JP2000336171A - Hyperbranched polymer having hole conductivity - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject hyperbranched polymer having a hole conductive structure at the molecular ends, not containing π electron conjugated system containing carbonyl group and benzene ring in the molecule center structure and useful as a material isotropically having conductive pathway of hole and having extremely high hole-conductive efficiency. SOLUTION: This hyperbranched polymer has a hole conductive structure at the molecular ends and does not contain π electron conjugated system in molecular center structure. The polymer is preferably dendrimer and preferably has polypropyleneimine structure. The polymer is obtained by reacting, e.g. polypropyleneiminedendrimer with a hole conductive structural unit such as ethyl 4-(N,N-diethylamino)benzoate. The polymer is useful for photoelectric devices.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hyperbranched polymer having hole (hole) conductivity and its application. Since the hyperbranched polymer of the present invention conducts holes generated by the charge generating substance with extremely high efficiency, it is used as a material for devices requiring hole conduction, for example, a photoelectric conversion device such as a solar cell or electrophotography. .

[0002]

BACKGROUND OF THE INVENTION Charged particles, such as lithium cations,
Efficient movement through conduction pathways designed at the molecular level is described, for example, in Spry et al .; Poly
m. Sci. (B), 35, 2925 (1997)
, A system in which lithium sulfonate is bonded and arranged as a side chain of a rigid polymer chain. Although this is an effective concept, it has also been reported that high charge conductivity is limited to the orientation direction of such a rigid molecular chain.

Attempts to achieve an isotropically high charge conductivity have been described, for example, in R. A .; G. FIG. Duan et al .; Am. Che
m. Soc. 117, 10783 (1995),
And L. L. Miller et al .; Am. Chem. S
oc. , 119, p. 1005 (1997) discloses that a polyamidoamine dendrimer having a 1,4,5,8-naphthalenetetracarboxylic acid diimide residue bonded to a quaternary pyridinium salt at a branched terminal isotropically conducting an electron. It has been shown that this conductivity is due to π-electron interaction due to the spatial overlap of the branched terminal structures. D. B. Cairns et al .; Polym. Prep
r. (American Chemical Society
ty), Vol. 39, No. 1, p. 60 (1998) states that when polypyrrole having conductivity is fixed on the surface of polystyrene latex having a particle diameter of about 0.1 μm, only 5.1 is obtained.
It has been reported that the bulk conductivity of the latex particles shows a high value of 2 S / cm using polypyrrole by weight, and this high conductivity is due to the fact that the surface of the latex particles is an electron conduction path. It is estimated that. Such an idea that the surface of the ultrafine particles is used as a charge conduction path is described in F.A. Croce et al .; N
Ature, 394, 456 (1998) suggests the use of ultrafine particle surfaces of metal oxides such as silica and titania.

On the other hand, the phenomenon that holes (holes) move as electric charges has been applied as a principle of a photoelectric conversion device such as a solar cell or an electronic camera. Conventionally, a substance having a chemical structure that stabilizes a positive charge, for example, a material in which a low molecular weight compound such as a triphenylamine derivative is dispersed in a binder polymer has been used as a hole conductive material.
There are also attempts to link such chemical structures to polymer chains. Also, M. Gratzel (a with umlaut)
Nature, vol. 395, p. 583 (1998) discloses an organic compound having an amorphous spiro carbon (2, 2 ', 7, 7'-tetrakis (N, Nd
ip-methoxyphenyl-amine)
It has been reported that using 9,9'-spirobifluorene) as a hole conducting material for a solar cell can convert photons into current with high efficiency.

[0005] In recent years, the effect of the energy of dendrimer molecules gathering at the center has been noted and studied. For example, M. E. FIG. Thompson et al .; Polym. Ma
ter. Sci. Eng. 80, 238 (199
In 9), when the hole transport structure bound to the branch end of the dendrimer is excited by light having the absorption band wavelength, the excitation energy received by the hole transport structure is converted to a dye (dye) arranged at the center of the dendrimer molecule. trap)
It is reported that it completely migrates to the molecular part. However, in any case, it cannot be said that the material technology is designed to control the conduction path of holes, and the development of a material having higher hole conductivity is required.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a material having an extremely high hole conduction efficiency having a hole conduction path isotropically. , And a photoelectric conversion device using the same.

[0007]

Means for Solving the Problems The present inventors have developed a hyperbranched structure represented by a dendrimer that realizes a spherical structure controlled at a molecular level based on a new technical idea that a spherical molecular surface is used as a hole conduction path. As a result of a systematic study on the chemistry and utilization of molecules, we found that a specific structure at the branch end and the molecular center of the hyperbranched polymer could result in a material with high hole conductivity.
The present invention has been completed. That is, the gist of the present invention is to provide a hyperbranched polymer having a hole (hole) conductive structure at a branch terminal and not having a π-electron conjugated system containing a carbonyl group and a benzene ring in its molecular center structure. There are three points: a sheet-shaped molded body containing a polymer, and a photoelectric conversion device having a hole conducting portion containing the hyperbranched polymer.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail. [Hyperbranched polymer and dendrimer] The hyperbranched polymer in the present invention is a polymer having at least one hyperbranched structural unit having a dendritic branched structure having an arbitrary shape. Here, the “hyperbranched structure” refers to G.A. R. Newcome et al .; “D
endric Molecules: Concep
ts, Synthesis, Perspective
s "; VCH Verlagsgesellschaf
tmbH (Weinheim, Germany,
1996), C.I. J. Hawker et al .; Chem.
Soc. Chem. Commun. , 1990, 1
010, D.C. A. Tomalia et al .; Angew. C
hem. Int. Ed. Engl. 29, p. 138 (1990); J. Hawker et al .; Am. C
hem. Soc. 112, 7638 (199
0); M. J. Frechet; Science,
263, 1710 (1994), or Kakimoto Masaaki; Kagaku, 50, 608 (1995).

As schematically shown in FIG. 1, one hyperbranched structural unit is composed of one focal point (Focal p).
oint, focus). Here, the focal point is the center point of the hyperbranched structure, or the starting point of the dendritic branch, more strictly, the last branch when the molecular chain is retrograde from any branch end of the dendritic structure in the direction of convergence of the branch. Means a point. In the hyperbranched polymer of the present invention, the number of branch points is not limited, and includes a structure in which only a focal point is a branch point. Also, as schematically shown in FIG.
Molecules in which the focal points of the plurality of hyperbranched structural units are bound to a polyfunctional molecule and surround the polyfunctional molecular residue as a molecular center structure also correspond to the hyperbranched polymer of the present invention. . FIG. 2 is a schematic diagram of a case where the molecular center structure is a trifunctional molecular residue, which is linked with three hyperbranched structural units at their focal points. Such a plurality of hyperbranched structural units may be different from each other.

The term "molecular center structure" as used in the present invention means a partial structure which is bonded to an arbitrary number of focal points and excludes a hyperbranched structure subsequent to the focal point, in other words,
It means a partial structure which is located at the molecular center of the hyperbranched polymer of the present invention and does not contain any repeating unit (or monomer unit) of any hyperbranched structural unit. As such a molecular center structure,
Ethylene glycol, propylene glycol, 1,4-
Residues of diols such as butanediol, residues of bisphenols such as bisphenol A and 4,4'-dihydroxybiphenyl, residues of dicarboxylic acids such as malonic acid, succinic acid and glutaric acid, 1,2-diaminoethane , 1,3
Residues of bifunctional molecules such as residues of α, ω-diamino-n-alkanes such as -diamino-n-propane and 1,4-diamino-n-butane, residues of triols such as glycerin, Residues of trisphenols such as 1,1,1-tris (4-hydroxyphenyl) ethane, residues of tricarboxylic acids such as nitrilotriacetic acid, and tri (2-aminoethyl)
3 such as the residue of a compound having three amino groups such as amine
Residues of functional molecules, residues of tetrafunctional molecules such as residues of tetraols such as pentaerythritol, a plurality of residues of 2-aminoethanol, thioacetic acid, glycidyl methacrylate, epichlorohydrin, α-amino acids, etc. Residues of bifunctional molecules having different functional groups, residues of trifunctional molecules having plural kinds of functional groups such as malic acid, thiomalic acid, citric acid, diethanolamine, 3,5-dihydroxybenzyl alcohol, and tris Residues of a tetrafunctional molecule having a plurality of types of functional groups such as (2-hydroxymethyl) aminomethane, and the like, and among them, bifunctional such as 1,2-diaminoethane and 1,3-diamino-n-propane Tri (2-
A residue of a trifunctional molecule such as aminoethyl) amine is preferably used.

Hyperbranched macromolecules, especially those having a completely regular branched structure collectively called dendrimers (see FIG. 1)
Is known to be a spherical polymer because the branched ends rapidly become crowded with an increase in molecular weight. Although its molecular diameter usually falls within the range of about 0.001 μm to 0.02 μm, in the case of the hyperbranched polymer of the present invention, this value is preferably 0.001 to 0.015 μm, more preferably 0.002 to 0 μm. 0.01 μm, most preferably 0.002
About 0.008 μm. The molecular diameter is observed by a light scattering method or a transmission electron microscope.

The dendrimer is most preferable as the structure of the hyperbranched polymer of the present invention because it can achieve the most efficient branch density per unit molecular weight. Although the molecular weight of a dendrimer can be almost completely controlled in principle, the molecular weight employed in the present invention is usually 300 to 50,000, more preferably 500 to 30,000, and still more preferably 700 to 200.
00, most preferably about 1,000 to 10,000.

[Chemical Structure of Hyperbranched Polymer] The structure of the hyperbranched polymer of the present invention is not particularly limited as long as it does not significantly inhibit the hole conductivity of the branch terminal described later. Since the purpose is to cause hole conduction at the branched terminal (molecular surface) of the polymer, interaction such as energy transfer from the surface to the inside is desirably minimized. Therefore, M. E. FIG. Thomp
A structure having a dye molecule residue serving as a dye trap as a molecular center structure, such as a dendrimer described in a document by Son et al., is very undesirable. That is, in general, when the hyperbranched polymer has a π-electron conjugated system containing a carbonyl group and a benzene ring in the molecular center structure, the molecular center structure may have the same effect as the above-mentioned dye trap. It is not preferable.

The specific structure of such a π-electron conjugated system containing a carbonyl group and a benzene ring is described, for example, in the aforementioned M.A. E. FIG. In addition to coumarin residues and anthraquinone residues described in the literature by Thompson et al., Acetophenone residues, benzophenone residues, 9-fluorenone residues,
Anthrone residue, benzanthrone residue, acenaphthenequinone residue, 1,4-naphthoquinone residue, phenanthrene-9,10-quinone residue, thioindoxyl residue, xanthone residue, indigo residue, thioindigo residue , A residue of a conjugated ketone such as a hemithioindigo residue, and a residue of a conjugated ester such as a phthalide.

Examples of the structure of the hyperbranched polymer that can be used in the present invention include those described in G. R. Various structures described in a new book by Newcome et al. Buhleier et al; Sy
nthesis, 1978, p. 155;
M. M. de Brabander-van den
Berg et al .; Angew. Chem. Int. Ed. E
ngl. 32, p. 1308 (1993); J. Ha
The polybenzyl ether structure reported in two documents by Wker et al., C.I. J. Hawker et al .; Am. Ch
em. Soc. , 113, p. 4583 (1991); Malm
Strom et al; Macromolecules, 28
[2,2-Bis (hydroxymethyl) propionic acid] structure, as reported in Vol. See Morikawa et al .; Polymer J. et al. ,
24, p. 573 (1992); Roovers et al .; Polym. P
G. reprints, vol. 33, p. 182 (1992); R. Newk
Ome et al .; Org. Chem. , 50 volumes, 2003
(1985), the polyether amide structure described in the above D.I. A. The polyamidoamine structure reported in the literature by Tomalia et al. Jaya
J. Raman et al .; Am. Chem. Soc. , 120
Vol. 12, pp. 12996 (1998), and the like. From the viewpoint of ease of synthesis and stability, the polypropylene imine structure, the polyamidoamine structure, the aliphatic polyether structure, and the polybenzyl The ether structure, the aromatic polyester structure and the like are preferable, and the polypropylene imine structure, the polyamidoamine structure, and the aliphatic polyether structure are more preferable as a structure not containing an aromatic ring for stabilizing a positive charge, and the following formula ( The polypropylene imine structure of 1) is most preferred.

[0016]

Embedded image

In formula (1), the structure of the second-generation dendrimer is shown for convenience, but the hyperbranched polymer used in the present invention is not limited in its branched structure as long as it has a hyperbranched structure. It does not have to be a fully controlled dendrimer, and even if it is a dendrimer, the number of generations is not limited. Note that the dendrimer generation is a term meaning the order of a regular branch as shown in FIG. The number of dendrimer generations is generally 1 to 10, preferably 2 to 8, more preferably 3 to 7, and most preferably 3 to 5 from the viewpoint of the density of terminal groups and the ease of synthesis.

[Hole Conducting Structure at Branch Terminal] The hyperbranched polymer of the present invention has a hole (hole) conductive structure at its branch terminal. Here, the hole conductive structure is a structure capable of stabilizing resonance when a positive charge is applied to the structure. Specifically, a structure having a nitrogen atom bonded to an aromatic ring, for example, a 4- (N, N-dimethylamino) phenyl group, a 4- (N, N-diethylamino) phenyl group,
4- (N, N-diisopropylamino) phenyl group, 4
-(N, N-dibutylamino) phenyl group, 4- (N,
Structure having a dialkylphenylamine residue such as N-dibenzylamino) phenyl group, 4- (N, N-diphenylamino) phenyl group, 4- {N, N-bis (4-methoxyphenyl) amino} phenyl group Preferred examples thereof include a structure having a triphenylamine residue such as N-alkylcarbazole residue, phenanthrene residue, oxazole residue, oxadiazole residue, imidazole residue, and phenylhydrazone residue.

There is no particular limitation on the bonding mode in which these hole conductive structures are bonded to the branched terminal of the hyperbranched polymer. For example, a carbon-carbon bond, a carbon-nitrogen bond, an amide bond, an ether bond, an ester bond, etc. It is possible, and an amide bond is particularly preferable. Therefore, specific preferred structural formulas of the hole conductive structure which the hyperbranched polymer of the present invention has at the branch terminal include amide-bonded structures represented by the following formula (2). However, the structural formula (a) of the formula (2)
In the formula, R ¹ represents a methyl group, an ethyl group, an isopropyl group,
Any one of a butyl group and a benzyl group is represented by the structural formula (b)
R ² represents a methyl group or a methoxy group, respectively.

[0020]

Embedded image

[Sheet-shaped molded article] The hyperbranched polymer of the present invention is particularly preferably used as an excellent hole-conductive sheet material when it is formed into a sheet-shaped molded article containing the same.
The sheet-shaped molded body of the present invention is a known production method, for example,
Thermoplastic molding methods such as injection molding, extrusion molding, hot press molding, and injection compression molding, wet methods such as coating and drying on a substrate, such as spin coating, dip coating, wetting film, and spraying It is manufactured by a coating method or the like.

The thickness and size of the sheet-like molded article of the present invention,
There are no particular restrictions on the shape and properties of the surface (eg, flat, spherical, curved, concave, convex, porous surface, smoothness, or thickness distribution, etc.).
1 to 5000 μm, preferably 0.05 to 3000 μ
m, more preferably about 0.08 to 2000 μm, and most preferably about 0.1 to 1000 μm. If necessary, an arbitrary number of surface protective layers, reflective layers, filter layers for cutting a specific wavelength region, light shielding layers, and the like may be laminated.

The sheet-shaped molded article of the present invention may be formed of the hyperbranched polymer of the present invention itself, or may be formed using a composition in which the hyperbranched polymer is dispersed in an appropriate resin matrix. It does not matter. When the hyperbranched polymer of the present invention is used as such a composition, its amount is usually 20 to 100% by weight, preferably 40 to 100% by weight.
%, More preferably 50 to 100% by weight, most preferably 60 to 100% by weight. The method for producing such a composition is not particularly limited. For example, tetrahydrofuran (THF), 1,4-dioxane, acetone, cyclohexanone, methyl ethyl ketone, N, N-
General-purpose means such as solution mixing in solvents such as dimethylformamide (DMF), toluene, chlorobenzene, methylene chloride, chloroform and dichloroethane, or melt mixing using a single screw extruder, twin screw extruder, Brabender, roll mixer, etc. Is possible.

The material used as the resin matrix is not particularly limited as long as the effects of the present invention are not significantly impaired. For example, 2,2-bis (4-hydroxyphenyl) propane (commonly called bisphenol A) is used as a raw material. Polycarbonate made from 2,2-bis (3-methyl-4-hydroxyphenyl) propane (commonly known as bisphenol C), polycarbonate made from bis (4-hydroxyphenyl) phenylmethane (commonly known as bisphenol P), Aromatic polycarbonate resins such as polycarbonate using 1,1-bis (4-hydroxyphenyl) cyclohexane (commonly known as bisphenol Z) as a raw material, and polycarbonate using bis (3-methyl-4-hydroxyphenyl) phenylmethane as a raw material;
Polyarylate resin which is a polycondensate of bisphenols such as bisphenol A and terephthalic acid or isophthalic acid,
Acrylic resins such as polymethyl methacrylate and polyethyl acrylate, polystyrene, polyvinyl toluenes, poly-α-methylstyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene such as styrene-maleic anhydride copolymer Resin, polyvinyl butyral, polyvinyl formal, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyvinylidene chloride, phenoxy resin, cellulose acetate resin, ethyl cellulose resin, poly-N-vinyl carbazole, silicone Thermoplastic or thermosetting resin such as resin, epoxy resin, melamine resin, urethane resin, phenol resin and alkyd resin. Of these, polycarbonates starting from 2,2-bis (4-hydroxyphenyl) propane (commonly known as bisphenol A) and 2,2-bis (3-methyl-4-hydroxyphenyl) propane (commonly known as bisphenol C)
Fragrances such as polycarbonates made from styrene, polycarbonates made from 1,1-bis (4-hydroxyphenyl) cyclohexane (commonly called bisphenol Z), and polycarbonates made from bis (3-methyl-4-hydroxyphenyl) phenylmethane Aromatic polycarbonate resins and polyarylate resins which are polycondensates of bisphenol A with terephthalic acid or isophthalic acid are particularly preferred.

The dispersion state of the hyperbranched polymer of the present invention in such a composition is particularly limited as long as irradiation light (usually having a wavelength from ultraviolet to infrared) used in a photoelectric conversion device described later is transmitted. Although not limited, the average diameter of the phase-separated domain of the hyperbranched polymer observed by a transmission electron microscope is usually 0.5 μm or less, preferably 0.3 μm or less.
m, more preferably 0.2 μm or less, and most preferably 0.1 μm or less, and the numerical value is preferably as small as possible.

The sheet-like molded article of the present invention may contain any additives, for example, various stabilizers such as an antioxidant, a heat stabilizer or a light stabilizer, glass fiber, glass, and the like, as long as the effects are not significantly impaired. Beads, mica, talc, kaolin, clay minerals, carbon fiber, carbon black, graphite,
Various fillers such as metal fibers and metal powders, antistatic agents, release agents, plasticizers, pigments and dyes, rubbers and elastomers, thermoplastic resins and the like may be mixed.

[Photoelectric Conversion Device] The hyperbranched polymer of the present invention is used as a photoelectric conversion device having a hole conducting portion containing the polymer. As shown in FIG. 4, such a photoelectric conversion device provided by the present invention necessarily has three components, that is, a charge generation unit, a hole conduction unit, and an electron conduction unit. Examples include a camera.

(1) Charge generating section: a charge generating substance which causes charge separation (a phenomenon of generating negatively charged electrons and positively charged holes) by light irradiation, for example, azo pigments having a carbazole skeleton, An azo pigment having a stilstilbene skeleton, an azo pigment having a triphenylamine skeleton, an azo pigment having a dibenzothiophene skeleton, an azo pigment having an oxadiazole skeleton, an azo pigment having a fluorenone skeleton, and a bisstilbene skeleton Azo pigments such as azo pigments having a distyryl oxadiazole skeleton, azo pigments having a distyryl carbazole skeleton, tris azo pigments having a carbazole skeleton, or phthalocyanine pigments and indigo pigments , Containing perylene pigments,
Polyamide, polyurethane, polyester,
A binder resin such as epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, poly-N-vinylcarbazole, and polyacrylamide is used in combination. These are suitable solvents such as tetrahydrofuran (THF), 1,4-
As a dispersion of dioxane, acetone, cyclohexanone, methyl ethyl ketone, dichloroethane or the like, it is usually formed into a film by a coating method such as spray coating, bead coating or dip coating. The film thickness is
Usually about 0.01 to 100 μm, preferably 0.1
The thickness is about 80 μm, more preferably about 0.5 to 70 μm, and most preferably about 1 to 70 μm.

When the photoelectric conversion device of the present invention is designed as a solar cell, Ru, F
Complexes of transition metal elements such as e and Ce are exemplified. Among them, a Ru complex is preferable, and a divalent Ru complex is particularly preferable.
As the ligand, 2,2′-bipyridyl, 4,4′-dicarboxyl-2,2′-bipyridyl, 4,4′-dimethyl-2,2′-bipyridyl, 4,4′-diisopropyldicarboxy Lat-2,2'-bipyridyl, 2,
2 ′: 6,2 ″ -terpyridine, diethyl-2,
2 ′: 6,2 ″ -terpyridine-4-phosphonate,
Ligands having a nitrogen-containing aromatic ring such as a pyridine ring such as 3- (pyrrole-1-ylmethyl) pyridine and pyridine, SC
N ^- and CN ^- coordinating anion such as chloride, bromide, halide anions such as iodide ions,
Examples thereof include compounds having a hydroxyl group such as water, methanol, and ethanol. A specific transition metal complex has a structure in which these ligands are arbitrarily combined, and preferably contains at least one of 2,2′-bipyridyl or a derivative thereof. Specifically, Ru (4,4′-dicarboxyl-2,2′-bipyridyl) ₂ (SCN) ₂ , Ru (4
4'-dicarboxyl-2,2'-bipyridyl) ₂ (C
N) ₂ , Ru (4,4′-dicarboxyl-2,2′-
Bipyridyl) ₂ Cl _{2 and the} like.

(2) Hole conduction part: A sheet-like molded article containing the above-described hyperbranched polymer of the present invention is used. (3) Electron conductive part: A conductive base material such as a sheet or pipe of any metal such as aluminum, copper, iron, nickel or the like in contact with the above-mentioned charge generating part is used, and among them, aluminum is preferable. In addition, when a layer of the metal oxide (which may be hydrated) or an appropriate undercoat layer of polyamide or the like is formed on the surface of the conductive substrate, good performance may be exhibited.

[0031]

EXAMPLES Specific examples of the present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the scope of the present invention.
The reagent used was supplied by Aldrich.

[Measurement method] <FT-IR> FT / IR-8000 manufactured by JASCO Corporation
Type FT-IR, cast film of sample solution was prepared on KBr crystal and measured. <NMR> JNM-EX270 type FT-N manufactured by JEOL Ltd.
^{MR (1 H: 270MHz, 13} C: 67.8MHz).
Solvent: CDCl _3.

<Synthesis of Hole Conductive Structural Unit> (1) Synthesis of ethyl 4- (N, N-diethylamino) benzoate 4-Diethylaminobenzoic acid (100 parts by weight) was dissolved in a large excess of anhydrous ethanol. Sulfuric acid (1 part by weight) was added and the mixture was heated to reflux. Ethanol was distilled off occasionally several times to azeotropically remove the generated water to promote the formation of ethyl ester. After concentration, the residue was dissolved in ethyl acetate, washed with water, washed with aqueous sodium bicarbonate, washed with water, and dried over sodium sulfate. The residue obtained by filtration and concentration was purified by silica gel column chromatography to obtain the desired product. The structure was obtained by observing the absorption band derived from the ester group in the FT-IR spectrum,
^{In the 1} H-NMR spectrum, it was confirmed from the fact that signals of protons derived from an ethoxy group, a diethylamino group, and a benzene ring were respectively observed at predetermined integration values.

(2) Synthesis of methyl 4- (1,8-naphthalimidyl) benzoate Methyl 4-aminobenzoate (1 equivalent) was dried in N, N
Dissolved in dimethylformamide and stirred for 1,8
-Naphthalic anhydride (1 equivalent) was added in small portions. This was heated at 100 ° C. under reduced pressure to evaporate generated water to promote the formation of imide. After concentration, the residue was purified by silica gel column chromatography to obtain the desired product. The structure was obtained by observing the absorption bands of a carbonyl group derived from an ester group and an imide group in the FT-IR spectrum,
^{In the 1} H-NMR spectrum, it was confirmed from the fact that signals of protons derived from the methoxy group and the aromatic ring were respectively observed at predetermined integrated values.

<Example 1: Hole-conductive dendrimer and sheet-like molded article> Polypropyleneimine dendrimer having 64 branched terminal amino groups (described as DAB-Am-64 in the catalog of Aldrich; 1 equivalent) And ethyl 4- (N, N-diethylamino) benzoate (80 equivalents) synthesized above were dissolved in N, N-dimethylformamide, and the resulting ethanol was distilled off while heating and stirring at 60 ° C. under reduced pressure. After concentration, the residue was purified by silica gel column chromatography to obtain a compound in which the amino group at the branched terminal of the dendrimer was converted to the corresponding amide of 4-diethylaminobenzoic acid. Structure, it was observed the appearance of the absorption band of the carbonyl group derived from the disappearance amide group absorption band of the carbonyl group derived from the ethyl ester of the starting material in the FT-IR spectra at ¹ H-NMR spectrum, a diethylamino group , A benzene ring, and a signal of a proton derived from the dendrimer were observed at predetermined integration values, respectively. This material gives a sheet-like molding by wet application from a tetrahydrofuran solution, which has a high hole conductivity.

<Example 2: Hole-conductive dendrimer and sheet-shaped molded article> In Example 1, methyl 4- (1,8-naphthalimidyl) benzoate (80) synthesized above was used in place of ethyl 4-diethylaminobenzoate. The same reaction and purification procedure were carried out using the same equivalent) to obtain a compound in which the amino group at the terminal end of the dendrimer was converted to the corresponding amide of 4- (1,8-naphthalimidyl) benzoic acid. Structure, it was observed the disappearance of the absorption band of the carbonyl group derived from the methyl ester of starting material by FT-IR spectra, ¹
In the H-NMR spectrum, signals of the aromatic ring and the proton derived from the dendrimer were respectively observed at predetermined integral values, and in the ¹³ C-NMR spectrum, the carbonyl carbon derived from the amide bond and the imide bond was observed. Was confirmed from the fact that each signal was observed. This material gives a sheet-like molding by wet application from a tetrahydrofuran solution, which has a high hole-hole conductivity.

<Example 3: Composition and sheet-like molded article> 20 parts of polypropyleneimine dendrimer (80 parts by weight) having an amide of 4- (1,8-naphthalimidyl) benzoic acid at the branch end synthesized in Example 2 were used. Part of bisphenol A polycarbonate resin (Mitsubishi Engineering Plastics, Novarex 7022PJ; Novarex is a registered trademark) was mixed with a solution in tetrahydrofuran, and an aluminum tube provided with a charge generation layer was immersed and dried while dipping. The composition of the dendrimer and the polycarbonate resin was formed into a sheet on the aluminum tube by a dip coating method. Since such a sheet-shaped molded article has high hole conductivity, the aluminum tube molded on the surface thereof is used as a photoreceptor for electrophotography.

[0038]

The hyperbranched polymer of the present invention has a very high hole conduction efficiency. Further, the hyperbranched polymer was prepared in Example 1.
As shown in Examples 2 and 3, it is possible to provide a good sheet-like molded body, and as shown in Example 3, a sheet-like molded body of a composition with, for example, an aromatic polycarbonate resin.
Since these sheet-shaped molded articles have high hole conductivity, they are applied as photoelectric conversion devices having such sheet-shaped molded articles as hole conducting portions.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing that a dendrimer is a special concept of a hyperbranched polymer whose branch structure is completely regularly controlled, and is included in the concept of a hyperbranched polymer.

FIG. 2 is a schematic diagram of a hyperbranched polymer in which a multifunctional molecule having a central structure is bonded to a plurality of hyperbranched polymers at their focal points.

FIG. 3 is an explanatory diagram of “generation” of dendrimer.

FIG. 4 is a schematic diagram illustrating a configuration of a photoelectric conversion device.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) // H01M 14/00 H01L 31/04 DF term (reference) 4F071 AA59 AH12 BB03 BB05 BB06 BC01 4J031 BB03 BB02 BB03 BB05 BC19 BD23 CA06 CD12 CD13 4J043 PA13 PB07 PB23 QB24 YB06 YB24 ZA41 ZA51 ZB21 ZB24 5F051 AA11 BA05 5H032 AA06 EE04

Claims (6)

[Claims] 1. A hyperbranched polymer having a hole (hole) conductive structure at a branch terminal and not including a π-electron conjugated system containing a carbonyl group and a benzene ring in a molecular center structure. 2. The hyperbranched polymer according to claim 1, wherein the hole conductive structure has a nitrogen atom bonded to an aromatic ring. 3. The hyperbranched polymer according to claim 1, wherein the hyperbranched polymer is a dendrimer. 4. The hyperbranched polymer according to claim 1, wherein the hyperbranched polymer has a polypropyleneimine structure. 5. A sheet-like molded article containing the hyperbranched polymer according to claim 1. 6. A photoelectric conversion device having a hole conducting part containing the hyperbranched polymer according to claim 1.