TW202039602A - Adhesive sheet - Google Patents

Abstract

Provided is an adhesive sheet containing an adhesive layer. The adhesive layer contains: a polymer A constituted by a polymerized product of a monomer feedstock A; and a polymer B constituted by a polymerized product of a monomer feedstock B containing a monomer, having a polyorganosiloxane skeleton, and a (meth)acrylic monomer. The polymer B has an Mw of 7*10<SP>4</SP> or higher. The relationship between the adhesive strength N50 of the adhesive sheet as measured at 23 DEG C after being applied to a stainless steel plate and kept at 50 DEG C for 30 minutes and the adhesive strength N80 of the sheet as measured at 23 DEG C after being applied to a stainless steel plate and kept at 80 DEG C for 5 minutes satisfy the formula (N80/N50) ≥ 3.

Description

Adhesive sheet

The present invention relates to an adhesive sheet. This application claims priority based on Japanese Patent Application No. 2018-225412 filed on November 30, 2018, and the entire content of the application is incorporated into this specification by reference.

The adhesive sheet is firmly attached to the adherend, and is used for the purpose of bonding the adherend to each other, fixing the article to the adherend, and reinforcing the adherend. Previously, for this purpose, an adhesive sheet that exerts a high adhesive force from the initial stage of attachment was used. In addition, recently, as shown in Patent Documents 1 to 3, there has been proposed an adhesive sheet that exhibits a low adhesive force at the initial stage of being attached to an adherend, and thereafter greatly increases the adhesive force. According to the adhesive sheet with such characteristics, the adhesiveness (secondary processability), which is useful for suppressing the decrease in yield caused by the wrong or bad attachment of the female adhesive sheet, can be exerted before the adhesive force increases, and the adhesive force increases After that, it exerts strong adhesiveness suitable for the original purpose of the adhesive sheet. Prior art literature Patent literature

Patent Document 1: Japanese Patent Application Publication No. 2014-224227 Patent Document 2: Japanese Patent No. 5890596 Patent Document 3: Japanese Patent No. 5951153

[The problem to be solved by the invention]

However, according to the usage pattern of the adhesive sheet, after attaching, after proceeding to the subsequent steps, secondary processing may occur due to judgement of wrong or broken attachment, or position shift caused by the influence of subsequent steps. The requirements of the situation. In this case, during the period during which secondary workability is required for the adhesive sheet attached to the adherend, for example, due to the operation of the equipment used in the manufacturing process (conveying equipment, inspection equipment, other various processing equipment, etc.) Incidental factors such as the influence of heat generation, heat removal from nearby devices, temperature rise of the manufacturing environment, etc., may apply a temperature of about 40°C to 50°C to the above-mentioned adhesive sheet. Therefore, the object of the present invention is to provide an adhesive sheet that can maintain secondary workability even if a temperature of about 50°C is applied to the adherend in the initial stage of attachment, and the adhesive force can be greatly increased afterwards. [Technical means to solve the problem]

According to this specification, an adhesive sheet including an adhesive layer is provided. The above-mentioned adhesive layer contains polymer A as the polymer of monomer raw material A and polymer B as the polymer of monomer raw material B. The monomer raw material B includes a monomer having a polyorganosiloxane skeleton and a (meth)acrylic monomer. That is, the polymer B is a copolymer of the monomer having a polyorganosiloxane skeleton and the (meth)acrylic monomer. The weight average molecular weight (Mw) of the aforementioned polymer B is 7×10 ⁴ or more. The above-mentioned adhesive sheet measured 30 minutes after the adhesion of the N ₅₀ and measured at 23 ℃ bonded to the stainless steel plate and heated at 80 ℃ 5 minutes at 23 ℃ after in is bonded to a stainless steel plate at 50 deg.] C and at The relationship of the adhesive force N ₈₀ satisfies the following formula: (N ₈₀ /N ₅₀ )≧3.

The adhesive sheet of this composition can increase the adhesive force N ₈₀ (hereinafter, also referred to as "adhesive force after heating") to more than 3 times the adhesive force N ₅₀ by containing polymer B with a Mw of 7×10 ⁴ or more . As a result, it can also show good secondary processability even in the use state where a temperature of about 50°C may be applied at the initial stage of attachment, and the adhesive force can be greatly increased by subsequent heating.

Regarding several types of adhesive sheets, the relationship between the above-mentioned adhesive force N ₅₀ and the adhesive force N ₂₃ measured at 23 ℃ after being attached to a stainless steel plate and placed at 23 ℃ for 30 minutes satisfies the following formula: (N ₅₀ / N ₂₃ )<10. This type of adhesive sheet has a small difference in adhesive strength (and therefore secondary processability) when it is maintained at room temperature at the initial stage of attachment and when it is exposed to a temperature of about 50°C. Therefore, it is necessary for workability or step management. It is better from the viewpoint of ease.

The adhesive sheet disclosed here is preferably that the relationship between the above-mentioned adhesive force N ₈₀ and the adhesive force N _H measured at 80° C after being attached to a stainless steel plate and kept at 80° C. for 30 minutes satisfies the following formula: (N _H /N ₈₀ )≧15%. This kind of adhesive sheet has excellent heat resistance compared with (N _H /N ₈₀ ) smaller adhesive sheet.

The (meth)acrylic monomer contained in the monomer raw material B preferably includes a monomer M2 whose homopolymer has a glass transition temperature (Tg) of 50°C or higher. According to the polymer B formed from the monomer raw material B containing a monomer having a polyorganosiloxane skeleton and a (meth)acrylic monomer M2 with a Tg of 50°C or higher, it is easy to obtain one that satisfies one of the above relations Or two or more adhesive sheets. As the above-mentioned monomer M2, an alkyl (meth)acrylate (ie, alkyl (meth)acrylate) having a homopolymer Tg of 50° C. or higher can be used well.

In some aspects, the content of the polymer B in the adhesive layer relative to 100 parts by weight of the polymer A is, for example, in the range of 0.5 parts by weight to 50 parts by weight. According to the content in the above range, it is easy to obtain an adhesive sheet with lower adhesive force at the initial stage of application and higher adhesive force after heating.

The above-mentioned polymer A is preferably an acrylic polymer. According to the adhesive layer containing polymer A as an acrylic polymer and polymer B as a copolymer of a monomer having a polyorganosiloxane skeleton and a (meth)acrylic monomer, it is easy to obtain the initial stage of attachment Adhesive sheet with lower adhesion and higher adhesion after heating.

In some aspects, the above-mentioned monomer raw material A is preferably a monomer containing a ring containing a nitrogen atom. By combining polymer A (for example, acrylic polymer) obtained from monomer raw material A containing a monomer having a nitrogen-containing ring with polymer B having an Mw of 7×10 ⁴ or more, it is easy to obtain adhesion Adhesive sheets with lower initial adhesion and higher adhesion after heating.

In some aspects, the adhesive layer may contain more than 0 parts by weight and less than 10 parts by weight of a crosslinking agent relative to 100 parts by weight of the polymer A. By using a cross-linking agent, the adhesive force at the initial stage of attachment can be effectively adjusted in the temperature range up to about 50°C. Thereby, there is a tendency to easily obtain an adhesive sheet that satisfies both the secondary processability at the initial stage of attachment and the strong adhesiveness after the adhesive force is increased.

The adhesive sheet disclosed herein may have a supporting substrate having a first surface and a second surface, and at least the first area layer of the supporting substrate has the form of the adhesive layer, that is, the form of the adhesive sheet attached to the substrate Implement. Such an adhesive sheet with a substrate can be one with good operability or processability. As the supporting substrate, for example, a resin film having a thickness of 30 μm or more can be preferably used.

Furthermore, the appropriate combination of the above elements can also be included in the scope of the invention claimed by this Japanese patent application.

Hereinafter, preferred embodiments of the present invention will be described. Regarding matters that are not specifically mentioned in this specification and required for the implementation of the present invention, the industry can understand based on the instructions on the implementation of the invention described in this specification and common technical knowledge at the time of 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 products actually provided.

In addition, in this specification, "acrylic polymer" refers to a polymer containing monomer units derived from (meth)acrylic monomers in the polymer structure, and typically refers to more than 50% by weight Ratio of polymers containing monomer units derived from (meth)acrylic monomers. In addition, the (meth)acrylic mono-system refers to a monomer having at least one (meth)acrylic group in one molecule. Here, "(meth)acryloyl group" includes the meaning of acryloyl group and methacryloyl group. Therefore, the concept of (meth)acrylic monomers here can include both monomers having acrylic groups (acrylic monomers) and monomers having methacrylic groups (methacrylic monomers). By. Similarly, in this specification, "(meth)acrylic acid" includes the meaning of acrylic acid and methacrylic acid, and "(meth)acrylate" includes the meaning of acrylate and methacrylate.

＜Structure example of adhesive sheet＞ The adhesive sheet disclosed here is composed of an adhesive layer. The adhesive sheet disclosed here may be in the form of a substrate-attached adhesive sheet with the above-mentioned adhesive layer layered on a single or double-area supporting substrate, or it may be a substrate-free adhesive sheet without a supporting substrate form. Hereinafter, the supporting substrate may also be simply referred to as "substrate".

Fig. 1 schematically shows the structure of the adhesive sheet of one embodiment. The adhesive sheet 1 is a single-sided adhesive sheet with a substrate having a sheet-like support base 10 having a first surface 10A and a second surface 10B, and an adhesive layer 21 provided on the side of the first surface 10A. constitute. The adhesive layer 21 is fixed on the first surface 10A side of the supporting substrate 10. The adhesive sheet 1 is used by attaching the adhesive layer 21 to the adherend. As shown in Figure 1, the adhesive sheet 1 before use (that is, before being attached to the adherend) can be the surface (adhesive surface) 21A of the adhesive layer 21 abutting at least on the side opposite to the adhesive layer 21 to be peeled A component of the release liner-attached adhesive sheet 100 in the form of the release liner 31 of the sexual surface (release surface). As the release liner 31, for example, a sheet-like base material (liner base material) provided with a release layer formed with a release treatment agent on one side of the sheet can be preferably used. . Alternatively, it is also possible to omit the release liner 31 and use the supporting substrate 10 with the second surface 10B as the release surface, and by winding the adhesive sheet 1 so that the adhesive surface 21A abuts against the second surface of the supporting substrate 10 10B form (reel form). When attaching the adhesive sheet 1 to the adherend, the release liner 31 or the second surface 10B of the support base 10 is peeled from the adhesive surface 21A, and the exposed adhesive surface 21A is pressed against the adherend.

The structure of the adhesive sheet of another embodiment is shown schematically in FIG. 2. The adhesive sheet 2 serves as a sheet-like support base 10 having a first surface 10A and a second surface 10B, an adhesive layer 21 provided on the side of the first surface 10A, and an adhesive layer provided on the side of the second surface 10B The agent layer 22 is composed of a double-sided adhesive sheet with a base material. The adhesive layer (first adhesive layer) 21 is fixed on the first surface 10A of the support substrate 10, and the adhesive layer (second adhesive layer) 22 is fixed on the second surface 10B of the support substrate 10. The adhesive sheet 2 is used by attaching the adhesive layers 21 and 22 to different parts of the adherend. The locations where the adhesive layers 21 and 22 are attached can be the locations of each of different components, or can be different locations within a single component. As shown in FIG. 2, the adhesive sheet 2 before use can be the surface (first adhesive surface) 21A of the adhesive layer 21 and the surface (second adhesive surface) 22A of the adhesive layer 22 in contact with at least the adhesive layer 21 , 22 is a component of the release liner adhesive sheet 200 in the form of release liners 31 and 32 on the opposite sides. As the release liners 31 and 32, for example, a method in which a release layer formed of a release treatment agent is provided on one side of a sheet-like substrate (liner substrate) so that the single side becomes a release surface Constructor. Alternatively, it is also possible to omit the release liner 32 and use the release liner 31 with both sides as the release surface. By overlapping it with the adhesive sheet 2 and winding it in a spiral shape, the second adhesive surface 22A is formed to abut against the release liner. 31 backside form (roll form) adhesive sheet with release liner.

Fig. 3 schematically shows the structure of the adhesive sheet of another embodiment. The adhesive sheet 3 is formed as a substrate-free double-sided adhesive sheet including an adhesive layer 21. The adhesive sheet 3 is a first adhesive surface 21A including one surface (first surface) of the adhesive layer 21 and a second adhesive surface 21B including the other surface (second surface) of the adhesive layer 21 on the substrate Used for different parts of the adhesive body. As shown in FIG. 3, the adhesive sheet 3 before use can be a first adhesive surface 21A and a second adhesive surface) 21B abuts against at least the side opposite to the adhesive layer 21 as a release liner 31, 32 respectively. The components of the adhesive sheet 300 with release liner in the form of. Alternatively, the release liner 32 may be omitted, and a release liner 31 with a release liner on both sides may be used. The second adhesive surface 21B is formed by overlapping the adhesive sheet 3 and winding it in a spiral shape to abut against the release liner. 31 backside form (roll form) adhesive sheet with release liner.

Furthermore, the concept of the so-called adhesive sheet here may include those called adhesive tape, adhesive film, adhesive label, etc. The adhesive sheet may be in the form of a roll, or in the form of a single sheet, or may be cut into an appropriate shape and punched according to the purpose or usage. The adhesive layer in the technology disclosed herein is typically formed continuously, but it is not limited to this. For example, it may be formed in a regular or random pattern such as dots and strips.

＜Adhesive layer＞ The adhesive sheet disclosed here has an adhesive layer containing polymer A as a polymer of monomer raw material A, and a monomer having a polyorganosiloxane skeleton and a (meth)acrylic monomer The copolymer of polymer B. Such an adhesive layer may be formed of an adhesive composition containing a complete polymer or a partial polymer of the monomer raw material A, and the polymer B. The form of the adhesive composition is not particularly limited. For example, various forms such as a solvent type, a water dispersion type, a hot melt type, an active energy ray hardening type (for example, a light hardening type), etc. are possible.

(Polymer A) As the polymer A, acrylic polymers, rubber-based polymers, polyester-based polymers, urethane-based polymers, polyether-based polymers, and silicone-based polymers known in the field of adhesives can be used. One or two or more of various polymers that exhibit rubber elasticity at room temperature, such as polyamide-based polymers and fluorine-based polymers. In the adhesive sheet disclosed here, the polymer A is typically the main component of the polymer component contained in the adhesive layer, that is, the component that accounts for more than 50% by weight. For example, it may be 75% by weight of the above polymer component. % Of ingredients. In several aspects, the above-mentioned polymer A is a component that accounts for more than 50% by weight of the entire adhesive layer, and may also be a component that accounts for more than 70% by weight.

The glass transition temperature T _{A of the} polymer A is not particularly limited, and it can be selected from the adhesive sheet disclosed herein to obtain better characteristics. In several aspects, polymer _A whose T _{A is} less than 0°C can be used well. Adhesives containing this polymer A show moderate fluidity (for example, the mobility of the polymer chains contained in the adhesive), so it is suitable for achieving both initial low adhesion and strong adhesion after heating The adhesive film. The adhesive sheet disclosed here can be implemented well using polymer A whose T _{A is} less than -10°C, less than -20°C, less than -30°C, or less than -35°C. In several aspects, T _A may not reach -40°C, or may not reach -50°C. The lower limit of T _A is not particularly limited. From the viewpoint of easy access to materials or improvement of the cohesive force of the adhesive layer, polymer A with a T _A of -80°C or higher, -70°C or higher, or -65°C or higher can generally be used well. Viewpoint of suppressing rising of the N _50, the state in several samples, T _A -63 deg.] C or higher for example, may be less than -55 deg.] C, -50 deg.] C or higher may be, also less than -45 ℃.

Here, in this specification, the glass transition temperature (Tg) of a polymer refers to the nominal value described in documents or catalogs, or is based on the composition of the monomer raw materials used in the preparation of the polymer according to the formula of Fox Find the Tg. The formula of Fox refers to the relationship between the Tg of the copolymer and the glass transition temperature Tgi of the homopolymer obtained by homopolymerizing each of the monomers constituting the copolymer as shown below. 1/Tg=Σ(Wi/Tgi) In the above formula of Fox, 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 the average of monomer i The glass transition temperature of the polymer (unit: K). When the target polymer specified by Tg is a homopolymer, the Tg of the homopolymer is the same as the Tg of the target polymer.

As the glass transition temperature of the homopolymer for calculating Tg, the value described in known data is used. Specifically, the values in the "Polymer Handbook (Polymer Handbook)" (3rd edition, John Wiley & Sons, Inc., 1989) can be cited. For monomers with multiple values described in the above polymer manual, the highest value is used.

As the glass transition temperature of a homopolymer of a monomer that is not described in the above polymer manual, the value obtained by the following measurement method is used. Specifically, 100 parts by weight of monomer, 0.2 parts by weight of 2,2'-azobisisobutyronitrile, and ethyl acetate as the polymerization solvent were put into a reactor equipped with a thermometer, a stirrer, a nitrogen introduction tube, and a reflux cooling tube. 200 parts by weight, stirring for 1 hour while flowing nitrogen gas. After removing oxygen in the polymerization system in this way, the temperature was raised to 63°C and reacted for 10 hours. Then, it was cooled to room temperature, and a homopolymer solution with a solid content concentration of 33% by weight was obtained. Then, the homopolymer solution was cast-coated on a release liner and dried to prepare a test sample (sheet-like homopolymer) with a thickness of about 2 mm. The test sample was punched into a disc shape with a diameter of 7.9 mm and sandwiched by parallel plates. A viscoelastic tester (manufactured by TA Instruments Japan, model name "ARES") was used to give a shear strain of 1 Hz on the other side. Measure the viscoelasticity in the shear mode at a temperature range of -70°C to 150°C at a heating rate of 5°C/min, and set the temperature corresponding to the peak top temperature of tanδ as the Tg of the homopolymer.

The weight average molecular weight (Mw) of the polymer A is usually preferably about 20×10 ⁴ or more, but it is not particularly limited. With the polymer A of Mw, it is easy to obtain an adhesive showing good cohesiveness. From the viewpoint of obtaining higher cohesive force, in several aspects, the Mw of polymer A may be 30×10 ⁴ or more, 40×10 ⁴ or more, 50×10 ⁴ or more, or 60×10 ⁴ or more, but also 80×10 ⁴ or more. In addition, the Mw of polymer A is usually preferably about 500×10 ⁴ or less. The Mw polymer A is easy to form an adhesive showing moderate fluidity (movement of polymer chains), so it is suitable for realizing an adhesive sheet with low adhesive force at the initial stage of attachment and higher adhesive force after heating. It is also preferable that the Mw of the polymer A is not too high from the viewpoint of improving the compatibility with the polymer B. In several aspects, the Mw of polymer A may be 250×10 ⁴ or less, 200×10 ⁴ or less, or 150×10 ⁴ or less, for example.

In addition, in this specification, the Mw of the polymer A and the polymer B can be obtained by polystyrene conversion by gel permeation chromatography (GPC). More specifically, Mw can be measured according to the method and conditions described in the following examples.

As the polymer A in the adhesive sheet disclosed here, an acrylic polymer can be used well. If an acrylic polymer is used as the polymer A, there is a tendency that good compatibility with the polymer B is easily obtained. The good compatibility of polymer A and polymer B can help reduce the initial adhesion and increase the adhesion after heating by increasing the mobility of the polymer B in the adhesive layer, so it is better.

The acrylic polymer may be, for example, a polymer containing 50% by weight or more of monomer units derived from alkyl (meth)acrylate, that is, the monomer component used to prepare the acrylic polymer (monomer raw material A) More than 50% by weight of the total amount is a polymer of alkyl (meth)acrylate. As the alkyl (meth)acrylate, an alkyl (meth)acrylate having a linear or branched alkyl group having 1 to 20 carbon atoms (that is, C _1-20 ) can be preferably used. In terms of easily obtaining the balance of characteristics, the ratio of the C _1-20 alkyl (meth)acrylate in the monomer raw material A can be, for example, 50% by weight or more, 60% by weight or more, or 70 More than weight%. For the same reason, the ratio of C _1-20 alkyl (meth)acrylate in the monomer raw material A may be, for example, 99.9% by weight or less, 98% by weight or less, or 95% by weight or less. In some _aspects , the ratio of the C _1-20 alkyl (meth)acrylate in the monomer raw material A can be, for example, 90% by weight or less, 85% by weight or less, or 80% by weight or less.

As non-limiting specific examples of the C _1-20 alkyl (meth)acrylate, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, (former) 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 _1-18 alkyl (meth)acrylate, and it is more preferable to use at least C _1-14 alkyl (meth)acrylate. In several aspects, the acrylic polymer may contain a C _4-12 alkyl (meth)acrylate (preferably a C _4-10 alkyl acrylate, such as a C _6-10 alkyl acrylate) At least one of them is used as a monomer unit. For example, it is preferably an acrylic polymer containing one or both of n-butyl acrylate (BA) and 2-ethylhexyl acrylate (2EHA), and particularly preferably an acrylic polymer containing at least 2EHA. Examples of other C _1-18 alkyl (meth)acrylates that can be used well include: methyl acrylate, methyl methacrylate (MMA), n-butyl methacrylate (BMA), methyl 2-ethylhexyl acrylate (2EHMA), isostearyl acrylate (ISTA), etc.

The monomer raw material A may also contain an alkyl (meth)acrylate as a main component and, if necessary, other monomers (copolymerizable monomers) that can be copolymerized with the alkyl (meth)acrylate. As the copolymerizable monomer, a monomer having a polar group (for example, a carboxyl group, a hydroxyl group, a ring containing a nitrogen atom, etc.) can be suitably used. Monomers with polar groups can help introduce cross-linking points to the acrylic polymer or improve the cohesion of the acrylic polymer. The copolymerizable monomer can be used alone or in combination of two or more.

啉、N-乙烯基-3-

啉酮、N-乙烯基-2-己內醯胺、N-乙烯基-1,3-㗁𠯤-2-酮、N-乙烯基-3,5-

啉二酮、N-乙烯基吡唑、N-乙烯基異㗁唑、N-乙烯基噻唑、N-乙烯基異噻唑、N-乙烯基嗒𠯤等； 例如N-(甲基)丙烯醯氧基亞甲基丁二醯亞胺、N-(甲基)丙烯醯基-6-氧基六亞甲基丁二醯亞胺、N-(甲基)丙烯醯基-8-氧基六亞甲基丁二醯亞胺等具有丁二醯亞胺骨架之單體； 例如N-環己基順丁烯二醯亞胺、N-異丙基順丁烯二醯亞胺、N-月桂基順丁烯二醯亞胺、N-苯基順丁烯二醯亞胺等順丁烯二醯亞胺類；及 例如N-甲基伊康醯亞胺、N-乙基伊康醯亞胺、N-丁基伊康醯亞胺、N-辛基伊康醯亞胺、N-2-乙基己基伊康醯亞胺、N-環己基伊康醯亞胺、N-月桂基伊康醯亞胺等伊康醯亞胺類。 含羧基單體：例如丙烯酸、甲基丙烯酸、丙烯酸羧基乙酯、丙烯酸羧基戊酯、伊康酸、順丁烯二酸、反丁烯二酸、丁烯酸、異丁烯酸等。 含酸酐基單體：例如順丁烯二酸酐、伊康酸酐。 含環氧基單體：例如(甲基)丙烯酸縮水甘油酯或(甲基)丙烯酸-2-乙基縮水甘油醚等含環氧基之丙烯酸酯、烯丙基縮水甘油醚、(甲基)丙烯酸縮水甘油醚等。 含氰基單體：例如丙烯腈、甲基丙烯腈等。 含異氰酸基單體：例如(甲基)丙烯酸2-異氰酸基乙酯等。 含醯胺基單體：例如(甲基)丙烯醯胺；N,N-二甲基(甲基)丙烯醯胺、N,N-二乙基(甲基)丙烯醯胺、N,N-二丙基(甲基)丙烯醯胺、N,N-二異丙基(甲基)丙烯醯胺、N,N-二(正丁基)(甲基)丙烯醯胺、N,N-二(第三丁基)(甲基)丙烯醯胺等N,N-二烷基(甲基)丙烯醯胺；N-乙基(甲基)丙烯醯胺、N-異丙基(甲基)丙烯醯胺、N-丁基(甲基)丙烯醯胺、N-正丁基(甲基)丙烯醯胺等N-烷基(甲基)丙烯醯胺；N-乙烯基乙醯胺等N-乙烯基羧醯胺類；具有羥基與醯胺基之單體，例如N-(2-羥基乙基)(甲基)丙烯醯胺、N-(2-羥基丙基)(甲基)丙烯醯胺、N-(1-羥基丙基)(甲基)丙烯醯胺、N-(3-羥基丙基)(甲基)丙烯醯胺、N-(2-羥基丁基)(甲基)丙烯醯胺、N-(3-羥基丁基)(甲基)丙烯醯胺、N-(4-羥基丁基)(甲基)丙烯醯胺等N-羥基烷基(甲基)丙烯醯胺；具有烷氧基與醯胺基之單體，例如N-甲氧基甲基(甲基)丙烯醯胺、N-甲氧基乙基(甲基)丙烯醯胺、N-丁氧基甲基(甲基)丙烯醯胺等N-烷氧基烷基(甲基)丙烯醯胺；此外，N,N-二甲基胺基丙基(甲基)丙烯醯胺、N-(甲基)丙烯醯基

啉等。 (甲基)丙烯酸胺基烷基酯類：例如(甲基)丙烯酸胺基乙酯、(甲基)丙烯酸N,N-二甲基胺基乙酯、(甲基)丙烯酸N,N-二乙基胺基乙酯、(甲基)丙烯酸第三丁基胺基乙酯。 含烷氧基單體：例如(甲基)丙烯酸2-甲氧基乙酯、(甲基)丙烯酸3-甲氧基丙酯、(甲基)丙烯酸2-乙氧基乙酯、(甲基)丙烯酸丙氧基乙酯、(甲基)丙烯酸丁氧基乙酯、(甲基)丙烯酸乙氧基丙酯等(甲基)丙烯酸烷氧基烷基酯類；(甲基)丙烯酸甲氧基乙二醇酯、(甲基)丙烯酸甲氧基聚丙二醇酯等(甲基)丙烯酸烷氧基伸烷基二醇酯類。 含有磺酸基或磷酸基之單體：例如苯乙烯磺酸、烯丙基磺酸、乙烯基磺酸鈉、2-(甲基)丙烯醯胺-2-甲基丙磺酸、(甲基)丙烯醯胺丙磺酸、(甲基)丙烯酸磺丙酯、(甲基)丙烯醯氧基萘磺酸、2-羥基乙基丙烯醯基磷酸酯等。 具有脂環式烴基之(甲基)丙烯酸酯：例如(甲基)丙烯酸環戊酯、(甲基)丙烯酸環己酯、(甲基)丙烯酸異𦯉酯、(甲基)丙烯酸二環戊酯等。 具有芳香族烴基之(甲基)丙烯酸酯：例如(甲基)丙烯酸苯酯、(甲基)丙烯酸苯氧基乙酯、(甲基)丙烯酸苄酯等。 乙烯醚類：例如甲基乙烯醚或乙基乙烯醚等乙烯基烷基醚。 乙烯酯類：例如乙酸乙烯酯、丙酸乙烯酯等。 芳香族乙烯基化合物：例如苯乙烯、α-甲基苯乙烯、乙烯基甲苯等。 烯烴類：例如乙烯、丁二烯、異戊二烯、異丁烯等。 此外，(甲基)丙烯酸四氫呋喃甲酯等含雜環之(甲基)丙烯酸酯、氯乙烯或含氟原子之(甲基)丙烯酸酯等含鹵素原子之(甲基)丙烯酸酯、聚矽氧(甲基)丙烯酸酯等含矽原子之(甲基)丙烯酸酯、由萜烯化合物衍生物醇所獲得之(甲基)丙烯酸酯等。As non-limiting specific examples of the copolymerizable monomer, the following can be cited. Hydroxyl-containing monomers: such as 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, 12 (meth)acrylate -Hydroxyalkyl (meth)acrylates such as hydroxylauryl ester, (4-hydroxymethylcyclohexyl)methyl (meth)acrylate and the like. Monomers with a ring containing nitrogen atoms: such as N-vinyl-2-pyrrolidone, N-methylvinylpyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinyl Pyrimidine, N-vinylpiperidine, N-vinylpyrrolidone, N-vinylpyrrole, N-vinylimidazole, N-vinyl azole, N-(meth)acrylic acid-2-pyrrolidone , N-(meth)acryloylpiperidine, N-(meth)acryloylpyrrolidine, N-vinyl

Morpholine, N-vinyl-3-

Ketone, N-vinyl-2-caprolactam, N-vinyl-1,3-㗁𠯤-2-one, N-vinyl-3,5-

Phyllodione, N-vinylpyrazole, N-vinylisoxazole, N-vinylthiazole, N-vinylisothiazole, N-vinyl thiazole, etc.; for example, N-(meth)acrylic acid N-(meth)acryloyl-6-oxyhexamethylene butadioximine, N-(meth)acryloyl-8-oxyhexaimide Methyl succinimide and other monomers with succinimide skeleton; such as N-cyclohexyl maleimide, N-isopropyl maleimide, N-lauryl cis Maleimines such as butenediimines, N-phenyl maleimines; and, for example, N-methyliconimines, N-ethyliconimines, N-Butyl Ikonimines, N-octyl Ikonimines, N-2-Ethylhexyl Ikonimines, N-Cyclohexyl Ikonimines, N-Lauryl Ikonimines Ikonimines such as imines. Carboxyl group-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. 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. Isocyanate group-containing monomers: for example, 2-isocyanatoethyl (meth)acrylate and the like. Amine group-containing monomers: 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-di (Tertiary butyl)(meth)acrylamide and other N,N-dialkyl(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; N-vinylacetamide, etc. -Vinylcarboxamides; monomers with hydroxyl and amide groups, such as N-(2-hydroxyethyl)(meth)acrylamide, N-(2-hydroxypropyl)(meth)propylene Amide, N-(1-hydroxypropyl)(meth)acrylamide, N-(3-hydroxypropyl)(meth)acrylamide, N-(2-hydroxybutyl)(methyl) N-hydroxyalkyl (meth)acrylamide, such as acrylamide, N-(3-hydroxybutyl)(meth)acrylamide, N-(4-hydroxybutyl)(meth)acrylamide, etc. ; Monomers with alkoxy and amide groups, such as N-methoxymethyl (meth) acrylamide, N-methoxyethyl (meth) acrylamide, N-butoxymethyl (Meth)acrylamide and other N-alkoxyalkyl(meth)acrylamides; in addition, N,N-dimethylaminopropyl(meth)acrylamide, N-(methyl) )Acrylic

Morpho etc. (Meth) acrylate amino alkyl esters: for example (meth) acrylate amino ethyl, (meth) acrylate N,N-dimethylamino ethyl, (meth) acrylate 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, (methyl) ) Alkoxyalkyl (meth)acrylates such as propoxyethyl acrylate, butoxyethyl (meth)acrylate, and ethoxypropyl (meth)acrylate; methoxy (meth)acrylate (Meth)acrylic acid alkoxyalkylene glycol esters such as ethylene glycol ester and methoxy polypropylene glycol (meth)acrylate. 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 amide propane sulfonic acid, sulfopropyl (meth)acrylate, (meth) acryloxy naphthalene sulfonic acid, 2-hydroxyethyl acryloyl phosphate, etc. (Meth) acrylates with alicyclic hydrocarbon groups: for example, cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, iso(meth)acrylate, dicyclopentyl (meth)acrylate Wait. (Meth)acrylates having aromatic hydrocarbon groups: for example, phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, benzyl (meth)acrylate, etc. Vinyl ethers: vinyl alkyl ethers such as methyl vinyl ether or ethyl vinyl ether. Vinyl esters: for example, vinyl acetate, vinyl propionate, etc. Aromatic vinyl compounds: for example, styrene, α-methylstyrene, vinyl toluene, etc. Olefins: For example, ethylene, butadiene, isoprene, isobutene, etc. In addition, (meth)acrylates containing heterocycles such as methyl tetrahydrofuran (meth)acrylate, (meth)acrylates containing halogen atoms, such as vinyl chloride or (meth)acrylates containing fluorine atoms, and polysiloxanes (Meth)acrylic acid esters containing silicon atoms such as (meth)acrylic acid esters, (meth)acrylic acid esters obtained 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 suitably set to 0.01% by weight or more of the monomer raw material A. From the viewpoint of better exerting the effect of using the copolymerizable monomer, the usage amount of the copolymerizable monomer may be 0.1% by weight or more of the monomer raw material A, or 1% by weight or more. In addition, the amount of the copolymerizable monomer used may be 50% by weight or less of the monomer raw material A, and preferably 45% by weight or less. This prevents the cohesive force of the adhesive from becoming too high, and improves the stickiness at room temperature (25°C). In some aspects, the usage amount of the comonomer can be less than 40% by weight of the monomer raw material A, or less than 35% by weight.

In some aspects, the monomer raw material A may include a monomer having a ring containing a nitrogen atom. By using monomers with a ring containing nitrogen atoms, the cohesive force or polarity of the adhesive can be adjusted to improve the adhesive force after heating. As disclosed here, it is particularly meaningful in the state where the Mw of polymer B is high to a certain level (typically 7×10 ⁴ or more, preferably 8×10 ⁴ or more, for example, more than 10×10 ⁴ ) It is a monomer having a ring containing a nitrogen atom in the monomer raw material A. Thereby, there is a tendency to improve the compatibility between the polymer A formed from the monomer raw material A and the polymer B. Thereby, it is easy to obtain an adhesive sheet that maintains secondary workability even if a temperature of about 50°C is applied to the adherend in the initial stage of application to the adherend, and subsequently greatly increases the adhesive force. It is also preferable to improve the compatibility of polymer B in the adhesive layer with a high Mw to a certain degree from the viewpoint of improving the heat resistance of the adhesive sheet.

The monomer having a nitrogen atom-containing ring can be appropriately selected, for example, from the above-mentioned examples, and used alone or in combination of two or more. In several aspects, the monomer raw material A preferably contains at least one monomer selected from the group consisting of N-vinyl cyclic amide represented by the following general formula (M1) as having a nitrogen-containing atom The monomer of the ring. The monomer raw material A may contain only one or two or more of the N-vinyl cyclic amides as a monomer having a ring containing a nitrogen atom.

此處，上述通式(M1)中之R¹ 為2價有機基。[化1]

Here, R ¹ in the general formula (M1) is a divalent organic group.

啉酮、N-乙烯基-2-己內醯胺、N-乙烯基-1,3-㗁𠯤-2-酮、N-乙烯基-3,5-

啉二酮等。尤佳為N-乙烯基-2-吡咯啶酮、N-乙烯基-2-己內醯胺。Specific examples of N-vinyl cyclic amides include: N-vinyl-2-pyrrolidone, N-vinyl-2-piperidone, and N-vinyl-3-

Ketone, N-vinyl-2-caprolactam, N-vinyl-1,3-㗁𠯤-2-one, N-vinyl-3,5-

Morpholinone and so on. Particularly preferred are N-vinyl-2-pyrrolidone and N-vinyl-2-caprolactam.

The usage amount of the monomer having a nitrogen atom-containing ring is not particularly limited, and is usually suitably set to 0.01% by weight or more of the monomer raw material A (preferably 0.1% by weight or more, for example, 0.5% by weight or more). In some aspects, the usage amount of the monomer having a nitrogen-containing ring can be set to 1% by weight or more of the monomer raw material A, can be set to 5% by weight or more, can be set to 10% by weight or more, or Set to 12% by weight or more. In addition, from the viewpoint of improving the stickiness at room temperature (25°C) or improving the flexibility at low temperature, the usage amount of the monomer having a ring containing nitrogen atoms is usually set to 40% by weight or less of the monomer raw material A , Can be 30% by weight or less, 20% by weight or less, or 18% by weight or less.

By using hydroxyl-containing monomers, the cohesive force or polarity of the adhesive can be adjusted to improve the adhesive force after heating. In addition, the hydroxyl-containing monomer provides a reaction point with the following cross-linking agent (for example, an isocyanate-based cross-linking agent), and the cohesive force of the adhesive can be improved by the cross-linking reaction.

As a hydroxyl-containing monomer, 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, N-(2-hydroxyethyl) can be used well. Group) (meth)acrylamide and the like. Among them, preferred examples include 2-hydroxyethyl acrylate (HEA), 4-hydroxybutyl acrylate (4HBA), and N-(2-hydroxyethyl)acrylamide (HEAA).

The usage amount of the hydroxyl-containing monomer is not particularly limited, and it is usually suitably set to 0.01% by weight or more of the monomer raw material A (preferably 0.1% by weight or more, for example, 0.5% by weight or more). In some aspects, the usage amount of the hydroxyl-containing monomer can be set to 1% by weight or more of the monomer raw material A, can be set to 5% by weight or more, or can be set to 10% by weight or more. In addition, from the viewpoint of improving the stickiness at room temperature (25°C) or the flexibility at low temperature, the usage amount of the hydroxyl-containing monomer is usually set to 40% by weight or less of the monomer raw material A, and it can be set to 30% by weight. % Or less may be 20% by weight or less, or 10% by weight or less or 5% by weight or less.

In some aspects, as a copolymerizable monomer, a monomer having a nitrogen-containing ring (for example, N-vinyl cyclic amide) can be used in combination with a hydroxyl-containing monomer. In this case, the total amount of the monomer having a nitrogen-containing ring and the hydroxyl-containing monomer can be set to, for example, 0.1% by weight or more of the monomer raw material A, 1% by weight or more, and 5% by weight. The above may be 10% by weight or more, 15% by weight or more, 20% by weight or more, or 25% by weight or more. In addition, the total amount of the monomer having a nitrogen atom-containing ring and the hydroxyl group-containing monomer can be, for example, 50% by weight or less of the monomer raw material A, and preferably 40% by weight or less.

In the case where the monomer raw material A combines a monomer having a nitrogen-containing ring and a hydroxyl-containing monomer, the content (W _N ) of the monomer having a nitrogen-containing ring in the monomer raw material A and The relationship (weight basis) of the content (W _OH ) of the hydroxyl-containing monomer is not particularly limited. W _N /W _OH may be, for example, 0.01 or more, and usually 0.05 or more is suitable, it may be 0.1 or more, it may be 0.2 or more, it may be 0.5 or more, or it may be 0.7 or more. In addition, W _N /W _OH may be, for example, 100 or less, and usually 20 or less is suitable, 10 or less, 5 or less, 2 or less, or 1.5 or less.

In some aspects, the monomer raw material A preferably does not contain a monomer having a polyorganosiloxane skeleton (monomer S1) that can be used as a constituent of the monomer raw material B below, or the monomer The content of the monomer is less than 10% by weight of the monomer raw material A (more preferably less than 5% by weight, for example, less than 2% by weight). According to the monomer raw material A of this composition, an adhesive sheet that has a good balance between the initial secondary processability and the strong adhesiveness after the adhesive force is increased can be realized. For the same reason, among several other aspects, monomer raw material A preferably does not contain monomer S1, or when it contains monomer S1, its content (weight basis) is lower than that of monomer raw material B The content of monomer S1.

The method of obtaining the polymer A is not particularly limited, and various polymerization methods such as solution polymerization, emulsion polymerization, bulk polymerization, suspension polymerization, and photopolymerization can be suitably adopted. In several aspects, the solution polymerization method can be used well. The polymerization temperature during solution polymerization can be appropriately selected according to the types of monomers and solvents used, the type of polymerization initiator, etc., for example, it can be set at about 20°C to 170°C (typically about 40°C to 140°C.

The initiator used for the polymerization can be appropriately selected from previously known thermal polymerization initiators, photopolymerization initiators, and the like according to the polymerization method. A polymerization initiator can be used individually by 1 type or in combination of 2 or more types.

As the thermal polymerization initiator, for example, an azo polymerization initiator (for example, 2,2'-azobisisobutyronitrile, 2,2'-azobis-2-methylbutyronitrile, 2, 2'-Azobis(2-methylpropionic acid) dimethyl ester, 4,4'-azobis-4-cyanovaleric acid, azobisisovaleronitrile, 2,2'-azobis( 2-amidinopropane) dihydrochloride, 2,2'-azobis[2-(5-methyl-2-imidazolin-2-yl)propane] dihydrochloride, 2,2'-co Azodis(2-methylpropionamidine) disulfate, 2,2'-azobis(N,N'-dimethylene isobutylamidine) dihydrochloride, etc.); persulfuric acid such as potassium persulfate Salts; peroxide-based polymerization initiators (for example, dibenzoyl peroxide, t-butyl maleate peroxide, lauric peroxide, etc.); redox-based polymerization initiators, etc. The amount of the thermal polymerization initiator used is not particularly limited. For example, relative to 100 parts by weight of the monomer component (monomer raw material A) used in the preparation of the acrylic polymer, it can be set to 0.01 to 5 parts by weight. It is preferably an amount in the range of 0.05 parts by weight to 3 parts by weight.

系光聚合起始劑、醯基氧化膦系光聚合起始劑等。光聚合起始劑之使用量並無特別限制，例如相對於100重量份單體原料A，可設為0.01重量份～5重量份、較佳為0.05重量份～3重量份之範圍內之量。The photopolymerization initiator is not particularly limited. For example, benzoin ether-based photopolymerization initiators, acetophenone-based photopolymerization initiators, α-ketol-based photopolymerization initiators, and aromatic sulfonyl chlorides can be used. Photopolymerization initiator, photoactive oxime-based photopolymerization initiator, benzoin-based photopolymerization initiator, benzyl-based photopolymerization initiator, benzophenone-based photopolymerization initiator, ketal-based photopolymerization initiator Polymerization initiator, 9-oxysulfur 𠮿

It is a photopolymerization initiator, an oxyphosphine oxide photopolymerization initiator, etc. The amount of the photopolymerization initiator used is not particularly limited. For example, relative to 100 parts by weight of the monomer raw material A, it can be set to an amount within the range of 0.01 to 5 parts by weight, preferably 0.05 to 3 parts by weight. .

In several aspects, the polymer A can irradiate ultraviolet rays (UV) to the mixture obtained by blending the polymerization initiator in the monomer raw material A as described above to cause a part of the monomer component to polymerize (polymerization). The form of the slurry) is contained in the adhesive composition used to form the adhesive layer. The adhesive composition containing the polymer slurry can be applied to a predetermined coated body, and the polymerization can be completed by irradiating ultraviolet rays. That is, the aforementioned polymer slurry can be understood as a precursor of polymer A. The adhesive layer disclosed here can be formed using, for example, an adhesive composition containing the polymer slurry and polymer B.

(Polymer B) The polymer B in the technology disclosed herein is a copolymer of a monomer having a polyorganosiloxane skeleton (hereinafter also referred to as "monomer S1") and a (meth)acrylic monomer. Polymer B, due to the low polarity and mobility of the polyorganosiloxane structure derived from monomer S1, can be used to inhibit the initial adhesion of the adherend, and by increasing the temperature above 50 ℃ The delay agent for increasing the adhesion force that increases the adhesion force to the adherend by heating or over time functions. The monomer S1 is not particularly limited, and any monomer containing a polyorganosiloxane skeleton can be used. Monomer S1 promotes polymer B to lean on the surface of the adhesive layer in the adhesive sheet before use (before attaching to the adherend) due to its low polarity derived from its structure, showing light peeling at the initial stage of lamination (Low adhesion). As the monomer S1, it can be suitably used for those having a structure having a polymerizable reactive group at one end. By the copolymerization of this monomer S1 and (meth)acrylic monomers, a polymer B with a polyorganosiloxane skeleton in the side chain is formed. Due to the mobility and ease of movement of the side chain, the polymer B of this structure tends to have lower initial adhesion and higher adhesion after heating. In addition, in some aspects, as the monomer S1, one having a polymerizable reactive group at one end and no functional group that causes a crosslinking reaction with the polymer A at the other end can be preferably used. The polymer B formed by copolymerizing monomer S1 of this structure can easily become the one with lower initial adhesion and higher after heating due to the mobility of the polyorganosiloxane structure derived from monomer S1.

[化3]

此處，上述通式(1)、(2)中之R³ 為氫或甲基，R⁴ 為甲基或1價有機基，m及n為0以上之整數。As the monomer S1, for example, a compound represented by the following general formula (1) or (2) can be used. More specifically, as single-end reactive silicone oil manufactured by Shin-Etsu Chemical Industry Co., Ltd., X-22-174ASX, X-22-2426, X-22-2475, KF-2012, etc. can be cited. The monomer S1 can be used alone or in combination of two or more. [化2]

[化3]

Here, R ³ in the above general formulas (1) and (2) is hydrogen or a methyl group, R ⁴ is a methyl group or a monovalent organic group, and m and n are integers of 0 or more.

The functional group equivalent of the monomer S1 can adopt an appropriate value within the range where the monomer S1 is used to exert the desired effect, and is not limited to a specific range. From the viewpoint of easily suppressing the initial adhesion, the functional group equivalent may be 140 g/mol or more, or 200 g/mol or more, usually 300 g/mol or more (e.g., 500 g/mol or more). It is preferably 700 g/mol or more, may be 800 g/mol or more, may be 850 g/mol or more, may be 1000 g/mol or more, or may be 1500 g/mol or more. The technology disclosed here can also allow the above functional group equivalent to be 2500 g/mol or more, 3000 g/mol or more, 4500 g/mol or more, 6000 g/mol or more, 9000 g/mol or more, 12000 g/mol or more, 15000 g /mol or more or 16000 g/mol or more. In addition, the functional group equivalent of the monomer S1 may be, for example, 50,000 g/mol or less. From the viewpoint of improving the adhesive force after heating, it is generally advantageous to be 30,000 g/mol or less, preferably 20,000 g/mol or less. From this point of view, the functional group equivalent may be less than 18000 g/mol, may be less than 15000 g/mol, may be less than 10,000 g/mol, may be less than 6000 g/mol, or may be less than 5000 g/mol. mol. In several aspects, the functional group equivalent of monomer S1 is, for example, preferably 700 g/mol or more and less than 15000 g/mol, more preferably 800 g/mol or more and less than 10,000 g/mol, and more preferably It is 850 g/mol or more and less than 6000 g/mol, particularly preferably 1500 g/mol or more and less than 5000 g/mol. If the functional group equivalent of the monomer S1 is within the above range, it is easy to adjust the compatibility (for example, the compatibility with polymer A) or mobility in the adhesive layer within an appropriate range, and it is easy to achieve a high level of consideration for the initial stage Adhesive sheet with low adhesion and strong adhesion after increasing adhesion.

Here, "functional group equivalent" refers to the weight of the main skeleton (for example, polydimethylsiloxane) bonded to each functional group. Regarding the labeling unit g/mol, it is converted to 1 mol of the functional group. The functional group equivalent of monomer S1 can be calculated, for example, based on ¹ H-NMR (proton NMR) spectral intensity based on nuclear magnetic resonance (NMR). The calculation of the functional group equivalent (g/mol) of the monomer S1 based on ¹ H-NMR spectral intensity can be based on the general structure analysis method related to ¹ H-NMR spectral analysis. If necessary, refer to the description of Japanese Patent No. 5951153 get on.

Furthermore, when two or more monomers with different functional group equivalents are used as monomer S1, as the functional group equivalent of monomer S1, an arithmetic average can be used. That is, the functional group equivalent of monomer S1 including n types of monomers (monomer S1 ₁ , monomer S1 ₂ ...monomer S1 _n ) having different functional group equivalents can be calculated by the following formula. S1 functional group equivalent of the monomer (g / mol) = the amount of the functional _{formulation. 1} S1 (group equivalent of the _{monomer. 1} × S1 + monomer amount of the monomer of the formulations S1 ₂ S1 ₂ equivalents of the functional group monomer + × · · · S1 + _n blending amount of the monomer _n × S1-functional monomer equivalents) / (the amount of monomer _{formulation. 1} S1 + blending amount of the monomer ₂ + S1 · S1 + _n blending amount of monomer)

The usage amount of the monomer S1 can adopt an appropriate value within the range where the monomer S1 is used to exert the desired effect, and is not limited to a specific range. In some aspects, the amount of monomer S1 in the total amount of monomer components (monomer raw material B) used to prepare polymer B can be, for example, 5% by weight or more from the viewpoint of easily suppressing the initial adhesion From the viewpoint of more satisfactorily exhibiting the effect as an adhesion force increase retardant, it is preferably 10% by weight or more, 15% by weight or more, or 20% by weight or more. In addition, the content of the monomer S1 in the monomer raw material B may be 80% by weight or less from the viewpoint of polymerization reactivity or compatibility, and from the viewpoint of improving the adhesive force after heating, it is usually preferably 60% by weight. % Or less, 50% by weight or less, 40% by weight or less, or 30% by weight or less. From the viewpoint of easy and good balance between the suppression of initial adhesion and the increase of adhesion by heating, the technology disclosed here can make the content of monomer S1 in monomer raw material B be, for example, 5% by weight to 50% by weight. , It is preferably 10% by weight or more and 40% by weight or less, and more preferably 15% by weight or more and 30% by weight or less.

In addition to the monomer S1, the monomer raw material B also contains a (meth)acrylic monomer that can be copolymerized with the monomer S1. By copolymerizing one or more (meth)acrylic monomers with monomer S1, the mobility of polymer B in the adhesive layer can be well adjusted. The copolymerization of monomer S1 and (meth)acrylic monomers can also help to improve the compatibility of polymer B and polymer A (for example, acrylic polymer).

Examples of (meth)acrylic monomers that can be used for the monomer raw material B include alkyl (meth)acrylates. For example, one or two or more of the monomers exemplified above as the alkyl (meth)acrylate that can be used when the polymer A is an acrylic polymer can be used as the constituent component of the monomer raw material B. In several aspects, the monomer raw material B may contain (meth)acrylate C _4-12 alkyl ester (preferably (meth)acrylate C _4-10 alkyl ester, for example (meth)acrylate C _{6 -10} alkyl ester) at least one kind. In several other aspects, the monomer raw material B may contain C _1-18 alkyl methacrylate (preferably C _1-14 alkyl methacrylate, for example, C _1-10 alkyl methacrylate ) At least one of. The monomer raw material B may contain, for example, one or two or more selected from MMA, BMA, and 2EHMA as a (meth)acrylic monomer.

As another example of the said (meth)acrylic-type monomer, the (meth)acrylate which has an alicyclic hydrocarbon group is mentioned. For example, cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, isopropyl (meth)acrylate, dicyclopentyl (meth)acrylate, 1-adamantyl (meth)acrylate can be used Ester etc. In several aspects, the monomer raw material B may contain at least one selected from the group consisting of dicyclopentyl methacrylate, isopropyl methacrylate, and cyclohexyl methacrylate as a (meth)acrylic monomer.

The content of the above-mentioned (meth)acrylic acid alkyl ester and the above-mentioned alicyclic hydrocarbon group-containing (meth)acrylate in the monomer raw material B can be, for example, 10% by weight or more and 95% by weight or less, and can be 20% by weight or more and 95% by weight. The weight% or less may be 30 weight% or more and 90 weight% or less, 40 weight% or more and 90 weight% or less, or 50 weight% or more and 85 weight% or less. The use of alkyl (meth)acrylate may be advantageous from the viewpoint of the ease of increase in adhesive force by heating to a temperature higher than 50°C. In some aspects, the content of (meth)acrylate with alicyclic hydrocarbon group may be less than 50% by weight of the monomer raw material B, less than 30% by weight, less than 15% by weight, or less than 10% by weight, or less than 5% by weight. The (meth)acrylate having an alicyclic hydrocarbon group may not be used.

In some preferred aspects, the (meth)acrylic monomer as a constituent of the monomer raw material B may include a monomer M2 having a homopolymer Tg of 50° C. or higher. In polymer B having a certain degree of Mw or more (for example, 7×10 ⁴ or more, 8×10 ⁴ or more, and more than 10×10 ⁴ ), by copolymerizing monomer S1 and monomer M2, N The tendency of ₅₀ /N ₂₃ . It is believed that the reason for this is that the repeating unit derived from the monomer M2 can effectively suppress the increase in the mobility or mobility of the polyorganosiloxane structural part accompanying the temperature rise from room temperature to about 50°C, which is more favorable To maintain the low adhesion due to the presence of the above-mentioned polyorganosiloxane structure. From the viewpoint of improving the effect of suppressing N ₅₀ /N ₂₃ , in several aspects, the Tg of the homopolymer of monomer M2 can be 60°C or higher, 70°C or higher, 80°C or higher, or It can be above 90°C. In addition, the upper limit of the Tg of the homopolymer of the monomer M2 is not particularly limited, but from the viewpoint of ease of synthesis of the polymer B and the like, it is usually preferably 200°C or less. In some aspects, the Tg of the homopolymer of the monomer M2 can be, for example, 180°C or less, 150°C or less, or 120°C or less.

As the monomer M2, for example, from the (meth)acrylic monomers exemplified above, a homopolymer whose Tg satisfies the condition can be used. For example, one or two or more monomers selected from the group consisting of alkyl (meth)acrylate and (meth)acrylate having an alicyclic hydrocarbon group can be used. As the alkyl (meth)acrylate, an alkyl methacrylate whose alkyl group has a carbon number in the range of 1 to 4 can be preferably used.

In the case where the monomer raw material B includes the monomer M2, the content of the monomer M2 may be, for example, 5 wt% or more of the monomer raw material B, 10 wt% or more, 15 wt% or more, or 20 wt% % Or more, may be 25% by weight or more, or may be 30% by weight or more. In several aspects, the content of the above-mentioned monomer M2 can be 35 wt% or more of the monomer raw material B, 40 wt% or more, 45 wt% or more, 50 wt% or more, or 55 wt% More than weight%. In addition, the content of the above-mentioned monomer M2 may be, for example, 90% by weight or less. From the viewpoint of increasing N ₈₀ /N ₅₀ , it is usually 80% by weight or less, preferably 75% by weight or less, and may be 70% by weight or less. , May be 65% by weight or less, or 60% by weight or less. The content of the above-mentioned monomer M2, for example, can be well applied to the monomer M2 including one or two selected from the group consisting of alkyl (meth)acrylate and (meth)acrylate having alicyclic hydrocarbon group. The aspect of the above monomers, or the aspect that the monomer M2 includes one or two or more monomers selected from alkyl (meth)acrylate (for example, alkyl methacrylate). As a preferred example of this aspect, the aspect in which the above-mentioned monomer M2 contains MMA can be cited.

In some aspects, the above-mentioned (meth)acrylic monomers may also include monomers M3 whose homopolymer Tg is less than 50°C (typically above -20°C and less than 50°C). By using the monomer M3, it is easy to obtain an adhesive sheet that balances the adhesion and cohesion after the adhesion is increased. From the viewpoint of easily exhibiting this effect, the monomer M3 is preferably used in combination with the monomer M2.

As the monomer M3, for example, from the (meth)acrylic monomers exemplified in the above, a homopolymer whose Tg satisfies the condition can be used. For example, one or two or more monomers selected from the group consisting of alkyl (meth)acrylates can be used.

In the case where the monomer raw material B contains the monomer M3, the content of the monomer M3 can be, for example, 5 wt% or more of the monomer raw material B, 10 wt% or more, 15 wt% or more, or 20 wt% % Or more, may be 25% by weight or more, may be 30% by weight or more, or may be 35% by weight or more. In addition, the content of the monomer M3 is usually preferably 70% by weight or less of the monomer raw material B, and may be 60% by weight or less, or 50% by weight or less. The content of the above-mentioned monomer M3, for example, can be well applied to the state where the monomer M3 contains one or two or more monomers selected from alkyl (meth)acrylate (for example, alkyl methacrylate).

Among the various aspects of the adhesive sheet disclosed here, the monomer raw material B is preferably a homopolymer with a Tg higher than 170° C. and a monomer content of 30% by weight or less. Here, the content of the monomer in this specification is X% by weight or less. Unless otherwise specified, the concept includes a state where the content of the monomer is 0% by weight, that is, the monomer is substantially free of the monomer. State. In addition, the term "substantially free" means that at least the above-mentioned monomer is not intentionally used. If the copolymerization ratio of monomers with a homopolymer Tg higher than 170°C becomes higher, the mobility of polymer B may be insufficient, resulting in an increase in the adhesive force generated by heating to a temperature region higher than 50°C A situation that becomes difficult. By setting the copolymerization ratio of monomers with homopolymer Tg higher than 170°C to less than 30% by weight, at least one effect of increasing N ₈₀ and increasing N ₅₀ /N ₈₀ can be achieved.

In several aspects, the monomer raw material B preferably contains at least MMA as a (meth)acrylic monomer. By copolymerizing polymer B with MMA, it is easy to obtain adhesive sheets with larger N ₈₀ /N ₅₀ . The ratio of the MMA contained in the monomer raw material B to the total amount of the (meth)acrylic monomers may be, for example, 5 wt% or more, 10 wt% or more, 20 wt% or more, or 30% by weight or more, but also 40% by weight or more. In some aspects, the ratio of MMA in the total amount of the above-mentioned (meth)acrylic monomers can exceed 50% by weight, can exceed 55% by weight, can exceed 60% by weight, and can exceed 65% by weight. , Can also exceed 70% by weight. In addition, the ratio of MMA to the total amount of the above-mentioned (meth)acrylic monomers is usually preferably 95% by weight or less, 90% by weight or less, or 85% by weight or less.

As other examples of the monomers that can be contained together with the monomer S1 in the monomer units constituting the polymer B, the following examples include the monomers that can be used when the polymer A is an acrylic polymer Carboxyl group-containing monomers, acid anhydride group-containing monomers, hydroxyl group-containing monomers, epoxy group-containing monomers, cyano group-containing monomers, isocyanate group-containing monomers, amide group-containing monomers, ring with nitrogen atoms Monomers (N-vinyl cyclic amides, monomers with succinimide skeleton, maleimines, Iconimines, etc.), (meth)acrylic amine alkyl Base esters, vinyl esters, vinyl ethers, olefins, (meth)acrylates with aromatic hydrocarbon groups, (meth)acrylates containing heterocycles, (meth)acrylates containing halogen atoms, (Meth)acrylates obtained from terpene compound derivatives alcohol.

Still other examples of monomers that can be contained together with monomer S1 in the monomer units constituting polymer B include: ethylene glycol di(meth)acrylate and diethylene glycol di(meth)acrylate , Triethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate ) Oxyalkylene di(meth)acrylates such as acrylates; monomers with polyoxyalkylene skeletons, such as polyethylene glycol or polypropylene glycol, and other polyoxyalkylene chains having (methyl) ) Polymerizable polyoxyalkylene ethers having polymerizable functional groups such as acryl, vinyl, and allyl groups with an ether structure (alkyl ether, aryl ether, aryl alkyl ether, etc.) at the other end; Methoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate, propoxyethyl (meth)acrylate, butoxyethyl (meth)acrylate, ethoxy (meth)acrylate (Meth)acrylic acid alkoxyalkyl esters such as propyl ester; (meth)acrylic acid alkali metal salts and other salts; trimethylolpropane tri(meth)acrylate and other poly(meth)acrylates: partial Halogenated vinyl compounds such as vinyl chloride and 2-chloroethyl (meth)acrylate; 2-vinyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropene Mono-2-oxazoline and other oxazoline-containing monomers; (meth)acryloyl aziridine, (meth)acrylic acid-2-aziridinyl ethyl ester and other aziridinyl-containing monomers Body; 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, adducts of lactones and 2-hydroxyethyl (meth)acrylate and other hydroxyl-containing ethylene Monomers; fluorine-containing vinyl monomers such as fluorine-substituted alkyl (meth)acrylate; vinyl monomers containing reactive halogens such as 2-chloroethyl vinyl ether and vinyl monochloroacetate; such as vinyl trimethyl Oxysilane, γ-(meth)acryloxypropyltrimethoxysilane, allyltrimethoxysilane, trimethoxysilylpropylallylamine, 2-methoxyethoxytrimethoxy Silane is a vinyl monomer containing organosilicon; in addition, examples include: macromonomers having a radical polymerizable vinyl group at the end of the vinyl polymerized monomer. These can be copolymerized with monomer S1 alone or in combination of two or more.

In some aspects, as the polymer B, a functional group that does not have a crosslinking reaction with the polymer A can be preferably used. In other words, the polymer B is preferably contained in the adhesive layer without being chemically bonded to the polymer A. Regarding the adhesive layer containing the polymer B in this form, the mobility of the polymer B when heated is good, and it is suitable for increasing the adhesion strength increase ratio. The functional group that produces crosslinking reaction with polymer A may be different depending on the type of functional group possessed by polymer A, for example, epoxy group, isocyanate group, carboxyl group, alkoxysilyl group, amino group, etc. .

The adhesive sheet disclosed here contains polymer B having a Mw of 7×10 ⁴ or more. According to the adhesive sheet which contains polymer B with Mw as high as above to a certain extent, and meets the requirements of (N ₈₀ /N ₅₀ )≧3, it is possible to apply a temperature of about 50°C during the initial stage of application. The sample can also show good secondary processability, and the adhesive force can be greatly increased by subsequent heating. In some aspects, the Mw of polymer B can be, for example, 7.5×10 ⁴ or more, and from the viewpoint of easily achieving higher N ₈₀ /N ₅₀ , it can also be 8×10 ⁴ or more. In several aspects to, the Mw of the polymer B to improve the heat resistance (e.g., improved according to the N _H, N _H / N ₈₀ is increased like the evaluation) of the viewpoint, for example, may be a 10 × 10 ⁴ or more , May exceed 10×10 ⁴ , may be 12×10 ⁴ or more, or may be 15×10 ⁴ or more. Increasing the Mw of polymer B may also be advantageous from the viewpoint of improving the cohesiveness of the adhesive and inhibiting cohesion failure during secondary processing.

In addition, the Mw of polymer B may be less than 50×10 ⁴ , for example. From the viewpoint of suppressing initial adhesion and improving secondary processing workability, it is advantageous to be less than 40×10 ⁴ and may be less than 35×10 ⁴ , It may be less than 30×10 ⁴ . If the Mw of polymer B is within the range of any of the above upper and lower limits, it is easy to adjust the compatibility or mobility in the adhesive layer to an appropriate range, and it is easy to achieve a high level of consideration for the initial stage of attachment Adhesive sheet with good secondary processability and strong adhesion after the adhesion is increased.

In several preferred aspects, the Mw of polymer B is preferably lower than the Mw of polymer A. Thereby, it is easy to realize an adhesive sheet with a high level of good secondary processability at the initial stage of attachment and strong adhesiveness after the adhesive force is increased. The Mw of the polymer B may be, for example, 0.8 times or less of the Mw of the polymer A, 0.75 times or less, 0.5 times or less, or 0.3 times or less. Furthermore, the Mw of the polymer B is suitably lower than the Mw of the polymer A by 10×10 ⁴ or more, preferably 20×10 ⁴ or more, and more preferably 30×10 ⁴ or more lower.

The polymer B can be produced, for example, by polymerizing the above-mentioned monomers by a known method such as a solution polymerization method, an emulsion polymerization method, a bulk polymerization method, a suspension polymerization method, and a photopolymerization method.

In order to adjust the molecular weight of polymer B, a chain transfer agent may be used as needed. Examples of chain transfer agents used include: octyl mercaptan, lauryl mercaptan, tertiary nonyl mercaptan, tertiary (dodecyl) mercaptan, mercaptoethanol, α-thioglycerol, etc. Sulfhydryl compounds; thioglycolic acid, methyl thioglycolate, ethyl thioglycolate, propyl thioglycolate, butyl thioglycolate, tert-butyl thioglycolate, thioglycolic acid 2-Ethylhexyl ester, octyl thioglycolate, isooctyl thioglycolate, decyl thioglycolate, lauryl thioglycolate, thioglycolate of ethylene glycol, neopentyl Thioglycolic acid esters such as glycol thioglycolate and pentaerythritol thioglycolate; α-methylstyrene dimer, etc.

The amount of the chain transfer agent used is not particularly limited. It is usually 0.05 to 20 parts by weight, preferably 0.1 to 15 parts by weight, and more preferably 0.2, relative to 100 parts by weight of the monomer. Parts by weight ~ 10 parts by weight. By adjusting the addition amount of the chain transfer agent in this way, polymer B with a better molecular weight can be obtained. A chain transfer agent can be used individually by 1 type or in combination of 2 or more types.

As a method of adjusting the molecular weight of the polymer B, various previously known methods including the use of the above-mentioned chain transfer agent can be used alone or in appropriate combination. The same applies to the molecular weight of polymer A. Non-limiting examples of this method include the choice of the polymerization method, the choice of the type or amount of the polymerization initiator, the choice of the polymerization temperature, the choice of the type or amount of the polymerization solvent in the solution polymerization method, and the choice of the photopolymerization method. Selection of light intensity, etc. The industry can understand how to obtain a polymer with a desired molecular weight based on the description of the specification of the case including the following specific examples and the technical common sense at the time of application of the case.

In the adhesive sheet disclosed here, the usage amount of polymer B relative to 100 parts by weight of the usage amount of polymer A, for example, can be set to 0.1 parts by weight or more, and from the viewpoint of obtaining higher effects, it can be set to 0.5 parts by weight or more, may be 1 part by weight or more, or 2 parts by weight or more. In some aspects, from the viewpoint of improvement of secondary processability, the amount of the above-mentioned polymer B used may be 3 parts by weight or more, 4 parts by weight or more, or 5 parts by weight or more. . In addition, the usage amount of the polymer B relative to 100 parts by weight of the usage amount of the polymer A may be, for example, 75 parts by weight or less, 60 parts by weight or less, or 50 parts by weight or less. From the viewpoint of avoiding excessive reduction in the cohesive force of the adhesive layer, in some aspects, the amount of polymer B used relative to 100 parts by weight of polymer A can be set to 40 parts by weight or less, or 35 parts by weight. Parts by weight or less, 30 parts by weight or less, or 25 parts by weight or less. From the viewpoint of obtaining higher adhesive force after heating, in several aspects, the usage amount of the above-mentioned polymer B can be 20 parts by weight or less, 17 parts by weight or less, and 15 parts by weight. Parts or less, may be 12 parts by weight or less, or may be 10 parts by weight or less.

The adhesive layer may optionally contain polymers (arbitrary polymers) other than polymer A and polymer B within a range that does not greatly impair the performance of the adhesive sheet disclosed herein. The usage amount of this arbitrary polymer is generally suitably set to be 20% by weight or less of the entire polymer component contained in the adhesive layer, may be 15% by weight or less, or may be 10% by weight or less. In some aspects, the usage amount of any of the aforementioned polymers can be less than 5% by weight, less than 3% by weight, or less than 1% by weight of the entire polymer component. It may also be an adhesive layer that does not substantially contain polymers other than polymer A and polymer B.

(Crosslinking agent) In the adhesive layer, a crosslinking agent can be used as needed for the purpose of adjusting cohesive force. As the cross-linking agent, a cross-linking agent known in the field of adhesives can be used, for example, epoxy-based cross-linking agents, isocyanate-based cross-linking agents, polysiloxane-based cross-linking agents, azoline-based cross-linking agents, An aziridine-based cross-linking agent, a silane-based cross-linking agent, an alkyl etherified melamine-based cross-linking agent, a metal chelate-based cross-linking agent, etc. The crosslinking agent can be used alone or in combination of two or more. Examples of crosslinking agents that can be used well include epoxy crosslinking agents, isocyanate crosslinking agents, silane crosslinking agents, alkyl etherified melamine crosslinking agents, and metal chelate crosslinking agents. Joint agent. Examples of particularly preferable crosslinking agents include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, and metal chelate-based crosslinking agents.

Specifically, examples of isocyanate-based crosslinking agents include: toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate Isocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, tetramethylxylylene diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate, polymethylene polyphenyl isocyanate, and the like Adducts with polyols such as trimethylolpropane. Or, compounds having at least one isocyanate group and one or more unsaturated bonds in one molecule, specifically 2-isocyanatoethyl (meth)acrylate, etc. can also be used as isocyanate-based crosslinking Agent. These can be used individually by 1 type or in combination of 2 or more types.

Examples of epoxy crosslinking agents include: bisphenol A, epichlorohydrin type epoxy resins, ethylene glycidyl ether, polyethylene glycol diglycidyl ether, glycerol diglycidyl ether, and glycerol triglycidyl Ether, 1,6-hexanediol glycidyl ether, trimethylolpropane triglycidyl ether, diglycidyl aniline, diamine glycidylamine, N,N,N',N'-tetraglycidyl Xylylenediamine and 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, etc. These can be used individually by 1 type or in combination of 2 or more types.

Regarding the metal chelate compound that can be used as a metal chelate crosslinking agent, examples of the metal component include aluminum, iron, tin, titanium, nickel, etc., and examples of the chelate component include acetylene, acetylene acetate, etc. Ester, ethyl lactate, etc. These can be used individually by 1 type or in combination of 2 or more types.

The amount of use in the case of using a crosslinking agent is not particularly limited. For example, it can be set to an amount exceeding 0 parts by weight relative to 100 parts by weight of polymer A. Moreover, the usage-amount of a crosslinking agent can be set to 0.01 weight part or more with respect to 100 weight part of polymer A, for example, Preferably it is set to 0.05 weight part or more. By increasing the amount of cross-linking agent used, there is a tendency to suppress the adhesion at the initial stage of attachment and improve the secondary processability. In some aspects, the amount of crosslinking agent used can be 0.1 part by weight or more, 0.5 part by weight or more, or 1 part by weight or more relative to 100 parts by weight of polymer A. On the other hand, from the viewpoint of avoiding the decrease in viscosity due to excessive increase in cohesive force, the amount of crosslinking agent used is generally preferably 15 parts by weight or less with respect to 100 parts by weight of polymer A, and can be set to 10 parts by weight. Parts or less, and may be 5 parts by weight or less. It may also be advantageous to use a crosslinking agent in an amount that is not too large, from the viewpoint of easy realization of an adhesive sheet with higher N ₈₀ /N ₅₀ .

The technique disclosed here can be implemented satisfactorily in a state where at least an isocyanate-based crosslinking agent is used as a crosslinking agent. From the point of view that it is easy to realize an adhesive sheet that has both good secondary processability at the initial stage of attachment and strong adhesiveness after the adhesion is increased, in several aspects, the amount of isocyanate-based crosslinking agent used is relative to 100 weight Parts of polymer A can be set to, for example, 0.1 parts by weight or more and 5 parts by weight or less, 0.3 parts by weight or more and 4 parts by weight or less, or 0.5 parts by weight or more and 3 parts by weight or less.

When an isocyanate-based crosslinking agent is used in the adhesive layer containing a hydroxyl-containing monomer as a monomer unit, the usage amount of the hydroxyl-containing monomer W _{OH is} relative to the usage amount of the isocyanate-based crosslinking agent W _NCO by weight The reference meter may be an amount such that W _OH /W _NCO becomes 2 or more, but it is not particularly limited. By increasing the usage amount of the hydroxyl-containing monomer relative to the isocyanate-based crosslinking agent in this way, a crosslinked structure suitable for greatly increasing the adhesive force after heating relative to the adhesive force at the initial stage of attachment can be formed. In some aspects, W _OH /W _NCO can be 3 or more, 5 or more, 10 or more, 20 or more, 30 or more, or 50 or more. The upper limit of W _OH /W _NCO is not particularly limited. W _OH /W _NCO may be 500 or less, 200 or less, or 100 or less, for example.

In order to make any of the above crosslinking reactions proceed more efficiently, a crosslinking catalyst may also be used. As the crosslinking catalyst, for example, a tin-based catalyst (especially dioctyltin dilaurate) can be suitably used. The amount of the crosslinking catalyst used is not particularly limited. For example, it can be about 0.0001 part by weight to 1 part by weight relative to 100 parts by weight of polymer A.

A multifunctional monomer may be used in the adhesive layer as needed. The multifunctional monomer can be used in place of the above-mentioned crosslinking agent or in combination with the crosslinking agent to help achieve the purpose of adjusting cohesive force. For example, in an adhesive layer formed of a light-curing adhesive composition, a polyfunctional monomer can be used well. Examples of multifunctional 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 , Butylene glycol (meth)acrylate, hexanediol di(meth)acrylate, etc. Among them, trimethylolpropane tri(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and dipentaerythritol hexa(meth)acrylate can be used favorably. 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 to 3.0 parts by weight with respect to 100 parts by weight of polymer A. In some aspects, the amount of the polyfunctional monomer used relative to 100 parts by weight of the polymer A may be, for example, 0.02 parts by weight or more, or 0.03 parts by weight or more. By increasing the amount of polyfunctional monomers used, there is a tendency to suppress the adhesion at the initial stage of attachment and improve the secondary processability. On the other hand, from the viewpoint of avoiding the decrease in viscosity due to excessive cohesive force increase, the amount of polyfunctional monomer used can be 2.0 parts by weight or less, or 1.0 part by weight relative to 100 parts by weight of polymer A. Below, it may be 0.5 parts by weight or less. It may also be advantageous from the viewpoint of easy realization of an adhesive sheet with higher N ₈₀ /N ₅₀ if the amount of the multifunctional monomer used is not too much.

(Adhesion imparting resin) The adhesive layer may optionally contain an adhesion-imparting resin. There are no particular limitations on the adhesion-imparting resin. Examples include rosin-based adhesion-imparting resins, terpene-based adhesion-imparting resins, phenol-based adhesion-imparting resins, hydrocarbon-based adhesion-imparting resins, ketone-based adhesion-imparting resins, and polyamide-based adhesion-imparting resins. Adhesive resin, epoxy resin, elastic system adhesive resin, etc. The adhesion-imparting resin can be used alone or in combination of two or more.

Examples of rosin-based adhesion-imparting resins include unmodified rosins (raw rosins) such as rosin gum, wood rosin, and tall oil rosin, or those modified by polymerization, disproportionation, hydrogenation, etc. Modified rosin (polymerized rosin, stabilized rosin, disproportionated rosin, fully hydrogenated rosin, partially hydrogenated rosin, or other chemically modified rosin, etc.), in addition to various rosin derivatives. As the above-mentioned rosin derivatives, for example: Rosin-phenolic resin obtained by adding phenol and rosin (unmodified rosin, modified rosin or various rosin derivatives, etc.) under acid catalyst and conducting thermal polymerization; The ester compound of rosin (unmodified rosin ester) that uses alcohol to esterify unmodified rosin, or the use of alcohol to make polymerized rosin, stabilized rosin, disproportionated rosin, fully hydrogenated rosin, partially hydrogenated rosin, and other modified rosin esters Rosin ester resins such as modified rosin ester compounds (polymerized rosin ester, stabilized rosin ester, disproportionated rosin ester, fully hydrogenated rosin ester, partially hydrogenated rosin ester, etc.); Unmodified rosin or modified rosin (polymerized rosin, stabilized rosin, disproportionated rosin, fully hydrogenated rosin, partially hydrogenated rosin, etc.) is modified by unsaturated fatty acid with unsaturated fatty acid modified rosin resin; Unsaturated fatty acid modified rosin ester resin with unsaturated fatty acid modified rosin ester resin; Unmodified rosin, modified rosin (polymerized rosin, stabilized rosin, disproportionated rosin, fully hydrogenated rosin, partially hydrogenated rosin, etc.), unsaturated fatty acid modified rosin resin or unsaturated fatty acid modified rosin ester resin Rosin alcohol resin obtained by reducing carboxyl groups; Metal salts of rosin resins (especially rosin ester resins) such as unmodified rosin, modified rosin, or various rosin derivatives.

Examples of terpene-based adhesion-imparting resins include terpene-based resins such as α-pinene polymers, β-pinene polymers, and dipentene polymers, or modification of these terpene-based resins (phenol modification). Modified terpene resins (such as terpene phenol resins, styrene modified terpene resins, aromatic modified terpene resins, hydrogenated Terpene-based resins, etc.).

Examples of phenol-based adhesion-imparting resins include condensation products of various phenols (such as phenol, m-cresol, 3,5-xylenol, p-alkylphenol, resorcinol, etc.) and formaldehyde (such as alkyl Phenolic resins, xylene formaldehyde resins, etc.), resol resins obtained by the addition reaction of the above-mentioned phenols and formaldehyde using an alkaline catalyst, or the condensation reaction of the above-mentioned phenols and formaldehyde using an acid catalyst Novolac resin obtained.

Examples of hydrocarbon-based adhesion-imparting resins include: aliphatic hydrocarbon resins, aromatic hydrocarbon resins, aliphatic cyclic hydrocarbon resins, aliphatic-aromatic petroleum resins (styrene-olefin copolymers, etc.) , Aliphatic-alicyclic petroleum resins, hydrogenated hydrocarbon resins, lavender-based resins, lavender-based resins and other hydrocarbon resins.

As a commercially available product of polymerized rosin esters that can be used well, examples include: "Pensel D-125", "Pensel D-135", "Pensel D-160", "Pensel" manufactured by Arakawa Chemical Industry Co., Ltd. KK", "Pensel C", etc., but not limited to these.

Examples of commercially available products of terpene phenol resins that can be used well are: "YS Polystar S-145", "YS Polystar G-125", "YS Polystar N125", and "YS Polystar S-145" manufactured by Yasuhara Chemical Co., Ltd. "YS Polystar U-115", "Tamanol 803L" and "Tamanol 901" manufactured by Arakawa Chemical Industry Co., Ltd., "Sumilite resin PR-12603" manufactured by Sumitomo Bakelite Co., Ltd., but not limited In these.

The content of the adhesion-imparting resin is not particularly limited, and it can be set in a manner that exerts an appropriate adhesion performance according to the purpose or use. The content of the adhesion-imparting resin relative to 100 parts by weight of the polymer A (in the case of containing two or more adhesion-imparting resins, the total amount thereof) can be, for example, about 5 to 500 parts by weight.

As the adhesion-imparting resin, those having a softening point (softening temperature) of about 80°C or higher (preferably about 100°C or higher, for example, about 120°C or higher) can be used well. According to the adhesion imparting resin having a softening point above the above lower limit, it is easy to obtain an adhesive sheet satisfying N ₈₀ /N ₅₀ ≧5. The upper limit of the softening point is not particularly limited. For example, it may be about 200°C or less (typically 180°C or less). Furthermore, the softening point of the adhesion imparting resin can be measured based on the softening point test method (Ring and Ball method) specified in JIS K2207.

In addition, the adhesive layer in the technology disclosed herein may also contain leveling agents, plasticizers, softeners, colorants (dyes, pigments, etc.), and fillers as needed within the range that does not significantly hinder the effects of the present invention. Agents, antistatic agents, anti-aging agents, ultraviolet absorbers, antioxidants, light stabilizers, preservatives and other known additives that can be used in adhesives.

The adhesive layer constituting the adhesive sheet disclosed herein may be the hardened layer of the adhesive composition. That is, the adhesive layer can be formed by applying (for example, coating) an adhesive composition such as a water-dispersed, solvent-based, light-curing type, and hot-melt type to a suitable surface and then appropriately hardening. In the case of two or more hardening treatments (drying, crosslinking, polymerization, cooling, etc.), these can be carried out simultaneously or in multiple stages. In the adhesive composition using part of the polymer (polymer slurry) of the monomer raw material, typically, the final copolymerization reaction is performed as the above-mentioned hardening treatment. That is, part of the polymer is subjected to further copolymerization to form a complete polymer. For example, if it is a photocurable adhesive composition, light irradiation is performed. If necessary, hardening treatments such as cross-linking and drying can be performed. For example, when it is necessary to dry the light-curable adhesive composition, light-curing may be performed after drying. In the adhesive composition using a complete polymer, typically, as the above-mentioned hardening treatment, treatments such as drying (heat drying), crosslinking, etc. are performed as necessary.

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 Implementation of commonly used coating machines.

The thickness of the adhesive layer is not particularly limited, and it can be set to 1 μm or more, for example. In some aspects, the thickness of the adhesive layer can be, for example, 3 μm or more, 5 μm or more, 8 μm or more, 10 μm or more, 15 μm or more, or 20 μm or more. More than 20 μm. By increasing the thickness of the adhesive layer, the adhesive force tends to increase after heating. In addition, in some aspects, the thickness of the adhesive layer may be, for example, 300 μm or less, 200 μm or less, 150 μm or less, 100 μm or less, 70 μm or less, or 50 μm or less. , Can also be 40 μm or less. The thickness of the adhesive layer is not too large, which may be advantageous from the viewpoint of thinning the adhesive sheet or preventing the cohesion and destruction of the adhesive layer. Furthermore, in the case of an adhesive sheet with a first adhesive layer and a second adhesive layer on the first and second sides of the substrate, the thickness of the adhesive layer can be at least applied to the thickness of the first adhesive layer thickness. The thickness of the second adhesive layer can also be selected from the same range. Furthermore, in the case of an adhesive sheet without a substrate, the thickness of the adhesive sheet is the same as the thickness of the adhesive layer.

The gel fraction of the adhesive constituting the adhesive layer is usually in the range of 20.0%-99.0%, preferably in the range of 30.0%-90.0%, but it is not particularly limited. By setting the gel fraction in the above range, it is easy to achieve a high-level adhesive sheet that balances the secondary processability at the initial stage of attachment and the strong adhesiveness after the adhesive force increases. The gel fraction is measured by the following method.

[Determination of Gel Fraction] A sample of about 0.1 g of adhesive (weight Wg ₁ ) was wrapped into a purse with a porous polytetrafluoroethylene membrane (weight Wg ₂ ) with an average pore diameter of 0.2 μm, and a kite string (weight Wg ₃ ) Tighten the mouth tightly. As the porous polytetrafluoroethylene membrane, the brand name "Nitoflon (registered trademark) NTF1122" (Nitto Denko Co., Ltd., average pore diameter 0.2 μm, porosity 75%, thickness 85 μm) or its equivalent is used. The coating was immersed in 50 mL of ethyl acetate and kept at room temperature (typically 23°C) for 7 days to elute the sol component (ethyl acetate soluble fraction) in the adhesive to the outside of the film. Then, the package was taken out, the ethyl acetate attached to the outer surface was wiped off, the package was dried at 130°C for 2 hours, and the weight (Wg ₄ ) of the package was measured. By substituting each value into the following formula, the gel fraction G _{C of the} adhesive can be calculated. Gel fraction G _C (%)=[(Wg ₄ －Wg ₂ －Wg ₃ )/Wg ₁ ]×100

＜Support base material＞ Several types of adhesive sheets can be in the form of a substrate-attached adhesive sheet with an adhesive layer on one or both sides of the supporting substrate. The material of the supporting base material is not particularly limited, and can be appropriately selected according to the purpose of use or usage of the adhesive sheet. Non-limiting examples of substrates that can be used include: polypropylene or ethylene-propylene copolymer and other polyolefin films with polyolefin as the main component, polyethylene terephthalate or polyethylene terephthalate Butylene and other plastic films such as polyester film with polyester as the main component, polyvinyl chloride film with polyvinyl chloride as the main component; polyurethane foam, polyethylene foam, polychloroprene Diene foam and other foam sheets containing foam; various fibrous materials (can be natural fibers such as hemp and cotton, synthetic fibers such as polyester and vinylon, semi-synthetic fibers such as acetate, etc.) Woven fabrics and non-woven fabrics made of single or blended fabrics; papers such as Japanese paper, Dolin paper, kraft paper, and crepe paper; metal foils such as aluminum foil and copper foil. It may also be a base material composed of these composites. As an example of such a composite base material, the base material of the structure which laminated|stacked the metal foil and the said plastic film, the plastic base material reinforced with inorganic fiber, such as glass cloth, etc. are mentioned.

As the base material of the adhesive sheet disclosed here, various film base materials can be used well. The above-mentioned film substrate may be a porous substrate such as a foam film or a non-woven sheet, a non-porous substrate, or a substrate with a structure in which a porous layer and a non-porous layer are laminated . In some aspects, as the above-mentioned film base material, a base film including a resin film capable of independently maintaining a shape (self-standing or irrelevant) can be used well. The term "resin film" here refers to a non-porous structure, and typically refers to a resin film that contains substantially no bubbles (non-porous). Therefore, the above-mentioned concept of resin film is different from foam film or non-woven fabric. As the above-mentioned resin film, those capable of independently maintaining the shape (self-supporting or irrelevant) can be preferably used. 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, polyamide (PA) such as polyester, polyolefin, nylon 6, nylon 66, and partially aromatic polyamide, polyimide (PI), and polyamide Imine (PAI), polyether ether ketone (PEEK), polyether ether (PES), polyphenylene sulfide (PPS), polycarbonate (PC), polyurethane (PU), ethylene-vinyl acetate Fluorine resin such as ester copolymer (EVA) and polytetrafluoroethylene (PTFE), acrylic resin, polyacrylate, polystyrene, polyvinyl chloride, polyvinylidene chloride and other resins. The above-mentioned resin film may be formed using a resin material containing one kind of such resin alone, or may be formed using a resin material blending two or more kinds of resin. The aforementioned resin film may not be stretched, or may be stretched (for example, uniaxially stretched or biaxially stretched).

Preferred examples of resin materials constituting the resin film include polyester resins, PPS resins, and polyolefin resins. Here, the so-called polyester-based resin means a resin containing polyester in a ratio exceeding 50% by weight. Similarly, the so-called PPS resin refers to a resin containing PPS in a ratio exceeding 50% by weight, and the so-called polyolefin resin refers to a resin containing polyolefin in a ratio exceeding 50% by weight.

As the polyester-based resin, a polyester-based resin containing a polyester obtained by polycondensing a dicarboxylic acid and a diol as a main component is typically used.

As the dicarboxylic acid constituting the polyester, for example, phthalic acid, isophthalic acid, terephthalic acid, 2-methylterephthalic acid, 5-sulfoisophthalic acid, 4,4 '-Diphenyl dicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, 4,4'-diphenyl ketone dicarboxylic acid, 4,4'-diphenoxyethane dicarboxylic acid, 4,4'-diphenyl dicarboxylic acid, 1,4-naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid and other aromatics Alicyclic dicarboxylic acid such as 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid; malonic acid, amber Acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanoic acid and other aliphatic dicarboxylic acids; maleic acid, maleic anhydride, trans Unsaturated dicarboxylic acids such as butenedioic acid; derivatives of these (for example, lower alkyl esters of the aforementioned dicarboxylic acids such as terephthalic acid), etc. These can be used individually by 1 type or in combination of 2 or more types. From the viewpoint of strength and the like, an aromatic dicarboxylic acid is preferred. Among them, preferred dicarboxylic acids include terephthalic acid and 2,6-naphthalenedicarboxylic acid. For example, it is preferable that 50% by weight or more (e.g., 80% by weight or more, typically 95% by weight or more) of the dicarboxylic acids constituting the polyester is terephthalic acid, 2,6-naphthalenedicarboxylic acid or the like And use. The said dicarboxylic acid may consist essentially of only terephthalic acid, consist essentially of only 2,6-naphthalenedicarboxylic acid, or consist essentially of only terephthalic acid and 2,6-naphthalenedicarboxylic acid.

Examples of the glycol constituting the polyester include ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, 1,3-propanediol, 1,5-pentanediol, and neopentyl glycol. Aliphatic diols such as diol, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, polyoxytetramethylene glycol; 1,2-cyclohexanediol, Alicyclic diols such as 1,4-cyclohexanediol, 1,1-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, benzenedimethanol, 4,4'-dihydroxybiphenyl, 2 , Aromatic diols such as 2-bis(4'-hydroxyphenyl) propane, bis(4-hydroxyphenyl) sulfide, etc. These can be used individually by 1 type or in combination of 2 or more types. Among them, from the viewpoint of transparency and the like, aliphatic diols are preferred, and ethylene glycol is particularly preferred. The ratio of the aliphatic diol (preferably ethylene glycol) in the diol constituting the polyester is preferably 50% by weight or more (for example, 80% by weight or more, typically 95% by weight or more). The aforementioned diol may consist essentially of only ethylene glycol.

Specific examples of polyester resins include: polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polyethylene naphthalate (PEN) Butylene formate and so on.

As the polyolefin resin, one type of polyolefin may be used alone, or two or more types of polyolefin may be used in combination. The polyolefin may be, for example, a homopolymer of α-olefin, a copolymer of two or more α-olefins, a copolymer of one or more α-olefins 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 two or more types of polyethylene (PE), blended with polypropylene (PP) and polyethylene (PE) PP/PE blended film, etc.

Specific examples of the resin film that can be used as the base film of the adhesive sheet disclosed herein include PET film, PEN film, PPS film, PEEK film, CPP film, and OPP film. As an example of a preferable base film from the viewpoint of strength or dimensional stability, a PET film, a PEN film, a PPS film, and a PEEK film can be cited. From the viewpoints of easy access to the substrate, PET film and PPS film are particularly preferred, and among them, PET film is preferred.

In the resin film, light stabilizers, antioxidants, antistatic agents, colorants (dyes, pigments, etc.), fillers, lubricants, and anti-sticking agents can be blended as needed within the range that does not significantly hinder the effects of the present invention. Linking agent and other well-known additives. The blending amount of additives is not particularly limited, and can be appropriately set according to the application of the adhesive sheet.

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 die casting molding, and calender roll molding can be suitably used.

The above-mentioned substrate may substantially include such a base film. Alternatively, the above-mentioned substrate may also include an auxiliary layer in addition to the above-mentioned base 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 for giving the substrate a desired appearance, an antistatic layer, an undercoat layer, Surface treatment layer such as release layer.

The thickness of the base material is not particularly limited, and can be selected according to the purpose of use or usage of the adhesive sheet. The thickness of the substrate may be 1000 μm or less, for example. In some aspects, the thickness of the substrate may be 500 μm or less, 300 μm or less, 250 μm or less, or 200 μm or less from the viewpoint of handling or processability of the adhesive sheet. . From the viewpoint of miniaturization or weight reduction of products using adhesive sheets, in some aspects, the thickness of the substrate may be 160 μm or less, 130 μm or less, 100 μm or less, or 90 μm or less. μm or less, can be 80 μm or less, can be 60 μm or less, can be 50 μm or less, can be 25 μm or less, can be 10 μm or less, or can be 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 workability or processability, the thickness of the substrate may be, for example, 2 μm or more, 5 μm or more, 10 μm or more, 20 μm or more, or 25 μm or more. 25 μm. In some aspects, the thickness of the substrate may be 30 μm or more, 35 μm or more, 55 μm or more, 70 μm or more, 75 μm or more, 90 μm or more, or It is 120 μm or more. For example, in an adhesive sheet that can be used for the purpose of reinforcement, support, and impact relaxation of the adherend, a substrate with a thickness of 30 μm or more can be used well.

If necessary, corona discharge treatment, plasma treatment, ultraviolet irradiation treatment, acid treatment, alkali treatment, primer coating and other known surfaces can be applied to the first surface of the substrate. deal with. Such surface treatment can be used to improve the grip of the adhesive layer to the substrate. For example, in an adhesive sheet provided with a base material containing a resin film as a base film, a base material subjected to this gripping improvement treatment can be used well. The above surface treatments can be applied alone or in combination. The composition of the primer used in the formation of the primer layer is not particularly limited, and can be appropriately selected from known ones. The thickness of the primer layer is not particularly limited, but it is usually about 0.01 μm to 1 μm, preferably about 0.1 μm to 1 μm. As other treatments that can be applied to the first surface of the substrate as necessary, antistatic layer formation treatment, colored layer formation treatment, printing treatment, etc. can be cited.

When the adhesive sheet disclosed here is in the form of a single-sided adhesive sheet with an adhesive layer only on the first surface of the substrate, the second surface of the substrate may be subjected to peeling treatment or antistatic treatment as needed Previously known surface treatment. For example, by using a release treatment agent to perform surface treatment on the back surface of the substrate (typically, by providing a release layer formed with a release treatment agent), the adhesive sheet wound into a roll shape can be released. The roll force becomes lighter. 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. In addition, for the purpose of improving printability, reducing light reflectivity, and improving overlap bonding, the second surface of the substrate can be treated with corona discharge treatment, plasma treatment, ultraviolet radiation treatment, acid treatment, alkali treatment, etc. . Moreover, in the case of a double-sided adhesive sheet, if necessary, the second surface of the substrate may be subjected to the same surface treatment as the surface treatment that can be performed on the first surface of the substrate as exemplified above. Furthermore, the surface treatment performed on the first side of the substrate and the surface treatment performed on the second side may be the same or different.

<Adhesive sheet> (Characteristics of the adhesive sheet, etc.) The adhesive sheet disclosed here is due to the ratio of the adhesive force N ₈₀ [N/25 mm] to the adhesive force N ₅₀ [N/25 mm], that is, the increase in adhesive force ratio N ₈₀ /N ₅₀ is 3 or more, so it can also show good secondary processability in the use state where a temperature of about 50 ℃ may be applied at the initial stage of attachment, and the subsequent heating, etc., can greatly increase the adhesion rise. From the viewpoint of obtaining higher effects, in some aspects, N ₈₀ /N ₅₀ may be 3.5 or higher, 4.5 or higher, 5.0 or higher, 5.5 or higher, or 6.0 or higher. The upper limit of N ₈₀ /N ₅₀ is not particularly limited. From the viewpoint of ease of manufacture or economy of the adhesive sheet, in several aspects, for example, it can be 50 or less, 30 or less, or 20 or less. It may be 10 or less. The adhesive sheet disclosed here can be implemented satisfactorily in the aspect of N ₈₀ /N ₅₀ being 3.0 or more and 50 or less, or 3.5 or more and 50 or less, or 5.0 or more and 30 or less.

In several aspects, the ratio of the adhesion force N ₅₀ [N/25 mm] to the adhesion force N ₂₃ [N/25 mm], that is, the increase ratio of the adhesion force N ₅₀ /N _{23 is} preferably less than 10, more Preferably, it is less than 7.0, can be less than 6.0, can be less than 5.5, can be less than 5.0, or less than 5.0. Adhesive sheets with smaller N ₅₀ /N ₂₃ have a tendency to exhibit good secondary processability even in usage conditions where a temperature of about 50°C may be applied at the initial stage of attachment. The lower limit of N ₅₀ /N ₂₃ is not particularly limited, and is usually 1.0 or more, typically more than 1.0, and may be 1.2 or more. From the viewpoint that it is easy to take into account the higher N ₈₀ /N ₅₀ , in some aspects, the N ₅₀ /N ₂₃ can be, for example, 1.5 or more, 2.0 or more, or 2.5 or more.

In several aspects, the ratio of the adhesion force N ₈₀ [N/25 mm] to the adhesion force N ₂₃ [N/25 mm], that is, the adhesion increase ratio N ₈₀ /N ₂₃ can be, for example, 5 or more, which can be 7 or more, but also 10 or more. According to the larger adhesive sheet of N ₈₀ / N ₂₃ , the low adhesiveness at the initial stage of attachment and the strong adhesiveness after the adhesive force increase can be exerted at a higher level. The adhesive sheet disclosed here can also be implemented well with N ₈₀ /N _{23 being,} for example, 15 or more, 20 or more, or 25 or more. The upper limit of N ₈₀ /N ₂₃ is not particularly limited. From the viewpoint of ease of manufacture or economy of the adhesive sheet, for example, it may be 100 or less, 80 or less, 60 or less, or 50 or less.

Here, the adhesive force N ₂₃ [N/25 mm] is obtained by crimping on a stainless steel (SUS) plate as the adherend and placing it in an environment of 23°C and 50%RH for 30 minutes Then, under the environment (ie, at 23° C.), the 180° peeling adhesive force was measured under the conditions of a peeling angle of 180 degrees and a stretching speed of 300 mm/min. Adhesive force N ₅₀ [N/25 mm] is obtained by crimping the SUS board as the adherend and keeping it at 50°C for 30 minutes, and then at 23°C, 50%RH After being placed in the environment for 30 minutes, the 180° peeling adhesive force was measured under the conditions of a peeling angle of 180 degrees and a tensile speed of 300 mm/min. Adhesive force N ₈₀ [N/25 mm] is obtained by crimping on the SUS plate as the adherend, heating at 80°C for 5 minutes, and then placing it in an environment of 23°C and 50%RH After 30 minutes, in this environment, the 180° peel adhesion was measured under the conditions of a peel angle of 180 degrees and a tensile speed of 300 mm/min. As the adherend, a SUS304BA board was used in the measurement of any one of the adhesive force N ₂₃ , N ₅₀ , and N ₈₀ . During the measurement, if necessary, attach an appropriate substrate (for example, a PET film with a thickness of about 25 μm) to the adhesive sheet of the measurement object for reinforcement. The adhesive force N ₂₃ , N ₅₀ , and N ₈₀ can be measured more specifically according to the method described in the following examples.

In some aspects, the adhesive force N ₂₃ can be 3 N/25 mm or less, preferably 2.5 N/25 mm or less, more preferably less than 2 N/25 mm, and can be 1.5 N/25 mm or less , Can be 1.2 N/25 mm or less, or 1 N/25 mm or less. The lower adhesive force N _{23 is} better in terms of secondary workability. The lower limit of the adhesive force N ₂₃ is not particularly limited, and for example, it may be 0.01 N/25 mm or more. From the viewpoint of the workability of attaching to the adherend, or preventing the position shift before the adhesive force increases, the adhesive force N ₂₃ is usually 0.1 N/25 mm or more. From the viewpoint of the improvement of the adhesive force after heating, among several aspects, the adhesive force N ₂₃ can be 0.2 N/25 mm or more, 0.3 N/25 mm or more, or 0.4 N/25 mm or more. , It can also be 0.5 N/25 mm or more.

In some aspects, the adhesive force N ₅₀ can be, for example, 8 N/25 mm or less, preferably 7 N/25 mm, more preferably 5 N/25 mm or less, and can be 4.5 N/25 mm or less. Below 4 N/25 mm, or less than 4 N/25 mm. Low adhesion to N ₅₀ may be bonded to the initial state is applied using the injection temperature of about 50 deg.] C also exhibit good in the viewpoint of workability of the second preferred terms. The lower limit of the adhesive force N ₅₀ is not particularly limited, and for example, it may be 0.05 N/25 mm or more. From the viewpoint of preventing the position shift before the adhesion force increases, the adhesion force N ₅₀ is usually 0.1 N/25 mm or more. From the viewpoint of improving the adhesive force after heating, in several aspects, the adhesive force N ₅₀ can be, for example, 0.5 N/25 mm or more, 1 N/25 mm or more, or 1.5 N/25 mm or more .

In some aspects, the adhesive force N ₈₀ (adhesive force after heating) can be, for example, 5 N/25 mm or more, 7 N/25 mm or more, 10 N/25 mm or more, or 13 N/ 25 mm or more, can be 15 N/25 mm or more, or 17 N/25 mm or more. The upper limit of the adhesive force after heating is not particularly limited. From the viewpoint of ease of manufacture or economy of the adhesive sheet, in some aspects, the adhesive force after heating can be, for example, 70 N/25 mm or less, 50 N/25 mm or less, or 40 N /25 mm or less.

Furthermore, the adhesive force after heating of the adhesive sheet disclosed here represents a characteristic of the adhesive sheet, and does not limit the usage of the adhesive sheet. In other words, the state of use of the adhesive sheet disclosed here is not limited to the state where it is heated at 80°C for 5 minutes. For example, it can also be used in a region that is not specifically heated to room temperature (usually 20°C to 30°C, typical It is the state of processing above 23℃～25℃). In this state of use, the adhesive force can also be increased for a long period of time to achieve firm bonding. In addition, the adhesive sheet disclosed herein can be heated at a temperature higher than 50° C. at any time after attachment to promote the increase in adhesive force. The heating temperature in the heat treatment is not particularly limited, and can be set in consideration of workability, economy, and heat resistance of the base material of the adhesive sheet or the adherend. The heating temperature may be less than 150°C, for example, 120°C or less, 100°C or less, 80°C or less, or 70°C or less. In addition, the heating temperature may be set to 55°C or higher, 60°C or higher, or 70°C or higher, for example, 80°C or higher, or 100°C or higher. With a higher heating temperature, it can be processed in a shorter time to increase the adhesion. The heating time is not particularly limited. For example, it may be 1 hour or less, 30 minutes or less, 10 minutes or less, or 5 minutes or less. In addition, the heating time may be, for example, 1 minute or more, 3 minutes or more, 7 minutes or more, or 15 minutes or more. Alternatively, it is also possible to perform a longer heat treatment within the limit of no significant thermal deterioration of the adhesive sheet or the adherend. In addition, the heat treatment may be performed at one time or may be divided into multiple times.

The adhesive sheet disclosed here has a Mw of 7×10 ⁴ or more (preferably 8×10 ⁴ or more, more preferably 10×10 ⁴ or more, for example, more than 10×10 ⁴ ) of polymer B, and the The temperature area (for example, 23℃) shows the initial low adhesiveness and the strong adhesion after the adhesive force rises, and after the adhesive force rises, it is easy to increase the adhesive force in the high temperature area (such as 80°C) relative to the room temperature area The retention rate of the next adhesion force N ₈₀ . In several aspects, the retention rate of the adhesion force N _H [N/25 mm] at 80°C relative to the adhesion force N ₅₀ [N/25 mm], namely N _H /N ₈₀ (hereinafter, also referred to as " The retention rate of heat-resistant adhesive force") is advantageously more than 10%, preferably more than 12%, more preferably more than 15%, may be more than 17%, or more than 20%. From the viewpoint of the heat resistance of the adhesive sheet, the higher the N _H /N _80, the better. Therefore, the upper limit of N _H /N ₈₀ is not particularly limited, and is typically 100% or less.

Here, the adhesive force N _H (hereinafter, also referred to as 80°C adhesive force) is obtained by crimping the SUS plate as the adherend and keeping it at 80°C for 30 minutes, Under this environment (ie, at 80°C), the 180° peel adhesion was measured under the conditions of a peel angle of 180 degrees and a tensile speed of 300 mm/min. As the adherend, a SUS304BA plate was used in the same manner as the measurement of the adhesive force N ₂₃ described above. During the measurement, the adhesive sheet of the object to be measured may be reinforced by attaching an appropriate substrate material (for example, a PET film with a thickness of about 25 μm). N _H adhesion may more specifically be measured according to the method described in Example of the embodiments described below.

In several aspects, for example, N _H adhesive force not less than 3 N / 25 mm, may be less than 3.5 N / 25 mm, can also be less than 4 N / 25 mm. After N _H higher adhesion means to increase adhesion, even in the high temperature region of higher reliability can be maintained engaged. The upper limit of the adhesive force N _H is not particularly limited. From the viewpoint of heat resistance, it can be said that the higher the better, but it is typically 40 N/25 mm or less, from the viewpoint of easy compatibility of the initial low adhesiveness , Can be 30 N/25 mm or less, or 20 N/25 mm or less.

(Adhesive sheet with base material) When the adhesive sheet disclosed here is in the form of an adhesive sheet with a substrate, the thickness of the adhesive sheet can be, for example, 1000 μm or less, 600 μm or less, 350 μm or less, or 250 μm or less . From the viewpoint of miniaturization, weight reduction, and thinning of products using the adhesive sheet, in several aspects, the thickness of the adhesive sheet can be, for example, 200 μm or less, 175 μm or less, or 140 μm or less, It can be 120 μm or less, or 100 μm or less (for example, less than 100 μm). In addition, the thickness of the adhesive sheet can be, for example, 5 μm or more, 10 μm or more, 15 μm or more, 20 μm or more, 25 μm or more, or 30 μm from the viewpoint of handleability. the above. In some aspects, the thickness of the adhesive sheet can be, for example, 50 μm or more, 60 μm or more, 80 μm or more, 100 μm or more, or 120 μm or more. The upper limit of the thickness of the adhesive sheet is not particularly limited. Furthermore, the thickness of the adhesive sheet refers to the thickness of the part attached to the adherend. For example, in the adhesive sheet 1 of the structure shown in FIG. 1, it refers to the thickness from the adhesive surface 21A of the adhesive sheet 1 to the second surface 10B of the substrate 10, excluding the thickness of the release liner 31.

The adhesive sheet disclosed here can, for example, support a state where the thickness Ts of the substrate is greater than the thickness Ta of the adhesive layer, that is, the state where Ts/Ta is greater than 1, and can be implemented well. Ts/Ta may be 1.1 or more, 1.2 or more, 1.5 or more, or 1.7 or more, for example, but it is not particularly limited. For example, in an adhesive sheet that can be used for the purpose of reinforcement, support, and impact mitigation of the adherend, by increasing Ts/Ta, there is a tendency that even if the adhesive sheet is thinned, it is easy to exert a good effect. In some aspects, Ts/Ta can be 2 or more (for example, more than 2), 2.5 or more, or 2.8 or more. In addition, Ts/Ta may be 50 or less, or 20 or less, for example. From the viewpoint that even if the adhesive sheet is thinned, it is easy to exhibit a higher adhesive force after heating, for example, Ts/Ta may be 10 or less, 8 or less, or 5 or less.

The adhesive layer is preferably fixed to the supporting substrate. The so-called fixation here refers to the degree of peeling of the interface between the adhesive layer and the supporting substrate when the adhesive sheet is peeled from the adherend in the adhesive sheet whose adhesive force increases after being attached to the adherend. The adhesive layer shows sufficient gripping properties for the supporting substrate. By fixing the adhesive layer to the substrate-attached adhesive sheet of the supporting substrate, the adherend and the supporting substrate can be firmly integrated. As a preferred example of an adhesive sheet in which the adhesive layer is fixed to the substrate, an adhesive sheet in which the adhesive layer and the supporting substrate do not peel off (gripping failure) during the measurement of the adhesive force after heating is mentioned. Adhesive sheets with an adhesive force of 15 N/25 mm or more after heating, and no gripping damage occurs when measuring the adhesive force after heating, are a preferred example of an adhesive sheet with an adhesive layer fixed on the substrate .

The adhesive sheet disclosed herein can be manufactured well, for example, by a method including the following steps in sequence: contacting the liquid adhesive composition with the first surface of the substrate; and applying the adhesive combination on the first surface The material hardens to form an adhesive layer. The curing of the adhesive composition may be accompanied by one or more of drying, crosslinking, polymerization, and cooling of the adhesive composition. According to the method of hardening the liquid adhesive composition on the first side of the substrate to form an adhesive layer, and bonding the hardened adhesive layer to the first side of the substrate to form an adhesive layer Compared with the method of arranging the adhesive layer on one side, the adhesive layer can improve the grip of the substrate. Taking advantage of this situation, an adhesive sheet in which the adhesive layer is fixed to the base material can be manufactured well.

In some aspects, as a method of bringing the liquid adhesive composition into contact with the first surface of the substrate, a method of directly coating the above-mentioned adhesive composition on the first surface of the substrate can be used. By making the first surface (adhesive surface) of the adhesive layer hardened on the first surface of the substrate abut against the peeling surface, the second surface of the adhesive layer can be fixed to the first surface of the substrate and The first surface of the adhesive layer abuts against the adhesive sheet formed by the peeling surface. As the above-mentioned release surface, the surface of the release liner or the back surface of the substrate after release treatment can be used.

In addition, for example, in the case of a light-curing adhesive composition using a part of the polymer (polymer slurry) of the monomer raw material, for example, the adhesive composition may be applied to the peeling surface and then applied to the adhesive composition. The adhesive composition covers the first surface of the substrate, thereby bringing the first surface of the substrate into contact with the uncured adhesive composition. In this state, it is sandwiched between the first surface and the peeling surface of the substrate The adhesive composition in between is irradiated with light to harden, thereby forming an adhesive layer.

Furthermore, the method illustrated above does not limit the manufacturing method of the adhesive sheet disclosed here. In the manufacture of the adhesive sheet disclosed herein, an appropriate method capable of fixing the adhesive layer to the first surface of the substrate can be used alone or in combination of two or more. Examples of this method include: the method of hardening the liquid adhesive composition on the first surface of the substrate to form an adhesive layer as described above, or the method of improving the adhesive layer on the first surface of the substrate Surface treatment methods for gripping properties, etc. For example, when a primer layer can be provided on the first surface of the substrate to sufficiently improve the grip of the adhesive layer to the substrate, the hardened adhesive layer can also be attached to The first side of the substrate is used to manufacture the adhesive sheet. In addition, by selecting the material of the substrate or the composition of the adhesive, the gripping property of the adhesive layer to the substrate can also be improved. In addition, by applying a temperature higher than room temperature to the adhesive sheet with the adhesive layer on the first surface of the substrate, the gripping property of the adhesive layer to the substrate can be improved. The temperature for improving the gripping property may be, for example, about 35°C to 80°C, about 40°C to 70°C or higher, or about 45°C to 60°C.

The adhesive sheet disclosed here is an adhesive sheet having a first adhesive layer provided on the first side of the substrate and a second adhesive layer provided on the second side of the substrate (ie, double-sided adhesive In the case of the form of the adhesive sheet attached to the substrate, the first adhesive layer and the second adhesive layer may have the same composition or different compositions. When the composition of the first adhesive layer and the second adhesive layer are different, the difference may be, for example, a difference in composition or a difference in structure (thickness, surface roughness, formation range, formation pattern, etc.). For example, the second adhesive layer may also be an adhesive layer without polymer B. In addition, regarding the surface of the second adhesive layer (second adhesive surface), N ₈₀ /N ₅₀ may be less than 3, may be less than 2, may be less than 1.5, or less than 1.

＜Adhesive sheet with release liner＞ The adhesive sheet disclosed here can adopt the form of an adhesive product in which the surface (adhesive surface) of the adhesive layer abuts against the release surface of the release liner. Therefore, according to this specification, an adhesive sheet (adhesive product) with a release liner including any one of the adhesive sheets disclosed herein, and a release liner having a release liner that abuts on the adhesive surface of the adhesive sheet can be provided.

The thickness of the release liner is not particularly limited, but it is usually about 5 μm to 200 μm. If the thickness of the release liner is within the above-mentioned range, the workability for attaching the adhesive layer and the peeling workability for the self-adhesive layer are excellent, which is preferable. In some aspects, the thickness of the release liner can be, for example, 10 μm or more, 20 μm or more, 30 μm or more, or 40 μm or more. In addition, the thickness of the release liner may be, for example, 100 μm or less, or 80 μm or less from the viewpoint of facilitating the release of the self-adhesive layer. If necessary, a known antistatic treatment such as a coating type, a kneading type, and a vapor deposition type may be applied to the release liner.

The release liner is not particularly limited. For example, it can be used for a release liner having a release layer on the surface of a liner substrate such as a resin film or paper (may be paper laminated with resin such as polyethylene), or it can be used such as Fluorine-based polymer (polytetrafluoroethylene, etc.) or polyolefin-based resin (polyethylene, polypropylene, etc.) resin film release liner formed by low adhesive materials. In terms of excellent surface smoothness, a release liner having a release layer on the surface of a resin film as a liner base material, or a release liner including a resin film formed of a low adhesive material can be suitably used. The resin film is not particularly limited as long as it can protect the adhesive layer. Examples include polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, Polyvinyl chloride film, vinyl chloride copolymer film, polyester film (PET film, PBT film, etc.), polyurethane film, ethylene-vinyl acetate copolymer film, etc. For the formation of the above-mentioned release layer, for example, 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, and dioxide Well-known peeling treatment agents such as silicon powder. It is particularly preferable to use a silicone-based release treatment agent.

The thickness of the peeling layer is not particularly limited, but it is usually about 0.01 μm to 1 μm, preferably about 0.1 μm to 1 μm. The method of forming the release layer is not particularly limited, and a known method corresponding to the type of release treatment agent used, etc. can be appropriately adopted.

<Use> The adhesive sheet provided by this specification, for example, after being attached to the adherend, in a temperature range from room temperature to about 50°C (for example, 20°C to 50°C), the adhesive force can be suppressed to be low in a short period of time, during which time it can exert Good secondary processability can help suppress the reduction in yield or improve the quality of products containing the adhesive sheet. Moreover, the above-mentioned adhesive sheet can greatly increase the adhesive force by curing (heating to a temperature higher than 50° C., elapsed time, a combination of these, etc.). For example, by heating at a desired time, the adhesive sheet can be firmly adhered to the adherend. Utilizing this feature, the adhesive sheet disclosed herein can be used in various fields for the purposes of fixing, joining, forming, decorating, protecting, reinforcing, supporting, and impact mitigation of components included in various products.

The adhesive sheet disclosed here can be in the form of an adhesive sheet with a substrate with an adhesive layer provided on at least the first surface of a film-like substrate having a first surface and a second surface, and is well used for attaching to the substrate. The adhesive body is a reinforcing film that reinforces the adherend. In this reinforcing film, as the above-mentioned film base material, those containing a resin film as a base film can be suitably used. In addition, from the viewpoint of enhancing the reinforcement performance, the adhesive layer is preferably fixed to the first surface of the film-like substrate. For example, with regard to optical components used in optical products, or electronic components used in electronic products, high integration, miniaturization, light weight, and thinning continue to develop. It is possible to laminate multiple thinner optical components with different linear expansion coefficients or thicknesses. /Electronic components. By attaching the above-mentioned reinforcing film to such a member, it is possible to impart appropriate rigidity to the above-mentioned optical member/electronic member. Thereby, in the manufacturing process and/or the product after manufacturing, curling or bending caused by the stress that may be generated between the plurality of members with different linear expansion coefficients or different thicknesses can be suppressed. In addition, in the optical product/electronic product manufacturing process, when the thin optical component/electronic component is subjected to shape processing such as cutting processing as described above, the processing is performed by attaching a reinforcing film to the component , It can alleviate the local stress concentration of optical components/electronic components accompanying processing, and can reduce the risk of cracks, cracks, and peeling of laminated components. The operation of attaching the reinforcing member to the optical member/electronic member can also help to relieve the local stress concentration during the transportation, stacking, and rotation of the member, or the bending or bending of the member due to its own weight Restrain etc. Furthermore, devices such as optical products or electronic products containing the above-mentioned reinforcing film are used by consumers in the market, even when the device is dropped, placed under a heavy object, or hit by flying objects, etc. When unexpected stress is applied, the device can also be made to include a reinforcing film to alleviate the stress applied to the device. Therefore, the durability of the device can be improved by including the reinforcing film.

In addition, the adhesive sheet disclosed here can be used well, for example, in a state of being attached to a member constituting various portable devices (portable devices). The so-called "carrying" here does not only mean being able to carry, but refers to the portability to the extent that an individual (standard adult) can carry it relatively easily. Also, examples of so-called portable devices here may include: mobile phones, smart phones, tablet personal computers, notebook personal computers, various portable devices, digital cameras, digital camcorders, audio equipment (portable music players) , Voice recorder, etc.), calculators (calculators, etc.), portable game devices, electronic dictionaries, electronic notebooks, e-books, in-vehicle information equipment, portable radios, portable TVs, portable printers, portable Portable electronic devices such as scanners and portable modems, in addition to mechanical watches or pocket watches, flashlights, magnifying glasses, etc. Examples of components constituting the aforementioned portable electronic device may include optical films or display panels used in image display devices such as liquid crystal displays and other thin-layer displays or film-type displays. The adhesive sheet disclosed here can also be used well in the form of being attached to various components in automobiles and household appliances.

The matters disclosed in this manual include the following. (1) An adhesive sheet comprising an adhesive layer, and the adhesive layer contains polymer A as a polymer of monomer raw material A and polymer B as a polymer of monomer raw material B. The body material B includes a monomer having a polyorganosiloxane skeleton and a (meth)acrylic monomer. The weight average molecular weight of the polymer B is 7×10 ⁴ or more. The adhesive sheet is attached to a stainless steel plate and The relationship between the adhesive force N ₅₀ measured at 23 °C after keeping at 50 °C for 30 minutes and the adhesive force N ₈₀ measured at 23 °C after being attached to a stainless steel plate and heated at 80 °C for 5 minutes satisfies the following formula: (N ₈₀ /N ₅₀ )≧3. (2) the above (1) described in the adhesive sheet, and further wherein the adhesion of the above ₅₀ N and bonded to a stainless steel plate and allowed to stand at 23 deg.] C, measured after 30 minutes of adhesion at ₂₃ N satisfies 23 deg.] C The following formula: (N ₅₀ /N ₂₃ )<10. (3) The adhesive sheet as described in (1) or (2) above, wherein the above-mentioned adhesive force N _{80 is the} same as the adhesive force measured at 80 ℃ after being attached to a stainless steel plate and kept at 80 ℃ for 30 minutes The relationship of N _H satisfies the following formula: (N _H /N ₈₀ )≧15%. (4) The adhesive sheet as described in any one of (1) to (3) above, which further satisfies the following formula: (N ₈₀ /N ₂₃ )≧15. (5) The adhesive sheet described in any one of (1) to (4) above, wherein the adhesive force N ₂₃ is 2 N/25 mm or less. (6) The adhesive sheet described in any one of (1) to (5) above, wherein the adhesive force N ₅₀ is 8 N/25 mm or less. (7) The adhesive sheet described in any one of (1) to (6) above, wherein the adhesive force N ₈₀ is 15 N/25 mm or more. (8) The adhesive sheet described in any one of (1) to (7) above, wherein the adhesive force NH is 3 N/25 mm or more.

(9) The adhesive sheet as described in any one of (1) to (8) above, wherein the functional group equivalent of the monomer having a polyorganosiloxane skeleton is 700 g/mol or more and less than 15000 g/mol mol. (10) The adhesive sheet as described in any one of (1) to (9) above, wherein the content of the monomer having a polyorganosiloxane skeleton in the monomer raw material B is 10% by weight or more and 60% by weight %the following. (11) The adhesive sheet according to any one of (1) to (10) above, wherein the (meth)acrylic monomer contained in the monomer raw material B includes a homopolymer glass transition temperature of Monomer M2 above 50℃. (12) The adhesive sheet as described in (11) above, wherein the monomer M2 includes one selected from the group consisting of alkyl (meth)acrylates and (meth)acrylates having alicyclic hydrocarbon groups Or two or more monomers. (13) The adhesive sheet as described in (11) above, wherein the monomer M2 contains one or two or more alkyl (meth)acrylates. (14) The adhesive sheet according to any one of (11) to (13) above, wherein the content of the monomer M2 in the monomer raw material B is 5% by weight or more and 80% by weight or less. (15) The adhesive sheet as described in any one of (1) to (14) above, wherein the (meth)acrylic monomer contained in the monomer raw material B includes a homopolymer glass transition temperature of Monomer M3 above -20℃ and below 50℃. (16) The adhesive sheet described in (14) above, wherein the content of the monomer M3 in the monomer raw material B is 5% by weight or more and 70% by weight or less. (17) The adhesive sheet described in any one of (1) to (16) above, wherein the weight average molecular weight of the polymer B is 8×10 ⁴ or more and less than 40×10 ⁴ . (18) The adhesive sheet according to any one of (1) to (17) above, wherein the content of the polymer B in the adhesive layer is 0.5 parts by weight or more relative to 100 parts by weight of the polymer A. Parts by weight or less.

(19) The adhesive sheet according to any one of (1) to (18) above, wherein the weight average molecular weight of the polymer A is 40×10 ⁴ or more. (20) The adhesive sheet described in any one of (1) to (19) above, wherein the polymer A is an acrylic polymer. (21) The adhesive sheet according to any one of (1) to (20) above, wherein the monomer raw material A includes a monomer having a ring containing a nitrogen atom. (22) The adhesive sheet as described in (21) above, wherein the monomer having a ring containing a nitrogen atom is N-vinyl cyclic amide. (23) The adhesive sheet as described in (20) above, wherein the monomer raw material A includes a hydroxyl-containing monomer. (24) The adhesive sheet as described in (20) above, wherein the monomer raw material A includes N-vinyl cyclic amide and a hydroxyl-containing monomer. (25) The adhesive sheet according to any one of (1) to (24) above, wherein the adhesive layer contains more than 0 parts by weight and less than 10 parts by weight relative to 100 parts by weight of the polymer A. Joint agent. (26) The pressure-sensitive adhesive sheet described in (25) above, wherein the crosslinking agent includes an isocyanate-based crosslinking agent.

(27) The adhesive sheet described in any one of (1) to (26) above, wherein the thickness of the adhesive layer is 3 μm or more and 100 μm or less. (28) The adhesive sheet as described in any one of (1) to (27) above, which has a supporting substrate having a first side and a second side, and the adhesive is laminated on at least the supporting substrate The first side above. (29) An adhesive sheet with a release liner, comprising: the adhesive sheet described in any one of (1) to (28) above, and A release liner with a releasable surface contacting the adhesive surface of the above-mentioned adhesive sheet. (30) The adhesive sheet with a release liner as described in (29) above, wherein the release surface is the surface of a release layer formed with a silicone-based release treatment agent. Example

Hereinafter, several embodiments of the present invention will be described, but it is not intended to limit the present invention to those shown in this specific example. Furthermore, the "parts" and "%" in the following descriptions are based on weight unless otherwise specified.

(Preparation of polymer A1) Add 60 parts of 2-ethylhexyl acrylate (2EHA), 15 parts of N-vinyl-2-pyrrolidone (NVP), and a reaction vessel equipped with a stirring blade, a thermometer, a nitrogen introduction tube, and a cooler. 10 parts of methyl acrylate (MMA), 15 parts of 2-hydroxyethyl acrylate (HEA), and 200 parts of ethyl acetate as a polymerization solvent. After stirring for 2 hours at 60°C in a nitrogen atmosphere, they were put into thermal polymerization 0.2 parts of 2,2'-azobisisobutyronitrile (AIBN) as the initiator was reacted at 60°C for 6 hours to obtain a solution of polymer A1. The Mw of the polymer A1 is 1.1 million.

(Preparation of polymer B1) Put 40 parts of MMA, 20 parts of n-butyl methacrylate (BMA), and 2-ethylhexyl methacrylate into a reaction vessel equipped with a stirring blade, a thermometer, a nitrogen introduction tube and a cooler. 20 parts of ester (2EHMA), 8.7 parts of methacrylate monomer containing polyorganosiloxane skeleton with functional group equivalent of 900 g/mol (trade name: X-22-174ASX, manufactured by Shin-Etsu Chemical Co., Ltd.) , Functional group equivalent of 4600 g/mol containing polyorganosiloxane skeleton methacrylate monomer (trade name: KF-2012, Shin-Etsu Chemical Co., Ltd.) 11.3 parts, 100 parts of ethyl acetate, and 0.5 part of thioglycerin as a chain transfer agent, after stirring for 1 hour at 70°C in a nitrogen atmosphere, add 0.2 part of AIBN as a thermal polymerization initiator, and after reacting at 70°C for 2 hours, add it as the thermal polymerization starter 0.1 parts by weight of AIBN, and then react at 80°C for 5 hours. Thus, a solution of polymer B1 was obtained. The Mw of the polymer B1 was 2.2×10 ⁴ .

(Preparation of polymer B2) Except for changing the usage amount of thioglycerin to 0.1 part, a solution of polymer B2 with Mw of 7.5×10 ⁴ was obtained in the same manner as the preparation of polymer B1.

(Preparation of polymer B3) Except not using thioglycerin, a solution of polymer B3 with Mw of 16.5×10 ⁴ was obtained in the same manner as the preparation of polymer B1.

(Preparation of polymer B4) Put 40 parts of MMA, 20 parts of BMA, 20 parts of 2EHMA, functional group equivalent of 900 g/mol into a reaction vessel equipped with stirring blades, thermometer, nitrogen introduction tube and cooler. Methacrylate monomer with alkane skeleton (trade name: X-22-174ASX, manufactured by Shin-Etsu Chemical Industry Co., Ltd.) 8.7 parts, functional group equivalent of 4600 g/mol containing polyorganosiloxane skeleton methacrylic acid Ester monomer (trade name: KF-2012, manufactured by Shin-Etsu Chemical Industry Co., Ltd.) 11.3 parts and ethyl acetate 82 parts, after stirring for 1 hour at 65°C in a nitrogen atmosphere, add 0.2 part of AIBN and hold at 65°C After reacting for 4 hours, 0.1 part by weight of AIBN was added, and the reaction was continued at 80°C for 4 hours. Thus, a solution of polymer B4 with Mw of 23.4×10 ⁴ was obtained.

(Preparation of polymer B5) Except for changing the usage amount of ethyl acetate to 67 parts, a solution of polymer B5 with Mw of 29.6×10 ⁴ was obtained in the same manner as the preparation of polymer B4.

In addition, the weight average molecular weight of each polymer mentioned above was measured under the following conditions using a GPC device (Tosoh Corporation make, HLC-8220GPC), and it calculated|required by polystyrene conversion. [GPC conditions] ・Sample concentration: 0.2 wt% (tetrahydrofuran (THF) solution) ・Sample injection volume: 10 μl ・Eluent: THF, flow rate: 0.6 ml/min ・Measurement temperature: 40°C ・Pipe string: Sample column: TSKguardcolumn SuperHZ-H (1) + TSKgel SuperHZM-H (2) Reference column: TSKgel SuperH-RC (1 piece) ・Detector: Differential Refractometer (RI)

＜Making of Adhesive Sheet＞ (example 1) In the polymer A1 solution, relative to 100 parts of the polymer A1 contained in the solution, add 5 parts of polymer B1 and 2.5 parts of isocyanate crosslinking agent (trade name: Takenate D110N, trimethylolpropane benzene Dimethyl diisocyanate (manufactured by Mitsui Chemicals Co., Ltd.) was uniformly mixed to prepare an adhesive composition C1. Coat the adhesive composition C1 directly on the first side of a 75 μm-thick polyethylene terephthalate (PET) film (manufactured by Toray, trade name "Lumirror") as a supporting substrate at 110°C Heat for 2 minutes to dry, thereby forming an adhesive layer with a thickness of 25 μm. Affix the release surface of the release liner to the surface (adhesive surface) of the adhesive layer. As a release liner, MRQ25T100 manufactured by Mitsubishi Chemical Corporation (a release liner with a release layer formed by a silicone release treatment agent on one side of a polyester film, thickness 25 μm) was used. In this way, the adhesive sheet of Example 1 was obtained in the form of an adhesive sheet with a release liner whose adhesive surface abuts against the release surface of the release liner.

(Example 2～Example 8) The type and usage amount of the polymer B were changed as shown in Table 1, except that the adhesive compositions C2 to C8 were prepared in the same manner as the preparation of the adhesive composition C1. The adhesive compositions C2～C11 were used respectively, except for this, in the same way as the production of the adhesive sheet of Example 1, the adhesive sheet of Examples 2 to 8 was peeled off with the release liner on the adhesive surface The surface of the adhesive sheet with release liner is obtained.

<Measurement of adhesive force (23°C)> Cut the adhesive sheets of each example together with the release liner into a width of 25 mm, use them as test pieces, and use toluene-cleaned SUS board (SUS304BA board) as the adherend , Determine the adhesion force N ₂₃ , adhesion force N ₅₀ and adhesion force N ₈₀ according to the following procedures. (Measurement of adhesive force N ₂₃ ) Under a standard environment of 23°C and 50%RH, peel off the release liner covering the adhesive surface of each test piece, and press a 2 kg roller back and forth to press the exposed adhesive surface In the adherend. After placing the test piece crimped on the adherend in the above standard environment for 30 minutes, use a universal tensile and compression testing machine (device name "tensile and compression testing machine, TCM-1kNB" manufactured by Minebea), based on JIS Z0237 , Measure the 180° peel adhesion (relative to the above-mentioned tensile resistance) under the conditions of a peeling angle of 180 degrees and a tensile speed of 300 mm/min. The measurement was performed 3 times, and the average value of the measurement was shown in Table 1 as the adhesive force N ₂₃ [N/25 mm]. (Measurement of Adhesive Force N ₅₀ ) The test piece crimped to the adherend by the same method as the above-mentioned measurement of Adhesive Force N ₂₃ is kept at 50°C for 30 minutes, and then placed in the above standard environment for 30 minutes After that, the 180° peel adhesion was measured in the same manner. The measurement was performed 3 times, and the average value of the measurement was shown in Table 1 as the adhesive force N ₅₀ [N/25 mm]. (Measurement of adhesive force N ₈₀ ) The test piece crimped to the adherend by the same method as the above-mentioned measurement of adhesive force N ₂₃ is heated at 80°C for 5 minutes, and then placed in the above-mentioned standard environment for 30 minutes, then Measure the 180° peel adhesion in the same way. The measurement was performed 3 times, and the average value of the measurement was shown in Table 1 as the adhesive force N ₈₀ [N/25 mm]. In addition, it was confirmed that none of the adhesive sheets of Examples 1 to 11 had a gripping failure during the measurement of the adhesive force N ₈₀ .

<Measurement of the adhesion force N _H at 80°C> After the test piece crimped to the adherend by the same method as the measurement of the adhesion force N ₂₃ above, it is kept at 80°C for 30 minutes. The 180° peel adhesion was measured in the same manner as described above. The measurement was performed 3 times, and the average value of the measurement was shown in Table 1 as the 80°C adhesive force N _H [N/25 mm]. Based on these adhesive force measurement results, the adhesive force increase ratios N ₈₀ /N ₅₀ and N ₅₀ /N ₂₃ and the heat-resistant adhesive force maintenance rate N _H /N ₈₀ were calculated. The results are shown in Table 1.

[Table 1] Table 1 example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Polymer B species B3 B4 B5 B2 B1 Mw(×10 ⁴ ) 16.5 23.4 29.6 7.5 2.2 Quantity ¹⁾ [Parts by weight] 5 7.5 7.5 7.5 5 7.5 5 7.5 Adhesion (23℃) [N/25 mm] N ₂₃ 0.8 1.0 0.9 0.6 1.0 0.8 0.7 0.5 N ₅₀ 3.8 2.8 3.8 3.0 8.0 7.0 12.0 7.8 N ₈₀ 23.0 20.8 23.8 23.4 24.5 22.2 22.2 19.8 Adhesion rise ratio N ₈₀ /N ₅₀ 6.1 7.4 6.3 7.8 3.1 3.2 1.8 2.5 N ₅₀ /N ₂₃ 4.8 2.8 4.2 5.0 8.0 8.8 17.1 15.5 Adhesion at 80℃ [N/25 mm] N _H 4.5 5.0 4.0 6.0 3.0 3.0 2.2 2.8 Heat-resistant adhesion maintenance rate (%) N _H /N ₈₀ 20% twenty four% 17% 26% 12% 14% 10% 14% 1) The usage amount of polymer B relative to 100 parts by weight of polymer A

As shown in Table 1, it was confirmed that Examples 1 to 6 using polymer B with a Mw of 7×10 ⁴ or more have an N ₈₀ /N ₅₀ of 3 or more, so even if a temperature of about 50°C is applied at the initial stage of attachment, the temperature remains appropriate. Low adhesiveness in secondary processing, and the adhesive force can be greatly increased by heating at 80°C for 5 minutes. The adhesive sheets of Examples 1 to 4 can obtain particularly good results.

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: Adhesive sheet 2: Adhesive sheet 3: Adhesive sheet 10: Support substrate 10A: First side 10B: Second side 21: Adhesive layer (first adhesive layer) 21A: Adhesive surface (first adhesive surface) 21B: Adhesive surface (second adhesive surface) 22: Adhesive layer (second adhesive layer) 22A: Adhesive surface (second adhesive surface) 31: Release the liner 32: Release the liner 100: Adhesive sheet with release liner (adhesive product) 200: Adhesive sheet with release liner (adhesive product) 300: Adhesive sheet with release liner (adhesive product)

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 of another embodiment. Fig. 3 is a cross-sectional view schematically showing the structure of an adhesive sheet of another embodiment.

1: Adhesive sheet

10: Support substrate

10A: First side

10B: Second side

21: Adhesive layer (first adhesive layer)

21A: Adhesive surface (first adhesive surface)

31: Release the liner

100: Adhesive sheet with release liner (adhesive product)

Claims (10)

An adhesive sheet comprising an adhesive layer, and the adhesive layer contains polymer A as a polymer of monomer raw material A and polymer B as a polymer of monomer raw material B. The monomer raw material B Contains a monomer having a polyorganosiloxane skeleton and a (meth)acrylic monomer. The weight average molecular weight of the polymer B is 7×10 ⁴ or more. The adhesive sheet is attached to a stainless steel plate at 50°C The relationship between the adhesive force N ₅₀ measured at 23°C after holding for 30 minutes and the adhesive force N ₈₀ measured at 23°C after being attached to a stainless steel plate and heated at 80°C for 5 minutes satisfies the following formula: (N ₈₀ / N ₅₀ )≧3. The requested item of the adhesive sheet 1, and further wherein the adhesion of the above-described N ₅₀ and bonded to a stainless steel plate and on the relationship of the adhesive force as measured at N ₂₃ 23 ℃ 30 minutes was allowed to stand at 23 ℃ satisfies the following formula: (N ₅₀ /N ₂₃ )<10. Such as the adhesive sheet of claim 1 or 2, wherein the relationship between the above-mentioned adhesive force N ₈₀ and the adhesive force N _H measured at 80 ℃ after being attached to a stainless steel plate and kept at 80 ℃ for 30 minutes satisfies the following formula: (N _H /N ₈₀ )≧15%. The adhesive sheet according to any one of claims 1 to 3, wherein the (meth)acrylic monomer contained in the monomer raw material B includes a monomer M2 whose homopolymer has a glass transition temperature of 50°C or higher. The adhesive sheet of claim 4, wherein the above-mentioned monomer M2 contains alkyl (meth)acrylate. The adhesive sheet according to any one of claims 1 to 5, wherein the content of the polymer B in the adhesive layer is 0.5 parts by weight to 50 parts by weight relative to 100 parts by weight of the polymer A. The adhesive sheet according to any one of claims 1 to 6, wherein the above-mentioned polymer A is an acrylic polymer. The adhesive sheet of any one of claims 1 to 7, wherein the monomer raw material A includes a monomer having a ring containing a nitrogen atom. The adhesive sheet according to any one of claims 1 to 8, wherein the adhesive layer contains a crosslinking agent of more than 0 parts by weight and 10 parts by weight relative to 100 parts by weight of the polymer A. An adhesive sheet according to any one of claims 1 to 9, which has a supporting substrate having a first surface and a second surface, and the adhesive is laminated on at least the first surface of the supporting substrate.

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