JP6618522B2 - Adhesive sheet and transparent substrate with adhesive sheet - Google Patents

Description

  The present invention relates to an adhesive sheet and a transparent substrate with an adhesive sheet.

  Conventionally, various devices including display devices such as a television, a personal computer, a portable terminal, an electronic notebook, an OA device, a game machine, a PDA, a bank terminal (cash dispenser), and a ticket vending machine are known. In these devices, there are, for example, a device to which a protective film for preventing scratches on the display surface is affixed, a device to which a touch panel for touch position detection is affixed, and the like. When a protective film, a touch panel, or the like is attached to the surface of the display device, it is often performed to attach both using a pressure sensitive adhesive sheet. In the case of slipping, it is necessary to peel off the protective film and the like together with the pressure-sensitive adhesive sheet and attach it again with a new pressure-sensitive adhesive sheet. However, when the pressure sensitive adhesive sheet is peeled off, there is a problem that adhesive residue remains on the adherend, or when the pressure sensitive adhesive sheet is peeled off, a display device such as a liquid crystal display device is damaged. It was.

  In view of such a problem, a pressure-sensitive adhesive sheet rich in so-called reworkability (reusability) is disclosed in Patent Document 1. According to the pressure-sensitive adhesive sheet disclosed in Patent Document 1, it is possible to peel the pressure-sensitive adhesive sheet from the adherend without leaving the pressure-sensitive adhesive on the adherend even after being attached to the adherend for a long time. Therefore, it has an excellent effect from the viewpoint of reworkability.

JP 2013-199544 A

  The pressure-sensitive adhesive sheet disclosed in Patent Document 1 is recognized as a useful pressure-sensitive adhesive sheet because it has the property of excellent reworkability. When applied to products distributed in the market, there has been a problem that members such as a protective sheet and a touch panel are easily peeled off from the display device during distribution and use.

  The present invention has been made in order to solve such a problem, and has excellent reworkability within a predetermined time after sticking, and a pressure-sensitive adhesive sheet that exhibits strong adhesiveness after a predetermined time has elapsed and the pressure-sensitive adhesive sheet It aims at providing the transparent substrate with an adhesive sheet which has these.

The object of the present invention is a pressure-sensitive adhesive sheet containing a first acrylic polymer having a reactive functional group and a second acrylic polymer not having the reactive functional group, wherein the reactive functional group Is a functional group selected from a hydroxyl group, a carboxyl group or an amino group, the weight average molecular weight of the first acrylic polymer is 200,000 to 600,000, and the weight average molecular weight of the second acrylic polymer Is 2000 to 9000, and the second acrylic polymer is contained in an amount of 0.75 to 10 parts by mass with respect to 100 parts by mass of the first acrylic polymer, and is attached to the polarizing plate. adhesion of 20 minutes elapsed time later, in JIS Z 0237 180 ° peel adhesion measurement method according to (2000), or less 5N / 25 mm or more 6.5 N / 25 mm, before After 20 minutes have elapsed after being attached to the polarizing plate, the adhesive strength after applying pressure and heat treatment for 20 minutes under the conditions of a temperature of 60 ° C. and a pressure of 0.5 MPa is 180 according to JIS Z 0237 (2000). This is achieved by a pressure-sensitive adhesive sheet measuring 8.0 N / 25 mm or more by the method of measuring the peel strength.

In the pressure-sensitive adhesive sheet, the second acrylic polymer preferably has a viscosity of 3000 to 25000 mPa · s.

  Moreover, the said objective of this invention is achieved by the transparent substrate with an adhesive sheet provided with said adhesive sheet and the transparent substrate provided in the at least one surface of the said adhesive sheet. A touch panel may be used as the transparent substrate.

  ADVANTAGE OF THE INVENTION According to this invention, the adhesive sheet which is excellent in rework within the predetermined time after sticking, and exhibits strong adhesiveness after predetermined time progress, and the transparent substrate with an adhesive sheet which has this adhesive sheet can be provided.

  Hereinafter, the adhesive sheet concerning embodiment of this invention is demonstrated. The pressure-sensitive adhesive sheet according to the present invention is composed of a pressure-sensitive adhesive composed mainly of a first acrylic polymer having a reactive functional group and a second acrylic polymer having no reactive functional group as an additive. The ratio between the adhesive strength (A) at the initial stage of application to an adherend such as the display surface of a liquid crystal display device and the adhesive strength (B) after a predetermined time has elapsed after being applied to the adherend. (B / A) is a pressure-sensitive adhesive sheet having a value of 1.5 or more. Here, the initial stage of pasting means a period from the pasting of the pressure-sensitive adhesive sheet to the adherend until 20 minutes have elapsed, and after the predetermined time has passed after pasting to the adherend, It means after 24 hours have passed since the adhesive sheet was attached to the body.

  A relatively high molecular weight polymer is used as the first acrylic polymer. By constituting the first acrylic polymer with such a relatively high molecular weight polymer, it becomes possible to form a three-dimensional network structure by cross-linking, and a strong adhesive force after a predetermined time has elapsed after being attached to the adherend. Contributes to grant. The weight average molecular weight of the first acrylic polymer is preferably 200,000 to 600,000, more preferably 300,000 to 500,000, and even more preferably 350,000 to 450,000. When the weight average molecular weight is less than 200,000, the cohesive force is too low and it is difficult to form a pressure-sensitive adhesive sheet. On the other hand, if it exceeds 600,000, the pressure-sensitive adhesive sheet becomes too hard and the adhesion to an adherend and the like is deteriorated.

  The first acrylic polymer is preferably a copolymer of an acrylic acid alkyl ester and a monomer having a reactive functional group. The first acrylic polymer may be used alone or in combination with other polymers.

  Examples of the alkyl acrylate ester include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, n-pentyl (meth) acrylate, (meth ) N-hexyl acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, n-decyl (meth) acrylate, n-dodecyl (meth) acrylate, (meth) ) Myristyl acrylate, palmityl (meth) acrylate, stearyl (meth) acrylate, and the like. These may be used alone or in combination of two or more.

  In addition, examples of the monomer having a reactive functional group include a hydroxyl group-containing monomer, a carboxyl group-containing monomer, and an amino group-containing monomer, and among them, a hydroxyl group-containing monomer is preferable. Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, (meth And (meth) acrylic acid hydroxyalkyl esters such as 3-hydroxybutyl acrylate and 4-hydroxybutyl (meth) acrylate. These may be used alone or in combination of two or more.

  As the second acrylic polymer, a relatively low molecular weight polymer having no reactive functional group is used. Since the second acrylic polymer does not have a reactive functional group, it is incorporated into a three-dimensional crosslinked structure formed by the first acrylic polymer via a crosslinking agent when added to the first acrylic polymer. In addition, since the second acrylic polymer has higher fluidity than the first acrylic polymer, it is not uniformly dispersed in the first acrylic polymer at room temperature and normal pressure. It is thought that aggregates are formed (so-called unishima structure). Furthermore, since the second acrylic polymer is a polymer having a relatively low molecular weight, the single acrylic polymer does not have an adhesive force by itself. A pressure-sensitive adhesive (adhesive composition) formed by adding the second acrylic polymer having such characteristics to the first acrylic polymer is part of the bonding interface when bonded to the adherend. Is occupied by the second acrylic polymer aggregate, it is possible to inhibit the adhesion with the adherend and to exhibit a decrease in the adhesive strength within a certain time after the application. In addition, the second acrylic polymer is formed by the first acrylic polymer after a predetermined time has elapsed in the bonded state of the adhesive composition and the adherend, or when a pressure / heat treatment is applied. Disperses so as to enter the inside of the dimensionally crosslinked structure, and at the same time the effect of lowering the adhesive strength due to the presence of the second acrylic polymer at the sticking interface disappears, and the second acrylic polymer that has entered is used as a plasticizer By exhibiting the above effect, it is considered that adhesion with the adherend is promoted, and as a result, the adhesive strength with the adherend can be significantly increased.

  The addition amount of the second acrylic polymer is about 0.1 to 10 parts by mass with respect to 100 parts by mass of the first acrylic polymer, although it depends on the characteristics of the first acrylic polymer as the main agent. 0.3-5 parts by mass is more preferable, and 0.5-1 part by mass is particularly preferable.

  The weight average molecular weight of the second acrylic polymer is preferably 2000 to 9000, more preferably 2500 to 8500, and still more preferably 3000 to 8000. When the weight average molecular weight is less than 2000, the initial adhesive strength (adhesive strength until 20 minutes after pasting) when the adhesive sheet to be formed is attached to the adherend increases, There is a risk that it may be difficult to ensure reworkability at the initial stage of application to the body. On the other hand, if it exceeds 9000, the compatibility with the first acrylic polymer becomes poor, and it may be difficult to ensure a uniform mixed state with the first acrylic polymer.

  The viscosity of the second acrylic polymer is preferably 3000 to 25000 mPa · s, more preferably 4000 to 10000 mPa · s, and still more preferably 5000 to 8000 mPa · s.

  The second acrylic polymer is preferably a copolymer of an acrylic acid alkyl ester and a monomer having no reactive functional group. Examples of the alkyl acrylate ester include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, n-pentyl (meth) acrylate, (meth ) N-hexyl acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, n-decyl (meth) acrylate, n-dodecyl (meth) acrylate, (meth) ) Myristyl acrylate, palmityl (meth) acrylate, stearyl (meth) acrylate, and the like. These may be used alone or in combination of two or more.

  Moreover, as a monomer which does not have a reactive functional group, (meth) acrylic acid ester which has aliphatic rings, such as (meth) acrylic acid cyclohexyl, (meth) acrylic acid which has aliphatic rings, such as (meth) acrylic acid phenyl, Non-crosslinkable tertiary amino groups such as non-crosslinkable acrylamide such as acid ester, acrylamide and methacrylamide, N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate (Meth) acrylic acid ester, vinyl acetate, styrene and the like having These may be used alone or in combination of two or more.

  Moreover, in order to improve the durability of the pressure-sensitive adhesive sheet, the pressure-sensitive adhesive sheet may be configured to further contain a crosslinking agent. Examples of the crosslinking agent include an isocyanate crosslinking agent, an epoxy crosslinking agent, an aziridine crosslinking agent, and a metal chelate crosslinking agent. In addition, regarding these various crosslinking agents, one type may be used alone, or two or more types may be used in combination. Although the addition amount of a crosslinking agent is based also on the characteristic of the 1st acrylic polymer which is a main ingredient, it is about 0.1-5 mass parts with respect to 100 mass parts of weights of a 1st acrylic polymer, 0.3 -3 parts by mass is more preferable, and 0.5-2 parts by mass is particularly preferable.

  The pressure-sensitive adhesive sheet according to the present invention comprises a pressure-sensitive adhesive formed by mixing the first acrylic polymer and the second acrylic polymer (mixing a cross-linking agent as necessary) and stirring sufficiently. It can be produced by dissolving in a solvent and coating and then removing the solvent. The coating method can be appropriately selected from methods such as a knife coater, micro bar coater, air knife coater, reverse roll coater, reverse gravure coater, bario gravure coater, die coater, curtain coater and the like. Usually, the pressure-sensitive adhesive sheet is produced by disposing release sheets (release sheets) on both sides thereof. For example, a pressure-sensitive adhesive sheet is formed on a release sheet provided with a release agent layer on a substrate such as a polymer film. It is preferable that the pressure-sensitive adhesive sheet is formed by applying and drying the pressure-sensitive adhesive, and another release sheet is stacked on the pressure-sensitive adhesive sheet.

  In addition, as a base material of a peeling sheet, it can form using a conventionally well-known material as base material materials of a peeling sheet, such as a polyethylene film (PET), a polypropylene film (PP), a polybutene film, for example. Examples of the material for the release agent layer provided on the substrate include conventionally known release agents such as alkyd, silicone, fluorine, unsaturated polyester, polyolefin, and wax.

  Further, instead of disposing release sheets on both sides of the pressure-sensitive adhesive sheet, a transparent substrate with a pressure-sensitive adhesive sheet may be formed by attaching a transparent substrate constituting the protective film to one side of the pressure-sensitive adhesive sheet. In addition, in such a structure, it is preferable to arrange | position a peeling sheet in the other surface of an adhesive sheet. Moreover, as a transparent substrate, it is not limited to the said protective film, For example, a touch panel is employ | adopted as a transparent substrate, a touch panel may be affixed on the one side of an adhesive sheet, and a transparent substrate with an adhesive sheet may be comprised. .

  In addition, when the pressure-sensitive adhesive sheet according to the present invention is attached to an adherend such as the display surface of a liquid crystal display device, the initial adhesive force (A) is 180 degrees according to JIS Z 0237 (2000). It is 6.5N / 25mm or less as measured by peeling adhesive strength, and the adhesive strength (A) at the initial stage of application is small. For example, the attachment position of the adhesive sheet or the attachment position of the protective film with the adhesive sheet, etc. Even if it is out of alignment with the adherend such as a device, it is possible to easily re-peel (rework) the adhesive sheet (such as a protective film with an adhesive sheet) without damaging the adherend. It becomes.

  In addition, since the adhesive strength (B) after a predetermined time has elapsed after pasting is 1.5 times or more of the initial adhesive strength (A), an adhesive sheet (such as a protective film with an adhesive sheet) is adhered. After affixing to the substrate, when a predetermined time elapses, strong adhesiveness is exhibited, and it is possible to extremely effectively prevent the adhesive sheet from being easily peeled off from the adherend.

  In order to confirm the above-described effects of the pressure-sensitive adhesive sheet according to the present invention, the inventors created four types of pressure-sensitive adhesive sheet samples (Comparative Example 1, Examples 1 to 3) and attached them to adherends. A sensory evaluation test on reworkability in the initial stage was conducted. Moreover, the adhesive force measurement test which measures the adhesive force (A) of the initial stage of sticking to a to-be-adhered body, and the adhesive force (B) after progress for a predetermined time after sticking to a to-be-adhered body was done. Hereinafter, the sensory evaluation test, the adhesive strength measurement test, and the results of each test will be described.

  First, the four types of prepared adhesive sheet samples (Comparative Example 1, Examples 1 to 3) will be described. In all the adhesive sheet samples, as the first acrylic polymer as the main agent, model number: SK Dyne 1811L manufactured by Soken Chemical Co., Ltd. is used, and for the second acrylic polymer as the additive, for Comparative Example 1, The model number: UP-1110 manufactured by Toa Gosei Co., Ltd. was used, and the model number: UP-1110 was used for Example 1. For Example 2, the company model number: UP-1080 was used, and for Example 3, the company model number: UP-1171 was used. In addition, in the following Table 1, the physical property of the 2nd acrylic polymer used in the comparative example 1 and Examples 1-3 is shown. The viscosities shown in Table 1 below are the viscosities measured in accordance with JIS Z 8803-1991 (Liquid Viscosity-Measurement Method) for 100% active ingredient (without solvent) of the second acrylic polymer. Specifically, the viscosity was measured under a temperature condition of 25.0 ± 0.5 ° C. using an E-type viscometer using a low viscosity rotor.

  For the pressure-sensitive adhesive sheet sample, after preparing the first acrylic polymer liquid, 1.0 part by mass with respect to 100 parts by weight of the first acrylic polymer liquid (model number: L- manufactured by Soken Chemical Co., Ltd.) 45) is further mixed with each second acrylic polymer liquid diluted with ethyl acetate at 0.75 parts by mass with respect to 100 parts by weight of the first acrylic polymer liquid. ) To prepare various pressure-sensitive adhesive solutions, and then the above pressure-sensitive adhesive solution was applied onto a substrate film (used as a release sheet; made by Nipper, model number: PET38 × 1-V0). Thereafter, it was dried at 90 ° C. for 2 minutes in an oven (model number: DRD620DA manufactured by Advantech) to prepare four types of pressure-sensitive adhesive sheet samples. Each adhesive sheet sample has a thickness (after drying) of 100 μm. Next, a release sheet (manufactured by Toyobo Co., Ltd., model number: E7006-38 μm) was bonded onto the exposed surface of each pressure-sensitive adhesive sheet sample, and an aging treatment was performed for 3 days in a 40 ° C. environment.

  Next, the content of the sensory evaluation test regarding reworkability at the initial stage of application to the adherend will be described. First, for the bonding surface (PET film surface) of the pseudo touch panel (10 cm × 12 cm, PET film (thickness 250 μm) / adhesion layer (thickness 75 μm) / PET film (thickness 250 μm)) The base film is removed from the prepared adhesive sheet sample and bonded to the entire surface. Next, after removing the release sheet from the polarizing surface of a pseudo liquid crystal display (LCD) formed by bonding a polarizing plate (model number: AQW252A manufactured by Sumitomo Chemical Co., Ltd.) to a 0.7 mm thick glass plate The pseudo touch panel with an adhesive sheet was bonded with a hand roller. After 20 minutes from pasting, the touch panel could be easily peeled without cracking, and when it was peeled off, it was visually observed whether there was adhesive residue or dirt on the polarizing surface of the pseudo LCD.

  Next, the adhesive strength measurement test contents for measuring the adhesive strength (A) at the time when 20 minutes have elapsed after being attached to the adherend and the adhesive strength (B) after the predetermined time has elapsed after being attached to the adherend. explain. First, for each prepared adhesive sheet sample, two pieces cut to a width of 25 mm are prepared, and for each, the base film is removed and a hand roller is used for the PET film for evaluation of the adhesive (thickness 25 μm). And paste. Thereafter, the release sheet was removed from the produced PET film with an adhesive sheet, and the adherend (polarized light of a pseudo LCD in which a polarizing plate (manufactured by Sumitomo Chemical Co., Ltd., model number: AQW252A) was bonded to a 1.1 mm-thick element glass plate) Surface) using a 2 kg rubber roll, and left for 20 minutes, and one of the two is used as a sample for measuring the adhesive strength (A) when 20 minutes have elapsed after being pasted. The remaining one is subjected to a pressurizing / heating treatment (autoclave treatment) for 20 minutes under the conditions of a temperature of 60 ° C. and a pressure of 0.5 MPa to obtain a sample for measuring adhesive force (B). In addition, when measuring the adhesive strength, the adhesive strength when peeling the PET film with the adhesive sheet from the polarizing surface (polarizing plate) of the pseudo LCD is measured in accordance with the 180 degree peeling adhesive strength measuring method of JIS Z 0237 (2000). did.

  Table 2 shows the results of the sensory evaluation test and the adhesive strength measurement test. In addition, in the “rework feeling” column of the reworkability in Table 2, the case where peeling is easily performed is indicated as “◯”, and the case where peeling is not easy is indicated as “X”. Similarly, in the “glue residue” column, a case where there is no glue residue or dirt is indicated as “◯”, and a case where there is glue residue or dirt is indicated as “X”.

  From Table 2 above, for Example 1 in which the weight average molecular weight of the second acrylic polymer is 2500, Example 2 in which the weight is 6000, and Example 3 in which the weight is 8000, 20 minutes have elapsed after being attached to the adherend. The adhesive strength (A) at the time is 5.1 N / 25 mm, 6.2 N / 25 mm, and 5 N / 25 mm, respectively, and all are 6.5 N / 25 mm or less. Moreover, about these, the rework feeling of rework property evaluation is favorable, and adhesive residue and stain | pollution | contamination have not generate | occur | produced, and it turns out that it is excellent in the rework property in the initial stage of sticking to a to-be-adhered body. Since the pressure-sensitive adhesive sheets according to Examples 1 to 3 correspond to the pressure-sensitive adhesive sheet according to the present invention, according to the present invention, an adherend such as a liquid crystal display device (LCD) is damaged in the initial stage of application. It can be seen that the adhesive sheet can be easily and neatly peeled (reworked).

  On the other hand, in Comparative Example 1, the adhesive force (A) at the time when 20 minutes had elapsed after being attached to the adherend was as high as 8.3 N / 25 mm, and the reworkability was poor. In Comparative Example 1, the weight average molecular weight of the second acrylic polymer is 1600, and the weight average molecular weight is 2500. In Example 1, since the reworkability is good, the weight average molecular weight is 1600 to 2500. It can be considered that there is a quality boundary regarding reworkability in the range, and the numerical value is considered to be about 2000. In Comparative Example 1 having poor reworkability, the viscosity of the second acrylic polymer is 550 mPa · s, and in Example 1 having excellent reworkability, the viscosity is 3500 mPa · s. Therefore, the viscosity is 550 to 3500 mPa · s. -It can be considered that there is a good / bad boundary regarding the reworkability of the viscosity in the range of s, and the numerical value is considered to be about 3000 mPa · s.

  Moreover, about 20 minutes after sticking to a to-be-adhered body, Example 1 is 9.2N / 25mm about Example 1 about the adhesive force (B) after performing pressurization and heat processing for 20 minutes. 2 is 9.3 N / 25 mm, and Example 3 is 8.1 N / 25 mm. Both have an adhesive strength of 8 N / 25 mm or more, and a protective film or touch panel is provided on the surface of a liquid crystal display (LCD) or the like. It can be seen that after sticking, after a predetermined time has elapsed, it exhibits strong adhesiveness that does not easily peel off.

  Moreover, as for Examples 1-3, all are the adhesive force (A) at the time of 20-minute progress after sticking to a to-be-adhered body, and the adhesive force (B) after performing a pressurization and heat processing for 20 minutes after that. It can be seen that the ratio (B / A) to 1.5) or more is secured. Also from this, in Examples 1 to 3 according to the present invention, the adhesive strength at the time when 20 minutes have elapsed after pasting to the adherend is greatly increased after the lapse of a predetermined time, and the strong adhesiveness is increased with the passage of time. You can see that it is demonstrating. In Comparative Example 1, the adhesive strength (B) is 9.6 N / 25 mm, and the ratio of adhesive strength: B / A is 1.2. The adhesive strength is so large when a predetermined time has elapsed after pasting. There is no increase.

  From the above sensory evaluation test and adhesive strength measurement test results, in Examples 1 to 3 according to the present invention, in the initial stage of application to the adherend, the adhesive strength is low enough to allow rework. On the other hand, it can be seen that it has a very excellent characteristic that it exhibits strong adhesiveness at a stage after a predetermined time has elapsed after sticking and can be prevented from peeling off from the adherend.

  Here, in the adhesive strength measurement test, a sample for measuring the adhesive strength (B) is subjected to a pressurization / heating treatment (autoclave treatment) for 20 minutes under the conditions of a temperature of 60 ° C. and a pressure of 0.5 MPa. For the sample for measuring the adhesive force (B) prepared by pasting a PET film with an adhesive sheet on the adherend without applying such pressure and heat treatment, the sample was allowed to stand for 24 hours. It was confirmed that the adhesive strength (B) equivalent to the result shown in FIG.

The pressure-sensitive adhesive of the present invention is excellent in reworkability and adhesiveness particularly when film members are bonded to each other, such as when a protective film or a touch panel is bonded to the surface of a polarizing plate of a liquid crystal display (LCD). It can be used when a film member is used as a glass substitute for thinning a display device or the like.

Claims (4)

A pressure-sensitive adhesive sheet containing a first acrylic polymer having a reactive functional group and a second acrylic polymer not having the reactive functional group,
The reactive functional group is a functional group selected from a hydroxyl group, a carboxyl group, or an amino group,
The weight average molecular weight of the first acrylic polymer is 200,000 to 600,000,
The weight average molecular weight of the second acrylic polymer is 2000 to 9000,
The second acrylic polymer is contained in an amount of 0.75 to 10 parts by mass with respect to 100 parts by mass of the first acrylic polymer.
Adhesive strength at the time of 20 minutes after pasting to the polarizing plate is a peel strength measurement method of 180 degrees according to JIS Z 0237 (2000), and is 5 N / 25 mm or more and 6.5 N / 25 mm or less,
After 20 minutes from pasting to the polarizing plate, the adhesive strength after 20 minutes of pressurizing and heating treatment under the conditions of a temperature of 60 ° C. and a pressure of 0.5 MPa conforms to JIS Z 0237 (2000). A pressure-sensitive adhesive sheet of 8.0 N / 25 mm or more as measured by a 180-degree peeling adhesive force measurement method.   The pressure-sensitive adhesive sheet according to claim 1, wherein the viscosity of the second acrylic polymer is 3000 to 25000 mPa · s.   A transparent substrate with an adhesive sheet comprising the adhesive sheet according to claim 1 and a transparent substrate provided on at least one surface of the adhesive sheet. The transparent substrate with an adhesive sheet according to claim 3, wherein the transparent substrate is a touch panel.