JP2007302886A - Organic electronic material and organic electronic device and organic electroluminescent device using the material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic electronic material which can be suitably used for forming a multi-layered device with ease and an organic electronic device and an organic electroluminescent device having improved luminescent efficiency and life. <P>SOLUTION: The organic electronic material contains a compound having an epoxy group or an oxetane group and a polymer expressed by general formula (1). In the formula, Ar<SB>1</SB>and Ar<SB>2</SB>are each independently an arylene group, a heteroarylene group or a triphenylamine derivative; l and m are each independently an integer of 0 or more and l+m≥1. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a material for organic electronics, an organic electronics element using the same, and an organic electroluminescence element (hereinafter referred to as an organic EL element).

  Organic electronics elements are elements that perform electrical operations using organic substances, and are expected to exhibit features such as energy saving, low cost, and flexibility. ing.

  Among organic electronics elements, organic EL elements are attracting attention as applications for large-area solid-state light sources as an alternative to incandescent lamps and gas-filled lamps, for example. It is also attracting attention as the most powerful self-luminous display that can replace the liquid crystal display (LCD) in the flat panel display (FPD) field, and its commercialization is progressing.

  Organic EL elements are roughly classified into two types, low molecular organic EL elements and polymer organic EL elements, depending on the materials and film forming methods used. High-molecular organic EL elements are composed of high-molecular materials, and can be used for simple film formation such as printing and ink-jet compared to low-molecular organic EL elements that require vacuum-based film formation. Therefore, it is an indispensable element for future large-screen organic EL displays.

  Although research has been conducted energetically for both low-molecular organic EL elements and high-molecular organic EL elements, low luminous efficiency and short element lifetime are still serious problems. As one means for solving this problem, multilayering is performed in the low molecular organic EL element.

  FIG. 1 shows an example of a multilayered organic EL element. In FIG. 1, the layer responsible for light emission is referred to as a light emitting layer 1, and the layer in contact with the anode 2 is referred to as a hole injection layer 3 and the layer in contact with the cathode 4 is referred to as an electron injection layer 5. Furthermore, when a different layer exists between the light emitting layer 1 and the hole injection layer 3, it is described as a hole transport layer 6, and when a different layer exists between the light emitting layer 1 and the electron injection layer 5, an electron transport is described. It is described as layer 7. In FIG. 1, 8 is a substrate.

  Since the low molecular organic EL element is formed by vapor deposition, multilayering can be easily achieved by performing vapor deposition while sequentially changing the compounds to be used. On the other hand, since a polymer type organic EL element is formed using a wet process such as printing or ink jetting, in order to make a multilayer, a layer already formed is not changed when a new layer is formed. A method is needed.

  In fact, most polymer type organic EL devices use a hole injection layer made of polythiophene: polystyrene sulfonic acid (PEDOT: PSS), which is formed using an aqueous dispersion, and an aromatic organic solvent such as toluene. Most devices have a two-layer structure of light emitting layers for film formation. In this case, since the PEDOT: PSS layer is not dissolved in toluene, a two-layer structure can be produced.

The reason why it is difficult to further increase the number of layers in the polymer organic EL element is that the lower layer dissolves when lamination is performed with a similar solvent. In order to cope with this problem, an element having a three-layer structure using compounds having greatly different solubilities has been proposed (for example, see Non-Patent Document 1). In addition, a device having a three-layer structure having a hole transport layer utilizing a photocuring reaction (see, for example, Non-Patent Document 2) and a device having a three-layer structure having a hole transport layer utilizing a crosslinking reaction of a siloxane compound ( For example, see Non-Patent Document 3). Although these are important techniques, there are problems that materials that can be used are limited from the viewpoint of solubility, and that siloxane compounds are unstable to moisture in the air, and the device characteristics are not sufficient.
Y. Goto, T .; Hayashida, M .; Noto, IDW '04 Proceedings of The 11th International Display Workshop, 1343-1346 (2004) Daisuke Kumaki, Kengo Hirose, Nobuaki Koike, Satoshi Kuriyama, Shizuka Tokito, Organic EL Discussion Group (2005) 1st Regular Meeting Proceedings, P27 H. Yan, P.M. Lee, N.M. R. Armstrong, A.M. Graham, G.M. A. Evmenenko, P.M. Dutta, T.A. J. et al. Marks, J.A. Am. Chem. Soc. , 127, 3172-4183 (2005)

  In order to increase the efficiency and extend the life of organic EL elements, it is desirable to make the organic layers multi-layered and to separate the functions of each layer. In order to make an organic layer into a multilayer by using a wet process that facilitates film formation, it is necessary to prevent the lower layer from being dissolved during the formation of the upper layer.

  An object of this invention is to provide the material for organic electronics which can be easily multilayered in view of the above-mentioned problem. Furthermore, an object of the present invention is to provide an organic electronics element and an organic EL element having light emission efficiency and light emission lifetime superior to those of the prior art.

  As a result of intensive studies, the inventors have found that a mixture containing a compound having an epoxy group or an oxetane group and a specific polymer can form a thin film stably and easily, and the solubility is changed by light irradiation. Furthermore, this mixture was found to be useful as a material for organic electronics, and this research was completed.

  That is, the present invention is characterized by the following items <1> to <7>.

（式中、Ａｒ_１及びＡｒ_２は、各々独立にアリーレン基もしくはヘテロアリーレン基またはトリフェニルアミン誘導体を表し、ｌおよびｍは各々独立に０以上の整数を表し、ｌ＋ｍ≧１である。） <1> An organic electronic material comprising a compound having an epoxy group or an oxetane group and a polymer represented by the following general formula (1).

(In the formula, Ar ₁ and Ar ₂ each independently represent an arylene group, a heteroarylene group, or a triphenylamine derivative, and l and m each independently represent an integer of 0 or more, and l + m ≧ 1.)

（式中、Ａｒ_１、Ａｒ_２およびＡｒ_３は各々独立にアリーレン基もしくはヘテロアリーレン基、トリフェニルアミン誘導体を表し、Ｚは単結合、酸素原子、エステル基、炭素数１〜３０のアルキレン基、炭素数６〜３０のアリーレン基、オキシアリーレン基、ヘテロアリーレン基を表し、Ｅは置換されていてもよいエポキシ基もしくはオキセタン基を表し、ｌおよびｍは各々独立に０以上の整数を表し、ｌ＋ｍ≧１であり、ｎは１以上の整数を表す。） <2> The organic electronics material according to <1>, wherein the polymer includes a crosslinkable polymer represented by the following general formula (2).

(In the formula, Ar ₁ , Ar ₂ and Ar ₃ each independently represent an arylene group or a heteroarylene group or a triphenylamine derivative, Z represents a single bond, an oxygen atom, an ester group, an alkylene group having 1 to 30 carbon atoms, Represents an arylene group having 6 to 30 carbon atoms, an oxyarylene group, or a heteroarylene group, E represents an optionally substituted epoxy group or oxetane group, l and m each independently represents an integer of 0 or more, and l + m ≧ 1 and n represents an integer of 1 or more.)

  <3> The organic electronics material according to <1> or <2>, further including a photoinitiator.

  <4> An organic electronics element produced using the organic electronics material according to any one of <1> to <3>.

  <5> An organic electroluminescent device produced using the organic electronics material according to any one of <1> to <3>.

  <6> An organic electroluminescence device comprising at least an anode, a light emitting layer, and a cathode, wherein the layer containing the organic electronics material according to any one of the above <1> to <3> An organic electroluminescence element having a light emitting layer.

  <7> An organic electroluminescent element formed by laminating at least an anode, a hole injection layer, a light emitting layer, and a cathode, the layer containing the organic electronics material according to any one of <1> to <3> above An organic electroluminescence device having a hole injection layer and a light emitting layer.

  The material for organic electronics of the present invention can form a thin film stably and easily, and the solubility is changed by light irradiation. Therefore, the organic thin film layer can be easily multi-layered. In particular, it is a material that is extremely useful in improving the light emission efficiency, light emission lifetime, and productivity of the polymer organic EL device.

（式中、Ａｒ_１及びＡｒ_２は、各々独立にアリーレン基もしくはヘテロアリーレン基、またはトリフェニルアミン誘導体を表し、ｌおよびｍは各々独立に０以上の整数を表し、ｌ＋ｍ≧１である。） The material for organic electronics of the present invention is characterized by containing a compound having an epoxy group or an oxetane group and a polymer represented by the following general formula (1).

(In the formula, Ar ₁ and Ar ₂ each independently represent an arylene group, a heteroarylene group, or a triphenylamine derivative, and l and m each independently represent an integer of 0 or more, and l + m ≧ 1.)

Here, in the present invention, the arylene group is an atomic group obtained by removing two hydrogen atoms from an aromatic hydrocarbon, and the heteroarylene group is obtained by removing two hydrogen atoms from an aromatic compound having a hetero atom. It is an atomic group. The arylene group and heteroarylene group may be substituted or unsubstituted. Examples of the arylene group include phenylene, biphenyl-diyl, terphenyl-diyl, naphthalene-diyl, anthracene-diyl, tetracene-diyl, fluorene-diyl, phenanthrene-diyl, and examples of the heteroarylene group include Pyridine-diyl, pyrazine-diyl, quinoline-diyl, isoquinoline-diyl, acridine-diyl, phenanthroline-diyl, furan-diyl, pyrrole-diyl, thiophene-diyl, oxazole-diyl, oxadiazole-diyl, thiadiazole-diyl, Examples include triazole-diyl, benzoxazole-diyl, benzooxadiazole-diyl, benzothiadiazole-diyl, benzotriazole-diyl, and benzothiophene-diyl. . Examples of the arylene group or heteroarylene group which may be substituted or unsubstituted are shown in the following structural formulas (1) to (30).

The substituents R of the arylene group or heteroarylene group in the above structural formula are each independently —R ¹ , —OR ² , —SR ³ , —OCOR ⁴ , —COOR ⁵ or SiR ⁶ R ⁷ R ⁸ (where R ¹ to R ⁸ represents a hydrogen atom, a substituent selected from the group consisting of linear 1 to 22 carbon atoms, represent a cyclic or branched alkyl group or having 6 to 30 carbon atoms aryl or heteroaryl group) Each of them may be the same or different and each is a substituent bonded to a substitutable position of an arylene or heteroarylene skeleton. Among these substituents, each R is independently an unsubstituted group, that is, a hydrogen atom, or a group directly substituted by an alkyl group, aryl group, or heteroaryl group represented by -R ¹ , —OR ² , a hydroxyl group, an alkoxy group, an aryloxy group, and a heteroaryloxy group are preferable from the viewpoints of polymerization reactivity and heat resistance. In the structural formulas (29) and (30), l, m, and n are integers from 1 to 5, and are preferably integers from 2 to 4. In addition, when the organic electronics material of the present invention is used for a hole transport layer or a hole injection layer of an organic EL element, in order to efficiently confine electrons in the light emitting layer and improve the light emission efficiency, It is desirable that the hole injection layer has a high LUMO level. From this viewpoint, the above structural formulas (29) and (30) having a polycyclic structure are more preferable.

  In the present invention, the triphenylamine derivative is not particularly limited as long as it has a substituted or unsubstituted triphenylamine skeleton. For example, triphenylamine, N- (4-butylphenyl)- N, N-diphenylamine, N, N′-diphenyl-N, N′-bis (3-methylphenyl)-[1,1′-biphenyl] -4,4′-diamine, N, N′-bis (3 -Methylphenyl-N, N′-bis (2-naphthyl)-[1,1′-biphenyl] -4,4′-diamine, etc. In addition, the aromatic ring of these triphenylamine derivatives Examples of the substitutable group include an alkyl group having 1 to 22 carbon atoms and an alkoxy group.

When the organic electronics material of the present invention is used for a hole injection layer and a hole transport layer of an organic EL device, it is preferable that the monomer unit Ar ₁ and / or Ar _{2 of the} polymer is a triphenylamine derivative. Particularly preferred are triphenylamine derivatives having the structures of the above structural formulas (29) and (30). The molar fraction of the triphenylamine derivative in the total number of monomer units is preferably 1 to 99%, more preferably 10 to 90%, and most preferably 25 to 75%. If the molar fraction of the triphenylamine derivative is less than 1%, the light emission efficiency of the organic EL device tends to decrease, and if it exceeds 99%, the solubility in an organic solvent tends to decrease, making it difficult to prepare a coating solution. There is.

  Moreover, it is preferable that the weight average molecular weights of the said polymer are 1,000-1,000,000, and it is preferable that it is 1,000-800,000. If it is less than 1,000, the film-forming ability tends to decrease, and if it exceeds 1,000,000, the solubility tends to decrease. In addition, said weight average molecular weight is a weight average molecular weight when measured in polystyrene conversion using gel permeation chromatography.

（式中、Ｘは、炭素数１〜２２のアルキル基、炭素数６〜３０個の、置換又は未置換のアリール基、ヘテロアリール基、アリーレン基、ヘテロアリーレン基、トリフェニルアミン誘導体を表し、ｐは１〜８の整数を表す。）

（式中、Ｘは、炭素数１〜２２のアルキル基、炭素数６〜３０個の、置換又は未置換のアリール基、ヘテロアリール基、アリーレン基、ヘテロアリーレン基、トリフェニルアミン誘導体を表し、ｑは１〜８の整数を表す。） The compound having an epoxy group or oxetane group contained in the organic electronics material of the present invention may be a compound having at least one epoxy group or oxetane group which may be substituted. There may be no particular limitation. The compound having an epoxy group can be represented by the following general formula (3), and the compound having the oxetane group can be represented by the following general formula (4).

(In the formula, X represents an alkyl group having 1 to 22 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a heteroaryl group, an arylene group, a heteroarylene group, or a triphenylamine derivative; p represents an integer of 1 to 8.)

(In the formula, X represents an alkyl group having 1 to 22 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a heteroaryl group, an arylene group, a heteroarylene group, or a triphenylamine derivative; q represents an integer of 1 to 8.)

  The number of epoxy groups or oxetane groups (p, q in the above general formula) contained in one molecule of the compound having an epoxy group or oxetane group is preferably an integer of 1 to 8, and an integer of 1 to 4 Is more preferable, and 2 is most preferable. If the number of epoxy groups or oxetane groups is too large, the electrical characteristics tend to be lowered, and if too small, lamination tends to be difficult.

（式中、Ｅは置換されていてもよいエポキシ基又はオキセタン基を表し、Ｚは単結合、酸素原子、エステル基、炭素数１〜３０のアルキレン基、炭素数６〜３０のアリーレン基、オキシアリーレン基、ヘテロアリーレン基を表す。） When the organic electronics material of the present invention is used for a hole injection layer or a hole transport layer of an organic EL device, the compound having an epoxy group or an oxetane group is represented by the above general formula (3) or the following general formula ( 4) X is preferably a triphenylamine derivative, more preferably a compound represented by the following general formula (5) or (6).

(In the formula, E represents an optionally substituted epoxy group or oxetane group, Z represents a single bond, an oxygen atom, an ester group, an alkylene group having 1 to 30 carbon atoms, an arylene group having 6 to 30 carbon atoms, an oxy group) Represents an arylene group or a heteroarylene group.)

（式中、Ａｒ_１、Ａｒ_２およびＡｒ_３は各々独立にアリーレン基もしくはヘテロアリーレン基、トリフェニルアミン誘導体を表し、Ｚは単結合、酸素原子、エステル基、炭素数１〜３０のアルキレン基、炭素数６〜３０のアリーレン基、オキシアリーレン基、ヘテロアリーレン基を表し、Ｅは置換されていてもよいエポキシ基もしくはオキセタン基を表し、ｌおよびｍは各々独立に０以上の整数を表し、ｌ＋ｍ≧１であり、ｎは１以上の整数を表す。） Moreover, you may mix the crosslinkable polymer shown to following General formula (2) as said polymer used for the material for organic electronics of this invention. This crosslinkable polymer is a monomer having an epoxy group or an oxetane group in the monomer unit of the polymer represented by the general formula (1) (hereinafter referred to as a crosslinkable monomer unit, Ar ₃ -ZE in the following general formula (2). ).

(In the formula, Ar ₁ , Ar ₂ and Ar ₃ each independently represent an arylene group or a heteroarylene group or a triphenylamine derivative, Z represents a single bond, an oxygen atom, an ester group, an alkylene group having 1 to 30 carbon atoms, Represents an arylene group having 6 to 30 carbon atoms, an oxyarylene group, or a heteroarylene group, E represents an optionally substituted epoxy group or oxetane group, l and m each independently represents an integer of 0 or more, and l + m ≧ 1 and n represents an integer of 1 or more.)

  The crosslinkable polymer is a polymer copolymer containing one or more types of crosslinkable monomer units, and has a crosslinkable monomer unit at the end of the polymer main chain, even if it is present in the polymer main chain. Alternatively, it may be present in both the main chain and the terminal.

An example of the crosslinkable monomer unit when the crosslinkable polymer has a crosslinkable monomer unit in the polymer main chain is shown in the following general formula (8).

Moreover, the crosslinkable polymer which has a crosslinkable monomer unit at the terminal of a polymer principal chain is represented by the following general formula (7), for example. The crosslinkable monomer units at both ends may be the same or different.

An example of the crosslinkable monomer unit when the crosslinkable polymer has a crosslinkable monomer unit at the end of the polymer main chain is shown in the following general formula (9).

  In addition, each monomer unit in the crosslinkable polymer may be randomly included in the copolymer such as a so-called random copolymer, or a specific monomer unit may be partially included in the copolymer such as a block copolymer or a graft copolymer. It may be a copolymer that exists and exists. Each of the two monomer units constituting the copolymer may be a single monomer or a combination of two or more monomers. Moreover, the number of the epoxy group or oxetane group contained in a crosslinkable monomer unit should just be one or more, and is not specifically limited.

  In the crosslinkable polymer, the molar fraction of the crosslinkable monomer units in the total number of all monomer units is preferably 0.1 to 99.9%, more preferably 1 to 50%. Most preferred is ˜50%. If the molar fraction of the crosslinkable monomer unit is less than 0.1%, multilayering tends to be difficult, and if it exceeds 99.9%, the electrical characteristics tend to be lowered.

  The polymer used in the organic electronics material of the present invention can be produced by various synthetic methods known to those skilled in the art. For example, when producing a polymer in which each monomer unit has an aromatic ring and the aromatic rings are bonded to each other, T. Yamamoto et al. (Bull. Chem. Soc. Jap., Vol. 51). No. 7, p. 2091 (1978)) and M. Zembayashi et al. (Tet.lett., 47, 4089 (1977)) can be used. (Suzuki) et al. (Synthetic Communications, Vol. 11, No. 7, p. 513 (1981)) is generally used.

The reaction reported by Suzuki et al. Causes a Pd-catalyzed cross-coupling reaction (usually called the Suzuki reaction) between an aromatic boronic acid derivative and an aromatic halide. The polymer used in the present invention can be produced by using it for the reaction of bonding aromatic rings to each other. This reaction also requires soluble Pd compounds in the form of Pd (II) salts or Pd (0) complexes. Aromatic reactants of 0.01 to 5 mole percent based on _{Pd (Ph 3 P) 4,} Pd and tertiary phosphine ligands (OAc) 2 complex and PdCl ₂ (dppf) complex is generally preferred Pd sources. Furthermore, this reaction also requires a base, and it is most preferred to use an aqueous alkali carbonate or bicarbonate. Moreover, reaction can also be accelerated | stimulated in a nonpolar solvent using a phase transfer catalyst, N, N- dimethylformamide, toluene, dimethoxyethane, tetrahydrofuran etc. are mentioned as a solvent used at this time.

（式中、ＸはＳｂＦ_６、（Ｃ_６Ｆ_５）_４Ｂ、ＣＦ_３ＳＯ_３、ＰＦ_６、ＢＦ_４、Ｃ_４Ｆ_９ＳＯ_３、ＣＨ_３Ｃ_６Ｈ_４ＳＯ_３などを表す。） The material for organic electronics of the present invention may further contain a photoinitiator. The photoinitiator is not particularly limited as long as it exhibits the ability to polymerize an epoxy group or an oxetane group by irradiation with light of 200 to 800 nm. For example, a sulfonium salt as shown in the following general formula (10) , Iodonium salts, ferrocene derivatives, naphthaleneimide derivatives, and the like.

(In the formula, X represents SbF ₆ , (C ₆ F ₅ ) ₄ B, CF ₃ SO ₃ , PF ₆ , BF ₄ , C ₄ F ₉ SO ₃ , CH ₃ C ₆ H ₄ SO _3, etc.)

  Moreover, you may use together with the said photoinitiator the photosensitizer for improving photosensitivity. Examples of the photosensitizer include anthracene derivatives and thioxanthone derivatives.

  In the organic electronics material of the present invention, the proportion of the compound having an epoxy group or oxetane group is preferably 1 to 99%, more preferably 20 to 80%, more preferably 25 to 25% with respect to the total weight of the mixture. Most preferred is 50%. When the ratio of the compound having an epoxy group or oxetane group is too small, lamination becomes difficult, and when it is too large, film-forming stability tends to be lowered. The proportion of the polymer is preferably 1 to 99%, more preferably 20 to 80%, and most preferably 50 to 75% with respect to the total weight of the mixture. If the proportion of the polymer is too small, the device characteristics tend to deteriorate, and if it is too large, lamination tends to be difficult. Furthermore, the ratio of the photoinitiator is preferably 0.1 to 10%, more preferably 0.2 to 8%, and most preferably 1 to 5% with respect to the total weight of the mixture. preferable. Lamination may be difficult if the ratio of the photoinitiator is too small, and if it is too large, the device characteristics tend to deteriorate.

  The organic electronics material of the present invention can be used alone as a functional material of an organic electronics element. For example, the organic EL element can be used alone as a hole injection layer, a hole transport layer, an electron block layer, a light emitting layer, a positive layer, an organic EL element. It can be used as a hole block layer, an electron transport layer, an electron injection layer, or the like.

  Furthermore, it can be used for an organic electronics element or an organic EL element even when various additives are added. Examples of the additive include a metal complex containing a central metal such as Ir or Pt if used in a light emitting layer of an organic EL element, or a triphenylamine derivative if used in a hole injection layer or a hole transport layer. , Electron acceptors such as tetracyanoquinodimethane, and various oxidizing agents can be used.

  In order to form various layers (thin films) used for an organic electronics element or the like using the organic electronics material of the present invention, for example, a solution containing the organic electronics material of the present invention is used, for example, an inkjet method, a cast Coating on a desired substrate by a known method such as a printing method, immersion method, letterpress printing, intaglio printing, offset printing, flat plate printing, letterpress reverse printing, screen printing, gravure printing, and spin coating. This can be achieved by irradiation, or heat treatment after light irradiation or simultaneously with light irradiation. By repeating this, it is possible to increase the number of organic electronics elements and organic EL elements.

  The coating method as described above can be usually carried out at a temperature range of -20 to + 300 ° C, preferably 10 to 100 ° C, particularly preferably 15 to 50 ° C. Although not particularly limited, examples thereof include chloroform, methylene chloride, dichloroethane, tetrahydrofuran, toluene, xylene, mesitylene, anisole, acetone, methyl ethyl ketone, ethyl acetate, butyl acetate, and ethyl cellosolve acetate.

  For the light irradiation, a light source such as a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a metal halide lamp, a xenon lamp, a fluorescent lamp, a light-emitting diode, or sunlight can be used. Moreover, the said heat processing can be performed on a hotplate or in oven, and can be implemented at the temperature range of 0- + 300 degreeC, Preferably it is 20-250 degreeC, Most preferably, it is 80-200 degreeC.

  The organic electronics element and the organic EL element of the present invention may be provided with a layer containing the organic electronics material of the present invention, and the structure thereof is not particularly limited. The general structure of organic EL is disclosed in, for example, US Pat. No. 4,539,507, US Pat. No. 5,151,629, etc., and polymer-containing organic EL elements Is disclosed in, for example, International Publication No. WO 90/13148 and European Patent Publication No. 04384861. These usually include an electroluminescent layer (light-emitting layer) between a cathode (cathode) and an anode (anode) in which at least one of the electrodes is transparent. Furthermore, one or more electron injection layers and / or electron transport layers are inserted between the electroluminescent layer (light emitting layer) and the cathode, one or more hole injection layers and / or hole transport In some cases, a layer is inserted between the electroluminescent layer (light emitting layer) and the anode.

  The cathode material is preferably a metal or metal alloy such as Li, Ca, Mg, Al, In, Cs, Ba, Mg / Ag, LiF, and CsF. As an anode material, a metal (for example, Au) or other material having metal conductivity, for example, an oxide (for example, ITO: indium oxide / tin oxide) on a transparent substrate (for example, glass or transparent polymer). It can also be used.

  As described above, the material for organic electronics of the present invention can be used as a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and the like of an organic electronics element. Are preferably used as a hole injection layer, a hole transport layer, and a light emitting layer, more preferably used as a hole injection layer and a hole transport layer, and most preferably used as a hole transport layer. The thickness of these layers is not particularly limited, but is preferably 10 to 100 nm, more preferably 20 to 60 nm, and still more preferably 20 to 40 nm.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not restrict | limited to these.

(Crosslinking monomer synthesis example 1)
Tetrahydrofuran (50 ml), methyltriphenylphosphonium bromide (10 mmol) and potassium-t-butoxide (10 mmol) were added to the round bottom flask and stirred for 30 minutes in a nitrogen stream. 3,5-Dibromobenzaldehyde (10 mmol) was added thereto and stirred for 5 hours in a nitrogen stream. Next, water was added, extracted with ether, and purified by column chromatography to obtain 3,5-dibromostyrene.

  Thereafter, 3,5-dibromostyrene (5 mmol), chloroform (20 ml) and m-chloroperbenzoic acid (5 mmol) obtained above were added to the round bottom flask, and the mixture was stirred in a nitrogen stream for 3 hours. Further, water was added, the mixture was extracted with ether, and purified by column chromatography to obtain a crosslinkable monomer A.

(Crosslinkable polymer synthesis example 1)
A round bottom flask was charged with 4,4′-bis (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) -4 ″ -n-butyltriphenylamine (0.4 mmol). ), 2,7-dibromo-9,9-dioctylfluorene (0.2 mmol), crosslinkable monomer A (0.2 mmol) obtained above, tetrakistriphenylphosphine palladium (0.004 mmol), 2M aqueous potassium carbonate solution ( 10.6 mmol), Aliquat 336 (0.4 mmol), and toluene (7 ml) were added, and the mixture was stirred at 80 ° C. for 48 hours under a nitrogen atmosphere.

The reaction solution was poured into a methanol / water mixed solvent (9: 1), and the precipitated polymer was filtered off. The reprecipitation was repeated twice to purify and obtain a crosslinkable polymer A having the following structure. The molecular weight of the obtained polymer was 13200 in terms of polystyrene.

(Crosslinking monomer synthesis example 2)
3-ethyl-3-hydroxymethyloxetane (1 mol) and pyridine (300 mL) were placed in a round bottom flask. While cooling with ice, p-toluenesulfonic acid chloride (2 mol) was slowly added, and the mixture was further stirred at room temperature for 6 hours. The reaction solution was poured into 2 L of ice water, and the organic layer was separated. The organic layer was washed with water, dried over anhydrous magnesium sulfate, and the solvent was distilled off to give 3-ethyl-3- (p-toluenesulfonyloxymethyl) oxetane.

  Thereafter, 3-ethyl-3- (p-toluenesulfonyloxymethyl) oxetane (12 mmol), 4-iodophenol (10 mmol), and dimethylacetamide (10 mL) obtained above were placed in a round bottom flask. To this was added potassium hydroxide (12 mmol), and the mixture was heated with stirring at 90 ° C. for 6 hours. After cooling, the resulting inorganic salt was filtered off, ethyl acetate was added to the organic layer, and the mixture was washed with 1% acetic acid and water. After drying over anhydrous magnesium sulfate, the solvent was distilled off and purified by column chromatography to obtain a crosslinkable monomer B.

(Crosslinkable polymer synthesis example 2)
In a round bottom flask, 2,7-bis (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) -9,9-dioctylfluorene (0.41 mmol), 4,4 '-Dibromo-4''-n-butyltriphenylamine (0.4 mmol), tetrakistriphenylphosphine palladium (0.004 mmol), 2M aqueous potassium carbonate solution (10.6 mmol), Aliquat 336 (0.4 mmol) and toluene ( 7 ml) and stirred at 80 ° C. for 48 hours under a nitrogen atmosphere.

The crosslinkable monomer B (0.08 mmol) obtained above was added thereto, and the mixture was further stirred at 80 ° C. for 12 hours. The reaction solution was poured into a methanol / water mixed solvent (9: 1), and the precipitated polymer was filtered off. The reprecipitation was repeated twice to purify it to obtain a crosslinkable polymer B having the following structure. The molecular weight of the obtained polymer was 8300 in terms of polystyrene.

(Example of hole transport polymer synthesis)
In a round bottom flask, 2,7-bis (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) -9,9-dioctylfluorene (0.4 mmol), 4,4 '-Dibromo-4''-n-butyltriphenylamine (0.4 mmol), tetrakistriphenylphosphine palladium (0.004 mmol), 2M aqueous potassium carbonate solution (10.6 mmol), Aliquat 336 (0.4 mmol) and toluene ( 7 ml) and stirred at 80 ° C. for 48 hours under a nitrogen atmosphere.

  The reaction solution was poured into a methanol / water mixed solvent (9: 1), and the precipitated polymer was filtered off. Reprecipitation was repeated twice to purify, and hole transport polymer A was obtained. The molecular weight of the obtained polymer was 60,216 in terms of polystyrene.

(Example of light-emitting polymer synthesis)
A round bottom flask was charged with 4,4′-bis (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) -4 ″ -n-butyltriphenylamine (0.4 mmol). ), 4,4′-dibromo-triphenylamine (0.08 mmol), 4,7-dibromo-2,1,3-benzothiadiazole (0.32 mmol), tetrakistriphenylphosphine palladium (0.004 mmol), 2M An aqueous potassium carbonate solution (10.6 mmol), Aliquat 336 (0.4 mmol) and toluene (7 ml) were added, and the mixture was stirred at 80 ° C. for 48 hours under a nitrogen atmosphere.

  The reaction solution was poured into a methanol / water mixed solvent (9: 1), and the precipitated polymer was filtered off. The reprecipitation was repeated twice to purify it to obtain a yellow light emitting polymer.

<Production of organic EL element>
Example 1
A PEDOT: PSS dispersion (Stark Vitec, CH8000-LVW233) is spin-coated at 4000 min ⁻¹ on a glass substrate patterned with ITO (Indium Tin Oxide) to a width of 1.6 mm, and air is applied on a hot plate. A hole injection layer (40 nm) was formed by heating and drying at 200 ° C. for 10 minutes. Subsequent experiments were performed in a dry nitrogen environment.

Next, the hole transporting polymer A (25 mg) obtained above on the hole injection layer, the compound having an oxetane group represented by the following general formula (11) (25 mg), a photoinitiator (PHI-, manufactured by RHODORSIL) 2074, 0.5 mg) and toluene (29 ml) mixed solution is spin-coated at 3000 min ⁻¹ and irradiated with light with a metal halide lamp (irradiation amount 1 J / cm ² ), and 180 ° C. for 60 minutes on a hot plate. A hole transport layer (20 nm) was formed by heating.

Next, a toluene solution (1.5 wt%) of a yellow light emitting polymer is spin-coated on the hole transport layer at 3000 min ⁻¹ and heated on a hot plate at 80 ° C. for 5 minutes to form a light emitting layer (film thickness 100 nm). Formed. The hole transport layer and the light emitting layer could be laminated without dissolving each other.

  Furthermore, the glass substrate obtained above was transferred into a vacuum deposition machine, and Ba (film thickness: 3 nm) and Al (film thickness: 100 nm) were deposited in this order on the light emitting layer to form electrodes.

  After forming the electrode, the substrate is moved into a dry nitrogen environment without opening to the atmosphere, and a sealing glass obtained by adding 0.4 mm counterbore to 0.7 mm non-alkali glass and an ITO substrate are formed into a photocurable epoxy resin. Sealing was performed by laminating the film, and a polymer type organic EL device having a multilayer structure was produced. Subsequent experiments were performed in the atmosphere at room temperature (25 ° C.).

The ITO of the organic EL element cathode, a voltage was applied as a cathode Al, yellow light emission was observed at about 5V, at the best luminance 5000 cd / ^{m 2,} the current efficiency at a luminance of 3000 cd / ^{m 2} is 1.65cd / A there were. The current-voltage characteristics were measured with a microammeter 4140B manufactured by Hewlett-Packard, and the luminance was measured with SR-3 manufactured by Topcon.

In addition, as a lifetime characteristic, the luminance was measured with a Topcon BM-7 while applying a constant current of 0.5 mA, and the time when the luminance was reduced by half from the initial luminance (100 cd / m ² ) was measured. there were.

(Comparative Example 1)
An organic EL device was produced in the same manner as in Example 1 except that the hole transport layer was not formed. When this organic EL device was evaluated in the same manner as in Example 1, yellow light emission was observed at 5 V, and the current efficiency at a maximum luminance of 3000 cd / m ² and a luminance of 3000 cd / m ² was 1.21 cd / A. Example 1 was about 1.4 times more efficient. Moreover, the lifetime was 14 hours, and the life of Example 1 was 7 times longer.

(Comparative Example 2)
Oxetane represented by the following general formula (12) with reference to the literature (Daisuke Kumaki, Kengo Hirose, Nobuaki Koike, Satoshi Kuriyama, Shizushi Tokito, Proc. Except that a well-known hole transport layer was formed using a coating solution in which a compound having a group (25 mg), a photoinitiator (RHODORSIL, PI-2074, 0.25 mg) and THF (28 ml) were mixed. An organic EL device was produced in the same manner as in Example 1.

When this organic EL element was evaluated in the same manner as in Example 1, yellow light emission was observed at about 7 V, and the maximum luminance was 780 cd / m ² . Moreover, the lifetime was 1 hour, and the direction of Example 1 was 100 times longer.

(Example 2)
On a glass substrate patterned with a width of 1.6 mm of ITO, the coating solution used to form the hole transport layer in Example 1 was spin-coated at 3000 rpm, irradiated with light with a metal halide lamp (irradiation amount 1 J / cm ² ) and heated on a hot plate at 180 ° C. for 60 minutes to form a hole injection layer (40 nm). Subsequent experiments were performed in a dry nitrogen environment.

  Then, a light emitting layer made of a yellow light emitting polymer and a Ba / Al electrode are formed on the hole injection layer in the same manner as in Example 1 and sealed to form a polymer organic EL element having a multilayer structure. Was made. The hole injection layer and the light emitting layer could be laminated without dissolving each other.

This organic EL device was evaluated in the same manner as in Example 1, a yellow light emission was observed at about 6V, the current efficiency at the highest luminance 8300cd / ^{m 2,} luminance 3000 cd / ^{m 2} is an 2.11cd / A , PEDOT: PSS was 1.7 times more efficient than Comparative Example 1 using the hole injection layer. The lifetime was 150 hours, which was 10.7 times longer than that of Comparative Example 1.

(Comparative Example 3)
After forming the hole injection layer in the same manner as in Example 1, a toluene solution (0.5 weight percent) of the hole transport polymer A was spin-coated at 3000 rpm ⁻¹ and heated on a hot plate at 80 ° C. for 5 minutes. A hole transport layer (40 nm) was formed. Thereafter, in the same manner as in Example 1, a light emitting layer and electrodes were formed and sealed to produce an organic EL element. This organic EL device was evaluated in the same manner as in Example 1, a yellow light emission was observed at 5V, the maximum luminance 3200cd / ^{m 2,} the current efficiency at a luminance of 3000 cd / ^{m 2} is 1.25cd / A, lifetime Was 15 hours. In addition, since the hole transport layer was eluted during the spin coating of the light emitting layer, there was no significant difference from Comparative Example 2.

It is the schematic of the organic EL element laminated | stacked.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light emitting layer 2 Anode 3 Hole injection layer 4 Cathode 5 Electron injection layer 6 Hole transport layer 7 Electron transport layer 8 Substrate

Claims (7)

An organic electronics material comprising a compound having an epoxy group or an oxetane group and a polymer represented by the following general formula (1).

(In the formula, Ar ₁ and Ar ₂ each independently represent an arylene group, a heteroarylene group, or a triphenylamine derivative, and l and m each independently represent an integer of 0 or more, and l + m ≧ 1.) The material for organic electronics according to claim 1, comprising a crosslinkable polymer represented by the following general formula (2) as the polymer.

(In the formula, Ar ₁ , Ar ₂ and Ar ₃ each independently represent an arylene group or a heteroarylene group or a triphenylamine derivative, Z represents a single bond, an oxygen atom, an ester group, an alkylene group having 1 to 30 carbon atoms, Represents an arylene group having 6 to 30 carbon atoms, an oxyarylene group, or a heteroarylene group, E represents an optionally substituted epoxy group or oxetane group, l and m each independently represents an integer of 0 or more, and l + m ≧ 1 and n represents an integer of 1 or more.)   The material for organic electronics according to claim 1 or 2, further comprising a photoinitiator.   The organic electronics element produced using the organic electronics material in any one of Claims 1-3.   The organic electroluminescent element produced using the material for organic electronics in any one of Claims 1-3.   It is an organic electroluminescent element which laminates at least an anode, a light emitting layer, and a cathode, Comprising: The layer containing the material for organic electronics in any one of Claims 1-3 between the said anode and the said light emitting layer An organic electroluminescent device having the same.   It is an organic electroluminescent element formed by laminating at least an anode, a hole injection layer, a light emitting layer, and a cathode, and the layer containing the organic electronics material according to any one of claims 1 to 3 is defined as a hole injection layer. An organic electroluminescence element having a light emitting layer.

Images