CN111972046A - Sealing agent for organic EL display element - Google Patents

Abstract

The purpose of the present invention is to provide a sealing agent for an organic EL display element, which has excellent coatability on a substrate or an inorganic material film even when the sealing agent is made thin. The present invention is a sealant for an organic EL display element, which contains a curable resin and a polymerization initiator, has a surface tension of 25mN/m or more and 38mN/m or less at 25 ℃, andand SiO with a surface free energy of 70mN/m or more and 80mN/m or less₂Both the substrate and the SiN substrate having a surface free energy of 50mN/m or more and 60mN/m or less have a contact angle of 13 degrees or less at 25 ℃.

Description

Sealant for organic EL display elements

technical field

The present invention relates to a sealing compound for an organic EL display element which is excellent in coatability to a substrate and an inorganic material film even when thinned.

Background technique

An organic electroluminescence (hereinafter, also referred to as "organic EL") display element has a laminate structure in which an organic light-emitting material layer is sandwiched between a pair of electrodes facing each other, and the organic light is emitted from one electrode to the organic light-emitting material. The material layer injects electrons, and injects holes into the organic light-emitting material layer from the other electrode, so that electrons and holes are combined in the organic light-emitting material layer and emit light. In this way, since the organic EL display element emits light by itself, it has the advantages of good visibility, thinning, and DC low-voltage driving, compared with liquid crystal display elements that require a backlight.

The organic light-emitting material layer and electrode constituting the organic EL display element have a problem that the characteristics are easily deteriorated by moisture, oxygen, and the like. Therefore, in order to obtain a practical organic EL display element, it is necessary to isolate the organic light-emitting material layer and the electrode from the atmosphere to achieve a longer lifetime. Patent Document 1 discloses a method of sealing an organic light-emitting material layer and an electrode of an organic EL display element with a laminated film of a silicon nitride film and a resin film formed by a CVD method. Here, the resin film has a function of preventing the organic layer and the electrode from being pressed by the internal stress of the silicon nitride film.

As a method for preventing moisture from infiltrating into the organic light-emitting material layer, Patent Document 2 discloses a method of alternately depositing an inorganic material film and a resin film, and Patent Document 3 and Patent Document 4 disclose a method in which an inorganic material film and a resin film are alternately deposited. A method of forming a resin film on a material film.

prior art literature

Patent Literature

Patent Document 1: Japanese Patent Laid-Open No. 2000-223264

Patent Document 2: Japanese Patent Publication No. 2005-522891

Patent Document 3: Japanese Patent Laid-Open No. 2001-307873

Patent Document 4: Japanese Patent Laid-Open No. 2008-149710

SUMMARY OF THE INVENTION

The problem to be solved by the invention

As a method of forming a resin film, there is a method of curing the sealant after applying the sealant on the substrate using the inkjet method. If such a coating method based on an inkjet method is used, a resin film can be formed at a high speed and uniformly.

On the other hand, since the organic EL display element is required to be curved or folded and used for flexibility, the sealant for organic EL display elements also needs to cope with the flexibility. As one method of making the sealant for organic EL display elements more flexible, it is conceivable to make the sealant into a thin film, but the conventional sealant has a problem that the coating property when the sealant is made into a thin film by an inkjet method or the like deteriorates, Pinholes are generated, and thus the reliability of the resulting organic EL display element is deteriorated.

The objective of this invention is to provide the sealing compound for organic electroluminescent display elements which is excellent in coatability with respect to a board|substrate and an inorganic material film even when thinning.

means of solving problems

This invention 1 is the sealing compound for organic EL display elements, which contains a curable resin and a polymerization initiator, and the surface tension of the sealing compound for organic EL display elements at 25 degreeC is 25 mN/m or more and 38 mN/m or less , and the contact angle with SiO ₂ substrates with surface free energy of 70mN/m or more and 80mN/m or less and SiN substrates with surface free energy of 50mN/m or more and 60mN/m or less at 25°C is 13 degrees or less. .

Moreover, this invention 2 is the sealing compound for organic EL display elements, which is a sealing compound for organic EL display elements used for coating by the inkjet method, which contains a curable resin and a polymerization initiator, and the organic EL display element contains a curable resin and a polymerization initiator. The surface tension of the encapsulant for EL display elements at 25°C is 25mN/m or more and 38mN/m or less, and the surface free energy is 70mN/m or more and 80mN/m or less SiO ₂ substrate and surface free energy of 50mN The contact angles at 25° C. of SiN substrates of not less than /m and not more than 60 mN/m are all 13 degrees or less.

The present invention is described in detail below. In addition, the matter common to the sealing compound for organic EL display elements of this invention 1 and the sealing compound for organic EL display elements of this invention 2 is described as "the sealing compound for organic EL display elements of this invention".

The inventors of the present invention consider that the reason why the coating properties deteriorate when it is desired to reduce the thickness of the sealant for an organic EL display element is due to the presence of SiO ₂ and other inorganic material films used for flexibility. A foreign matter such as SiN serves as a starting point, and shrinkage occurs in the sealant around the foreign matter (Japanese text: はじき), or the sealant cannot follow the unevenness of the substrate or the inorganic material film. Therefore, as a result of intensive research by the present inventors, it was found that by setting the contact angles with the SiO ₂ substrate and the SiN substrate each of which has a surface free energy in a predetermined range to a predetermined value or less, it is possible to obtain a film even when the film is thinned. The sealing compound for organic EL display elements which is excellent also in coating property with respect to a board|substrate and an inorganic material film has completed this invention.

The sealing agent for an organic EL display element of the present invention, a SiO ₂ substrate having a surface free energy of 70 mN/m or more and 80 mN/m or less, and a SiN substrate having a surface free energy of 50 mN/m or more and 60 mN/m or less at 25° C. The contact angles were all below 13 degrees. By making the said contact angle 13 degrees or less, the sealing compound for organic EL display elements of this invention is excellent in the effect of preventing shrinkage originating from a foreign material, and the wettability with respect to a board|substrate and an inorganic material film. All of the above-mentioned contact angles are preferably 10 degrees or less, more preferably 8 degrees or less, and still more preferably 6 degrees or less. On the other hand, from the viewpoint of suppressing edge flow due to surface unevenness, the above-mentioned contact angle is preferably 5 degrees or more, and more preferably 8 degrees or more.

In this specification, the above-mentioned "surface free energy" is measured from the contact angle of water and diiodomethane at 25° C. by an evaluation method based on the Owens-Wendy method, and specifically refers to the value measured using a contact angle meter. value. As said contact angle meter, MSA (made by KRUSS company) etc. are mentioned, for example.

In addition, in this specification, the above-mentioned "contact angle" refers to a height of 0.5 mm from the SiO ₂ substrate having the above surface free energy and the SiN substrate with a droplet amount of 10 pL using an ink jet ejection apparatus at 25° C. The value measured as the angle of the droplet of the sealant with respect to each substrate about 10 seconds after landing when the sealant was discharged to each substrate. As said inkjet discharge apparatus, NanoPrinter500 (made by MICROJET Corporation) etc. are mentioned, for example, and discharge of a sealant is performed on the condition of a frequency of 20 kHz. The said "angle of the droplet of a sealant with respect to each board|substrate" means the value measured using the image processing software with respect to the image read by the board|substrate observation camera with the contact angle meter. As said contact angle meter, CAM200 (made by KSV INSTRUMENTS company) etc. are mentioned, for example, As said image processing software, CAM2008 (made by KSV INSTRUMENTS company) etc. are mentioned, for example.

As a method of making the said contact angle all 13 degrees or less, the method of making the solubility parameter of the whole curable resin into the range mentioned later, the method of combining resin with good wettability for each substrate, etc. are mentioned, for example.

In addition, as a method of making the above-mentioned contact angles all 5 degrees or more, for example, a method of adding a resin with high surface tension, a method of combining a resin with good wettability and a resin with poor wettability for each substrate, etc. .

The preferable upper limit of the viscosity at 25 degreeC of the sealing compound for organic EL display elements of this invention 1 is 30 mPa*s. By making the said viscosity 30 mPa*s or less, the inkjet coatability of the sealing compound for organic EL display elements of this invention 1 becomes excellent. The more preferable upper limit of the viscosity of the sealing compound for organic EL display elements of this invention 1 is 20 mPa*s.

Moreover, the preferable lower limit of the viscosity of the sealing compound for organic EL display elements of this invention 1 is 5 mPa*s.

In addition, in this specification, the said "viscosity" means the value measured on the conditions of 25 degreeC and 100 rpm using an E-type viscometer.

The preferable upper limit of the viscosity at 25 degreeC of the sealing compound for organic EL display elements of this invention 2 is 30 mPa*s. By making the said viscosity 30 mPa*s or less, the inkjet coatability of the sealing compound for organic EL display elements of this invention 2 becomes more excellent. The more preferable upper limit of the viscosity of the sealing compound for organic EL display elements of this invention 2 is 20 mPa*s.

Moreover, the preferable lower limit of the viscosity of the sealing compound for organic EL display elements of this invention 2 is 5 mPa*s.

The surface tension of the whole sealing compound for organic EL display elements at 25 degreeC of the sealing compound for organic EL display elements of this invention 1 is 25 mN/m or more and 38 mN/m or less. By making the said surface tension into this range, the inkjet coatability of the sealing compound for organic EL display elements of this invention 1 becomes excellent. The preferable lower limit of the surface tension of the entire sealing compound for organic EL display elements of the present invention is 26 mN/m, the preferable upper limit is 37 mN/m, the more preferable lower limit is 27 mN/m, and the more preferable upper limit is 35 mN/m.

In addition, in this specification, the said "surface tension" means the value measured by the dynamic wettability tester at 25 degreeC.

The surface tension of the whole sealing compound for organic EL display elements at 25 degreeC of the sealing compound for organic EL display elements of this invention 2 is 25 mN/m or more and 38 mN/m or less. By making the said surface tension into this range, the inkjet coatability of the sealing compound for organic EL display elements of this invention 2 becomes more excellent. The preferable lower limit of the surface tension of the entire sealing compound for organic EL display elements of the present invention is 26 mN/m, the preferable upper limit is 37 mN/m, the more preferable lower limit is 27 mN/m, and the more preferable upper limit is 35 mN/m.

The sealing compound for organic EL display elements of this invention contains curable resin.

In the sealing compound for organic EL display elements of the present invention, the solubility parameter of the entire curable resin (hereinafter also referred to as "SP value") is preferably 16.5 (J/cm ³ ) ^1/2 or more and 19.5 (J/cm ³ ). ) ^1/2 or less. By making the SP value of the whole curable resin in this range, the sealing compound for organic EL display elements of the present invention is more excellent in the effect of preventing shrinkage from foreign matter and the wettability with respect to the substrate and the inorganic material film. . A more preferable lower limit of the SP value of the entire curable resin is 17.0 (J/cm ³ ) ^1/2 , a more preferable upper limit is 19.2 (J/cm ³ ) ^1/2 , and a more preferable lower limit is 17.7 (J/cm ³ ) ^1/2 , and more preferably the upper limit is 19.0 (J/cm ³ ) ^1/2 .

In addition, in this specification, the said "solubility parameter" is a value calculated by the estimation method of Fedors. In addition, the said "solubility parameter of the whole curable resin" means the average value of the solubility parameter by weight percentage of each curable resin structural component used for the sealing compound for organic EL display elements.

It is preferable that the sealing compound for organic EL display elements of this invention contains 2 or more types of curable resins as said curable resin, and the difference of SP value between each curable resin becomes 5 (J/cm ³ ) ¹ The content of the curable resin of ^/2 or less is 95% by weight or more with respect to the total curable resin. That is, when there is no combination of curable resins in which the difference in SP value between the curable resins exceeds 5 (J/cm ³ ) ^1/2 , the sum of the contents of two or more curable resins is obtained, There is a combination of 95% by weight or more with respect to the entire curable resin. By setting the content of the curable resin to be 5 (J/cm ³ ) ^1/2 or less in the SP value of each curable resin to be 95% by weight or more, the sealant for organic EL display elements obtained can prevent foreign matter as the The effect of the shrinkage of the origin and the wettability to the substrate and the inorganic material film become more excellent. The content of the curable resin in which the difference in SP value between the curable resins is 5 (J/cm ³ ) ^1/2 or less is more preferably 98% by weight or more, still more preferably 99% by weight or more, and still more preferably 99.9% by weight % or more, particularly preferably 99.99% by weight or more.

The sealing compound for organic EL display elements of the present invention preferably contains two or more types of the above-mentioned curable resins as the above-mentioned curable resins, and the maximum difference in SP value between the respective curable resins is 5 (J/cm ^{3 )} . ) ^1/2 or less. That is, it is preferable that there is no combination of curable resins in which the difference in SP value exceeds 5 (J/cm ³ ) ^1/2 . By making the maximum difference in SP value between the respective curable resins to be 5 (J/cm ³ ) ^1/2 or less, the effect of preventing the shrinkage from the foreign matter as a starting point of the resulting sealant for organic EL display elements and the The wettability of the substrate and the inorganic material film becomes more excellent. The maximum difference in SP value between the respective curable resins is more preferably 4 (J/cm ³ ) ^1/2 or less.

The SP value of the curable resin as a whole and the SP value of each curable resin component in the sealant for organic EL display elements of the present invention can be purified by chromatographic analysis, or by GC- The structure and composition are determined by composition analysis such as MS, LC-MS, and the like, and the SP value is calculated and obtained.

It is preferable that the said curable resin contains the compound which has a siloxane skeleton. By containing the compound which has the said siloxane skeleton, it becomes easy to adjust the surface tension of the sealing compound for organic EL display elements obtained, and the flatness of the coating film obtained becomes more excellent.

Examples of the compound having a siloxane skeleton include epoxy compounds having a siloxane skeleton, oxetane compounds having a siloxane skeleton, and (meth)acrylic compounds having a siloxane skeleton. Wait. Among them, the compound represented by the following formula (1) is preferable.

In addition, in this specification, the above-mentioned "(meth)acrylic" refers to acrylic or methacrylic, and the above-mentioned "(meth)acrylic compound" refers to a compound having a (meth)acryloyl group, The above-mentioned "(meth)acryloyl group" means an acryloyl group or a methacryloyl group.

In formula (1), R ¹ represents an alkyl group having 1 to 10 carbon atoms, and X ¹ and X ² each independently represent an alkyl group having 1 to 10 carbon atoms, or the following formula (2-1) , (2-2), (2-3) or (2-4), X ³ represents the following formula (2-1), (2-2), (2-3) or (2) -4) the group shown. m is an integer of 0 or more and 100 or less, and n is an integer of 0 or more and 100 or less. However, when n is 0, at least one of X ¹ and X ² represents a group represented by the following formula (2-1), (2-2), (2-3) or (2-4).

In formulas (2-1) to (2-4), R ² represents a bond or an alkylene group having 1 to 6 carbon atoms; in formula (2-3), R ³ represents hydrogen or carbon atoms In the alkyl group of 1 or more and 6 or less, R ⁴ represents a bond or a methylene group; in formula (2-4), R ⁵ represents hydrogen or a methyl group.

From the viewpoints of storage stability of the resulting sealant for organic EL display elements, adhesion to substrates and inorganic material films, and discharge stability during ink jet coating, the compound having a siloxane skeleton is preferably The high molecular weight body having a number average molecular weight of 100,000 or more is removed by preliminarily purifying before blending in the sealing compound for organic EL display elements.

Specifically, in the compound having a siloxane skeleton, the content ratio of the high molecular weight body having a number average molecular weight of 100,000 or more is preferably 0.5% or less.

In addition, in this specification, the content ratio of the above-mentioned number average molecular weight and the above-mentioned high molecular weight substance is measured by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent, and calculated based on polystyrene conversion. . In addition, the content ratio of the said high molecular weight body can also be measured by GPC. As a column for measuring the number average molecular weight in terms of polystyrene and the content ratio of the high molecular weight substance by GPC, for example, ShodexLF-804 (manufactured by Showa Denko Co., Ltd.) and the like can be mentioned. In addition, the content ratio of a high molecular weight body was calculated from the area ratio of the said GPC.

As a method of purifying the compound which has the said siloxane skeleton, the method of purifying by distillation, the method of purifying using a chromatographic column, etc. are mentioned, for example.

The compound which has the said siloxane skeleton may be used individually or in combination of 2 or more types.

It is preferable that content of the compound which has the said siloxane skeleton in the said curable resin is less than 40 weight%. By making content of the compound which has the said siloxane skeleton less than 40 weight%, the wetting spreadability of the sealing compound for organic EL display elements obtained becomes more excellent. The more preferable upper limit of content of the compound which has the said siloxane skeleton is 35 weight%.

Moreover, the preferable minimum of content of the compound which has the said siloxane skeleton in the said curable resin is 0.1 weight%. By making content of the compound which has the said siloxane skeleton into 0.1 weight% or more, it becomes easier to adjust the surface tension of the sealing compound for organic EL display elements obtained.

Examples of the curable resin other than the compound having a siloxane skeleton include epoxy compounds that do not have a siloxane skeleton (hereinafter also simply referred to as "epoxy compounds"), and resins that do not have a siloxane skeleton. Oxetane compound (hereinafter also abbreviated as "oxetane compound"), vinyl ether compound without siloxane skeleton (hereinafter also abbreviated as "vinyl ether compound"), without siloxane The (meth)acrylic compound of the backbone (hereinafter also simply referred to as "(meth)acrylic compound") and the like.

As said epoxy compound, bisphenol A type epoxy compound, bisphenol E type epoxy compound, bisphenol F type epoxy compound, bisphenol S type epoxy compound, bisphenol O type epoxy compound, 2,2'-Diallyl bisphenol A type epoxy compound, alicyclic epoxy compound, hydrogenated bisphenol type epoxy compound, propylene oxide addition bisphenol A type epoxy compound, resorcinol type Epoxy compound, biphenyl type epoxy compound, sulfide type epoxy compound, diphenyl ether type epoxy compound, dicyclopentadiene type epoxy compound, naphthalene type epoxy compound, phenol novolac type epoxy compound Compounds, o-cresol novolac epoxy compounds, dicyclopentadiene novolac epoxy compounds, biphenyl novolac epoxy compounds, naphthol novolak epoxy compounds, glycidylamine type Epoxy compounds, alkyl polyol type epoxy compounds, rubber-modified epoxy compounds, glycidyl ester compounds, and the like. Among them, alkyl polyol type epoxy compounds are preferable, and neopentyl glycol diglycidyl ether is the most preferable from the viewpoints of being less volatile and more excellent in inkjet coatability of the resulting sealant for organic EL display elements.

The above epoxy compounds may be used alone or in combination of two or more.

As said oxetane compound, 3-(allyloxy) oxetane, phenoxymethyl oxetane, 3-ethyl-3-hydroxymethyl oxetane, for example is mentioned Hetetane, 3-ethyl-3-(phenoxymethyl)oxetane, 3-ethyl-3-((2-ethylhexyloxy)methyl)oxetane , 3-ethyl-3-(((3-(triethoxysilyl)propoxy)methyl)oxetane, 3-ethyl-3(((3-ethyloxetane Butan-3-yl)methoxy)methyl)oxetane, phenol novolac oxetane, 1,4-bis(((3-ethyl-3-oxetanyl ) methoxy) methyl) benzene and the like. Among them, 3-ethyl-3(((3-ethyloxetan-3-yl)methoxy) is preferable because of its excellent curability and low outgassing properties yl)methyl)oxetane.

The above-mentioned oxetane compounds may be used alone or in combination of two or more.

Examples of the vinyl ether compound include benzyl vinyl ether, cyclohexanedimethanol monovinyl ether, dicyclopentadiene vinyl ether, 1,4-butanediol divinyl ether, and cyclohexane Alkane dimethanol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, dipropylene glycol divinyl ether, tripropylene glycol divinyl ether, etc.

The above vinyl ether compounds may be used alone or in combination of two or more.

Examples of the (meth)acrylic compound include glycidyl (meth)acrylate, 1,6-hexanediol di(meth)acrylate, and 1,9-nonanediol di(meth)acrylate. Acrylates, Dicyclopentenyl (meth)acrylate, Dicyclopentenyloxyethyl (meth)acrylate, Dicyclopentenyl (meth)acrylate, Benzyl (meth)acrylate, Trimethylol Propane tri(meth)acrylate, 1,12-dodecanediol di(meth)acrylate, lauryl (meth)acrylate, etc.

The above-mentioned (meth)acrylic compounds may be used alone or in combination of two or more.

In addition, in this specification, the said "(meth)acrylate" means acrylate or methacrylate.

The sealing compound for organic EL display elements of this invention contains a polymerization initiator.

As the above-mentioned polymerization initiator, a photocationic polymerization initiator and a thermal cationic polymerization initiator are suitably used. Moreover, depending on the kind of the said curable resin, a photo radical polymerization initiator and a thermal radical polymerization initiator are also suitably used.

The photocationic polymerization initiator described above is not particularly limited as long as it generates a protonic acid or a Lewis acid by light irradiation, and may be an ionic photoacid generating type or a nonionic photoacid generating type.

Examples of the anion moiety of the ionic photoacid-generating photocationic polymerization initiator include BF ₄ ⁻ , PF ₆ ⁻ , SbF ₆ ⁻ , and (BX ₄ ) ⁻ (wherein X represents at least two or more fluorine or trifluoromethyl substituted phenyl) and the like. Further, as the anion moiety, PF _m (C _n F _2n+1 ) _6-m ⁻ (wherein, m is an integer of 0 or more and 5 or less, and n is an integer of 1 or more and 6 or less) can also be mentioned. )Wait.

Examples of the ionic photoacid-generating photocationic polymerization initiator include aromatic sulfonium salts, aromatic iodonium salts, aromatic diazonium salts, aromatic ammonium salts, (2,4 -Cyclopentadien-1-yl)((1-methylethyl)benzene)-Fe salt, etc.

Examples of the above-mentioned aromatic sulfonium salt include bis(4-(diphenylsulfonium)phenyl)sulfide bishexafluorophosphate, bis(4-(diphenylsulfonium)phenyl)sulfide bishexafluorophosphate, and Antimonate, bis(4-(diphenylsulfonium)phenyl)sulfide bistetrafluoroborate, bis(4-(diphenylsulfonium)phenyl)sulfide tetrakis(pentafluorophenyl)boronic acid salt, diphenyl-4-(phenylthio)phenylsulfonium hexafluorophosphate, diphenyl-4-(phenylthio)phenylsulfonium hexafluoroantimonate, diphenyl-4-(phenylthio) base) phenylsulfonium tetrafluoroborate, diphenyl-4-(phenylthio)phenylsulfonium tetrakis(pentafluorophenyl)borate, triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexa Fluoroantimonate, triphenylsulfonium tetrafluoroborate, triphenylsulfonium tetrakis(pentafluorophenyl)borate, bis(4-(bis(4-(2-hydroxyethoxy))phenyl) Sulfonium)phenyl)sulfide bishexafluorophosphate, bis(4-(bis(4-(2-hydroxyethoxy))phenylsulfonium)phenyl)sulfide bishexafluoroantimonate, bis(4 -(bis(4-(2-hydroxyethoxy))phenylsulfonium)phenyl)sulfide bistetrafluoroborate, bis(4-(bis(4-(2-hydroxyethoxy))benzene sulfonium) phenyl) sulfide tetrakis (pentafluorophenyl) borate, tris (4-(4-acetylphenyl) thiophenyl) sulfonium tetrakis (pentafluorophenyl) borate and the like.

Examples of the above-mentioned aromatic iodonium salt include diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, diphenyliodonium tetrafluoroborate, and diphenyliodonium tetrafluorophosphate. (Pentafluorophenyl) borate, bis(dodecylphenyl) iodonium hexafluorophosphate, bis(dodecylphenyl) iodonium hexafluoroantimonate, bis(dodecylbenzene) base) iodonium tetrafluoroborate, bis(dodecylphenyl) iodonium tetrakis(pentafluorophenyl) borate, 4-methylphenyl-4-(1-methylethyl)benzene Iodonium hexafluorophosphate, 4-methylphenyl-4-(1-methylethyl)phenyliodonium hexafluoroantimonate, 4-methylphenyl-4-(1-methylethyl) base) phenyliodonium tetrafluoroborate, 4-methylphenyl-4-(1-methylethyl)phenyliodonium tetrakis(pentafluorophenyl)borate, and the like.

Examples of the above-mentioned aromatic diazonium salt include phenyldiazonium hexafluorophosphate, phenyldiazonium hexafluoroantimonate, phenyldiazonium tetrafluoroborate, and phenyldiazonium tetrakis(pentafluorobenzene) base) borate, etc.

Examples of the above-mentioned aromatic ammonium salt include 1-benzyl-2-cyanopyridinium hexafluorophosphate, 1-benzyl-2-cyanopyridinium hexafluoroantimonate, and 1-benzyl-2 -Cyanopyridinium tetrafluoroborate, 1-benzyl-2-cyanopyridinium tetrakis(pentafluorophenyl)borate, 1-(naphthylmethyl)-2-cyanopyridinium hexafluoro Phosphate, 1-(naphthylmethyl)-2-cyanopyridinium hexafluoroantimonate, 1-(naphthylmethyl)-2-cyanopyridinium tetrafluoroborate, 1-(naphthyl Methyl)-2-cyanopyridinium tetrakis (pentafluorophenyl) borate, etc.

Examples of the above-mentioned (2,4-cyclopentadien-1-yl)((1-methylethyl)benzene)-Fe salt include (2,4-cyclopentadien-1-yl)( (1-Methylethyl)benzene)-Fe(II) hexafluorophosphate, (2,4-cyclopentadien-1-yl)((1-methylethyl)benzene)-Fe(II) Hexafluoroantimonate, (2,4-cyclopentadien-1-yl)((1-methylethyl)benzene)-Fe(II) tetrafluoroborate, (2,4-cyclopentadienyl) Alken-1-yl)((1-methylethyl)benzene)-Fe(II) tetrakis(pentafluorophenyl)borate, etc.

Examples of the above-mentioned nonionic photoacid-generating photocationic polymerization initiators include nitrobenzyl esters, sulfonic acid derivatives, phosphoric acid esters, phenolsulfonic acid esters, naphthoquinone diazonium, and N-hydroxyimide. Sulfonates, etc.

As a commercial item among the said photocationic polymerization initiators, for example, photocationic polymerization initiators manufactured by Midori Chemical Co., Ltd., photocationic polymerization initiators manufactured by Union Carbide Corporation, photocationic polymerization initiators manufactured by ADEKA Corporation, 3M Photocationic polymerization initiators manufactured by the company, photocationic polymerization initiators manufactured by BASF, photocationic polymerization initiators manufactured by Rhodia, photocationic polymerization initiators manufactured by SAN-APRO, and the like.

As a photocationic polymerization initiator by the said Green Chemical Co., Ltd. product, DTS-200 etc. are mentioned, for example.

As a photocationic polymerization initiator by the said Union Carbide company, UVI6990, UVI6974 etc. are mentioned, for example.

As a photocationic polymerization initiator by the said ADEKA company, SP-150, SP-170 etc. are mentioned, for example.

As a photocationic polymerization initiator by the said 3M company, FC-508, FC-512 etc. are mentioned, for example.

As a photocationic polymerization initiator by the said BASF company, IRGACURE261, IRGACURE290 etc. are mentioned, for example.

As a photocationic polymerization initiator by the said Rhodia company, PI2074 etc. are mentioned, for example.

As a photocationic polymerization initiator by the said SAN-APRO company, CPI-100P, CPI-200K, CPI-210S etc. are mentioned, for example.

Examples of the thermal cationic polymerization initiator include BF ₄ ^- , PF ₆ ^- , SbF ₆ ^- or (BX ₄ ) ^- (wherein X represents at least two or more fluorine or trifluoromethyl groups substituted with an anion moiety) Sulfonium salts, phosphonium salts, ammonium salts, etc. Among them, sulfonium salts and ammonium salts are preferred.

As said sulfonium salt, triphenylsulfonium tetrafluoroborate, triphenylsulfonium hexafluoroantimonate, etc. are mentioned.

As said phosphonium salt, ethyltriphenylphosphonium hexafluoroantimonate, tetrabutylphosphonium hexafluoroantimonate, etc. are mentioned.

As said ammonium salt, for example, dimethylphenyl(4-methoxybenzyl)ammonium hexafluorophosphate, dimethylphenyl(4-methoxybenzyl)ammonium hexafluoroantimonate, Dimethylphenyl(4-methoxybenzyl)ammonium tetrakis(pentafluorophenyl)borate, dimethylphenyl(4-methylbenzyl)ammonium hexafluorophosphate, dimethylphenyl (4-methylbenzyl)ammonium hexafluoroantimonate, dimethylphenyl(4-methylbenzyl)ammonium hexafluorotetrakis(pentafluorophenyl)borate, methylphenyldibenzylammonium Hexafluorophosphate, methylphenyldibenzylammonium hexafluoroantimonate, methylphenyldibenzylammonium tetrakis(pentafluorophenyl)borate, phenyltribenzylammonium tetrakis(pentafluorophenyl) ) borate, dimethylphenyl(3,4-dimethylbenzyl)ammonium tetrakis(pentafluorophenyl)borate, N,N-dimethyl-N-benzylanilinium hexafluoroantimony acid salt, N,N-diethyl-N-benzylanilinium tetrafluoroborate, N,N-dimethyl-N-benzylpyridinium hexafluoroantimonate, N,N-diethyl -N-benzylpyridinium trifluoromethanesulfonic acid, etc.

As a commercial item among the said thermal cationic polymerization initiators, the thermal cationic polymerization initiator by Sanshin Chemical Industry Co., Ltd., the thermal cationic polymerization initiator by King Industries, etc. are mentioned, for example.

Examples of thermal cationic polymerization initiators manufactured by Sanshin Chemical Industry Co., Ltd. include San-Aid SI-60, San-Aid SI-80, San-Aid SI-B3, San-Aid SI-B3A, and San-Aid SI. -B4 etc.

As a thermal cationic polymerization initiator by the said King Industries company, CXC1612, CXC1821 etc. are mentioned, for example.

Examples of the photoradical polymerization initiator include benzophenone-based compounds, acetophenone-based compounds, acylphosphine oxide-based compounds, titanocene-based compounds, oxime ester-based compounds, benzoin ether-based compounds, benzil, thioxanthone-based compounds, etc.

As a commercial item among the said photoradical polymerization initiators, the photoradical polymerization initiator by BASF Corporation, the photoradical polymerization initiator by Tokyo Chemical Industry Co., Ltd., etc. are mentioned, for example.

As a photoradical polymerization initiator by the said BASF company, IRGACURE184, IRGACURE369, IRGACURE379, IRGACURE651, IRGACURE819, IRGACURE907, IRGACURE2959, IRGACURE OXE01, Lucirin TPO etc. are mentioned, for example.

As a photoradical polymerization initiator by the said Tokyo Chemical Industry Co., Ltd. product, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, etc. are mentioned, for example.

As said thermal radical polymerization initiator, the polymerization initiator containing an azo compound, an organic peroxide, etc. is mentioned, for example.

Examples of the azo compound include 2,2'-azobis(2,4-dimethylvaleronitrile), azobisisobutyronitrile, and the like.

Examples of the above-mentioned organic peroxides include benzoyl peroxide, ketone peroxides, ketal peroxides, hydroperoxides, dialkyl peroxides, peroxyesters, diacyl peroxides, peroxides Oxidized dicarbonate, etc.

Among the above-mentioned thermal radical polymerization initiators, commercially available products include, for example, VPE-0201, VPE-0401, VPE-0601, VPS-0501, VPS-1001, and V-501 (all of which are Fujifilm Wako Pure Chemical Industries, Ltd.). company), etc.

The preferable lower limit of content of the said polymerization initiator is 0.01 weight part with respect to 100 weight part of said curable resins, and a preferable upper limit is 10 weight part. By making content of the said polymerization initiator 0.01 weight part or more, the sclerosis|hardenability of the sealing compound for organic EL display elements obtained becomes more excellent. By making content of the said polymerization initiator 10 weight part or less, the hardening reaction of the sealing compound for organic EL display elements obtained will not become too fast, workability|operativity will become more excellent, and hardened|cured material can be made more uniform. The more preferable lower limit of content of the said polymerization initiator is 0.05 weight part, and a more preferable upper limit is 5 weight part.

The sealing compound for organic EL display elements of this invention may contain a sensitizer. The said sensitizer has the effect|action of further improving the polymerization initiation efficiency of the said polymerization initiator, and further promoting the hardening reaction of the sealing compound for organic EL display elements of this invention.

Examples of the sensitizer include anthracene compounds, thioxanthone compounds, 2,2-dimethoxy-1,2-diphenylethan-1-one, benzophenone, 2,4- Dichlorobenzophenone, methyl o-benzoylbenzoate, 4,4'-bis(dimethylamino)benzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, etc.

As said anthracene compound, 9, 10- dibutoxy anthracene etc. are mentioned, for example.

As said thioxanthone compound, 2, 4- diethyl thioxanthone etc. are mentioned, for example.

The preferable lower limit of content of the said sensitizer is 0.01 weight part with respect to 100 weight part of said curable resins, and a preferable upper limit is 3 weight part. By making content of the said sensitizer into 0.01 weight part or more, the sensitization effect is exhibited more. By making content of the said sensitizer 3 weight part or less, absorption does not become too large, and light can be propagated to a deep part. The more preferable lower limit of content of the said sensitizer is 0.1 weight part, and a more preferable upper limit is 1 weight part.

The sealant for organic EL display elements of the present invention may contain additives such as a silane coupling agent, a surface modifier, a reinforcing agent, a softener, a plasticizer, a viscosity modifier, an ultraviolet absorber, and an antioxidant as necessary.

When the above-mentioned additives are contained, from the viewpoints that the obtained sealant for organic EL display elements is more excellent in the performance of preventing shrinkage originating from foreign matter and the followability to the unevenness of the substrate and the inorganic material film, each of the above-mentioned curable resins contains The maximum difference between the SP value of the component and the additive is preferably 5 (J/cm ³ ) ^1/2 or less.

The said silane coupling agent has the effect|action which further improves the adhesiveness of the sealing compound for organic EL display elements of this invention, a board|substrate, and an inorganic material film.

Examples of the silane coupling agent include 3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 3-isocyanatopropyl Trimethoxysilane, etc. These silane coupling agents may be used alone or in combination of two or more.

The preferable lower limit of content of the said silane coupling agent is 0.1 weight part with respect to 100 weight part of said polymerizable compounds, and a preferable upper limit is 10 weight part. By making content of the said silane coupling agent into this range, the effect of suppressing bleed-out of excess silane coupling agent and improving adhesiveness becomes more excellent. The more preferable lower limit of content of the said silane coupling agent is 0.5 weight part, and a more preferable upper limit is 5 weight part.

The said surface modifier has the effect|action which further improves the flatness of the coating film of the sealing compound for organic EL display elements of this invention.

As said surface modifier, a surfactant, a leveling agent, etc. are mentioned, for example.

As said surface modifier, the surface modifier, such as a silicone type and a fluorine type, is mentioned, for example.

As a commercial item among the said surface modifier, the surface modifier by BYK-Chemie JAPAN, the surface modifier by AGC Seimi Chemical, etc. are mentioned, for example.

As a surface modifier by the said BYK-Chemie JAPAN company, BYK-340, BYK-345 etc. are mentioned, for example.

As a surface modifier by the said AGC Seimi Chemical company, Surflon S-611 etc. are mentioned, for example.

The sealing compound for organic EL display elements of the present invention may contain a solvent for the purpose of adjusting the viscosity, etc. However, there is a concern that problems such as deterioration of the organic light-emitting material layer or degassing may occur due to the residual solvent. Therefore, the content of the solvent is preferably 0.05% by weight or less, most preferably no solvent is contained.

As a method of manufacturing the sealing compound for organic EL display elements of this invention, the method of mixing curable resin, a polymerization initiator, and additives, such as a silane coupling agent as needed, using a mixer, etc. are mentioned, for example.

As said mixer, a homogeneous dispersing agent, a homomixer, a universal mixer, a planetary mixer, a kneader, a three-roll mill etc. are mentioned, for example.

The preferable minimum of the total light transmittance of the light of wavelength 380 nm or more and 800 nm or less of the hardened|cured material of the sealing compound for organic EL display elements of this invention is 80%. By making the said total light transmittance 80% or more, the optical characteristic of the organic electroluminescent display element obtained becomes more excellent. A more preferable lower limit of the above-mentioned total light transmittance is 85%.

The above-mentioned total light transmittance can be measured using, for example, a spectrometer. As said spectrometer, AUTOMATIC HAZE METER MODEL TC-III DPK (made by Tokyo Denshoku Corporation) etc. are mentioned, for example.

Moreover, the said light transmittance, and the hardened|cured material used for the measurement of the moisture permeability and water content mentioned later can be obtained by irradiating the ultraviolet-ray of wavelength 365nm at 3000mJ/cm< ² > using a light source, such as an LED lamp, for example.

Regarding the sealing compound for organic EL display elements of the present invention, the transmittance at 400 nm after irradiating the cured product with ultraviolet rays for 100 hours is preferably 85% or more as an optical path length of 20 μm. By making the transmittance after 100 hours of ultraviolet irradiation above 85% or more, the transparency becomes high, the loss of light emission becomes small, and the color reproducibility becomes more excellent. A more preferable lower limit of the transmittance after 100 hours of ultraviolet irradiation is 90%, and a further preferable lower limit is 95%.

As a light source for irradiating the above-mentioned ultraviolet rays, for example, a conventionally known light source such as a xenon lamp and a carbon arc lamp can be used.

The sealing compound for organic EL display elements of the present invention preferably has a moisture permeability of 100 g/m ² in accordance with JIS Z 0208 when the cured product is exposed to an environment of 85° C. and 85% RH for 24 hours under a 100 μm thickness condition. the following. By setting the above-mentioned moisture permeability to 100 g/m ² or less, the effect of preventing deterioration of the organic light-emitting material layer due to moisture in the cured product is more excellent, and the reliability of the obtained organic EL display element is more excellent.

Regarding the sealing compound for organic EL display elements of the present invention, when the cured product is exposed to an environment of 85° C. and 85% RH for 24 hours, the moisture content of the cured product is preferably less than 0.5%. By making the moisture content of the cured product less than 0.5%, the effect of preventing deterioration of the organic light-emitting material layer due to moisture in the cured product becomes more excellent, and the reliability of the obtained organic EL display element becomes more excellent. The more preferable upper limit of the moisture content of the said hardened|cured material is 0.3 %.

As a measuring method of the said water content, the method of calculating|requiring by the Karl Fischer method based on JIS K 7251, the method of calculating the weight gain after water absorption based on JIS K 7209-2, etc. are mentioned, for example.

As a method for producing an organic EL display element using the sealant for organic EL display elements of the present invention, for example, a method having a step of applying the sealant for organic EL display elements of the present invention by an inkjet method, etc. A process of applying to a base material; and a process of curing the applied sealant for organic EL display elements by light irradiation and/or heating.

In the step of applying the sealant for organic EL display elements of the present invention to the substrate, the sealant for organic EL display elements of the present invention may be applied to the entire surface of the substrate, or may be applied to a part of the substrate. The shape of the sealing portion of the sealant for organic EL display elements of the present invention formed by coating is not particularly limited as long as it is a shape that can protect the laminate having the organic light-emitting material layer from outside air, and may be The shape which completely covers the laminated body may be formed in a pattern closed in the peripheral part of the laminated body, or in a shape in which a part of the opening part is provided in the peripheral part of the laminated body.

When the sealing agent for organic EL display elements of the present invention is cured by light irradiation, the sealing agent for organic EL display elements of the present invention can be cured by the irradiation wavelength of 300 nm or more and 400 nm or less and the cumulative light amount of 300 mJ/cm ² or more and 3000 mJ/ light below cm ² to cure well.

Examples of light sources used for the above-mentioned light irradiation include low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high pressure mercury lamps, excimer lasers, chemical lamps, black light lamps, microwave-excited mercury lamps, and metal halide lamps. , sodium lamp, halogen lamp, xenon lamp, LED lamp, fluorescent lamp, sunlight, electron beam irradiation device, etc. These light sources may be used alone or in combination of two or more.

These light sources can be appropriately selected according to the absorption wavelengths of the above-mentioned photocationic polymerization initiators and photoradical polymerization initiators.

Examples of the method of irradiating the sealant for organic EL display elements of the present invention with light include simultaneous irradiation of various light sources, sequential irradiation with a time difference, combined irradiation of simultaneous irradiation and sequential irradiation, and the like, and any irradiation method can be used.

The hardened|cured material obtained by the process of hardening the said sealing compound for organic EL display elements by light irradiation and/or heating can be covered with an inorganic material film further.

As the inorganic material constituting the inorganic material film, conventionally known inorganic materials can be used, and examples thereof include silicon nitride (SiN _x or SiO _X N _Y ), silicon oxide (SiO _x ), and the like. The above-mentioned inorganic material film may be composed of one layer, or a plurality of layers may be laminated. Moreover, you may cover the said laminated body alternately and repeatedly with the said inorganic material film and the resin film which consists of the sealing compound for organic EL display elements of this invention.

The method for producing the above-mentioned organic EL display element may include a step of laminating a base material (hereinafter also referred to as "one base material") to which the sealant for organic EL display elements of the present invention is applied and another base material .

The substrate to which the sealant for organic EL display elements of the present invention is applied (hereinafter, also referred to as “one substrate”) may be a substrate on which a laminate having an organic light-emitting material layer is formed, or may not be a laminate. substrate.

When the above-mentioned one base material is a base material on which the above-mentioned laminated body is not formed, when the above-mentioned other base material is bonded, the above-mentioned one base material may be coated so as to protect the above-mentioned laminated body from external air. What is necessary is just to distribute the sealant for organic EL display elements of this invention. That is, when the other base material is bonded, the entire surface may be coated on the portion that becomes the position of the laminate, or the portion that can be closed to become the position of the laminate may be formed when the other substrate is bonded. The sealant part of the pattern of the fully accommodated shape.

The step of curing the above-mentioned sealant for organic EL display elements by light irradiation and/or heating may be performed before the step of laminating the above-mentioned one substrate and the above-mentioned other substrate, or may be performed before the above-mentioned one substrate and the above-mentioned It is performed after the process of laminating another base material.

When the step of curing the above-mentioned sealant for organic EL display elements by light irradiation and/or heating is performed before the step of bonding the above-mentioned one base material and the above-mentioned other base material, the organic EL display element of the present invention is used for It is preferable that the usable time of a sealing compound from performing light irradiation and/or heating until a hardening reaction progresses and it becomes impossible to adhere|attach is 1 minute or more. By setting the said usable time to be 1 minute or more, it is possible to obtain higher adhesive strength without excessively advancing curing until the above-mentioned one base material and the above-mentioned other base material are bonded together.

In the step of laminating the one base material and the other base material, the method of laminating the one base material to the other base material is not particularly limited, but the lamination is preferably performed under a reduced pressure atmosphere.

A preferable lower limit of the degree of vacuum in the above-mentioned reduced pressure atmosphere is 0.01 kPa, and a preferable upper limit is 10 kPa. By setting the degree of vacuum in the decompressed atmosphere within this range, from the airtightness of the vacuum apparatus and the capability of the vacuum pump, it does not take a long time to reach the vacuum state, and the one substrate and the other can be removed more effectively. Air bubbles in the sealing compound for organic EL display elements of this invention when one base material is bonded together.

Invention effect

ADVANTAGE OF THE INVENTION According to this invention, the sealing compound for organic electroluminescent display elements which is excellent in coatability with respect to a board|substrate and an inorganic material film can be provided even when thinning.

Detailed ways

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

(Fabrication of SiO ₂ substrate)

On the alkali-free glass, chemical vapor deposition of SiO ₂ was performed with a film thickness of 1000 nm using an ICP-CVD apparatus (manufactured by SELVAC) to prepare a SiO ₂ substrate. Using a contact angle meter, the surface free energy after vapor deposition was measured by an evaluation method based on the Owens-Wendy method from the contact angle between water and diiodomethane, and it was 73.0 mN/m. As a contact angle meter, MSA (manufactured by KRUSS) was used. Further, the atomic ratio in the SiO ₂ film was measured by an XPS apparatus (manufactured by ULVAC-PHI), and as a result, Si atoms were 31.3%, whereas O atoms were 63.2%.

(Fabrication of SiN substrate)

On the alkali-free glass, SiN was chemically vapor-deposited with a film thickness of 1000 nm using an ICP-CVD apparatus (manufactured by SELVAC) to prepare a SiN substrate. Using a contact angle meter, the surface free energy after vapor deposition was measured by an evaluation method based on the Owens-Wendy method from the contact angle between water and diiodomethane, and it was 58.0 mN/m. As a contact angle meter, MSA (manufactured by KRUSS) was used. Furthermore, the atomic ratio in the SiN film was measured by an XPS apparatus (manufactured by ULVAC-PHI), and as a result, Si atoms were 44.8%, whereas N atoms were 48.0%.

(Examples 1 to 9, Comparative Examples 1 to 4)

According to the mixing ratios described in Tables 1 and 2, each material was uniformly stirred and mixed at a stirring speed of 300 rpm using a homodisper-type stirring mixer to prepare Examples 1 to 9 and Comparative Examples 1 to 4. A sealing compound for each organic EL display element. As a homodisper-type stirring mixer, a HOMODISPER L type (manufactured by Primix Corporation) was used. As the compound which has a siloxane skeleton in the table|surface, the compound which was previously purified by distillation before mixing with other components was used.

As an oxetane compound which has a siloxane skeleton in the table|surface, the compound obtained by the following method was used. That is, 0.1 mol of 1,1,3,3-tetramethyldisiloxane, 0.2 mol of allyloxyoxetane, and platinum(0)-1,3-divinyl-1,1, A 3,3-tetramethyldisiloxane complex solution (manufactured by Sigma-Aldrich) was mixed at 100 ppm and heated at 80°C for 5 hours. As the allyloxy oxetane, AL-OX (manufactured by Yokkaichi Gosei Co., Ltd.) was used. The completion of the reaction was confirmed by NMR, and the obtained solution was purified by distillation, whereby a high-purity oxetane-modified disiloxane compound was obtained as an oxetane compound having a siloxane skeleton. . It was confirmed by ¹ H-NMR, GPC and FT-IR analysis that the obtained oxetane-modified disiloxane compound was a compound represented by the following formula (3).

Each sealant for organic EL display elements obtained in the examples and comparative examples was discharged to a surface having a free energy of 73.0 mN/m obtained by the above-mentioned "(production of SiO ₂ substrate)" using an ink jet discharge apparatus, respectively. A SiO ₂ substrate and a SiN substrate having a surface free energy of 58.0 mN/m obtained by the above-mentioned "(production of SiN substrate)". As an ink jet ejection device, NanoPrinter 500 (manufactured by MICROJET Corporation) was used, and the sealing agent was ejected at 25° C., droplet volume of 10 pL, pitch of 800 μm, and height of 0.5 mm from the substrate, and the frequency was 20 kHz. conditions. About 10 seconds after the droplet of the sealant was applied, the image read by the substrate observation camera of the contact angle meter was measured using image processing software, and the obtained contact angle with respect to each substrate was shown in the table. 1, 2. As the contact angle meter, CAM200 (manufactured by KSV INSTRUMENTS) was used, and as the image processing software, CAM2008 was used.

Table 1, Table 1, Table 1, 2.

Moreover, about each sealing compound for organic electroluminescent display elements obtained by the Example and the comparative example, the surface tension measured by the Wilhelmy method at 25 degreeC is shown in Tables 1 and 2. As the surface tensiometer, DY-300 (manufactured by Kyowa Interface Science Co., Ltd.) was used.

Furthermore, Tables 1 and 2 show the viscosities obtained by measuring each of the sealing compounds for organic EL display elements obtained in Examples and Comparative Examples under the conditions of 25° C. and 100 rpm using an E-type viscometer.

As the E-type viscometer, VISCOMETER TV-22 (manufactured by Toki Sangyo Co., Ltd.) was used.

<Evaluation>

The following evaluation was performed about each sealing compound for organic electroluminescent display elements obtained by the Example and the comparative example. The results are shown in Tables 1 and 2.

(1) Wetting spreadability

Using an ink jet ejection device, the surface free energy obtained in the above "(Preparation of SiO ₂ substrate)" was 73.0 mN/m with a droplet volume of 10 pL, a pitch of 48 μm, and an area of 8 cm × 8 cm. The SiO ₂ substrate was coated with each of the sealants for organic EL display elements obtained in Examples and Comparative Examples. As an ink jet ejection apparatus, NanoPrinter 500 (manufactured by MICROJET) was used. The sealant on the substrate 3 minutes after coating was visually observed, and the number of uncoated portions in which wetting and spreading did not occur and showed streaks was confirmed.

The case where the number of stripe-shaped uncoated parts was 0 was marked as "⊚", the case where it was 1 or more and less than 2 was marked as "○", and the case where it was 2 or more and less than 5 was marked. The case where five or more pieces were set as "△" was marked with "X", and the wet spreadability was evaluated.

(2) Foreign body coverage

Using a spreader, silicon nitride particles and silicon dioxide particles were spread on the SiO ₂ substrate having a surface free energy of 73.0 mN/m obtained in the above-mentioned "(Preparation of SiO ₂ substrate)". As the silicon nitride particles, SN-E10 (manufactured by Ube Industries, Ltd.) was used, and as the silica particles, SEAHOSTAR (manufactured by Nippon Shokubai Corporation) was used. Using an ink jet ejection apparatus, each of the organic EL display element sealants obtained in the Examples and Comparative Examples was applied to the obtained SiO ₂ substrate at a droplet volume of 10 pL, a pitch of 48 μm, and an area of 8 cm×8 cm. . As an ink jet discharge apparatus, NanoPrinter 500 (manufactured by MICROJE Corporation) was used. After 3 minutes from the coating, irradiation was performed with a 395 nm UV LED with an illuminance of 1000 mW/cm ² so that the cumulative light amount would reach 1000 mJ/cm ² , and the scattered silicon nitride particles and silica particles were recognized as foreign matter, and it was confirmed that The number of pinholes per 10 foreign objects randomly extracted.

The case where the number of pinholes per 10 foreign objects is 0 is marked as "◎", the case where it is more than 1 and less than 2 is marked as "○", and the case where there are more than 2 and less than 3 is marked as For "Δ", three or more cases were marked as "x", and the foreign matter coverage was evaluated. In addition, about the sample which could not be evaluated due to poor wetting and spreading, it was described as "-".

(3) Reliability of organic EL display elements

(3-1) Preparation of a substrate on which a laminate having an organic light-emitting material layer is arranged

的方式成膜有ITO电极的产物设为基板。将上述基板用丙酮、碱水溶液、离子交换水和异丙醇分别超声波清洗15分钟后，用煮沸了的异丙醇清洗10分钟，进而，利用UV-臭氧清洁器进行前处理。作为UV-臭氧清洁器，使用了NL-UV253(日本激光电子公司制)。It will reach the thickness of 25mm in length, 25mm in width and 0.7mm in thickness of glass.

The product formed with the ITO electrode in the manner of filming is set as the substrate. The substrates were ultrasonically cleaned with acetone, aqueous alkaline solution, ion-exchanged water, and isopropanol for 15 minutes, respectively, and then cleaned with boiled isopropanol for 10 minutes, and further pretreated with a UV-ozone cleaner. As the UV-ozone cleaner, NL-UV253 (manufactured by Nippon Laser Electronics Co., Ltd.) was used.

的蒸镀速度堆积至基板，成膜为膜厚

的空穴运输层。接着，将装有Alq₃的坩埚进行加热，以

的蒸镀速度成膜为膜厚

的有机发光材料层。其后，将形成有空穴运输层和有机发光材料层的基板转移至具有钨制电阻加热舟的另一真空蒸镀装置中，向真空蒸镀装置内的一个钨制电阻加热舟中装入氟化锂200mg，向另一个钨制电阻加热舟中装入铝线1.0g。其后，将真空蒸镀装置的蒸镀器内减压至2×10^-4Pa为止，将氟化锂以

的蒸镀速度成膜为

后，将铝以

的速度成膜为

利用氮气使蒸镀器内恢复至常压，取出配置有具有10mm×10mm的有机发光材料层的层叠体的基板。Next, the pretreated substrate was fixed to the substrate holder of the vacuum vapor deposition apparatus, and N,N'-bis(1-naphthyl)-N,N'-diphenylbenzidine (α) was put into the bisque-fired crucible. 200 mg of -NPD), 200 mg of tris(8-hydroxyquinoline)aluminum (Alq ₃ ) was put into another biscuit-fired crucible, and the pressure in the vacuum chamber was reduced to 1×10 ^-4 Pa. After that, the crucible containing α-NPD was heated so that α-NPD was

The deposition rate of the deposition to the substrate, the film thickness is

the hole transport layer. Next, the crucible containing Alq ₃ was heated to

The evaporation rate of film formation is the film thickness

the organic light-emitting material layer. After that, the substrate on which the hole transport layer and the organic light-emitting material layer were formed was transferred to another vacuum evaporation device with a resistance heating boat made of tungsten, and loaded into one resistance heating boat made of tungsten in the vacuum evaporation device. 200 mg of lithium fluoride and 1.0 g of aluminum wire were placed in another resistance heating boat made of tungsten. After that, the inside of the vapor deposition device of the vacuum vapor deposition apparatus was depressurized to 2×10 ^-4 Pa, and lithium fluoride was

The evaporation rate of film formation is

After that, the aluminum is

The speed of film formation is

The inside of the vapor deposition device was returned to normal pressure with nitrogen gas, and the substrate on which the laminate having the organic light-emitting material layer of 10 mm×10 mm was arranged was taken out.

(3-2) Covering by Inorganic Material Film A

A mask having an opening of 13 mm×13 mm was provided so as to cover the entire laminate in the obtained substrate on which the laminate was arranged, and the inorganic material film A was formed by the plasma CVD method. The plasma CVD method was performed under the following conditions: SiH ₄ gas and nitrogen gas were used as raw material gases, the flow rates of SiH ₄ gas were 10 sccm and nitrogen gas was 200 sccm, the RF power was 10 W (frequency: 2.45 GHz), and the cavity was The room temperature was set to 100°C, and the pressure in the chamber was set to 0.9 Torr. The thickness of the formed inorganic material film A was about 1 μm.

(3-3) Formation of Resin Protective Film

About the obtained board|substrate, each sealant for organic EL display elements obtained by the Example and the comparative example was pattern-coated on the board|substrate using an inkjet discharge apparatus. As an ink jet ejection apparatus, NanoPrinter 500 (manufactured by MICROJET) was used. Then, the ultraviolet-ray of wavelength 365nm of 3000mJ/cm< ² > was irradiated using an LED lamp, and the sealing compound for organic electroluminescent display elements was hardened, and the resin protective film was formed.

(3-4) Covering by Inorganic Material Film B

After the resin protective film was formed, a 12 mm×12 mm mask with openings was provided so as to cover the resin protective film, and an inorganic material film B was formed by plasma CVD to obtain an organic EL display element. The plasma CVD method is carried out under the same conditions as the above-mentioned "(3-2) Covering by the inorganic material film A". The thickness of the formed inorganic material film B was about 1 μm.

(3-5) Light-emitting state of organic EL display element

After the obtained organic EL display element was exposed to an environment with a temperature of 85° C. and a humidity of 85% for 100 hours, a voltage of 3 V was applied, and the light-emitting state of the organic EL display element (the presence or absence of dark spots and pixel peripheral extinction) was visually observed. ).

The case where there is no dark spot and peripheral extinction and uniform light emission is marked as "○", the case where a slight decrease in brightness is observed although there is no dark spot and peripheral extinction is marked as "△", and the case where dark spot and peripheral extinction are observed The reliability of the organic EL display element was evaluated as "x".

(4) uneven surface

Using an ink jet ejection device, the surface free energy obtained in the above "(Preparation of SiO ₂ substrate)" was 73.0 mN/m with a droplet volume of 10 pL, a pitch of 48 μm, and an area of 8 cm × 8 cm. Each of the sealing compounds for organic EL display elements obtained in Examples 6 and 7 and Comparative Examples 1 and 2 was coated on a SiO ₂ substrate. As an ink jet ejection apparatus, NanoPrinter 500 (manufactured by MICROJET) was used. About the sealing compound on the board|substrate 3 minutes after application|coating, the ultraviolet-ray of wavelength 365nm of 3000mJ/cm< ² > was irradiated using an LED lamp, and the sealing compound was hardened. The height of the convex portion was measured on the cured sealant with a surface roughness measuring device, a 2CR filter and a stylus of R2 μm, and a feeding speed of 0.2 mm/s in accordance with JIS1982. As a surface roughness measuring instrument, SE300 (manufactured by Kosaka Laboratory) was used. The height of the convex portion was confirmed by setting the concave portion on the surface to zero.

The case where the height of the convex portion is less than 0.5 μm is written as “⊚”, the case where it is 0.5 μm or more and less than 1.0 μm is written as “○”, and the case where it is 1.0 μm or more and less than 1.5 μm is written as “△”, When the height was 1.5 μm or more, “×” was used to evaluate the surface unevenness. In addition, about the sample which did not perform the evaluation of surface unevenness, it described as "-".

[Table 1]

[Table 2]

Industrial Availability

ADVANTAGE OF THE INVENTION According to this invention, the sealing compound for organic electroluminescent display elements which is excellent in coatability with respect to a board|substrate and an inorganic material film can be provided even when thinning.

Claims (4)

1. A sealant for an organic EL display element, comprising a curable resin and a polymerization initiator, The sealing agent for organic EL display elements has a surface tension of 25 mN/m or more and 38 mN/m or less at 25° C., and has a surface free energy of 70 mN/m or more and 80 mN/m or less. SiO ₂ substrate and surface free energy The contact angles at 25° C. of SiN substrates that can be 50 mN/m or more and 60 mN/m or less are all 13 degrees or less. 2 . The sealing compound for organic EL display elements according to claim 1 , which has a viscosity at 25° C. of 5 mPa·s or more and 30 mPa·s or less. 3 . 3. A sealant for organic EL display elements, which is a sealant for organic EL display elements used in coating by an inkjet method, It contains curable resin and polymerization initiator, The sealing agent for organic EL display elements has a surface tension of 25 mN/m or more and 38 mN/m or less at 25° C., and has a surface free energy of 70 mN/m or more and 80 mN/m or less. SiO ₂ substrate and surface free energy The contact angles at 25° C. of SiN substrates that can be 50 mN/m or more and 60 mN/m or less are all 13 degrees or less. 4 . The sealant for organic EL display elements according to claim 1 , wherein the solubility parameter of the entire curable resin is 16.5 (J/cm ³ ) ^1/2 or more and 19.5 (J/cm ³ ). 5 . ^1/2 or less.