TW201601905A - Double-sided pressure-sensitive adhesive sheet - Google Patents

Abstract

A double-sided pressure-sensitive adhesive sheet (1) used to adhere a first hard object (4) and a second hard object (5) together. Said double-sided pressure-sensitive adhesive sheet (1) has a first pressure-sensitive adhesive surface (11S) that adheres to the first hard object (4) and a second pressure-sensitive adhesive surface (12S) that adheres to the second hard object (5). The ratio (F1/F2) of the strength (F1) of the adhesion between the first pressure-sensitive adhesive surface (11S) and the first hard object (4) to the strength (F2) of the adhesion between the second pressure-sensitive adhesive surface (12S) and the second hard object (5) is between 0.0001 and 0.1, inclusive. This double-sided pressure-sensitive adhesive sheet (1) excels in terms of reworkability, and the first hard object (4) and the second hard object (5) bonded together using this double-sided pressure-sensitive adhesive sheet (1) can be separated such that at least the first hard object (4) can be reused.

Description

Double-sided adhesive sheet

The present invention relates to a double-sided adhesive sheet for use between a plurality of hard bodies.

In recent years, various mobile electronic devices such as mobile phones and tablet computers include displays using a display body module having a liquid crystal element, a light emitting diode (LED element), and an organic electroluminescence (organic EL) element.

In the above display, a polarizing film or the like is attached to the display body module using a double-sided adhesive sheet, but when the bonding is performed, the bonding position may be deviated. Here, since the display body module is expensive, it is usually reused. Therefore, the above-mentioned adhesive sheet is required to be reworkable from the display body module, so that the display body module can be reused. Therefore, Patent Documents 1 and 2 propose a double-sided adhesive sheet having reworkability.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2004-231723

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2013-32483

In recent years, the above-mentioned displays have also adopted the touch panel method. Gradually, at this time, a touch panel including a glass plate or a plastic plate is provided on the surface side of the display body module. When the display body module and the touch panel are attached, the use of the double-sided adhesive sheet is gradually increased, but as described above, the hard material (hard body) is bonded to each other by the double-sided adhesive sheet or the film is bonded to each other or The situation of the film and the hard body is more difficult, and the yield at the time of bonding is liable to lower.

Therefore, in the above case, the necessity of stripping two hard bodies Higher so that the display body module can be reused, but it is very difficult to peel off the two hard systems adhered by the double-sided adhesive sheet. The adhesive sheet disclosed in Patent Document 1 only considers the reworkability when peeling off the film or the film and the hard body, and it is difficult to peel off the two hard bodies. Further, the adhesive sheet disclosed in Patent Document 2 is considered to be in the case of peeling off two hard bodies, but the reworkability is not sufficient.

The present invention has been made in view of the above actual circumstances, and its purpose is Provided is a double-sided adhesive sheet excellent in reworkability, which is used for re-use of a first hard body and a second hard body for reuse, and peels off the first hard body and the second bonded body using the adhesive layer In the case of a hard body, it can be peeled off so that the first hard body can be reused.

In order to achieve the above object, the first aspect of the present invention provides a double-sided The adhesive sheet is used for the adhesion between the first hard body and the second hard body, wherein the double-sided adhesive sheet includes: a first adhesive surface, which is followed by the first hard body or is located more than the double-sided adhesive sheet And the second adhesive surface, wherein the second adhesive surface is adjacent to the second hard body or a member located on the second hard body side of the double-sided adhesive sheet, and the first adhesive surface is For the aforementioned The first hard body or the member located on the first hard body side of the double-sided adhesive sheet has an adhesive force F1, and the second adhesive surface is located on the second hard body or on the double-sided adhesive sheet. When the adhesive force of the member on the second hard body side is F2, the ratio (F1/F2) of the F1 to the F2 is 0.0001 to 0.1 (Invention 1).

The double-sided adhesive sheet of the above invention (Invention 1) is adhered by the above At least, the reworkability of the first hard body is excellent. Therefore, when the first hard body and the second hard body to which the double-sided adhesive sheet is bonded are peeled off, the first hard body can be peeled off at least.

In the above invention (Invention 1), the double-sided adhesive sheet includes: An adhesive layer having the first adhesive surface; and a second adhesive layer preferably having the second adhesive surface (Invention 2).

In the above invention (Invention 2), the thickness of the first adhesive layer The ratio of the thickness of the second adhesive layer to 0.01 to 10 is preferable (Invention 3).

In the above inventions (Inventions 2 and 3), it is preferred to provide a core material between the first adhesive layer and the second adhesive layer (Invention 4).

In the above invention (Inventions 2 to 4), the first adhesive layer is preferably composed of an anthrone adhesive containing an organic polyoxyalkylene (Invention 5).

In the above invention (Invention 5), it is preferred that the anthrone adhesive contains an organopolysiloxane and an organopolysiloxane having a trifunctional or tetrafunctional siloxane unit (Invention 6).

In the above invention (Invention 6), the addition-molding organopolyoxyalkylene is an organopolyoxane having an alkenyl group as a main skeleton and having an alkenyl group. It is preferred to obtain a hydrogenated polyoxyalkylene reaction (Invention 7).

In the above invention (Inventions 2 to 7), the first adhesive layer is The adhesion of the first adhesive surface to the float glass in accordance with JIS Z0237:2009 is preferably 0.01 to 1 N/25 mm (Invention 8).

In the above invention (Inventions 2 to 8), the first adhesive layer is A 100% modulus of 0.3 to 1.5 MPa is preferred (Invention 9).

In the above invention (Inventions 2 to 9), the second adhesive layer is composed of An acrylic pressure-sensitive adhesive or a UV-curable pressure-sensitive adhesive containing a (meth) acrylate polymer is preferred (Invention 10).

In the above invention (Inventions 4 to 10), the core material is made of a polyester film The configuration is preferable (Invention 11).

In the above invention (Inventions 1 to 11), the first hard body is marked The display module is preferred (Invention 12).

In the above invention (Inventions 1 to 12), the second hard body is covered A cover material is preferred (Invention 13).

In the above invention (Inventions 1 to 13), the first hard body and the front The second hard body is preferably a member constituting the touch panel (Invention 14).

The double-sided adhesive sheet of the present invention is excellent in reworkability when peeled off When the first hard body and the second hard body are bonded together by the double-sided adhesive sheet, the first hard body can be peeled off at least.

1‧‧‧Double-sided adhesive sheet

11‧‧‧1st adhesive layer

11S‧‧‧1st adhesive surface

12‧‧‧2nd adhesive layer

12S‧‧‧2nd adhesive surface

13‧‧‧ core material

2a, 2b‧‧‧ peeling tablets

3‧‧‧With peeling sheet double-sided adhesive sheet

4‧‧‧1st hard body

5‧‧‧2nd hard body

10‧‧‧Layer

Fig. 1 is a cross-sectional view showing a double-sided adhesive sheet according to an embodiment of the present invention.

Fig. 2 is a cross-sectional view showing a laminate in which a first hard body and a second hard body are bonded together using a double-sided adhesive sheet.

Fig. 3 is a plan view showing a laminate produced by laminating a first hard body and a second hard body with a double-sided adhesive sheet in the examples/comparative examples.

Hereinafter, embodiments of the present invention will be described.

As shown in Fig. 1, the double-sided adhesive sheet 1 of the present embodiment is sandwiched between the two release sheets 2a and 2b so as to be in contact with the peeling surfaces of the two release sheets 2a and 2b. Hereinafter, the laminated body composed of the release sheet 2a, the double-sided adhesive sheet 1 and the release sheet 2b is referred to as a release-coated sheet double-sided adhesive sheet 3.

In the present embodiment, the release sheets 2a and 2b are not essential components, and are peeled off or removed when the double-sided adhesive sheet 1 is used. In addition, the peeling surface of the peeling sheet in this specification is a surface which has the peeling property in the peeling sheet, and is the surface which carried out the peeling process, and the surface which shows the peeling property, even if it is not peeling process.

As shown in Fig. 2, the double-sided adhesive sheet 1 of the present embodiment is used for the first hard body 4 and the laminated body 10 in which the first hard body 4 and the second hard body 5 to be reused are laminated. The follower between the second hard bodies 5. The double-sided adhesive sheet 1 may be directly attached to the first hard body 4 and/or the second hard body 5, or may be subsequently laminated on the first hard body 4 side and/or laminated on the second hard body 5 side. member. In other words, in the second drawing, the double-sided adhesive sheet 1 is directly attached to the first hard body 4 and the second hard body 5, and the two are directly bonded to each other, but the present invention is not limited thereto.

In addition, "hard body" in this specification means in accordance with JIS. K7127: The Young's modulus measured in 1999 is 10 GPa or more. The hard body may be composed of a single layer or a single member, or may be composed of a plurality of layers or a plurality of members. In the latter case, as an object composed of a plurality of layers or a plurality of members, as long as the Young's modulus is satisfied, the object may be referred to as a hard body even if a part of the layer or member of the object does not satisfy the Young's modulus.

As shown in Fig. 2, the double-sided adhesive sheet 1 of the present embodiment includes: The first adhesive surface 11S is next to the first hard body 4 or the member of the obtained laminated body 10 which is located closer to the first hard body 4 than the double-sided adhesive sheet 1 (hereinafter referred to as "first" a hard body side member"); and a second adhesive surface 12S which is next to the second hard body 5 or the member of the obtained laminated body 10 which is located closer to the second hard body 5 than the double-sided adhesive sheet 1 ( Hereinafter, it is sometimes referred to as "second hard body side member").

In the double-sided adhesive sheet 1 of the present embodiment, the first adhesive surface is used The ratio of F1 to F2 when the adhesion of 11S to the hard body (for example, glass plate) is F1 and the adhesion of the second adhesive surface 12S to the hard body (for example, glass plate) is F2 (F1) /F2) is preferably 0.0001 to 0.1, 0.0003 to 0.08 is preferred, and 0.0005 to 0.05 is particularly preferred.

By the ratio of F1 to F2 within the above range, when peeling off When the first hard body 4 and the second hard body 5 are bonded together by the double-sided adhesive sheet 1, the sheet 1 and the first hard body 4 are bonded to each other at the interface between the first adhesive surface 11S and the first hard body 4 of the double-sided adhesive sheet 1. The first hard body 4 is well separated, and the first hard body 4 or the second hard body 5 is not broken, or no residue is generated on the first hard body 4. Thereby, at least the first hard body 4 can be reused. Thus, the double-sided adhesive sheet 1 having a ratio of F1 to F2 within the above range is excellent in reworkability.

If the ratio of F1 to F2 is less than 0.0001, the first adhesive surface The adhesive force of 11S is too small, and when the laminated body 10 is used, accidental peeling occurs at the interface between the first adhesive surface 11S and the first hard body 4. On the other hand, when the ratio of F1 to F2 exceeds 0.1, when the first hard body 4 and the second hard body 5 are peeled off, the second hard body 5 is broken or the first hard body 4 is broken. The paste is not peeled off so that the first hard body can be reused.

The double-sided adhesive sheet 1 is only the first adhesive surface 11S and the second adhesive surface The 12S may have a ratio of F1 to F2 within the above range, and may be composed of a single layer, a plurality of layers, or a plurality of materials having unclear layers. From the viewpoint of ease of manufacture, as shown in FIGS. 1 and 2, the double-sided adhesive sheet 1 includes a first adhesive layer 11 having a first adhesive surface 11S and a second adhesive having a second adhesive surface 12S. Layer 12 is preferred. Further, it is particularly preferable to provide the core material 13 between the first adhesive layer 11 and the second adhesive layer 12 from the viewpoint of workability of the double-sided adhesive sheet 1. Further, the first adhesive surface 11S is a surface of the first adhesive layer 11 opposite to the second adhesive layer 12, and the second adhesive surface 12S is the first adhesive layer 12 and the first adhesive layer 11 The opposite side of the surface.

Further, in the test examples described later, a glass plate was used as the adherend. That is, the hard body measures the adhesion and evaluates the reworkability, but it is considered that the same evaluation result can be obtained even if other materials are used as the adherend, that is, the hard body.

1. Double-sided adhesive sheet (1) The first adhesive layer

The first adhesive layer 11 satisfies the above physical properties as long as the first adhesive surface 11S (F1) The adhesive composition may be formed with respect to the ratio of F2. Specifically, it is preferably composed of an anthrone adhesive containing an organic polysiloxane, particularly a cured organic polyoxyalkylene. The anthrone adhesive is easy to satisfy the above physical properties.

Addition of organopolyoxyalkylene system to make the decane bond as the main skeleton It is preferred that the organic polyoxyalkylene having an alkenyl group is reacted with an organic hydrogenated polyoxyalkylene.

An organopolyoxy group having an alkenyl group as a main skeleton and having an alkenyl group The alkane is a compound represented by the following average unit formula (1), and is preferably a compound having at least two alkenyl groups in the molecule.

R ¹ _a SiO _(4-a)/2 ......(1)

(wherein R ¹ is a mutually unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 or 1 to 8 carbon atoms which are the same or different types, and _a is 1.5 to 2.8, preferably 1.8 to 2.5, and preferably 1.95. ~2.05 is a positive range of better range.)

Examples of the unsubstituted or substituted monovalent hydrocarbon group bonded to the fluorene atom represented by the above R ¹ include a vinyl group, an allyl group, a propenyl group, an isopropenyl group, a butenyl group, a hexenyl group, and a cyclohexane group. Alkenyl, octenyl and the like alkenyl, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, cyclohexyl, octyl, anthracene An aryl group such as an alkyl group, a phenyl group, a phenyl group, a tolyl group, a xylyl group or a naphthyl group; an aralkyl group such as a benzyl group, a phenethyl group or a phenylpropyl group; and a hydrogen atom of the group Some or all of them are substituted with a halogen atom such as fluorine, bromine or chlorine, a cyano group or the like, such as a chloromethyl group, a chloropropyl group, a bromoethyl group, a trifluoropropyl group or a cyanoethyl group. As the alkenyl group, a vinyl group is preferable from the viewpoint of the length of the curing time and productivity.

The organohydrogenated polyoxyalkylene has a SiH group in the molecule. By using The alkenyl group of the organopolyoxyalkylene and the SiH group of the organohydrogenated polyoxyalkylene are reacted to form an addition reaction, thereby obtaining an addition organopolyoxane.

Addition of organopolyoxane in the presence of a platinum catalyst It is hardened, and therefore it is preferred that the above fluorenone adhesive contains a platinum catalyst. The platinum catalyst may, for example, be a reaction product of platinum black, platinum chloride, chloroplatinic acid, chloroplatinic acid and a monovalent alcohol, a complex of chloroplatinic acid and an olefin, platinum acetoacetic acid or the like.

The content of the platinum catalyst in the above anthrone adhesive is relative to the addition 100 parts by mass of the organic polysiloxane is preferably from 0.01 to 3 parts by mass, more preferably from 0.05 to 2 parts by mass. When the content of the platinum catalyst is within the above range, the addition of the organopolysiloxane is hardened without hindering the coating, and the first adhesive layer 11 can be formed.

In order to improve adhesion within the scope of not impairing the object of the present invention The force-added organopolyoxane may contain an organopolyoxane (an oxime resin) containing a trifunctional or tetrafunctional siloxane unit in the molecule.

The above-mentioned anthrone adhesive contains trifunctional or tetrafunctional The content of the organopolysiloxane of the decane unit is preferably from 10 to 200 parts by mass, more preferably from 15 to 100 parts by mass, and further preferably from 20 to 80 parts by mass, based on 100 parts by mass of the added organopolysiloxane. good. When the content of the organopolysiloxane having a trifunctional or tetrafunctional siloxane unit is too large, the adhesion of the first adhesive layer 11 may increase and the reworkability may be lowered.

The thickness of the first adhesive layer 11 is preferably 5 to 50 μm, and 10 It is particularly preferable that it is ~40 μm, and further preferably 15 to 35 μm. When the thickness of the first adhesive layer 11 is 5 μm or more, a desired adhesive force can be exhibited. Further, since the thickness of the first adhesive layer 11 is 50 μm or less, it is possible to effectively prevent the production. In the process of mixing residual solvents or bubbles caused by the process, it is possible to achieve excellent adhesion stability and optical characteristics.

In order to form the first adhesive layer 11, for example, a coating solution is provided It is applied to the object to be coated (for example, the core material 13) and is heated and hardened. The coating solution is a compounded polyorganosiloxane, and if necessary, a trifunctional or tetrafunctional helium oxygen is contained. The organopolysiloxane and the platinum catalyst of the alkane unit are diluted with a solvent such as methyl ethyl ketone, toluene, ethyl acetate or xylene to form a coating solution of about 10 to 60% by mass. The heating temperature is preferably about 90 to 180 ° C, and the heating time is preferably about 1 to 5 minutes.

Here, the first adhesive surface 11S of the first adhesive layer 11 is followed. JIS Z0237:2009 has an adhesion to float glass of 0.01 to 1 N/25 mm, preferably 0.015 to 0.7 N/25 mm, and further preferably 0.02 to 0.5 N/25 mm. When the adhesive force is 0.01 N/25 mm or more, when the laminated body 10 is used, it is possible to prevent accidental peeling from occurring at the interface between the first adhesive surface 11S and the first hard body 4. In addition, when the adhesive force is 1 N/25 mm or less, the peelability of the first adhesive layer 11 with respect to the adherend is favorably maintained, and excellent reworkability can be exhibited. Moreover, the specific measuring method of the said adhesive force is shown by the test example mentioned later.

The 100% modulus of the first adhesive layer 11 is 0.3 to 1.5 MPa. Preferably, 0.4 to 1.2 MPa is particularly preferred, and 0.5 to 1.0 MPa is further preferred. When the 100% modulus is 0.3 MPa or more, the adhesion of the first adhesive layer 11 to the adherend is favorably maintained. Further, when the 100% modulus is 1.5 MPa or less, when the first adhesive layer 11 is attached to the adherend, it is possible to prevent air from entering between the two.

(2) 2nd adhesive layer

In the second adhesive layer 12, the second adhesive surface 12S may be composed of an adhesive that satisfies the above physical properties (the ratio of F1 to F2), and specifically, an acrylic adhesive containing a (meth) acrylate polymer. Or an ultraviolet curable adhesive is preferably formed. Such an adhesive easily satisfies the above physical properties.

The above acrylic adhesive contains (meth) acrylate polymerization The substance (a) preferably contains the (meth) acrylate polymer (a) which is crosslinked by the crosslinking agent (b). In the present specification, (meth) acrylate means both acrylate and methacrylate. Other similar terms are also the same. Moreover, the concept of "copolymer" is also included in "polymer". Further, from the viewpoint of easily adjusting the adhesion, the (meth) acrylate polymer (a) is preferably not provided with an ultraviolet curable group.

In the (meth) acrylate polymer (a), the composition is composed The monomer of the compound is preferably an alkyl (meth)acrylate having an alkyl group and having 1 to 20 carbon atoms. Thereby, the obtained adhesive can exhibit better adhesion. Further, the (meth) acrylate polymer (a) is an alkyl (meth) acrylate having an alkyl group having 1 to 20 carbon atoms, and a monomer having a functional group reactive with the crosslinking agent (b) ( Copolymers containing reactive functional group monomers and other monomers used as needed are particularly preferred.

(meth)acrylic acid having 1 to 20 carbon atoms as an alkyl group Examples of the alkyl esters include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, and n-amyl (meth)acrylate. N-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-decyl (meth)acrylate, N-dodecyl (meth)acrylate, tetradecyl (meth)acrylate, cetyl (meth)acrylate, octadecyl (meth)acrylate, and the like. Among them, from the viewpoint of further improving the adhesion, a (meth) acrylate having an alkyl group having 1 to 8 carbon atoms is preferred, methyl (meth) acrylate, n-butyl (meth) acrylate and ( 2-ethylhexyl methacrylate is especially preferred. Further, these may be used alone or in combination of two or more.

In the (meth) acrylate polymer (a), the composition is composed The monomer unit of the compound, preferably having 40 to 99% by mass of an alkyl group, of an alkyl (meth)acrylate having 1 to 20 carbon atoms, particularly preferably 50 to 90% by mass, and preferably 60 to 80% by weight. The mass % is further preferred.

As the reactive functional group-containing monomer, it is preferably exemplified in A monomer having a hydroxyl group in the molecule (a hydroxyl group-containing monomer), a monomer having a carboxyl group in the molecule (a carboxyl group-containing monomer), a monomer having an amino group in the molecule (an amino group-containing monomer), and the like. These may be used alone or in combination of two or more.

As the hydroxyl group-containing monomer, for example, (meth)acrylic acid is exemplified. 2-hydroxyethyl ester, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, A hydroxyalkyl (meth) acrylate such as 4-hydroxybutyl (meth)acrylate. Among them, from the viewpoint of the reactivity of the hydroxyl group in the obtained (meth)acrylate polymer (a) with the crosslinking agent (b) and the copolymerization property with other monomers, (meth)acrylic acid 2- Hydroxyethyl ester and 4-hydroxybutyl (meth)acrylate are preferred. These may be used alone or in combination of two or more.

Examples of the carboxyl group-containing monomer include acrylic acid and methyl propyl acrylate. An ethylenically unsaturated carboxylic acid such as an acid, a crotonic acid, a maleic acid, an itaconic acid or a citraconic acid. Among them, acrylic acid is preferred from the viewpoints of the reactivity of the carboxyl group in the obtained (meth)acrylate polymer (a) with the crosslinking agent (b) and the copolymerization property with other monomers. These may be used alone or in combination of two or more.

As the amino group-containing monomer, for example, (meth)acrylic acid is exemplified. Aminoethyl ester, n-butylaminoethyl (meth)acrylate, and the like. These may be used alone or in combination of two or more.

In the (meth) acrylate polymer (a), the composition is composed The monomer unit of the compound preferably contains 1 to 40% by mass of a reactive functional group-containing monomer, more preferably 10 to 35% by mass, even more preferably 20 to 30% by mass.

As the other monomer, for example, (meth) propylene is exemplified. (meth) acrylate having an aliphatic ring such as an alkoxyalkyl (meth) acrylate such as methoxyethyl acrylate or ethoxyethyl (meth) acrylate or a cyclohexyl (meth) acrylate Non-crosslinkable acrylamide, acrylamide, methacrylamide, N,N-dimethylaminoethyl (meth)acrylate, N,N-dimethylaminopropyl (meth)acrylate A non-crosslinkable (meth) acrylate having a tertiary amino group such as an ester, vinyl acetate, styrene or the like. These may be used alone or in combination of two or more.

The polymerization state of the (meth) acrylate polymer (a) may be The random copolymer may also be a block copolymer.

Weight average molecular weight of (meth) acrylate polymer (a) It is preferably 100,000 to 2.2 million, 200,000 to 1.8 million, and 400,000 to 1.6 million. In addition, the weight average molecular weight in the present specification is The polystyrene-converted value measured by gel permeation chromatography (GPC).

Further, among the above acrylic adhesives, (meth)acrylic acid The ester polymer (a) may be used alone or in combination of two or more.

As the crosslinking agent (b), as long as it is polymerized with (meth) acrylate The reactive functional group reactive with the compound (a) may be, for example, an isocyanate crosslinking agent, an epoxy crosslinking agent, an amine crosslinking agent, a melamine crosslinking agent, or an aziridine system. Crosslinking agent, hydrazine crosslinking agent, aldehyde crosslinking agent, oxazoline crosslinking agent, metal alkoxide crosslinking agent, metal chelate crosslinking agent, metal salt crosslinking agent, ammonium salt A crosslinking agent or the like. In the above, when the reactive functional group of the (meth) acrylate polymer (a) is a hydroxyl group, an isocyanate crosslinking agent excellent in reactivity with a hydroxyl group is preferably used, and (meth)acrylic acid is preferred. When the reactive functional group of the ester polymer (a) is a carboxyl group, an epoxy-based crosslinking agent excellent in reactivity with a carboxyl group is preferably used. Further, the crosslinking agent (b) may be used alone or in combination of two or more.

The isocyanate crosslinking agent contains at least a polyisocyanate compound By. Examples of the polyisocyanate compound include an aromatic polyisocyanate such as toluene diisocyanate, diphenylmethane diisocyanate or xylene diisocyanate; an aliphatic polyisocyanate such as hexamethylene diisocyanate; isophorone diisocyanate; and hydrogenation. An alicyclic polyisocyanate such as diphenylmethane diisocyanate or the like and the biuret, isocyanurate, and as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, hydrazine An adduct of a reactant containing a low molecular weight active hydrogen compound such as sesame oil or the like. Among them, from the viewpoint of reactivity with a hydroxyl group, trimethylolpropane-modified aromatic polyisocyanate, especially trimethylolpropane-modified toluene diisocyanate and trimethylolpropane-modified xylene diisocyanate are Preferably.

Examples of the epoxy-based crosslinking agent include 1,3-bis(N,N'- Diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-m-xylylenediamine, ethylene glycol diglycidyl ether, 1,6-hexanediol Glycidyl ether, trimethylolpropane diglycidyl ether, diglycidyl aniline, diglycidylamine, and the like.

The amount of the crosslinking agent (b) used is relative to the (meth) acrylate polymerization The compound (a) is preferably 0.001 to 10 parts by mass, more preferably 0.01 to 1 part by mass, even more preferably 0.05 to 0.5 part by mass.

If it contains a monomer containing a reactive functional group as a constituent polymerization The adhesive composition of the (meth) acrylate polymer (a) and the crosslinking agent (b) of the monomer unit is heated, and the crosslinking agent (b) and the (meth) acrylate polymer are formed. The reactive functional group containing the reactive functional group monomer of (a) is reacted. Thereby, the structure in which the (meth) acrylate polymer (a) is crosslinked by the crosslinking agent (b) is formed, and the cohesive force, strength and durability of the obtained adhesive layer are improved.

In the above acrylic adhesive, it is usually added as needed Various additives such as a refractive index modifier, an antistatic agent, a tackifier, a decane coupling agent, an antioxidant, an ultraviolet absorber, a light stabilizer, a softener, a filler, and the like are used.

As the ultraviolet curable adhesive, it contains ultraviolet rays It is preferable that the curable (meth) acrylate polymer or the (meth) acrylate polymer having no ultraviolet curability and the ultraviolet curable compound are contained, and a photopolymerization initiator is particularly preferable.

Polymerization as a (meth) acrylate having ultraviolet curability An addition acrylate polymer having a group having a (meth)acryl fluorenyl group introduced into the side chain is preferred. The addition acrylate-based polymer can have a (meth) acrylonitrile group and crosslinkability by using a copolymer of a (meth) acrylate and a monomer having a crosslinkable functional group in a molecule. The compound of the functional group reactive group is obtained by reacting a part of the crosslinkable functional group of the copolymer.

As the above ultraviolet curable compound, weight average molecular weight A polyfunctional acrylate-based oligomer of 50,000 or less or a polyfunctional acrylate-based monomer having a molecular weight of 1,000 or less is preferred.

The thickness of the second adhesive layer 12 is preferably 5 to 300 μm, and 10 It is particularly preferable that it is ~200 μm, and further preferably 15 to 150 μm. When the thickness of the second adhesive layer 12 is 5 μm or more, a desired adhesive force can be exhibited. Further, since the thickness of the second adhesive layer 12 is 300 μm or less, it is possible to prevent the obtained laminate from becoming too thick.

The thickness of the first adhesive layer 11 is relative to the second adhesive layer 12 The thickness ratio is preferably 0.01 to 10, more preferably 0.05 to 5, and further preferably 0.1 to 3. When the ratio of the thickness of the both is within the above range, the physical properties (the ratio of F1 to F2) are easily satisfied, and the reworkability of the double-sided adhesive sheet 1 is further excellent.

When the second adhesive layer 12 is composed of an acrylic adhesive, The second adhesive layer 12 is formed, and a coating solution containing an acrylic adhesive and optionally containing a solvent is applied to a coating target (for example, a peeling surface of the release sheet 2b), and heat-treated to form a coating film. When the formed coating film does not require a curing period, it directly becomes the second adhesive layer 12, and it is necessary to raise the period during the maintenance period. After the growth period, the second adhesive layer 12 is formed.

It is also possible to dry by volatilizing a dilution solvent or the like of the coating solution. The treatment also serves as the above heat treatment. When the heat treatment is performed, the heating temperature is preferably from 50 to 150 ° C, and particularly preferably from 70 to 120 ° C. Further, the heating time is preferably from 30 seconds to 10 minutes, and particularly preferably from 50 seconds to 2 minutes. After the heat treatment, a health period of about 1 to 2 weeks at normal temperature (for example, 23 ° C, 50% RH) can be set as needed.

When the acrylic adhesive contains a (meth) acrylate polymer (a) having a reactive functional group and a crosslinking agent (b), a (meth) acrylate polymer (a) is formed by the above heat treatment. a structure crosslinked by a crosslinking agent (b).

On the other hand, when the second adhesive layer 12 is composed of an ultraviolet curable adhesive, in order to form the second adhesive layer 12, a coating solution containing an ultraviolet curable adhesive and optionally containing a solvent is applied to the coating. The object (for example, the peeling surface of the peeling sheet 2b) is heat-treated to form a coating film. Thereafter, the coating film is irradiated with ultraviolet rays to cure the ultraviolet curable adhesive to form the second adhesive layer 12.

Here, the adhesion of the second adhesive surface 11S of the second adhesive layer 12 to the float glass in accordance with JIS Z0237:2009 is preferably 1 to 50 N/25 mm, particularly preferably 2 to 40 N/25 mm, and 5 to 30 N. /25mm is further preferred. When the adhesive force is 1 N/25 mm or more, accidental peeling at the interface between the second adhesive surface 12S and the second hard body 5 can be prevented when the laminated body 10 is used. On the other hand, when the adhesive force exceeds 50 N/25 mm, when the hard body 5 is intended to be reused, a residue may be generated on the side of the hard body 5 and may not be reused.

(3) core material

The core material 13 imparts rigidity to the double-sided adhesive sheet 1 to improve the operability of the double-sided adhesive sheet 1. The core material 13 is preferably made of a plastic film. Examples of the type of the plastic film include a polyester film composed of a polyester such as polyethylene terephthalate, polybutylene terephthalate or polyethylene naphthalate, a polyurethane film, and a poly Cellulose film such as vinyl film, polypropylene film, triacetyl cellulose, polyvinyl chloride film, polyvinylidene chloride film, polyvinyl alcohol film, ethylene-vinyl acetate film, polystyrene film, polycarbonate A plastic film such as a film, an acrylic resin film, a norbornene resin film or a cycloolefin resin film; or a laminate of two or more of these. The plastic film can be either uniaxially stretched or biaxially stretched. Among these, a polyester film is preferred, and a polyethylene terephthalate film is particularly preferred.

In the core material 13 composed of the above plastic film, to improve and adjacent For the purpose of adhering the first adhesive layer 11 and/or the second adhesive layer 12, a surface treatment or a primer treatment by an oxidation method or the like may be performed on one surface or both surfaces as needed. Examples of the oxidation method include corona discharge treatment, plasma discharge treatment, chromium oxidation treatment (wet), flame treatment, hot air treatment, and ozone/ultraviolet irradiation treatment. These surface treatment methods can be appropriately selected depending on the type of the plastic film, but in view of effects and workability, a corona discharge treatment method is generally preferred.

From the viewpoint of improving the operability of the double-sided adhesive sheet 1, the core material The thickness of 13 is preferably 2 to 250 μm, particularly preferably 5 to 125 μm, and further preferably 10 to 75 μm.

2. Peeling piece

The release sheets 2a and 2b are not particularly limited, and a known plastic film can be used. For example, a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, a polymethylpentene film, a polyvinyl chloride film, a vinyl chloride copolymer film, or a polyethylene terephthalate film can be used. , polyethylene naphthalate film, polybutylene terephthalate film, polyurethane film, ethylene vinyl acetate film, ionomer resin film, ethylene-(meth)acrylic copolymer film, ethylene-(A Acrylate copolymer film, polystyrene film, polycarbonate film, polyimide film, fluororesin film, and the like. Further, these crosslinked films can also be used. In addition, these laminated films can also be used.

On the peeling surface of the above-mentioned release sheets 2a, 2b (especially with double-sided adhesive It is preferable to carry out the release treatment on the surface on which the sheet 1 is contacted (wherein, when the adhesive layer 11 is an anthrone adhesive, it is also preferable to directly use a plastic film which is not subjected to the release treatment). Examples of the release agent used in the release treatment include an alkyd type, an anthrone type, a fluorine type, an unsaturated polyester type, a polyolefin type, and a paraffin type release agent. Further, in the release sheets 2a and 2b, one release sheet is a heavy release type release sheet having a large peeling force, and the other release sheet is preferably a light release type release sheet having a small peeling force.

The thickness of the release sheets 2a and 2b is not particularly limited, but is not limited. Usually 20~150μm.

3. Manufacture of double-sided adhesive sheets with release sheets

As a manufacturing example of the double-sided adhesive sheet 3 with a release sheet, after the first adhesive layer 11 is formed on one surface of the core material 13, the release sheet 2a is laminated on the exposed surface of the adhesive layer 11 so as to be in contact with the release surface. This is taken as the first laminate. On the other hand, the second adhesive layer 12 is formed on the peeling surface of the release sheet 2b, and this is done. It is the second layered body. Then, the first laminate and the second laminate are bonded to each other so that the core material 13 of the first laminate and the second adhesive layer 12 of the second laminate are stacked to obtain a release sheet double-sided adhesive sheet 3.

4. Use of double-sided adhesive sheets

The laminated body 10 shown in Fig. 2 is a combination of the first hard body 4 and the second hard body 5 to be reused by using the double-sided adhesive sheet 1. That is, the laminated body 10 is composed of the first hard body 4, the second hard body 5, and the double-sided adhesive sheet 1 interposed therebetween.

The double-sided adhesive sheet 1 of the present embodiment includes a first adhesive layer 11. The core material 13 and the second adhesive layer 12, the first adhesive surface 11S of the first adhesive layer 11 is followed by the first hard body 4, and the second adhesive surface 12S of the second adhesive layer 12 is followed by 2 hard body 5.

As the first hard body 4 to be reused, for example, high price is mentioned. Specific examples of the member include a display body module, a solar battery module, and the like. Examples of the display body module include a liquid crystal (LCD) module, a light emitting diode (LED) module, an organic electroluminescence (organic EL) module, and electronic paper. Further, various functional layers (such as a transparent conductive film) may be provided on the double-sided adhesive sheet 1 side of the display body module.

The material of the portion of the above member that is in contact with the double-sided adhesive sheet 1 is usually a glass plate, a plastic plate, a metal plate, a semiconductor plate or the like, and a glass plate is preferable.

Further, examples of the second hard body 5 include a glass plate, a plastic plate, a metal plate, a semiconductor plate, and the like, and a glass plate is preferable.

The glass plate is not particularly limited, and examples thereof include chemically strengthened glass, alkali-free glass, quartz glass, soda lime glass, and yttrium/lanthanum. Glass, aluminosilicate glass, lead glass, borosilicate glass, bismuth boron silicate glass, and the like. The thickness of the glass plate is not particularly limited, but is usually 0.1 to 5 mm, and preferably 0.2 to 2 mm.

The plastic plate is not particularly limited, and for example, An acrylic plate, a polycarbonate plate or the like composed of polymethyl methacrylate or the like. The thickness of the plastic plate is not particularly limited, but it is usually 0.2 to 5 mm, and 0.4 to 3 mm is preferable.

In addition, one or both sides of the above glass plate or plastic plate may Various functional layers (transparent conductive film, metal layer, silicon oxide layer, hard coat layer, antiglare layer, etc.) may be provided, metal wiring may be formed, and an optical member may be laminated.

As the optical member, for example, a polarizing plate (polarized light) Film), polarizer, retardation film (retardation film), viewing angle compensation film, brightness enhancement film, contrast enhancement film, liquid crystal polymer film, diffusion film, hard coat film, semi-transmissive reflection film, and the like.

In order to manufacture the above-mentioned laminated body 10, as an example, first, peeling is performed. One of the release sheets 2b with the release sheet double-sided adhesive sheet 3 is bonded to the exposed second adhesive layer 12 and the second hard sheet 5. Next, the other release sheet 2a is peeled off from the release sheet double-sided adhesive sheet 3, and the exposed first adhesive layer 11 and the first hard sheet 4 are bonded together.

In the laminated body 10 manufactured as above, when a deviation occurs at the bonding position In this case, it is necessary to peel off the first hard body 4 and the second hard body 5 . In the laminated body 10, when the first hard body 4 and the second hard body 5 are peeled off, the first adhesive surface 11S of the double-sided adhesive sheet 1 (first adhesive layer 11) and the first hard body 4 are The double-sided adhesive sheet 1 (first adhesive layer 11) and the first hard body 4 are good at the interface. In the ground separation, the first hard body 4 or the second hard body 5 is not broken, or no residue is generated on the first hard body 4. Thereby, at least the first hard body 4 can be reused. As described above, the double-sided adhesive sheet 1 of the present embodiment is excellent in reworkability.

The laminated body 10 in the present embodiment is a touch panel, and is particularly static. The capacitive touch panel is preferable. Therefore, the first hard body 4 and the second hard body 5 are preferably members constituting the touch panel. In this case, it is preferable that the first hard body 4 is a display body module or a member including the display body module, and the second hard body 5 is a cover material made of a glass plate or a plastic plate or a member including a cover member. . The second hard body 5 may be a cover-integrated sensor (OGS: One Glass Solution) provided with a sensor function on the cover material (a circuit in which a transparent conductive film is formed on the cover material).

Although not shown in Fig. 2, the double-sided adhesion in the laminated body 10 A film sensor for one or a plurality of touch panels may be provided between the sheet 1 and the first hard body 4 and/or between the double-sided adhesive sheet 1 and the second hard body 5. Also, a desired layer of adhesive may be provided between the plurality of layers of film sensors. The thin film sensor is composed of, for example, a base film and a patterned transparent conductive film made of tin-doped indium oxide (ITO).

The embodiments described above are for the purpose of facilitating understanding of the present invention. The carrier is not described to limit the invention. Therefore, each of the embodiments disclosed in the above embodiments includes all the design changes and equivalents belonging to the technical scope of the present invention.

For example, the peeling in the double-sided adhesive sheet 3 with the release sheet can be omitted. Any one of the sheets 2a, 2b. Further, between the double-sided adhesive sheet 1 and the first hard body in the laminated body 10 and/or between the double-sided adhesive sheet 1 and the second hard body, There are other components.

[Examples]

Hereinafter, the present invention will be specifically described by way of examples, but the scope of the invention is not limited to the embodiments.

[Manufacturing Example 1]

An addition type organic polyoxyalkylene (manufactured by Shin-Etsu Chemical Co., Ltd.), which is composed of an organopolysiloxane having a vinyl group as a main skeleton and having a vinyl group and an organic hydrogenated polyoxyalkylene. : KS-847H) 100 parts by mass (converted solid content; the same below), an organopolyoxane containing a trifunctional or tetrafunctional siloxane unit (an ketone resin; Dow Corning Toray Co., Ltd. Manufactured, trade name: SD-4584) 20 parts by mass and platinum catalyst (manufactured by Dow Corning Toray Co., Ltd., trade name: SRX-212) 1.5 parts by mass and stirred thoroughly, and diluted with methyl ethyl ketone to obtain adhesion Agent coating solution.

Using a knife coater, the obtained adhesive coating liquid is dried. After the thickness was 25 μm, it was applied to one side of a polyethylene terephthalate (PET) film (PET A4300, thickness: 38 μm, manufactured by TOYOBO Co., Ltd.) as a core material, and then at 120 ° C. The heat treatment was carried out for 2 minutes to form an adhesive layer (anthrone adhesive layer A) composed of an anthrone adhesive. Thereafter, the adhesive surface of the anthrone adhesive layer A was protected with an untreated PET film (T60, thickness: 50 μm, manufactured by Toray Industries, Inc.) which was not subjected to a release treatment or an easy-to-treat treatment as a release sheet.

[Manufacturing Example 2]

Addition of an organopolyoxane composed of an organopolysiloxane having a vinyl group as a main skeleton and having a vinyl group and an organic hydrogenated polyoxyalkylene oxide (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KS-847H) 100 parts by mass of an organopolysiloxane containing a trifunctional or tetrafunctional siloxane unit (an ketone resin; Dow Corning Toray) Co., Ltd., trade name: SD-4584) 50 parts by mass and platinum catalyst (manufactured by Dow Corning Toray Co., Ltd., trade name: SRX-212) 1.5 parts by mass and thoroughly stirred, and diluted with methyl ethyl ketone Thereby, an adhesive coating liquid is obtained.

Using a knife coater, the obtained adhesive coating liquid is dried. After the thickness was 25 μm, it was applied to one side of a polyethylene terephthalate film (manufactured by TOYOBO Co., Ltd., PET A4300, thickness: 38 μm) as a core material, and then heat-treated at 120 ° C. In minutes, an adhesive layer (anthrone adhesive layer B) composed of an anthrone adhesive was formed. Thereafter, the adhesive surface of the anthrone adhesive layer B was protected with an untreated PET film (T60, thickness: 50 μm, manufactured by Toray Industries, Inc.) which was not subjected to a release treatment or an easy-to-treat treatment as a release sheet.

[Manufacturing Example 3]

A (meth) acrylate polymer was prepared by copolymerizing 90 parts by mass of n-butyl acrylate (BA) and 10 parts by mass of acrylic acid (AA). The molecular weight of the (meth) acrylate polymer was measured by the method described later, and the weight average molecular weight was 500,000.

Mixing the (meth) acrylate polymer obtained in the above process 100 parts by mass and 1,3-bis(N,N'-diglycidylaminomethyl)cyclohexane (manufactured by Mitsubishi Gas Chemical Company, TERAD-C) as an epoxy crosslinking agent, 0.05 parts by mass and charged The mixture was stirred and diluted with ethyl acetate to obtain an adhesive coating liquid.

Using a knife coater, the obtained adhesive coating liquid is dried. Peeling treatment of a release sheet (SP-PET3811, thickness: 38 μm, manufactured by LINTEC Corporation) in which one side of the polyethylene terephthalate film was peeled off with an oxime-based release agent, was applied to a thickness of 25 μm. After the surface, heat treatment was performed at 90 ° C for 1 minute to form an adhesive layer (acrylic adhesive layer A) composed of an acrylic adhesive.

[Manufacturing Example 4]

The adhesive coating liquid obtained in Production Example 3 was applied to the side of the polyethylene terephthalate film by an oxime-based release agent by a doctor blade coating machine to have a thickness of 50 μm after drying. After the release-treated surface of the treated release sheet (SP-PET 3811, thickness: 38 μm, manufactured by LINTEC Corporation), heat treatment was performed at 90 ° C for 2 minutes to form an adhesive layer (acrylic adhesive layer A') composed of an acrylic adhesive. .

[Manufacturing Example 5]

A (meth) acrylate polymer was prepared by copolymerizing 60 parts by mass of n-butyl acrylate (BA), 20 parts by mass of methyl acrylate (MA), and 20 parts by mass of 2-hydroxyethyl acrylate (HEA). The molecular weight of the (meth) acrylate polymer was measured by the method described later, and the weight average molecular weight was 600,000.

Mixing the (meth) acrylate polymer obtained in the above process 100 parts by mass and 0.2 parts by mass of trimethylolpropane-modified toluene diisocyanate (TDI; manufactured by Soken Chemical & Engineering Co., Ltd., L-45) as an isocyanate-based crosslinking agent and stirred well, and acetic acid was used. The ethyl ester was diluted to obtain an adhesive coating liquid.

Using a knife coater, the obtained adhesive coating liquid is dried. Peeling treatment of a release sheet (SP-PET3811, thickness: 38 μm, manufactured by LINTEC Corporation) in which one side of the polyethylene terephthalate film was peeled off with an oxime-based release agent, was applied to a thickness of 25 μm. After the surface, heat treatment was performed at 90 ° C for 1 minute to form an adhesive layer (acrylic adhesive layer B) composed of an acrylic adhesive.

[Manufacturing Example 6]

(Meth) acrylate polymerization by copolymerizing 70 parts by mass of 2-ethylhexyl acrylate (2EHA), 10 parts by mass of methyl methacrylate (MA), and 20 parts by mass of 2-hydroxyethyl acrylate (HEA) Things. The molecular weight of the (meth) acrylate polymer was measured by the method described later, and the weight average molecular weight was 600,000.

Mixing the (meth) acrylate polymer obtained in the above process 100 parts by mass and 0.2 parts by mass of trimethylolpropane-modified toluene diisocyanate (TDI; manufactured by Soken Chemical & Engineering Co., Ltd., L-45) as an isocyanate-based crosslinking agent and stirred well, and acetic acid was used. The ethyl ester was diluted to obtain an adhesive coating liquid.

Using a knife coater, the obtained adhesive coating liquid is dried. Peeling treatment of a release sheet (SP-PET3811, thickness: 38 μm, manufactured by LINTEC Corporation) in which one side of the polyethylene terephthalate film was peeled off with an oxime-based release agent, was applied to a thickness of 25 μm. After the surface, heat treatment was performed at 90 ° C for 1 minute to form an adhesive layer (acrylic adhesive layer C) composed of an acrylic adhesive.

[Manufacturing Example 7]

99 parts by mass of n-butyl acrylate (BA) and 4-hydroxybutyl acrylate (4HBA) 1 part by mass of copolymerization to prepare a (meth) acrylate polymer. The molecular weight of the (meth) acrylate polymer was measured by the method described later, and the weight average molecular weight was 1.5 million.

Mixing the (meth) acrylate polymer obtained in the above process 100 parts by mass and 0.15 parts by mass of trimethylolpropane-modified xylene diisocyanate (XDI; manufactured by Soken Chemical & Engineering Co., Ltd., TD-75) as an isocyanate crosslinking agent and thoroughly stirred, and It was diluted with ethyl acetate to obtain an adhesive coating liquid.

Using a knife coater, the obtained adhesive coating liquid is dried. Peeling treatment of a release sheet (SP-PET3811, thickness: 38 μm, manufactured by LINTEC Corporation) in which one side of the polyethylene terephthalate film was peeled off with an oxime-based release agent, was applied to a thickness of 25 μm. After the surface, heat treatment was performed at 90 ° C for 1 minute to form an adhesive layer (acrylic adhesive layer D) composed of an acrylic adhesive.

[Manufacturing Example 8]

A (meth) acrylate polymer was prepared by copolymerizing 85 parts by mass of n-butyl acrylate (BA) and 15 parts by mass of acrylic acid (AA). The molecular weight of the (meth) acrylate polymer was measured by the method described later, and the weight average molecular weight was 500,000.

Mixing the (meth) acrylate polymer obtained in the above process 100 parts by mass and 1,3-bis(N,N'-diglycidylaminomethyl)cyclohexane (manufactured by Mitsubishi Gas Chemical Company, TERAD-C) as an epoxy crosslinking agent, 0.05 parts by mass and charged The mixture was stirred and diluted with ethyl acetate to obtain an adhesive coating liquid.

Using a knife coater, the obtained adhesive coating liquid is dried. Peeling treatment of a release sheet (SP-PET3811, thickness: 38 μm, manufactured by LINTEC Corporation) in which one side of the polyethylene terephthalate film was peeled off with an oxime-based release agent, was applied to a thickness of 25 μm. After the surface, heat treatment was performed at 90 ° C for 1 minute to form an adhesive layer (acrylic adhesive layer E) composed of an acrylic adhesive.

The composition of the adhesive (main agent) prepared in each of the production examples and (a) The weight average molecular weight (Mw) of the acrylate polymer, the kind and amount of the crosslinking agent, and the thickness of the adhesive layer are shown in Table 1.

Here, the weight average molecular weight (Mw) is a polystyrene-equivalent weight average molecular weight measured by a gel permeation chromatography (GPC) method under the following conditions (GPC measurement).

<Measurement conditions>

. GPC measuring device: manufactured by TOSOH CORPORATION, HLC-8020

. GPC column (passed in the following order): manufactured by TOSOH CORPORATION

TSK guard column HXL-H

TSKgel GMHXL (×2)

TSK gel G2000HXL

. Determination of solvent: tetrahydrofuran

. Measuring temperature: 40 ° C

[Example 1]

A laminate comprising a PET film (core material)/anthrone adhesive layer A (first adhesive layer)/untreated PET film (release sheet) obtained in Production Example 1 The surface of the PET film (core material) side was adhered to the acrylic adhesive layer A formed in Production Example 3 as the second adhesive layer. The obtained laminated body was cut into a width of 25 mm × a length of 200 mm to obtain a release sheet/acrylic adhesive layer A (second adhesive layer)/PET film (core material)/anthrone adhesive layer A (first adhesive) Layer)/Untreated PET film (release sheet) consisting of a release sheet double-sided adhesive sheet.

Peeling the first adhesive from the obtained double-sided adhesive sheet of the release sheet The peeling sheet on the layer side, the exposed ketone adhesive layer A and the soda lime glass of the size of 105 mm × 140 mm as the first hard body (manufactured by Central Glass Co., Ltd., thickness: 1.1 mm, Young's modulus: 71GPa; in Fig. 3, the method of the symbol 4) is contacted, and the double-sided adhesive sheet is attached to the first hard body so as to protrude in the longitudinal direction (see Fig. 3).

Next, the second adhesive layer is peeled off from the double-sided adhesive sheet The peeling sheet was attached to the exposed acrylic adhesive layer A as a soda lime glass having a size of 35 mm × 70 mm of the second hard body (manufactured by Central Glass Co., Ltd., thickness: 1.1 mm, Young's modulus: 71 GPa; 3 is the symbol 5). At this time, the second hard body is bonded to the double-sided adhesive sheet so that the end portion in the longitudinal direction of the double-sided adhesive sheet on the first hard body and the end portion in the longitudinal direction of the second hard body are located at the same position ( See Figure 3). Thus, a soda lime glass (second hard body) / acrylic adhesive layer A (second adhesive layer) / PET film (core material) / anthrone adhesive layer A (first adhesive layer) / sodium calcium was obtained A laminated body composed of glass (first hard body).

In addition, in this embodiment, the attachment position based on manual operation From the viewpoint of the ease of adjustment, the first layer of the anthrone adhesive layer A is attached to the first A hard body, but in consideration of industrial production, the second hard body and the acrylic adhesive layer A may be bonded together, and then the fluorene ketone adhesive layer A and the first hard body may be bonded.

[Examples 2 to 11 and Comparative Examples 1 to 2]

In the same manner as in Example 1, except that the first adhesive layer, the second adhesive layer, the first hard body, and the second hard body were changed as shown in Table 2, the second hard body/second was produced. Adhesive layer/core material/first adhesive layer/first hard body laminated body. In Comparative Examples 1 and 2, a layered body of an acrylic adhesive layer/release sheet obtained in the production example was attached to both sides of a PET film (TOYOBO Co., Ltd., PET A4300; thickness: 38 μm) which was a core material. Thereby, a release sheet double-sided adhesive sheet composed of a release sheet/acrylic adhesive layer B or a D/PET film (core material)/acrylic adhesive layer A/release sheet is obtained, and is produced by using the double-sided adhesive sheet A layered body composed of a second hard body/second adhesive layer/core material/first adhesive layer/first hard body.

Here, in the tenth embodiment, as the first hard body and the second hard body For the body, a chemically strengthened glass plate (Gorilla glass, thickness: 1.1 mm, Young's modulus: 72 GPa) was used. Further, in the eleventh embodiment, a stainless steel plate (SUS304, BA polishing surface, thickness: 1.0 mm, Young's modulus: 200 GPa) was used as the first hard body and the second hard body.

[Test Example 1] (Measurement of adhesion)

The adhesive layer formed on the release sheet in each of the production examples was bonded to one side of a PET film (PET A4300, thickness: 100 μm, manufactured by TOYOBO Co., Ltd.) to obtain a laminate of the release sheet/adhesive layer/PET film. . Among them, in Production Examples 1 and 2, since the same configuration was obtained, it was directly used as a laminate. The obtained laminate was cut into a width of 25 mm and a length of 100 mm, and this was taken as a sample.

Peeling and peeling from the above sample in an environment of 23 ° C and 50% RH The sheet was attached to a glass plate (manufactured by Nippon Sheet Glass Co., Ltd., thickness: 1.1 mm) made of float glass (soda lime glass) using a 2 kg rubber roller, and left for 20 minutes. .

Thereafter, a universal tensile tester (ORIENTEC Co., Ltd.) was used. TENSILON UTM-4-100), according to JIS Z0237:2009, the adhesion (N/25 mm) was measured under the conditions of a peeling speed of 300 mm/min and a peeling angle of 180°. The results are shown in Table 1.

And, based on the above results, the adhesion of the first adhesive layer is calculated. The ratio (F1/F2) of the force (F1) of the force (F1) to the second adhesive layer used in the examples and the comparative examples. The results are shown in Table 2.

[Test Example 2] (Measurement of 100% modulus)

For the first adhesive layer used in the examples and the comparative examples (the fluorene ketone adhesive layers A and B and the acrylic adhesive layers B and D formed on the release sheet in the above production example), a universal tensile tester (ORIENTEC) was used. Co., Ltd., TENSILON UTM-4-100), measured the stress-stretch rate curve with a sample width of 5 mm, a stretching interval of 20 mm, and a tensile speed of 300 mm/min, and converted the stress value of the elongation to 100% into MPa unit as a 100% modulus. The results are shown in Table 2.

[Test Example 3] (Evaluation of reworkability)

The double-sided adhesive sheet protruding from the laminate produced in the examples and the comparative examples was fixed to a universal tensile tester (TENSILON UTM-4-100, manufactured by ORIENTEC Co., Ltd.) in accordance with JIS Z0237:2009. The double was measured under the conditions of a peeling speed of 300 mm/min and a peeling angle of 90° (peeling upward) The peeling force (N/25 mm) of the first adhesive layer in the surface adhesive sheet with respect to the first hard body. The results are shown in Table 2.

After the peeling test described above, the presence or absence of the residue on the surface of the first hard body was visually confirmed, and the residual paste was evaluated on the following basis. The results are shown in Table 2.

◎... There is no residue at all.

○... There is a residue that is less than 20% of the bonding area.

△... There is a paste of 20% or more and less than 50% of the bonded area.

×... There is a paste of 50% or more of the bonded area.

In addition, it can be said that the peeling force is 50 N/25 mm or less, and 30 N/25 mm or less is preferable, and when there is no residual paste, the reworkability is excellent.

As can be seen from Table 2, the double-sided adhesive sheets obtained in the examples were peeled off. Excellent reworkability in hard bodies.

[Industrial availability]

The double-sided adhesive sheet of the present invention can be suitably used, for example, for a display body module used in a capacitive touch panel or a member including a display body module and a cover member or a member including a cover member.

1‧‧‧Double-sided adhesive sheet

11‧‧‧1st adhesive layer

11S‧‧‧1st adhesive surface

12‧‧‧2nd adhesive layer

12S‧‧‧2nd adhesive surface

13‧‧‧ core material

2a, 2b‧‧‧ peeling tablets

3‧‧‧With peeling sheet double-sided adhesive sheet

4‧‧‧1st hard body

5‧‧‧2nd hard body

10‧‧‧Layer

Claims (14)

A double-sided adhesive sheet for use between a first hard body and a second hard body, wherein the double-sided adhesive sheet comprises: a first adhesive surface, which is next to the first hard body or located The double-sided adhesive sheet further faces the member on the first hard body side; and the second adhesive surface is next to the second hard body or a member located on the second hard body side than the double-sided adhesive sheet The first adhesive surface has an adhesive force with respect to the first hard body or a member located closer to the first hard body than the double-sided adhesive sheet, and the second adhesive surface is located relative to the second hard body. When the adhesive force of the member on the second hard body side of the double-sided adhesive sheet is F2, the ratio of F1 to F2, that is, F1/F2 is 0.0001 to 0.1. The double-sided adhesive sheet according to the first aspect of the invention, wherein the double-sided adhesive sheet comprises: a first adhesive layer having the first adhesive surface; and a second adhesive layer having the second adhesive layer Adhesive surface. The double-sided adhesive sheet according to claim 2, wherein a ratio of a thickness of the first adhesive layer to a thickness of the second adhesive layer is 0.01 to 10. The double-sided adhesive sheet according to claim 2, wherein a core material is provided between the first adhesive layer and the second adhesive layer. The double-sided adhesive sheet according to claim 2, wherein the first adhesive layer is composed of an anthrone adhesive containing an organic polyoxyalkylene. The double-sided adhesive sheet according to claim 5, wherein the foregoing 矽 The ketone adhesive contains an addition organopolysiloxane and an organopolyoxane containing a trifunctional or tetrafunctional siloxane unit. The double-sided adhesive sheet according to claim 6, wherein the above-mentioned addition-formed organopolyoxane is an organopolysiloxane having an alkenyl group as a main skeleton and an alkenyl group and an organic hydrogenated polyfluorene. Obtained by oxyalkylene reaction. The double-sided adhesive sheet according to claim 2, wherein the first adhesive surface of the first adhesive layer has an adhesive force to the float glass of 0.01 to 1 N/25 mm in accordance with JIS Z0237:2009. The double-sided adhesive sheet according to claim 2, wherein the first adhesive layer has a 100% modulus of 0.3 to 1.5 MPa. The double-sided adhesive sheet according to claim 2, wherein the second adhesive layer is composed of an acrylic adhesive containing a (meth) acrylate polymer or an ultraviolet curable adhesive. The double-sided adhesive sheet according to claim 4, wherein the core material is composed of a polyester film. The double-sided adhesive sheet according to claim 1, wherein the first hard body is a display body module. The double-sided adhesive sheet according to claim 1, wherein the second hard body is a cover material. The double-sided adhesive sheet according to the first aspect of the invention, wherein the first hard body and the second hard body are members constituting a touch panel.