JP2020200481A - Joint/separation method for adherend - Google Patents

Abstract

To provide a joint/separation method for an adherend capable of easily separate an adherend by applying low voltage (lower than 20 V).SOLUTION: A joint/separation method for an adherend includes: after jointing, with an adherend, a pressure sensitive adhesive sheet including at least an adhesive layer containing an electrolyte, applying voltage of less than 20 V to the adhesive layer so that electric potential difference is caused in a thickness direction of the adhesive layer; and then separating the adherend. The adhesive layer containing the electrolyte is preferably 1-1000 μm thick. The application of the voltage is preferably within 60 seconds. The electrolyte is preferably ionic liquid.SELECTED DRAWING: Figure 1

Description

The present invention relates to a technique for joining adherends with an adhesive sheet and a technique for separating the adherends.

In recent years, adhesive sheets have been used to join members in various technical fields. The pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet used for joining members is required to exert a certain adhesive force with respect to the member to be adhered.

On the other hand, for example, in the manufacture of electronic parts and electronic devices, rework for improving the yield of manufactured parts and devices, and recycling for disassembling once manufactured parts and devices and collecting the components thereof. There is a request. Under such demands, for example, when an adhesive sheet (particularly, a double-sided adhesive sheet) is used to join members in the manufacturing process of electronic parts and electronic devices, the adhesive sheet is used in manufacturing parts and devices. It is required that the adhesive force of the adhesive layer to the member to be adhered can be intentionally reduced so that the joining members can be separated for rework or recycling. Examples of the pressure-sensitive adhesive sheet configured to be able to intentionally reduce the adhesive strength of the pressure-sensitive adhesive layer include a heat-release type pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer whose adhesive strength decreases when heated, and adhesion when a voltage is applied. An electro-peelable pressure-sensitive adhesive sheet having a pressure-reducing pressure-sensitive adhesive layer is known.

Conventionally, in order to separate members joined by an electro-peelable pressure-sensitive adhesive sheet, first, a predetermined voltage according to the composition and thickness of the electro-peeling pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet is applied to the pressure-sensitive adhesive layer. It is applied. Then, after the voltage application is stopped, the members are separated from each other. For example, Patent Document 1 and Patent Document 2 below describe techniques relating to an electrically peelable double-sided pressure-sensitive adhesive sheet for carrying out such a separation operation between joint members.

Further, conventionally, as a method of separating an adherend by reducing an adhesive force after bonding by a method other than applying a voltage using the electro-peelable pressure-sensitive adhesive sheet, heat separation, ultraviolet irradiation separation, and the like are known.

Japanese Unexamined Patent Publication No. 2010-0373555 Japanese Unexamined Patent Publication No. 2014-189671

However, in the case of the method by heat separation, there are restrictions such as not being able to heat before separation, and in the case of the method by ultraviolet irradiation separation, the adherend and the adhesive sheet must be transparent so that ultraviolet rays can be irradiated. In addition, large-scale equipment such as a heating device and an ultraviolet irradiation device is required. Further, in the case of the separation method by applying a voltage such as Patent Document 1 and Patent Document 2, it is necessary to apply a high voltage of 100 V or more for a long time, the influence on the adherend is large, and the operator performs the separation work. There is a risk of electric shock and injury.

Therefore, an object of the present invention is to provide a method for joining and separating adherends, which can easily separate adherends by applying a low voltage (less than 20 V).

As a result of diligent studies to solve the above problems, the present inventors have found that an adherend can be separated even when a low voltage is applied by using an adhesive sheet containing at least an adhesive layer containing an electrolyte. It was. The present invention has been completed based on these findings.

That is, in the present invention, after a pressure-sensitive adhesive sheet containing at least a pressure-sensitive adhesive layer containing an electrolyte is bonded to an adherend, the pressure of the pressure-sensitive adhesive layer is less than 20 V so as to generate a potential difference in the thickness direction of the pressure-sensitive adhesive layer. Provided is a method for joining / separating adherends by applying a voltage to separate the adherends.

Further, the present invention relates to a pressure-sensitive adhesive sheet containing at least a pressure-sensitive adhesive layer containing an electrolyte.
After joining one surface of the pressure-sensitive adhesive layer to the first conductive adherend and joining the other surface of the pressure-sensitive adhesive layer to the second conductive adherend,
By applying a voltage of less than 20 V to the pressure-sensitive adhesive layer via the first conductive adherend and the second conductive adherend,
Provided is a method for joining / separating an adherend, which separates the first conductive adherend and the second conductive adherend from the pressure-sensitive adhesive layer.

Further, the present invention is located between the pressure-sensitive adhesive layer containing an electrolyte, the pressure-sensitive adhesive layer not containing an electrolyte, and the pressure-sensitive adhesive layer containing the electrolyte and the pressure-sensitive adhesive layer not containing the electrolyte. In an adhesive sheet having a laminated structure including a conductive layer to be bonded to an adhesive layer containing an electrolyte,
After joining the pressure-sensitive adhesive layer containing the electrolyte and the conductive adherend, and sticking the pressure-sensitive adhesive layer not containing the electrolyte with another adherend,
By applying a voltage of less than 20 V to the pressure-sensitive adhesive layer containing the electrolyte via the conductive layer and the conductive adherend.
Provided is a method for joining / separating an adherend, which separates the conductive adherend and the other adherend from the pressure-sensitive adhesive layer containing the electrolyte.

Further, the present invention includes a first pressure-sensitive adhesive layer that does not contain an electrolyte, a pressure-sensitive adhesive layer that contains an electrolyte, a second pressure-sensitive adhesive layer that does not contain an electrolyte, and a first pressure-sensitive adhesive layer that does not contain the electrolyte. A first conductive layer that is located between the pressure-sensitive adhesive layer containing the electrolyte and is bonded to the pressure-sensitive adhesive layer containing the electrolyte, and contains a second pressure-sensitive adhesive layer that does not contain the electrolyte and the electrolyte. In a pressure-sensitive adhesive sheet having a laminated structure including a second conductive layer to be bonded to the pressure-sensitive adhesive layer containing the electrolyte, which is located between the pressure-sensitive adhesive layer.
After the first pressure-sensitive adhesive layer and the first adherend that do not contain the electrolyte are attached, and the second pressure-sensitive adhesive layer that does not contain the electrolyte and the second adherend are attached.
By applying a voltage of less than 20 V to the pressure-sensitive adhesive layer containing the electrolyte via the first conductive layer and the second conductive layer.
Provided is a method for joining / separating an adherend, which separates the first adherend and the second adherend from the pressure-sensitive adhesive layer containing the electrolyte.

Further, in the present invention, the pressure-sensitive adhesive layer containing the electrolyte preferably has a thickness of 1 μm or more and 1000 μm or less.

Further, in the present invention, the application time of the voltage is preferably 60 seconds or less.

Further, in the present invention, the electrolyte is preferably an ionic liquid.

Further, in the present invention, the anions of the ionic liquid are (FSO ₂ ) ₂ N ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (CF ₃ CF ₂ SO ₂ ) ₂ N ⁻ , (CF ₃ SO ₂ ) ₃ C ⁻ , CH ₃ COO ⁻ , CF ₃ COO ⁻ , CF ₃ CF ₂ CF ₂ COO ⁻ _, CF ₃ SO ₃ ⁻ , CF ₃ (CF ₂ ) ₃ SO ₃ ⁻ , Br ⁻ , AlCl ₄ ⁻ , Al ₂ Cl ₇ ^At least one anion selected from the group consisting of ⁻ , NO ₃ ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , AsF ₆ ⁻ , SbF ₆ ⁻ , and F (HF) _n ⁻ (n represents an integer greater than or equal to 1). Is preferable.

Further, in the present invention, the ionic liquid cation is preferably at least one cation selected from the group consisting of an imidazolium-based cation, a pyridinium-based cation, a pyrrolidinium-based cation, and an ammonium-based cation.

Further, in the present invention, the molecular weight of the cation of the ionic liquid is preferably 200 or less.

Further, the present invention contains a polymer as a pressure-sensitive adhesive composition for forming the pressure-sensitive adhesive layer containing the electrolyte, and the content of the ionic liquid is 0.5 mass by mass with respect to 100 parts by weight of the polymer. It is preferably 10 parts or more and 30 parts by mass or less.

The method for joining and separating adherends of the present invention can easily separate adherends by applying a voltage for a short time even at a low voltage (less than 20 V). Further, since the adherend joining / separating method of the present invention can separate the adherend by applying a low voltage, a dry battery or the like can be used without the need for large-scale equipment such as a heating device and an ultraviolet irradiation device. With the simple device used, workability is good and separation work can be performed.

It is sectional drawing which shows the example of the 1st aspect of this invention. It is sectional drawing which shows the example of the 2nd aspect of this invention. It is sectional drawing which shows the example of the 3rd aspect of this invention. It is sectional drawing which shows the outline of the method of 180 ° peel test in an Example.

[How to join / separate adherends]
In the method for joining and separating adherends of the present invention (sometimes referred to as "the present invention"), at least one pressure-sensitive adhesive layer containing an electrolyte (hereinafter, sometimes referred to as "electrolyte-containing pressure-sensitive adhesive layer") is used. This is a method in which a pressure-sensitive adhesive sheet containing a layer is bonded to an adherend, and then a voltage of less than 20 V is applied so as to generate a potential difference in the thickness direction of the pressure-sensitive adhesive layer to separate the adherend.

In the present invention, "bonding (bonding method)" means joining the electrolyte-containing pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet and the adherend, and "separation (separation method)" means the electrolyte-containing pressure-sensitive adhesive of the pressure-sensitive adhesive sheet. It means separating the adherend from the layer. In the present invention, the "joining / separating method" may be only "joining (joining method)" or only "separation (separation method)", and is a general term for these (joining method and separation method). Both) means. In the present invention, "joining" and "separation" are not limited to one time, but may be repeated many times. Further, in the present invention, a material in which the pressure-sensitive adhesive sheet and at least one adherend are bonded via an electrolyte-containing pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet is referred to as an "adhesive sheet-bonded body".

In the present invention, the pressure-sensitive adhesive sheet may include at least one electrolyte-containing pressure-sensitive adhesive layer as the pressure-sensitive adhesive layer, and the pressure-sensitive adhesive layer containing no electrolyte (hereinafter referred to as "electrolyte-free pressure-sensitive adhesive layer"). May have. In the present invention, the pressure-sensitive adhesive sheet may be a double-sided pressure-sensitive adhesive sheet having adhesive surfaces on both sides, or a single-sided pressure-sensitive adhesive sheet having an adhesive surface on only one side. Further, the pressure-sensitive adhesive sheet may have a base material, a conductive layer, a base material for energization, and the like in addition to the electrolyte-containing pressure-sensitive adhesive layer and the electrolyte-free pressure-sensitive adhesive layer. In the present invention, the adherend in the pressure-sensitive adhesive sheet joint may be a conductive adherend that conducts electricity or a non-conductive adherend that does not conduct electricity. Details of the pressure-sensitive adhesive sheet and the pressure-sensitive adhesive sheet joint will be described later. The present invention mainly has the following first aspect, second aspect, and third aspect, and each aspect will be described in detail below.

The first aspect of the present invention is that in a pressure-sensitive adhesive sheet containing at least an electrolyte-containing pressure-sensitive adhesive layer, one surface of the electrolyte-containing pressure-sensitive adhesive layer is bonded to the first conductive adherend, and the electrolyte-containing pressure-sensitive adhesive is bonded. After joining the other surface of the agent layer and the second conductive adherend, 20 V is applied to the electrolyte-containing pressure-sensitive adhesive layer via the first conductive adherend and the second conductive adherend. This is a method of separating the first conductive adherend and the second conductive adherend from the electrolyte-containing pressure-sensitive adhesive layer by applying a voltage of less than. The first conductive adherend and the second conductive adherend may be the same or different, and are the conductive adherends described later.

As a separation method in the case of the first side surface, for example, the first conductive adherend and the second conductive adherend are energized, and the first conductive adherend and the second conductive adherend are energized. By applying a voltage through the conductor, a potential difference is generated in the thickness direction of the electrolyte-containing pressure-sensitive adhesive layer, and the first conductive adherend and the second conductive adherend are separated from the electrolyte-containing pressure-sensitive adhesive layer. There is a way to do it. Further, as a joining method in the case of the first side surface, for example, a method of joining the electrolyte-containing pressure-sensitive adhesive layer and the first conductive adherend, and / or a method of joining the electrolyte-containing pressure-sensitive adhesive layer and the second Examples thereof include a method of joining with an adherend. The first conductive adherend and the second conductive adherend separated by the separation method can be joined by the joining method and then separated again by the separation method. The first aspect of the present invention is particularly preferably used when joining and separating two conductive adherends to each other.

FIG. 1 is a cross-sectional configuration diagram showing an example of an pressure-sensitive adhesive sheet joint according to the first side surface of the present invention. The pressure-sensitive adhesive sheet X1 shown in FIG. 1 is a double-sided pressure-sensitive adhesive sheet composed of only the electrolyte-containing pressure-sensitive adhesive layer 11, and the pressure-sensitive adhesive sheet joint is a first conductive adherend Y1 / electrolyte-containing pressure-sensitive adhesive layer 11 / second conductive. It has a laminated structure of the adherend Y2. In this case, the separation method is as follows: the α portion of the first conductive adherend Y1 and the β portion of the second conductive adherend Y2 in FIG. 1 are energized to energize the first conductive adherend Y1 and the second conductive adherend Y1. By applying a voltage through the sex adherent Y2, a potential difference is generated in the thickness direction of the electrolyte-containing pressure-sensitive adhesive layer 11, and the first conductive coating is formed from the pressure-sensitive adhesive sheet X1 (electrolyte-containing pressure-sensitive adhesive layer 11). This is a method of separating the body Y1 and the second conductive adherend Y2. Further, the joining method in this case is a method of joining one surface of the electrolyte-containing pressure-sensitive adhesive layer 11 and the first conductive adherend Y1 and / or a method of joining the other surface of the electrolyte-containing pressure-sensitive adhesive layer 11 and the first. 2 This is a method of joining the conductive adherend Y2.

The second aspect of the present invention is located between the electrolyte-containing pressure-sensitive adhesive layer, the electrolyte-free pressure-sensitive adhesive layer, and the electrolyte-containing pressure-sensitive adhesive layer and the electrolyte-free pressure-sensitive adhesive layer, and the electrolyte-containing pressure-sensitive adhesive. In a pressure-sensitive adhesive sheet having a laminated structure including a conductive layer to be bonded to an agent layer, the electrolyte-containing pressure-sensitive adhesive layer and a conductive adherend are bonded, and the electrolyte-free pressure-sensitive adhesive layer and another adherend are used. By applying a voltage of less than 20 V to the electrolyte-containing pressure-sensitive adhesive layer via the conductive layer and the conductive adherend, the conductive adherence is performed from the electrolyte-containing pressure-sensitive adhesive layer. This is a method of separating the body from the other adherend.

As a separation method in the case of the second side surface, for example, by energizing the conductive adherend and the conductive layer and applying a voltage to the conductive adherend and the conductive layer, the electrolyte-containing adhesive Examples thereof include a method in which a potential difference is generated in the thickness direction of the agent layer to separate the conductive adherend from the electrolyte-containing pressure-sensitive adhesive layer and another adherend containing the conductive layer. Examples of the bonding method in the case of the second side surface include a method of bonding the electrolyte-containing pressure-sensitive adhesive layer and the conductive adherend, and / or another adhesion including the electrolyte-containing pressure-sensitive adhesive layer and the conductive layer. Examples thereof include a method of joining the conductive layer of the body. When the other adherend containing the conductive layer is separated from the electrolyte-containing pressure-sensitive adhesive layer, the separation occurs at the interface between the electrolyte-containing pressure-sensitive adhesive layer and the conductive layer in contact with the electrolyte-containing pressure-sensitive adhesive layer. Thereby, other adherends including the conductive layer can be separated from the electrolyte-containing pressure-sensitive adhesive layer. It is also possible to join the conductive adherend separated by the above separation method and another adherend containing the conductive layer by the above joining method, and then separate again by the above separation method. In the second aspect of the present invention, the other adherend is preferably an adherend having no conductivity (non-conductive adherend). The second aspect of the present invention is preferably used when joining and separating a conductive adherend and a non-conductive adherend (non-conductive adherend).

FIG. 2 is a cross-sectional configuration diagram showing an example of an pressure-sensitive adhesive sheet joint according to a second side surface of the present invention. The pressure-sensitive adhesive sheet X2 shown in FIG. 2 is a double-sided pressure-sensitive adhesive sheet having a layer structure of an electrolyte-free pressure-sensitive adhesive layer 21 / base material 31 / conductive layer 32 / electrolyte-containing pressure-sensitive adhesive layer 12, and the pressure-sensitive adhesive sheet joint is the pressure-sensitive adhesive. A non-conductive adherend having a non-conductive adherend Y3 on one surface of the electrolyte-free pressure-sensitive adhesive layer 21 of the sheet and a conductive adherend Y4 on one surface of the electrolyte-containing pressure-sensitive adhesive layer 12. It has a laminated structure of body Y3 / electrolyte-free pressure-sensitive adhesive layer 21 / base material 31 / conductive layer 32 / electrolyte-containing pressure-sensitive adhesive layer 12 / conductive adherend Y4. In this case, the separation method is to energize the α portion of the conductive layer 32 and the β portion of the conductive adherend Y4 in FIG. 2 and apply a voltage via the conductive layer 32 and the conductive adherend Y4. This is a method of causing a potential difference in the thickness direction of the electrolyte-containing pressure-sensitive adhesive layer 12 to separate the non-conductive adherend Y4 and the conductive adherend Y3 from the electrolyte-containing pressure-sensitive adhesive layer 12. Further, the joining method in this case is a method of joining the electrolyte-containing pressure-sensitive adhesive layer 12 and the first conductive adherend Y4, and / or the electrolyte-containing pressure-sensitive adhesive layer 12 and the conductive adherend Y3 side (non-). This is a method of joining the conductive layer 32 in the conductive adherend Y3 / electrolyte-free pressure-sensitive adhesive layer 21 / base material 31 / conductive layer 32). When the separation occurs on the conductive adherend Y3 side, the separation occurs at the interface between the conductive layer 32 and the electrolyte-containing adhesive layer 12. As a result, the electrolyte-containing pressure-sensitive adhesive layer 12 and the conductive adherend Y3 side can be separated. In FIG. 2, the base material 31 and the conductive layer 32 are an integrated current-carrying base material 30.

A third aspect of the present invention is a first electrolyte-free pressure-sensitive adhesive layer, an electrolyte-containing pressure-sensitive adhesive layer, a second electrolyte-free pressure-sensitive adhesive layer, and the first electrolyte-free pressure-sensitive adhesive layer and the electrolyte. It is located between the electrolyte-containing pressure-sensitive adhesive layer and the first conductive layer to be bonded to the electrolyte-containing pressure-sensitive adhesive layer, and between the second electrolyte-free pressure-sensitive adhesive layer and the electrolyte-containing pressure-sensitive adhesive layer. Then, in the pressure-sensitive adhesive sheet having a laminated structure including the second conductive layer to be bonded to the electrolyte-containing pressure-sensitive adhesive layer, the first electrolyte-free pressure-sensitive adhesive layer and the first adherend are attached and bonded. After the second electrolyte-free pressure-sensitive adhesive layer and the second adherend are attached, a voltage of less than 20 V is applied to the electrolyte-containing pressure-sensitive adhesive layer via the first conductive layer and the second conductive layer. Is a method for separating the first adherend and the second adherend from the electrolyte-containing pressure-sensitive adhesive layer. The first electrolyte-free pressure-sensitive adhesive layer and the second electrolyte-free pressure-sensitive adhesive layer may be the same or different, and are electrolyte-free pressure-sensitive adhesive layers. Further, the first conductive layer and the second conductive layer may be the same or different, and are the conductive layers described later. Further, the first adherend and the second adherend may be the same or different, and are the adherends described later.

As a method for separating the third side surface, for example, by energizing the first conductive layer and the second conductive layer and applying a voltage to the first conductive layer and the second conductive layer, the electrolyte-containing adhesive is adhered. A method of causing a potential difference in the thickness direction of the agent layer to separate the first adherend containing the first conductive layer and the second adherend containing the second conductive layer from the electrolyte-containing pressure-sensitive adhesive layer. Can be mentioned. As a method of joining the third side surface, for example, a method of joining the electrolyte-containing pressure-sensitive adhesive layer and the first conductive layer surface of the first adherend including the first conductive layer, and / or with the electrolyte-containing pressure-sensitive adhesive layer. Examples thereof include a method of joining the second conductive layer surface of the second adherend including the second conductive layer. When separation occurs between the first adherend and the electrolyte-containing pressure-sensitive adhesive layer, separation occurs at the interface between the electrolyte-containing pressure-sensitive adhesive layer and the first conductive layer in contact with the electrolyte-containing pressure-sensitive adhesive layer. When the second adherend and the electrolyte-containing pressure-sensitive adhesive layer are separated from each other, the separation occurs at the interface between the electrolyte-containing pressure-sensitive adhesive layer and the second conductive layer in contact with the electrolyte-containing pressure-sensitive adhesive layer. Thereby, the first adherend including the first conductive layer and the second adherend including the second conductive layer can be separated from the electrolyte-containing pressure-sensitive adhesive layer. The first adherend containing the first conductive layer and the second adherend containing the second conductive layer separated by the separation method can be joined by the joining method and then separated again by the separation method. In the third aspect of the present invention, the first adherend and the second adherend are preferably adherends having no conductivity (non-conductive adherends), and the present invention preferably The third side surface is preferably used when joining / separating non-conductive adherends to each other.

FIG. 3 is a cross-sectional configuration diagram showing an example of an adhesive sheet bonded body according to a third side surface of the present invention. The pressure-sensitive adhesive sheet X3 shown in FIG. 3 has a layer structure of an electrolyte-free pressure-sensitive adhesive layer 23 / base material 51 / conductive layer 52 / electrolyte-containing pressure-sensitive adhesive layer 13 / conductive layer 42 / base material 41 / electrolyte-free pressure-sensitive adhesive layer 22. It is a double-sided adhesive sheet having. The pressure-sensitive adhesive sheet joint has the non-conductive adherend Y5 on one surface of the electrolyte-free pressure-sensitive adhesive layer 23 of the pressure-sensitive adhesive sheet, and the non-conductive adherend on one surface of the electrolyte-free pressure-sensitive adhesive layer 22. Non-conductive adherend Y5 having body Y6 / electrolyte-free pressure-sensitive adhesive layer 23 / base material 51 / conductive layer 52 / electrolyte-containing pressure-sensitive adhesive layer 13 / conductive layer 42 / base material 41 / electrolyte-free pressure-sensitive adhesive layer 22 / Has a laminated structure of the non-conductive adherend Y6. In this case, the separation method is as follows: an electrolyte-containing pressure-sensitive adhesive layer is formed by energizing the α portion of the conductive layer 52 and the β portion of the conductive layer 42 in FIG. 3 and applying a voltage through the conductive layer 52 and the conductive layer 42. This is a method of separating the non-conductive adherend Y5 and the non-conductive adherend Y6 from the electrolyte-containing pressure-sensitive adhesive layer 13 by causing a potential difference in the thickness direction of 13. Further, the bonding method in this case is the conductivity between the electrolyte-containing pressure-sensitive adhesive layer 13 and the conductive adherend Y5 side (non-conductive adherend Y5 / electrolyte-free pressure-sensitive adhesive layer 23 / base material 51 / conductive layer 52). A method of joining the layer 52 and / or the electrolyte-containing pressure-sensitive adhesive layer 13 and the conductive adherend Y6 side (non-conductive adherend Y6 / electrolyte-free pressure-sensitive adhesive layer 41 / base material 41 / conductive layer 42). ) Is a method of joining with the conductive layer 42. When separation occurs on the conductive adherend Y5 side, separation occurs at the interface between the conductive layer 52 and the electrolyte-containing adhesive layer 13, and when separation occurs on the conductive adherend Y6 side, separation occurs between the conductive layer 42 and the electrolyte. Separation occurs at the interface of the containing pressure-sensitive adhesive layer 13. As a result, the conductive adherend Y5 side and the conductive adherend Y4 side can be separated from the electrolyte-containing pressure-sensitive adhesive layer 13. In FIG. 3, the base material 51 and the conductive layer 52 are an integrated current-carrying base material 50, and the base material 41 and the conductive layer 42 are an integrated current-carrying base material 40.

In the present invention including the first side surface, the second side surface, and the third side surface, as described above, the voltage is applied so that a potential difference occurs in the thickness direction of the electrolyte-containing pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet (double-sided pressure-sensitive adhesive sheet). It is applied. Due to the application of this voltage, the electrolyte in the electrolyte-containing pressure-sensitive adhesive layer changes its orientation and the electrolyte substance moves in the thickness direction of the layer, and the surface composition of the electrolyte-containing pressure-sensitive adhesive layer changes. Adhesive strength to the adherend is reduced. Therefore, the longer the voltage is applied, the lower the adhesive strength of the electrolyte-containing pressure-sensitive adhesive layer, the higher the peelability of the electrolyte-containing pressure-sensitive adhesive layer, and the bonded adherend becomes the electrolyte-containing pressure-sensitive adhesive. Separated from the layer. Further, since the surface composition of the electrolyte-containing pressure-sensitive adhesive layer returns to the original state after a certain period of time (for example, 30 seconds later) after the voltage application is stopped, the separated adherends can be rejoined. In the present invention, the adherend can be easily separated by applying a low voltage (less than 20 V), and the joining / separating work can be performed even with a simple device such as using a dry battery, and the workability is good.

In the present invention, the applied voltage to the electrolyte-containing pressure-sensitive adhesive layer is less than 20V, but the upper limit of the voltage is preferably 16V, more preferably 13V, still more preferably 10V, and the lower limit is preferably 2V, more preferably. Is 4V, more preferably 6V. Since the voltage is less than 20 V, the separation work can be performed with a device using an easily available device such as a dry cell as a power source for the voltage application device. The time for applying the voltage to the electrolyte-containing pressure-sensitive adhesive layer varies depending on the electrolyte used, but is preferably 60 seconds or less, more preferably 40 seconds or less, and further preferably 20 seconds or less. When the voltage application time is 60 seconds or less, the separation work can be efficiently performed.

(Adhesive sheet joint)
In the pressure-sensitive adhesive sheet bonded body, the pressure-sensitive adhesive sheet and at least one adherend are bonded to each other via an electrolyte-containing pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet. Examples of the pressure-sensitive adhesive sheet joint include a first conductive adherend / electrolyte-containing pressure-sensitive adhesive layer / second conductive adherend (for example, the pressure-sensitive adhesive sheet joint shown in FIG. 1), and a non-conductive adherend / electrolyte. Non-containing adhesive layer / base material / conductive layer / electrolyte-containing pressure-sensitive adhesive layer / conductive adherend (for example, pressure-sensitive adhesive sheet joint shown in FIG. 2), non-conductive adherend / electrolyte-free pressure-sensitive adhesive layer / A bonded body having a laminated structure of a base material / conductive layer / electrolyte-containing pressure-sensitive adhesive layer / conductive layer / base material / electrolyte-free pressure-sensitive adhesive layer / non-conductive adherend (for example, a pressure-sensitive adhesive sheet bonded body shown in FIG. 3). Is preferably mentioned.

Examples of the adherend include a conductive adherend that conducts electricity and a non-conductive adherend that does not conduct electricity. The conductive adherend is not particularly limited as long as it has conductivity, but is a sheet-shaped metal (for example, mainly composed of aluminum, copper, iron, tin, gold, silver, lead, etc.). , Board, etc. The non-conductive adherend is not particularly limited as long as it does not have conductivity, but is limited to paper, cloth, fiber sheets such as non-woven fabrics, and various plastics (polyolefin resins such as polyethylene and polypropylene, polyethylene). Examples include polyester-based resins such as terephthalate, acrylic resins such as polymethylmethacrylate) films and sheets, and laminates thereof. The thickness of the adherend is not particularly limited, but is preferably 0.1 mm or more and 100 mm or less, the upper limit of the thickness is more preferably 50 mm, further preferably 30 mm, and the lower limit of the thickness is more preferably. It is 0.3 mm, more preferably 1 mm.

The thickness of the pressure-sensitive adhesive sheet joint in the present invention is not particularly limited, but is preferably 0.1 mm or more and 300 mm or less, and the upper limit of the thickness is more preferably 200 mm, further preferably 100 mm, and particularly preferably. It is 50 mm, and the lower limit is more preferably 0.2 mm, further preferably 0.3 mm, and particularly preferably 0.5 mm.

(Adhesive sheet)
The pressure-sensitive adhesive sheet is not particularly limited as long as it has at least one electrolyte-containing pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition described later, and other than this, a base material, a conductive layer, a current-carrying base material, and an electrolyte-free pressure-sensitive adhesive. It may have a layer or the like. The electrolyte-free pressure-sensitive adhesive layer may be provided with only one layer or two or more layers. Further, an intermediate layer, an undercoat layer and the like may be provided as long as the effects of the present invention are not impaired. The pressure-sensitive adhesive sheet of the present invention may be, for example, rolled in a roll shape or in a sheet shape. The term "adhesive sheet" also includes the meaning of "adhesive tape". That is, the adhesive sheet of the present invention may be an adhesive tape having a tape-like form.

The pressure-sensitive adhesive sheet may be a double-sided pressure-sensitive adhesive sheet that does not contain a base material (base material-less), has a base material, and both sides of the sheet have an adhesive layer (electrolyte-containing pressure-sensitive adhesive layer or electrolyte-free pressure-sensitive adhesive). It may be a double-sided pressure-sensitive adhesive sheet (agent layer), and is a single-sided pressure-sensitive adhesive sheet having a base material and having only one side of the sheet is a pressure-sensitive adhesive layer (electrolyte-containing pressure-sensitive adhesive layer or electrolyte-free pressure-sensitive adhesive layer). There may be.

The pressure-sensitive adhesive sheet is not particularly limited, but is a pressure-sensitive adhesive sheet composed of only an electrolyte-containing pressure-sensitive adhesive layer, a pressure-sensitive adhesive sheet having a layer structure of an electrolyte-free pressure-sensitive adhesive layer / base material / conductive layer / electrolyte-containing pressure-sensitive adhesive layer, and a non-electrolyte. Examples thereof include a pressure-sensitive adhesive sheet having a layer structure of a contained pressure-sensitive adhesive layer / base material / conductive layer / electrolyte-containing pressure-sensitive adhesive layer / conductive layer / base material / electrolyte-free pressure-sensitive adhesive layer.

The thickness of the electrolyte-containing pressure-sensitive adhesive layer is not particularly limited, but is preferably 1 μm or more and 1000 μm or less from the viewpoint of adhesiveness when a non-voltage is applied (usually). The upper limit of the thickness is more preferably 500 μm, further preferably 100 μm, particularly preferably 30 μm, and the lower limit is more preferably 3 μm, further preferably 5 μm, and particularly preferably 8 μm. .. When the pressure-sensitive adhesive sheet is a base-less double-sided pressure-sensitive adhesive sheet composed of only one electrolyte-containing pressure-sensitive adhesive layer, the thickness of the electrolyte-containing pressure-sensitive adhesive layer is the thickness of the pressure-sensitive adhesive sheet.

The thickness of the electrolyte-free pressure-sensitive adhesive layer is not particularly limited, but is preferably 1 μm or more and 2000 μm or less from the viewpoint of adhesiveness. The upper limit of the thickness is more preferably 1000 μm, further preferably 500 μm, particularly preferably 100 μm, and the lower limit is more preferably 3 μm, further preferably 5 μm, and particularly preferably 8 μm. ..

The base material is not particularly limited, and examples thereof include paper-based base materials such as paper, fiber-based base materials such as cloth and non-woven fabric, plastic-based base materials such as films and sheets made of the above-mentioned various plastics, and laminates thereof. Be done. The base material may have a single-layer form or may have a multi-layer form. The base material may be subjected to various treatments such as back surface treatment, antistatic treatment, and undercoating treatment, if necessary.

The thickness of the base material is not particularly limited, but is preferably 50 μm or more and 1000 μm or less. The upper limit of the thickness is more preferably 500 μm, further preferably 300 μm, and the lower limit is more preferably 80 μm, still more preferably 100 μm.

The conductive layer is not particularly limited as long as it is a conductive layer, but is a metal-based base material such as a sheet, film, or plate made of the metal, a conductive polymer, and a laminate of the various plastics and the metal-based base material. The body etc. can be mentioned.

The thickness of the conductive layer is not particularly limited, but is preferably 10 μm or more and 1000 μm or less. The upper limit of the thickness is more preferably 500 μm, further preferably 300 μm, and the lower limit is more preferably 30 μm, still more preferably 50 μm.

The energizing base material is not particularly limited as long as it is a base material having a conductive layer (energizing), and examples thereof include a base material having a metal layer formed on the surface of the base material. For example, the base material 3 Examples thereof include those in which a metal layer is formed on the surface of the base material mentioned in the above by a method such as a plating method, a chemical vapor deposition method, or a sputtering method. Examples of the metal layer include the metals, metal plates, and conductive polymers mentioned in the conductive layer.

The thickness of the current-carrying base material is not particularly limited, but is preferably 50 μm or more and 1000 μm or less. The upper limit of the thickness is more preferably 500 μm, further preferably 300 μm, and the lower limit is more preferably 80 μm, still more preferably 100 μm.

The thickness of the pressure-sensitive adhesive sheet is not particularly limited, but is preferably 20 μm or more and 3000 μm or less. The upper limit of the thickness is more preferably 1000 μm, further preferably 300 μm, particularly preferably 200 μm, and the lower limit is more preferably 30 μm, further preferably 50 μm, and particularly preferably 70 μm.

(Electrolyte-containing adhesive layer)
The electrolyte-containing pressure-sensitive adhesive layer contains at least a polymer and an electrolyte as a pressure-sensitive adhesive composition for forming the electrolyte-containing pressure-sensitive adhesive layer. Examples of the polymer contained in the pressure-sensitive adhesive composition include an acrylic polymer, a rubber polymer, a vinyl alkyl ether polymer, a silicon polymer, a polyester polymer, a polyamide polymer, a urethane polymer, a fluorine polymer, and an epoxy. Included are based polymers. The above polymers can be used alone or in combination of two or more.

As the polymer contained in the pressure-sensitive adhesive composition, an acrylic polymer is preferable from the viewpoint of cost reduction and high productivity. The acrylic polymer is a polymer containing a monomer unit derived from an acrylic acid alkyl ester and / or a methacrylic acid alkyl ester as the main monomer unit having the largest mass ratio. In the following, "(meth) acrylic" is used to represent "acrylic" and / or "methacryl".

The acrylic polymer is not particularly limited, but preferably contains a monomer unit derived from a (meth) acrylic acid alkyl ester having an alkyl group having 1 to 14 carbon atoms. Examples of the (meth) acrylic acid alkyl ester include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, and sec-butyl (meth). ) Acrylate, 1,3-dimethylbutyl acrylate, pentyl (meth) acrylate, isopentyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylbutyl (meth) acrylate, heptyl (meth) acrylate, n-octyl (meth) Acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, n-dodecyl (meth) Examples thereof include acrylate, n-tridecyl (meth) acrylate, and n-tetradecyl (meth) acrylate. Of these, n-butyl acrylate, 2-ethylhexyl acrylate, and isononyl (meth) acrylate are preferable. The acrylic polymer can be used alone or in combination of two or more.

The proportion of the monomer unit derived from the (meth) acrylic acid alkyl ester having an alkyl group having 1 to 14 carbon atoms in the acrylic polymer is such that high adhesive strength is realized for the electrolyte-containing pressure-sensitive adhesive layer. It is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more, and particularly preferably 80% by mass or more, based on all the monomer components constituting the system polymer.

The acrylic polymer preferably contains a monomer unit derived from a polar group-containing monomer from the viewpoint of achieving high adhesive strength in the electrolyte-containing pressure-sensitive adhesive layer. Examples of the polar group-containing monomer include a carboxyl group-containing monomer, a hydroxyl group-containing monomer, and a vinyl group-containing monomer.

Examples of the carboxyl group-containing monomer include acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, isocrotonic acid, carboxyethyl (meth) acrylate, and carboxypentyl (meth) acrylate. Of these, acrylic acid and methacrylic acid are preferable. The above-mentioned carboxyl group-containing monomer can be used alone or in combination of two or more.

Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, and 8-hydroxyoctyl ( Meta) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, (4-hydroxymethylcyclohexyl) methyl acrylate, N-methylol (meth) acrylamide, vinyl alcohol, allyl alcohol, 2- Examples thereof include hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, diethylene glycol monovinyl ether and the like. Of these, 2-hydroxyethyl (meth) acrylate is preferable. The hydroxyl group-containing monomer can be used alone or in combination of two or more.

Examples of the vinyl group-containing monomer include vinyl acetate, vinyl propionate, vinyl laurate and the like. Of these, vinyl acetate is preferable. The vinyl group-containing monomer can be used alone or in combination of two or more.

The proportion of the monomer unit derived from the polar group-containing monomer in the acrylic polymer is preferably 0.1% by mass or more and 30% by mass or less with respect to all the monomer components constituting the acrylic polymer. When the proportion of the monomer unit derived from the polar group-containing monomer is 0.1% by mass or more, it is possible to secure the cohesive force and suppress the adhesive residue on the surface of the adherend after the electrolyte-containing pressure-sensitive adhesive layer is separated. .. Further, when the proportion of the monomer unit derived from the polar group-containing monomer is 30% by mass or less, the characteristics of the monomer unit derived from the (meth) acrylic acid alkyl ester having an alkyl group having 1 to 14 carbon atoms are acrylic-based. It can be properly expressed in polymers.

Further, as the monomer component constituting the acrylic polymer, a polyfunctional monomer may be contained from the viewpoint of introducing a crosslinked structure into the acrylic polymer to facilitate obtaining the required cohesive force.

Examples of the polyfunctional monomer include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, and 1,6-hexanediol di. Examples thereof include (meth) acrylate, trimethylrol propantri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, divinylbenzene, N, N'-methylenebisacrylamide and the like. The polyfunctional monomer can be used alone or in combination of two or more.

The content of the polyfunctional monomer is preferably 0.1 part by mass or more and 15 parts by mass or less with respect to all the monomer components (100 parts by mass) constituting the acrylic polymer. The upper limit of the content of the polyfunctional monomer is more preferably 10 parts by mass, and the lower limit is more preferably 3 parts by mass. When the content of the polyfunctional monomer is 0.1 parts by mass or more, the flexibility and adhesiveness of the pressure-sensitive adhesive layer are likely to be improved, which is preferable. When the content of the polyfunctional monomer is 15 parts by mass or less, the cohesive force does not become too high, and it becomes easy to obtain an appropriate adhesiveness.

The content of the polymer in the pressure-sensitive adhesive composition is preferably 70% by mass or more, more preferably 80% by mass, based on the entire pressure-sensitive adhesive composition, from the viewpoint of achieving sufficient adhesive strength in the electrolyte-containing pressure-sensitive adhesive layer. % Or more, more preferably 85% by mass or more.

The polymer can be obtained by (co) polymerizing the monomer components. The polymerization method is not particularly limited, and examples thereof include solution polymerization, emulsion polymerization, bulk polymerization, suspension polymerization, and photopolymerization (active energy ray polymerization). In particular, the solution polymerization method is preferable from the viewpoint of cost and productivity. When copolymerized, the polymer may be any of a random copolymer, a block copolymer, an alternating copolymer, a graft copolymer and the like.

The solution polymerization method is not particularly limited, and examples thereof include a method in which a monomer component, a polymerization initiator and the like are dissolved in a solvent and heated to polymerize to obtain a polymer solution containing a polymer.

As the solvent used in the solution polymerization method, various general solvents can be used. Such a solvent (polymerization solvent) is not particularly limited, but is limited to aromatic hydrocarbons such as toluene, benzene and xylene; esters such as ethyl acetate and n-butyl acetate; n-hexane, n-heptane and the like. Aliphatic hydrocarbons; alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; organic solvents such as ketones such as methylethylketone and methylisobutylketone can be mentioned. The above solvent can be used alone or in combination of two or more.

The content of the solvent is not particularly limited, but is preferably 10 parts by mass or more and 1000 parts by mass or less with respect to the total amount (100 parts by mass) of all the monomer components constituting the polymer. The upper limit of the content of the solvent is more preferably 500 parts by mass, and the lower limit is more preferably 50 parts by mass.

The above-mentioned polymerization initiator used in the solution polymerization method is not particularly limited, and examples thereof include peroxide-based polymerization initiators and azo-based polymerization initiators. The peroxide-based polymerization initiator is not particularly limited, and examples thereof include peroxycarbonate, ketone peroxide, peroxyketal, hydroperoxide, dialkyl peroxide, diacyl peroxide, and peroxy ester, and more specific examples thereof. Specifically, benzoyl peroxide, t-butyl hydroperoxide, di-t-butyl peroxide, t-butyl peroxybenzoate, dicumyl peroxide, 1,1-bis (t-butyl peroxy) -3, Examples thereof include 3,5-trimethylcyclohexane and 1,1-bis (t-butylperoxy) cyclododecane. The azo-based polymerization initiator is not particularly limited, but is 2,2'-azobisisobutyronitrile, 2,2'-azobis-2-methylbutyronitrile, and 2,2'-azobis (2,4). -Dimethylvaleronitrile), 2,2'-azobis (2-methylpropionic acid) dimethyl, 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile), 1,1'-azobis (cyclohexane-) 1-Carbonitrile), 2,2'-azobis (2,4,4-trimethylpentane), 4,4'-azobis-4-cyanovalerian acid, 2,2'-azobis (2-amidinopropane) dihydrochloride , 2,2'-azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis (2-methylpropionamidine) disulfate, 2,2'- Examples thereof include azobis (N, N'-dimethyleneisobutyramidine) hydrochloride, 2,2'-azobis [N- (2-carboxyethyl) -2-methylpropion amidine] hydrate and the like. The above-mentioned polymerization initiator can be used alone or in combination of two or more.

The content of the polymerization initiator is not particularly limited, but is preferably 0.01 parts by mass or more and 5 parts by mass or less with respect to the total amount (100 parts by mass) of all the monomer components constituting the polymer. The upper limit of the content of the polymerization initiator is more preferably 3 parts by mass. The lower limit of the content of the polymerization initiator is more preferably 0.05 parts by mass.

The heating temperature when polymerizing by heating in the above solution polymerization method is not particularly limited, but is preferably 50 ° C. or higher and 80 ° C. or lower. The heating time is not particularly limited, but is preferably 1 hour or more and 24 hours or less.

The weight average molecular weight of the polymer (particularly, the acrylic polymer) is not particularly limited, but is preferably 100,000 or more and 5 million or less. The upper limit of the weight average molecular weight is more preferably 4 million, further preferably 3 million, and the lower limit is more preferably 200,000, further preferably 300,000. When the weight average molecular weight is larger than 100,000, the cohesive force becomes small, adhesive residue is generated on the surface of the adherend after the adhesive layer is separated, and the effect of wettability and adhesiveness on the surface of the adherend after separation is obtained. Can be effectively suppressed. Further, when the weight average molecular weight is less than 5 million, the problem that the wettability of the surface of the adherend after separating the pressure-sensitive adhesive layer becomes insufficient can be effectively suppressed.

The weight average molecular weight is obtained by measuring by a gel permeation chromatography (GPC) method. More specifically, for example, as a GPC measuring device, the trade name is "HLC-8220GPC" (manufactured by Tosoh Corporation). ) Can be measured under the following conditions and calculated by the standard polystyrene conversion value.
(Molecular weight measurement conditions)
-Sample concentration: 0.2% by weight (tetrahydrofuran solution)
-Sample injection volume: 10 μL
-Sample column: TSKguardcolum SuperHZ-H (1) + TSKgel SuperHZM-H (2)
-Reference column: TSKgel SuperH-RC (1)
-Eluent: tetrahydrofuran (THF)
・ Flow rate: 0.6 mL / min
・ Detector: Differential refractometer (RI)
-Column temperature (measurement temperature): 40 ° C

The glass transition temperature (Tg) of the above polymer (particularly an acrylic polymer) is not particularly limited, but is preferably 0 ° C. or lower, more preferably -10 ° C. or lower, still more preferably -20 ° C. or lower, and particularly preferably −40 ° C. Hereinafter, it is most preferably −50 ° C. or lower. When the glass transition temperature is 0 ° C. or lower, the decrease in the initial adhesive force can be suppressed.

The glass transition temperature (Tg) can be calculated based on, for example, the following equations (X) (Fox equation).
1 / Tg = W1 / Tg1 + W2 / Tg2 + ... + Wn / Tgn (X)
[In the formula (X), Tg is the glass transition temperature (unit: K) of the polymer, and Tgi (i = 1, 2, ... n) is the glass transition temperature (unit: unit:) when the monomer i forms a homopolymer. K), Wi (i = 1, 2, ... n) represent the mass fraction of the monomer i in all the monomer components]
The above formula (X) is a calculation formula when the polymer is composed of n kinds of monomer components of monomer 1, monomer 2, ..., Monomer n.

The glass transition temperature when the homopolymer is formed means the glass transition temperature of the homopolymer of the monomer, and only a certain monomer (sometimes referred to as "monomer X") is formed as a monomer component. It means the glass transition temperature (Tg) of the polymer. Specifically, the numerical values are listed in "Polymer Handbook" (3rd edition, John Wiley & Sons, Inc., 1989). The glass transition temperature (Tg) of the homopolymer not described in the above-mentioned document means, for example, a value obtained by the following measuring method. That is, in a reactor equipped with a thermometer, a stirrer, a nitrogen introduction tube and a reflux condenser, 100 parts by mass of monomer X, 0.2 parts by mass of 2,2'-azobisisobutyronitrile, and ethyl acetate 200 as a polymerization solvent. Add parts by mass and stir for 1 hour while introducing nitrogen gas. After removing oxygen in the polymerization system in this way, the temperature is raised to 63 ° C. and the reaction is carried out for 10 hours. Then, the mixture is cooled to room temperature to obtain a homopolymer solution having a solid content concentration of 33% by mass. Next, this homopolymer solution is cast-coated on a release liner and dried to prepare a test sample (sheet-shaped homopolymer) having a thickness of about 2 mm. Then, about 1 to 2 mg of this test sample was weighed in an aluminum open cell, and a temperature-modulated DSC (trade name “Q-2000” manufactured by TA Instruments) was used to create a nitrogen atmosphere of 50 ml / min. Below, at a heating rate of 5 ° C./min, the Reversing Heat Flow (specific heat component) behavior of the homopolymer is obtained. With reference to JIS-K-7121, a straight line extending the baseline on the low temperature side and the baseline on the high temperature side of the obtained Reversing Heat Flow at equal distances in the vertical direction, and a stepwise change in the glass transition. The temperature at the point where the curve of the portion intersects is defined as the glass transition temperature (Tg) when homopolymer is used.

The electrolyte contained in the electrolyte-containing pressure-sensitive adhesive layer is a substance that can be ionized into anions and cations, and examples of such an electrolyte include an ionic liquid, an alkali metal salt, and an alkaline earth metal salt. An ionic liquid is preferable as the electrolyte contained in the electrolyte-containing pressure-sensitive adhesive layer from the viewpoint of achieving good electrical peelability in the electrolyte-containing pressure-sensitive adhesive layer. An ionic liquid is a salt of a liquid at room temperature (about 25 ° C.) and contains anions and cations.

Examples of the anion of the ionic liquid include (FSO ₂ ) ₂ N ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (CF ₃ CF ₂ SO ₂ ) ₂ N ⁻ , (CF ₃ SO ₂ ) ₃ C ⁻ ,. Br ⁻ , AlCl ₄ ⁻ , Al ₂ Cl ₇ ⁻ , NO ₃ ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , CH ₃ COO ⁻ , CF ₃ COO ⁻ , CF ₃ CF ₂ CF ₂ COO ⁻ , CF ₃ SO ₃ ⁻ , CF ₃ (CF ₂ ) ₃ SO ₃ ⁻ , AsF ₆ ⁻ , SbF ₆ ⁻ , F (HF) _n ⁻ (n represents an integer of 1 or more) and the like. The above anions can be used alone or in combination of two or more.

Examples of the ionic liquid cation include an imidazolium-based cation, a pyridinium-based cation, a pyrrolidinium-based cation, and an ammonium-based cation. The above cations can be used alone or in combination of two or more.

Examples of the imidazolium-based cation include 1-methyl imidazolium cation, 1-ethyl-3-methyl imidazolium cation, 1-propyl-3-methyl imidazolium cation, 1-butyl-3-methyl imidazolium cation, and the like. 1-Pentyl-3-methylimidazolium cation, 1-hexyl-3-methylimidazolium cation, 1-heptyl-3-methylimidazolium cation, 1-octyl-3-methylimidazolium cation, 1-nonyl-3 − Methyl imidazolium cation, 1-undecyl-3-methyl imidazolium cation, 1-dodecyl-3-methyl imidazolium cation, 1-tridecyl-3-methyl imidazolium cation, 1-tetradecyl-3-methyl imidazolium cation, 1-Pentadecyl-3-methylimidazolium cation, 1-hexadecyl-3-methylimidazolium cation, 1-heptadecyl-3-methylimidazolium cation, 1-octadecyl-3-methylimidazolium cation, 1-undecyl-3-3 Examples thereof include methyl imidazolium cation, 1-benzyl-3-methyl imidazolium cation, 1-butyl-2,3-dimethyl imidazolium cation, 1,3-bis (dodecyl) imidazolium cation and the like.

Examples of the pyridinium-based cation include 1-butylpyridinium cation, 1-hexylpyridinium cation, 1-butyl-3-methylpyridinium cation, 1-butyl-4-methylpyridinium cation, and 1-octyl-4-methylpyridinium cation. And so on.

Examples of the pyrrolidinium-based cation include 1-ethyl-1-methylpyrrolidinium cation, 1-butyl-1-methylpyrrolidinium cation and the like.

Examples of the ammonium-based cation include tetraethylammonium cation, tetrabutylammonium cation, methyltrioctylammonium cation, tetradecitrihexylammonium cation, glycidyltrimethylammonium cation, trimethylaminoethylacrylate cation and the like.

Examples of commercially available products of the above ionic liquid include "Elexel AS-110", "Elexel MP-442", "Elexel IL-210", "Elexel MP-471", and "Elexel MP" manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd. -456 ”,“ Elexel AS-804 ”and the like can be used.

When an ionic liquid is used as the electrolyte, in the thickness direction of the electrolyte-containing pressure-sensitive adhesive layer, the cation mainly moves to the cathode (negative electrode) side when a voltage is applied and is biased toward the interface between the pressure-sensitive adhesive layer and the adherend. It is considered that peelability occurs in. As the cation of the ionic liquid, it is preferable to use a cation having a molecular weight of 200 or less, more preferably 180 or less, and further preferably 160 or less. When a cation having a molecular weight of 200 or less is used, the cation can be easily moved to the cathode (negative electrode) side in the electrolyte-containing pressure-sensitive adhesive layer, and as a result, the peelability is released even when a low voltage is applied for a short time. Is expected to be better.

The ionic conductivity of the ionic liquid is not particularly limited, but is preferably 0.1 mS / cm or more and 10 mS / cm or less. The upper limit of the ionic conductivity is more preferably 5 mS / cm, further preferably 3 mS / cm, and the lower limit is more preferably 0.3 mS / cm, still more preferably 0.5 mS / cm. When the ionic liquid has an ionic conductivity in this range, sufficient peelability can be obtained even at a low voltage. The ionic conductivity can be measured by the AC impedance method using, for example, a 1260 frequency response analyzer manufactured by Solartron.

The content of the ionic liquid is not particularly limited, but is preferably 0.5 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the polymer, and the upper limit of the ionic liquid is more preferably 20 parts by mass, further. It is preferably 15 parts by mass, particularly preferably 10 parts by mass, most preferably 5 parts by mass, and the lower limit is more preferably 0.6 parts by mass, further preferably 0.8 parts by mass, and particularly preferably 1.0 part by mass. Parts, most preferably 1.5 parts by mass. If it is less than 0.5 parts by mass, it becomes difficult to obtain peelability even when energized. If it exceeds 30 parts by mass, no further peelability can be obtained, and the adhesiveness when a non-voltage is applied (normally) may decrease.

Examples of the alkali metal salt include LiCl, Li ₂ SO ₄ , LiBF ₄ , LiPF ₆ , LiClO ₄ , LiAsF ₆ , LiCF ₃ SO ₃ , LiN (SO ₂ CF ₃ ) ₂ , LiN (SO ₂ C ₂ F _5). ) ₂ , LiC (SO ₂ CF ₃ ) ₃ , NaCl, Na ₂ SO ₄ , NaBF ₄ , NaPF ₆ , NaClO ₄ , NaAsF ₆ , NaCF ₃ SO ₃ , NaN (SO ₂ CF ₃ ) ₂ , NaN (SO ₂ C) ₂ F ₅ ) ₂ , NaCl (SO ₂ CF ₃ ) ₃ , KCl, K ₂ SO ₄ , KBF ₄ , KPF ₆ , KClO ₄ , KAsF ₆ , KCF ₃ SO ₃ , KN (SO ₂ CF ₃ ) ₂ , KN ( SO ₂ C ₂ F ₅ ) ₂ , KC (SO ₂ CF ₃ ) _3, etc. can be mentioned.

The content of the electrolyte is 0, with respect to the entire pressure-sensitive adhesive composition forming the electrolyte-containing pressure-sensitive adhesive layer, from the viewpoint of achieving good adhesive strength and electroleapability in the electrolyte-containing pressure-sensitive adhesive layer in a well-balanced manner. It is preferably 1% by mass or more and 30 parts by mass or less. The upper limit of the content of the electrolyte is more preferably 20% by mass, further preferably 10% by mass, particularly preferably 8% by mass, and the lower limit of the content of the electrolyte is more preferably 0.5% by mass. It is more preferably 1.0% by mass, and particularly preferably 1.5% by mass.

The content of the electrolyte is preferably 0.5 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the polymer. The upper limit of the content of the electrolyte is more preferably 15 parts by mass or less, further preferably 10 parts by mass or less, particularly preferably 5 parts by mass or less, and the lower limit of the content of the electrolyte is more preferably 0.8 parts or less. It is by mass or more, more preferably 1.0 part by mass or more, and particularly preferably 1.5 parts by mass or more.

If necessary, the pressure-sensitive adhesive composition may contain a cross-linking agent for the purpose of improving creepability and shearing property by cross-linking the polymer. Examples of the cross-linking agent include isocyanate-based cross-linking agents, epoxy-based cross-linking agents, melamine-based cross-linking agents, peroxide-based cross-linking agents, urea-based cross-linking agents, metal alkoxide-based cross-linking agents, metal chelate-based cross-linking agents, and metal salt-based cross-linking agents. Examples thereof include a cross-linking agent, a carbodiimide-based cross-linking agent, an oxazoline-based cross-linking agent, an aziridine-based cross-linking agent, and an amine-based cross-linking agent. Examples of the isocyanate-based cross-linking agent include toluene diisocyanate and methylene bisphenyl isocyanate. Examples of the epoxy-based cross-linking agent include N, N, N', N'-tetraglycidyl-m-xylenediol, diglycidyl aniline, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, and 1 , 6-Hexanediol diglycidyl ether and the like. The content of the cross-linking agent is preferably 0.1 part by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the polymer. The above-mentioned cross-linking agent can be used alone or in combination of two or more.

In the present invention, polyethylene glycol may be contained, if necessary, for the purpose of assisting the movement of the ionic liquid when a voltage is applied. As the polyethylene glycol, those having a number average molecular weight of 200 to 6000 can be used. The content of the polyethylene glycol is preferably 0.1 part by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the polymer.

In the present invention, the pressure-sensitive adhesive composition may contain a conductive filler, if necessary, for the purpose of imparting conductivity to the electrolyte-containing pressure-sensitive adhesive layer. The conductive filler is not particularly limited, and a general known or commonly used conductive filler can be used. For example, graphite, carbon black, carbon fiber, metal powder such as silver or copper can be used. .. The content of the conductive filler is preferably 0.1 part by mass or more and 200 parts by mass or less with respect to 100 parts by mass of the polymer.

In the above-mentioned pressure-sensitive adhesive composition, if necessary, as long as the effect of the present invention is not impaired, the above-mentioned cross-linking agent, polyethylene glycol, filler other than conductive filler, plasticizer, antistatic agent, antioxidant, pigment ( It can contain various additives such as dyes), flame retardants, solvents, surfactants (leveling agents), rust preventives, adhesive-imparting resins, and antistatic agents. The above additives can be used alone or in combination of two or more.

Examples of the filler include silica, iron oxide, zinc oxide, aluminum oxide, titanium oxide, barium oxide, magnesium oxide, calcium carbonate, magnesium carbonate, zinc carbonate, pyrophyllite clay, kaolin clay, and fired clay. ..

As the plasticizer, a known or commonly used plasticizer used in a general resin composition or the like can be used. For example, paraffin oil, oil such as process oil, liquid polyisoprene, liquid polybutadiene, liquid ethylene-propylene rubber. Liquid rubber, tetrahydrophthalic acid, azelaic acid, benzoic acid, phthalic acid, trimellitic acid, pyromellitic acid, adipic acid, sebacic acid, fumaric acid, maleic acid, itaconic acid, citric acid and derivatives thereof, dioctylphthalate (DOP), dibutylphthalate (DBP), dioctyl adipate, diisononyl adipate (DINA), isodecyl succinate and the like.

Examples of the anti-aging agent include hindered phenolic compounds, aliphatic and aromatic hindered amine compounds and the like. Examples of the antioxidant include butylhydroxytoluene (BHT) and butylhydroxyanisole (BHA). Examples of the pigment include inorganic pigments such as titanium dioxide, zinc oxide, ultramarine, red iron oxide, lithopone, lead, cadmium, iron, cobalt, aluminum, hydrochloride and sulfate, and organic pigments such as azo pigments and copper phthalocyanine pigments. Can be mentioned. Examples of the rust preventive agent include zinc phosphate, tannic acid derivative, phosphoric acid ester, basic sulfonate, various rust preventive pigments and the like. Examples of the adhesive-imparting agent include titanium coupling agents and zirconium coupling agents. Examples of the antistatic agent generally include a quaternary ammonium salt, a hydrophilic compound such as a polyglycol or an ethylene oxide derivative, and the like.

Examples of the tackifier resin include rosin-based tackifier resins, terpene-based tackifier resins, phenol-based tackifier resins, hydrocarbon-based tackifier resins, ketone-based tackifier resins, polyamide-based tackifier resins, and epoxy-based tackifier resins. Examples thereof include tackifier resins and elastomeric tackifier resins. The tackifier resin can be used alone or in combination of two or more.

The content (blending amount) of the additive is not particularly limited, but is preferably 0 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the polymer, and the upper limit of the additive is more preferably 10 parts by mass. , More preferably 5 parts by mass.

The pressure-sensitive adhesive composition for forming the electrolyte-containing pressure-sensitive adhesive layer is not particularly limited, but the polymer, electrolyte, and if necessary, the cross-linking agent, polyethylene glycol, conductive filler, additive, and the like are appropriately stirred. It can be manufactured by mixing the mixture. The pressure-sensitive adhesive composition may contain the solvent used when polymerizing the polymer.

As the method for producing the electrolyte-containing pressure-sensitive adhesive layer, a known or conventional manufacturing method can be used. For example, the electrolyte-containing pressure-sensitive adhesive layer includes a method in which a solution of the pressure-sensitive adhesive composition dissolved in a solvent is applied onto a separator and dried and / or cured. Further, as the electrolyte-free pressure-sensitive adhesive layer, a method of applying a solution of an electrolyte-free pressure-sensitive adhesive composition in a solvent, if necessary, onto a separator, and drying and / or curing may be mentioned. As the solvent, those listed above can be used.

For the above coating, a conventional coater (for example, a gravure roll coater, a reverse roll coater, a kiss roll coater, a dip roll coater, a bar coater, a knife coater, a spray roll coater, etc.) can be used.

An electrolyte-containing pressure-sensitive adhesive layer can be produced by the above method, and the electrolyte-containing pressure-sensitive adhesive layer and the electrolyte-free pressure-sensitive adhesive layer are appropriately laminated on the base material, the conductive layer, and the current-carrying base material to obtain the above-mentioned adhesion. Sheets can be manufactured. In addition, instead of the separator, the base material, the conductive layer, and the base material for energization may be used, and the pressure-sensitive adhesive composition may be applied thereto to produce a pressure-sensitive adhesive sheet. The electrolyte-free pressure-sensitive adhesive layer containing no electrolyte can be produced in the same manner as the above-mentioned method for producing an electrolyte-containing pressure-sensitive adhesive layer, except that an electrolyte is not used in the pressure-sensitive adhesive composition.

The adhesive force (initial adhesive force) of the electrolyte-containing adhesive layer when a non-voltage application (normal) is not particularly limited, but the adhesive force in the 180 ° peel test (tensile speed: 300 mm / min) is 0.1 or more and 40. The following is preferable. The upper limit of the adhesive force is more preferably 20, still more preferably 10, particularly preferably 5, and the lower limit is more preferably 0.3, still more preferably 0.5, and particularly preferably 0. It is 8.8. If the adhesive strength is less than 0.1, the adhesive strength may not be sufficient and the adhesive force may be peeled off, and if it exceeds 40, the adhesive force may not be peeled off even when a voltage is applied. The unit of the adhesive force is N / cm. The initial adhesive force is the adhesive force when the adhesive sheet is attached to the adherend (SUS304), pressed once with a 2 kg roller, left for 30 minutes, and then peeled at 180 ° with a peeling tester. is there.

The adhesive force (peeling force) of the electrolyte-containing pressure-sensitive adhesive layer after the voltage is applied (10 seconds after the voltage is stopped) is not particularly limited, but as the adhesive force in the 180 ° peel test (tensile speed: 300 mm / min). , 1.0 or less, more preferably 0.5 or less, still more preferably 0.3 or less, and particularly preferably 0.1 or less. If the adhesive strength exceeds 1.0, it may not be able to be peeled off from the adherend. The unit of the adhesive force is N / cm. The adhesive strength is obtained after the adhesive sheet is attached to the adherend (SUS304), pressed once with a 2 kg roller, left for 30 minutes, applied with a voltage of 10 V for 30 seconds, and then stopped. After 10 seconds, it is the adhesive strength when peeling 180 ° with a peeling tester.

The adhesive strength recovery rate after applying the voltage of the electrolyte-containing adhesive layer [(adhesive strength after applying the voltage of the adhesive sheet (10 seconds after the voltage is stopped) / initial adhesive strength) × 100] is particularly limited. Although not, it is preferably 30% or less, more preferably 20% or less, still more preferably 10% or less, and particularly preferably 5% or less. The above-mentioned adhesive force recovery rate is a recovery rate 10 seconds after the voltage is stopped, and when the adhesive force recovery rate exceeds 30%, the voltage is stopped even if the peelability at the time of applying the voltage or immediately after is good. After that, the adhesive strength is restored in a short time (for example, 3 seconds), and the separation work cannot be performed. Therefore, it is preferable that the adhesive force recovery rate 10 seconds after the voltage is stopped is as small as possible.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. The weight average molecular weights in Synthesis Examples 1 to 4 were measured by the method described above by the gel permeation chromatography (GPC) method. The glass transition temperature (Tg) in Synthesis Examples 1 to 4 below is a temperature calculated from the Fox formula described in the above specification.

[Synthesis Example 1]
(Preparation of 1 solution of acrylic polymer)
N-Butyl acrylate (BA): 95 parts by mass, acrylic acid (AA): 5 parts by mass as a monomer component, and ethyl acetate: 150 parts by mass as a polymerization solvent were put into a separable flask, and nitrogen gas was introduced. While stirring for 1 hour. After removing oxygen in the polymerization system in this way, 2,2'-azobisisobutyronitrile (AIBN): 0.2 parts by mass was added as a polymerization initiator, and the temperature was raised to 63 ° C. for 6 hours. It was reacted. Then, ethyl acetate was added to obtain one solution of an acrylic polymer having a solid content concentration of 40% by weight. The weight average molecular weight of the acrylic polymer 1 in the acrylic polymer 1 solution was 500,000, and the glass transition temperature (Tg) when this was cured was −50 ° C.

[Synthesis Example 2]
(Preparation of 2 solutions of acrylic polymer)
Isononyl acrylate (iNA): 80 parts by mass, methoxyethyl acrylate (MEA): 15 parts by mass, acrylic acid (AA): 5 parts by mass as a monomer component, and ethyl acetate: 150 parts by mass as a polymerization solvent can be separated. It was put into a flask and stirred for 1 hour while introducing nitrogen gas. After removing oxygen in the polymerization system in this manner, 2,2'-azobisisobutyronitrile: 0.2 parts by mass was added as a polymerization initiator, and the temperature was raised to 63 ° C. for 10 hours. .. Then, ethyl acetate was added to obtain two solutions of acrylic polymers having a solid content concentration of 40% by weight. The weight average molecular weight of the acrylic polymer 2 in the acrylic polymer 2 solution was 600,000, and the glass transition temperature (Tg) when this was cured was −55 ° C.

[Synthesis Example 3]
(Preparation of 3 solutions of acrylic polymer)
Separable n-butyl acrylate (BA): 80 parts by mass, vinyl acetate (VAc): 15 parts by mass, acrylic acid (AA): 5 parts by mass as a monomer component, and ethyl acetate: 150 parts by mass as a polymerization solvent. It was put into a flask and stirred for 1 hour while introducing nitrogen gas. After removing oxygen in the polymerization system in this way, 2,2'-azobisisobutyronitrile (AIBN): 0.2 parts by mass was added as a polymerization initiator, and the temperature was raised to 63 ° C. for 10 hours. It was reacted. Then, ethyl acetate was added to obtain a solution of 3 acrylic polymers having a solid content concentration of 40% by weight. The weight average molecular weight of the acrylic polymer 3 in the acrylic polymer 3 solution was 700,000, and the glass transition temperature (Tg) when this was cured was −40 ° C.

[Synthesis Example 4]
(Preparation of 4 solutions of acrylic polymer)
As the monomer component, n-butyl acrylate (BA): 70 parts by mass, 2-ethylhexyl acrylate (2EHA): 25 parts by mass, acrylic acid (AA): 5 parts by mass, and ethyl acetate: 150 parts by mass as the polymerization solvent. It was put into a separable flask and stirred for 1 hour while introducing nitrogen gas. After removing oxygen in the polymerization system in this way, 2,2'-azobisisobutyronitrile (AIBN): 0.2 parts by mass was added as a polymerization initiator, and the temperature was raised to 63 ° C. for 10 hours. It was reacted. Then, ethyl acetate was added to obtain a solution of 4 acrylic polymers having a solid content concentration of 40% by weight. The weight average molecular weight of the acrylic polymer 4 in the acrylic polymer 4 solution was 700,000, and the glass transition temperature (Tg) when this was cured was −54 ° C.

[Examples 1 to 15]
The acrylic polymers 1 to 4 obtained in Synthesis Examples 1 to 4 and each electrolyte (ionic liquid) are added, stirred and mixed at the ratios shown in Table 1 below to form each electrolyte-containing pressure-sensitive adhesive layer. The pressure-sensitive adhesive composition for this was obtained.
The obtained pressure-sensitive adhesive composition was placed on a peel-treated surface of a polyethylene terephthalate separator (trade name "MRF38", manufactured by Mitsubishi Plastics Co., Ltd.) whose surface was peel-treated to a thickness of 30 μm using an applicator. The pressure-sensitive adhesive composition layer was obtained. Next, it was dried by heating at 130 ° C. for 3 minutes to form an adhesive layer, and each electrolyte-containing adhesive layer (adhesive sheet; S1 to 15) was obtained. The following evaluations were performed on each of the obtained electrolyte-containing pressure-sensitive adhesive layers (adhesive sheets). The results are shown in Table 1. No evaluation has been carried out for-in Table 1. The unit of the blending amount of the polymer and the ionic liquid is a mass part.

[Evaluation]
(Initial adhesive strength)
The electrolyte-containing adhesive layer (adhesive sheet; S1 to 15) is a sheet with a size of 10 mm x 80 mm, and a film with a metal layer as a base material on the surface without a separator (trade name "BR1075", Toray Film Processing Co., Ltd. Made of 25 μm in thickness and 10 mm × 100 mm in size), the metal layer surfaces were laminated to form a single-sided adhesive sheet with a base material. Peel off the separator of the single-sided adhesive sheet with a base material, and attach a stainless steel plate (SUS304, size: 30 mm x 120 mm) as an adherend to the peeled surface so that one end of the adhesive sheet protrudes from the adherend by about 2 mm, 2 kg. Pressed once with the roller of the above, left for 30 minutes, and adhered consisting of a stainless steel plate 6 / adhesive layer (adhesive sheet) 1'/ film with metal layer (energization base material) 5', which is outlined in FIG. A sheet joint was obtained. After that, a peeling tester (trade name "variable angle peel tester YSP", manufactured by Asahi Seiko Co., Ltd.) was used to peel according to the arrow method in FIG. 4, and a 180 ° peel test (tensile speed: 300 mm / min, The adhesive strength at a peeling temperature of 23 ° C.) was measured.

(Electrical peeling property: peeling force 10 seconds after voltage stop, adhesive recovery rate after 10 seconds)
An adhesive sheet bonded body composed of a stainless steel plate 6 / an adhesive layer (adhesive sheet) 1'/ a film with a metal layer (energizing base material) 5', which is outlined in FIG. 4 in the same manner as the initial adhesive force, was produced. ..
The positive electrode and the negative electrode of the DC current machine were attached to the positions α and β in FIG. 4 of this junction, and a voltage was applied at a voltage of 10 V for 30 seconds. Then, the electrode was removed, and after 10 seconds had passed, the peeling tester was used to peel according to the arrow method in FIG. 4, and the adhesive strength in the 180 ° peel test (tensile speed: 300 mm / min, peeling temperature 23 ° C.) was measured. did. This measurement result is defined as the peeling force [N / cm] after 10 s of voltage stop.
[(Peeling force after 10 s of voltage stop / initial adhesive force) × 100] was defined as the adhesive force recovery rate [%] after 10 s.

(Electrical peeling property: peeling force after voltage application 30s)
A bonded body similar to the above (electrical peeling property: peeling force after 10 seconds of voltage stop) and adhesive force recovery rate after 10 seconds was prepared, and a DC current machine was added to the α and β points in FIG. 4 of this bonded body. Electrodes of pole and minus pole were attached respectively, and voltage was applied at a voltage of 10 V for 30 seconds. After 30 seconds of applying this voltage (while applying the voltage), peeling is performed by the method indicated by the arrow in FIG. 4 with the peeling tester, and adhesion in a 180 ° peel test (tensile speed: 300 mm / min, peeling temperature 23 ° C.). The force was measured and used as the peeling force [N / cm] after 30 seconds of voltage application.

[Examples 16 to 20]
Using the pressure-sensitive adhesive sheet S1, only the applied voltage was changed as shown in Table 2, and the same test as described above (electrical peelability: peeling force after voltage application 30 s) was performed. The results are shown in Table 2.

The abbreviations of the ionic liquids in Table 1 above are as follows.
AS-110 ... cation; 1-ethyl-3-methylimidazolium cation, _{anion; (FSO 2)} 2 N ^-, trade name "Erekuseru AS-110" (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.)
MP-442 ... cation; glycidyl trimethyl ammonium cation, ^{_{anion; (FSO 2) 2 N -}} , trade name "Erekuseru MP-442" (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.)
IL-210 ... cation; 1-ethyl-3-methylimidazolium cation, _{anion; (CF 3 SO 2) 2} N -, trade name "Erekuseru IL-210" (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.)
Ionic liquids BMP ... cation; 1-butyl-1-methyl pyrrolidinium cation, _{anion; (CF 3 SO 2) 2} N -, trade name "N- butyl -N- methyl-pyrrolidinium bis (trifluoromethanesulfonyl) imide (Made by Kanto Chemical Co., Ltd.)
MP-471 ... cation; trimethyl aminoethyl acrylate cationic, _{anionic; (FSO 2)} 2 N ^-, trade name "Erekuseru MP-471" (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.)
CIL-312 ... cation; 1-butyl-3-methylpyridinium cation, _{anion; (CF 3 SO 2) 2} N -, trade name "CIL-312" (Nippon Carlit Co., Ltd.)
Ionic liquids EMI ... cation; 1-ethyl-3-methylimidazolium cation, _{anion; (FSO 2)} 2 N ^-, trade name "1-ethyl-3-methylimidazolium tetrafluoroborate" (Kanto Chemical Co., Made by the company)

As a summary of the above, the configurations of the present invention and variations thereof are listed below as additional notes.

(Appendix 1)
After bonding the pressure-sensitive adhesive sheet containing at least the pressure-sensitive adhesive layer containing an electrolyte to the adherend, a voltage of less than 20 V is applied to the pressure-sensitive adhesive layer so as to generate a potential difference in the thickness direction of the pressure-sensitive adhesive layer. A method of joining and separating adherends to separate the adherends.
(Appendix 2)
In a pressure-sensitive adhesive sheet containing at least a pressure-sensitive adhesive layer containing an electrolyte,
After joining one surface of the pressure-sensitive adhesive layer to the first conductive adherend and joining the other surface of the pressure-sensitive adhesive layer to the second conductive adherend,
By applying a voltage of less than 20 V to the pressure-sensitive adhesive layer via the first conductive adherend and the second conductive adherend,
A method for joining / separating an adherend, which separates the first conductive adherend and the second conductive adherend from the pressure-sensitive adhesive layer.
(Appendix 3)
An electrolyte-containing pressure-sensitive adhesive layer, an electrolyte-free pressure-sensitive adhesive layer, and an electrolyte-containing pressure-sensitive adhesive layer located between the electrolyte-containing pressure-sensitive adhesive layer and the electrolyte-free pressure-sensitive adhesive layer. In an adhesive sheet having a laminated structure including a conductive layer to be bonded to the layer,
After joining the pressure-sensitive adhesive layer containing the electrolyte and the conductive adherend, and sticking the pressure-sensitive adhesive layer not containing the electrolyte with another adherend,
By applying a voltage of less than 20 V to the pressure-sensitive adhesive layer containing the electrolyte via the conductive layer and the conductive adherend.
A method for joining / separating an adherend, which separates the conductive adherend and the other adherend from the pressure-sensitive adhesive layer containing the electrolyte.
(Appendix 4)
A first pressure-sensitive adhesive layer containing no electrolyte, a pressure-sensitive adhesive layer containing an electrolyte, a second pressure-sensitive adhesive layer containing no electrolyte, and a first pressure-sensitive adhesive layer containing no electrolyte and a pressure-sensitive adhesive containing the electrolyte. A first conductive layer that is located between the agent layer and joins with the pressure-sensitive adhesive layer containing the electrolyte, and a second pressure-sensitive adhesive layer that does not contain the electrolyte and a pressure-sensitive adhesive layer that contains the electrolyte. In a pressure-sensitive adhesive sheet having a laminated structure including a second conductive layer to be bonded to a pressure-sensitive adhesive layer containing the electrolyte, which is located in between.
After the first pressure-sensitive adhesive layer and the first adherend that do not contain the electrolyte are attached, and the second pressure-sensitive adhesive layer that does not contain the electrolyte and the second adherend are attached.
By applying a voltage of less than 20 V to the pressure-sensitive adhesive layer containing the electrolyte via the first conductive layer and the second conductive layer.
A method for joining and separating adherends, which separates the first adherend and the second adherend from the pressure-sensitive adhesive layer containing the electrolyte.
(Appendix 5)
The method for joining / separating an adherend according to any one of Appendix 1 to 4, wherein the pressure-sensitive adhesive layer containing the electrolyte has a thickness of 1 μm or more and 1000 μm or less.
(Appendix 6)
The method for joining / separating adherends according to any one of Appendix 1 to 5, wherein the application time of the voltage is 60 seconds or less.
(Appendix 7)
The method for joining / separating adherends according to any one of Appendix 1 to 6, wherein the electrolyte is an ionic liquid.
(Appendix 8)
As anions of the ionic liquid, (FSO ₂ ) ₂ N ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (CF ₃ CF ₂ SO ₂ ) ₂ N ⁻ , (CF ₃ SO ₂ ) ₃ C ⁻ , CH ₃ COO ⁻ , CF ₃ COO ⁻ , CF ₃ CF ₂ CF ₂ COO ⁻ _, CF ₃ SO ₃ ⁻ , CF ₃ (CF ₂ ) ₃ SO ₃ ⁻ , Br ⁻ , AlCl ₄ ⁻ , Al ₂ Cl ₇ ⁻ , NO ₃ ⁻ , ^{_{BF 4 -, PF 6 -,}} AsF 6 -, SbF 6 -, and F _{(HF) n} ^- _(n is an integer of 1 or more) at least one selected from the group consisting of, according to Appendix 7 How to join / separate the adherends.
(Appendix 9)
The junction of the adherend according to Appendix 7 or 8, wherein the ionic liquid cation is at least one cation selected from the group consisting of an imidazolium-based cation, a pyridinium-based cation, a pyrrolidinium-based cation, and an ammonium-based cation. -Separation method.
(Appendix 10)
The method for joining / separating an adherend according to any one of Supplementary note 7 to 9, wherein the ionic liquid has a molecular weight of 200 or less.
(Appendix 11)
The pressure-sensitive adhesive composition for forming the pressure-sensitive adhesive layer containing the electrolyte contains a polymer, and the content of the ionic liquid is 0.5 parts by mass or more and 30 parts by mass or less with respect to 100 parts by weight of the polymer. The method for joining / separating an adherend according to any one of Supplementary note 7 to 10.
(Appendix 12)
The method for joining / separating an adherend according to any one of Supplementary note 7 to 11, wherein the anion of the ionic liquid is a bis (fluorosulfonyl) imide anion.
(Appendix 13)
The method for joining / separating adherends according to Appendix 11 or 12, wherein the glass transition temperature (Tg) of the polymer is 0 ° C. or lower.
(Appendix 14)
The method for joining and separating adherends according to Appendix 13, wherein the polymer is an acrylic polymer.
(Appendix 15)
The method for joining and separating an adherend according to Appendix 14, wherein the acrylic polymer contains a monomer unit derived from a (meth) acrylic acid alkyl ester having an alkyl group having 1 to 14 carbon atoms.
(Appendix 16)
The method for joining / separating adherends according to any one of Appendix 1 to 14, wherein the thickness of the pressure-sensitive adhesive sheet is 20 μm or more and 3000 μm.

X1, X2, X3 Adhesive sheet Y1, Y2, Y4 Conductive adherends Y3, Y5, Y6 Non-conductive adherends 11,12,13 Electrolyte-containing adhesive layer 21,22,23 Electrolyte-free adhesive layer 30 , 40,50 Energizing base material 31, 41, 51 Base material 32, 42, 52 Conductive layer

Claims (11)

After bonding the pressure-sensitive adhesive sheet containing at least the pressure-sensitive adhesive layer containing an electrolyte to the adherend, a voltage of less than 20 V is applied to the pressure-sensitive adhesive layer so as to generate a potential difference in the thickness direction of the pressure-sensitive adhesive layer. A method of joining and separating adherends to separate the adherends. In a pressure-sensitive adhesive sheet containing at least a pressure-sensitive adhesive layer containing an electrolyte,
After joining one surface of the pressure-sensitive adhesive layer to the first conductive adherend and joining the other surface of the pressure-sensitive adhesive layer to the second conductive adherend,
By applying a voltage of less than 20 V to the pressure-sensitive adhesive layer via the first conductive adherend and the second conductive adherend,
A method for joining / separating an adherend, which separates the first conductive adherend and the second conductive adherend from the pressure-sensitive adhesive layer. An electrolyte-containing pressure-sensitive adhesive layer, an electrolyte-free pressure-sensitive adhesive layer, and an electrolyte-containing pressure-sensitive adhesive layer located between the electrolyte-containing pressure-sensitive adhesive layer and the electrolyte-free pressure-sensitive adhesive layer. In an adhesive sheet having a laminated structure including a conductive layer to be bonded to the layer,
After joining the pressure-sensitive adhesive layer containing the electrolyte and the conductive adherend, and sticking the pressure-sensitive adhesive layer not containing the electrolyte with another adherend,
By applying a voltage of less than 20 V to the pressure-sensitive adhesive layer containing the electrolyte via the conductive layer and the conductive adherend.
A method for joining / separating an adherend, which separates the conductive adherend and the other adherend from the pressure-sensitive adhesive layer containing the electrolyte. A first pressure-sensitive adhesive layer containing no electrolyte, a pressure-sensitive adhesive layer containing an electrolyte, a second pressure-sensitive adhesive layer containing no electrolyte, and a first pressure-sensitive adhesive layer containing no electrolyte and a pressure-sensitive adhesive containing the electrolyte. A first conductive layer that is located between the agent layer and joins with the pressure-sensitive adhesive layer containing the electrolyte, and a second pressure-sensitive adhesive layer that does not contain the electrolyte and a pressure-sensitive adhesive layer that contains the electrolyte. In a pressure-sensitive adhesive sheet having a laminated structure including a second conductive layer to be bonded to a pressure-sensitive adhesive layer containing the electrolyte, which is located in between.
After the first pressure-sensitive adhesive layer and the first adherend that do not contain the electrolyte are attached, and the second pressure-sensitive adhesive layer that does not contain the electrolyte and the second adherend are attached.
By applying a voltage of less than 20 V to the pressure-sensitive adhesive layer containing the electrolyte via the first conductive layer and the second conductive layer.
A method for joining and separating adherends, which separates the first adherend and the second adherend from the pressure-sensitive adhesive layer containing the electrolyte. The method for joining / separating an adherend according to any one of claims 1 to 4, wherein the pressure-sensitive adhesive layer containing the electrolyte has a thickness of 1 μm or more and 1000 μm or less. The method for joining / separating adherends according to any one of claims 1 to 5, wherein the application time of the voltage is 60 seconds or less. The method for joining / separating an adherend according to any one of claims 1 to 6, wherein the electrolyte is an ionic liquid. The anions of the ionic liquid are (FSO ₂ ) ₂ N ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (CF ₃ CF ₂ SO ₂ ) ₂ N ⁻ , (CF ₃ SO ₂ ) ₃ C ⁻ , CH ₃ COO. ⁻ , CF ₃ COO ⁻ , CF ₃ CF ₂ CF ₂ COO ⁻ _, CF ₃ SO ₃ ⁻ , CF ₃ (CF ₂ ) ₃ SO ₃ ⁻ , Br ⁻ , AlCl ₄ ⁻ , Al ₂ Cl ₇ ⁻ , NO ₃ ⁻ , ^{_{BF 4 -, PF 6 -,}} AsF 6 -, SbF 6 -, and F _{(HF) n} ^- _(n is an integer of 1 or more) is at least one anion selected from the group consisting of, claim 7 The method for joining / separating adherends according to. The adherend according to claim 7 or 8, wherein the cation of the ionic liquid is at least one cation selected from the group consisting of an imidazolium-based cation, a pyridinium-based cation, a pyrrolidinium-based cation, and an ammonium-based cation. Joining / separating method. The method for joining / separating an adherend according to any one of claims 7 to 9, wherein the ionic liquid has a molecular weight of 200 or less. The pressure-sensitive adhesive composition for forming the pressure-sensitive adhesive layer containing the electrolyte contains a polymer, and the content of the ionic liquid is 0.5 parts by mass or more and 30 parts by mass or less with respect to 100 parts by weight of the polymer. The method for joining / separating an adherend according to any one of claims 7 to 10.

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