JP2020063391A - Adhesive body, adhesive, method for producing binding body and method for peeling adhesive body - Google Patents

Abstract

To provide an adhesive body that can express high adhesion and can be easily peeled.SOLUTION: An adhesive body has an adhesive surface containing an adhesive component, and a decomposable adhesion face containing a π conjugated compound represented by the formula (1) [where Ris a group having at least one C3 to 20 alkyl group, and n is an integer of 1-3. A plurality of Rmay be the same or different, and a plurality of n may be the same or different].SELECTED DRAWING: Figure 1

Description

  The present invention relates to an adhesive body using a π-conjugated compound. The present invention also relates to a pressure-sensitive adhesive using a π-conjugated compound. The present invention also relates to a method for manufacturing a bonded body using the above-mentioned pressure-sensitive adhesive body. Furthermore, the present invention relates to a peeling method for peeling an adhesive body from a bonded body.

  BACKGROUND ART Conventionally, there has been studied a pressure-sensitive adhesive that can continuously maintain an adhesive state and can be easily peeled off when peeled. For example, Patent Document 1 discloses an easily peelable pressure-sensitive adhesive sheet having a print area in which a partial non-adhesive area is formed on an adhesive surface.

JP, 2008-075072, A

  However, it is difficult for the conventional easily peelable pressure-sensitive adhesive to have both adhesive strength and easy peelability. For example, the easily peelable pressure-sensitive adhesive sheet of Patent Document 1 has a non-adhesive region on the pressure-sensitive adhesive surface, and thus it is difficult to exhibit high adhesive strength. Further, if the non-adhesive region is enlarged to improve the peeling property, the adhesive force may be further reduced.

  An object of the present invention is to provide a pressure-sensitive adhesive body that can exhibit high adhesive strength and can be easily peeled off. Further, the present invention aims to provide a pressure-sensitive adhesive capable of forming the pressure-sensitive adhesive body, a bonded body obtained by bonding the pressure-sensitive adhesive body and an adherend, and a peeling method for peeling the pressure-sensitive adhesive body from the bonded body. To do.

  In order to achieve the above-mentioned objects, the present inventors have a special π-conjugated skeleton that has both features of a highly planar and rigid π-conjugated skeleton and a flexible π-conjugated skeleton that can convert molecular physical properties according to the movement of the molecular skeleton. Attention was paid to the conjugated compound. Then, they have found that the use of the π-conjugated compound makes it possible to form a pressure-sensitive adhesive body that has both high adhesive strength and easy peeling property.

［式中、Ｒ^１は炭素原子数３〜２０のアルキル基を少なくとも一つ有する基を示し、ｎは１〜３の整数を示す。複数のＲ^１は互いに同一であっても異なっていてもよく、複数のｎは互いに同一であっても異なっていてもよい。］ A first aspect of the present invention relates to a pressure-sensitive adhesive body including a pressure-sensitive adhesive surface containing a pressure-sensitive adhesive component and a disassembly adhesive surface containing a π-conjugated compound represented by the following formula (1).

[In the formula, R ¹ represents a group having at least one alkyl group having 3 to 20 carbon atoms, and n represents an integer of 1 to 3. A plurality of R ¹ may be the same or different from each other, and a plurality of n may be the same or different from each other. ]

  The π-conjugated compound has a rigid acene skeleton and a flexible cyclooctatetraene skeleton. Further, the π-conjugated compound has a temperature range showing a solid state, a temperature range showing a liquid crystal state, and a temperature range showing a liquid state, and a temperature range showing a liquid crystal state or a temperature exceeding the temperature range. The adhesive force can be exhibited by bringing the adherend into contact with and then cooling it to a solid state. Further, the above π-conjugated compound hardly changes in physical properties even when irradiated with light in the solid state, but when irradiated with light in the liquid crystal state, a part of the molecular structure is changed to be transferred to a fluid liquid state. Therefore, the dismantling adhesive surface containing the π-conjugated compound can exhibit an adhesive force, and the adhesive force can be easily reduced by irradiating light in a predetermined temperature range. .

  The pressure-sensitive adhesive body has a pressure-sensitive adhesive surface and a disassembly adhesive surface. Therefore, at the time of sticking to an adherend, a high adhesive force can be expressed by contribution of both the adhesive surface and the dismantling adhesive surface. Further, at the time of peeling, the peeling can be easily performed by irradiating light under a predetermined temperature range to reduce the adhesive force of the disassembly adhesive surface.

  A second aspect of the present invention is a pressure-sensitive adhesive layer containing a pressure-sensitive adhesive component, a disassembly adhesive layer disposed on the pressure-sensitive adhesive layer and containing a π-conjugated compound represented by the above formula (1), The present invention relates to an adhesive body.

  When such a pressure-sensitive adhesive body has a disassembling adhesive layer partially formed on the pressure-sensitive adhesive layer, the adhesive surface of the pressure-sensitive adhesive layer and the dismantling property of the disassembling adhesive layer when pressed against the adherend. The adhesive surface can be brought into contact with the adherend. In addition, even when the disassembling adhesive layer is formed on the entire surface of the pressure-sensitive adhesive layer, a strong pressure is applied when sticking to the adherend to break a part of the disassembling adhesive layer. By applying a pressure-sensitive adhesive layer on the joint surface with the adherend by a method such as stretching in-plane before sticking to the body or peeling off a part of the dismantling adhesive layer before sticking to the adherend. It is possible to form a sticky surface and a disassembly adhesive surface by the disassembly adhesive layer. Therefore, according to the above-mentioned pressure-sensitive adhesive body, when it is attached to an adherend, a high adhesive force can be expressed by the contribution of both the pressure-sensitive adhesive surface and the disassembly adhesive surface. Further, at the time of peeling, the peeling can be easily performed by irradiating light under a predetermined temperature range to reduce the adhesive force of the disassembly adhesive surface.

  The third aspect of the present invention relates to a pressure-sensitive adhesive body including a pressure-sensitive adhesive layer containing a pressure-sensitive adhesive component and a π-conjugated compound represented by the above formula (1).

  In such an adhesive, the presence of the adhesive component and the π-conjugated compound on the joint surface with the adherend makes it possible to realize a high adhesive force by their contribution. Further, at the time of peeling, the π-conjugated compound can be fluidized by light irradiation in a predetermined temperature range, and the peelability of the pressure-sensitive adhesive layer can be improved.

［式中、Ｒ^２は炭素原子数３〜２０のアルキル基又は炭素原子数３〜２０のアルコキシ基を示し、ｐは１〜５の整数を示す。ｐが２以上のとき、複数のＲ^２は互いに同一であっても異なっていてもよい。］ The above R ¹ may be a group represented by the following formula (2).

[In the formula, R ² represents an alkyl group having 3 to 20 carbon atoms or an alkoxy group having 3 to 20 carbon atoms, and p represents an integer of 1 to 5. When p is 2 or more, a plurality of R ² may be the same or different. ]

The π-conjugated compound in which R ¹ is the group represented by the above formula (2) is easy to produce, and the temperature range in which the liquid crystal state is exhibited can be appropriately adjusted by changing R ² and p.

  The π-conjugated compound may exhibit a liquid crystal state in at least a partial temperature range of 35 to 150 ° C. The pressure-sensitive adhesive body using such a π-conjugated compound can be peeled off in a temperature range in which the adherend is less likely to be adversely affected.

  The above-mentioned adhesive component may contain at least one selected from the group consisting of an adhesive resin and a tackifier.

The storage elastic modulus of the pressure-sensitive adhesive composed of the above-mentioned pressure-sensitive adhesive component may be 10 ³ Pa to 10 ⁷ Pa.

［式中、Ｒ^１は炭素原子数３〜２０のアルキル基を少なくとも一つ有する基を示し、ｎは１〜３の整数を示す。複数のＲ^１は互いに同一であっても異なっていてもよく、複数のｎは互いに同一であっても異なっていてもよい。］ The fourth aspect of the present invention relates to a pressure-sensitive adhesive containing a pressure-sensitive adhesive component and a π-conjugated compound represented by the following formula (1).

[In the formula, R ¹ represents a group having at least one alkyl group having 3 to 20 carbon atoms, and n represents an integer of 1 to 3. A plurality of R ¹ may be the same or different from each other, and a plurality of n may be the same or different from each other. ]

［式中、Ｒ^２は炭素原子数３〜２０のアルキル基又は炭素原子数３〜２０のアルコキシ基を示し、ｐは１〜５の整数を示す。ｐが２以上のとき、複数のＲ^２は互いに同一であっても異なっていてもよい。］ The above R ¹ may be a group represented by the following formula (2).

[In the formula, R ² represents an alkyl group having 3 to 20 carbon atoms or an alkoxy group having 3 to 20 carbon atoms, and p represents an integer of 1 to 5. When p is 2 or more, a plurality of R ² may be the same or different. ]

  A fifth aspect of the present invention is a method for producing a joined body in which the pressure-sensitive adhesive body and an adherend are joined together, wherein the pressure-sensitive adhesive body is pressed against the adherend to give the pressure-sensitive adhesive body and the adherend. The present invention relates to a method for manufacturing a joined body, including a joining step of joining and.

  The bonding step may be a step of pressing the pressure-sensitive adhesive body to the adherend at a temperature range in which the π-conjugated compound exhibits a liquid crystal state or at a temperature higher than the temperature range. According to such a bonding step, the π-conjugated compound contributes to the adhesiveness and the sticky body is firmly bonded to the adherend.

  The manufacturing method may further include a heating step of heating the bonding surface between the adhesive body and the adherend to a temperature range in which the π-conjugated compound exhibits a liquid crystal state or a temperature exceeding the temperature range. According to such a heating step, the π-conjugated compound contributes to the adhesiveness, so that the tacky body temporarily bonded in the bonding step is firmly bonded to the adherend.

  A sixth aspect of the present invention is a method of peeling the adhesive body from a joined body in which the adhesive body and the adherend are joined, wherein at least one of the joint surfaces of the adhesive body and the adherend is The method relates to a method for peeling an adhesive body, which comprises a step of irradiating a part with light in a temperature range in which the π-conjugated compound exhibits a liquid crystal state. In such a peeling method, since the contribution of the π-conjugated compound to the adhesiveness is eliminated by the light irradiation, the pressure sensitive adhesive body can be easily peeled off.

  ADVANTAGE OF THE INVENTION According to this invention, the adhesive body which can express high adhesive force and can be peeled easily is provided. Further, according to the present invention, there are provided a pressure-sensitive adhesive capable of forming the pressure-sensitive adhesive body, a bonded body obtained by bonding the pressure-sensitive adhesive body and an adherend, and a peeling method for peeling the pressure-sensitive adhesive body from the bonded body.

It is sectional drawing which shows one suitable form of an adhesive body. (A) is a top view which shows one suitable form of an adhesive body, (b) is sectional drawing which shows the cross section along II-II. (A) is a top view which shows one suitable form of an adhesive body, (b) is sectional drawing which shows the cross section along III-III. It is sectional drawing which shows one suitable form of an adhesive body. It is sectional drawing which shows one suitable form of an adhesive body. It is sectional drawing which shows one suitable form of an adhesive body. It is sectional drawing which shows one suitable form of an adhesive body.

  A preferred embodiment of the present invention will be described below.

(Π-conjugated compound)
The π-conjugated compound according to this embodiment is a compound represented by the following formula (1).

In the formula, R ¹ represents a group having at least one alkyl group having 3 to 20 carbon atoms, and n represents an integer of 1 to 3. A plurality of R ¹ may be the same or different from each other, and a plurality of n may be the same or different from each other.

  The π-conjugated compound has a temperature range showing a solid state, a temperature range showing a liquid crystal state, and a temperature range showing a liquid state, and is exposed to a temperature range showing a liquid crystal state or a temperature exceeding the temperature range. The adhesive force can be developed by bringing the adhesive body into contact with it and then cooling it to a solid state. Further, the above π-conjugated compound hardly changes in physical properties even when irradiated with light in the solid state, but when irradiated with light in the liquid crystal state, a part of the molecular structure is changed to be transferred to a fluid liquid state. Therefore, according to the π-conjugated compound, it is possible to form an adhesive force, and it is possible to form a disassembling adhesive surface which can easily reduce the adhesive force by irradiating light in a predetermined temperature range. .

  After the light irradiation in the liquid crystal state, the molecular structure of the π-conjugated compound is returned to the initial state by, for example, heating the π-conjugated compound to a temperature at which the π-conjugated compound exhibits a liquid state (for example, a temperature exceeding 150 ° C.) and then cooling. Can be returned. That is, the dismantling adhesive surface containing the π-conjugated compound can be reused by being subjected to a heat treatment after being peeled from the adherend.

  More specifically, the π-conjugated compound is considered to have a V-shaped molecular skeleton bent with a cyclooctatetraene skeleton, and has an integrated structure in which the V-shaped molecular skeletons are stacked in a certain temperature range. It is considered that the liquid crystal state is shown by taking it.

The following formula (1-a) is a V-shaped compound in which R ¹ of the formula (1) is a group having an alkyl group having 12 carbon atoms and n is 2 as an example. It is a formula for explaining the molecular skeleton. Other π-conjugated compounds also have the same V-shaped molecular skeleton.

  It is considered that the π-conjugated compound forms a dimer by photodimerization reaction of an acene skeleton or a cyclooctatetraene skeleton when it is irradiated with light in a liquid crystal state. Then, it is considered that a part of the π-conjugated compound in the liquid crystal state is dimerized, the above-mentioned integrated structure is broken, the liquid crystal state is changed to the liquid state, and fluidity is exhibited. Further, this dimerization reaction is caused by light irradiation in the liquid crystal state, and does not occur by light irradiation in the solid state, so that fluidization does not occur even when light is irradiated in the temperature range showing the solid state. .

  Further, in the π-conjugated compound, it is considered that the π-conjugated compound is heated to a temperature at which the π-conjugated compound is in a liquid state to cause a reverse reaction of the dimerization reaction to generate a monomer from the dimer. Therefore, the π-conjugated compound is heated again to cause a reverse reaction of the dimerization reaction even when a dimer is mixed due to light irradiation in the liquid crystal state and the liquid crystal state is no longer exhibited. Will be shown.

  The light irradiation may be performed as long as the π-conjugated compound in the liquid crystal state can form a dimer. For example, the light irradiation may be irradiation with ultraviolet rays having a wavelength of 300 to 400 nm. With such ultraviolet rays, the π-conjugated compound in the liquid crystal state can be easily fluidized.

  Further, when n in the formula (1) is 1, the irradiated light preferably includes light having a wavelength of 254 nm, and when n in the formula (1) is 2, the irradiated light has a wavelength of 365 nm. It is preferable to include the ultraviolet rays. This makes it possible to efficiently fluidize the π-conjugated compound.

In formula (1), R ¹ represents a group having at least one alkyl group having 3 to 20 carbon atoms. When R ¹ is such a group, a π-conjugated compound which has a rigid acene skeleton and a flexible cyclooctatetraene skeleton and exhibits a liquid crystal state in a predetermined temperature range is realized. In such a π-conjugated compound, the temperature range in which the liquid crystal state is exhibited can be easily adjusted by changing the number of carbon atoms of the alkyl group contained in R ¹ .

The alkyl group contained in R ¹ may be branched or linear, but is preferably linear. The number of carbon atoms in the alkyl group is preferably 4-20, more preferably 6-20. A plurality of R ¹ 's may be the same or different, but are preferably the same. A π-conjugated compound in which a plurality of R ¹ 's are the same has an advantage of easy production.

  In Formula (1), n shows the integer of 1-3. n may be the same as or different from each other, but are preferably the same. A π-conjugated compound in which a plurality of n's are the same has an advantage of easy production.

As R ¹ , a group represented by the following formula (2) is preferable. Such a π-conjugated compound having R ¹ can be easily produced by the production method described below. Further, such a π-conjugated compound can easily adjust the temperature range in which it exhibits a liquid crystal state by changing R ² and p.

In the formula, R ² represents an alkyl group having 3 to 20 carbon atoms or an alkoxy group having 3 to 20 carbon atoms, and p represents an integer of 1 to 5. When p is 2 or more, a plurality of R ² may be the same or different.

The alkyl group for R ² may be branched or linear, but is preferably linear. The number of carbon atoms in the alkyl group is preferably 4-20, more preferably 6-20.

The alkoxy group for R ² may be branched or linear, but is preferably linear. Moreover, the number of carbon atoms of the alkoxy group is preferably 4 to 20, and more preferably 6 to 20.

  p is preferably 1 to 3, and more preferably 1 or 2.

Among the groups represented by the formula (2), R ¹ is particularly preferably a group represented by the following formula (2-1), (2-2), (2-3) or (2-4). is there.

R ¹ is not limited to the above groups and may be any group having at least one alkyl group having 3 to 20 carbon atoms. R ¹ may be a group that imparts liquid crystallinity to the π-conjugated compound, and R ¹ may be a group selected so that the π-conjugated compound exhibits a liquid crystal state in a predetermined temperature range. Further, R ¹ can also be selected from all substituents introduced for imparting liquid crystallinity, such as those described in Chemical Review, 2009, vol 109, 6275-6540.

  The π-conjugated compound preferably exhibits a liquid crystal state in at least a partial temperature range of 35 to 150 ° C. (more preferably 40 to 140 ° C., further preferably 70 to 100 ° C.). The pressure-sensitive adhesive body using such a π-conjugated compound can be peeled off in a temperature range in which the adherend is less likely to be adversely affected.

  The temperature range in which the π-conjugated compound exhibits a liquid crystal state is preferably 35 ° C or higher, more preferably 40 ° C or higher, and further preferably 50 ° C or higher. When the temperature range showing the liquid crystal state is 35 ° C. or higher, fluidization due to unexpected light irradiation during the process hardly occurs.

  The temperature range in which the π-conjugated compound exhibits a liquid crystal state is preferably 150 ° C. or lower, more preferably 145 ° C. or lower. Since such a π-conjugated compound can relatively easily bring the π-conjugated compound into a liquid crystal state, the use of such a π-conjugated compound facilitates adhesion and peeling of the pressure-sensitive adhesive body.

(Method for producing π-conjugated compound)
One aspect of the method for producing the π-conjugated compound will be described below. The production method of this embodiment includes a step of reacting a tetraformyl compound represented by the following formula (3) with 2-butenedioic acid diester. In the formula, n represents an integer of 1 to 3.

By the reaction of such a tetraformyl compound and 2-butenedioic acid diester, the acene skeleton can be extended and two ester groups can be provided on each of the benzene rings at both ends. That is, according to the above reaction, a compound represented by the following formula (5) can be obtained. In the formula, R ³ represents a group derived from the ester moiety of 2-butenedioic acid diester.

The compound represented by the formula (5) corresponds to the compound represented by the formula (1) when R ³ is a group having at least one alkyl group having 3 to 20 carbon atoms. That is, when the 2-butenedioic acid diester having a group corresponding to R ¹ of the formula (1) in the ester portion is used as the 2-butenedioic acid diester, the π-conjugated compound can be obtained by the above reaction. As the 2-butenedioic acid diester, fumaric acid diester or maleic acid diester can be used.

Here, the 2-butenedioic acid diester having a group corresponding to R ¹ of the formula (1) in the ester portion can be represented by the following formula (4-1) or (4-2). Wherein, ^{R 1} has the same meaning as ^{R 1} in formula (1).

Further, in the compound represented by the formula (5), R ³ does not have to be a group corresponding to R ¹ in the formula (1). In this case, the π-conjugated compound can be obtained by transesterifying the compound represented by the formula (5) to convert R ³ into a group corresponding to R ¹ in the formula (1).

  The tetraformyl compound represented by the formula (3) can be produced by a known method. Am. Chem. Soc. , 2013, 135, 8842 (Yuan, C .; Saito, S .; Camacho, C .; Irle, S .; Hisaki, I .; Yamaguchi, S.) and the like.

  The reaction conditions for the tetraformyl compound and 2-butenedioic acid diester are, for example, C.I. Lin et al, Chem. Commun. 2009, 45, 803, Y. Lin et al, Org. Biomol. Chem. It can be appropriately set with reference to the description of the extension reaction of acenes described in 2011, 9, 4507.

  For example, the above reaction can be carried out by reacting a tetraformyl compound with a 2-butenedioic acid diester in the presence of tributylphosphine and diazabicycloundecene in a methylene chloride solvent under a nitrogen atmosphere. The compound obtained by the reaction can be purified by, for example, column chromatography (silica gel column chromatography and / or high performance liquid chromatography).

  As the reaction solvent used in the above reaction, in addition to the above-mentioned methylene chloride, for example, a halogen-based solvent such as 1,2-dichloroethane or an aromatic solvent such as toluene can be used.

  In the above reaction, a trialkylphosphine such as trimethylphosphine, triethylphosphine and tripropylphosphine may be used instead of the above tributylphosphine. Further, in the above reaction, the above-mentioned base of diazabicycloundecene can be used. Specifically, strong bases such as potassium tert-butoxide and sodium hydride can be preferably used.

  The reaction temperature of the above reaction can be, for example, 25 ° C. or higher, and may be raised to the boiling point of the solvent used.

(Adhesive body)
The pressure-sensitive adhesive body according to the present embodiment may be one that achieves both high adhesion to an adherend and easy peelability by combining the pressure-sensitive adhesive component and the π-conjugated compound.

  The pressure-sensitive adhesive body according to the present embodiment can exhibit a high adhesive force due to the contributions of both the pressure-sensitive adhesive component and the π-conjugated compound. Further, by irradiating with light in a predetermined temperature range, the contribution of the π-conjugated compound to the adhesiveness can be reduced, so that it can be easily peeled from the adherend.

  Further, in the pressure-sensitive adhesive body according to the present embodiment, while the pressure-sensitive adhesive component exhibits tackiness at room temperature, the π-conjugated compound does not exhibit tackiness in the solid state, and in order to exhibit adhesive force, the liquid crystal state or liquid state is used. Need to be transferred to the state. Due to such a difference in adhesion form, the pressure-sensitive adhesive body according to the present embodiment can be applied to various bonding methods such as temporary bonding by the function of the pressure-sensitive adhesive component and then bonding by expressing the function of the π-conjugated compound.

  Further, the pressure-sensitive adhesive body according to the present embodiment can be applied to various applications because the adhesive strength and the peeling property can be adjusted by changing the ratio of the pressure-sensitive adhesive component and the π-conjugated compound on the bonding surface with the adherend.

  In one aspect, the pressure-sensitive adhesive body may be provided with a pressure-sensitive adhesive surface containing a pressure-sensitive adhesive component and a disassembly adhesive surface containing the π-conjugated compound. Such an adhesive can exhibit a high adhesive force when it is attached to an adherend due to the contribution of both the adhesive surface and the disassembly adhesive surface. Further, at the time of peeling, the peeling can be easily performed by irradiating light under a predetermined temperature range to reduce the adhesive force of the disassembly adhesive surface.

  The above-mentioned pressure-sensitive adhesive body may include the above-mentioned pressure-sensitive adhesive surface and the above-mentioned dismantling adhesive surface in the bonding surface with the adherend, and it is not necessary to have the above-mentioned form before bonding with the adherend. .

  In one aspect, the pressure-sensitive adhesive body may include a pressure-sensitive adhesive layer containing a pressure-sensitive adhesive component, and a disassembling adhesive layer disposed on the pressure-sensitive adhesive layer and containing the π-conjugated compound.

  In the pressure-sensitive adhesive body, a disassembling adhesive layer may be partially formed on the pressure-sensitive adhesive layer. In this case, the pressure-sensitive adhesive surface of the adhesive layer and the disbondable adhesive surface of the disassembling adhesive layer can be brought into contact with the adherend by pressing against the adherend.

  Further, the adhesive body may have a disassembly adhesive layer formed on the entire surface of the adhesive layer. In this case, when it is attached to the adherend, it is strongly pressed to break a part of the disintegrating adhesive layer, it is stretched in the in-plane direction before being attached to the adherend, and disassembled before being attached to the adherend. The adhesive surface formed by the adhesive layer and the disassembly adhesive surface formed by the disassembly adhesive layer can be formed on the joint surface with the adherend by a method such as peeling off a part of the adhesive adhesive layer.

  In one aspect, the pressure-sensitive adhesive body has a pressure-sensitive adhesive portion containing a pressure-sensitive adhesive component, and a dismantling adhesive portion containing a π-conjugated compound, and a pressure-sensitive adhesive surface made of the pressure-sensitive adhesive portion and a disassembling adhesive surface made of the dismantleable adhesive portion. It may have a joint surface having.

  The above-mentioned pressure-sensitive adhesive body may have, for example, a structure in which a disperse phase including a dismantling adhesive portion is dispersed in a continuous phase including a pressure-sensitive adhesive portion. In addition, the above-mentioned pressure-sensitive adhesive body may have a structure in which a disperse phase including a pressure-sensitive adhesive portion is dispersed in a continuous phase including a disassembling adhesive portion. Further, the pressure-sensitive adhesive body may have a structure in which a pressure-sensitive adhesive portion and a disassembling adhesive portion are respectively formed on a base material, and a plurality of pressure-sensitive adhesive portions and disassembling adhesive portions may be formed respectively, and they are in contact with each other. They may be separated or separated.

  In one aspect, the pressure-sensitive adhesive body may include a pressure-sensitive adhesive layer composed of a pressure-sensitive adhesive containing a pressure-sensitive adhesive component and a π-conjugated compound. Such an adhesive body can be regarded, for example, as a mixture of a fine adhesive surface and a disassembly adhesive surface on the adhesive layer.

  The pressure-sensitive adhesive body can firmly adhere the pressure-sensitive adhesive layer to the adherend due to the contributions of both the pressure-sensitive adhesive component and the π-conjugated compound. In addition, the pressure-sensitive adhesive body has a reduced adhesive force and can be easily peeled off.

  In the present embodiment, the adhesive component is not particularly limited as long as it can be used as an adhesive. As the adhesive component, for example, a known adhesive may be used.

  The adhesive component may be, for example, a composition capable of forming an adhesive (pressure-sensitive adhesive) that exhibits adhesiveness at room temperature (for example, 25 ° C.).

The storage elastic modulus of the pressure-sensitive adhesive composed of the pressure-sensitive adhesive component may be, for example, 10 ³ Pa to 10 ⁷ Pa.

  The adhesive component may contain at least one selected from the group consisting of an adhesive resin and a tackifier, for example. The adhesive resin may be a known adhesive resin, for example, a resin having the above-mentioned storage elastic modulus. The tackifier may be a known tackifier, for example, petroleum resin, terpene resin, terpene phenol resin, aromatic modified terpene resin, coumarone-indene resin, natural resin rosin, modified rosin, glycerin ester rosin, It may be pentaerythritol ester rosin, phenol resin, xylene resin, alicyclic petroleum resin, styrene resin, dicyclopentadiene resin and the like. These may be used alone or in combination of two or more.

  In the present embodiment, the disassembling adhesive layer and the disassembling adhesive portion may contain components other than the π-conjugated compound within the range in which the effects of the present invention are exhibited. Examples of other components include thermoplastic polymers such as poly (meth) acrylic acid ester, polysiloxane, polyimide, polyamideimide, polyester, polyamide, and styrene-based polymer; (meth) acrylic acid ester, epoxy-based compound, and the like. Curable monomer component; photoinitiator and the like can be mentioned.

  Hereinafter, a suitable form of the adhesive body will be described with reference to the drawings. Note that the drawings are partially exaggerated for easy understanding, and dimensional ratios and the like are not limited to those illustrated in the drawings.

(First form)
FIG. 1 is a cross-sectional view showing a preferred form of an adhesive body. The pressure-sensitive adhesive body 10 shown in FIG. 1 includes a disassembling adhesive layer 11 containing a π-conjugated compound, a pressure-sensitive adhesive layer 12 containing a pressure-sensitive adhesive component, and a substrate 13. The pressure-sensitive adhesive body 10 includes the dismantling adhesive layer 11 on one main surface of the pressure-sensitive adhesive layer 12, and the base material 13 on the other main surface of the pressure-sensitive adhesive layer 12.

  The pressure-sensitive adhesive body 10 may be, for example, a tape-shaped or film-shaped pressure-sensitive adhesive body in which one main surface is composed of the disassembly adhesive layer 11 and the other main surface is composed of the base material 13. Since the pressure-sensitive adhesive layer 12 is less exposed, the pressure-sensitive adhesive body 10 is excellent in handleability during storage and use.

  The pressure-sensitive adhesive body 10 is bonded to the adherend on the surface (bonding surface) on the disassembly adhesive layer 11 side. For example, in the pressure sensitive adhesive body 10, the pressure sensitive adhesive body 10 is arranged on the adherend such that the disassembling adhesive layer 11 and the adherend are in contact with each other, and the pressure sensitive adhesive body 10 is strongly pressed against the adherend to form the dismantling adhesive layer. By breaking a part of 11, the pressure-sensitive adhesive layer 12 and the adherend can be brought into contact with each other and temporarily adhered to the adherend.

  Further, the pressure-sensitive adhesive body 10 may expose the pressure-sensitive adhesive layer 12 on the joint surface by stretching in the in-plane direction and breaking a part of the disassembly adhesive layer 11. In this case, by lightly pressing the pressure-sensitive adhesive body 10 arranged on the adherend, the pressure-sensitive adhesive layer 12 and the adherend adhere to each other, and the pressure-sensitive adhesive body 10 can be temporarily adhered to the adherend.

  In the pressure-sensitive adhesive body 10, the pressure-sensitive adhesive layer 12 may be exposed on the bonding surface by peeling off a part of the disassembling adhesive layer 11. In this case, by lightly pressing the pressure-sensitive adhesive body 10 arranged on the adherend, the pressure-sensitive adhesive layer 12 and the adherend adhere to each other, and the pressure-sensitive adhesive body 10 can be temporarily adhered to the adherend.

  The pressure-sensitive adhesive body 10 temporarily adhered to the adherend is heated to a temperature range in which the π-conjugated compound exhibits a liquid crystal state or a temperature exceeding the temperature range, and then cooled to a temperature range in which the π-conjugated compound exhibits a solid state. Thereby, it can be firmly bonded to the adherend.

  The pressure-sensitive adhesive body 10 may be bonded to the adherend by pressing the pressure-sensitive adhesive body 10 against the adherend while being heated to a temperature range in which the π-conjugated compound exhibits a liquid crystal state or a temperature exceeding the temperature range. In this case, the fluidized disassembly adhesive layer 11 is pushed away and a part of the pressure-sensitive adhesive layer 12 comes into contact with the adherend, whereby the adhesive force of the pressure-sensitive adhesive layer 12 is developed. In addition, after being attached to the adherend, the π-conjugated compound is cooled to a temperature range in which it is in a solid state, so that the adhesive force of the dismantling adhesive layer 11 is developed, and the adhesive body 10 and the adherend are firmly bonded to each other. To be joined.

  As long as the π-conjugated compound can form a laminated structure, the disassemblable adhesive layer 11 can exhibit an adhesive force even when it is extremely thin. From this viewpoint, the thickness of the disassembling adhesive layer 11 may be, for example, 0.1 μm or more. In addition, the thickness of the disassembling adhesive layer 11 may be, for example, 50 μm or less, preferably 30 μm or less, from the viewpoint of facilitating breakage of the disassembling adhesive layer 11 and from the viewpoint of cost reduction. The following is more preferable.

  The thickness of the pressure-sensitive adhesive layer 12 is not particularly limited, and may be, for example, a thickness that allows the pressure-sensitive adhesive layer 12 to flow into the breaking point of the disassembling adhesive layer 11 and come into contact with the adherend. The thickness of the pressure-sensitive adhesive layer 12 may be appropriately changed depending on the type of pressure-sensitive adhesive forming the pressure-sensitive adhesive layer 12, the application of the pressure-sensitive adhesive body 10, and the like. The pressure-sensitive adhesive layer 12 may have a thickness of, for example, 0.1 to 100 μm, and preferably 0.1 to 60 μm.

  In FIG. 1, the pressure-sensitive adhesive body 10 includes a base material 13 on the main surface of the pressure-sensitive adhesive layer 12 opposite to the disassembling adhesive layer 11. Note that the pressure-sensitive adhesive body 10 does not necessarily have to include a base material, and may be composed of the disassembling adhesive layer 11 and the pressure-sensitive adhesive layer 12.

  The type and shape of the base material 13 are not particularly limited, and can be appropriately changed depending on the type of the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer 12, the use of the pressure-sensitive adhesive body 10, and the like. The base material 13 may be, for example, a metal base material, an inorganic base material, a resin base material, or the like. The shape of the base material 13 may be, for example, a film shape, a tape shape, a rectangular parallelepiped shape, or the like.

  The base material 13 may be one of the members constituting the assembly together with the adherend. Moreover, the base material 13 may be a support member or a protection member that is temporarily attached to an adherend.

  The adhesive body 10 may further have another structure on the surface of the base material 13 opposite to the adhesive layer 12. For example, the pressure-sensitive adhesive body 10 may further have an adhesive structure formed by a combination of a pressure-sensitive adhesive component and a π-conjugated compound on the surface of the base material 13 opposite to the pressure-sensitive adhesive layer 12. The adhesive structure may be, for example, the same structure as that of the disassembling adhesive layer 11 and the pressure-sensitive adhesive layer 12, or may be the same structure as the adhesive structure of another embodiment described later.

(Second form)
FIG. 2A is a top view showing a preferred form of the pressure-sensitive adhesive body, and FIG. 2B is a cross-sectional view showing a II-II cross section of FIG. 2A. The pressure-sensitive adhesive body 20 shown in FIG. 2 includes a disassembling adhesive layer 21 containing a π-conjugated compound, a pressure-sensitive adhesive layer 22 containing a pressure-sensitive adhesive component, and a base material 23. The pressure-sensitive adhesive body 20 includes a plurality of strip-shaped disassembling adhesive layers 21 on one main surface of the pressure-sensitive adhesive layer 22, and a base material 23 on the other main surface of the pressure-sensitive adhesive layer 22.

  The adhesive body 20 may be, for example, a tape-shaped or film-shaped adhesive body. Since the pressure-sensitive adhesive layer 22 is partially exposed, the pressure-sensitive adhesive body 20 can be easily temporarily bonded by being pressed against the adherend. The pressure-sensitive adhesive body 20 temporarily adhered to the adherend is heated to a temperature range in which the π-conjugated compound exhibits a liquid crystal state or a temperature exceeding the temperature range, and then cooled to a temperature range in which the π-conjugated compound exhibits a solid state. Thereby, it can be firmly bonded to the adherend.

  The pressure-sensitive adhesive body 20 may be bonded to the adherend by pressing the pressure-sensitive adhesive body 20 against the adherend while being heated to a temperature range in which the π-conjugated compound exhibits a liquid crystal state or a temperature exceeding the temperature range. In this case, the adhesive force of the pressure-sensitive adhesive layer 22 is developed by the contact between the exposed part of the pressure-sensitive adhesive layer 22 and the adherend, and after the sticking to the adherend, the π-conjugated compound has a temperature range up to a solid state. By cooling, the adhesive force by the disassembling adhesive layer 21 is developed, and the adhesive body 20 and the adherend are firmly bonded.

  As long as the π-conjugated compound can form a laminated structure, the disassembly adhesive layer 21 can exhibit an adhesive force even when it is extremely thin. From this viewpoint, the thickness of the disassembling adhesive layer 21 may be, for example, 0.1 μm or more. Further, from the viewpoint of cost reduction, the thickness of the disassembling adhesive layer 21 may be, for example, 50 μm or less, preferably 30 μm or less, and more preferably 10 μm or less.

  The width of the disassembling adhesive layer 21 and the distance between the adjacent disassembling adhesive layers 21 (that is, the width of the exposed portion of the pressure-sensitive adhesive layer 22) are not particularly limited, and may be set depending on desired adhesiveness and peelability. May be changed as appropriate. Releasability is further improved by increasing the proportion of the disassembling adhesive layer 21 in the bonding surface. Further, by increasing the ratio of the pressure-sensitive adhesive layer 22 exposed on the bonding surface, the adhesive force at the time of temporary bonding and the bonding strength with the adherend are improved.

  In the pressure-sensitive adhesive body 20, the plurality of disassemblable adhesive layers 21 preferably have substantially the same width, and are preferably arranged regularly on the pressure-sensitive adhesive layer 22.

  In the pressure-sensitive adhesive body 20, the disassembling adhesive layer 21 is formed at an angle with respect to the width direction and the length direction of the tape-shaped pressure-sensitive adhesive body 20, but the angle of the disassembling adhesive layer 21 is the width direction. Alternatively, it may be parallel to the length direction. By forming the disassembling adhesive layer 21 like the pressure-sensitive adhesive body 20, the disassembling adhesive layer 21 is present at the interface with the adherend, regardless of the peeling from the width direction or the length direction. It is possible to improve the peelability.

  The thickness of the pressure-sensitive adhesive layer 22 is not particularly limited, and may be appropriately changed depending on the type of pressure-sensitive adhesive forming the pressure-sensitive adhesive layer 22, the use of the pressure-sensitive adhesive body 20, and the like. The pressure-sensitive adhesive layer 22 may have a thickness of, for example, 0.1 to 100 μm, and preferably 0.1 to 60 μm.

  In FIG. 2, the pressure-sensitive adhesive body 20 includes a base material 23 on the main surface of the pressure-sensitive adhesive layer 22 opposite to the disassembling adhesive layer 21. The pressure-sensitive adhesive body 20 does not necessarily need to include a base material, and may be composed of a disassembling adhesive layer 21 and a pressure-sensitive adhesive layer 22.

  The type and shape of the base material 23 are not particularly limited, and can be appropriately changed depending on the type of the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer 22, the use of the pressure-sensitive adhesive body 20, and the like. The base material 23 may be, for example, a metal base material, an inorganic base material, a resin base material, or the like. Further, the shape of the base material 23 may be, for example, a film shape, a tape shape, a rectangular parallelepiped shape, or the like.

  The base material 23 may be one of the members that form an assembly together with the adherend. The base material 23 may be a support member or a protection member that is temporarily attached to the adherend.

  The pressure-sensitive adhesive body 20 may further have another structure on the surface of the base material 23 opposite to the pressure-sensitive adhesive layer 22. For example, the pressure-sensitive adhesive body 20 may further have an adhesive structure formed on the surface of the base material 23 opposite to the pressure-sensitive adhesive layer 22 by combining a pressure-sensitive adhesive component and a π-conjugated compound. The adhesive structure may be, for example, the same structure as the disassembling adhesive layer 21 and the pressure-sensitive adhesive layer 22, or may be the same structure as the adhesive structure of the other embodiments of the present specification.

(Third form)
FIG. 3A is a top view showing a preferred form of the pressure-sensitive adhesive body, and FIG. 3B is a cross-sectional view showing the III-III cross section of FIG. 3A. The pressure sensitive adhesive body 30 shown in FIG. 3 includes a disassembling adhesive layer 31 containing a π-conjugated compound, a pressure sensitive adhesive layer 32 containing a pressure sensitive adhesive component, and a substrate 33. In the adhesive body 30, a plurality of disassembling adhesive layers 31 are provided apart from each other on one main surface of the adhesive layer 32, and the base material 33 is provided on the other main surface of the adhesive layer 32. It is provided.

  The adhesive body 30 may be, for example, a tape-shaped or film-shaped adhesive body. Since the pressure-sensitive adhesive layer 32 is partially exposed, the pressure-sensitive adhesive body 30 can be easily temporarily bonded by being pressed against the adherend. The pressure-sensitive adhesive body 30 temporarily adhered to the adherend is heated to a temperature range in which the π-conjugated compound exhibits a liquid crystal state or a temperature exceeding the temperature range, and then cooled to a temperature range in which the π-conjugated compound exhibits a solid state. Thereby, it can be firmly bonded to the adherend.

  In addition, the pressure-sensitive adhesive body 30 may be bonded to the adherend by being pressed against the adherend while being heated to a temperature range in which the π-conjugated compound exhibits a liquid crystal state or a temperature higher than the temperature range. In this case, the adhesive force of the pressure-sensitive adhesive layer 32 is developed due to the contact between the exposed part of the pressure-sensitive adhesive layer 32 and the adherend, and the temperature range in which the π-conjugated compound shows a solid state after being attached to the adherend. By cooling, the adhesive force by the disassembling adhesive layer 31 is developed, and the adhesive body 30 and the adherend are firmly bonded.

  If the π-conjugated compound can form a laminated structure, the dismantling adhesive layer 31 can exhibit an adhesive force even when it is extremely thin. From this viewpoint, the thickness of the disassembling adhesive layer 31 may be, for example, 0.1 μm or more. Further, from the viewpoint of cost reduction, the thickness of the disassembling adhesive layer 31 may be, for example, 50 μm or less, preferably 30 μm or less, and more preferably 10 μm or less.

  The shape of the disassembling adhesive layer 31 and the distance between the adjacent disassembling adhesive layers 21 are not particularly limited, and may be appropriately changed depending on the desired tackiness and peelability. Releasability is further improved by increasing the proportion of the disassembling adhesive layer 31 in the bonding surface. Further, by increasing the ratio of the pressure-sensitive adhesive layer 32 exposed on the bonding surface, the adhesive force at the time of temporary bonding and the bonding strength with the adherend are improved.

  In the pressure-sensitive adhesive body 30, the plurality of disassembling adhesive layers 31 preferably have substantially the same shape as each other, and are preferably arranged regularly on the pressure-sensitive adhesive layer 32.

  The thickness of the pressure-sensitive adhesive layer 32 is not particularly limited, and may be appropriately changed depending on the type of pressure-sensitive adhesive forming the pressure-sensitive adhesive layer 32, the use of the pressure-sensitive adhesive body 30, and the like. The pressure-sensitive adhesive layer 32 may have a thickness of, for example, 0.1 to 100 μm, and preferably 0.1 to 60 μm.

  In FIG. 3, the pressure-sensitive adhesive body 30 includes a base material 33 on the main surface of the pressure-sensitive adhesive layer 32 opposite to the disassembling adhesive layer 31. The adhesive body 30 does not necessarily have to include a base material, and may be composed of a disassembling adhesive layer 31 and an adhesive layer 32.

  The type and shape of the base material 33 are not particularly limited, and can be appropriately changed depending on the type of the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer 32, the use of the pressure-sensitive adhesive body 30, and the like. The base material 33 may be, for example, a metal base material, an inorganic base material, a resin base material, or the like. The shape of the base material 33 may be, for example, a film shape, a tape shape, a rectangular parallelepiped shape, or the like.

  The base material 33 may be one of the members that form an assembly together with the adherend. Further, the base material 33 may be a support member or a protection member that is temporarily attached to the adherend.

  The adhesive body 30 may further have another structure on the surface of the base material 33 opposite to the adhesive layer 32. For example, the pressure-sensitive adhesive body 30 may further have an adhesive structure formed by combining the pressure-sensitive adhesive component and the π-conjugated compound on the surface of the base material 33 opposite to the pressure-sensitive adhesive layer 32. The adhesive structure may be, for example, the same structure as the disassemblable adhesive layer 31 and the pressure-sensitive adhesive layer 32, or may be the same structure as the adhesive structure of other embodiments of the present specification.

(Fourth form)
FIG. 4 is a cross-sectional view showing a preferred form of the adhesive body. The pressure-sensitive adhesive body 40 shown in FIG. 4 includes a disassembling adhesive layer 41 containing a π-conjugated compound, a pressure-sensitive adhesive layer 42 containing a pressure-sensitive adhesive component, and a base material 43. In the pressure-sensitive adhesive body 40, the pressure-sensitive adhesive layer 42 is provided with a plurality of recesses on one main surface side, and the disassembly adhesive layer 41 is provided in the recesses. As a result, in the pressure-sensitive adhesive body 40, the disassembly adhesive surface formed by the disassembly adhesive layer 41 and the adhesion surface formed by the adhesive layer 42 are formed on the same surface.

  The adhesive 40 may be, for example, a tape-shaped or film-shaped adhesive. Since the pressure-sensitive adhesive layer 42 is partially exposed, the pressure-sensitive adhesive body 40 can be easily temporarily bonded by being pressed against the adherend. The pressure-sensitive adhesive body 40 temporarily adhered to the adherend is heated to a temperature range in which the π-conjugated compound exhibits a liquid crystal state or a temperature exceeding the temperature range, and then cooled to a temperature range in which the π-conjugated compound exhibits a solid state. Thereby, it can be firmly bonded to the adherend.

  In addition, the pressure sensitive adhesive body 40 may be bonded to the adherend by being pressed against the adherend while being heated to a temperature range in which the π-conjugated compound exhibits a liquid crystal state or a temperature exceeding the temperature range. In this case, the adhesive force of the pressure-sensitive adhesive layer 42 is developed by contact between the exposed part of the pressure-sensitive adhesive layer 42 and the adherend, and after the sticking to the adherend, the π-conjugated compound has a temperature range up to a solid state. By cooling, the adhesive force by the disassembling adhesive layer 41 is developed, and the adhesive body 40 and the adherend are firmly bonded.

  As long as the π-conjugated compound can form a laminated structure, the disassembly adhesive layer 41 can exhibit an adhesive force even when it is extremely thin. From this viewpoint, the thickness of the disassembling adhesive layer 41 may be, for example, 0.1 μm or more. From the viewpoint of cost reduction, the thickness of the disassembling adhesive layer 41 may be, for example, 50 μm or less, preferably 30 μm or less, and more preferably 10 μm or less.

  The shape of the disassembling adhesive layer 41 and the distance between the adjacent disassembling adhesive layers 41 are not particularly limited, and may be appropriately changed depending on the desired tackiness and peelability. Releasability is further improved by increasing the proportion of the disassembling adhesive layer 41 in the bonding surface. Further, by increasing the ratio of the pressure-sensitive adhesive layer 42 exposed on the bonding surface, the adhesive force at the time of temporary bonding and the bonding strength with the adherend are improved. The disassembling adhesive layer 41 may be formed to have, for example, the same top view as FIG. 2A, or may be formed to have the same top view as FIG. 3A. .

  In the pressure-sensitive adhesive body 40, the plurality of disassembling adhesive layers 41 preferably have substantially the same shape, and are preferably regularly arranged on the pressure-sensitive adhesive layer 42.

  The thickness of the pressure-sensitive adhesive layer 42 is not particularly limited, and may be appropriately changed depending on the type of pressure-sensitive adhesive forming the pressure-sensitive adhesive layer 42, the use of the pressure-sensitive adhesive body 40, and the like. The pressure-sensitive adhesive layer 42 may have a thickness of, for example, 0.1 to 100 μm, and preferably 0.1 to 60 μm.

  In FIG. 4, the pressure-sensitive adhesive body 40 includes a base material 43 on the main surface of the pressure-sensitive adhesive layer 42 opposite to the disassembling adhesive layer 41. The adhesive body 40 does not necessarily have to include a base material, and may be composed of a disassembling adhesive layer 41 and an adhesive layer 42.

  The type and shape of the base material 43 are not particularly limited, and can be appropriately changed depending on the type of the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer 42, the use of the pressure-sensitive adhesive body 40, and the like. The base material 43 may be, for example, a metal base material, an inorganic base material, a resin base material, or the like. The shape of the base material 43 may be, for example, a film shape, a tape shape, a rectangular parallelepiped shape, or the like.

  The base material 43 may be one of the members that form an assembly together with the adherend. The base material 43 may be a support member or a protection member that is temporarily attached to the adherend.

  The adhesive body 40 may further have another structure on the surface of the base material 43 opposite to the adhesive layer 42. For example, the pressure-sensitive adhesive body 40 may further have an adhesive structure formed by combining a pressure-sensitive adhesive component and a π-conjugated compound on the surface of the base material 43 opposite to the pressure-sensitive adhesive layer 42. The adhesive structure may be, for example, the same structure as the disassemblable adhesive layer 41 and the pressure-sensitive adhesive layer 42, or may be the same structure as the adhesive structure of the other embodiments of the present specification.

(Fifth form)
FIG. 5: is sectional drawing which shows one suitable form of an adhesive body. The pressure-sensitive adhesive body 50 shown in FIG. 5 includes a disassembling adhesive portion 51 containing a π-conjugated compound, an adhesive portion 52 containing an adhesive component, and a base material 53. In the pressure-sensitive adhesive body 50, a dismantling adhesive portion 51 and a pressure-sensitive adhesive portion 52 are provided on one surface of the base material 53, and the dismantleable adhesive surface formed by the dismantleable adhesive portion 51 and the pressure-sensitive adhesive surface formed by the pressure-sensitive adhesive portion 52 are provided. Are formed. The adhesive body 50 may have a disassembly adhesive surface formed by the disassembly adhesive portion 51 and an adhesive surface formed by the adhesive portion 52 on the joint surface on the side opposite to the base material 53.

  The adhesive body 50 may be, for example, a tape-shaped or film-shaped adhesive body. Since the adhesive body 50 has the adhesive surface partially formed on the joint surface, the adhesive body 50 can be easily temporarily bonded by pressing the joint surface against the adherend. The pressure-sensitive adhesive body 50 temporarily adhered to the adherend is heated to a temperature range in which the π-conjugated compound exhibits a liquid crystal state or a temperature exceeding the temperature range, and then cooled to a temperature range in which the π-conjugated compound exhibits a solid state. Thereby, it can be firmly bonded to the adherend.

  The pressure-sensitive adhesive body 50 may be bonded to the adherend by being pressed against the adherend while being heated to a temperature range in which the π-conjugated compound exhibits a liquid crystal state or a temperature higher than the temperature range. In this case, the adhesive force due to the adhesive portion 52 is developed by the contact between the adhesive surface and the adherend, and the π-conjugated compound is cooled to a temperature range in which the π-conjugated compound shows a solid state after being attached to the adherend and then disassembled. The adhesive force of the elastic adhesive portion 51 is developed, and the adhesive body 50 and the adherend are firmly joined.

  The shapes of the disassembling adhesive portion 51 and the adhesive portion 52 are not particularly limited, and may be appropriately changed depending on the desired adhesiveness and peelability. By increasing the ratio of the disassembly adhesive surface to the bonding surface, the peeling property is further improved. Further, by increasing the ratio of the adhesive surface exposed on the bonding surface, the adhesive force at the time of temporary bonding and the bonding strength with the adherend are improved. The disassembling adhesive portion 51 and the adhesive portion 52 may be formed, for example, so as to form a top view similar to that of FIG. 2A, or formed to form a top view similar to that of FIG. 3A. May be.

  The thicknesses of the disassembling adhesive portion 51 and the adhesive portion 52 are not particularly limited, and may be appropriately changed depending on the type of the adhesive forming the adhesive portion 52, the use of the adhesive body 50, and the like. The thickness of the disassembling adhesive portion 51 and the adhesive portion 52 may be, for example, 0.1 to 100 μm, and preferably 0.1 to 60 μm.

  In FIG. 5, the pressure-sensitive adhesive body 50 includes a base material 53 on the main surface of the pressure-sensitive adhesive section 52 opposite to the disassembly adhesive section 51. The adhesive body 50 does not necessarily have to include a base material and may be composed of the disassembling adhesive portion 51 and the adhesive portion 52.

  The type and shape of the base material 53 are not particularly limited, and can be appropriately changed depending on the type of the pressure-sensitive adhesive forming the pressure-sensitive adhesive portion 52, the use of the pressure-sensitive adhesive body 50, and the like. The base material 53 may be, for example, a metal base material, an inorganic base material, a resin base material, or the like. The shape of the base material 53 may be, for example, a film shape, a tape shape, a rectangular parallelepiped shape, or the like.

  The base material 53 may be one of the members that form an assembly together with the adherend. The base material 53 may be a support member or a protection member that is temporarily attached to the adherend.

  The adhesive body 50 may further have another structure on the surface of the base material 53 opposite to the disassembling adhesive portion 51 and the adhesive portion 52. For example, the pressure-sensitive adhesive body 50 may further have an adhesive structure formed by combining the pressure-sensitive adhesive component and the π-conjugated compound on the surface of the base material 53 opposite to the disassembling adhesive portion 51 and the adhesive portion 52. The adhesive structure may be, for example, the same structure as the disassembling adhesive part 51 and the adhesive part 52, or may be the same structure as the adhesive structure that other forms of the present specification have.

(Sixth form)
FIG. 6 is a cross-sectional view showing a preferred form of the adhesive body. The pressure-sensitive adhesive body 60 shown in FIG. 6 includes a first disassembling adhesive layer 61a and a second disassembling adhesive layer 61b containing a π-conjugated compound, and a pressure-sensitive adhesive layer 62 containing a pressure-sensitive adhesive component. There is. In the pressure-sensitive adhesive body 60, the first disassembling adhesive layer 61 a is provided on one main surface of the pressure-sensitive adhesive layer 62, and the second disassembling adhesive agent is provided on the other main surface of the pressure-sensitive adhesive layer 62. A layer 61b is provided.

  The pressure-sensitive adhesive body 60 may be, for example, a tape-shaped or film-shaped pressure-sensitive adhesive body in which each main surface is composed of the first disassembling adhesive layer 61a and the second disassembling adhesive layer 61b. Since the pressure-sensitive adhesive layer 62 is less exposed, the pressure-sensitive adhesive body 60 is excellent in handleability during storage and use.

  The pressure-sensitive adhesive body 60 is adhered on both the surface on the first disassembling adhesive layer 61a side (first bonding surface) and the surface on the second disassembling adhesive layer 61b side (second bonding surface). Can be joined with. For example, the pressure-sensitive adhesive body 60 is formed by arranging the pressure-sensitive adhesive body 60 on the adherend such that the first disassembling adhesive layer 61a and the adherend are in contact with each other and strongly pressing the pressure-sensitive adhesive body 60 against the adherend. By breaking a part of the one disassembly adhesive layer 61a, the pressure-sensitive adhesive layer 62 and the adherend can be brought into contact with each other and temporarily adhered to the adherend. In addition, the pressure-sensitive adhesive body 60 sandwiches the pressure-sensitive adhesive body 60 between the first adherend and the second adherend, and pressure is applied from both sides of the pressure-sensitive adhesive body 60, whereby the first dismantling adhesive layer 61a. It is also possible to rupture a part of the above and a part of the second disassembling adhesive layer 61b to temporarily bond the first adherend and the second adherend.

  In addition, the adhesive body 60 expands in the in-plane direction to break a part of the first disassembling adhesive layer 61a and a part of the second disassembling adhesive layer 61b, so that the first bonding surface and The adhesive layer 62 may be exposed on the second joint surface. In this case, the first adherend and the second adherend sandwich the adhesive body 60, and pressure is applied lightly from both sides, so that the first adherend and the second adherend are intervened via the adhesive body 60. It can be temporarily bonded to the adherend.

  Moreover, the adhesive body 60 peels off a part of 1st disassembly adhesive layer 61a and / or a part of 2nd disassembly adhesive layer 61b, and the 1st joint surface and / or the 2nd The pressure-sensitive adhesive layer 62 may be exposed on the bonding surface of. In this case, the adherend and the pressure-sensitive adhesive body 60 can be easily temporarily bonded.

  The tacky body 60 that has been temporarily adhered is heated to a temperature range in which the π-conjugated compound exhibits a liquid crystal state or a temperature exceeding the temperature range, and then cooled to a temperature range in which the π-conjugated compound exhibits a solid state. Can be firmly joined to.

  In addition, with respect to the pressure-sensitive adhesive body 60 disposed between the first adherend and the second adherend, both sides of the pressure-sensitive adhesive body 60 are heated to a temperature range in which the π-conjugated compound exhibits a liquid crystal state or a temperature exceeding the temperature range. You may join to an adherend by applying pressure from. In this case, the first disassembling adhesive layer 61a and the second disassembling adhesive layer 61b are pushed away and a part of the pressure-sensitive adhesive layer 62 comes into contact with the first adherend and the second adherend. As a result, the adhesive force of the pressure-sensitive adhesive layer 62 is developed. Further, by cooling the π-conjugated compound to a temperature range in which it is in a solid state, the adhesive force of the first disassembling adhesive layer 61a and the second disassembling adhesive layer 61b is developed, and the first adherend The adhesive body 60 and the second adherend are firmly joined together.

  The first disassembling adhesive layer 61a and the second disassembling adhesive layer 61b can exhibit an adhesive force even if they are extremely thin as long as the π-conjugated compound can form a laminated structure. From this viewpoint, the thickness of each of the first disassembling adhesive layer 61a and the second disassembling adhesive layer 61b may be, for example, 0.1 μm or more. From the viewpoint of easy breakage and cost reduction, the thickness of each of the first disassembling adhesive layer 61a and the second disassembling adhesive layer 61b is, for example, 50 μm or less. Well, 30 μm or less is preferable, and 10 μm or less is more preferable.

  The thickness of the pressure-sensitive adhesive layer 62 is not particularly limited, and for example, the thickness that allows the pressure-sensitive adhesive layer 62 to flow into the breakage points of the first disassembling adhesive layer 61a and the second disassembling adhesive layer 61b and contact with the adherend. I wish I had it. The thickness of the pressure-sensitive adhesive layer 62 may be appropriately changed depending on the type of pressure-sensitive adhesive forming the pressure-sensitive adhesive layer 62, the use of the pressure-sensitive adhesive body 60, and the like. The pressure-sensitive adhesive layer 62 may have a thickness of, for example, 0.1 to 100 μm, and preferably 0.1 to 60 μm.

(Seventh form)
FIG. 7: is sectional drawing which shows one suitable form of an adhesive body. The pressure-sensitive adhesive body 70 shown in FIG. 7 includes a pressure-sensitive adhesive layer 72 composed of a pressure-sensitive adhesive containing a pressure-sensitive adhesive component and a π-conjugated compound, and a substrate 73, and the pressure-sensitive adhesive is provided on one main surface of the substrate 73. A layer 72 is provided.

  The adhesive body 70 may be, for example, a tape-shaped or film-shaped adhesive body. Since the pressure-sensitive adhesive layer 72 contains the pressure-sensitive adhesive component, the pressure-sensitive adhesive body 70 can be easily temporarily bonded by being pressed against the adherend. The pressure-sensitive adhesive body 70 temporarily adhered to the adherend is heated to a temperature range in which the π-conjugated compound exhibits a liquid crystal state or a temperature exceeding the temperature range, and then cooled to a temperature range in which the π-conjugated compound exhibits a solid state. Thereby, it can be firmly bonded to the adherend.

  The thickness of the pressure-sensitive adhesive layer 72 is not particularly limited, and may be appropriately changed depending on the type of pressure-sensitive adhesive component, the use of the pressure-sensitive adhesive body 70, and the like. The pressure-sensitive adhesive layer 72 may have a thickness of, for example, 0.1 to 100 μm, and preferably 0.1 to 60 μm.

  The content of the π-conjugated compound in the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer 72 is not particularly limited, and may be appropriately changed within a range in which the pressure-sensitive adhesive layer 72 can exhibit adhesiveness. By increasing the ratio of the π-conjugated compound in the adhesive, the releasability is further improved. Further, by reducing the proportion of the π-conjugated compound in the pressure-sensitive adhesive, the adhesive force at the time of temporary adhesion and the bonding strength with the adherend are improved. The content of the π-conjugated compound is, for example, 0.1% by mass or more, and preferably 5% by mass or more, based on the total amount of the pressure-sensitive adhesive. The content of the π-conjugated compound may be, for example, 50% by mass or less, and preferably 30% by mass or less, based on the total amount of the adhesive.

  In FIG. 7, the pressure sensitive adhesive body 70 includes a base material 73 on one main surface of the pressure sensitive adhesive layer 72. The adhesive body 70 does not necessarily have to include a base material, and may be composed of only the adhesive layer 72.

  The type and shape of the base material 73 are not particularly limited, and can be appropriately changed depending on the type of the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer 72, the use of the pressure-sensitive adhesive body 70, and the like. The base material 73 may be, for example, a metal base material, an inorganic base material, a resin base material, or the like. The shape of the base material 73 may be, for example, a film shape, a tape shape, a rectangular parallelepiped shape, or the like.

  The base material 73 may be one of the members that form an assembly together with the adherend. Further, the base material 73 may be a support member or a protection member that is temporarily attached to the adherend.

  The adhesive body 70 may further have another structure on the surface of the base material 73 opposite to the adhesive layer 72. For example, the pressure-sensitive adhesive body 70 may further have an adhesive structure formed by a combination of a pressure-sensitive adhesive component and a π-conjugated compound on the surface of the base material 73 opposite to the pressure-sensitive adhesive layer 72. The adhesive structure may be, for example, the same as that of the pressure-sensitive adhesive layer 72, or may be the same structure as the adhesive structure of the other embodiments of the present specification.

(Method for manufacturing bonded body)
The method for manufacturing a bonded body according to the present embodiment includes a bonding step of pressing the above-described adhesive body against an adherend to bond the adhesive body and the adherend.

  The bonding step may be performed so that the pressure-sensitive adhesive body and the adherend adhere to each other by the action of the pressure-sensitive adhesive component in the pressure-sensitive adhesive body.

  The bonding step may be a step of pressing the pressure-sensitive adhesive body against the adherend at a temperature range in which the π-conjugated compound exhibits a liquid crystal state or at a temperature higher than the temperature range. According to such a joining step, the adhesive body can be firmly joined to the adherend due to the contributions of both the adhesive component and the π-conjugated compound.

  Further, the joining step may be a step of temporarily adhering the adhesive body and the adherend. In this case, the manufacturing method according to the present embodiment further includes a heating step of heating the bonding surface between the adhesive body and the adherend to a temperature range in which the π-conjugated compound exhibits a liquid crystal state or a temperature exceeding the temperature range. You can stay. According to such a heating step, the adhesive body can be firmly bonded to the adherend due to the contributions of both the adhesive component and the π-conjugated compound.

  The adherend is not particularly limited. Specific examples of the adherend include glass, sapphire, quartz, calcium fluoride, stainless steel, aluminum, iron, silicon wafer, gallium nitride, and silicon carbide.

(Peeling method for adhesive)
The method for peeling off the pressure-sensitive adhesive body according to the present embodiment includes an irradiation step of irradiating at least a part of the bonding surface between the pressure-sensitive adhesive body and the adherend with light in a temperature range where the π-conjugated compound exhibits a liquid crystal state.

  When the adherend has a light-transmitting property, the irradiation step may be a step of irradiating the bonding surface with light from the adherend side. Further, when the pressure-sensitive adhesive body does not have a base material or the base material has a light-transmitting property, the irradiation step may be a step of irradiating light from the side of the pressure-sensitive adhesive body opposite to the adherend. The adhesive body can be easily peeled off through the irradiation step.

  Further, the irradiation step may be a step of peeling the adhesive body while irradiating the interface between the adhesive body and the adherend with light from a direction parallel to the joint surface.

  The wavelength of the light irradiated in the irradiation step may be a wavelength that can be absorbed by the π-conjugated compound. The wavelength of the irradiation light may be, for example, 200 to 450 nm.

The irradiation amount of the light irradiated in the irradiation step may be appropriately changed according to the content of the π-conjugated compound in the bonding surface. For example, the irradiation amount of light may be such that the integrated surface has an integrated light amount of 100 to 100,000 mJ / cm ² . The integrated light amount is preferably 200 to 50000 mJ / cm ² , and more preferably 200 to 30000 mJ / cm ² .

  Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the above embodiment.

  Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the examples.

(Synthesis of fumaric acid diester)
Maleic acid (81.7 mg, 0.70 mmol) and cesium carbonate (688.2 mg, 2.10 mmol) were dissolved in anhydrous dimethylformamide (3 mL), and the mixture was stirred at room temperature under a nitrogen atmosphere for 50 minutes. 3,4-Bis (dodecyloxy) benzyl bromide (1.91 g, 3.50 mmol) was added dropwise to the reaction solution, and the mixture was stirred at 60 ° C for 3 days. After returning to room temperature, water was added to the reaction solution to stop the reaction, and the mixture was extracted with methylene chloride. The organic layer was washed with saturated brine, dried over anhydrous sodium sulfate, and the solvent was evaporated. The residue was separated and purified by silica gel column chromatography using a hexane-methylene chloride mixed solvent (mixing ratio 1: 2, R _f = 0.35) to give bis (3,4-bis (dodecyloxy) as a white solid. ) Benzyl) fumarate (305.3 mg, 0.29 mmol, yield 42%) was obtained.

The spectral data of bis (3,4-bis (dodecyloxy) benzyl) fumarate are as follows.
¹ H NMR (400 MHz, CDCl ₃ ): δ 6.83-6.92 (m, 8H), 5.13 (s, 4H), 3.98 (t, J = 6.6 Hz, 8H), 1. 77-1.84 (m, 8H), 1.26-1.45 (m, 72H), 0.86-0.89 (m, 12H);
¹³ C NMR (100 MHz, CDCl ₃ ): δ 164.9, 149.7, 149.4, 133.9, 127.9, 121.7, 114.7, 113.9, 69.6, 69.5. , 67.4, 32.1, 29.9, 29.8, 29.8, 29.6, 29.6, 29.5, 29.5, 29.4, 26.2, 26.2, 22. .8, 14.2;
HRMS (high resolution mass spectrometer) (APCI (atmospheric pressure chemical ionization method), positive): [M ⁺ ] calcd. for C ₆₆ H ₁₁₂ O ₈ , 1032.8352; found 1032.8379.

(Production of π-conjugated compound A1)
The π-conjugated compound A1 was produced by the reaction represented by the following formula.

Specifically, tributylphosphine (325 μL, 1.30 mmol) was added to a methylene chloride solution (30 mL) of bis (3,4-bis (dodecyloxy) benzyl) fumarate 2 (1.25 g, 1.20 mmol) under a nitrogen atmosphere. It was added dropwise at 0 ° C., and the reaction solution was stirred at room temperature for 40 minutes. Then, the reaction solution was added dropwise to a methylene chloride solution (60 mL) of tetraformyl compound 1 (208.6 mg, 0.50 mmol) (compound 1 in the above formula) cooled to 0 ° C. under a nitrogen atmosphere, and the solution was a base. Diazabicycloundecene (5 μL, 0.05 mmol) was added dropwise. After stirring at 50 ° C. for 2 days, water was added to the reaction solution to stop the reaction, and the mixture was extracted 3 times with methylene chloride. The organic layer after extraction was dehydrated with anhydrous sodium sulfate, and then the solvent was distilled off. The residue was separated by silica gel column chromatography using a mixed solvent of hexane-methylene chloride-triethylamine (mixing ratio 2: 48: 1) (R _f value (retention factor value) = 0.80) to obtain a crude product. Obtained. Further, by purification by high performance liquid chromatography using a chloroform-triethylamine mixed solvent (mixing ratio 50: 1) as a solvent, the π-conjugated compound A1 (343.6 mg, 0.14 mmol, yield 28%) was obtained as a yellow solid (above-mentioned). Compound A1) in the formula was obtained.

[Measurement by inspection scanning calorimeter]
The π-conjugated compound A1 was heated at a rate of 2 ° C./minute to 200 ° C., which is a liquid state, under a nitrogen atmosphere with a scanning scanning calorimeter (model: Exstar 6000 DSC 6200) manufactured by Seiko Instruments Inc. After holding at 200 ° C. for 10 minutes and cooling at a rate of 2 ° C./min, an exothermic peak of 18.3 mJ / mg accompanying a phase transition from liquid to liquid crystal was observed at an extrapolation starting point of 142.7 ° C. It was Further, at the extrapolation start point of 67.3 ° C., an exothermic peak of 14.8 mJ / mg accompanying the phase transition from liquid crystal to crystal was observed.

(Production of adhesive component A)
Septon 2004 (100 g, styrene-ethylene / propylene-styrene copolymer, manufactured by Kuraray Co., Ltd.) and CLEARON P-105 (100 g, tackifier, manufactured by Yasuhara Chemical Co., Ltd.) were blended, and a kneader equipped with a propeller-type stirring blade was used. Adhesive component A was produced by melt-kneading at 200 ° C.

<Example 1>
(Production of adhesive)
The pressure-sensitive adhesive component A was coated on a polyethylene terephthalate film (thickness 50 μm) at a temperature of 180 ° C. using a coater and then cooled to obtain a pressure-sensitive adhesive tape T1 having a pressure-sensitive adhesive layer. The thickness of the adhesive layer was 20 μm.

  Then, the release treated film (Toray, Serapile MFA, thickness 38 μm) was coated with the π-conjugated compound melted at 170 ° C. and cooled to form a disassembling adhesive layer. The disassemblable adhesive layer thus obtained was laminated on the adhesive layer of the adhesive tape T1 to obtain the adhesive body A1 of Example 1. The thickness of the disassembly adhesive layer was 3 μm.

(Use of adhesive)
The pressure-sensitive adhesive body A1 was pressed against the glass plate for temporary bonding, and heated to 70 ° C. to obtain a bonded body of the glass plate and the pressure-sensitive adhesive body A1 (bonding area 1.2 cm × 1.2 cm). One side of the obtained joined body was fixed with a clamp, and the tip of a push-pull gauge (Shiro Sangyo Co., Ltd., WPARX-10) was hooked in the hole formed in the end of the adhesive tape T1. The push-pull gauge was pulled and the 180 ° peel strength was measured. This measurement was repeated 5 times, and the peel strength measured at each time was arithmetically averaged, resulting in 4.4 N / 1.2 cm.

Next, a joined body was formed by the same method as above, and while keeping the joined body at 100 ° C., ultraviolet rays (illuminance 2.6 W / cm ² ) having a wavelength of 365 nm were applied to the joined surface from the glass side from the glass side for 10 seconds. Irradiated. Then, as a result of measuring the peel strength in the same manner as above, the average of the peel strength was 2.8 N / 1.2 cm.

  From this result, it was confirmed that, in the pressure-sensitive adhesive body A1 of Example 1, the adhesive force of the bonding surface can be reduced and the releasability can be improved by the light irradiation in the predetermined temperature range.

<Comparative Example 1>
(Production of adhesive)
No dismantling adhesive was used. Specifically, the pressure-sensitive adhesive component A was coated on a polyethylene terephthalate film (thickness 50 μm) at a temperature of 180 ° C. using a coater and then cooled to obtain a pressure-sensitive adhesive tape T1 having a pressure-sensitive adhesive layer. The thickness of the adhesive layer was 20 μm. This adhesive tape T1 was used as the adhesive body B1 of Comparative Example 1.

(Use of adhesive)
The pressure-sensitive adhesive body B1 was attached to a glass plate to obtain a bonded body of the glass plate and the pressure-sensitive adhesive body B1 (bonding area 1.2 cm × 1.2 cm). The peel strength of the obtained joined body was measured in the same manner as in Example 1. As a result, the average peel strength was 4.3 N / 1.2 cm.

Next, a joined body was formed by the same method as above, and while keeping the joined body at 100 ° C., ultraviolet rays (illuminance 2.6 W / cm ² ) having a wavelength of 365 nm were applied to the joined surface from the glass side from the glass side for 10 seconds. Irradiated. Then, as a result of measuring the peel strength in the same manner as above, the average of the peel strength was 6.3 N / 1.2 cm.

<Comparative example 2>
A disassembling adhesive layer was formed directly on a polyethylene terephthalate film (thickness 50 μm) without using the adhesive component A to form a laminate. This laminate was not tacky and did not adhere to the glass plate when pressed against it at room temperature.

  The pressure-sensitive adhesive body of the present invention can exhibit a high adhesive force due to the contribution of the pressure-sensitive adhesive component and the π-conjugated compound, and can be easily peeled by reducing the adhesive force of the bonding surface by light irradiation. Therefore, the pressure-sensitive adhesive body of the present invention can be expected to be applied in various fields as a peelable pressure-sensitive adhesive body.

10, 20, 30, 40, 50, 60, 70 ... Adhesive body 11, 21, 31, 31, 41 ... Dismantling adhesive layer, 51 ... Dismantling adhesive portion, 61a ... First dismantling adhesive layer, 61b ... Second dismantling adhesive layer, 12, 22, 32, 42, 62, 72 ... Adhesive layer, 52 ... Adhesive part, 13, 23, 33, 43, 53, 73 ... Base material.

Claims (13)

An adhesive surface containing an adhesive component,
A disassembly adhesive surface containing a π-conjugated compound represented by the following formula (1),
Adhesive body comprising.

[In the formula, R ¹ represents a group having at least one alkyl group having 3 to 20 carbon atoms, and n represents an integer of 1 to 3. A plurality of R ¹ may be the same or different from each other, and a plurality of n may be the same or different from each other. ] An adhesive layer containing an adhesive component,
A disassembling adhesive layer disposed on the pressure-sensitive adhesive layer and containing a π-conjugated compound represented by the following formula (1):
Adhesive body comprising.

[In the formula, R ¹ represents a group having at least one alkyl group having 3 to 20 carbon atoms, and n represents an integer of 1 to 3. A plurality of R ¹ may be the same or different from each other, and a plurality of n may be the same or different from each other. ] An adhesive body comprising an adhesive layer containing an adhesive component and a π-conjugated compound represented by the following formula (1).

[In the formula, R ¹ represents a group having at least one alkyl group having 3 to 20 carbon atoms, and n represents an integer of 1 to 3. A plurality of R ¹ may be the same or different from each other, and a plurality of n may be the same or different from each other. ] The pressure sensitive adhesive body according to any one of claims 1 to 3, wherein R ¹ is a group represented by the following formula (2).

[In the formula, R ² represents an alkyl group having 3 to 20 carbon atoms or an alkoxy group having 3 to 20 carbon atoms, and p represents an integer of 1 to 5. When p is 2 or more, a plurality of R ² may be the same or different. ]   The pressure sensitive adhesive body according to any one of claims 1 to 4, wherein the π-conjugated compound exhibits a liquid crystal state in at least a partial temperature range of 35 to 150 ° C.   The pressure-sensitive adhesive body according to any one of claims 1 to 5, wherein the pressure-sensitive adhesive component contains at least one selected from the group consisting of a pressure-sensitive adhesive resin and a tackifier. The pressure-sensitive adhesive body according to any one of claims 1 to 6, wherein the pressure-sensitive adhesive composed of the pressure-sensitive adhesive component has a storage elastic modulus of 10 ³ Pa to 10 ⁷ Pa. An adhesive containing an adhesive component and a π-conjugated compound represented by the following formula (1).

[In the formula, R ¹ represents a group having at least one alkyl group having 3 to 20 carbon atoms, and n represents an integer of 1 to 3. A plurality of R ¹ may be the same or different from each other, and a plurality of n may be the same or different from each other. ] The pressure-sensitive adhesive according to claim 8, wherein R ¹ is a group represented by the following formula (2).

[In the formula, R ² represents an alkyl group having 3 to 20 carbon atoms or an alkoxy group having 3 to 20 carbon atoms, and p represents an integer of 1 to 5. When p is 2 or more, a plurality of R ² may be the same or different. ] A method for producing a joined body in which the pressure-sensitive adhesive body according to any one of claims 1 to 7 and an adherend are joined,
A method for manufacturing a bonded body, comprising a bonding step of pressing the pressure-sensitive adhesive body against the adherend to bond the pressure-sensitive adhesive body and the adherend.   The manufacturing of the bonded body according to claim 10, wherein the bonding step is a step of pressing the pressure-sensitive adhesive body to the adherend at a temperature range in which the π-conjugated compound exhibits a liquid crystal state or at a temperature higher than the temperature range. Method.   11. The joined body according to claim 10, further comprising a heating step of heating a joint surface between the adhesive body and the adherend to a temperature range in which the π-conjugated compound exhibits a liquid crystal state or a temperature higher than the temperature range. Production method. A method for peeling off the pressure-sensitive adhesive body from a bonded body in which the pressure-sensitive adhesive body according to any one of claims 1 to 7 and an adherend are bonded together,
A method for peeling an adhesive body, which comprises a step of irradiating at least a part of a bonding surface between the adhesive body and the adherend with light in a temperature range in which the π-conjugated compound exhibits a liquid crystal state.

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