TW201923006A - Adhesive sheet capable of maintaining the re-workability and further increasing the adhesive force subsequently - Google Patents

Abstract

The present invention provides an adhesive sheet, which is capable of maintaining the re-workability and further increasing the adhesive force subsequently even when a temperature of about 50 DEG C is applied at an initial stage of being attached to an adhered object. The present invention provides an adhesive sheet including an adhesive layer. The adhesive layer includes a polymer A and a polymer B serving as a copolymer of a monomer having a polyorganosiloxane skeleton and a (meth)acrylic monomer. The glass transition temperature Tml of the composition of the polymer B based on the composition of the (meth)acrylic monomer is 50 DEG C or more and 100 DEG C or less. The adhesive force N80 of the adhesive sheet, heated at 80 DEG C for 5 minutes after attachment, is 5 times or more than the adhesive force N50 of the adhesive sheet, laid aside at 50 DEG C for 30 minutes after attachment.

Description

Adhesive sheet

The present invention relates to an adhesive sheet. The present application claims priority to Japanese Patent Application No. 2017-222778, filed on Nov. 20, 2011, the entire content of which is hereby incorporated by reference.

The adhesive sheet is used for the purpose of adhering to the adherends, fixing the articles to the adherends, reinforcing the adherends, and the like by firmly adhering to the adherends. Previously, for this purpose, an adhesive sheet having a high adhesion from the initial stage of attachment was used. Further, as disclosed in Patent Documents 1 to 3, there has been proposed an adhesive sheet which can exhibit a low adhesive force at the initial stage of adhering to the adherend and then greatly increase the adhesive force. According to the adhesive sheet having such a characteristic, it is possible to exhibit a reproducibility (secondary workability) for suppressing a decrease in yield due to mislabeling or sticking of the adhesive sheet before the adhesion is increased, and to adhere thereto. When the force rises, it exerts a strong adhesiveness suitable for the original purpose of use of the adhesive sheet. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Application Laid-Open No. Hei. No. Hei. No. 5,915, 596.

[The problem that the invention wants to solve]

However, depending on the use of the adhesive sheet, after the attachment, after proceeding to the subsequent step, there may be a second occurrence due to the judgment of the mislabeling or sticking, or the positional shift caused by the influence of the subsequent steps. The requirements for processing. In such a case, during the period in which the adhesive sheet attached to the adherend is required to have secondary workability, for example, a device (transporting device, inspection device, various other processing devices, etc.) used in the manufacturing process is used. The effect of the heat generated by the action, the heat generation of the device close to the device, and the rise in the temperature of the manufacturing environment may cause a temperature of about 40 ° C to 50 ° C to be applied to the adhesive sheet. Accordingly, an object of the present invention is to provide an adhesive sheet which can maintain secondary workability even when a temperature of about 50 ° C is applied to the initial stage of the adherend, and thereafter the adhesive force is greatly increased. [Technical means to solve the problem]

According to the present specification, an adhesive sheet comprising an adhesive layer is provided. The pressure-sensitive adhesive layer contains a polymer A and a polymer B as a copolymer of a monomer having a polyorganosiloxane chain and a (meth)acrylic monomer. The glass transition temperature T _m1 of the polymer B based on the composition of the (meth)acrylic monomer is 50° C. or higher and 100° C. or lower. After the adhesive sheet was bonded to a stainless steel plate and heated at 80 ° C for 5 minutes, the adhesive force N ₈₀ was 5 times or more of the adhesive force N ₅₀ after being adhered to the stainless steel plate and kept at 50 ° C for 30 minutes.

The adhesive sheet of this configuration can have an adhesive force N ₈₀ (hereinafter also referred to as "post-heating adhesive force") with respect to the adhesive force N by containing the polymer B having a glass transition temperature T _m1 of 50 ° C or more and 100 ° C or less. _{50 is} increased by more than 5 times (ie, N ₈₀ /N ₅₀ ≧ 5). Thereby, it is possible to exhibit good secondary workability in a use form in which a temperature of about 50 ° C may be applied in the initial stage of attachment, and the adhesion is greatly increased by heating or the like thereafter.

With respect to a plurality of kinds of adhesive sheets, the adhesive force N ₅₀ and the adhesive force N ₂₃ after being placed at 23 ° C for 30 minutes after being attached to a stainless steel sheet satisfy the following formula: (N ₅₀ /N ₂₃ ) <10 . According to such an adhesive sheet, since the difference in adhesion (and thus secondary workability) when the temperature is maintained at room temperature at the initial stage of attachment and the temperature at about 50 ° C is small, workability or It is preferable from the viewpoint of ease of step management.

In some aspects, the glass transition temperature T _{A of the} above polymer A may be, for example, -80 ° C or more and less than 0 ° C. The adhesive sheet disclosed herein can be suitably used using the polymer A having such a glass transition temperature T _A .

In some aspects, the glass transition temperature T _{B of the} above polymer B may be, for example, -10 ° C or more and 10 ° C or less. The adhesive sheet disclosed herein can be suitably used using the polymer B having such a glass transition temperature T _B .

In some embodiments, the copolymerization ratio of the monomer having a glass transition temperature of more than 170 ° C in the above polymer B may be 30% by weight or less. The adhesive sheet disclosed herein can be suitably used using the polymer B of such a copolymer composition.

In some aspects, the above adhesive layer may contain more than 0 parts by weight and 10 parts by weight or less of a crosslinking agent with respect to 100 parts by weight of the above polymer A. By using a crosslinking agent, the adhesion in the initial stage of attachment can be effectively adjusted in a temperature range of about 50 °C. As a result, there is a tendency to easily obtain an adhesive sheet which is excellent in both the secondary workability at the initial stage of attachment and the strong adhesiveness after the adhesion is increased.

In the above-described polymer B, the weight average molecular weight (Mw) of 10,000 or more and 50,000 or less can be favorably used as the polymer B. According to the polymer B having the Mw in the above range, it is easy to obtain an adhesive sheet having a low adhesive strength at the initial stage of attachment and a high adhesive force after heating.

In some aspects, the content of the polymer B in the adhesive layer may be in the range of 0.05 part by weight or more and 20 parts by weight or less based on 100 parts by weight of the polymer A. According to the content of the above range, it is easy to obtain an adhesive sheet having a low adhesive strength at the initial stage of attachment and a high adhesive force after heating.

The adhesive sheet disclosed herein may be provided with a support substrate having a first surface and a second surface, and at least the first surface layer of the support substrate has the adhesive layer, that is, an adhesive sheet attached to the substrate. The form is implemented. Such an adhesive sheet with a substrate can be excellent in workability or workability. As the support substrate, for example, a thickness of 30 μm or more can be favorably used.

Furthermore, the appropriate combination of the above-mentioned elements may be included in the scope of the invention claimed by the Japanese Patent Application.

Hereinafter, preferred embodiments of the present invention will be described. The matters necessary for the implementation of the present invention other than those specifically mentioned in the present specification can be understood based on the instructions for the implementation of the invention and the technical common sense at the time of application. The present invention can be implemented based on the contents disclosed in the present specification and the technical common sense in the field. In the following description, members and portions that perform the same functions are denoted by the same reference numerals, and the description thereof will be omitted or simplified. Further, the embodiments described in the drawings are modeled to clearly illustrate the present invention, and the dimensions or scales of the products actually provided are not necessarily accurately indicated.

In the present specification, the term "acrylic polymer" means a polymer containing a monomer unit derived from a (meth)acrylic monomer in a polymer structure, and typically means more than 50% by weight. The ratio contains a polymer derived from a monomer unit of a (meth)acrylic monomer. Further, the (meth)acrylic monosystem refers to a monomer having at least one (meth)acrylonitrile group in one molecule. Here, "(meth)acryl fluorenyl" means the meaning of an acryl fluorenyl group and a methacryl fluorenyl group. Therefore, the concept of a (meth)acrylic monomer herein may include a monomer having an acrylonitrile group (acrylic monomer) and a monomer having a methacryl group (methacrylic monomer). By. Similarly, in the present specification, "(meth)acrylic acid" means acrylic acid and methacrylic acid, and "(meth)acrylate" means acrylate and methacrylate.

<Example of Structure of Adhesive Sheet> The adhesive sheet disclosed herein is composed of an adhesive layer. The adhesive sheet disclosed herein may be in the form of an adhesive sheet attached to the substrate having the above-mentioned adhesive layer on one or both sides of the support substrate, or a substrate-free adhesive without the support substrate. The form of the sheet. Hereinafter, the support substrate may be simply referred to as "substrate".

The structure of the adhesive sheet of one embodiment is schematically shown in Fig. 1. The adhesive sheet 1 is a single-sided adhesive sheet having a substrate having a sheet-like support substrate 10 having a first surface 10A and a second surface 10B and an adhesive layer 21 provided on the first surface 10A side. Made of wood. The adhesive layer 21 is fixed to the first surface 10A side of the support substrate 10. The adhesive sheet 1 is used by attaching the adhesive layer 21 to the adherend. As shown in Fig. 1, the adhesive sheet 1 before use (i.e., before being attached to the adherend) may be such that the surface (adhesive surface) 21A of the adhesive layer 21 abuts on at least the side opposite to the adhesive layer 21. The constituent elements of the adhesive sheet 100 with the release liner attached to the release liner 31 of the release surface (release surface). As the release liner 31, for example, a release layer formed by a release treatment agent may be provided on one surface of a sheet-form substrate (pad substrate), and the single surface may be a release surface. . Alternatively, the release liner 31 may be omitted, and the support substrate 10 having the second surface 10B as a release surface may be used, and the adhesive sheet 1 may be wound to bring the adhesive surface 21A into contact with the second support substrate 10. The form of the face 10B (reel form). When the adhesive sheet 1 is attached to the adherend, the release liner 31 or the second surface 10B of the support substrate 10 is peeled off from the adhesive surface 21A, and the exposed adhesive surface 21A is pressure-bonded to the adherend.

The structure of the adhesive sheet of another embodiment is schematically shown in Fig. 2 . The adhesive sheet 2 is a support substrate 10 having a sheet shape having a first surface 10A and a second surface 10B, an adhesive layer 21 provided on the first surface 10A side, and a second surface 10B side. The adhesive layer 22 is composed of a double-sided adhesive sheet attached to a substrate. The adhesive layer (first adhesive layer) 21 is fixed to the first surface 10A of the support substrate 10, and the adhesive layer (second adhesive layer) 22 is fixed to 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 portions of the adherend. The portions to which the adhesive layers 21, 22 are attached may be portions of different members, or may be different portions within a single member. As shown in FIG. 2, the adhesive sheet 2 before use can be such that the surface (first adhesive surface) 21A of the adhesive layer 21 and the surface (second adhesive surface) 22A of the adhesive layer 22 abut against at least the adhesive layer. 21 and 22 are the constituent elements of the adhesive sheet 200 with the release liner in the form of the release liners 31 and 32 of the release surface, respectively. As the release liners 31 and 32, for example, a release layer formed of a release treatment agent may be provided on one surface of a sheet-form substrate (pad substrate), and the single surface may be a release surface. Constitute. Alternatively, the release liner 32 may be omitted, and the release liner 31 which is a release surface on both sides may be used, and the second adhesive surface 22A may be abutted against the release liner by being superposed on the adhesive sheet 2 and wound into a spiral shape. The adhesive sheet of the release liner attached to the back surface of the mat 31 (reel form).

The structure of the adhesive sheet of still another embodiment is schematically shown in Fig. 3. The adhesive sheet 3 is configured as a substrate-free double-sided adhesive sheet including the adhesive layer 21. The adhesive sheet 3 is attached to the first adhesive surface 21A including one surface (first surface) of the adhesive layer 21 and the second adhesive surface 21B including the other surface (second surface) of the adhesive layer 21. Used by different parts of the adhesive body. As shown in FIG. 3, the adhesive sheet 3 before use may have the first adhesive surface 21A and the second adhesive surface 21B abutting on the release liner 31 which is a release surface at least on the side opposite to the adhesive layer 21, The constituent elements of the adhesive sheet 300 of the release liner attached to the form of 32. Alternatively, the release liner 32 may be omitted, and the release liner 31 which is a release surface on both sides may be used, and the second adhesive surface 21B may be abutted against the release liner by being superposed on the adhesive sheet 3 and wound into a spiral shape. The adhesive sheet of the release liner attached to the back surface of the mat 31 (reel form).

Furthermore, the concept of an adhesive sheet herein may include an adhesive tape, an adhesive film, an adhesive label, and the like. The adhesive sheet may be in the form of a roll, and may be in the form of a single piece, or may be cut into an appropriate shape according to the use or use, and subjected to die cutting. The adhesive layer in the technique disclosed herein is typically formed continuously, but is not limited thereto. For example, it may be formed into a regular or random pattern such as a dot shape or a strip shape.

<Adhesive Layer> The adhesive sheet disclosed herein has an adhesive layer containing a polymer A, and a copolymer of a monomer having a polyorganosiloxane skeleton and a (meth)acrylic monomer. Polymer B. Such an adhesive layer may be formed from an adhesive composition containing Polymer A or its precursor and Polymer B. The form of the adhesive composition is not particularly limited, and examples thereof include various forms such as a water dispersion type, a solvent type, a hot melt type, and an active energy ray hardening type (for example, a photocuring type).

(Polymer A) As the polymer A, an acrylic polymer, a rubber-based polymer, a polyester-based polymer, a urethane-based polymer, or a polyether-based polymer which is known in the field of an adhesive can be used. The polyoxymethylene-based polymer, the polyamine-based polymer, and the fluorine-based polymer are one or more selected from the group consisting of various polymers exhibiting rubber elasticity at room temperature.

The glass transition temperature T _{A of the} polymer A is not particularly limited, and is selected in such a manner that a preferred property can be obtained in the adhesive sheet disclosed herein. In a number of ways, polymer _A having a T _{A of} less than 0 ° C can be suitably employed. The adhesive containing such a polymer A exhibits moderate fluidity (for example, the mobility of the polymer chain contained in the adhesive), and thus is suitable for achieving both initial low adhesion and strong adhesion after heating. Adhesive sheet. The adhesive sheet disclosed herein can be suitably used using Polymer A having a T _{A of} less than -10 ° C, less than -20 ° C, less than -30 ° C or less than -35 ° C. In several aspects, the T _A may be less than -40 ° C or less than -50 ° C. The lower limit of T _A is not particularly limited. From the viewpoint of facilitating the availability of materials or improving the cohesive force of the adhesive layer, the polymer _A having a T _A of -80 ° C or more, -70 ° C or more, or -65 ° C or more is usually preferably used. From the viewpoint of suppressing the rise of N ₅₀ , in some kinds of aspects, T _A may be, for example, -63 ° C or higher, may be -55 ° C or higher, may be -50 ° C or higher, or may be -45 ° C or higher.

Here, in the present specification, the glass transition temperature (Tg) of the polymer means a nominal value described in a literature or a catalog, or a composition based on the monomer component used in the preparation of the polymer according to the formula of Fox. Find the Tg. The formula of Fox means a relational expression of 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 (unit: K) of the copolymer, and Wi represents the weight fraction of the monomer i in the copolymer (weight-based copolymerization) Ratio), Tgi represents the glass transition temperature (unit: K) of the homopolymer of monomer i. In the case where the polymer of the specific target of Tg is a homopolymer, the Tg of the homopolymer is identical to the Tg of the polymer of the object.

The glass transition temperature of the homopolymer used for the calculation of Tg is determined by using the values described in the publicly known materials. Specifically, the numerical value in "Polymer Handbook" (3rd edition, John Wiley & Sons, Inc., 1989) can be cited. The highest value is used for the monomer having a plurality of values described in the above polymer manual.

The glass transition temperature of the homopolymer of the monomer which is not described in the above-mentioned polymer manual is a value obtained by the following measurement method, except for the monomer having a polyorganosiloxane skeleton. Specifically, 100 parts by weight of a monomer, 0.2 parts by weight of 2,2'-azobisisobutyronitrile, and ethyl acetate as a polymerization solvent are placed in a reactor equipped with a thermometer, a stirrer, a nitrogen gas introduction tube, and a reflux cooling tube. 200 parts by weight, and the mixture was stirred while allowing nitrogen gas to flow for 1 hour. After removing oxygen in the polymerization system in this manner, the temperature was raised to 63 ° C and allowed to react for 10 hours. Then, the mixture was cooled to room temperature to obtain a homopolymer solution having a solid content concentration of 33% by weight. Then, the homopolymer solution was cast-coated on a release liner and dried to prepare a test sample (sheet-like homopolymer) having a thickness of about 2 mm. The test sample was die-cut into a disk shape of 7.9 mm in diameter and sandwiched by a parallel plate, and a shear strain of 1 Hz was applied to the surface using a viscoelasticity tester (manufactured by TA Instruments Japan, model name "ARES"). The viscoelasticity was measured by a shearing mode at a temperature rising rate of -70 ° C to 150 ° C at a temperature of 5 ° C / min, and the temperature corresponding to the peak top temperature of tan δ was defined as the Tg of the homopolymer.

Further, the monomer having a polyorganosiloxane skeleton is obtained by DSC (differential scanning calorimetry) of the monomer, more specifically, according to the method described in the following examples. The value is the glass transition temperature of the monomer having the polyorganosiloxane skeleton, and the formula of Fox is applied.

The weight average molecular weight (Mw) of the polymer A is usually preferably about 5 × 10 ⁴ or more, but is not particularly limited. According to the polymer A of the Mw, an adhesive which exhibits good cohesiveness is easily obtained. In some aspects, the Mw of the polymer A may be, for example, 10 × 10 ⁴ or more, may be 20 × 10 ⁴ or more, or may be 30 × 10 ⁴ or more. Further, the Mw of the polymer A is usually suitably about 500 × 10 ⁴ or less. The polymer A of Mw easily forms an adhesive which exhibits moderate fluidity (mobility of a polymer chain), and therefore is suitable for an adhesive sheet having a low adhesive strength at the initial stage of attachment and a high adhesive force after heating.

Further, in the present specification, the Mw of the polymer A and the polymer B can be determined by polystyrene conversion by gel permeation chromatography (GPC). More specifically, Mw can be measured according to the methods and conditions described in the following examples.

As the polymer A in the adhesive sheet disclosed herein, an acrylic polymer can be preferably used. When an acrylic polymer is used as the polymer A, it is easy to obtain good compatibility with the polymer B. The good compatibility between the polymer A and the polymer B is preferable because it improves the mobility of the polymer B in the adhesive layer to contribute to the reduction of the initial adhesive force and the improvement of the adhesive force after heating.

The acrylic polymer may be, for example, a polymer containing 50% by weight or more of a monomer unit derived from an alkyl (meth) acrylate, that is, 50% by weight of the total amount of the monomer components for preparing the acrylic polymer. More than % is a polymer of an 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 (i.e., C _1-20 ) can be preferably used. In terms of the balance of the characteristics, the ratio of the C _1-20 alkyl (meth)acrylate in the total amount of the monomer components may be, for example, 50% by weight or more, and may be 60% by weight or more, or may be 70% by weight or more. For the same reason, the ratio of the C _1-20 alkyl (meth)acrylate in the total amount of the monomer components 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 total amount of the monomer components may be, for example, 90% by weight or less, may be 85% by weight or less, or may be 80% by weight or less. .

Specific examples of non-limiting examples of the C _1-20 alkyl (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, and propyl (meth)acrylate. Isopropyl acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, second butyl (meth)acrylate, tert-butyl (meth)acrylate, (meth)acrylic acid Amyl ester, isoamyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, (A) Isooctyl acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate Ester, dodecyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, (methyl) Cetyl acrylate, heptadecyl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, pentadecyl (meth) acrylate, (a) Ethyl acrylate or the like.

Among these, it is preferred to use at least a C _1-18 alkyl (meth)acrylate, more preferably at least a 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 a monomer unit. For example, an acrylic polymer containing one or both of n-butyl acrylate (BA) and 2-ethylhexyl acrylate (2EHA) is preferable, and an acrylic polymer containing at least 2EHA is particularly preferable. Examples of other C _1-18 alkyl (meth)acrylate which can be suitably used include methyl acrylate, methyl methacrylate (MMA), n-butyl methacrylate (BMA), and methyl group. 2-ethylhexyl acrylate (2EHMA), isostearyl acrylate (ISTA), and the like.

The monomer unit constituting the acrylic polymer may further contain, as a main component, an alkyl (meth)acrylate and, if necessary, another monomer (copolymerizable monomer) capable of copolymerizing with an 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, or the like) can be preferably used. The monomer having a polar group can contribute to introduction of a crosslinking point to the acrylic polymer or increase cohesion of the acrylic polymer. The copolymerizable monomers may be used singly or in combination of two or more.

Specific examples of non-limiting examples of the copolymerizable monomer include the following. A carboxyl group-containing monomer: for example, acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, methacrylic acid, and the like. An acid anhydride group-containing monomer: for example, maleic anhydride, itaconic anhydride. Hydroxy-containing monomers: for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, (meth)acrylic acid 12 a hydroxyalkyl (meth) acrylate such as hydroxylauryl ester or (4-hydroxymethylcyclohexyl)methyl (meth)acrylate. a monomer having a sulfonic acid group or a phosphoric acid group: for example, styrenesulfonic acid, allylsulfonic acid, sodium vinylsulfonate, 2-(methyl)acrylamido-2-methylpropanesulfonic acid, (methyl And acrylamide propyl sulfonic acid, sulfopropyl (meth) acrylate, (meth) propylene decyl naphthalene sulfonic acid, 2-hydroxyethyl propylene decyl phosphate, and the like. The epoxy group-containing monomer: an epoxy group-containing acrylate such as glycidyl (meth)acrylate or 2-ethyl glycidyl (meth)acrylate, allyl glycidyl ether, (methyl) Glycidyl ether and the like. A cyano group-containing monomer: for example, acrylonitrile, methacrylonitrile or the like. The isocyanate group-containing monomer: for example, 2-isocyanatoethyl (meth)acrylate or the like. Amidino group-containing monomer: 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-di(n-butyl) (meth) acrylamide, N, N- (t-butyl) N,N-dialkyl(meth)acrylamide such as (meth) acrylamide; N-ethyl (meth) acrylamide, N-isopropyl (methyl) N-alkyl (meth) acrylamide such as acrylamide, N-butyl (meth) acrylamide, N-n-butyl (meth) acrylamide; N-vinyl acetamide, etc. - Vinyl carbamides; monomers having a hydroxyl group and a guanamine group, such as N-(2-hydroxyethyl)(meth)acrylamide, N-(2-hydroxypropyl)(methyl)propene Indoleamine, 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 a monomer having an alkoxy group and a guanamine group, such as N-methoxymethyl (meth) acrylamide, N-methoxyethyl (A) N-alkoxyalkyl (meth) acrylamide such as acrylamide or N-butoxymethyl (meth) acrylamide; in addition, N,N-dimethylaminopropyl ( Methyl) acrylamide, N-(methyl) propylene sulfhydryl &#134156; porphyrin and the like. a monomer having a ring containing a nitrogen atom: for example, N-vinyl-2-pyrrolidone, N-methylvinylpyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinyl Pyrimidine, N-vinylpiped &#134116;, N-vinylpyran&#134116;, N-vinylpyrrole, N-vinylimidazole, N-vinylcarbazole, N-(methyl)acrylonitrile -2-pyrrolidone, N-(meth)acrylopylpiperidine, N-(methyl)propenylpyrrolidine, N-vinyl &#134156; porphyrin, N-vinyl-3-&# 134156; ketone, N-vinyl-2-caprolactam, N-vinyl-1,3-㗁&#134116;-2 ketone, N-vinyl-3,5-&#134156; Ketone, N-vinylpyrazole, N-vinylisoxazole, N-vinylthiazole, N-vinylisothiazole, N-vinyl oxime &#134116; etc. (eg N-vinyl-2-hexyl) Indoleamines such as indoleamine). a monomer having a butadiene imine skeleton: for example, N-(methyl)propenyloxymethylenebutaneimine, N-(methyl)propenyl-6-oxyhexamethylenebutene Diimine, N-(meth)acryloyl-8-oxyhexamethylenebutaneimine, and the like. Maleimide: for example, N-cyclohexylmethyleneimine, N-isopropyl maleimide, N-lauryl maleimide, N-benzene A cis-butenylene imine or the like. Ikonium imines: for example, N-methyl Ikonide, N-ethyl Ikonide, N-butyl Ikonide, N-octyl Icinoimine, N- 2-ethylhexylkampwine imine, N-cyclohexylkkonium imine, N-lauryl Ikonide, and the like. Aminoalkyl (meth)acrylates: for example, aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, N,N-di(meth)acrylate Ethylaminoethyl ester, tert-butylaminoethyl (meth)acrylate. Alkoxy-containing monomers: for example, 2-methoxyethyl (meth)acrylate, 3-methoxypropyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, (methyl) ) alkoxyalkyl (meth)acrylate such as propoxyethyl acrylate, butoxyethyl (meth)acrylate, ethoxypropyl (meth)acrylate; methoxy (meth)acrylate (A) alkoxyalkylene glycol (meth)acrylate, such as a glycol glycol ester or a methoxypolypropylene glycol (meth)acrylate. Vinyl esters: for example, vinyl acetate, vinyl propionate, and the like. Vinyl ethers: vinyl vinyl ethers such as methyl vinyl ether or ethyl vinyl ether. An aromatic vinyl compound: for example, styrene, α-methylstyrene, vinyltoluene or the like. Olefins: for example, ethylene, butadiene, isoprene, isobutylene, and the like. (meth) acrylate having an alicyclic hydrocarbon group: for example, cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, (meth) acrylate, &lt;158665; ester, (meth) acrylate Cyclopentyl ester and the like. The (meth) acrylate having an aromatic hydrocarbon group: for example, phenyl (meth) acrylate, phenoxyethyl (meth) acrylate, benzyl (meth) acrylate or the like. Further, a halogen-containing (meth) acrylate such as a heterocyclic-containing (meth) acrylate such as tetrahydrofuran methyl (meth)acrylate, a vinyl chloride or a fluorine atom-containing (meth) acrylate, or a polyoxyl group. (meth) acrylate containing a halogen atom such as (meth) acrylate, (meth) acrylate obtained from a terpene compound derivative alcohol, or the like.

In the case of using such a copolymerizable monomer, the amount thereof to be used is not particularly limited, and it is usually suitably 0.01% by weight or more based on the total amount of the monomer components. The amount of the copolymerizable monomer used may be 0.1% by weight or more based on the total amount of the monomer components, or may be 1% by weight, from the viewpoint of exhibiting the effect of the use of the copolymerizable monomer more satisfactorily. the above. Further, the amount of the copolymerizable monomer used may be 50% by weight or less based on the total amount of the monomer components, and preferably 40% by weight or less. Thereby, the cohesive force of the adhesive can be prevented from becoming too high, and the adhesive feeling at normal temperature (25 ° C) can be improved.

In some aspects, the acrylic polymer preferably contains an N-vinyl cyclic decylamine represented by the following formula (M1) and a hydroxyl group-containing monomer (a monomer having a hydroxyl group and other functional groups) For example, at least one monomer selected from the group consisting of a hydroxyl group and a mercapto group may be used as a monomer unit.

[Chemical 1] Here, R ¹ in the above formula (M1) is a divalent organic group.

By using N-vinyl cyclic guanamine, the cohesive force or polarity of the adhesive can be adjusted to improve the adhesion after heating. Specific examples of the N-vinyl cyclic guanamine include N-vinyl-2-pyrrolidone, N-vinyl-2-piperidone, and N-vinyl-3-&#134156; Ketone, N-vinyl-2-caprolactam, N-vinyl-1,3-indole &lt;RTI ID=0.0&gt;&gt;&gt;&gt; More preferably, it is N-vinyl-2-pyrrolidone and N-vinyl-2-caprolactam.

The amount of use of the N-vinyl cyclic guanamine is not particularly limited, and is usually suitably 0.01% by weight or more based on the total amount of the monomer components for preparing the acrylic polymer (preferably 0.1% by weight or more, for example, 0.5% by weight). %the above). In some cases, the amount of the N-vinyl cyclic guanamine used may be 1% by weight or more based on the total amount of the monomer components, and may be 5% by weight or more, or may be 10% by weight or more. Further, from the viewpoint of improving the adhesiveness at normal temperature (25 ° C) or improving the flexibility at low temperature, the amount of N-vinyl cyclic guanamine used is usually suitably 40% by weight based on the total amount of the above monomer components. Hereinafter, it may be 30% by weight or less, or may be 20% by weight or less.

By using a hydroxyl group-containing monomer, the cohesive force or polarity of the adhesive can be adjusted to improve the adhesion after heating. Further, the hydroxyl group-containing single system provides a reaction point with a crosslinking agent (for example, an isocyanate crosslinking agent), and the cohesive force of the adhesive can be improved by a crosslinking reaction.

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

The amount of the hydroxyl group-containing monomer to be used is not particularly limited, and is usually preferably 0.01% by weight or more (preferably 0.1% by weight or more, for example, 0.5% by weight or more) based on the total amount of the monomer components for preparing the acrylic polymer. In some cases, the amount of the hydroxyl group-containing monomer to be used may be 1% by weight or more based on the total amount of the monomer components, and may be 5% by weight or more, or may be 10% by weight or more. In addition, the amount of the hydroxyl group-containing monomer is usually preferably 40% by weight or less based on the total amount of the monomer components, from the viewpoint of improving the adhesiveness at normal temperature (25° C.) or improving the flexibility at a low temperature. 30% by weight or less may be 20% by weight or less, or may be 10% by weight or less or 5% by weight or less.

In several aspects, as a copolymerizable monomer, N-vinyl cyclic guanamine can be used in combination with a hydroxyl group-containing monomer. In this case, the total amount of the N-vinyl cyclic guanamine and the hydroxyl group-containing monomer can be, for example, 0.1% by weight or more based on the total amount of the monomer components for preparing the acrylic polymer, and can be 1% by weight. The above may be 5% by weight or more, may be 10% by weight or more, may be 15% by weight or more, may be 20% by weight or more, or may be 25% by weight or more. Further, the total amount of the N-vinyl cyclic guanamine and the hydroxyl group-containing monomer can be, for example, 50% by weight or less based on the total amount of the monomer components, and preferably 40% by weight or less.

The method for obtaining the acrylic polymer is not particularly limited, and various polymerization methods known as a method for synthesizing an acrylic polymer can be suitably employed, such as a solution polymerization method, an emulsion polymerization method, a bulk polymerization method, a suspension polymerization method, or a photopolymerization method. . Among several kinds of conditions, solution polymerization can be preferably employed. The polymerization temperature at the time of solution polymerization can be appropriately selected depending on the type of the monomer and solvent to be used, the type of the polymerization initiator, and the like, and can be, for example, about 20 to 170 ° C (typically about 40 to 140 ° C). .

The initiator for the polymerization can be appropriately selected from previously known thermal polymerization initiators or photopolymerization initiators and the like according to the polymerization method. The polymerization initiators may be used alone or in combination of two or more.

Examples of the thermal polymerization initiator include 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-mercaptopropane) dihydrochloride, 2,2'-azobis[2-(5-methyl-2-imidazolin-2-yl)propane] dihydrochloride, 2,2'-couple Nitrogen bis(2-methylpropionamidine) disulfate, 2,2'-azobis(N,N'-dimethyleneisobutylphosphonium) dihydrochloride, etc.; persulfate such as potassium persulfate a salt; a peroxide-based polymerization initiator (for example, benzamidine peroxide, tert-butyl peroxymaleate, laurel, etc.); a redox polymerization initiator; and the like. The amount of the thermal polymerization initiator to be used is not particularly limited. For example, it may be 0.01 parts by weight to 5 parts by weight, preferably 0.05 parts by weight, per 100 parts by weight of the monomer component used for the preparation of the acrylic polymer. An amount within the range of 3 parts by weight.

The photopolymerization initiator is not particularly limited, and for example, a benzoin ether photopolymerization initiator, an acetophenone photopolymerization initiator, an α-keto alcohol photopolymerization initiator, an aromatic sulfonium chloride can be used. Photopolymerization initiator, photoactive oxime photopolymerization initiator, benzoin photopolymerization initiator, benzoin photopolymerization initiator, benzophenone photopolymerization initiator, ketal light Polymerization initiator, 9-oxopurine A photopolymerization initiator, a fluorenylphosphine oxide-based photopolymerization initiator, and the like. The amount of the photopolymerization initiator to be used is not particularly limited. For example, it may be 0.01 parts by weight to 5 parts by weight, preferably 0.05 parts by weight, per 100 parts by weight of the monomer component used for the preparation of the acrylic polymer. An amount within the range of 3 parts by weight.

In some aspects, the acrylic polymer may irradiate ultraviolet light (UV) to a mixture obtained by formulating a polymerization initiator in the monomer component as described above to partially polymerize one of the monomer components (acrylic acid). The form of the polymer slurry) is contained in the adhesive composition for forming the adhesive layer. The adhesive composition containing the acrylic polymer slurry can be applied to a specific coated body, and the polymerization can be completed by irradiating ultraviolet rays. That is, the above acrylic polymer slurry can be understood as a precursor of an acrylic polymer. The adhesive layer disclosed herein can be formed, for example, by using an adhesive composition containing the above acrylic polymer slurry and polymer B.

(Polymer B) The polymer B in the technique disclosed herein is a copolymer of a monomer having a polyorganosiloxane skeleton (hereinafter also referred to as "monomer S1") and a (meth)acrylic monomer. The low polarity and movability of the polymer B by the polyorganosiloxane structure derived from the monomer S1 can be used as an adhesive for inhibiting adhesion to the initial stage of the adherend, and by a temperature higher than 50 ° C. The adhesion-increasing retarder that increases the adhesion to the adherend due to heating or the passage of time functions. The monomer S1 is not particularly limited, and any monomer containing a polyorganosiloxane skeleton can be used. The monomer S1 promotes the polymer B to the surface of the adhesive layer by adhering to the low polarity of the structure and before use (attached to the adherend), and exhibits light peeling at the initial stage of bonding. Sex (low adhesion). As the monomer S1, it can be suitably used for a structure having a polymerizable reactive group at one terminal. The copolymer B having a polyorganosiloxane skeleton in a side chain is formed by copolymerization of such a monomer S1 and a (meth)acrylic monomer. The polymer B of this structure is likely to have a low initial adhesion and a high adhesion after heating due to the mobility of the side chain and the ease of movement.

As the monomer S1, for example, a compound represented by the following formula (1) or (2) can be used. More specifically, examples of the single-end reactive polysiloxane oil manufactured by Shin-Etsu Chemical Co., Ltd. include X-22-174ASX, X-22-2426, X-22-2475, and KF-2012. The monomer S1 may be used alone or in combination of two or more. [Chemical 2] [Chemical 3] Here, in the above formulas (1) and (2), R ³ 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 is, for example, preferably 700 g/mol or more and less than 15,000 g/mol, more preferably 800 g/mol or more and less than 10,000 g/mol, and further preferably 850 g/mol or more. It is 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 less than 700 g/mol, the initial adhesion may not be sufficiently suppressed. When the functional group equivalent of the monomer S1 is 15,000 g/mol or more, the increase in the adhesive strength may be insufficient. When the functional group equivalent of the monomer S1 is within the above range, it is easy to adjust the compatibility (for example, compatibility with the polymer A) or the mobility in the adhesive layer to an appropriate range, and it is easy to achieve a high level. Adhesive sheet with high adhesion and strong adhesion after the initial adhesion.

Here, "functional group equivalent" means the weight of a main skeleton (for example, polydimethylsiloxane) bonded to each functional group. The label unit g/mol is converted into a functional group of 1 mol. The functional group equivalent of the monomer S1 can be calculated, for example, from the spectral intensity of ¹ H-NMR (proton NMR) based on nuclear magnetic resonance (NMR). Based on the functional group equivalent of the sum of spectral intensities monomer S1 ¹ H-NMR of (g / mol) can be calculated from the general structure of the analysis method of the related analytical spectroscopy based on ¹ H-NMR, as necessary of Japanese Patent Publication No. 5951153 describes the get on.

Further, when two or more kinds of monomers having different functional group equivalents are used as the monomer S1, an arithmetic mean value can be used as the functional group equivalent of the monomer S1. In other words, the functional group equivalent of the monomer S1 containing n kinds of monomers having different functional group equivalents (monomer S1 ₁ , monomer S1 ₂ ..., monomer S1 _n ) 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 content of the monomer S1 is preferably 5% by weight or more based on the total monomer component for preparing the polymer B, and is more preferably used as an effect of the adhesion-increasing retardation agent. 10% by weight or more may be 15% by weight or more, and may be 20% by weight or more. In addition, the content of the monomer S1 is preferably 60% by weight or less, and may be 50% by weight or less, based on the polymerization reactivity or compatibility, with respect to all the monomer components for preparing the polymer B. It can be 40% by weight or less, and can be 30% by weight or less. When the content of the monomer S1 is less than 5% by weight, the initial adhesion may not be sufficiently suppressed. When the content of the monomer S1 is more than 60% by weight, the increase in the adhesion may be insufficient.

The monomer component used for the preparation of the polymer B contains a (meth)acrylic monomer copolymerizable with the monomer S1 in addition to the monomer S1. By copolymerizing one or two or more (meth)acrylic monomers with the monomer S1, the mobility of the polymer B in the adhesive layer can be favorably adjusted. Copolymerization of the monomer S1 with the (meth)acrylic monomer can also help to improve the compatibility of the polymer B with the polymer A (for example, an acrylic polymer).

In the polymer B in the technique disclosed herein, the composition of the (meth)acrylic monomer contained in the above monomer component is preferably a glass transition based on the composition of the (meth)acrylic monomer. The temperature T _{m1 is set to} be 50 ° C or more and 100 ° C or less. According to the polymer B having a T _m1 of 50 ° C or more, there is a tendency to suppress an increase in N ₅₀ in the adhesive sheet containing the polymer B. The reason for this is that the polymer B having a T _m1 of 50 ° C or higher is effectively inhibited from room temperature to 50 ° C by the monomer unit derived from the (meth)acrylic monomer contained in the polymer B. The improvement in the mobility or mobility of the polyorganosiloxane structure portion having a temperature rise from the left and right can better maintain the low adhesion due to the presence of the polyorganosiloxane structure. When T _m1 becomes lower than 50 ° C, the effect of suppressing the rise of N ₅₀ is reduced. Further, when T _m1 becomes higher than 100 ° C, the adhesion (N ₈₀ ) tends to decrease after heating. According to the polymer B having a T _m1 of 50 ° C or more and 100 ° C or less, N ₈₀ can be greatly increased with respect to N ₅₀ . Therefore, the polymer B having a composition of T _m1 in the above range is suitable for realizing an adhesive sheet satisfying N ₈₀ /N ₅₀ ≧5.

In some kinds of aspects, the glass transition temperature T _m1 may be, for example, 53 ° C or more, may be 56 ° C or higher, may be 59 ° C or higher, may be 62 ° C or higher, may be 65 ° C or higher, or may be 68 ° C or higher. Or above 70 °C. According to the polymer B having a higher T _m1 , there is a tendency that the effect of suppressing the increase in N ₅₀ becomes larger. Further, from the viewpoint of facilitating an increase in the adhesive force generated by heating to a temperature region higher than 50 ° C, in some kinds of aspects, T _m1 may be, for example, 100 ° C or lower, and may be 90 ° C. Hereinafter, it may be 85 ° C or less, or may be 80 ° C or less or less than 80 ° C.

Here, the glass transition temperature T _m1 based on the composition of the above (meth)acrylic monomer means the composition of only the (meth)acrylic monomer in the monomer component used for the preparation of the polymer B, The Tg obtained by the formula of Fox. T _m1 can be used as the target of only the (meth)acrylic monomer in the monomer component used for the preparation of the polymer B, and the above-mentioned Fox formula is used, and the homopolymer of each (meth)acrylic monomer is used. The glass transition temperature and the weight fraction of each (meth)acrylic monomer which is contained in the total amount of the (meth)acrylic monomer are calculated. The total amount of the monomer S1 and the (meth)acrylic monomer which are used in the preparation of all the monomer components of the polymer B, for example, is easy to exert the effect obtained by appropriately setting the T _m1 . It may be 50% by weight or more, may be 70% by weight or more, may be 85% by weight or more, may be 90% by weight or more, may be 95% by weight or more, or may be substantially 100% by weight.

The glass transition temperature T _{B of the} polymer B is not particularly limited and can be selected in such a manner that preferred characteristics are obtained in the adhesive sheet disclosed herein. The T _{B of the} polymer B may be, for example, less than 50 ° C, may be 30 ° C or less, may be 20 ° C or less, may be 15 ° C or less, or may be 10 ° C or less. When the T _B of the polymer _B is lowered, the mobility of the polymer B is improved, and the adhesion tends to increase easily by heating in a temperature region higher than 50 ° C. Further, in some aspects, the T _{B of the} polymer B may be, for example, -40 ° C or higher, may be -30 ° C or higher, may be -20 ° C or higher, or may be -10 ° C or higher. When the T _{B of the} polymer B becomes high, there is a tendency that N ₅₀ is easily suppressed.

In several aspects of the adhesive sheet disclosed herein, the polymer B preferably has a copolymerization ratio of a monomer having a glass transition temperature of higher than 170 ° C of a homopolymer of 30% by weight or less. Here, in the present specification, the copolymerization ratio of the monomer is not more than X% by weight, and when it is not particularly described, the copolymerization ratio of the monomer is 0% by weight, that is, the monomer is not substantially carried out. The concept of cohesion. Further, substantially no copolymerization means that the above monomers are copolymerized at least unintentionally. If the copolymerization ratio of the monomer having a glass transition temperature of higher than 170 ° C of the homopolymer is higher, the mobility of the polymer B tends to become insufficient, and there may be a heating by a temperature region higher than 50 ° C. The increase in adhesion becomes difficult. By setting the copolymerization ratio of the monomer having a glass transition temperature of the homopolymer of higher than 170 ° C to less than 30% by weight, at least one of an improvement in N ₈₀ and an improvement in N ₅₀ /N ₈₀ can be achieved.

In several aspects, for the preparation of the polymer composition of the monomer component B is made higher than T _m1 T can _B, i.e. T _m1 -T _B becomes greater than 0 ℃ manner of setting. According to such a composition, the effect of adjusting the mobility of the polymer B by the composition of the (meth)acrylic monomer contained in the monomer component can be easily exhibited. T _{m1 -} T _B may be, for example, about 40 ° C to 100 ° C, may be about 50 ° C to 90 ° C, or about 65 ° C to 85 ° C.

From the viewpoint of easily controlling the mobility of the polymer B in the adhesive layer, in some aspects, the composition of the monomer component used to prepare the polymer B is the glass transition temperature T _A of the polymer A. The relationship can be set such that T _{m1 is} higher than T _A by 20° C. or higher, that is, T _m1 −T _{A is} 20° C. or higher. In some _aspects , T _m1 -T _A may be, for example, 50 ° C to 130 ° C, or may be about 60 ° C to 120 ° C or about 70 ° C to 120 ° C.

As the (meth)acrylic monomer which can be used for preparing the monomer component of the polymer B, for example, an alkyl (meth)acrylate can be mentioned. For example, as the alkyl (meth)acrylate which can be used when the polymer A is an acrylic polymer, one or two or more of the above-exemplified monomers can be used as a copolymerization component of the polymer B. In several aspects, the polymer B may contain a C _4-12 alkyl (meth)acrylate (preferably a C _4-10 alkyl (meth)acrylate such as ( ₆ ) alkyl (meth)acrylate. At least one of the ₁₀ alkyl esters is used as a monomer unit. In several other aspects, the polymer B may contain a C _1-18 alkyl methacrylate (preferably a C _1-14 alkyl methacrylate such as a C _1-10 alkyl methacrylate). At least one of them is a monomer unit. The monomer unit constituting the polymer B may contain, for example, one or more selected from the group consisting of MMA, BMA, and 2EHMA.

Other examples of the (meth)acrylic monomer include a (meth) acrylate having an alicyclic hydrocarbon group. For example, cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, (meth)acrylic acid &lt;158665; ester, dicyclopentanyl (meth)acrylate, (meth)acrylic acid 1- Adamantyl ester and the like. In several aspects, the polymer B may contain at least one selected from the group consisting of dicyclopentanyl methacrylate, methacrylic acid &lt;158665; ester and cyclohexyl methacrylate as monomer units.

The (meth)acrylic acid alkyl ester and the above-mentioned (meth) acrylate having an alicyclic hydrocarbon group are used in an amount of, for example, 10% by weight or more and 95% by weight based on the entire monomer component for preparing the polymer B. % or less may be 20% by weight or more and 95% by weight or less, may be 30% by weight or more and 90% by weight or less, may be 40% by weight or more and 90% by weight or less, or may be 50% by weight or more and 85% by weight or less the following. It is possible to use an alkyl (meth)acrylate from the viewpoint of easiness of the adhesion by heating to a temperature higher than 50 ° C. In some embodiments, the (meth) acrylate having an alicyclic hydrocarbon group may be used in an amount less than the total amount of the (meth)acrylic monomer contained in the monomer component used to prepare the polymer B. 50% by weight, may be less than 30% by weight, may be less than 15% by weight, may be less than 10% by weight, or may be less than 5% by weight. It is also possible not to use a (meth) acrylate having an alicyclic hydrocarbon group.

In some aspects, the monomer component used to prepare polymer B preferably contains at least MMA. So MMA copolymerization will be a useful method for regulating T _m1 disclosed in the preferred range for this location. Further, according to the polymer B obtained by copolymerizing MMA, it is easy to obtain an adhesive sheet having a large N ₈₀ /N ₅₀ . The ratio of the MMA to the total amount of the (meth)acrylic monomer contained in the monomer component for preparing the polymer B may be, for example, 5% by weight or more, may be 10% by weight or more, and may be 20 The weight% or more may be 30% by weight or more, and may be 40% by weight or more. In some aspects, the ratio of MMA to the total amount of the above (meth)acrylic monomers may be, for example, more than 50% by weight, may exceed 55% by weight, may exceed 60% by weight, and may exceed 65% by weight. It can also exceed 70% by weight. In addition, the ratio of the MMA to the total amount of the (meth)acrylic monomer may be in the range of T _m1 to 100° C. or less, and is usually preferably 95% by weight or less, and may be 90% by weight or less. It may be 85% by weight or less.

Other examples of the monomer which can be contained together with the monomer S1 in the monomer unit constituting the polymer B include the above-exemplified examples of the monomer which can be used when the polymer A is an acrylic polymer. a monomer containing a carboxyl group, an acid anhydride group-containing monomer, a hydroxyl group-containing monomer, an epoxy group-containing monomer, a cyano group-containing monomer, an isocyanate group-containing monomer, a guanamine-containing monomer, and a ring having a nitrogen atom Monomers, monomers having a butylenediamine skeleton, maleimide, Ikonium imines, aminoalkyl (meth)acrylates, vinyl esters, vinyl ethers, olefins a (meth) acrylate having an aromatic hydrocarbon group, a (meth) acrylate containing a hetero ring, a (meth) acrylate containing a halogen atom, (meth) obtained from a decene compound derivative alcohol Acrylate and the like.

Further examples of the monomer which can be contained together with the monomer S1 in the monomer unit constituting the 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(methyl) An oxyalkylene di(meth)acrylate such as acrylate; a monomer having a polyoxyalkylene group, for example, one end of a polyoxyalkylene chain such as polyethylene glycol or polypropylene glycol (methyl) a polymerizable functional group such as an alkylene group, a vinyl group or an allyl group, and a polymerizable polyoxyalkylene ether having an ether structure (alkyl ether, aryl ether, arylalkyl ether or the like) at the other end; Methyl) methoxyethyl acrylate, ethoxyethyl (meth) acrylate, propoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, ethoxy (meth) acrylate Alkoxyalkyl (meth)acrylate such as propyl acrylate; salt such as alkali metal salt of (meth)acrylic acid; polyvalent (methyl) such as trimethylolpropane tri(meth)acrylate Acrylate: a vinyl halide compound such as vinylidene chloride or 2-chloroethyl (meth)acrylate; 2-vinyl-2-oxazoline, 2-vinyl-5-methyl-2-carbazole An oxazoline group-containing monomer such as a porphyrin or a 2-isopropenyl-2-oxazoline; (meth)acryloyl aziridine or 2-aziridine ethyl (meth)acrylate; Aziridine-based monomer; addition of 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, lactone and 2-hydroxyethyl (meth)acrylate a hydroxyl group-containing vinyl monomer; a fluorine-containing vinyl monomer such as a fluorine-substituted (meth)acrylic acid ester; a vinyl monomer containing a reactive halogen such as 2-chloroethyl vinyl ether or a monochloroacetic acid vinyl ester; For example; vinyl trimethoxy decane, γ-(meth) propylene methoxy propyl trimethoxy decane, allyl trimethoxy decane, trimethoxy decyl propyl allylamine, 2-methoxy The ethoxylated trimethoxy decane is a vinyl monomer containing an organic oxime; and a macromonomer having a radical polymerizable vinyl group at a monomer terminal which polymerizes a vinyl group, etc. are mentioned. These may be copolymerized with the monomer S1 either alone or in combination.

The Mw of the polymer B is not particularly limited. The Mw of the polymer B may be, for example, 1,000 or more, or may be 5,000 or more. If the Mw of the polymer B is too low, the increase in the adhesion may be insufficient. In some preferred embodiments, the Mw of the polymer B may be, for example, 10,000 or more, may be 12,000 or more, may be 15,000 or more, may be 17,000 or more, or may be 20,000 or more. Further, the Mw of the polymer B may be, for example, 100,000 or less, or may be 70,000 or less. If the Mw of the polymer B is too high, the initial adhesion may not be sufficiently suppressed. In some preferred embodiments, the Mw of the polymer B may be, for example, 50,000 or less, may be less than 50,000, may be less than 40,000, may be less than 35,000, may be 30,000 or less, may be 28,000 or less, or may be 25,000 or less. . When the Mw of the polymer B is within the range of any of the above upper limit and lower limit, 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 attachment. Adhesive sheet with good initial secondary workability and strong adhesion after adhesion.

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

In order to adjust the molecular weight of the polymer B, a chain transfer agent can be used. Examples of the chain transfer agent to be used include octyl mercaptan, lauryl mercaptan, third mercapto mercaptan, third (dodecyl) mercaptan, mercaptoethanol, and α-thioglycerol. a compound of thiol; 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 a thioglycolate such as a thioglycolate of a diol or a thioglycolate of pentaerythritol; an α-methylstyrene dimer or the like.

The amount of the chain transfer agent to be used is not particularly limited, and is usually 0.05 to 20 parts by weight, preferably 0.1 to 15 parts by weight, more preferably 0.2, based on 100 parts by weight of the monomer. Parts by weight to 10 parts by weight. By adjusting the amount of the chain transfer agent so adjusted, a polymer B of a preferred molecular weight can be obtained. Further, the chain transfer agent may be used singly or in combination of two or more.

The amount of the polymer B to be used is, for example, 0.1 part by weight or more based on 100 parts by weight of the polymer A, and may be 0.3 part by weight or more, and may be 0.4, from the viewpoint of obtaining a higher effect. The weight portion or more may be 0.5 parts by weight or more, but is not particularly limited. From the viewpoint of improving the secondary workability, the amount of the polymer B used in 100 parts by weight of the polymer A may be 1 part by weight or more, and may be 2 parts by weight or more. It can be set to 3 parts by weight or more. Further, the amount of the polymer B to be used in an amount of, for example, 75 parts by weight or less based on 100 parts by weight of the polymer A may be 60 parts by weight or less, or may be 50 parts by weight or less. From the viewpoint of avoiding an excessive decrease in the cohesive force of the adhesive layer, the amount of the polymer B used in 100 parts by weight of the polymer A may be, for example, 40 parts by weight or less, or may be 35. It is below the weight part, 30 parts by weight or less, or 25 parts by weight or less. From the viewpoint of obtaining a higher adhesion after heating, the amount of the polymer B used may be 20 parts by weight or less, 17 parts by weight or less, and 15 parts by weight. In the following, it may be 10 parts by weight or less. In several aspects of the adhesive sheet disclosed herein, the amount of the polymer B relative to 100 parts by weight of the polymer A may be, for example, less than 10 parts by weight, may be 8 parts by weight or less, and may be 5 parts by weight. The following may be less than 5 parts by weight, and may be 4 parts by weight or less, or may be 3 parts by weight or less.

The adhesive layer may contain a polymer (any polymer) other than the polymer A and the polymer B as needed within a range that does not greatly impair the performance of the adhesive sheet disclosed herein. The amount of the polymer to be used is usually 20% by weight or less based on the total amount of the polymer component contained in the adhesive layer, and may be 15% by weight or less, and may be 10% by weight or less. In some aspects, the amount of any of the above polymers may be 5% by weight or less based on the total amount of the polymer component, and may be 3% by weight or less, or may be 1% by weight or less. It may also be an adhesive layer which does not substantially contain a polymer other than the polymer A and the polymer B.

(Crosslinking Agent) A crosslinking agent may be used as needed in order to adjust the cohesive force or the like in the adhesive layer. As the crosslinking agent, a crosslinking agent known in the field of an adhesive can be used, and examples thereof include an epoxy crosslinking agent, an isocyanate crosslinking agent, a polyfluorene crosslinking agent, and an oxazoline crosslinking agent. An aziridine-based crosslinking agent, a decane-based crosslinking agent, an alkyletherated melamine-based crosslinking agent, and a metal chelate-based crosslinking agent. In particular, an isocyanate crosslinking agent, an epoxy crosslinking agent, and a metal chelate crosslinking agent can be preferably used. The crosslinking agent may be used alone or in combination of two or more.

Specific examples of the isocyanate crosslinking agent include toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, benzodimethyl diisocyanate, hydrogenated dimethyl diisocyanate, and Phenyl (methane) diisocyanate, hydrogenated diphenyl (methane) diisocyanate, tetramethyl dimethyl diisocyanate, naphthalene diisocyanate, triphenyl (methane) triisocyanate, polymethylene polyphenyl isocyanate, And these adducts with polyols such as trimethylolpropane. Alternatively, a compound having at least one or more isocyanate groups and one or more unsaturated bonds in one molecule, specifically, 2-isocyanatoethyl (meth)acrylate or the like may be used as the isocyanate crosslinking. Agent. These may be used alone or in combination of two or more.

Examples of the epoxy-based crosslinking agent include bisphenol A, epichlorohydrin epoxy resin, ethyl diglycidyl ether, polyethylene glycol diglycidyl ether, glycerol diglycidyl ether, and glycerol triglycidyl alcohol. Ether, 1,6-hexanediol glycidyl ether, trimethylolpropane triglycidyl ether, diglycidylaniline, diamine glycidylamine, N,N,N',N'-tetraglycidyl Xylylenediamine and 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane. These may be used alone or in combination of two or more.

Examples of the metal chelate compound include aluminum, iron, tin, titanium, nickel, and the like as a metal component, and acetylene, ethyl acetacetate, ethyl lactate, and the like as a chelate component. These may be used alone or in combination of two or more.

The amount used in the case of using a crosslinking agent is not particularly limited, and for example, it may be set to be more than 0 part by weight based on 100 parts by weight of the polymer A. Further, the amount of the crosslinking agent used is, for example, 0.01 parts by weight or more, preferably 0.05 parts by weight or more, per 100 parts by weight of the polymer A. By increasing the amount of the crosslinking agent used, it is possible to suppress the adhesion at the initial stage of the adhesion and to improve the secondary workability. In some aspects, the crosslinking agent may be used in an amount of 0.1 part by weight or more based on 100 parts by weight of the polymer A, and may be 0.5 part by weight or more, or may be 1 part by weight or more. On the other hand, the amount of the crosslinking agent to be used with respect to 100 parts by weight of the polymer A is usually suitably 15 parts by weight or less, and can be set to 10, from the viewpoint of avoiding a decrease in viscosity due to an excessive increase in cohesive force. It may be 5 parts by weight or less in parts by weight or less. It may also be advantageous from the viewpoint that the use amount of the crosslinking agent is too large to easily achieve an adhesive sheet having a higher N ₈₀ /N ₅₀ .

The technique disclosed herein can be suitably carried out using at least an isocyanate crosslinking agent as a crosslinking agent. From the viewpoint of easily attaching an adhesive sheet having excellent secondary workability at the initial stage and strong adhesiveness after an increase in adhesion, the amount of the isocyanate crosslinking agent used is relatively 100 in several aspects. The component A by weight may be, for example, 0.1 parts by weight or more and 5 parts by weight or less, and may be 0.3 parts by weight or more and 4 parts by weight or less, and may be 0.5 parts by weight or more and 3 parts by weight or less.

In the case where an isocyanate crosslinking agent is used in the constitution in which the adhesive layer contains a hydroxyl group-containing monomer as a monomer unit, the amount of the hydroxyl group-containing monomer W _OH is used relative to the isocyanate crosslinking agent W _NCO by weight. The reference meter may be set to have an amount of W _OH /W _NCO of 2 or more, but is not particularly limited. By increasing the amount of the hydroxyl group-containing monomer to be used with the isocyanate crosslinking agent in this manner, it is possible to form a crosslinked structure which is suitable for greatly increasing the adhesion after heating to the adhesion at the initial stage of attachment. In some kinds of aspects, W _OH /W _NCO may be 3 or more, may be 5 or more, may be 10 or more, may be 20 or more, may be 30 or more, or may be 50 or more. The upper limit of W _OH /W _NCO is not particularly limited. The W _OH /W _NCO may be, for example, 500 or less, and may be 200 or less, or may be 100 or less.

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

A polyfunctional monomer can be used as needed in the adhesive layer. The polyfunctional monomer can contribute to the adjustment of cohesive force by replacing the crosslinking agent as described above or in combination with the crosslinking agent. For example, in the adhesive layer formed of the photocurable adhesive composition, a polyfunctional monomer can be preferably used. Examples of the polyfunctional monomer include ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, and polypropylene glycol di(methyl). Acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, ethylene glycol di(methyl) Acrylate, 1,6-hexanediol di(meth)acrylate, 1,12-dodecanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, four Methyl hydroxymethane tri(meth) acrylate, allyl (meth) acrylate, vinyl (meth) acrylate, divinyl benzene, epoxy acrylate, polyester acrylate, urethane acrylate, Butylene glycol (meth) acrylate, hexane diol di(meth) acrylate, and the like. Among them, trimethylolpropane tri(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and dipentaerythritol hexa(meth)acrylate can be preferably used. The polyfunctional monomer may be used singly or in combination of two or more.

The amount of the polyfunctional monomer used varies depending on the molecular weight, the number of functional groups, and the like, and is usually in the range of about 0.01 part by weight to about 3.0 parts by weight based on 100 parts by weight of the polymer A. In some cases, the amount of the polyfunctional monomer used may be, for example, 0.02 parts by weight or more, or 0.03 parts by weight or more, per 100 parts by weight of the polymer A. By increasing the amount of the polyfunctional monomer used, it is possible to suppress the adhesion at the initial stage of the adhesion and to improve the secondary workability. On the other hand, the amount of the polyfunctional monomer to be used may be 2.0 parts by weight or less, and may be 1.0 part by weight, per 100 parts by weight of the polymer A, from the viewpoint of avoiding a decrease in viscosity due to an excessive increase in cohesive force. Hereinafter, it may be 0.5 parts by weight or less. It is also possible that the amount of the polyfunctional monomer used is too large to easily achieve an adhesive sheet having a higher N ₈₀ /N ₅₀ .

(Adhesive-imparting resin) The adhesive-imparting resin may be contained in the adhesive layer as needed. The adhesiveness-imparting resin is not particularly limited, and examples thereof include a rosin-based adhesion-imparting resin, a terpene-based adhesion-imparting resin, a phenol-based adhesion-imparting resin, a hydrocarbon-based adhesion-imparting resin, a ketone-based adhesion-imparting resin, and a polyamide-based adhesive. A resin, an epoxy-based adhesion-imparting resin, an elastic system adhesion-imparting resin, and the like are provided. The adhesion-imparting resin may be used singly or in combination of two or more.

Examples of the rosin-based adhesion-providing resin include unmodified rosin (raw rosin) such as rosin gum, wood rosin, and tall oil rosin, or modified unmodified rosin by polymerization, disproportionation, hydrogenation, or the like. Modified rosin (polymerized rosin, stabilized rosin, disproportionated rosin, fully hydrogenated rosin, partially hydrogenated rosin, or other chemically modified rosin, etc.), and various rosin derivatives and the like are also exemplified. Examples of the rosin derivative include rosin phenol obtained by adding phenol and rosin (unmodified rosin, modified rosin, or various rosin derivatives) under an acid catalyst and thermally polymerizing it. Resin; an ester compound of rosin esterified with an unmodified rosin by an alcohol (unmodified rosin ester), or a polymerized rosin, stabilized rosin, disproportionated rosin, fully hydrogenated rosin, partially hydrogenated rosin, etc. Rosin ester resin such as rosin esterified modified rosin ester compound (polymerized rosin ester, stabilized rosin ester, disproportionated rosin ester, fully hydrogenated rosin ester, partially hydrogenated rosin ester, etc.); unmodified with unsaturated fatty acid Unsaturated fatty acid modified rosin resin modified with rosin or modified rosin (polymerized rosin, stabilized rosin, disproportionated rosin, fully hydrogenated rosin, partially hydrogenated rosin, etc.); modified with rosin ester resin using unsaturated fatty acid Saturated fatty acid modified rosin ester resin; unmodified rosin, modified rosin (polymerized rosin, stabilized rosin, disproportionated rosin, fully hydrogenated rosin, partially hydrogenated Aromatic resin based on unsaturated fatty acid modified rosin resin or unsaturated fatty acid modified rosin ester resin; rosin alcohol resin; unmodified rosin, modified rosin, or various rosin derivatives A metal salt or the like of a resin (particularly a rosin ester resin).

Examples of the terpene-based adhesion-imparting resin include a terpene-based resin such as an α-pinene polymer, a β-pinene polymer, and a dipentene polymer, or a modification of the terpene-based resin (phenolic modification) Modified terpene resin (for example, terpene phenol resin, styrene modified terpene resin, aromatic modified terpene resin, hydrogenation) Terpene resin, etc.).

Examples of the phenol-based adhesion-imparting resin include condensates of various phenols (for example, phenol, m-cresol, 3,5-xylenol, p-alkylphenol, resorcin, etc.) and formaldehyde (for example, an alkyl group). a phenol resin, a xylene formaldehyde resin, or the like, a resol resin obtained by subjecting the phenol to formaldehyde with an alkali catalyst, or a condensation reaction of the phenol with formaldehyde by an acid catalyst The obtained novolak resin and the like.

Examples of the hydrocarbon-based adhesion-imparting resin include an aliphatic hydrocarbon resin, an aromatic hydrocarbon resin, an aliphatic cyclic hydrocarbon resin, and an aliphatic-aromatic petroleum resin (styrene-olefin copolymer). Various hydrocarbon-based resins such as an aliphatic-alicyclic petroleum resin, a hydrogenated hydrocarbon resin, a chlorpyrifos resin, and a kasuga resin.

As a commercial product of the polymerized rosin ester which can be used satisfactorily, the product name "Pensel D-125", "Pensel D-135", "Pensel D-160", "Pensel" manufactured by Arakawa Chemical Industry Co., Ltd. can be exemplified. KK", "Pensel C", etc., but not limited to these.

As a commercial item of a terpene phenol type resin which can be used suitably, the brand name "YS Polystar S-145", "YS Polystar G-125", "YS Polystar N125" by Yasuhara Chemical Co., Ltd., YS Polystar U-115, trade name "Tamanol 803L", "Tamanol 901" manufactured by Arakawa Chemical Industry Co., Ltd., and "Sumilite resin PR-12603" manufactured by Sumitomo Bakelite Co., Ltd., but not limited In these.

The content of the adhesive-imparting resin is not particularly limited, and can be set in such a manner that appropriate adhesive properties can be exerted depending on the purpose or use. The content of the adhesion-imparting resin to 100 parts by weight of the polymer A (the total amount of the resin to be added in the case of containing two or more types of the adhesion-imparting resin) can be, for example, about 5 to 500 parts by weight.

As the adhesion-imparting resin, 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 preferably used. It is easy to obtain an adhesive sheet satisfying N ₈₀ /N ₅₀ ≧5 based on the adhesion-imparting resin having a softening point equal to or higher than the above lower limit. The upper limit of the softening point is not particularly limited and may be, for example, about 200 ° C or lower (typically 180 ° C or lower). Further, the softening point of the adhesion-imparting resin can be measured based on the softening point test method (ring and ball method) prescribed in JIS K2207.

In addition, the adhesive layer in the technology disclosed herein may also contain a leveling agent, a plasticizer, a softener, a colorant (dye, pigment, etc.), and may be filled as needed within a range that does not significantly impair the effects of the present invention. Agents, antistatic agents, anti-aging agents, ultraviolet absorbers, antioxidants, light stabilizers, preservatives and the like can be used as known additives for the adhesive.

The adhesive layer constituting the adhesive sheet disclosed herein may be a hardened layer of the adhesive composition. That is, the pressure-sensitive adhesive layer can be formed by applying (for example, applying) an adhesive composition such as a water-dispersible type, a solvent-based type, a photo-curing type, or a hot-melt type to a suitable surface, followed by a suitable curing treatment. In the case where two or more kinds of hardening treatments (drying, crosslinking, polymerization, cooling, etc.) are carried out, these may be carried out simultaneously or in multiple stages. In the adhesive composition using a partial polymer (acrylic polymer slurry) of a monomer component, the final copolymerization reaction is typically carried out as the above-mentioned hardening treatment. That is, a portion of the polymer is supplied to a further copolymerization reaction to form a complete polymer. For example, in the case of a photocurable adhesive composition, light irradiation is performed. Hardening treatment such as cross-linking or drying may be carried out as needed. For example, when it is necessary to dry with a photocurable adhesive composition, photocuring may be performed after drying. In the adhesive composition using a complete polymer, for example, drying (heat drying), crosslinking, or the like is performed as the above-described hardening treatment.

For the application of the adhesive composition, for example, a gravure roll coater, a reverse roll coater, a contact roll coater, a dip roll coater, a bar coater, a knife coater, a spray coater, or the like can be used. It is implemented by a commonly used coater.

The thickness of the adhesive layer is not particularly limited, and may be, for example, 1 μm or more. In some aspects, the thickness of the adhesive layer may be, for example, 3 μm or more, may be 5 μm or more, may be 8 μm or more, may be 10 μm or more, may be 15 μm or more, or may be 20 μm or more or More than 20 μm. By increasing the thickness of the adhesive layer, there is a tendency for the adhesive force to rise after heating. Further, in some aspects, the thickness of the adhesive layer may be, for example, 300 μm or less, may be 200 μm or less, may be 150 μm or less, may be 100 μm or less, may be 70 μm or less, or may be 50 μm or less. It can also be 40 μm or less. If the thickness of the adhesive layer is too large, it may be advantageous from the viewpoints of thinning of the adhesive sheet or prevention of aggregation damage of the adhesive layer. Furthermore, in the case where the first adhesive layer and the second adhesive layer are provided on the first side and the second side of the substrate, the thickness of the adhesive layer can be applied to at least the first adhesive layer. The thickness. The thickness of the second adhesive layer can also be selected from the same range. Further, in the case of a substrate-free adhesive sheet, 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% to 99.0%, preferably in the range of 30.0% to 90.0%, but is not particularly limited. By setting the gel fraction to the above range, it is easy to achieve an adhesive sheet having a high level of compatibility between the secondary workability at the initial stage of adhesion and the strong adhesion after the adhesion is increased. The gel fraction was measured by the following method.

[Measurement of gel fraction] Approximately 0.1 g of the adhesive sample (weight Wg ₁ ) was wrapped into a purse shape using a porous polytetrafluoroethylene film (weight Wg ₂ ) having an average pore diameter of 0.2 μm, and a kite line (weight) was used. Wg ₃ ) Tightening the mouth. As the porous polytetrafluoroethylene film, the trade name "Nitoflon (registered trademark) NTF1122" (Nitto Denko Co., Ltd., average pore diameter: 0.2 μm, porosity: 75%, thickness: 85 μm) or its equivalent was used. The wrap 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 above-mentioned wrap was taken out, the ethyl acetate adhered to the outer surface was wiped off, and the wrap was dried at 130 ° C for 2 hours, and the weight (Wg ₄ ) of the wrap was measured. The gel fraction G _{C of the} adhesive can be calculated by substituting each value into the following formula. Gel fraction G _C (%) = [(Wg _{4 -} Wg _{2 -} Wg ₃ ) / Wg ₁ ] × 100

<Support Substrate> A plurality of types of adhesive sheets may be in the form of an adhesive sheet attached to a substrate having an adhesive layer on one side or both sides of the support substrate. The material of the support substrate is not particularly limited, and may be appropriately selected depending on the purpose of use of the adhesive sheet or the use state. Non-limiting examples of the substrate that can be used include a polyolefin film containing a polyolefin as a main component such as polypropylene or an ethylene-propylene copolymer, polyethylene terephthalate or polyterephthalic acid. a polyester film such as a polyester film containing polyester as a main component, a polyvinyl chloride film containing polyvinyl chloride as a main component, a polyurethane foam, a polyethylene foam, and a polychloroprene A foam sheet containing a foam such as a diene foam; various fibrous materials (may be natural fibers such as hemp and cotton, synthetic fibers such as polyester and vinylon, and semi-synthetic fibers such as acetate). Woven fabrics and non-woven fabrics formed by blending or the like; papers such as Japanese paper, Daolin paper, kraft paper, and crepe paper; metal foils such as aluminum foil and copper foil. It may also be a substrate composed of these composite materials. Examples of the composite base material include a base material having a metal foil and a structure of the plastic film, and a plastic base material reinforced with an inorganic fiber such as a glass cloth.

As the substrate of the adhesive sheet disclosed herein, various film substrates can be favorably used. The film substrate may be a porous substrate such as a foam film or a non-woven sheet, and may be a non-porous substrate or a substrate having a structure in which a porous layer and a non-porous layer are laminated. . In a plurality of aspects, as the film substrate, a resin film containing a (self-standing or non-dependent) resin film capable of independently maintaining a shape can be preferably used as the base film. The term "resin film" as used herein refers to a non-porous structure, and typically refers to a (non-porous) resin film that does not substantially contain bubbles. Therefore, the concept of the above resin film is different from that of a foam film or a nonwoven fabric. As the resin film, those capable of independently maintaining the shape (self-standing or non-dependent) can be used favorably. The resin film may have a single layer structure or a multilayer structure of two or more layers (for example, a three-layer structure).

Examples of the resin material constituting the resin film include polyamine (PA) such as polyester, polyolefin, nylon 6, nylon 66, and partially aromatic polyamine, polyimine (PI), and polyamidoxime. Imine (PAI), polyetheretherketone (PEEK), polyether oxime (PES), polyphenylene sulfide (PPS), polycarbonate (PC), polyurethane (PU), ethylene vinyl acetate A resin such as an ester copolymer (EVA) or a fluororesin such as polytetrafluoroethylene (PTFE), an acrylic resin, a polyacrylate, a polystyrene, a polyvinyl chloride or a polyvinylidene chloride. The resin film may be formed by using a resin material containing one of the resins alone, or may be formed by using two or more kinds of resin materials. The above resin film may be unextended or may be extended (for example, uniaxially stretched or biaxially stretched).

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

Examples of the dicarboxylic acid constituting the polyester include phthalic acid, isophthalic acid, terephthalic acid, 2-methylterephthalic acid, 5-sulfoisophthalic acid, and 4,4. '-Diphenyldicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, 4,4'-diphenyl ketone dicarboxylic acid, 4,4'-diphenoxyethane dicarboxylic acid, Aromatic compounds such as 4,4'-diphenylstilbene dicarboxylic acid, 1,4-naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid a dicarboxylic acid; an alicyclic dicarboxylic acid such as 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid or 1,4-cyclohexanedicarboxylic acid; malonic acid, amber An aliphatic dicarboxylic acid such as acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid or dodecanoic acid; maleic acid, maleic anhydride, anti An unsaturated dicarboxylic acid such as butenedioic acid; a derivative such as a lower alkyl ester of the above dicarboxylic acid such as terephthalic acid; and the like. These may be used alone or in combination of two or more. From the viewpoint of strength and the like, an aromatic dicarboxylic acid is preferred. Among them, preferred examples of the dicarboxylic acid include terephthalic acid and 2,6-naphthalene dicarboxylic acid. For example, it is preferred that 50% by weight or more (for example, 80% by weight or more, and typically 95% by weight or more) of the dicarboxylic acid constituting the polyester is terephthalic acid, 2,6-naphthalenedicarboxylic acid or the like. And use it. The dicarboxylic acid may be substantially composed only of terephthalic acid, substantially consisting of only 2,6-naphthalene dicarboxylic acid, or substantially only terephthalic acid and 2,6-naphthalene dicarboxylic acid.

Examples of the diol constituting the polyester include ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, 1,3-propanediol, 1,5-pentanediol, and neopentane. An aliphatic diol such as a diol, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol or polyoxytetramethylene glycol; 1,2-cyclohexanediol, An alicyclic diol such as 1,4-cyclohexanediol, 1,1-cyclohexanedimethylol, 1,4-cyclohexanedimethylol, benzenedimethanol, 4,4'-dihydroxyl An aromatic diol such as biphenyl, 2,2-bis(4'-hydroxyphenyl)propane or bis(4-hydroxyphenyl)fluorene. These may be used alone or in combination of two or more. Among them, from the viewpoint of transparency and the like, an aliphatic diol is preferred, and ethylene glycol is particularly preferred. The ratio of the aliphatic diol (preferably ethylene glycol) to the diol constituting the polyester is preferably 50% by weight or more (for example, 80% by weight or more, and typically 95% by weight or more). The above diol may also consist essentially of only ethylene glycol.

Specific examples of the polyester resin include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), and polynaphthalene. Butylene formate and the like.

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

Specific examples of the resin film which can be suitably used as the base film of the adhesive sheet disclosed herein include a PET film, a PEN film, a PPS film, a PEEK film, a CPP film, and an OPP film. Examples of the base film which is preferable from the viewpoint of strength or dimensional stability include a PET film, a PEN film, a PPS film, and a PEEK film. From the viewpoints of ease of obtaining the substrate, etc., a PET film and a PPS film are preferable, and among them, a PET film is preferable.

In the resin film, light stabilizers, antioxidants, antistatic agents, colorants (dyes, pigments, etc.), fillers, slip agents, anti-adhesives may be blended as needed within a range that does not significantly impair the effects of the present invention. A known additive such as a continuous agent. The amount of the additive to be added is not particularly limited and may be appropriately set depending on the use of the adhesive sheet or the like.

The method for producing the resin film is not particularly limited. For example, a conventionally known general resin film forming method such as extrusion molding, inflation molding, T-die die-casting, or calender roll molding can be suitably employed.

The above substrate may be one that substantially comprises such a base film. Alternatively, the substrate may be an auxiliary layer in addition to the base film. Examples of the auxiliary layer include an optical property adjusting layer (for example, a coloring layer and an antireflection layer), a printing layer or a laminate layer for imparting a desired appearance to a substrate, an antistatic layer, and an undercoat layer. A surface treatment layer such as a release layer.

The thickness of the substrate is not particularly limited, and may be selected depending on the purpose of use of the adhesive sheet, the use state, and the like. The thickness of the substrate may be, for example, 1000 μm or less. In a plurality of aspects, the thickness of the substrate may be, for example, 500 μm or less, and may be 300 μm or less, 250 μm or less, or 200 μm from the viewpoint of handleability or workability of the adhesive sheet. the following. The thickness of the substrate may be, for example, 160 μm or less, and may be 130 μm or less, and may be 100 μm or less, from the viewpoint of miniaturization or weight reduction of the article to which the adhesive sheet is applied. 90 μm or less, 70 μm or less, 50 μm or less, 25 μm or less, 10 μm or less, or 5 μm or less. When the thickness of the base material is small, the flexibility of the adhesive sheet or the followability to the surface shape of the adherend tends to be improved. Further, the thickness of the substrate may be, for example, 2 μm or more, and may be 5 μm or more, 10 μm or more, 20 μm or more, or 25 μm or more, or more, from the viewpoints of workability and workability. 25 μm. In some cases, the thickness of the substrate may be, for example, 30 μm or more, 35 μm or more, 55 μm or more, 75 μm or more, or 120 μm or more. For example, in an adhesive sheet which can be used for reinforcement, support, impact relaxation, and the like of the adhesive, a substrate having a thickness of 30 μm or more can be preferably used.

If necessary, the first surface of the substrate may be subjected to a corona discharge treatment, a plasma treatment, an ultraviolet irradiation treatment, an acid treatment, an alkali treatment, or a primer coating to form a primer layer or the like. deal with. Such a surface treatment can be a treatment for improving the grip of the adhesive layer on the substrate. For example, in the adhesive sheet having the substrate including the resin film as the base film, the substrate subjected to the improvement in the gripping property can be suitably used. The above surface treatments can be applied individually or in combination. The composition of the primer used for the formation of the undercoat layer is not particularly limited, and can be appropriately selected from known ones. The thickness of the undercoat layer is not particularly limited, but is usually about 0.01 μm to 1 μm, preferably about 0.1 μm to 1 μm. Other treatments that can be performed on the first surface of the substrate as needed include an antistatic layer forming treatment, a colored layer forming treatment, a printing treatment, and the like.

When the adhesive sheet disclosed herein is in the form of a single-sided adhesive sheet having an adhesive layer on the first side of the substrate, the second side of the substrate may be subjected to a peeling treatment or antistatic treatment as needed. Processing such as previously known surface treatments. For example, the surface of the substrate can be surface-treated by a release treatment agent (typically, by providing a release layer formed by a release treatment agent), and the adhesive sheet of the form wound into a roll can be obtained. The rolling force is lighter. As the release treatment agent, a polyfluorene-based release treatment agent, a long-chain alkyl release treatment agent, an olefin-based release treatment agent, a fluorine-based release treatment agent, a fatty acid amide-based release treatment agent, molybdenum sulfide, and cerium oxide can be used. Powder and so on. Further, for the purpose of improving printability, reducing light reflectivity, and improving lamination adhesion, the second surface of the substrate may be subjected to corona discharge treatment, plasma treatment, ultraviolet irradiation treatment, acid treatment, alkali treatment, or the like. . Further, in the case of a double-sided adhesive sheet, the second surface of the substrate may be subjected to the same surface treatment as that exemplified above as the surface treatment which can be performed on the first surface of the substrate, as needed. Further, the surface treatment performed on the first side of the substrate may be the same as or different from the surface treatment performed on the second side.

<Adhesive sheet> (Characteristics of the adhesive sheet, etc.) The adhesive sheet disclosed herein has a ratio of the adhesive force N ₈₀ (adhesive force after heating) to the adhesive force N ₅₀ , that is, N ₈₀ /N ₅₀ is 5 or more. Therefore, in the use form in which a temperature of about 50 ° C is applied at the initial stage of attachment, good secondary workability is also exhibited, and the adhesion can be greatly increased by heating or the like thereafter. From the viewpoint of obtaining a higher effect, in some kinds of aspects, N ₈₀ /N ₅₀ may be, for example, 7 or more, may be 10 or more, may be 15 or more, or may be 20 or more. The upper limit of the N ₈₀ /N ₅₀ is not particularly limited, and may be, for example, 80 or less, and may be 60 or less, and may be 50 or less, or 40 or less, from the viewpoint of ease of production of the adhesive sheet or economy. The adhesive sheet disclosed herein can be suitably carried out in such a manner that N ₈₀ /N ₅₀ is 5 or more and 60 or less, 7 or more and 50 or less, or 10 or more and 40 or less.

In several aspects of the adhesive sheet disclosed herein, the ratio of the adhesive force N ₅₀ [N/25 mm] to the adhesive force N ₂₃ [N/25 mm], that is, N ₅₀ /N ₂₃ may not be reached. 10, preferably less than 7, may not be 5 or less than 4, but is not particularly limited. The adhesive sheet having a small N ₅₀ /N ₂₃ tends to exhibit good secondary workability in a use form in which 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, but is usually 1.0 or more, and typically exceeds 1.0, and may be, for example, 1.2 or more.

In several aspects of the adhesive sheet disclosed herein, the ratio of the adhesive force N ₈₀ [N/25 mm] to the adhesive force N ₂₃ [N/25 mm], that is, N ₈₀ /N ₂₃ can be, for example, 7 The above may be 10 or more, and may be 15 or more, but is not particularly limited. According to the N ₈₀ /N ₂₃ large adhesive sheet, the low adhesion at the initial stage of adhesion and the strong adhesion after the adhesion is increased can be exhibited at a higher level. The adhesive sheet disclosed herein can also be suitably carried out in such a manner that N ₈₀ /N ₂₃ is, for example, 20 or more, 30 or more, or 40 or more. The upper limit of the N ₈₀ /N ₂₃ is not particularly limited, and may be, for example, 100 or less, and may be 80 or less, and may be 60 or less, or 50 or less, from the viewpoint of ease of production of the adhesive sheet or economy.

Here, the adhesive force N ₂₃ [N/25 mm] is obtained by crimping on a stainless steel (SUS) plate as an adherend and placing it in an environment of 23 ° C, 50% RH for 30 minutes. Thereafter, the 180° peel adhesion was measured under the conditions of a peeling angle of 180 degrees and a tensile speed of 300 mm/min. The adhesive force N ₅₀ [N/25 mm] was obtained by crimping on a stainless steel (SUS) plate as an adherend and holding it at 50 ° C for 30 minutes, followed by 23 ° C, 50%. After standing for 30 minutes in an RH environment, the 180° peel adhesion was measured under the conditions of a peeling angle of 180 degrees and a tensile speed of 300 mm/min. The adhesive force N ₈₀ [N/25 mm] was obtained by crimping on a SUS plate as an adherend and heating at 80 ° C for 5 minutes, followed by placing at 23 ° C, 50% RH. After 30 minutes, the 180° peel adhesion was measured under the conditions of a peeling angle of 180 degrees and a stretching speed of 300 mm/min. As the adherend, a SUS304BA plate was used for the measurement of any of the adhesive forces N ₂₃ , N ₅₀ and N ₈₀ . At the time of measurement, if necessary, a suitable substrate (for example, a PET film having a thickness of about 25 μm) is attached to the adhesive sheet to be measured and reinforced. More specifically, the adhesion forces N ₂₃ , N ₅₀ and N ₈₀ can be measured according to the methods described in the following examples.

In several aspects of the adhesive sheet disclosed herein, the adhesive sheet N ₂₃ may be, for example, 2.0 N/25 mm or less, or less than 1.5 N/25 mm, and may be 1.2 N/25 mm. Hereinafter, it may be 1.0 N/25 mm or less, or may be 0.8 N/25 mm or less, but is not particularly limited. The lower adhesive strength N ₂₃ is preferred from the viewpoint of secondary workability. The lower limit of the adhesive force N ₂₃ is not particularly limited and may be, for example, 0.01 N/25 mm or more. The adhesive force N ₂₃ is usually suitably 0.1 N/25 mm or more from the viewpoint of attaching workability to the adherend or preventing displacement of the position before the adhesion is increased. The adhesion force N ₂₃ may be, for example, 0.2 N/25 mm or more, and may be 0.3 N/25 mm or more, and may be 0.4 N/25 mm or more, from the viewpoints of improvement in adhesion after heating, and the like. It can also be 0.5 N/25 mm or more.

In several aspects of the adhesive sheet disclosed herein, the adhesive sheet has an adhesion force N _{50 of,} for example, 7 N/25 mm or less, 5 N/25 mm or less, and 4 N/25 mm. Hereinafter, it may be 3.5 N/25 mm or less, or may be 3 N/25 mm or less, 2.5 N/25 mm or less, or 2 N/25 mm or less, but is not particularly limited. The lower adhesive strength N ₅₀ is preferable from the viewpoint of exhibiting good secondary workability in a use form in which a temperature of about 50 ° C may be applied at the initial stage of attachment. The lower limit of the adhesive force N ₅₀ is not particularly limited and may be, for example, 0.05 N/25 mm or more. The adhesive force N ₅₀ is usually suitably 0.1 N/25 mm or more from the viewpoint of preventing the positional shift before the adhesion is increased. The adhesion N ₅₀ can be, for example, 0.2 N/25 mm or more, and can be 0.5 N/25 mm or more, or 0.7 N/25 mm, from the viewpoints of improvement in adhesion after heating, and the like. the above.

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

In several aspects of the adhesive sheet disclosed herein, the difference between the adhesive force N ₅₀ [N/25 mm] and the adhesive force N ₂₃ [N/25 mm], that is, N ₅₀ -N ₂₃ is generally preferably not Up to 5 N/25 mm, eg up to 4 N/25 mm, less than 3 N/25 mm, less than 2.5 N/25 mm, less than 2 N/25 mm or less than 1.5 N /25 mm, but there is no special limit. The adhesive sheet having a small N ₅₀ -N ₂₃ tends to exhibit good secondary workability in a use form in which 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 0 N/25 mm or more, typically more than 0 N/25 mm, and may be 0.2 N/25 mm or more.

The difference between the adhesion of the adhesive sheet N ₈₀ [N/25 mm] and the adhesive force N ₅₀ [N/25 mm] relative to the adhesion force N ₅₀ [N/25 mm] and the adhesion force N ₂₃ [N The ratio of the difference of /25 mm], that is, (N ₈₀ - N ₅₀ ) / (N ₅₀ - N ₂₃ ) may be, for example, 2 or more, but is not particularly limited. A larger value of (N ₈₀ -N ₅₀ )/(N ₅₀ -N ₂₃ ) means an increase in the adhesion force after heating with respect to the adhesion at the initial stage of application in a state in which a temperature of about 50 ° C may be applied. Bigger. In some aspects, (N ₈₀ -N ₅₀ )/(N ₅₀ -N ₂₃ ) may be 3 or more, may be 5 or more, may be 7 or more, may be 10 or more, may be 15 or more, or may be It is 20 or more. The upper limit of (N ₈₀ - N ₅₀ ) / (N ₅₀ - N ₂₃ ) is not particularly limited, and may be, for example, 100 or less.

Furthermore, the post-heating adhesion of the adhesive sheet disclosed herein indicates one of the characteristics of the adhesive sheet, and does not limit the use of the adhesive sheet. In other words, the use of the adhesive sheet disclosed herein is not limited to the case of heating at 80 ° C for 5 minutes, and may be used, for example, for heating to room temperature (usually 20 ° C to 30 ° C, Typically, it is a treatment of 23 ° C to 25 ° C). In this aspect of use, the adhesion can be increased for a long period of time to achieve a firm bond. Further, the adhesive sheet disclosed herein can promote the increase in the adhesive force by heat treatment at a temperature higher than 50 ° C at any time after the attachment. The heating temperature in the heat treatment is not particularly limited, and can be set in consideration of workability, economy, heat resistance of the substrate to which the sheet is adhered, or the adherend. The heating temperature may be, for example, less than 150 ° C, may be 120 ° C or less, may be 100 ° C or less, may be 80 ° C or less, or may be 70 ° C or less. Further, the heating temperature may be, for example, 55° C. or higher, 60° C. or higher, or 70° C. or higher, and may be 80° C. or higher, or may be 100° C. or higher. If a higher heating temperature is used, the adhesion can be increased by a shorter period of time. The heating time is not particularly limited, and may be, for example, 1 hour or shorter, 30 minutes or shorter, or 10 minutes or shorter, or 5 minutes or shorter. Alternatively, the heat treatment may be carried out for a longer period of time in which the adhesive sheet or the adherend does not undergo significant thermal deterioration. Further, the heat treatment may be carried out once, or may be carried out in plural times.

(Adhesive sheet with a substrate) When the adhesive sheet disclosed herein is in the form of an adhesive sheet with a substrate, the thickness of the adhesive sheet may be, for example, 1000 μm or less, and may be 600 μm or less. It can be 350 μm or less or 250 μm or less. The thickness of the adhesive sheet can be, for example, 200 μm or less, and can be 175 μm or less, and can be 140 μm, in terms of miniaturization, weight reduction, and thinning of the product to which the adhesive sheet is applied. Hereinafter, it may be 120 μm or less, or may be 100 μm or less (for example, less than 100 μm). Further, the thickness of the adhesive sheet may be, for example, 5 μm or more, and may be 10 μm or more, 15 μm or more, 20 μm or more, 25 μm or more, or 30 in terms of operability. More than μm. In some cases, the thickness of the adhesive sheet may be, for example, 50 μm or more, 60 μm or more, 80 μm or more, 100 μm or more, or 130 μm or more. The upper limit of the thickness of the adhesive sheet is not particularly limited. Further, the thickness of the adhesive sheet refers to the thickness of the portion attached to the adherend. For example, in the adhesive sheet 1 having the configuration shown in FIG. 1, the thickness from the adhesive surface 21A of the adhesive sheet 1 to the second surface 10B of the substrate 10 does not include the thickness of the release liner 31.

The adhesive sheet disclosed herein can be suitably carried out, for example, in such a manner that the thickness Ts of the substrate is larger than the thickness Ta of the adhesive layer, that is, the Ts/Ta is larger than 1. Ts/Ta may be, for example, 1.1 or more, and may be 1.2 or more, 1.5 or more, or 1.7 or more, but is not particularly limited. For example, in an adhesive sheet which can be used for the purpose of reinforcement, support, impact relaxation, etc. of the adherend, it is easy to exhibit a good effect by increasing the Ts/Ta even if the adhesive sheet is made thinner. In some aspects, Ts/Ta may be 2 or more (for example, more than 2), may be 3 or more, or may be 4 or more. Further, Ts/Ta can be, for example, 50 or less, or 20 or less. The Ts/Ta can be, for example, 10 or less, or 8 or less, from the viewpoint of easily exhibiting a high adhesion after heating, even if the pressure-sensitive adhesive sheet is made thinner.

The above adhesive layer is preferably fixed to the support substrate. The above-mentioned fixing means an adhesive sheet in which the adhesive force is increased after being attached to the adherend, and the peeling of the interface between the adhesive layer and the supporting substrate is not caused when the adhesive sheet is peeled off from the adherend. The adhesive layer exhibits sufficient grip for the support substrate. The adherend and the support substrate can be firmly integrated according to the adhesive sheet to which the adhesive layer is fixed to the base material of the support substrate. Thereby, for example, functions such as reinforcement, support, and shock relaxation of the adherend can be effectively exhibited. A preferred example of the adhesive sheet to which the adhesive layer is fixed to the substrate is an adhesive sheet which exhibits at least 5 N/25 mm, preferably 10 after being attached to the adherend. Adhesion of N/25 mm or more, more preferably 15 N/25 mm or more (180° peel adhesion measured at a peeling angle of 180 degrees and a tensile speed of 300 mm/min), and adhered to the above Peeling (grab damage) between the adhesive layer and the support substrate does not occur when the body is peeled off. The adhesive sheet after heating (N ₈₀ ) is 15 N/25 mm or more, and the adhesive sheet which does not cause scratch damage during the measurement of the adhesive force after heating belongs to the adhesive sheet having the adhesive layer fixed on the substrate. A preferred example of the material.

The adhesive sheet disclosed herein can be suitably produced, for example, by sequentially including the following steps: contacting the liquid adhesive composition with the first side of the substrate; and applying the adhesive to the first side. The composition hardens to form an adhesive layer. The curing of the above adhesive composition may be accompanied by one or more of drying, crosslinking, polymerization, cooling, and the like of the adhesive composition. The method of forming the adhesive layer by curing the liquid adhesive composition on the first surface of the substrate in this manner, and bonding the adhesive layer after curing to the first side of the substrate Compared with the method of disposing the adhesive layer on one side, the adhesion of the adhesive layer to the substrate can be improved. In this case, the adhesive sheet to which the adhesive layer is fixed to the substrate can be favorably produced.

In some aspects, as a method of bringing the liquid adhesive composition into contact with the first side of the substrate, a method of directly applying the above-described adhesive composition to the first side of the substrate may be employed. The second surface of the adhesive layer is fixed to the first side of the substrate by abutting the first surface (adhesive surface) of the adhesive layer hardened on the first surface of the substrate to the peeling surface The first surface of the adhesive layer abuts against the adhesive sheet formed by the peeling surface. As the peeling surface, the surface of the release liner or the back surface of the substrate subjected to the release treatment can be used.

Further, for example, in the case of using a photocurable adhesive composition of a partial polymer (acrylic polymer slurry) of a monomer component, for example, after the adhesive composition is applied to a release surface, The applied adhesive composition coats the first side of the substrate, whereby the first side of the substrate is brought into contact with the uncured adhesive composition, and in this state, the first side of the substrate is sandwiched The adhesive composition between the peeling faces is hardened by light irradiation, thereby forming an adhesive layer.

Furthermore, the method exemplified above does not limit the method of manufacturing the adhesive sheet disclosed herein. In the production of the adhesive sheet disclosed herein, one or a combination of two or more of them may be used alone or in combination of two or more suitable methods for fixing the adhesive layer to the first surface of the substrate. Examples of such a method include a method of curing a liquid adhesive composition on a first surface of a substrate to form an adhesive layer, or applying an adhesive layer to the first surface of the substrate. The method of surface treatment for grasping and the like. For example, when the adhesive layer is sufficiently improved on the substrate by a method such as providing an undercoat layer on the first surface of the substrate, the cured adhesive layer may be attached thereto. An adhesive sheet is produced by the method of the first side of the substrate. Moreover, the choice of the material of the substrate or the composition of the adhesive can also improve the grip of the adhesive layer on the substrate. Further, by applying a temperature higher than room temperature to the adhesive sheet having the adhesive layer on the first side of the substrate, the adhesion 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, may be 40 ° C to 70 ° C or higher, or may be about 45 ° C to 60 ° C.

The adhesive sheet disclosed herein is an adhesive sheet having a first adhesive layer disposed on a first side of the substrate and a second adhesive layer disposed on a second side of the substrate (ie, double-sidedly 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 configurations. In the case where 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, pattern formation, etc.). For example, the second adhesive layer may also be an adhesive layer free of polymer B. Further, regarding the surface (second adhesive surface) of the second adhesive layer, N ₈₀ /N ₅₀ may be less than 5, may be less than 2, may be less than 1.5, or may not be 1.

<Adhesive sheet with release liner> The adhesive sheet disclosed herein may be in the form of an adhesive article in which the surface (adhesive surface) of the adhesive layer is brought into contact with the release surface of the release liner. Therefore, by means of the present specification, there is provided an adhesive sheet (adhesive sheet) comprising a release liner comprising any of the adhesive sheets disclosed herein and a release liner having a release surface abutting the adhesive surface of the adhesive sheet. product).

The thickness of the release liner is not particularly limited, but is usually about 5 μm to 200 μm. When the thickness of the release liner is within the above range, the adhesion between the adhesive layer and the self-adhesive layer is excellent, and therefore it is preferable. In some aspects, the thickness of the release liner may be, for example, 10 μm or more, may be 20 μm or more, may be 30 μm or more, or may be 40 μm or more. Moreover, the thickness of the release liner can be, for example, 100 μm or less, or 80 μm or less from the viewpoint of facilitating the peeling of the adhesive layer. The release liner may be subjected to a known antistatic treatment such as a coating type, a kneading type, or a vapor deposition type as needed.

The release liner is not particularly limited, and for example, a release liner having a release layer on the surface of a liner substrate such as a resin film or paper (which may be a resin laminated with a resin such as polyethylene) may be used, or may be used as A release liner of a resin film formed of a low-adhesive material of a fluorine-based polymer (such as polytetrafluoroethylene) or a polyolefin-based resin (such as polyethylene or polypropylene). In terms of excellent surface smoothness, it can be suitably used as a release liner having a release layer on the surface of a resin film as a liner substrate, or a release liner comprising a resin film formed using a low adhesion material. The resin film is not particularly limited as long as it is a film that can protect the adhesive layer, and examples thereof include a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, and a polymethylpentene film. A polyvinyl chloride film, a vinyl chloride copolymer film, a polyester film (PET film, PBT film, etc.), a polyurethane film, an ethylene-vinyl acetate copolymer film, or the like. For the formation of the release layer, for example, a polyoxynitride-based release treatment agent, a long-chain alkyl release treatment agent, an olefin-based release treatment agent, a fluorine-based release treatment agent, a fatty acid amide-based release treatment agent, molybdenum sulfide, and a dioxide can be used. A known release treatment agent such as tantalum powder. It is especially preferred to use a polyfluorene-based release treatment agent.

The thickness of the release layer is not particularly limited, but is usually about 0.01 μm to 1 μm, preferably about 0.1 μm to 1 μm. The method for forming the release layer is not particularly limited, and a known method corresponding to the type of the release treatment agent to be used or the like can be suitably employed.

<Application> The adhesive sheet provided by the present specification is, for example, bonded to the adherend, and is in a temperature range of from room temperature to about 50 ° C (for example, 20 ° C to 50 ° C), and the adhesive force is suppressed to be low in a short time. In the meantime, good secondary workability can be exerted, which contributes to the suppression of yield or the high quality of the product comprising the adhesive sheet. Further, the adhesive sheet can be greatly increased in adhesion by aging (may be heating to a temperature higher than 50 ° C, time-lapse, combinations thereof, etc.). For example, by heating at a desired timing, the adhesive sheet can be firmly adhered to the adherend. With such a feature, the adhesive sheet disclosed herein can be suitably used for the purpose of fixing, joining, forming, decorating, protecting, reinforcing, supporting, impact-relieving, etc. of members contained in various articles in various fields.

The adhesive sheet disclosed herein may be in the form of an adhesive sheet with a base material provided with an adhesive layer on at least a first surface of the film-form substrate having the first surface and the second surface, and is preferably used as a sticker. A reinforced film that is reinforced by the adherend. In the reinforced film, as the film substrate, a resin film as a base film can be preferably used. Further, from the viewpoint of improving the reinforcing performance, the pressure-sensitive adhesive layer is preferably fixed to the first surface of the film-form substrate. For example, regarding an optical member for an optical product or an electronic member for an electronic product, a high degree of integration, small size, light weight, and thinning are continuously developed, and a plurality of thin optical members having different linear expansion coefficients or thicknesses can be laminated. / Electronic components. By attaching the reinforcing film as described above to such a member, it is possible to impart appropriate rigidity to the optical member/electronic member. Thereby, in the manufacturing process and/or the manufactured product, curling or bending due to stress which may occur between a plurality of members having different linear expansion coefficients or thicknesses can be suppressed. Further, in the manufacturing process of the optical product/electronic product, when the thin optical member/electronic member is subjected to a shape processing such as cutting processing as described above, the reinforcing film is attached to the member to be processed. The stress concentration to the optical member/electronic member accompanying the processing can be alleviated, and the risk of cracking, cracking, and peeling of the laminated member can be reduced. The operation of attaching the reinforcing member to the optical member/electronic member may also contribute to the relaxation of the local stress concentration during the conveyance, lamination, rotation, etc. of the member, or the bending or bending due to the weight of the member. Suppression, etc. Further, the optical product or the electronic product including the above-mentioned reinforcing film is used in the market for consumers, even in the case where the device is dropped, placed under a weight, a collision of a flying object, etc. In the case where an unexpected stress is applied, the stress applied to the device can also be alleviated by including the reinforced film in the device. Therefore, by including the above-described device with a reinforcing film, the durability of the device can be improved.

Further, the adhesive sheet disclosed herein can be used satisfactorily, for example, in the form of members constituting various portable devices (portable devices). The term "carrying" as used herein does not mean merely being portable, but refers to the portability of a person (standard adult) who can carry it relatively easily. Moreover, examples of the portable device herein may include: a mobile phone, a smart phone, a tablet personal computer, a notebook personal computer, various portable devices, a digital camera, a digital video camera, and an audio device (with a music player) , recording pen, etc.), computer (calculator, etc.), portable game equipment, electronic dictionary, electronic notebook, electronic books, car information equipment, portable radio, portable TV, portable printer, portable scanning Instruments, portable data sets and other portable electronic devices, in addition, may also include mechanical watches or pocket watches, flashlights, magnifiers and so on. Examples of the member constituting the above-described portable electronic device may include an optical film or a display panel or the like for an image display device such as a thin layer display such as a liquid crystal display or a film type display. The adhesive sheet disclosed herein can also be used in a good manner by being attached to various members of automobiles, home electric appliances, and the like.

The matters disclosed in the present specification include the following. (1) An adhesive sheet comprising an adhesive layer comprising the polymer A, and a copolymer of a monomer having a polyorganosiloxane skeleton and a (meth)acrylic monomer. Polymer B, the glass transition temperature T _m1 of the polymer B based on the composition of the (meth)acrylic monomer is 50° C. or more and 100° C. or less, and is bonded to a stainless steel plate and then heated at 80° C. for 5 minutes. The adhesive force N ₈₀ is 5 times or more of the adhesive force N ₅₀ after being adhered to the stainless steel sheet and kept at 50 ° C for 30 minutes. (2) The adhesive sheet according to the above (1), wherein the adhesive force N ₅₀ and the adhesive force N ₂₃ after being held at 23 ° C for 30 minutes after being bonded to the stainless steel sheet satisfy the following formula: (N ₅₀ /N ₂₃ )<10. (3) The adhesive sheet according to the above (1) or (2), wherein the adhesive force N ₈₀ is 10 times or more of the adhesive force N ₂₃ after being placed on the stainless steel sheet and left at 23 ° C for 30 minutes. (4) The adhesive sheet according to any one of (1) to (3) above, wherein the adhesion force N ₂₃ [N/25 mm], the adhesive force N ₅₀ [N/25 mm], and the adhesive force N ₈₀ [N/25 mm] satisfies the following relationship: (N ₈₀ -N ₅₀ )/(N ₅₀ -N ₂₃ )≧2. (5) The adhesive sheet according to any one of the above (1), wherein the adhesive force N ₂₃ is 2.0 N/25 mm or less. (6) The adhesive sheet according to any one of the above (1), wherein the adhesive force N ₅₀ is 4 N/25 mm or less. (7) The adhesive sheet according to any one of the above (1), wherein the adhesive force N ₈₀ is 15 N/25 mm or more.

(8) The adhesive sheet according to any one of the above (1), wherein the glass transition temperature T _A of the polymer _A is -63 ° C or more and less than 0 ° C. (9) The adhesive sheet according to any one of the above (1), wherein the polymer B has a glass transition temperature T _B of -10 ° C or more and 10 ° C or less. (10) The adhesive sheet according to any one of the above (1), wherein a copolymerization ratio of a monomer having a glass transition temperature of more than 170 ° C in the polymer B of the polymer B is 30% by weight. %the following. The adhesive sheet according to any one of the above aspects, wherein the adhesive layer contains more than 0 parts by weight and 10 parts by weight or less per 100 parts by weight of the polymer A. Crosslinker. (12) The adhesive sheet according to any one of the above-mentioned (1), wherein the polymer B has a weight average molecular weight of 10,000 or more and 50,000 or less. The adhesive sheet according to any one of the above-mentioned (1), wherein the content of the polymer B in the adhesive layer is 0.05 parts by weight or more based on 100 parts by weight of the polymer A. And 20 parts by weight or less.

(14) The adhesive sheet according to any one of the above-mentioned (1), wherein the polymer A is an acrylic polymer. (15) The adhesive sheet according to the above (14), wherein the monomer component for preparing the acrylic polymer comprises a hydroxyl group-containing monomer. (16) The adhesive sheet according to the above (14), wherein the monomer component for preparing the acrylic polymer comprises N-vinyl cyclic decylamine and a hydroxyl group-containing monomer. The adhesive sheet according to any one of the above-mentioned (1), wherein the adhesive layer contains an isocyanate crosslinking agent. (18) The adhesive sheet according to any one of the above (1), wherein the monomer component for preparing the polymer B comprises methyl methacrylate (MMA). (19) The adhesive sheet according to the above (18), wherein the ratio of MMA to the total amount of the (meth)acrylic monomer contained in the monomer component is 55 wt% or more and 95 wt% %the following. The adhesive sheet according to any one of the above aspects, wherein the thickness of the adhesive layer is 3 μm or more and 100 μm or less (for example, 20 μm or more and 50 μm or less).

The adhesive sheet according to any one of the above aspects, comprising the support substrate having the first surface and the second surface, and at least the first surface of the support substrate The above adhesive layer is laminated. (22) The adhesive sheet according to the above (21), wherein the support substrate has a thickness of 30 μm or more. (23) The adhesive sheet according to the above aspect (21), wherein the thickness of the support substrate is 1.1 times or more and 10 times or less the thickness of the pressure-sensitive adhesive layer. The adhesive sheet according to any one of the above-mentioned (21), wherein the support substrate comprises a resin film as a base film. (25) The adhesive sheet according to the above (24), wherein the base film is a polyester film having a thickness of 35 μm or more (for example, a thickness of 35 μm or more and 500 μm or less). The adhesive sheet according to any one of the above-mentioned (21), wherein the adhesive layer is fixed to the first surface of the support substrate. (27) The adhesive sheet according to any one of the above (21) to (26), which is attached to the adherend and used for reinforcement of the adherend. The adhesive sheet according to any one of the above aspects, wherein the surface (adhesive surface) of the pressure-sensitive adhesive layer abuts on a peeling surface having a water contact angle of 100 or more.

(29) An adhesive sheet comprising a release liner, comprising the adhesive sheet according to any one of the above (1) to (28), and a release property having an adhesive surface abutting on the adhesive sheet The release liner of the surface, and the water contact angle of the above peelable surface is 100 degrees or more. (30) The adhesive sheet with a release liner according to the above (29), wherein the peelable surface is a surface of a release layer formed by a polyoxynitride-based release treatment agent. [Examples]

In the following, several embodiments of the invention are described, but the invention is not intended to be limited to the specific examples. In addition, the "parts" and "%" in the following description are based on weight unless otherwise specified.

(Preparation of Polymer A1) In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen introduction tube, and a cooler, 60 parts of 2EHA, 15 parts of N-vinyl-2-pyrrolidone (NVP), and methacrylic acid were added. 10 parts of ester (MMA), 15 parts of 2-hydroxyethyl acrylate (HEA), and 200 parts of ethyl acetate as a polymerization solvent, and stirred at 60 ° C for 2 hours under a nitrogen atmosphere, and then charged as a thermal polymerization initiator. 0.2 part of AIBN was reacted at 60 ° C for 6 hours to obtain a solution of polymer A1. The polymer A1 had a Mw of 1.1 million.

(Preparation of the polymer B1) Into a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, a cooler, and a dropping funnel, 100 parts of toluene, 40 parts of MMA, and 20 parts of n-butyl methacrylate (BMA) were placed. 20 parts of 2-ethylhexyl methacrylate (2EHMA) and a methacrylate monomer containing a polyorganosiloxane skeleton having a functional group equivalent of 900 g/mol (trade name: X-22-174ASX, Shin-Etsu Chemical Co., Ltd. Industrial Co., Ltd.) 8.7 parts of a methacrylate monomer containing a polyorganosiloxane skeleton (trade name: KF-2012, manufactured by Shin-Etsu Chemical Co., Ltd.), 11.3 parts, having a functional group equivalent of 4,600 g/mol And 0.51 part of methyl thioglycolate as a chain transfer agent. Then, after stirring at 70 ° C for 1 hour under a nitrogen atmosphere, 0.2 part of AIBN as a thermal polymerization initiator was introduced, and after reacting at 70 ° C for 2 hours, 0.1 part by weight of AIBN as a thermal polymerization initiator was charged. Then, it was allowed to react at 80 ° C for 5 hours. A solution of the polymer B1 was thus obtained. The polymer B1 had a Mw of 22,000.

(Preparation of Polymers B2 to B7) The composition of the monomer component was changed as shown in Table 1, and 0.8 parts of thioglycerol was used as a chain transfer agent, and ethyl acetate was used as a polymerization solvent, and further, the preparation was the same as that of the polymer B1. The polymers B2 to B7 were prepared in the same manner. Regarding the Mw of each polymer, the polymer B2 was 19,100, the polymer B3 was 19,700, the polymer B4 was 19,600, the polymer B5 was 20,000, the polymer B6 was 18,900, and the polymer B7 was 19,500.

The composition of the monomer component used in the preparation of the polymers B1 to B7, the glass transition temperature T _m1 based on the composition of the (meth)acrylic monomer in the monomer component, and the glass transfer of the polymers B1 to B7 The temperature T _{B is} summarized in Table 1.

[Table 1]

In addition, the weight average molecular weight of each of the above polymers was measured under the following conditions using a GPC apparatus (manufactured by Tosoh Corporation, HLC-8220GPC), and was determined by polystyrene conversion. [GPC condition] ・Sample concentration: 0.2 wt% (tetrahydrofuran (THF) solution) ・Sample injection amount: 10 μl ・Solution solution: THF ・Flow rate: 0.6 ml/min ・Measurement temperature: 40 °C ・Tube: Sample tube Column; TSKguardcolumn SuperHZ-H (1) + TSKgel SuperHZM-H (2) Reference column; TSKgel SuperH-RC (1) ・ Detector: Differential refractometer (RI)

Further, in the calculation of T _B shown in Table 1, 126 ° C was used as the value of Tg of X-22-174ASX, and -127 ° C was used as the value of Tg of KF-2012. The Tg of the methacrylate monomer containing the polyorganosiloxane skeleton is placed in a simple sealed container made of aluminum and subjected to DSC (differential scanning) under the following conditions. Determined by calorie measurement. [DSC condition] Device: TA Instruments, Q-2000 Temperature control program: -160 °C ~ 40 °C Heating rate: 10 °C / min Ambient gas: He (50 ml / min)

<Preparation of Adhesive Sheet> (Example 1) In the solution of the above polymer A1, 2.5 parts of the polymer B1 and 2.5 parts of isocyanate-based cross-linking were added with respect to 100 parts of the polymer A1 contained in the solution. The agent (trade name: Takenate D110N, trimethylolpropane phthalyl diisocyanate, manufactured by Mitsui Chemicals, Inc.) was uniformly mixed to prepare an adhesive composition C1. The adhesive composition C1 was directly applied to the first side of a polyethylene terephthalate (PET) film (manufactured by Toray Co., Ltd., trade name "Lumirror") having a thickness of 125 μm as a supporting substrate, at 110 ° C. It was dried by heating for 2 minutes, thereby forming an adhesive layer having a thickness of 25 μm. The peeling surface of the release liner R1 is bonded to the surface (adhesive surface) of the adhesive layer. In this manner, the adhesive sheet of Example 1 was obtained in the form of an adhesive sheet with a release liner which abuts against the release surface of the release liner. Further, as the release liner, MRQ25T100 (a release liner having a release layer formed of a polyfluorene-based release treatment agent on one side of the polyester film, thickness: 25 μm) was used by Mitsubishi Chemical Co., Ltd.

(Examples 2 to 11) Adhesive compositions C2 to C11 were prepared in the same manner as in the preparation of the adhesive composition C1 except that the amounts of the polymer B and the crosslinking agent were changed as shown in Table 2. Adhesive sheets of Examples 2 to 11 were obtained in the same manner as in the production of the adhesive sheet of Example 1, except that the adhesive compositions C2 to C11 were used, respectively.

<Measurement of Adhesive Strength of SUS> The adhesive sheet of each example was cut into a width of 25 mm together with a release liner, and the like was used as a test piece, and a SUS plate (SUS304BA plate) cleaned with toluene was used as an adherend. The adhesion force N ₂₃ , the adhesion force N _{50 ,} and the adhesion force N _{80 were} measured in the following order. (Measurement of Adhesion N ₂₃ ) The release liner covering the adhesive faces of each test piece was peeled off in a standard environment of 23 ° C and 50% RH, and the exposed surface of the test was crimped by a roll of 2 kg. It is stuck to the body. The test piece thus pressure-bonded to the adherend was placed in the above-mentioned standard environment for 30 minutes, and then a universal tensile compression tester (device name "Tensile Compression Tester, TCM-1kNB" manufactured by Minebea Co., Ltd.) was used, in accordance with JIS Z0237. The 180° peel adhesion (relative to the resistance of the above stretching) was measured under the conditions of a peeling angle of 180 degrees and a tensile speed of 300 mm/min. The measurement system was carried out three times, and the average value thereof was defined as the adhesion force (N ₂₃ ) [N/25 mm] after 30 minutes at 23 ° C. (Measurement of Adhesion N ₅₀ ) The test piece crimped to the adherend in the same manner as the measurement of the adhesive force ₂₃ was kept at 50 ° C for 30 minutes, and then placed in the above standard environment for 30 minutes. Thereafter, the 180° peel adhesion was measured in the same manner. The measurement system was carried out three times, and the average value of these was shown in Table 2 as the adhesion (N ₅₀ ) [N/25 mm] after 30 minutes at 50 °C. (Measurement of Adhesion N ₈₀ ) The test piece crimped to the adherend was heated at 80 ° C for 5 minutes in the same manner as the above-described measurement of the adhesive force ₂₃ , and then left in the above-mentioned standard environment for 30 minutes, and thereafter. The 180° peel adhesion was measured in the same manner. The measurement system was carried out three times, and the average value thereof was shown in Table 2 as the adhesion force (N ₈₀ ) [N/25 mm] after 5 minutes at 80 °C. Further, it was confirmed that the adhesive sheets of Examples 1 to 11 did not cause scratching damage at the time of measurement of the adhesive force N ₈₀ . Based on the results of the measurement of the adhesion, N ₈₀ /N ₅₀ , N ₅₀ /N ₂₃ , N ₈₀ /N ₂₃ , N ₅₀ -N ₂₃ , and (N ₈₀ -N ₅₀ )/(N ₅₀ -N ₂₃ ) were calculated. The results obtained are shown in Table 2.

[Table 2]

As shown in Table 2, it was confirmed that the adhesive sheets of Examples 5 to 9 in which the polymers B3 to B5 having the glass transition temperature T _{m1 were} in the range of 50 ° C to 100 ° C had a N ₈₀ /N ₅₀ of 5 or more, and thus even Applying a temperature of about 50 ° C at the initial stage of attachment also maintains low adhesion suitable for secondary processing, and the adhesion can be greatly increased by heating at 80 ° C for 5 minutes.

On the other hand, the adhesive sheets N ₈₀ /N ₅₀ of Examples 1 to 4 and Example 11 of the polymers B1, B2, and B7 having a glass transition temperature T _{m1 of} less than 50 ° C were less than 5, which were applied at the initial stage of attachment. The temperature is about 50 ° C and the adhesion is easy to rise. In the adhesive sheet of Example 4, N _{50 was} relatively low, but the adhesion could not be greatly increased by heating at 80 ° C for 5 minutes. Further, in the case of using the polymer B6 having a glass transition temperature T _m1 exceeding 100 ° C, the adhesion could not be increased by heating at 80 ° C for 5 minutes.

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

1‧‧‧Adhesive sheet

2‧‧‧Adhesive sheets

3‧‧‧Adhesive sheets

10‧‧‧Support substrate

10A‧‧‧ first side

10B‧‧‧ second side

21‧‧‧Adhesive layer (first adhesive layer)

21A‧‧‧Adhesive surface (first adhesive side)

21B‧‧‧Adhesive surface (second adhesive surface)

22‧‧‧Adhesive layer (second adhesive layer)

22A‧‧‧Adhesive surface (second adhesive surface)

31‧‧‧Release liner

32‧‧‧Release 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 configuration of an adhesive sheet of an embodiment. Fig. 2 is a cross-sectional view schematically showing the configuration of an adhesive sheet of another embodiment. Fig. 3 is a cross-sectional view schematically showing the configuration of an adhesive sheet of another embodiment.

Claims (10)

An adhesive sheet comprising an adhesive layer, the adhesive layer comprising a polymer A, and a polymer B as a copolymer of a monomer having a polyorganosiloxane skeleton and a (meth)acrylic monomer The glass transition temperature T _m1 of the polymer B based on the composition of the (meth)acrylic monomer is 50° C. or more and 100° C. or less, and is adhered to a stainless steel plate and then heated at 80° C. for 5 minutes. The force N ₈₀ is 5 times or more the adhesive force N ₅₀ after being held at 50 ° C for 30 minutes after being bonded to a stainless steel plate. The adhesive sheet of claim 1, wherein the adhesive force N ₅₀ and the adhesive force N ₂₃ after being placed at 23 ° C for 30 minutes after being attached to the stainless steel sheet satisfy the following formula: (N ₅₀ /N ₂₃ ) <10 . The adhesive sheet of claim 1 or 2, wherein the glass transition temperature T _A of the above polymer _A is ‐80° C. or more and less than 0° C. The adhesive sheet according to any one of claims 1 to 3, wherein the polymer B has a glass transition temperature T _B of -10 ° C or more and 10 ° C or less. The adhesive sheet according to any one of claims 1 to 4, wherein a copolymerization ratio of a monomer having a glass transition temperature of more than 170 ° C in the above polymer B is 30% by weight or less. The adhesive sheet according to any one of claims 1 to 5, wherein the adhesive layer contains more than 0 parts by weight and 10 parts by weight or less of the crosslinking agent with respect to 100 parts by weight of the above polymer A. The adhesive sheet according to any one of claims 1 to 6, wherein the polymer B has a weight average molecular weight of 10,000 or more and 50,000 or less. The adhesive sheet according to any one of claims 1 to 7, wherein the content of the polymer B in the adhesive layer is 0.05 parts by weight or more and 20 parts by weight or less based on 100 parts by weight of the polymer A. The adhesive sheet according to any one of claims 1 to 8, comprising a support substrate having a first side and a second side, and at least the first area layer of the support substrate has the adhesive layer. The adhesive sheet of claim 9, wherein the support substrate has a thickness of 30 μm or more.