KR102370314B1 - Adhesive sheet - Google Patents

Abstract

It is to provide an adhesive sheet which maintains reworkability even when a temperature of about 50°C is applied at the initial stage of sticking to an adherend, and can greatly increase adhesive strength thereafter.
A pressure-sensitive adhesive sheet including a pressure-sensitive adhesive layer is provided. The pressure-sensitive adhesive layer includes a polymer A and a polymer B, which is a copolymer of a monomer having a polyorganosiloxane skeleton and a (meth)acrylic monomer. The polymer B has a glass transition temperature T _m1 of 50°C or more and 100°C or less based on the composition of the (meth)acrylic monomer. After sticking, the adhesive force N80 after heating at ₈₀ degreeC for 5 minutes of the said adhesive sheet is 5 times or more of adhesive force N50 after leaving it to stand at ₅₀ degreeC after sticking for 30 minutes.

Description

Adhesive sheet {ADHESIVE SHEET}

The present invention relates to an adhesive sheet.

This application claims the priority based on Japanese Patent Application No. 2017-222778 for which it applied on November 20, 2017, The whole content of the application is incorporated by reference in this specification.

The pressure-sensitive adhesive sheet is firmly adhered to an adherend, and thus is used for the purposes of bonding adherends to each other, fixing an article to an adherend, reinforcing the adherend, and the like. Conventionally, for this purpose, the adhesive sheet which exhibits high adhesive force from the initial stage of pasting was used. Moreover, like patent documents 1 - 3, the adhesive sheet which shows low adhesive force at the initial stage of pasting to a to-be-adhered body, and can raise adhesive force largely after that is proposed. According to the pressure-sensitive adhesive sheet having such properties, before the increase in the adhesive strength, the re-adhesive property (reworkability) useful for suppressing the yield decrease due to the adhesion error or adhesion damage of the pressure-sensitive adhesive sheet is exhibited. It can exhibit strong adhesion suitable for the purpose of use.

Japanese Patent Application Laid-Open No. 2014-224227 Japanese Patent Publication No. 5890596 Japanese Patent No. 5951153

However, depending on the usage mode of the adhesive sheet, after adhering, after advancing to the subsequent process, an adhesion error or adhesion damage is identified, or a rework request occurs due to the occurrence of a positional shift due to the influence of the subsequent process. There may be cases. In this case, within the period in which reworkability is required for the pressure-sensitive adhesive sheet affixed to the adherend, for example, the generation of heat accompanying the operation of an apparatus (conveying apparatus, inspection apparatus, other processing apparatus, etc.) used in the manufacturing process is reduced. In some cases, a temperature of about 40°C to 50°C may be applied to the pressure-sensitive adhesive sheet due to an influence, an arrangement from a nearby device, or an accidental factor such as a temperature rise in the manufacturing environment. Then, an object of this invention is to provide the adhesive sheet which can maintain rework property even if a temperature of about 50 degreeC is applied at the initial stage of sticking to a to-be-adhered body, and can raise adhesive force significantly after that.

According to this specification, there is provided a pressure-sensitive adhesive sheet including a pressure-sensitive adhesive layer. The pressure-sensitive adhesive layer includes a polymer A and a polymer B, which is a copolymer of a monomer having a polyorganosiloxane skeleton and a (meth)acrylic monomer. The polymer B has a glass transition temperature T _m1 of 50°C or more and 100°C or less based on the composition of the (meth)acrylic monomer. The pressure-sensitive adhesive sheet, after bonding to a stainless steel sheet, the adhesive force N ₈₀ after heating at 80 ° C. for 5 minutes is 5 times or more of the adhesive force N ₅₀ after bonding to the stainless steel sheet and holding it at 50 ° C. for 30 minutes.

5). 이에 의해, 첩부 초기에 50℃ 정도의 온도가 가해질 수 있는 사용 양태에 있어서도 양호한 리워크성을 나타내며, 또한 그 후의 가열 등에 의해 점착력을 크게 상승시킬 수 있다.The pressure-sensitive adhesive sheet having such a configuration includes a polymer B having a glass transition temperature T _m1 of 50° C. or more and 100° C. or less, thereby increasing the adhesive strength N ₈₀ (hereinafter also referred to as “adhesive strength after heating”) to 5 times or more with respect to the adhesive strength N ₅₀ . can be (i.e. N ₈₀ /N ₅₀

5). Thereby, also in the usage aspect in which the temperature of about 50 degreeC can be applied at the initial stage of sticking, favorable rework property can be exhibited, and adhesive force can be raised largely by subsequent heating etc.

In the pressure-sensitive adhesive sheet according to some embodiments, the relationship between the adhesive force N ₅₀ and the adhesive force N ₂₃ after bonding to a stainless steel sheet and leaving it at 23° C. for 30 minutes satisfies the following formula: (N ₅₀ /N ₂₃ )<10; do. According to such an adhesive sheet, since the difference in adhesive force (and reworkability) when it is maintained at room temperature at the initial stage of sticking and when exposed to a temperature of up to about 50°C is small, it is preferable from the viewpoint of workability and ease of process control. Do.

In some embodiments, the glass transition temperature T _A of the polymer A may be, for example, greater than or equal to -80°C and less than 0°C. The pressure-sensitive adhesive sheet disclosed herein can be suitably implemented using the polymer A having such a glass transition temperature T _A .

In some embodiments, the glass transition temperature TB of the polymer _B may be, for example, -10°C or more and 10°C or less. The pressure-sensitive adhesive sheet disclosed herein can be suitably implemented using the polymer _B having such a glass transition temperature TB .

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

In some embodiments, the pressure-sensitive adhesive layer may include more than 0 parts by weight and not more than 10 parts by weight of a crosslinking agent based on 100 parts by weight of the polymer A. By using a crosslinking agent, the adhesive force of an affixing initial stage can be adjusted effectively in the temperature range to about 50 degreeC. Thereby, there exists a tendency for it to become easy to obtain the adhesive sheet which makes compatible the rework property of an initial stage of pasting, and the strong adhesiveness after an adhesive force rise suitably.

In some embodiments, as the polymer B, those having a weight average molecular weight (Mw) of 10000 or more and 50000 or less can be preferably used. According to the polymer B in which Mw is in the said range, the adhesive force of an initial stage of pasting is low, and the adhesive sheet with high adhesive force after heating is easy to be obtained.

In some aspects, content of the said polymer B in the said adhesive layer can be made into the range of 0.05 weight part or more and 20 weight part or less with respect to 100 weight part of said polymer A. According to content in the said range, the adhesive force of an initial stage of pasting is low, and the adhesive sheet with high adhesive force after heating is easy to be obtained.

The pressure-sensitive adhesive sheet disclosed herein is provided with a support substrate having a first surface and a second surface, and the pressure-sensitive adhesive layer is laminated on at least the first surface of the support substrate, that is, in the form of a pressure-sensitive adhesive sheet provided with a substrate. can be carried out. Such an adhesive sheet with a base material can be made into a thing with good handleability and processability. As said support base material, a thing with a thickness of 30 micrometers or more can be employ|adopted preferably, for example.

In addition, appropriate combinations of the above elements may also be included in the scope of the invention for which protection by a patent is sought by the present patent application.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows typically the structure of the adhesive sheet which concerns on one Embodiment.
2 : is sectional drawing which shows typically the structure of the adhesive sheet which concerns on another one Embodiment.
3 : is sectional drawing which shows typically the structure of the adhesive sheet which concerns on another one Embodiment.

Hereinafter, preferred embodiments of the present invention will be described. Matters other than those specifically mentioned in this specification and necessary for the implementation of the present invention can be understood by those skilled in the art based on the teachings for the implementation of the invention described in this specification and the technical common sense at the time of filing. The present invention can be implemented based on the content disclosed in this specification and common technical knowledge in this field.

In addition, in the following drawings, the same code|symbol may be attached|subjected to the member and site|part exhibiting the same effect|action, and description may be given, and overlapping description may be abbreviate|omitted or simplified. In addition, embodiment described in the drawing is schematic for demonstrating this invention clearly, and does not necessarily show exactly the size or scale of the actually provided product.

In addition, in this specification, "acrylic polymer" refers to a polymer containing a monomer unit derived from a (meth)acrylic monomer in the polymer structure, and typically 50% by weight of a monomer unit derived from a (meth)acrylic monomer. It refers to a polymer containing in an excess ratio. In addition, a (meth)acrylic-type monomer means the monomer which has at least 1 (meth)acryloyl group in 1 molecule. Here, "(meth)acryloyl group" is the meaning which points out an acryloyl group and a methacryloyl group comprehensively. Accordingly, the concept of the (meth)acrylic monomer referred to herein may include both a monomer having an acryloyl group (acrylic monomer) and a monomer having a methacryloyl group (methacrylic monomer). Similarly, in this specification, "(meth)acrylic acid" refers to acrylic acid and methacrylic acid, and "(meth)acrylate" refers to acrylate and methacrylate inclusively, respectively.

<Structural example of adhesive sheet>

The adhesive sheet disclosed here is comprised including the adhesive layer. The pressure-sensitive adhesive sheet disclosed herein may be in the form of an adhesive sheet provided with a base material in which the pressure-sensitive adhesive layer is laminated on one side or both surfaces of a supporting base material, or may be in the form of a base material-free pressure-sensitive adhesive sheet having no supporting base material. Hereinafter, the supporting base material may be simply referred to as a "base material".

The structure of the adhesive sheet which concerns on one Embodiment is schematically shown in FIG. This pressure-sensitive adhesive sheet 1 is provided with a sheet-shaped support substrate 10 having a first surface 10A and a second surface 10B, and an pressure-sensitive adhesive layer 21 formed on the first surface 10A side. It is comprised as a single-sided adhesive sheet with a base material. The pressure-sensitive adhesive layer 21 is adhered to the side of the first surface 10A of the support substrate 10 . The adhesive sheet 1 is used by affixing the adhesive layer 21 to a to-be-adhered body. As shown in FIG. 1, the adhesive sheet 1 before use (that is, before sticking to a to-be-adhered body) 21 A of surfaces (adhesive surface) of the adhesive layer 21 is at least adhesive layer 21. It may be a component of the pressure-sensitive adhesive sheet 100 provided with a release liner in a form in which the side opposite to the release liner 31 is in contact with the release liner 31 having a release surface (release surface). As the release liner 31, for example, by forming a release layer with a release agent on one surface of a sheet-like base material (liner base material), one configured so that the single surface becomes a release surface can be preferably used. Alternatively, the release liner 31 is omitted and the pressure-sensitive adhesive surface 21A is formed on the support substrate 10 by winding the pressure-sensitive adhesive sheet 1 using the support substrate 10 having the second surface 10B serving as the release surface. ) may be in a form (roll form) in contact with the second surface 10B. When the pressure-sensitive adhesive sheet 1 is attached to an adherend, the release liner 31 or the second surface 10B of the supporting substrate 10 is peeled off from the pressure-sensitive adhesive surface 21A, and the exposed pressure-sensitive adhesive surface 21A is removed. Compress to the complex.

The structure of the adhesive sheet which concerns on another one Embodiment is shown typically in FIG. This pressure-sensitive adhesive sheet 2 includes a sheet-shaped support base 10 having a first surface 10A and a second surface 10B, an pressure-sensitive adhesive layer 21 formed on the first surface 10A side thereof; It is comprised as a double-sided adhesive sheet with a base material provided with the adhesive layer 22 provided in the 2 side 10B side. The pressure-sensitive adhesive layer (first pressure-sensitive adhesive layer) 21 is on the first surface 10A of the support substrate 10 , and the pressure-sensitive adhesive layer (second pressure-sensitive adhesive layer) 22 is on the second surface 10B of the support substrate 10 . , respectively, are fixed. The pressure-sensitive adhesive sheet 2 is used by affixing the pressure-sensitive adhesive layers 21 and 22 to different locations of the adherend. Each location of a different member may be sufficient as the location to which the adhesive layers 21 and 22 are affixed, and the different location in a single member may be sufficient as it. As shown in FIG. 2, the adhesive sheet 2 before use is 21 A of surfaces (1st adhesive surface) of the adhesive layer 21, and 22 A of surfaces (2nd adhesive surfaces) of the adhesive layer 22. This may be a component of the pressure-sensitive adhesive sheet 200 provided with a release liner in which at least the side facing the pressure-sensitive adhesive layers 21 and 22 is in contact with the release liners 31 and 32 serving as release surfaces, respectively. As the release liners 31 and 32, for example, a release layer made of a release agent is formed on one surface of a sheet-like base material (liner base material), so that one surface is preferably used so that the single surface becomes a release surface. Alternatively, by omitting the release liner 32 and using a release liner 31 having a release surface on both sides, overlapping this and the pressure-sensitive adhesive sheet 2 and winding the pressure-sensitive adhesive sheet 2 in a spiral wound shape, so that the second pressure-sensitive adhesive surface 22A is formed. You may comprise the adhesive sheet with a release liner of the form (roll form) contact|abutted to the back surface of the release liner 31.

The structure of the pressure-sensitive adhesive sheet according to still another embodiment is schematically shown in FIG. 3 . This adhesive sheet 3 is comprised as an inorganic material double-sided adhesive sheet containing the adhesive layer 21. As shown in FIG. The pressure-sensitive adhesive sheet 3 includes a first pressure-sensitive adhesive surface 21A formed by one surface (first surface) of the pressure-sensitive adhesive layer 21 and a second surface (second surface) formed by the other surface (second surface) of the pressure-sensitive adhesive layer 21 . It is used by affixing the 2 adhesive surfaces 21B to different locations of a to-be-adhered body. As shown in FIG. 3 , the pressure-sensitive adhesive sheet 3 before use has a first adhesive surface 21A and a second adhesive surface 21B, and at least the side facing the pressure-sensitive adhesive layer 21 serves as a peeling surface, respectively. It may be a component of the pressure-sensitive adhesive sheet 300 having a release liner in contact with the release liners 31 and 32 . Alternatively, by omitting the release liner 32 and using a release liner 31 having both surfaces as release surfaces, overlapping this and the pressure-sensitive adhesive sheet 3 and winding it in a spiral wound shape, the second adhesive surface 21B is formed. You may comprise the adhesive sheet with a release liner of the form (roll form) contact|abutted to the back surface of the release liner 31.

In addition, what is called an adhesive tape, an adhesive film, an adhesive label, etc. can be contained in the concept of the adhesive sheet here. The pressure-sensitive adhesive sheet may be in the form of a roll or in the form of a sheet, or may be one that has been cut, punched, or the like into an appropriate shape according to the use or usage mode. Although the adhesive layer in the technique disclosed herein is typically continuously formed, it is not limited to this, For example, you may form in regular or random patterns, such as a dotted form and stripe form.

<Adhesive layer>

The pressure-sensitive adhesive sheet disclosed herein includes a pressure-sensitive adhesive layer comprising a polymer A and a polymer B which is a copolymer of a monomer having a polyorganosiloxane skeleton and a (meth)acrylic monomer. Such a pressure-sensitive adhesive layer may be formed of a pressure-sensitive adhesive composition containing the polymer A or its precursor and the polymer B. The form of the pressure-sensitive adhesive composition is not particularly limited, and for example, may be in various forms such as water dispersion type, solvent type, hot melt type, active energy ray curing type (eg, photocurable type).

(Polymer A)

As polymer A, in the field of adhesives, known acrylic polymers, rubber polymers, polyester polymers, urethane polymers, polyether polymers, silicone polymers, polyamide polymers, fluorine polymers, etc., have rubber elasticity in the room temperature range. One type or two or more types can be used among the various polymers shown.

Glass transition temperature T _A of polymer A is not specifically limited, In the adhesive sheet disclosed here, it can select so that preferable characteristics may be obtained. In some embodiments, Polymer A having a T _A of less than 0° C. may be preferably employed. The pressure-sensitive adhesive containing such a polymer A is suitable for realization of a pressure-sensitive adhesive sheet that has both low tackiness in the initial stage and strong adhesion after heating in that it exhibits moderate fluidity (for example, the mobility of polymer chains contained in the pressure-sensitive adhesive). . The pressure-sensitive adhesive sheet disclosed herein can be preferably implemented 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 some embodiments, 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 easiness of material availability and improvement of the cohesive force of the pressure-sensitive adhesive layer, generally, polymer A having a T _A of -80°C or higher, -70°C or higher, or -65°C or higher can be preferably employed. From the viewpoint of suppressing the rise of N ₅₀ , in some embodiments, T _A may be, for example, -63°C or higher, -55°C or higher, -50°C or higher, or -45°C or higher.

Here, in this specification, the glass transition temperature (Tg) of a polymer is a nominal value described in literature or catalogs, etc. . The Fox formula is a relational expression between Tg of the copolymer and the glass transition temperature Tgi of a homopolymer obtained by homopolymerizing each of the monomers constituting the copolymer, as described below.

1/Tg=Σ(Wi/Tgi)

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

As the glass transition temperature of the homopolymer used in the calculation of Tg, the value described in known materials is used. Specifically, numerical values are exemplified in "Polymer Handbook" (3rd ed., John Wiley & Sons, Inc., 1989). For the monomers for which a plurality of types of values are described in the Polymer Handbook, the highest value is employed.

As the glass transition temperature of the homopolymer of the monomer not described in the Polymer Handbook, a value obtained by the following measurement method is used except for the monomer having a polyorganosiloxane skeleton.

Specifically, 100 parts by weight of the monomer, 0.2 parts by weight of 2,2'-azobisisobutyronitrile and 200 parts by weight of ethyl acetate as a polymerization solvent were introduced into a reactor equipped with a thermometer, a stirrer, a nitrogen introduction tube and a reflux cooling tube. and stirred for 1 hour while flowing nitrogen gas. After removing oxygen in the polymerization system in this way, the temperature is raised to 63° C. and reacted for 10 hours. Then, it cools to room temperature, and obtains the homopolymer solution with a solid content concentration of 33 weight%. Next, this homopolymer solution is applied by casting on a release liner and dried to prepare a test sample (sheet-shaped homopolymer) having a thickness of about 2 mm. This test sample was punched into a disk shape with a diameter of 7.9 mm, sandwiched between parallel plates, and sheared at a frequency of 1 Hz using a viscoelasticity tester (manufactured by TA Instruments Japan, model name "ARES"), while giving a temperature range of -70°C to The viscoelasticity is measured in a shear mode at 150°C and a temperature increase rate of 5°C/min, and the temperature corresponding to the peak top temperature of tan δ is Tg of the homopolymer.

In addition, for a monomer having a polyorganosiloxane skeleton, a value obtained by performing DSC (differential scanning calorimetry) on the monomer, more specifically, a value obtained according to the method described in Examples to be described later As the glass transition temperature of the monomer having a organosiloxane skeleton, the Fox equation is applied.

Although it does not specifically limit, It is suitable that the weight average molecular weight (Mw) of polymer A is about ^5x104 or more normally. According to the polymer A of such Mw, the adhesive which shows favorable cohesiveness is easy to be obtained. In some embodiments, Mw of the polymer A may be, for example, 10×10 ⁴ or more, 20×10 ⁴ or more, or 30×10 ⁴ or more. In addition, it is suitable that Mw of polymer A is about 500x10< ⁴ > or less normally. Polymer A of such Mw is suitable for realization of a pressure-sensitive adhesive sheet having a low adhesive strength at the initial stage of pasting and high adhesive strength after heating in that it is easy to form a pressure-sensitive adhesive exhibiting suitable fluidity (movability of polymer chains).

In addition, in this specification, Mw of polymer A and polymer B can be calculated|required in terms of polystyrene by gel permeation chromatography (GPC). More specifically, Mw can be measured in accordance with the methods and conditions described in Examples to be described later.

As the polymer A in the pressure-sensitive adhesive sheet disclosed herein, an acrylic polymer can be preferably employed. When an acrylic polymer is used as the polymer A, good compatibility with the polymer B tends to be easily obtained. It is preferable that the compatibility of the polymer A and the polymer B is good, since it can contribute to the reduction of the initial adhesive force and the improvement of the adhesive force after heating through the improvement of the mobility of the polymer B in the pressure-sensitive adhesive layer.

The acrylic polymer is, for example, a polymer containing 50 wt% or more of monomer units derived from (meth)acrylic acid alkylester, that is, 50 wt% or more of the total amount of monomer components for preparing the acrylic acid alkylester (meth)acrylic acid alkylester It may be a phosphorus polymer. As the (meth)acrylic acid alkyl ester, a (meth)acrylic acid alkyl ester having a C 1-20 (ie, C _1-20 ) linear or branched alkyl group can be preferably used. From the viewpoint of easy to balance the characteristics, the proportion of (meth)acrylic acid C _1-20 alkyl ester in the total amount of the monomer component may be, for example, 50% by weight or more, 60% by weight or more, and 70% by weight or more. do. From the same reason, the ratio of (meth)acrylic acid C _1-20 alkylester in the total amount of the monomer component may be, for example, 99.9% by weight or less, 98% by weight or less, or 95% by weight or less. In some embodiments, the proportion of (meth)acrylic acid C _1-20 alkylester in the total amount of the monomer component may be, for example, 90% by weight or less, 85% by weight or less, or 80% by weight or less.

As a non-limiting example of the (meth)acrylic acid C _1-20 alkyl ester, (meth) methyl acrylate, (meth) ethyl acrylate, (meth) acrylic acid propyl, (meth) acrylate isopropyl, (meth) acrylate n-butyl, (meth) acrylate isobutyl, (meth) acrylate s-butyl, (meth) acrylate t-butyl, (meth) acrylate pentyl, (meth) acrylate isopentyl, (meth) acrylate hexyl, (meth) acrylate heptyl, (meth) acrylate ) octyl acrylate, (meth) acrylate 2-ethylhexyl, (meth) acrylate isooctyl, (meth) acrylate nonyl, (meth) acrylate isononyl, (meth) decyl acrylate, (meth) acrylate isodecyl, (meth) Undecyl acrylate, (meth) acrylate dodecyl, (meth) acrylic acid tridecyl, (meth) acrylic acid tetradecyl, (meth) acrylic acid pentadecyl, (meth) acrylic acid hexadecyl, (meth) acrylic acid heptadecyl, (meth) acrylic acid Stearyl, (meth)acrylic acid isostearyl, (meth)acrylic acid nonadecyl, (meth)acrylic acid eicosyl, etc. are mentioned.

Among these, it is preferable to use at least (meth)acrylic acid C _1-18 alkylester, and it is more preferable to use at least (meth)acrylic acid C _1-14 alkylester. In some embodiments, the acrylic polymer is at least one selected from (meth)acrylic acid C _4-12 alkyl ester (preferably acrylic acid C _4-10 alkyl ester, for example, acrylic acid C _6-10 alkyl ester) as a monomer. It can be contained as a 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 (meth)acrylic acid C _1-18 alkyl esters that can be preferably used include methyl acrylate, methyl methacrylate (MMA), n-butyl methacrylate (BMA), and 2-ethylhexyl methacrylate (2EHMA). , isostearyl acrylate (ISTA), and the like.

The monomer unit constituting the acrylic polymer may contain, if necessary, other monomers copolymerizable with the (meth)acrylic acid alkylester (copolymerizable monomer) together with the (meth)acrylic acid alkyl ester as the main component. As a copolymerizable monomer, the monomer which has a polar group (For example, a carboxy group, a hydroxyl group, a nitrogen atom containing ring, etc.) can be used suitably. The monomer having a polar group can be helpful in introducing a crosslinking point to the acrylic polymer or in increasing the cohesive force of the acrylic polymer. A copolymerizable monomer can be used individually by 1 type or in combination of 2 or more type.

The following are mentioned as a non-limiting specific example of a copolymerizable monomer.

Carboxylic group-containing monomers: For example, acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, isocrotonic acid and the like.

Acid anhydride group-containing monomers: for example, maleic anhydride, itaconic anhydride.

Hydroxyl group-containing monomers: for example, (meth)acrylic acid 2-hydroxyethyl, (meth)acrylic acid 2-hydroxypropyl, (meth)acrylic acid 2-hydroxybutyl, (meth)acrylic acid 3-hydroxypropyl, (meth)acrylic acid ) Acrylic acid 4-hydroxybutyl, (meth)acrylic acid 6-hydroxyhexyl, (meth)acrylic acid 8-hydroxyoctyl, (meth)acrylic acid 10-hydroxydecyl, (meth)acrylic acid 12-hydroxylauryl, ( (meth)acrylic acid hydroxyalkyl, such as 4-hydroxymethylcyclohexyl)methyl (meth)acrylate.

Monomers containing a sulfonic acid group or a phosphoric acid group: for example, styrenesulfonic acid, allylsulfonic acid, sodium vinylsulfonate, 2-(meth)acrylamido-2-methylpropanesulfonic acid, (meth)acrylamidopropanesulfonic acid, sulfopropyl ( meth)acrylate, (meth)acryloyloxynaphthalenesulfonic acid, 2-hydroxyethylacryloylphosphate, and the like.

Epoxy group-containing monomers: For example, epoxy group-containing acrylates such as (meth)acrylic acid glycidyl and (meth)acrylic acid-2-ethylglycidyl ether, allyl glycidyl ether, (meth)acrylic acid glycidyl ether, etc. .

Cyano group-containing monomers: for example, acrylonitrile, methacrylonitrile, and the like.

Isocyanate group-containing monomers: For example, 2-isocyanatoethyl (meth)acrylate and the like.

Amide group-containing monomers: for example, (meth)acrylamide; N,N-dimethyl (meth)acrylamide, N,N-diethyl (meth)acrylamide, N,N-dipropyl (meth)acrylamide, N,N-diisopropyl (meth)acrylamide, N, N,N-dialkyl (meth)acrylamide, such as N-di(n-butyl)(meth)acrylamide and N,N-di(t-butyl)(meth)acrylamide; N-alkyl (meth)acrylamide, such as N-ethyl (meth)acrylamide, N-isopropyl (meth)acrylamide, N-butyl (meth)acrylamide, and N-n-butyl (meth)acrylamide; N-vinylcarboxylic acid amides, such as N-vinylacetamide; Monomers having a hydroxyl group and an amide group, for example N-(2-hydroxyethyl)(meth)acrylamide, N-(2-hydroxypropyl)(meth)acrylamide, N-(1-hydroxypropyl)( Meth)acrylamide, N-(3-hydroxypropyl)(meth)acrylamide, N-(2-hydroxybutyl)(meth)acrylamide, N-(3-hydroxybutyl)(meth)acrylamide, N-hydroxyalkyl (meth)acrylamide, such as N-(4-hydroxybutyl)(meth)acrylamide; Monomers having an alkoxy group and an amide group, for example, N-alkoxyalkyl (meth) such as N-methoxymethyl (meth) acrylamide, N-methoxyethyl (meth) acrylamide, N-butoxymethyl (meth) ) acrylamide; In addition, N,N-dimethylaminopropyl (meth)acrylamide, N-(meth)acryloylmorpholine, etc.

Monomers having a nitrogen atom-containing ring: for example, N-vinyl-2-pyrrolidone, N-methylvinylpyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperidone Razine, N-vinylpyrazine, N-vinylpyrrole, N-vinylimidazole, N-vinyloxazole, N-(meth)acryloyl-2-pyrrolidone, N-(meth)acryloylpiperidine , N-(meth)acryloylpyrrolidine, N-vinylmorpholine, N-vinyl-3-morpholinone, N-vinyl-2-caprolactam, N-vinyl-1,3-oxazin-2- one, N-vinyl-3,5-morpholinedione, N-vinylpyrazole, N-vinylisooxazole, N-vinylthiazole, N-vinylisothiazole, N-vinylpyridazine, etc. (eg, lactams such as N-vinyl-2-caprolactam).

Monomers having a succinimide skeleton: for example, N-(meth)acryloyloxymethylenesuccinimide, N-(meth)acryloyl-6-oxyhexamethylenesuccinimide, N-(meth)acryl Royl-8-oxyhexamethylenesuccinimide and the like.

Maleimides: For example, N-cyclohexyl maleimide, N-isopropyl maleimide, N-lauryl maleimide, N-phenyl maleimide and the like.

Itaconimides: For example, N-methyl itaconimide, N-ethyl itaconimide, N-butyl itaconimide, N-octyl itaconimide, N-2-ethylhexyl itacon mide, N-cyclohexyl itaconimide, N-lauril itaconimide, and the like.

(meth)acrylic acid aminoalkyl: For example, (meth)acrylic acid aminoethyl, (meth)acrylic acid N,N-dimethylaminoethyl, (meth)acrylic acid N,N-diethylaminoethyl, (meth)acrylic acid t- Butylaminoethyl.

Alkoxy group-containing monomers: for example, (meth)acrylic acid 2-methoxyethyl, (meth)acrylic acid 3-methoxypropyl, (meth)acrylic acid 2-ethoxyethyl, (meth)acrylic acid propoxyethyl, (meth) (meth)acrylic acid alkoxyalkyls, such as butoxyethyl acrylate and (meth)acrylic acid ethoxypropyl; (meth)acrylic acid alkoxyalkylene glycols, such as (meth)acrylic-acid methoxyethylene glycol and (meth)acrylic-acid methoxypolypropylene glycol.

Vinyl esters: For example, vinyl acetate, vinyl propionate, etc.

Vinyl ethers: For example, vinyl alkyl ethers such as methyl vinyl ether and ethyl vinyl ether.

Aromatic vinyl compounds: For example, styrene, ?-methylstyrene, vinyltoluene, and the like.

Olefins: For example, ethylene, butadiene, isoprene, isobutylene, and the like.

(meth)acrylic acid ester having an alicyclic hydrocarbon group: For example, cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate and the like.

(meth)acrylic acid ester having an aromatic hydrocarbon group: For example, phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, benzyl (meth)acrylate, and the like.

In addition, heterocyclic-containing (meth)acrylates such as (meth)acrylic acid tetrahydrofurfuryl, halogen atom-containing (meth)acrylates such as vinyl chloride and fluorine atom-containing (meth)acrylates, silicone (meth)acrylates Silicon atom-containing (meth)acrylates, such as (meth)acrylic acid ester obtained from terpene compound derivative alcohol.

When using such a copolymerizable monomer, although the usage-amount is not specifically limited, Usually, it is suitable to set it as 0.01 weight% or more of the monomer component whole quantity. From a viewpoint of exhibiting the effect by use of a copolymerizable monomer better, it is good also considering the usage-amount of a copolymerizable monomer as 0.1 weight% or more of monomer component whole quantity, and good also as 1 weight% or more. In addition, the usage-amount of a copolymerizable monomer can be made into 50 weight% or less of monomer component whole quantity, and it is preferable to set it as 40 weight% or less. Thereby, it can prevent that the cohesive force of an adhesive becomes high too much, and can improve the tack feeling in normal temperature (25 degreeC).

In some embodiments, the acrylic polymer is, as a monomer unit, an N-vinyl cyclic amide represented by the following general formula (M1) and a hydroxyl group-containing monomer (a monomer having a functional group different from a hydroxyl group, for example, a hydroxyl group and an amide group-containing monomer It is preferable to contain at least one monomer selected from the group consisting of).

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

By use of N-vinyl cyclic amide, the cohesive force and polarity of an adhesive can be adjusted, and the adhesive force after heating can be improved. Specific examples of N-vinyl cyclic amide include N-vinyl-2-pyrrolidone, N-vinyl-2-piperidone, N-vinyl-3-morpholinone, N-vinyl-2-caprolactam, N-vinyl -1,3-oxazin-2-one, N-vinyl-3,5-morpholinedione, etc. are mentioned. Particularly preferred are N-vinyl-2-pyrrolidone and N-vinyl-2-caprolactam.

The amount of N-vinyl cyclic amide to be used is not particularly limited, but is usually 0.01% by weight or more (preferably 0.1% by weight or more, for example 0.5% by weight or more) of the total amount of the monomer component for preparing the acrylic polymer. Do. In some embodiments, the amount of N-vinyl cyclic amide to be used may be 1 wt% or more, 5 wt% or more, or 10 wt% or more of the total amount of the monomer component. In addition, from the viewpoint of improving the tackiness at room temperature (25°C) and improving the flexibility at low temperature, it is appropriate that the amount of N-vinyl cyclic amide to be used is usually 40% by weight or less of the total amount of the monomer component, and 30% by weight. % or less, and good also as 20 weight% or less.

By use of a hydroxyl-containing monomer, the cohesive force and polarity of an adhesive can be adjusted, and adhesive force after heating can be improved. In addition, the hydroxyl group-containing monomer provides a reaction point with a crosslinking agent (eg, an isocyanate-based crosslinking agent) described later, and can increase the cohesive force of the pressure-sensitive adhesive by the crosslinking reaction.

As a hydroxyl-containing monomer, (meth)acrylic acid 2-hydroxyethyl, (meth)acrylic acid 4-hydroxybutyl, (meth)acrylic acid 6-hydroxyhexyl, N-(2-hydroxyethyl) (meth)acrylamide, etc. can be used appropriately. Among these, 2-hydroxyethyl acrylate (HEA), 4-hydroxybutyl acrylate (4HBA), and N-(2-hydroxyethyl) acrylamide (HEAA) are mentioned as preferable examples.

The amount of the hydroxyl-containing monomer to be used is not particularly limited, but is usually 0.01% by weight or more (preferably 0.1% by weight or more, for example 0.5% by weight or more) of the total amount of the monomer component for preparing the acrylic polymer. In some aspects, the usage-amount of a hydroxyl-containing monomer is good also as 1 weight% or more of the said monomer component whole quantity, it is good also as 5 weight% or more, and it is good also as 10 weight% or more. In addition, from the viewpoint of improving the tackiness at room temperature (25°C) and improving the flexibility at low temperature, the amount of the hydroxyl group-containing monomer to be used is usually 40% by weight or less of the total amount of the monomer component, and 30% by weight or less It is good also as 20 weight% or less, and is good also as 10 weight% or less or 5 weight% or less.

In some embodiments, as the copolymerizable monomer, N-vinyl cyclic amide and a hydroxyl group-containing monomer may be used in combination. In this case, the total amount of the N-vinyl cyclic amide and the hydroxyl group-containing monomer can be, for example, 0.1 wt% or more of the total amount of the monomer components for preparing the acrylic polymer, 1 wt% or more, 5 wt% or more It is good also as 10 weight% or more, and may be 15 weight% or more, is good also as 20 weight% or more, and is good also as 25 weight% or more. In addition, the total amount of N-vinyl cyclic amide and a hydroxyl-containing monomer can be made into 50 weight% or less of monomer component whole quantity, for example, and it is preferable to set it as 40 weight% or less.

The method for obtaining the acrylic polymer is not particularly limited, and various polymerization methods known as acrylic polymer synthesis methods such as solution polymerization, emulsion polymerization, bulk polymerization, suspension polymerization, and photopolymerization can be appropriately employed. . In some embodiments, a solution polymerization method may be preferably employed. The polymerization temperature when performing solution polymerization can be appropriately selected depending on the type of monomer and solvent used, the type of polymerization initiator, etc., for example, about 20°C to 170°C (typically about 40°C to 140°C) can be done with

The initiator used for polymerization can be suitably selected from conventionally well-known thermal polymerization initiator, a photoinitiator, etc. according to a polymerization method. A polymerization initiator can be used individually by 1 type or in combination of 2 or more type.

As the thermal polymerization initiator, for example, an azo polymerization initiator (for example, 2,2'-azobisisobutyronitrile, 2,2'-azobis-2-methylbutyronitrile, 2,2'-azo Bis(2-methylpropionic acid)dimethyl, 4,4'-azobis-4-cyanovaleric acid, azobisisovaleronitrile, 2,2'-azobis(2-amidinopropane)dihydrochloride, 2 ,2'-azobis[2-(5-methyl-2-imidazolin-2-yl)propane]dihydrochloride, 2,2'-azobis(2-methylpropionamidine) disulfate, 2, 2'-azobis(N,N'-dimethyleneisobutylamidine)dihydrochloride, etc.); persulfates such as potassium persulfate; peroxide polymerization initiators (eg, dibenzoyl peroxide, t-butyl permaleate, lauroyl peroxide, etc.); A redox polymerization initiator etc. are mentioned. The amount of the thermal polymerization initiator to be used is not particularly limited, but for example, 0.01 parts by weight to 5 parts by weight, preferably 0.05 parts by weight to 3 parts by weight, based on 100 parts by weight of the monomer component used in the preparation of the acrylic polymer. can be done with

Although it does not restrict|limit especially as a photoinitiator, For example, A benzoin ether type photoinitiator, an acetophenone type photoinitiator, alpha-ketol type photoinitiator, an aromatic sulfonyl chloride type photoinitiator, a photoactive oxime type photoinitiator, a benzoin type photoinitiator. Initiators, benzyl-based photoinitiators, benzophenone-based photopolymerization initiators, ketal-based photopolymerization initiators, thioxanthone-based photopolymerization initiators, acylphosphine oxide-based photopolymerization initiators, and the like can be used. The amount of the photopolymerization initiator to be used is not particularly limited, but for example, 0.01 parts by weight to 5 parts by weight, preferably 0.05 parts by weight to 3 parts by weight, based on 100 parts by weight of the monomer component used in the preparation of the acrylic polymer. can do.

In some embodiments, the acrylic polymer is in the form of a partial polymerization product (acrylic polymer syrup) in which a part of the monomer component is polymerized by irradiating ultraviolet (UV) light to a mixture in which a polymerization initiator is mixed with a monomer component as described above. It may be included in the pressure-sensitive adhesive composition for forming a layer. The pressure-sensitive adhesive composition including the acrylic polymer syrup may be applied to a predetermined object to be coated, and polymerization may be completed by irradiating ultraviolet rays. That is, the acrylic polymer syrup may be identified as a precursor of the acrylic polymer. The pressure-sensitive adhesive layer disclosed herein may be formed using, for example, the pressure-sensitive adhesive composition including the acrylic polymer syrup and the polymer B.

(Polymer B)

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. Polymer B suppresses the adhesive force at the initial stage of sticking to the adherend due to the low polarity and mobility of the polyorganosiloxane structure derived from the monomer S1, and also prevents the adherend by heating to a temperature higher than 50° C. or over time. It can function as an adhesive strength increase retardant that increases the adhesive strength to the skin. It does not specifically limit as monomer S1, Arbitrary monomers containing polyorganosiloxane frame|skeleton can be used. The monomer S1 promotes the localization of the polymer B on the surface of the pressure-sensitive adhesive layer in the pressure-sensitive adhesive sheet before use (before sticking to the adherend) due to the low polarity derived from its structure, and provides light peelability (low tackiness) at the initial stage of bonding. ) is expressed. As monomer S1, the thing of the structure which has a polymerizable reactive group at one end can be used preferably. According to the copolymerization of the monomer S1 and the (meth)acrylic monomer, the polymer B having a polyorganosiloxane skeleton in the side chain is formed. Polymer B having such a structure tends to have a low initial adhesive force and a high adhesive force after heating due to the mobility and ease of movement of the side chain.

As the monomer S1, for example, a compound represented by the following general formula (1) or (2) can be used. More specifically, X-22-174ASX, X-22-2426, X-22-2475, KF-2012 etc. are mentioned as a single-terminal reactive silicone oil manufactured by Shin-Etsu Chemical Co., Ltd. Monomer S1 can be used individually by 1 type or in combination of 2 or more type.

Here, R ³ in the general formulas (1) and (2) is hydrogen or methyl, 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 15000 g/mol, more preferably 800 g/mol or more and less than 10000 g/mol, more preferably 850 g/mol or more and less than 6000 g/mol, and more preferably 1500 g/mol or more and less than 6000 g/mol. It is especially preferable that it is 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 adhesive force may not be sufficiently suppressed in some cases. When the functional group equivalent of the monomer S1 is 15000 g/mol or more, there may be cases where the increase in the adhesive force becomes 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 polymer A) and mobility in the pressure-sensitive adhesive layer to an appropriate range, low tackiness at the initial stage, and strong adhesion after an increase in adhesive force It becomes easy to implement|achieve the adhesive sheet which is compatible with a high level.

Here, "functional group equivalent" means the weight of the main skeleton (for example, polydimethylsiloxane) couple|bonded per one functional group. Regarding the notation unit g/mol, it is converted into 1 mol of the functional group. The functional group equivalent of the monomer S1 can be calculated from, for example, the spectral intensity of ¹ H-NMR (proton NMR) based on nuclear magnetic resonance (NMR). Calculation of the functional group equivalent (g/mol) of the monomer S1 based on the spectral intensity of ¹ H-NMR is based on a general structural analysis method related to ¹ H-NMR spectral analysis, if necessary, described in Japanese Patent No. 5951153 can be done with reference to

In addition, when using two or more types of monomers from which a functional group equivalent differs as monomer S1, an arithmetic average value can be used as a functional group equivalent of monomer S1. That is, the functional group equivalent of the monomer S1 including n types of monomers (monomer S1 ₁ , monomer S1 ₂ ... monomer S1 _n ) having different functional group equivalents can be calculated by the following formula.

Functional group equivalent of monomer S1 (g/mol) = (functional group equivalent of monomer S1 ₁ × compounding amount of monomer S1 ₁ + functional group equivalent of monomer S1 ₂ × compounding amount of monomer S1 ₂ + … + functional group equivalent of monomer S1 _n × monomer S1 _n of)/(the amount of the monomer S1 ₁ + the amount of the monomer S1 ₂ + … + the amount of the monomer S1 _n )

The content of the monomer S1 may be, for example, 5% by weight or more with respect to all the monomer components for preparing the polymer B, and is preferably 10% by weight or more from the viewpoint of better exhibiting the effect as an adhesive strength increase retardant. , may be 15 wt% or more, or may be 20 wt% or more. In addition, the content of the monomer S1 is preferably 60% by weight or less with respect to all the monomer components for preparing the polymer B from the viewpoint of polymerization reactivity and compatibility, and may be 50% by weight or less, or 40% by weight or less It is good also as it is good also as 30 weight% or less. When the content of the monomer S1 is less than 5% by weight, there may be cases in which the initial adhesive force is not sufficiently suppressed. When there is more content of monomer S1 than 60 weight%, the raise of adhesive force may become inadequate.

The monomer component used for preparation of the polymer B contains the (meth)acrylic-type monomer copolymerizable with the monomer S1 in addition to the monomer S1. By copolymerizing 1 type or 2 or more types of (meth)acrylic-type monomer and monomer S1, the mobility of the polymer B in an adhesive layer can be suitably adjusted. Copolymerizing the monomer S1 and the (meth)acrylic monomer may also help improve the compatibility between the polymer B and the polymer A (eg, an acrylic polymer).

In the polymer B in the technique disclosed herein, the composition of the (meth)acrylic monomer contained in the monomer component has a glass transition temperature T _m1 based on the composition of the (meth)acrylic monomer of 50° C. or more and 100° C. It is preferable to set it so that it may become below. According to the polymer B having T _m1 of 50° C. or higher, in the pressure-sensitive adhesive sheet containing the polymer B, the increase in N ₅₀ tends to be suppressed. According to the polymer B having a T _m1 of 50°C or higher, the (meth)acrylic monomer contained in the polymer B improves the mobility and mobility of the polyorganosiloxane structural moiety accompanying the temperature rise from room temperature to about 50°C. It is effectively suppressed by the derived monomer unit, and it is thought that it is because the low adhesiveness resulting from the presence of the said polyorganosiloxane structural moiety can be maintained better. When T _m1 is lower than 50° C., the effect of suppressing the increase of N ₅₀ is reduced. In addition, when T _m1 becomes higher than 100° C., the adhesive force N ₈₀ after heating tends to decrease. 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 . Accordingly, the polymer B having a composition in which T _m1 is within the above range is suitable for realization of an adhesive sheet satisfying N ₈₀ /N ₅₀ ≥ 5.

In some embodiments, the glass transition temperature T _m1 may be, for example, 53 °C or higher, 56 °C or higher, 59 °C or higher, 62 °C or higher, 65 °C or higher, 68 °C or higher, or 70 °C or higher, for example. °C or higher may be sufficient. According to the polymer B having a higher T _m1 , the effect of suppressing the increase of N ₅₀ tends to be larger. In addition, from the viewpoint of facilitating increase in adhesive strength by heating to a temperature region higher than 50°C, in some embodiments, T _m1 may be, for example, 100°C or less, 90°C or less, or 85°C or less. may be sufficient, and 80 degrees C or less or less than 80 degrees C may be sufficient.

Here, the glass transition temperature T _m1 based on the composition of the (meth)acrylic monomer is the Tg obtained by the Fox formula based on the composition of only the (meth)acrylic monomer among the monomer components used for the preparation of the polymer B. say T _m1 is the glass transition temperature of the homopolymer of each (meth)acrylic monomer by applying the Fox formula described above, targeting only the (meth)acrylic monomer among the monomer components used in the preparation of the polymer B, and the (meth) ) can be calculated from the weight fraction of each (meth)acrylic monomer occupied in the total amount of the acrylic monomer. From the viewpoint of facilitating the effect of setting T _m1 appropriately, the total amount of the monomer S1 and the (meth)acrylic monomer occupied in the total monomer components for preparing the polymer B may be, for example, 50% by weight or more, 70 weight% or more may be sufficient, 85 weight% or more may be sufficient, 90 weight% or more may be sufficient, 95 weight% or more may be sufficient, and 100 weight% may be sufficient as it substantially.

Glass transition temperature TB of polymer _B is not specifically limited, In the adhesive sheet disclosed here, it can select so that preferable characteristics may be acquired. TB 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 TB of the polymer _B is lowered, the mobility of the polymer B is improved and the adhesive force tends to be easily increased by heating in a temperature range higher than 50°C. Further, in some aspects, TB of the polymer _B may be, for example, -40°C or higher, -30°C or higher, -20°C or higher, or -10°C or higher. When TB of polymer _B becomes high, there exists a tendency for N ₅₀ to be suppressed easily.

In some aspects of the pressure-sensitive adhesive sheet disclosed herein, the polymer B preferably has a copolymerization ratio of 30% by weight or less of a monomer having a homopolymer having a glass transition temperature higher than 170°C. Here, in the present specification, unless otherwise specified, that the copolymerization ratio of the monomer is X% by weight or less is a concept including an embodiment in which the copolymerization ratio of the monomer is 0% by weight, that is, an embodiment in which the monomer is not substantially copolymerized. am. In addition, that it is not copolymerized substantially means that the said monomer is not copolymerized, at least intentionally. When the homopolymer glass transition temperature of the homopolymer is higher than 170 ° C. If the copolymerization ratio of the monomer is high, the mobility of the polymer B tends to be insufficient, and it may be difficult to increase the adhesive force by heating to a temperature range higher than 50 ° C. . When the copolymerization ratio of the monomer having a glass transition temperature of the homopolymer higher than 170° C. is less than 30% by weight, at least one effect of the improvement of N ₈₀ and the improvement of N ₅₀ /N ₈₀ can be realized.

In some embodiments, the composition of the monomer component for preparing Polymer B can be set such that T _m1 is higher than T _B , ie, T _m1 -T _B is greater than 0°C. According to such a composition, the effect of controlling the mobility of the polymer B by the composition of the (meth)acrylic monomer contained in the monomer component is easily exhibited suitably. T _m1 -T _B may be, for example, about 40°C to 100°C, about 50°C to 90°C, or about 65°C to 85°C, for example.

From the viewpoint of making it easy to control the mobility of the polymer B in the pressure-sensitive adhesive layer, in some embodiments, the composition of the monomer component for preparing the polymer B is, in relation to the glass transition temperature T _A of the polymer A, T _m1 is T It can be set so that it is higher than _A by 20°C or more, that is, T _m1 -T _A is 20°C or more. In some embodiments, T _m1 -T _A may be, for example, about 50°C to 130°C, about 60°C to 120°C, or about 70°C to 120°C.

As a (meth)acrylic-type monomer which can be used for the monomer component for preparing polymer B, (meth)acrylic-acid alkylester is mentioned, for example. For example, as a (meth)acrylic acid alkylester that can be used when the polymer A is an acrylic polymer, one or more of the monomers exemplified above can be used as the copolymerization component of the polymer B. In some embodiments, polymer B is at least one of (meth)acrylic acid C _4-12 alkylesters (preferably (meth)acrylic acid C _4-10 alkylesters, for example (meth)acrylic acid C _6-10 alkylesters). One type can be contained as a monomer unit. In some other embodiments, polymer B is at least one of methacrylic acid C _1-18 alkylesters (preferably methacrylic acid C _1-14 alkylesters, for example methacrylic acid C _1-10 alkylesters). may be contained as a monomer unit. The monomer unit constituting the polymer B may include, for example, one or two or more selected from MMA, BMA, and 2EHMA.

As another example of the said (meth)acrylic-type monomer, the (meth)acrylic acid ester which has an alicyclic hydrocarbon group is mentioned. For example, cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, 1-adamantyl (meth) acrylate, etc. can be used In some embodiments, the polymer B may contain at least one selected from dicyclopentanyl methacrylate, isobornyl methacrylate and cyclohexyl methacrylate as a monomer unit.

The amount of the (meth)acrylic acid alkyl ester and the (meth)acrylic acid ester having an alicyclic hydrocarbon group to be used is, for example, 10% by weight or more and 95% by weight or less, with respect to all the monomer components for preparing the polymer B, 20 Weight % or more and 95 weight% or less may be sufficient, 30 weight% or more and 90 weight% or less may be sufficient, 40 weight% or more and 90 weight% or less may be sufficient, and 50 weight% or more and 85 weight% or less may be sufficient. From the viewpoint of easiness of increasing the adhesive force by heating to a temperature higher than 50° C., the use of (meth)acrylic acid alkylester may be advantageous. In some embodiments, the amount of (meth)acrylic acid ester having an alicyclic hydrocarbon group may be less than 50% by weight, or less than 30% by weight of the total amount of (meth)acrylic monomers contained in the monomer component for preparing the polymer B. and less than 15 weight% may be sufficient, less than 10 weight% may be sufficient, and less than 5 weight% may be sufficient. It is not necessary to use the (meth)acrylic acid ester which has an alicyclic hydrocarbon group.

In some embodiments, the monomer component for preparing Polymer B preferably contains at least MMA. Copolymerizing MMA can be a useful means for adjusting T _m1 to the preferred range disclosed herein. Moreover, according to the polymer B in which MMA was copolymerized, an adhesive sheet with large N ₈₀ /N ₅₀ is easy to be obtained. The ratio of MMA to the total amount of (meth)acrylic monomers contained in the monomer component for preparing the polymer B may be, for example, 5% by weight or more, 10% by weight or more, 20% by weight or more, 30 Weight % or more may be sufficient, and 40 weight% or more may be sufficient. In some embodiments, the proportion of MMA in the total amount of the (meth)acrylic monomers may be, for example, more than 50% by weight, more than 55% by weight, more than 60% by weight, or more than 65% by weight. , more than 70% by weight may be sufficient. In addition, the ratio of MMA to the total amount of the (meth)acrylic monomers may be in a range where T _m1 is 100° C. or less, and usually 95 wt% or less is suitable, 90 wt% or less may be sufficient, and 85 wt% or less may be

As another example of a monomer that may be included together with the monomer S1 as a monomer unit constituting the polymer B, the carboxyl group-containing monomer exemplified above as a monomer that can be used when the polymer A is an acrylic polymer, an acid anhydride group-containing monomer, a hydroxyl group-containing monomer Monomers, epoxy group-containing monomers, cyano group-containing monomers, isocyanate group-containing monomers, amide group-containing monomers, nitrogen atom-containing ring monomers, succinimide skeleton monomers, maleimides, itaconimides, amino (meth)acrylic acid Alkyls, vinyl esters, vinyl ethers, olefins, (meth)acrylic acid esters having an aromatic hydrocarbon group, heterocycle-containing (meth)acrylates, halogen atom-containing (meth)acrylates, terpene compound derivatives obtained from alcohol (meth) ) and acrylic acid esters.

As another example of a monomer that may be included together with the monomer S1 as a monomer unit constituting the polymer B, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate , oxyalkylene di(meth)acrylates such as polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, and tripropylene glycol di(meth)acrylate; A monomer having a polyoxyalkylene skeleton, for example, has a polymerizable functional group such as a (meth)acryloyl group, a vinyl group, an allyl group, etc. at one end of a polyoxyalkylene chain such as polyethylene glycol or polypropylene glycol, and the other polymerizable polyoxyalkylene ethers having an ether structure (such as an alkyl ether, an aryl ether, an arylalkyl ether) at the terminal; (meth)acrylic acid alkoxyalkyl, such as (meth)acrylic-acid methoxyethyl, (meth)acrylic-acid ethoxyethyl, (meth)acrylic-acid propoxyethyl, (meth)acrylic-acid butoxyethyl, (meth)acrylic-acid ethoxypropyl; salts such as (meth)acrylic acid alkali metal salts; Polyvalent (meth)acrylates, such as trimethylolpropane tri(meth)acrylic acid ester: Vinyl halide compounds, such as vinylidene chloride and (meth)acrylic acid 2-chloroethyl; oxazoline group-containing monomers such as 2-vinyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, and 2-isopropenyl-2-oxazoline; aziridine group-containing monomers such as (meth)acryloylaziridine and (meth)acrylic acid-2-aziridinylethyl; hydroxyl group-containing vinyl monomers such as (meth)acrylic acid-2-hydroxyethyl, (meth)acrylic acid-2-hydroxypropyl, and adducts of lactones and (meth)acrylic acid-2-hydroxyethyl; fluorine-containing vinyl monomers such as fluorine-substituted (meth)acrylic acid alkyl esters; Reactive halogen-containing vinyl monomers, such as 2-chloroethyl vinyl ether and monochloro vinyl acetate; Organic silicon-containing vinyl monomers such as vinyltrimethoxysilane, γ-(meth)acryloxypropyltrimethoxysilane, allyltrimethoxysilane, trimethoxysilylpropylallylamine, and 2-methoxyethoxytrimethoxysilane ; In addition, macromonomers which have a radically polymerizable vinyl group at the monomer terminal which superposed|polymerized the vinyl group; and the like. These can be copolymerized with monomer S1 individually or in combination of 1 type.

Mw of polymer B is not specifically limited. Mw of the polymer B may be 1000 or more, for example, and 5000 or more may be sufficient as it. When the Mw of the polymer B is too low, there may be cases where the increase in the adhesive force becomes insufficient. In some preferred embodiments, Mw of the polymer B may be, for example, 10000 or more, 12000 or more, 15000 or more, 17000 or more, or 20000 or more. In addition, Mw of the polymer B may be 100000 or less, and 70000 or less may be sufficient as it, for example. When the Mw of the polymer B is too high, there may be a case where the initial adhesive force is not sufficiently suppressed. In some preferred embodiments, the Mw of the polymer B may be, for example, 50000 or less, 50000 or less, 40000 or less, 35000 or less, 30000 or less, 28000 or less, 25000 or less. When the Mw of the polymer B is within any of the above-mentioned upper and lower limits, it is easy to adjust the compatibility and mobility in the pressure-sensitive adhesive layer to an appropriate range, and the good reworkability at the initial stage of sticking and the strong adhesion after the increase of the adhesive force are compatible at a high level. It becomes easy to implement|achieve an adhesive sheet.

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

A chain transfer agent can be used to adjust the molecular weight of polymer B. Examples of the chain transfer agent to be used include compounds having a mercapto group such as octyl mercaptan, lauryl mercaptan, t-nonyl mercaptan, t-dodecyl mercaptan, mercaptoethanol and α-thioglycerol; Thioglycolic acid, methyl thioglycolate, ethyl thioglycolate, propyl thioglycolate, butyl thioglycolate, t-butyl thioglycolate, 2-ethylhexyl thioglycolate, octyl thioglycolate, isooctyl thioglycolate, thioglycolic acid esters such as decyl thioglycolate, dodecyl thioglycolate, thioglycolic acid ester of ethylene glycol, thioglycolic acid ester of neopentyl glycol, and thioglycolic acid ester of pentaerythritol; α-methylstyrene dimer; and the like.

The amount of the chain transfer agent to be used is not particularly limited, but the amount of the chain transfer agent is usually 0.05 to 20 parts by weight, preferably 0.1 to 15 parts by weight, more preferably 0.2 to 10 parts by weight based on 100 parts by weight of the monomer. contains parts by weight. Thus, by adjusting the addition amount of a chain transfer agent, the polymer B of suitable molecular weight can be obtained. In addition, a chain transfer agent can be used individually by 1 type or in combination of 2 or more type.

Although not particularly limited, the amount of the polymer B used may be, for example, 0.1 parts by weight or more with respect to 100 parts by weight of the amount of the polymer A, and may be 0.3 parts by weight or more from the viewpoint of obtaining a higher effect, It is good also as 0.4 weight part or more, and is good also as 0.5 weight part or more. From the viewpoint of improvement of reworkability, etc., in some aspects, the usage-amount of polymer B with respect to 100 weight part of polymer A is good also as 1 weight part or more, it is good also as 2 weight part or more, and it is good also as 3 weight part or more. . Moreover, the usage-amount of polymer B with respect to 100 weight part of polymer A may be 75 weight part or less, 60 weight part or less may be sufficient, and 50 weight part or less may be sufficient, for example. From the viewpoint of avoiding excessive lowering of the cohesive force of the pressure-sensitive adhesive layer, in some embodiments, the amount of polymer B used relative to 100 parts by weight of polymer A may be, for example, 40 parts by weight or less, and 35 parts by weight or less; It is good also as 30 weight part or less or 25 weight part or less. From the viewpoint of obtaining higher adhesive strength after heating, in some embodiments, the amount of the polymer B used may be 20 parts by weight or less, 17 parts by weight or less, 15 parts by weight or less, and 10 parts by weight or less. can be done with In some aspects of the pressure-sensitive adhesive sheet disclosed herein, the amount of the polymer B used relative to 100 parts by weight of the polymer A may be, for example, less than 10 parts by weight, 8 parts by weight or less, 5 parts by weight or less, or 5 parts by weight. Less than may be sufficient, 4 weight part or less may be sufficient, and 3 weight part or less may be sufficient.

The pressure-sensitive adhesive layer can contain polymers (arbitrary polymers) other than the polymer A and the polymer B as needed within a range that does not significantly impair the performance of the pressure-sensitive adhesive sheet disclosed herein. It is suitable that the usage-amount of such an arbitrary polymer shall be 20 weight% or less of the whole polymer component normally contained in an adhesive layer, 15 weight% or less may be sufficient, and 10 weight% or less may be sufficient as it. In some aspects, the usage-amount of the said arbitrary polymer may be 5 weight% or less, 3 weight% or less, and 1 weight% or less of the whole polymer component may be sufficient. The adhesive layer which does not contain polymers other than the polymer A and the polymer B substantially may be sufficient.

(crosslinking agent)

In the pressure-sensitive adhesive layer, a crosslinking agent may be used as needed for the purpose of adjusting cohesive force or the like. As the crosslinking agent, a known crosslinking agent in the field of pressure-sensitive adhesives can be used, for example, an epoxy-based crosslinking agent, an isocyanate-based crosslinking agent, a silicone-based crosslinking agent, an oxazoline-based crosslinking agent, an aziridine-based crosslinking agent, a silane-based crosslinking agent, an alkyl etherified melamine-based crosslinking agent, A metal chelate type crosslinking agent etc. are mentioned. In particular, an isocyanate-based crosslinking agent, an epoxy-based crosslinking agent, and a metal chelate-based crosslinking agent can be suitably used. A crosslinking agent can be used individually by 1 type or in combination of 2 or more type.

Specifically, examples of the isocyanate-based crosslinking agent include tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, diphenyl (meth) diisocyanate, hydrogenated diphenyl (meth). ) isocyanate, tetramethylxylylene diisocyanate, naphthalene diisocyanate, triphenyl (meth) triisocyanate, polymethylene polyphenyl isocyanate, and the adduct body of these and polyols, such as trimethylol propane, are mentioned. Alternatively, a compound having at least one isocyanate group and one or more unsaturated bonds in one molecule, specifically 2-isocyanatoethyl (meth)acrylate, can also be used as the isocyanate-based crosslinking agent. These can be used individually by 1 type or in combination of 2 or more type.

Examples of the epoxy crosslinking agent include bisphenol A, epichlorohydrin type epoxy resin, ethylene glycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1,6-hexanediol Glycidyl ether, trimethylolpropane triglycidyl ether, diglycidyl aniline, diamine glycidylamine, N,N,N',N'-tetraglycidyl-m-xylylenediamine and 1,3 -bis(N,N-diglycidylaminomethyl)cyclohexane etc. are mentioned. These can be used individually by 1 type or in combination of 2 or more type.

As a metal chelate compound, aluminum, iron, tin, titanium, nickel, etc. as a metal component, acetylene, methyl acetoacetate, ethyl lactate, etc. are mentioned as a chelate component. These can be used individually by 1 type or in combination of 2 or more type.

The usage-amount in the case of using a crosslinking agent is not specifically limited, For example, it can be set as the quantity exceeding 0 weight part with respect to 100 weight part of polymer A. In addition, the usage-amount of a crosslinking agent can be made into 0.01 weight part or more with respect to 100 weight part of polymer A, and it is preferable to set it as 0.05 weight part or more. By increase in the usage-amount of a crosslinking agent, the adhesive force of an affixing initial stage is suppressed and there exists a tendency for rework property to improve. In some aspects, the usage-amount of the crosslinking agent with respect to 100 weight part of polymer A may be 0.1 weight part or more, 0.5 weight part or more may be sufficient, and 1 weight part or more may be sufficient as it. On the other hand, from the viewpoint of avoiding the reduction of the tack due to excessive cohesion improvement, the amount of the crosslinking agent to be used relative to 100 parts by weight of the polymer A is usually 15 parts by weight or less, preferably 10 parts by weight or less, or 5 parts by weight. You may do it below. The fact that the amount of the crosslinking agent to be used is not too large can be advantageous also from the viewpoint of making it easy to realize a pressure-sensitive adhesive sheet having a high N ₈₀ /N ₅₀ .

The technique disclosed herein can be preferably implemented in an embodiment using at least an isocyanate-based crosslinking agent as a crosslinking agent. From the viewpoint of making it easy to realize a pressure-sensitive adhesive sheet having both good reworkability at the initial stage of sticking and strong adhesion after increasing the adhesive strength, in some embodiments, the amount of the isocyanate-based crosslinking agent to be used with respect to 100 parts by weight of the polymer A is, for example, 0.1 parts by weight or more. It can be set as 5 weight part or less, and it is good also as 0.3 weight part or more and 4 weight part or less, and is good also as 0.5 weight part or more and 3 weight part or less.

Although not particularly limited, when an isocyanate-based crosslinking agent is used in a configuration in which the pressure-sensitive adhesive layer includes a hydroxyl group-containing monomer as a monomer unit, the amount of the isocyanate-based crosslinking agent W used and the amount of the hydroxyl group-containing monomer with respect to _NCO W _OH is , W _OH /W _NCO can be set to an amount of 2 or more. As described above, by increasing the amount of the hydroxyl group-containing monomer to the isocyanate-based crosslinking agent, a suitable crosslinked structure can be formed in order to greatly increase the adhesive strength after heating with respect to the adhesive strength at the initial stage of pasting. In some embodiments, W _OH /W _NCO may be 3 or more, 5 or more, 10 or more, 20 or more, 30 or more, or 50 or more. The upper limit of W _OH /W _NCO is not particularly limited. W _OH /W _NCO may be, for example, 500 or less, 200 or less, or 100 or less.

In order to advance any of the crosslinking reactions mentioned above more effectively, you may use a crosslinking catalyst. As the crosslinking catalyst, for example, a tin-based catalyst (especially dioctyl tin dilaurate) can be preferably used. The amount of the crosslinking catalyst to be used is not particularly limited, but may be, for example, approximately 0.0001 parts by weight to 1 part by weight based on 100 parts by weight of the polymer A.

For the pressure-sensitive adhesive layer, a polyfunctional monomer may be used as needed. The polyfunctional monomer may be useful for purposes such as adjustment of cohesive force by being used instead of or in combination with a crosslinking agent as described above. For example, in the pressure-sensitive adhesive layer formed of the photo-curable pressure-sensitive adhesive composition, a polyfunctional monomer may be preferably used.

Examples of the polyfunctional monomer include ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, neopentyl glycol di ( Meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, ethylene glycol di (meth) acrylate, 1,6-hexane Diol di (meth) acrylate, 1,12-dodecanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, allyl (meth) acrylate, vinyl (meth)acrylate, divinylbenzene, epoxy acrylate, polyester acrylate, urethane acrylate, butyldiol (meth)acrylate, hexyldiol di(meth)acrylate, etc. are mentioned. Among them, trimethylolpropane tri(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and dipentaerythritol hexa(meth)acrylate can be preferably used. A polyfunctional monomer can be used individually by 1 type or in combination of 2 or more type.

Although the usage-amount of a polyfunctional monomer changes with the molecular weight, the number of functional groups, etc., it is usually suitable to set it as the range of about 0.01 weight part - 3.0 weight part with respect to 100 weight part of polymer A. In some aspects, the usage-amount of a polyfunctional monomer may be, for example, 0.02 weight part or more, and 0.03 weight part or more may be sufficient with respect to 100 weight part of polymer A. By an increase in the usage-amount of a polyfunctional monomer, the adhesive force in the initial stage of pasting is suppressed, and there exists a tendency for rework property to improve. On the other hand, from the viewpoint of avoiding the deterioration of the tack due to excessive cohesion improvement, the usage amount of the polyfunctional monomer may be 2.0 parts by weight or less, 1.0 parts by weight or less, or 0.5 parts by weight or less with respect to 100 parts by weight of the polymer A. . That the usage-amount of a polyfunctional monomer is not too much can be advantageous also from a viewpoint of making it easy to implement|achieve a high N ₈₀ /N ₅₀ adhesive sheet.

(Tackifying resin)

A tackifying resin can be included in an adhesive layer as needed. Although it does not restrict|limit especially as tackifying resin, For example, Rosin type tackifying resin, terpene type tackifying resin, phenol type tackifying resin, hydrocarbon type tackifying resin, ketone type tackifying resin, polyamide type tackifying resin, Epoxy-type tackifying resin, elastomer-type tackifying resin, etc. are mentioned. Tackifying resin can be used individually by 1 type or in combination of 2 or more type.

Examples of the rosin-based tackifying resin include unmodified rosin (raw rosin) such as gum rosin, wood rosin, and tall oil rosin, and modified rosin obtained by modifying these unmodified rosins by polymerization, disproportionation, hydrogenation, or the like ( polymerized rosin, stabilized rosin, disproportionated rosin, fully hydrogenated rosin, partially hydrogenated rosin, other chemically modified rosin, etc.) and various rosin derivatives.

As said rosin derivative, for example,

Rosin phenolic resin obtained by adding phenol to rosins (unmodified rosin, modified rosin, various rosin derivatives, etc.) with an acid catalyst and thermally polymerizing them;

An ester compound of rosin obtained by esterifying unmodified rosin with alcohol (unmodified rosin ester), or modified rosin such as polymerized rosin, stabilized rosin, disproportionated rosin, fully hydrogenated rosin, and partially hydrogenated rosin, to alcohol. rosin ester-based resins such as modified rosin ester compounds (polymerized rosin esters, stabilized rosin esters, disproportionated rosin esters, fully hydrogenated rosin esters, partially hydrogenated rosin esters, etc.);

unsaturated fatty acid-modified rosin-based resins obtained by modifying unmodified rosin or modified rosin (polymerized rosin, stabilized rosin, disproportionated rosin, fully hydrogenated rosin, partially hydrogenated rosin, etc.) with unsaturated fatty acids;

an unsaturated fatty acid-modified rosin ester-based resin obtained by modifying a rosin ester-based resin with an unsaturated fatty acid;

Reduction treatment of carboxyl groups in unmodified rosin, modified rosin (polymerized rosin, stabilized rosin, disproportionated rosin, fully hydrogenated rosin, partially hydrogenated rosin, etc.), unsaturated fatty acid-modified rosin-based resin or unsaturated fatty acid-modified rosin ester-based resin one rosin alcohol-based resin;

and metal salts of rosin-based resins (particularly, rosin ester-based resins) such as unmodified rosin, modified rosin, and various rosin derivatives.

Examples of the terpene-based tackifying resin include terpene-based resins such as α-pinene polymer, β-pinene polymer, and dipentene polymer, and modifications of these terpene-based resins (phenol modification, aromatic modification, hydrogenation modification, hydrocarbon modification, etc.) ) modified terpene-based resins (eg, terpene phenol-based resins, styrene-modified terpene-based resins, aromatic modified terpene-based resins, hydrogenated terpene-based resins, etc.);

As the phenolic tackifying resin, for example, a condensate of various phenols (eg, phenol, m-cresol, 3,5-xylenol, p-alkylphenol, resorcin, etc.) and formaldehyde (eg, , alkylphenol-based resins, xyleneformaldehyde-based resins, etc.), resols obtained by addition-reacting the above phenols and formaldehyde with an alkali catalyst, and novolacs obtained by condensation reaction of the above-mentioned phenols with formaldehyde with an acid catalyst.

Examples of the hydrocarbon-based tackifying resin include aliphatic hydrocarbon resins, aromatic hydrocarbon resins, aliphatic cyclic hydrocarbon resins, aliphatic/aromatic petroleum resins (styrene-olefin copolymers, etc.), aliphatic/alicyclic petroleum resins, hydrogenated hydrocarbons Various hydrocarbon-type resins, such as resin, a coumarone-type resin, and a coumarone indene-type resin, are mentioned.

Commercially available polymeric rosin esters that can be preferably used include Arakawa Chemical Co., Ltd. trade names "Pencel D-125", "Pencel D-135", "Pencel D-160", "Pencel KK", "Pencel" C" etc. are illustrated, but it is not limited to these.

Examples of commercially available terpene phenolic resins that can be preferably used include "YS Polystar S-145", "YS Polystar G-125", "YS Polystar N125", and "YS Poly" manufactured by Yasuhara Chemical. Star U-115", Arakawa Chemical Co., Ltd. brand name "Tamanol 803L", "Tamanol 901", Sumitomo Bakelite Co., Ltd. brand name "Sumilite Resin PR-12603" etc. are exemplified, It is not limited to these.

Content of tackifying resin is not specifically limited, According to the objective and a use, it can set so that appropriate adhesion performance may be exhibited. Content of tackifying resin with respect to 100 weight part of polymer A (When 2 or more types of tackifying resin are included, their total amount) can be made into about 5-500 weight part, for example.

As tackifying resin, the thing with a softening point (softening temperature) of about 80 degreeC or more (preferably about 100 degreeC or more, for example, about 120 degreeC or more) can use it preferably. According to the tackifying resin which has a softening point more than the above-mentioned lower limit, the adhesive sheet which satisfy|fills N80 _{/ N50≥5} is easy to be obtained. The upper limit of the softening point is not particularly limited, and may be, for example, approximately 200°C or less (typically 180°C or less). In addition, the softening point of tackifying resin can be measured based on the softening point test method (round ball method) prescribed|regulated to JISK2207.

In addition, the pressure-sensitive adhesive layer in the technology disclosed herein is a leveling agent, a plasticizer, a softening agent, a colorant (dye, pigment, etc.), a filler, an antistatic agent, an anti-aging agent, within the range in which the effect of the present invention is not significantly hindered. , UV absorbers, antioxidants, light stabilizers, preservatives, and other known additives that can be used in the pressure-sensitive adhesive may be included as needed.

The pressure-sensitive adhesive layer constituting the pressure-sensitive adhesive sheet disclosed herein may be a cured layer of the pressure-sensitive adhesive composition. That is, the pressure-sensitive adhesive layer may be formed by applying (for example, coating) an appropriate surface with an adhesive composition such as a water dispersion type, solvent type, photocuring type, or hot melt type, followed by appropriately curing treatment. In the case of performing two or more curing treatments (drying, crosslinking, polymerization, cooling, etc.), these can be performed simultaneously or in multiple steps. In the pressure-sensitive adhesive composition using the partial polymer (acrylic polymer syrup) of the monomer component, a final copolymerization reaction is typically performed as the curing treatment. That is, the partial polymerization product is subjected to further copolymerization reaction to form a complete polymerization product. For example, if it is a photocurable adhesive composition, light irradiation is performed. If necessary, curing treatment such as crosslinking and drying may be performed. For example, when it is necessary to dry with a photocurable adhesive composition, what is necessary is just to photocurate after drying. In the pressure-sensitive adhesive composition using the complete polymer, typically, as the curing treatment, drying (heat drying), crosslinking, or the like is performed as needed.

Application|coating of an adhesive composition can be performed using common coaters, such as a gravure roll coater, a reverse roll coater, a kiss roll coater, a dip roll coater, a bar coater, a knife coater, and a spray coater, for example.

The thickness of the pressure-sensitive adhesive layer is not particularly limited, and may be, for example, 1 µm or more. In some aspects, the thickness of the pressure-sensitive adhesive layer may be, for example, 3 µm or more, 5 µm or more, 8 µm or more, 10 µm or more, 15 µm or more, 20 µm or more, or 20 µm or more. may be in excess. There exists a tendency for adhesive force to rise after a heating by increase in the thickness of an adhesive layer. Further, in some embodiments, the thickness of the pressure-sensitive adhesive layer may be, for example, 300 µm or less, 200 µm or less, 150 µm or less, 100 µm or less, 70 µm or less, or 50 µm or less. and may be 40 µm or less. The fact that the thickness of the pressure-sensitive adhesive layer is not too large may be advantageous from the viewpoint of reducing the thickness of the pressure-sensitive adhesive sheet or preventing cohesive failure of the pressure-sensitive adhesive layer. In addition, in the case of a pressure-sensitive adhesive sheet having a first pressure-sensitive adhesive layer and a second pressure-sensitive adhesive layer on the first and second surfaces of the substrate, the thickness of the above-described pressure-sensitive adhesive layer may be applied to at least the thickness of the first pressure-sensitive adhesive layer. The thickness of the second pressure-sensitive adhesive layer may also be selected from the same range. Moreover, in the case of an inorganic adhesive sheet, the thickness of the said adhesive sheet coincides with the thickness of an adhesive layer.

Although not particularly limited, the gel fraction of the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer is usually preferably in the range of 20.0% to 99.0%, and preferably in the range of 30.0% to 90.0%. By making a gel fraction into the said range, it becomes easy to implement|achieve the adhesive sheet which is compatible with the rework property of the initial stage of pasting, and the strong adhesiveness after an adhesive force rise at a high level. The gel fraction is measured by the following method.

[Measurement of gel fraction]

About 0.1 g of a pressure-sensitive adhesive sample (weight Wg ₁ ) is wrapped in a bag shape with a porous polytetrafluoroethylene membrane (weight Wg ₂ ) having an average pore diameter of 0.2 μm, and the mouth is tied with twisted yarn (weight Wg ₃ ). As the porous polytetrafluoroethylene membrane, trade name "Nitoflon (registered trademark) NTF1122" (Nitto Denko Co., Ltd., average pore diameter 0.2 µm, porosity 75%, thickness 85 µm) or an equivalent thereof is used. The package is immersed in 50 mL of ethyl acetate and maintained at room temperature (typically 23° C.) for 7 days to elute the sol powder (ethyl acetate soluble content) in the pressure-sensitive adhesive out of the membrane. Next, the package is taken out, ethyl acetate adhering to the outer surface is wiped off, the package is dried at 130° C. for 2 hours, and the weight (Wg ₄ ) of the package is measured. By substituting each value into the following formula|equation, gel fraction G _C of an adhesive is computable.

Gel fraction G _C (%)=[(Wg ₄ -Wg ₂ -Wg ₃ )/Wg ₁ ]×100

<Support description>

The pressure-sensitive adhesive sheet according to some embodiments may be in the form of a pressure-sensitive adhesive sheet provided with a substrate having pressure-sensitive adhesive layers on one or both surfaces of a supporting substrate. The material of the supporting base material is not particularly limited, and may be appropriately selected depending on the purpose of use of the pressure-sensitive adhesive sheet, the mode of use, and the like. Non-limiting examples of the substrate that can be used include a polyolefin film mainly composed of polyolefin such as polypropylene or ethylene-propylene copolymer, a polyester film composed mainly of polyester such as polyethylene terephthalate and polybutylene terephthalate, poly Plastic films, such as a polyvinyl chloride film which has vinyl chloride as a main component; foam sheets including foams such as polyurethane foam, polyethylene foam, and polychloroprene foam; Woven and nonwoven fabrics made of various fibrous materials (such as natural fibers such as hemp and cotton, synthetic fibers such as polyester and vinylon, and semi-synthetic fibers such as acetate) alone or by blending; papers such as Japanese paper, fine paper, kraft paper, and crepe paper; metal foils such as aluminum foil and copper foil; and the like. The description of the structure in which these were combined may be sufficient. Examples of such a composite substrate include a substrate having a structure in which a metal foil and the plastic film are laminated, and a plastic substrate reinforced with inorganic fibers such as glass cloth.

As a base material of the adhesive sheet disclosed herein, various film base materials can be used preferably. The film substrate may be a porous substrate, such as a foam film or a nonwoven fabric sheet, or a non-porous substrate, or a substrate having a structure in which a porous layer and a non-porous layer are laminated. In some embodiments, as the film substrate, a resin film capable of independently maintaining a shape (self-supporting or non-dependent) is preferably used as the base film. Here, a "resin film" has a non-porous structure and typically means a resin film substantially free of air bubbles (voidless). Therefore, the said resin film is a concept distinguished from a foam film and a nonwoven fabric. As said resin film, the thing which can maintain shape independently (a self-supporting type or non-dependent) can be used preferably. A single-layer structure may be sufficient as the said resin film, and the multilayer structure (for example, three-layer structure) of two or more layers may be sufficient as it.

As a resin material constituting the resin film, for example, polyamide (PA) such as polyester, polyolefin, nylon 6, nylon 66, and partially aromatic polyamide, polyimide (PI), polyamideimide (PAI), polyether Ether ketone (PEEK), polyether sulfone (PES), polyphenylene sulfide (PPS), polycarbonate (PC), polyurethane (PU), ethylene-vinyl acetate copolymer (EVA), polytetrafluoroethylene Resins, such as a fluororesin, such as (PTFE), an acrylic resin, polyacrylate, polystyrene, polyvinyl chloride, and polyvinylidene chloride, can be used. The said resin film may be formed using the resin material containing individually 1 type of such resin, and may be formed using the resin material in which 2 or more types were blended. Unstretched may be sufficient as the said resin film, and the thing extended|stretched (for example, uniaxial stretching or biaxial stretching) may be sufficient as it.

Suitable examples of the resin material constituting the resin film include polyester-based resins, PPS resins, and polyolefin-based resins. Here, polyester-type resin means resin which contains polyester in the ratio of more than 50 weight%. Similarly, the PPS resin refers to a resin containing PPS in a proportion exceeding 50% by weight, and the polyolefin-based resin refers to a resin containing a polyolefin in a proportion exceeding 50% by weight.

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

As dicarboxylic acid constituting the polyester, for example, phthalic acid, isophthalic acid, terephthalic acid, 2-methylterephthalic acid, 5-sulfoisophthalic acid, 4,4'-diphenyldicarboxylic acid, 4,4' -diphenyletherdicarboxylic acid, 4,4'-diphenylketonedicarboxylic acid, 4,4'-diphenoxyethanedicarboxylic acid, 4,4'-diphenylsulfonedicarboxylic acid, 1 aromatic dicarboxylic acids such as ,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and 2,7-naphthalenedicarboxylic acid; alicyclic dicarboxylic acids such as 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid; aliphatic dicarboxylic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid and dodecanoic acid; unsaturated dicarboxylic acids such as maleic acid, maleic anhydride, and fumaric acid; derivatives thereof (eg, lower alkyl esters of dicarboxylic acids such as terephthalic acid); and the like. These can be used individually by 1 type or in combination of 2 or more type. An aromatic dicarboxylic acid is preferable from a viewpoint of intensity|strength etc. Among them, terephthalic acid and 2,6-naphthalenedicarboxylic acid are exemplified as preferable dicarboxylic acid. For example, in the dicarboxylic acid constituting the polyester, 50% by weight or more (eg 80% by weight or more, typically 95% by weight or more) is terephthalic acid, 2,6-naphthalenedicarboxylic acid or these It is preferable that the combination of The dicarboxylic acid may consist substantially only of terephthalic acid, substantially only of 2,6-naphthalenedicarboxylic acid, or substantially only of terephthalic acid and 2,6-naphthalenedicarboxylic 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, neopentyl glycol, 1,4 -aliphatic diols such as butanediol, 1,6-hexanediol, 1,8-octanediol, and polyoxytetramethylene glycol; Alicyclic diols such as 1,2-cyclohexanediol, 1,4-cyclohexanediol, 1,1-cyclohexanedimethylol and 1,4-cyclohexanedimethylol, xylylene glycol, 4,4'-diol aromatic diols such as hydroxybiphenyl, 2,2-bis(4'-hydroxyphenyl)propane, and bis(4-hydroxyphenyl)sulfone; and the like. These can be used individually by 1 type or in combination of 2 or more type. Among them, aliphatic diols are preferable from the viewpoint of transparency and the like, and ethylene glycol is particularly preferable. It is preferable that the ratio of the aliphatic diol (preferably ethylene glycol) to the diol which comprises the said polyester is 50 weight% or more (for example, 80 weight% or more, typically 95 weight% or more). The said diol may be comprised substantially only from ethylene glycol.

Specific examples of the polyester-based resin include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), and polybutylene naphthalate.

As polyolefin resin, 1 type of polyolefin can be used individually or in combination of 2 or more types of polyolefins. The polyolefin may be, for example, an α-olefin homopolymer, a copolymer of two or more α-olefins, or a copolymer of one or two or more α-olefins and other vinyl monomers. Specific examples include ethylene-propylene copolymers such as polyethylene (PE), polypropylene (PP), poly-1-butene, poly-4-methyl-1-pentene, and ethylene propylene rubber (EPR), ethylene-propylene-butene copolymer a copolymer, an ethylene-butene copolymer, an ethylene-vinyl alcohol copolymer, an ethylene-ethyl acrylate copolymer, etc. are mentioned. Both 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 stretched polypropylene (OPP) film, a low density polyethylene (LDPE) film, a linear low density polyethylene (LLDPE) film, a medium density polyethylene (MDPE) film, a high density A polyethylene (HDPE) film, a polyethylene (PE) film in which two or more types of polyethylene (PE) are blended, a PP/PE blend film in which a polypropylene (PP) and polyethylene (PE) are blended, etc. are mentioned.

A PET film, a PEN film, a PPS film, a PEEK film, a CPP film, and an OPP film are mentioned as a specific example of the resin film preferably used as a base film of the adhesive sheet disclosed herein. A PET film, a PEN film, a PPS film, and a PEEK film are mentioned as an example of a preferable base film from a viewpoint of strength or dimensional stability. From viewpoints, such as the availability of a base material, a PET film and a PPS film are especially preferable, and a PET film is especially preferable.

In the resin film, in the range in which the effects of the present invention are not significantly hindered, known additives such as light stabilizers, antioxidants, antistatic agents, colorants (dyes, pigments, etc.), fillers, slip agents, and anti-blocking agents are required. can be combined according to The compounding quantity of an additive is not specifically limited, According to the use of an adhesive sheet, etc., it can set suitably.

The manufacturing method of a resin film is not specifically limited. For example, conventionally well-known general resin film molding methods, such as extrusion molding, inflation molding, T-die cast molding, and calender roll molding, can be employ|adopted suitably.

The substrate may be substantially composed of such a base film. Alternatively, the substrate may include an auxiliary layer in addition to the base film. Examples of the auxiliary layer include an optical property adjusting layer (eg, a colored layer, an antireflection layer), a printed layer or laminate layer for imparting a desired appearance to the substrate, a surface treatment layer such as an antistatic layer, an undercoat layer, and a release layer. can be heard

The thickness of the base material is not particularly limited, and can be selected according to the purpose of use of the pressure-sensitive adhesive sheet, the mode of use, and the like. The thickness of the substrate may be, for example, 1000 μm or less. In some aspects, from the viewpoint of handleability and workability of the pressure-sensitive adhesive sheet, the thickness of the substrate may be, for example, 500 µm or less, 300 µm or less, 250 µm or less, or 200 µm or less. From the viewpoint of size reduction or weight reduction of the product to which the pressure-sensitive adhesive sheet is applied, in some embodiments, the thickness of the substrate may be, for example, 160 µm or less, 130 µm or less, 100 µm or less, or 90 µm or less. , may be 70 µm or less, may be 50 µm or less, may be 25 µm or less, may be 10 µm or less, or may be 5 µm or less. When the thickness of a base material becomes thin, there exists a tendency for the flexibility of an adhesive sheet and the followability|trackability with respect to the surface shape of a to-be-adhered body to improve. In addition, from the viewpoint of handleability, workability, etc., the thickness of the substrate may be, for example, 2 µm or more, 5 µm or more, 10 µm or more, 20 µm or more, 25 µm or more, or more than 25 µm. may be In some embodiments, 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 a pressure-sensitive adhesive sheet that can be used for the purpose of reinforcing, supporting, and cushioning an adherend, a substrate having a thickness of 30 µm or more can be preferably employed.

On the first surface of the substrate, if necessary, a conventionally known surface treatment such as corona discharge treatment, plasma treatment, ultraviolet irradiation treatment, acid treatment, alkali treatment, formation of an undercoat layer by application of a primer (primer), etc. may be carried out. Such surface treatment may be a treatment for improving anchoring properties of the pressure-sensitive adhesive layer to the substrate. For example, the adhesive sheet provided with the base material which contains a resin film as a base film WHEREIN: The base material to which this anchoring property improvement process was given can be employ|adopted preferably. The said surface treatment can be applied individually or in combination. The composition of the primer used for formation of an undercoat layer is not specifically limited, It can select suitably from a well-known thing. The thickness of the undercoating layer is not particularly limited, but is usually about 0.01 μm to 1 μm, and preferably about 0.1 μm to 1 μm. Other treatments that may be applied to 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 pressure-sensitive adhesive sheet disclosed herein is in the form of a single-sided pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer only on the first surface of the substrate, the second surface of the substrate is subjected to a conventionally known surface treatment such as peeling treatment or antistatic treatment, if necessary. may be carried out. For example, by surface-treating the back surface of a base material with a peeling agent (typically by forming a peeling layer by a peeling agent), the rewinding force of the adhesive sheet wound in roll shape can be made light. As the peeling agent, a silicone-based peeling agent, a long-chain alkyl-based peeling agent, an olefin-based peeling agent, a fluorine-based peeling agent, a fatty acid amide-based peeling agent, molybdenum sulfide, silica powder, or the like can be used. In addition, for the purpose of improvement of printability, reduction of light reflectivity, improvement of overlapping properties, etc., the second surface of the substrate may be subjected to a treatment such as corona discharge treatment, plasma treatment, ultraviolet irradiation treatment, acid treatment, alkali treatment, or the like. In the case of a double-sided pressure-sensitive adhesive sheet, the second surface of the substrate may be subjected to the same surface treatment as exemplified above as a surface treatment that may be applied to the first surface of the substrate, if necessary. In addition, the surface treatment performed on the 1st surface of a base material, and the surface treatment performed on the 2nd surface may be same or different.

<Adhesive sheet>

(Characteristics of the adhesive sheet, etc.)

The pressure-sensitive adhesive sheet disclosed herein has a ratio of adhesive force N ₈₀ (adhesion after heating) to adhesive force N ₅₀ , that is, N ₈₀ /N ₅₀ is 5 or more. Also, good rework property can be shown and adhesive force can be raised significantly by subsequent heating etc. From the viewpoint of obtaining a higher effect, in some embodiments, N ₈₀ /N ₅₀ may be, for example, 7 or more, 10 or more, 15 or more, or 20 or more. Although the upper limit in particular of N80/N50 is not restrict|limited, For example, ₈₀ or less may be sufficient, 60 or less may be sufficient, ₅₀ or less may be sufficient, and 40 or less may be sufficient from the manufacturing easiness of manufacture of an adhesive sheet, or a viewpoint of economical efficiency. The pressure-sensitive adhesive sheet disclosed herein may be suitably implemented in an embodiment in which N ₈₀ /N ₅₀ is, for example, 5 or more and 60 or less, 7 or more and 50 or less, or 10 or more and 40 or less.

Although not particularly limited, in some embodiments of the pressure-sensitive 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 is, for example, Less than 10 may be sufficient, Preferably it is less than 7, and less than 5 or less than 4 may be sufficient. According to the pressure-sensitive adhesive sheet having a small N ₅₀ /N ₂₃ , good reworkability tends to be exhibited also in a usage mode in which a temperature of about 50° C. can be applied at the initial stage of pasting. The lower limit of N ₅₀ /N ₂₃ is not particularly limited, but is usually 1.0 or more, typically more than 1.0, and may be, for example, 1.2 or more.

Although not particularly limited, in some embodiments 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 is, for example, 7 or more may be sufficient, 10 or more may be sufficient, and 15 or more may be sufficient as it. According to the pressure-sensitive adhesive sheet having a large N ₈₀ /N ₂₃ , the low tackiness at the initial stage of pasting and the strong tackiness after an increase in adhesive force can be exhibited at a higher level. The pressure-sensitive adhesive sheet disclosed herein can also be suitably implemented in an aspect in which N ₈₀ /N ₂₃ is, for example, 20 or more, 30 or more, or 40 or more. Although the upper limit in particular of N ₈₀ /N ₂₃ is not restrict|limited, From a viewpoint of the ease of manufacture or economical efficiency of an adhesive sheet, 100 or less may be sufficient, 80 or less may be sufficient, 60 or less may be sufficient, and 50 or less may be sufficient, for example.

Here, the adhesive force N ₂₃ [N/25 mm] is pressure-bonded to a stainless steel (SUS) plate as an adherend and left for 30 minutes in an environment of 23° C. and 50% RH, followed by a peeling angle of 180 degrees and a tensile rate of 300 mm/min. It is determined by measuring the 180° peel adhesion under the conditions. Adhesive force N ₅₀ [N/25 mm] is pressure-bonded to a stainless steel (SUS) plate as an adherend, held in an environment of 50 ° C. for 30 minutes, and then left in an environment of 23 ° C. and 50% RH for 30 minutes, followed by a peeling angle It is grasped by measuring the 180 degree peel adhesive force under the conditions of 180 degree|times and a tensile speed of 300 mm/min. Adhesive force N ₈₀ [N/25 mm] is pressure-bonded to a SUS plate as an adherend, heated at 80° C. for 5 minutes, and then left in an environment of 23° C. and 50% RH for 30 minutes, peeling angle 180 degrees, tensile rate 300 mm It is determined by measuring the 180° peel adhesion under the condition of /min. As a to-be-adhered body, also in any measurement _of adhesive force _N23 , N50, N80, a _SUS304BA board is used. In a measurement, if necessary, an appropriate backing material (for example, PET film with a thickness of about 25 micrometers) can be affixed to the adhesive sheet of a measurement object, and can be reinforced. Adhesive force N ₂₃ , N ₅₀ , and N ₈₀ can be measured according to the method described in Examples described below more specifically.

Although not particularly limited, in some aspects of the pressure-sensitive adhesive sheet disclosed herein, the adhesive force N ₂₃ of the pressure-sensitive adhesive sheet may be, for example, 2.0 N/25 mm or less, 1.5 N/25 mm or less, and 1.2 N/25 mm. It may be less than, 1.0N/25mm or less may be sufficient, and 0.8N/25mm or less may be sufficient. It is preferable from a viewpoint of rework property that adhesive force _N23 is low. The lower limit of the adhesive force N ₂₃ is not particularly limited, and may be, for example, 0.01N/25mm or more. From viewpoints, such as sticking workability with respect to to-be-adhered body, position shift prevention before an adhesive force rise, etc., it is suitable that adhesive force N ₂₃ is 0.1 N/25 mm or more normally. From the viewpoint of improving the adhesive force after heating, etc., in some embodiments, the adhesive force N ₂₃ may be, for example, 0.2 N/25 mm or more, 0.3 N/25 mm or more, 0.4 N/25 mm or more, and 0.5 N/ 25 mm or more may be sufficient.

Although not particularly limited, in some aspects of the pressure-sensitive adhesive sheet disclosed herein, the adhesive force N ₅₀ of the pressure-sensitive adhesive sheet may be, for example, 7N/25mm or less, 5N/25mm or less, or 4N/25mm or less. , 3.5N/25mm or less may be sufficient, 3N/25mm or less, 2.5N/25mm or less, or 2N/25mm or less may be sufficient. It is preferable that adhesive force N50 is low from a viewpoint of exhibiting favorable rework property also in the use aspect to which the temperature of about ₅₀ degreeC can be applied in the initial stage of pasting. 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. From a viewpoint of position shift prevention before an adhesive force rise, etc., it is suitable that adhesive force _N50 is 0.1 N/25mm or more normally. From a viewpoint of improvement of adhesive force after heating, etc., in some aspects, adhesive force N ₅₀ may be, for example, 0.2 N/25 mm or more, 0.5 N/25 mm or more, and 0.7 N/25 mm or more may be sufficient as it.

Although not particularly limited, in some aspects of the adhesive sheet disclosed herein, the adhesive force N ₈₀ (adhesive force after heating) of the adhesive sheet may be, for example, 5N/25mm or more, 7N/25mm or more, and 10N /25 mm or more may be sufficient, 13 N/25 mm or more may be sufficient, 15 N/25 mm or more may be sufficient, and 17 N/25 mm or more may be sufficient as it. The upper limit of the adhesive force after heating is not particularly limited. From the viewpoint of the ease of manufacture and economical efficiency of the pressure-sensitive adhesive sheet, in some embodiments, 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.

Although not particularly limited, in some embodiments of the pressure-sensitive 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 usually 5N/25 mm It is preferably less than, for example, may be less than 4N/25mm, may be less than 3N/25mm, may be less than 2.5N/25mm, may be less than 2N/25mm, or may be less than 1.5N/25mm. According to the small pressure-sensitive adhesive sheet of N ₅₀ -N ₂₃ , good reworkability tends to be exhibited also in a usage mode in which a temperature of about 50°C can be applied at the initial stage of pasting. Although the lower limit of _N50 - _N23 is not specifically limited, Usually, it is 0N/25mm or more, Typically, it is more than 0N/25mm, For example, 0.2N/25mm or more may be sufficient.

Although not particularly limited, the adhesive force N ₈₀ [N/25 mm] and the adhesive force N ₅₀ [N/25 mm] for the difference between the adhesive force N ₅₀ [N/25 mm] and the adhesive force N ₂₃ [N/25 mm] of the adhesive sheet disclosed herein ], that is, (N ₈₀ -N ₅₀ )/(N ₅₀ -N ₂₃ ) may be, for example, 2 or more. A larger value of (N ₈₀ -N ₅₀ )/(N ₅₀ -N ₂₃ ) means the degree of increase in adhesive strength after heating with respect to the adhesive strength at the initial stage of sticking in a usage aspect in which a temperature of about 50° C. can be applied. means greater than In some embodiments, (N ₈₀ -N ₅₀ )/(N ₅₀ -N ₂₃ ) may be, for example, 3 or more, 5 or more, 7 or more, 10 or more, 15 or more, 20 or more may be sufficient. The upper limit of (N ₈₀ -N ₅₀ )/(N ₅₀ -N ₂₃ ) is not particularly limited, and may be, for example, 100 or less.

In addition, the adhesive force after heating of the adhesive sheet disclosed here shows one characteristic of this adhesive sheet, and does not limit the usage aspect of this adhesive sheet. In other words, the usage aspect of the adhesive sheet disclosed here is not limited to the aspect which heats at 80 degreeC for 5 minutes, For example, a room temperature range (usually 20 degreeC - 30 degreeC, typically 23 degreeC - 25 degreeC) ), it can also be used in an aspect in which a treatment to be heated above is not particularly performed. Also in such a usage mode, adhesive force rises in a long term, and firm bonding can be implement|achieved. Moreover, the raise of adhesive force can be accelerated|stimulated by heat-processing the adhesive sheet disclosed here at the temperature higher than 50 degreeC at arbitrary timings after sticking. The heating temperature in such heat treatment is not particularly limited, and can be set in consideration of workability, economic efficiency, heat resistance of the base material of the pressure-sensitive adhesive sheet or the adherend, and the like. The heating temperature may be, for example, less than 150°C, 120°C or less, 100°C or less, 80°C or less, and 70°C or less. In addition, the said heating temperature can be 55 degreeC or more, 60 degreeC or more, or 70 degreeC or more, for example, is good also as 80 degreeC or more, and is good also as 100 degreeC or more. According to a higher heating temperature, adhesive force can be raised by the process for a shorter time. Heating time is not specifically limited, For example, 1 hour or less may be sufficient, 30 minutes or less may be sufficient, 10 minutes or less may be sufficient, and 5 minutes or less may be sufficient. Alternatively, as long as no significant thermal deterioration occurs in the pressure-sensitive adhesive sheet or the adherend, heat treatment for a longer period of time may be performed. In addition, heat processing may be performed at once, and may be divided into multiple times and may be performed.

(Adhesive sheet with base material)

When the adhesive sheet disclosed herein is in the form of an adhesive sheet with a base material, the thickness of this adhesive sheet may be 1000 micrometers or less, 600 micrometers or less may be sufficient, 350 micrometers or less may be sufficient, and 250 micrometers or less may be sufficient, for example. From the viewpoint of size reduction, weight reduction, thinning, etc. of the product to which the pressure-sensitive adhesive sheet is applied, in some embodiments, the thickness of the pressure-sensitive adhesive sheet may be, for example, 200 µm or less, 175 µm or less, 140 µm or less, 120 Micrometer or less may be sufficient, and 100 micrometers or less (for example, less than 100 micrometers) may be sufficient. In addition, from a viewpoint of handleability, etc., the thickness of an adhesive sheet may be 5 micrometers or more, 10 micrometers or more, 15 micrometers or more, 20 micrometers or more, 25 micrometers or more, and for example, may be sufficient from a viewpoint of handleability, etc., for example. It may be more than Some aspects WHEREIN: 50 micrometers or more, 60 micrometers or more may be sufficient as the thickness of an adhesive sheet, 80 micrometers or more may be sufficient, 100 micrometers or more, and 130 micrometers or more may be sufficient, for example. The upper limit of the thickness of an adhesive sheet is not specifically limited.

In addition, the thickness of an adhesive sheet means the thickness of the part affixed to a to-be-adhered body. For example, in the adhesive sheet 1 of the structure shown in FIG. 1, the thickness from the adhesive surface 21A of the adhesive sheet 1 to the 2nd surface 10B of the base material 10 is indicated, and the release liner 31 ) is not included.

The pressure-sensitive adhesive sheet disclosed herein can be suitably implemented, for example, in an aspect in which the thickness Ts of the supporting substrate is larger than the thickness Ta of the pressure-sensitive adhesive layer, that is, in an aspect in which Ts/Ta is larger than one. Although it does not specifically limit, For example, 1.1 or more, 1.2 or more, 1.5 or more, and 1.7 or more may be sufficient as Ts/Ta. For example, in the adhesive sheet which can be used for the purpose of reinforcement, support, shock mitigation, etc. of a to-be-adhered body, it exists in the tendency for a favorable effect to be easily exhibited even if the adhesive sheet is thinned by Ts/Ta increase. In some embodiments, Ts/Ta may be 2 or more (eg, greater than 2), 3 or more, or 4 or more. In addition, Ts/Ta can be made into 50 or less, for example, and it is good also as 20 or less. From a viewpoint of making it easy to exhibit high post-heat adhesive force even if an adhesive sheet is made thin, 10 or less may be sufficient, and 8 or less may be sufficient as Ts/Ta, for example.

It is preferable that the said adhesive layer is adhered to the support base material. The above-mentioned sticking means that, in an adhesive sheet having an increased adhesive strength after sticking to an adherend, the adhesive layer is a supporting substrate to such an extent that peeling does not occur at the interface between the pressure-sensitive adhesive layer and the supporting substrate when the adhesive sheet is peeled from the adherend. indicates sufficient anchoring properties for According to the pressure-sensitive adhesive sheet provided with the base material in which the pressure-sensitive adhesive layer is fixed to the support base material, the adherend and the support base material can be firmly integrated. Thereby, functions, such as reinforcement of a to-be-adhered body, support, and shock mitigation, can be exhibited effectively, for example. As a preferred example of the pressure-sensitive adhesive sheet in which the pressure-sensitive adhesive layer is adhered to the substrate, after sticking to the adherend, at least 5 N/25 mm, preferably 10 N/25 mm or more, more preferably 15 N/25 mm or more, the adhesive force (peel angle 180 degrees) , when peeling from the adherend while expressing 180° peeling adhesive force measured at a tensile rate of 300 mm/min) there is. A pressure-sensitive adhesive sheet having an adhesive force (N ₈₀ ) of 15N/25 mm or more after heating, and in which anchorage breakage does not occur when measuring the adhesive strength after heating, corresponds to a pressure-sensitive adhesive sheet in which the pressure-sensitive adhesive layer is adhered to the substrate. .

The pressure-sensitive adhesive sheet disclosed herein is, for example, in a method comprising contacting a liquid pressure-sensitive adhesive composition to a first surface of a substrate, and curing the pressure-sensitive adhesive composition on the first surface to form a pressure-sensitive adhesive layer in this order It can be preferably prepared by Curing of the pressure-sensitive adhesive composition may be accompanied by one or two or more of drying, crosslinking, polymerization, cooling, and the like of the pressure-sensitive adhesive composition. According to the method of forming the pressure-sensitive adhesive layer by curing the liquid pressure-sensitive adhesive composition on the first surface of the substrate as described above, by bonding the cured pressure-sensitive adhesive layer to the first surface of the substrate, the method of disposing the pressure-sensitive adhesive layer on the first surface On the other hand, anchoring property with respect to the base material of an adhesive layer can be improved. By using this, the adhesive sheet in which the adhesive layer adhered to the base material can be manufactured suitably.

In some embodiments, as a method of contacting the liquid pressure-sensitive adhesive composition to the first surface of the substrate, a method of directly applying the pressure-sensitive adhesive composition to the first surface of the substrate may be employed. By bringing the first surface (adhesive surface) of the pressure-sensitive adhesive layer cured on the first surface of the substrate into contact with the release surface, the second surface of the pressure-sensitive adhesive layer is fixed to the first surface of the substrate, and the first surface of the pressure-sensitive adhesive layer is adhered to the first surface of the substrate. The adhesive sheet of the structure in which the surface contact|connected the peeling surface can be obtained. As said release surface, the surface of a release liner, the back surface of the base material by which the release process was carried out, etc. can be used.

In addition, for example, in the case of a photo-curable pressure-sensitive adhesive composition using a partial polymerization product (acrylic polymer syrup) of a monomer component, for example, after the pressure-sensitive adhesive composition is applied to the release surface, the first side of the substrate is applied to the applied pressure-sensitive adhesive composition You may form an adhesive layer by making the 1st surface of a base material contact the said non-hardened adhesive composition by covering, and in that state, by irradiating light to the adhesive composition sandwiched between the 1st surface of a base material and a peeling surface, and hardening it.

In addition, the method illustrated above does not limit the manufacturing method of the adhesive sheet disclosed here. In the production of the pressure-sensitive adhesive sheet disclosed herein, an appropriate method capable of adhering the pressure-sensitive adhesive layer to the first surface of the substrate may be used alone or in combination of two or more thereof. Examples of such a method include a method of curing the liquid pressure-sensitive adhesive composition on the first surface of the substrate to form a pressure-sensitive adhesive layer as described above, or a method of subjecting the first surface of the substrate to a surface treatment to improve anchoring properties of the pressure-sensitive adhesive layer. and the like. For example, if the anchoring property of the pressure-sensitive adhesive layer to the substrate can be sufficiently improved by a method such as forming an undercoating layer on the first surface of the substrate, the cured pressure-sensitive adhesive layer is bonded to the first surface of the substrate. You may manufacture an adhesive sheet by this method. Moreover, anchoring property with respect to the base material of an adhesive layer can be improved also by selection of the material of a base material, or selection of a composition of an adhesive. In addition, by applying a temperature higher than room temperature to the pressure-sensitive adhesive sheet having the pressure-sensitive adhesive layer on the first surface of the substrate, anchoring properties of the pressure-sensitive adhesive layer to the substrate can be improved. The temperature applied in order to improve anchoring property may be, for example, about 35 degreeC - 80 degreeC, about 40 degreeC - 70 degreeC or more may be sufficient, and 45 degreeC - about 60 degreeC may be sufficient, for example.

The pressure-sensitive adhesive sheet disclosed herein is in the form of a pressure-sensitive adhesive sheet having a first pressure-sensitive adhesive layer formed on a first surface of a substrate and a second pressure-sensitive adhesive layer formed on a second surface of the substrate (that is, a double-sided adhesive pressure-sensitive adhesive sheet with a substrate) In the case of , the same structure may be sufficient as a 1st adhesive layer and a 2nd adhesive layer, and a different structure may be sufficient as them. When the configuration of the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer are different, the difference may be, for example, a difference in composition or a difference in structure (thickness, surface roughness, formation range, formation pattern, etc.). For example, the adhesive layer which does not contain the polymer B may be sufficient as a 2nd adhesive layer. Moreover, less than 5 may be sufficient as the surface (2nd adhesive surface) of a 2nd adhesive layer, and _N80 /N50 may be less than ₅ , less than 2 may be sufficient as it, and less than 1.5 may be sufficient as it, and less than 1 may be sufficient as it.

<Adhesive sheet with release liner>

The pressure-sensitive adhesive sheet disclosed herein can take the form of a pressure-sensitive adhesive product in which the surface (adhesive surface) of the pressure-sensitive adhesive layer is brought into contact with the release surface of the release liner. Accordingly, by this specification, there can be provided a pressure-sensitive adhesive sheet (adhesive product) with a release liner comprising any of the pressure-sensitive adhesive sheets disclosed herein and a release liner having a release surface that abuts against the pressure-sensitive adhesive surface of the pressure-sensitive adhesive sheet.

Although the thickness of a release liner is not specifically limited, Usually, 5 micrometers - about 200 micrometers are suitable. When the thickness of a release liner exists in the said range, since it is excellent in the bonding workability|operativity with respect to an adhesive layer, and peeling workability|operativity from an adhesive layer, it is preferable. In some aspects, the thickness of the release liner may be, for example, 10 µm or more, 20 µm or more, 30 µm or more, or 40 µm or more. In addition, from a viewpoint of facilitating peeling from an adhesive layer, the thickness of a release liner may be 100 micrometers or less, and may be 80 micrometers or less, for example. If necessary, the release liner may be subjected to a known antistatic treatment such as a coating type, a kneading type, and a vapor deposition type.

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 paper laminated with a resin such as polyethylene), or a fluorine-based polymer (polytetra A release liner comprising a resin film formed of a low-adhesive material such as fluoroethylene or the like) or a polyolefin-based resin (polyethylene, polypropylene, etc.) can be used. From the viewpoint of excellent surface smoothness, 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 of a low-adhesive material can be preferably employed. The resin film is not particularly limited as long as it is a film capable of protecting the pressure-sensitive adhesive layer, and for example, a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, a polymethylpentene film, a polyvinyl chloride film, and a vinyl chloride copolymer. A film, a polyester film (PET film, PBT film, etc.), a polyurethane film, an ethylene-vinyl acetate copolymer film, etc. are mentioned. In the formation of the release layer, for example, a silicone-based release agent, a long-chain alkyl-based release agent, an olefin-based release agent, a fluorine-based release agent, a fatty acid amide-based release agent, molybdenum sulfide, silica powder, and other known release agents can be used. there is. Use of a silicone type peeling treatment agent is especially preferable.

The thickness of the release layer is not particularly limited, but is usually about 0.01 µm to 1 µm, and preferably about 0.1 µm to 1 µm. The formation method of a peeling layer is not specifically limited, A well-known method according to the kind etc. of the peeling agent to be used can be employ|adopted suitably.

<Use>

The pressure-sensitive adhesive sheet provided by this specification, for example, after bonding to an adherend, has low adhesive strength for a while in a temperature range from room temperature to about 50°C (eg, 20°C to 50°C), , during this period, good rework properties can be exhibited, so it can contribute to suppression of yield and improvement in quality of products including the pressure-sensitive adhesive sheet. In addition, the adhesive sheet can greatly increase the adhesive strength by aging (which may be heating to a temperature higher than 50° C., aging, a combination thereof, etc.). For example, by heating at a desired timing, the pressure-sensitive adhesive sheet can be firmly adhered to the adherend. Taking advantage of these characteristics, the pressure-sensitive adhesive sheet disclosed herein can be preferably used for the purposes of fixing, bonding, molding, decorating, protecting, reinforcing, supporting, and shock mitigation of members included in various products in various fields. there is.

The pressure-sensitive adhesive sheet disclosed herein is in the form of an adhesive sheet provided with a base material in which an pressure-sensitive adhesive layer is formed on at least a first surface of a film-like substrate having a first surface and a second surface, and is attached to an adherend to reinforce the adherend. It can be preferably used as a film. Such a reinforcing film WHEREIN: As said film base material, what contains a resin film as a base film can be used preferably. In addition, from the viewpoint of improving the reinforcing performance, the pressure-sensitive adhesive layer is preferably fixed to the first surface of the film-like substrate.

For example, in an optical member used for an optical product or an electronic member used for an electronic product, a high degree of integration, miniaturization, weight reduction, and thickness reduction are progressing, and a plurality of thin optical members/electronic members having different coefficients of linear expansion and thickness are present. can be stacked. By affixing the above reinforcing films to such a member, moderate rigidity can be provided to the said optical member/electronic member. Thereby, in the manufacturing process and/or the product after manufacture, the curl and curvature resulting from the stress which may generate|occur|produce between the several members from which the said linear expansion coefficient and thickness differ can be suppressed.

Further, in the optical product / electronic product manufacturing process, in the situation where the thin optical member / electronic member is subjected to shape processing such as cutting processing as described above, by attaching a reinforcing film to the member and processing, The local stress concentration to the accompanying optical member/electronic member can be relieved, and risks, such as a crack, a crack, and peeling of a lamination|stacking member, can be reduced. Attaching the reinforcing member to the optical member/electronic member and handling it is helpful in relieving local stress concentration during conveyance, lamination, rotation, etc. of the member, as well as suppression of bending or bending due to the member's own weight. can be

In addition, when the device such as an optical product or an electronic product including the reinforcing film is used by consumers in the market, when the device falls, when placed under a heavy object, when a flying object collides, etc., Even when unintentional stress is applied, the stress applied to the device can be alleviated by including the reinforcing film in the device. Therefore, by including the reinforcing film in the device, durability of the device can be improved.

In addition, the adhesive sheet disclosed here can be used suitably in the aspect affixed to the member which comprises various portable devices (portable device), for example. Here, "portability" is considered to mean that it is not sufficient to simply be able to carry it, and has a level of portability that an individual (a standard adult) can carry relatively easily. In addition, examples of the mobile device mentioned herein include a mobile phone, a smartphone, a tablet-type personal computer, a notebook computer, various wearable devices, a digital camera, a digital video camera, an audio device (a portable music player, an IC recorder, etc.), a calculator (electronic type) desktop calculators), portable game devices, electronic dictionaries, electronic notebooks, electronic books, in-vehicle information devices, portable radios, portable TVs, portable printers, portable scanners, portable modems, etc., as well as mechanical watches and pockets. This may include a watch, a flashlight, a hand mirror, and the like. Examples of the member constituting the portable electronic device may include an optical film or a display panel used in an image display device such as a thin-layer display such as a liquid crystal display or a film-type display. The pressure-sensitive adhesive sheet disclosed herein can be preferably used also in an aspect affixed to various members in automobiles, household appliances, and the like.

The matters disclosed by this specification include the following.

(1) an adhesive sheet comprising an adhesive layer,

The pressure-sensitive adhesive layer includes a polymer A and a polymer B, which is a copolymer of a monomer having a polyorganosiloxane skeleton and a (meth)acrylic monomer,

The polymer B has a glass transition temperature T _m1 of 50° C. or more and 100° C. or less based on the composition of the (meth)acrylic monomer,

After bonding to a stainless steel sheet, the adhesive force N ₈₀ after heating at 80 ° C. for 5 minutes is 5 times or more of the adhesive force N ₅₀ after bonding to a stainless steel sheet and holding at 50 ° C. for 30 minutes, the pressure-sensitive adhesive sheet.

(2) The relationship between the adhesive force N ₅₀ and the adhesive force N ₂₃ after bonding to a stainless steel plate and maintaining at 23° C. for 30 minutes is expressed by the following formula:

(N ₅₀ /N ₂₃ )<10;

The adhesive sheet as described in said (1) which satisfy|fills.

(3) The adhesive sheet according to (1) or (2), wherein the adhesive force N ₈₀ is 10 times or more of the adhesive force N ₂₃ after being left at 23° C. for 30 minutes after bonding to a stainless steel sheet.

(4) The adhesive force N ₂₃ [N/25mm], the adhesive force N ₅₀ [N/25mm] and the adhesive force N ₈₀ [N/25mm] are the following relational expressions:

(N ₈₀ -N ₅₀ )/(N ₅₀ -N ₂₃ )≥2;

The pressure-sensitive adhesive sheet according to any one of (1) to (3), which satisfies

(5) The adhesive sheet according to any one of (1) to (4), wherein the adhesive force N ₂₃ is 2.0 N/25 mm or less.

(6) The adhesive sheet according to any one of (1) to (5), wherein the adhesive force N ₅₀ is 4 N/25 mm or less.

(7) The adhesive sheet according to any one of (1) to (6), wherein the adhesive force N ₈₀ is 15 N/25 mm or more.

(8) The adhesive sheet in any one of said (1)-(7) whose glass transition temperature T _A of the said polymer A is -63 degreeC or more and less than 0 degreeC.

(9) The adhesive sheet in any one of said (1)-(8) whose glass transition temperature TB of the said polymer _B is -10 degreeC or more and 10 degrees C or less.

(10) The adhesive sheet according to any one of (1) to (9), wherein the polymer B has a copolymerization ratio of a monomer having a homopolymer having a glass transition temperature higher than 170°C of 30% by weight or less.

(11) The pressure-sensitive adhesive sheet according to any one of (1) to (10), wherein the pressure-sensitive adhesive layer contains more than 0 parts by weight and not more than 10 parts by weight of a crosslinking agent with respect to 100 parts by weight of the polymer A.

(12) The adhesive sheet according to any one of (1) to (11), wherein the polymer B has a weight average molecular weight of 10000 or more and 50000 or less.

(13) The adhesive sheet in any one of said (1)-(12) whose content of the said polymer B in the said adhesive layer is 0.05 weight part or more and 20 weight part or less with respect to 100 weight part of said polymer A.

(14) The adhesive sheet according to any one of (1) to (13), wherein the polymer A is an acrylic polymer.

(15) The adhesive sheet according to (14), wherein the monomer component for preparing the acrylic polymer contains a hydroxyl group-containing monomer.

(16) The adhesive sheet according to (14), wherein the monomer component for preparing the acrylic polymer contains N-vinyl cyclic amide and a hydroxyl group-containing monomer.

(17) The pressure-sensitive adhesive sheet according to any one of (1) to (16), wherein the pressure-sensitive adhesive layer contains an isocyanate-based crosslinking agent.

(18) The adhesive sheet according to any one of (1) to (17), wherein the monomer component for preparing the polymer B contains methyl methacrylate (MMA).

(19) The adhesive sheet as described in said (18) whose ratio of MMA to the total amount of the (meth)acrylic-type monomer contained in the said monomer component is 55 weight% or more and 95 weight% or less.

(20) The pressure-sensitive adhesive sheet according to any one of (1) to (19), wherein the pressure-sensitive adhesive layer has a thickness of 3 µm or more and 100 µm or less (eg, 20 µm or more and 50 µm or less).

(21) The pressure-sensitive adhesive sheet according to any one of (1) to (20), comprising a support substrate having a first surface and a second surface, wherein the pressure-sensitive adhesive layer is laminated on at least the first surface of the support substrate. .

(22) The adhesive sheet as described in said (21) whose thickness of the said support base material is 30 micrometers or more.

(23) The adhesive sheet as described in said (21) or (22) whose thickness of the said support base material is 1.1 times or more and 10 times or less of the thickness of the said adhesive layer.

(24) The adhesive sheet according to any one of (21) to (23), wherein the supporting substrate includes a resin film as a base film.

(25) The adhesive sheet according to (24), wherein the base film is a polyester film having a thickness of 35 µm or more (eg, 35 µm or more and 500 µm or less in thickness).

(26) The pressure-sensitive adhesive sheet according to any one of (21) to (25), wherein the pressure-sensitive adhesive layer is adhered to the first surface of the supporting substrate.

(27) The adhesive sheet according to any one of (21) to (26), which is affixed to an adherend and used for reinforcement of the adherend.

(28) The pressure-sensitive adhesive sheet according to any one of (1) to (27), wherein the surface (adhesive surface) of the pressure-sensitive adhesive layer is in contact with the peelable surface at a water contact angle of 100 degrees or more.

(29) The pressure-sensitive adhesive sheet according to any one of (1) to (28), and a release liner having a release surface in contact with the pressure-sensitive adhesive surface of the pressure-sensitive adhesive sheet;

The water contact angle of the said peelable surface is 100 degrees or more, The adhesive sheet with a release liner.

(30) The adhesive sheet with a release liner as described in said (29) whose said peelable surface is the surface of the peeling layer formed with the silicone type peeling agent.

<Example>

Hereinafter, some examples related to the present invention will be described, but it is not intended to limit the present invention to those shown in these specific examples. In addition, unless otherwise indicated, "part" and "%" in the following description are based on weight.

(Preparation of polymer A1)

In a 4-neck flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube and a cooler, 60 parts of 2EHA, 15 parts of N-vinyl-2-pyrrolidone (NVP), 10 parts of methyl methacrylate (MMA), 2- After adding 15 parts of hydroxyethyl acrylate (HEA) and 200 parts of ethyl acetate as a polymerization solvent, stirring at 60° C. under a nitrogen atmosphere for 2 hours, 0.2 parts of AIBN as a thermal polymerization initiator, and reaction at 60° C. for 6 hours was carried out to obtain a solution of polymer A1. The Mw of this polymer A1 was 1.1 million.

(Preparation of polymer B1)

To a four-neck 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, 20 parts of n-butyl methacrylate (BMA), 2-ethylhexyl methacrylate ( 2EHMA) 20 parts, a methacrylate monomer containing a polyorganosiloxane skeleton having a functional group equivalent of 900 g/mol (trade name: X-22-174ASX, manufactured by Shin-Etsu Chemical Co., Ltd.) 8.7 parts, a functional group equivalent of 4600 g/mol 11.3 parts of polyorganosiloxane skeleton-containing methacrylate monomers (trade name: KF-2012, manufactured by Shin-Etsu Chemical Co., Ltd.) and 0.51 parts of methyl thioglycolate as a chain transfer agent were added. Then, after stirring at 70 ° C. under a nitrogen atmosphere for 1 hour, 0.2 parts of AIBN as a thermal polymerization initiator was added, and after reacting at 70 ° C. for 2 hours, 0.1 parts by weight of AIBN was added as a thermal polymerization initiator, followed by 5 parts at 80 ° C. time was reacted. In this way, a solution of polymer B1 was obtained. The Mw of this polymer B1 was 22000.

(Preparation of polymers B2 to B7)

Polymers B2 to B7 were prepared in the same manner as in preparation of polymer B1, except that the composition of the monomer component was changed as shown in Table 1, 0.8 parts of thioglycerol was used as the chain transfer agent, and ethyl acetate was used as the polymerization solvent. The Mw of each polymer was 19100 for Polymer B2, 19700 for Polymer B3, 19600 for Polymer B4, 20000 for Polymer B5, 18900 for Polymer B6, and 19500 for Polymer B7.

The composition of the monomer component used to prepare the polymers B1 to B7, the glass transition temperature T _m1 based on the composition of the (meth)acrylic monomer among the monomer components, and the glass transition temperature T _B of the polymers B1 to B7 are incorporated in Table 1 to indicate

In addition, the weight average molecular weight of each polymer mentioned above measured on the following conditions using the GPC apparatus (made by Tosoh Corporation, HLC-8220GPC), and calculated|required by polystyrene conversion.

[GPC conditions]

ㆍSample concentration: 0.2 wt% (tetrahydrofuran (THF) solution)

ㆍSample injection amount: 10μl

ㆍEluent: THF

ㆍFlow rate: 0.6ml/min

ㆍMeasurement temperature: 40℃

ㆍColumn:

sample column; TSKguardcolumn SuperHZ-H (1 pc.) + TSKgel SuperHZM-H (2 pc.)

reference column; TSKgel SuperH-RC (1 pc.)

ㆍDetector: Differential Refractometer (RI)

In addition, in calculation of TB shown in Table 1, -126 degreeC was used as a value of Tg of X- _22-174ASX , and -127 degreeC was used as a value of Tg of KF-2012. Tg of these polyorganosiloxane skeleton containing methacrylate monomers is calculated|required by putting this monomer (measurement sample) in a simple airtight container made from aluminum, and performing DSC (differential scanning calorimetry) under the following conditions.

[DSC conditions]

Device: TA Instruments, Q-2000

Temperature program: -160℃ to 40℃

Temperature increase rate: 10℃/min

Atmospheric gas: He (50 mL/min)

<Production of adhesive sheet>

(Example 1)

To the solution of polymer A1, 2.5 parts of polymer B1 and 2.5 parts of an isocyanate-based crosslinking agent (trade name: Takenate D110N, trimethylolpropanesilylene diisocyanate, manufactured by Mitsui Chemicals Co., Ltd.) per 100 parts of polymer A1 contained in the solution were added and uniformly mixed to prepare an adhesive composition C1.

The pressure-sensitive adhesive composition C1 is directly applied to the first surface of a 125 µm-thick polyethylene terephthalate (PET) film (manufactured by Toray Corporation, trade name “Lumirer”) as a supporting base material, and dried by heating at 110° C. for 2 minutes, thereby 25 µm in thickness of the pressure-sensitive adhesive layer was formed. The release surface of the release liner R1 was bonded to the surface (adhesive surface) of this pressure-sensitive adhesive layer. In this way, the pressure-sensitive adhesive sheet according to Example 1 was obtained in the form of a pressure-sensitive adhesive sheet with a release liner in which the pressure-sensitive adhesive surface was in contact with the release surface of the release liner.

As the release liner, MRQ25T100 manufactured by Mitsubishi Chemical Corporation (a release liner having a release layer made of a silicone release treatment agent on one side of a polyester film, a thickness of 25 µm) was used.

(Examples 2 to 11)

Except having changed the usage-amount of the polymer B and a crosslinking agent as shown in Table 2, it carried out similarly to preparation of the adhesive composition C1, and prepared the adhesive compositions C2 - C11. Except having used these adhesive compositions C2-C11, respectively, it carried out similarly to preparation of the adhesive sheet concerning Example 1, and obtained the adhesive sheet concerning Examples 2-11.

<Measurement of adhesion to SUS>

As a test piece, the pressure-sensitive adhesive sheet according to each example was cut with the release liner to a width of 25 mm, and a SUS plate (SUS304BA plate) cleaned with toluene was used as an adherend, and the adhesive force N ₂₃ , the adhesive force N ₅₀ and the adhesive force N ₈₀ in the following procedure was measured.

(Measurement of adhesive force N ₂₃ )

In a standard environment of 23° C. and 50% RH, the release liner covering the adhesive surface of each test piece was peeled off, and the exposed adhesive surface was pressed against the adherend by one reciprocating 2 kg roller. After leaving the test piece crimped to the adherend in this way for 30 minutes under the standard environment, it was peeled off in accordance with JIS Z0237 using a universal tensile and compression tester (device name "Tensile Compression Tester, TCM-1kNB" manufactured by Minebea Corporation). Under the conditions of an angle of 180 degrees and a tensile rate of 300 mm/min, the 180 degree peel adhesive force (resistance to the tensile force) was measured. The measurement was performed 3 times, and the average value is shown in Table 2 as the adhesive force (N23) [N/25mm] after ₂₃ degreeC 30 minutes.

(Measurement of adhesive force N ₅₀ )

The test piece crimped to the adherend in the same manner as in the measurement of the adhesive force N ₂₃ was held in an environment of 50° C. for 30 minutes, and then left to stand for 30 minutes in the standard environment, and the 180° peel adhesive force was similarly measured. The measurement was performed 3 times, and the average value is shown in Table 2 as adhesive force (N50) [N/25mm] after ₅₀ degreeC 30 minutes.

(Measurement of adhesive force N ₈₀ )

The test piece crimped to the adherend in the same manner as in the measurement of the adhesive force N ₂₃ was heated at 80° C. for 5 minutes, and then left to stand for 30 minutes under the standard environment, and then the 180° peel adhesive force was similarly measured. The measurement was performed 3 times, and the average value is shown in Table 2 as adhesive force (N80) [N/25mm] after ₈₀ degreeC 5 minutes. Moreover, it was confirmed that all of the adhesive sheets concerning Examples 1-11 did not raise|generate anchorage breakage at the time of the measurement of adhesive force _N80 .

Based on these adhesive force measurement results, 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 obtained results are shown in Table 2.

As shown in Table 2, in the pressure-sensitive adhesive sheets of Examples 5 to 9 using polymers B3 to B5 having a glass transition temperature T _m1 in the range of 50°C to 100°C, N ₈₀ /N ₅₀ is 5 or more, so that at the initial stage of attachment It was confirmed that even when a temperature of about 50° C. is applied, low tackiness suitable for rework is maintained, and adhesive strength can be greatly increased by heating at 80° C. for 5 minutes.

On the other hand, in the pressure-sensitive adhesive sheets of Examples 1 to 4 and Example 11 using polymers B1, B2, and B7 having a glass transition temperature T _m1 lower than 50° C., N ₈₀ /N ₅₀ is less than 5, and the temperature of about 50° C. at the initial stage of pasting. It was easy to raise the adhesive force by being added. In the adhesive sheet of Example 4, although N50 was comparatively low, the adhesive force was not able to raise large by heating at 80 _degreeC for 5 minutes. Moreover, in Example 10 using the polymer B6 whose glass transition temperature T _m1 exceeds 100 degreeC, the adhesive force was not able to raise by heating at 80 degreeC for 5 minutes.

As mentioned above, although the specific example of this invention was described in detail, these are only an illustration and do not limit a claim. The technology described in the claims includes various modifications and changes of the specific examples exemplified above.

1, 2, 3: Adhesive sheet
10: support substrate
10A: first side
10B: second side
21: adhesive layer (first adhesive layer)
21A: adhesive side (first adhesive side)
21B: adhesive side (second adhesive side)
22: adhesive layer (second adhesive layer)
22A: adhesive side (second adhesive side)
31, 32: release liner
100, 200, 300: adhesive sheet with release liner (adhesive product)

Claims (10)

It is an adhesive sheet comprising an adhesive layer,
The pressure-sensitive adhesive layer includes a polymer A and a polymer B, which is a copolymer of a monomer having a polyorganosiloxane skeleton and a (meth)acrylic monomer,
The polymer A is an acrylic polymer,
The glass transition temperature T _A of the polymer A is -55 ℃ or more and less than 0 ℃,
The monomer component for preparing the said polymer A contains N-vinyl cyclic amide and a hydroxyl-containing monomer,
The polymer B has a glass transition temperature T _m1 of 50° C. or more and 100° C. or less based on the composition of the (meth)acrylic monomer,
The polymer B has a copolymerization ratio of 30% by weight or less of a monomer having a glass transition temperature higher than 170° C. of the homopolymer,
Adhesive force _N80 is ₅ times or more of adhesive force N50, The adhesive sheet.
(The adhesive force N ₈₀ is pressure-bonded to a stainless steel (SUS) plate as an adherend, heated at 80° C. for 5 minutes, and then left in an environment of 23° C. and 50% RH for 30 minutes, peeling angle 180 degrees, tensile rate 180 ° peel adhesive force measured under the condition of 300 mm / min,
The adhesive force N ₅₀ is pressed to a stainless steel (SUS) plate as an adherend and maintained in an environment of 50° C. for 30 minutes, and then left in an environment of 23° C. and 50% RH for 30 minutes, peeling angle 180 degrees, tensile 180° peel adhesive force measured at a speed of 300 mm/min.) According to claim 1, wherein the relationship between the adhesive force N ₅₀ and the adhesive force N ₂₃ , the following formula:
(N ₅₀ /N ₂₃ )<10;
to satisfy, the adhesive sheet.
(The adhesive force N ₂₃ is pressure-bonded to a stainless steel (SUS) plate as an adherend and left for 30 minutes in an environment of 23° C. and 50% RH, and then 180 measured under the conditions of a peeling angle of 180 degrees and a tensile rate of 300 mm/min. ° Indicates peel adhesion.) The adhesive sheet of Claim 1 or 2 whose glass transition temperature T _A of the said polymer A is -50 degreeC or more and less than -10 degreeC. The adhesive sheet of Claim 1 or 2 whose glass transition temperature TB of the said polymer _B is -10 degreeC or more and 10 degrees C or less. The pressure-sensitive adhesive sheet according to claim 1 or 2, wherein the pressure-sensitive adhesive layer contains more than 0 parts by weight and not more than 10 parts by weight of a crosslinking agent with respect to 100 parts by weight of the polymer A. The adhesive sheet according to claim 1 or 2, wherein the polymer B has a weight average molecular weight of 10000 or more and 50000 or less. The adhesive sheet of Claim 1 or 2 whose content of the said polymer B in the said adhesive layer is 0.05 weight part or more and 20 weight part or less with respect to 100 weight part of said polymer A. The pressure-sensitive adhesive sheet according to claim 1 or 2, comprising a support base material having a first surface and a second surface, wherein the pressure-sensitive adhesive layer is laminated on at least the first surface of the support base material. The pressure-sensitive adhesive sheet according to claim 8, wherein the supporting substrate has a thickness of 30 µm or more. delete

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