KR20190058278A - Adhesive sheet - Google Patents

Abstract

Provided is an adhesive sheet, which maintains reworkability even if a temperature of approximately 50°C is applied to an object to be attached at an attachment intial stage and can greatly increase adhesion thereafter. The adhesive sheet of the present invention comprises an adhesive layer. The 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 50 to 100°C of a glass transition temperature T_m1 based on a composition of the (meth)acrylic monomer. In the adhesive sheet, an adhesive strength N_80 after being heated at 80°C for 5 minutes after attachment is at least 5 times an adhesive strength N_50 after being stood at 50°C for 30 minutes after attachment.

Description

ADHESIVE SHEET [0002]

The present invention relates to a pressure-sensitive adhesive sheet.

This application claims priority based on Japanese Patent Application No. 2017-222778, filed on November 20, 2017, the entire contents of which are incorporated herein by reference.

The pressure-sensitive adhesive sheet is firmly adhered to an adherend to be used for adhesion of the adherends, fixing of the adherend to the adherend, reinforcement of the adherend, and the like. Conventionally, for this purpose, a pressure-sensitive adhesive sheet that exhibits a high adhesive force from the beginning of a patch has been used. Recently, as in Patent Documents 1 to 3, there has been proposed a pressure-sensitive adhesive sheet which exhibits a low adhesive force at the beginning of the adherend to an adherend, and can thereby greatly increase the adhesive force. According to the pressure-sensitive adhesive sheet having such properties, before the increase of the pressure-sensitive adhesive force, reattachability (reworkability) useful for restraining the yield of the pressure-sensitive adhesive sheet due to errors in adhesion or damage to the pressure-sensitive adhesive sheet is exhibited, It is possible to exhibit a strong adhesive property suitable for the purpose of use.

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

However, depending on the use of the adhesive sheet, a request for rework may occur due to, for example, an error in adhesion or adhesion damage after the attachment, a subsequent positional shift due to the influence of the subsequent process, There may be cases. In such a case, it is preferable that the pressure-sensitive adhesive sheet applied to the adherend is heated within a period in which the reworkability is required, for example, in a case where the heat of the device (the conveying device, the inspection device, There may be a case where a temperature of about 40 캜 to 50 캜 is applied to the pressure-sensitive adhesive sheet due to an influence, an arrangement from a nearby device, an increase in the temperature of the manufacturing environment, or the like. Therefore, an object of the present invention is to provide a pressure-sensitive adhesive sheet which can maintain the reworkability even when a temperature of about 50 캜 is applied at the beginning of the adherend to an adherend, and can further increase the adhesive force thereafter.

According to this specification, there is provided an adhesive sheet comprising a pressure-sensitive adhesive layer. The pressure-sensitive adhesive layer includes a polymer A and a polymer B as a copolymer of a monomer having a polyorganosiloxane skeleton and a (meth) acrylic monomer. The polymer B has a glass transition temperature _Tm1 based on the composition of the (meth) acrylic monomer of 50 占 폚 to 100 占 폚. The pressure-sensitive adhesive sheet has an adhesive force N ₈₀ after heating at 80 ° C for 5 minutes after bonding to a stainless steel sheet, at least five times the adhesive force N ₅₀ after holding at 50 ° C for 30 minutes after bonding to a stainless steel sheet.

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.Pressure-sensitive adhesive sheet having such a structure, the glass transition temperature T _m1 is by including more than 50 ℃ polymer B not more than 100 ℃, (hereinafter also referred to as "adhesive strength after heating") Adhesion N ₈₀ with respect to the adhesive force N ₅₀ to increase by 5 times or more (I.e., N ₈₀ / N ₅₀

5). As a result, good releasability is exhibited even in a use mode in which a temperature of about 50 캜 can be applied at the beginning of the application, and the adhesive force can be greatly increased by subsequent heating or the like.

The pressure-sensitive adhesive sheet according to some embodiments is characterized in that the relationship between the adhesive force N ₅₀ and the adhesive force N ₂₃ after being left at 23 캜 for 30 minutes after bonding to the stainless steel sheet satisfies the following formula: (N ₅₀ / N ₂₃ ) <10 do. According to such a pressure-sensitive adhesive sheet, the difference between the case where the pressure-sensitive adhesive sheet is maintained at room temperature at the beginning of the application and the pressure-sensitive adhesive force (and the workability) when the pressure-sensitive adhesive sheet is exposed to a temperature of about 50 DEG C is small. Do.

In some embodiments, the glass transition temperature T _A of the polymer A may be, for example, less than -80 ℃ 0 ℃. The pressure-sensitive adhesive sheet disclosed herein can be suitably applied using the polymer A having such a glass transition temperature T _A.

In some embodiments, the glass transition temperature T _B of the polymer B are, for example, it is up to at least -10 ℃ 10 ℃. The pressure-sensitive adhesive sheet disclosed herein can suitably be implemented using a polymer B having such a glass transition temperature T _B.

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

In some embodiments, the pressure-sensitive adhesive layer may include a crosslinking agent in an amount of more than 0 parts by weight and not more than 10 parts by weight based on 100 parts by weight of the polymer A. By using the cross-linking agent, the adhesive strength at the initial stage of the application can be effectively controlled in the temperature range up to about 50 캜. This tends to make it easier to obtain a pressure-sensitive adhesive sheet that satisfactorily exhibits the reworkability at the initial stage of application and the strong tackiness after the increase in the tackiness.

In some embodiments, the polymer B preferably has a weight average molecular weight (Mw) of 10000 or more and 50,000 or less. According to the polymer B having the Mw in the above range, the adhesive strength at the initial stage of the application is low and a pressure-sensitive adhesive sheet having a high adhesive strength after heating is apt to be obtained.

In some embodiments, the content of the polymer B in the pressure-sensitive adhesive layer may be in the range of 0.05 to 20 parts by weight based on 100 parts by weight of the polymer A. [ According to the content of the above range, the pressure-sensitive adhesive sheet at the initial stage of the application is low, and a pressure-sensitive adhesive sheet having a high adhesive force after heating is easily obtained.

The pressure-sensitive adhesive sheet disclosed herein has a supporting base material having a first surface and a second surface, and the pressure-sensitive adhesive layer is laminated on at least the first surface of the supporting base material, that is, in the form of a pressure- . Such a pressure-sensitive adhesive sheet with a substrate can be handled with good processability. As the supporting substrate, for example, those having a thickness of 30 mu m or more can be preferably employed.

It should be noted that the appropriate combination of the above-described elements can also be included in the scope of the invention for obtaining the protection by the patent of the present patent application.

1 is a cross-sectional view schematically showing the structure of a pressure-sensitive adhesive sheet according to an embodiment.
2 is a cross-sectional view schematically showing the structure of a pressure-sensitive adhesive sheet according to another embodiment.
3 is a cross-sectional view schematically showing the structure of a pressure-sensitive adhesive sheet according to another embodiment.

Hereinafter, preferred embodiments of the present invention will be described. The matters other than the matters specifically mentioned in this specification are to be understood by those skilled in the art based on the teaching of the invention described in this specification and the technical knowledge at the time of filing. The present invention can be carried out based on the contents disclosed in this specification and the technical knowledge in the field.

Also, in the following drawings, members and parts that exert the same function are sometimes given the same reference numerals, and redundant descriptions may be omitted or simplified. In addition, the embodiments shown in the drawings are schematized to clarify the present invention, and the size and scale of a product actually provided are not always accurately shown.

In this specification, the term &quot; acrylic polymer &quot; refers to a polymeric material containing a monomer unit derived from a (meth) acrylic monomer in a polymer structure. Typically, 50% by weight or less of monomer units derived from a (meth) By weight of the polymer. The (meth) acryl-based monomer refers to a monomer having at least one (meth) acryloyl group in one molecule. Here, the term "(meth) acryloyl group" is meant to refer collectively to an acryloyl group and a methacryloyl group. 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" means acrylic acid and methacrylic acid, and "(meth) acrylate" means acrylate and methacrylate, respectively.

&Lt; Structural Example of Adhesive Sheet >

The pressure-sensitive adhesive sheet disclosed herein comprises a pressure-sensitive adhesive layer. The pressure-sensitive adhesive sheet disclosed herein may be in the form of a pressure-sensitive adhesive sheet having the pressure-sensitive adhesive layer laminated on one side or both sides of the supporting substrate, or in the form of a non-pressure-sensitive adhesive sheet having no supporting substrate. Hereinafter, the supporting substrate may be simply referred to as a &quot; substrate &quot;.

The structure of the pressure-sensitive adhesive sheet according to one embodiment is schematically shown in Fig. This adhesive sheet 1 is provided with a sheet-like supporting substrate 10 having a first surface 10A and a second surface 10B and a pressure-sensitive adhesive layer 21 formed on the first surface 10A side Side single-sided pressure-sensitive adhesive sheet having a base. The pressure-sensitive adhesive layer (21) is fixed to the first surface (10A) side of the supporting substrate (10). The pressure-sensitive adhesive sheet (1) is used by pasting the pressure-sensitive adhesive layer (21) to an adherend. 1, the pressure-sensitive adhesive sheet 1 before use (that is, before adherence to an adherend) is formed such that the surface (pressure-sensitive adhesive surface) 21A of the pressure- The release liner 31 may be a component of the release liner-equipped pressure-sensitive adhesive sheet 100, which is in contact with the release liner 31 having a releasable surface (release surface). As the release liner 31, for example, a release layer made of a release agent may be formed on one side of a sheet-like base material (liner base) so that the one side is peeled off. Alternatively, the adhesive liner 31 may be omitted, and the adhesive sheet 1 may be wound by using the supporting substrate 10 whose second surface 10B is a peeled surface, (Roll shape) as shown in FIG. The release liner 31 or the second surface 10B of the supporting substrate 10 is peeled from the adhesive surface 21A and the exposed adhesive surface 21A is peeled off from the adhesive surface 21A Lt; / RTI &gt;

The structure of the pressure-sensitive adhesive sheet according to another embodiment is schematically shown in Fig. The adhesive sheet 2 includes a sheet-like supporting substrate 10 having a first surface 10A and a second surface 10B, a pressure-sensitive adhesive layer 21 formed on the first surface 10A side, And a pressure-sensitive adhesive layer (22) formed on the side of the second surface (10B). The pressure sensitive adhesive layer (first pressure sensitive adhesive layer) 21 is applied to the first surface 10A of the supporting substrate 10 and the pressure sensitive adhesive layer (second pressure sensitive adhesive layer) 22 is applied to the second surface 10B of the supporting substrate 10, Respectively. The pressure-sensitive adhesive sheet (2) is used by pasting the pressure-sensitive adhesive layers (21, 22) to different parts of an adherend. The portions to which the pressure-sensitive adhesive layers 21 and 22 are pasted may be the respective portions of the different members or may be different portions in the single member. The pressure-sensitive adhesive sheet 2 before use has the surface (first pressure-sensitive adhesive surface) 21A of the pressure-sensitive adhesive layer 21 and the surface (second pressure-sensitive adhesive surface) 22A of the pressure-sensitive adhesive layer 22, May be constituent elements of the release liner-equipped pressure-sensitive adhesive sheet 200 in which at least the side opposite to the pressure-sensitive adhesive layers 21 and 22 are in contact with the release liner 31 and 32, respectively. As the release liner 31, 32, for example, a release layer made of a release agent may be formed on one side of a sheet-like base material (liner base) so that the one side is peeled off. Alternatively, the peeling liner 32 may be omitted, and the peeling liner 31 may be peeled off on both sides, and the peeling liner 31 may be overlapped with the peeling liner 31, The release liner 31 may be in the form of a roll (in the form of being in contact with the back surface of the release liner 31).

Fig. 3 schematically shows the structure of a pressure-sensitive adhesive sheet according to another embodiment. This adhesive sheet 3 is constituted as a double-faced adhesive sheet of an inorganic material containing a pressure-sensitive adhesive layer 21. [ The pressure sensitive adhesive sheet 3 is composed of a first adhesive surface 21A constituted by one surface (first surface) of the pressure sensitive adhesive layer 21 and a second pressure sensitive adhesive layer 21 composed of the other surface (second surface) 2 adhesive surface 21B is attached to a different portion of the adherend. As shown in Fig. 3, the pressure-sensitive adhesive sheet 3 before use is such that at least the side of the first adhesive surface 21A and the side of the second pressure-sensitive adhesive surface 21B opposite to the pressure-sensitive adhesive layer 21 is peeled And may be a component of the release liner-equipped pressure-sensitive adhesive sheet 300 in contact with the release liner 31, 32. Alternatively, the peeling liner 32 may be omitted, and the peeling liner 31 may be peeled off on both sides of the peeling liner 31, and the peeling liner 31 may be wound on the peeling liner 31 in a roll- The release liner 31 may be in the form of a roll (in the form of being in contact with the back surface of the release liner 31).

Incidentally, the concept of the pressure-sensitive adhesive sheet referred to herein may include what is referred to as an adhesive tape, an adhesive film, an adhesive label, or the like. The pressure-sensitive adhesive sheet may be in the form of a roll, a sheet, or may be cut or punched in a suitable shape depending on the application and the mode of use. The pressure-sensitive adhesive layer in the technique disclosed herein is typically formed continuously but is not limited thereto, and may be formed in a regular or random pattern such as, for example, a dot or stripe.

<Pressure-sensitive adhesive layer>

The pressure-sensitive adhesive sheet disclosed herein comprises a pressure-sensitive adhesive layer comprising a polymer A and a polymer B as a copolymer of a monomer having a polyorganosiloxane skeleton and a (meth) acrylic monomer. Such a pressure-sensitive adhesive layer may be formed of a pressure-sensitive adhesive composition containing the polymer A or a precursor thereof and the polymer B. [ The form of the pressure-sensitive adhesive composition is not particularly limited and may be various forms such as an aqueous dispersion type, a solvent type, a hot melt type, an active energy ray curable type (for example, a light curable type).

(Polymer A)

As the polymer A, rubber elasticity in a room temperature region such as an acrylic polymer, a rubber polymer, a polyester polymer, a urethane polymer, a polyether polymer, a silicone polymer, a polyamide polymer and a fluoropolymer known in the field of the pressure- May be used alone or in combination of two or more.

The glass transition temperature T _A of the polymer A is not particularly limited, and the desired properties in the pressure-sensitive adhesive sheet disclosed herein can be selected is obtained. In some embodiments, polymer A having a T _A of less than 0 캜 can be preferably employed. The pressure sensitive adhesive containing such a polymer A is suitable for realizing a pressure sensitive adhesive sheet having low initial tackiness and strong tackiness after heating since it exhibits appropriate fluidity (for example, the mobility of the polymer chain contained in the pressure sensitive adhesive) . The pressure-sensitive adhesive sheet disclosed herein can be preferably applied using a polymer A having a T _A of less than -10 캜, less than -20 캜, less than -30 캜, or less than -35 캜. 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. _A polymer A having a T _A of -80 캜 or more, -70 캜 or more, or -65 캜 or more can be preferably employed in view of the availability of the material and the cohesive force of the pressure-sensitive adhesive layer. From the viewpoint of suppressing the rise of N ₅₀ , in some embodiments, T _A may be, for example, -63 캜 or higher, -55 캜 or higher, -50 캜 or higher, or -45 캜 or higher.

Here, in this specification, the glass transition temperature (Tg) of the polymer is a nominal value described in the literature or catalog, or Tg obtained by the Fox equation based on the composition of the monomer component used for preparing the polymer . The Fox formula is a relational expression of the Tg of the copolymer and the glass transition temperature Tgi of the homopolymer homopolymerized with each of the monomers constituting the copolymer as described below.

1 / Tg =? (Wi / Tgi)

In the Fox formula, Tg is the glass transition temperature (unit: K) of the copolymer, Wi is the weight fraction (copolymerization ratio based on weight) of the monomer i in the copolymer, Tgi is the glass transition temperature of the homopolymer of monomer i And the transition temperature (unit: K). If the polymer of interest in the specification of Tg is a homopolymer, the Tg of the homopolymer and the Tg of the polymer of interest are consistent.

As the glass transition temperature of the homopolymer used for calculation of Tg, the values described in the known data are to be used. Specifically, numerical values are illustrated in "Polymer Handbook" (3rd edition, John Wiley & Sons, Inc., 1989). The highest value is adopted for the monomers in which a plurality of kinds of values are described in the Polymer Handbook.

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

Specifically, 100 parts by weight of a monomer, 0.2 parts by weight of 2,2'-azobisisobutyronitrile and 200 parts by weight of ethyl acetate as a polymerization solvent were charged into a reactor equipped with a thermometer, a stirrer, a nitrogen inlet tube and a reflux condenser tube And stirred for 1 hour while flowing nitrogen gas. After the oxygen in the polymerization system was removed in this way, the temperature was raised to 63 캜 and the reaction was carried out for 10 hours. Subsequently, the solution is cooled to room temperature to obtain a homopolymer solution having a solid concentration of 33% by weight. Subsequently, this homopolymer solution is applied on the release liner in a pourable manner and dried to prepare a test sample (homopolymer of sheet form) having a thickness of about 2 mm. This test sample was punched into a disc having a diameter of 7.9 mm, sandwiched between parallel plates, and subjected to shear deformation at a frequency of 1 Hz using a viscoelasticity tester (product name: "ARES" manufactured by TA Instrument Japan) The viscoelasticity is measured by a shearing mode at a heating rate of 5 DEG C / min at 150 DEG C, and the temperature corresponding to the peak top temperature of tan delta is defined as the Tg of the homopolymer.

For the monomer having a polyorganosiloxane skeleton, a value obtained by subjecting the monomer to differential scanning calorimetry (DSC), more specifically, a value obtained in accordance with the method described in the following Examples, As the glass transition temperature of the monomer having a siloxane skeleton, the Fox equation is applied.

Although not particularly limited, the weight average molecular weight (Mw) of the polymer A is usually about 5 × 10 ⁴ or more. According to such a polymer A of Mw, a pressure-sensitive adhesive exhibiting good cohesiveness is easily obtained. In some embodiments, the Mw of the polymer A may be, for example, 10 x 10 ⁴ or more, 20 x 10 ⁴ or more, or 30 x 10 ⁴ or more. The Mw of the polymer A is usually suitably about 500 x 10 &lt; ⁴ &gt; or less. Such a polymer A of Mw is suitable for realizing a pressure-sensitive adhesive sheet in which the pressure-sensitive adhesive exhibiting moderate flowability (mobility of the polymer chain) is easy to form and has low adhesive force at the initial stage of application and high adhesive force after heating.

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

As the polymer A in the pressure-sensitive adhesive sheet disclosed herein, an acryl-based 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. Good compatibility between the polymer A and the polymer B is preferable because it improves the mobility of the polymer B in the pressure-sensitive adhesive layer and can contribute to the reduction of the initial adhesive force and the improvement of the adhesive force after heating.

The acrylic polymer includes, for example, a polymer containing 50% by weight or more of monomer units derived from (meth) acrylic acid alkyl ester, that is, 50% by weight or more of the total monomer components for preparing the acrylic polymer is (meth) acrylic acid alkyl ester Lt; / RTI &gt; As the (meth) acrylic acid alkyl ester, a (meth) acrylic acid alkyl ester having a straight chain or branched chain alkyl group having 1 to 20 carbon atoms (i.e., C _1-20 ) can be preferably used. The proportion of the (meth) acrylic acid C _1-20 alkyl ester in the total amount of the monomer components may be, for example, 50% by weight or more, 60% by weight or more, and 70% do. For the same reason, the proportion of the (meth) acrylic acid C _1-20 alkyl ester in the whole 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 the (meth) acrylic acid C _1-20 alkyl ester in the whole monomer component may be, for example, 90 wt% or less, or 85 wt% or less, or 80 wt% or less.

Specific examples of the (meth) acrylic acid C _1-20 alkyl ester include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, (Meth) acrylate, isobutyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, (Meth) acrylate, octyl acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, nonyl acrylate, isononyl (meth) acrylate, decyl (Meth) acrylate, undecyl (meth) acrylate, heptadecyl (meth) acrylate, tridecyl (meth) acrylate, Stearyl, isostearyl (meth) acrylate, (meth) acryl (Meth) acrylate eicosyl, and the like.

Of these, at least (C _1-18 ) alkyl esters of (meth) acrylic acid are preferably used, and it is more preferable to use at least (C _1-4 ) alkyl esters of (meth) acrylic acid. In some embodiments, the acrylic polymer comprises at least one selected from (meth) acrylic acid C _4-12 alkyl esters (preferably acrylic acid C _4-10 alkyl esters such as acrylic acid C _6-10 alkyl esters) May 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), 2-ethylhexyl methacrylate (2EHMA) , Isostearyl acrylate (ISTA), and the like.

The monomer unit constituting the acrylic polymer may contain other monomer (copolymerizable monomer) copolymerizable with the (meth) acrylic acid alkyl ester, if necessary, together with the (meth) acrylic acid alkyl ester as the main component. As the copolymerizable monomer, a monomer having a polar group (for example, a carboxyl group, a hydroxyl group, a nitrogen atom-containing ring, etc.) may be suitably used. The monomer having a polar group may be useful for introducing a crosslinking point to the acrylic polymer or for enhancing cohesion of the acrylic polymer. The copolymerizable monomers may be used singly or in combination of two or more kinds.

Non-limiting specific examples of the copolymerizable monomer include the following.

Examples of the monomer having a carboxyl group include acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, isocrotonic acid and the like.

Monomers containing acid anhydride groups: maleic anhydride, itaconic anhydride, for example.

Hydroxy group-containing monomers include, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxypropyl Acrylate such as 4-hydroxybutyl acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (Meth) acrylate such as methyl (meth) acrylate and 4-hydroxymethylcyclohexyl) methyl (meth) acrylate.

Monomers containing sulfonic acid groups or phosphoric acid groups such as styrenesulfonic acid, allylsulfonic acid, sodium vinylsulfonate, 2- (meth) acrylamido-2-methylpropanesulfonic acid, (meth) acrylamidopropanesulfonic acid, sulfopropyl (Meth) acryloyloxynaphthalenesulfonic acid, 2-hydroxyethyl acryloyl phosphate, and the like.

Examples of the epoxy group-containing monomer include epoxy group-containing acrylates such as glycidyl (meth) acrylate and (meth) acrylate-2-ethyl glycidyl ether, allyl glycidyl ether, glycidyl (meth) .

Cyano group-containing monomers such as acrylonitrile, methacrylonitrile and the like.

Isocyanato group-containing monomers such as 2-isocyanatoethyl (meth) acrylate and the like.

Amide group-containing monomers such as (meth) acrylamide; (Meth) acrylamide, N, N-diethyl (meth) acrylamide, N, N-dipropyl N, N-dialkyl (meth) acrylamides such as N-di (n-butyl) (meth) acrylamide and N, N-di (t-butyl) (meth) acrylamide; N-alkyl (meth) acrylamides 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; (Meth) acrylamide, N- (2-hydroxypropyl) (meth) acrylamide, N- (1-hydroxypropyl) (Meth) acrylamide, N- (3-hydroxybutyl) (meth) acrylamide, N- (3- hydroxypropyl) N-hydroxyalkyl (meth) acrylamides such as N- (4-hydroxybutyl) (meth) acrylamide; (Meth) acrylates such as N-methoxymethyl (meth) acrylamide, N-methoxyethyl (meth) acrylamide and N-butoxymethyl (meth) acrylamide; monomers having an alkoxy group and an amide group; ) Acrylamide; In addition, N, N-dimethylaminopropyl (meth) acrylamide, N- (meth) acryloylmorpholine and the like.

Examples of the monomer having a nitrogen atom-containing ring include N-vinyl-2-pyrrolidone, N-methylvinylpyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, 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- N-vinylisothiazole, N-vinylisothiazole, N-vinylpyridazine and the like (for example, N-vinylpyrrolidone, N-vinylpyrrolidone, N-vinyl-2-caprolactam and the like).

(Meth) acryloyloxymethylene succinimide, N- (meth) acryloyl-6-oxyhexamethylene succinimide, N- (meth) acrylate Roile-8-oxyhexamethylene succinimide and the like.

Maleimides: for example, N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, N-phenylmaleimide and the like.

Itaconimides: for example, N-methyl itaconimide, N-ethyl itaconimide, N-butyl itaconimide, N-octyl itaconimide, N-2-ethylhexyl itaconate N-cyclohexyl itaconimide, N-lauryl itaconimide, and the like.

(Meth) acrylic acid aminoalkyls include, for example, aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl Butylaminoethyl.

(Meth) acrylic acid esters such as 2-methoxyethyl (meth) acrylate, 3-methoxypropyl (meth) acrylate, 2-ethoxyethyl Alkoxyalkyl (meth) acrylates such as butoxyethyl acrylate and ethoxypropyl (meth) acrylate; (Meth) acrylic acid alkoxyalkylene glycols such as methoxyethylene glycol (meth) acrylate and methoxypolypropylene glycol (meth) acrylate.

Vinyl esters: for example, vinyl acetate, vinyl propionate and the like.

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) acrylate having an alicyclic hydrocarbon group: e.g., cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate and the like.

(Meth) acrylate having an aromatic hydrocarbon group: for example, phenyl (meth) acrylate, phenoxyethyl (meth) acrylate, benzyl (meth) acrylate and the like.

(Meth) acrylates such as methyl (meth) acrylate and tetrahydrofurfuryl (meth) acrylate; halogen atom-containing (meth) acrylates such as vinyl chloride or fluorine atom- (Meth) acrylates obtained from terpene compound derivative alcohols such as methyl (meth) acrylate, ethyl

When such a copolymerizable monomer is used, its amount to be used is not particularly limited, but it is usually 0.01% by weight or more based on the total amount of the monomer components. The amount of the copolymerizable monomer to be used may be 0.1% by weight or more, more preferably 1% by weight or more, based on the total amount of the monomer components, from the viewpoint that the effect of the use of the copolymerizable monomer is better exhibited. The amount of the copolymerizable monomer to be used may be 50% by weight or less, preferably 40% by weight or less of the total amount of the monomer components. As a result, it is possible to prevent the cohesive force of the pressure-sensitive adhesive from becoming too high, and to improve the feel at the normal temperature (25 DEG C).

In some embodiments, the acrylic polymer includes, as monomer units, an N-vinyl cyclic amide represented by the following formula (M1) and a hydroxyl group-containing monomer (a monomer having a functional group different from the hydroxyl group, for example, a monomer containing a hydroxyl group and an amide group ), And the like.

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

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

The amount of the N-vinyl cyclic amide to be used is not particularly limited, but it 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 components for preparing the acrylic polymer Do. In some embodiments, the amount of the 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 components. The amount of the N-vinyl cyclic amide to be used is usually 40% by weight or less, preferably 30% by weight or less, more preferably 30% by weight or less based on the total amount of the monomer components from the viewpoints of improving the tack feel at room temperature (25 캜) Or less, and may be 20 wt% or less.

By using the monomer containing a hydroxyl group, the cohesive force or the polarity of the pressure-sensitive adhesive can be adjusted and the adhesive force after heating can be improved. Further, the hydroxyl group-containing monomer can provide a reaction point with a crosslinking agent (for example, an isocyanate crosslinking agent) described later, and increase the cohesive force of the pressure-sensitive adhesive by a crosslinking reaction.

Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, N- (2-hydroxyethyl) Can be suitably used. Among them, preferred examples include 2-hydroxyethyl acrylate (HEA), 4-hydroxybutyl acrylate (4HBA) and N- (2-hydroxyethyl) acrylamide (HEAA).

The amount of the hydroxyl group-containing monomer to be used is not particularly limited, 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 components for preparing the acrylic polymer. In some embodiments, the amount of the hydroxyl group-containing monomer may be 1 wt% or more, 5 wt% or more, or 10 wt% or more of the total amount of the monomer components. The amount of the hydroxyl group-containing monomer to be used is usually not more than 40% by weight, preferably not more than 30% by weight, based on the total amount of the monomer components, from the viewpoints of improving the tack feel at room temperature (25 캜) And may be 20% by weight or less, or 10% by weight or less, or 5% by weight or less.

In some embodiments, as the copolymerizable monomer, an 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 may be 0.1% by weight or more, more preferably 1% by weight or more, more preferably 5% by weight or more, based on the total amount of the monomer components for preparing the acrylic polymer And may be 10% by weight or more, 15% by weight or more, 20% by weight or more, and 25% by weight or more. The total amount of the N-vinyl cyclic amide and the hydroxyl group-containing monomer may be, for example, 50% by weight or less, preferably 40% by weight or less based on the total amount of the monomer components.

The method of obtaining the acrylic polymer is not particularly limited and various polymerization methods known as methods for synthesizing an acrylic polymer such as solution polymerization, emulsion polymerization, bulk polymerization, suspension polymerization and photopolymerization can be suitably employed . In some embodiments, a solution polymerization method can be preferably employed. The polymerization temperature at the time of performing the solution polymerization may be appropriately selected according to the type of the monomer and solvent to be used, the kind of the polymerization initiator, and the like. For example, the polymerization temperature may be about 20 캜 to 170 캜 (typically about 40 캜 to 140 캜) .

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

As the thermal polymerization initiator, for example, azo-based polymerization initiators (for example, 2,2'-azobisisobutyronitrile, 2,2'-azobis-2-methylbutyronitrile, Bis (2-methylpropionic acid) dimethyl, 4,4'-azobis-4-cyanovaleric acid, azobisisobalonitrile, 2,2'-azobis (2-amidinopropane) dihydrochloride, 2 , 2'-azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis (2-methylpropionamidine) 2'-azobis (N, N'-dimethyleneisobutylamidine) dihydrochloride, etc.); Persulfates such as potassium persulfate; Peroxide-based polymerization initiators (e.g., dibenzoyl peroxide, t-butyl fumarate, and lauroyl peroxide); Redox polymerization initiators, and the like. The amount of the thermal polymerization initiator to be used is not particularly limited and may be, for example, from 0.01 to 5 parts by weight, preferably from 0.05 to 3 parts by weight, based on 100 parts by weight of the monomer component used for preparing the acrylic polymer .

Examples of the photopolymerization initiator include, but are not limited to, benzoin ether photopolymerization initiators, acetophenone photopolymerization initiators,? -Ketol photopolymerization initiators, aromatic sulfonyl chloride photopolymerization initiators, photoactive oxime photopolymerization initiators, An initiator, a benzyl photopolymerization initiator, a benzophenone photopolymerization initiator, a ketal photopolymerization initiator, a thioxanthone photopolymerization initiator, and an acylphosphine oxide photopolymerization initiator. The amount of the photopolymerization initiator to be used is not particularly limited. For example, the photopolymerization initiator may be used in an amount within a range of 0.01 to 5 parts by weight, preferably 0.05 to 3 parts by weight, based on 100 parts by weight of the monomer component used for preparing the acrylic polymer can do.

In some embodiments, the acrylic polymer is obtained by irradiating ultraviolet (UV) light onto a mixture of the above-mentioned monomer components and a polymerization initiator to form a partial polymer (acrylic polymer syrup) polymerized with a part of the monomer component, Layer may be included in the pressure-sensitive adhesive composition. The pressure-sensitive adhesive composition comprising such an acrylic polymer syrup may be applied to a predetermined adherend and ultraviolet light may be applied to complete the polymerization. That is, the acrylic polymer syrup can be recognized as a precursor of an acrylic polymer. The pressure-sensitive adhesive layer disclosed herein can be formed using, for example, a pressure-sensitive adhesive composition comprising the acrylic polymer syrup and polymer B. [

(Polymer B)

The polymer B in the technique disclosed here is a copolymer of a monomer having a polyorganosiloxane skeleton (hereinafter also referred to as &quot; monomer S1 &quot;) and a (meth) acrylic monomer. Polymer B suppresses the initial adhesion of the adherend to the adherend due to the low polarity and motility of the polyorganosiloxane structure derived from the monomer S1 and also suppresses adhesion to the adherend at a temperature higher than 50 deg. It can function as an adhesion-increasing retarder for increasing the adhesive force for the adhesive. The monomer S1 is not particularly limited, and any monomer containing a polyorganosiloxane 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 the adherend is attached to the adherend) due to the low polarity derived from the structure thereof, ). As the monomer S1, those having a polymerizable reactive group at one terminal can be preferably used. According to the copolymerization of the monomer S1 and the (meth) acrylic monomer, a polymer B having a polyorganosiloxane skeleton is formed in the side chain. Polymer B having such a structure tends to have low initial adhesion and high adhesion after heating due to mobility and ease of movement of side chains.

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 and the like can be given as the one-end reactive silicone oil of Shin-Etsu Chemical Co., The monomers S1 may be used singly or in combination of two or more.

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 preferably from 700 g / mol to 15,000 g / mol, more preferably from 800 g / mol to less than 10000 g / mol, even more preferably from 850 g / mol to less than 6,000 g / mol, mol or more and less than 5000 g / mol. If the functional group equivalent of the monomer S1 is less than 700 g / mol, the initial adhesion may not be sufficiently suppressed. If the functional group equivalent of the monomer S1 is 15,000 g / mol or more, the increase of the adhesive strength may be insufficient. When the equivalent of the functional group of the monomer S1 is within the above range, compatibility (for example, compatibility with the polymer A) and mobility in the pressure-sensitive adhesive layer can be easily adjusted to an appropriate range and initial low stickiness and high stickiness The pressure-sensitive adhesive sheet can be easily realized at a high level.

Here, the &quot; functional group equivalent &quot; means the weight of the main skeleton (e.g., polydimethylsiloxane) bonded to one functional group. Concerning the expressed 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 the spectral intensity of ¹ H-NMR (proton NMR) based on, for example, nuclear magnetic resonance (NMR). The 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 for ¹ H-NMR spectrum analysis, As shown in Fig.

When two or more kinds of monomers having different functional group equivalents are used as the monomer S 1, an arithmetic average value can be used as the functional group equivalent of the monomer S 1. That is, the functional group equivalent of the monomer S1 containing n kinds 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 weight of the monomer S1 of the functional group equivalent weight (g / mol) = (monomer S1 ₁ of the functional group equivalent weight × monomer S1 ₁ the amount + monomer S1 ₂ of the functional group equivalent weight × monomer S1 ₂ amount + a ... + monomer S1 _n × monomer S1 _n (Blending amount of monomer S1 ₁ + blending amount of monomer S1 ₂ + ... + blending amount of monomer S1 _n )

The content of the monomer S1 may be, for example, 5% by weight or more with respect to the total monomer components for preparing the polymer B, and it is preferably 10% by weight or more from the viewpoint of exhibiting the effect as the adhesion- , 15 wt% or more, or 20 wt% or more. The content of the monomer S1 is preferably 60% by weight or less, preferably 50% by weight or less, and 40% by weight or less, based on the total monomer components for preparing the polymer B from the viewpoints of polymerization reactivity and compatibility. Or may be 30 wt% or less. If the content of the monomer S1 is less than 5% by weight, the initial adhesive strength may not be sufficiently suppressed. If the content of the monomer S1 is more than 60% by weight, the increase in the adhesive strength may be insufficient.

The monomer component used in the preparation of the polymer B includes, in addition to the monomer S1, a (meth) acrylic monomer copolymerizable with the monomer S1. The mobility of the polymer B in the pressure-sensitive adhesive layer can be suitably controlled by copolymerizing one or more (meth) acrylic monomers with the monomer S1. The copolymerization of the monomer S1 with the (meth) acrylic monomer can also help improve the compatibility of the polymer B and the polymer A (for example, acrylic polymer).

In the polymer B in the technique disclosed herein, the composition of the (meth) acrylic monomer contained in the monomer component is such that the glass transition temperature T _m1 based on the composition of the (meth) acrylic monomer is 50 ° C or more and 100 ° C Or less. T _m1 is tends to be, according to polymer B at least 50 ℃, in the pressure-sensitive adhesive sheet containing the polymer B, the increase of the N ₅₀ inhibition. This is because, according to the polymer B having a _Tm1 of 50 占 폚 or higher, the improvement in mobility and mobility of the polyorganosiloxane structure moiety accompanied by the temperature rise from room temperature to about 50 占 폚 is suppressed by the fact that the (meth) Derived monomer unit, and the low stickiness due to the presence of the polyorganosiloxane structure moiety can be better maintained. When the T _m1 is lower than 50 ℃, it reduces the effect of suppressing the increase in the N _50. In addition, there is a tendency that the higher T _m1 surface, the adhesive force (N ₈₀₎ decreases after heating than 100 ℃. T _m1 according to the above 50 ℃ polymer B not more than 100 ℃, can significantly increase the ₈₀ N with respect to N _50. Therefore, polymer B having a composition in which _Tm1 is in the above range is suitable for realizing a pressure-sensitive 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, Lt; 0 &gt; C or more. According to a more T _m1 polymer B is high, the effect of suppressing the increase in the N ₅₀ tends to increase more. In some aspects, T _m1 may be, for example, 100 占 폚 or less, 90 占 폚 or less, or 85 占 폚 or less in some aspects from the viewpoint of facilitating an increase in adhesive force by heating to a temperature region higher than 50 占 폚 And may be 80 DEG C or less or 80 DEG C or less.

Here, the glass transition temperature _Tm1 based on the composition of the (meth) acrylic monomer is the Tg determined by the Fox equation based on the composition of only the (meth) acrylic monomer among the monomer components used for preparing the polymer B It says. _Tm1 is determined by applying the above Fox formula to the glass transition temperature of the homopolymer of each (meth) acrylic monomer and the corresponding (meta) acrylic monomer in the corresponding (meth) acrylic monomer, ) Acrylic monomer in the total amount of the (meth) acrylic monomer. In view to achieve the effect resulting from the appropriately setting the T _m1 that easily monomer S1 and a (meth) the total amount of acrylic monomer in the entire monomer components for preparing the polymer B is, for example, may be a least 50% by weight, It may be 70 wt% or more, 85 wt% or more, 90 wt% or more, 95 wt% or more, or substantially 100 wt%.

The glass transition temperature of polymer B T _B is not particularly limited, and the desired properties in the pressure-sensitive adhesive sheet disclosed herein can be selected is obtained. The T _B of the polymer B may be, for example, less than 50 ° C, not more than 30 ° C, not more than 20 ° C, not more than 15 ° C, or not more than 10 ° C. When the T _B of the polymer _B is lowered, the mobility of the polymer B is improved, and the adhesive force tends to be increased by heating in a temperature region higher than 50 ° C. Further, in some embodiments, T _B of the polymer B may be, for example, -40 캜 or higher, -30 캜 or higher, -20 캜 or higher, or -10 캜 or higher. The higher of the polymer B T _B, tends to be easier to inhibit N _50.

In some embodiments of the pressure-sensitive adhesive sheet disclosed herein, the polymer B preferably has a copolymerization ratio of the homopolymer having a glass transition temperature higher than 170 캜 of 30% by weight or less. Here, in the present specification, when the copolymerization ratio of the monomer is X% by weight or less, if it is not special, the concept that the copolymerization ratio of the monomer is 0% by weight, that is, the mode in which the monomer is not substantially copolymerized to be. In addition, the fact that they are not substantially copolymerized means that the monomer is not copolymerized at least intentionally. If the copolymerization ratio of the monomer having a glass transition temperature higher than 170 DEG C is high, the mobility of the polymer B tends to become insufficient, and it may become difficult to increase the adhesive force by heating to a temperature region higher than 50 DEG C . By the copolymerization ratio of the high glass transition temperature of the homopolymer than 170 ℃ monomer to less than 30% by weight, at least one of the effect of improvement in the improvement of the N ₈₀ and N ₅₀ / N ₈₀ can be realized.

In some embodiments, the composition of the monomer components for preparing the polymer B is, to T _m1 is higher than T _B, that is, be set to _m1 T -T _B is larger than 0 ℃. According to such a composition, the effect of controlling the mobility of polymer B is likely to be exerted suitably depending on the composition of the (meth) acrylic monomer contained in the monomer component. T _m1 -T _B may be, for example, about 40 캜 to 100 캜, about 50 캜 to 90 캜, or about 65 캜 to 85 캜.

From the viewpoint controlling the polymer B mobility in in the pressure-sensitive adhesive layer that easily, in some aspects, the composition of the monomer components for preparing the polymer B is, in relation to the glass transition temperature T _A Polymer A, T _m1 is T _A , that is, T _m1 -T _A is set to 20 ° C or more. In some embodiments, T _m1 -T _A may be, for example, from 50 캜 to 130 캜, or from about 60 캜 to 120 캜 or from 70 캜 to 120 캜.

Examples of the (meth) acrylic monomers that can be used for the monomer component for preparing the polymer B include (meth) acrylic acid alkyl esters. For example, as the (meth) acrylic acid alkyl ester which can be used when the polymer A is an acrylic polymer, one or more of the monomers exemplified above can be used as a copolymer component of the polymer B. In some embodiments, the polymer B is at least one of (meth) acrylic acid C _4-12 alkyl esters (preferably (meth) acrylic acid C _4-10 alkyl esters such as (meth) acrylic acid C _6-10 alkyl esters) One kind may be contained as a monomer unit. In some other embodiments, the polymer B is at least one of the C _1-18 alkyl esters methacrylate (preferably methacrylic acid C _1-14 alkyl esters, e.g., methacrylic acid C _1-10 alkyl esters) As a monomer unit. The monomer unit constituting the polymer B may include, for example, one or more kinds selected from MMA, BMA and 2EHMA.

As another example of the (meth) acrylic monomer, a (meth) acrylic acid ester having an alicyclic hydrocarbon group can be given. (Meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, 1-adamantyl (meth) acrylate and the like can be used. Can be used. In some embodiments, the polymer B may contain at least one member selected from dicyclopentanyl methacrylate, isobornyl methacrylate, and cyclohexyl methacrylate as monomer units.

The amount of the (meth) acrylic acid alkyl ester and the (meth) acrylic ester having the alicyclic hydrocarbon group may be, for example, 10% by weight or more and 95% by weight or less relative to the total monomer components for preparing the polymer B, Or more, more preferably 30 weight% or more and 90 weight% or less, 40 weight% or more and 90 weight% or less, or 50 weight% or more and 85 weight% or less. From the viewpoint of easiness of increasing the adhesive force by heating to a temperature higher than 50 DEG C, the use of (meth) acrylic acid alkyl ester may be advantageous. In some embodiments, the amount of the (meth) acrylic ester having an alicyclic hydrocarbon group may be less than 50% by weight or less than 30% by weight based on the total amount of the (meth) acrylic monomers contained in the monomer component for preparing the polymer B Less than 15% by weight, less than 10% by weight, or less than 5% by weight. (Meth) acrylate ester having an alicyclic hydrocarbon group may not be used.

In some embodiments, the monomer component for preparing polymer B preferably comprises at least MMA. The copolymerization of MMA can be a useful means for adjusting T _m1 to the preferred range disclosed herein. Further, according to the polymer B copolymerized with MMA, a pressure-sensitive adhesive sheet having a large N ₈₀ / N ₅₀ tends to be obtained. The proportion of MMA in the total amount of the (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% Or more, and may be 40 wt% or more. In some embodiments, the proportion of MMA in the total amount of the (meth) acrylic monomers may be, for example, greater than 50%, greater than 55%, greater than 60%, greater than 65% , Or more than 70% by weight. The ratio of MMA in the total amount of the (meth) acrylic monomers may be in a range where _Tm1 is 100 占 폚 or less, preferably 95% by weight or less, 90% by weight or less, 85% It may be.

Other examples of the monomers that can be included together with the monomer S1 as the monomer unit constituting the polymer B include monomers containing the carboxyl group-containing monomers, acid anhydride group-containing monomers and hydroxyl group-containing monomers, which are exemplified above as the monomers that can be used when the polymer A is an acrylic polymer. (Meth) acrylate monomer, an epoxy group-containing monomer, a cyano group-containing monomer, an isocyanate group-containing monomer, an amide group-containing monomer, a monomer having a nitrogen atom- containing ring, a monomer having a succinimide skeleton, (Meth) acrylates obtained from alkyl ethers, vinyl esters, vinyl ethers, olefins, aromatic hydrocarbon groups, (meth) acrylic esters, heterocyclic ring containing (meth) acrylates, halogen atom containing (meth) acrylates and terpene compound derivative alcohols ) Acrylate esters.

As another example of the monomer which can be contained together with the monomer S1 as a monomer unit constituting the polymer B, there are ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol 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, a polymer having a polymerizable functional group such as a (meth) acryloyl group, a vinyl group or an allyl group at one end of a polyoxyalkylene chain such as polyethylene glycol or polypropylene glycol, Polymerizable polyoxyalkylene ethers having an ether structure (alkyl ether, aryl ether, arylalkyl ether, etc.) at the terminal; (Meth) acrylic acid alkoxyalkyl such as methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, propoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, and ethoxypropyl (Meth) acrylic acid alkali metal salts; Poly (meth) acrylates such as trimethylolpropane tri (meth) acrylate; halogenated vinyl compounds such as vinylidene chloride and (meth) acrylate-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) acryloyl aziridine and (meth) acrylate-2-aziridinyl ethyl; Hydroxyl group-containing vinyl monomers such as (meth) acrylic acid-2-hydroxyethyl, (meth) acrylic acid-2-hydroxypropyl, lactones and adducts of 2-hydroxyethyl (meth) acrylate; 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 vinyl monochloroacetate; Containing vinyl monomers such as vinyltrimethoxysilane,? - (meth) acryloxypropyltrimethoxysilane, allyltrimethoxysilane, trimethoxysilylpropylallylamine and 2-methoxyethoxytrimethoxysilane ; In addition, macromonomers having a radical polymerizable vinyl group at the terminal of a monomer polymerized with a vinyl group; And the like. These can be copolymerized with monomer S1 alone or in combination.

The Mw of the polymer B is not particularly limited. The Mw of the polymer B may be, for example, 1000 or more, or 5000 or more. If the Mw of the polymer B is too low, there is a case where the increase of the adhesion force becomes insufficient. In some preferred embodiments, the Mw of the polymer B may be, for example, 10,000 or more, 12,000 or more, 15,000 or more, 17,000 or more, and 20,000 or more. The Mw of the polymer B may be, for example, 100000 or less, or may be 70000 or less. If the Mw of the polymer B is too high, the initial adhesion may not be sufficiently suppressed. In some preferred embodiments, the Mw of polymer B may be, for example, less than 50,000, less than 50,000, less than 40,000, less than 35,000, less than 30,000, less than or equal to 28,000, or less than 25,000. When the Mw of the polymer B is within the range of any of the upper limit and the lower limit described above, the compatibility and mobility in the pressure-sensitive adhesive layer can be easily adjusted to an appropriate range, the good reworkability at the beginning of the application and the high- The pressure-sensitive adhesive sheet can be easily realized.

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

A chain transfer agent may be used to adjust the molecular weight of the polymer B. Examples of the chain transfer agent to be used include compounds having a mercapto group such as octylmercaptan, lauryl mercaptan, t-nonylmercaptan, t-dodecylmercaptan, mercaptoethanol and? -Thioglycerol; Thioglycolic acid, thioglycolic acid, methyl thioglycolate, ethyl thioglycolate, propyl thioglycolate, butyl thioglycolate, t-butyl thioglycolate, 2-ethylhexyl thioglycolate, octyl thioglycolate, Thioglycolic acid esters such as thioglycolic acid decyl, thioglycol dodecyl, thioglycolic acid esters of ethylene glycol, thioglycolic acid esters of neopentyl glycol, and thioglycolic acid esters of pentaerythritol; ? -methylstyrene dimer; And the like.

The amount of the chain transfer agent to be used is not particularly limited, but 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, per 100 parts by weight of the monomer, By weight. By adjusting the addition amount of the chain transfer agent in this way, a polymer B having a suitable molecular weight can be obtained. The chain transfer agent may be used singly or in combination of two or more kinds.

The amount of the polymer B to be used may be, for example, not less than 0.1 part by weight based on 100 parts by weight of the amount of the polymer A, and may be not less than 0.3 parts by weight from the viewpoint of obtaining a higher effect, 0.4 part by weight or more, or 0.5 part by weight or more. In some aspects, the amount of the polymer B to 100 parts by weight of the polymer A may be 1 part by weight or more, 2 parts by weight or more, and 3 parts by weight or more . The polymer B may be used in an amount of, for example, 75 parts by weight or less, 60 parts by weight or less, and 50 parts by weight or less, based on 100 parts by weight of the polymer A. In some aspects, the amount of polymer B to 100 parts by weight of polymer A may be, for example, not more than 40 parts by weight and not more than 35 parts by weight, for example, from the viewpoint of avoiding excessive deterioration of cohesive strength of the pressure- 30 parts by weight or less, or 25 parts by weight or less. In some aspects, the use amount of the polymer B may be 20 parts by weight or less, 17 parts by weight or less, 15 parts by weight or less, 10 parts by weight or less . In some embodiments of the pressure sensitive adhesive sheet disclosed herein, the amount of polymer B to 100 parts by weight of polymer A may be less than 10 parts by weight, may be less than 8 parts by weight, may be less than 5 parts by weight, And may be 4 parts by weight or less, or 3 parts by weight or less.

The pressure-sensitive adhesive layer may contain a polymer (optional polymer) other than the polymer A and the polymer B, if necessary, within a range that does not significantly impair the performance of the pressure-sensitive adhesive sheet disclosed herein. The amount of such optional polymer is usually 20% by weight or less, preferably 15% by weight or less, and 10% by weight or less, based on the total amount of polymer components contained in the pressure-sensitive adhesive layer. In some embodiments, the amount of the optional polymer may be 5 wt% or less, 3 wt% or less, or 1 wt% or less of the entire polymer component. Or may be a pressure-sensitive adhesive layer substantially containing no polymer other than the polymer A and the polymer B.

(Crosslinking agent)

For the purpose of adjusting the cohesive force or the like, a crosslinking agent may be used in the pressure-sensitive adhesive layer, if necessary. As the crosslinking agent, a known crosslinking agent in the field of the pressure-sensitive adhesive can be used. Examples of the crosslinking agent include epoxy crosslinking agents, isocyanate crosslinking agents, silicone crosslinking agents, oxazoline crosslinking agents, aziridine crosslinking agents, silane crosslinking agents, alkyletherified melamine crosslinking agents, Metal chelate crosslinking agents and the like. In particular, an isocyanate-based crosslinking agent, an epoxy-based crosslinking agent, and a metal chelate-based crosslinking agent can be suitably used. The crosslinking agent may be used singly or in combination of two or more kinds.

Specifically, examples of the isocyanate crosslinking agent include tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, diphenyl (meth) diisocyanate, hydrogenated diphenyl ) Isocyanate, tetramethyl xylylene diisocyanate, naphthalene diisocyanate, triphenyl (meth) triisocyanate, polymethylene polyphenyl isocyanate, and adducts of these and polyols such as trimethylolpropane. Alternatively, a compound having at least one isocyanate group in one molecule and at least one unsaturated bond, specifically, 2-isocyanatoethyl (meth) acrylate and the like can also be used as an isocyanate crosslinking agent. These may be used singly or in combination of two or more.

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 glycidyl amine, N, N, N ', N'-tetraglycidyl-m-xylylenediamine and 1,3 -Bis (N, N-diglycidylaminomethyl) cyclohexane, and the like. These may be used singly or in combination of two or more.

Examples of the metal chelate compound include aluminum, iron, tin, titanium and nickel as metal components, and acetylene, methyl acetoacetate and ethyl lactate as chelate components. These may be used singly or in combination of two or more.

The amount of the crosslinking agent to be used is not particularly limited and may be, for example, an amount exceeding 0 parts by weight based on 100 parts by weight of the polymer A. [ The amount of the crosslinking agent to be used may be, for example, 0.01 part by weight or more, and preferably 0.05 part by weight or more based on 100 parts by weight of the polymer A. The increase in the amount of the cross-linking agent tends to suppress the adhesive force at the initial stage of the application and improve the reworkability. In some embodiments, the amount of the crosslinking agent to be used for 100 parts by weight of the polymer A may be 0.1 parts by weight or more, 0.5 parts by weight or more, or 1 part by weight or more. On the other hand, the amount of the crosslinking agent to be used is usually 15 parts by weight or less, preferably 10 parts by weight or less, more preferably 5 parts by weight or less, Or less. If the amount of the cross-linking agent to be used is not excessively small, N ₈₀ / N ₅₀ may be advantageous in view of facilitating the production of a high-adhesive sheet.

The technique disclosed here can preferably be carried out in the form of using at least an isocyanate-based cross-linking agent as a cross-linking agent. The amount of the isocyanate crosslinking agent to 100 parts by weight of the polymer A is, for example, not less than 0.1 parts by weight, more preferably not less than 0.1 parts by weight, 5 parts by weight or less, and may be 0.3 parts by weight or more and 4 parts by weight or less, or 0.5 parts by weight or more and 3 parts by weight or less.

When an isocyanate-based crosslinking agent is used in a constitution in which the pressure-sensitive adhesive layer contains a hydroxyl group-containing monomer as a monomer unit, the amount W _OH of the hydroxyl group-containing monomer with respect to the use amount W _NCO of the isocyanate- , And W _OH / W _NCO is 2 or more. By thus increasing the amount of the hydroxyl group-containing monomer used in the isocyanate-based crosslinking agent, a crosslinking structure suitable for greatly increasing the adhesive force after heating can be formed with respect to the initial adhesive strength. In some embodiments, W _OH / W _NCO may be 3 or more, 5 or more, 10 or more, 20 or more, 30 or more, and 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 more effectively progress any of the crosslinking reactions described above, a crosslinking catalyst may be used. As the crosslinking catalyst, for example, a tin catalyst (particularly, di-octyltin dilaurate) can be preferably used. The amount of the crosslinking catalyst to be used is not particularly limited, but may be, for example, about 0.0001 part by weight to 1 part by weight with respect to 100 parts by weight of the polymer A.

If necessary, a multi-functional monomer may be used for the pressure-sensitive adhesive layer. The polyfunctional monomer may be used in place of the crosslinking agent as described above or in combination with the crosslinking agent for the purpose of adjusting the cohesive force or the like. For example, in the pressure-sensitive adhesive layer formed from the photocurable pressure-sensitive adhesive composition, a multifunctional 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 Acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, ethylene glycol di (meth) acrylate, 1,6-hexane (Meth) acrylate, allyl (meth) acrylate, vinyltoluene (meth) acrylate, tetramethylolmethane tri (meth) acrylate, (Meth) acrylate, divinylbenzene, epoxy acrylate, polyester acrylate, urethane acrylate, butyldiol (meth) acrylate, hexyldiol di And the like. Among them, trimethylolpropane tri (meth) acrylate, 1,6-hexane diol di (meth) acrylate and dipentaerythritol hexa (meth) acrylate can be suitably used. The polyfunctional monomer may be used singly or in combination of two or more.

The amount of the polyfunctional monomer to be used varies depending on the molecular weight and the number of functional groups, and is usually in the range of about 0.01 to 3.0 parts by weight based on 100 parts by weight of the polymer A. In some embodiments, the amount of the polyfunctional monomer to be used may be, for example, 0.02 parts by weight or more and 0.03 parts by weight or more based on 100 parts by weight of the polymer A. The increase in the amount of the multifunctional monomer tends to suppress the adhesive force at the initial stage of the application and improve the workability. On the other hand, the amount of the polyfunctional monomer to be used may be 2.0 parts by weight or less, 1.0 parts by weight or less, and 0.5 parts by weight or less based on 100 parts by weight of the polymer A from the viewpoint of avoiding deterioration of the tack due to excessive cohesion . If the amount of the polyfunctional monomer to be used is not excessively small, N ₈₀ / N ₅₀ may be advantageous from the viewpoint of facilitating the production of a high-adhesive sheet.

(Tackifier resin)

The pressure-sensitive adhesive layer may contain a tackifier resin if necessary. Examples of the tackifying resin include, but are not limited to, rosin-based tackifying resins, terpene-based tackifying resins, phenol-based tackifying resins, hydrocarbon-based tackifying resins, ketone-based tackifying resins, An epoxy-based tackifying resin, and an elastomer-based tackifying resin. The tackifier resin may be used alone or in combination of two or more.

Examples of the rosin-based tackifier resin include unmodified rosins (raw rosin) such as gum rosin, wood rosin and tall oil rosin, and modified rosin (modified rosin) obtained by modifying these unmodified rosin by polymerization, disproportionation, Various rosin derivatives and the like can be mentioned in addition to the above-mentioned rosins, such as polymerized rosin, stabilized rosin, disproportionated rosin, completely hydrogenated rosin, partially hydrogenated rosin and other chemically modified rosin.

As the rosin derivative, for example,

A rosin phenol-based resin obtained by adding phenol to a rosin (unmodified rosin, modified rosin, or various rosin derivatives) by an acid catalyst to effect thermal polymerization;

(Unmodified rosin esters) obtained by esterification of unmodified rosin with alcohols and modified rosins such as polymerized rosin, stabilized rosin, disproportionated rosin, completely hydrogenated rosin and partially hydrogenated rosin can be added to alcohols Rosin ester type resins such as esterified compounds of modified rosin esterified by esterification (polymerized rosin esters, stabilized rosin esters, disproportionated rosin esters, fully hydrogenated rosin esters, partially hydrogenated rosin esters and the like);

An unsaturated fatty acid-modified rosin-based resin obtained by modifying unmodified rosin or modified rosin (polymerized rosin, stabilized rosin, disproportionated rosin, completely 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;

Modified rosin, modified rosin (polymerized rosin, stabilized rosin, disproportionated rosin, completely hydrogenated rosin, partially hydrogenated rosin, etc.), unsaturated fatty acid-modified rosin resin or unsaturated fatty acid-modified rosin ester resin One rosin alcohol based resin;

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

Examples of the terpene-based tackifier resin include terpene resins such as an? -Pinene polymer, a? -Pinene polymer and a dipentene polymer; and resins obtained by modifying these terpene resins (phenol denaturation, aromatic denaturation, hydrogenation denaturation, (For example, terpene phenol resin, styrene-modified terpene resin, aromatic modified terpene resin, hydrogenated terpene resin, etc.) and the like.

Examples of the phenolic tackifier resin include condensates of formaldehyde with various phenols (e.g., phenol, m-cresol, 3,5-xylenol, p-alkylphenol, resorcin, etc.) , An alkylphenol resin, a xylene formaldehyde resin, etc.), a resole obtained by subjecting the phenol and formaldehyde to an addition reaction with an alkali catalyst, or a novolac obtained by condensation reaction of the phenol and formaldehyde with an acid catalyst.

Examples of the hydrocarbon-based tackifying resin include an aliphatic hydrocarbon resin, an aromatic hydrocarbon resin, an aliphatic cyclic hydrocarbon resin, an aliphatic aromatic petroleum resin (such as a styrene-olefin copolymer), an aliphatic or alicyclic petroleum resin, And various hydrocarbon resins such as a resin, a coumarone resin, and a coumaroneindene resin.

Examples of commercially available polymerized rosin esters that can be preferably used include trade name "PENCEL D-125", "PENCEL D-135", "PENCEL D-160", "PENCEL KK" C &quot; and the like, but are not limited thereto.

Examples of commercially available terpenephenol resins that can be preferably used include YS POLYSTAR S-145, YS POLYSTAR G-125, YS POLYSTAR N125, YS POLYSTAR N-125, and YS POLYSTAR N-125 manufactured by YASUHARA CHEMICAL Co., TAMANOL 803L &quot;, &quot; TAMANOL 901 &quot;, trade name &quot; SUMILITE RESIN PR-12603 &quot;, manufactured by Sumitomo Bakelite K.K., But are not limited thereto.

The content of the tackifier resin is not particularly limited and may be set so as to exhibit an appropriate tacking performance depending on the purpose and use. The content of the tackifier resin (when the two or more tackifier resins are included, the total amount thereof) relative to 100 parts by weight of the polymer A may be, for example, about 5 to 500 parts by weight.

As the tackifier resin, those having a softening point (softening temperature) of about 80 DEG C or higher (preferably about 100 DEG C or higher, for example, about 120 DEG C or higher) can be preferably used. According to the tackifier resin having the softening point above the lower limit value described above, it is easy to obtain a pressure-sensitive adhesive sheet satisfying N ₈₀ / N _50? 5. The upper limit of the softening point is not particularly limited and may be, for example, about 200 占 폚 or lower (typically 180 占 폚 or lower). The softening point of the tackifier resin can be measured based on the softening point test method (rolling method) specified in JIS K2207.

In addition, the pressure-sensitive adhesive layer in the techniques disclosed herein can be suitably used as a leveling agent, a plasticizer, a softener, a colorant (dye, pigment, etc.), a filler, an antistatic agent, , Ultraviolet absorbers, antioxidants, light stabilizers, preservatives, and the like may be included as needed.

The pressure-sensitive adhesive layer constituting the pressure-sensitive adhesive sheet disclosed herein may be a cured layer of a pressure-sensitive adhesive composition. That is, the pressure-sensitive adhesive layer may be formed by applying (for example, applying) a pressure-sensitive adhesive composition such as an aqueous dispersion type, a solvent type, a light-curing type, and a hot melt type onto an appropriate surface and then performing a curing treatment appropriately. When two or more kinds of curing treatments (drying, crosslinking, polymerization, cooling, etc.) are carried out, they can be carried out simultaneously or in multiple steps. In a pressure-sensitive adhesive composition using a partial polymerized product of a monomer component (acrylic polymer syrup), a final copolymerization reaction is typically carried out as the curing treatment. That is, partial polymerizations are added to the copolymerization reaction to form a complete polymerizate. For example, in the case of a photocurable pressure-sensitive adhesive composition, light irradiation is performed. If necessary, curing treatment such as crosslinking and drying may be carried out. For example, when it is necessary to dry with the photo-curable pressure-sensitive adhesive composition, photo-curing may be performed after drying. In the pressure-sensitive adhesive composition using the complete polymer, typically, as the curing treatment, a treatment such as drying (heating and drying), crosslinking and the like is carried out as necessary.

The application of the pressure-sensitive adhesive composition can be carried out using a conventional coater such as a gravure roll coater, a reverse roll coater, a kiss roll coater, a dip roll coater, a bar coater, a knife coater or a spray coater.

The thickness of the pressure-sensitive adhesive layer is not particularly limited, and may be, for example, 1 占 퐉 or more. In some embodiments, the thickness of the pressure-sensitive adhesive layer may be, for example, 3 占 퐉 or more, 5 占 퐉 or more, 8 占 퐉 or more, 10 占 퐉 or more, 15 占 퐉 or more, Or more. The adhesive force tends to increase after heating due to the increase in the thickness of the pressure-sensitive adhesive layer. Further, in some embodiments, the thickness of the pressure-sensitive adhesive layer may be, for example, 300 mu m or less, 200 mu m or less, 150 mu m or less, 100 mu m or less, 70 mu m or less, And may be 40 μm or less. The fact that the thickness of the pressure-sensitive adhesive layer is not excessively large may be advantageous in terms of thinning of the pressure-sensitive adhesive sheet and prevention of cohesive failure of the pressure-sensitive adhesive layer. 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 pressure-sensitive adhesive layer described above can be applied to at least the thickness of the first pressure-sensitive adhesive layer. The thickness of the second pressure sensitive adhesive layer can also be selected from the same range. Further, in the case of an adhesive sheet of an inorganic material, the thickness of the pressure sensitive adhesive sheet coincides with the thickness of the pressure sensitive adhesive layer.

The gel fraction of the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer is suitably in the range of usually 20.0% to 99.0%, and preferably in the range of 30.0% to 90.0%. By setting the gel fraction in the above range, it becomes easy to realize a pressure-sensitive adhesive sheet in which both the reworkability at the beginning of the patch and the high tackiness of the tackiness after the tackiness is increased. 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 ) was wrapped in a porous polytetrafluoroethylene film (weight Wg ₂ ) having an average pore diameter of 0.2 탆, and the inlet was bundled with twist (weight Wg ₃ ). As the porous polytetrafluoroethylene film, trade name "Nitoflon (registered trademark) NTF1122" (Nitto Denko Co., average pore diameter: 0.2 μm, porosity of 75%, thickness of 85 μm) or its equivalent is used. The package is immersed in 50 mL of ethyl acetate and maintained at room temperature (typically 23 DEG C) for 7 days to elute the sol (ethyl acetate-soluble fraction) in the pressure-sensitive adhesive out of the film. Then, the package is taken out, the ethyl acetate attached 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 equation, the gel fraction G _C of the pressure-sensitive adhesive can be calculated.

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

&Lt; Support substrate &

The pressure sensitive adhesive sheet according to some embodiments may be in the form of a pressure sensitive adhesive sheet having a substrate having a pressure sensitive adhesive layer on one side or both sides of the supporting substrate. The material of the supporting substrate is not particularly limited and can be appropriately selected depending on the intended use and the mode of use of the adhesive sheet. Non-limiting examples of usable substrates include polyolefin films mainly composed of polyolefins such as polypropylene and ethylene-propylene copolymer, polyester films mainly composed of polyester such as polyethylene terephthalate and polybutylene terephthalate, A plastic film such as a polyvinyl chloride film containing vinyl chloride as a main component; A foam sheet including a foam such as a polyurethane foam, a polyethylene foam, and a polychloroprene foam; Woven fabrics and woven fabrics of various fibrous materials (natural fibers such as hemp, cotton, synthetic fibers such as polyester and vinylon, semi-synthetic fibers such as acetate, etc.) alone or in blends; Paper such as Japanese paper, high-quality paper, kraft paper, and crepe paper; Metal foil such as aluminum foil and copper foil; And the like. Or a combination of these. Examples of such a composite material include a substrate having a structure in which a metal foil and the plastic film are laminated, a plastic substrate reinforced with inorganic fibers such as glass cloth, and the like.

As the base material of the pressure-sensitive adhesive sheet disclosed herein, various film base materials can be preferably used. The film substrate may be a porous substrate such as a foam film or a nonwoven fabric sheet, 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, it is preferable to use a resin film which can be independently maintained in shape (independent or independent) as a base film. Here, the term &quot; resin film &quot; means a non-porous structure, typically a resin film (voidless) which does not substantially contain bubbles. Therefore, the resin film is a concept distinct from a foam film or a nonwoven fabric. As the resin film, it is preferable that the film can be independently maintained in shape (independent or independent). The resin film may have a single-layer structure or a multilayer structure of two or more layers (for example, a three-layer structure).

Examples of the resin material constituting the resin film include polyamide (PA) such as polyester, polyolefin, nylon 6, nylon 66 and partially aromatic polyamide, polyimide (PI), polyamideimide (PAI) (PEEK), polyether sulfone (PES), polyphenylene sulfide (PPS), polycarbonate (PC), polyurethane (PU), ethylene-vinyl acetate copolymer (EVA), polytetrafluoroethylene (PTFE), acrylic resin, polyacrylate, polystyrene, polyvinyl chloride, polyvinylidene chloride and the like can be used. The resin film may be formed using a resin material containing one of these resins singly, or may be formed by using a resin material in which two or more resins are blended. The resin film may be unoriented, and may be stretched (for example, uniaxially stretched or biaxially stretched).

Suitable examples of the resin material constituting the resin film include a polyester-based resin, a PPS resin and a polyolefin-based resin. Here, the polyester resin means a resin containing a polyester in a proportion exceeding 50% by weight. Similarly, a PPS resin is a resin containing PPS in a proportion exceeding 50% by weight, and a polyolefin resin is a resin containing a polyolefin in a proportion exceeding 50% by weight.

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

Examples of the dicarboxylic acid constituting the polyester include phthalic acid, isophthalic acid, terephthalic acid, 2-methylterephthalic acid, 5-sulfoisophthalic acid, 4,4'-diphenyldicarboxylic acid, Diphenyl ether dicarboxylic acid, 4,4'-diphenyl ketone dicarboxylic acid, 4,4'-diphenoxyethane dicarboxylic acid, 4,4'-diphenyl sulfone dicarboxylic acid, 1 , Aromatic dicarboxylic acids such as 4-naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, and 2,7-naphthalene dicarboxylic acid; Alicyclic dicarboxylic acids such as 1,2-cyclohexane dicarboxylic acid, 1,3-cyclohexane dicarboxylic acid and 1,4-cyclohexane dicarboxylic 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 (e.g., lower alkyl esters of the above dicarboxylic acids such as terephthalic acid and the like); And the like. These may be used singly or in combination of two or more. From the viewpoint of strength and the like, aromatic dicarboxylic acid is preferable. Among them, preferred dicarboxylic acids include terephthalic acid and 2,6-naphthalene dicarboxylic acid. For example, at least 50 wt% (e.g., at least 80 wt%, and typically at least 95 wt%) of the dicarboxylic acid constituting the polyester is terephthalic acid, 2,6-naphthalene dicarboxylic acid, Is preferably used in combination. The dicarboxylic acid may be composed substantially of only terephthalic acid, substantially 2,6-naphthalenedicarboxylic acid, or substantially 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-cyclohexanedimethanol and 1,4-cyclohexanedimethanol, xylylene glycol, 4,4'-di Aromatic diols such as hydroxybiphenyl, 2,2-bis (4'-hydroxyphenyl) propane, and bis (4-hydroxyphenyl) sulfone; And the like. These may be used singly or in combination of two or more. Among them, an aliphatic diol is preferable from the viewpoint of transparency and the like, and ethylene glycol is particularly preferable. The proportion of the aliphatic diol (preferably ethylene glycol) in the diol constituting the polyester is preferably 50% by weight or more (for example, 80% by weight or more, typically 95% by weight or more). The diol may be substantially composed of ethylene glycol only.

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

As the polyolefin resin, one kind of polyolefin may be used alone, or two or more kinds of polyolefins may be used in combination. The polyolefin may be, for example, a homopolymer of? -Olefin, a copolymer of two or more? -Olefins, a copolymer of one or more? -Olefins with another vinyl monomer, and the like. Specific examples thereof include ethylene-propylene copolymers such as polyethylene (PE), polypropylene (PP), poly-1-butene, poly-4-methyl-1-pentene and ethylene propylene rubber An ethylene-butene copolymer, an ethylene-vinyl alcohol copolymer, and an ethylene-ethyl acrylate copolymer. Both low density (LD) polyolefins and high density (HD) polyolefins are available. Examples of the polyolefin resin film include a non-oriented polypropylene (CPP) film, a biaxially oriented polypropylene (OPP) film, a low density polyethylene (LDPE) film, a linear low density polyethylene (LLDPE) film, a medium density polyethylene (MDPE) A polyethylene (PE) film blended with two or more kinds of polyethylene (PE), and a PP / PE blend film blended with polypropylene (PP) and polyethylene (PE).

Specific examples of the resin film preferably usable as the base film of the pressure sensitive adhesive sheet disclosed herein include a PET film, a PEN film, a PPS film, a PEEK film, a CPP film and an OPP film. Examples of preferred base films from the viewpoint of strength and dimensional stability include PET films, PEN films, PPS films and PEEK films. PET films and PPS films are particularly preferable from the viewpoint of availability of the substrate and the like, and among them PET films are preferable.

The resin film may contain known additives such as a light stabilizer, an antioxidant, an antistatic agent, a colorant (dye, pigment, etc.), a filler, a slip agent and an anti-blocking agent in a range that does not significantly interfere with the effect of the present invention . &Lt; / RTI &gt; The blending amount of the additive is not particularly limited and may be appropriately set depending on the use of the pressure-sensitive adhesive sheet.

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

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 (for example, a colored layer, an antireflection layer), a surface treatment layer such as a print layer or a laminate layer, an antistatic layer, a primer layer, .

The thickness of the base material is not particularly limited and may be selected depending on the intended use and the mode of use of the adhesive sheet. The thickness of the substrate may be, for example, 1000 mu m or less. In some aspects, the thickness of the base material may be, for example, not more than 500 mu m, not more than 300 mu m, not more than 250 mu m, or not more than 200 mu m, from the viewpoints of handleability and workability of the adhesive sheet. From the viewpoint of downsizing and lightening of the product to which the pressure-sensitive adhesive sheet is applied, in some aspects, the thickness of the substrate may be, for example, 160 탆 or less, 130 탆 or less, 100 탆 or less, , Not more than 70 mu m, not more than 50 mu m, not more than 25 mu m, not more than 10 mu m, or not more than 5 mu m. If the thickness of the substrate is reduced, the flexibility of the pressure-sensitive adhesive sheet and the ability to follow the surface shape of the adherend tend to be improved. The thickness of the substrate may be, for example, 2 mu m or more, 5 mu m or more, 10 mu m or more, 20 mu m or more, 25 mu m or more, or 25 mu m or more It may be. In some embodiments, the thickness of the base material may be, for example, 30 占 퐉 or more, 35 占 퐉, 55 占 퐉, 75 占 퐉, or 120 占 퐉 or more. For example, in the case of a pressure-sensitive adhesive sheet which can be used for the purpose of reinforcement of an adherend, support, impact relaxation, etc., a substrate having a thickness of 30 탆 or more can be preferably employed.

Conventionally known surface treatments such as corona discharge treatment, plasma treatment, ultraviolet ray irradiation treatment, acid treatment, alkali treatment, formation of a primer layer by applying a primer (primer) are carried out on the first surface of the base material . Such a surface treatment may be a treatment for improving an embossability of a pressure-sensitive adhesive layer to a substrate. For example, in the case of a pressure-sensitive adhesive sheet having a base material containing a resin film as a base film, a base material on which such an improvement in transparency is applied can be preferably employed. The surface treatment may be applied alone or in combination. The composition of the primer used for forming the undercoat layer is not particularly limited and may be appropriately selected from known ones. The thickness of the primer layer is not particularly limited, but is usually suitably about 0.01 탆 to 1 탆, and preferably about 0.1 탆 to 1 탆. Other treatments which can be carried out on the first side of the substrate as required include antistatic layer forming treatment, colored layer forming treatment, 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 surface of the substrate may be subjected to conventional surface treatment such as peeling treatment or antistatic treatment . For example, the rewinding force of the rolled-up adhesive sheet can be lightened by surface-treating the back surface of the base material with a peeling treatment agent (typically, by forming a release layer by a peeling agent). As the peeling treatment agent, a silicone peeling agent, a long chain alkyl peeling agent, an olefin peeling agent, a fluorine peeling agent, a fatty acid amide peeling agent, molybdenum sulfide, a silica powder and the like can be used. The second surface of the substrate may be subjected to a treatment such as a corona discharge treatment, a plasma treatment, an ultraviolet ray irradiation treatment, an acid treatment, or an alkali treatment for the purpose of improving the printability, reducing the light reflectivity, improving the overlapability and the like. Further, in the case of a double-sided pressure-sensitive adhesive sheet, surface treatment similar to that exemplified above may be performed on the second surface of the substrate as the surface treatment that can be performed on the first surface of the substrate, if necessary. The surface treatment performed on the first surface of the substrate and the surface treatment performed on the second surface may be the same or different.

<Adhesive sheet>

(Characteristics of the pressure-sensitive adhesive sheet, etc.)

Since the ratio of the adhesive force N ₈₀ (adhesive force after heating) to the adhesive force N ₅₀ , that is, N ₈₀ / N _50, is 5 or more, the pressure-sensitive adhesive sheet disclosed herein can be used at a temperature of about 50 ° C , It is possible to exhibit good reworkability and to greatly increase the adhesive force by subsequent heating or the like. In some aspects, N ₈₀ / N ₅₀ may be, for example, at least 7, at least 10, at least 15, or at least 20 in order to obtain a higher effect. The upper limit of N ₈₀ / N ₅₀ is not particularly limited, but may be, for example, 80 or less, or 60 or less, or 50 or less, or 40 or less, from the viewpoints of easiness of production and economical efficiency of the pressure-sensitive adhesive sheet. The pressure-sensitive adhesive sheet disclosed herein may suitably be implemented in such a manner that 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 , May be less than 10, preferably less than 7, less than 5, or less than 4. According to the pressure-sensitive adhesive sheet having a small N ₅₀ / N ₂₃ , good releasability tends to be exerted even in a use mode in which a temperature of about 50 ° C can be applied at the beginning of the application. The lower limit of N ₅₀ / N ₂₃ is not particularly limited, but is usually 1.0 or higher, typically higher than 1.0, for example, 1.2 or higher.

Although not particularly limited, in some embodiments of the pressure-sensitive 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 , 7 or more, 10 or more, or 15 or more. According to the pressure-sensitive adhesive sheet having a large N ₈₀ / N ₂₃ , the low stickiness at the initial stage of sticking and the high stickiness after the sticking force can be exerted at a higher level. The pressure-sensitive adhesive sheet disclosed herein can also be suitably applied to an embodiment in which N ₈₀ / N ₂₃ is, for example, 20 or more, 30 or more, or 40 or more. The upper limit of N ₈₀ / N ₂₃ is not particularly limited, but may be, for example, 100 or less, or 80 or less, or 60 or less, or 50 or less, from the viewpoints of ease of manufacture and economical efficiency of the pressure-sensitive adhesive sheet.

The adhesive force N ₂₃ [N / 25 mm] was pressure-bonded to a stainless steel (SUS) plate as an adherend and allowed to stand in an environment of 23 ° C. and 50% RH for 30 minutes. Then, a peel angle of 180 ° and a tensile rate of 300 mm / 180 DEG peel adhering force under the condition. The adhesive force N ₅₀ [N / 25 mm] was pressed on a stainless steel (SUS) plate as an adherend, held in an environment of 50 캜 for 30 minutes, then left in an environment of 23 캜 and 50% RH for 30 minutes, 180 deg., And a tensile rate of 300 mm / min. The adhesive strength N ₈₀ [N / 25 mm] was pressed on an SUS plate as an adherend, heated at 80 ° C for 5 minutes, and then allowed to stand for 30 minutes in an environment of 23 ° C and 50% RH. / Min. &Lt; / RTI &gt; As the adherend, the SUS304BA plate is used for any of the adhesion forces N ₂₃ , N ₅₀ and N ₈₀ . In the measurement, an adhesive material (for example, a PET film having a thickness of about 25 mu m) suitable for the adhesive sheet to be measured can be stuck and reinforced, if necessary. More specifically, the adhesion forces N ₂₃ , N ₅₀ and N ₈₀ can be measured in accordance with the methods described in the following examples.

In some embodiments of the pressure-sensitive adhesive sheet disclosed herein, the pressure-sensitive adhesive force N ₂₃ of the pressure-sensitive adhesive sheet may be 2.0 N / 25 mm or less, 1.5 N / 25 mm or less, 1.2 N / Or less, or 1.0 N / 25 mm or less, or 0.8 N / 25 mm or less. It is preferable from the viewpoint of reworkability that the adhesive force N ₂₃ is low. The lower limit of the adhesive force N ₂₃ is not particularly limited, and may be, for example, 0.01 N / 25 mm or more. From the viewpoints of sticking workability to an adherend and prevention of positional deviation before the adhesive force is increased, it is appropriate that the adhesive force N ₂₃ is usually 0.1 N / 25 mm or more. In some aspects, 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, or 0.5 N / 25 mm or more.

In some embodiments of the pressure-sensitive adhesive sheet disclosed herein, the adhesive force N ₅₀ of the pressure-sensitive adhesive sheet may be, for example, 7 N / 25 mm or less, 5 N / 25 mm or less, , 3.5 N / 25 mm or less, 3 N / 25 mm or less, 2.5 N / 25 mm or less, or 2 N / 25 mm or less. A low adhesive force N ₅₀ is preferable from the viewpoint of exhibiting good releasability even in a use mode in which a temperature of about 50 캜 can be applied at the beginning of the application. 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 the standpoint of prevention of positional deviation before the adhesive force is increased, the adhesive force N ₅₀ is usually suitably 0.1 N / 25 mm or more. In some aspects, the adhesive force N ₅₀ may be, for example, 0.2 N / 25 mm or more, 0.5 N / 25 mm or more, or 0.7 N / 25 mm or more from the viewpoints of improvement of adhesion after heating.

In some embodiments of the pressure-sensitive adhesive sheet disclosed herein, the pressure-sensitive adhesive force N ₈₀ (adhesive force after heating) of the pressure-sensitive adhesive sheet may be 5 N / 25 mm or more, 7 N / 25 mm or more, / 25 mm or more, 13 N / 25 mm or more, 15 N / 25 mm or more, and 17 N / 25 mm or more. The upper limit of the adhesive force after heating is not particularly limited. 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 from the viewpoints of easiness in manufacturing the pressure-sensitive adhesive sheet and economical efficiency.

It is not particularly limited, in some aspects of the pressure-sensitive adhesive sheet disclosed herein, the adhesive strength difference between the N ₅₀ [N / 25mm] and the adhesive strength ₂₃ N [N / 25mm], i.e., N ₅₀ -N ₂₃ is usually 5N / 25mm For example, less than 4 N / 25 mm, less than 3 N / 25 mm, less than 2.5 N / 25 mm, less than 2 N / 25 mm, or less than 1.5 N / 25 mm. N ₅₀ -N ₂₃ According to this small adhesive sheet, good reworkability tends to be exerted even in a use mode in which a temperature of about 50 캜 can be applied at the beginning of the adhesive application. The lower limit of N ₅₀ -N ₂₃ is not particularly limited, but it is usually ₀ N / 25 mm or more, typically 0 N / 25 mm or more, for example, 0.2 N / 25 mm or more.

Is not particularly limited and the adhesion of the pressure-sensitive adhesive sheet disclosed herein N ₅₀ [N / 25mm] and the adhesive strength N ₂₃ adhesion to the difference in _{[N / 25mm] N 80 [} N / 25mm] and the adhesive strength N ₅₀ [N / 25mm ], That is, (N ₈₀ -N ₅₀ ) / (N ₅₀ -N ₂₃ ) may be, for example, two or more. (N ₈₀ -N ₅₀ ) / (N ₅₀ -N ₂₃ ) is larger than the initial adhesive strength in the use mode in which a temperature of about 50 ° C can be applied, the degree of increase of the adhesive force after heating Is greater. 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. The upper limit of (N ₈₀ -N ₅₀ ) / (N ₅₀ -N ₂₃ ) is not particularly limited and may be, for example, 100 or less.

The pressure-sensitive adhesive force after heating of the pressure-sensitive adhesive sheet disclosed here represents one characteristic of the pressure-sensitive adhesive sheet, and the mode of use of the pressure-sensitive adhesive sheet is not limited. In other words, the mode of use of the pressure-sensitive adhesive sheet disclosed herein is not limited to the mode of heating at 80 DEG C for 5 minutes, but may be applied to, for example, a room temperature region (usually 20 DEG C to 30 DEG C, typically 23 DEG C to 25 DEG C ) Or more can be used. Also in such a use mode, the adhesive force is increased over the long term, and a strong bonding can be realized. Further, the pressure-sensitive adhesive sheet disclosed herein can promote the increase of the adhesive force by performing the heat treatment at a temperature higher than 50 deg. C at an arbitrary timing after the application. The heating temperature in this heat treatment is not particularly limited and may be set in consideration of workability, economy, heat resistance of the substrate of the pressure-sensitive adhesive sheet and the adherend. The heating temperature may be, for example, less than 150 占 폚, less than 120 占 폚, less than 100 占 폚, less than 80 占 폚, or less than 70 占 폚. The heating temperature may be, for example, 55 占 폚 or higher, 60 占 폚 or higher, or 70 占 폚 or higher, and may be 80 占 폚 or higher, or 100 占 폚 or higher. According to the higher heating temperature, the adhesive force can be increased by the treatment in a shorter time. The heating time is not particularly limited and may be, for example, 1 hour or less, 30 minutes or less, 10 minutes or less, or 5 minutes or less. Alternatively, the heat treatment may be performed for a longer period of time as long as the adhesive sheet and the adherend do not cause significant thermal deterioration. The heat treatment may be performed at one time or may be performed in a plurality of circuits.

(Adhesive sheet with substrate)

When the pressure-sensitive adhesive sheet disclosed herein is in the form of a pressure-sensitive adhesive sheet having a substrate, the thickness of the pressure-sensitive adhesive sheet may be, for example, 1000 탆 or less, 600 탆 or less, 350 탆 or less, or 250 탆 or less. In some aspects, the thickness of the pressure-sensitive adhesive sheet may be 200 탆 or less, 175 탆 or less, 140 탆 or less, or 120 탆 or less, for example, from the viewpoint of downsizing, Mu m or less, and may be 100 mu m or less (for example, less than 100 mu m). The thickness of the pressure-sensitive adhesive sheet may be, for example, 5 mu m or more, 10 mu m or more, 15 mu m or more, 20 mu m or more, 25 mu m or more, Or more. In some embodiments, the thickness of the pressure-sensitive adhesive sheet may be, for example, 50 占 퐉 or more, 60 占 퐉 or more, 80 占 퐉 or more, 100 占 퐉 or more, or 130 占 퐉 or more. The upper limit of the thickness of the pressure-sensitive adhesive sheet is not particularly limited.

Further, the thickness of the pressure-sensitive adhesive sheet means the thickness of the portion to be attached to the adherend. 1 indicates the thickness from the adhesive surface 21A of the adhesive sheet 1 to the second surface 10B of the base material 10 and the peeling liner 31 ) Is not included.

The pressure-sensitive adhesive sheet disclosed herein can be suitably applied, for example, in a mode in which the thickness Ts of the supporting substrate is larger than the thickness Ta of the pressure-sensitive adhesive layer, that is, Ts / Ta is larger than 1. [ Although not particularly limited, Ts / Ta may be, for example, 1.1 or more, 1.2 or more, 1.5 or more, or 1.7 or more. For example, in a pressure-sensitive adhesive sheet which can be used for the purpose of reinforcing, supporting, or shock-absorbing an adherend, a good effect tends to be exhibited even if the pressure-sensitive adhesive sheet is made thin by the increase of Ts / Ta. In some embodiments, Ts / Ta may be 2 or more (e.g., greater than 2), 3 or more, or 4 or more. Further, Ts / Ta may be set to, for example, 50 or less, and may be 20 or less. Ts / Ta may be, for example, 10 or less, and may be 8 or less, from the viewpoint that even if the pressure-sensitive adhesive sheet is thinned, the adhesive force after high heating is easily exhibited.

The pressure-sensitive adhesive layer is preferably fixed to the supporting substrate. The above-mentioned fixation means that in the pressure-sensitive adhesive sheet in which the adhesive strength of the pressure-sensitive adhesive sheet after the application to the adherend is increased, the pressure-sensitive adhesive layer does not peel off from the support substrate And a sufficient anchoring property with respect to the above. According to the pressure-sensitive adhesive sheet having the substrate in which the pressure-sensitive adhesive layer is fixed to the supporting substrate, the adherend and the supporting substrate can be solidly integrated. This makes it possible to effectively exert functions such as reinforcement, support, impact reduction, and the like of an adherend. As a preferable example of the pressure-sensitive adhesive sheet in which the pressure-sensitive adhesive layer is adhered to a substrate, an adhesive force of at least 5 N / 25 mm, preferably 10 N / 25 mm or more, more preferably 15 N / , A 180 ° peeling adhesive force measured at a tensile speed of 300 mm / min) and peeling (peeling breakage) between the pressure-sensitive adhesive layer and the supporting substrate when peeling from the adherend have. The pressure-sensitive adhesive sheet (N ₈₀ ) after heating is 15 N / 25 mm or more and the pressure-sensitive adhesive sheet which does not cause tar break at the time of measuring the adhesive force after heating is a suitable example corresponding to the pressure-sensitive adhesive sheet adhered to the substrate .

The pressure-sensitive adhesive sheet disclosed here is a method in which a pressure-sensitive adhesive composition in a liquid state is brought into contact with a first surface of a substrate, and a pressure-sensitive adhesive layer is formed by curing the pressure-sensitive adhesive composition on the first surface . &Lt; / RTI &gt; The curing of the pressure-sensitive adhesive composition may involve one or more of drying, crosslinking, polymerization, cooling, etc. 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, the pressure-sensitive adhesive layer after curing is bonded to the first surface of the substrate to thereby arrange the pressure- It is possible to enhance the anchoring property of the pressure-sensitive adhesive layer to the substrate. By using this, an adhesive sheet having a pressure-sensitive adhesive layer fixed to a substrate can be suitably produced.

In some embodiments, as a method of contacting the liquid surface pressure-sensitive adhesive composition on the first surface of the base material, a method of directly applying the pressure-sensitive adhesive composition on the first surface of the base material may be employed. The first surface (pressure-sensitive adhesive surface) of the pressure-sensitive adhesive layer cured on the first surface of the substrate is brought into contact with the release surface so that the second surface of the pressure-sensitive adhesive layer is fixed to the first surface of the substrate, It is possible to obtain a pressure-sensitive adhesive sheet having a configuration in which the surface is in contact with the peeling surface. As the release surface, a surface of a release liner, a back surface of a release-treated substrate, or the like can be used.

Further, for example, in the case of a photocurable pressure-sensitive adhesive composition using a partial polymerized product of a monomer component (acrylic polymer syrup), for example, the pressure-sensitive adhesive composition is applied to a release face, The pressure-sensitive adhesive layer may be formed by contacting the first surface of the base material with the non-cured pressure-sensitive adhesive composition by covering and then irradiating the pressure-sensitive adhesive composition sandwiched between the first surface and the release surface of the base material.

In addition, the method exemplified above does not limit the production method of the pressure-sensitive adhesive sheet disclosed herein. In the production of the pressure-sensitive adhesive sheet disclosed herein, suitable methods for fixing the pressure-sensitive adhesive layer on the first surface of the substrate may be used alone or in combination of two or more. Examples of such methods include a method of forming a pressure-sensitive adhesive layer by curing a liquid pressure-sensitive adhesive composition on a first surface of a base material, a method of performing a surface treatment on the first surface of the base material to enhance the attractability of the pressure- And the like. For example, when the embossability of the pressure-sensitive adhesive layer to the substrate can be sufficiently improved by a method such as forming a subbing layer on the first surface of the substrate, the pressure-sensitive adhesive layer after curing is bonded to the first surface of the substrate Sensitive adhesive sheet. In addition, the selection of the material of the base material and the selection of the composition of the pressure-sensitive adhesive can also improve the anchoring properties of the pressure-sensitive adhesive layer to the base material. Further, by applying a temperature higher than the room temperature to the pressure-sensitive adhesive sheet having the pressure-sensitive adhesive layer on the first surface of the substrate, the pressure-sensitive adhesive layer can be enhanced in an embossing property with respect to the substrate. The temperature applied to increase the anchoring property may be, for example, about 35 ° C to about 80 ° C, about 40 ° C to about 70 ° C or about 45 ° C to about 60 ° C.

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 the first surface of the substrate and a second pressure-sensitive adhesive layer formed on the second surface of the substrate (i.e., a pressure- , The first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer may have the same constitution or different configurations. When the constitution of the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer is different, the difference may be, for example, a difference in composition or a difference in structure (thickness, surface roughness, formation range, formation pattern, etc.). For example, the second pressure sensitive adhesive layer may be a pressure sensitive adhesive layer containing no polymer B. [ The surface (second adhesive surface) of the second pressure-sensitive adhesive layer may have N ₈₀ / N ₅₀ of less than 5, less than 2, less than 1.5, or less than 1.

&Lt; 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 (pressure-sensitive adhesive surface) of the pressure-sensitive adhesive layer is brought into contact with the release surface of the release liner. Therefore, according to this specification, there can be provided a release liner-equipped pressure-sensitive adhesive sheet (pressure-sensitive adhesive article) comprising a pressure-sensitive adhesive sheet described herein and a release liner having a release face abutting the pressure-sensitive adhesive surface of the pressure-sensitive adhesive sheet.

The thickness of the release liner is not particularly limited, but usually it is suitably about 5 탆 to 200 탆. When the thickness of the release liner is within the above-mentioned range, it is preferable because the bonding workability to the pressure-sensitive adhesive layer and the peeling workability from the pressure-sensitive adhesive layer are excellent. In some embodiments, the thickness of the release liner may be, for example, 10 占 퐉 or more, 20 占 퐉 or more, 30 占 퐉 or more, or 40 占 퐉 or more. The thickness of the release liner may be, for example, 100 탆 or less, or 80 탆 or less from the viewpoint of facilitating peeling from the pressure-sensitive adhesive layer. The release liner may be subjected to known antistatic treatment, such as a coating type, a kneading type, and a deposition type, if necessary.

The release liner is not particularly limited and may be, for example, a release liner having a release layer on the surface of a liner base such as a resin film or paper (which may be a paper laminated with a resin such as polyethylene), or a fluorine- A release liner including a resin film formed of a low adhesive material such as polyolefin resin (polyethylene, polypropylene, etc.), or the like can be used. A release liner including a release layer having a release layer on the surface of a resin film as a liner base material or a release liner including a resin film formed from a low adhesion material can be preferably employed in view of excellent surface smoothness. The resin film is not particularly limited as long as it can protect the pressure-sensitive adhesive layer, and examples thereof include a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, a polymethylpentene film, a polyvinyl chloride film, Film, a polyester film (PET film, PBT film, etc.), a polyurethane film, and an ethylene-vinyl acetate copolymer film. For the formation of the release layer, a known release agent such as 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, have. The use of a silicone-based peeling agent is particularly preferred.

The thickness of the release layer is not particularly limited, but it is usually about 0.01 탆 to 1 탆, preferably about 0.1 탆 to 1 탆. The method of forming the release layer is not particularly limited, and a known method can be suitably adopted depending on the kind of the release agent to be used and the like.

<Applications>

The pressure-sensitive adhesive sheet provided by this specification has a low adhesive force for a while under a temperature range from room temperature to about 50 ° C (for example, from 20 ° C to 50 ° C) after being bonded to an adherend , Good reworkability can be exhibited during this time, and consequently, the yield can be suppressed and the quality of the product including the pressure-sensitive adhesive sheet can be improved. The pressure-sensitive adhesive sheet can greatly increase the adhesive force by aging (heating to a temperature higher than 50 占 폚, aging, or a combination thereof). For example, by heating at a desired timing, the adhesive sheet can be firmly adhered to an adherend. Taking advantage of these features, the pressure-sensitive adhesive sheet disclosed herein can be preferably used for the purpose of fixing, joining, molding, decorating, protecting, reinforcing, supporting, impact reduction, etc. in various fields in various fields have.

The pressure-sensitive adhesive sheet disclosed herein is a pressure-sensitive adhesive sheet in the form of a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer formed on at least a first surface of a film-like base material having a first surface and a second surface, Can be preferably used as a film. In such reinforced films, those containing a resin film as a base film can be preferably used as the film base. Further, from the viewpoint of enhancing the reinforcing performance, it is preferable that the pressure-sensitive adhesive layer is fixed to the first surface of the film-like substrate.

For example, in optical members used in optical products and electronic members used in electronic products, high integration, small size, light weight, and thinness have been advanced, and a plurality of thin optical members / electronic members having different coefficients of linear expansion and thickness Can be stacked. By attaching such a reinforcing film to such a member, appropriate rigidity can be given to the optical member / electronic member. This makes it possible to suppress the curl or curvature due to the stress that may occur between the plurality of members having different coefficients of linear expansion and thickness in the manufacturing process and / or the product after the manufacturing process.

Further, in the process of manufacturing the optical product / electronic product, in the phase of performing the shape processing such as the cutting process on the thin optical member / electronic member as described above, the reinforcing film is attached to the member and processed, It is possible to mitigate the local stress concentration on the accompanying optical / electronic member, and to reduce the risk of cracking, cracking, peeling of the lamination member, and the like. The handling of the reinforcement member by sticking to the optical member / electronic member can also help alleviate the local stress concentration at the time of carrying, laminating, and rotating the member, suppressing bending and curvature due to the weight of the member .

In addition, a device such as an optical product or an electronic product including the reinforcing film can be used in a market that is used by a consumer, for example, when the device falls, when the device falls below a heavy object, Even when unintentional stress is applied, since the reinforcing film is included in the device, the stress applied to the device can be alleviated. Therefore, by including the reinforcing film in the device, the durability of the device can be improved.

In addition, the pressure-sensitive adhesive sheet disclosed herein can be preferably used in the form of being affixed to a member constituting various portable devices (portable devices), for example. Here, the term &quot; portable &quot; means that it is not sufficient to simply carry it, and it means that an individual (standard adult) has a portable level that is relatively easy to carry. Examples of the portable device include portable phones, smart phones, tablet personal computers, notebook computers, various wearable devices, digital cameras, digital video cameras, sound devices (portable music players, IC recorders, etc.) Portable electronic devices, in-vehicle information devices, portable radios, portable TVs, portable printers, portable scanners, portable modems, etc., as well as portable electronic devices such as mechanical wrist watches and conglomerates A clock, a flashlight, a hand mirror, and the like. Examples of members constituting the portable electronic device may include an optical film or a display panel used in an image display device such as a thin film display such as a liquid crystal display or a film type display. The pressure-sensitive adhesive sheet disclosed herein can also be preferably used in the form of being affixed to various members in automobiles, household appliances, and the like.

The matters disclosed by this specification include the following.

(1) A pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer,

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

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

Wherein the adhesive force N ₈₀ after heating at 80 캜 for 5 minutes after bonding to the stainless steel sheet is at least 5 times the adhesive force N ₅₀ after bonding to the stainless steel sheet and holding at 50 캜 for 30 minutes.

(2) The relationship between the adhesive force N ₅₀ and the adhesive force N ₂₃ after being held at 23 캜 for 30 minutes after being bonded to the stainless steel plate is represented by the following formula:

(N ₅₀ / N ₂₃ ) &lt;10;

Sensitive adhesive sheet according to (1).

(3) The pressure-sensitive adhesive sheet according to the above (1) or (2), wherein the adhesive force N ₈₀ is 10 times or more as large as the adhesive force N ₂₃ after being allowed to stand at 23 캜 for 30 minutes after being bonded to the stainless steel sheet.

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

(N ₈₀ -N ₅₀ ) / (N ₅₀ -N ₂₃ ) 2;

Sensitive adhesive sheet according to any one of (1) to (3) above.

(5) The pressure-sensitive 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 pressure-sensitive 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 pressure-sensitive 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 pressure-sensitive adhesive sheet according to any one of (1) to (7), wherein the polymer A has a glass transition temperature T _A of -63 캜 or more and less than 0 캜.

(9) The pressure-sensitive adhesive sheet according to any one of (1) to (8), wherein the polymer B has a glass transition temperature T _{B of} from -10 ° C to 10 ° C.

(10) The pressure-sensitive adhesive sheet according to any one of (1) to (9), wherein the polymer B has a homopolymer having a copolymerization ratio of monomer 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) above, wherein the pressure-sensitive adhesive layer comprises a crosslinking agent which is more than 0 parts by weight and not more than 10 parts by weight based on 100 parts by weight of the polymer A.

(12) The pressure-sensitive 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 50,000 or less.

(13) The pressure-sensitive adhesive sheet according to any one of (1) to (12) above, wherein the content of the polymer B in the pressure-sensitive adhesive layer is 0.05 parts by weight or more and 20 parts by weight or less based on 100 parts by weight of the polymer A.

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

(15) The pressure-sensitive adhesive sheet according to (14), wherein the monomer component for preparing the acryl-based polymer comprises a hydroxyl-containing monomer.

(16) The pressure-sensitive adhesive sheet according to (14), wherein the monomer component for preparing the acryl-based polymer comprises an N-vinyl cyclic amide and a hydroxyl group-containing monomer.

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

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

(19) The pressure-sensitive adhesive sheet according to (18), wherein the proportion of MMA in the total amount of the (meth) acrylic monomers contained in the monomer component is 55 wt% or more and 95 wt% or less.

(20) The pressure-sensitive adhesive sheet according to any one of (1) to (19), wherein the thickness of the pressure-sensitive adhesive layer is not less than 3 μm and not more than 100 μm (for example, not less than 20 μm and not more than 50 μm).

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

(22) The pressure-sensitive adhesive sheet according to (21), wherein the thickness of the supporting substrate is 30 占 퐉 or more.

(23) The pressure-sensitive adhesive sheet according to (21) or (22), wherein the thickness of the supporting substrate is 1.1 times or more and 10 times or less the thickness of the pressure-sensitive adhesive layer.

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

(25) The pressure-sensitive adhesive sheet according to the above (24), wherein the base film is a polyester film having a thickness of 35 μm or more (for example, 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 pressure-sensitive adhesive sheet according to any one of (21) to (26), which is applied to an adherend to reinforce the adherend.

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

(29) A pressure sensitive adhesive sheet comprising the pressure sensitive adhesive sheet as described in any one of (1) to (28) above, and a release liner having a releasable surface abutting against the pressure sensitive adhesive surface of the pressure sensitive adhesive sheet,

Wherein the peelable surface has a water contact angle of 100 degrees or more.

(30) The release sheet according to (29), wherein the releasable surface is a surface of a release layer formed by a silicone-based release agent.

<Examples>

Hereinafter, some embodiments of the present invention will be described, but the present invention is not intended to be limited to these embodiments. In the following description, &quot; part &quot; and &quot;% &quot; are by weight unless otherwise specified.

(Preparation of polymer A1)

60 parts of 2EHA, 15 parts of N-vinyl-2-pyrrolidone (NVP), 10 parts of methyl methacrylate (MMA), and 2 parts of 2- 15 parts of hydroxyethyl acrylate (HEA) and 200 parts of ethyl acetate as a polymerization solvent were charged and stirred at 60 DEG C under a nitrogen atmosphere for 2 hours. Then, 0.2 part of AIBN was added as a thermal polymerization initiator, and the mixture was reacted at 60 DEG C for 6 hours Was performed to obtain a solution of the polymer A1. The Mw of this polymer A1 was 1.1 million.

(Preparation of polymer B1)

100 parts of toluene, 40 parts of MMA, 20 parts of n-butyl methacrylate (BMA), 2 parts of 2-ethylhexyl methacrylate (manufactured by Wako Pure Chemical Industries, Ltd.) were added to a four-necked flask equipped with a stirrer, a thermometer, a nitrogen gas introducing tube, a condenser and a dropping funnel 2EHMA), 8.7 parts of a polyorganosiloxane skeleton-containing methacrylate monomer (trade name: X-22-174ASX, Shin-Etsu Chemical Co., Ltd.) having a functional group equivalent of 900 g / mol, , 11.3 parts of a polyorganosiloxane skeleton-containing methacrylate monomer (trade name: KF-2012, manufactured by Shin-Etsu Chemical Co., Ltd.) and 0.51 parts of methyl thioglycolate as a chain transfer agent. Then, 0.2 part of AIBN was added as a thermal polymerization initiator, and the mixture was reacted at 70 DEG C for 2 hours. Then, 0.1 part by weight of AIBN was added as a thermal polymerization initiator, Lt; / RTI &gt; Thus, a solution of the polymer B1 was obtained. The Mw of this polymer B1 was 22,000.

(Preparation of polymers B2 to B7)

Polymers B2 to B7 were prepared in the same manner as the preparation of polymer B1, except that the composition of the monomer components was changed as shown in Table 1, 0.8 part of thioglycerol was used as a chain transfer agent, and ethyl acetate was used as a polymerization solvent. The Mw of each polymer was 19100 for polymer B2, 19700 for polymer B3, 19600 for polymer B4, 20,000 for polymer B5, 18900 for polymer B6 and 19500 for polymer B7.

The glass transition temperature T _m1 based on the composition of the monomer components used in the preparation of the polymers B1 to B7, the composition of the (meth) acrylic monomer in the monomer components, and the glass transition temperature T _B of the polymers B1 to B7 are shown in Table 1 Respectively.

The weight average molecular weight of each of the above-mentioned polymers was determined by polystyrene conversion by using a GPC apparatus (HLC-8220GPC manufactured by TOSOH CORPORATION) under the following conditions.

[GPC condition]

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

Sample injection amount: 10 μl

- Eluent: THF

ㆍ Flow rate: 0.6 ml / min

ㆍ Measuring temperature: 40 ℃

ㆍ Column:

Sample column; TSKguardcolumn SuperHZ-H (1) + TSKgel SuperHZM-H (2)

Reference column; TSKgel SuperH-RC (1)

ㆍ Detector: Differential refractometer (RI)

In the calculation of T _B shown in Table 1, -126 캜 was used as the Tg of X-22-174 ASX and -127 캜 was used as the Tg of KF-2012. The Tg of the polyorganosiloxane skeleton-containing methacrylate monomer was obtained by placing the monomer (measurement sample) in a sealed container made of aluminum and performing DSC (differential scanning calorimetry) under the following conditions.

[DSC condition]

Device: TA Instruments, Q-2000

Temperature program: -160 ° C to 40 ° C

Heating rate: 10 ° C / min

Atmosphere gas: He (50 ml / min)

<Production of pressure-sensitive adhesive sheet>

(Example 1)

To the solution of the polymer A1 was added 2.5 parts of polymer B1 per 100 parts of the polymer A1 contained in the solution, 2.5 parts of an isocyanate crosslinking agent (trade name: Takenate D110N, trimethylolpropane silylene diisocyanate, Mitsui Chemical) And uniformly mixed to prepare a pressure-sensitive adhesive composition C1.

The pressure-sensitive adhesive composition C1 was directly applied on the first surface of a 125 탆 -thick polyethylene terephthalate (PET) film (manufactured by Toray Co., Ltd. under the trade name of "Lumirror") as a supporting substrate and heated at 110 캜 for 2 minutes to dryness, Sensitive adhesive layer was formed. The release surface of the release liner R1 was bonded to the surface (pressure-sensitive adhesive surface) of the pressure-sensitive adhesive layer. Thus, the pressure-sensitive adhesive sheet of Example 1 was obtained in the form of a release liner-equipped pressure-sensitive adhesive sheet in which the pressure-sensitive adhesive surface was in contact with the release surface of the release liner.

As the release liner, MRQ25T100 (a release liner having a release layer by a silicone-based release agent on one side of a polyester film, thickness: 25 mu m) manufactured by Mitsubishi Chemical Co., Ltd. was used.

(Examples 2 to 11)

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

&Lt; Measurement of cohesive force against SUS &

That a pressure-sensitive adhesive sheet according to each example of cutting the release liner second 25mm width with the test piece, and the body is deposited a SUS plate (SUS304BA board) cleaned with toluene, the adhesive strength according to the following procedures N _23, the adhesive strength N ₅₀ and the adhesive force N ₈₀ Were measured.

(Measurement of adhesive force N ₂₃ )

The release liner covering the pressure-sensitive adhesive surface of each test piece was peeled off under a standard environment of 23 占 폚 and 50% RH, and the exposed pressure-sensitive adhesive surface was pressed and adhered to the adherend for one round of 2 kg roller. The test piece pressed on the adherend was allowed to stand under the standard environment for 30 minutes and then peeled off in accordance with JIS Z0237 using a universal tensile compression tester (equipment name: "tensile compression tester, TCM-1kNB" manufactured by Minerva Corp.) 180 DEG peel adhesion (resistance to tensile strength) was measured under the conditions of an angle of 180 degrees and a tensile rate of 300 mm / min. The measurement was carried out three times and the average value thereof is shown in Table 2 as the adhesive force (N ₂₃ ) [N / 25 mm] after 23 minutes and 30 minutes.

(Measurement of adhesive force N ₅₀ )

The test piece pressed onto the adherend similarly to the measurement of the adhesive force N ₂₃ was held in an environment of 50 캜 for 30 minutes and then left in the standard environment for 30 minutes and likewise the 180 캜 peel adhesion was measured. The measurement was carried out three times, and the average value thereof is shown in Table 2 as the adhesive force (N ₅₀ ) [N / 25 mm] after 50 minutes and 30 minutes.

(Measurement of adhesive force N ₈₀ )

The test piece pressed onto the adherend similarly to the measurement of the adhesive force N ₂₃ was heated at 80 캜 for 5 minutes and then left in the standard environment for 30 minutes and likewise the 180 캜 peel adhesion was measured. The measurement was carried out three times, and the average value thereof is shown in Table 2 as the adhesive force (N ₈₀ ) [N / 25 mm] after 80 minutes and 5 minutes. It was also confirmed that the pressure-sensitive adhesive sheets of Examples 1 to 11 did not cause turf destruction at the time of measurement of the adhesive force N ₈₀ .

Based on the adhesion 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 ) . The obtained results are shown in Table 2.

As shown in Table 2, the pressure-sensitive adhesive sheets of Examples 5 to 9 using polymers B3 to B5 having a glass transition temperature _Tm1 in the range of 50 占 폚 to 100 占 폚 had N ₈₀ / N ₅₀ of 5 or more, It was confirmed that even when a temperature of about 50 ° C was applied, the low sticking property suitable for the rework was maintained and the adhesive strength could 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 _Tm1 lower than 50 deg. C, N ₈₀ / N ₅₀ was less than 5, The adhesive force is likely to rise. In the pressure-sensitive adhesive sheet of Example 4, N ₅₀ was relatively low, but the adhesive force could not be increased significantly by heating at 80 ° C for 5 minutes. In Example 10 using the polymer B6 having a glass transition temperature _Tm1 of more than 100 占 폚, the adhesion could not be increased by heating at 80 占 폚 for 5 minutes.

While specific embodiments of the present invention have been described in detail hereinabove, these are merely illustrative and do not limit the scope of the claims. The techniques described in the claims include various modifications and changes to the embodiments described above.

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

Claims (10)

A pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer,
The pressure-sensitive adhesive layer comprises a polymer A, a polymer B as a copolymer of a monomer having a polyorganosiloxane skeleton and a (meth) acrylic monomer,
The polymer B preferably has a glass transition temperature T _m1 based on the composition of the (meth) acrylic monomer of 50 ° C or more and 100 ° C or less,
Wherein the adhesive force N ₈₀ after heating at 80 캜 for 5 minutes after bonding to the stainless steel sheet is at least 5 times the adhesive force N ₅₀ after bonding to the stainless steel sheet and holding at 50 캜 for 30 minutes. The method of claim 1, wherein the adhesive force between the N ₂₃ after then bonded to the adhesive force and ₅₀ N, a stainless steel plate allowed to stand at 23 ℃ 30 minutes, the formula:
(N ₅₀ / N ₂₃ ) &lt;10;
Of the pressure-sensitive adhesive sheet. The adhesive sheet according to claim 1 or 2, wherein the polymer A has a glass transition temperature T _A of -80 ° C or higher and lower than 0 ° C. The pressure-sensitive adhesive sheet according to any one of claims 1 to 3, wherein the polymer B has a glass transition temperature T _B of -10 ° C to 10 ° C. The pressure-sensitive adhesive sheet according to any one of claims 1 to 4, wherein the polymer B has a copolymerization ratio of the homopolymer having a glass transition temperature higher than 170 캜 of 30% by weight or less. The pressure-sensitive adhesive sheet according to any one of claims 1 to 5, wherein the pressure-sensitive adhesive layer comprises 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. The pressure-sensitive adhesive sheet according to any one of claims 1 to 6, wherein the polymer B has a weight average molecular weight of 10000 or more and 50,000 or less. The pressure-sensitive adhesive sheet according to any one of claims 1 to 7, wherein the content of the polymer B in the pressure-sensitive adhesive layer is 0.05 parts by weight or more and 20 parts by weight or less based on 100 parts by weight of the polymer A. The pressure-sensitive adhesive sheet according to any one of claims 1 to 8, further comprising a supporting 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 supporting substrate. The pressure-sensitive adhesive sheet according to claim 9, wherein the thickness of the supporting substrate is 30 占 퐉 or more.

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