WO2010084938A1

WO2010084938A1 - Resin composition

Info

Publication number: WO2010084938A1
Application number: PCT/JP2010/050758
Authority: WO
Inventors: 栄一林; 基之高田; 裕一影山; 浩恭小藤; 博天野; 滋河原
Original assignee: 味の素株式会社
Priority date: 2009-01-23
Filing date: 2010-01-22
Publication date: 2010-07-29
Also published as: TW201038659A; TWI473854B

Abstract

A resin composition which has excellent low-temperature curability and can give a cured object having excellent moisture impermeability. The resin composition comprises an epoxy resin and an ionic liquid.

Description

Resin composition

The present invention relates to a resin composition and a film for sealing an organic EL device using the same.

Organic EL (Electroluminescence) elements are vulnerable to moisture, and when organic EL elements are used to construct displays and lighting devices, the organic materials themselves are altered by moisture, resulting in a decrease in luminance or even no light emission. Or the interface between the electrode and the organic EL layer is peeled off due to the influence of moisture, or the metal is oxidized to increase the resistance. Therefore, for example, as shown in FIG. 4, the glass plate 4 provided with the hygroscopic material 3 is opposed to the organic EL element 2 formed on the glass substrate 1 at a predetermined interval, so that the substrate 1 and the glass plate 4 are aligned. Can sealing is performed in which the gap is sealed in an inert gas atmosphere or in a vacuum state. However, since the thickness of the sealing structure portion including the organic EL element and the two glass plates is increased, the display and the lighting device cannot be sufficiently thinned.

For this reason, as shown in FIG. 1, a curable resin composition layer 6 is formed on a glass substrate 1 having an organic EL element 2 formed on one side so as to cover the entire surface of the organic EL element 2, and from above A sealing structure in which the sealing substrate 7 is bonded and the curable resin composition layer 6 is cured to form a cured layer (hereinafter, this sealing structure is referred to as “entire surface sealing of an organic EL element” or simply “entire surface”). (Also referred to as “sealing”) has been proposed (Patent Document 1). However, since the curable resin composition described in Patent Document 1 is an acrylic ultraviolet curable resin composition, there is a problem of deterioration of the organic EL element due to ultraviolet rays and a place where ultraviolet rays do not reach (uncured portion). It occurs and there is a problem that it is difficult to obtain a highly reliable sealing structure. Moreover, compared with an epoxy resin, an acrylic resin is inferior in physical properties, such as heat resistance.

Therefore, in recent years, the use of a thermosetting composition mainly composed of an epoxy resin has been studied (for example, Patent Document 2). However, in order to suppress the thermal degradation of the organic EL element, excellent low-temperature curability is necessary, and the cured epoxy resin is inferior in moisture permeability compared to the cured acrylic resin, Although it is essential to improve the moisture permeability of the cured product, a curable resin composition based on an epoxy resin that can sufficiently satisfy such a requirement has not been achieved yet.

JP-A-5-182759 JP 2006-70221 A

An object of the present invention is to provide a resin composition that can be cured rapidly at a low temperature, exhibit excellent adhesion, and form a cured product excellent in moisture permeability resistance.

As a result of intensive studies to solve the above problems, the present inventors have completed the present invention by using a resin composition containing an epoxy resin and an ionic liquid.

That is, the present invention includes the following contents.
(1) A resin composition comprising an epoxy resin and an ionic liquid.
(2) The resin composition as described in (1) above, wherein the ionic liquid comprises an ammonium cation or a phosphonium cation and an N-acylamino acid ion or a carboxylic acid anion.
(3) The resin composition as described in (1) or (2) above, further comprising a hygroscopic metal oxide.
(4) The resin composition as described in any one of (1) to (3) above, which further contains an inorganic filler.
(5) A resin composition sheet, wherein the resin composition layer according to any one of (1) to (4) is formed on a support.
(6) The resin composition sheet according to (5), which is for sealing an organic EL element.
(7) An organic EL device comprising the resin composition sheet for sealing an organic EL element according to (6) above.

According to the resin composition of the present invention, it cures quickly at a low temperature of 140 ° C. or lower, preferably 120 ° C. or lower, and forms a cured product that is excellent in moisture permeability resistance and has excellent adhesion strength. be able to. Therefore, the resin composition of the present invention and the resin composition sheet using the resin composition are easily deteriorated by heat, and need to be moisture-proof. It can be suitably used as a material or the like, and a highly reliable covering structure, adhesive structure, sealing structure and the like having high moisture resistance can be easily formed. In particular, it is possible to provide a highly reliable organic EL display and organic EL lighting device.

FIG. 1 is a schematic cross-sectional view of a whole surface sealing structure of an organic EL element. FIG. 2 is a schematic view of a production process of a test piece used in the evaluation test of Examples and Comparative Examples. FIG. 3 is a schematic diagram of a sample (bonded product of two test pieces) subjected to a tensile test in an evaluation test of Examples and Comparative Examples. FIG. 4 is a schematic cross-sectional view of a can sealing structure of an organic EL element.

Hereinafter, the present invention will be described with reference to preferred embodiments thereof.
The resin composition of the present invention is characterized by containing an epoxy resin and an ionic liquid.

Here, the term “ionic liquid” generally means “a salt composed of an anion and a cation that can be melted in a temperature range of about 100 ° C. or lower”. It means a salt which can be melted in a temperature range below the curing temperature, which is composed of an anion and a cation. That is, it is a salt that can be melted in a temperature range of 140 ° C. or lower (preferably 120 ° C. or lower), and has an epoxy resin curing action.

[Epoxy resin]
The epoxy resin used in the present invention only needs to have an average of two or more epoxy groups per molecule. For example, bisphenol A type epoxy resin, biphenyl type epoxy resin, biphenyl aralkyl type epoxy resin, naphthol type epoxy resin, naphthalene type epoxy resin, bisphenol F type epoxy resin, phosphorus-containing epoxy resin, bisphenol S type epoxy resin, aromatic glycidylamine Type epoxy resin (for example, tetraglycidyl diaminodiphenylmethane, triglycidyl-p-aminophenol, diglycidyl toluidine, diglycidyl aniline, etc.), alicyclic epoxy resin, aliphatic chain epoxy resin, phenol novolac type epoxy resin, cresol novolac Type epoxy resin, bisphenol A novolac type epoxy resin, epoxy resin having butadiene structure, diglycidyl etherified product of bisphenol, naphthalenediol Diglycidyl ethers of Le, glycidyl ethers of phenols, and diglycidyl ethers of alcohols, and alkyl substituted derivatives of these epoxy resins, halides and hydrogenated products or the like. Any one of these epoxy resins can be used or a mixture of two or more can be used.

Among these, the epoxy resin is a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a phenol novolac type epoxy resin, a biphenyl aralkyl type, etc. Epoxy resins, phenol aralkyl type epoxy resins, aromatic glycidyl amine type epoxy resins, epoxy resins having a dicyclopentadiene structure, and the like are preferable.

In addition, the epoxy resin may be liquid, solid, or both liquid and solid. Here, “liquid” and “solid” are states of the epoxy resin at normal temperature (25 ° C.). From the viewpoint of coatability, workability, and adhesiveness, it is preferable that at least 10% by weight or more of the entire epoxy resin to be used is liquid.

In the present invention, the epoxy resin preferably has an epoxy equivalent in the range of 100 to 1000, more preferably in the range of 120 to 1000, from the viewpoint of reactivity. Here, the epoxy equivalent is the gram number (g / eq) of a resin containing 1 gram equivalent of an epoxy group, and is measured according to the method defined in JIS K 7236.

[Ionic liquid]
The ionic liquid used in the present invention functions as a resin curing agent. In the resin composition of the present invention, it is desirable that the ionic liquid is uniformly dissolved in the epoxy resin.

Examples of cations constituting the ionic liquid include imidazolium ions, piperidinium ions, pyrrolidinium ions, pyrazonium ions, guanidinium ions, pyridinium ions, and other ammonium cations; tetraalkylphosphonium cations (for example, tetrabutylphosphonium ions, tributyl) Phosphonium cations such as hexylphosphonium ion; sulfonium cations such as triethylsulfonium ion, and the like.

As anions constituting the ionic liquid, halide anions such as fluoride ions, chloride ions, bromide ions and iodide ions; alkylsulfuric acid type anions such as methanesulfonate ions; trifluoromethanesulfonate ions and hexafluorophosphones Fluorine-containing compound anions such as acid ion, trifluorotris (pentafluoroethyl) phosphonate ion, bis (trifluoromethanesulfonyl) imide ion, trifluoroacetate ion, tetrafluoroborate ion; phenol ion, 2-methoxyphenol ion, Phenolic anions such as 2,6-di-tert-butylphenol ion; acidic amino acid ions such as aspartate ion and glutamate ion; glycine ion, alanine ion, phenylalanine ion Neutral amino acid ions such as ON; N-acyl amino acid ions represented by the following general formula (1) such as N-benzoylalanine ion, N-acetylphenylalanine ion, N-acetylglycine ion; formate ion, acetate ion, decanoic acid Examples thereof include carboxylic acid anions such as ions, 2-pyrrolidone-5-carboxylate ions, α-lipoic acid ions, lactate ions, tartrate ions, hippurate ions, N-methylhippurate ions, and benzoate ions.

(Wherein R—CO— is an acyl group derived from a linear or branched fatty acid having 1 to 5 carbon atoms, or a substituted or unsubstituted benzoyl group, and —NH—CHX—CO ₂ is Acidic amino acid ions such as aspartic acid and glutamic acid, or neutral amino acid ions such as glycine, alanine and phenylalanine.)

Among the above, as the cation constituting the ionic liquid, an ammonium cation and a phosphonium cation are preferable, and an imidazolium ion and a phosphonium ion are more preferable. More specifically, the imidazolium ion is 1-ethyl-3-methylimidazolium ion, 1-butyl-3-methylimidazolium ion, 1-propyl-3-methylimidazolium ion or the like.

The anion constituting the ionic liquid is preferably a phenolic anion, an N-acylamino acid ion or a carboxylic acid anion represented by the general formula (1), and more preferably an N-acylamino acid ion or a carboxylic acid anion.

Specific examples of phenol anions include 2,6-di-tert-butylphenol ion. Specific examples of the carboxylate anion include acetate ion, decanoate ion, 2-pyrrolidone-5-carboxylate ion, formate ion, α-lipoic acid ion, lactate ion, tartrate ion, hippurate ion, N- Methyl hippurate ion and the like, among which acetate ion, 2-pyrrolidone-5-carboxylate ion, formate ion, lactate ion, tartrate ion, hippurate ion and N-methylhippurate ion are preferable, acetate ion, N -Methyl hippurate ion and formate ion are particularly preferred. Specific examples of the N-acylamino acid ion represented by the general formula (1) include N-benzoylalanine ion, N-acetylphenylalanine ion, aspartate ion, glycine ion, N-acetylglycine ion, and the like. Among these, N-benzoylalanine ion, N-acetylphenylalanine ion and N-acetylglycine ion are preferable, and N-acetylglycine ion is particularly preferable.

Specific ionic liquids include, for example, 1-butyl-3-methylimidazolium lactate, tetrabutylphosphonium-2-pyrrolidone-5-carboxylate, tetrabutylphosphonium acetate, tetrabutylphosphonium decanoate, tetrabutylphosphonium tri Fluoroacetate, tetrabutylphosphonium α-lipoate, tetrabutylphosphonium formate, tetrabutylphosphonium lactate, bis (tetrabutylphosphonium) tartrate, tetrabutylphosphonium hippurate, tetrabutylphosphonium N-methylhippurate, benzoyl-DL -Alanine tetrabutylphosphonium salt, N-acetylphenylalanine tetrabutylphosphonium salt, 2,6-di-tert-butylphenoltetrabutylphosphonium Salt, L-aspartate monotetrabutylphosphonium salt, glycine tetrabutylphosphonium salt, N-acetylglycine tetrabutylphosphonium salt, 1-ethyl-3-methylimidazolium lactate, 1-ethyl-3-methylimidazolium acetate, 1-ethyl-3-methylimidazolium formate, 1-ethyl-3-methylimidazolium hippurate, 1-ethyl-3-methylimidazolium N-methylhippurate, bis (1-ethyl-3-tartrate) Methyl imidazolium) salt, N-acetylglycine 1-ethyl-3-methylimidazolium salt, N-acetylglycine tetrabutylphosphonium salt, 1-ethyl-3-methylimidazolium acetate, 1-ethyl-3-formate Methylimidazolium salt, 1-ethyl-3 hippurate -Methylimidazolium salt, 1-ethyl-3-methylimidazolium salt of N-methylhippuric acid are particularly preferred.

As a method for synthesizing the ionic liquid used in the present invention, a precursor composed of a cation moiety such as an alkylimidazolium, alkylpyridinium, alkylammonium, and alkylsulfonium ions and an anion moiety containing a halogen is added to NaBF ₄ , NaPF _6. , CF ₃ SO ₃ Na, LiN (SO ₂ CF ₃ ) _2, etc., an anion exchange method, an amine substance reacts with an acid ester to introduce an alkyl group, and an organic acid residue becomes a counter anion Examples thereof include, but are not limited to, an acid ester method and a neutralization method in which amines are neutralized with an organic acid to obtain a salt. In the neutralization method using an anion, a cation, and a solvent, an anion and a cation are used in an equivalent amount, and the solvent in the obtained reaction solution can be distilled off and used as it is, or an organic solvent (methanol, toluene, etc.). , Ethyl acetate, acetone, etc.) may be added and the solution concentrated.

The amount of the ionic liquid is not particularly limited as long as the epoxy resin is cured, but is preferably 0.1 to 10 parts by weight, more preferably 0.5 to 5 parts by weight per 100 parts by weight of the epoxy resin. When the amount is less than 0.1 parts by weight, the curability tends to decrease, and when the amount is more than 10 parts by weight, the pot life of the composition and the moisture permeability resistance of the cured product tend to decrease.

[Polythiol compound]
The resin composition of the present invention may contain a polythiol compound having two or more thiol groups in the molecule together with the ionic liquid. Inclusion of a polythiol compound having two or more thiol groups in the molecule can increase the curing speed. Specifically, trimethylolpropane tris (thioglycolate), pentaerythritol tetrakis (thioglycolate), ethylene glycol dithioglycolate, trimethylolpropane tris (β-thiopropionate), pentaerythritol tetrakis (β-thiol) Propionate) and dipentaerythritol poly (β-thiopropionate). There is a thiol compound having two or more thiol groups in the molecule that does not require the use of a basic substance in production, such as a thiol compound obtained by an esterification reaction of a polyol and a mercapto organic acid.

Similarly, alkyl polythiol compounds such as 1,4-butanedithiol, 1,6-hexanedithiol, 1,10-decanedithiol; terminal thiol group-containing polyether; terminal thiol group-containing polythioether; epoxy compound and hydrogen sulfide For those using a basic substance as a reaction catalyst in the production process, such as a thiol compound obtained by reaction; a thiol compound having a terminal thiol group obtained by reaction of a polythiol compound and an epoxy compound, A thiol compound having two or more thiol groups in the molecule that has been subjected to dealkalization treatment and has an alkali metal ion concentration of 50 ppm or less can be used. As a method for such dealkalization treatment, for example, the polythiol compound to be treated is dissolved in an organic solvent such as acetone or methanol, neutralized by adding an acid such as dilute hydrochloric acid or dilute sulfuric acid, and then desalted by extraction or washing. A method of adsorbing using an ion exchange resin, a method of purification by distillation, and the like, but are not limited thereto.

樹脂 When the polythiol compound is used in the resin composition of the present invention, the mixing ratio of the epoxy resin and the polythiol compound is preferably 0.2 to 1.2 in terms of SH equivalent number / epoxy equivalent number. If it is less than 0.2, sufficient rapid curability may not be obtained, while if it is more than 1.2, the physical properties of the cured product such as heat resistance may be impaired. From the viewpoint of stable adhesion, 0.5 to 1.0 is more preferable.

[Hygroscopic metal oxides]
In the resin composition of the present invention, a hygroscopic metal oxide can be blended together with the ionic liquid in order to further improve the moisture permeability of the cured product. Here, the “hygroscopic metal oxide” means a metal oxide that has a capability of absorbing moisture and chemically reacts with moisture that has been absorbed to become a hydroxide. Specific examples include calcium oxide, magnesium oxide, strontium oxide, and barium oxide. These may be used alone or in combination of two or more. Among them, calcium oxide is preferable from the viewpoint of high hygroscopicity, cost, and stability of raw materials.

If the particle diameter of the hygroscopic metal oxide is too large, there is a risk that the coarse particles may damage the organic EL element in the sealing step, and from the viewpoint of increasing the interfacial bond strength with the resin component. The smaller the particle size, the more advantageous, but the smaller the particle size, the easier the aggregation of the particles, so it is difficult to impart sufficiently high moisture resistance to the cured product due to poor dispersion in the composition. There is a fear. Therefore, the hygroscopic metal oxide has an average particle size of. The average particle size is preferably in the range of 0.001 to 5 μm, more preferably in the range of 001 to 10 μm.

In addition, it is particularly preferable that the hygroscopic metal oxide has an average particle diameter in the above-described preferable range and does not include coarse particles having a particle diameter of 20 μm or more. By not including such coarse particles, it is advantageous in that the EL element is hardly damaged in the sealing process.

平均 The average particle diameter of the hygroscopic metal oxide can be measured by a laser diffraction / scattering method based on Mie scattering theory. Specifically, the particle size distribution of the hygroscopic metal oxide can be created on a volume basis by a laser diffraction particle size distribution measuring device, and the median diameter can be measured as the average particle diameter. As the measurement sample, a hygroscopic metal oxide dispersed in water by ultrasonic waves can be preferably used. As a laser diffraction type particle size distribution measuring device, LA-500 manufactured by Horiba Ltd. can be used.

As the hygroscopic metal oxide, a surface treated with a surface treatment agent can be used. By using such a surface-treated hygroscopic metal oxide, the adhesion stability of the cured product can be further increased, and the moisture in the resin and the hygroscopic metal oxide react in the stage before curing. In addition, the thickening of the composition over time can be prevented.

As the surface treatment agent used for the surface treatment, for example, higher fatty acids, alkylsilanes, silane coupling agents and the like can be used, among which higher fatty acids or alkylsilanes are preferable.

The higher fatty acid is preferably a higher fatty acid having 18 or more carbon atoms such as stearic acid, montanic acid, myristic acid and palmitic acid. These can be used by selecting one or more. Of these, stearic acid is preferred.

Alkylsilanes include methyltrimethoxysilane, ethyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane, decyltrimethoxysilane, octadecyltrimethoxysilane, dimethyldimethoxysilane, octyltriethoxysilane, n-octadecyldimethyl ( 3- (trimethoxysilyl) propyl) ammonium chloride and the like can be mentioned, and these can be used alone or in combination of two or more.

Examples of the silane coupling agent include 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxypropyl (dimethoxy) methylsilane, and 2- (3,4-epoxycyclohexyl) ethyltrimethoxy. Epoxy silane coupling agents such as silane; mercapto silane coupling agents such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane and 11-mercaptoundecyltrimethoxysilane ; 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldimethoxymethylsilane, N-phenyl-3-aminopropyltri Amino silanes such as methoxysilane, N-methylaminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane and N- (2-aminoethyl) -3-aminopropyldimethoxymethylsilane Coupling agents; Ureido silane coupling agents such as 3-ureidopropyltriethoxysilane, vinyl silane coupling agents such as vinyltrimethoxysilane, vinyltriethoxysilane and vinylmethyldiethoxysilane; p-styryltrimethoxysilane Styryl-based silane coupling agents such as; acrylate-based silane coupling agents such as 3-acryloxypropyltrimethoxysilane and 3-methacryloxypropyltrimethoxysilane; 3-isocyanatopropyltrimeth Isocyanate-based silane coupling agents such as silane, sulfide-based silane coupling agents such as bis (triethoxysilylpropyl) disulfide and bis (triethoxysilylpropyl) tetrasulfide; phenyltrimethoxysilane, methacryloxypropyltrimethoxysilane, imidazole Examples thereof include silane and triazine silane. These can be used by selecting one or more.

In the surface treatment, for example, a surface treatment agent (higher fatty acid, alkylsilanes or silane coupling agent) is added and sprayed while stirring and dispersing an untreated hygroscopic metal oxide at room temperature with a mixer. This can be done by stirring for a minute. As a mixer, a well-known mixer can be used, For example, blenders, such as V blender, a ribbon blender, and a bubble cone blender, mixers, such as a Henschel mixer and a concrete mixer, a ball mill, a cutter mill, etc. are mentioned. Further, when the hygroscopic material is pulverized with a ball mill or the like, a method of surface treatment by mixing the higher fatty acid, alkylsilanes or silane coupling agent is also possible. The treatment amount of the surface treatment agent (higher fatty acid, alkylsilanes or silane coupling agent) varies depending on the type of the hygroscopic metal oxide or the type of the surface treatment agent, but is 1 to 10 for the hygroscopic metal oxide. % By weight is preferred, and 1 to 5% by weight is more preferred.

In the resin composition of the present invention, the content of the hygroscopic metal oxide is preferably in the range of 1 to 40% by weight, more preferably in the range of 1 to 30% by weight with respect to 100% by weight of the nonvolatile content in the resin composition. The range of 5 to 20% by weight is more preferred, 7 to 18% by weight is even more preferred, and 9 to 16% by weight is even more preferred. If the content is too small, the effect of blending the hygroscopic metal oxide is not sufficiently obtained. If the content is too large, the viscosity of the composition tends to increase and the strength of the cured product decreases. It tends to be brittle.

[Inorganic filler]
The resin composition of the present invention can contain an inorganic filler from the viewpoints of moisture permeability of the cured product, prevention of repelling during film processing, and improvement in adhesion. Examples of the inorganic filler include silica, alumina, barium sulfate, talc, clay, mica, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, boron nitride, aluminum borate, barium titanate, strontium titanate, Examples include calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, barium zirconate, and calcium zirconate. Among these, talc and mica are preferable from the viewpoint of maintaining low moisture permeability and high adhesion of the cured resin, and talc is particularly preferable. The inorganic filler may be used alone or in combination of two or more.

In the resin composition of the present invention, when an inorganic filler is used, the content of the inorganic filler is preferably in the range of 1 to 50% by weight with respect to 100% by weight of the nonvolatile content in the resin composition. The range is preferably 1 to 40% by weight, more preferably 5 to 30% by weight, still more preferably 10 to 20% by weight. If the content is too small, the effect of blending the inorganic filler cannot be obtained sufficiently. If the content is too large, the viscosity of the composition tends to increase, and the strength of the cured product decreases and becomes brittle. It becomes a trend.

The upper limit of the average particle size of the inorganic filler used in the present invention is preferably 10 μm, more preferably 5 μm, even more preferably 2.5 μm, and even more preferably 1.5 μm from the viewpoint of handleability. On the other hand, the lower limit of the average particle diameter of the inorganic filler is preferably 0.5 μm from the viewpoint of preventing the viscosity of the resin composition from increasing.

The average particle diameter of the inorganic filler can be measured by a laser diffraction / scattering method based on the Mie scattering theory. Specifically, the particle size distribution of the inorganic filler can be created on a volume basis with a laser diffraction particle size distribution measuring device, and the median diameter can be measured as the average particle diameter. As the measurement sample, an inorganic filler dispersed in water by ultrasonic waves can be preferably used. As a laser diffraction type particle size distribution measuring device, for example, LA-500 manufactured by Horiba Ltd. can be used.

[Rubber particles]
The resin composition of the present invention may contain rubber particles for the purpose of improving the mechanical strength of the cured product and relaxing the stress. The rubber particles are not dissolved in an organic solvent when preparing the resin composition, are not compatible with components in the resin composition such as an epoxy resin, and exist in a dispersed state in the varnish of the resin composition Is preferred. Such rubber particles can generally be prepared by increasing the molecular weight of the rubber component to a level that does not dissolve in an organic solvent or resin and making it into particles. Specifically, core-shell type rubber particles, Examples thereof include acrylonitrile butadiene rubber particles, crosslinked styrene butadiene rubber particles, and acrylic rubber particles. The core-shell type rubber particles are rubber particles having a core layer and a shell layer. For example, the outer shell layer is a glassy polymer and the inner core layer is a rubbery polymer. Examples include a three-layer structure in which the shell layer is a glassy polymer, the intermediate layer is a rubbery polymer, and the core layer is a glassy polymer. The glass layer is made of, for example, a polymer of methyl methacrylate, and the rubbery polymer layer is made of, for example, a butyl acrylate polymer (butyl rubber). Specific examples of the core-shell type rubber particles include Staphyloid AC3832, AC3816N (manufactured by Ganz Kasei Co., Ltd.), Metabrene KW-4426 (manufactured by Mitsubishi Rayon Co., Ltd.), F351 (manufactured by Nippon Zeon Co., Ltd.), and the like. Can be mentioned. Specific examples of acrylonitrile butadiene rubber (NBR) particles include XER-91 (manufactured by JSR Corporation). Specific examples of styrene butadiene rubber (SBR) particles include XSK-500 (manufactured by JSR Corporation). Specific examples of the acrylic rubber particles include Methbrene W300A and W450A (manufactured by Mitsubishi Rayon Co., Ltd.).

The average particle diameter of the rubber particles is preferably in the range of 0.005 to 1 μm, more preferably in the range of 0.2 to 0.6 μm. The average particle diameter of such rubber particles can be measured using a dynamic light scattering method. For example, rubber particles are uniformly dispersed in an appropriate organic solvent by ultrasonic waves, etc., and using FPRA-1000 (manufactured by Otsuka Electronics Co., Ltd.), the particle size distribution of the rubber particles is created on a weight basis, and the median diameter is determined. The average particle diameter is measured.

When rubber particles are used in the resin composition of the present invention, the content of the rubber particles is preferably 0.1 to 20% by weight, preferably 0.1 to 10% by weight with respect to 100% by weight of the nonvolatile content in the resin composition. Weight percent is more preferred. If the amount is less than 0.1% by weight, the effect of blending the rubber particles cannot be sufficiently obtained. If the amount is more than 20% by weight, the heat resistance and moisture permeability may be lowered.

[Thermoplastic resin]
The resin composition of the present invention can contain a thermoplastic resin from the viewpoints of imparting flexibility to the cured product and maintaining good processability when coating the resin composition. Examples of the thermoplastic resin include phenoxy resin, polyvinyl acetal resin, polyimide resin, polyamideimide resin, polyethersulfone resin, and polysulfone resin. Any one of these thermoplastic resins may be used, or two or more thereof may be mixed and used. The thermoplastic resin preferably has a weight average molecular weight of 30,000 or more, more preferably 50,000 or more, from the viewpoint of imparting flexibility and preventing repelling during coating. However, if the weight average molecular weight is too large, the compatibility with the epoxy resin tends to be reduced. Therefore, the weight average molecular weight is preferably 1,000,000 or less, more preferably 800,000 or less. .

Note that the “weight average molecular weight of the thermoplastic resin” herein is measured by a gel permeation chromatography (GPC) method (polystyrene conversion). Specifically, the weight average molecular weight by the GPC method is LC-9A / RID-6A manufactured by Shimadzu Corporation as a measuring device, and Shodex K-800P / K-804L / K manufactured by Showa Denko KK as a column. -804L can be measured using chloroform or the like as a mobile phase at a column temperature of 40 ° C. and calculated using a standard polystyrene calibration curve.

Among the above-mentioned examples, the phenoxy resin is particularly preferable as the thermoplastic resin. The phenoxy resin is preferable because it has good compatibility with the “epoxy resin” and has little influence on the adhesion and moisture resistance of the cured product of the resin composition of the present invention.

Examples of the phenoxy resin include bisphenol A skeleton, bisphenol F skeleton, bisphenol S skeleton, bisphenolacetophenone skeleton, novolac skeleton, biphenyl skeleton, fluorene skeleton, dicyclopentadiene skeleton, norbornene skeleton, naphthalene skeleton, anthracene skeleton, adamantane skeleton, terpene skeleton, Examples thereof include those having one or more skeletons selected from a trimethylcyclohexane skeleton. Two or more phenoxy resins may be mixed and used.

Examples of commercially available phenoxy resins include 1256, 4250 (bisphenol A skeleton-containing phenoxy resin) manufactured by Japan Epoxy Resin Co., Ltd., YX8100 (bisphenol S skeleton-containing phenoxy resin) manufactured by Japan Epoxy Resin Co., Ltd., Japan Epoxy Resin ( YX6954 (bisphenol acetophenone skeleton-containing phenoxy resin), Union Carbide PKHH (weight average molecular weight (Mw) 42600, number average molecular weight (Mn) 11200), and the like are suitable. FX280, FX293 manufactured by Toto Kasei Co., Ltd. YL7553BH30, YL6794, YL7213, YL7290, YL7482 etc. manufactured by Japan Epoxy Resins Co., Ltd. can also be mentioned.

In the resin composition of the present invention, when a thermoplastic resin is used, the content of the thermoplastic resin is preferably 1 to 50% by weight, preferably 3 to 25% by weight with respect to 100% by weight of the nonvolatile content in the resin composition. Is more preferable. If the amount is less than 1% by weight, the effect of blending the thermoplastic resin cannot be sufficiently obtained. If the amount is more than 50% by weight, the moisture permeability of the cured product tends to be lowered.

[Coupling agent]
The resin composition of the present invention can contain a coupling agent from the viewpoints of adhesion to the adherend, cured product, moisture permeability resistance, and the like. Examples of such coupling agents include titanium coupling agents, aluminum coupling agents, silane coupling agents, and the like. Among these, a silane coupling agent is preferable. Moreover, a coupling agent can be used 1 type or in combination of 2 or more types.

Examples of the silane coupling agent include 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxypropyl (dimethoxy) methylsilane, and 2- (3,4-epoxycyclohexyl) ethyltrimethoxy. Epoxy silane coupling agents such as silane; mercapto silane coupling agents such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane and 11-mercaptoundecyltrimethoxysilane ; 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldimethoxymethylsilane, N-phenyl-3-aminopropyltri Amino silanes such as methoxysilane, N-methylaminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane and N- (2-aminoethyl) -3-aminopropyldimethoxymethylsilane Coupling agents; Ureido silane coupling agents such as 3-ureidopropyltriethoxysilane, vinyl silane coupling agents such as vinyltrimethoxysilane, vinyltriethoxysilane and vinylmethyldiethoxysilane; p-styryltrimethoxysilane Styryl-based silane coupling agents such as; acrylate-based silane coupling agents such as 3-acryloxypropyltrimethoxysilane and 3-methacryloxypropyltrimethoxysilane; 3-isocyanatopropyltrimeth Isocyanate-based silane coupling agents such as silane, sulfide-based silane coupling agents such as bis (triethoxysilylpropyl) disulfide and bis (triethoxysilylpropyl) tetrasulfide; phenyltrimethoxysilane, methacryloxypropyltrimethoxysilane, imidazole Examples thereof include silane and triazine silane. Among these, an epoxy-based silane coupling agent is particularly suitable.

In the resin composition of the present invention, when a coupling agent is used, the content of the coupling agent is preferably 0.5 to 10% by weight with respect to 100% by weight of the nonvolatile content in the resin composition, More preferred is ˜5% by weight. When it contains outside this range, the adhesive improvement effect by coupling agent addition cannot be acquired.

樹脂 The resin composition of the present invention may optionally contain various resin additives other than the components described above within the range where the effects of the present invention are exhibited. Examples of such resin additives include organic fillers such as silicon powder, nylon powder, and fluorine powder, thickeners such as olben and benton, silicone-based, fluorine-based, and polymer-based antifoaming agents or leveling agents. , Adhesion imparting agents such as triazole compounds, thiazole compounds, triazine compounds, and porphyrin compounds.

[Resin composition sheet]
The resin composition of the present invention can be directly applied to an object to be coated or an object to be bonded to form a resin composition film (layer), but a resin having a layer of the resin composition of the present invention formed on a support A composition sheet may be prepared, and the resin composition sheet may be laminated on a necessary part of the covering object or the bonding object, and the resin composition layer may be transferred to the covering object or the bonding object. Industrially, a method using such a resin composition sheet is preferable.

The resin composition sheet is prepared by a method known to those skilled in the art, for example, by preparing a varnish in which the resin composition is dissolved in an organic solvent, applying the varnish on the support, and further heating or blowing hot air to the organic solvent. It can manufacture by making it dry and forming a resin composition layer.

Examples of the support used for the resin composition sheet include polyolefins such as polyethylene, polypropylene, and polyvinyl chloride, polyethylene terephthalate (hereinafter sometimes abbreviated as “PET”), polyesters such as polyethylene naphthalate, polycarbonate, polyimide, and the like. The plastic film is mentioned. As the plastic film, PET is particularly preferable. The support may be subjected to a release treatment in addition to a mat treatment and a corona treatment. Examples of the release treatment include a release treatment with a release agent such as a silicone resin release agent, an alkyd resin release agent, and a fluororesin release agent.

The thickness of the heel support is not particularly limited, but is preferably in the range of 10 to 150 μm, more preferably in the range of 20 to 100 μm, from the viewpoint of the handleability of the resin composition sheet.

Examples of the organic solvent include ketones such as acetone, methyl ethyl ketone (hereinafter abbreviated as “MEK”), cyclohexanone, and acetates such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, carbitol acetate, and the like. Carbitols such as cellosolve and butyl carbitol, aromatic hydrocarbons such as toluene and xylene, dimethylformamide, dimethylacetamide, N-methylpyrrolidone and the like. One of these organic solvents may be used alone, or two or more thereof may be used in combination.

Drying conditions are not particularly limited, but 50 to 100 ° C for 3 to 15 minutes is preferable.

The thickness of the resin composition layer formed after drying is preferably 3 μm to 200 μm, more preferably 5 μm to 100 μm, still more preferably 5 μm to 50 μm. As described later, when used as a resin composition sheet for sealing an organic EL element, in the sealing structure, a sealing substrate is laminated on a resin composition layer (cured layer) (see FIG. 1), since the intrusion of moisture is only from the side of the resin composition layer (cured layer), reducing the layer thickness of the resin composition layer reduces the contact area with the outside air and blocks moisture Desirable above. If the layer thickness is too small, the uniformity of the thickness of the coating film may be reduced after sealing on the substrate on which the organic EL element is formed (hereinafter also referred to as “organic EL element forming substrate”), There exists a tendency for workability | operativity in the case of bonding a stop base material to fall.

The resin composition layer may be protected with a protective film, and by protecting with a protective film, it is possible to prevent adhesion or scratches of dust or the like to the surface of the resin composition layer. The protective film is preferably a plastic film similar to the support. Further, the protective film may be subjected to a release treatment in addition to the mat treatment and the corona treatment. The thickness of the protective film is not particularly limited, but is preferably in the range of 1 to 40 μm, more preferably in the range of 10 to 30 μm.

[Encapsulation of organic EL elements]
Specific examples of uses of the resin composition and the resin composition sheet of the present invention include an organic EL element sealing resin composition and an organic EL element sealing resin composition sheet. When sealing an organic EL element using the resin composition or resin composition sheet of the present invention, first, a resin composition layer is formed so as to cover the organic EL element on the organic EL element forming substrate.

If the resin composition is used directly, it is applied to form a resin composition layer. The resin composition is preferably used in a varnish state in which an epoxy resin, an ionic liquid, and other materials blended as necessary are mixed. The above-described solvents and the like may be added as necessary to the extent that they do not affect the organic EL element. When a solvent is used, the resin composition layer is formed by drying after coating. The thickness of the resin composition layer is the same as the thickness of the above-described resin composition sheet.

When a resin composition sheet is used, if a resin composition sheet support having moisture resistance is used, it is used as a sealing substrate (that is, a substrate specified by reference numeral 7 in FIG. 1). Can be used. For such a moisture-proof support (= sealing substrate), a moisture-proof plastic film or a metal foil such as a copper foil or an aluminum foil is used. Examples of the plastic film having moisture resistance include a plastic film in which an inorganic substance such as silicon oxide (silica), silicon nitride, SiCN, or amorphous silicon is deposited on the surface. Here, the same plastic film as exemplified above can be used. Examples of commercially available plastic films with moisture resistance include Tech Barrier HX, AX, LX, L series (Mitsubishi Resin Co., Ltd.) and X-BARRIER (Mitsubishi Resin Co., Ltd.) with further improved moisture resistance. It is done. A sealing substrate having a multilayer structure of two or more layers may be used.

When the resin composition layer of the resin composition sheet is protected by a protective film, after peeling it off, the organic EL element is formed so that the resin composition sheet is in direct contact with the organic EL element formation substrate. Laminate to substrate. The laminating method may be a batch method or a continuous method using a roll. In the case where the support of the resin composition sheet has moisture resistance (that is, a sealing substrate), after laminating the resin composition sheet on the organic EL element forming substrate, the support is not peeled off, and is described later. The resin composition layer is thermally cured (this completes the sealing of the organic EL element).

On the other hand, when the support does not have moisture resistance, it is preferable to peel the support, press the sealing substrate onto the exposed resin composition layer, and perform the thermosetting operation of the resin composition layer described below. In this case, as the sealing substrate, in addition to the above-mentioned moisture-proof plastic film, copper foil, aluminum foil or other metal foil, a glass plate or metal plate that is unsuitable for use as a support for a resin composition sheet The base material which does not have flexibility, such as, can also be used. The pressure at the time of pressure bonding of the sealing substrate is preferably about 0.5 to 10 kgf / cm ² , and the temperature is about 50 to 130 ° C. when the pressure is applied under heating. The thickness of the sealing substrate is preferably 5 mm or less from the viewpoint of making the organic EL device itself thin and light, more preferably 1 mm or less, particularly preferably 100 μm or less, and 5 μm or more from the viewpoint of preventing moisture permeation. More preferably, it is 10 μm or more, and particularly preferably 20 μm or more. Two or more sealing substrates may be bonded together.

As shown in FIG. 1, when the organic EL element 2 is formed on the glass substrate 1, the sealing substrate 7 is not necessarily transparent if the glass substrate 1 side is used as a display surface of a display or a light emitting surface of a lighting fixture. There is no need to use a material, and a metal plate, a metal foil, or the like can be used. On the contrary, when the organic EL element is formed on a substrate made of an opaque or low-transparency material, since the sealing substrate side needs to be the display surface of the display or the light emitting surface of the lighting fixture, As the sealing substrate, a glass plate, a transparent plastic film (or plate), or the like is used.

After pressure bonding of the sealing substrate (when the support of the resin composition sheet for sealing an organic EL element is used as a sealing substrate, after laminating the resin composition sheet for sealing an organic EL element), the resin composition The target sealing structure (sealing structure shown in FIG. 1) can be formed by thermosetting the layer. There is no restriction | limiting in particular in the method of thermosetting a resin composition layer, A various thing can be used. For example, a hot air circulation oven, an infrared heater, a heat gun, a high frequency induction heating device, heating by pressure bonding of a heat tool, and the like can be mentioned. The resin composition of the present invention has extremely good low-temperature curability, and is generally not more than 120 minutes, preferably in a low temperature range of 140 ° C. or less, preferably 120 ° C. or less, more preferably 110 ° C. or less. It can be cured in a short time of 90 minutes or less, more preferably 60 minutes or less. Therefore, the deterioration of the organic EL element due to heat can be extremely reduced. The lower limit of each of the curing temperature and the curing time is preferably 50 ° C. or higher, more preferably 55 ° C. or higher, from the viewpoint of ensuring sufficiently satisfactory adhesiveness (adhesiveness) of the cured product. The curing time is preferably 20 minutes or longer, and more preferably 30 minutes or longer.

As can be seen from the examples and comparative examples described below, the resin composition of the present invention is a resin composition containing an epoxy resin and an ionic liquid. A cured product having excellent wettability and excellent adhesion strength can be formed. In particular, it is possible to realize a cured film (layer) having excellent moisture resistance and having stable adhesiveness that does not reduce the adhesive strength over time. Moreover, the hardened | cured material which further improved moisture permeability resistance can be formed by mix | blending a hygroscopic metal oxide with an ionic liquid with an epoxy resin.

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

The materials (raw materials) used in Examples and Comparative Examples are as follows.
(A) Epoxy resin 828EL (manufactured by Japan Epoxy Resin Co., Ltd.): Liquid bisphenol A type epoxy resin, epoxy equivalent (185 g / eq), low chlorine type epoxy resin.
NC3000 (manufactured by Nippon Kayaku Co., Ltd.): Biphenylaralkyl type epoxy resin, epoxy equivalent (275 g / eq), prepared in MEK solution with 70 wt% solid content.
GOT (manufactured by Nippon Kayaku Co., Ltd.): orthotoluidine diglycidylamine (liquid), epoxy equivalent (135 g / eq).
Epicron EXA835LV (manufactured by DIC): liquid bisphenol F type epoxy resin, epoxy equivalent 160-170 g / eq.
Epicoat 828 (manufactured by Japan Epoxy Resin): Bisphenol A type epoxy resin low chlorine type.
Epicoat 1001 (manufactured by Japan Epoxy Resin Co., Ltd.): solid bisphenol A type epoxy resin, epoxy equivalent (475 g / eq)

(B) Curing agent (ionic liquid)
N-acetylglycine tetrabutylphosphonium salt N-methylhippuric acid 1-ethyl-3-methylimidazolium salt
・ Acetic acid 1-ethyl-3-methylimidazolium salt (1-ethyl-3-methylimidazolium acetate)
・ 1-ethyl-3-methylimidazolium formate (solid dispersion type curing agent)
・ Amicure MY-24 (manufactured by Ajinomoto Fine Techno Co., average particle size 10μm)
2PZ-CNS-PW (manufactured by Shikoku Kasei Co., Ltd.): 1-cyanoethyl-2-phenylimidazolium trimellitate ground product, average particle size 10 μm
(Acid anhydride type curing agent)
・ Licacid MH-700 (manufactured by Shin Nippon Chemical Co., Ltd.): Methylhexahydrophthalic anhydride (liquid curing agent)
2E4MZ (manufactured by Shikoku Chemicals): 2-ethyl-4-methylimidazole
1B2MZ (manufactured by Shikoku Chemicals): 1-benzyl-2-methylimidazole

(C) Phenoxy resin YX6954 (manufactured by Japan Epoxy Resin Co., Ltd.): A heat-resistant phenoxy resin, a weight average molecular weight (40000), and a 35 wt% solid MEK solution.
YL7213 (manufactured by Japan Epoxy Resin Co., Ltd.): A heat-resistant phenoxy resin, a weight average molecular weight (35000), and a 35 wt% solid MEK solution prepared for use.
-PKHH (manufactured by InChem): A heat-resistant phenoxy resin, a weight average molecular weight (42600), and a 20 wt% solid MEK solution prepared for use.

(D) Rubber particles F351 (manufactured by Zeon Corporation): acrylic core-shell resin particles, average particle size (0.3 μm).

(E) Hygroscopic metal oxide Moistop # 10 (manufactured by Sankyo Flour Mills): calcium oxide, average particle size (4 μm), maximum particle size (15 μm).
Firing dolomite: MEK slurry (40 wt% as solid content, average particle size: 0.87 μm) of wet pulverized “light calcined dolomite” manufactured by Yoshizawa Lime Company.

(F) Inorganic filler SG95S (manufactured by Nippon Talc): Talc, average particle size (1.4 μm).
D-600 (manufactured by Nippon Talc Co., Ltd.): MEK slurry of wet pulverized talc (30 wt% as solid content, average particle size: 0.72 μm)

(G) Surface treatment agent KBM3103 (manufactured by Shin-Etsu Silicone): Decyltrimethoxysilane Stearic acid (manufactured by Junsei Kagaku)

(H) Coupling agent KBM-403 (manufactured by Shin-Etsu Silicone): 3-glycidoxypropyltrimethoxysilane

The compositions of Examples and Comparative Examples were prepared by the following procedure. The blending was carried out in the amounts by weight shown in Tables 1 and 2.

Example 1
Roll dispersion of acrylic core-shell resin (“F351” manufactured by Nippon Zeon Co., Ltd.) and liquid epoxy resin (“GOT” manufactured by Nippon Kayaku Co., Ltd.) with liquid bisphenol A type epoxy resin (“Japan EL Resin” “828EL”) MEK solution containing 70 wt% solids of the mixture (mixture G), biphenyl aralkyl type epoxy resin (“NC3000” manufactured by Nippon Kayaku Co., Ltd.), 35 wt% solid content of phenoxy resin (“YX6954” manufactured by Japan Epoxy Resin Co., Ltd.) MEK solution, talc powder (“SG95S” manufactured by Nippon Talc Co., Ltd.) and a coupling agent (“KBM-403” manufactured by Shin-Etsu Silicone Co., Ltd.) were blended and mixed with an Ajihomo mixer Robomix type mixing stirrer (manufactured by Primex). (Mixture H). Then, this mixture (mixture H), an ionic liquid curing agent (N-acetylglycine tetrabutylphosphonium salt) and an organic solvent (MEK, acetone) are mixed and dispersed uniformly with a high-speed rotary mixer to obtain a varnish-like resin composition I got a thing. Next, the thickness of the resin composition layer after drying is 40 μm on the release treatment surface of a PET film (thickness 38 μm) obtained by treating this varnish-like resin composition with an alkyd mold release agent. The resin composition sheet was obtained by uniformly coating with a die coater and drying at 60 to 80 ° C. for 6 minutes.

(Example 2)
A varnish-like resin composition was prepared in the same manner as in Example 1 except that N-methylhippuric acid imidazolium salt was used as the ionic liquid curing agent, and a resin composition sheet was prepared.

(Example 3)
A varnish-like resin composition was prepared in the same manner as in Example 1 except that an imidazolium acetate salt was used as the ionic liquid curing agent, and a resin composition sheet was prepared.

Example 4
A varnish-like resin composition was prepared in the same manner as in Example 1 except that an imidazolium formate salt was used as the ionic liquid curing agent, and a resin composition sheet was prepared.

(Example 5)
Surface treatment was carried out by stirring calcium oxide (“Moystop # 10” manufactured by Sankyo Flour Milling Co., Ltd.) and a surface treatment agent (“Stearic acid” manufactured by Junsei Chemical Co., Ltd.) with a cutter mill pulverizer. Then, instead of the mixture H in Example 1, a liquid bisphenol A type epoxy resin (“828EL” manufactured by Japan Epoxy Resin Co., Ltd.) and a liquid epoxy resin (“GOT” manufactured by Nippon Kayaku Co., Ltd.) are used. 70% by weight solid MEK solution of phenoxy resin, mixture obtained by roll dispersion of “F351” manufactured by Nippon Zeon Co., Ltd., surface-treated calcium oxide, biphenyl aralkyl type epoxy resin (“NC3000” manufactured by Nippon Kayaku Co., Ltd.) A 35 wt% solid MEK solution (“Japan Epoxy Resin” “YX6954”), talc powder (“SG95S” manufactured by Nippon Talc), and a coupling agent (“KBM-403” manufactured by Shin-Etsu Silicone Co., Ltd.) Use a mixture mixed with a homomixer Robomix type mixing stirrer (manufactured by Primex) Other than the can, a varnish-like resin composition was prepared in the same manner as in Example 1 to prepare a resin composition sheet.

(Comparative Example 1)
In place of the mixture G in Example 1, a liquid bisphenol A type epoxy resin (“828EL” manufactured by Japan Epoxy Resin Co., Ltd.) and a liquid epoxy resin (“GOT” manufactured by Nippon Kayaku Co., Ltd.) were replaced with an acrylic core-shell resin (Japan). Zeon's "F351"), a solid dispersion type curing agent (Ajinomoto Fine Techno's "MY-24") is used in a roll-dispersed mixture, and an ionic liquid curing agent (N-acetylglycine tetrabutylphosphonium salt) is added. A varnish-like resin composition was prepared in the same manner as described in Example 1 except that it was not used, and a resin composition sheet was prepared.

(Comparative Example 2)
In place of the mixture G in Example 1, a liquid bisphenol A type epoxy resin (“828EL” manufactured by Japan Epoxy Resin Co., Ltd.) and a liquid epoxy resin (“GOT” manufactured by Nippon Kayaku Co., Ltd.) were replaced with an acrylic core-shell resin (Japan). Zeon's "F351") and a cationic polymerization catalyst type curing agent (2-ethyl-4-methylimidazole, Shikoku Kasei's "2E4MZ") are used in a roll-dispersed mixture, and further an ionic liquid curing agent (N-acetyl) A varnish-like resin composition was prepared in the same manner as described in Example 1 except that glycine tetrabutylphosphonium salt) was not used, and a resin composition sheet was prepared.

(Comparative Example 3)
Liquid dispersion bisphenol F type epoxy resin (“EXA-835LV” manufactured by DIC) and bisphenol A type epoxy resin (“Epicoat 1001” manufactured by Japan Epoxy Resin Co., Ltd.) and solid dispersion curing agent (1-cyanoethyl-2-phenylimidazolium) Trimellite ground product, “2PZ-CNS-PW” manufactured by Shikoku Kasei Co., Ltd.), 20 wt% solid MEK solution of phenoxy resin (“PKHH” manufactured by InChem), silane coupling agent ( “KBM403” manufactured by Shin-Etsu Silicone Co., Ltd.) was blended in a predetermined amount to obtain a resin composition. Using this resin composition, a resin composition sheet was produced in the same manner as described in Example 1.

(Comparative Example 4)
Epicron EXA-835LV (Liquid bisphenol F type epoxy resin, manufactured by DIC), Ricacid MH-700 (Methylhexahydrophthalic anhydride, manufactured by Shin Nippon Chemical Co., Ltd.), 1B2MZ (1-benzyl-2-methylimidazole, Shikoku Chemicals) A resin composition was obtained by mixing a predetermined amount. Using this resin composition, a sheet-like cured product having a thickness of 40 μm was obtained using a mold.

(Comparative Example 5)
Epicoat 828 (bisphenol A type epoxy resin low chlorine type, manufactured by Japan Epoxy Resin Co., Ltd.), Ricacid MH-700 (methylhexahydrophthalic anhydride, manufactured by Shin Nippon Rika Co., Ltd.), 1B2MZ (1-benzyl-2-methylimidazole, Shikoku) A predetermined amount of (made by Kasei Co., Ltd.) was mixed to obtain a resin composition. Using this resin composition, a sheet-like cured product having a thickness of 40 μm was obtained using a mold.

(Example 6)
Roll dispersion of acrylic core-shell resin (“F351” manufactured by Nippon Zeon Co., Ltd.) and liquid epoxy resin (“GOT” manufactured by Nippon Kayaku Co., Ltd.) with liquid bisphenol A type epoxy resin (“Japan EL Resin” “828EL”) A 70 wt% MEK solution of calcium oxide (“Moystop # 10” manufactured by Sankyo Flour & Co., Ltd.), biphenyl aralkyl type epoxy resin (“NC3000” manufactured by Nippon Kayaku Co., Ltd.), phenoxy resin (Japan Epoxy) A 35 wt% MEK solution of Resin “YX6954”), talc powder (“SG95S” manufactured by Nippon Talc Co., Ltd.), and a coupling agent (“KBM-403” manufactured by Shin-Etsu Silicone) are mixed together. The mixture was mixed with a stirrer (manufactured by Primics) (mixture H). Then, this mixture (mixture H), an ionic liquid curing agent (N-acetylglycine tetrabutylphosphonium salt) and an organic solvent (MEK, acetone) are mixed and uniformly dispersed with a high-speed rotary mixer to obtain a varnish-like resin composition I got a thing. Next, the thickness of the resin composition layer after drying is 40 μm on the release treatment surface of a PET film (thickness 38 μm) obtained by treating this varnish-like resin composition with an alkyd mold release agent. The resin composition sheet was obtained by uniformly coating with a die coater and drying at 60 to 80 ° C. for 6 minutes.

(Example 7)
After performing a surface treatment with decyltrimethoxysilane (“KBM3103” manufactured by Shin-Etsu Silicone Co., Ltd.) on calcium oxide (“MOYSTOP # 10” manufactured by Sankyo Flour Milling Co., Ltd.) using a stirring type surface processing apparatus, the same as in Example 6 By the method, a varnish-like resin composition was prepared to prepare a resin composition sheet. The treatment amount of decyltrimethoxysilane in the surface treatment of calcium oxide was 2% by weight with respect to calcium oxide.

(Example 8)
After surface treatment with stearic acid (manufactured by Junsei Chemical Co., Ltd.) on calcium oxide (“MOISTOP # 10” manufactured by Sankyo Flour Milling Co., Ltd.) using a stirring type surface treatment apparatus, N-methyl hippuric acid 1 as an ionic liquid curing agent A varnish-like resin composition was prepared in the same manner as in Example 6 except that -ethyl-3-methylimidazolium salt was used to prepare a resin composition sheet. The treatment amount of stearic acid in the surface treatment of calcium oxide was 2% by weight with respect to calcium oxide.

Example 9
A mixture A in which a solid epoxy resin (“HP7200H” manufactured by DIC) was dissolved in a phenoxy resin (“YL7213” manufactured by Japan Epoxy Resin, 35 wt% solid MEK solution) was prepared. On the other hand, a mixture B was prepared by adding and dispersing stearic acid to a MEK slurry (40 wt% as solid content) of calcined dolomite (made by wet grinding from Yoshizawa Lime Company). Mixture A, Mixture B, Talc (“D-600” manufactured by Nippon Talc Co., Ltd., wet pulverized, MEK slurry having a solid content of 30 wt%), rubber fine particle dispersed liquid epoxy resin (“BPA328” manufactured by Nippon Shokubai Co., Ltd.), Contains latent curing accelerator for epoxy resin ("U-CAT3502T" manufactured by Sun Apro), liquid epoxy resin ("GOT" manufactured by Nippon Kayaku Co., Ltd.), and silane coupling agent ("KBM-403" manufactured by Shin-Etsu Chemical Co., Ltd.) Then, the mixture was mixed with an Ajihomo mixer Robomix type mixing stirrer (manufactured by Primics). An ionic liquid curing agent (N-acetylglycine tetrabutylphosphonium salt) was added thereto and dispersed uniformly with a high-speed rotary mixer to obtain a varnish-like resin composition. Using this resin composition, a resin composition sheet was produced in the same manner as described in Example 1.

(Example 10)
A varnish-like resin composition was prepared in the same manner as in Example 9 according to the formulation table in Table 3 below. Using this resin composition, a resin composition sheet was produced in the same manner as described in Example 1.

Example 11
A varnish-like resin composition was prepared in the same manner as in Example 9 according to the formulation table in Table 3 below. Using this resin composition, a resin composition sheet was produced in the same manner as described in Example 1.

Note that Comparative Examples 4 and 5 correspond to Examples 1 and 2 of Patent Document 2 (Japanese Patent Laid-Open No. 2006-70221).

Various measurement methods and evaluation methods will be described.
1. Measurement and evaluation of low-temperature curability and storage stability About resin composition sheets obtained in Examples and Comparative Examples, low-temperature curing of mild steel sheet when the resin composition layer is heat-cured at 120 ° C. for 90 minutes. And storage stability were evaluated.

First, a mild steel plate (JIS G3141, SPCD, first width: 100 mm × second width: 25 mm × thickness: 1.6 mm) whose surface is polished with an endless belt (JIS # 120) is prepared as shown in FIG. As shown in FIG. 1, the resin composition sheet 12 (first width: 12.5 mm × second width: 25 mm) 12 having a rectangular planar shape is formed on one end portion in the longitudinal direction of one side 11A of the mild steel plate 11. The layer 12A was superposed and laminated by a vacuum laminator under conditions of a temperature of 80 ° C. and a pressure of 1 kgf / cm ² (9.8 × 104 Pa) to produce a test piece 13. Note that two similar test pieces 13 were produced.

Next, as shown in FIG. 3, the two PET films 12B of the two test pieces 13 are peeled, the resin composition layers 12A are opposed to each other, and are bonded so as to overlap each other with a width of 12 mm. It was fixed with a clip so as to be a pressure of / cm ² , and cured by heating at 120 ° C. for 90 minutes. The tensile shear bond strength between the two test pieces was measured with a Tensilon universal tester (TENSILON UTM-5T manufactured by Toyo Seiki Co., Ltd.). The measurement conditions were such that the measurement temperature was 25 ° C. and the tensile speed was 1 mm / min. The tensile shear bond strength after storage for 24 hours at room temperature (25 ° C., 40% RH) immediately after the curing process (initial stage) and after the curing process was measured.
When the initial tensile shear bond strength immediately after the curing treatment is less than 17 MPa, the low-temperature curability is determined to be poor (x), and the case of 17 MPa or more and less than 19 MPa is determined as “good”, and the case of 19 MPa or more is extremely Good “◎”.

In addition, when the storage stability is defined as “tension shear bond strength after 24 hours storage” / “initial tensile shear bond strength” × 100 (%), and the bond retention is less than 70%, Storage stability is judged to be inadequate (x), 70% or more and less than 85% is acceptable “△”, 85% or more and less than 100% is “good”, and 100% or more is extremely Good “◎”. However, when the tensile shear adhesive strength after storage for 24 hours was reduced to less than 15 MPa, it was judged as “unsatisfactory” from the viewpoint of insufficient adhesive strength, and when it was 15 MPa or more, it was judged as “good”.

2. Measurement and evaluation of moisture permeation resistance (560 μm) 14 resin composition sheets having a resin composition layer having a thickness of 40 μm obtained in Examples and Comparative Examples were prepared, and these were sequentially laminated under the conditions described in the previous section to obtain 14 layers. A laminated sheet material having a total thickness of 560 μm obtained by stacking the resin composition layers was obtained. A cured product obtained by thermally curing this at 120 ° C. for 90 minutes was measured by a method in accordance with JISZ0208 under the conditions of a temperature of 85 ° C., a humidity of 85% RH, and 24 hours, and water vapor per 1 m ² was measured. The amount of permeation was determined. When the water vapor transmission rate is 250 g / m ² · 24 hr or more, the moisture permeation resistance (560 μm) is judged as poor “x”, and the case where it is less than 250 g / m ² · 24 hr and 150 g / m ² · 24 hr or more is allowed “Δ ”, Less than 150 g / m ² · 24 hr, 100 g / m ² · 24 hr or more was rated as“ good ”, and less than 100 g / m ² · 24 hr was marked as“ good ”. When evaluation was not performed, “−” was shown.
In addition, the cured product of the laminated sheet-like material having a thickness of 560 μm was used as the measurement sample, assuming the entire sealing structure of the organic EL element shown in FIG. 1, and the thickness of the cured product of the laminated sheet-like material (560 μm). Is based on the width (W1 in FIG. 1) of the portion of the curable resin composition layer (cured layer) 6 in FIG. 1 that is in contact with the outside air located on the side of the organic EL element 2.

3. Measurement and evaluation of moisture permeation resistance (40 μm) The resin composition layers (thickness: 40 μm) of the resin composition sheets prepared in Examples and Comparative Examples were thermally cured at 120 ° C. for 90 minutes, and peeled off from the support (PET film). With respect to the cured layer, the amount of water vapor transmission per 1 m ² was determined by measuring the amount of water vapor transmission under the conditions of temperature 85 ° C., humidity 85% RH, and 24 hours by a method according to JISZ0208.
When the water vapor transmission rate is 300 g / m ² · 24 hr or more, the moisture permeation resistance is judged as “poor”, and when it is less than 300 g / m ² · 24 hr and 250 g / m ² · 24 hr or more, “good” is given, and 250 g / M ² · The case where it was less than 24 hr was marked as “Excellent”. When evaluation was not performed, “−” was shown.

4). Evaluation of laminating workability The laminating workability was evaluated by the value of the minimum melt viscosity at the time of measuring the temperature rise of the resin composition layer in the resin composition sheets obtained in Examples and Comparative Examples. The minimum melt viscosity is a model Rheosol-G3000 manufactured by UBM, the amount of resin is 1 g, a parallel plate with a diameter of 18 mm is used, a measurement start temperature of 60 ° C., a temperature increase rate of 5 ° C./min, and a measurement temperature of 60 ° C.- Measurement was performed at 200 ° C. and a frequency of 1 Hz / deg. The lowest viscosity value (η) was taken as the lowest melt viscosity. As for the laminate processability, the minimum melt viscosity was determined to be good (◯) when the minimum melt viscosity was less than 20,000 poise, and poor (x) when the minimum melt viscosity was 20000 poise. When evaluation was not performed, “−” was shown.

5). Measurement of Adhesiveness with Base Material Two aluminum foils (width 50 mm, length 50 mm, thickness 50 um) were prepared, and on one side of the first aluminum foil, a resin composition layer (width 40 mm, 50 mm in length) and laminated by a vacuum laminator under the conditions of a temperature of 80 ° C. and a pressure of 1 kgf / cm ² (9.8 × 10 4 Pa). Then, the support is peeled off, and a second aluminum foil is laminated on the exposed resin composition layer and laminated under the same conditions, and a test piece having a three-layer structure of the aluminum foil, the resin composition layer, and the aluminum foil. It was created. The test piece was heat-cured at 110 ° C. for 30 minutes, then cut into a rectangular test piece having a width of 10 mm and a length of 50 mm, and the length of the test piece was measured in accordance with the T-type peel test method of JIS K-6854. Directional adhesion was measured.

Tables 1 and 2 show the test results of and above.

From the comparison between the examples and the comparative examples, the resin composition of the present invention is cured at a low temperature of 120 ° C. in a short time and is adhered with a high adhesive strength to obtain a stable adhesiveness, and the cured product is practical. It turns out that it has a sufficiently low moisture permeability. Further, it can be seen from Examples 9 to 11 that the adhesiveness to the base material is improved by containing an inorganic filler. Thereby, it turns out that it becomes still more useful for sealing of an organic EL element. Therefore, the resin composition of the present invention and the resin composition sheet using the resin composition are easily deteriorated by heat, and need to be moisture-proof. A highly reliable coating structure, adhesive structure, sealing structure and the like that can be suitably used as a material or the like and have high moisture resistance can be easily formed. It turns out that it is particularly suitable for providing an organic EL display device.

The resin composition of the present invention can be cured quickly at low temperatures to form a cured product with excellent adhesiveness and low moisture permeability. It can also be applied to applications such as resins, moisture-proof protective films for printed circuit boards, moisture-proof films for lithium ion batteries, and laminate films for packaging.

1, 4 Glass plate 2 Organic EL element 3 Hygroscopic material 5 Sealing material 6 Curable resin composition layer (cured layer)
7 Sealing base material 11 Mild steel sheet 12 Resin composition sheet 12A Resin composition layer 12B PET film 13 Test piece

This application is based on Japanese Patent Application Nos. 2009-013684 and 2009-013686 filed in Japan, the contents of which are incorporated in full herein.

Claims

A resin composition comprising an epoxy resin and an ionic liquid.
2. The resin composition according to claim 1, wherein the ionic liquid comprises an ammonium cation or a phosphonium cation and an N-acylamino acid ion or a carboxylic acid anion.
The resin composition according to claim 1 or 2, further comprising a hygroscopic metal oxide.
The resin composition according to any one of claims 1 to 3, further comprising an inorganic filler.
A resin composition sheet, wherein the layer of the resin composition according to any one of claims 1 to 4 is formed on a support.
The resin composition sheet according to claim 5, which is for sealing an organic EL element.
An organic EL device comprising the resin composition sheet for sealing an organic EL element according to claim 6.