JPH028856A - Production of electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To improve photosensitivity and printing resistance by using a high- polymer film contg. oxygen as a photoconductive layer which generates carriers transferable by light stimulation or using the same by laminating the photoconductive layer and a charge transfer layer. CONSTITUTION:The layer 2 which consists essentially of the straight chain compd. high polymer having P-phenylene and having at least one kind of group VIb elements such as S, Se and Te in the para position is formed by heating and fusing the straight chain high-polymer layer film 3 having <=30% degree of crystallization in an atmosphere essentially consisting of oxygen in the process for production of the electrophotographic sensitive body having the stages of forming the layer 2 which consists essentially of the above-mentioned straight chain compd. high polymer on a base 1 and further adding O atoms thereto. The sensitivity is enhanced and the printing resistance is improved in this way; moreover, the inexpensive production is possible.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for manufacturing an electrophotographic photoreceptor used in electrophotographic copying machines, optical printers, and the like.

2. Description of the Related Art Among electrophotographic photoreceptors, functionally separated electrophotographic photoreceptors are widely used in which a photoconductive layer that generates carriers by photoexcitation and a charge transfer layer that transports carriers are made of different materials. By selecting materials according to function in this way, we can not only provide an excellent photoreceptor with highly sensitive electrophotographic properties, but also improve mechanical strength, thermal stability, printing durability,
You can consider the optimal combination from a wide range of materials in terms of environmental resistance, manufacturing cost, and other aspects.

Examples of inexpensive electrophotographic photoreceptors using several mechanical materials, which are typical examples of such material combinations, include methyl squarate and triarylbirazoline, Diane blue and oxadiazole, and perylene pigment and oxadiazole. Azor,
Examples include bisazo pigments and styria anthracene.

Further, examples of using inorganic materials as the photoconductive layer include amorphous selenium and polyvinyl carbazole, JP-A-54-143G
No. 45 proposes a functionally separated photoreceptor using an amorphous silicon-based photoconductive layer and an organic semiconductor material as a charge transfer layer.

However, the functionally separated photoreceptor using the above-mentioned organic material,
There are many problems that need to be resolved in terms of printing durability, lifespan, and reliability.

A photoreceptor using such an organic material is a cylindrical drum made by a molding method such as an impact method or a cutting method, or a sheet substrate such as an endless belt. In order to increase the hardness of the surface, it is necessary to uniformly form various layers such as a surface layer depending on the electrophotographic process.

As a method for forming each of the above layers, a dip coating method, a spray coating method using a spray gun, a US spray coating method using ultrasonic waves, etc. are used, and a large investment in equipment is required.

In addition, in the latter case, attempts have been made to improve printing durability by using a highly hard inorganic photoconductive layer on the surface, but many of the photoconductive layers with excellent printing durability are difficult to maintain sufficient properties. Photoreceptors with sufficient characteristics cannot be obtained with conventional organic charge transfer layers, which have poor heat resistance, because they require substrate heating or a process such as plasma that effectively raises the surface temperature. is the current situation.

Under these circumstances, JP-A-55-90954 and JP-A-59353 disclose P as a charge transfer layer.
P5 (poly P-phenylene sulfide) has been proposed as an excellent material that can be manufactured at low cost by using it in film form as a charge transfer layer, or as a vapor deposited polymer film with high carrier mobility.

Problems to be Solved by the Invention In order to achieve higher sensitivity in electrophotographic photoreceptors,
It is necessary to have a smaller dielectric constant, higher mobility and carrier lifetime, and higher charge generation ability. For this reason, in a functionally separated photoreceptor, a combination of a charge transfer layer with greater mobility and carrier life and a photoconductive layer with a high charge generation ability is desirable. However, even if the respective required conditions are satisfied, carrier injection between the two must be performed efficiently.

In addition, the charge acceptance ability required in the electrophotographic process,
It must have sufficient wear resistance, environmental resistance, etc.

JP-A No. 110-59353 describes that PPS is formed as a charge transfer layer by thinning it and improving its charge transport ability by vacuum evaporation, but generally in this state the charge transport ability is small and the sensitivity is low. , residual potential is not sufficient. Furthermore, since a vacuum evaporation method is used, the film forming speed is not sufficient and the photoreceptor is expensive as a photoreceptor using an organic material.

In addition, the hardness of the film is low and the printing durability cannot be said to be sufficient.

In addition, in Japanese Patent Application Laid-open No. 55-90954, PP
An inexpensive photoreceptor has been proposed by using an S film as a charge transfer layer. However, since the charge transport ability is not sufficient, the photosensitivity has not reached the practical level of today's electrophotographic photoreceptors.

Furthermore, since functionally separated photoreceptors using organic materials are used with negative polarity, there are many problems that need to be solved, such as downsizing of electrophotographic devices and the effects of ozone generation on the human body.

The main object of the present invention is to provide an inexpensive electrophotographic photoreceptor with excellent productivity that does not require a coating device.

A further object of the present invention is to provide a high-performance photoreceptor with high sensitivity, excellent printing durability, and long life.

Another object of the present invention is to provide an electrophotographic photoreceptor that can be positively charged, has high sensitivity, and has a low residual potential, at a low cost.

Means for Solving the Problems Having P-phenylene on a support and having SlS in the para position
e1 Form a layer mainly composed of a linear compound polymer containing at least one of group b elements of Te, and further
In a method for manufacturing an electrophotographic photoreceptor that includes a step of adding atoms, a layer containing the above-mentioned linear compound polymer as a main component is added to a linear polymer layer film having a crystallinity of 30% or less, and a layer containing oxygen as a main component is added. It is formed by a step of heating and fusing in an atmosphere containing the components.

Moreover, a biaxially stretched film is used as the linear polymer layer film.

As a result of various studies to overcome the shortcomings of PPS films such as low carrier mobility and carrier life, we found that PPS films contain P-phenylene and a chalcogen element at the para position (p-). It has been discovered that by heat-treating a polymer layer mainly composed of a linear compound polymer layer having the following properties in an atmosphere containing oxygen atoms, the charge transport ability can be dramatically improved.

It is clear that such an effect is related to oxygen atoms, and it has been confirmed that, for example, no improvement in charge transport ability is observed in a vacuum or in an inert gas such as nitrogen.

In addition, the polymer film after the above treatment has a concentration of 1 to 35 at.
It has been confirmed that it contains m% of oxygen atoms, preferably 1 to 20 atm%.

For this reason, a film with low crystallinity obtained by biaxially stretching a film rapidly cooled by extrusion is heated at a temperature of 150 to 350°C.
0.2-50 hours, preferably 250-290"C
It is thought that by performing the treatment for 1-12 hours, the crystallinity is improved and, at the same time, many oxygen atoms are taken in, thereby dramatically improving the charge transport ability.

Of course, these processes may be repeated several times.

Further, the polymer film is hardened due to the heat treatment. In fact, PPS filmed by biaxial stretching
Its hardness is so soft that it cannot be measured accurately with a micro Vickers hardness tester. On the other hand, the Vickers hardness of the film subjected to the above treatment increases to Iθ ~ 80, and the oxygen atoms that improve charge transport ability are stably incorporated into the film at the same time as curing, improving heat resistance and high charge. It is thought that the acquisition of the ability to generate electricity was the result.

Here, as mentioned above, charge acceptance ability, abrasion resistance, environmental resistance, high photosensitivity, and
It is necessary to satisfy the requirements such as low residual potential.

However, in general, photoconductive materials with high photoconductivity and hardness that have a Vickers hardness of 100 or more require high substrate heating or a film forming process using plasma. Through such treatment, the resulting layer is stable to heat, and has high sensitivity without changing the film formation of the photoconductive material described above, has excellent printing durability, and is an electrophotographic photosensitive material with a low residual potential. body can be made possible.

A polymer film typified by PPS can be formed by directly heating and fusing it onto a conductive support of an electrophotographic photoreceptor. Therefore, an inexpensive photoreceptor can be manufactured without requiring a vapor deposition device or a coating device.

Embodiment FIG. 1 schematically shows a cross section of an embodiment of a basic electrophotographic photoreceptor according to the present invention.

The electrophotographic photoreceptor shown in FIG. 1 is a support as an electrophotographic photoreceptor! A charge transfer layer 2 made of a polymer layer and a photoconductive layer 3 are provided on top of the charge transfer layer 2, and the photoconductive layer 3 is provided on top of the charge transfer layer 2 made of a polymer layer. ! ! Layer 3 has on the one hand a free surface 4 .

The electrophotographic photoreceptor shown in FIG. 2 has a photoconductive layer 6 made of a polymer layer containing a pigment or an inorganic photoconductor such as CdS on a support 5 as an electrophotographic photoreceptor. The conductive layer 6 has on the one hand a free surface 7 .

In the present invention, an amorphous layer containing silicon with high hardness is used as the photoconductive layer 3, and as the photoconductive layer, a-
5t(:H:X), a-Sll-vcv('H'X)
(0”Y<1), a-Sit-yOy (:H:X
)(0<y<1), a-Sit-Jv (:H:X
)(0kuy<1), a-Sl, -tGet (:11:
X) (0<z<1>, a-(Sit-zGez)+
-vNv('old X)(ly, z<1), a-(Si
t-2Gez )+-yOv('H'X)(Okuy, Z
〈or a-(Sit-zGez)+-vcv(:
It consists of a single layer of H'X)(O<Y, Z(1), or a stack of these layers. It can also be used when y is changed continuously.

On the other hand, typical organic materials include metal-free phthalocyanine (B2Pc), m-phthalocyanine, (CuP
c), metal phthalocyanine represented by magnesium phthalocyanine (MgPc), indium phthalocyanine (InCIPc), aluminum phthalocyanine (
AICIPc), a metal halogenated phthalocyanine represented by AlClPcC1, or a phthalocyanine-based raw material such as Ti0Pc can be formed by vapor deposition or the like.

At this time, the thickness of the charge transfer layer is 5 to 50 μm, preferably 1 μm.
0 to 25 μm1 The thickness of the photoconductive layer is 0.5 to 10 μm.
m is preferably 1 to 5 μm.

In the present invention, in order to further improve the electrophotographic characteristics, in FIG. 1, between the support l and the charge transfer layer 2,
Support! A barrier layer may be provided to effectively block charge transfer/carriers from injecting into the layer 2.

Materials for forming the barrier layer include Al20a and BaO1.
Ba02, Bed, B120s, Cab, Ce
nt, Ce20s, Lae03, Dy*0s1LLI*
0a1Cr201, Cub, Cu2O, FedlPbO
1Mg0, SrO, Ta2O3, Th02, ZrO2
,)IrO2, TlO2, Tl01SIQ2, GeO2
, 5IO1GeO or TIN.

AlN15nN1NbN1TaN, metal nitride such as GaN, or metal carbide such as WC, 5nC1T IC, SIC, SIN.

Insulators such as G eC and G eN1BC18N, and heat-resistant organic compounds such as polyimide, polyamideimide, and polyacrylonitrile are used.

In addition, in order to improve cleaning performance, abrasion resistance, or corona resistance, in Figures 1 and 2,
Surface coating J on free surface 4! form. Suitable materials for the surface coating layer include Sl, O,-,,5txC+-1
ls 5l-N+-x, Gex ol-XX G
e, cl-X1Gex N+ -w, BXNI-X,
BxC+-xl AlxN+-x (OxXxl),
Examples include inorganic substances such as carne and layers containing hydrogen or halogen.

a-St (:H:X
) creation Niha, S I H4,512H6,513)1
e, 5IFa, 5IC1,, 5IHFi, 5IH2F2
．． 5IHiFs 5IHC13, 5IH2C12, S
A plasma CVD method using a raw material gas of Sl atoms such as In2O2, or using polycrystalline silicon as a target.
A reactive sputtering method is used in a mixed gas of r and B2 (F2 or C12 may also be mixed). Also,
a-SI+-yCv(:H:X)(0<ycl), a
-S11-, O, (:H:X) (0<y<l), a-5
1+-, Nv(')I'X) (O<y<1), CHJ, C2&, Ca HaN
CJ fl llh C2Ha, Ca) 16, Ca
)Is1C2&l Hydrocarbons such as C3H4, CJ&, C1l■6, CLFlCllz C11CHsls C
Allyl halides such as 2Hs C11Ca [5Br), CCIFi, CFJ1CHF3, Ca Fa, Ca
Freon gas such as Fs, CaHa-mFs (m = 1
~ [i) The raw material gas of C atoms such as Hensen's fluoride is mixed with the silicon raw material gas used in the plasma CVD method, or mixed with a sputtering gas such as Ar in the reactive sputtering method. In addition, as an oxygen source, 02, C01C0
2, N01SOW, etc. Also, as a nitrogen source, N2, Nl
A mixture of l3, NO, etc. is used.

Also, when adding Ge to a-Sl(:H:X), G
eL, Ge*He1Ges&, GeFa, GeCl4,
GeHF3, GeB2F2, GeHsF%Get101
3.Ge) 12C12, GeHaCl, etc., in the above S
It can also be formed by mixing with a raw material gas of i atoms and using a plasma CVD method.

Furthermore, in the present invention, the above a-SIIH:X)
, a-5it-ycv('H:X)(0(y(1),
a-Sll-, O, (:H:X) (lycl)% a-
By adding impurities to SI+-yN, (:■:X)(ly<1), or Ge-added films, conductivity can be controlled to obtain desired electrophotographic properties. . As a p-type impurity that gives p-type conductivity,
BXAl, , Ga11n, which belongs to Group II of the periodic table
etc., B1Al, Ga are preferably used, and n
Examples of n-type impurities that provide type conductivity include N1P1As and Sb, which belong to Group 1 of the periodic table, and PlAs is preferably used.

In addition, as a method of adding these impurities, in the case of p-type impurities, B2H6, Ha Hoes Bs He
, B6HII, B11H12, BaH+a, BFz, B
Cli, BBr2, AlC1a, (CH3)3Al,
(CJshAl, (1-C4H11)3A11(
Cu5)aGa, (C2tls)30a11 n C1
3. (02H6)s In, in the case of n-type impurity, N
a, NB2, N01N20, NO2, PH3, P21L
, PHallPFs, PF6, PClz, PCl3, P
Br3+PBr6, p13, AsH3, ASF3, As
Cl3, ASBrz, 5bHi, SbF3.5bF6,
Gases such as sbc+2, SbCl2, etc., or these gases are converted into B2. In the plasma CVD method, a gas diluted with Ar is used to form each film.

It can be used by mixing with raw material gas such as Si atoms, and in the reactive sputtering method, Ar or H2 or F2.011
It may be used by mixing with.

As other inorganic photoconductive metals, including chalcogen elements, As
An amorphous layer such as 2Se1 may also be used. As2Se.

Although the hardness varies depending on the substrate heating temperature during vapor deposition, it is 60~! At a substrate temperature of 20°C, Pickers hardness is 1
It showed 00-140. In addition, in order to have high sensitivity to visible light or near infrared light, As5eTe doped with Te is used.
A single layer or a stack of these can be used as the photoconductive layer. In addition to this, a layer may be formed in which crystal powder of CdS or CdSe is bonded with a resin. Because it was difficult to measure the hardness of the latter layer, which is a layer in which photoconductive crystals containing chalcogen elements are bonded together with resin, a relative comparison with the As2Se3 film revealed that it was slightly brittle. The hardness of the material was greater than As2Se3 film.

For reference, in order to understand the progress of heat treatment, the hardness of the linear compound polymer layer was measured. The hardness was measured using a micro Vickers hardness meter, and the load of the diamond indenter was expressed as log.

Furthermore, when used as the photoconductive layer 6, a phthalocyanine-based raw material was used as an example of a pigment to be mixed into the film.

These include metal-free phthalocyanine (82PC), copper phthalocyanine (CuPc), metal phthalocyanine (MgPc), indium phthalocyanine (InCIPc), aluminum phthalocyanine (AICIPc), or A
Metal halogenated phthalocyanine represented by lClPcC1, Ti0PC, etc. are used.

As the inorganic photoconductor mixed into the film, Cd
SlCd Se etc. are used.

At this time, when the photoconductive layer is used as a single layer, the film thickness is 5 to 5.
It is desirable that the thickness be 50 μm, preferably 10 to 25 μm. Further, the photoconductive layer B has a thickness of 0.5 to IO μm, preferably 1 to 10 μm.
5μmc) 11! If it is used with a thickness of I, it can also be used as the photoconductive layer 3 in FIG.

Further, the crystallinity of the linear compound polymer film was determined from X-ray diffraction. In PPS, a 2θ peak can be measured at about 21°C. The ratio of the area of this sharp crystalline peak (denoted as [k) to the area of the broad amorphous peak extending at the foot of this peak (denoted as Ia) of 1/(lk+la) was defined as the degree of crystallinity.

Example 1 A film-shaped PPS (poly p-phenylene
sulfide), wrap the fluororesin sheet from the top of the film, heat it in a heat treatment furnace, and then
The film was fused onto an aluminum substrate.

The film used was an amorphous film obtained by extruding a molten material and rapidly cooling it, and then biaxially stretching it to 1.5 times.

The crystallinity at this time was 1% or less.

The heating temperature was 290°C, which is higher than the melting temperature of PPS, 285°C, and the treatment was carried out for 3 hours.

The heating atmosphere is oxygen at atmospheric pressure. After taking out the substrate from the heat treatment furnace, remove the fluororesin/resin sheet, place it in the heat treatment furnace again, and further heat treat it in an oxygen atmosphere.
provided. The heating temperature was controlled within the range of 285°C to 300°C, and the heat treatment time was 3 hours. - After this treatment, the thickness of the PPS film was 10 to 25 μm.

This layer is used as the charge transfer layer 2 in FIG.
．． A film having a thickness of 8 μm was formed by vacuum evaporation to obtain an electrophotographic photoreceptor.

At this time, the electrophotographic photoreceptor with a charge transfer layer made of PPS with a film thickness of 12 μm was charged to a surface potential of +500 μm.
When exposed to light of 500 nm, the half-potential exposure amount was 0.51 ux-sec in terms of illuminance, showing very high sensitivity. Further, the residual potential was 90 V or less, which showed excellent characteristics.

In addition, an electrophotographic photoreceptor with a charge transfer layer made of PPS with a film thickness of 25 μm was evaluated under the same conditions as above.
Although the half-potential exposure amount was as high as 0.71 ux-sec, the residual potential was 100 to 120 V, which was somewhat large.

On the other hand, after biaxial stretching, the film was fixed at 150 to 200°.
The crystallinity of the film treated with C increases to 30-50%. When such an electrophotographic photoreceptor with a 25 μm thick PPS charge transfer layer was produced and evaluated under the same conditions as above, the half-potential exposure amount was 0.71 ux.
Although it is as high as sec, the residual potential is 150 to 22
The result was often 0V.

Example 2 Cylindrical P with a film thickness of 15 μm was formed by the inflation method.
A PS film was created. The crystallinity of the film at this time was about 20 to 30%, and the diameter of the cylindrical film was 92φ.

To create an electrophotographic photoreceptor, use the above cylindrical film with an 88φ
TCNQ (7,
The heat treatment was performed in an atmosphere to which 7,8,8,-tetracyanoquinodimethane) was added. Furthermore, it was placed in a heat treatment apparatus in oxygen, and treated at 265°C for 6 hours.

Similarly, a film was simultaneously treated as a sample for hardness measurement, and the hardness was measured by adhering it onto a quartz substrate.

The Vickers hardness of the film at this time was 25±4.

Further, the drum was immersed in a solution containing 100:20 parts by weight of CdS photoconductive powder and a binder resin (the binder resin was a polyurethane resin), and dried at 170°C for 30 minutes to form a 5 μm film. A photoconductive layer was formed.

The photosensitive drum thus obtained has a surface potential of +〇0
After being charged to 0V, the photosensitive drum was exposed to white light, and a photosensitive drum was obtained which exhibited high sensitivity with a half-potential exposure of 2.31 ux-sec and a sufficiently small residual potential of 90V or less.

The electrophotographic photoreceptor thus obtained has a lifespan of 80,000 sheets or more, and is long-life and inexpensive.

Example 3 A surface-polished aluminum drum substrate with a cylindrical shape of ~20 μm thick, slightly smaller than 1 ram outer diameter, 0.05-20
A PPS film produced in the same manner as in Example 2 in which wt% of H2Pc was mixed was used.

The drum substrate is cooled in a dry atmosphere, and the drum whose outer diameter has become smaller due to heat shrinkage is inserted into the above PPS, and when the temperature is raised to room temperature, the film and substrate come into close contact, and even in the case of a drum-shaped substrate, the initial Can be coated with a uniform film thickness.

Such a drum substrate is heated at 280 to 260°C in oxygen.
A photoconductive layer was obtained by heating for 0.5 to lθ hours and heat treatment at the same time as fusion bonding.

When a single-layer photoreceptor using this photoconductive layer was charged to +900V and exposed to white light, the half-potential exposure amount was 3.
．． It showed good sensitivity of 0.01 ux-sec or less.

Further, when a photoreceptor was prepared by forming a polyimide layer with a thickness of 0.2 μm as a surface layer, there was little change in surface potential even after repeated use, and good characteristics were obtained.

Example 4 As a barrier layer on a surface-polished aluminum drum substrate,
A 0.5 μm thick Ge, N1-8 layer was formed, and a 1 μm thick a-51:H layer was formed as a photoconductive layer. It is inserted into a cylindrical PPS film with a thickness of ~25 μm produced in the same manner as in Example 2, which is slightly larger than the outside diameter of this dome, and the whole is heated to 150 to 250° C. in oxygen. At this time PPS
The film shrinks and adheres tightly onto the photoconductive layer.

Thereafter, it is further heated to 250 to 290'C in an oxygen atmosphere to form a charge transfer layer.

When this drum was negatively charged, a clear image was confirmed at a surface potential of 1,500 to 800 cm. The half-potential exposure of this drum was 11 ux-sec, which showed high sensitivity, and the residual potential was -100 to 200 V.

In addition, a-(Sl, -,
The sensitivity was further improved by using Ge, ):11.

Furthermore, no major changes in properties were observed even when a substituent in place of hydrogen was provided at the 2,5 or 3.4 position of the phenylene group.

Further, the same results were obtained even when a linear compound polymer containing at least one of Se1 and Te as the b-group element was mixed and used.

Effects of the Invention According to the present invention, a linear compound polymer film with a low degree of crystallinity, which has a ring (p-phenylene) structure in the main chain represented by PPS and has a group ■/b element at the para position. By performing heat treatment in an atmosphere containing oxygen as the main component,
The charge transport ability can be dramatically improved.

This oxygen-containing polymer film can be used as a photoconductive layer that generates mobile carriers by photoexcitation, or
An electrophotographic photoreceptor with high photosensitivity and excellent printing durability can be provided at a low cost by using it as an electrophotographic photoreceptor in which a photoconductive layer that generates movable carriers by photoexcitation and a charge transfer layer are laminated. You can.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 are sectional views of an electrophotographic photoreceptor in an embodiment of the present invention, respectively. 1.5--Support, 2--Charge transfer layer, 3.6--
- Photoconductive layer, 4.7...free surface. Name of agent: Patent attorney Shigetaka Kurino (1 person) Figure 1 Figure 2

Claims (3)

[Claims] (1) Having P-phenylene on the support and S at the para position
In the method for manufacturing an electrophotographic photoreceptor, the method includes the step of forming a layer mainly composed of a linear compound polymer containing at least one of group VIb elements such as , Se, and Te, and further adding O atoms. A layer mainly composed of a chain compound polymer is formed by a process of heating and fusing a linear polymer layer film with a degree of crystallinity of 30% or less in an atmosphere mainly composed of oxygen. A method for manufacturing an electrophotographic photoreceptor. (2) The method for producing an electrophotographic photoreceptor according to claim 1, wherein a biaxially stretched film is used as the linear polymer layer film. (3) The method for manufacturing an electrophotographic photoreceptor according to claim 1, wherein the heating temperature of the heat treatment in an atmosphere containing oxygen as a main component is in the range of 150 to 350°C.