JP2003193017A - Adhesive material, adhesive sheet, and display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a thermally-polymerizing and radioactively-polymerizing adhesive material capable of together joining a substrate of a display device and a protective substrate for the display device at a relatively low temperature and, moreover, having excellent high oxygen and water-vapor impermeabilities, to provide an adhesive sheet having excellent workability, and to provide the display device having a high quality level and high reliability. <P>SOLUTION: The thermally-polymerizing and radioactively-polymerizing adhesive material contains (A) an epoxy resin and a hardener for the epoxy resin, (B) a polymer having functional groups and a weight-average molecular weight of ≥100,000, (C) a compound generating a base when irradiated with radioactive rays, and (D) a hyperfine filler. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive material, an adhesive sheet and a display device using the same.

[0002]

2. Description of the Related Art Conventionally, in a display device such as a liquid crystal display or an organic EL display, a paste-like sealing material has been used for joining a display device substrate and a display device protective substrate. Particularly, in the organic EL element, a desiccant and a sealant have been used together in order to protect the electrode material from oxygen and moisture. However, in recent years, the bottom emission method has been changed from the conventional bottom emission method to the top emission method for the purpose of improving emission intensity and luminance. However, in the top emission method, since the desiccant that has been used conventionally cannot be used as before, a highly oxygen and moisture impermeable adhesive material that replaces the conventional sealing material has been required. On the other hand, in a display element such as an organic EL display, the element is destroyed due to overheating at a high temperature, and therefore an adhesive that can bond the display element substrate and the display element protection substrate at a relatively low temperature is required.

[0003]

The inventions according to claims 1 to 5 provide an adhesive not only for bonding the display element substrate and the display element protection substrate at a relatively low temperature but also having high oxygen and water impermeability. To do. The invention described in claim 6 provides an adhesive sheet having excellent workability in addition to the effects of the invention described in claims 1 to 5. The invention according to claim 7 provides a display device having high quality and high reliability.

[0004]

The present invention relates to the following. 1. (A) Epoxy resin and epoxy resin curing agent,
A thermopolymerizable and radiation-polymerizable adhesive containing (B) a polymer having a functional group and having a weight average molecular weight of 100,000 or more, (C) a compound that generates a base upon irradiation with radiation, and (D) an ultrafine filler. 2. (B) The polymer having a functional group and a weight average molecular weight of 100,000 or more has an epoxy group-containing repeating unit of 0.5 to 6
The above-mentioned adhesive, which is an epoxy group-containing (meth) acrylic copolymer contained in mass%. 3. (A) Epoxy resin and epoxy resin curing agent 1
00 parts by weight, (B) functional group-containing weight average molecular weight is 1
The above adhesive containing 10 to 400 parts by mass of a polymer having a molecular weight of 0,000 or more and 0.01 to 200 parts by mass of (C) a compound capable of generating a base upon irradiation with radiation. 4. (C) The adhesive as described above, wherein the compound that generates a base upon irradiation with radiation is a compound that generates a base having a pKa of 7 or more in an aqueous solution upon irradiation with radiation. 10-2000 MPa at 5.25 ° C and 3 at 260 ° C
The above adhesive having a storage elastic modulus after heat curing of ˜50 MPa. 6. An adhesive sheet obtained by forming the above-mentioned heat-polymerizable and radiation-polymerizable adhesive into a sheet shape. 7. A display device in which a display element substrate and a display element protection substrate are bonded using the above adhesive material or adhesive sheet.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The adhesive of the present invention comprises (A) an epoxy resin and an epoxy resin curing agent, (B) a functional group-containing polymer having a weight average molecular weight of 100,000 or more, and (C) radiation irradiation. It contains a compound that generates a base and (D) an ultrafine filler, and has heat-polymerizability and radiation-polymerizability.

This adhesive has a sufficient adhesive force when the display element substrate and the display element protection substrate are bonded together, and then can be irradiated with radiation to firmly bond the viscous adhesive and the substrate. .

The epoxy resin in the component (A) used in the present invention is not particularly limited as long as it cures and has an adhesive action. A bifunctional epoxy resin such as bisphenol A type epoxy, a novolac type epoxy resin such as a phenol novolac type epoxy resin or a cresol novolac type epoxy resin can be used. In addition, polyfunctional epoxy resin, glycidyl amine type epoxy resin,
A generally known one such as a heterocycle-containing epoxy resin or an alicyclic epoxy resin can be applied.

As such an epoxy resin, a bisphenol A type epoxy resin may be Epicoat 807, 815, 825, 82 manufactured by Yuka Shell Epoxy Co., Ltd.
7,828,834,1001,1004,1007,
1009, DER-330, 301 manufactured by Dow Chemical Company,
361, Toto Kasei Co., Ltd. YD8125, YDF81
70 and the like. Examples of the phenol novolac type epoxy resin include Epicoat 152 and 154 manufactured by Yuka Shell Epoxy Co., Ltd. and EPPN-2 manufactured by Nippon Kayaku Co., Ltd.
01, DEN-438 manufactured by Dow Chemical Co., Ltd., and as o-cresol novolac type epoxy resin, EOCN-102S, 103 manufactured by Nippon Kayaku Co., Ltd.
S, 104S, 1012, 1025, 1027, YDCN701, 702, 703, 704 manufactured by Tohto Kasei Co., Ltd.
And so on. Examples of the polyfunctional epoxy resin include Epon 1031S manufactured by Yuka Shell Epoxy Co., Ltd. and Araldite 016 manufactured by Ciba Specialty Chemicals.
3, Denacol EX-611,6 manufactured by Nagase Kasei Co., Ltd.
14,614B, 622,512,521,421,4
11, 321 and the like. As the amine type epoxy resin, Epicoat 6 manufactured by Yuka Shell Epoxy Co., Ltd.
04, Tohto Kasei Co., Ltd. YH-434, Mitsubishi Gas Chemical Co., Inc. TETRAD-X, TETRAD-C, Sumitomo Chemical Co., Ltd. ELM-120, etc. are mentioned. Examples of the heterocycle-containing epoxy resin include ERL4234, 4299, 4221, 4206 manufactured by UCC, such as Araldite PT810 manufactured by Ciba Specialty Chemicals. These epoxy resins can be used alone or in combination of two or more.

As the epoxy resin curing agent in the component (A) used in the present invention, known curing agents which are usually used can be used. For example, amines, polyamides, acid anhydrides, polysulfides, boron trifluoride, bisphenol A, bisphenol F, bisphenol S
Examples thereof include bisphenols having two or more phenolic hydroxyl groups in one molecule, phenol novolac resins, bisphenol A novolac resins, and cresol novolac resins. Particularly, a phenol resin such as a phenol novolac resin, a bisphenol A novolac resin, or a cresol novolac resin is preferable because it has excellent electrolytic corrosion resistance when absorbing moisture.

The preferred phenol resin curing agent is
For example, manufactured by Dainippon Ink and Chemicals, Inc., trade names: Phenolite LF2882, Phenolite LF2822,
Phenolite TD-2090, Phenolite TD-21
49, Phenolite VH-4150, Phenolite VH
4170 and the like.

The polymer (B) having a functional group and having a weight average molecular weight of 100,000 or more used in the present invention contains a functional monomer such as glycidyl acrylate or glycidyl methacrylate and has a weight average molecular weight of 1 or less.
An epoxy group-containing (meth) acrylic copolymer having a molecular weight of at least 10,000 is preferable, and it is preferable that it is incompatible with the epoxy resin.

As the epoxy group-containing (meth) acrylic copolymer, for example, (meth) acrylic ester copolymer, acrylic rubber and the like can be used, and acrylic rubber is more preferable. Acrylic rubber is a rubber containing acrylic acid ester as a main component and mainly composed of a copolymer such as butyl acrylate and acrylonitrile, or a copolymer such as ethyl acrylate and acrylonitrile.

It is preferable to use glycidyl acrylate or glycidyl methacrylate as the functional monomer. As such an epoxy group-containing (meth) acrylic copolymer having a weight average molecular weight of 100,000 or more, for example, HTR-86 manufactured by Teikoku Kagaku Sangyo Co., Ltd.
0P-3 and the like.

The amount of the repeating unit containing an epoxy resin such as glycidyl acrylate or glycidyl methacrylate is preferably 0.5 to 6.0% by mass, and 0.5 to 5.0% by mass.
Mass% is more preferable, and 0.8-5.0 mass% is especially preferable. When the amount of the epoxy group-containing repeating unit is within this range, the adhesive force can be secured and gelation can be prevented.

Examples of the functional monomer include glycidyl acrylate and glycidyl methacrylate as well as ethyl (meth) acrylate and butyl (meth) acrylate. These are used alone or in combination of two or more kinds. You can also In addition, in this invention, ethyl (meth) acrylate shows both ethyl acrylate and ethyl methacrylate.
The mixing ratio when the functional monomers are used in combination is determined in consideration of the glass transition temperature (hereinafter referred to as “Tg”) of the epoxy group-containing (meth) acrylic copolymer,
It is preferable that g is -10 ° C or higher. Tg is -10
This is because when the temperature is not lower than 0 ° C, the tackiness of the adhesive layer when formed into a sheet is appropriate, and there is no problem in handleability.

When the high molecular weight component having a functional group and a weight average molecular weight of 100,000 or more is produced by polymerizing the above-mentioned monomers, the polymerization method is not particularly limited, and for example, pearl polymerization or solution. A method such as polymerization can be used.

In the present invention, the polymer having a functional group (B) has a weight average molecular weight of 100,000 or more, preferably 300,000 to 3,000,000, and more preferably 500,000 to 2,000,000. preferable. When the weight average molecular weight is within this range, the strength when formed into a sheet or film,
Flexibility and tackiness are appropriate. In addition, in this invention, a weight average molecular weight shows the value measured by gel permeation chromatography and converted using the standard polystyrene calibration curve.

The amount of the polymer (B) having a functional group and having a weight average molecular weight of 100,000 or more is 10 to 400 parts by mass based on 100 parts by mass of the epoxy resin (A) and the epoxy resin curing agent. Is preferred. Within this range, it is possible to secure the elastic modulus and the suppression of the flowability during molding, and it is possible to obtain sufficient handleability at high temperatures. The amount of the polymer used is more preferably 15 to 350 parts by mass, and 20 to 30
0 part by mass is particularly preferred.

The compound (C) which generates a base upon irradiation with radiation used in the present invention is not particularly limited as long as it is a compound which generates a base upon irradiation with radiation. As the base to be generated, a strongly basic compound is preferable in terms of reactivity and curing rate. Generally, the pKa value, which is the logarithm of the acid dissociation constant, is used as an index of basicity, and the pKa value in an aqueous solution is used.
A base having a value of 7 or more is preferable, and a base having a value of 9 or more is more preferable.

Examples of such basicity include imidazole derivatives such as imidazole, 2,4-dimethylimidazole and 1-methylimidazole, piperazine,
2,5-Dimethylpiperazine and other piperazine derivatives, piperidine, 1,2-dimethylpiperidine and other piperidine derivatives, proline derivatives, trimethylamine, triethylamine, triethanolamine and other trialkylamine derivatives, 4-methylaminopyridine, 4-dimethyl A pyridine derivative in which an amino group or an alkylamino group is substituted at the 4-position such as aminopyridine, pyrrolidine, a pyrrolidine derivative such as n-methylpyrrolidine, triethylenediamine, 1,8-diazabiscyclo (5,4,0) undecene-1 (DBU A) and other alicyclic amine derivatives, and benzylamine derivatives such as benzylmethylamine, benzyldimethylamine, and benzyldiethylamine.

The basic compound produced by irradiation with radiation is, for example, Journal of of
Photopolymer Science and
Technology, Volume 12, Sections 313-314 (1
(1999) and Chemistry of Material
The quaternary ammonium salt derivative described in, for example, als 11, volume 170 to 176 (1999) can be used. These are most suitable for curing an epoxy resin because they generate highly basic trialkylamine upon irradiation with actinic rays.

In addition, Journal of Ameri
Can Chemical Society Volume 118
12925 (1996) and Polymer Jou
The carbamic acid derivative described in rnal 28, page 795 (1996) and the like can be used.

In addition, oxime derivatives which generate primary amino groups upon irradiation with actinic rays, and 2-methyl-1 (4- (methylthio) phenyl) -2-morpholinopropane- which is commercially available as a photoradical generator. 1-on (Ci
ba Specialty Chemicals Irgacure 907), 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1.
-On (Ciba Specialty Chemical
Irgacure 369 manufactured by Als Co., a hexaarylbisimidazole derivative (a substituent such as a halogen, an alkoxy group, a nitro group or a cyano group may be substituted with a phenyl group), a benzisoxazolone derivative or the like can be used.

In addition to the base generator by the above-mentioned actinic rays, a basic compound is generated by photo-Fries rearrangement, photo-Claisen rearrangement (optical Cleisen rearrangement), Curtius rearrangement (Curtius rearrangement), and Stevens rearrangement (Stevens rearrangement) to generate an epoxy resin. Can be cured.

The base generator may be used as a low molecular weight compound having a molecular weight of 500 or less, or a compound introduced into the main chain and side chain of a polymer. In this case, the molecular weight is preferably 1,000 to 100,000, more preferably 5,000 to 30,000, as the weight average molecular weight from the viewpoints of tackiness and adhesiveness as a tackiness adhesive and fluidity. Since these compounds do not show reactivity with the epoxy resin in the state where they are not irradiated with radiation at room temperature, they are very excellent in storage stability at room temperature. The ultrafine filler (D) used in the present invention is a so-called nanofiller such as Nanotech manufactured by CI Kasei Co., Ltd., and any of them having excellent desiccant property or moistureproof property can be used. The material of the (D) ultrafine filler used in the present invention is not particularly limited, and examples thereof include calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, titanium oxide, and oxide. Iron, zinc oxide, cerium oxide, yttrium oxide, silicon oxide, barium oxide, zirconium oxide, aluminum nitride, aluminum borate whiskers, boron nitride, crystalline silica, amorphous silica, and the like,
(D) The shape of the ultrafine filler is not particularly limited. These (D) ultrafine fillers can be used alone or in combination of two or more kinds. The (D) ultrafine filler used in the present invention has an average particle size of preferably less than 1 μm, more preferably less than 500 nm, further preferably less than 200 nm, and less than 100 nm. It is even more preferred to be present. The amount of (D) ultrafine filler used is
1 to 99 parts by mass is preferable with respect to 100 parts by mass of the adhesive. If it is less than 1 part by mass, the effect of addition tends not to be obtained, and if it exceeds 99 parts by mass, the adhesive property tends to be poor.

A curing accelerator can also be added to the adhesive of the present invention. The curing accelerator is not particularly limited and includes imidazoles, dicyandiamide derivative, dicarboxylic acid dihydrazide, triphenylphosphine, tetraphenylphosphonium tetraphenylborate, 2-ethyl-4-methylimidazole tetraphenylborate, 1,8-diazabicyclo ( 5,4,0) undecene-7-tetraphenylborate and the like can be used. These may be used alone or in combination of two or more.

The amount of the curing accelerator added is (A) epoxy resin and 100 parts by weight of the epoxy resin curing agent.
0.1-5 parts by mass is preferable, and 0.2-3 parts by mass is more preferable. When the amount added is in this range, both curability and storage stability can be achieved.

The adhesive of the present invention, when cured by heating,
Storage modulus is 10 to 2000 MPa at 25 ° C., 2
It is preferably 3 to 50 MPa at 60 ° C. 25 ° C
More preferably, the elastic modulus at 20 to 1900 MPa,
50 to 1800 MPa is particularly preferable. Also, 260 ℃
The elastic modulus at 5 to 50 MPa is more preferable, and the elastic modulus at 7 to 5 is
0 MPa is particularly preferred. When the storage elastic modulus is in this range, the effect of relaxing the thermal stress generated by the difference in thermal expansion coefficient between the display element substrate and the display element protective substrate is maintained,
It is possible to suppress the occurrence of peeling and cracks, and improve the handleability of the adhesive and the accuracy of the thickness of the adhesive layer. The storage elastic modulus is, for example, using a dynamic viscoelasticity measuring device (DVE-V4 manufactured by Rheology Co., Ltd.), a tensile load is applied to the cured adhesive, and the frequency is 10 Hz and the temperature rising rate is 5 to 10 ° C./m.
It can be performed in a temperature-dependent measurement mode in which the temperature is measured from −50 ° C. to 300 ° C. under the condition of in.

The adhesive material of the present invention may contain a high molecular weight resin compatible with an epoxy resin for the purpose of improving flexibility and reflow crack resistance. The high molecular weight resin is not particularly limited, and examples thereof include a phenoxy resin, a high molecular weight epoxy resin, and an ultrahigh molecular weight epoxy resin. These can be either alone or 2
Combinations of more than one type can also be used. The amount of the high molecular weight resin compatible with the epoxy resin is preferably 40 parts by mass or less with respect to 100 parts by mass of the epoxy resin and the epoxy resin curing agent. Within this range, the Tg of the epoxy resin layer can be secured.

In addition, an inorganic filler having an average particle size of more than 1 μm can be added to the adhesive of the present invention for the purpose of imparting a spacer function to the joint between the display element substrate and the display element protective substrate. The inorganic filler having an average particle size of more than 1 μm is not particularly limited, and examples thereof include aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, and nitriding. Examples of the filler include aluminum, aluminum borate whiskers, boron nitride, crystalline silica, and amorphous silica, and the shape of the filler is not particularly limited. These fillers having an average particle size of 1 μm or more can be used alone or in combination of two or more kinds.

The amount of the inorganic filler having an average particle size of more than 1 μm is preferably 0.01 to 20 parts by mass with respect to 100 parts by mass of the adhesive. If it is less than 0.01 parts by mass, the effect of addition tends not to be obtained, and if it exceeds 20 parts by mass, problems such as an increase in storage elastic modulus, a decrease in adhesiveness, and a decrease in electrical properties due to residual voids tend to occur. is there.

Further, the adhesive material of the present invention may contain various coupling agents in order to improve interfacial bonding between different materials. Examples of the coupling agent include silane-based, titanium-based, and aluminum-based coupling agents, and among them, the silane-based coupling agent is preferable because of its high effect.

The silane coupling agent is not particularly limited, and examples thereof include vinyltrichlorosilane, vinyltris (β-methoxyethoxy) silane, vinyltriethoxysilane, vinyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane. , Γ-methacryloxypropylmethyldimethoxysilane, β- (3,4
-Epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ
-Glycidoxypropylmethyldimethoxysilane, γ-
Glycidoxypropylmethyldiethoxysilane, N-β
(Aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercapto Propyltrimethoxysilane,
γ-mercaptopropyltriethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-ureidopropyltriethoxysilane, 3-ureidopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyl-tris (2- (Methoxy-ethoxy-ethoxy) silane, N-methyl-3-aminopropyltrimethoxysilane, triaminopropyltrimethoxysilane, 3-4,5-dihydroimidazole-1-
Ile-propyltrimethoxysilane, 3-methacryloxypropyl-trimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyldimethoxysilane, 3-cyanopropyltriethoxysilane, hexamethyl Disilazane, N, O-bis (trimethylsilyl)
Acetamide, methyltrimethoxysilane, methyltriethoxysilane, ethyltrichlorosilane, n-propyltrimethoxysilane, isobutyltrimethoxysilane, amyltrichlorosilane, octyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, methyltri (methacryloyl) Oxyethoxy) silane, methyltri (glycidyloxy) silane,
N-β (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane, octadecyldimethyl [3- (trimethoxysilyl) propyl] ammonium chloride, γ-chloropropylmethyldichlorosilane, γ-chloropropylmethyldimethoxysilane , Γ−
Chloropropylmethyldiethoxysilane, trimethylsilyl isocyanate, dimethylsilyl isocyanate,
Methyl silyl triisocyanate, vinyl silyl triisocyanate, phenyl silyl triisocyanate, tetraisocyanate silane, ethoxy silane isocyanate, etc. can be used, and they can be used individually or in combination of 2 or more types.

As the titanium-based coupling agent,
For example, isopropyl trioctanoyl titanate, isopropyl dimethacryl isostearoyl titanate,
Isopropyl tridodecyl benzene sulfonyl titanate, isopropyl isostearoyl diacrylic titanate, isopropyl tri (dioctyl phosphate) titanate, isopropyl tricumyl phenyl titanate,
Isopropyl tris (dioctyl pyrophosphate)
Titanate, isopropyl tris (n-aminoethyl)
Titanate, tetraisopropyl bis (dioctyl phosphite) titanate, tetraoctyl bis (ditridecyl phosphite) titanate, tetra (2,2-diallyloxymethyl-1-butyl) bis (ditridecyl)
Phosphite titanate, dicumylphenyl oxyacetate titanate, bis (dioctyl pyrophosphate) oxyacetate titanate, tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium Ethyl acetonate, titanium octylene glycolate,
Titanium lactate ammonium salt, titanium lactate,
Titanium lactate ethyl ester, titanium chilliethanol aminate, polyhydroxytitanium stearate, tetramethyl orthotitanate, tetraethyl orthotitanate, tetarapropyl orthotitanate, tetraisobutyl orthotitanate, stearyl titanate, cresyl titanate monomer, cresyl titanate polymer, di Isopropoxy-bis (2,4-pentadionate) titanium (IV), diisopropyl-bis-triethanolaminotitanate, octyleneglycol titanate, tetra-n-butoxytitanium polymer, tri-n-butoxytitanium monostearate polymer , Tri-n-butoxytitanium monostearate and the like can be used, and can be used alone or in combination of two or more kinds.

As the aluminum-based coupling agent,
For example, ethyl acetoacetate aluminum diisopropylate, aluminum tooth (ethyl acetoacetate), alkyl acetoacetate aluminum diisopropylate, aluminum monoacetylacetate bis (ethylacetoacetate), aluminum tris (acetylacetonate), aluminum = monoisopropoxy. Aluminum chelate compounds such as monooleoxyethyl acetoacetate, aluminum-di-n-butoxide monoethyl acetoacetate, aluminum-di-iso-propoxide-monoethyl acetoacetate, aluminum isopropylate, mono-sec-butoxyaluminum diisopropylate. Rate, aluminum-sec-butyrate, aluminum ethylate and other aluminum alcohol Can be used bets like, alone or in combination of two or more kinds may be used.

From the viewpoints of its effect, heat resistance and cost, the amount of the above-mentioned coupling agent to be used is 0.01 with respect to 100 parts by mass of the epoxy resin (A) and the epoxy resin curing agent.
It is preferably 10 to 10 parts by mass.

The adhesive of the present invention may further contain an ion scavenger in order to adsorb ionic impurities and improve insulation reliability when absorbing moisture. Such an ion scavenger is not particularly limited, and examples thereof include triazine thiol compounds, bisphenol-based reducing agents, and the like, compounds known as copper damage inhibitors for preventing copper from being ionized and dissolved, and zirconium-based compounds. Inorganic ion adsorbents such as antimony bismuth magnesium aluminum compounds. The amount of the ion scavenger used is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the epoxy resin (A) and the epoxy resin curing agent, from the viewpoints of the effect of addition, heat resistance, cost, and the like.

The adhesive sheet of the present invention can be obtained by applying the adhesive material of the present invention onto a base film and heating it to remove the solvent. The substrate used for the adhesive sheet of the present invention is not particularly limited, and examples thereof include plastic films such as polytetrafluoroethylene film, polyethylene terephthalate film, polyethylene film, polypropylene film, polymethylpentene film, and polyimide film. To be

The solvent for applying the adhesive on the substrate film is not particularly limited, but considering the volatility at the time of film production, for example, methanol, ethanol, 2-methoxyethanol, 2 -It is preferable to use a solvent having a relatively low boiling point, such as ethoxyethanol, 2-butoxyethanol, methyl ethyl ketone, acetone, methyl isobutyl ketone, toluene, xylene. Further, for the purpose of improving the coating property, for example, a solvent having a relatively high boiling point such as dimethylacetamide, dimethylformamide, N-methylpyrrolidone or cyclohexanone may be used. These solvents can be used alone or in combination of two or more kinds.

In the production of the adhesive when the inorganic filler is added, it is preferable to use a raider, a three-roll mill, a ball mill, a bead mill, etc. in consideration of the dispersibility of the inorganic filler. It can also be used in combination. It is also possible to shorten the mixing time by mixing the inorganic filler and the low molecular weight raw material in advance and then mixing the high molecular weight raw material. Further, air bubbles in the adhesive can be removed by vacuum deaeration or the like. As a method for applying the adhesive to the base film, a known method can be used, for example, a knife coating method,
A roll coating method, a spray coating method, a gravure coating method, a bar coating method, a curtain coating method and the like can be mentioned.

The thickness of the adhesive sheet is not particularly limited,
Both the adhesive material and the base material are preferably 5 to 250 μm. 5 μm
If the thickness is thinner, the stress relaxation effect tends to be poor.
If it is thicker than 0 μm, it is not economical and it is not possible to meet the demand for miniaturization of the display device. Further, in the adhesive sheet of the present invention, in order to obtain a desired thickness, two or more separately prepared adhesive material layers can be attached to the adhesive material layer side of the adhesive sheet. In this case, the bonding conditions are required so that the adhesive material layers are not separated from each other.

The adhesive of the present invention may be used not only for irradiation with radiation but also for heating simultaneously with or after irradiation with radiation. The combined use of heating makes it possible to lower the adhesive strength at a lower temperature and in a shorter time. The heating is not particularly limited as long as it is equal to or lower than the decomposition point of the adhesive, but 30 to 170
A time of 1 to 300 minutes at a temperature of ° C is preferred.

An example of the method of using the adhesive according to the present invention will be described below. When the adhesive material is a paste, the width is about 2 mm around the display element on the display element substrate.
An adhesive is applied using a printing / applying device such as a dispenser and dried, and then a display element protection substrate is laminated. In order to bond the display element substrate and the display element protection substrate with the adhesive material, in the laminated state, at least the adhesive material adhesion portion is irradiated with radiation to cure the adhesive material. The temperature at which the adhesive is applied and dried is preferably room temperature or higher in the case of performing at normal pressure, but it is preferably a temperature at which the display element is not destroyed, and is in the range of 30 to 200 ° C. Should be done in. As a laminating method for laminating the display element substrates, it is preferable to use a pressure bonding device such as a laminator. The radiation used for joining is UV (U
V), infrared rays (IR), electron beams (EB), ultrasonic waves, etc., but these may be used in combination. Radiation irradiation to the adhesive layer can be performed from either side of the display element substrate or the display element protection substrate, but when the substrate has a property of not transmitting radiation, radiation is transmitted from the side of the transmitting substrate. There is a need. Further, when both substrates are transparent to radiation, both substrates can be simultaneously irradiated.

[0044]

EXAMPLES The present invention will be described in more detail below with reference to examples. The present invention is not limited to these.

(Production Example 1) 30 g of 2-nitrobenzyl alcohol was dissolved in 300 g of tetrahydrofuran by stirring at room temperature using a magnetic stirrer.
A solution of 24.5 g of 4,4′-diphenylmethane diisocyanate and 100 g of tetrahydrofuran, which had been mixed in advance, was added dropwise to this solution over 30 minutes, and the mixture was stirred at room temperature for 1 hour. Then, a Liebig cooling tube was set, and the reaction was carried out for 2 hours while heating to 60 ° C. in an oil bath. After the reaction, the mixture was cooled to room temperature and concentrated using a rotary evaporator until the reaction liquid became half. When the obtained concentrate was added to 1000 parts by mass of n-hexane, a white precipitate was obtained. The precipitate was suction filtered and dried under vacuum at 60 ° C. overnight to obtain the desired 2-nitrobenzylcarbamic acid derivative. Yield 49.5 g (yield 91
%)Met.

(Production Example 2) 42.3 mass of YDCN-703 (trade name of Toto Kasei Co., Ltd., o-cresol novolac type epoxy resin, epoxy equivalent 210) which has been sufficiently dried in a vacuum dryer at 60 ° C. Part, plyofen LF2882 that has been thoroughly dried in advance with a vacuum dryer at 60 ° C.
(Trade name of Dainippon Ink and Chemicals, Inc., bisphenol A novolac resin) 23.9 parts by mass, HTR-860P-3 (manufactured by Teikoku Kagaku Sangyo Co., Ltd.) fully dried in a vacuum dryer at 60 ° C. in advance. Trade name, epoxy group-containing acrylic rubber, molecular weight 1,000,000, Tg-7 ° C) 44.1 parts by mass, CureZol 2PZ-CN (product of Shikoku Chemicals Co., Ltd.) sufficiently dried in advance with a vacuum dryer at 60 ° C. Name, 1-cyanoethyl-2-phenylimidazole) 0.4 parts by mass,
NUC A-189 (trade name, manufactured by Nippon Unicar Co., Ltd., γ
-Glycidoxypropyltrimethoxysilane) 0.7 parts by mass and 2-nitrobenzylcarbamic acid derivative 0.5 parts by mass, to which methyl ethyl ketone that has been sufficiently dried with potassium carbonate in advance is added, and the mixture is stirred and mixed under vacuum. By degassing, an adhesive varnish (A) was obtained. (Production Example 3) In Production Example 2, the 2-nitrobenzylcarbamic acid derivative was replaced with 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1-.
On (Ciba Specialty Chemical
A pressure-sensitive adhesive varnish (B) was obtained by completely the same operation as in Production Example 2 except that the product name was manufactured by ALS Co., Ltd. and the product name was Irgacure 369).

Example 1 100 parts by mass of the adhesive varnish (A) obtained in Production Example 2 was treated with a vacuum dryer at 200 ° C. for 1 hour to obtain silica ultrafine particle filler (NanoTekSiO 2 manufactured by CI Kasei Co., Ltd.). ) 10 parts by mass were added, and the mixture was kneaded with a foam-removing taro (AR-250 manufactured by Shinky Co.), stirred and defoamed to obtain an adhesive (A). (Example 2) Adhesive varnish (B) 10 obtained in Production Example 3
0 parts by mass of silica ultrafine filler (NanoT manufactured by SI Kasei Co., Ltd.) treated with a vacuum dryer at 200 ° C. for 1 hour.
ekSiO2) (11 parts by mass) was added, and the mixture was kneaded with a defoaming Rentaro (AR-250 manufactured by Shinky Co.), stirred and defoamed to obtain an adhesive (B). (Example 3) Adhesive (A) was applied on polyethylene terephthalate (Teijin Tetron film: G2-50, manufactured by Teijin Ltd.) having a thickness of 50 μm, and dried by heating at 110 ° C. for 5 minutes to obtain a substrate. An adhesive sheet (thickness of the adhesive sheet excluding the substrate was 20 μm) having a film thickness of 20 μm provided with (polyethylene terephthalate film) (Adhesive sheet A) was produced.

(Example 4) Adhesive (B) was applied to a thickness of 50 μm.
m polyethylene terephthalate (manufactured by Teijin Ltd., Teijin Tetoron film: G2-50), 11
By heating and drying at 0 ° C. for 5 minutes, an adhesive sheet having a base material (polyethylene terephthalate film) and having a film thickness of 20 μm (adhesive sheet thickness excluding the base material was 20 μm) (adhesive sheet B) was produced. (Example 5) The adhesive (A) having a width of 2 mm was applied to the periphery of the display element protection substrate using a dispenser and dried at 70 ° C for 10 minutes, and then the adhesive (A) was coated with Oak Co., Ltd. 5 using the UV-330 HQP-2 type exposure machine manufactured by Seisakusho
Light irradiation was performed with an exposure dose of 00 mJ / cm 2. In a dry nitrogen atmosphere, the adhesive (A) layer irradiated with light is arranged so as to face the periphery of the display element forming region of the display element substrate, and the display element substrate and the display element protection substrate are pressure-bonded, and then at 90 ° C. 1
After heating for a period of time, the display element substrate and the display element protection substrate were bonded. (Example 6) After the adhesive sheet A having a width of 2 mm was laminated and attached to the periphery of the display element protection substrate, the adhesive sheet A was UV-330 HQP- manufactured by Oak Manufacturing Co., Ltd.
Light irradiation was performed using a type 2 exposure machine at an exposure dose of 500 mJ / cm 2. In a dry nitrogen atmosphere, the adhesive sheet A layer is arranged so as to face the periphery of the display element forming region of the display element substrate, and the display element substrate and the display element protection substrate are pressure-bonded, and then at 90 ° C. for 1 hour. After heating, the display element substrate and the display element protection substrate were bonded.

Example 7 The adhesive (B) having a width of 2 mm was applied to the periphery of the display element protective substrate using a dispenser and dried at 70 ° C. for 10 minutes, and then the adhesive (B) was applied.
It was irradiated with light at an exposure dose of 500 mJ / cm 2 using a UV-330 HQP-2 type exposure machine manufactured by Oak Manufacturing Co., Ltd. Adhesive (B) exposed to light under dry nitrogen atmosphere
The layers are arranged so as to face the periphery of the display element forming region of the display element substrate, the display element substrate and the display element protective substrate are pressure bonded, and then heated at 90 ° C. for 1 hour to bond the display element substrate and the display element protective substrate. . (Example 8) After the adhesive sheet B having a width of 2 mm was laminated and attached to the periphery of the display element protection substrate, UV-330 HQP- manufactured by Oak Manufacturing Co., Ltd. was attached to the adhesive sheet B.
Light irradiation was performed using a type 2 exposure machine at an exposure dose of 500 mJ / cm 2. In a dry nitrogen atmosphere, the adhesive sheet B layer that has been irradiated with light is arranged so as to face the periphery of the display element forming region of the display element substrate, and the display element substrate and the display element protection substrate are pressure-bonded, and then at 90 ° C. for 1 hour. After heating, the display element substrate and the display element protection substrate were bonded. (Test Example 1) The display devices obtained in Examples 5 to 8 were heated to 85 ° C.
The display quality as a display device was evaluated before and after storage under 85% RH conditions for 50 hours. The results are shown in Table 1.

(Comparative Example 1) In Example 5, instead of the adhesive material (A), 30Y-296G manufactured by ThreeBond Co., Ltd.
The same operation as in Example 5 was carried out by omitting the drying step after coating to bond the display element substrate and the display element protection substrate. The results of evaluation of the obtained display device under the same conditions as in Test Example 1 are also shown in Table 1.

[0051]

[Table 1]

[0052]

The adhesives according to the first to fifth aspects are not only capable of bonding the display element substrate and the display element protection substrate at a relatively low temperature, but also excellent in high oxygen and water impermeability.
The adhesive sheet according to claim 6 is excellent in workability in addition to the effects of the inventions according to claims 1 to 5. The display device according to claim 7 is of high quality and has high reliability.

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) C08L 63/00 C08L 63/00 C 4J040 C09J 7/02 C09J 7/02 Z 133/00 133/00 (72) Inventor Hiroyuki Kawakami 48 Wadai, Tsukuba-shi, Ibaraki 48, Research Institute, Hitachi Chemical Co., Ltd. (72) Inventor Shigeki Kato 48 48, Wadai, Tsukuba, Tsukuba, Ibaraki F-Term (Reference) 4J002 BG04X BG10X CC03Y CD02W CD04W CD05W CD06W CD13W DE077 DE087 DE147 DE237 DF017 DJ007 DJ017 DK007 EJ036 EL136 EN006 EN008 EN058 EU048 EU078 EU118 EU138 EV046 EY016 FD017 FD14Y FD146 FD150 FD200 FD208 AD56A6JA46 AB06 PA56A6 AB06 PA56A6 AB06 PA56A6 AB06 PA56A6 AB13 AB05 PA0714J046 AF01 AF06 AH00 AJ08 DA01 DB05 DB15 DC02 DD02 FB07 4J040 DF042 DF052 EB052 EC061 EC071 EC161 EC261 EG002 GA11 HA116 HA196 HA206 HA296 HA306 HB10 HB22 HC01 HD38 KA03 KA16

Claims (7)

[Claims] 1. An epoxy resin and an epoxy resin curing agent, (B) a functional group-containing polymer having a weight average molecular weight of 100,000 or more, (C) a compound which generates a base upon irradiation with radiation, and (D). A heat-polymerizable and radiation-polymerizable adhesive containing an ultrafine filler. 2. An epoxy group-containing (meth) acrylic copolymer in which the polymer (B) having a functional group and a weight average molecular weight of 100,000 or more contains an epoxy group-containing repeating unit in an amount of 0.5 to 6% by mass. The adhesive material according to claim 1, which is 3. An epoxy resin (A) and an epoxy resin curing agent (100 parts by mass), (B) a functional group-containing polymer having a weight average molecular weight of 100,000 or more, 10 to 400 parts by mass, and (C) radiation irradiation. 3. The adhesive material according to claim 1, which contains 0.01 to 200 parts by mass of a compound capable of generating a base and a radiation-polymerizable compound. 4. The compound (C) which generates a base upon irradiation with radiation is a compound which generates upon irradiation, a base having a pKa of 7 or more in an aqueous solution.
Adhesive described. 5. 10 to 2000 MPa and 2 at 25 ° C.
The adhesive material according to claim 1, which has a storage elastic modulus after heat curing of 3 to 50 MPa at 60 ° C. 6. An adhesive sheet obtained by forming the heat-polymerizable and radiation-polymerizable adhesive according to claim 1 into a sheet shape. 7. A display device in which a display element substrate and a display element protection substrate are bonded using the adhesive material or the adhesive sheet according to claim 1.