JPS63221355A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain always high-quality images without causing scratches and image flow not only at the time of an initial stage but also after repeated long uses by incorporating fluororesin powder and a graft fluoropolymer in the surface layer of a photosensitive layer formed no a conductive substrate. CONSTITUTION:The surface layer of the photosensitive body provided with the photosensitive layer on the conductive substrate contains the powder of the fluororesin, preferably, such as a homopolymer or copolymer of tetrafluoroethylene, trifluoroethylene, hexafluoropropylene, vinylfluoride, vinyli dene fluoride, or difluorodichloroethylene, in an amount of 1-50wt.% of the constituents of the surface layer, and the graft fluoropolymer, preferably, in an amount of 0.1-0.3wt.% of the fluororesin powder. It is preferred to use polymethyl methacrylate or polycarbonate as the binder resin of the surface layer, thus permitting the fluororesin powder to be uniformly dispersed into the surface layer and improved in dispersion stability by adding said fluororesin powder and said graft fluoropolymer to the surface layer, and accordingly, a uniform surface layer to be always obtained, and high-quality images high in durability to be successively obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an electrophotographic photoreceptor, and more particularly to a highly durable electrophotographic photoreceptor with excellent moisture resistance and mechanical strength.

[Conventional technique lfI]

Electrophotographic photoreceptors are required to have predetermined sensitivity, electrical properties, and optical properties depending on the electrophotographic process to which they are applied. The surface layer of the body, that is, the layer furthest from the substrate, is directly subjected to electrical and mechanical external forces such as corona charging, toner development, transfer to paper, and cleaning processing, so durability against these forces is required. Ru.

Specifically, durability is required against surface abrasion and scratches caused by rubbing, and surface deterioration due to ozone generated during corona charging under high humidity conditions.

On the other hand, there is also a problem of toner adhesion to the surface layer due to repeated toner development and cleaning, and to solve this problem, it is required to improve the cleaning properties of the surface layer.

Various methods have been studied to satisfy the above-mentioned characteristics required for the surface layer, and among them, the method of dispersing fluororesin powder in the surface layer is effective. The dispersion of fluororesin powder reduces the coefficient of friction of the surface layer, which improves cleaning performance and durability against abrasion and scratches.

Furthermore, since the water repellency and mold releasability of the surface layer are improved, it is also effective in preventing surface deterioration under high humidity.

However, when dispersing fluororesin powder, there are problems with its dispersibility and cohesiveness, making it difficult to form a uniform and smooth film. It was inevitable that it would have defects.

In addition, some binder resins or dispersion aids can evenly disperse fluororesin powder and form a smooth film, but most of them have hydroxyl groups, carboxyl groups, ether bonds, etc. However, it becomes a carrier trap particularly under high temperature and high humidity conditions, causing deterioration of electrophotographic properties, and the current situation is that no one has been found that can be put to practical use.

[Problems to be Solved by the Invention] An object of the present invention is to provide an electrophotographic photoreceptor that meets the above-mentioned requirements.

That is, a first object of the present invention is to provide an electrophotographic photoreceptor that has durability against surface abrasion and scratches caused by rubbing.

The second objective is to provide an electrophotographic photoreceptor that can provide stable, high-quality images even under high humidity conditions.

The second object is to provide an electrophotographic photoreceptor that has good cleaning properties and does not have toner attached to its surface layer.

The fourth object is to provide an electrophotographic photoreceptor that has no excessive pinholes in the coating film on the surface, and that does not accumulate residual potential during repeated electrophotographic processes and can always produce high-quality images.

[Means and effects for solving the problem] The present inventors
As a result of studies conducted in accordance with the above objectives, the present inventors discovered that an electrophotographic photoreceptor having a surface layer in which fluorine resin powder is dispersed in the presence of a fluorine graft polymer satisfies the above requirements, and the present invention has been completed. .

That is, the present invention relates to an electrophotographic photoreceptor having a photosensitive layer on a conductive support, in which one surface layer contains a fluorine-based resin powder and a fluorine-based graft polymer. configured.

The fluororesin powder applicable to the present invention is tetrafluoroethylene resin, chlorofluoroethylene resin, tetrafluoroethylene hexafluoropylene resin, vinyl fluoride resin, vinylidene fluoride resin, ethylene dichloride difluoride. One or more resins and copolymers thereof are appropriately selected, and tetrafluoroethylene resin and vinylidene fluoride resin are particularly preferred.The molecular weight and powder particle size of the resin are appropriately selected from commercially available grades. Although it can be used.

Particularly preferred are those of low molecular weight grade and having secondary particles of 1p or less.

The content of the fluororesin powder dispersed in the surface layer is suitably 1 to 50% by weight, particularly preferably 2 to 30% by weight, based on the solid weight of the surface layer.

If the content is less than 1% by weight, the effect of modifying the surface layer by the fluororesin powder will not be sufficient, while if it exceeds 50% by weight, the light transmittance will decrease and carrier mobility will also decrease.

The fluorine-based graft polymer applied to the present invention is an oligomer (hereinafter referred to as a macromer) having a polymerizable functional group at one end and a certain repeating unit and a molecular weight of about 1,000 to 10,000 and a polymerizable monomer. It can be obtained by copolymerization with The structure of a fluorine-based graft polymer is as follows: (i) In the case of copolymerization of a non-fluorine-based macromer synthesized from a non-fluorine-based polymerizable monomer and a fluorine-based polymerizable monomer, the trunk is a fluorine-based segment and the branches are non-fluorine-based segments. System segment (ii) In the case of copolymerization of a fluorine-based macromer synthesized from a fluorine-based polymerizable monomer and a non-fluorine-based polymerizable monomer,
The trunk is a non-fluorinated segment and the branches are fluorinated segments.

As mentioned above, in the fluorine-based graft polymer, the 7-/ elemental segment and the non-fluorine-based segment are localized, and the fluorine-based segment is a resin layer in which the fluorine-based segment is added to the fluorine-based resin powder and the non-fluorine-based segment is added. They have a functionally separated form with each oriented in the opposite direction. In particular, since the fluorine-based segments are arranged continuously, the fluorine-based segments adsorb to the fluorine-based resin powder with high density and efficiency.
Furthermore, since the non-fluorine segments are oriented in the resin layer,
It exhibits an effect of improving the dispersion stability of fluororesin powder, which has not been seen in conventional dispersants.

In addition, although fluororesin powder generally exists in the form of aggregates on the order of a few hundredths of an inch, by using the fluorine-based graft polymer of the present invention as a dispersant, it is possible to
The following primary particles are uniformly dispersed.

In order to make the most of this functional separation effect,
The molecular weight of the macromer is 1000-1000 as above.
It is necessary to adjust it to about 0.

That is, if the molecular weight is less than 1000, the length of the segment is too short, so in the case of a fluorine-based segment, the adsorption efficiency to the fluororesin powder decreases, and in the case of a non-fluorine-based segment, the surface layer Orientation to the resin layer is weakened, and in either case, the dispersion stability of the fluororesin powder is inhibited.

On the other hand, if the molecular weight exceeds 1oooo, the compatibility with the added surface layer resin layer decreases. This phenomenon is particularly noticeable in fluorine-based segments, and since the segments take a contracted coil-like form in the resin layer, the adsorption activity for the fluorine-based resin powder is reduced, and dispersion stability is inhibited.

In addition, the molecular weight of the fluorine-based graft polymer itself has a large influence, and fa is preferably 10,000 to 100,000.
When the zero molecular weight is less than 10,000, the dispersion stabilizing function is insufficiently expressed, and when it is more than 100,000, the dispersion stabilizing function is similarly not expressed because the compatibility with the added surface layer resin layer decreases. It disappears.

The ratio of the fluorine-based segment in the fluorine-based graft polymer is preferably 5 to 90% by weight, more preferably 10 to 70% by weight.

If the proportion of the fluorine-based segment is less than 5% by weight, the dispersion stabilizing function of the fluororesin powder cannot be sufficiently exhibited, and if it exceeds 90% by weight, the compatibility with the added surface layer resin layer becomes poor.

The appropriate amount of the fluorine-based graft polymer added is 0.1 to 30% by weight, particularly 1 to 2% by weight, based on the fluororesin powder.
0% by weight is preferred.

If the amount added is less than 0.1% by weight, the dispersion stability effect of the fluororesin powder will not be sufficient; on the other hand, if it exceeds 30% by weight, the fluorine-based graft polymer will not exist adsorbed to the fluororesin powder. It comes to exist inside the surface layer resin layer in a free state, and when electrophotographic processes are repeated, a residual potential accumulates.

Preferred specific examples of the fluorine-based graft polymer used in the present invention are shown below.

The fluorine-based graft polymer has a polymerizable functional group at one end and a non-fluorine-based oligomer represented by the general formula (1) having a certain repeating unit, and a fluorine-based polymerizable monomer selected from compound (II). Copolymer with general formula (I) υ where R1 represents a hydrogen atom, an alkyl group, a halogen atom, a halogen-substituted alkyl group, or an aryl group, Al represents an alkylene chain or a halogen-substituted alkylene chain, and A2 (R2-R11 represents a hydrogen atom, an alkyl group, or a halogen-substituted alkyl group), A3 represents an alkylene chain or a halogen-substituted alkylene chain, and A4 represents a low molecular weight linear unsaturated monomer as a polymerizable monomer. One of the following: hydrocarbons, vinyl halides, vinyl esters of organic acids, vinyl aromatic compounds, acrylic and methacrylic esters, N-vinyl compounds, vinyl silicon compounds, maleic anhydride, esters of maleic acid and fumaric acid and a repeating unit unit in which two or more types are polymerized, and a represents a positive integer.

Compound (II) is a fluorine-substituted low molecular weight linear unsaturated hydrocarbon, a fluorine-substituted vinyl halide, a fluorine-substituted vinyl ester of an organic acid, a fluorine-substituted alkyl vinyl ether, a fluorine-substituted alkyl ester of acrylic acid and methacrylic acid, and amides, fluorinated aromatic-containing esters and amides of acrylic acid and methacrylic acid,
Shown are fluorinated maleic anhydride, fluorinated alkyl esters of maleic acid and fumaric acid, α-fluorinated styrene and α, β, β-7 fluorinated styrene.

The fluorine-based graft polymer has a polymerizable functional group at one end and a fluorine-based oligomer represented by the general formula (m) having a certain repeating unit, and a non-fluorine-based polymerizable monomer selected from compound (IV). General formula (■) υ of a copolymer with a fluorine-substituted monomer (■) υ In the formula, A5 is a fluorine-substituted low molecular weight linear unsaturated hydrocarbon, a fluorine-substituted vinyl halide,
Vinyl esters of fluorinated organic acids, fluorinated alkyl vinyl esters, fluorinated alkyl esters and amides of acrylic and methacrylic acids, fluorinated aromatic-containing esters, esters and amides of acrylic and methacrylic acids, fluorinated maleic anhydrides, It shows a repeating unit unit in which one or more of fluorine-substituted alkyl esters of maleic acid and fumaric acid, α-fluorinated styrene, and α, β, β-fluorinated styrene are polymerized.

R,, A, , A2, A3 and a have the same meanings as above.

Compound (ff) is 2. low molecular weight linear unsaturated hydrocarbons,
Vinyl halides, vinyl esters of organic acids, vinyl aromatic compounds, acrylic and methacrylic esters, N-vinyl compounds, vinyl silicon compounds, maleic anhydride, esters of maleic acid and fumaric acid.

The synthesis of the macromer in A-1 is described in British Patent No. 1,0
As disclosed in No. 96,912, a prepolymer of terminal carboxylic acid, alcohol, etc. is synthesized by radical polymerization using a chain transfer agent, and a double bond is introduced by reaction with an epoxy group. achieved.

An example of synthesis of a macromer of methyl methacrylate is shown in the following synthesis formula (1).

HJ By copolymerizing the methyl methacrylate macromer synthesized in this way with a fluorine-based polymerizable monomer, a fluorine-based graft polymer having a fluorine-based segment in the trunk and non-fluorine-based segments (methyl methacrylate oligomer) in the branches can be obtained. Can be done.

A fluorine-based polymerizable monomer has a fluorine atom in its molecule,
Any compound may be used as long as it has a polymerizable functional group and is polymerized in a reaction mode depending on the functional group.

Preferred specific examples of the fluoropolymerizable monomer are shown below, but the range of compounds that can be used is not limited to the ranges listed here.

Specific examples of fluorine-based polymerizable monomers (1) GHz-CHF (2) OH YuIIICFλ (3) CHF Seal CF Yu
(4) OF, L Snow CF Yu (5
) CFx=CFC statement (
8) CFz-CFCFs(7) Ch-C
F-Rf (8) CFz-ICF-0-Rf
(9) CH Engineering CH-Rf (1
0) CHz proverb CH-0-Rf (among the above compounds,
R1 represents a hydrogen atom, a halogen atom or a methyl group,
R2 represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, or a nitrile group, and may be a combination of several types thereof.
(k+mm5, and Rf represents a furkyl group substituted with at least one fluorine atom) Examples of non-fluorinated polymerizable monomers include low molecular weight linear unsaturated hydrocarbons, vinyl halides, and organic acids. Vinyl esters, vinyl aromatic 1m compounds, acrylic and methacrylic esters, N-vinyl compounds, vinyl silicon compounds, maleic anhydride.

One or 21 esters of maleic acid and fumaric acid gw! ! The above materials can be used, but those that are compatible with the resin layer of the surface layer to which the formed fluorine-based graft polymer is added, or those that have a similar structure and have a similar structure even if not completely compatible, and have a slight gap between the two. It is preferable to select one with affinity.

For example, if the surface resin layer is poly(meth)acrylic ester, (meth)acrylic ester is preferable as the non-fluorinated polymerizable monomer, and in the case of polystyrene or polycarbonate, styrene-based Preferably, the compounds are selected.

In the synthesis of the methyl methacrylate macromer described above, if a fluorine-based polymerizable monomer is used instead of methyl methacrylate, a fluorine-based macromer can be obtained,
A fluorine-based graft polymer having fluorine-based segments as branches and non-fluorine-based segments as the trunk can be obtained by copolymerizing this macromer with a non-fluorine-based polymerizable monomer.

The fluorinated graft polymer has a polymerizable functional group at one end and a fluorinated polymerizable monomer selected from a non-fluorinated oligomer represented by the general formula (V) having a certain repeating unit and a compound (II). Copolymer with general formula (V) lz where R12 is a hydrogen atom, an alkyl group, a halogen atom,
represents a halogen-substituted alkyl group, A6 represents a (R13 represents a hydrogen atom or a furkyl group), b represents O or a positive integer, A7 represents [R14 represents a hydrogen atom or an alkyl group, A9, A9
, A10 is an alkylene chain, a cycloalkylene chain, a substituted or unsubstituted 7-arylene chain; may form a ring).

As, A4, a and compound (n) have the same meanings as above.

A fluorine-based graft polymer having a polymerizable functional group at one end and a non-fluorine-based polymerizable monomer selected from a fluorine-based oligomer represented by the general formula 1) having a certain repeating unit and compound (IV) Copolymer with general formula (VI) R12 υ where R12,
, a, b and compound (IV) have the same meanings as above.

The synthesis of the macromer in B-1 is described in U.S. Pat.
As disclosed in No. 89,593, by a method of synthesizing a prepolymer of terminal carbon atoms, alcohol, etc. using a chain transfer agent by radical polymerization, and reacting with an incyanate group to introduce a double bond. achieved.

An example of the synthesis of a macromer of methyl methacrylate is shown in the synthesis formula (
2).

Even if the methyl methacrylate macromer synthesized as described above and the fluorine-based polymerizable monomer are copolymerized in the same way as above,
Fluorinated segments on the trunk and non-fluorinated segments on the branches (
methyl methacrylate oligomer) can be obtained.

゛ In the synthesis of the methyl methacrylate macromer described above, a fluorine-based macromer can be obtained by using a fluorine-based polymerizable monomer instead of methyl methacrylate, and from copolymerization of this macromer with a non-fluorine-based polymerizable monomer. A fluorine-based graft polymer can be obtained in which the branches are fluorine-based segments and the trunk is non-fluorine-based segments.

-i The fluorine-based graft polymer has a polymerizable functional group at one end and has a certain repeating unit according to the general formula (VI)
The living polymer intermediate represented by the general formula (VIII
) A copolymer of a fluorine-free oligomer formed by the reaction with a compound represented by the formula (VI) and a fluorine-containing polymerizable monomer selected from compound (II). In the formula, R15 is a hydrogen atom, a furkyl group, aryl group, All represents styrene, α-furkylstyrene, α-olefin, acrylic acid and methacrylic esters,
Indicates a repeating unit in which at least 111 of α-cyanoacrylic acid and α-cyanomethalyl ester are polymerized, n represents a positive integer, 120 represents an alkylene steel% m represents a positive integer, and 1M represents a positive integer. Indicates an alkali metal.

-a formula (w) a) + 2-c (a12i013 kYRco I In the formula, R21 represents a hydrogen atom, an alkyl group or a,
A13 represents substituted or unsubstituted alkylene steel, C and d are 0 or l, and Y represents a halogen atom.

The synthesis of the macromer in C-1 is described in U.S. Patent No. 3.7.
No. 861,1°6 and U.S. Patent No. 3°928.25
This is achieved by using an anionic polymerization method using a compound having an unsaturated double bond as a terminator, as disclosed in No. 5.

An example of synthesis of a styrene macromer is shown in Synthesis Formula (3)%Formula% If the styrene macromer synthesized in this way is copolymerized with a fluorine-based polymerizable monomer, a fluorine-based segment is formed on the trunk, and a non-fluorine-based segment (styrene segment is formed on the branches). It is possible to obtain a fluorine-based graft polymer having an oligomer).

In this case, the polymerization component of the macromer is compatible with the resin layer of the surface layer to which the formed fluorine-based graft polymer is added, or has a similar structure even if not completely compatible, so that there is even a slight affinity between the two. It is necessary to choose one that has a certain gender.

For example, if the surface resin layer is made of poly(meth)acrylic esters, (meth)acrylic esters are preferable as the macromer polymerization component, and in the case of polystyrene or polycarbonate, styrene compounds are preferably selected. preferable.

The binder resin for forming the surface layer may be any polymer that has film-forming properties, but polymethacrylate ester is used because it has a certain degree of hardness even when used alone and does not interfere with carrier transport.

Preferred are polystyrene, methacrylic acid ester-styrene copolymer, polycarbonate, polyarylate, polyester, polysulfone, and the like.

When producing the electrophotographic photoreceptor of the present invention, the conductive support is made of aluminum, stainless steel, paper, plastic, or the like, and a conductive layer in which conductive particles are dispersed in a suitable binder resin is provided on the support. A cylindrical cylinder or film is used. However, if the support itself is conductive, the conductive support does not need to be provided with a conductive layer.

A subbing layer (adhesive layer) having a barrier function and a subbing function can be provided on these conductive supports.

The undercoat layer improves adhesion of the photosensitive layer, improves coating properties, protects the conductive support, covers defects on the conductive support, improves charge injection from the conductive support, and improves the electrical properties of the photosensitive layer. Formed for purposes such as protection against destruction. The material for the undercoat layer is
Known examples include polyvinyl alcohol, poly-N-vinylimidazole, polyethylene oxide, ethyl cellulose, methyl cellulose, ethylene-acrylic copolymer, casein, polyamide, copolymerized nylon, glue, and gelatin.

These are each dissolved in a suitable solvent and applied onto a conductive support. The film thickness is about 0.2 to 2 l.

Examples of charge-generating substances include cyanine dyes, azulene dyes, scuvarylium dyes, biryllium dyes, thiapyrylium dyes, phthalocyanine pigments, anthacytron pigments, dibenzpyrenequinone pigments, pyranthrone pigments, and heptanoazo pigments. Azo pigments such as , disazo pigments and trisazo pigments, indigo pigments, quinacridone pigments, asymmetric quinocyanine, quinocyanine, etc. can be used.

As the charge transport substance, pyrene, N-ethylcarbazole, N-inpropylcarbazole, N-methyl-N-
Phenylhydrazino-3-methylidene-9-ethylcarbazole, N,N-diphenylhydrazino-3-methylidene-9-ethylcarbazole, N,N-diphenylhydrazino-3-methylidene-10-ditylphenothiazine, N, N-diphenylhydrazino-3-methylidene-
10-ethylphenoxazine, p-diethylaminobenzaldehyde N, N-diphenylhydracine, p-
Diethylaminobenzaldehyde-N-α-naphthyl-
N-phecolhydrazone, p-pyrrolidinobenzaldehyde-N,N-diphenylhydrazone, 1,3.3-)
rifthylindolenine-ω-aldehyde-N,N-diphenylhydrazone, p-diethylbenzaldehyde-3
-Hydrazones such as methylbenzthiazolinone-2-hydrazone, 2,5-bis(p-diethylaminophenyl)-1,3,4-oxadiazole, 1-phenyl-
3-(p-diethyl7minostyryl)-5-(p-diethylaminophenyl)pyrazoline, 1-[quinolyl(2
)]-3-(p-diethylaminostyryl)-5-(p
-diethylaminophenyl)pyrazoline, 1-[pyridyl(2)]-3-(p-diethylaminostyryl)-5
-(p-diethylaminophenyl)pyrazoline, 1-[
6-Medoxybilidyl(2)]-3-(p-diethylaminostyryl)-5-(p-diethylaminophenyl)
Pyrazoline, 1-[pyridyl(3)]-3-(p-diethylaminostyryl)-5-(p-diethylaminophenyl)pyrazoline, 1-[levidyl(2)]-3-(p
-diethylaminostyryl)-5-(p-diethylaminophenyl)pyrazoline, 1-[pyridyl(2)]-3
-(p-diethyl7minostyryl)-4-methyl-5-
(p-diethylaminophenyl)pyrazoline, 1-[pyridyl(2)]-3-(α-methyl-P-diethylaminostyryl)-5-(p-diethylaminophenyl)
Pyrazoline, 1-7enyl-3-(p-diethylaminostyryl)-4-methyl-5-(p-diethylaminophenyl)pyrazoline, 1-phenyl-3-(α-benzyl-p-diethylaminostyryl)-5-(p -diethylaminophenyl)pyrazoline, spiropyrazoline and other pyrazolines, 2-(p-diethylaminostyryl)
-6-ethylaminobenzoxazole, 2-(p-
oxazole compounds such as diethylaminophenyl)-4-(p-dimethylaminophenyl)-5-(2-chlorophenyl)oxazole, thiazole compounds such as 2-(p-diethylaminestyryl)-6-dinithylaminobenzthiazole, Bis(4-diethylamino-
Triarylmethane compounds such as 2-methylphenyl)phenylmethane, 1,1-bis(4-N,N-diethylamino-2-methylphenyl)hebutane, 1,1,2
．． 2-tetrakis(4-N,N-dimethylamino-2-
Polyarylalkanes such as methylphenyl)ethane, 5-(4-diphenylaminobenzylidene)-5H dibenzo[a,d]cycloheftene, 1,2-benzo-3
Stilbene compounds such as -(d-phenylstyryl)-9-n-butylcarbazole and the like can be used.

The method for producing an electrophotographic photoreceptor of the present invention will be explained using an example of a functionally separated photoreceptor in which a charge transport layer is laminated on a charge generation layer.

The charge generating material is well dispersed together with a binder resin and a solvent in an amount of 0.3 to 10 times using a homogenizer, an ultrasonic wave, a ball mill, a vibrating ball mill, a sand mill, an attritor, a roll mill, or the like. This dispersion was coated on the conductive support coated with the subbing layer, dried, and
~Ig, degree.

Form a coating film.

In this example, one surface layer serves as a charge transport layer, so fluororesin powder is dispersed there.

That is, the binder resin, fluorine-based resin powder, and fluorine-based graft polymer are well dispersed together with a solvent using a homogenizer, ultrasonic wave, ball mill, vibrating ball mill, sand mill, attritor, roll mill, etc., and then a solution of the charge transporting substance and the binder resin is added. is added to prepare a desired charge transport layer dispersion.

Adding the fluorine-based graft polymer at the time of dispersing the fluorine-based resin powder is most effective in contributing to the stability of the fluorine-based resin powder.

However, the fluororesin powder may be dispersed in advance, and then the fluororesin graft polymer may be added.

The mixing ratio of charge transport material and binder resin is 2:l~
The ratio is about 1:4.

As a solvent, aromatic hydrocarbons such as toluene and xylene1
Chlorinated hydrocarbons such as dichloromethane, chlorobenzene, chloroform, and carbon tetrachloride are used.

When applying this solution, coating methods such as dip coating, spray coating, spinner coating, bead coating, blade coating, and curtain coating can be used, and drying is carried out at 10 to 200°C. Preferably 20-1
The drying can be carried out at a temperature in the range of 50° C. for 5 minutes to 5 hours, preferably 10 minutes to 2 hours, under blow drying or static drying. The thickness of the charge transport layer to be formed is about 10 to 30 μl.

In addition, in the case of a photoreceptor in which a charge generation layer is coated on a charge transport layer, the charge generation layer becomes a surface layer, so fluororesin powder whose dispersion is stabilized with a fluorine graft polymer is contained here. .

This charge generation layer dispersion is prepared by adding a dispersion in which fluororesin powder is dispersed in a binder resin used for the charge generation layer using a fluorine graft polymer as a dispersant to a dispersion of a charge generation substance prepared as described above. It can be prepared by a method of adding and mixing, and the electrophotographic photoreceptor of the present invention can be prepared by coating this dispersion on a charge transport layer.

When the photosensitive layer has wIM retention, the protective layer becomes the surface layer of the photosensitive layer, and the fluororesin powder stabilized with the fluorine-based graft polymer is contained in this protective layer.

This protective layer can be formed, as described above, by coating the photosensitive layer with a dispersion of fluororesin powder stabilized with a fluorine-containing graft polymer in the resin forming the protective layer.

The present invention will be explained in detail below using examples.

[Example] 'Synthesis of O fluorine-based graft polymers (A-1 and A-2) The synthesis of fluorine-based graft polymers is described in JP-A-58-16
The experiment was carried out based on the macromer synthesis method disclosed in Japanese Patent No. 4656, in which a terminal double bond is introduced with glycidyl methacrylate using thioglycolic acid as a chain transfer agent.

When this macromer is a non-fluorine segment, it is copolymerized with a fluorine-based polymerizable monomer, and when the macromer is a fluorine-based segment, it is copolymerized with a non-fluorine-based polymerizable monomer, A fluorine-based graft polymer was synthesized.

(i) Fluorine-based graft polymer No. 1 (a) Synthesis of terminal methacrylate type methyl methacrylate macromer Methyl methacrylate (hereinafter abbreviated as MMA) was placed in a glass flask equipped with a stirrer, reflux condenser, dropping funnel, thermometer and gas inlet. ) and 10 copies of A7ton (1
7.5%)-toluene a mixture was charged, and after introducing N2, 0.5 part of azobisisobutyronitrile (hereinafter abbreviated as AIBN) as a polymerization initiator and thio as a chain transfer agent were added under reflux. Polymerization was initiated by adding 0.35 parts of glycolic acid. Thereafter, 90 parts of MMA was continuously added dropwise over a period of 5 hours, and 2.9 parts of thioglycolic acid was dissolved in 10 parts of toluene and added in 9 portions every 30 minutes. Polymerization was carried out by adding 1 part in 4 portions every hour.

Thereafter, the polymerization was completed by refluxing for 2 hours to obtain a polymer solution having the following structural formula (1).

A part of the 6 reaction solution whose reaction temperature was 77 to 87°C was converted into n-
When reprecipitated with hexane, dried and measured the acid value, it was 0.
．． The amount was 350 mg equivalent/g.

Structural formula (1) Next, after distilling off a portion of the a7ton from the above reaction solution, 0.5% of triethylamine as a catalyst and 250 ppm of hydroquinone 7methyl ether as a polymerization initiator were added to 1.2 times the mole of glycidyl methacrylate was added, and the mixture was reacted under reflux (approximately 110°C) for 12 hours. The reaction rate determined from the decrease in acid value was 96%.

The reaction solution was poured into 10 times the volume of n-hexane, reprecipitated, and then dried under reduced pressure at 80°C to obtain 85 parts of a macromonomer of the following structural formula (II). The polystyrene-equivalent molecular weight determined by Gelno-Koumier Schromer chromatography (hereinafter abbreviated as GPC) is 2780 (number average) and 835.
0 (weight average) Structural formula (II) (b) Synthesis of fluoroalkyl acrylate (trunk)/methyl methacrylate (branch)-graft polymer The macromer of the above structural formula (n) was placed in the same apparatus as in (a). 7
0 parts and 30 parts of fluoroalkyl acrylate of the following structural formula (m), trifluorotoluene CC4HtCFj)
jo, 0 parts, AIBNIo, prepare 35 parts, N2
The mixture was introduced and reacted under reflux (100″O) for 5 hours.

Structural formula (m) However, a mixture of n=4 to 12 (The average value of n is approximately 7) This reaction solution was poured into 10 times the volume of methanol.

It was reprecipitated and dried under reduced pressure at 80°C to obtain 65 parts of a graft polymer.

This product showed a single peak by GPC, and the polystyrene equivalent molecular weight was 18,500 (number average) and 294
00 (weight average).

In addition, trifluorotoluene was added as an internal standard substance, and the 'H-NMR spectrum was measured in CDCl2 solvent, and the peak area ratio between H of trifluorotoluene and H of 10 -CHs in the MMA unit in the polymer was measured. from,
The content of MMA units in the graft polymer was determined to be 60%.

The remaining 40% was made into fluoroalkyl acrylate.

In this way, a fluorine-based graft polymer having a fluorine-based segment content of 40% was obtained.

(51) Fluorine-based graft polymer No. 2 No. 3 Fluorine-based segment content 21 by changing the amount of fluoroalkyl acrylate and performing the same operation as in (i) above.
% (No, 2), 61% (No.

3), molecular weight each 24000.18000 (number average)
A fluorine-based graft polymer was synthesized.

(iii) Fluorine-based graft polymer No. 4 In the above (i), methyl methacrylate is replaced with styrene, and fluoroalkyl acrylate is replaced with 2 of the following structural formula (IV).
．． In place of 3,5.6-titrafluorophenyl methacrylamide structural formula (IV) (the amount charged was adjusted so that the double bond concentration was the same), fluorine was added using the same equipment and operation as in (i). System segment content 25%, number average molecular weight 3600
A fluorine-based graft polymer of No. 0 was synthesized.

The molecular weight of the styrene macromer at this time was 7,000.

(1v) Fluorine-based graft polymer No. 5 above (i
)-(&) methyl methacrylate in (i)-
In place of (b) fluoroalkyl acrylate, (i)
A fluorine-based macromer having a number average molecular weight of 6,600 was synthesized under the same reaction conditions as -(&). Furthermore, the above (1)-(
A fluorine-based graft polymer whose branches are composed of fluorine-based segments was synthesized under the same conditions as in (i)-(b) using methyl methacrylate in place of the fluoroalkyl acrylate in b).

The content of fluorine-based segments was 25%, and the number average molecular weight was 42,000.

(V) Fluorine-based graft polymer No. 6 (i) above
-A polymer solution having the following structural formula (V) was obtained in the same manner as in (i)-(a) except that 2.4 parts of 2-mercaptoethanol was used in place of thioglycolic acid in (a).

Structural Formula (V) H Furthermore, a macromer was synthesized by reacting with glycidyl methacrylate in the same manner as in (i)-(a). The polystyrene equivalent molecular weight by GPC was 3250 (number average) and 7800 (weight average).Next, a graft polymer with fluoroalkyl acrylate as the trunk and methyl methacrylate as the branches was synthesized in the same manner as in (i) and (b). .

Fluorine segment content is 30%, number average molecular weight 32
It was 000.

(vf) Fluorine-based graft polymer No. 7 above (
2- in place of thioglycolic acid in i)-(L),
Using 2.4 parts of aminoethyl mercaptan, using the same amount of styrene instead of methyl methacrylate, and other (i)
-A polymer solution having the following structural formula (VT) was obtained in the same manner as in (a).

Structural formula 1) Next, a macromer was synthesized by reacting with glycidyl methacrylate in the same manner as in (i)-(a).

The polystyrene equivalent molecular weight determined by GPC was 3450 (number average) and 7700 (weight average).

Next, a graft polymer having fluoroalkyl acrylate as the trunk and methyl methacrylate as the branches was synthesized in the same manner as in (i)-(b).

Fluorine segment content is 32%, number average molecular weight 46
It was 000.

■Synthesis of fluorine-based graft polymers (B-1 and B-2)
The macromer synthesis method disclosed in Japanese Patent No. 4656 and 2-mercaptoethanol as a chain transfer agent disclosed in U.S. Pat. No. 3,689,593, using tolylene diisocyanate and 2-hydroxyethyl methacrylate. The method was based on a macromer synthesis method that introduces a terminal double bond.

If this macromer is a non-fluorinated segment, it is copolymerized with a fluorinated polymerizable monomer, and if the macromer is a fluorinated segment, it is copolymerized with a non-fluorinated polymerizable monomer, and the fluorinated segment is copolymerized with a fluorinated polymerizable monomer. A graft polymer was obtained.

(vH) Fluorine-based graft polymer No. 8 (a) Synthesis of terminal methacrylate type methyl methacrylate macromer In a glass flask equipped with a stirrer, a reflux condenser, a dropping funnel, a thermometer and a gas inlet, MMAIO portion and a seven ton (17 , 5%)-toluene mixed solvent was charged, and after introducing N2, 0% of AIBN was added as a polymerization initiator under reflux.
．． 5 parts and 0 2-mercaptoethanol as chain transfer agent
．． 27 parts were added to initiate polymerization. Thereafter, 90 parts of MMA was continuously added dropwise over a period of 5 hours, and 2.4 parts of 2-mercaptoethanol was dissolved in 8 parts of toluene.
Add every minute, divided into 9 times, similarly AIBNl, 5 parts in 1
．． Polymerization was carried out by adding 3 times every 5 hours.

Thereafter, the mixture was refluxed for 2 hours to complete the polymerization.

A polymer solution having the structural formula (V) was obtained.

The reaction temperature was 77-88°C.

Next, 6.0 parts of 2.4-)lylene diincyanate and 0.35 parts of dibutyltin dilaure were added to the above polymer solution, and the reaction was carried out at 78 to 82°C for 30 minutes. ) was obtained.

Structural formula (VI) and 4.45 2-hydroxyethyl methacrylate
The reaction was carried out at 78-82°C for 1 hour.

Thereafter, one reaction solution was poured into 10 times the volume of n-hexane, precipitated, and then dried under reduced pressure at 80°C to obtain 94 parts of a macromer having the following structural formula (■).

Structural formula (vI[) 9hG
The polystyrene equivalent molecular weight determined by PC was 3040 (number average) and 6850 (weight average).

(b) Synthesis of fluoroalkyl acrylate (trunk)/methyl methacrylate (branch)-graft polymer In the same apparatus as in (a), 70 parts of the macro6mer of the above structural formula (VI) and the fluoroalkyl acrylate of the above structural formula (m) were added. 30 parts of alkyl acrylate, trifluorotoluene, CfHsCF
3) Prepare 300 copies, AIB No., 35 copies, N2
The mixture was introduced and reacted under reflux (approximately 100°C) for 5 hours.

This reaction solution was poured into 10 times the volume of methanol, reprecipitated, and dried under reduced pressure at 80°C to obtain 62 parts of a graft polymer.

This product showed a single peak by GPC, and the polystyrene equivalent molecular weight was 20500 (number average) and 320
00 (weight average).

In addition, trifluorotoluene was added as an internal standard substance, and 'H-NMR spectrum e 11 was obtained using CDCuλ solvent.
H of trifluorotoluene and MMA in the polymer
The content of MMA units in the graft polymer was determined from the peak area ratio with the unit -0-CH3, and was found to be 72%. The remaining 28% was made into fluoroalkyl acrylate.

In this way, fluorine-based graft polymer No. 8 having a fluorine-based segment content of 28% was obtained.

(Cap) Other fluorine-based graft polymers Various fluorine-based grafts and polymers (No. 9 to 13 degrees) were synthesized using the following raw materials and according to the above synthesis method.

Fluorine-based graft polymer No. 9 Macromer one component vinyl heptanomer: styrene chain transfer agent: 2-mercaptoamine ethane isocyanate compound: 1,6-hexamethylene diisocyanate vinyl-terminated polymer introduced: 2-hydroxyethyl methacrylate Number average molecular weight: 2130 Trunk segment constituent vinyl monomer: Fluoroalkyl acrylate (
Same product as No. 1) Physical properties of fluorine-based graft polymer Number average molecular weight: 44200 Fluorine-based segment content: 22 wt% Fluorine-based graft polymer No. 10 Macromer constituent vinyl monomer: Methyl methacrylate/styrene (weight ratio 20780) Chain transfer Agent: 3-mercaptopropionic acid isocyanate Compound: 2.4-TDI terminal vinyl-introduced monomer: Methacrylic acid Number average molecular weight: 3170 Stem segment structure and vinyl monomer m: 2.3,4.5-tetrafluorophenyl cu3
Physical properties of methacrylate fluorine-based graft polymer Number average molecular weight: 60800 Fluorine-based segment content: 10 wt% Fluorine-based graft polymer No., 11 Macroma 1 component Vinyl heptanomer: Styrene chain transfer agent: 2-mercaptoethanol incyanate compound: 4 .4°-diphenylmethane diisocyanate vinyl-terminated polymer: 2-aminoethyl methacrylate Number average molecular weight: 6620 Vinyl monomer constituting the trunk segment: average of fluoroalkyl acrylic n 7) Physical properties of fluorine-based graft polymer Number average molecular weight: 8481 ) 0 Fluorine segment content: 28wt% Fluorine based graft polymer No. 12 Macromer one component Vinyl monomer: Fluoroalkyl acrylate Chain transfer agent: 2-mercaptoethanol incyanate Compound: 4,4'-diphenylmethane diisocyanate Terminal vinyl introduced monomer: 2-7 minoethyl methacrylate Number average molecular weight: 3920 Stem segment constituent vinyl monomer: Physical properties of styrene fluorine graft polymer Number average molecular weight: 57300 Fluorine segment content: 15wt% Fluorine graft polymer No. 13 Macromer One constituent vinyl monomer: Fluoroalkyl acrylate Chain transfer agent = 3-mercaptopropionic acid isocyanate compound: Inphorone diisocyanate Vinyl-terminated monomer: 3-hydroxypropyl methacrylate Number average molecular weight:
1860 Trunk segment constituent vinyl monomer: Methyl methacrylate Physical properties of fluorine-based graft polymer Number average molecular weight: 19400 Fluorine-based segment content: 43 wt% ■Synthesis of fluorine-based graft polymer (C-1) Synthesis of fluorine-based graft polymer is described in U.S. Patent No. The method was based on the macromer synthesis method using an anionic polymerization method using a compound having an unsaturated double bond as a terminator, which is disclosed in U.S. Pat. No. 3,788,118 and U.S. Pat. No. 3,928,255. . A fluorine-based graft polymer is obtained by copolymerizing these macromers with a fluorine-based polymerizable monomer.

(ix) Fluorine-based graft polymer No. 14 (&
) Synthesis of terminal vinyl styrene macromer 80 parts of dehydrated benzene was placed in a stainless steel reactor. Raise the temperature to 40°C and add one drop of diphenylethylene. 30 ml of a 1296 pentane solution of t-butyllithium and 321 parts of styrene were added, and the reaction was carried out at 40°C for 130 minutes.

Next, 8 m of vinyl-2-chloroethyl ether is added to stop the reaction. This reaction solution is dropped into methanol to reprecipitate the polymer.

After filtering, drying at 80°C under reduced pressure gives the following structural formula (IK)
of styrene macromer.

Structural formula (IK) Polystyrene equivalent molecular weight by GPC is 640 on number average
It was 0.

(b) Synthesis of fluoroacrylate (trunk)/styrene (branch)-graft polymer 70 parts of the styrene macromer of the above structural formula (IX) was placed in a glass flask equipped with a stirrer, reflux condenser, dropping funnel, thermometer and gas inlet. and 30 parts of fluoroacrylate of the above structural formula (m), trifluorotoluene CC1HrCFJ)
280 parts and 0.35 parts of AIBN were charged, N2 was introduced, and the reaction was carried out under reflux (approximately 100°C) for 5 hours.

This reaction solution was poured into 10 times the amount of methanol, reprecipitated, and dried under reduced pressure at 80° C. to obtain a graft polymer. GP
The number average molecular weight of C was 48,300. In addition, trifluorotoluene was added as an internal standard substance, and 'H-NMR spectra were measured in CDCfL2 solvent. The content of styrene units in the graft polymer was determined from the peak area ratio with the aromatic ring H, and it was found to be 72%.
Met.

The remaining 28% was made into fluoroalkyl acrylate.

In this way, fluorine-based graft polymer No. 14 having a fluorine-based segment content of 28% was obtained.

(x) Other fluorine-based graft polymers Various fluorine-based graft polymers (Nos. 15 to 19) were synthesized using the following raw materials and according to the synthesis method described above.

Fluorine-based graft polymer No. 15 Macromer 1 component Vinyl monomer: α-methylstyrene terminator: CHz-CHOCHx, CH, C1 Number average molecular weight: 4370 Trunk segment constituent fluorine-based vinyl monomer: Fluoroalkyl acrylate Physical properties of fluorine-based graft polymer Number average molecular weight: 56300 Fluorine segment content: 24wt% Fluorine graft polymer No. 16 Macroma constituent vinyl monomer: α-cyanoethyl acrylate Number average molecular weight: 6480 Trunk segment constituent fluorine vinyl monomer: Fluoroalkyl acrylate (No. Same product as 1) Physical properties of fluorine-based graft polymer Number average molecular weight: 72500 Fluorine-based segment content: 41 wt% Fluorine-based graft polymer No. 17 Macromer 1 constituent vinyl monomer - styrene terminator: C) 12. -C) I-@-cHyuCHzCf
L number average molecular weight: 2410' Trunk segment constituent fluorine-based vinyl monomer: 2.3,5.6-titrafluorophenyl methacrylate (mentioned above) Physical properties of fluorine-based graft polymer Number average molecular weight: 28600 Fluorine-based segment content: 18 wt% Fluorine-based graft polymer No. 18 Macromer 1 component Vinyl monomer: α-methylstyrene terminator: CH2-CH-QC-CHxCHzNumber average molecular weight: 3850 Trunk segment constituent fluorine-based vinyl monomer: Fluoroalkylacrylamide (described above) Physical properties of fluorine-based graft polymer Number average molecular weight: 49,400 Fluorine-based segment content: 12wt% Fluorine-based graft polymer No., 19 Macromer 1 component Vinyl monomer: Methyl methacrylate Number average molecular weight:
28.70 Trunk segment constituent fluorine-based vinyl monomer: Fluoroalkyl vinyl ether CH2L4C cap (n: 4-12 (7) mixture, n average 7) Physical properties of fluorine-based graft polymer Number average molecular weight: 38600 Contains fluorine-based segment Amount: 37 wt% Example 1 An aluminum cylinder of 80 mmφ x 300 mm was used as a conductive support, and polyamide (trade name Amilan C)
A 5% methanol solution of M-4000 (manufactured by Toshida Co., Ltd.) was applied by dip coating to provide a 1 ml thick subbing layer.

Next, add 10 parts (parts by weight, the same applies hereinafter) of a disazo pigment having the following structural formula.

5 parts of polyvinyl butyral (trade name Kosuretsu BM-2, manufactured by Sekisui Chemical Co., Ltd.) and 50 parts of cyclohexanone were added in
Dispersion was carried out for 200 hours using a sand mill using nφ glass beads. 70 to 120 (appropriate) parts of methyl ethyl ketone were added to this dispersion and coated on the undercoat layer to a film thickness of 0.20.
A charge generation layer of 1.5 mm was formed.

Next, polymethyl methacrylate (product name DIANAL B)
R-85, manufactured by Mitsubishi Rayon ■) 10 parts, polytetrafluoroethylene (trade name Lubron L-2, manufactured by Daikin Industries ■) 1
0 parts and the fluorine-based graft polymer No., 1 of 0
．． 5 parts was dissolved in 40 parts of monochlorobenzene and 30 parts of tetrahydrofuran, and 48 parts was dissolved in a stainless steel ball mill.
Spread out time. A charge transport layer solution was prepared by mixing 10 parts of the resulting dispersion with 70 parts of a resin solution in which 10 parts of a hydrazone compound having the following structural formula and 10 parts of the above polymethyl methacrylate were dissolved in 60 parts of monochlorobenzene.

In addition, the fluorine-based graft polymer No. 8, the same No.
Charge transport layer solutions were prepared in the same manner as above using No. 14.

The average particle size of the polytetrafluoroethylene powder in this charge transport layer solution was measured using a particle size distribution analyzer (CAPA-500, manufactured by Horiba, Ltd.), and was found to be 0.45p and 0.45p, respectively.
They were 0.461L and 0.48jL.

This solution was coated on the charge generation layer and 110'0.9
It was dried with hot air for 0 minutes to form a charge transport layer of 18 liters.

The electrophotographic photoreceptors thus prepared were sample 1 and sample 1, respectively.
Sample 2 and Sample 3.

The surface of the charge transport layer of each of the above samples was uniform and smooth. The average surface roughness of this surface layer was 0.2p or less, which was equivalent to the average roughness of the surface of the charge transport layer formed from a binder resin and a charge transport material containing no fluororesin powder.

For comparison, an electrophotographic photoreceptor was prepared using a material to which no fluorine-based graft polymer was added, but in the same manner as above. This is designated as sample (comparison) 4.

In sample 4, the agglomeration of polytetrafluoroethylene powder in the first surface layer was so severe that it was not worth evaluating one image.On the other hand, no polytetrafluoroethylene and fluorine-based graft polymer were added, and the other samples were An electrophotographic photoreceptor was prepared in the same manner as described above. This is designated as sample (comparison) 5.

For each of the above samples, 30,000 sheets were produced using an electrophotographic process consisting of -5.5KV corona charging, image exposure, dry toner development, transfer to plain paper, silicone rubber cleaning roller, urethane rubber blade, and pre-exposure. We conducted a durability evaluation. Show the results.

Sample 1 l Good 2 8 Good
3 14 Good 4
Fully black pochi〃 5 Good 2
3℃55S R, H32, 5℃90% R,H sample 1
Up to 30,000 sheets High-quality stable images up to 30,000 sheets High-quality stable images Up to 230,000 sheets High-quality stable images up to 30,000 sheets High-quality stable images〃 Up to 330,000 sheets High-quality stable images up to 30,000 sheets High-quality stable images 〃 4 Not worthy of evaluation Not worthy of evaluation 〃 Scratches at 510,000 sheets Image deletion occurred at 8,000 sheets and on the surface at 20,000 sheets Toner fusion Example 2 An aluminum cylinder of 80 mm φ x 300 mm was used as a conductive support. polyamide (product name Amilan C)
A 5% methanol solution of M-8000 (manufactured by Toshida Co., Ltd.) was applied by dip coating to provide an IIL thick subbing layer.

Next, a charge generation layer was formed using the same materials and method as in Example 1.

Next, 10 parts of bisphenol Z type polycarbonate (manufactured by Mitsubishi Gas Chemical ■), 20 parts of polyvinylidene fluoride (trade name Kyna-ni-301F, manufactured by Pennwald) and 3 parts of the above fluorine-based graft polymer were mixed with 50 parts of cyclohexanone and 20 parts of tetrahydrofuran. and dispersed in a sand mill using 1 mm diameter glass beads for 20 hours.

A charge transport layer solution was prepared by mixing 10 parts of the obtained dispersion with 70 parts of a resin solution in which 10 parts of the Bisphe, Nor ZW polycarbonate having the structural formula shown below was dissolved in 40 parts of cyclohexanone and 20 parts of tetrahydrofuran. .

In addition, the fluorine-based graft polymer No. 9, the same No.
Charge transport layer solutions were prepared using No. 15 in the same manner as above.

The average particle size of the polyvinyrizonated polysulfate powder in this charge transport layer solution was 0.42%.

It was 0.481L at the end of 0.45.

This solution was applied onto the charge generation layer, and heated to 90°C at 110°C.
A 20% charge transport layer was formed by drying with hot air for a minute.

The electrophotographic photoreceptors thus prepared were sample 6 and sample 6, respectively.
Sample 7 and Sample 8.

The surface roughness was less than 0.2 l.

For comparison, an electrophotographic photoreceptor was prepared using a material to which no fluorine-based graft polymer was added, but in the same manner as above. This is designated as sample (comparison) 9.

In sample 9, the agglomeration of polyvinylidene fluoride powder in the surface layer was so severe that it was not worthy of image evaluation. On the other hand, polyvinylidene fluoride and fluorine-based graft polymer were not added, and the other conditions were the same as above. A photographic photoreceptor was created. This is designated as sample (comparison) 10.

Each of the above samples was subjected to an electrophotographic process consisting of -5.5 KV corona charging, image exposure, dry toner development, transfer to plain paper, cleaning with a urethane rubber blade, silicone rubber cleaning roller, and pre-exposure. The durability of the sheet was evaluated. Electronic results.

Sample 6 4 Good〃7 9 Good〃815 Good〃 9 Full black spot ttl Q Good 23℃55 R, H32, 5℃902 R,H sample 6
Up to 30,000 sheets High-quality stable images up to 30,000 sheets High-quality stable images / Up to 730,000 sheets High-quality stable images up to 30,000 sheets High-quality stable images Up to 830,000 sheets High-quality stable images up to 30,000 sheets High-quality stable images Image〃 9 Not worthy of evaluation Not worthy of evaluation // Toner fusion occurred at 106,000 sheets Image deletion occurred at 5,000 sheets Example 3 10 parts of the hydrazone compound used in Example 1 and styrene /
Methyl methacrylate copolymer (trade name: Estyrene MS)
-200, manufactured by Shinnichiki Tetsuya Co., Ltd.) was dissolved in 60 parts of monochlorobenzene.

A subbing layer was coated with this solution in the same manner as in the example.
It was applied by dip coating onto an aluminum cylinder of mφ×300 mm and dried at 100° C. for 1 hour to form a charge transport layer of 12 JL.

Next, 10 parts of a disazo pigment having the following structural formula, 5 parts of polytrifluorochloroethylene (manufactured by Daikin Industries, Ltd.), and 70 to 120 parts of methyl ethyl ketone (as appropriate) are added to this dispersion, and the mixture is coated on the undercoat layer. Then, a charge generation layer having a thickness of 0.20 l was formed.

Next, polymethyl methacrylate (product name DIANAL B)
R-85, made by Mitsubishi Rayon ■), 10 parts of polytetrafluoroethylene (trade name: Lublon L-2, made by Daikin), and 1 part of the above fluorine-based graft polymer No. 2 were combined with the above styrene/methyl methacrylate. 10w of polymer
The mixture was added to 100 parts of t% cyclohexanone solution and dispersed in a stainless steel ball mill for 50 hours. This solution was applied onto the charge transport layer at 100°C and 20°C.
It was dried for 2 minutes to form a charge generation layer 2 μl thick.

In addition, the fluorine-based graft polymer No. 10, the same No.
, 16 was used to form a charge generation layer in the same manner as above.

The average particle size of the polytrifluorochloroethylene powder in this charge generation layer solution was 0.52p.

It was 0.501L, o, 541L.

The produced electrophotographic photoreceptors were sample 11, sample 12, and sample 1.
The surface roughness of 0.3 was 0.2 l or less, respectively.

For comparison, an electrophotographic photoreceptor was prepared using a material to which no fluorine-based graft polymer was added, but in the same manner as above. This is designated as sample (comparison) 14.

Sample 14 had severe agglomeration of the polytrifluorochloroethylene powder in the surface layer, and was in a state unworthy of image evaluation.

On the other hand, an electrophotographic photoreceptor was prepared in the same manner as above except that polytrifluorochloroethylene and fluorine-based graft polymer were not added.

This is designated as sample (comparison) 15.

Each sample was attached to an electrophotographic copying machine with +5.6KV corona charging, image exposure, dry toner development, transfer to plain paper, cleaning process with a urethane rubber blade, and pre-exposure to evaluate the durability of io and oooo sheets. I did it. Show the results.

Fluorine-based graft Initial image sample 11 2 Good/l 1 2 1 0 Good// 1 3 1 &
Good l/14 - Fully black pochi 15 - Good 23
℃55% R, H32, 5℃80R9H Sample 11 Up to 10,000 sheets High quality stable images up to 10,000 sheets High quality stable images〃Up to 1.21 million sheets High quality stable images up to 10,000 sheets High quality stable images〃Up to 1.31 million sheets High-quality stable images up to 10,000 sheets High-quality stable images l/14 Not worthy of evaluation Not worthy of evaluation/1153
Scratches caused by rubbing after 1,000 sheets Image blur occurred after 2,000 sheets Example 4 1 part of aluminum chloride phthalocyanine, 10 parts of porsulfone (trade name: Cordelborisulfone p-3500, manufactured by Nissan Chemical ■), polytetrafluoroethylene/hexafluoride 7 parts of propylene copolymer (manufactured by Daikin Industries, Ltd.) and 2 parts of the above fluorine-based graft polymer No. 3 were added together with 40 parts of monochlorobenzene and 10 parts of tetrahydrofuran.
The mixture was dispersed for 20 hours in a sand mill using mmφ glass beads, and 6 parts of the pyrazoline compound used in Example 2 was added thereto to prepare a solution.

In addition, the fluorine-based graft polymer No. 11, the same No.
, 17 was used to prepare a solution in the same manner as above.

The average particle size of the polytetrafluoroethylene/hexafluoropropylene copolymer powder in this solution was 0.38 JL,
It was 0.46JL% 0.481L.

A subbing layer was applied using this solution in the same manner as in Example 2.
This was applied by dip coating onto an aluminum cylinder of 0 mmφ x 300 mm and dried to provide a photosensitive layer of 14 JL. The surface roughness was 0.2w or less.

The prepared electrophotographic photoreceptors were sample 16 and sample 1, respectively.
7. Sample 18.

For comparison, an electrophotographic photoreceptor was prepared using a material to which no fluorine-based graft polymer was added, but in the same manner as above. This is designated as sample (comparison) 19.

Sample 19 was in a state in which the polytetrafluoroethylene/hexafluoropropylene copolymer powder in the surface layer had severe agglomeration and was not worthy of image evaluation.

On the other hand, an electrophotographic photoreceptor was prepared in the same manner as above except that the polytetrafluoroethylene/hexafluoropropylene copolymer powder and the fluorine-based graft polymer were not added.

This is designated as sample (comparison) 20.

Each sample was subjected to -5.5 KV corona charging, image exposure, dry toner development, transfer to plain paper, and cleaning using a urethane rubber blade.

Durability evaluation was performed on 10,000 sheets using an electrophotographic process consisting of pre-exposure. Show the results.

Sample 16 3 Good // 1 7 1 1 Good / l l 8 1 7
Good l/19 - Fully black pochi // 20 Good
Good 23℃ 55% R, H32, 5℃ log
R,H samples Up to 1.61 million sheets High-quality stable images up to 10,000 sheets High-quality stable images // Up to 1.71 million sheets High-quality stable images up to 10,000 sheets High-quality stable images // Up to 1.81 million sheets High-quality images up to 10,000 sheets Stable image High quality stable image l/19 Not worthy of evaluation Not worthy of evaluation //201
Toner fusion occurred on 1,500 sheets at 1,000 sheets Image deletion occurred Example 5 10 parts of bisphenol Z-type polycarbonate (mentioned above), 20 parts of polysulfated vinyl (Daikin ■M), and the above-mentioned two, base-based graft polymer No. 5 A dispersion was prepared in the same manner as in Example 2 using 3 parts of the following.

The above polycarbonate 2 was added to 90 parts of the obtained dispersion.
0 parts to 40 parts of cyclohexanone, 2 parts of tetrahydrofuran
A protective layer solution was prepared by mixing 70 parts of a resin solution dissolved in 0 parts.

In addition, the fluorine-based graft polymer No. 12, the same No.
, 18 was used to prepare a protective layer solution in the same manner as above.

The average particle diameters of the polyvinyl fluoride powder in this solution were 0.457 L, 0.471 L, and 0.48 JL, respectively.

Sample (comparison) 10 prepared using this protective layer solution in Example 2
The surface roughness was 0.21L or less when applied on the surface layer of 100'(100') and dried with hot air for 30 minutes to form a glFt of 3p.

Each of the electrophotographic photoreceptors prepared above was used as sample 21.
, sample 22, and sample 23.

Each sample was subjected to a durability test of 30,000 sheets in the same manner as in Example 2.
High quality and stable images were obtained up to 30,000 sheets for both 90% R and 90% H.

Example 6 Polymethyl methacrylate (trade name DIANAL BR-
85 (manufactured by Mitsubishi Rayon ■), 10 parts of borinifluorodichloride ethylene (manufactured by Daikin Industries, Ltd.) and 0.5 parts of the above fluorine-based graft polymer No. 6 were dissolved in 40 parts of monochlorobenzene and 30 parts of tetrahydrofuran. The mixture was dispersed in a stainless steel ball mill for 48 hours.

In the obtained dispersion, 6 parts of the hydrazone compound used in Example 1 was dissolved to prepare a charge transport layer solution.

This charge transport layer solution was applied onto a charge generation layer formed in the same manner as in Example 1 to produce an electrophotographic photoreceptor. The average particle size of the borinifluorodichloride ethylene powder in the charge transport layer warm liquid was 0.481L.

The surface of the obtained charge transport layer was uniform and smooth, and the average surface roughness was 0.21L or less.

This is designated as sample 24.

This sample was subjected to a durability test of 30,000 sheets in the same manner as in Example 1.
, 90% R, and H, high quality and stable images were obtained up to 30,000 sheets.

Example 7 In place of fluorine-based graft polymer No. 4.

An electrophotographic photoreceptor was produced in exactly the same manner as in Example 2, except that the fluorine-based graft polymer No. 7 was replaced with polyvinylidene fluoride and a vinylidene fluoride/propylene hexane copolymer was used. Created.

The average particle size of the vinylidene fluoride/propylene hexafluoride copolymer powder in the charge transport layer solution was 0.49μ, and the surface of the resulting charge transport layer was uniform and smooth, with an average surface roughness of 0.
．． It was less than 2g.

This is designated as sample 25.

This sample was subjected to a durability test of 30,000 sheets in the same manner as in Example 2.
High quality and stable images were obtained up to 30,000 sheets at both 90% R0H.

Next, using the same material, the content of vinylidene fluoride/psepylene hexafluoride copolymer was 0, 5 wt% and 60 wt%.
A wt % charge transport layer solution was prepared, an electrophotographic photoreceptor was prepared in the same manner as above, and durability was evaluated.

The results showed that an electrophotographic photoreceptor with a vinylidene fluoride/propylene hexafluoride copolymer content of 0.5 wt%
In the 3° C., 55% R,H durability test, toner fusion occurred after 6,500 sheets, and in the 32.5° C., 90% R,H durability test, image deletion occurred after 5,000 sheets.

On the other hand, the electrophotographic photoreceptor with the copolymer content of 60 wt% has 1. Under both of the above environmental conditions, toner fusion and image deletion did not occur until 30,000 sheets were printed.
It occurred from around 000.

[Effects of the Invention] In the electrophotographic photoreceptor of the present invention, the fluororesin powder and the fluorine graft polymer are contained in the surface layer, so that the fluororesin powder is uniformly dispersed and its dispersion stability is improved. As a result, a uniform surface layer is always obtained, and as a result, high-quality images can always be obtained without scratches or image blurring, not only in the initial image but also after repeated durability.

Claims (20)

[Claims] (1) An electrophotographic photoreceptor having a photosensitive layer on a conductive support, wherein the surface layer contains a fluorine-based resin powder and a fluorine-based graft polymer. (2) The fluororesin powder is a tetrafluoroethylene resin,
The claimed material is selected from trifluorochloroethylene resin, tetrafluoroethylene hexafluoropropylene resin, vinyl fluoride resin, vinylidene fluoride resin, difluorodichloride ethylene resin, and copolymers thereof. The electrophotographic photoreceptor according to scope 1. (3) The electrophotographic photoreceptor according to claim 2, wherein the fluororesin powder is selected from tetrafluoroethylene resin and vinylidene fluoride resin. (4) The electrophotographic photoreceptor according to claim 2, wherein the fluororesin powder is a tetrafluoroethylene resin. (5) The electrophotographic photoreceptor according to claim 1, wherein the content of the fluororesin powder is 1 to 50% by weight of the surface layer constituent components. (6) The electrophotographic photoreceptor according to claim 1, wherein the amount of the fluorine-based graft polymer added is 0.1 to 30% by weight based on the fluororesin powder. (7) The electrophotographic photoreceptor according to claim 1, wherein the binder resin of the surface layer is selected from polymethyl methacrylate and polycarbonate. (8) The electrophotographic photosensitive layer according to claim 1, wherein the photosensitive layer has a laminated structure of a charge generation layer and a charge transport layer, and the charge transport layer is laminated on the charge generation layer. body. (9) The electrophotographic photosensitive layer according to claim 1, wherein the photosensitive layer has a laminated structure of a charge generation layer and a charge transport layer, and the charge generation layer is laminated on the charge transport layer. body. (10) The electrophotographic photoreceptor according to claim 1, wherein the photosensitive layer is a single layer containing a charge-generating substance and a charge-transporting substance. (11) The electrophotographic photoreceptor according to claim 1, wherein the photosensitive layer has a protective layer as a surface layer. (12) Claims in which the fluorine-based graft polymer has a polymerizable functional group at one end and is a copolymer of a non-fluorine-based oligomer and a fluorine-based polymerizable monomer having a certain repeating unit. 2. The electrophotographic photoreceptor according to item 1. (13) A claim in which the fluorine-based graft polymer has a polymerizable functional group at one end and is a copolymer of a fluorine-based oligomer having a certain repeating unit and a non-fluorine-based polymerizable monomer. 2. The electrophotographic photoreceptor according to item 1. (14) The molecular weight of the non-fluorine oligomer is 1000
13. The electrophotographic photoreceptor according to claim 12, wherein the molecular weight of the fluorine-based graft polymer is 10,000 to 100,000. (15) The molecular weight of the fluorine-based oligomer is from 1000 to
10,000, and the fluorine-based graft polymer has a molecular weight of 10,000 to 100,000. (16) The electrophotographic photosensitive material according to claim 12, wherein the non-fluorine-based oligomer is represented by the general formula (I), and the fluorine-based polymerizable monomer is selected from compounds (II). body. General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ In the formula, R_1 is a hydrogen atom, an alkyl group, a halogen atom,
Indicates a halogen-substituted alkyl group or aryl group, A_1 indicates an alkylene chain or a halogen-substituted alkylene chain, A_
2 represents (R_2 to R_1_1 represent a hydrogen atom, an alkyl group, or a halogen-substituted alkyl group), A_3 represents an alkylene chain or a halogen-substituted alkylene chain, and A_4 represents a low molecular weight linear unchained monomer as a polymerizable monomer. Saturated hydrocarbons, vinyl halides, vinyl esters of organic acids, vinyl aromatic compounds, acrylic and methacrylic esters, N-
Vinyl compounds, vinyl silicon compounds, maleic anhydride,
1 and 2 esters of maleic acid and fumaric acid
It represents a repeating unit in which more than one species is polymerized, and a represents a positive integer. Compound (II) is a fluorinated low molecular weight linear unsaturated hydrocarbon, a fluorinated vinyl halide, a vinyl ester of a fluorinated organic acid, a fluorinated alkyl vinyl ether, a fluorinated alkyl ester and amide of acrylic acid and methacrylic acid. , fluorinated aromatic-containing esters and amides of acrylic and methacrylic acids, fluorinated maleic anhydride, fluorinated alkyl esters of maleic and fumaric acids, α-fluorinated styrene and α, β
, indicates β-fluorinated styrene. (17) The electrophotographic photosensitive material according to claim 13, wherein the fluorine-based oligomer is represented by the general formula (III), and the non-fluorine-based polymerizable monomer is selected from compounds (IV). body. General formula (III) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ In the formula, R_1 is a hydrogen atom, an alkyl group, a halogen atom,
Indicates a halogen-substituted alkyl group or aryl group, A_1 indicates an alkylene chain or a halogen-substituted alkylene chain, A_
2 represents (R_2 to R_1_1 represent a hydrogen atom, an alkyl group, or a halogen-substituted alkyl group), A_3 represents an alkylene chain or a halogen-substituted alkylene chain, and A_5 represents a fluorine-substituted low molecular weight linear chain as a polymerizable monomer. unsaturated hydrocarbons, fluorine-substituted vinyl halides, fluorine-substituted vinyl esters of organic acids, fluorine-substituted alkyl vinyl ethers,
Fluorinated alkyl esters and amides of acrylic and methacrylic acids, fluorinated aromatic-containing esters and amides of acrylic and methacrylic acids, fluorinated maleic anhydride, fluorinated alkyl esters of maleic and fumaric acids, α-fluorinated styrene and α, β,
It represents a repeating unit in which one or more β-fluorinated styrenes are polymerized, and a represents a positive integer. Compound (IV) includes low molecular weight linear unsaturated hydrocarbons, vinyl halides, vinyl esters of organic acids, vinyl aromatic compounds, acrylic acid and methacrylic esters, N
- Vinyl compounds, vinyl silicon compounds, maleic anhydride, esters of maleic acid and fumaric acid. (18) The electrophotographic photosensitive material according to claim 12, wherein the non-fluorine-based oligomer is represented by the general formula (V), and the fluorine-based polymerizable monomer is selected from compounds (II). body. General formula (V) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ In the formula, R_1_2 represents a hydrogen atom, an alkyl group, a halogen atom, or a halogen-substituted alkyl group, A_3 represents an alkylene chain or a halogen-substituted alkylene chain, and A_4 represents a halogen-substituted alkylene chain. As polymerizable monomers, low molecular weight linear unsaturated hydrocarbons, vinyl halides, vinyl esters of organic acids, vinyl aromatic compounds, acrylic acid and methacrylic acid esters, N
-Represents a repeating unit unit in which one or more of vinyl compounds, vinyl silicon compounds, maleic anhydride, maleic acid, and fumaric acid esters are polymerized, and A_
6 represents an alkylene chain, X represents -O-, ▲ there are mathematical formulas, chemical formulas, tables, etc. ▼ - (R_1_3 represents a hydrogen atom or an alkyl group), and A_7 represents ▲ there are mathematical formulas, chemical formulas, tables, etc. ▼ [R_1_4 is a hydrogen atom or an alkyl group, A_8, A
_9, A_1_0 are alkylene chains, cycloalkylene chains, substituted or unsubstituted arylene chains, ▲ Numerical formulas, chemical formulas, tables, etc. ▼ (R_1_5, R_1_6, R_1_7 and R_1_
7 is a hydrogen atom, an alkyl group, or an alkylene chain, and R_1_5 and R_1_6 or R_1_7 and R_1_
8 may form a ring], a is a positive integer, and b is 0 or a positive integer. Compound (II) is a fluorine-substituted low molecular weight linear unsaturated hydrocarbon, a fluorine-substituted vinyl halide, a fluorine-substituted vinyl ester of an organic acid, a fluorine-substituted alkyl vinyl ether, a fluorine-substituted alkyl ester and amide of acrylic acid and methacrylic acid, Fluorinated aromatic-containing esters and amides of acrylic and methacrylic acids, fluorinated maleic anhydride, fluorinated alkyl esters of maleic and fumaric acids, α-fluorinated styrene and α, β
, indicates β-fluorinated styrene. (19) The electrophotographic photosensitive material according to claim 13, wherein the fluorine-based oligomer is represented by the general formula (VI), and the non-fluorine-based polymerizable monomer is selected from compounds (IV). body. General formula (VI) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ In the formula, R_1_2 represents a hydrogen atom, an alkyl group, a halogen atom, or a halogen-substituted alkyl group, A_3 represents an alkylene chain or a halogen-substituted alkylene chain, and A_5 represents a halogen-substituted alkylene chain. As polymerizable monomers, fluorine-substituted low molecular weight linear unsaturated hydrocarbons, fluorine-substituted vinyl halides, vinyl esters of fluorine-substituted organic acids, fluorine-substituted alkyl vinyl ethers, fluorine-substituted alkyl esters and amides of acrylic acid and methacrylic acid. , fluorinated aromatic-containing esters and amides of acrylic and methacrylic acids, fluorinated maleic anhydride, fluorinated alkyl esters of maleic and fumaric acids, α-fluorinated styrene and α, β
, indicates a repeating unit in which one type or two or more types of β-styrene fluoride are polymerized, A_6 indicates an alkylene chain, X is -O-, ▲ Numerical formula, chemical formula, table, etc.
(R_1_3 represents a hydrogen atom or an alkyl group), A_7 is [R_1_4 is a hydrogen atom or an alkyl group, A_8, A
_9, A_1_0 are alkylene chains, cycloalkylene chains, substituted or unsubstituted arylene chains, ▲ Numerical formulas, chemical formulas, tables, etc. ▼ (R_1_5, R_1_6, R_1_7 and R_1_
8 is a hydrogen atom, an alkyl group, or an alkylene chain, and R_1_5 and R_1_6 or R_1_7 and R_1_
8 may form a ring], a is a positive integer, and b is 0 or a positive integer. Compound (IV) includes low molecular weight linear unsaturated hydrocarbons, vinyl halides, vinyl esters of organic acids, vinyl aromatic compounds, acrylic acid and methacrylic esters, N
- Vinyl compounds, vinyl silicon compounds, maleic anhydride, esters of maleic acid and fumaric acid. (20) The general formula (
VII) and general formula (VII)
The electrophotographic photoreceptor according to claim 12, which is formed by a reaction with a compound represented by II), and wherein the fluorine-based polymerizable monomer is selected from compound (II). . General formula (VII) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ In the formula, R_1_9 represents a hydrogen atom, an alkyl group, or an aryl group, and A_1_1 represents styrene, α-alkylstyrene, α-olefin, acrylic acid, and methacrylic acid ester. represents a repeating unit in which at least one of α-cyanoacrylic acid and α-cyanomethacrylic acid ester is polymerized, R_2_0 is an alkylene chain, m is 0
or a positive integer, n represents a positive integer, and M represents an alkali metal. General formula (VIII) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ In the formula, R_2_1 represents a hydrogen atom, an alkyl group, or an aryl group, A_1_2 is -O-, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲Mathematical formulas , chemical formulas, tables, etc.▼,
, ▲There are mathematical formulas, chemical formulas, tables, etc.▼-, A_1_3 represents a substituted or unsubstituted alkylene chain, c and d are 0 or 1,
Y represents a halogen atom. Compound (II) is a fluorine-substituted low molecular weight linear unsaturated hydrocarbon, a fluorine-substituted vinyl halide, a fluorine-substituted vinyl ester of an organic acid, a fluorine-substituted alkyl vinyl ether, a fluorine-substituted alkyl ester and amide of acrylic acid and methacrylic acid. , fluorinated aromatic-containing esters and amides of acrylic and methacrylic acids, fluorinated maleic anhydride, fluorinated alkyl esters of maleic and fumaric acids, α-fluorinated styrene and α, β
, indicates β-fluorinated styrene.