, 3-(meth) (Meth)acrylic acid esters containing alkoxysilyl groups such as acryloxypropylmethyldimethoxysilane, 3-(meth)acryloxypropylmethyldiethoxysilane, etc. Or vinyl compounds containing alkoxysilyl groups such as vinyl trimethoxysilane and vinyl triethoxysilane. Vinyl esters: for example, vinyl acetate, vinyl propionate, etc. Vinyl ethers: vinyl alkyl ethers such as methyl vinyl ether or ethyl vinyl ether. Aromatic vinyl compounds: for example, styrene, α-methylstyrene, vinyl toluene, etc. Olefins: For example, ethylene, butadiene, isoprene, isobutene, etc. (Meth) acrylates with alicyclic hydrocarbon groups: for example, cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, iso(meth)acrylate, dicyclopentyl (meth)acrylate (Meth)acrylates containing alicyclic hydrocarbon groups such as esters and adamantyl (meth)acrylates. (Meth)acrylates with aromatic hydrocarbon groups: for example, phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, benzyl (meth)acrylate, etc. (meth)acrylic acid containing aromatic hydrocarbon groups ester. In addition, (meth)acrylates containing heterocycles such as tetrahydrofurfuryl (meth)acrylate, (meth)acrylates containing halogen atoms, such as vinyl chloride or (meth)acrylates containing fluorine atoms, and polysilicone Oxygen (meth)acrylates and other silicon-containing (meth)acrylates, (meth)acrylates derived from terpene compound derivative alcohols, etc.

In the case of using such a copolymerizable monomer, the amount used is not particularly limited, but it is usually appropriately set to 0.01% by weight or more of the entire monomer component. From the standpoint of more satisfactorily exerting the use effect of the copolymerizable monomer, the usage amount of the copolymerizable monomer may be 0.1% by weight or more of the entire monomer component, or 0.5% by weight or more. In addition, from the viewpoint of easily obtaining a balance of adhesive properties, the amount of the copolymerizable monomer used is usually appropriately set to 50% by weight or less of the entire monomer component, preferably 40% by weight or less.

In the case of using such a copolymerizable monomer, the amount used is not particularly limited, but it is usually appropriately set to 0.01% by weight or more of the entire monomer component. From the standpoint of more satisfactorily exerting the use effect of the copolymerizable monomer, the usage amount of the copolymerizable monomer may be 0.1% by weight or more of the entire monomer component, or 0.5% by weight or more. In addition, from the viewpoint of easily obtaining a balance of adhesive properties, the amount of the copolymerizable monomer used is usually 50% by weight or less of the entire monomer component, preferably 40% by weight or less.

所表示之N-乙烯基環狀醯胺。此處，通式(1)中，R¹ 為2價有機基，具體而言為-(CH2₂ )_n -。n為2～7(較佳為2、3或4)之整數。其中，可較佳地採用N-乙烯基-2-吡咯啶酮。作為具有氮原子之單體之其他較佳例，可列舉(甲基)丙烯醯胺。In some aspects, the monomer component constituting the acrylic polymer may include a monomer having a nitrogen atom. Thereby, the cohesive force of the adhesive can be improved, and the peeling force after time is preferably improved. As a preferable example of the monomer having a nitrogen atom, a monomer having a ring containing a nitrogen atom can be cited. As the monomer having a ring containing a nitrogen atom, those exemplified above can be used, for example, the general formula (1): [化1]

Said N-vinyl cyclic amide. Here, in the general formula (1), R ¹ is a divalent organic group, specifically -(CH2 ₂ ) _n -. n is an integer of 2-7 (preferably 2, 3 or 4). Among them, N-vinyl-2-pyrrolidone can be preferably used. As another preferable example of the monomer having a nitrogen atom, (meth)acrylamide can be cited.

Usage amount when using monomers with nitrogen atoms (preferably N-vinyl cyclic amides or N-(meth)acrylic cyclic amides and other monomers having a ring containing nitrogen atoms) It is not particularly limited. For example, it may be 1% by weight or more of the entire monomer component, 2% by weight or more, 3% by weight or more, and further 5% by weight or more or 7% by weight or more. In one aspect, the usage amount of the monomer having a nitrogen atom may be 10% by weight or more of the entire monomer component, or 15% by weight or more, or 20% by weight or more. In addition, the usage amount of the monomer having a nitrogen atom is appropriately set to, for example, 40% by weight or less of the total monomer components, or 35% by weight or less, 30% by weight or less, or 25% by weight. the following. In another aspect, the usage amount of the monomer having a nitrogen atom can be set to, for example, 20% by weight or less of the entire monomer component, or 15% by weight or less.

In some aspects, the monomer components constituting the acrylic polymer may include hydroxyl-containing monomers. By using hydroxyl-containing monomers, the cohesive force of the adhesive or the degree of cross-linking (for example, cross-linking with an isocyanate cross-linking agent) can be better adjusted. When using hydroxyl-containing monomers, the usage amount is not particularly limited. For example, it can be 0.01% by weight or more of the total monomer components, or 0.1% by weight or more, 0.5% by weight or more, or 1 The weight% or more may also be 5 weight% or more or 10 weight% or more. In addition, from the viewpoint of suppressing the water absorption of the adhesive layer, in some aspects, the usage amount of the hydroxyl-containing monomer is appropriately set to 40% by weight or less of the total monomer components, for example, or 30% by weight or less. It may be 25% by weight or less, or 20% by weight or less. In another aspect, the usage amount of the hydroxyl-containing monomer can be set to, for example, 15% by weight or less of the entire monomer component, or 10% by weight or less, or 5% by weight or less.

In the adhesive layer of the adhesive sheet disclosed herein, the monomer component of the acrylic polymer may include the alkoxyalkyl (meth)acrylate or alkoxypolyalkylene glycol (meth) exemplified above. (Base) acrylate, which may not be included. In one aspect of the technology disclosed herein, the ratio of the alkoxyalkyl (meth)acrylate in the monomer component of the acrylic polymer is less than 20% by weight, and the alkoxy polyalkylene glycol The ratio of (meth)acrylate is less than 20% by weight. Thereby, the adhesive layer can be easily formed into a sheet without problems such as gelation. The ratio of the alkoxyalkyl (meth)acrylate in the above-mentioned monomer components is preferably less than 10% by weight, more preferably less than 3% by weight, and still more preferably less than 1% by weight. In a particularly preferred aspect, the monomer component does not substantially contain alkoxyalkyl (meth)acrylate (content is 0 to 0.3% by weight). Similarly, the ratio of alkoxy polyalkylene glycol (meth)acrylate in the above monomer components is preferably less than 10% by weight, more preferably less than 3% by weight, and still more preferably It is less than 1% by weight. In a particularly preferred aspect, the above-mentioned monomer component does not substantially contain alkoxy polyalkylene glycol (meth)acrylate (content 0-0.3% by weight).

In some aspects, the ratio of the carboxyl group-containing monomer in the monomer component of the acrylic polymer may be, for example, 2% by weight or less, 1% by weight or less, or 0.5% by weight or less (for example Less than 0.1% by weight). It is also possible to substantially not use a carboxyl group-containing monomer as the monomer component of the acrylic polymer. Here, the term "substantially not using a carboxyl group-containing monomer" means at least not intentionally using a carboxyl group-containing monomer. The acrylic polymer of such a composition tends to be highly reliable in water resistance, and can also be resistant to metal corrosion to adherends containing metals.

In addition, in a preferred aspect, the ratio of the hydrophilic monomer in the monomer component of the acrylic polymer is limited. Thereby, the water releasability provided by the following water affinity agent can be better exerted. Here, the "hydrophilic monomer" in this specification refers to a carboxyl group-containing monomer, an acid anhydride group-containing monomer, a hydroxyl group-containing monomer, and a nitrogen atom-containing monomer (typically, (meth)propylene Amido group-containing monomers, N-vinyl-2-pyrrolidone and other monomers having a nitrogen-containing ring) and alkoxy-containing monomers (typically, (meth)acrylic acid) Alkoxy alkyl ester and alkoxy polyalkylene glycol (meth)acrylate). In this aspect, the ratio of the hydrophilic monomer in the monomer component of the acrylic polymer is preferably 35% by weight or less, for example, it may be 30% by weight or less, or 28% by weight or less. It is not particularly limited, and the ratio of the hydrophilic monomer in the monomer component of the acrylic polymer may be 1% by weight or more, may be 10% by weight or more, or may be 20% by weight or more.

In some aspects, the monomer components constituting the acrylic polymer may include (meth)acrylates containing alicyclic hydrocarbon groups. Thereby, the cohesive force of the adhesive can be improved, and the peeling force after time can be improved. As the alicyclic hydrocarbon group-containing (meth)acrylate, those exemplified above can be used, and for example, cyclohexyl acrylate or isopropyl acrylate can be preferably used. There is no particular limitation on the amount of use in the case of using alicyclic hydrocarbon group-containing (meth)acrylate. For example, it can be set to 1% by weight or more, 3% by weight or more, or 5% by weight or more of the entire monomer component. In one aspect, the usage amount of the (meth)acrylate containing alicyclic hydrocarbon groups may be 10% by weight or more of the entire monomer component, or 15% by weight or more. The upper limit of the amount of the (meth)acrylate containing alicyclic hydrocarbon group is appropriately set to about 40% by weight or less, for example, it may be 30% by weight or less, or it may be 25% by weight or less (for example, 15% by weight or less, and further 10% by weight or less).

The composition of the monomer components constituting the acrylic polymer can be set such that the glass transition temperature Tg obtained by the Fox formula based on the composition of the monomer components becomes, for example, -75°C or higher and 10°C or lower. In some aspects, from the viewpoint of the surface shape followability of the adhesive layer, the above-mentioned Tg is suitably below 0°C, preferably below -10°C, may also be below -20°C, or may be -30°C the following. In addition, from the viewpoint of the cohesiveness of the adhesive layer, the above-mentioned Tg may be, for example, -60°C or higher, may be -50°C or higher, or may be -45°C or higher or -40°C or higher.

The above-mentioned Fox formula is the relationship between the Tg of the copolymer and the glass transition temperature Tgi of the homopolymer obtained by homopolymerizing the monomers constituting the copolymer as shown below. 1/Tg=Σ(Wi/Tgi) Furthermore, in the above Fox formula, Tg represents the glass transition temperature of the copolymer (unit: K), Wi represents the weight fraction of monomer i in the copolymer (copolymerization ratio on a weight basis), and Tgi represents monomer i The glass transition temperature of the homopolymer (unit: K).

As the glass transition temperature of the homopolymer for calculating Tg, the value described in a known document is used. For example, regarding the monomers listed below, the following values are used for the glass transition temperature of the homopolymer of the monomer. 2-Ethylhexyl acrylate -70°C N-Butyl acrylate -55°C Isostearyl acrylate -18°C Methyl methacrylate 105°C Methyl acrylate 8°C Cyclohexyl acrylate 15°C N-vinyl-2-pyrrolidone 54°C 2-Hydroxyethyl acrylate -15°C 4-Hydroxybutyl acrylate -40°C Dicyclopentyl methacrylate 175°C Isopropyl acrylate 94°C Acrylic 106°C Methacrylic acid 228°C

Regarding the glass transition temperature of homopolymers of monomers other than those exemplified above, the value described in the "Polymer Handbook" (3rd edition, John Wiley & Sons, Inc., 1989) is used. When multiple values are recorded in this document, the highest value is used. Regarding the monomer whose glass transition temperature of the homopolymer is not described in the above-mentioned Polymer Handbook, the value obtained by the method described in Japanese Patent Application Publication No. 2007-51271 is used.

The acrylic polymer disclosed herein is not particularly limited, but preferably has an SP value of 23.0 (MJ/m ³ ) ^1/2 or less. By including the following water affinity agent in the adhesive containing the acrylic polymer with such SP value, the initial water peeling force (FW0) is lower and the water peeling force (FW2) after heating is better. High adhesive. The SP value is more preferably 21.0 (MJ/m ³ ) ^1/2 or less (for example, 20.0 (MJ/m ³ ) ^1/2 or less). The lower limit of the SP value is not particularly limited. For example, it is about 10.0 (MJ/m ³ ) ^1/2 or more, and suitably about 15.0 (MJ/m ³ ) ^1/2 or more, preferably 18.0 (MJ/m ³ ) ^1/2 or more.

Furthermore, the SP value of acrylic polymers can be calculated according to Fedors' calculation method [refer to "Polymer Engineering and Science (POLYMER ENG. &SCI.)", Volume 14, No. 2 (1974), pages 148-154 ] That is, the formula: SP value δ=(ΣΔe/ΣΔv) ^1/2 (In the above formula, Δe is the evaporation energy of each atom or group of atoms at 25°C, Δe, and Δv is the mole of each atom or group of atoms at the same temperature Volume) for calculation. The acrylic polymer having the above SP value can be obtained by appropriately determining the monomer composition based on the technical knowledge of the industry.

The adhesive layer of the adhesive sheet disclosed herein can be composed of a monomer containing the above composition in the form of a polymer, an unpolymer (that is, a polymerizable functional group is in an unreacted form) or a mixture of these The layer formed by the adhesive composition of the ingredients. The above-mentioned adhesive composition can be a water-dispersible adhesive composition in the form of an adhesive (adhesive component) dispersed in water, a solvent-based adhesive composition in a form in which an adhesive is contained in an organic solvent, to be exposed to ultraviolet light or radiation. Active energy ray hardening adhesive composition prepared by the way that the active energy rays are hardened to form an adhesive, and a hot melt adhesive composition that is applied in a heated and melted state and forms an adhesive when cooled to around room temperature And other forms. A preferred aspect of the adhesive composition is a solvent-based adhesive composition or a solvent-free adhesive composition. The solvent-free adhesive composition includes an active energy ray hardening adhesive composition and a hot-melt adhesive composition.

At the time of polymerization, a well-known or commonly used thermal polymerization initiator or photopolymerization initiator can be used according to the polymerization method, the polymerization state, and the like. Such a polymerization initiator can be used individually by 1 type or in combination of 2 or more types suitably.

The thermal polymerization initiator is not particularly limited. For example, an azo-based polymerization initiator, a peroxide-based initiator, a redox-based initiator obtained by a combination of a peroxide and a reducing agent, and a substitute can be used. Ethane-based starter, etc. More specifically, for example, 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2-methylpropionamidine) disulfate, 2,2'-co Azobis(2-amidinopropane) dihydrochloride, 2,2'-azobis[2-(5-methyl-2-imidazolin-2-yl)propane] dihydrochloride, 2,2 '-Azobis(N,N'-dimethylisobutylamidine), 2,2'-Azobis[N-(2-carboxyethyl)-2-methylpropionamidine] hydrate, etc. Azo-based initiators; for example, persulfates such as potassium persulfate and ammonium persulfate; peroxide-based initiators such as benzyl peroxide, tertiary butyl hydroperoxide, hydrogen peroxide, etc.; for example, phenyl substitution Substituted ethane-based initiators such as ethane; for example, redox initiators such as a combination of persulfate and sodium bisulfite, a combination of peroxide and sodium ascorbate, etc., but are not limited to these. Furthermore, the thermal polymerization can be preferably carried out at a temperature of about 20 to 100°C (typically, 40 to 80°C), for example.

系光聚合起始劑等。The photopolymerization initiator is not particularly limited. For example, a ketal-based photopolymerization initiator, an acetophenone-based photopolymerization initiator, a benzoin ether-based photopolymerization initiator, and an phosphine oxide-based photopolymerization agent can be used. Initiator, α-ketol-based photopolymerization initiator, aromatic sulfonyl chloride-based photopolymerization initiator, photoactive oxime-based photopolymerization initiator, benzoin-based photopolymerization initiator, benzalkonium-based photopolymerization initiator Polymerization initiator, benzophenone-based photopolymerization initiator, alkylphenone-based photopolymerization initiator, 9-oxysulfur 𠮿

Department of photopolymerization initiator and so on.

The usage amount of such a thermal polymerization initiator or photopolymerization initiator can be set to a usual usage amount corresponding to the polymerization method, polymerization state, etc., and is not particularly limited. For example, about 0.001 to 5 parts by weight (typically, about 0.01 to 2 parts by weight, for example, about 0.01 to 1 part by weight) of the polymerization initiator can be used relative to 100 parts by weight of the monomer to be polymerized.

In the above polymerization, various previously known chain transfer agents (also understood as molecular weight regulators or polymerization degree regulators) can be used as needed. As the chain transfer agent, mercaptans such as n-dodecyl mercaptan, tertiary dodecyl mercaptan, thioglycolic acid, and α-thioglycerol can be used. Alternatively, a chain transfer agent containing no sulfur atom (non-sulfur tethered chain transfer agent) can also be used. Specific examples of non-sulfur-based chain transfer agents include anilines such as N,N-dimethylaniline and N,N-diethylaniline; terpenes such as α-pinene and terpinolene; α- Styrenes such as methyl styrene and α-methyl styrene dimer; compounds with benzylidene groups such as dibenzylidene acetone, cinnamyl alcohol, and cinnamaldehyde; hydroquinone and naphthoquinone Phenols; quinones such as benzoquinone and naphthoquinone; olefins such as 2,3-dimethyl-2-butene and 1,5-cyclooctadiene; alcohols such as phenol, benzyl alcohol, and allyl alcohol; two Benzyl hydrogens such as phenylbenzene and triphenylbenzene. A chain transfer agent can be used individually by 1 type or in combination of 2 or more types. In the case of using a chain transfer agent, the amount used can be, for example, about 0.01 to 1 part by weight with respect to 100 parts by weight of the monomer component. The technology disclosed herein can also be better implemented without using a chain transfer agent.

The molecular weight of the acrylic polymer obtained by suitably adopting the above-mentioned various polymerization methods is not particularly limited, and can be set in an appropriate range according to the required performance. The weight average molecular weight (Mw) of the acrylic polymer is usually about 10×10 ⁴ or more (for example, 20×10 ⁴ or more). From the viewpoint of achieving a good balance between cohesive force and adhesive force, it is appropriately set to exceed 30×10 ⁴ . From the viewpoint of obtaining good bonding reliability even in a high-temperature environment, one aspect of the acrylic polymer preferably has 40×10 ⁴ or more (typically, about 50×10 ⁴ or more, for example, about 55 ×10 ⁴ or more) Mw. The upper limit of the Mw of the acrylic polymer may generally be about 500×10 ⁴ or less (for example, about 150×10 ⁴ or less). The above-mentioned Mw may be about 75×10 ⁴ or less. Here, the so-called Mw refers to the value obtained by gel permeation chromatography (GPC) in terms of standard polystyrene. As the GPC device, for example, the model name "HLC-8320GPC" (column: TSKgelGMH-H(S), manufactured by Tosoh Corporation) can be used. The same is true in the following embodiments. The above-mentioned Mw may be the Mw of the acrylic polymer in any one of the adhesive composition and the adhesive layer.

Several types of adhesive sheets have an adhesive layer formed from an active energy ray-curable adhesive composition. In this specification, the so-called "active energy rays" refer to energy rays with energy that can cause chemical reactions such as polymerization reactions, cross-linking reactions, and decomposition of initiators. Examples of active energy rays referred to herein include light such as ultraviolet rays, visible rays, and infrared rays, or radiation rays such as α rays, β rays, γ rays, electron beams, neutron rays, and X rays. As a preferable example of the active energy ray-curable adhesive composition, a photo-curable adhesive composition can be cited. The light-curing adhesive composition has the advantage that even a thicker adhesive layer can be easily formed. Among them, an ultraviolet curable adhesive composition is preferred.

The light-curing adhesive composition typically contains at least a part of the monomer components of the composition in the form of a polymer (may be a part of the monomer type, or a part of the component). The polymerization method when forming the above-mentioned polymer is not particularly limited, and various previously known polymerization methods can be suitably used. For example, thermal polymerization such as solution polymerization, emulsion polymerization, and bulk polymerization (typically carried out in the presence of a thermal polymerization initiator) can be suitably used; photopolymerization carried out by irradiating light such as ultraviolet rays (typically, in light In the presence of a polymerization initiator); radiation polymerization performed by irradiating radiation such as β-rays and γ-rays. Among them, photopolymerization is preferred.

A preferred aspect of the light-curing adhesive composition includes a partial polymer of monomer components. Such a partial polymer is typically a mixture of a polymer derived from a monomer component and an unreacted monomer, and is preferably in the form of a slurry (liquid with viscosity). Hereinafter, some polymers of the above-mentioned properties are sometimes referred to as "monomer slurry" or simply "slurry". The polymerization method when partially polymerizing the monomer components is not particularly limited, and various polymerization methods as described above can be appropriately selected and used. From the viewpoint of efficiency or simplicity, a photopolymerization method can be preferably used. According to photopolymerization, the polymerization conversion rate (monomer conversion rate) of the monomer components can be easily controlled by polymerization conditions such as the amount of light irradiation (light amount).

The polymerization conversion rate of the monomer mixture in the above-mentioned partial polymer is not particularly limited. The said polymerization conversion rate can be set to about 70 weight% or less, for example, Preferably it is set to about 60 weight% or less. From the viewpoints of ease of preparation or coating properties of the adhesive composition containing the above-mentioned partial polymer, generally the above-mentioned polymerization conversion rate is suitably about 50% by weight or less, preferably about 40% by weight or less (for example, about 35 weight%). %the following). The lower limit of the polymerization conversion rate is not particularly limited, but is typically about 1% by weight or more, and usually is appropriately set to about 5% by weight or more.

The adhesive composition containing the partial polymer of the monomer component can be prepared, for example, by using a suitable polymerization method (such as a photopolymerization method) to make a monomer mixture containing the entire amount of the monomer component used to prepare the adhesive composition Partially obtained by polymerization. In addition, the adhesive composition containing a partial polymer of the monomer component may also be a partial polymer or a complete polymer containing a monomer mixture of a part of the monomer components used to prepare the adhesive composition, and the remaining A mixture of monomer components or partial polymers. In addition, in this specification, the so-called "complete polymer" means that the polymerization conversion rate exceeds 95% by weight.

The adhesive composition containing the above-mentioned partial polymer can be equipped with other components (for example, photopolymerization initiator, or peel force enhancer, water affinity agent, crosslinking agent, multifunctional monomer as described below) as needed. , Acrylic oligomers, adhesion-imparting resins, etc.). The method of compounding such other components is not particularly limited. For example, it may be contained in the above-mentioned monomer mixture in advance, or may be added to the above-mentioned partial polymer.

Several aspects of the adhesive sheet have an adhesive layer formed from a solvent-based adhesive composition. The solvent-based adhesive composition typically contains a solution polymer of monomer components, and additives used as needed. The solvent (polymerization solvent) used for solution polymerization can be appropriately selected from previously known organic solvents. For example, it is possible to use aromatic compounds (typically aromatic hydrocarbons) such as toluene; esters such as ethyl acetate or butyl acetate; aliphatic or alicyclic hydrocarbons such as hexane or cyclohexane; Halogenated alkanes such as 1,2-dichloroethane; lower alcohols such as isopropanol (for example, monohydric alcohols with 1 to 4 carbon atoms); ethers such as tertiary butyl methyl ether; ketones such as methyl ethyl ketone Any one solvent or a mixture of two or more solvents. According to the solution polymerization, a polymerization reaction solution in a form in which the polymer of the monomer component is dissolved in the polymerization solvent can be obtained. The solvent-based adhesive composition disclosed herein can be preferably manufactured using the above-mentioned polymerization reaction solution.

The above-mentioned solvent-based adhesive composition can be equipped with other components (for example, photopolymerization initiator, or peel force enhancer, water affinity agent, crosslinking agent, multifunctional monomer, acrylic-based Oligomers, etc.). The solvent-based adhesive composition may be one that has been imparted with photocrosslinkability by adding a polyfunctional monomer and a photopolymerization initiator to the polymerization reaction solution, for example.

(Peeling force enhancer) The adhesive layer of the adhesive sheet disclosed herein may contain a peeling force enhancer. As the peeling force enhancer, a material that can perform the following functions can be appropriately selected and used, that is, after the surface (adhesive surface) of the adhesive layer is attached to the adherend, the adhesive sheet is peeled from the adherend Power increase.

As the peeling force enhancer, for example, a compound S having an alkoxysilyl group and a hydrophobic part in the molecule can be used. The alkoxysilyl group is a functional group having at least one alkoxy group on the silicon atom. The above-mentioned alkoxysilyl group is hydrolyzed to generate a silanol group that reacts with the hydroxyl group on the surface of the adherend. Therefore, the aforementioned alkoxysilyl group is a radical precursor that reacts with the aforementioned hydroxyl group. By making the adhesive layer contain the compound S, the reaction or interaction between the hydroxyl group on the adherend and the above-mentioned silanol group can be used to increase the peeling force of the adhesive sheet from the adherend. In addition, the hydrophobic portion of the compound S has a higher affinity for the base polymer (for example, acrylic polymer) of the adhesive layer in general than the alkoxysilyl group. By selecting the hydrophobic part, the distribution or mobility of the compound S in the adhesive layer can be adjusted, and the improvement of the water peeling force can be controlled.

The alkoxy group constituting the above-mentioned alkoxysilyl group is typically a methoxy group or an ethoxy group. The above-mentioned alkoxysilyl group may be a trialkoxysilyl group or a dialkoxysilyl group. From the viewpoint of enhancing the effect of enhancing the peeling force, in some aspects, the compound S having a trialkoxysilyl group may be preferably used. Compound S can be used alone or in combination of two or more.

In some aspects, as the above-mentioned peeling force enhancer, a compound S having an alkoxysilyl group represented by the following general formula (A) and a hydrophobic part in the molecule can be preferably used. -Si(CH ₃ ) _n (OR) _3-n (A) Here, n is 0 or 1, and R is selected from methyl and ethyl. For example, the compound S having an alkoxysilyl group in which n is 0 in the general formula (A) can be preferably used.

The hydrophobic part of the compound S may have a reactive functional group (which may be a functional group capable of reacting with the base polymer of the adhesive layer) or not. In one aspect, a compound S (hereinafter, sometimes referred to as compound S1) having at least one reactive functional group in the hydrophobic portion can be used. The number of reactive functional groups possessed by the hydrophobic portion of the compound S1 may be, for example, about 1 to 5. From the viewpoint of gelation inhibition of the adhesive composition, the compound S1 having 1 reactive functional group in the hydrophobic portion can be preferably used. Examples of the above-mentioned reactive functional groups include epoxy groups, amine groups, isocyanurate groups (which may also constitute isocyanurate bodies), acetyl acetyl groups, (meth)acrylic groups, and mercapto groups. , Vinyl, halogenated alkyl, etc. As the compound S1, various silane coupling agents can be used. Examples of the silane coupling agent having the above-mentioned reactive functional group include: for example, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxy 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, etc. containing epoxy groups The silane coupling agent; for example, 3-aminopropyltrimethoxysilane, N-(2-aminoethyl)3-aminopropyltrimethoxysilane, N-(2-aminoethyl)3- The amine group of aminopropylmethyldimethoxysilane, etc. contains a silane coupling agent; for example, 3-isocyanatopropyltriethoxysilane, tris(trimethoxysilylpropyl)isocyanurate, etc. Silane coupling agents containing isocyanate groups; for example, trimethoxysilane containing acetyl acetyl groups, etc. silane coupling agents containing acetyl acetyl groups; such as 3-methacryloxy propyl trimethoxy silane, (Meth)acrylic acid group-containing silane coupling agents such as 3-methacryloxypropyltriethoxysilane, 3-propyleneoxypropyltrimethoxysilane, etc.; vinyl trimethoxysilane, ethylene Silane coupling agents containing vinyl groups such as triethoxysilane; 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, etc. containing mercapto groups The silane coupling agent; 3-chloropropyl trimethoxysilane and other halogenated alkyl-containing silane coupling agents. Among them, glycidoxypropyltrialkoxysilane (for example, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane) and the like are preferred. Silane coupling agent containing epoxy group.

In another aspect, a compound S (hereinafter, sometimes referred to as compound S2) having a structure in which the hydrophobic portion does not have a reactive functional group can be used. The hydrophobic part having no reactive functional group may be, for example, a hydrocarbon group, a hydrocarbon group having a chain ether bond, a hydrocarbon group having a carbonyl group, a hydrocarbon group having an ester bond, a fluoride of these groups, and the like. The hydrocarbyl groups in these examples may be alkyl groups, cycloalkyl groups, aryl groups, alkylcycloalkyl groups, aralkyl groups, and the like. When the above-mentioned hydrocarbon group is an alkyl group, the number of carbon atoms of the alkyl group is preferably 6 or more, more preferably 8 or more. The number of carbon atoms of the above-mentioned alkyl group may be 32 or less, or 28 or less, or 24 or less, or 20 or less, for example. For example, a C _8-18 alkyl trialkoxysilane can be used as the compound S2. As _{non-limiting specific examples of C 8-18} alkyl trialkoxy silanes, octyl trimethoxy silane, octyl triethoxy silane, decyl trimethoxy silane, decyl triethoxy silane can be cited. Cetyl silane, hexadecyl trimethoxy silane and hexadecyl triethoxy silane. In addition, the number of carbon atoms of the cycloalkyl group, aryl group, alkylcycloalkyl group, and aralkyl group may be about 6-20, for example. Furthermore, the above-mentioned silane coupling agent is excluded from the concept of compound S (compound S2) which does not have a structure with a reactive functional group in the hydrophobic part.

The molecular weight [g/mole] of the compound S is not particularly limited, and may be about 120 to 30,000, for example. For example, compound S having a molecular weight of 180 or more, 200 or more, or 230 or more can be used. From the viewpoint of the ease of controlling the time for secondary processing, or the mobility in the adhesive layer (especially the mobility to the adhesive surface), it is preferable to use those with a molecular weight of 240 or more (and thus 260 or more) Compound S. In some aspects, compound S with a molecular weight of 500 or more, 700 or more, 900 or more, 1200 or more, or 1500 or more can be preferably used. In addition, from the viewpoints of the ease of preparation or coating of the adhesive composition, the mobility of the compound S in the adhesive layer, etc., among several aspects, a molecular weight of 20,000 or less, 10,000 or less, Compound S below 7000 or below 5000 (for example, below 3000). Furthermore, as the molecular weight of the compound S, the molecular weight based on the chemical formula (formula weight) or the weight average molecular weight based on the above-mentioned GPC can be used. When a commercially available product is used as the compound S, as the value of the molecular weight of the compound, the nominal value provided by the manufacturer can also be used.

The hydrophobic part of compound S may also have a repeating structure. For example, the hydrophobic portion of compound S may be a polymer of acrylic monomers with or without reactive functional groups other than (meth)acrylic groups. As an example of the acrylic monomer which does not have a reactive functional group other than a (meth)acryl group, the alkyl (meth)acrylate is mentioned. The above-mentioned (meth)acrylic acid alkyl ester may be, for example, (meth)acrylic acid C _1-20 alkyl ester, may also be (meth)acrylic acid C _1-18 alkyl ester, or (meth)acrylic acid C _{The 4-9} alkyl ester may also be a C _6-9 alkyl (meth)acrylate. The above-mentioned alkyl (meth)acrylate polymer may be a homopolymer or a copolymer of two or more alkyl (meth)acrylates.

In the adhesive sheet disclosed herein, as a preferred example of a material that can be preferably used as the compound S, there can be cited: a compound having an alkoxysilyl group and a hydrophobic part in the molecule (preferably the above-mentioned The compound represented by the general formula (A)), and satisfies (1) the above-mentioned alkoxysilyl group is an ethoxysilyl group (for example, a triethoxysilyl group) and (2) the molecular weight is 500 [g/mole] Compound S of one or both of the above. By using the compound S that meets at least one of (1) and (2) above, the early increase in water peeling force can be suppressed, and an adhesive sheet with higher water peeling force FW2 can be better realized. As the reason, it can be considered that the reaction between the hydroxyl group on the surface of the adherend of the compound S and the ethoxysilyl group is significantly slower than the reaction with the methoxysilyl group; and/or because the molecular weight of the compound S is lower than a certain The degree is larger and the mobility in the adhesive layer is low. It takes time until the compound S present in the adhesive layer reaches the adhesive surface and contacts the hydroxyl group on the surface of the adherend. However, it is not limitedly explained by this reason alone.

The hydrophobic portion of the compound S meeting the above (1) may be a structure having a reactive functional group (compound S1) or a structure not having a reactive functional group (compound S2). In some aspects, from the viewpoint of wet-heat durability and the like, the compound S having a reactive functional group (for example, an epoxy group) in the hydrophobic portion can be preferably used. For example, a compound S1 containing a hydrophobic portion having an epoxy group as a reactive functional group (may be a hydrophobic portion having only an epoxy group as a reactive functional group) and a triethoxysilyl group can be used. The molecular weight of the compound S conforming to the above (1) may be, for example, 10000 or less, usually 5000 or less appropriately, or 2500 or less or 1500 or less. From the viewpoint of improving the effect of improving the water peeling force obtained by the heat treatment, in some aspects, the molecular weight of the above-mentioned compound S may be 800 or less, or 500 or less, or less than 500, or 400 or less, 340 or less, or 310 or less. In addition, from the viewpoints of suppression of the early increase of water peeling force, or non-staining properties of adherends, the above-mentioned molecular weight may be, for example, 240 or more, 260 or more, or 270 or more.

The hydrophobic portion of the compound S meeting the above (2) may be a structure having a reactive functional group (compound S1), or a structure not having a reactive functional group (compound S2). For example, a compound S2 containing a trimethoxysilyl group or an ethoxysilyl group, and a hydrophobic portion without a reactive functional group can be used. The hydrophobic portion having no reactive functional group may be, for example, a polymer of one or two or more monomers selected from acrylic monomers having no reactive functional groups other than (meth)acrylic groups, or Hydrocarbyl (for example, alkyl, cycloalkyl, aryl, alkylcycloalkyl, aralkyl) and the like.

The peel force enhancer is preferably contained in the adhesive layer in a free form. The above-mentioned peeling force enhancer preferably does not chemically bond with other constituent components that may be included in the adhesive layer. The peeling force enhancer contained in the adhesive composition in this form can effectively contribute to the improvement of water peeling force or the improvement of water resistance reliability.

When the adhesive layer contains a peeling force enhancer, the content of the peeling force enhancer in the adhesive layer is set in a manner that can obtain the desired effect of use, and is not particularly limited. The amount of the above-mentioned peeling force enhancer is per 100 parts by weight of the acrylic polymer contained in the adhesive composition of the adhesive layer, and can be set to 0.005 parts by weight or more, for example. The content of the acrylic polymer per 100 parts by weight of the release force enhancer is usually appropriately set to 0.01 parts by weight or more, preferably 0.03 parts by weight or more, for example, 0.05 parts by weight or more, or 0.08 parts by weight or more. In some aspects, the content of the peeling force enhancer can be set to 0.10 parts by weight or more, can also be set to 0.20 parts by weight or more, or can be set to 0.30 parts by weight or more. By increasing the content of the peel force enhancer, the peel force enhancement effect can be exerted. In addition, depending on the state of use, if the period at room temperature until the peeling force increases over time is too short, the period during which secondary processing is possible may become too short and the process management may become complicated. From this point of view, in some aspects, the content of the acrylic polymer in the adhesive composition per 100 parts by weight of the release force enhancer may be, for example, 5 parts by weight or less, or 3 parts by weight or less, or It may be 1 part by weight or less, may be 0.7 parts by weight or less, may be 0.5 parts by weight or less, or may be 0.3 parts by weight or less.

(Water affinity agent) The adhesive layer in the technology disclosed herein may contain a water affinity agent as required. By including a water affinity agent in the adhesive layer, an aqueous liquid such as water can be used to effectively reduce the peeling force. The reason is not specifically explained, but it is believed that generally, the water affinity agent has a hydrophilic region and is easily concentrated on the surface (adhesive surface) of the adhesive layer, thereby enhancing the adhesive surface efficiently. The water affinity function effectively reduces the peeling force when the adhesive layer is in contact with water.

As a water affinity agent, in terms of ease of preparation of the adhesive composition, etc., it can be preferably used in a liquid form at room temperature (about 25°C). A water affinity agent can be used individually by 1 type or in combination of 2 or more types.

In some aspects, as the water affinity agent, at least one compound A selected from surfactants and compounds having a polyoxyalkylene skeleton can be used. As the surfactant and the compound having a polyoxyalkylene skeleton, one or two or more of known surfactants and compounds having a polyoxyalkylene skeleton can be used without particular limitation. Furthermore, among the above-mentioned surfactants, there are compounds having a polyoxyalkylene skeleton, and of course vice versa.

As the surfactant that can be used as compound A, well-known nonionic surfactants, anionic surfactants, cationic surfactants, and the like can be used. Among them, nonionic surfactants are preferred. Surfactant can be used individually by 1 type or in combination of 2 or more types.

Examples of nonionic surfactants include: polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, and polyoxyethylene oleyl ether; polyoxyethylene octane Polyoxyethylene alkyl phenyl ether such as phenyl phenyl ether and polyoxyethylene nonyl phenyl ether; sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitol Anhydride monooleate and other sorbitan fatty acid esters; polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene Polyoxyethylene sorbitan such as sorbitan tristearate, polyoxyethylene sorbitan triisostearate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan trioleate, etc. Fatty acid esters; polyoxyethylene glyceryl ether fatty acid esters; polyoxyethylene-polyoxypropylene block copolymers, etc. These nonionic surfactants can be used individually by 1 type or in combination of 2 or more types.

Examples of anionic surfactants include alkylbenzene sulfonates such as nonylbenzene sulfonate and dodecylbenzene sulfonate (for example, sodium dodecylbenzene sulfonate); lauryl sulfate (Such as sodium lauryl sulfate, ammonium lauryl sulfate), octadecyl sulfate and other alkyl sulfates; fatty acid salts; polyoxyethylene stearyl ether sulfate, polyoxyethylene lauryl ether sulfate and other polyoxyethylene Alkyl ether sulfates (e.g. polyoxyethylene alkyl ether sodium sulfate), polyoxyethylene lauryl phenyl ether sulfate and other polyoxyethylene alkyl phenyl ether sulfates (e.g. polyoxyethylene alkyl phenyl ether ammonium sulfate, polyoxyethylene Vinyl alkyl phenyl ether sodium sulfate, etc.), polyoxyethylene styrenated phenyl ether sulfate and other polyether sulfates; polyoxyethylene stearyl ether phosphate, polyoxyethylene lauryl ether phosphate and other polyoxyethylene alkyl ether phosphoric acid Ester; the sodium salt and potassium salt of the above-mentioned polyoxyethylene alkyl ether phosphate; polyoxyethylene alkyl ether phosphate salt; lauryl sulfosuccinate, polyoxyethylene lauryl sulfosuccinate (for example, polyoxyethylene Sodium ethylene alkyl sulfosuccinate) and other sulfosuccinates; polyoxyethylene alkyl ether acetate, etc. When the anionic surfactant forms a salt, the salt may be, for example, a metal salt (preferably a salt of a monovalent metal) such as a sodium salt, a potassium salt, a calcium salt, and a magnesium salt, an ammonium salt, an amine salt, and the like. An anionic surfactant can be used individually by 1 type or in combination of 2 or more types.

In some aspects, for example, an anionic surfactant having at least one of -POH group, -COH group and -SOH group can be preferably used. Among them, a surfactant having a -POH group is preferred. Such surfactants typically contain a phosphate structure, such as monoester of phosphoric acid (ROP(=O)(OH) ₂ ; here, R is a monovalent organic group), diester ((RO) ₂ P (=O)OH; here, R is the same or different monovalent organic group), a mixture containing both monoester and diester, etc. As a preferable example of the surfactant having a -POH group, polyoxyethylene alkyl ether phosphate can be cited. The number of carbon atoms of the alkyl group in the polyoxyethylene alkyl ether phosphate ester can be, for example, 6-20, 8-20, 10-20, 12-20, or 14-20. .

Examples of cationic surfactants include polyether amines such as polyoxyethylene lauryl amine and polyoxyethylene stearyl amine. A cationic surfactant can be used individually by 1 type or in combination of 2 or more types.

As a compound having a polyoxyalkylene skeleton that can be used as compound A, for example, polyethylene glycol (PEG), polypropylene glycol (PPG) and other polyalkylene glycols can be used; Ethers, polyethers containing polyoxypropylene units, compounds containing oxyethylene units and oxypropylene units (the arrangement of these units may be random or block-like); derivatives of these Things and so on. In addition, a compound having a polyoxyalkylene skeleton among the above-mentioned surfactants can also be used. These can be used individually by 1 type or in combination of 2 or more types. Among them, it is preferable to use a compound containing a polyoxyethylene skeleton (also referred to as a polyoxyethylene segment), and more preferably PEG.

The molecular weight (chemical formula weight) of the compound having a polyoxyalkylene skeleton (for example, polyethylene glycol) is not particularly limited. For example, it is suitably less than 1000. From the aspect of the preparation property of the adhesive composition, it is preferably about 600 or less (for example, 500 or less). The lower limit of the molecular weight of the compound having a polyoxyalkylene skeleton (for example, polyethylene glycol) is not particularly limited, and those having a molecular weight of about 100 or more (for example, about 200 or more, and further about 300 or more) can be preferably used.

Other examples of the water affinity agent include water-soluble polymers such as polyvinyl alcohol, polyvinylpyrrolidone, and polyacrylic acid. A water-soluble polymer can be used individually by 1 type or in combination of 2 or more types. In the technique disclosed herein, as the water affinity agent, one or more of compound A may be used, or one or more of water-soluble polymers may be used, or these may be used in combination.

The HLB of the water affinity agent is not particularly limited, and is, for example, 3 or more, suitably about 6 or more, and may be 8 or more (for example, 9 or more). In some preferred aspects, the HLB of the water affinity agent is 10 or more. By this, there is a tendency to better exhibit water releasability. The above-mentioned HLB is more preferably 11 or more, still more preferably 12 or more, and particularly preferably 13 or more (for example, 14 or more). By including a water affinity agent (typically, a surfactant) having an HLB in the above range in the adhesive layer, the water releasability can be more effectively expressed. The upper limit of the above-mentioned HLB is 20 or less, for example, it may be 18 or less, or it may be 16 or less, or it may be 15 or less.

Furthermore, the HLB in this specification is based on Griffin's Hydrophile-Lipophile Balance, which indicates the degree of affinity between the surfactant and water or oil, and is a value between 0 and 20 Represents the ratio of hydrophilicity to lipophilicity. The definition of HLB is such as WC Griffin: J. Soc. Cosmetic Chemists, 1,311 (1949), or "Surface Active Agent Handbook" co-written by Takahashi Etsumin, Namba Yoshiro, Koike Motogi, Kobayashi Masao, 3rd edition, Engineering Book Published by the company, November 25, 1972, p179-182, etc. The water affinity agent with the above-mentioned HLB can be selected based on the technical knowledge of the industry by referring to the above-mentioned reference documents as needed.

Such a water affinity agent is preferably contained in the adhesive layer in a free form. As the water affinity agent, in terms of the preparation properties of the adhesive composition, those that are liquid at normal temperature (about 25° C.) can be preferably used.

The adhesive layer containing the water affinity agent is typically formed of the adhesive composition A containing the water affinity agent. The above-mentioned adhesive composition A may be any of the above-mentioned water-dispersible adhesive compositions, solvent-based adhesive compositions, active energy ray hardening adhesive compositions, hot-melt adhesive compositions, and the like. In some preferred aspects, the adhesive layer containing the water affinity agent may be an adhesive layer formed of a light-curing or solvent-based adhesive composition A. In such an adhesive layer, the effect of adding a water affinity agent can be better exerted. The adhesive layer may also have photocrosslinkability.

The content of the water affinity agent in the adhesive layer is not particularly limited, and it can be set in a way to properly exert the effect of the water affinity agent. In some aspects, the content of the water affinity agent is per 100 parts by weight of the monomer components constituting the polymer (for example, acrylic polymer) contained in the adhesive layer, for example, it can be set to 0.001 parts by weight or more, which is appropriately set 0.01 parts by weight or more, or 0.03 parts by weight or more, or 0.07 parts by weight or more, or 0.1 parts by weight or more. In some preferred aspects, the content of the water affinity agent relative to 100 parts by weight of the monomer components can be, for example, 0.2 parts by weight or more, and from the viewpoint of obtaining higher effects, it can also be 0.5 parts by weight or more. It may be 1.0 part by weight or more, or 1.5 parts by weight or more. Also, from the viewpoint of suppressing excessive water diffusion into the entire adhesive layer, in some aspects, the amount of water affinity agent used relative to 100 parts by weight of the monomer component may be, for example, 20 parts by weight or less, It is suitably 10 parts by weight or less, preferably 5 parts by weight or less, and may be 3 parts by weight or less. It is also preferable that the content of the water affinity agent is not too much from the viewpoint of improving the transparency of the adhesive layer. For example, in some aspects, the content of the water affinity agent relative to 100 parts by weight of the monomer component may be less than 2 parts by weight, less than 1 part by weight, or less than 0.7 parts by weight, or It is less than 0.3 parts by weight, or less than 0.2 parts by weight. By using a small amount of a water affinity agent with an HLB of 10 or more, there is also a tendency to exert good water releasability.

(Crosslinking agent) In the adhesive layer, for the purpose of cross-linking within the adhesive layer or between the adhesive layer and its adjacent surface, a cross-linking agent may also be used as needed. The cross-linking agent may be included in the adhesive layer in the form after the cross-linking reaction, or may be included in the adhesive layer in the form before the cross-linking reaction. The type of the cross-linking agent is not particularly limited, and it can be selected from previously known cross-linking agents, for example, according to the composition of the adhesive composition, in such a way that the cross-linking agent exerts an appropriate cross-linking function in the adhesive layer. Examples of crosslinking agents that can be used include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, azoline-based crosslinking agents, aziridine-based crosslinking agents, carbodiimide-based crosslinking agents, Melamine-based cross-linking agents, urea-based cross-linking agents, metal alkoxide-based cross-linking agents, metal chelate-based cross-linking agents, metal salt-based cross-linking agents, hydrazine-based cross-linking agents, amine-based cross-linking agents, etc. These can be used individually by 1 type or in combination of 2 or more types.

As the isocyanate-based crosslinking agent, a polyfunctional isocyanate compound having two or more functions can be used. Examples include aromatic isocyanates such as toluene diisocyanate, xylene diisocyanate, polymethylene polyphenyl diisocyanate, tris(p-isocyanatophenyl) thiophosphate, and diphenylmethane diisocyanate; isocyanate; Alicyclic isocyanates such as phorone diisocyanate; aliphatic isocyanates such as hexamethylene diisocyanate, etc. Examples of commercially available products include trimethylolpropane/toluene diisocyanate trimer adduct (manufactured by Tosoh Corporation, trade name "Coronate L"), trimethylolpropane/hexamethylene diisocyanate tripolymer Polymer adducts (manufactured by Tosoh Corporation, trade name "Coronate HL"), isocyanurate compounds of hexamethylene diisocyanate (manufactured by Tosoh Corporation, trade name "Coronate HX") and other isocyanate adducts Wait.

As the epoxy-based crosslinking agent, those having two or more epoxy groups in one molecule can be used without particular limitation. It is preferably an epoxy-based crosslinking agent having 3 to 5 epoxy groups in one molecule. Specific examples of epoxy-based crosslinking agents include: N,N,N',N'-tetraglycidyl metaxylylenediamine, 1,3-bis(N,N-diglycidylamino group) (Methyl) cyclohexane, 1,6-hexanediol diglycidyl ether, polyethylene glycol diglycidyl ether, polyglycerol polyglycidyl ether, etc. Commercial products of epoxy-based crosslinking agents include: "TETRAD-X" and "TETRAD-C" manufactured by Mitsubishi Gas Chemical Corporation, "EPICLON CR-5L" manufactured by DIC, and Nagase ChemteX The brand name "DENACOL EX-512" manufactured by the company, the brand name "TEPIC-G" manufactured by Nissan Chemical Industries, etc.

As the azoline-based crosslinking agent, those having one or more azoline groups in one molecule can be used without particular limitation. Examples of aziridine-based crosslinking agents include: trimethylolpropane tris[3-(1-aziridinyl)propionate], trimethylolpropane tris[3-(1-(2 -Methyl)aziridinyl propionate)] etc. As the carbodiimide-based crosslinking agent, a low-molecular compound or polymer compound having two or more carbodiimide groups can be used.

In some aspects, peroxides can also be used as crosslinking agents. Examples of peroxides include: bis(2-ethylhexyl) peroxydicarbonate, bis(4-tertiarybutylcyclohexyl)peroxydicarbonate, di-second butyl peroxydicarbonate, peroxydicarbonate Oxidized tert-butyl neodecanoate, tert-hexyl peroxide pivalate, tert-butyl peroxide pivalate, dilaurin peroxide, di-n-octyl peroxide, isobutyrate peroxide 1,1 ,3,3-Tetramethylbutyl ester, dibenzyl peroxide, etc. Among them, as peroxides particularly excellent in crosslinking reaction efficiency, bis(4-tertiarybutylcyclohexyl) peroxydicarbonate, dilaurin peroxide, diphenylmethyl peroxide, etc. . Furthermore, when peroxide is used as the above-mentioned polymerization initiator, the remaining peroxide that has not been used for the polymerization reaction can also be used for the crosslinking reaction. In this case, the residual amount of peroxide is quantified, and when the ratio of peroxide does not reach the specified amount, the peroxide may be added in such a way that it becomes a specified amount if necessary. The quantification of peroxide can be performed by the method described in Japanese Patent No. 4971517.

The content of the crosslinking agent (in the case of containing two or more crosslinking agents, the total amount thereof) is not particularly limited. From the viewpoint of realizing an adhesive that exhibits adhesive properties such as adhesive force and cohesive force in a well-balanced manner, the content of the crosslinking agent relative to 100 parts by weight of the acrylic polymer contained in the adhesive composition is usually appropriately set to about 5 The part by weight or less is preferably about 0.001 to 5 parts by weight, more preferably about 0.001 to 4 parts by weight, and still more preferably about 0.001 to 3 parts by weight. Alternatively, it may also be an adhesive composition that does not contain the above-mentioned crosslinking agent. When a light-curing adhesive composition is used as the adhesive composition disclosed herein, the adhesive composition may be substantially free of cross-linking agents such as isocyanate-based cross-linking agents. Here the adhesive composition does not substantially contain a crosslinking agent (typically, an isocyanate-based crosslinking agent) means that the amount of the crosslinking agent relative to 100 parts by weight of the above-mentioned acrylic polymer is less than 0.05 parts by weight (for example, Less than 0.01 parts by weight).

In order to make the crosslinking reaction proceed more efficiently, a crosslinking catalyst may also be used. Examples of crosslinking catalysts include metal crosslinking catalysts such as tetra-n-butyl phthalate, tetraisopropyl phthalate, iron triacetone, butyl tin oxide, and dioctyl tin dilaurate. Among them, tin-based crosslinking catalysts such as dioctyltin dilaurate are preferred. The amount of crosslinking catalyst used is not particularly limited. The usage amount of the crosslinking catalyst relative to 100 parts by weight of the acrylic polymer in the adhesive composition can be, for example, about 0.0001 part by weight or more and 1 part by weight or less, or 0.001 part by weight or more and 0.1 part by weight or less, It may be 0.005 part by weight or more and 0.5 part by weight or less.

(Multifunctional monomer) In the adhesive layer, a multifunctional monomer may be used as needed. The multifunctional monomer can be used in place of the above-mentioned cross-linking agent or in combination with the cross-linking agent to help the adjustment of cohesive force and other purposes. As the polyfunctional monomer, a compound having two or more ethylenically unsaturated groups can be used. The multifunctional monomer may be included in the adhesive layer in an unreacted form, or may be included in the adhesive layer in a reacted (after crosslinking) form. The adhesive layer containing the unreacted polyfunctional monomer may be a photo-crosslinkable adhesive layer that can react the above-mentioned polyfunctional monomer by irradiating the adhesive layer with active energy rays such as ultraviolet rays to form a crosslinked structure .

Examples of polyfunctional monomers include ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, and polypropylene glycol di(meth)acrylate. Acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, ethylene glycol di(meth)acrylate ) Acrylate, 1,6-hexanediol di(meth)acrylate, 1,12-dodecanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, four Hydroxymethylmethane tri(meth)acrylate, allyl (meth)acrylate, vinyl (meth)acrylate, divinylbenzene, epoxy acrylate, polyester acrylate, urethane acrylate , Butyl diol (meth) acrylate, hexyl diol di (meth) acrylate, etc. Among them, trimethylolpropane tri(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and dipentaerythritol hexa(meth)acrylate can be preferably used. A polyfunctional monomer can be used individually by 1 type or in combination of 2 or more types.

The amount of the polyfunctional monomer used varies depending on its molecular weight, the number of functional groups, etc., but it is usually appropriately set to a range of about 0.01 parts by weight to 3.0 parts by weight with respect to 100 parts by weight of the acrylic polymer. In some aspects, the usage amount of the polyfunctional monomer relative to 100 parts by weight of the acrylic polymer may be, for example, 0.02 parts by weight or more, or 0.1 parts by weight or more, or 0.5 parts by weight or more and 1.0 parts by weight. Parts or more or 2.0 parts by weight or more. By increasing the amount of polyfunctional monomer used, there is a tendency to obtain higher cohesion. On the other hand, from the viewpoint of avoiding the decrease in adhesion between the adhesive layer and the adjacent layer due to excessive increase in cohesive force, the usage amount of the polyfunctional monomer relative to 100 parts by weight of the acrylic polymer can be, for example, 10 parts by weight or less, may be 5.0 parts by weight or less, or may be 3.0 parts by weight or less.

(Acrylic oligomer) In the adhesive composition (and then the adhesive layer) disclosed herein, from the viewpoints of improving cohesive force or improving adhesion with the surface adjacent to the adhesive layer (for example, the surface of the substrate, etc.), it can be Contains acrylic oligomers. As the acrylic oligomer, it is preferable to use a polymer having a Tg higher than that of the aforementioned acrylic polymer.

The Tg of the acrylic oligomer is not particularly limited, and may be, for example, about 20°C or more and 300°C or less. The above-mentioned Tg may be, for example, about 30°C or higher, or about 40°C or higher, or about 60°C or higher, or about 80°C or higher or about 100°C or higher. If the Tg of the acrylic oligomer becomes higher, the effect of improving the cohesive force tends to become higher overall. In addition, from the viewpoint of gripping properties or impact absorption of the substrate, the Tg of the acrylic oligomer may be, for example, about 250°C or less, or about 200°C or less, or about 180°C or less. Below about 150°C. In addition, the Tg of the acrylic oligomer is the same as the Tg of the acrylic polymer corresponding to the composition of the above-mentioned monomer components, and is a value calculated based on the Fox formula.

The Mw of the acrylic oligomer is typically about 1,000 or more and less than about 30,000, preferably about 1,500 or more and less than about 10,000, and more preferably about 2,000 or more and less than about 5,000. If Mw is in the above range, it is easier to better exhibit the effect of improving cohesion or adhesion to the adjacent surface. The Mw of the acrylic oligomer can be measured by gel permeation chromatography (GPC) and calculated as a value in terms of standard polystyrene. Specifically, the HPLC8020 manufactured by Tosoh Corporation uses TSKgelGMH-H(20)×2 as the column, and the measurement is performed with a tetrahydrofuran solvent at a flow rate of about 0.5 mL/min.

Examples of monomer components constituting the acrylic oligomer include: the above-mentioned various (meth)acrylate C _1-20 alkyl esters; the above-mentioned various alicyclic hydrocarbon group-containing (meth)acrylates; the above-mentioned various (Meth) acrylates containing aromatic hydrocarbon groups; (meth) acrylate monomers such as (meth) acrylates obtained from terpene compound derivative alcohols. These can be used individually by 1 type or in combination of 2 or more types.

From the viewpoint of improving adhesiveness, the acrylic oligomer preferably contains (former) having a branched structure with an alkyl group such as isobutyl (meth)acrylate or tert-butyl (meth)acrylate. Alkyl acrylate, (meth) acrylate containing alicyclic hydrocarbon group, or (meth) acrylate containing aromatic hydrocarbon group, etc. are represented by acrylic monomers with relatively large structures as monomers unit. In addition, when ultraviolet rays are used in the synthesis of the acrylic oligomer or the production of the adhesive layer, it is less likely to cause polymerization inhibition, preferably a monomer having a saturated hydrocarbon group at the end of the ester, for example, Preferably, an alkyl (meth)acrylate with a branched alkyl group or a (meth)acrylate containing a saturated alicyclic hydrocarbon group is used.

The ratio of (meth)acrylate monomer to all monomer components constituting the acrylic oligomer is typically more than 50% by weight, preferably 60% by weight or more, more preferably 70% by weight or more ( For example, 80% by weight or more, and 90% by weight or more). In a preferred aspect, the acrylic oligomer has a monomer composition substantially containing only one or more (meth)acrylate monomers. When the monomer component contains alicyclic hydrocarbon group-containing (meth)acrylate and (meth)acrylate C _1-20 alkyl ester, the weight ratio thereof is not particularly limited. For example, it can be set to 10/ The range of 90～90/10, the range of 20/80～80/20, the range of 70/30～30/70, etc.

As the constituent monomer components of the acrylic oligomer, in addition to the above-mentioned (meth)acrylate monomers, functional group-containing monomers can also be used as needed. Examples of functional group-containing monomers include: N-vinyl-2-pyrrolidone, N-propenyl 𠰌line and other monomers having a heterocyclic ring containing nitrogen atoms; (meth)acrylic acid N,N- Monomers containing amine groups such as dimethylaminoethyl; monomers containing amine groups such as N,N-diethyl(meth)acrylamide; monomers containing carboxyl groups such as AA and MAA; Base) 2-hydroxyethyl acrylate and other hydroxyl-containing monomers. These functional group-containing monomers can be used individually by 1 type or in combination of 2 or more types. In the case of using a functional group-containing monomer, the ratio of the functional group-containing monomer to all monomer components constituting the acrylic oligomer can be set to, for example, 1% by weight or more, 2% by weight or more, or 3 The weight% or more, for example, can be 15 weight% or less, 10 weight% or less, or 7 weight% or less.

Preferred acrylic oligomers include, for example, dicyclopentyl methacrylate (DCPMA), cyclohexyl methacrylate (CHMA), iso(IBXMA), and iso(meth)acrylate (IBXA), dicyclopentyl acrylate (DCPA), 1-adamantyl methacrylate (ADMA), 1-adamantyl acrylate (ADA) homopolymers, copolymers of DCPMA and MMA, DCPMA Copolymers with IBXMA, copolymers of ADA and methyl methacrylate (MMA), copolymers of CHMA and isobutyl methacrylate (IBMA), copolymers of CHMA and IBXMA, CHMA and acryloyl 𠰌line ( ACMO) copolymer, CHMA and diethylacrylamide (DEAA) copolymer, CHMA and AA copolymer, etc.

The acrylic oligomer can be formed by polymerizing its constituent monomer components. The polymerization method or polymerization state is not particularly limited, and various previously known polymerization methods (for example, solution polymerization, emulsion polymerization, bulk polymerization, photopolymerization, radiation polymerization, etc.) can be adopted as appropriate. The types of polymerization initiators (such as azo-based polymerization initiators) that can be used as needed are roughly as exemplified for the synthesis of acrylic polymers, and the amount of polymerization initiators or chain transfer agents (such as mercaptans) that can be used arbitrarily The amount is appropriately set based on technical common sense so that it becomes the desired molecular weight, and therefore detailed description is omitted.

When an acrylic oligomer is contained in the adhesive composition, its content can be set to, for example, 0.01 part by weight or more with respect to 100 parts by weight of the above-mentioned acrylic polymer. From the viewpoint of obtaining a higher effect, It may be 0.05 parts by weight or more, or 0.1 parts by weight or more or 0.2 parts by weight or more. In addition, from the viewpoint of compatibility with acrylic polymers, etc., the content of the acrylic oligomer is usually appropriately set to less than 50 parts by weight, preferably less than 30 parts by weight, more preferably 25 parts by weight or less For example, it may be 10 parts by weight or less, or 5 parts by weight or less or 1 part by weight or less.

The adhesive composition disclosed herein may optionally include adhesion-imparting resins (for example, rosin-based, petroleum-based, terpene-based, phenol-based, ketone-based adhesion-imparting resins), viscosity modifiers (e.g., tackifiers), and Coloring agents such as leveling agents, plasticizers, fillers, pigments or dyes, stabilizers, preservatives, antioxidants, and anti-aging agents are equivalent to various additives generally used in the field of adhesive compositions as other optional ingredients. Regarding such various additives, those previously known can be used by conventional methods, and they are not particularly characteristic of the present invention, so detailed descriptions are omitted. Furthermore, the technology disclosed in this paper can exert a good adhesive force without using the above-mentioned adhesion-imparting resin. Therefore, the content of the above-mentioned adhesion-imparting resin in the adhesive composition relative to 100 parts by weight of the acrylic polymer can be set to no Up to 10 parts by weight, and further less than 5 parts by weight. The content of the adhesion-imparting resin may be less than 1 part by weight (for example, less than 0.5 parts by weight), or less than 0.1 parts by weight (more than 0 parts by weight and less than 0.1 parts by weight), and the adhesive composition may be Does not contain adhesive imparting resin.

The adhesive composition disclosed herein can be used for optical purposes, so it can be one that also has prescribed optical properties (such as transparency) after the adhesive layer is formed. From the viewpoint of such optical characteristics, it is preferable to limit the amount of components other than the acrylic polymer in the adhesive composition. In the technology disclosed herein, the amount of components other than the acrylic polymer in the adhesive composition is usually about 30% by weight or less, suitably about 15% by weight or less, preferably about 12% by weight or less (for example, about 10% by weight). Weight% or less). The amount of components other than the acrylic polymer in the adhesive composition of one aspect may be about 5% by weight or less, or about 3% by weight or less, or about 1.5% by weight or less (for example, about 1% by weight). the following). Such a composition in which the amount of components other than the acrylic polymer is restricted can be preferably used for the photocurable adhesive composition.

＜Adhesive layer＞ The adhesive layer constituting the adhesive sheet disclosed herein may be a hardened layer of the adhesive composition. That is, the adhesive layer can be formed by applying (for example, coating) the adhesive composition to a suitable surface, and then suitably performing a hardening treatment. When two or more kinds of hardening treatments (drying, crosslinking, polymerization, etc.) are carried out, these can be carried out at the same time or through multiple stages. In an adhesive composition using a partial polymer of a monomer component (acrylic polymer slurry), typically, the final copolymerization reaction is performed as the above-mentioned hardening treatment. That is, part of the polymer is further subjected to a copolymerization reaction to form a complete polymer. For example, if it is a photocurable adhesive composition, light irradiation is performed. If necessary, cross-linking, drying and other hardening treatments can also be implemented. For example, when it is necessary to dry the photo-curable adhesive composition (for example, in the case of a photo-curable adhesive composition in which a part of the polymer of the monomer component is dissolved in an organic solvent), the combination can be After the material is dried, it is photocured. For the adhesive composition using a complete polymer, typically, treatments such as drying (heat drying), cross-linking, and the like are performed as the above-mentioned curing treatment as necessary. In the case of providing a solvent-based adhesive composition with photocrosslinkability by adding a multifunctional monomer, the composition can be photocrosslinked after being dried. Here, after drying the above-mentioned composition, it may also be after bonding the adhesive sheet obtained by the above-mentioned drying to the to-be-adhered body. The adhesive sheet disclosed herein can be used in the manner of attaching the above-mentioned adherend by a method including photocrosslinking the adherend after being attached to the adherend. Adhesive layers with more than two layers of multilayer structure can be made by laminating pre-formed adhesive layers. Alternatively, the adhesive composition may be coated on the pre-formed first adhesive layer to harden the adhesive composition to form the second adhesive layer. When the adhesive layer used in the adhesive sheet used in the photo-crosslinked attachment state after being attached to the adherend has a multi-layer structure, the photo-crosslinked adhesive layer may be the above-mentioned multi-layer A part of the layers (for example, one layer) included in the structure may also be all the layers.

For coating of the adhesive composition, for example, a gravure roll coater, a reverse roll coater, a touch roll coater, a dip roll coater, a bar coater, a knife coater, a spray coater, etc. can be used It is implemented with a conventional coating machine. In an adhesive sheet having the form of a base material, as a method of disposing an adhesive layer on the base material, a direct method of directly applying an adhesive composition to the base material to form an adhesive layer can also be used. A transfer method in which the adhesive layer on the peeling surface is transferred to the substrate.

The thickness of the adhesive layer is not particularly limited, and may be, for example, about 3 μm to 2000 μm. From the viewpoint of the adhesiveness of the level difference, etc. with the adherend, in some aspects, the thickness of the adhesive layer may be, for example, 5 μm or more, suitably 10 μm or more, preferably 20 μm or more, and more Preferably, it is 30 μm or more. The thickness of the adhesive layer can be 50 μm or more, or more than 50 μm, or more than 70 μm, or more than 100 μm, or more than 120 μm. In addition, from the viewpoint of preventing the generation of paste residue caused by the cohesive destruction of the adhesive layer, in some aspects, the thickness of the adhesive layer can be, for example, 1000 μm or less, or 700 μm or less, or It may be 500 μm or less, 300 μm or less, and furthermore, 200 μm or less or 170 μm or less. The technology disclosed herein can also be preferably implemented in the form of an adhesive sheet whose thickness of the adhesive layer can be 130 μm or less, 90 μm or less, or 60 μm or less (for example, 40 μm or less). Furthermore, in an adhesive sheet with an adhesive layer having a multilayer structure of two or more layers, the thickness of the adhesive layer refers to the surface from the adhesive surface of the adherend to the surface opposite to the adhesive surface The thickness.

(Photocrosslinkable adhesive layer) Among several aspects of the adhesive sheet disclosed herein, the adhesive sheet has a photo-crosslinkable adhesive layer composed of a photo-crosslinkable adhesive. In a preferred aspect, the adhesive layer constituting the adhesive surface of the adhesive sheet is a photo-crosslinkable adhesive layer. The adhesive sheet with the photo-crosslinkable adhesive layer can improve the deformation resistance by photo-crosslinking the adhesive layer. Thereby, the surface shape of the adhesive layer has good followability when it is attached to the adherend, and after attaching, the adhesive layer is photo-crosslinked to form a joint with higher deformation resistance. The adhesive layer with good surface shape followability deforms along the level difference (absorption level) that may exist on the surface of the adherend, and can better adhere to the surface of the adherend.

The photocrosslinkable adhesive constituting the photocrosslinkable adhesive layer may be, for example, one that imparts photocrosslinkability by containing unreacted polyfunctional monomers as described above, or it may be by containing photocrosslinkable It is a kind of polymer and imparted with photocrosslinkability. A polyfunctional monomer and a photocrosslinkable polymer can be used individually by 1 type or in combination of 2 or more types, respectively. It can also be a combination of a photocrosslinkable adhesive containing a multifunctional monomer and a photocrosslinkable polymer. The photocrosslinkable adhesive may contain a photoinitiator according to the type of photocrosslinking.

As a preferable example of the above-mentioned photocrosslinkable polymer, a polymer having a benzophenone structure in a side chain can be cited. The adhesive containing the polymer can be photo-crosslinked using the above-mentioned benzophenone structure. As the polymer having a benzophenone structure in the side chain, an acrylic polymer having a benzophenone structure in the side chain can be preferably used. As another preferable example of the above-mentioned photocrosslinkable polymer, a polymer having a carbon-carbon double bond can be cited. The adhesive containing the polymer can be photocrosslinked by reacting the above-mentioned carbon-carbon double bond. As a preferable example of the polymer having a carbon-carbon double bond, for example, an acrylic polymer having a (meth)acryloyl group introduced into the side chain can be cited. Such an acrylic polymer can be, for example, reacted by copolymerizing an acrylic primary polymer into which a hydroxyl group is introduced and a compound having a carbon-carbon double bond and an isocyanate group so that the carbon-carbon double bond does not disappear. obtain.

＜Substrate＞ Several aspects of the adhesive sheet may be in the form of a substrate-attached adhesive sheet including a substrate bonded to the other back side of the adhesive layer. The material of the base material is not particularly limited, and can be appropriately selected according to the purpose of use or the state of use of the adhesive sheet. Non-limiting examples of substrates that can be used include: polyolefin films with polyolefins such as polypropylene or ethylene-propylene copolymers as the main component, polyethylene terephthalate or polyethylene terephthalate Plastic films (resin films) such as polyester films with polyesters such as butylene formate as the main component, polyvinyl chloride films with polyvinyl chloride as the main component (resin films); including polyurethane foam, polyethylene foam, and polychloride Foam sheets for foams such as butadiene foam; use various fibrous materials (which can be natural fibers such as hemp and cotton, synthetic fibers such as polyester and vinylon, and semi-synthetic fibers such as acetate) Or blended fabrics and non-woven fabrics; Japanese paper, Dolin paper, kraft paper, crepe paper and other papers; aluminum foil, copper foil and other metal foils. It may also be a base material composed of these composites. As an example of the base material of such a composite structure, the base material of the structure in which metal foil and the above-mentioned plastic film are laminated|stacked, the plastic sheet reinforced with inorganic fiber, such as glass cloth, etc. are mentioned, for example.

As the base material of the adhesive sheet disclosed herein, various films (hereinafter, also referred to as support films) can be preferably used. The support film may be a porous film such as a foam film or a non-woven fabric sheet, or a non-porous film, or a porous layer and a non-porous laminated layer structure. In some aspects, as the above-mentioned support film, it is preferable to use a resin film that can independently maintain a shape (independent or independent) as a base film. Here, the "resin film" means a non-porous structure, typically a resin film that contains substantially no bubbles (no voids). Therefore, the above-mentioned resin film is a concept that distinguishes it from a foam film or a non-woven fabric. The above-mentioned resin film may have a single-layer structure or a multilayer structure of two or more layers (for example, a three-layer structure).

As the resin material constituting the resin film, for example, polyester, polyolefin, polycyclic olefin derived from a monomer having aliphatic ring structure such as a norene structure, nylon 6, nylon 66, partially aromatic polyamide, etc. can be used Polyimide (PI) such as polyamide (PA), transparent polyimide (CPI), polyimide imide (PAI), polyether ether ketone (PEEK), polyether ether (PES), polyimide Phenyl sulfide (PPS), polycarbonate (PC), polyurethane (PU), ethylene-vinyl acetate copolymer (EVA), polyvinyl alcohol (PVA), polystyrene, ABS (Acrylonitrile Butadiene) Styrene, acrylonitrile-butadiene-styrene) resin, polyvinyl chloride, polyvinylidene chloride, polytetrafluoroethylene (PTFE) and other fluorine resins, polymethyl methacrylate and other acrylic resins, and diacetyl fiber Resins such as cellulosic polymers such as plain or triacetyl cellulose (TAC), vinyl butyral polymers, aryl ester polymers, polyoxymethylene polymers, epoxy polymers and the like. The above-mentioned resin film may be formed using a resin material containing one type of such resin alone, or may be formed using a resin material in which two or more types are blended. The above-mentioned resin film may be unstretched or stretched (for example, uniaxially stretched or biaxially stretched).

Preferred examples of the resin material constituting the resin film include polyester resins, PPS resins, polyolefin resins, and polyimide resins. Here, the term “polyester resin” refers to a resin containing polyester at a ratio of more than 50% by weight. Similarly, the so-called PPS resin refers to a resin containing PPS at a ratio of more than 50% by weight, and the so-called polyolefin resin refers to a resin containing polyolefin at a ratio of more than 50% by weight. The so-called polyimide resin is Refers to a resin containing polyimide at a ratio of more than 50% by weight.

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

As the polyolefin resin, one type of polyolefin may be used alone or in combination of two or more types of polyolefin. The polyolefin may be, for example, a homopolymer of α-olefin, a copolymer of two or more kinds of α-olefin, a copolymer of one or more kinds of α-olefin and other vinyl monomers, and the like. Specific examples include ethylene-propylene copolymers such as polyethylene (PE), polypropylene (PP), poly-1-butene, poly-4-methyl-1-pentene, and ethylene propylene rubber (EPR) , Ethylene-propylene-butene copolymer, ethylene-butene copolymer, ethylene-vinyl alcohol copolymer, ethylene-ethyl acrylate copolymer, etc. Either low density (LD) polyolefin and high density (HD) polyolefin can be used. Examples of polyolefin resin films include: unstretched polypropylene (CPP) film, biaxially stretched polypropylene (OPP) film, low-density polyethylene (LDPE) film, linear low-density polyethylene (LLDPE) ) Film, medium density polyethylene (MDPE) film, high density polyethylene (HDPE) film, polyethylene (PE) film blended with more than two types of polyethylene (PE), blended with polypropylene (PP) and Polyethylene (PE) PP/PE blended film, etc.

Specific examples of resin films that can be preferably used as substrates include PET films, PEN films, PPS films, PEEK films, CPI films, CPP films, and OPP films. In terms of strength, preferred examples include PET film, PEN film, PPS film, PEEK film, and CPI film. From the viewpoints of ease of availability, dimensional stability, optical properties, etc., preferred examples include PET films, CPI films, and TAC films.

In the resin film, light stabilizers, antioxidants, antistatic agents, colorants (dyes, pigments, etc.), fillers, lubricants, anti-blocking agents, and other well-known additives can be blended as needed. The blending amount of the additives is not particularly limited, and can be appropriately set according to the application of the adhesive sheet, etc.

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

The above-mentioned base material may consist essentially of such a resin film. Alternatively, the above-mentioned base material may include an auxiliary layer in addition to the above-mentioned resin film. Examples of the above-mentioned auxiliary layer include: an optical characteristic adjustment layer (for example, a coloring layer, an anti-reflection layer), a printed layer or a laminate layer, an antistatic layer, and an anti-static layer for imparting a desired appearance to a substrate or an adhesive sheet. Surface treatment layers such as primer and release layer. In addition, the above-mentioned support material may be the following optical member.

The thickness of the substrate is not particularly limited, and it can be selected according to the purpose of use or usage of the adhesive sheet. The thickness of the substrate can be, for example, 1000 μm or less, 500 μm or less, 100 μm or less, 70 μm or less, 50 μm or less, 25 μm or less, or 10 μm or less, but also 5 μm or less. If the thickness of the substrate becomes smaller, the flexibility of the adhesive sheet or the followability to the surface shape of the adherend tends to increase. In addition, from the viewpoint of handleability and processability, the thickness of the substrate may be, for example, 2 μm or more, or may exceed 5 μm or exceed 10 μm. In some aspects, the thickness of the substrate may be 20 μm or more, 35 μm or more, or 55 μm or more, for example.

For the surface of the base material that is bonded to the adhesive layer, corona discharge treatment, plasma treatment, ultraviolet irradiation treatment, acid treatment, alkali treatment, primer coating, and antistatic treatment can also be performed as needed Such as previously known surface treatment. Such surface treatment can be a treatment for improving the adhesion between the substrate and the adhesive layer, in other words, the adhesive layer's grip on the substrate. The composition of the primer is not particularly limited, and can be appropriately selected from known ones. The thickness of the undercoat layer is not particularly limited, but it is usually about 0.01 μm to 1 μm, preferably about 0.1 μm to 1 μm.

For the surface of the substrate on the opposite side to the side bonded to the adhesive layer (hereinafter, also referred to as the back surface), if necessary, peeling treatment, adhesion or adhesion improvement treatment, antistatic treatment and other known surface treatments can also be applied. . For example, by using a release treatment agent to perform surface treatment on the back surface of the substrate, the unwinding force of the adhesive sheet wound into a roll shape can be reduced. As the release treatment agent, silicone-based release treatment agent, long-chain alkyl-based release treatment agent, olefin-based release treatment agent, fluorine-based release treatment agent, fatty acid amide-based release treatment agent, molybdenum sulfide, silicon dioxide can be used Powder etc.

＜Additional adhesive layer＞ The adhesive sheet disclosed herein may also have an adhesive layer that can be additionally configured, different from the above-mentioned adhesive layer. The above-mentioned additional adhesive layer may be selected from acrylic adhesives, rubber-based adhesives (natural rubber-based, synthetic rubber-based, mixed systems of these, etc.), silicone-based adhesives, and polyester-based adhesives, for example. , Urethane-based adhesives, polyether-based adhesives, polyamide-based adhesives, fluorine-based adhesives, etc., an adhesive layer composed of one or two or more of various well-known adhesives . From the viewpoint of transparency or weather resistance, among several aspects, it is preferable to use an acrylic adhesive as the constituent material of the additional adhesive layer. Regarding other matters of the additional adhesive layer, the same configuration as the above-mentioned adhesive layer can be adopted, or an appropriate configuration can be adopted according to the application or purpose based on publicly known or customary techniques and technical common sense. Therefore, detailed descriptions are omitted here. .

＜Use＞ The use of the adhesive sheet disclosed herein is not particularly limited, and can be used for various purposes. For example, the adhesive sheet disclosed herein can be used for fixing, joining, forming, decorating, protecting, supporting, etc., the members constituting various products. The material constituting at least the surface of the above-mentioned member can be, for example, glass such as alkali glass or alkali-free glass; metal materials such as resin film, stainless steel (SUS), aluminum, etc.; ceramic materials such as alumina and silicon dioxide; acrylic resin, ABS resin, etc. Polycarbonate resin, polystyrene resin, transparent polyimide resin and other resin materials. The above-mentioned components may be components constituting various portable devices (portable devices), automobiles, household appliances, and the like, for example. In addition, the surface of the above-mentioned component on which the adhesive sheet is attached can also be made of acrylic, polyester, alkyd, melamine, urethane, acid-epoxy cross-linking, or a combination of these It is a coating surface formed by paint such as acrylic melamine series, alkyd melamine series, etc., or a galvanized steel plate and the like. In addition, the above-mentioned member may be any support film (for example, a resin film) exemplified as a material that can be used for the substrate. The adhesive sheet disclosed herein may be, for example, a constituent element of a member attached to the adhesive sheet in which such a member is bonded to at least one surface of the adhesive layer.

The adhesive sheet disclosed herein can be preferably used in the state of being attached to an adherend having a glass material on at least the surface. In this aspect, good water releasability is shown in the initial stage of attachment (preferably after attachment, for a certain period of time), and the effect of bonding to the adherend with good water resistance and reliability can be better exhibited. The above-mentioned adherend may be a plate-shaped body containing glass materials such as alkali glass or alkali-free glass, or may be formed on a dissimilar material such as a resin film containing a glass material (typically, silicon oxide represented by _{SiO X, or} The compound film of the hydrophilic layer of silicon dioxide represented by SiO _2. The above-mentioned hydrophilic layer (surface modification layer) can be formed by vacuum evaporation, sputtering, ion plating and other physical vapor deposition methods (PVD), or atomic layer deposition and other chemical vapor deposition methods (CVD), etc. The film method is formed. Alternatively, the hydrophilic layer may be formed by applying a coating agent containing a powder of glass material. The above-mentioned coating agent may contain various organic materials containing organic polymer compounds that can be used as binders, or may not contain them.

As an example of a preferable application of the adhesive sheet disclosed herein, optical applications can be cited. More specifically, for example, it can be preferably used as an optical adhesive sheet used in the use of bonding optical members (for optical member bonding) or the manufacturing use of products (optical products) using the above-mentioned optical members. The adhesive sheet disclosed in this article.

The above-mentioned optical member refers to a member having optical properties (for example, polarization, light refraction, light scattering, light reflectivity, light transmittance, light absorption, light diffraction, optical rotation, visibility, etc.). The above-mentioned optical member is not particularly limited as long as it is a member having optical characteristics. For example, a member constituting a display device (image display device), an input device, etc. (optical device) or a member used in these devices can be cited Examples include: polarizing plate, wave plate, phase difference plate, optical compensation film, brightness enhancement film, light guide plate, reflective film, anti-reflection film, hard coat (HC) film, impact absorption film, antifouling film, photoinduced Color changing film, dimming film, transparent conductive film (ITO (Indium Tin Oxide, indium tin oxide) film), design film, decorative film, surface protection board, scallop, lens, color filter, transparent substrate, or laminated There are such components (sometimes collectively referred to as "functional films") and the like. Furthermore, the above-mentioned "plate" and "film" are set to include plate-shaped, film-shaped, sheet-like, etc., respectively. For example, "polarizing film" is set to include "polarizing plate", "polarizing plate", and the like.

As the above-mentioned display device, for example, a liquid crystal display device, an organic EL (electroluminescence) display device, a PDP (plasma display panel), electronic paper, etc. can be cited, and it can be particularly preferably applied to a foldable display device or a vehicle-mounted device. The display device generally contains expensive components. In addition, as the above-mentioned input device, a touch panel or the like can be cited.

The above-mentioned optical member is not particularly limited. For example, a member containing glass, acrylic resin, polycarbonate, polyethylene terephthalate, metal thin film, etc. (for example, a sheet-like or film-like shape, a plate-like shape) may be mentioned. Component) and so on. Furthermore, the "optical component" in this specification also includes components that maintain the visibility of the display device or the input device and are responsible for decoration or protection (design film, decorative film, or surface protection film, etc.).

There is no particular limitation on the aspect of bonding optical members using the adhesive sheet disclosed herein. For example, it may be (1) the aspect in which the optical members are bonded to each other via the adhesive sheet disclosed herein, (2) The state in which the optical member is bonded to a member other than the optical member through the adhesive sheet disclosed herein may also be (3) The adhesive sheet disclosed herein is a form including the optical member and the adhesive sheet is bonded The aspect of optical components or components other than optical components. Furthermore, in the aspect of (3) above, the adhesive sheet in the form of an optical member may be, for example, an adhesive sheet in which the base material is an optical member (for example, an optical film). Such an adhesive sheet including an optical member as a base material can also be understood as an adhesive optical member (for example, an adhesive optical film). In addition, when the adhesive sheet disclosed herein is a type of adhesive sheet with a substrate, and the above-mentioned functional film is used as the above-mentioned substrate, the adhesive sheet disclosed herein can also be understood as a functional film At least one side has an "adhesive functional film" with the adhesive layer disclosed herein.

＜Water contact angle＞ The adhesive sheet disclosed herein can be preferably used in a state where it is attached to a surface showing a hydrophilicity with a contact angle of distilled water of, for example, 60 degrees or less, preferably 50 degrees or less. In some aspects, the contact angle of the joint surface may be 45 degrees or less, 40 degrees or less, 35 degrees or less, or 30 degrees or less, for example. If the contact angle of the joint surface becomes small, water tends to wet and spread along the joint surface, and the water releasability of the adhesive sheet tends to improve. In this case, it is preferable from the viewpoint of improvement in secondary workability when the adhesive sheet is bonded to the bonding surface to produce an adhesive sheet-attached member. In addition, in such a highly hydrophilic surface, for example, in the case of using compound S as a peeling force enhancer, the bonding reliability (such as water resistance reliability) brought by the compound S can be better utilized Improve results. Furthermore, as long as the contact angle of the above-mentioned joint surface is less than any of the above-mentioned angles at least at the time of bonding the adhesive sheet (for example, 30 minutes before bonding), it can be brought into play by the contact angle being below the prescribed value. Improved secondary workability. In principle, the lower limit of the contact angle is 0 degrees. In some aspects, the contact angle of the joint surface may be more than 0 degree, may be 1 degree or more, may be 3 degrees or more, or may be 5 degrees or more. The contact angle of the joint surface of the member can be measured in the same way as the contact angle of the above-mentioned alkali glass plate.

For the joint surface of the components, in order to reduce the contact angle to distilled water, hydrophilization treatment can also be carried out. As the hydrophilization treatment, for example, corona treatment, plasma treatment, treatment for forming a hydrophilic layer, etc., treatments that contribute to the improvement of hydrophilicity can be cited. The apparatus or processing conditions used in corona treatment or plasma treatment can be set based on the previously known technology to obtain a joint surface showing the desired contact angle.

The above-mentioned hydrophilic layer forming treatment may be a treatment of forming a hydrophilic coating. The formation of the hydrophilic coating can be suitably selected from known coating agents that can obtain a bonding surface showing the desired contact angle, and used by conventional methods. The thickness of the hydrophilic coating may be 0.01 μm or more, 0.05 μm or more, or 0.1 μm or more, for example, 10 μm or less, 5 μm or less, or 2 μm or less.

The above-mentioned hydrophilic layer forming treatment may be a treatment of forming a hydrophilic layer containing an inorganic material. Since the hydrophilic layer contains inorganic materials, it is easy to obtain good water releasability. As the inorganic material, various metal materials including simple substances of transition metal elements or semimetal elements, alloys, or materials that can form a hydrophilic surface in inorganic compounds such as inorganic oxides can be used. The above-mentioned inorganic material can be used individually by 1 type or in combination of 2 or more types. Preferred examples of inorganic materials include: titanium oxide, zinc oxide, magnesium oxide, aluminum oxide, silicon oxide, cerium oxide, chromium oxide, zirconium oxide, manganese oxide, zinc oxide, iron oxide, tin oxide, niobium oxide, etc. Oxide (inorganic oxide, typically metal oxide). Among them, inorganic oxides such as silicon oxide can be used as a preferable inorganic material. In the hydrophilic layer, in addition to inorganic materials, various organic materials containing organic polymer compounds that can be used as coating agents or binders may or may not be included.

The amount of the inorganic material (for example, inorganic oxide such as silicon oxide) in the hydrophilic layer can be set to an appropriate amount to obtain the target hydrophilic surface, and is not limited to a specific range. For example, the content ratio of the inorganic material in the hydrophilic layer can be set to about 30% by weight or more, suitably about 50% by weight or more (for example, more than 50% by weight), or about 70% by weight or more. In some preferred aspects, the content ratio of the inorganic material in the hydrophilic layer is about 90-100% by weight (for example, about 95% by weight or more).

In some preferred aspects, as the above-mentioned inorganic material, an inorganic oxide such as _{silicon oxide (typically, silicon oxide represented by SiO X} or silicon dioxide represented by SiO _{2) can be used.} The proportion of inorganic oxide (typically, silicon oxide) in the above-mentioned inorganic material can be set to an appropriate amount to obtain the target hydrophilic surface, and is not limited to a specific range, for example, it can be set to about 30% by weight The above is appropriately about 50% by weight or more (for example, more than 50% by weight), and it may also be about 70% by weight or more. In some preferred aspects, the ratio of the inorganic oxide (typically, silicon oxide) in the above-mentioned inorganic material is about 90-100% by weight (for example, about 95% by weight or more).

The method for forming the above-mentioned hydrophilic layer is not particularly limited, and it can be formed by an appropriate method according to the target thickness and the like. For example, as the hydrophilic layer, an inorganic material formed into a layer by a known film forming method such as a vacuum vapor deposition method, a sputtering method, or a plating method can be used. When an inorganic compound is used as an inorganic material, various vapor deposition methods can be used. For example, physical vapor deposition (PVD) such as vacuum vapor deposition, sputtering, ion plating, or chemical vapor deposition such as atomic layer deposition can be used. Vapor deposition method (CVD) and so on. The formation of the coating containing inorganic polymers such as polysiloxane can be suitably selected from known coating agents that can obtain a surface showing the desired water contact angle, and used by conventional methods.

＜Peeling method＞ According to this specification, a method of peeling off an adhesive sheet attached to an adherend is provided. This peeling method is suitable as any of the peeling methods of the adhesive sheet disclosed herein. The peeling method includes a water peeling step, which is in the state where an aqueous liquid exists at the interface between the adherend and the adhesive sheet at the front line of the adhesive sheet to be peeled from the adherend, and the aqueous liquid is applied Follow the movement of the peeling front line to enter the interface, and peel the adhesive sheet from the adherend. Here, the “peeling front line” refers to the position where the adhesive sheet starts to separate from the adherend when the adhesive sheet is peeled from the adherend. According to the water peeling step, the aqueous liquid can be effectively used to peel the adhesive sheet from the adherend. As an aqueous liquid, water or a mixed solvent containing water as the main component may contain a small amount of additives as necessary. As a solvent other than water constituting the above-mentioned mixed solvent, a lower alcohol (for example, ethanol) or a lower ketone (for example, acetone) that can be uniformly mixed with water can be used. As the above-mentioned additives, well-known surfactants and the like can be used. From the viewpoint of avoiding contamination of the adherend, in some aspects, it is preferable to use an aqueous liquid that does not substantially contain additives. From the viewpoint of environmental sanitation, it is particularly preferable to use water as an aqueous liquid. There are no particular restrictions on the water, and the required purity or ease of availability can be considered according to the use. For example, distilled water, ion-exchanged water, tap water, etc. can be used.

Among several aspects, the above-mentioned peeling method can be preferably carried out in the following aspect, that is, an aqueous liquid is supplied to the adherend near the outer edge of the adhesive sheet attached to the adherend, so that the aqueous liquid is removed from the above After the outer edge of the adhesive sheet enters one end of the interface between the adhesive sheet and the adherend, no new water is supplied (that is, only the aqueous liquid supplied to the adherend before the start of peeling) is used for adhesion. Peeling of the sheet. Among several other aspects, the above peeling method can be preferably carried out in the following aspect, that is, on a part of the adhesive sheet attached to the adherend (typically, a part connected to the outer edge of the adhesive sheet ) In the state where the adherend is lifted, the remaining adhesive sheet is supplied with an aqueous liquid to the part where the adherend begins to separate, and the adhesive sheet is peeled off without supplying new water. Furthermore, in the middle of the water stripping step, if the water entering the interface between the adhesive sheet and the adherend following the movement of the stripping front line is exhausted in the middle, it may be intermittently or after the start of the water stripping step. Continuously add water supply. For example, in the case where the adherend has water absorption, or the case where the aqueous liquid is likely to remain on the surface of the adherend after peeling or the adhesion surface, etc., it is preferable to use the state of adding water after the start of the water peeling step .

The amount of the aqueous liquid supplied before the start of peeling is not particularly limited as long as the amount of the aqueous liquid can be introduced into the interface between the adhesive sheet and the adherend. The amount of the above-mentioned aqueous liquid may be, for example, 5 μL or more, and usually suitably 10 μL or more, or 20 μL or more. In addition, there is no particular restriction on the upper limit of the amount of the above-mentioned aqueous liquid. In some aspects, from the viewpoint of improving workability, the amount of the above-mentioned aqueous liquid may be, for example, 10 mL or less, 5 mL or less, 1 mL or less, 0.5 mL or less, or It is less than 0.1 mL, or less than 0.05 mL. By reducing the amount of the above-mentioned aqueous liquid, the operation of removing the above-mentioned aqueous liquid by drying or wiping after peeling off the adhesive sheet can be omitted or simplified.

At the start of peeling, the operation of allowing the aqueous liquid to enter the interface between the adhesive sheet and the adherend from the outer edge of the adhesive sheet can be performed in the following manner: insert a cut at the interface outside the adhesive sheet The tip of a jig such as a knife or a needle, using a hook or nail, etc., to scratch the outer edge of the adhesive sheet and lift it up, so that a strong adhesive tape or suction cup is attached to the backside near the outer edge of the adhesive sheet to lift the adhesive The end of the sheet and so on. By forcibly entering the aqueous liquid from the outer edge of the adhesive sheet to the interface in this way, it can be efficiently formed in a state where there is an aqueous liquid at the interface between the adherend and the adhesive sheet. In addition, it is possible to better balance the good water releasability after the operation of forcibly entering the aqueous liquid into the interface to form the starting point of the peeling, and the high water resistance reliability when the operation is not performed. Furthermore, the above-mentioned operation of forming the starting point of peeling can also be used to form a part of the adhesive sheet that is attached to the adherend before supplying the aqueous liquid (typically, the part connected to the outer edge of the adhesive sheet) It is used deliberately from the operation of the state where the adherend is lifted.

The water stripping steps of several aspects can be preferably implemented in the aspect in which the stripping front line is moved at a speed of 10 mm/min or more. Moving the peeling front line at a speed of 10 mm/min or more is equivalent to peeling the adhesive sheet at a stretching speed of 20 mm/min or more under the condition of a peeling angle of 180 degrees. The speed at which the aforementioned peeling front line moves may be, for example, 50 mm/min or more, 150 mm/min or more, 300 mm/min or more, or 500 mm/min or more. According to the peeling method disclosed in this article, by allowing the aqueous liquid to enter the interface on one side, and peeling off the adhesive sheet from the adherend on the other side, even with such a relatively fast peeling speed, it can perform well. Water releasability. The upper limit of the speed at which the peeling front line moves is not particularly limited. The speed at which the aforementioned peeling front line moves can be, for example, 1000 mm/min or less.

The peeling method disclosed herein, for example, the volume of the aqueous liquid (e.g., water) used in the method can be such that the peeling area of the adhesive sheet per 10 μL is 50 cm ² or more, preferably 100 cm ² or more. In the implementation.

The peeling method disclosed herein can be preferably applied to peel off adhesive sheets attached to non-water-absorbent smooth surfaces such as glass plates, metal plates, and resin plates. In addition, the peeling method disclosed herein can be preferably used as a method for peeling the adhesive sheet from any of the above-mentioned optical components. Among them, it is suitable as a method for peeling an adhesive sheet attached to a glass plate such as alkali glass or alkali-free glass.

Hereinafter, several embodiments related to the present invention will be described, but it is not intended to limit the present invention to those shown in these embodiments. In addition, in the following description, as long as there is no special description, "parts" and "%" are based on weight.

<Example 1> (Preparation of adhesive composition) Add 65 parts of n-butyl acrylate (BA), 6 parts of cyclohexyl acrylate (CHA), and N-vinyl-2 as monomer components in a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer, and a stirring device. -18 parts of pyrrolidone (NVP), 1 part of isostearyl acrylate (iSTA), 15 parts of 4-hydroxybutyl acrylate (4HBA), 0.07 parts of α-thioglycerol as a chain transfer agent, and one of the polymerization solvents 122 parts of ethyl acetate, 0.2 parts of 2,2'-azobisisobutyronitrile (AIBN) as a thermal polymerization initiator, and solution polymerization in a nitrogen atmosphere, thereby obtaining an acrylic system with a Mw of 300,000 Polymer solution.

In the solution obtained above, for every 100 parts of the monomer components used to prepare the solution, add the compound S-1 (3-glycidoxypropyltriethoxysilane, trade name: KBE) as a peel force enhancer -403, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.1 part, nonionic surfactant A (polyoxyethylene sorbitan monolaurate, HLB 13.3, trade name: RHEODOL TW-L106, Kao Corporation) as a water affinity agent Manufacturing) 0.3 parts, isocyanate-based crosslinking agent (trimethylolpropane/xylylene diisocyanate adduct (manufactured by Mitsui Chemicals, Takenate 110 N, solid content concentration 75% by mass)) based on solid content 0.09 parts, 0.4 parts of acrylic oligomer, 0.02 parts of dioctyltin dilaurate (manufactured by Tokyo Fine Chemical Co., Ltd., EMBILIZER OL-1) as a crosslinking accelerator, and acetone acetone as a crosslinking retarder 3 parts, 3 parts of dipentaerythritol hexaacrylate (DPHA) as a multifunctional monomer, 0.22 parts of photopolymerization initiator (manufactured by IGM Regins, trade name: Omnirad 184), and uniformly mixed to prepare a solvent type Adhesive composition.

As the acrylic oligomer, one synthesized by the following method is used. [Synthesis of acrylic oligomers] 100 parts of toluene, dicyclopentyl methacrylate (DCPMA) (trade name: FA-513M, manufactured by Hitachi Chemical Co., Ltd.) 60 parts, methyl methacrylate (MMA) 40 parts, and α as a chain transfer agent -3.5 parts of thioglycerol was put into a four-necked flask. Then, after stirring for 1 hour at 70°C under a nitrogen atmosphere, 0.2 part of AIBN as a thermal polymerization initiator was added, and the reaction was carried out at 70°C for 2 hours, and then at 80°C for 2 hours. After that, the reaction liquid was put into a temperature atmosphere of 130° C., toluene, chain transfer agent, and unreacted monomers were dried and removed, thereby obtaining a solid acrylic oligomer. The Tg of the acrylic oligomer was 144°C and the Mw was 4300.

(Making of Adhesive Sheet) Coat the adhesive composition obtained above on a release film R1 (manufactured by Mitsubishi Plastics Corporation, MRF#38) with a thickness of 38 μm, which is the release surface on one side of the polyester film, and dried at 135°C for 2 minutes to form a thickness of 50 μm The adhesive layer (adhesive sheet without substrate). The peeling surface of peeling film R2 (manufactured by Mitsubishi Plastics Corporation, MRE#38), which is a peeling surface, is attached to the adhesive layer on one side of the polyester film to protect it. In this way, a laminated sheet in which a release film R1, a base-free adhesive sheet, and a release film R2 are sequentially laminated is obtained.

<Example 2> 0.1 part of compound S-2 (hexadecyltriethoxysilane (manufactured by Tokyo Chemical Industry Co., Ltd.)) was used instead of compound S-1 used in Example 1 as a peeling force enhancer. In other respects, the adhesive composition was prepared in the same manner as in Example 1, and the adhesive sheet of this example was obtained.

<Example 3> 0.1 part of compound S-3 (3-glycidoxypropyltrimethoxysilane (trade name: KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.)) was used instead of compound S-1 used in Example 1 as the peel force enhancement Agent. In other respects, the adhesive composition was prepared in the same manner as in Example 1, and the adhesive sheet of this example was obtained.

<Example 4> Except not using the peeling force enhancer, an adhesive composition was prepared in the same manner as in Example 1, and the adhesive sheet of this example was obtained.

<Measurement and evaluation> (1) Water peeling force measurement (1-1) Adhesion of the test piece to the adherend Cut the adhesive layer (adhesive sheet without base material) of each example into a width of 20 mm and a length of 120 The test piece was prepared with a rectangular shape of mm. Use a hand roller to affix the adhesive surface of the test piece to an alkali glass plate (manufactured by Matsunami Glass Industry Co., Ltd., manufactured by the float method, thickness 1.35 mm, green glass edging product, contact angle to distilled water) : 8 degrees), after standing for 2 hours in an environment of 23° C. and 50% RH, light irradiation is carried out through the above-mentioned alkali glass plate in the same environment. The above-mentioned light irradiation was performed using a high-pressure mercury lamp (manufactured by Toshiba Corporation, trade name H3000L/22N, illuminance 300 mW/cm ² ) from the glass plate side under the condition of a cumulative light quantity of 3000 mJ/cm ^2. After that, let it stand for 1 hour in an environment of 23° C. and 50% RH.

(1-2) Measurement of initial water peeling force (FW0) For the sample obtained in (1-1) above, 3 hours after the test piece was attached to the adherend (that is, just after 1 hour after light irradiation), 20 μL of the test piece was applied to the adherend. Distilled water, after the distilled water enters one end of the interface between the adhesive layer and the substrate layer, according to 10.4.1 of JIS Z0237:2009 Method 1: 180° peeling adhesive force of the test board, specifically, in the test The water peeling force FW0 was measured at a temperature of 23°C using a tensile testing machine at a tensile speed of 300 mm/min and a peeling angle of 180 degrees. The obtained results are converted to the value per 10 mm of width and are shown in Table 1.

(1-3) Measurement of water peel strength (FW2) after heat treatment The sample obtained by the above (1-1) was kept (heat treatment) at 60°C for 5 hours, and then kept at 23°C and 50% for 1 hour, and the initial water peel strength (FW0) ) The water peeling force FW2 was measured in the same way. The obtained results are converted to the value per 10 mm of width and are shown in Table 1.

(1-4) Measurement of water peel strength after 3 days, 7 days, and 14 days at room temperature The sample obtained by the above (1-1) was allowed to stand for 3 days, 7 days, or 14 days in an environment of 23°C and 50% RH, and then measured in the same manner as the measurement of the initial water peeling force (FW0) above Water peeling force. The obtained results are converted to the value of 10 mm in width and shown in Table 2. Furthermore, the water peel strength of the adhesive sheet of Example 4 was 0.3 N/10 mm after 3 days, 7 days, and 14 days.

(2) Damp heat durability test For the adhesive layers (adhesive sheets without base material) produced in Examples 1 to 3, the following damp heat durability test was performed.

(2-1) Production of polarizing plate with adhesive layer Using a polyvinyl alcohol-based adhesive, a 25 μm-thick triacetyl cellulose (TAC) film was attached to the visible side of a polarizing element containing a 12 μm-thick stretched polyvinyl alcohol film impregnated with iodine. A polyvinyl alcohol-based Then, an acrylic film with a thickness of 20 μm on the surface area of the image display part of the polarizing element was applied to form a polarizing film (P-1). The degree of polarization of the polarizing film is 99.995. The following acrylic adhesive composition C was applied to the peeling surface of the peeling film R1 (MRF#38) and dried to produce an acrylic adhesive layer A with a thickness of 20 μm. The acrylic adhesive layer A was bonded to the acrylic film side of the polarizing film (P-1) to produce an adhesive polarizing plate. [Acrylic Adhesive Composition C] Use 0.3 parts of 2,2'-azobisisobutyronitrile (AIBN) as a thermal polymerization initiator, and ethyl acetate as a polymerization solvent to contain 98 parts of BA and 1 part of 2-hydroxyethyl acrylate (HEA) A monomer mixture of 1 part of acrylic acid (AA) and 1 part of acrylic acid (AA) was reacted for 4 hours at 60°C under nitrogen flow to obtain a solution containing an acrylic polymer with a Mw of 1.8 million (solid content 30%). The acrylic polymer For every 100 parts of the solid component of the body solution, prepare 0.3 parts of diphenylmethyl peroxide (manufactured by Nippon Oil & Fats, Nyper BO-Y) and 0.02 parts of trimethylolpropane/toluene diisocyanate trimer adduct ( Coronate L) manufactured by Tosoh, and 0.1 parts of silane coupling agent (3-glycidoxypropyltrimethoxysilane), and uniformly stirred and mixed to prepare solvent-based acrylic adhesive composition C.

(2-2) Preparation of samples for wet-heat durability evaluation. The adhesive sheet (thickness 50 μm) of each example without a substrate was attached to the TAC film side of the above-mentioned polarizing plate with adhesive to produce a light-interlaced adhesive sheet. The polarizing sheet of the interlinkable adhesive layer. Cut the above-mentioned polarizer sheet into short strips with a width of 40 mm and a length of 70 mm. Next, use a hand roller to attach the above-mentioned alkali glass plate (manufactured by Songnang Glass Industry Co., Ltd., manufactured by the float method, thickness 1.35 mm, green glass edging product, contact angle to distilled water: 8 degrees) as the adherend Polaroid sheet cut by the middle length. Then, the peeling film R1 covering the acrylic adhesive layer A of the polarizing plate sheet was peeled off, and an aluminum foil (manufactured by Mitsubishi Aluminum Foil, trade name "Nippaku Foil") was attached to the exposed acrylic adhesive layer A using a hand roller. ", thickness 12 μm), cut into the same size as the polarizer sheet. Thereby, a laminate having the composition of alkali glass plate/adhesive layer/polarizing plate/aluminum foil is obtained. The laminate was put into an autoclave and treated under the conditions of a pressure of 5 atm and a temperature of 50°C for 15 minutes, and then light was irradiated through the alkali glass plate in an environment of 23°C and 50% RH. The above-mentioned light irradiation was performed by using a high-pressure mercury lamp (300 mW/cm ² ) to irradiate ultraviolet rays with a cumulative light amount of 3000 mJ/cm ^{2 from the side of the alkali glass.}

(2-3) Peel strength after damp and heat After keeping the sample obtained in (2-2) above for 24 hours in an environment of 85°C and 85% RH, it was allowed to stand for 5 hours in an environment of 23°C and 50% RH. Thereafter, according to 10.4.1 of JIS Z0237:2009, Method 1: For the 180° peel adhesion of the test panel, specifically, use a tensile testing machine at a test temperature of 23°C at a tensile speed of 300 mm/min, peeling The peel strength was measured under the condition of an angle of 180 degrees. The obtained results are converted to the value of 10 mm in width and shown in Table 2.

(2-4) Damp heat durability evaluation After keeping the sample obtained in (2-2) above for 500 hours in an environment of 85°C and 85% RH, it was allowed to stand for 5 hours in an environment of 23°C and 50% RH. Thereafter, the presence or absence of peeling and the generation of bubbles at the interface between the adhesive layer and the glass plate were visually observed, and the durability was evaluated according to the following three levels. The results are shown in Table 2. In addition, in the case of using the adhesive sheet of any example, no bubbles were confirmed at all immediately after the production of the above-mentioned durability evaluation sample. A: Neither peeling nor bubble generation was confirmed. B: No bubbles are generated, but less than 3 mm peeling is confirmed at the end of the sample. C: No bubbles are generated, but peeling of 3 mm or more is confirmed at the end of the sample.

[Table 1] Table 1 Compound S Water peeling force [N/10 mm] species Alkoxysilyl Reactive functional group of hydrophobic part Molecular weight After 3 hours (FW0) After heat treatment (FW2) example 1 S-1 -Si(OCH2CH3)3 Epoxy 278 0.4 8.3 Example 2 S-2 -Si(OCH2CH3)3 no 347 0.3 4.5 Example 3 S-3 -Si(OCH3)3 Epoxy 284 0.3 8.3 Example 4 no - - - 0.3 2.9

[Table 2] Table 2 Compound S Water peeling force [N/10 mm] 85℃85%RH damp heat endurance test species After 3 days at room temperature After 7 days at room temperature (FW1) After 14 days at room temperature (FW3) Peel strength after damp heat [N/10 mm] (FN1) Appearance evaluation after 500 hours example 1 S-1 0.4 0.5 0.8 15.0 A Example 2 S-2 0.3 0.4 0.4 1.3 B Example 3 S-3 0.3 1.2 3.4 16.3 A

As shown in Table 1, the adhesive sheets of Examples 1 to 4 all have a low water peeling force FW0, and show good water peeling properties at the initial stage of attachment. In addition, the pressure-sensitive adhesive sheets of Examples 1 to 3 can be heat-treated, and compared with the pressure-sensitive adhesive sheet of Example 4, the water peeling force FW2 can be increased significantly, thereby improving the reliability of water resistance. In addition, the adhesive sheets of Examples 1 and 2 out of the adhesive sheets of Examples 1 to 3 in which the water peeling force was greatly improved by the heat treatment, as shown in Table 2, are more than the adhesive sheets of Example 3. Long-term suppression of the increase in water peeling force. Among them, the adhesive sheet of Example 1 had higher peel strength after damp heat, and the appearance after damp heat durability test was also excellent.

The specific examples of the present invention have been described in detail above, but these are only examples and do not limit the scope of patent applications. The technology described in the scope of the patent application includes various changes and modifications to the specific examples illustrated above.

1,2: Adhesive sheet 10: Adhesive layer 10A: One surface (adhesive surface) 10B: another surface 20: Substrate 20A: First side 20B: Second side (back side) 30, 31, 32: Release the liner 50: Adhesive sheet with release liner 70: Optical components 100: Attached to the member of the adhesive sheet

Fig. 1 is a cross-sectional view schematically showing the structure of an adhesive sheet according to an embodiment. Fig. 2 is a cross-sectional view schematically showing the structure of an adhesive sheet according to another embodiment. 3 is a cross-sectional view schematically showing an optical member with an adhesive sheet obtained by attaching an adhesive sheet according to an embodiment to an optical member.

1: Adhesive sheet

10: Adhesive layer

10A: One surface (adhesive surface)

10B: another surface

20: Substrate

20A: First side

20B: Second side (back side)

30: Peel off the liner

50: Adhesive sheet with release liner

Claims (10)

An adhesive sheet, which has an adhesive layer, and The adhesive layer has an adhesive surface that can be attached to the adherend, The water peeling force FW0 of the adhesive sheet is 1.0 N/10 mm or less. The water peeling force FW0 is that after attaching the adhesive surface to the alkali glass plate for 3 hours, 20 μL of peeling water is supplied and the stretching speed is 300 mm Measured under the condition of 180 degree peeling angle, and The water peeling force FW2 is 4.0 N/10 mm or more. The water peeling force FW2 is to attach the above-mentioned adhesive surface to an alkali glass plate and heat-treat it at 60°C for 5 hours, then supply 20 μL of peeling water and set it at the stretching speed. Measured at room temperature under conditions of 300 mm/min and a peeling angle of 180 degrees. For example, the adhesive sheet of claim 1 has a water peeling force FW1 of 1.0 N/10 mm or less, and the water peeling force FW1 is to attach the above-mentioned adhesive surface to an alkali glass plate and after 7 days at room temperature, 20 μL of peeling water is measured under the conditions of a stretching speed of 300 mm/min and a peeling angle of 180 degrees. The adhesive sheet of claim 1 or 2, wherein the adhesive layer contains a compound S as a peel force enhancer, and the compound S has the following general formula (A) in the molecule: -Si(CH ₃ ) _n (OR) _3-n (A) (here, n is 0 or 1, and R is selected from methyl and ethyl) alkoxysilyl group and hydrophobic part. The adhesive sheet of claim 3, wherein the adhesive layer contains a compound having an ethoxysilyl group as the compound S. The adhesive sheet according to any one of claims 1 to 4, wherein the adhesive layer contains a water affinity agent. The adhesive sheet according to any one of claims 1 to 5, wherein the adhesive layer is a layer formed of a light-curing or solvent-based adhesive composition. The adhesive sheet according to any one of claims 1 to 6, wherein the adhesive layer is a photo-crosslinkable adhesive layer. For example, the adhesive sheet of any one of claims 1 to 7 has a peel strength FN1 of 3.0 N/10 mm or more after heat and humidity, and the peel strength after heat and humidity FN1 is that the above-mentioned adhesive surface is attached to an alkali glass plate and held at 85°C , 85% RH in a humid and hot environment for 24 hours, and then at 23 ℃, 50% RH environment for 5 hours and then measured in the same environment under the conditions of a tensile speed of 300 mm/min and a peeling angle of 180 degrees . A laminated body comprising a member and an adhesive sheet layer laminated on the member, and The above-mentioned adhesive sheet layer is a layer formed by attaching the adhesive sheet according to any one of claims 1 to 8 to the above-mentioned member. The laminate of claim 9, wherein the contact angle of the surface of the above-mentioned member to which the above-mentioned adhesive sheet is attached to distilled water is 50 degrees or less.

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