DE60121724T2 - Single-layer type electrophotographic material - Google Patents

Description

BACKGROUND THE INVENTION

The The present invention relates to an electrophotographic material single-layer type used in imaging devices such as electrostatic copiers, fax machines and laser beam printers can be used. The present The invention particularly relates to an electrophotographic material of Single-layer type superior in abrasion resistance can be and has a long life.

In the above Imaging devices are various electrophotographic Materials with sensitivity within the wavelength range one in these devices used light source used. One of them is an inorganic one photosensitive material in which an inorganic material how selenium is used in a photosensitive layer, while another material is an organic photosensitive material (organic photosensitive material, OPC), in which in a photosensitive Layer an organic material is used. Of these photosensitive Materials became extensive organic photosensitive material Investigations as it compared to the inorganic Photosensitive material is easy to make and one further Range of choice of photosensitive materials such as Charge transfer materials and charge generation materials as well as resin binders as well as a high functional one Design freedom available.

The organic photosensitive materials can be roughly classified in electrophotographic materials of the so-called multi-layer type (hereinafter sometimes referred to as "photosensitive Multi-layer type material "abbreviated") a charge generating layer structure which is a charge generation material contains and a charge transfer layer, which is a charge transfer material contains which are laminated together, as well as photosensitive materials of the single-layer type (hereinafter sometimes abbreviated as "single-layer type photosensitive material") a charge generation material and a charge transfer material are dispersed in the same photosensitive layer. From It is the photosensitive material of these organic photosensitive materials Multilayer-type material that has a monopoly position on the world market has. The multilayer type photosensitive material is exclusively a photosensitive material of the negative charge type, the conductive substrate, and a charge generation layer and a Charge transfer layer formed on the conductive substrate in this order are.

On the other side enjoys in the most recent Time the single-layer type photosensitive material because of its benefits described below are of greater interest. Namely, the single-layer type photosensitive material is because of superior to its simple layer structure in terms of productivity, wherein the occurrence of layer defects of the photosensitive layer is prevented; furthermore the optical properties are improved because fewer interfaces between Layers are present. Furthermore, a single photosensitive Material as positive charge type photosensitive material and used as a negative charge type photosensitive material, by acting as a charge transfer material an electron transfer material and a hole transfer material used in combination.

The electrophotographic material is used in the imaging process the repeated steps of charging, exposure, development, the transmission, used for cleaning and charge neutralization. A through Charge / Exposure is generated electrostatic latent image developed with a toner as a powder in the form of microparticles. The developed toner is further transferred to a transfer material in the transfer process like paper transfer. However, the toner is not transferred completely (100%) and partly remains on the photosensitive material. If the remaining toner is not removed, it is impossible to to achieve high quality picture, the repeated Processes is free of impurities. It is therefore necessary the remaining one Remove toner by cleaning.

in the Cleaning process will typically be a fur brush, a magnetic brush or used a blade. In terms of accuracy of cleaning and the rationalization of the device structure In general, a blade cleaning is selected in which the cleaning by directly contacting a blade-shaped synthetic resin plate with a photosensitive material is performed.

Although blade cleaning provides high accuracy, it increases the mechanical stress of the photosensitive material, thereby increasing problems such as increase of photosensitive layer wear, reduction of surface potential, reduction in sensitivity, and so on the like, thereby making it difficult to obtain high-quality images.

Different as the photosensitive material of the multilayer type is in Case of the single-layer type photosensitive material, the charge generation layer also in the extreme surface the photosensitive layer, if no cover layer is formed is. In contrast, in the case of the photosensitive material of the multilayer type and the negative charge type, the charge generation layer the charge transfer layer protected. In the case of the single-layer type photosensitive material, the charge generation material is often exposed to active gases such as ozone and NOx in the image-forming Device arise. Therefore, the charging ability becomes of the photosensitive material, and defects such as fog in the picture can caused by a reduction of the surface potential.

at the development of a so-called "durable" photosensitive material in which Image defects such as fogging even after a significant Number of pressure does not occur, a method was specified in a resin with improved wear resistance or different Lubricants from ester derivatives of stearic acid and lauric acid, fluororesins and the like can be used. Following the procedures described above becomes the wear resistance the photosensitive layer improved. However, it will be difficult the surface area the photosensitive layer, thereby reducing the chargeability thereof is that it is exposed to reactive gases such as ozone and NOx, the in the image-forming device be formed, thereby making it impossible to a "long-lasting" photosensitive Material to achieve.

The unaudited published Japanese Patent Applications (Kokai Tokkyo Koho Hei) No. 5-333577, 5-333578, 5-333579 and 5-346674 disclose that a multilayer type photosensitive material, a special charge generation material and polyethylene glycol having a molecular weight of 2,000 or less in a charge generation layer contains a better charge stability having. Since polyethylene glycol can also serve as a lubricant, It is expected that both the wear resistance and the durability across from Gases such as ozone and NOx are improved simultaneously when polyethylene glycol is applied to the single-layer type photosensitive material.

If however, polyethylene glycol in the photosensitive material of Single-layer type is used, the sensitivity is drastically reduced. It was therefore found that the resulting Photosensitive material not suitable for practical use is.

JP-A-03 191360 discloses a photosensitive layer comprising a special Azo pigment, a specific polyalkylene glycol and a binder resin contains wherein the layer is coated on a conductive substrate.

US-A-5319069 discloses an electrophotographic photoconductor having an electrical conducting carrier and a photoconductive layer having a special Polyether, a charge generation material, a charge transfer material and a binder resin.

SUMMARY THE INVENTION

To solve the above-described problems, in-depth studies have been made by the present inventors and found that a single-layer type electrophotographic material can be obtained by incorporating into a photosensitive layer a polyalkylene glycol compound whose end groups are esterified or etherified which has the general formula [1], A _{1 is} -O - [(CH ₂ ) _m -O] _n -A ₂ , in which mean
A ₁ and A ₂ , which are the same or different, represent an alkyl or aryl group of 1 to 50 carbon atoms or a group -CO-R ¹⁰ , wherein R ^{10 represents} an alkyl or aryl group of 1 to 50 carbon atoms,
m is an integer from 1 to 5 and
n is an integer from 2 to 100.

The present invention provides a single-layer type electrophotographic material comprising a conductive substrate and a photosensitive layer comprising a resin binder containing at least a charge-generating material and a charge-transferring material, and conductive material Substrate is formed, wherein the photosensitive layer comprises a polyalkylene glycol compound of the general formula [1]: A _{1 is} -O - [(CH ₂ ) _m -O] _n -A ₂ , in which mean
A ₁ and A ₂ , which are the same or different, represent an alkyl or aryl group of 1 to 50 carbon atoms or a group -CO-R ¹⁰ , wherein R ^{10 represents} an alkyl or aryl group of 1 to 50 carbon atoms,
m is an integer from 1 to 5 and
n is an integer from 2 to 100;
it is characterized in that the charge transfer material comprises a hole transferring material and an electron transferring material, and the solid content of the charge transferring material is not less than 30% by weight and not more than 55% by weight based on the total solid content.

One single-layer type electrophotographic material of the present invention Invention can have a long life and a remarkably better wear resistance and sensitivity, and also better durability across from Have gases such as ozone and NOx.

It It is assumed that according to the present Invention a pseudo-three-dimensional network by binding of hydrophilic functional groups (e.g., hydroxyl groups, carbonyl groups, etc.) in the resin binder having an ester group or an ether group in a polyalkylene glycol compound of the general formula [1] via van der Waals forces, hydrogen bonds or a chemical bond is formed, in addition to the mere role the polyalkylene glycol compound as a lubricant and the film hardness of the resin binder and thus the entire photosensitive layer, making it possible to obtain a single-layer type electrophotographic material which is less sensitive to abrasion, that is, an electrophotographic Material with excellent wear resistance.

There the formation of the above network micropores on the surface of reduced light-sensitive layer, ozone and NOx can be less easily from the surface the photosensitive layer into the photosensitive layer penetrate, reducing the resistance across from the gases is improved.

BRIEF DESCRIPTION OF THE DRAWINGS

1 FIG. 12 is a graph showing the relationship between the solid content of an electric charge transferring material (ECTM) based on the total solid content and the wear based on evaluation data of Examples 1 to 4 and FIGS. 26 to 29.

2 Fig. 12 is a graph showing the relationship between the solid content of a charge transfer material (ECTM) based on the total solid content and the residual potential (sensitivity) based on evaluation data of Examples 1 to 4 and 26 to 29.

3 Fig. 15 is a graph showing the relationship between the solid content of a charge transfer material (ECTM) based on the total solid content and ΔV ₀ (ozone resistance) based on evaluation data of Examples 1 to 4 and 26 to 29.

4 Fig. 15 is a graph showing the relationship between the solid content of a charge transfer material (ECTM) based on the total solid content and the wear based on evaluation data of Examples 30 to 33 and 60 to 63.

5 Fig. 15 is a graph showing the relationship between the solid content of a charge transfer material (ECTM) based on the total solid content and the residual potential (sensitivity) based on evaluation data of Examples 30 to 33 and 60 to 63.

6 Fig. 15 is a graph showing the relationship between the solid content of a charge transfer material (ECTM) based on the total solid content and ΔV ₀ (ozone resistance) based on evaluation data of Examples 30 to 33 and 60 to 63.

DETAILED DESCRIPTION OF THE INVENTION

The single-layer type electrophotographic material of the present invention will be described below described in detail.

polyalkylene glycol

The in the single-layer type electrophotographic material of the present invention Polyalkylene compound used in the invention is characterized that the terminal ones Hydroxy groups (-OH groups) are esterified or etherified, such as represented by the general formula [1]. When the terminal groups remain as hydroxy groups and not esterified or etherified are, that is, when a polyethylene glycol is used, which in the Japanese published unaudited Patent Applications (Kokai Tokkyo Koho Hei) No. 5-333577, 5-333578 and 5-346674, the sensitivity of the electrophotographic Material of the single-layer type drastically reduced.

It It is believed that the following are reasons for reducing the sensitivity available. If the hydroxy groups are left untreated, the compatibility the polyalkylene glycol compound because of their high hydrophilicity in a resin binder with comparatively high hydrophobicity, the in the photosensitive layer of the photosensitive material is used of the single-layer type, e.g. a polycarbonate resin, reduced. Therefore, agglomeration of the molecules of the polyalkylene glycol compound occur, and the agglomerates of the molecules of this compound act as impurity detention centers.

Preferably, a polyalkylene glycol compound of the general formula [1] is used in which the number of carbon atoms of the groups A ₁ and A _{2 is} in the range of 1 to 25. In addition, in the general formula [1], the integer m is preferably 2 or 3, and the integer n is preferably 3 to 15 from the viewpoint of resistance to gases such as ozone and NOx. As preferred embodiments, PEG-1 (eg IONET DL-200, manufacturer Sanyo Chemicals, Co., Ltd.), PEG-2 (eg, IONET DS-300, manufacturer Sanyo Chemicals, Co., Ltd.), PEG-3 (eg, product of Aldrich Co.), PEG -4 or PEG-5 whose chemical formulas are shown later.

Of the Content of polyalkylene glycol compound [1] is according to the structure the polyalkylene glycol compound and the structure of the resin binder in suitable Is set and is not particularly limited, however preferably not less than 50% by weight and not more than 500% by weight, based on the amount of charge generating material.

Of the Amount of the charge generating material is preferably in the range from 0.1 to 20% by weight, based on the total weight of the resin binder, as described below. The proportion of the polyalkylene glycol compound [1] is preferably in a range of 0.05 to 100% by weight and still more preferably in the range of 1 to 15% by weight, based on the weight of the resin binder.

If the amount of the polyalkylene glycol compound [1] exceeds 500% by weight, based on the content of charge generation material, the dispersibility and the solubility the charge generation material and the charge transfer material used in the Resin binders are reduced, resulting in a bad one Sensitivity leads. On the other hand, when the proportion of the polyalkylene glycol compound [1] is less than 50% by weight based on the amount of the charge generation material, is the number of bonds between an ester group or one Ether group of the polyalkylene glycol group and a hydrophilic functional Group of resin binder reduced.

It is therefore for improving wear resistance and gas resistance less effective.

Resin binder

When Resin binder used in the electrophotographic material of Single-layer type of the present invention is used, various Resins are used conventionally be used in photosensitive materials. Thus, e.g. are used: thermoplastic resins, such as styrene-butadiene copolymers, styrene-acrylonitrile copolymers, Styrene-maleic acid copolymers, acrylic copolymers, Styrene-acrylic acid copolymers, Polyethylene, ethylene-vinyl acetate copolymers, chlorinated polyethylene, Polyvinyl chloride, polypropylene, vinyl chloride-vinyl acetate copolymers, Polyesters, alkyd resins, polyamides, polyurethanes, polycarbonates, polyallylates, Polysulfones, diallyl phthalate polymers, ketone resins, polyvinyl butyral and polyether resins; crosslinkable thermosetting resins, such as silicone resins, Epoxy resins, phenolic resins, urea resins and melamine resins, as well curable Resins, such as epoxy acrylates and urethane acrylates. These resin binders can be used alone, or there may be two or more types of such Resin binder copolymerized or mixed.

worin R²⁰ und R²¹, die gleich oder verschieden sind, ein Wasserstoffatom oder eine Alkylgruppe mit 1 bis 3 Kohlenstoffatomen bedeuten.It is particularly preferable to use a resin binder containing a polycarbonate having a repeating unit represented by the general formula [2]:

wherein R ²⁰ and R ²¹ , which are the same or different, represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

The Polycarbonate with a repeating unit of the general formula [2] is effective for improving wear resistance, as its Molecular structure has high rigidity.

At the Further preferred is a polycarbonate resin having a through the general formula [2] shown recurring unit used, which is copolymerized with bisphenol Z.

The Polycarbonate having a compound represented by the general formula [2] recurrent unit is to improve the wear resistance effective, but is less compatible with the polyalkylene glycol compound, the represented by the general formula [1]. If the compatibility between the polyalkylene glycol compound and the resin binder bad, there is a tendency to reduce the sensitivity, as described above.

On on the other hand, a bisphenol Z type polycarbonate has good compatibility with the polyalkylene glycol compound. It therefore becomes possible at the same time an improvement in wear resistance and to achieve an improvement in sensitivity by the Polycarbonate resin with a repeating unit, which is characterized by general formula [2] is used, which with Bisphenol Z is copolymerized.

at the copolymerization is the molar ratio of polycarbonate with a recurrent unit represented by the general formula [2] is preferred to the bisphenol Z type polycarbonate in the range of 5:95 to 50:50.

The The resin binder described above preferably has a weight average of the molecular weight in the range of 10,000 to 500,000 and still more preferably in the range of 30,000 to 200,000.

CGM

Examples for the Charge generating material used in the electrophotographic material The single-layer type of the present invention is used conventional known charge generation materials, e.g. organic photoconductive Materials such as metal-free phthalocyanine, oxotitanyl phthalocyanine, hydroxygallium phthalocyanine, Perylene pigment, bisazo pigment, dithioketopyrrolopyrrole pigment, metal-free naphthalocyanine pigment, metal-containing naphthalocyanine pigment, squaline pigment, trisazo pigment, Indigo pigment, azulenium pigment, cyanine pigment, pyrylium salt pigment, Anthanthrone pigment, triphenylmethane pigment, Threne pigment, toluidine pigment, Pyrrazoline pigment and quinacridone pigment, as well as inorganic photoconductive Materials such as selenium, selenium-tellurium, selenium-arsenic, cadmium sulfide and amorphous silicon.

These Charge generating materials can Used alone or in combination, the resulting electrophotographic material has an absorption wavelength within a desired range having.

at digital optical imaging devices (e.g., laser printers, fax machines, etc.), where a light source such as a semiconductor laser is used is a photoconductive material with a sensitivity at a wavelength range of 700 nm or above required. Therefore, phthalocyanine pigments, such as metal-free Phthalocyanine, oxotitanyl phthalocyanine and hydroxygallium phthalocyanine of the charge generation materials described above used. The crystal form of the above phthalocyanine pigment is subject no special restriction, and it can various phthalocyanine pigments are used.

The proportion of the charge generation layer is preferably in a range of 0.1 to 20 Wt .-% and more preferably in a range of 0.5 to 15 wt .-%, based on the total weight of the resin binder.

Charge transfer material

To the examples of the charge transfer material, that in the single-layer type electrophotographic material of The present invention includes conventionally known electron transfer materials and hole transfer materials. In the single-layer type electrophotographic material, the photosensitive one contains Material a combination of the electron transfer material with the Hole transfer material.

Hole transferring material

To the examples of the hole transfer material, that in the single-layer type electrophotographic material of The present invention uses nitrogen-containing compounds and condensed polycyclic compounds, e.g. N, N, N ', N'-tetraphenylbenzidine derivatives, N, N, N ', N'-tetraphenylphenylenediamine derivatives N, N, N ', N'-tetraphenylnaphthylenediamine derivatives, N, N, N', N'-tetraphenylphenantolylenediamine derivatives, Oxadiazole compounds (e.g., 2,5-bis (4-methylaminophenyl) -1,3,4-oxadiazole), styryl compounds (e.g., 9- (4-diethylaminostyryl) anthracene), Carbazole compounds (e.g., poly-N-vinylcarbazole), organopolysilane compounds, Pyrazoline compounds (e.g., 1-phenyl-3- (p-dimethylaminophenyl) pyrazoline), hydrazone compounds, Indole compounds, oxazole compounds, isoxazole compounds, thiazole compounds, Thiadiazole compounds, imidazole compounds, pyrazole compounds and triazole compounds.

It is particularly preferred when the charge transfer material one or several types of hole transfer materials contains selected from the group are, which consists of hole transfer materials, represented by the general formula [3], [4], [5] and [6] become.

worin bedeuten:
R³⁰, R³¹, R³² und R³³, die gleich oder verschieden sind, eine Alkylgruppe, eine Alkoxygruppe, eine Arylgruppe, eine Aralkylgruppe oder ein Halogenatom,
m, n, p und q, die gleich oder verschieden sind, eine ganze Zahl von 0 bis 3,
R³⁴ und R³⁵, die gleich oder verschieden sind, ein Wasserstoffatom oder eine Alkylgruppe und
-X-Hole transfer material of the general formula [3]:

in which mean:
R ³⁰ , R ³¹ , R ³² and R ³³ , which are the same or different, an alkyl group, an alkoxy group, an aryl group, an aralkyl group or a halogen atom,
m, n, p and q which are the same or different, an integer from 0 to 3,
R ³⁴ and R ³⁵ , which are the same or different, represent a hydrogen atom or an alkyl group and
-X-

worin bedeuten:
R⁴⁰ und R⁴², die gleich oder verschieden sind, eine wahlweise substituierte Alkylgruppe und
R⁴¹ und R⁴³, die gleich oder verschieden sind, ein Wasserstoffatom oder eine wahlweise substituierte Alkylgruppe.Hole transfer material of the general formula [4]:

in which mean:
R ⁴⁰ and R ⁴² , which are the same or different, are an optionally substituted alkyl group and
R ⁴¹ and R ⁴³ , which are the same or different, represent a hydrogen atom or an optionally substituted alkyl group.

in der R⁵⁰, R⁵¹, R⁵², R⁵³ und R⁵⁴, die gleich oder verschieden sind, ein Wasserstoffatom, ein Halogenatom, eine wahlweise substituierte Alkylgruppe oder eine wahlweise substituierte Alkoxygruppe bedeuten.Hole transfer material of the general formula [5]:

wherein R ⁵⁰ , R ⁵¹ , R ⁵² , R ⁵³ and R ⁵⁴ , which are the same or different, represent a hydrogen atom, a halogen atom, an optionally substituted alkyl group or an optionally substituted alkoxy group.

in der bedeuten:
R⁶⁰, R⁶¹, R⁶² und R⁶³, die gleich oder verschieden sind, ein Halogenatom, eine wahlweise substituierte Alkylgruppe, eine wahlweise substituierte Alkoxygruppe oder eine wahlweise substituierte Arylgruppe, und
a, b, c und d, die gleich oder verschieden sind, eine ganze Zahl von 0 bis 5,
mit der Maßgabe, dass R⁶⁰, R⁶¹, R⁶² und R⁶³ verschieden sein können, wenn a, b, c oder d nicht kleiner als 2 ist.Hole transfer material of the general formula [6]:

in which mean
R ⁶⁰ , R ⁶¹ , R ⁶² and R ⁶³ , which are the same or different, are a halogen atom, an optionally substituted alkyl group, an optionally substituted alkoxy group or an optionally substituted aryl group, and
a, b, c and d, which are the same or different, an integer from 0 to 5,
with the proviso that R ⁶⁰ , R ⁶¹ , R ⁶² and R ⁶³ may be different if a, b, c or d is not less than 2.

The Hole transferring material, represented by the general formula [3], [4], [5] or [6] is to improve the sensitivity of the photosensitive Effective material, as it has a very high mobility and effectively for hole transfer capable is.

at of the present invention these hole transfer materials can be used alone, or it can be two or more types of it be used in combination.

Electron transfer material

Examples for the Electron transfer material, that in the single-layer type electrophotographic material of can be used in the present invention are various Compounds with electron acceptor property, e.g. the diphenoquinone derivatives, Benzoquinone derivatives, azoquinone derivatives, which are published in the unaudited Japanese Patent Applications (Kokai, Tokkyo Koho) No. 2000.147806 and 2000-242009, monochinone derivatives which are described in U.S. Pat published unaudited Japanese Patent Application (Kokai Tokkyo Koho) No. 2000-075520 and 2000-258936, dinaphthylquinone derivatives, diimide-tetracarboxylic acid derivatives, Imidcarboxylate derivatives, stilbene quinone derivatives, anthraquinone derivatives, malononitrile derivatives, Thiopyran compounds, trinitrothioxantane derivatives, 3,4,5,7-tetranitro-9-fluorenone derivatives, Dinitroanthracene derivatives, dinitroacridine derivatives, nitroanthraquinone derivatives, Dinitroanthraquinone derivatives, tetracyanoethylene, 2,4,8-trinitrothoxanthone, Dinitrobenzene, dinitroanthracene, dinitroacridine, nitroanthraquinone, Dinitroanthraquinone, succinic anhydride, maleic anhydride and dibromomaleic anhydride.

It is particularly preferred when the charge transfer material one or several types of hole transfer materials contains selected from the group are made of hole transfer materials of the general formula [7], [8], [9] and [10].

in der R⁷⁰ und R⁷¹, die gleich oder verschieden sind, eine wahlweise substituierte Alkylgruppe bedeuten.Compounds of the general formula [7]:

in R ⁷⁰ and R ⁷¹ , which are the same or different, represent an optionally substituted alkyl group.

in der R⁸⁰ und R⁸¹, die gleich oder verschieden sind, eine wahlweise substituierte einwertige Kohlenwasserstoffgruppe bedeuten.Compounds of the general formula [8]:

wherein R ⁸⁰ and R ⁸¹ , which are the same or different, represent an optionally substituted monovalent hydrocarbon group.

in der R⁹⁰ ein Halogenatom, eine wahlweise substituierte Alkylgruppe oder eine wahlweise substituierte Arylgruppe bedeutet und R⁹¹ eine wahlweise substituierte Alkylgruppe oder eine wahlweise substituierte Arylgruppe oder eine Gruppe -O-R^91a darstellt, worin R^91a eine wahlweise substituierte Alkylgruppe oder eine wahlweise substituierte Arylgruppe darstellt.Compounds of the general formula [9]:

wherein R ^{90 represents} a halogen atom, an optionally substituted alkyl group or an optionally substituted aryl group and R ^{91 represents} an optionally substituted alkyl group or an optionally substituted aryl group or an -OR ^91a group wherein R ^{91a represents} an optionally substituted alkyl group or an optionally substituted aryl group ,

worin R¹⁰⁰, R¹⁰¹, R¹⁰² und R¹⁰³, die gleich oder verschieden sind, eine wahlweise substituierte Alkylgruppe bedeuten.Compounds of the general formula [10]:

wherein R ¹⁰⁰ , R ¹⁰¹ , R ¹⁰² and R ¹⁰³ , which are the same or different, represent an optionally substituted alkyl group.

at of the present invention these electron transfer materials used alone or in combination.

Of the Solid content of the charge transfer material in the single-layer type electrophotographic material is not less than 30 wt .-% and not more than 55 wt .-%, based on the total solids content.

It is known that the wear resistance the photosensitive layer is reduced when the proportion on charge transfer material elevated becomes. Therefore, the solids content is ideally reduced to the wear resistance to improve. In the case of the single-layer type photosensitive material contains the photosensitive layer for improving the sensitivity, as described above, both the hole transfer material and the electron transfer material. The solids content of the charge transfer material is sometimes higher as 50 wt .-%, based on the total solids content.

Indeed For example, a single-layer type photosensitive material that can be used in the case of a small solid content of not less than 30 Wt .-% and not more than 50 wt .-%, based on the total solids content, to a good wear resistance leads, has a good sensitivity using the hole transfer material of the general formulas [3], [4], [5] or [6] or of the electron transfer material of the general formulas [7], [8], [9] or [10].

The Thickness of the photosensitive layer of the photosensitive material The single-layer type of the present invention is preferably in a range of 5 to 100 microns and more preferably in the range of 10 to 50 microns.

In addition to The above-described corresponding components may be conventionally known various Additives are introduced, such as e.g. Oxidation inhibitors, radical scavengers, singlet quenchers, antioxidants (e.g., ultraviolet absorbers), emollients, plasticizers, surface modifiers, excipients, Thickeners, dispersion stabilizers, waxes, acceptors and donors, unless the electrophotographic properties are be adversely affected. To improve the sensitivity of the photosensitive layer can For example, known sensitizers such as terphenyl, halonaphthoquinones and acenaphthylene, in combination with the charge generation material be used.

Between the conductive substrate and the photosensitive layer may have a Barrier layer are formed, provided the characteristics of photosensitive material are not affected.

When Substrate on which the photosensitive layer is formed, can e.g. different materials can be used with conductivity. To the examples for this belong Metals such as iron, aluminum, copper, tin, platinum, silver, vanadium, Molybdenum, Chromium, cadmium, titanium, nickel, palladium, indium, stainless steel and brass; Substrates made of plastic materials, which are deposited by deposition or lamination of the above materials, as well as substrates made of glasses, which are coated with aluminum iodide, tin oxide and indium oxide.

The Substrate may, depending on the structure of the image-forming to be used Device in the form of a sheet or a cylinder. The substrate itself may have the conductivity, or the surface the substrate may be conductive be. The substrates are preferably substrates with sufficient mechanical Strength.

When the photosensitive layer is produced by the coating process, a disper by dispersing and mixing the above charge-generating material, the charge-transferring material and the resin binder together with a suitable solvent, using a known method such as a roll mill, a ball mill, an attritor, a color mixing device or an ultrasonic dispersing device to produce a dispersion, whereupon the resulting dispersion is coated and dried using known means.

When solvent For the preparation of the above dispersion, various organic solvent be used. Examples include alcohols such as methanol, Ethanol, isopropanol and butanol; aliphatic hydrocarbons like n-hexane, octane and cyclohexane; aromatic hydrocarbons such as benzene toluene and xylene; halogenated hydrocarbons, such as dichloromethane, dichloroethane, Carbon tetrachloride and chlorobenzene; Ethers, such as dimethyl ether, Diethyl ether, tetrahydrofuran, ethylene glycol dimethyl ether and diethylene glycol dimethyl ether; Ketones such as acetone, methyl ethyl ketone and cyclohexanone; Esters like Ethyl acetate and methyl acetate, as well as dimethylformaldehyde, dimethylformamide and dimethyl sulfoxide.

to Improvement of the dispersibility of the charge generation material and the charge transfer material as well as the smoothness of the surface the photosensitive layer can for example, surface-active Medium and leveling agents are added.

Examples

The The following examples and comparative examples serve to further explanation of the present invention. The following embodiments are therefore only as illustrative and the technical scope of the present invention is through the embodiments not limited.

The Examples 1 and 26 are not within the scope of the claims and are for explanation only.

Electrophotographic Single-layer type materials described in the examples below and Comparative Examples were prepared according to the the following methods.

Test for evaluation the wear resistance

each the electrophotographic materials of the examples concerned and Comparative Examples was used in a digital copying machine, having a blade cleaner (Creage 7340, manufacturer Kyocera Mita Corporation).

Under Use of 250 000 sheets of A4 sized paper was made with the above specified copier performed a copy test, after which the thickness of the photosensitive layer was measured. The wear was as the difference between the thickness before copying and the thickness calculated after copying. The smaller the difference, the more better is the wear resistance. A difference of 3 μm or more was called "test classified ", while a difference of more than 3 microns as a "test not passed " has been.

rating the sensitivity

Using a drum sensitivity tester manufactured by GENETEC Co., a voltage was applied to the surface of each of the single-layer type electrophotographic materials of the respective Examples and Comparative Examples to charge the surface to +700V. Subsequently, 780 nm wavelength monochromatic light (half width: 20 nm, 1.0 μJ / cm ² ) of white light from a halogen lamp as the exposure light source of the above test apparatus was irradiated through a band pass filter to the surface of each of the electrophotographic materials. The surface potential at the time when 0.5 sec passed from the exposure start was the residual potential V _L (V). The smaller the residual potential, the higher the sensitivity of the photosensitive material.

Test for evaluation the ozone resistance

The surface potential of each of the electrophotographic materials of the respective Examples and Comparative Examples was measured by a digital copying machine (Creage 7340, manufactured by Kyocera Mita Corporation); subsequently, the above photosensitive material was kept at ordinary temperature for 10 hours in the dark in an atmosphere containing an ozone concentration of 10 ppm. The Surface potential was measured immediately after exposure. .DELTA.V 0 = (initial surface potential) - (surface potential immediately after exposure).

The smaller ΔV ₀ , the better the ozone resistance; A value .DELTA.V ₀ of less than 60 V was "passed the test" rated, while a value .DELTA.V ₀ of 60 V or more "failed the test" rated.

Furthermore are the chemical formulas of electron transfer materials, the Hole transferring materials, the resin binder and the polyalkylene glycol compounds which used in the following Examples and Comparative Examples were listed below.

The following abbreviations are used in the following tables:
Ex .: Example, Co. Ex. Comparative Example, PAGC (polyalkylene glycol compound): polyalkylene glycol compound, hole transferring material: hole transfer material, ETM (electron transferring material): electron transfer material, ECTM: charge transfer materials-solid content , based on the total solids content.

Examples 1 to 23

example 1 falls not within the scope of the invention and is merely illustrative.

to Preparation of a coating solution for one Single-layer type photosensitive layer became 3.5 parts by weight X-type metal-free phthalocyanine (CGM) as charge generation material, 35 Parts by weight ETM-3 as electron transfer material, 10, 30, 55 or 75 parts by weight of the compounds of the general formulas [3] to [6] as a hole transfer material (referred to as HTM-1, HTM-2, HTM-3 and HTM-4, respectively), 100 parts by weight of a copolymerized carbonate resin (Resin-1, molar ratio of Copolymerization a: b = 20.0: 80.0, weight average molecular weight: 100 000), the recurring units of the general formula [2] and from bisphenol Z, and 3 parts by weight of a polyalkylene glycol compound (selected from PEG-1, PEG-2, PEG-3, PEG-4 and PEG-5) of the general formula [1] together with 800 parts by weight of tetrahydrofuran in a ball mill for 24 hours mixed and dispersed. This coating solution was then used of the dip coating method on an aluminum tube as conductive Substrate coated, followed by 45 minutes with hot air at Dried 125 ° C. to give each a single-layer type photosensitive material with a single photosensitive layer of one layer thickness of 30 μm was obtained.

Examples 24 and 25

In same as in Example 3, but using HTM-5 or HTM-6 as hole transfer material, For example, single-layer type photosensitive materials have been prepared.

Examples 26 to 29

example 26 falls not within the scope of the claims, but only for explanation.

In same as in Examples 1 to 4, but using a bisphenol Z type polycarbonate resin with a weight average molecular weight of 100,000 (Resin-2) as a resin binder, Each photosensitive material was of a single-layer type produced.

Comparative Examples 1 to 4

In same as in Examples 3 and 5 to 7, but without Use of polyalkylene glycol compounds, each were photosensitive Materials made of single-layer type.

Comparative Examples 5 and 6

In same as in Example 3, but using PEG-6 (Trade name: IONET MS-300, manufacturer Sanyo Chemicals, Co. Ltd.) or PEG-7 (manufactured by Aldrich Co.) as polyalkylene glycol compounds, their terminal Hydroxy groups (-OH groups are not esterified or etherified, Each photosensitive material was of a single-layer type produced.

Comparative Examples 7 and 8

In same as Example 3, but using MCA-001 (fine particles of melamine isocyanate, manufacturer Mitsubishi Chemicals, Co. Ltd.) or LUBRON 12 (fine particles of fluororesin, manufacturer Dikin, Co., Ltd.) as additives for improving wear resistance, which are not polyalkylene glycol compounds, were each photosensitive Materials made of single-layer type.

The Evaluation results for the photosensitive ones prepared in the above Examples and Comparative Examples Single-layer type materials are listed in Tables 1 to 4.

From the results of Tables 1 to 3, it can be seen that when the polyalkylene glycol compounds of the general formula [1] are incorporated in the resin binder, the resulting electrophoresis monolayer-type tographic materials have better wear resistance, better sensitivity, and better ozone resistance.

The In particular, results of Table 1 show that HTM-1, HTM-2, HTM-3 and HTM-4 as hole transfer material preferred together with PEG-1, PEG-2, PEG-3, PEG-4 and PEG-5 as Polyalkylene glycol compounds of the general formula [1] in the context can be used in the present invention. Table 2 shows that HTM-5 and HTM-6 as hole transfer material for producing the single-layer type electrophotographic material of the present invention are also effective. Furthermore, can Resin-2 also preferably be used as a resin binder, as shown in Table 3.

On the other hand, Comparative Examples 1 to 4 (Table 4) show that the wear is more than 3 μm and ΔV _{0 is} 60 V or more because no additive for improving the wear resistance was added. Accordingly, the wear resistance and the ozone resistance were inferior.

The Comparative Examples 5 and 6 (Table 4) show that the corresponding Sensitivities are worse, as shown by the results, after which the residual potentials over Reached 120V. This is because in these comparative examples Polyalkylene glycol compounds (PEG-6 and PEG-7) were used, the at the terminal Hydroxy groups were not esterified or etherified.

Comparative Examples 7 and 8 (Table 4) show that the ozone resistance is inferior because ΔV _{0 is} more than 60V. This is because the additives (MCA-001 or LUBRON L2) were used to improve the wear resistance in these comparative examples which are not polyalkylene glycol compounds.

Table 5 also shows dependency (1) of wear, (2) residual potential (sensitivity) and (3) ΔV ₀ (ozone resistance) of solids content of charge transfer materials by total solids (ECTM) based on evaluation data of Examples 1 to 4 and 26 to 29.

Table 5

The 1 to 3 are also graphs showing the dependence of the above properties (1), (2) and (3) on the solids content of the charge transfer materials in terms of the total solids content on the basis of the data of Table 5.

From the 1 to 3 It is apparent that when the solid content of the charge transfer materials is about 30% to about 50% by weight based on the total solid content, the resulting single-layer type photosensitive materials are in wear, residual potential and ozone resistance are improved.

Examples 30 to 57

to Preparation of a coating solution for one Single-layer type photosensitive layer became 2.5 parts by weight X-type metal-free phthalocyanine (CGM) as charge generation material, 60 Parts by weight HTM-7 as hole transfer material, 5, 20, 30 or 50 parts by weight of the compounds of the general Formulas [7] to [10] as the electron transfer material (selected from ETM-1, ETM-2, ETM-3, ETM-4 and ETM-5), 100 parts by weight of a copolymerized Carbonate resin (Resin-2, molar ratio copolymerization a: b = 25.0: 75.0), the repeating units of the general formula [2] and of bisphenol Z, and 3.5 parts by weight of a polyalkylene glycol compound (selected from PEG-1, PEG-2, PEG-3, PEG-4 and PEG-5) of the general formula [1] together with 750 parts by weight of tetrahydrofuran in a ball mill for 20 hours mixed and dispersed. This coating solution was then used of the dip coating method on an aluminum tube as conductive Substrate coated, followed by 35 minutes with hot air at Dried 130 ° C. to give each a single-layer type photosensitive material with a single photosensitive layer of one layer thickness of 26 μm was obtained.

Examples 58 and 59

In same as in Examples 32 and 34 to 37, but under Use of ETM-6 and ETM-7 as electron transfer material, were Single-layer type photosensitive materials.

Examples 60 to 63

In same as in Examples 30 to 33, but using a bisphenol Z type polycarbonate resin with a weight average the molecular weight of 80,000 (Resin-2) as a resin binder, For example, single-layer type photosensitive materials have been prepared.

Comparative Examples 9 to 13

In same as in Examples 32 and 34 to 37, but without Use of polyalkylene glycol compounds, each were photosensitive Materials made of single-layer type.

Comparative Examples 14 and 15

In same as in Example 32, but using PEG-6 or PEG-7 as a polyalkylene glycol compound whose terminal hydroxy groups (OH groups) are not esterified or etherified, were photosensitive Single-layer type materials produced.

Comparative Examples 16 and 17

In same as Example 32, but using MCA-001 (fine particles of melamine isocyanate, manufacturer Mitsubishi Chemicals, Co. Ltd.) and LUBRON 12 (fine particles of fluororesin, manufacturer Dikin, Co., Ltd.) as additives for improving wear resistance, which are not polyalkylene glycol compounds became photosensitive Materials made of single-layer type.

The Results of the evaluation of the above Examples 30 to 63 and Comparative Examples 9 to 17 produced photosensitive Single-layer type materials are listed in Tables 6 to 9.

From the results of Tables 6 to 8, it can be seen that when the polyalkylene glycol compounds of the general formula [1] are incorporated in the resin binder, the resulting electrophoresis monolayer-type tographic materials have better wear resistance, better sensitivity, and better ozone resistance.

in the Specifically, the results of Table 6 show that ETM-1, ETM-2, ETM-3 and ETM-4 as electron transfer material preferred together with PEG-1, PEG-2, PEG-3, PEG-4 and PEG-5 as Polyalkylene glycol compound of general formula 1 in the present Invention can be used.

table Figure 7 shows that ETM-6 and ETM-7 are used as the electron transfer material for the preparation of the single-layer type electrophotographic material of the present invention Invention are equally effective. Resin-2 may also be preferred can be used as a resin binder, as shown in Table 8.

On the other hand, Comparative Examples 9 to 13 (Table 9) show that the wear is more than 3 μm and ΔV _{0 is} 60 V or more, since no additive for improving the wear resistance was added, accordingly, the wear resistance and the ozone resistance are inferior.

The Comparative Examples 14 and 15 (Table 9) show that the corresponding Sensitivities are worse, as the results show that the residual potentials over Assume 120V. This is because in these comparative examples Polyalkylene glycol compounds (PEG-6 and PEG-7) are used, whose terminal Hydroxy groups are not esterified or etherified.

Comparative Examples 16 and 17 (Table 9) show that the ozone resistance is inferior because ΔV _{0 is} more than 60V. This is because the additives (MCA-001) or LUBRON L2 used in these comparative examples for improving the wear resistance are not polyalkylene glycol compounds.

In addition, Table 10 shows the dependency (1) of wear, (2) the residual potential (sensitivity), and (3) ΔV ₀ (ozone resistance) of the solid content of the charge transfer materials by total solids (ECTM) based on the evaluation data Examples 30 to 33 and 60 to 63.

Table 10

The 4 to 6 Further, diagrams showing the dependency of the above properties (1), (2) and (3) on the solid content of the respective charge transfer materials in terms of the total solid content on the basis of the data of Table 5 are shown.

From the 4 to 6 It can be seen that when the solid content of the charge transfer materials is about 30% to about 50% by weight based on the total solid content, the resulting single layer type photosensitive materials are in wear, residual potential and ozone resistance are improved.

List of chemical formulas: HTM-1

HTM-2

HTM-3

HTM-4

HTM-5

HTM-6

HTM-7

ETM-1

ETM-2

ETM-3

ETM-4

ETM-5

ETM-6

ETM-7

Resin-1

Resin-2

PEG-1 (number average of the Molecular weight: 560)

polyethylene glycol dilaurate

• C ₁₁ H ₂₃ -COO- (CH ₂ -CH ₂ -O) _n -CO-C ₁₁ H ₂₃

PEG-2 (number average of the Molecular weight: 830)

polyethylene glycol distearate

• C ₁₇ H ₃₅ -COO- (CH ₂ -CH ₂ -O) _n -CO-C ₁₇ H ₃₅

PEG-3 (number average of Molecular weight: 500)

polyethylene glycol dimethyl ether

• CH ₃ -O- (CH ₂ -CH ₂ -O) _n -CH ₃

PEG-4 (number average of the Molecular weight: 1000)

Polyethylene-polypropylene block copolymer diethyl ether

• C ₂ H ₅ -O- (CH ₂ -CH ₂ -O) _l - (CH ₂ CH ₂ CH ₂ -O) _m - (CH ₂ -CH ₂ -O) _n -C ₂ H ₅

PEG-5 (Number Average Molecular Weight: 800) Polyethylene glycol diphenyl ether

PEG-6 (number average of the Molecular weight: 570)

• HO- (CH ₂ -CH ₂ -O) _n -CO-C ₁₇ H ₃₅

PEG-7 (number average of the Molecular weight: 200)

• HO- (CH ₂ -CH ₂ -O) _n -H

Claims (8)

A single-layer type electrophotographic material comprising a conductive substrate and a photosensitive layer comprising a resin binder containing at least a charge-generating material and a charge-transferring material and formed on the conductive substrate, the photosensitive layer being a polyalkylene glycol compound of the general formula [1] contains A _{1 is} -O - [(CH ₂ ) _m -O] _n -A ₂ , in which mean A ₁ and A ₂ , which are the same or different, are an alkyl or aryl group having 1 to 50 carbon atoms or a group -CO-R ¹⁰ , wherein R ^{10 is} an alkyl or aryl group having 1 to 50 carbon atoms, m is an integer from 1 to 5 and n is an integer of 2 to 100, characterized in that the charge transfer material comprises a hole transfer material and an electron transfer material, and the solid content of the charge transfer material is not less than 30% by weight and not more than 55% by weight, based on the total solids content. Single-layer type electrophotographic material according to claim 1, wherein the content of the polyalkylene glycol compound is not less than 50% by weight and not more than 500% by weight on the content of charge generation material. A single-layer type electrophotographic material according to claim 1 or 2, wherein the resin binder is a polycarbonate resin having a repeating unit of the general formula [2]

wherein R ²⁰ and R ²¹ , which are the same or different, represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Single-layer type electrophotographic material according to claim 1 or 2, wherein the main component of the resin binder a copolymerized polycarbonate resin having a recurring one Unit of the general formula [2] and of bisphenol Z is. Single-layer type electrophotographic material according to one of the preceding claims, wherein the charge-generating material is a phthalocyanine. A single-layer type electrophotographic material according to any one of claims 1 to 5, wherein the charge transfer material comprises one or more of the following hole transfer materials: a compound of the general formula [3],

wherein R ³⁰ , R ³¹ , R ³² and R ³³ , which are the same or different, represent an alkyl group, an alkoxy group, an aryl group, an aralkyl group or a halogen atom, m, n, p and q, which are the same or different, an integer from 0 to 3, R ³⁴ and R ³⁵ , which are the same or different, represent a hydrogen atom or an alkyl group and -X-

a compound of general formula [4],

wherein R ⁴⁰ and R ⁴² , which are the same or different, are an optionally substituted alkyl group and R ⁴¹ and R ⁴³ , which are the same or different, are a hydrogen atom or an optionally substituted alkyl group, a compound of the general formula [5],

wherein R ⁵⁰ , R ⁵¹ , R ⁵² , R ⁵³ and R ⁵⁴ , which are the same or different, represent a hydrogen atom, a halogen atom, an optionally substituted alkyl group or an optionally substituted alkoxy group, and a compound of the general formula [6],

in which: R ⁶⁰ , R ⁶¹ , R ⁶² and R ⁶³ , which are the same or different, are a halogen atom, an optionally substituted alkyl group, an optionally substituted alkoxy group or an optionally substituted aryl group, and a, b, c and d are the same or different, an integer from 0 to 5, with the proviso that R ⁶⁰ , R ⁶¹ , R ⁶² and R ⁶³ may be different if a, b, c or d is not less than 2. A single-layer type electrophotographic material according to any one of claims 1 to 5, wherein the charge transfer material comprises one or more of the following electron transfer materials: a compound of the general formula [7],

in which R ⁷⁰ and R ⁷¹ , which are identical or different, represent an optionally substituted alkyl group, a compound of the general formula [8],

wherein R ⁸⁰ and R ⁸¹ , which are the same or different, represent an optionally substituted monovalent hydrocarbon group, a compound of the general formula [9],

wherein R ^{90 represents} a halogen atom, an optionally substituted alkyl group or an optionally substituted aryl group, and R ^{91 represents} an optionally substituted alkyl group or an optionally substituted aryl group or an -OR ^91a group wherein R ^{91a is} an optionally substituted alkyl group or an optionally substituted aryl group represents, and a compound of general formula [10],

wherein R ¹⁰⁰ , R ¹⁰¹ , R ¹⁰² and R ¹⁰³ , which are the same or different, represent an optionally substituted alkyl group. Single-layer type electrophotographic material according to one of the preceding claims for image-forming apparatus which a means for removing untransferred toner by a Have scraper blade.