JP5136795B2 - Electron-accepting material precursor comprising sulfonate compound and use thereof - Google Patents

Description

  The present invention relates to a sulfonic acid ester compound and use thereof, and more specifically, a sulfonic acid ester compound capable of forming a cyclic complex in a molecule, use of this compound as an electron-accepting substance, and use as a thermal acid generator. Regarding usage.

In low-molecular organic EL (hereinafter abbreviated as OLED) elements, by providing a copper phthalocyanine (CuPC) layer as a hole injection layer, it is possible to improve initial characteristics such as lower drive voltage and improved luminous efficiency, and further improve life characteristics. (Non-patent document 1: Applied Physics Letters, USA, 1996, 69, p. 2160-2162).
On the other hand, in an organic EL (hereinafter abbreviated as PLED) element using a polymer light emitting material, a polyaniline-based material (Patent Document 1: Japanese Patent Laid-Open No. 3-273877, Non-Patent Document 2: Nature, UK, 1992, 357, pp. 477-479) and a thin film made of a polythiophene-based material (Non-patent Document 3: Applied Physics Letters, USA, 1998, Vol. 72, pp. 2660-2661). It has been reported that the same effect as that of the OLED element can be obtained by using it as the hole transport layer.

In recent years, a charge transporting varnish consisting of a homogeneous solution in which a low molecular weight oligoaniline-based material or oligothiophene-based material is dissolved in an organic solvent has been found, and a hole injection layer obtained from this varnish is inserted into the organic EL device. By doing so, it has been reported that a flattening effect of the base substrate and excellent EL element characteristics can be obtained (Patent Document 2: JP 2002-151272 A, Patent Document 3: WO 2004-043117, Patent Document 4). : WO 2005-03962).
Furthermore, it has been reported that the driving voltage of an OLED element can be lowered by using a 1,4-benzodioxanesulfonic acid compound (Patent Document 5: WO2005-000832) as an electron-accepting substance.

However, since a sulfonic acid compound generally has low solubility in an organic solvent, the solvent to be used is easily limited when preparing an organic solution, and high solubility of N, N-dimethylacetamide, N-methylpyrrolidone and the like is high. It is necessary to use a polar organic solvent in a high ratio. An organic solution containing a high-polarity organic solvent in a high ratio may damage a part of an ink jet coating apparatus or an organic structure such as an insulating film and a partition formed on a substrate.
Moreover, since the sulfonic acid compound is highly polar, it is difficult to remove salts by operations such as purification by silica gel column chromatography, liquid separation extraction, and water washing.

On the other hand, sulfonic acid ester compounds are known as materials that have high solubility in various organic solvents and generate strong organic acids by external stimuli such as heating and chemical action.
As a specific example of a compound that generates sulfonic acid by heating, cyclohexyl ester of sulfonic acid or the like has been reported (Non-patent Document 4: Chemische Berichte, Germany, 1957, 90, p. 585-592. In recent years, this sulfonic acid ester has also attracted attention in the concept of a thermal acid proliferator (Patent Document 5: JP-A-7-134416, Non-Patent Document 5: Functional Materials, Japan, 2004, Vol. 24, p. 72-82).
However, in particular, a sulfonic acid ester substituted with an electron-deficient aromatic ring such as an aromatic disulfonic acid is likely to be decomposed by reaction with slight heat, water, a basic substance, etc., and has a high stability. Creation of ester compounds is desired.

JP-A-3-230787 JP 2002-151272 A International Publication No. 2004/043117 Pamphlet International Publication No. 2005/043962 Pamphlet International Publication No. 2005/000832 Pamphlet Applied Physics Letters, USA, 1996, 69, p. 2160-2162 Nature, UK, 1992, 357, p. 477-479 Applied Physics Letters, USA, 1998, 72, p. 2660-2662 Chemichet Berichte, Germany, 1957, 90, p. 585-592 Functional Materials, Japan, 2004, 24, p. 72-82

  The present invention has been made in view of such circumstances, and has high stability and high solubility in a wide range of organic solvents, so that it is easy to form a uniform solution, and an OLED element. An object of the present invention is to provide a sulfonic acid ester compound suitable as an electron-accepting substance or a thermal acid generator that makes it possible to realize excellent device characteristics when applied to the above.

  As a result of intensive studies in order to achieve the above object, the present inventors have found that a sulfonic acid ester compound having an atom capable of coordinating with a sulfur atom in an ester substituent forms a cyclic complex by coordination of the atom. In order to improve the electron density of the sulfur atom in the sulfonate ester, it inhibits side reactions caused by water and basic substances during the synthesis of the compound, and inhibits the thermal decomposition reaction and exhibits high stability. It has been found that it facilitates the synthesis and purification of certain sulfonate compounds and that the sulfonate compounds exhibit high solubility in a wide range of low polarity solvents. Furthermore, after forming this sulfonic acid ester compound on a thin film, by applying external stimuli such as heating, it has been found that it can act as a good electron accepting substance and can exhibit high charge transporting properties. Has been found to enable a low driving voltage of the device when used as a hole injection layer of an OLED device, and the present invention has been completed.

（式中、Ａは置換または非置換の芳香環基を示し、Ｘは置換または非置換の、炭素数２〜５のアルキレン基、炭素数１〜２アルキレンオキシ炭素数１〜２アルキレン基、炭素数１〜２アルキレンチオ炭素数１〜２アルキレン基、または炭素数１〜２アルキレンカルボニル炭素数１〜２アルキレン基を示し、ＹはＯ、Ｓ、または置換もしくは非置換の２価アミノ基を示し、Ｚは水素原子または置換もしくは非置換の一価炭化水素基を示す。）
２． 式（２）または式（２′）で表される１の電子受容性物質前駆体、

（式中、Ｒ¹〜Ｒ⁴は、それぞれ独立して、水素原子、炭素数１〜６のアルキル基、またはハロゲン原子を示し、Ａ²は置換基を有していてもよいアリーレン基を示す。ＡおよびＺは前記と同じ。）
３． 式（３）または式（４）で表されるスルホン酸エステル化合物からなることを特徴とする電子受容性物質前駆体、

（式中、Ａ′は（ＳＯ₃Ｈ）ｍ、Ｘ′および（ＳＯ₃−Ｘ−Ｙ−Ｚ）ｎ¹または（ＳＯ₃−Ｘ−Ｙ−Ｚ）ｎ²で置換されるとともに、非置換または置換の一価炭化水素基で置換されていてもよい芳香環基を示し、Ｘは置換または非置換の、炭素数２〜５のアルキレン基、炭素数１〜２アルキレンオキシ炭素数１〜２アルキレン基、炭素数１〜２アルキレンチオ炭素数１〜２アルキレン基、または炭素数１〜２アルキレンカルボニル炭素数１〜２アルキレン基を示し、ＹはＯ、Ｓ、または置換もしくは非置換の２価アミノ基を示し、Ｚは水素原子または置換もしくは非置換の一価炭化水素基を示し、Ｘ′は、Ｏ、ＳまたはＮＨを示し、Ｂは、置換もしくは非置換の炭化水素基、１，３，５−トリアジン基、または置換もしくは非置換の式（５）もしくは（６）

で示される基（式中、Ｗ¹およびＷ²は、それぞれ独立して、Ｏ、Ｓ、Ｓ（Ｏ）基、Ｓ（Ｏ₂）基、または非置換もしくは置換基が結合したＮ、Ｓｉ、Ｐ、Ｐ（Ｏ）基を示す。）を表し、ｑは、ＢとＸ′との結合数を示し、１≦ｑを満たす整数であり、ｒは繰り返し単位数を示し、１≦ｒを満たす整数であり、ｍは０以上の整数であり、ｎ¹は１以上の整数であり、ｎ²は１以上の整数である。なお、ｎ¹＋ｍは式（３）においてＡ′が許容する置換数以下を満たし、ｎ²＋ｍは式（４）においてＡ′の許容する置換数以下を満たす。）
４． 前記ｍが０である３の電子受容性物質前駆体、
５． 式（７）または式（８）で表されるスルホン酸エステル化合物からなることを特徴とする電子受容性物質前駆体、

（式中、Ｗは、置換または非置換の３価炭化水素基を示し、Ａ”は、置換もしくは非置換の２価芳香環基を示し、Ｘは置換または非置換の、炭素数２〜５のアルキレン基、炭素数１〜２アルキレンオキシ炭素数１〜２アルキレン基、炭素数１〜２アルキレンチオ炭素数１〜２アルキレン基、または炭素数１〜２アルキレンカルボニル炭素数１〜２アルキレン基を示し、ＹはＯ、Ｓ、または置換もしくは非置換の２価アミノ基を示し、Ｚは、水素原子または置換もしくは非置換の一価炭化水素基を示す。ｓは、２〜１０００００の整数を示す。ｔは、１〜１０００００の整数を示し、ｕは、１〜１０００００の整数を示し、ｔ＋ｕは、２〜１０００００を満たす。）
６． 式（９）または式（１０）で表される５の電子受容性物質前駆体、

（式中、Ｒ⁵〜Ｒ⁷は、それぞれ独立して、水素原子、非置換もしくは置換の一価炭化水素基、またはハロゲン原子を示す。Ａ”、Ｘ、Ｙ、Ｚ、ｓ、ｔおよびｕは、前記と同じ。）
７． 数平均分子量が、５０００〜１００００００である５または６の電子受容性物質前駆体、
８． 前記２価アミノ基が、Ｎ（ＣＨ₃）、Ｎ（Ｃ₂Ｈ₅）、またはＮ（Ｃ₃Ｈ₇）であり、前記Ｚの一価炭化水素基が、メチル基、エチル基またはｎ−プロピル基である１および３〜７のいずれかの電子受容性物質前駆体、
９． 式（３）で表されることを特徴とするスルホン酸エステル化合物、

（式中、Ａ′は（ＳＯ₃Ｈ）ｍ、Ｘ′および（ＳＯ₃−Ｘ−Ｙ−Ｚ）ｎ¹で置換されるとともに、非置換または置換の一価炭化水素基で置換されていてもよい芳香環基を示し、Ｘは置換または非置換の、炭素数２〜５のアルキレン基、炭素数１〜２アルキレンオキシ炭素数１〜２アルキレン基、炭素数１〜２アルキレンチオ炭素数１〜２アルキレン基、または炭素数１〜２アルキレンカルボニル炭素数１〜２アルキレン基を示し、ＹはＯ、Ｓ、または置換もしくは非置換の２価アミノ基を示し、Ｚは水素原子または置換もしくは非置換の一価炭化水素基を示し、Ｘ′は、Ｏ、ＳまたはＮＨを示し、Ｂは、置換もしくは非置換の炭化水素基、１，３，５−トリアジン基、または置換もしくは非置換の式（５）もしくは（６）

で示される基（式中、Ｗ¹およびＷ²は、それぞれ独立して、Ｏ、Ｓ、Ｓ（Ｏ）基、Ｓ（Ｏ₂）基、または非置換もしくは置換基が結合したＮ、Ｓｉ、Ｐ、Ｐ（Ｏ）基を示す。）を表し、ｑは、ＢとＸ′との結合数を示し、２≦ｑを満たす整数であり、ｍは０以上の整数であり、ｎ¹は１以上の整数である。なお、ｎ¹＋ｍはＡ′が許容する置換数以下を満たす。）
１０． 前記２価アミノ基が、Ｎ（ＣＨ₃）、Ｎ（Ｃ₂Ｈ₅）、またはＮ（Ｃ₃Ｈ₇）であり、前記Ｚの一価炭化水素基が、メチル基、エチル基またはｎ−プロピル基である９のスルホン酸エステル化合物、
１１． ９または１０のスルホン酸エステル化合物からなる酸発生剤、
１２． １〜８のいずれかの電子受容性物質前駆体を含む電荷輸送性ワニス、
１３． １〜８のいずれかの電子受容性物質前駆体を含む電荷輸送性薄膜、
１４． １２の電荷輸送性ワニスから得られる電荷輸送性薄膜、
１５． １２の電荷輸送性ワニスを基材上に塗布し、加熱することを特徴とする電荷輸送性薄膜の製造方法、
１６． １３または１４の電荷輸送性薄膜を備える有機エレクトロルミネッセンス素子
を提供する。
That is, the present invention
1. An electron-accepting substance precursor comprising a sulfonic acid ester compound represented by the formula (1),

(In the formula, A represents a substituted or unsubstituted aromatic ring group, X represents a substituted or unsubstituted alkylene group having 2 to 5 carbon atoms, 1 to 2 alkyleneoxy carbon atoms or 1 to 2 alkylene groups, carbon 1 to 2 alkylenethio represents a C1 to C2 alkylene group, or C1 to C2 alkylenecarbonyl represents a C1 to C2 alkylene group, and Y represents O, S, or a substituted or unsubstituted divalent amino group. Z represents a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group.)
2. 1 electron acceptor precursor represented by formula (2) or formula (2 ′),

(In the formula, R ^{1 to} R ⁴ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a halogen atom, and A ² represents an arylene group which may have a substituent. A and Z are the same as above.)
3. An electron-accepting substance precursor comprising a sulfonate compound represented by formula (3) or formula (4);

Wherein A ′ is substituted with (SO ₃ H) m, X ′ and (SO ₃ —XYZ) n ¹ or (SO ₃ —XYZ) n ² and is unsubstituted Or an aromatic ring group which may be substituted with a substituted monovalent hydrocarbon group, wherein X is a substituted or unsubstituted alkylene group having 2 to 5 carbon atoms, 1 to 2 alkyleneoxy carbon atoms or 1 to 2 carbon atoms; An alkylene group, a C1-C2 alkylenethio C1-C2 alkylene group, or a C1-C2 alkylenecarbonyl C1-C2 alkylene group is shown, Y is O, S, or substituted or unsubstituted bivalent. A represents an amino group, Z represents a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group, X ′ represents O, S or NH, B represents a substituted or unsubstituted hydrocarbon group, 1, 3 , 5-triazine group, or substituted or unsubstituted formula (5) (6)

Wherein W ¹ and W ² are each independently O, S, S (O) group, S (O ₂ ) group, or unsubstituted or substituted N, Si, P represents a P (O) group), q represents the number of bonds between B and X ′, is an integer satisfying 1 ≦ q, r is the number of repeating units, and satisfies 1 ≦ r It is an integer, m is an integer of 0 or more, n ¹ is an integer of 1 or more, and n ² is an integer of 1 or more. Note that n ¹ + m satisfies the number of substitutions allowed by A ′ in formula (3), and n ² + m satisfies the number of substitutions allowed by A ′ in formula (4). )
4). An electron acceptor precursor of 3 in which m is 0;
5. An electron-accepting substance precursor comprising a sulfonate compound represented by formula (7) or formula (8);

Wherein W represents a substituted or unsubstituted trivalent hydrocarbon group, A ″ represents a substituted or unsubstituted divalent aromatic ring group, and X represents a substituted or unsubstituted C 2-5 carbon atom. An alkylene group, an alkyleneoxy group having 1 to 2 carbon atoms, an alkylene group having 1 to 2 carbon atoms, an alkylene group having 1 to 2 carbon atoms, or an alkylene group having 1 to 2 carbon atoms. Y represents O, S, or a substituted or unsubstituted divalent amino group, Z represents a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group, and s represents an integer of 2 to 100,000. T represents an integer of 1 to 100,000, u represents an integer of 1 to 100,000, and t + u satisfies 2 to 100,000.)
6). 5 electron acceptor precursors represented by formula (9) or formula (10),

(Wherein R ^{5 to} R ⁷ each independently represents a hydrogen atom, an unsubstituted or substituted monovalent hydrocarbon group, or a halogen atom. A ″, X, Y, Z, s, t, and u) Is the same as above.)
7). 5 or 6 electron acceptor precursor having a number average molecular weight of 5,000 to 1,000,000,
8). The divalent amino group is N (CH ₃ ), N (C ₂ H ₅ ), or N (C ₃ H ₇ ), and the monovalent hydrocarbon group of Z is a methyl group, an ethyl group, or n- An electron acceptor precursor of any one of 1 and 3-7 which is a propyl group;
9. A sulfonic acid ester compound represented by the formula (3):

Wherein A ′ is substituted with (SO ₃ H) m, X ′ and (SO ₃ —XYZ) n ¹ and is substituted with an unsubstituted or substituted monovalent hydrocarbon group. X represents a substituted or unsubstituted alkylene group having 2 to 5 carbon atoms, an alkylene group having 1 to 2 carbon atoms, an alkylene group having 1 to 2 carbon atoms, or an alkylenethio group having 1 to 2 carbon atoms. Represents an alkylene group, or an alkylenecarbonyl group having 1 to 2 carbon atoms, Y represents O, S, or a substituted or unsubstituted divalent amino group, and Z represents a hydrogen atom or a substituted or non-substituted group. Represents a substituted monovalent hydrocarbon group, X ′ represents O, S or NH, B represents a substituted or unsubstituted hydrocarbon group, 1,3,5-triazine group, or a substituted or unsubstituted formula; (5) or (6)

Wherein W ¹ and W ² are each independently O, S, S (O) group, S (O ₂ ) group, or unsubstituted or substituted N, Si, P represents a P (P) group), q represents the number of bonds between B and X ′, is an integer satisfying 2 ≦ q, m is an integer of 0 or more, and n ¹ is 1 It is an integer above. Note that n ¹ + m satisfies the number of substitutions allowed by A ′. )
10. The divalent amino group is N (CH ₃ ), N (C ₂ H ₅ ), or N (C ₃ H ₇ ), and the monovalent hydrocarbon group of Z is a methyl group, an ethyl group, or n- 9 sulfonic acid ester compounds which are propyl groups,
11. An acid generator comprising 9 or 10 sulfonic acid ester compounds;
12 A charge transporting varnish comprising any of the electron acceptor precursors 1 to 8;
13. A charge transporting thin film comprising any one of the electron acceptor precursors 1 to 8;
14 A charge transporting thin film obtained from 12 charge transporting varnishes;
15. 12 charge transporting varnishes are coated on a substrate and heated, a method for producing a charge transporting thin film,
16. An organic electroluminescent device comprising 13 or 14 charge transporting thin films is provided.

The sulfonic acid ester compound of the present invention has high stability to heat and water and exhibits high solubility in a wide range of organic solvents including low polar solvents. Even if the ratio is decreased, the charge transporting varnish can be prepared. As described above, the sulfonic acid ester compound of the present invention has a wider range of applicable solvents when used as a charge transporting varnish than conventional sulfonic acid compounds, so that it is easier to produce an amorphous solid thin film having high flatness. Become.
Moreover, since the thin film obtained from the sulfonate compound of the present invention exhibits high charge transportability, the drive voltage of the organic EL device can be lowered when used as a hole injection layer or a hole transport layer. . By utilizing the high flatness and high charge transport property of this thin film, it can be applied to a positive hole transport layer of a solar cell, a fuel cell electrode, a capacitor electrode protective film, and an antistatic film.
Furthermore, since the sulfonic acid ester compound of the present invention also has a function as a thermal acid generator or a cation conductive material, it can be applied to resist auxiliary materials, ion conductive membranes, and solid electrolytes.

Hereinafter, the present invention will be described in more detail.
The first sulfonic acid ester compound according to the present invention is represented by the following formula (1).

  In the formula (1), A represents a substituted or unsubstituted monovalent hydrocarbon group, and specific examples thereof include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i- Alkyl groups such as butyl group, t-butyl group, n-hexyl group, n-octyl group, 2-ethylhexyl group and decyl group; cycloalkyl groups such as cyclopentyl group and cyclohexyl group; bicycloalkyl groups such as bicyclohexyl group; Alkenyl groups such as vinyl group, 1-propenyl group, 2-propenyl group, isopropenyl group, 1-methyl-2-propenyl group, 1 or 2 or 3-butenyl group, hexenyl group; phenyl group, xylyl group, tolyl group Aromatic ring groups (aryl groups) such as biphenyl group and naphthyl group; aralkyl groups such as benzyl group, phenylethyl group and phenylcyclohexyl group; Some or all of the hydrogen atoms of these groups are further hydroxyl groups, amino groups, silanol groups, thiol groups, carboxyl groups, sulfonate groups, phosphate groups, phosphate ester groups, ester groups, thioester groups, amide groups. Nitro group, monovalent hydrocarbon group, organooxy group, organoamino group, organosilyl group, organothio group, acyl group, sulfone group, halogen atom and the like.

Here, examples of the halogen atom include fluorine, chlorine, bromine and iodine atoms.
Specific examples of the organooxy group include an alkoxy group, an alkenyloxy group, and an aryloxy group. These alkyl groups, alkenyl groups, and aryl groups include the same substituents as exemplified above. .
Specific examples of the organoamino group include methylamino group, ethylamino group, propylamino group, butylamino group, pentylamino group, hexylamino group, heptylamino group, octylamino group, nonylamino group, decylamino group, and laurylamino group. Alkylamino groups such as dimethylamino groups, diethylamino groups, dipropylamino groups, dibutylamino groups, dipentylamino groups, dihexylamino groups, diheptylamino groups, dioctylamino groups, dinonylamino groups, and didecylamino groups; A dicycloalkylamino group such as a cyclohexylamino group; a morpholino group, and the like.

Specific examples of the organosilyl group include trimethylsilyl group, triethylsilyl group, tripropylsilyl group, tributylsilyl group, tripentylsilyl group, trihexylsilyl group, pentyldimethylsilyl group, hexyldimethylsilyl group, octyldimethylsilyl group, Examples include decyldimethylsilyl group.
Specific examples of the organothio group include alkylthio groups such as methylthio group, ethylthio group, propylthio group, butylthio group, pentylthio group, hexylthio group, heptylthio group, octylthio group, nonylthio group, decylthio group and laurylthio group.

Specific examples of the acyl group include formyl group, acetyl group, propionyl group, butyryl group, isobutyryl group, valeryl group, isovaleryl group, benzoyl group and the like.
The number of carbon atoms in the monovalent hydrocarbon group, organooxy group, organoamino group, organoamino group, organosilyl group, organothio group and acyl group is not particularly limited, but generally 1 to 20 carbon atoms, Preferably it is 1-8.
Among the above substituents, fluorine, sulfonic acid group, substituted or unsubstituted organooxy group, alkyl group, and organosilyl group are more preferable.
The term “non-substituted” means that a hydrogen atom is bonded. Moreover, in the above substituents, the substituents may be connected to each other to include a cyclic part.

  In view of applying the sulfonate compound of the present invention to an electron accepting substance, A is particularly preferably a substituted or unsubstituted aromatic ring group, and a substituted or unsubstituted phenyl group, naphthyl group, anthracenyl group. Etc. are preferred, and a substituted or unsubstituted phenyl group or naphthyl group is most preferred.

  In the formula (1), X represents a substituted or unsubstituted divalent hydrocarbon group, and specific examples thereof include a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms and an alkyleneoxy carbon number having 1 to 2 carbon atoms. C 1-2 alkylene group, C 1-2 alkylene group, C 1-2 alkylene carbonyl C 1-2 alkylene group and the like are mentioned, and Y is an S atom in the sulfonate ester A group that easily forms a cyclic complex represented by the following formula is preferable. In addition, as a substituent, the thing similar to the above is mentioned.

（式中、Ａ、Ｘ、Ｙ、およびＺは上記と同じ。）

(In the formula, A, X, Y, and Z are the same as above.)

In particular, when the number of constituent atoms of the main chain is 2 or 3, the sulfonic acid ester compound (1) can form a 5-membered ring or a 6-membered ring complex. Therefore, X is a substituted or unsubstituted ethylene group, A trimethylene group, a methyleneoxymethylene group, a methylenethiomethylene group and the like are preferable.
In the formula (1), Y is not particularly limited as long as Y is a group capable of forming a cyclic complex with the S atom of the sulfonate compound, but O, S, or a substituted or unsubstituted divalent amino group is preferable. In particular, O is preferable.
Here, examples of the divalent substituted amino group include —N (CH ₃ ) —, —N (C ₂ H ₅ ) —, —N (C ₃ H ₇ ) —, and the like.

  In particular, from the viewpoint of facilitating the formation of a cyclic complex, a compound represented by the following formula (2) in which X is a substituted or unsubstituted ethylene group and Y is O, or represented by the following formula (2 ′) Compounds are preferred.

（式中、Ａ²は、置換基を有していてもよい二価炭化水素基を表す。）

(In the formula, A ² represents a divalent hydrocarbon group which may have a substituent.)

In the formulas (2) and (2 ′), R ^{1 to} R ⁴ are each independently a hydrogen atom, an unsubstituted or substituted monovalent hydrocarbon group, or a halogen atom, among which a hydrogen atom; a methyl group C1-C6 alkyl groups such as ethyl group, propyl group, and butyl group are preferred. Specific examples of other monovalent hydrocarbon groups are as described above.
In the formulas (1), (2) and (2 ′), Z is not particularly limited as long as Z is a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group. Specific examples of the monovalent hydrocarbon group are as described above. Preferably, a methyl group, an ethyl group, and an n-propyl group are mentioned.
In the formula (2 ′), A ² is a divalent hydrocarbon group which may have a substituent, for example, an alkylene group (methylene group, ethylene group, trimethylene group) which may have a substituent. And arylene groups (phenylene group, naphthylene group, biphenylene group, etc.) which may have a substituent. Substituents include hydroxyl groups, amino groups, silanol groups, thiol groups, carboxyl groups, sulfonate ester groups, phosphate groups, phosphate ester groups, ester groups, thioester groups, amide groups, nitro groups, monovalent hydrocarbon groups , Organooxy groups, organoamino groups, organosilyl groups, organothio groups, acyl groups, sulfone groups, halogen atoms and the like.

Although the following method is mentioned as a manufacturing method of the compound shown by Formula (1), It is not restrict | limited to this.
That is, the sulfonic acid compound represented by formula (11) is reacted with a base to derive a sulfonate compound represented by formula (12), and this sulfonate compound is reacted with a halogenating reagent to form the formula It can derive to the sulfonyl halide compound represented by (13), and this sulfonyl halide compound can be made to react with the alcohol compound represented by Formula (14), and the sulfonate compound of Formula (1) can be obtained. In addition, a commercial item may be used for the sulfonic acid compound shown by Formula (11), and it is a well-known method as needed (New Experimental Chemistry Lecture 14 Synthesis and Reaction of Organic Compound III, p.1773 to 1784). Etc. can be synthesized.

（式中、Ａ、Ｘ、Ｙ、およびＺは上記と同じ。Ｖ⁺は、ナトリウムイオン、カリウムイオン、ピリジニウムイオンまたは第４級アンモニウムイオンを示し、Ｗはハロゲン原子を示す。）

(In the formula, A, X, Y, and Z are the same as above. V ⁺ represents a sodium ion, a potassium ion, a pyridinium ion, or a quaternary ammonium ion, and W represents a halogen atom.)

Examples of the base used in the step of inducing the sulfonic acid compound represented by the formula (11) to the sulfonate compound represented by the formula (12) by reacting with a base include sodium hydride, potassium hydride, and carbonic acid. Various bases such as sodium, potassium carbonate, sodium hydrogen carbonate, pyridine, pyrimidine, triethylamine and the like can be mentioned, but the solubility of the sulfonate compound (11) in an organic solvent is improved and the reaction in the next step is not affected. As the base, amines such as pyridine, pyrimidine and triethylamine are preferable, and pyridine is particularly preferable.
Although the usage-amount of a base will not be limited if it is 1 times mole or more with respect to a sulfonic acid compound (11), 1-5 times mole is suitable.
As the reaction solvent, those capable of dissolving the sulfonic acid compound (11) are preferable, and water, N-methylpyrrolidone (NMP), dimethylimidazolidinone (DMI), acetic anhydride, methanol, ethanol, isopropanol, pyridine and the like are preferable. It is.
Although reaction temperature is not specifically limited, 0-150 degreeC is preferable.
After completion of the reaction, a pure sulfonate compound can be obtained by purification using conventional methods such as solvent distillation under reduced pressure, liquid separation extraction operation, reprecipitation, recrystallization and the like.

Examples of the halogenating reagent used in the step of reacting the sulfonate compound represented by the formula (12) with the halogenating reagent to derive the sulfonyl halide compound represented by the formula (13) include thionyl chloride and oxychloride. Examples of the halogenating reagent include phosphorus and phosphorus (V) chloride, and thionyl chloride is preferable.
Although the usage-amount of a halogenating reagent will not be limited if it is 1 times mole or more with respect to a sulfonate compound, It is preferable to use 2-10 times amount by mass ratio with respect to a sulfonate compound.
As the reaction solvent, a solvent that does not react with the halogenating reagent is preferable, and examples thereof include chloroform, dichloroethane, carbon tetrachloride, hexane, heptane, and the like, but no solvent is preferable. When the reaction is carried out without a solvent, it is preferable to use the halogenating reagent in an amount that is equal to or greater than the amount that makes a homogeneous solution at the end of the reaction.
Although reaction temperature can be about 0-150 degreeC, 20-100 degreeC and below the boiling point of the halogenating reagent to be used are preferable.
After completion of the reaction, the crude product obtained by concentration under reduced pressure is generally used in the next step.

In the step of reacting the sulfonyl halide compound represented by the formula (13) with the alcohol compound represented by the formula (14), a base can be used in combination.
Examples of the base that can be used include sodium hydride, pyridine, triethylamine, diisopropylethylamine, and the like, and sodium hydride, pyridine, and triethylamine are preferable.
The amount of the base used is suitably 1-fold mol to the amount of solvent relative to the sulfonyl halide compound (13).
As the reaction solvent, various organic solvents can be used, and tetrahydrofuran, dichloroethane, and pyridine are preferable.
Although reaction temperature is not specifically limited, 0-80 degreeC is suitable.
After completion of the reaction, a pure sulfonic acid ester compound can be obtained by post-treatment and purification using conventional methods such as vacuum concentration, liquid separation extraction, water washing, reprecipitation, recrystallization, chromatography and the like.
In addition, it can also guide | induce to a highly purified sulfonic acid compound by performing heat processing etc. to the obtained pure sulfonic acid ester compound.

  The second sulfonic acid ester compound according to the present invention is represented by the following formula (3) or (4).

In the formulas (3) and (4), A ′ represents a hydrocarbon group substituted with (SO ₃ H) m, X ′ and (SO ₃ —XYZ) n ¹ , and this hydrocarbon group May be substituted with a substituent other than (SO ₃ H) m, X ′ and (SO ₃ —XYZ) n ¹ . Examples of such a substituent include the same groups as those described for the substituted or unsubstituted monovalent hydrocarbon group. Specific examples of A ′ include the same hydrocarbon groups that are polyvalent by removing the hydrogen atom of A and converting the bond to a bond, and the same applies to preferable hydrocarbon groups.
X ′ represents O, S or NH, and O is particularly preferable. Two X ′ in the formula (3) may be the same as or different from each other.
X, Y, and Z are the same as described above.

（式中、Ｗ¹およびＷ²は、それぞれ独立して、Ｏ、Ｓ、Ｓ（Ｏ）基、Ｓ（Ｏ₂）基、または非置換もしくは置換基が結合したＮ、Ｓｉ、Ｐ、Ｐ（Ｏ）基を示す。）B is a substituted or unsubstituted hydrocarbon group, a 1,3,5-triazine group, or a substituted or unsubstituted group represented by the following formula (5) or (6).

Wherein W ¹ and W ² are each independently O, S, S (O) group, S (O ₂ ) group, or N, Si, P, P (bonded to an unsubstituted or substituted group. O) represents a group.)

  In consideration of improving the durability and charge transporting property of the compounds of the above formulas (3) and (4), B is an unsubstituted or substituted divalent or higher valent group containing one or more aromatic rings. A hydrocarbon group, a divalent or trivalent 1,3,5-triazine group, a substituted or unsubstituted divalent diphenylsulfone group is preferred, and in particular, a divalent or trivalent substituted or unsubstituted benzyl group, divalent Substituted or unsubstituted p-xylylene group, divalent or trivalent substituted or unsubstituted naphthyl group, divalent or trivalent 1,3,5-triazine group, divalent substituted or unsubstituted diphenylsulfone group, 2 Preferred are a tetravalent perfluorobiphenyl group, a divalent substituted or unsubstituted 2,2-bis ((hydroxypropoxy) phenyl) propyl group, and a substituted or unsubstituted polyvinylbenzyl group. A.

m represents the number of sulfonic acid groups bonded to A ′, and is an integer of 0 or more, preferably 0 to 4, and increases the solubility of the compounds represented by formulas (3) and (4) in a solvent. In consideration of 0 to 2, 1 or 2 is preferable in consideration of increasing the electron acceptability of the compound.
q represents the number of bonds between B and X ′, and is not particularly limited as long as it is an integer satisfying 1 ≦ q, but preferably 2 ≦ q.
r represents the number of repeating units and is not particularly limited as long as it is an integer satisfying 1 ≦ r, but 2 ≦ r is preferable.
n ¹ is an integer of 1 or more, preferably an integer of 1 to 4, and n ² is an integer of 1 or more, preferably an integer of 1 to 4, but 1 is optimal for all. Note that n ¹ + m satisfies the number of substitutions allowed by A ′ in formula (3), and n ² + m satisfies the number of substitutions allowed by A ′ in formula (4).

As a manufacturing method of the sulfonic acid ester compound represented by Formula (3), (4), the following method can be mentioned, for example.
That is, it can be obtained by reacting the above-described B-providing (crosslinking) reagent to the X′H group of the sulfonic acid ester compound (15) or (16) produced using the above-described production method. At this time, the reaction method is not particularly limited, and for example, a general nucleophilic substitution reaction can be used.

Examples of such a reagent include a hydrocarbon compound substituted with a halogen atom, a hydroxyl group, an amino group, an aldehyde group, a carboxyl group, an ester group, or an alkoxy group. As described in the explanation of B above, A compound containing one or more aromatic rings is preferable from the viewpoint of improving heat resistance, charge transportability, solubility in an organic solvent, and the like.
In addition, when a hydrocarbon compound or the like containing two or more substituents such as a halogen atom, a hydroxyl group, an amino group, an aldehyde group, a carboxyl group, an ester group, or an alkoxy group is used, the compound acts as a crosslinking reagent. It can also be set as the compound which has this. When the compound of the formula (15) is q-quantized using a reagent having q or more reactive substituents (crosslinking part), the amount of the reagent used is 1 / q times that of the compound of the formula (15). Mole is preferred.

  Specific examples of the reagent reacted with the X′H group of the sulfonic acid ester compound (15) or (16) include benzaldehyde, benzoic acid, benzoic acid ester, 1-naphthaldehyde, 2-naphthaldehyde, 2, 4, 6 -Trimethoxy-1,3,5-triazine, bis (4-fluorophenyl) sulfone, bis (4-fluoro-3-nitrophenyl) sulfone, perfluorobiphenyl, 2,2-bis (4-glycidyloxyphenyl) Examples include propane and polyvinyl benzyl chloride.

When the sulfonic acid ester compound (15) or (16) is reacted with the reagent, a catalyst can also be used.
Examples of the catalyst include lithium, potassium, lithium hydride, sodium hydride, t-butoxylithium, t-butoxysodium, t-butoxypotassium, lithium-diisopropylamide, n-butyllithium, s-butyllithium, t- Butyllithium, lithium hexamethyldisilazide, sodium hexamethyldisilazide, potassium hexamethyldisilazide, lithium hydroxide, sodium hydroxide, potassium hydroxide, barium hydroxide, barium oxide, lithium carbonate, sodium carbonate, carbonic acid Bases such as potassium, cesium carbonate, calcium carbonate, sodium hydrogen carbonate, triethylamine, diisopropylethylamine, tetramethylethylenediamine, triethylenediamine, pyridine, dimethylaminopyridine, imidazole; hydrochloric acid Dehydration condensing agents such as sulfuric acid, diphosphorus pentoxide, aluminum (III) chloride, boron trifluoride diethyl ether complex, ethyl aluminum dichloride, diethyl aluminum chloride can be used. Among them, sodium hydride, sodium carbonate, It is preferred to use potassium carbonate. Although the usage-amount of these catalysts does not have a restriction | limiting in particular, It is preferable to use 1.0-1.5 times mole with respect to the compound of Formula (15) or Formula (16).

The reaction solvent is preferably an aprotic polar organic solvent, and for example, DMF, DMAc, NMP, DMI, DMSO, THF, dioxane and the like are suitable. Since a compound having a plurality of sulfonic acid groups has low solubility in an organic solvent, in this case, DMI and NMP which are solvents having a high solubility of the sulfonic acid compound and low thermal decomposability are suitable.
The reaction temperature is usually from −50 ° C. to the boiling point of the solvent used, but a range of 0 to 140 ° C. is preferred. The reaction time is usually 0.1 to 100 hours.
After completion of the reaction, the reaction solvent can be purified by distillation, and when it has a sulfonic acid group, it can be purified by protonation of a sulfonate with a cation exchange resin, extraction with a solvent such as methanol, reprecipitation.

  The third sulfonic acid ester compound according to the present invention is represented by the following formula (7) or (8).

In the formula, W represents a substituted or unsubstituted trivalent hydrocarbon group, has at least one bond with A ″ or S atom, and has at least one bond other than this bond, that is, a bond for forming a polymer chain. If it has two, it will not specifically limit.
Specific examples thereof include ethylene (—CH ₂ CH ₂ —), vinylene (—CH═CH—), acetylene (—C≡C—), propylene in which at least one hydrogen is substituted with an A ″ or S atom. _{(-CH 2 CH 2 CH 2 -} ), isopropylene _{(-CH 2 CH (CH 3)} -), ethylene vinyl _{(-CH 2 CH (CH = CH} 2) -), methoxy ethylene (-CH ₂ CH (OCH ₃₎ -), ethoxyethylene _{(-CH 2 CH (OCH 2 CH} 3) -), ( methylamino) ethylene _{(-CH 2 CH (NHCH 3)} -), ( dimethylamino) ethylene (-CH ₂ CH (N _{(CH 3) 2) -)} , acrylic acid methyl ester derivative _{(-CH 2 CH (C (O} ) OCH 3) -), methacrylic acid methyl ester derivative _{(-CH 2 C (CH 3)} (C (O) OCH ₃₎ -), Fe Len (-C ₆ H ₄ -), biphenylene _{(-C 6 H 4 -C 6 H} 4 -) and the like, each of hydrogen may be further substituted monovalent hydrocarbon radical.
Preferably, a sulfonic acid ester compound represented by the following formula (9) or (10) is used.

In the above formula, R ^{5 to} R ⁷ each independently represent a hydrogen atom, an unsubstituted or substituted monovalent hydrocarbon group, or a halogen atom. Specific examples of the monovalent hydrocarbon group include those described above.

A ″ is a divalent hydrocarbon group or a single bond, and specific examples of the divalent hydrocarbon group include one bonded portion bonded to hydrogen in the monovalent hydrocarbon group represented by A above. In particular, a substituted or unsubstituted divalent aromatic ring group or a single bond is preferable, and in the case of a single bond, W and S atoms are directly Join.
s is an integer of 2 to 100,000, preferably 20 to 5000. t is an integer of 1 to 100,000, preferably 20 to 5000, u is an integer of 1 to 100,000, preferably 1 to 5000, and t + u satisfies 2 to 100,000, preferably 20 to 5000. .
X, Y, and Z are the same as those described in the above formula (1).

Although the following method is mentioned as a manufacturing method of the compound shown by Formula (7) or Formula (8), It is not restrict | limited to this.
First, a sulfonic acid ester compound (20) is synthesized from a sulfonic acid compound (17) containing a polymerizable functional group (W ′) by the same method as described above. Further, it is subjected to a polymerization reaction to induce a compound represented by the formula (7). In that case, a part of sulfonic acid ester may become a free sulfonic acid, and may become a compound shown by Formula (8).

Since the sulfonic acid ester compounds represented by the above formulas (1) to (10) generate sulfonic acid by heat treatment or the like, and since the sulfonic acid compound exhibits electron accepting property, the acid generator and the electron accepting property are obtained. It can be suitably used as a material precursor.
Since the sulfonic acid ester compound exhibits high solubility in a wide range of solvents including a low polarity solvent, the physical properties of the solution can be prepared using a wide variety of solvents, and the coating properties are high. Therefore, it is preferable to apply in the state of sulfonic acid ester and generate sulfonic acid at the time of drying or baking the coating film.
The temperature at which sulfonic acid is generated from the sulfonic acid ester is preferably 40 to 300 ° C. because it is stable at room temperature and preferably equal to or lower than the firing temperature. Furthermore, when considering the high stability in the varnish and the ease of desorption during firing, the temperature is preferably from 80 to 230 ° C, more preferably from 120 to 180 ° C.

The sulfonic acid ester compounds represented by the above formulas (1) to (10) can themselves be used as an electron accepting substance. In particular, in the compounds of formulas (3) and (4), when m is 1 or more, a sulfonic acid group is present and itself exhibits a strong electron accepting property, so that it can be suitably used as an electron accepting substance.
The sulfonic acid ester compounds represented by the above formulas (4) and (7) to (10) can be used as high molecular weight substances. The molecular weight is not particularly limited, but if the molecular weight is increased while maintaining high solubility, it can be expected to suppress mobility in the film and stabilize the coating film during film formation. However, if the molecular weight is too large, the solubility may be reduced or the aggregation may occur. As a specific range, the number average molecular weight is preferably 5,000 to 100,000, and more preferably 20,000 to 50,000.

The sulfonic acid ester compounds represented by the above formulas (1) to (10) can be made into a charge transporting varnish by dissolving or dispersing them in a solvent together with the charge transporting substance which is the main body of the charge transporting mechanism. it can. Here, the charge-accepting substance is used for improving the charge transport ability and the film formation uniformity, and is synonymous with the charge-accepting dopant substance.
The charge transportability is synonymous with conductivity, and is synonymous with hole transportability in the present invention. The charge transport varnish itself may have a charge transport property, or the solid film obtained from the varnish may have a charge transport property.
The charge transporting substance is not particularly limited as long as it is a charge transporting oligomer or polymer that dissolves or uniformly disperses in a solvent. However, the charge transporting substance is an oligomer having one kind of continuous conjugated units or a combination of different consecutive conjugated units. Oligomer having is desirable.

Here, the conjugated unit is not particularly limited as long as it is an atom capable of transporting a charge, an aromatic ring, or a conjugated group, but is preferably a substituted or unsubstituted divalent to tetravalent aniline group, thiophene group, furan. Group, pyrrole group, ethynylene group, vinylene group, phenylene group, naphthalene group, oxadiazole group, quinoline group, silole group, silicon atom, pyridine group, phenylene vinylene group, fluorene group, carbazole group, triarylamine group, metal -Or a metal-free phthalocyanine group, a metal- or metal-free-porphyrin group, etc. are mentioned.
Specific examples of the substituent are independently hydrogen, hydroxyl group, halogen group, amino group, silanol group, thiol group, carboxyl group, sulfonic acid group, phosphate group, phosphate ester group, ester group, thioester group, Amide group, nitro group, monovalent hydrocarbon group, organooxy group, organoamino group, organosilyl group, organothio group, acyl group, sulfone group, etc. are mentioned, and these functional groups are any functional groups. May be substituted.
The number of carbon atoms in the monovalent hydrocarbon group, organooxy group, organoamino group, organosilyl group, organothio group, and acyl group is not particularly limited, but generally 1 to 20 carbon atoms, preferably 1 to 1 carbon atoms. 8.

Specific examples of the monovalent hydrocarbon group, organooxy group, organoamino group, organosilyl group, organothio group, and acyl group are as described above.
Preferred substituents include fluorine, sulfonic acid groups, substituted or unsubstituted organooxy groups, alkyl groups, and organosilyl groups. In addition, the conjugated chain formed by coupling conjugated units may include a cyclic part.

  The number average molecular weight of the charge transporting material is desirably 5000 or less in view of enhancing solubility, and desirably has a molecular weight of 200 or more for low volatility and expression of charge transporting property. A substance having high solubility in at least one kind of solvent is good, and a number average molecular weight of 5,000 to 500,000 may be used as long as it is a substance showing high solubility in at least one kind of solvent.

  As the charge transport material, in particular, an oligoaniline derivative described in JP-A No. 2002-151272 is preferably used. That is, an oligoaniline derivative represented by the formula (21) is preferable. In the following, examples of the monovalent hydrocarbon group, organooxy group, and acyl group include the same groups as those described above.

（式中、Ｒ⁸は、水素原子、一価炭化水素基、またはオルガノオキシ基を示し、Ｒ⁹およびＲ¹¹は、それぞれ独立して水素原子または一価炭化水素基を示し、Ｄ¹およびＤ²は、それぞれ独立して下記式（２２）または（２３）

(Wherein R ⁸ represents a hydrogen atom, a monovalent hydrocarbon group, or an organooxy group, R ⁹ and R ¹¹ each independently represent a hydrogen atom or a monovalent hydrocarbon group, and D ¹ and D ² each independently represents the following formula (22) or (23)

R ^{11 to} R ¹⁸ each independently represent hydrogen, a hydroxyl group, a monovalent hydrocarbon group, an organooxy group, an acyl group, or a sulfonic acid group, and s ′ and t ′ Is an integer of 1 or more and each satisfies s ′ + t ′ ≦ 20. )

  Furthermore, since the charge transporting property of the resulting charge transporting thin film is improved when the π-conjugated system in the molecule is expanded as much as possible, in particular, the oligoaniline derivative represented by the formula (24) or its oxidant is used. It is preferable to use a certain quinonediimine derivative. In the two benzene rings of the formula (24), the substituents having the same symbols may be the same or different at the same time.

（式中、Ｒ⁸〜Ｒ¹⁴、ｓ′およびｔ′は、上記と同じ意味を示す。）

(Wherein R ^{8 to} R ¹⁴ , s ′ and t ′ have the same meaning as described above.)

In the formulas (21) and (24), s ′ + t ′ is preferably 4 or more from the viewpoint of exhibiting good charge transportability, and is 16 or less from the viewpoint of ensuring solubility in a solvent. Preferably there is.
Furthermore, when R ⁸ is a hydrogen atom and R ¹⁰ is a phenyl group, that is, it is preferable that both ends of the oligoaniline derivative of the formula (24) are sealed with a phenyl group.
These charge transport materials may be used alone or in combination of two or more materials.
Specific examples of the compound represented by the formula (21) include soluble oligoanilines soluble in organic solvents such as phenyltetraaniline, phenylpentaaniline, tetraaniline (aniline tetramer), and octaaniline (aniline octamer). Derivatives.

  Furthermore, the method for synthesizing other charge transporting substances is not particularly limited. For example, the literature, Bulletin of Chemical Society of Japan, 1994, Vol. 67, p. . 1749-1752, Synthetic Metals, USA, 1997, 84, p. 119-120, for example, the literature, Heterocycles, 1987, Vol. 26, p. 939-942, Heterocycles, 1987, 26, p. Examples include oligothiophene synthesis methods described in 1793-1796.

In the charge transporting varnish of the present invention, a highly soluble solvent capable of dissolving the charge transporting substance and the charge accepting substance satisfactorily is used at a ratio of 5 to 100% by weight based on the whole solvent used in the varnish. Also good. In this case, it is preferable that the varnish is completely dissolved or uniformly dispersed by the highly soluble solvent.
The highly soluble solvent is not particularly limited, and examples thereof include water, methanol, N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, N, N′-dimethylimidazolidinone, Examples include dimethyl sulfoxide, chloroform, toluene, and methanol.

The charge transporting varnish of the present invention desirably contains at least one high-viscosity organic solvent having a viscosity of 10 to 200 mPa · s at 20 ° C. and a boiling point of 50 to 300 ° C. at normal pressure. Furthermore, the charge transporting varnish preferably contains an organic solvent having a viscosity of 50 to 150 mPa · s at 20 ° C. and a boiling point of 150 to 250 ° C. at normal pressure.
The high-viscosity organic solvent is not particularly limited, and examples thereof include cyclohexanol, ethylene glycol, ethylene glycol diglycidyl ether, 1,3-octylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, and tripropylene glycol. 1,3-butanediol, 1,4-butanediol, propylene glycol, hexylene glycol and the like.

The addition ratio of the high-viscosity organic solvent to the entire solvent used in the varnish of the present invention is preferably within a range where no solid precipitates, and unless the solid precipitates, the addition ratio should be 5 to 80% by mass. Can do.
In addition, for the purpose of improving the wettability with respect to the substrate, adjusting the surface tension of the solvent, adjusting the polarity, adjusting the boiling point, etc., other solvents that can impart film flatness during firing are used as a whole solvent used in the varnish. 1 to 90% by mass, preferably 1 to 50% by mass can be mixed.
Such a solvent is not particularly limited, and examples thereof include butyl cellosolve, diethylene glycol diethyl ether, dipropylene glycol monomethyl ether, ethyl carbitol, diacetone alcohol, γ-butyrolactone, and ethyl lactate.

A charge transporting coating film can be formed on a substrate by applying the charge transporting varnish described above on the substrate and evaporating the solvent.
The method for applying the varnish is not particularly limited, and examples thereof include a dipping method, a spin coating method, a spray method, an ink jet method, a transfer printing method, a roll coating method, and a brush coating method. A membrane is possible.

The method for evaporating the solvent is not particularly limited, however, using a hot plate or an oven, evaporation is performed in an appropriate atmosphere, that is, in an atmosphere such as air, an inert gas such as nitrogen, in a vacuum, etc., to form a uniform film. It is possible to obtain a film having a surface.
Although a calcination temperature will not be specifically limited if a solvent can be evaporated, 40-250 degreeC is preferable. In order to develop a higher uniform film forming property and to allow the reaction to proceed on the substrate, two or more stages of temperature changes may be applied.
The thickness of the charge transporting thin film obtained by coating and evaporation operations is not particularly limited, but is preferably 5 to 200 nm when used as a charge injection layer in an organic EL device. As a method of changing the film thickness, there are methods such as a change in the solid content concentration in the varnish and a change in the amount of solution on the substrate during coating.

Examples of the method for producing an OLED element using the charge transporting varnish of the present invention and the materials used include, but are not limited to, the following methods and materials.
The electrode substrate to be used is preferably cleaned in advance by washing with a detergent, alcohol, pure water or the like, and the anode substrate is preferably subjected to surface treatment such as ozone treatment or oxygen-plasma treatment immediately before use. However, when the anode material is mainly composed of an organic material, the surface treatment may not be performed.

When using a hole transporting varnish for an OLED element, for example, the following method may be employed.
That is, a hole transporting thin film is formed on the electrode by the above film manufacturing method using the hole transporting varnish for the anode substrate. This is introduced into a vacuum deposition apparatus, and a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and a cathode metal are sequentially deposited to form an OLED element. At this time, a carrier block layer may be provided between arbitrary layers in order to control the light emitting region.

Examples of the anode material include transparent electrodes typified by indium tin oxide (ITO) and indium zinc oxide (IZO), and those subjected to planarization treatment are preferable. Polythiophene derivatives having high charge transportability and polyanilines can also be used.
As a material for forming the hole transport layer, (triphenylamine) dimer derivative (TPD), (α-naphthyldiphenylamine) dimer (α-NPD), [(triphenylamine) dimer] spiro-dimer (Spiro-TAD) Triarylamines such as 4,4 ′, 4 ″ -tris [3-methylphenyl (phenyl) amino] triphenylamine (m-MTDATA), 4,4 ′, 4 ″ -tris [1-naphthyl (phenyl) ) Starburstamines such as amino] triphenylamine (1-TNATA), 5,5 ″ -bis- {4- [bis (4-methylphenyl) amino] phenyl} -2,2 ′: 5 ′, 2 And oligothiophenes such as “terthiophene (BMA-3T)”.
Materials for forming the light-emitting layer include tris (8-quinolinolato) aluminum (III) (Alq ₃ ), bis (8-quinolinolato) zinc (II) (Znq ₂ ), bis (2-methyl-8-quinolinolato) ( p-phenylphenolate) aluminum (III) (BAlq), 4,4′-bis (2,2-diphenylvinyl) biphenyl (DPVBi) and the like. Note that the light-emitting layer may be formed by co-evaporation of an electron transport material or a hole transport material and a light-emitting dopant.

As an electron transport material, Alq ₃ , BAlq, DPVBi, (2- (4-biphenyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole) (PBD), triazole derivatives ( TAZ), bathocuproine (BCP), silole derivatives and the like.
Examples of the luminescent dopant include quinacridone, rubrene, coumarin 540, 4- (dicyanomethylene) -2-methyl-6- (p-dimethylaminostyryl) -4H-pyran (DCM), tris (2-phenylpyridine) iridium ( III) (Ir (ppy) ₃ ), (1,10-phenanthroline) -tris (4,4,4-trifluoro-1- (2-thienyl) -butane-1,3-dionate) europium (III) ( Eu (TTA) ₃ phen) and the like.
Examples of the material for forming the carrier block layer include PBD, TAZ, and BCP.

As the electron injection layer, lithium oxide (Li ₂ O), magnesium oxide (MgO), alumina (Al ₂ O ₃ ), lithium fluoride (LiF), magnesium fluoride (MgF ₂ ), strontium fluoride (SrF ₂ ) , Lithium quinonolide (Liq), lithium acetylacetonate complex (Li (acac)), lithium acetate, lithium benzoate and the like.
Examples of the cathode material include aluminum, magnesium-silver alloy, aluminum-lithium alloy, lithium, sodium, potassium, cesium and the like.

When the charge transporting varnish of the present invention is used for an OLED element, for example, the following method may be employed.
An electron transporting thin film is produced on the cathode substrate using the electron transporting varnish, introduced into a vacuum deposition apparatus, and using the same materials as described above, an electron transporting layer, a light emitting layer, a hole transporting layer, After the hole injection layer is formed, an anode material is formed by a method such as sputtering to form an OLED element.

Examples of the method for producing a PLED element using the charge transporting varnish of the present invention include the following methods, but are not limited thereto.
In the preparation of the OLED element, the charge transport property of the present invention is formed by forming a light emitting charge transporting polymer layer instead of performing vacuum deposition operation of the hole transport layer, the light emitting layer, the electron transport layer, and the electron injection layer. A PLED element including a charge transporting thin film formed of varnish can be produced.
Specifically, the hole transporting varnish is applied to the anode substrate by the above method to produce a hole transporting thin film on the electrode, and a light emitting charge transporting polymer layer is formed thereon. Further, a cathode electrode is deposited to form a PLED element.
Alternatively, the electron transporting varnish is used for the cathode substrate, an electron transporting thin film is formed on the electrode by the above method, a light emitting charge transporting polymer layer is formed thereon, and the anode electrode is sputtered. , Vapor deposition, spin coating, etc. to produce a PLED element.

As the cathode and anode materials, the same materials as those exemplified for the OLED element can be used, and the same cleaning treatment and surface treatment can be performed.
As a method for forming a light emitting charge transporting polymer layer, a solvent is added to a light emitting charge transporting polymer material or a material to which a light emitting dopant is added and dissolved or uniformly dispersed to transport holes. And a method of forming a film by evaporation of a solvent after coating on an electrode substrate on which a conductive thin film is formed.
Examples of the light-emitting charge transporting polymer material include polyfluorene derivatives such as poly (9,9-dialkylfluorene) (PDAF), and poly (2-methoxy-5- (2′-ethylhexoxy) -1,4-phenylenevinylene. ) (MEH-PPV) and other polyphenylene vinylene derivatives, poly (3-alkylthiophene) (PAT) and other polythiophene derivatives, and polyvinylcarbazole (PVCz).

Examples of the solvent include toluene, xylene, chloroform and the like. Examples of the dissolution or uniform dispersion method include a method of dissolving or uniformly dispersing by a method such as stirring, heating and stirring, and ultrasonic dispersion.
The application method is not particularly limited, and examples thereof include a dipping method, a spin coating method, a transfer printing method, a roll coating method, and brush coating. The application is preferably performed under an inert gas such as nitrogen or argon.
Examples of the solvent evaporation method include a method of heating in an oven or a hot plate under an inert gas or in a vacuum.

Hereinafter, although a synthesis example, an Example, and a comparative example are given and this invention is demonstrated more concretely, this invention is not limited to the following Example.
[Synthesis Example 1]
Naphthalenedisulfonic acid compound oligomer 2 (hereinafter abbreviated as NSO-2) was synthesized according to the following reaction formula.

In a well-dried sodium 1-naphthol-3,6-disulfonate (manufactured by Tokyo Chemical Industry Co., Ltd.) 934 mg, under a nitrogen atmosphere, 450 mg of perfluorobiphenyl, 166 mg of 60% sodium hydride, and anhydrous N, N- 50 ml of dimethylimidazolidinone was sequentially added, and the reaction system was purged with nitrogen, followed by stirring at 80 ° C. for 43 hours.
After allowing to cool to room temperature, water was added to stop the reaction, and the mixture was concentrated to dryness under reduced pressure. 5 ml of methanol was added to the residue, and the resulting suspension was added to 100 ml of diethyl ether with stirring. After stirring at room temperature for 1 hour, the precipitated solid was collected by filtration, and 25 ml of methanol was added to the filtrate and suspended with ultrasound. Insoluble solids were removed by filtration, and the filtrate was concentrated to dryness under reduced pressure. To the residue, 12 ml of methanol-water (1: 2) was added to dissolve, about 2 ml of cation exchange resin Dowex 650C (H type) was added and stirred for 10 minutes, followed by filtration. The filtrate was cation exchange resin Dowex 650C (H It was purified by column chromatography using about 40 ml of type, distillate solvent: methanol-water (1: 2)).

The fraction having a pH of 1 or less was concentrated to dryness under reduced pressure, azeotroped once with isopropanol, 2 ml of isopropanol was added to the residue, and the resulting solution was added to 50 ml of diethyl ether with stirring. After stirring at room temperature for 1 hour, the supernatant was removed, and the residue was dried under reduced pressure to obtain 984 mg of a yellow powder (yield 81%).
As a result of analyzing this yellow powder by MALDI-TOF-MS, a main peak considered to be derived from NSO-2 was detected.
MS (MALDI-TOF-MS-): m / z 901 (MH) ^-

[Example 1]

Under a nitrogen atmosphere, 20 mL of dehydrated tetrahydrofuran (hereinafter referred to as THF) was added to 998 mg of 1,3-benzenedisulfonic acid dichloride (manufactured by Aldrich) to dissolve it. To this solution, 0.85 mL of dehydrated propylene glycol monomethyl ether (hereinafter referred to as PGME) and 325 mg of 60% sodium hydride were sequentially added in an ice bath, and the mixture was stirred as it was for 15 minutes. The mixture was warmed to room temperature and stirred for 40 minutes. Further, 526 mg of 60% sodium hydride was added, and the mixture was stirred at room temperature for 30 minutes. The reaction mixture was filtered through celite, washed successively with dichloroethane and PGME, CG-50 (manufactured by Aldrich) and water were added to the combined filtrate to adjust to pH 7, and celite was filtered again.
The filtrate was concentrated, dichloroethane was added, silica gel filtration (silica gel 18 g), dichloroethane washing was performed, and the combined filtrate was concentrated to dryness. The residue was washed three times with hexane, and then dried under reduced pressure. 936 mg (colorless oil, yield 68%) of the sulfonic acid ester compound represented by the formula (25) was obtained.
¹ H-NMR (300 MHz, CDCl ₃ ) δ (ppm): 1.35 (6H, d), 3.19 (6H, s), 3.3-3.5 (4H, m), 4.83 (2H, ddt), 7.72 (1H, dd ), 8.16 (2H, dd), 8.50 (1H, dd).
Rf value (1,2-dichloroethane (DCE)): 0.13-0.36.

[Example 2]

Under a nitrogen atmosphere, 20 mL of dehydrated THF was added to 998 mg of 1,3-benzenedisulfonic acid dichloride (manufactured by Aldrich) to dissolve it. To this solution, 0.58 mL of glycidol and 351 mg of 60% sodium hydride were sequentially added in a water bath (20 ° C.), and the mixture was stirred for 2.5 hours. The reaction mixture was filtered through Celite and washed with dichloroethane, and then the combined filtrate was concentrated to dryness under reduced pressure. Dichloroethane was added to the residue, followed by silica gel filtration (silica gel 8 g) and washing with dichloroethane. The combined filtrate was concentrated to dryness under reduced pressure, and the residue was washed three times with hexane and then dried under reduced pressure to obtain 472 mg (colorless oil, yield 37%) of the sulfonic acid ester compound represented by formula (26). It was.
Rf value (DCE): 0.22-0.54; (DCE: EtOAc = 10: 1): 0.50-0.67

[Example 3]
12.6 mL of acetic anhydride was added to 2.664 g of NSO-2 obtained in Synthesis Example 1 under a nitrogen atmosphere and dispersed uniformly with ultrasound, and then 4.8 mL of dehydrated pyridine was added in a water bath (20 ° C.). In addition, the mixture was stirred at room temperature for 26 hours. Thereafter, 80 mL of diethyl ether was added to the reaction system, and the mixture was uniformly dispersed with ultrasonic waves, followed by suction filtration. The residue was dried under reduced pressure to obtain 2.977 g of a sulfonic acid pyridine salt represented by the formula (27) (white). A powder, yield 83%) was obtained.

  Under a nitrogen atmosphere, 7.5 mL of thionyl chloride was added to 1.506 g of the obtained sulfonic acid pyridine salt, and the mixture was stirred at 80 ° C. for 8 hours. The reaction mixture was concentrated to dryness under reduced pressure to obtain a crude product (brown powder) of sulfonic acid chloride represented by formula (28).

To the obtained brown powder, 15 mL of dehydrated pyridine and 3 mL of dehydrated PGME were sequentially added in a water bath (20 ° C.), and the mixture was stirred at room temperature for 2 hours. The reaction mixture was concentrated to dryness under reduced pressure, azeotroped twice with dichloroethane, the residue was purified by silica gel column chromatography (silica gel 50 g, dichloroethane → dichloroethane: ethyl acetate 10: 1), and Rf value (dichloroethane: acetic acid). Ethyl 10: 1) A fraction in the vicinity of 0.4 to 0.5 was concentrated to dryness under reduced pressure to obtain 712 mg (orange oil, yield 48%) of the sulfonic acid ester compound represented by formula (29). .
MS (ESI +, in MeOH-0.02M NH ₄ OAc): 1207 [M + NH ₃ ] ⁺

[Comparative Example 1]

To 1.003 g of 1,3-benzenedisulfonic acid dichloride (manufactured by Aldrich), 10 mL of pyridine was added and dissolved in a nitrogen atmosphere, and then 0.90 mL of cyclohexanol was added in a water bath (20 ° C.), and 20 hours at room temperature. Stir. The reaction mixture was poured into 50 mL of diethyl ether and the insoluble solid was removed by suction filtration. The filtrate was concentrated to dryness under reduced pressure and subjected to toluene azeotropy once, followed by silica gel filtration (silica gel 20 g) and dichloroethane washing. The combined filtrates were concentrated to dryness under reduced pressure to obtain 529 mg (colorless oil, yield 36%) of the sulfonic acid ester compound represented by formula (30).
¹ H-NMR (300 MHz, CDCl ₃ ) δ (ppm): 1.2-1.9 (20H, m), 4.63 (2H, dddd), 7.75 (1H, dd), 8.16 (2H, dd), 8.45 (1H, dd ).
Rf value (DCE): 0.5-0.6

[Comparative Example 2]

The crude product of sulfonic acid chloride (28) was obtained from 260 mg of sulfonic acid pyridine salt (27) by the method described in Example 3. To the obtained sulfonic acid chloride (28), 2.5 mL of dehydrated pyridine was added in a water bath (15 ° C.) and dispersed uniformly with ultrasonic waves, and then dehydrated cyclohexanol in a water bath (15 ° C.) was added in an amount of 0. 5 mL was added and stirred at room temperature for 7 hours. The reaction mixture was poured into 15 mL of diethyl ether, the insoluble solid was removed by filtration under reduced pressure, the filtrate was dried under reduced pressure, and azeotroped twice with toluene, and the sulfonic acid ester compound represented by formula (31) As a result, 326 mg of an oily substance was obtained.
MS (ESI +, in MeOH-0.02M NH ₄ OAc): 1247 [M + NH ₃ ] ⁺ , 1165 [MC ₆ H ₁₀ + NH ₃ ] ⁺ , 1083 [M-2C ₆ H ₁₀ + NH ₃ ] ⁺ .
From the above MS analysis values, it was found that elimination of cyclohexyl group occurred during the reaction or purification operation, and free sulfonic acid was contained in the final product. Further, the obtained oily substance was decomposed by a separation washing treatment with ethyl acetate and water or a silica gel purification treatment, and further purification could not be performed. From these facts, it can be seen that the elimination of the cyclohexyl group is higher than that of the PGME group, and purification is difficult.

[Comparative Example 3]

A crude product of sulfonic acid chloride (28) was obtained from 251 mg of sulfonic acid pyridine salt (27) by the method described in Example 3. To the obtained sulfonic acid chloride (28), 2.0 mL of dehydrated pyridine was added in a water bath (15 ° C.) and dispersed uniformly with ultrasonic waves, and then 0.5 mL of dehydrated isobutanol in a water bath (15 ° C.). And stirred at room temperature for 20 hours. The reaction mixture was poured into 12.5 mL of diethyl ether, the insoluble solid was removed by vacuum filtration, the filtrate was evaporated to dryness under reduced pressure, and azeotroped once with toluene to give the sulfonic acid represented by formula (32). 84 mg of an oily substance containing an ester compound was obtained.
The resulting oily substance was decomposed by a separation washing treatment with toluene and water or a silica gel purification treatment, and further purification could not be performed. From these facts, it can be seen that isobutyl ester is highly degradable and difficult to purify.

[Comparative Example 4]

  The crude product of sulfonic acid chloride (28) was obtained from 101 mg of sulfonic acid pyridine salt (27) by the method described in Example 3. To the resulting sulfonic acid chloride (28), 1.0 mL of dehydrated pyridine was added in a water bath (15 ° C.) and dispersed uniformly with ultrasonic waves, and then dehydrated n-butanol in a water bath (15 ° C.) 2 mL was added and stirred at room temperature for 4 hours. The reaction was followed by TLC, but only a few low-polarity points derived from the target product were generated. From this fact, it can be seen that n-butyl ester (33) is difficult to synthesize in high yield because of low reactivity or high decomposability.

[Comparative Example 5]

  The crude product of sulfonic acid chloride (28) was obtained from 100 mg of sulfonic acid pyridine salt (27) by the method described in Example 3. To the obtained sulfonic acid chloride (28), 1.0 mL of dehydrated pyridine was added in a water bath (15 ° C.) and dispersed uniformly by ultrasonic wave, and then dehydrated cycloheptanol 0. 0 in a water bath (15 ° C.). 2 mL was added and stirred at room temperature for 4 hours. The reaction was followed by TLC, but only a few low-polarity points derived from the target product were generated. From this fact, it can be seen that the cycloheptyl ester (34) has low reactivity or high decomposability, so that it is difficult to synthesize with high yield.

[Example 4]

To 40.00 g of sodium 4-styrenesulfonate (manufactured by Aldrich), 250 mL of pure water was added and dissolved, and 25 mL of cation exchange resin Dowex 650C (H type, hereinafter abbreviated as 650C) was added and stirred for 5 minutes. To the collected supernatant, 25 ml of 650C was added and stirred for 5 minutes. To the collected supernatant, 50 ml of 650C was added and stirred for 5 minutes. Finally, the collected supernatant was added to 650C (500 ml). And purified by column chromatography using distillate solvent: water).
To the aqueous solution of 4-styrenesulfonic acid obtained by ion exchange, 100 mL of methanol and 27 mL of pyridine were sequentially added, stirred for 10 minutes, concentrated to dryness under reduced pressure, and azeotroped once with methanol. Thereafter, 58 mL of methanol was added for dissolution, and the resulting solution was added dropwise to 1.16 L of diethyl ether with stirring. After stirring at room temperature for 15 minutes, the supernatant was removed, and the residue was dried under reduced pressure to obtain 50.20 g of 4-styrenesulfonic acid pyridine salt (white powder, yield: 85%).

  To 38.41 g of the 4-pyridinesulfonic acid pyridine salt crude product obtained by the above method, 115 mL of thionyl chloride was added, heated under reflux for 12 minutes, allowed to cool to room temperature, and then concentrated to dryness under reduced pressure. After adding 4 mL of anhydrous pyridine to the obtained pale yellow oil and dissolving, 1.0 mL of anhydrous PGME was added, suspended by sonication and grinding with a glass rod, and stirred at room temperature for 30 minutes. The reaction system was concentrated to dryness under reduced pressure, azeotroped once with 1,2-dichloroethane, and then filtered through silica gel (silica gel 8 g, solvent and washing solution: 1,2-dichloroethane). The filtrate was concentrated to dryness under reduced pressure to obtain 22.77 g of a crude product of a sulfonic acid ester compound as a monomer. The resulting crude monomer product was purified by silica gel column chromatography (solvent: dichloroethane → dichloroethane: ethyl acetate = 20: 1 → 10: 1) to give 11.98 g of a sulfonic acid ester compound monomer (colorless liquid, yield 32). %).

To 9.31 g of the sulfonic acid ester compound monomer obtained by the above method, 37 mL of anhydrous ethyl acetate was added and dissolved in a nitrogen atmosphere, deaerated by nitrogen bubbling, and then 23.5 mg of AIBN in anhydrous ethyl acetate 0.38 mL The solution was added under a nitrogen atmosphere and stirred at 80 ° C. for 6 hours. The mixture was allowed to cool to room temperature, concentrated under reduced pressure to about 30 mL, and poured into 200 mL of methanol with stirring. After stirring at room temperature for 20 minutes, suction filtration was performed, and the residue was dried under reduced pressure to obtain 5.01 g (white powder, yield 54%) of a polystyrene sulfonate compound represented by the formula (35).
¹ H-NMR (300 MHz, CDCl ₃ ) δ (ppm): 1.1-1.9 (6H, br), 3.1-3.3 (3H, br), 3.3-3.6 (2H, br), 4.6-4.9 (1H, br) , 6.4-6.9 (2H, br), 7.5-7.9 (2H, br).
GPC: Mn (number average molecular weight) 26408; Mw (weight average molecular weight) 71420; Mz (Z average molecular weight) 235146

TG-DTA was measured for the sulfonic acid ester compounds obtained in Examples 1 to 4 and Comparative Example 1. The evaluation results are shown in Table 1. The measuring apparatus and conditions are as follows.
Measuring device: Thermal analyzer system WS002, manufactured by Mac Science Co., Ltd. Temperature rising rate: 5 ° C./min

Moreover, the solubility with respect to the various sulfonate compound obtained in Examples 1-4 and NSO-2 with respect to the various solvent was evaluated with the following method. The results are shown in Table 2.
<Solubility evaluation method>
A 20-fold mass ratio of each solvent was added to each sample, and dissolution was attempted by adding room temperature stirring, heating stirring, or ultrasonic vibration. What was heated and stirred was observed after cooling to room temperature. In the table, “◯” indicates complete dissolution and no solid precipitation or solid residue, and “×” in the table indicates solid precipitation or solid residue.

  As shown in Table 2, the sulfonic acid ester compounds obtained in Examples 1 to 4 exhibit higher solubility in various organic solvents than NSO-2 having free sulfonic acid. I understand.

[Example 5]
136 mg of the sulfonic acid ester compound (29) obtained in Example 3 and Bulletin of Chemical Society of Japan, 1994, Vol. 67, p. 1.44 ml of dimethylacetamide (DMAc) was added to a mixture with 50 mg of phenyltetraaniline (PTA) represented by the following formula synthesized according to the method described in 1749-1752 under a nitrogen atmosphere and dissolved. Further, 4.28 ml of cyclohexanol was added under a nitrogen atmosphere and stirred at room temperature to obtain a green transparent varnish (solid content: 3.3% by mass). The obtained varnish did not show solid precipitation even when cooled to -25 ° C.

[Example 6]
The varnish obtained in Example 5 was spin-coated on an ITO substrate that had been subjected to ozone cleaning for 40 minutes until immediately before, and then baked to form a charge transporting thin film (hole transporting thin film) having a thickness of 22 nm. . The obtained charge transporting thin film was an amorphous solid.

[Example 7]
The varnish obtained in Example 5 was spin coated on an ITO substrate that had been subjected to ozone cleaning for 40 minutes until immediately before, and then baked to form a charge transporting thin film (hole transporting thin film) having a thickness of 67 nm. . The obtained charge transporting thin film was an amorphous solid.

[Example 8]
To a mixture of 116 mg of the sulfonic acid ester compound (35) obtained in Example 4 and 50 mg of PTA shown above, 2.40 ml of dimethylacetamide (DMAc) was added and dissolved in a nitrogen atmosphere. Then, 2.40 ml of cyclohexanol was added and stirred at room temperature to obtain a green transparent varnish (solid content: 3.5% by mass). The obtained varnish did not show solid precipitation even when cooled to 0 ° C.
The obtained varnish was spin-coated on an ITO substrate that had been subjected to ozone cleaning for 40 minutes until immediately before, and then baked to form a charge transporting thin film (hole transporting thin film) having a thickness of 36 nm. The obtained charge transporting thin film was an amorphous solid.

[Comparative Example 6]
To a mixture of (+)-10-camphorsulfonic acid (206 mg) and PTA (100 mg), DMAc (1.87 ml) was added and dissolved in a nitrogen atmosphere. Further, cyclohexanol (5.53 ml) was added and stirred at room temperature to give a green transparent varnish. (Solid content 4.2 mass%) was obtained. Using the obtained varnish, a 12 nm-thick charge transporting thin film (hole transporting thin film) was obtained by the method described in Example 6. The obtained charge transporting thin film was an amorphous solid.

[Comparative Example 7]
In the same manner as in Comparative Example 6, a charge transporting thin film (hole transporting thin film) having a thickness of 24 nm was obtained. The obtained charge transporting thin film was an amorphous solid.

[Comparative Example 8]
To 1.000 g of PTA, 2.298 g of 5-sulfosalicylic acid dihydrate and 17.50 g of N, N-dimethylacetamide (DMAc) were added and dissolved in a nitrogen atmosphere, and 52.50 g of cyclohexanol was added to the resulting solution. Was added and stirred to prepare a varnish (solid content 4.1 mass%).
The obtained varnish was applied on an ITO glass substrate that had been subjected to ozone cleaning for 40 minutes by spin coating, and then baked at 180 ° C. for 2 hours in air to form a charge transporting thin film having a thickness of 21 nm (hole transporting thin film). Got.

Table 3 also shows the viscosity of the varnishes used in Examples 6 to 8 and Comparative Examples 6 to 8, firing conditions at the time of thin film preparation, film thickness of the thin film, and ionization potential (hereinafter abbreviated as I _p ) values.
In addition, the varnish viscosity, the film thickness, and the I _p value were measured by the following apparatus.
[1] Viscosity E type viscometer (ELD-50, manufactured by Tokyo Keiki Co., Ltd.), measuring temperature: 20 ° C.
[2] Film thickness Measured with a surface shape measuring device (DEKTAK3ST, manufactured by Nippon Vacuum Technology Co., Ltd.).
[3] I _p value Measured with a photoelectron spectrometer (AC-2, manufactured by Riken Keiki Co., Ltd.).

As shown in Table 3, the I _p values of the thin films obtained in Examples 6 to 8 are sufficiently high, and the sulfonic acid ester compounds (29) and (35) are heat-treated after the coating film. It can be seen that it functions as a good charge-accepting substance.

[Example 9]
The ITO substrate on which the hole transporting thin film was formed by the method of Example 6 was introduced into a vacuum deposition apparatus, and α-NPD, Alq ₃ , LiF, and Al were sequentially deposited to obtain an OLED element. The film thicknesses were 40 nm, 60 nm, 0.5 nm, and 100 nm, respectively, and the vapor deposition operation was performed after the pressure was 8 × 10 ⁻⁴ Pa or less. The deposition rate was 0.3 to 0.4 nm / s excluding LiF, and 0.02 to 0.04 nm / s for LiF. The transfer operation between the vapor deposition operations was performed in a vacuum.

[Example 10]
An ITO substrate on which a hole transporting thin film was formed by the method of Example 8 was introduced into a vacuum deposition apparatus, and α-NPD, Alq ₃ , LiF, and Al were sequentially deposited under the same conditions as in Example 9 to obtain an OLED element. Got.

[Comparative Example 9]
After the ITO glass substrate was ozone-cleaned for 40 minutes, it was introduced into a vacuum deposition apparatus, and α-NPD, Alq ₃ , LiF, and Al were sequentially deposited under the same conditions as in Example 9 to obtain an OLED element.

[Comparative Example 10]
An ITO substrate on which a hole transporting thin film was formed by the method of Comparative Example 6 was introduced into a vacuum deposition apparatus, and α-NPD, Alq ₃ , LiF, and Al were sequentially deposited under the same conditions as in Example 9 to obtain an OLED element. Got.

[Comparative Example 11]
An ITO substrate on which a hole transporting thin film was formed by the method of Comparative Example 7 was introduced into a vacuum deposition apparatus, and α-NPD, Alq ₃ , LiF, and Al were sequentially deposited under the same conditions as in Example 9 to obtain an OLED element. Got.

[Comparative Example 12]
An ITO substrate on which a hole transporting thin film was formed by the method of Comparative Example 8 was introduced into a vacuum deposition apparatus, and α-NPD, Alq ₃ , LiF, and Al were sequentially deposited under the same conditions as in Example 9 to obtain an OLED element. Got.

The characteristics of the OLED elements obtained in Examples 9 and 10 and Comparative Examples 9 to 12 were measured using the following apparatus. The results are shown in Table 4.
[1] EL measurement system: luminescence quantum efficiency measurement device (EL1003, manufactured by Precise Gauge)
[2] Voltmeter (voltage generation source): Programmable DC voltage / current source (R6145, manufactured by Advantest)
[3] Ammeter: Digital multimeter (R6581D, manufactured by Advantest)
[4] Luminance meter: LS-110 (manufactured by Minolta)

As shown in Table 4, the OLED element (Example 9) comprising the hole transporting thin film prepared from the varnish obtained in Example 6 was compared with the OLED element not including this hole transporting thin film. It can be seen that the driving voltage is reduced, and the current efficiency and the maximum luminance are equal or higher. In addition, the OLED device of Example 9 has a lower driving voltage and higher maximum brightness than the device of Comparative Example 12 using 5-SSA as a dopant instead of the sulfonate compound defined in the present invention. You can see that In addition, the uniformity of the light emission surface of the OLED element produced in Example 9 was favorable, and a dark spot was not recognized.
It can be seen that the OLED element of Example 10 shows good current efficiency together with the OLED element of Example 9. That is, it can be seen that the sulfonic acid ester compound described in Example 4 effectively functions as an electron-accepting substance for the hole injection layer after film formation.

[Example 11]
To a mixture of 24.5 mg of the sulfonic acid ester compound (29) obtained in Example 3 and 19.0 mg of the charge transporting host material BBD synthesized by the method described in Patent Document 4, 3.24 ml of toluene was added at room temperature. And a red-orange transparent varnish was obtained (solid content concentration 1.5% by mass). The obtained varnish did not show solid precipitation even when cooled to -25 ° C. From this result, the sulfonic acid ester compound is used in combination with a charge transporting host material having high solubility in a low polarity solvent such as BBD, so that even if only a low polarity solvent such as toluene is used, it is solid. It can be seen that the charge transporting varnish can be prepared without precipitation.

Claims (16)

An electron-accepting substance precursor comprising a sulfonic acid ester compound represented by the formula (1).

(In the formula, A represents a substituted or unsubstituted aromatic ring group, X represents a substituted or unsubstituted alkylene group having 2 to 5 carbon atoms, 1 to 2 alkyleneoxy carbon atoms or 1 to 2 alkylene groups, carbon 1 to 2 alkylenethio represents a C1 to C2 alkylene group, or C1 to C2 alkylenecarbonyl represents a C1 to C2 alkylene group, and Y represents O, S, or a substituted or unsubstituted divalent amino group. Z represents a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group.) The electron-accepting substance precursor according to claim 1 represented by formula (2) or formula (2 ').

(In the formula, R ^{1 to} R ⁴ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a halogen atom, and A ² represents an arylene group which may have a substituent. A and Z are the same as above.) An electron-accepting substance precursor comprising a sulfonate compound represented by formula (3) or formula (4).

Wherein A ′ is substituted with (SO ₃ H) m, X ′ and (SO ₃ —XYZ) n ¹ or (SO ₃ —XYZ) n ² and is unsubstituted Or an aromatic ring group which may be substituted with a substituted monovalent hydrocarbon group, wherein X is a substituted or unsubstituted alkylene group having 2 to 5 carbon atoms, 1 to 2 alkyleneoxy carbon atoms or 1 to 2 carbon atoms; An alkylene group, a C1-C2 alkylenethio C1-C2 alkylene group, or a C1-C2 alkylenecarbonyl C1-C2 alkylene group is shown, Y is O, S, or substituted or unsubstituted bivalent. A represents an amino group, Z represents a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group, X ′ represents O, S or NH, B represents a substituted or unsubstituted hydrocarbon group, 1, 3 , 5-triazine group, or substituted or unsubstituted formula (5) (6)

Wherein W ¹ and W ² are each independently O, S, S (O) group, S (O ₂ ) group, or unsubstituted or substituted N, Si, P represents a P (O) group), q represents the number of bonds between B and X ′, is an integer satisfying 1 ≦ q, r is the number of repeating units, and satisfies 1 ≦ r It is an integer, m is an integer of 0 or more, n ¹ is an integer of 1 or more, and n ² is an integer of 1 or more. Note that n ¹ + m satisfies the number of substitutions allowed by A ′ in formula (3), and n ² + m satisfies the number of substitutions allowed by A ′ in formula (4). )   The electron-accepting substance precursor according to claim 3, wherein m is 0. An electron-accepting substance precursor comprising a sulfonate compound represented by formula (7) or formula (8).

Wherein W represents a substituted or unsubstituted trivalent hydrocarbon group, A ″ represents a substituted or unsubstituted divalent aromatic ring group, and X represents a substituted or unsubstituted C 2-5 carbon atom. An alkylene group, an alkyleneoxy group having 1 to 2 carbon atoms, an alkylene group having 1 to 2 carbon atoms, an alkylene group having 1 to 2 carbon atoms, or an alkylene group having 1 to 2 carbon atoms. Y represents O, S, or a substituted or unsubstituted divalent amino group, Z represents a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group, and s represents an integer of 2 to 100,000. T represents an integer of 1 to 100,000, u represents an integer of 1 to 100,000, and t + u satisfies 2 to 100,000.) The electron-accepting substance precursor according to claim 5 represented by formula (9) or formula (10).

(Wherein R ^{5 to} R ⁷ each independently represents a hydrogen atom, an unsubstituted or substituted monovalent hydrocarbon group, or a halogen atom. A ″, X, Y, Z, s, t, and u) Is the same as above.)   The number average molecular weight is 5000-1 million, The electron-accepting substance precursor of Claim 5 or 6. The divalent amino group is N (CH ₃ ), N (C ₂ H ₅ ), or N (C ₃ H ₇ ), and the monovalent hydrocarbon group of Z is a methyl group, an ethyl group, or n- The electron-accepting substance precursor according to any one of claims 1 and 3 to 7, which is a propyl group. A sulfonic acid ester compound represented by the formula (3):

Wherein A ′ is substituted with (SO ₃ H) m, X ′ and (SO ₃ —XYZ) n ¹ and is substituted with an unsubstituted or substituted monovalent hydrocarbon group. X represents a substituted or unsubstituted alkylene group having 2 to 5 carbon atoms, an alkylene group having 1 to 2 carbon atoms, an alkylene group having 1 to 2 carbon atoms, or an alkylenethio group having 1 to 2 carbon atoms. Represents an alkylene group, or an alkylenecarbonyl group having 1 to 2 carbon atoms, Y represents O, S, or a substituted or unsubstituted divalent amino group, and Z represents a hydrogen atom or a substituted or non-substituted group. Represents a substituted monovalent hydrocarbon group, X ′ represents O, S or NH, B represents a substituted or unsubstituted hydrocarbon group, 1,3,5-triazine group, or a substituted or unsubstituted formula; (5) or (6)

Wherein W ¹ and W ² are each independently O, S, S (O) group, S (O ₂ ) group, or unsubstituted or substituted N, Si, P represents a P (P) group), q represents the number of bonds between B and X ′, is an integer satisfying 2 ≦ q, m is an integer of 0 or more, and n ¹ is 1 It is an integer above. Note that n ¹ + m satisfies the number of substitutions allowed by A ′. ) The divalent amino group is N (CH ₃ ), N (C ₂ H ₅ ), or N (C ₃ H ₇ ), and the monovalent hydrocarbon group of Z is a methyl group, an ethyl group, or n- The sulfonic acid ester compound according to claim 9, which is a propyl group.   An acid generator comprising the sulfonic acid ester compound according to claim 9 or 10.   A charge transporting varnish comprising the electron acceptor precursor according to any one of claims 1 to 8.   A charge transporting thin film comprising the electron acceptor precursor according to any one of claims 1 to 8.   A charge transporting thin film obtained from the charge transporting varnish according to claim 12.   A method for producing a charge-transporting thin film, comprising applying the charge-transporting varnish according to claim 12 on a substrate and heating.   An organic electroluminescent device comprising the charge transporting thin film according to claim 13 or 14.