JP2011236298A - Adhesive composition, information-displaying flexible panel and method for producing information-displaying flexible panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive composition providing high reactivity at curing, exhibiting strong toughness and low moisture permeability after the curing, providing high adhesive force in long-term use, and suppressing the electrolytic corrosion when used as an adhesive or a sealing agent of an information-displaying flexible panel; to provide the information-displaying flexible panel using the adhesive composition; and to provide a method for producing the information-displaying flexible panel.SOLUTION: The adhesive composition contains (2) 3-70 pts.mass of a (meth)acrylate monomer, (3) 0.01-5 pts.mass of a photoradical polymerization initiator and (4) 0.1-10 pts.mass of a thermosetting component based on (1) 100 pts.mass of a liquid resin obtained by reacting a hydrogenated or unhydrogenated conjugated diene-aromatic vinyl-based copolymer polyol with an unsaturated hydrocarbon group-containing compound.

Description

  The present invention relates to an adhesive composition containing a liquid resin, a (meth) acrylate monomer, a thermosetting component and a radical photopolymerization initiator, a flexible information display panel using the adhesive composition, and production of the flexible information display panel It is about the method.

In recent years, an information display panel made of a flexible resin substrate has attracted a great deal of attention as a new form of display panel and has been actively developed. In the flexible information display panel, various kinds of materials such as a sealant for preventing outside air from entering the gap space between the substrates, an adhesive used for bonding the substrates and the substrates and the partition walls, and electrodes formed on the substrates. This member needs to exhibit sufficient strength against mechanical deformation of the panel. For this reason, it is important to use materials that can obtain appropriate flexibility as materials for various members. Most glass panel sealants and adhesives used in plasma TVs and LCD TVs that are currently on the market are composed of epoxy-based compounds that are closely three-dimensionally crosslinked and lack flexibility. Therefore, it cannot be used for flexible information display panels.
Moreover, as a sealing compound for various members, a composition for a photocurable sealing agent containing a terminal acrylic-modified hydrogenated polybutadiene polymer, a (meth) acrylate monomer, and a radical photopolymerization initiator (see Patent Document 1) is used as a hard disk. However, when these are applied as sealants and adhesives for flexible information display panels, carbon-carbon in (meth) acrylic groups in terminal acrylic-modified hydrogenated polybutadiene polymers and (meth) acrylate monomers There was a problem that the reaction rate of the double bond was difficult to be 90% or more. Furthermore, there has been a problem that heat is suddenly applied in a short time by ultraviolet (UV light) irradiation, and the flexible film substrate contracts and bends.
On the other hand, an adhesive containing butyl rubber, SEBS (styrene-ethylene-butylene-styrene block copolymer), (meth) acrylate monomer, and thermal radical polymerization initiator as a sealant capable of following the deformation of the flexible information display panel A composition is known (see Patent Document 2).

JP 2006-298964 A JP 2008-150550 A

In the adhesive composition described in Patent Document 2, the active site of the cross-linking reaction becomes a double bond portion in the polymer chain and its adjacent carbon, and the cross-linking reaction is randomly performed between the polymer chains at the active site. Therefore, (1) the toughness of the cured product, (2) low moisture permeability, and (3) the adhesive strength during long-term use is still not sufficient, and in terms of display reliability of the flexible information display panel, There is room for improvement.
In addition, when energization is repeated to drive the flexible information display panel, a corrosion phenomenon (electric corrosion) that dissolves the electrode in direct contact with the adhesive or the sealant may occur. In particular, it becomes easier to galvanize in a high temperature and high humidity environment. When electric corrosion occurs, it is visually recognized as a defect on the display screen, and thus a fatal malfunction occurs. Also in this respect, development of an adhesive or a sealing agent that can further improve the durability of the flexible information display panel is desired.
The present invention has been made under such circumstances, and a high reaction rate is obtained at the time of curing. After curing, it has toughness, low moisture permeability, high adhesive strength during long-term use, and is flexible. To provide an adhesive composition capable of suppressing electrolytic corrosion when used as an adhesive or sealant for an information display panel, a flexible information display panel using the adhesive composition, and a method for producing the flexible information display panel Is an issue.

  As a result of intensive studies to solve the above problems, the present inventors have reacted hydrogenated or non-hydrogenated conjugated diene-aromatic vinyl copolymer polyols with unsaturated hydrocarbon group-containing compounds. It has been found that an adhesive composition having the above-described effect can be obtained by using the obtained liquid resin in combination with a thermosetting component and a radical photopolymerization initiator. The present invention has been completed based on such findings.

That is, the present invention relates to the following [1] to [7].
[1] (1) For 100 parts by mass of a liquid resin obtained by reacting a hydrogenated or non-hydrogenated conjugated diene-aromatic vinyl copolymer polyol and an unsaturated hydrocarbon group-containing compound, (2) An adhesive composition containing 3 to 70 parts by weight of a (meth) acrylate monomer, (3) 0.01 to 5 parts by weight of a radical photopolymerization initiator, and (4) 0.1 to 10 parts by weight of a thermosetting component.
[2] The hydrogenated or non-hydrogenated conjugated diene-aromatic vinyl copolymer polyol is a hydrogenated styrene-butadiene copolymer polyol, and the unsaturated hydrocarbon group of the unsaturated hydrocarbon group-containing compound is ( The adhesive composition according to the above [1], which is a (meth) acryloyl group.
[3] The adhesive composition according to the above [1] or [2], wherein the thermosetting component is a thermal radical polymerization initiator.
[4] The thermal radical polymerization initiator is a ketone peroxide polymerization initiator, a hydroperoxide polymerization initiator, a dialkyl peroxide polymerization initiator, a peroxyketal polymerization initiator, or a peroxyester polymerization initiator. The adhesive composition according to [3] above, which is at least one selected from the group consisting of a peroxydicarbonate polymerization initiator and a diacyl peroxide polymerization initiator.
[5] A flexible information display panel in which two flexible substrates are arranged opposite to each other, wherein the adhesive composition according to any one of the above [1] to [4] is used as a sealant for the flexible information display panel. Flexible information display panel.
[6] A flexible information display panel in which two flexible substrates are arranged to face each other, wherein the adhesive composition according to any one of [1] to [4] is used as an adhesive for the flexible information display panel. Flexible information display panel.
[7] A method for producing a flexible information display panel, comprising a step of two-stage curing and bonding the adhesive composition according to any one of [1] to [4].

  The adhesive composition of the present invention has a high reaction rate upon curing, has toughness after curing, has low moisture permeability, and has high adhesive strength during long-term use. When used as a sealant, electrolytic corrosion is suppressed. A flexible information display panel using the adhesive composition has high reliability during long-term use.

It is a schematic diagram which shows an example of the flexible information display panel of this invention. It is a schematic diagram which shows an example of the manufacturing method of the flexible information display panel of this invention. It is a graph which shows the long-term reliability of the adhesive force of the adhesive composition obtained in Example 1 and Comparative Examples 1 and 4. It is a graph which shows the relationship between the ultraviolet irradiation amount of the adhesive composition obtained by the comparative example 1, and the reaction rate. It is a graph which shows the image quality change of the flexible information display panel using the adhesive composition obtained in Example 1 and Comparative Examples 1 and 4. It is a graph which shows the image quality change of the flexible information display panel using the adhesive composition obtained by the comparative examples 1, 3, and 5. FIG. It is a schematic diagram which shows the electrode pattern of the flexible information display panel used by the corrosion resistance test.

[Adhesive composition]
The present invention relates to (1) 100 parts by mass of a liquid resin obtained by reacting a hydrogenated or non-hydrogenated conjugated diene-aromatic vinyl copolymer polyol and an unsaturated hydrocarbon group-containing compound with (2 3) 70 parts by weight of (meth) acrylate monomer, 3) 0.01-5 parts by weight of radical photopolymerization initiator, and (4) 0.1-10 parts by weight of thermosetting component. It is.
Hereinafter, components (1) to (4) will be described in order.

((1) Liquid resin)
Component (1) is a liquid resin obtained by reacting a hydrogenated or non-hydrogenated conjugated diene-aromatic vinyl copolymer polyol with an unsaturated hydrocarbon group-containing compound. The liquid resin can be cured by light or heat. Such hydrogenated or non-hydrogenated conjugated diene-aromatic vinyl copolymer polyol can be easily produced by the following steps (A) to (B) or (A) to (C).
(A) A conjugated diene monomer and an aromatic vinyl monomer are copolymerized with a dilithium initiator in a saturated hydrocarbon solvent to obtain a weight average molecular weight of 5,000 to 40,000 and a molecular weight distribution. A step of producing a conjugated diene-aromatic vinyl copolymer having 3.0 or less.
(B) A step of producing a conjugated diene-aromatic vinyl copolymer polyol by reacting the conjugated diene-aromatic vinyl copolymer with an alkylene oxide.
(C) A step of producing a hydrogenated conjugated diene-aromatic vinyl copolymer polyol by hydrogenating the conjugated diene-aromatic vinyl copolymer polyol.

Since the reaction in the step (A) is living anionic polymerization, it can be polymerized by controlling the molecular weight and molecular weight distribution. The molecular weight can be obtained by polymerizing a polymer having a predetermined molecular weight depending on the amount of the dilithium initiator and the above monomer. In particular, when the weight average molecular weight is 5,000 or more, a narrow polymer having a molecular weight distribution of 2 or less is used. Easy to get. If desired, anionic polymerization may be carried out in the presence of a randomizer.
Next, as the step (B), the copolymer obtained in the above step (A) is subjected to an equivalent reaction between the polymer terminal which is a living anion and alkylene oxide, so that a non-hydrogenated compound having hydroxyl groups at both terminals is obtained. The conjugated diene-aromatic vinyl copolymer polyol (hereinafter sometimes referred to as copolymer polyol) can be obtained.
Furthermore, as a step (C), a hydrogenation reaction (hereinafter referred to as a hydrogenation reaction) is carried out on the copolymer polyol obtained in the step (B) having a double bond in the main chain, whereby a hydrogenated conjugated diene- An aromatic vinyl copolymer polyol (hereinafter sometimes referred to as a hydrogenated copolymer polyol) can be obtained.

Examples of the conjugated diene monomer that can be used in the step (A) include 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethylbutadiene, 2-phenyl-1,3-butadiene, 1,3-hexadiene and the like can be mentioned. These may be used alone or in combination of two or more. Among these, 1,3-butadiene is preferable from the viewpoint of securing rubber elasticity which is preferably possessed after curing.
The aromatic vinyl monomer is preferably styrene, α-methylstyrene or paramethylstyrene from the viewpoint of rubber physical properties after curing. An aromatic vinyl-type monomer may be used individually by 1 type, and may use 2 or more types together.

It does not specifically limit as a dilithium initiator used at the said process (A), A well-known thing can be used. For example, JP-B-1-53681 discloses monolithium compounds such as ethyllithium, n-butyllithium, sec-butyllithium and the like containing a disubstituted vinyl or alkenyl group in the presence of a tertiary amine such as triethylamine. A method for producing a dilithium initiator by reacting with an aromatic hydrocarbon such as 1,3- (diisopropenyl) benzene is described.
The solvent used in the preparation of the dilithium initiator and the production of the (co) polymer may be any organic solvent inert to the reaction, and hydrocarbon solvents such as aliphatic, alicyclic, and aromatic hydrocarbon compounds. Is used. In addition, about this solvent, JP, 2007-145949, A can be referred to.

  Moreover, as an alkylene oxide used at a process (B), ethylene oxide, a propylene oxide, or a butylene oxide etc. are mentioned, for example. This polyol reaction (step (B)) is preferably carried out immediately after the polymerization reaction (step (A)).

If the weight average molecular weight of the (co) polymer polyol obtained in the step (B) is 5,000 or more, the molecular weight between crosslinking points can be increased, and after the curing reaction, the elastic modulus is lowered and the elongation (Eb ) Can be increased, which is preferable. On the other hand, if the (co) polymer polyol having a weight average molecular weight of 40,000 or less is produced, the polymerization viscosity does not become too high when the polymerization is performed with the dilithium catalyst in the step (A). Since it is not necessary to lower the solid content concentration as a polymerization process, the cost is preferable. As for the weight average molecular weight of the (co) polymer polyol obtained by the process (B), 5,000-30,000 are more preferable.
Moreover, if molecular weight distribution is 3.0 or less, the various influence by a low molecular weight component and a high molecular weight component can be suppressed. In particular, since the viscosity is greatly affected by the molecular weight, the fluctuation of the molecular weight causes the viscosity variation. If it is the said method, since the (co) polymer of narrow molecular weight distribution can be synthesize | combined, the (co) polymer of the same molecular weight can be obtained with good reproducibility, and the effect of stabilizing a viscosity can be expected.
The liquid material (liquid resin) used in the present invention is often dispensed by a dispenser. In this case, variation in material viscosity results in variation in dimensions after coating, so viscosity stabilization is important. The molecular weight distribution is preferably 3.0 or less, more preferably 2.0 or less.

The hydrogenation reaction in step (C) is carried out by hydrogenating the (co) polymer polyol obtained in step (B) in an organic solvent under hydrogen pressure and in the presence of a hydrogenation catalyst.
The hydrogenation catalyst used in the method of the present invention is a heterogeneous catalyst such as palladium-carbon, reduced nickel, rhodium, or the like, or an organic nickel compound such as nickel naphthenate or nickel octoate, or an organic cobalt such as cobalt naphthenate or cobalt octoate. A homogeneous catalyst in which the compound is combined with an organoaluminum compound such as triethylaluminum or triisobutylaluminum or an organolithium compound such as n-butyllithium or sec-butyllithium can be used. As a cocatalyst, an ether compound such as tetrahydrofuran, ethylene glycol dimethyl ether, or diethylene glycol dimethyl ether may be used.
In addition, as another hydrogenation reaction method, for example, the copolymer polyol before hydrogenation is dicyclopentadienyl titanium halide, organic carboxylate nickel, organic carboxylate nickel and periodic groups I to III of the periodic table. 1 to 100 by using a hydrogenation catalyst composed of an organometallic compound, nickel, platinum, baradium, ruthenium, rhenium, rhodium metal catalyst or cobalt, nickel, rhodium, ruthenium complex, etc. supported on carbon, silica, diatomaceous earth, etc. Under hydrogen pressurized to atmospheric pressure, or in the presence of lithium aluminum hydride, p-toluenesulfonyl hydrazide, Zr—Ti—Fe—V—Cr alloy, Zr—Ti—Nb—Fe—V—Cr alloy, LaNi ₅ Hydrogen in the presence of a hydrogen storage alloy such as an alloy or under hydrogen pressurized to 1 to 100 atmospheres And a hydrogenation catalyst obtained by mixing a cyclohexane solution of di-p-tolyl-bis (1-cyclopentadienyl) titanium and an n-hexane solution of n-butyllithium under hydrogen, Examples thereof include a method of adding hydrogen under hydrogen pressurized to 1 to 100 atm.

Among the various hydrogenation catalysts described above, a Ziegler hydrogenation catalyst or a palladium-carbon hydrogenation catalyst comprising a combination of a transition metal compound and an alkylaluminum compound is preferred.
Such transition metal compounds include tris (acetylacetonato) cobalt, bis (acetylacetonato) nickel, tris (acetylacetonato) iron, tris (acetylacetonato) chromium, tris (acetylacetonato) manganese, bis (acetyl). Acetonato) manganese, tris (acetylacetonato) ruthenium, bis (acetylacetonato) cobalt, bis (cyclopentadienyl) dichlorotitanium, bis (cyclopentadienyl) dichlorozirconium, bis (triphenylphosphine) cobalt dichloride, Examples thereof include bis (2-hexanoate) nickel, bis (2-hexanoate) cobalt, titanium tetraisopropoxide, and titanium tetraethoxide. Among these, bis (acetylacetonato) nickel and tris (acetylacetonato) cobalt are preferable from the viewpoint of high hydrogenation activity.
Examples of the alkylaluminum compound used in the Ziegler hydrogenation catalyst include trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, tri-n-butylaluminum, dimethylaluminum chloride, diethylaluminum chloride, diisobutylaluminum chloride, methylaluminum dichloride. , Ethylaluminum dichloride, isobutylaluminum dichloride, diethylaluminum hydride, diisobutylaluminum hydride, ethylaluminum sesquichloride. Among these, triisobutylaluminum, triethylaluminum, and diisobutylaluminum hydride are preferable from the viewpoint of hydrogenation activity, and triisobutylaluminum is most preferable.

  Although there is no restriction | limiting in particular in the usage form of a Ziegler type | system | group hydrogenation catalyst, The method of preparing the catalyst solution which made the transition metal compound and the alkyl aluminum compound react previously and adding it to a polymerization solution can be mentioned preferably. The amount of the alkylaluminum compound used in this case is preferably 0.2 to 5 mol with respect to 1 mol of the transition metal compound. The catalyst preparation reaction is carried out in the temperature range of −40 to 100 ° C., preferably 0 to 80 ° C., and the reaction time is usually preferably 1 minute to 3 hours.

  Moreover, the temperature of the hydrogenation reaction in the step (C) is usually preferably 50 to 180 ° C, more preferably 70 to 150 ° C. The hydrogenation reaction is preferably carried out at a hydrogen pressure of 5 to 100 atmospheres (5,06.25 to 101,325 hPa), more preferably 10 to 50 atmospheres (10132.5 to 50,662.5 hPa). Is called. If the reaction temperature and the hydrogen pressure are within this range, the catalyst activity can be kept high, and the catalyst is hardly deactivated or side reaction is preferable.

The hydrogenated (co) polymer polyol obtained as described above is reacted with an unsaturated hydrocarbon group-containing compound to introduce an unsaturated hydrocarbon group at the terminal of the hydrogenated (co) polymer polyol.
As the unsaturated hydrocarbon group, a (meth) acryloyl group is preferable. As the unsaturated hydrocarbon group-containing compound, (meth) acryloyl isocyanate is preferable, and the hydrogenated (co) polymer polyol is (meth) acrylated by reaction with them.
Examples of (meth) acryloyl isocyanate include 2-acryloyloxyethyl isocyanate and 2-methacryloyloxyethyl isocyanate.

((2) (Meth) acrylate monomer)
The (meth) acrylate monomer preferably has a molecular weight of less than 1,000, and more preferably 150 to 600.
Examples of the (meth) acrylate monomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, Isoamyl (meth) acrylate, isobornyl (meth) acrylate, isobutyl (meth) acrylate, isodecyl (meth) acrylate, isooctyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, iso Myristyl (meth) acrylate, benzyl (meth) acrylate, lauroxypolyethylene glycol (meth) acrylate, lauryl (meth) acrylate, cyclohexyl (meth) acrylic , Dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, bornyl (meth) acrylate, isobornyl (meth) acrylate, 2-methyl-2-adamantyl (meth) acrylate, phenoxyethyl (meth) acrylate , Dicyclopentenyloxyethyl (meth) acrylate, diethylene glycol monoethyl ether (meth) acrylate, dimethylaminoethyl (meth) acrylate, dipropylene glycol (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, ethoxylated phenyl (meth) acrylate , Methoxydipropylene glycol (meth) acrylate, methoxytripylene glycol (meth) acrylate, methoxypolyethylene glycol (me ) Monofunctional (meth) acrylate monomers such as acrylate and methoxy triethylene glycol acrylate. These may be used individually by 1 type and may use 2 or more types together. As the monofunctional (meth) acrylate monomer, isobornyl methacrylate, dodecyl methacrylate, dicyclopentanyl acrylate, and dicyclopentenyl acrylate are preferable.
Furthermore, a polyfunctional (meth) acrylate monomer such as bifunctional or trifunctional may be used as the (meth) acrylate monomer. Examples of the bifunctional (meth) acrylate monomer include tetraethylene glycol diacrylate, 2-hydroxy-3-acryloyloxypropyl methacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, 1 , 10-decanediol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, dimethylol dicyclopentane di (meth) acrylate, tricyclodecane dimethanol diacrylate and the like, and tetraethylene glycol diacrylate is preferred. . Examples of the trifunctional (meth) acrylate monomer include trimethylolpropane triacrylate, pentaerythritol triacrylate, and the like, and trimethylolpropane triacrylate is preferable. In addition, tetrafunctional or more polyfunctional (meth) acrylates such as ditrimethylolpropane tetraacrylate, pentaerythritol tetraacrylate, and dipentaerythritol hexaacrylate may be used.
Among these, as a (meth) acrylate monomer, a monofunctional, bifunctional, and trifunctional (meth) acrylate monomer is preferable.
The compounding quantity of a (meth) acrylate monomer is 3-70 mass parts with respect to 100 mass parts of component (1), Preferably it is 5-50 mass parts, More preferably, it is 5-40 mass parts. If it is less than 3 parts by mass, the adhesive strength will be insufficient. Moreover, when it exceeds 70 mass parts, the viscosity of an adhesive composition will become low and a moldability will fall.

((3) Photoradical polymerization initiator)
As radical photopolymerization initiators, benzoin derivatives and benzyl ketals [for example, Ciba Specialty Chemicals, trade name: Irgacure 651], α-hydroxyacetophenones [for example, Ciba Specialty Chemicals, Inc., trade names: Darocur 1173, Irgacure 184, Irgacure 127], α-aminoacetophenones [eg, Ciba Specialty Chemicals, Inc., trade names: Irgacure 907, Irgacure 369], α-amino Combination of acetophenones and thioxanthones (for example, isopropylthioxanthone, diethylthioxanthone), acylphosphine oxides [for example, Ciba Specialty Chemicals Co., Ltd., trade name: Irga It includes Interview A 819], etc., as a hydrogen abstraction type, combined use of benzophenones and amines, combination and the like of the thioxanthone and amine. Further, an intramolecular cleavage type and a hydrogen abstraction type may be used in combination. Of these, oligomerized α-hydroxyacetophenone and acrylated benzophenones are preferred. More specifically, oligo [2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propanone] [for example, Lamberti S. et al. p. A product, trade name: ESACURE KIP150, etc.], acrylated benzophenone [e.g., trade name: Ebecryl P136, etc., manufactured by Daicel UC Corporation], imide acrylate, and the like.
In addition to the above-mentioned radical photopolymerization initiators, 1- [4- (2-hydroxyethoxy) phenyl] -2-methyl-1-propan-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone 1-hydroxy-cyclohexyl-ketone and benzophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 2,4,6-trimethylbenzoylphenylphosphine oxide, 2,4,6- Trimethylbenzoylphenylphenylethoxyphosphine oxide, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone-1,2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2- Methyl-1-[(4-methylthio) phenyl] -2-morpholinopro 1-one, benzoyl methyl ether, benzoyl ethyl ether, benzoyl butyl ether, benzoyl isopropyl ether, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, 2-hydroxy-2-methyl- [4- (1- Methylvinyl) phenyl] propanol oligomer, mixture of 2-hydroxy-2-methyl- [4- (1-methylvinyl) phenyl] propanol oligomer and 2-hydroxy-2-methyl-1-phenyl-1-propanone, isopropylthioxanthone , Methyl o-benzoylbenzoate, [4- (methylphenylthio) phenyl] phenylmethane, and the like can also be used.
Content of radical photopolymerization initiator is 0.01-5 mass parts with respect to 100 mass parts of component (1), Preferably it is 0.05-2 mass parts, More preferably, it is 0.05-1 mass. Part.

((4) Thermosetting component)
The thermosetting component is not particularly limited as long as it is a component capable of curing the adhesive composition by heating at about 50 to 180 ° C., but a thermal radical polymerization initiator is preferably used.
Examples of thermal radical polymerization initiators include ketone peroxide polymerization initiators (H—OO—CR′R ″ —OO—H, etc.), hydroperoxide polymerization initiators (R—OOH), and dialkyl peroxides. Polymerization initiator (R—OO—R ′), peroxyketal (peroxyacetal) polymerization initiator (R—OO—CR′R ″ —OO—R ′ ″), peroxyester polymerization initiator (R—CO—OO—R ′), peroxydicarbonate polymerization initiator (R—O—CO—OO—CO—O—R ′), diacyl peroxide polymerization initiator (R—CO—OO—) CO-R ′) and the like; and azo compounds such as 2,2′-azobisisobutyronitrile. R, R ′, R ″, R ′ ″ each independently represents an alkyl group or an aryl group, and the “—CR′R ″ —” site is combined with a carbon atom. An aliphatic ring (for example, a cyclohexane ring) may be formed. These may be used individually by 1 type and may use 2 or more types together.
As the thermal radical polymerization initiator, organic oxides are preferable from the viewpoint of easy generation of radicals at the heating temperature described below, and high reactivity and storage stability, and a ketone peroxide polymerization initiator, Hydroperoxide polymerization initiators, dialkyl peroxide polymerization initiators, peroxyketal polymerization initiators, and peroxyester polymerization initiators are more preferable. Further, from the viewpoint of hydrogen abstraction ability in the molecular chain, a ketone peroxide polymerization initiator, a hydroperoxide polymerization initiator, a dialkyl peroxide polymerization initiator, and a peroxyketal polymerization initiator are more preferable. From the viewpoint of storage stability of the adhesive composition, a peroxyketal polymerization initiator is more preferable.

Examples of the ketone peroxide polymerization initiator include methyl isobutyl ketone peroxide, methyl ethyl ketone peroxide, and cyclohexanone peroxide.
Examples of the hydroperoxide-based polymerization initiator include 2,5-bis (hydroperoxy) -2,5-dimethylhexane, t-butyl hydroperoxide, cumene hydroperoxide, tetramethylbutyl hydroperoxide, and the like. It is done.
Examples of the dialkyl peroxide polymerization initiator include 2,5-dimethyl-2,5-bis (t-butyldioxy) -3-hexane, di-t-butyl peroxide, dicumyl peroxide, and the like.
Examples of the peroxyketal polymerization initiator include 1,1-di (t-butylperoxy) cyclohexane, 1,1-bis (t-butyldioxy) -3,3,5-trimethylcyclohexane, butyl-4,4. -Bis (t-butyldioxy) valerate etc. are mentioned.
Examples of peroxyester polymerization initiators include acetyl peroxide, lauroyl peroxide, di-t-butyldiperoxyisophthalate, 3,3 ′, 4,4′-tetrakis (t-butyldioxycarbonyl) benzophenone. 1,1,3,3-tetramethylbutylperoxyneodecanate and the like.
Examples of the peroxydicarbonate-based polymerization initiator include diisopropyl peroxydicarbonate, di-sec-butyl peroxydicarbonate, and the like.
Examples of the diacyl peroxide polymerization initiator include dibenzoyl peroxide, di (3-methylbenzoyl) peroxide, 3,5,5-trimethylhexanoyl peroxide, and dilauroyl peroxide.

(Other ingredients)
In addition to the components (1) to (4), the adhesive composition of the present invention may further contain a polythiol compound having 2 to 6 mercapto groups in the molecule.
The polythiol compound is not particularly limited as long as it has 2 to 6 mercapto groups in the molecule. For example, aliphatic polythiols such as alkanedithiol having about 2 to 20 carbon atoms, xylylene dithiol, etc. Aro-aliphatic polythiols, polythiols formed by replacing halogen atoms of halohydrin adducts of alcohols with mercapto groups, polythiols made of hydrogen sulfide reaction products of polyepoxide compounds, and having 2 to 6 hydroxyl groups in the molecule Examples include polythiols composed of esterified products of polyhydric alcohols and thioglycolic acid, β-mercaptopropionic acid, or β-mercaptobutanoic acid.
Examples of the polyhydric alcohol having 2 to 6 hydroxyl groups in the molecule include alkanediol having 2 to 20 carbon atoms, poly (oxyalkylene) glycol, glycerol, diglycerol, trimethylolpropane, ditrimethylolpropane, and pentaerythritol. And dipentaerythritol.

  Specific examples of the polythiol compound include, for example, ethylene glycol di (thioglycolate), ethylene glycol di (β-mercaptopropionate), ethylene glycol di (β-mercaptobutanoate), trimethylene glycol di (thioglycolate). , Trimethylene glycol di (β-mercaptopropionate), trimethylene glycol di (β-mercaptobutanate), propylene glycol di (thioglycolate), propylene glycol di (β-mercaptopropionate), propylene glycol di (Β-mercaptobutanate), 1,3-butanediol di (thioglycolate), 1,3-butanediol di (β-mercaptopropionate), 1,3-butanediol di (β-mercaptobutanate) ), 1,4-butane All di (thioglycolate), 1,4-butanediol di (β-mercaptopropionate), 1,4-butanediol di (β-mercaptobutanate), neopentyl glycol di (thioglycolate), neopentyl Glycol di (β-mercaptopropionate), neopentyl glycol di (β-mercaptobutanate), 1,6-hexanediol di (thioglycolate), 1,6-hexanediol di (β-mercaptopropionate) ), 1,6-hexanediol di (β-mercaptobutanate), 1,8-octanediol di (thioglycolate), 1,8-octanediol di (β-mercaptopropionate), 1,8- Octanediol di (β-mercaptobutanate), 1,9-nonanediol di (thioglycolate) 1,9-nonanediol di (β-mercaptopropionate), 1,9-nonanediol di (β-mercaptobutanate), cyclohexane-1,4-dimethanoldi (thioglycolate), cyclohexane-1,4 -Dimethanol di (β-mercaptopropionate), cyclohexane-1,4-dimethanol di (β-mercaptobutanate), diethylene glycol di (thioglycolate), diethylene glycol di (β-mercaptopropionate), diethylene glycol di (β- Mercaptobutanate), triethylene glycol di (thioglycolate), triethylene glycol di (β-mercaptopropionate), triethylene glycol di (β-mercaptobutanate), polyethylene glycol di (thioglycolate), poly Reethylene glycol di (β-mercaptopropionate), polyethylene glycol di (β-mercaptobutanate), dipropylene glycol di (thioglycolate), dipropylene glycol di (β-mercaptopropionate), dipropylene glycol di (Β-mercaptobutanate), tripropylene glycol di (thioglycolate), tripropylene glycol di (β-mercaptopropionate), tripropylene glycol di (β-mercaptobutanate), polypropylene glycol di (thioglycolate) ), Polypropylene glycol di (β-mercaptopropionate), polypropylene glycol di (β-mercaptobutanoate), polytetramethylene ether glycol di (thioglycolate), polytetramethyle Ether glycol di (β-mercaptopropionate), polytetramethylene ether glycol di (β-mercaptobutanate), di (thioglycolate) of cyclohexane-1,4-dimethanol ethylene oxide adduct, cyclohexane-1 , 4-dimethanol ethylene oxide adduct di (β-mercaptopropionate), cyclohexane-1,4-dimethanol ethylene oxide adduct di (β-mercaptobutanate), hydrogenated bisphenol A ethylene oxide adduct Di (thioglycolate), hydrogenated bisphenol A ethylene oxide adduct di (β-mercaptopropionate), hydrogenated bisphenol A ethylene oxide adduct di (β-mercaptobutanate), cyclohexane-1,4 -Dimethanol Di (thioglycolate) of pyrene oxide adduct, di (β-mercaptopropionate) of cyclohexane-1,4-dimethanol propylene oxide adduct, (β of cyclohexane-1,4-dimethanol propylene oxide adduct -Mercaptobutanate), di (thioglycolate) of hydrogenated bisphenol A propylene oxide adduct, di (β-mercaptopropionate) of hydrogenated bisphenol A propylene oxide adduct, hydrogenated bisphenol A propylene oxide adduct Di (β-mercaptobutanate), glycerol tri (thioglycolate), glycerol tri (β-mercaptopropionate), glycerol tri (β-mercaptobutanate), diglycerol tetra (thioglycolate), diglycerol Tiger (β-mercaptopropionate), diglyceroltetra (β-mercaptobutanate), trimethylolpropane tri (thioglycolate), trimethylolpropane tri (β-mercaptopropionate), trimethylolpropane tri (β -Mercaptobutanate), ditrimethylolpropane tetra (thioglycolate), ditrimethylolpropane tetra (β-mercaptopropionate), ditrimethylolpropane tetra (β-mercaptobutanate), pentaerythritol tetra (thioglycolate), Pentaerythritol tetra (β-mercaptopropionate), pentaerythritol tetra (β-mercaptobutanate), dipentaerythritol hexa (thioglycolate), dipentaerythritol hexa beta-mercaptopropionate), dipentaerythritol hexa (beta-mercapto pig sulfonate) and the like.

In addition, when an inorganic filler and / or an organic thickener is added to the adhesive composition of the present invention, the composition can have thixotropy and the moldability of the mixture can be improved.
Examples of the inorganic filler include silica (SiO ₂ ), alumina, titania, and viscosity mineral. Among these, silica powder, silica powder subjected to hydrophobic treatment or a mixture thereof is preferable. More specifically, silica fine powder pulverized by a dry method [for example, product name: Aerosil 300, manufactured by Nippon Aerosil Co., Ltd.], fine powder obtained by modifying this silica fine powder with trimethyldisilazane [for example, Nippon Aerosil Product name: Aerosil RX300 etc.] and fine powder obtained by modifying the silica fine powder with polydimethylsiloxane [for example, product name: Aerosil RY300, manufactured by Nippon Aerosil Co., Ltd.].
The average particle size of the inorganic filler is preferably 5 to 50 μm, more preferably 5 to 12 μm, from the viewpoints of thickening and thixotropy.
When the inorganic filler is contained, the content thereof is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 7 parts by mass, and further preferably 1 to 5 parts per 100 parts by mass of the component (1). Part by mass.

As the organic thickener, hydrogenated castor oil, amide wax or a mixture thereof is preferable. Specific examples of the organic thickener include hydrogenated castor oil which is a hydrogenated product of castor oil (non-drying oil whose main component is ricinoleic acid) [for example, manufactured by Zude Chemie Catalysts Co., Ltd., trade name: ADVITOLL100, manufactured by Enomoto Kasei Co., Ltd. , Trade name: Disparone 305, etc.] and higher amide waxes that are compounds having an amide bond [for example, trade name: Disparon 6500, produced by Enomoto Kasei Co., Ltd.].
When the organic thickener is contained, the content thereof is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 7 parts by mass, further preferably 1 to 100 parts by mass of the component (1). 5 parts by mass.

The adhesive composition of the present invention may further contain a terminal (meth) acrylate oligomer. By blending the terminal (meth) acrylate oligomer, the viscosity of the adhesive composition can be adjusted. Physically, the hardness is decreased, the Eb (elongation) and the Tb (breaking strength) are improved. You can plan. The terminal (meth) acrylate oligomer refers to an oligomer having an acryloyl group or a methacryloyl group at one end or both ends.
The terminal (meth) acrylate oligomer is preferably a hydrocarbon oligomer, that is, a hydrogenated oligomer or a terminal (meth) acrylate hydrogenated oligomer, from the viewpoint of moisture permeability, weather resistance and heat resistance. The weight average molecular weight of the terminal (meth) acrylate oligomer is preferably 5,000 to 40,000, more preferably 5,000 to 15,000. When the weight average molecular weight is within this range, there are advantages that it is easy to handle as a liquid raw material and the cured product has low hardness.

Examples of the terminal (meth) acrylate oligomer include hydrogenated polybutadiene (meth) acrylate oligomer, polyester (meth) acrylate oligomer, epoxy (meth) acrylate oligomer, urethane (meth) acrylate oligomer, and polyol (meth) acrylate. System oligomers and the like.
When the terminal (meth) acrylate oligomer is contained, the content is preferably 150 parts by mass or less with respect to 100 parts by mass of the component (1) from the viewpoint of maintaining the heat resistance of the cured product and maintaining low moisture permeability. More preferably, it is 110 mass parts or less, More preferably, it is 100 mass parts or less.

The adhesive composition of the present invention may further contain a stabilizer and the like.
As the stabilizer, triethylene glycol bis [3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionate] [for example, Ciba Specialty Chemicals, trade name: IRGANOX245, Asahi Denka Manufactured by Kogyo Co., Ltd., trade name: ADK STAB AO-70, etc.], 3,9-bis {2- [3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1,1- Phenolic antioxidants such as dimethylethyl} -2,4,8,10-tetraoxaspiro [5,5] undecane [for example, manufactured by Asahi Denka Kogyo Co., Ltd., trade name: ADK STAB AO-80, etc.] It is done.
When the stabilizer is contained, the content thereof is preferably 0.1 to 5 parts by mass, more preferably 0.5 to 3 parts by mass, and still more preferably 0.001 parts by mass with respect to 100 parts by mass of the component (1). 5 to 2 parts by mass.

  Furthermore, from the viewpoint of improving adhesiveness or sealing properties when the adhesive composition of the present invention is used as a sealing agent or adhesive for flexible information display panels, terpene resins, terpene phenol resins, coumarone resins, coumarone-indene resins, Additives such as various tackifiers such as petroleum hydrocarbons and rosin derivatives, and colorants such as titanium black may be included. When these are contained, the content thereof is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 3 parts by mass with respect to 100 parts by mass of the component (1).

In this invention, the said component (1)-(4) and the said other component as needed are mixed by the said compounding ratio, and it is set as an adhesive composition.
There is no restriction | limiting in particular in the mixing method of each component, A well-known method is applicable. For example, each component can be kneaded using a kneader capable of adjusting the temperature, for example, a single screw extruder, a twin screw extruder, a planetary mixer, a twin screw mixer, a high shear mixer, and the like.
The adhesive composition of the present invention can be cured only by irradiation with active energy rays or heating, but it can also be cured by heating after curing with active energy rays. It is useful as a panel sealant and adhesive. A method of using the flexible information display panel as a sealant or an adhesive will be described later.
Examples of the active energy rays include ionizing radiation such as ultraviolet rays and electron beams, α rays, β rays, and γ rays. Among these, ultraviolet rays are preferable. Examples of the ultraviolet ray source include a xenon lamp, a low-pressure mercury lamp, a high-pressure mercury lamp, a metal halide lamp, and a microwave excimer lamp. The atmosphere for irradiating the active energy rays is preferably an inert gas atmosphere such as nitrogen gas or carbon dioxide gas, or an atmosphere with a reduced oxygen concentration, but can be sufficiently cured even in a normal air atmosphere. The irradiation atmosphere temperature is usually preferably 10 to 200 ° C, more preferably 10 to 100 ° C, and further preferably 10 to 80 ° C. The integrated light quantity is preferably 20,000 mJ / cm ² or less, but is preferably 5000 mJ / cm ² or less, more preferably 2000 mJ / cm when used as a sealant or adhesive for a flexible information display panel described later. ² or less, more preferably 500 mJ / cm ² or less, and by applying heat, the reaction rate of the carbon-carbon double bond in the (meth) acryl group in the liquid resin and the (meth) acrylate monomer is 90% or more, Furthermore, it can be increased to 95% or more. The heating temperature is preferably 80 to 180 ° C, more preferably 80 to 160 ° C, and still more preferably 90 to 130 ° C.
In addition, a property can also be stabilized by irradiating an active energy ray again to the obtained hardened | cured material.

The cured product thus obtained has a breaking strength of 2 to 3 kgf (19.6 to 29.4 N), an elongation at break of 200 to 300%, and has high toughness.
The moisture permeability of the cured product thus obtained is usually 40 g / m ² · 24 h or less, and the function as a sealing agent or adhesive for flexible information display panels, particularly as a sealing agent, is sufficiently exhibited. Moisture permeability, more preferably be less ^{25g / m 2 · 24h, 10~25g} / m 2 · 24h about in detail, the moisture permeability of 15~20g / m ² · 24h, more detail. Moreover, it is speculated that this low moisture permeability leads to suppression of electrolytic corrosion.
Moreover, since the reaction rate of the carbon-carbon double bond in the (meth) acryl group in the liquid resin and (meth) acrylate monomer tends to be 90% or more by irradiation with active energy rays, it is not necessary to irradiate excessively. The problem that the flexible information display panel bends does not occur.

[Flexible information display panel]
The basic configuration of the flexible information display panel of the present invention is as follows.
A display medium sealed between two opposing flexible substrates (however, at least one is transparent) is electrically driven. For example, when a group of particles containing chargeable particles is used as a display medium, an electric field is applied. The display medium is attracted along the applied electric field direction by the force of the electric field, the Coulomb force, or the like, and the display medium is moved by the change in the electric field direction, whereby information such as an image is displayed. Note that the force applied to the particles constituting the display medium may be not only the Coulomb force between the particles, but also the electric mirror image force between the electrode and the substrate, intermolecular force, liquid cross-linking force, gravity and the like. The chargeable particles constituting the display medium may be two or more kinds of chargeable particles having different colors and charge characteristics, or one kind of chargeable particles. For example, negatively charged particles are attracted by a Coulomb force toward a positively charged substrate, and positively charged particles are attracted by a Coulomb force and the like toward a negatively charged substrate. When the display medium to be moved reciprocates between the opposing substrates, information such as an image is displayed.
The flexible information display panel of the present invention is configured in a dot matrix display system, and for example, a passive drive system, an active drive system, or the like can be used. In addition, a segment display method can be used. As the driving method, a method suitable for the display method such as a segment driving method or a dynamic driving method can be adopted.
In the present invention, in such a flexible information display panel, the adhesive composition of the present invention is used as a sealing agent or an adhesive, and all known flexible information display panels are configured. Can do. Examples of the sealant include a sealant that prevents outside air from entering the gap space between the substrates. Examples of the adhesive include adhesives used for bonding between substrates, bonding between a substrate and a spacer, and bonding between a substrate and a partition (arranged between two substrates).

An example of the flexible information display panel of the present invention will be described with reference to FIG.
FIG. 1 shows an example of a passive drive type information display panel. At least two types of display media configured as a particle group including particles having optical reflectance and chargeability (here, two types of display media, a white display medium and a black display medium, are shown. The medium is configured as a group of particles including negatively charged white particles, and the black display medium is configured as a group of particles including positively charged black particles. ) In each cell formed by 4 and the partition wall 7, the electrode 5 (line electrode) provided on the flexible substrate 1 and the electrode 6 (line electrode) provided on the flexible substrate 2 are formed so as to cross each other at right angles. The substrate 1 is moved vertically from the substrate 1 to the substrate 2 or from the substrate 2 to the substrate 1 in accordance with an electric field generated by applying a voltage therebetween. As shown in FIG. 1, when the white display medium is on the transparent substrate 2 side, the white display is visually recognized. When the black display medium is on the transparent substrate 2 side, the black display is visually recognized. Is displayed. In FIG. 1, the partition in front is omitted. The electrode may be provided outside the substrate, inside the substrate, or embedded in the substrate.

  In such a flexible information display panel, as shown in FIG. 1, a sealant 8 may be used to prevent outside air from entering the gap space between the substrates. The adhesive composition of the present invention can be used as a material for this sealant. In addition, the adhesive 9 may be used for bonding between substrates, bonding between a substrate and a spacer, bonding between a substrate and a partition wall, and the adhesive composition of the present invention is used as the adhesive. Can do. The flexible information display panel of the present invention (however, it is not limited to the configuration shown in FIG. 1) uses the adhesive composition of the present invention as the sealing agent 8 or the adhesive 9.

Hereinafter, each member which comprises the flexible information display panel of this invention is demonstrated. In addition, about the name of each member, FIG. 1 can be referred.
(substrate)
As the substrate, at least one of the opposing substrates is a flexible transparent substrate in which the color of the display medium can be confirmed from the outside of the panel, and a material having high visible light transmittance and good heat resistance is preferable. The back substrate as the other substrate may be transparent or opaque.
Examples of the material for the substrate include organic polymer systems such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethylene (PE), polycarbonate (PC), polyimide (PI), polyethersulfine (PES), and acrylic. A substrate, a glass sheet, a quartz sheet, a metal sheet, or the like can be selected.
The thickness of the substrate is usually preferably 2 to 2000 μm, more preferably 5 to 1000 μm. If the thickness is within this range, it is easy to maintain the strength and the uniformity of the distance between the substrates, and it is inconvenient for a “thin” and “flexible” information display panel.
Further, the distance between the substrates is not particularly limited as long as the display medium can be moved and the contrast can be maintained, and is usually preferably adjusted to 10 to 500 μm, more preferably 10 to 200 μm.
In particular, in an information display panel that is driven in a gas space (including in a vacuum), the thickness is preferably adjusted to 10 to 200 μm, more preferably 10 to 100 μm. In this case, the volume occupation ratio of the display medium in the gas space between the opposing substrates is preferably 5 to 70%, more preferably 5 to 60%, and still more preferably 10 to 60%. Within this range, there is no hindrance to the movement of the display medium, and the contrast becomes clear.

(electrode)
The flexible information display panel of the present invention may have a configuration in which an electrode (conductive film) is provided on the substrate. As the material for forming the electrode, indium tin oxide (ITO), indium oxide, zinc-doped indium oxide (IZO), aluminum-doped zinc oxide (AZO), antimony tin oxide (ATO), conductive tin oxide, conductive oxide Conductive metal oxides such as zinc; conductive polymers such as polyaniline, polypyrrole, polythiophene, poly (3,4-ethylenedioxythiophene) polystyrenesulfonate are listed as transparent electrodes on the display surface side, and the back substrate side In addition to the above materials, metals such as aluminum, silver, nickel, copper, and gold can also be used for the electrode. Since conductive metal oxides such as ITO are less flexible than metal materials, when forming a line-shaped (striped) electrode using conductive metal oxides, It is preferable to use together. The width of the fine metal wire is preferably 1 to 10 μm from the viewpoint of display visibility.
The electrode can be formed by sputtering, vacuum deposition, CVD (chemical vapor deposition), coating, or the like, by patterning the electrode material into a thin film, or by laminating a metal foil (eg, rolled copper foil). Or a method of patterning by mixing and applying a conductive agent to a solvent or a synthetic resin binder.
The electrode provided on the display side substrate needs to be transparent, but the electrode provided on the back side substrate may not be transparent.
Note that the thickness of the electrode provided in the display region of the display surface side substrate is not particularly limited as long as the conductivity can be secured and the light transmittance is not hindered, but is preferably 0.01 to 10 μm, more preferably 0.00. It is 05-5 micrometers. Moreover, the thickness of the electrode provided outside the display region or on the back substrate side is sufficient if electrical conductivity can be ensured, and is preferably 0.01 to 10 μm, more preferably 0.05 to 5 μm.

(Partition wall)
In the case where the display medium is composed of particles, it is preferable to provide the partition walls 7 in order to prevent uneven distribution of the particles, but it is not necessary to provide them. The partition wall 7 can be manufactured by a photolithography technique using a resist material. As the resist material, a liquid resist material or a dry film resist material is preferably used. Examples of the dry film resist material include “Alfo NIT2” (manufactured by Nichigo Morton), “PDF300” (manufactured by Nippon Steel Chemical Co., Ltd.), and the like.
The shape of the partition wall 7 is appropriately set according to the type of display medium involved in display and the shape and arrangement of electrodes to be arranged.
The width | variety of the partition 7 becomes like this. Preferably it is 2-100 micrometers, More preferably, it is 3-50 micrometers. The height of the partition (including the height of the adhesive part) is within the inter-substrate gap, the inter-substrate gap securing portion is the same as the inter-substrate gap, and the other cell forming portions are the same as the inter-substrate gap. Or it can be lower.
In forming the partition wall, either a double rib method in which ribs are formed on each of the opposing substrates 1 and 2 after bonding, or a single rib method in which ribs are formed only on one substrate may be employed. . As for the cells formed by the partition walls made of these ribs, reference can be made to FIG. 9 of JP 2010-66298 A, and a square shape, a triangular shape, a line shape, a circular shape, a hexagonal shape, etc. can be seen from the substrate plane direction. Examples of the arrangement include a lattice shape, a honeycomb (hexagonal) shape, and a mesh shape. It is better to make the portion corresponding to the cross section of the partition wall visible from the display surface side (the area of the cell frame portion) as small as possible, and the clearness of the display state can be increased.
The size of the cell opening is such that if the cell opening is rectangular, the length of one side is preferably about 50 to 1000 μm, more preferably 100 to 300 μm. The distance is preferably about 100 to 1000 μm, more preferably 100 to 300 μm.
Here, examples of the method for forming the partition include a mold transfer method, a screen printing method, a sand blast method, a photolithography method, and an additive method. Any method can be suitably used for the flexible information display panel of the present invention, but a photolithography method and a mold transfer method are preferable.

Furthermore, in an information display panel that drives a display medium composed of charged particles in a gas (including vacuum) space, it is important to manage the gas in the void surrounding the display medium between the substrates. Contributes to improved performance. Specifically, it is important that the relative humidity at 25 ° C. is 60% RH or less, preferably 50% RH or less with respect to the humidity of the gas in the void portion.
In the present specification, the “void portion” is described with reference to FIG. 1, and is surrounded by opposing substrates 1 and 2, electrodes 5 and 6, an inter-substrate distance securing member 4, and a partition wall 7. It refers to the space where the display medium exists.
Although there is no restriction | limiting in particular in the kind of gas of a space | gap part, Dry air, dry nitrogen, dry argon, dry helium, dry carbon dioxide, dry methane, etc. are preferable. This gas needs to be sealed in the information display panel so that the humidity is maintained. For example, filling of the display medium, assembly of the information display panel, etc. are performed in a predetermined humidity environment, and further from the outside. It is important to use a sealing agent and a sealing method that prevent moisture from entering. This will be described in detail in the column of the manufacturing method of the flexible information display panel described later.

(Particles constituting the display medium)
The display medium includes particles including charged particles, particles including conductive particles, particles including semiconductive particles, and liquid crystals. A display medium composed of groups will be described.
The particle group including the chargeable particles may be a particle group composed of only the chargeable particles, or may be a particle group composed of the chargeable particles combined with other particles. The chargeable particles can contain a charge control agent, a colorant, an additive, and the like, if necessary, in the resin as the main component.
-Resin-
Examples of the resin that is the main component of the chargeable particles include urethane resin, urea resin, acrylic resin, polyester resin, acrylic urethane resin, acrylic urethane silicone resin, acrylic urethane fluororesin, acrylic fluororesin, silicone resin, and acrylic silicone resin. Epoxy resin, polystyrene resin, styrene acrylic resin, polyolefin resin, butyral resin, vinylidene chloride resin, melamine resin, phenol resin, fluororesin, polycarbonate resin, polysulfone resin, polyether resin, polyamide resin, and the like. These may be used alone or in combination of two or more.
Among these, acrylic urethane resin, acrylic silicone resin, acrylic fluororesin, acrylic urethane silicone resin, acrylic urethane fluororesin, fluororesin, and silicone resin are preferable from the viewpoint of controlling the adhesive force with the substrate.

-Charge control agent-
As the charge control agent that may be contained in the chargeable particles, known negative charge control agents and positive charge control agents that are contained in the chargeable particles used in the information display panel can be used.
Examples of negative charge control agents include salicylic acid metal complexes, metal-containing azo dyes, metal-containing oil-soluble dyes (including metal ions and metal atoms), quaternary ammonium salt compounds, calixarene compounds, boron-containing compounds ( Benzyl acid boron complex), nitroimidazole derivatives and the like.
Examples of the positive charge control agent include nigrosine dyes, triphenylmethane compounds, quaternary ammonium salt compounds, polyamine resins, imidazole derivatives, and the like.
In addition, metal oxides such as ultrafine silica, ultrafine titanium oxide, ultrafine alumina, nitrogen-containing cyclic compounds such as pyridine and derivatives and salts thereof, various organic pigments, resins containing fluorine, chlorine, nitrogen, etc. are also charged. It can also be used as a control agent.

-Colorant-
Organic or inorganic pigments or dyes of various colors can be used.
Examples of the black colorant include carbon black, copper oxide, manganese dioxide, aniline black, activated carbon and the like.
Examples of blue colorants include C.I. I. Pigment blue 15: 3, C.I. I. Pigment Blue 15, Bituminous Blue, Cobalt Blue, Alkaline Blue Lake, Victoria Blue Lake, Phthalocyanine Blue, Metal-free Phthalocyanine Blue, Partially Chlorinated Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue BC and the like.
Examples of red colorants include bengara, cadmium red, red lead, mercury sulfide, cadmium, permanent red 4R, resol red, pyrazolone red, watching red, calcium salt, lake red D, brilliant carmine 6B, eosin lake, rhodamine lake B, Alizarin Lake, Brilliant Carmine 3B, C.I. I. Pigment red 2 and the like.
As yellow colorants, yellow lead, zinc yellow, cadmium yellow, yellow iron oxide, mineral first yellow, nickel titanium yellow, navel yellow, naphthol yellow S, Hansa Yellow G, Hansa Yellow 10G, Benzidine Yellow G, Benzidine Yellow GR, Quinoline Yellow Lake, Permanent Yellow NCG, Tartrazine Lake, C.I. I. Pigment yellow 12 and the like.
Examples of green colorants include chrome green, chromium oxide, pigment green B, C.I. I. Pigment Green 7, Malachite Green Lake, Final Yellow Green G and the like. Examples of the orange colorant include red yellow lead, molybdenum orange, permanent orange GTR, pyrazolone orange, Vulcan orange, Indanthrene Brilliant Orange RK, Benzidine Orange G, Indanthren Brilliant Orange GK, C.I. I. And CI Pigment Orange 31. Examples of purple colorants include manganese purple, first violet B, and methyl violet lake. Examples of white colorants include zinc white, titanium oxide, antimony white, and zinc sulfide.
Examples of extender pigments include barite powder, barium carbonate, clay, silica, white carbon, talc, and alumina white. Examples of various dyes such as basic, acidic, disperse, and direct dyes include nigrosine, methylene blue, rose bengal, quinoline yellow, and ultramarine blue.

-Additives-
Examples of additives include titanium oxide, zinc oxide, zinc sulfide, antimony oxide, calcium carbonate, lead white, talc, silica, calcium silicate, alumina white, cadmium yellow, cadmium red, cadmium orange, titanium yellow, bitumen, and ultramarine blue. Inorganic additives such as cobalt blue, cobalt green, cobalt violet, iron oxide, carbon black, manganese ferrite black, cobalt ferrite black, copper powder, and aluminum powder.
These pigments and additives may be used alone or in combination of two or more. In particular, carbon black is preferable as the black pigment, and titanium oxide is preferable as the white pigment. By blending the colorant, chargeable particles having a desired color can be produced.

(Physical properties of particles constituting display media)
The particles constituting the display medium preferably have a solvent insolubility represented by the following formula of 50% or more, and more preferably 70% or more.
Solvent insolubility (%) = (B / A) × 100
(In formula, A shows the mass before solvent immersion of particle | grains. B shows the mass after immersing particle | grains in a good solvent at 25 degreeC for 24 hours.)
If the solvent insolubility is 50% or more, bleeding is unlikely to occur on the particle surface during long-term storage. If bleed occurs, it affects the adhesion between the particles, hinders the movement of the particles, and may impair display properties.
Here, the good solvent that can be used when measuring the solvent insolubility is methyl ethyl ketone when the main component of the chargeable particles is a fluororesin, methanol when it is a polyamide resin, and methyl ethyl ketone when it is an acrylic urethane resin. Or, in the case of toluene, melamine resin, acetone or isopropanol, and in the case of silicone resin, toluene is used.
Furthermore, since the charged particles need to hold a charged charge, the specific volume resistivity is preferably 1 × 10 ¹⁰ Ω · cm or more, more preferably 1 × 10 ¹² Ω · cm or more. It is preferable.

The average particle diameter d _0.5 of the chargeable particles is preferably 1 to 20 μm and is preferably uniform and uniform. The d _0.5 indicates a particle diameter (μm) in which 50% of the particles are larger than this and 50% are smaller than this.
If the average particle diameter d _0.5 is within this range, the clearness on display is ensured, and the cohesive force between the particles does not become too large, so that there is no problem when moving as a display medium.
Furthermore, regarding the particle size distribution of each display medium (particle group), the particle size distribution Span shown by the following formula is preferably 5 or less, more preferably 3 or less, still more preferably 2 or less, and particularly preferably 1 or less. To.
Span = (d _0.9 −d _0.1 ) / d _0.5
Incidentally, d _0.1 shows the particle size ratio of less than this particle is 10% (μm), the particle diameter d _0.9 This following particles is 90% (μm).
If Span is 5 or less, the size of each particle is uniform and it can be expected to move as a uniform display medium.
Furthermore, it is preferable that the ratio of d _0.5 of the display medium (particle group) having the minimum diameter to d _0.5 of the display medium (particle group) having the maximum diameter among the display media (particle groups) to be used is 10 or less. . Even if the particle size distribution Span is reduced, display media (particle groups) having different charging characteristics move in opposite directions, so that the sizes of the particles constituting each display medium (particle group) are set to the same level. This is because it is preferable that the (particle group) can be easily moved in directions opposite to each other.

The above particle size distribution and particle size can be obtained from a laser diffraction / scattering method or the like. When laser light is irradiated onto the particles to be measured, a light intensity distribution pattern of diffracted / scattered light is spatially generated, and this light intensity pattern has a corresponding relationship with the particle diameter, so that the particle diameter and particle diameter distribution can be measured. .
Here, the particle size and particle size distribution in the present invention are obtained from a volume-based distribution. Specifically, using a Mastersizer2000 (Malvern Instruments Ltd.) measuring instrument, particles are introduced into a nitrogen stream and the attached analysis software (software based on volume-based distribution using Mie theory) The diameter and particle size distribution can be measured.

[Method for manufacturing flexible information display panel]
The flexible information display panel of the present invention is as described above, but in order to maximize the effects of using the adhesive composition of the present invention as an adhesive or sealant, the following manufacturing method is adopted. It is preferable. However, the production method is not particularly limited as long as the adhesive composition of the present invention is used as an adhesive or a sealant for a flexible information display panel.
Specifically, the preferable manufacturing method is a method for manufacturing a flexible information display panel, which includes a step of bonding the adhesive composition of the present invention by two-stage curing. Here, it demonstrates easily as the manufacturing method 1 below using (1)-(4) of FIG.
(Manufacturing method 1)
(1) An adhesive, which is an adhesive composition of the present invention, is placed on the upper surface of a partition wall provided on a striped electrode formed on a substrate, and photocured by irradiating active energy rays [1. Stage curing].
(2) Fill the cell with a particle group containing the chargeable particles as the display medium.
(3) The sealing agent which is the adhesive composition of the present invention is disposed on the substrate outside the display area so as to surround the entire display area.
(4) After the striped electrode formed on the other substrate is placed on the sealant on the partition wall, the adhesive and the sealant are thermally cured [second-stage curing], thereby the bonding step Exit.
The adhesive composition of the present invention is used as the adhesive or sealant. When the adhesive composition of the present invention is used, a high reaction rate is obtained at the time of curing, and after curing, it has toughness, low moisture permeability, high adhesive strength during long-term use, and adhesion of a flexible information display panel It is preferable because electrolytic corrosion is suppressed when used as an agent or sealant.

Another flexible information display panel manufacturing method will be briefly described as manufacturing method 2 below.
(Manufacturing method 2)
(1 ′) A cell is prepared by providing a partition on a striped electrode formed on a substrate, and a particle group containing a chargeable particle as a display medium is filled in the cell.
(2 ′) An adhesive which is the adhesive composition of the present invention is disposed on the partition wall.
(3 ′) The sealing agent which is the adhesive composition of the present invention is disposed on the substrate outside the display area so as to surround the entire display area.
(4 ′) After the stripe-shaped electrode formed on the other substrate is placed on the sealant on the partition wall, it is photocured by irradiating with active energy rays [first-stage curing]. Subsequently, using the autoclave device, the adhesive and sealant that have been arranged are thermally cured [second-stage curing], thereby completing the bonding step.
In addition, in the said manufacturing method 2, it replaces with the adhesive composition of this invention arrange | positioned on the partition, and can also use a well-known adhesive agent. The adhesive in this case is also preferably a two-stage curable adhesive capable of photocuring and heat curing.

  By using the manufacturing method as described above, a tough information display panel in which separation of the partition walls and the substrate does not occur can be obtained, the humidity of the void surrounding the display medium can be kept low, and no electrolytic corrosion occurs. A flexible information display panel that can withstand long-term use can be obtained.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.

<Production Example 1> Production of terminal-modified hydrogenated SBR First, 1 mol of 1,3- (diisopropenyl) benzene was added to cyclohexane that had been sufficiently dehydrated and purified, and then 2 mol of triethylamine and 2 mol of sec-butyllithium were sequentially added. The mixture was stirred at 50 ° C. for 2 hours to prepare a dilithium polymerization initiator.
In a 7 L polymerization reactor purged with argon, 1.9 kg of dehydrated and purified cyclohexane, 2.0 kg of a hexane solution of 12.9-butadiene monomer of 22.9% by mass, and a cyclohexane solution of 20.0% by mass of styrene monomer were added. After adding 130.4 ml of a hexane solution of 0.765 kg, 1.6 mol / L of 2,2-di (tetrahydrofuryl) propane, 108.0 ml of a 0.5 mol / L dilithium polymerization initiator was added to perform polymerization. Started.
Polymerization was carried out for 1.5 hours while raising the temperature of the polymerization reactor to 50 ° C., then 108.0 ml of 1 mol / L ethylene oxide cyclohexane solution was added, and the mixture was further stirred for 2 hours, and then 50 ml of isopropyl alcohol was added. did. A hexane solution of the polymer was precipitated in isopropyl alcohol and sufficiently dried to obtain a polymer polyol. This polymer polyol B is a non-hydrogenated styrene-butadiene copolymer containing hydroxyl groups at both ends, the styrene content is 25% by mass, and polystyrene using a gel permeation chromatography (GP) method. The weight average molecular weight determined by conversion was 14,500, and the molecular weight distribution was 1.20.
(Hydrogenation treatment)
After 120 g of the obtained OH group styrene-butadiene copolymer at both ends was dissolved in 1 L of sufficiently dehydrated and purified hexane, nickel naphthenate, triethylaluminum, and butadiene prepared in a separate container in advance were 1: 3: 3 (moles). Ratio) catalyst solution was charged to 1 mol of nickel with respect to 1,000 mol of butadiene in the copolymer solution. Hydrogen was added under pressure to 27,580 hPa (400 psi) in a sealed reaction vessel, and a hydrogenation reaction was performed at 110 ° C. for 4 hours. Thereafter, the catalyst residue was extracted and separated with hydrochloric acid of 3N concentration, and further centrifuged to separate the catalyst residue by sedimentation. Thereafter, the obtained hydrogenated polymer polyol was precipitated in isopropyl alcohol and further sufficiently dried.
(Reaction with unsaturated hydrocarbon group-containing compound)
100 g of the sufficiently dried hydrogenated polymer polyol was dissolved in cyclohexane, and 3.76 g of 2-acryloyloxyethyl isocyanate (manufactured by Showa Denko KK: Karenz AOI) was slowly added dropwise while maintaining the temperature at 40 ° C. and sufficiently stirring. Thereafter, the mixture was further stirred for 4 hours, precipitated in isopropyl alcohol and dried to obtain a terminal-modified hydrogenated styrene-butadiene copolymer (terminal-modified hydrogenated SBR) which is a liquid resin.

<Examples 1-5 and Comparative Examples 1-8>
Each component shown in Table 1 was kneaded at each blending amount at 25 ° C. to obtain an adhesive composition.
In each test, the obtained adhesive composition was cured according to the following conditions.
Further, the toughness and moisture permeability of the obtained adhesive composition were evaluated, and the results are shown in Table 1.

(Curing conditions)
Formulations of Comparative Examples 1 to 3: Curing was performed by irradiating ultraviolet rays with an integrated light amount of 9,000 mJ / cm ² at an illuminance of 100 mW / cm ² (wavelength 320 to 390 nm).
Formulations of Examples 1 to 5 and Comparative Examples 4 to 6: After irradiating ultraviolet rays with an integrated light quantity of 500 mJ / cm ² at an illuminance of 100 mW / cm ² (wavelength of 320 to 390 nm), heating and curing at 110 ° C. for 30 minutes It was.

-Evaluation method of characteristics-
(Toughness)
Using a cured product having a length of 2 cm, a width of 1 cm, and a thickness of 0.3 cm, the tensile strength tester “Autograph AGS-100D” (manufactured by Shimadzu Corporation) was used to measure the breaking strength and the breaking elongation. It was used as an index. The results are shown in Table 1.
(Moisture permeability)
Using an applicator (a rod-like instrument that coats with a gap between the substrate fixed), the adhesive composition was deposited to a thickness of 100 μm and cured. Using this cured product, in accordance with JIS Z0208, the moisture permeability was measured by the cup method under the conditions of 40 ° C. and relative humidity of 95%, and used as a moisture permeability index. The results are shown in Table 1.

The annotations in the table are explained as follows.
* 1: Terminally modified hydrogenated SBR obtained in Production Example 1
* 2: Trade name “Clayton Liquid Polymer L-1253”, single-end methacrylated hydrogenated polybutadiene, manufactured by Kraton Polymer Japan Co., Ltd., weight average molecular weight 10,000
* 3: Trade name “LIR-30”, manufactured by Kuraray Co., Ltd., weight average molecular weight 29,000
* 4: Trade name “Irgacure 184” (1-hydroxycyclohexyl-phenyl-ketone, manufactured by Ciba Specialty Chemicals Co., Ltd.)
* 5: 1,1-di (t-butylperoxy) cyclohexane
* 6: Benzoyl peroxide
* 7: 1,1,3,3-tetramethylbutylperoxyneodecanate

  From Table 1, in the adhesive composition obtained in Comparative Example 4, the breaking strength and elongation at break were small, the cured product was mechanically fragile, and the moisture permeability was extremely high. It turns out that it is not suitable as an agent. On the other hand, in the adhesive compositions obtained in Examples 1 to 5 and Comparative Examples 1 to 3 containing terminal-modified hydrogenated SBR and containing both a photoradical polymerization initiator and a thermal radical polymerization initiator, the breaking strength and A cured product having a high elongation at break and low moisture permeability could be obtained. The adhesive composition obtained in Comparative Example 6 also has high breaking strength and elongation at break, and moisture permeability is kept low, but moisture permeability is not sufficiently suppressed.

  Moreover, about the adhesive composition obtained in Example 1 or 5, the storage stability at room temperature was investigated. For measurement of the viscosity, “Rheometres RS300” (manufactured by HAAKE) was used. The results are shown in Table 2.

  From Table 2, it was found that all showed excellent storage stability, but there was a slight difference in storage stability depending on the type of thermal radical polymerization initiator. From the viewpoint of storage stability, it can be said that a peroxyketal polymerization initiator is more preferable.

Furthermore, about the adhesive composition obtained in each example, it measured and evaluated in accordance with the following method about adhesive force and its long-term reliability, reaction rate, sealing performance, and corrosion resistance.
(Adhesive strength and long-term reliability)
Using the adhesive compositions obtained in Example 1 and Comparative Examples 1 and 4, the adhesive strength was evaluated by a 180 degree peel test on a film substrate. As the film substrate, a polyethylene terephthalate film having a thickness of 125 μm and having an ITO electrode on its surface was used.
The adhesive composition was coated on the film with an applicator to a thickness of 100 μm, and the opposing films were bonded together and cured under the above conditions. Next, the film was cut into a width of 1 cm, the upper and lower ends of the film were pulled at a rate of 5 cm / min by an autograph, and the average value of the stress was defined as the adhesive strength.
Furthermore, the long-term reliability of the adhesive strength was evaluated by measuring the adhesive strength in the same manner as described above while maintaining the temperature at 60 ° C. and 90% relative humidity. The results are shown in FIG.
From FIG. 3, the adhesive compositions obtained in Example 1 and Comparative Example 1 have high long-term reliability of adhesive strength, but the adhesive composition obtained in Comparative Example 4 has low long-term reliability of adhesiveness. I understand.

(Reaction rate)
Using the adhesive compositions obtained in Examples 1 and 4 and Comparative Example 1, using a halogen lamp, the UV irradiation amount was changed at an illuminance of 100 mW, and the reaction of the carbon-carbon double bond in the adhesive composition The rate was measured by an infrared spectrophotometer “NICOLET6700” (manufactured by Thermo Scientific).
In the adhesive compositions obtained in Examples 1 and 4, the reaction rate was increased to 95% or more by heat treatment at 80 to 110 ° C. for 30 minutes after irradiation with ultraviolet rays having an integrated light amount of about 100 mJ / cm ² . There was no deflection.
On the other hand, in the adhesive composition obtained in Comparative Example 1, as shown in FIG. 4, the reaction rate increased only to about 80% when irradiated with ultraviolet rays having an integrated light amount of about 500 mJ / cm ² , and the reaction rate was 95% or more. In order to achieve this, it was necessary to irradiate ultraviolet rays with an integrated light amount of about 5,000 to 10,000 mJ / cm ² . It should be noted that the film was bent by the heat of ultraviolet irradiation when the ultraviolet light was irradiated with an integrated light quantity of 5,000 mJ / cm ² or more.

-The following was used as the display medium of the flexible information display panel used in the following evaluation tests.
(Positively charged black particles)
Nigrosine compound “Bontron N07” as a positively charged charge control agent in 60 parts by mass of methyl methacrylate monomer (manufactured by Kanto Chemical Co., Ltd.) and 40 parts by mass (about 25 mol%) of ethylene glycol dimethacrylate (manufactured by Wako Pure Chemical Industries, Ltd.) 3 parts by mass (produced by Orient Chemical Co., Ltd.) and 5 parts by mass of carbon black (special black, produced by Degussa) as a black pigment were dispersed by a sand mill, and a (meth) acrylic resin-hydrocarbon resin block copolymer “Modiper 5 parts by mass of “F600” (manufactured by NOF Corporation) was dissolved, and 2 parts by mass of lauryl peroxide “PAROIL L” (manufactured by NOF Corporation) was dissolved. The resulting solution was polymerized by suspending it in purified water to which 0.5% of sodium polyoxyethylene alkyl ether sulfate “Latemul E-118B” (manufactured by Kao Corporation) was added as a surfactant.
The obtained suspension is filtered, dried, and classified using a classifier “MDS-2” (manufactured by Nippon Pneumatic Industry Co., Ltd.) to obtain positively charged black particles having an average particle size of 9.2 μm. It was.
(Negatively charged white particles)
100 parts by mass of polymethylpentene “TPX-R18” (Mitsui Chemicals Co., Ltd.), 100 parts by mass of titanium dioxide “Taipaque CR-90” (manufactured by Ishihara Sangyo Co., Ltd.) as a colorant, and a charge control agent of negative charge 5 parts by mass of a phenol-based condensate “Bontron E89” (manufactured by Orient Chemical Co., Ltd.) was melt-kneaded with a twin-screw kneader and used in a jet mill (Lab Jet Mill IDS-LJ type, manufactured by Nippon Pneumatic Industrial Co., Ltd.). Finely pulverized, classified using a classifier “MDS-2” (manufactured by Nippon Pneumatic Industry Co., Ltd.), and then melt spheroidized using a melt spheronizer “MR-10” (manufactured by Nippon Pneumatic Industry Co., Ltd.) As a result, negatively charged white particles having an average particle diameter of 9.5 μm were obtained.

<Evaluation test>
(Sealability)
A flexible information display panel of the type shown in FIG. 1 was prepared, and the change in image quality after being kept at 40 ° C. and relative humidity of 95% in a constant temperature and humidity chamber was investigated, and the suitability of the adhesive composition as a sealing agent (seal Sex).
Note that a 125 μm-thick polyethylene terephthalate film was used for the substrate of the flexible information display panel, and ITO was used for the electrode member. As the sealing agent, the adhesive composition obtained in Example 1, Comparative Example 1 or 4 was used. As the adhesive, “World Rock (registered trademark) CML-61” (manufactured by Kyoritsu Chemical Industry Co., Ltd.) was used. For the display medium, the particle group containing the positively charged black particles and the particle group containing the negatively charged white particles were used.
As a manufacturing method of a flexible information display panel, it implemented by implementing in order of the following (1)-(4).
(1) An adhesive is placed on the upper surface of the partition wall provided on the stripe-shaped electrode formed on the substrate, and photocuring is performed by irradiating active energy rays. (2) Fill the cell with a particle group containing the chargeable particles as the display medium. (3) The sealing agent is disposed on the substrate outside the display area so as to surround the entire display area. (4) After the striped electrode formed on the other substrate is placed on the sealing agent on the partition wall, the bonding step is completed by thermosetting the adhesive and the sealing agent.
The panel uses a passive drive system, and has a resolution of 90 dpi and the number of pixels (number of lines) per panel is 320 × 280.
For the image quality, a Macbeth densitometer “Spectro Eye” (manufactured by Gretag Macbeth) was used, and the contrast ratio calculated from the optical density was evaluated as an index. The measurement location was the end of the display area so that the sealability could be measured more accurately. The contrast was measured after taking out from the thermostatic chamber for 1 day and displaying 10 pages. The results are shown in FIGS.
When the adhesive composition obtained in Comparative Example 4 or 5 was used, the contrast ratio greatly decreased as the time of keeping in a high temperature and high humidity environment became longer, and it became less than half after 300 hours. . On the other hand, it can be seen that the adhesive composition obtained in Example 1, Comparative Example 1 or 3 containing the terminal-modified hydrogenated SBR has a reduced contrast ratio and high sealing properties.

(Corrosion resistance-1: Investigation of electric corrosion)
Amorphous ITO was patterned as an electrode member on a polyethylene terephthalate film having a surface resistance value of 200Ω / sq and a transmittance of 88% and a thickness of 125 μm by a photolithography technique. At this time, an etching solution “IT006N” (manufactured by Tokyo Ohka Kogyo Co., Ltd.) was used. An electrode pattern is shown in FIG. The line / space is 80 μm / 80 μm.
The adhesive composition obtained in each example was applied by bar coating to a portion surrounded by a dotted line of the substrate in FIG. 7 and then cured. The obtained sample substrate was left standing in a constant temperature and humidity chamber at 60 ° C. and 90% relative humidity while applying a voltage of direct current 80V, and AB, A′-B ′ and A− in FIG. The degree of change in resistance value was investigated by measuring the change with time in resistance between A ′. The greater the change in resistance value, the more corrosion is occurring.
As a result, when the adhesive compositions obtained in Examples 1, 3 or 4 and Comparative Examples 1 to 3 containing terminal-modified hydrogenated SBR were used, the resistance did not change at all, and the corrosion reaction (electric corrosion) ) Was not happening. Similarly, when the adhesive composition obtained in Comparative Example 6 containing one-end-modified hydrogenated polybutadiene was used, the resistance did not change at all, and no corrosion reaction (electric corrosion) occurred.
On the other hand, when the adhesive composition obtained in Comparative Example 4 or 5 was used, the resistance value between A and B of the anode gradually increased and became unmeasurable after 200 hours. As a result of microscopic observation, corrosion was confirmed. Since the resistance value did not change between A ′ and B ′, which are the cathodes, it is presumed that an oxidation reaction involving ITO on the anode occurs on the ITO electrode.
Furthermore, when the above test was performed using an IZO electrode instead of an ITO electrode, the same result was obtained. However, when a copper electrode was used, no change in resistance value occurred in either case. It was. From this, it can be said that the adhesive composition of the present invention is particularly useful when an electrode comprising a transparent inorganic oxide is used.
Further, when the same test was performed using an epoxy-based material “World Rock (registered trademark) 798L” (manufactured by Kyoritsu Chemical Industry Co., Ltd.) which is a sealing agent for liquid crystal displays, the adhesion obtained in Comparative Example 4 As in the case of the adhesive composition, an increase in resistance between A and B occurred, and a corrosion phenomenon was observed.
In addition, although resistance value between AA 'becomes an parameter | index of insulation ensuring in a panel, when any adhesive composition was used, the insulation fall was not seen.

(Corrosion resistance-2: Investigation of electric corrosion)
A flexible information display panel of the method shown in FIG. 1 is prepared, held at 60 ° C. and a relative humidity of 90% in a constant temperature and humidity chamber, displayed on one page in 10 seconds, 50 hours, 100 hours, 300 hours and 500 hours. The number of disconnections after time was counted.
Note that a 125 μm-thick polyethylene terephthalate film was used for the substrate of the flexible information display panel, and ITO was used for the electrode member. As the sealing agent, the adhesive composition obtained in each example was used. As the adhesive, “World Rock (registered trademark) CML-61” (manufactured by Kyoritsu Chemical Industry Co., Ltd.) was used. For the display medium, the particle group containing the positively charged black particles and the particle group containing the negatively charged white particles were used.
As a manufacturing method of a flexible information display panel, it implemented by implementing in order of the following (1)-(4).
(1) An adhesive is placed on the upper surface of the partition wall provided on the stripe-shaped electrode formed on the substrate, and photocuring is performed by irradiating active energy rays. (2) Fill the cell with a particle group containing the chargeable particles as the display medium. (3) The sealing agent is disposed on the substrate outside the display area so as to surround the entire display area. (4) After the striped electrode formed on the other substrate is placed on the sealing agent on the partition wall, the bonding step is completed by thermosetting the adhesive and the sealing agent.
The panel uses a passive drive format, and has a resolution of 90 dpi and the number of pixels (number of lines) per panel is 320 × 280.
The results are shown in Table 3.

  From Table 3, when the adhesive compositions obtained in Examples 1 to 5 and Comparative Examples 1 to 3 were used, no disconnection occurred, but it was obtained in Comparative Example 4 or 5. In the case of the adhesive composition, disconnection occurred in about 100 hours, and the number of disconnections increased with the passage of time.

(Corrosion resistance-3: Investigation of electric corrosion and sealing properties)
In the test method (corrosion resistance-2), the test was performed in the same manner except that the sealing agent and the adhesive used in the production of the flexible information display panel were changed to those shown in Table 4.
As a result, when the adhesive composition obtained in Comparative Example 4 was used for both the sealant and the adhesive, disconnection of 5 after 100 hours, 20 after 300 hours, and 83 after 500 hours was observed. Further, when a commercially available epoxy-based material “World Rock (registered trademark) CML-61” (manufactured by Kyoritsu Chemical Industry Co., Ltd.) is used for both the sealant and the adhesive, 9 after 100 hours and 26 after 300 hours. 172 breaks were observed after 500 hours. In other cases, no disconnection was confirmed.
In addition, the same flexible information display panel was manufactured, and after pressing 10 times on a cylinder with a diameter of 20 mm and bending the angle to 90 degrees, the state of the panel was confirmed with a microscope (magnification: about 50 times). However, only in the case of a flexible information display panel using commercially available products as a sealant and an adhesive, peeling occurred in the adhesive placement portion.
The results are shown in Table 4.

  From the above test results, a high reaction rate is obtained at the time of curing, and after curing, it has toughness, low moisture permeability, high adhesive strength during long-term use, and as an adhesive or sealant for flexible information display panels It can be seen that it is only the adhesive compositions obtained in Examples 1 to 5 that satisfy all that the electrolytic corrosion is effectively suppressed when used.

  The adhesive composition of the present invention can be suitably used for a flexible panel structure. In particular, liquid crystal display panels, electrochromic display elements, electrophoretic display panels, and electro-powder fluid display panels that display information such as images by placing a display medium in the inter-substrate space of the panel structure are configured flexibly. The flexible information display panel manufactured using the adhesive composition of the present invention has flexibility and is thin, so that a notebook computer, an electronic notebook, a portable information device called PDA (Personal Digital Assistants), Display devices for mobile devices such as mobile phones and handy terminals, electronic paper such as electronic books, electronic newspapers, and electronic manuals (instruction manuals), signboards, posters, bulletin boards such as blackboards (whiteboards), electronic desk calculators, and home appliances , Display parts for car supplies, card display parts for point cards, IC cards, electronic advertisements, information boards, electronic POs (Point Of Presence, Point Of Purchase advertising), electronic price tag, electronic shelf label, electronic score, display part of RF-ID device, information used for display part of various electronic devices such as POS terminal, car navigation device, clock, etc. It is useful as a display panel. In addition, it is also useful as a rewritable paper (which can be rewritten using an external electric field forming means).

1: Substrate 2: Substrate (transparent)
3a: Negatively charged white particles 3b: Positively charged black particles 4: Member for securing distance between substrates 5: Electrode (stripe shape)
6: Electrode (stripe shape)
7: Partition 8: Sealing agent 9: Adhesive

Claims (7)

  (1) For 100 parts by mass of a liquid resin obtained by reacting a hydrogenated or non-hydrogenated conjugated diene-aromatic vinyl copolymer polyol and an unsaturated hydrocarbon group-containing compound, (2) (meth) An adhesive composition containing 3 to 70 parts by mass of an acrylate monomer, (3) 0.01 to 5 parts by mass of a radical photopolymerization initiator, and (4) 0.1 to 10 parts by mass of a thermosetting component.   The hydrogenated or non-hydrogenated conjugated diene-aromatic vinyl copolymer polyol is a hydrogenated styrene-butadiene copolymer polyol, and the unsaturated hydrocarbon group of the unsaturated hydrocarbon group-containing compound is (meth) acryloyl. The adhesive composition according to claim 1, which is a group.   The adhesive composition according to claim 1 or 2, wherein the thermosetting component is a thermal radical polymerization initiator.   The thermal radical polymerization initiator is a ketone peroxide polymerization initiator, a hydroperoxide polymerization initiator, a dialkyl peroxide polymerization initiator, a peroxyketal polymerization initiator, a peroxyester polymerization initiator, a peroxy ester The adhesive composition according to claim 3, which is at least one selected from the group consisting of a dicarbonate polymerization initiator and a diacyl peroxide polymerization initiator.   A flexible information display panel in which two flexible substrates are arranged opposite to each other, wherein the adhesive composition according to any one of claims 1 to 4 is used as a sealant for the flexible information display panel.   A flexible information display panel in which two flexible substrates are arranged to face each other, wherein the adhesive composition according to any one of claims 1 to 4 is used as an adhesive for the flexible information display panel.   The manufacturing method of a flexible information display panel which has the process of making the adhesive composition in any one of Claims 1-4 harden | cure, and bonding together.