JPS6326658A - Photosensitive body - Google Patents

Abstract

PURPOSE:To enhance electric charge transfer performance and electrifiability by forming a charge transfer layer through plasma polymerization of hydrocarbon, and specifying a ratio of the peak adsorption coefficient of methyl and methylene groups to that of methyl group in the infrared absorption spectra. CONSTITUTION:The functionally separated photosensitive body is provided on a conductive substrate 1 with a charge generating layer 3 and the charge transfer layer 2, and this layer 2 is formed by the plasma polymerization of hydrocarbon, and this polymer film 2 has the peak absorption coefficient alpha1 of the infrared absorption spectra due to the methyl (-CH3-) and methylene (-CH2-) groups near 1,460-1,470cm<-1> and that alpha2 due to the methyl (-CH3-) near 1,380cm<-1>, and the ratio alpha1/alpha2 is regulated to 0.5-5.0, thus permitting the polymer film 2 to be superior in light transmittance, considerably high in dark resistivity, and rich in charge transfer performance, and the film 2 to transfer carriers without producing charge traps.

Description

[Detailed description of the invention] Industrial applications The present invention relates to photoreceptors, particularly electrophotographic photoreceptors.

BACKGROUND OF THE INVENTION Since the invention of the Carlson method, the application field of electrophotography has continued to make remarkable progress, and various materials have been developed and put into practical use for electrophotographic photoreceptors.

The main electrophotographic photoreceptor materials conventionally used include inorganic substances such as amorphous selenium, selenium arsenide, selenium telluride, cadmium sulfide, zinc oxide, amorphous silicon, polyvinyl carbazole, metal phthalocyanine,
Examples of organic substances include nosazo pigments, trisazo pigments, perylene pigments, triphenylmethane compounds, triphenylamine compounds, hydrazone compounds, styryl compounds, pyrazoline compounds, oxazole compounds, and oxadiazole compounds.

The configurations include a single-layer structure using these substances alone, a bander-type structure using them dispersed in a binder, and a multilayer structure in which a charge generation layer and a charge transport layer are provided for each function. etc.

However, the conventionally used electrophotographic photoreceptor materials each have drawbacks.

One of these is its toxicity to the human body, but all inorganic substances other than the aforementioned amorphous silicon have unfavorable properties.

In addition, in order for an electrophotographic photoreceptor to be actually used in a copying machine, it must always have stable performance even when exposed to harsh environmental conditions such as charging, exposure, development, transfer, static elimination, and T# cleaning. However, all of the organic substances mentioned above have poor durability and many unstable factors in terms of performance.

In order to solve these problems, in recent years, plasma chemical vapor deposition (hereinafter referred to as plasma chemical vapor deposition) has been applied to photoreceptors, especially electrophotographic photoreceptors.
Amorphous silicon (hereinafter abbreviated as a-Si) produced by a VD method (VD method) has come to be used.

The a-9i sensitizer has various excellent properties. But a
-Si has a large relative dielectric constant ε of about 12, so in order to obtain a sufficient surface potential as a photoreceptor, essentially a minimum of 20
There is a problem in that a film thickness of approximately μm is required. a-
In the plasma CVD method, the Si photoreceptor requires a long time to produce because the film deposition rate is slow, and the longer the production time becomes, the more difficult it becomes to obtain a homogeneous a-Si film. As a result, the a-9t photoreceptor has a high probability of generating image defects such as white spot noise (and also has drawbacks such as high raw material costs).

Although various attempts have been made to improve the above drawbacks, it is essentially not desirable to make the film thinner than this.

On the other hand, the a-Si photoreceptor also has drawbacks such as poor adhesion between the substrate and a-9i, as well as poor corona resistance, environmental resistance, and chemical resistance.

In order to solve such problems, it has been proposed to provide an organic plasma polymerized film as an overcoat layer or undercoat layer of an a-Si photoreceptor. Examples of the former are, for example, JP-A-60-61761 and JP-A-59.
JP-A-214859, JP-A-5.1-46130, JP-A-50-20728, etc. are known, and examples of the latter include, for example, JP-A-60-6354.
Publication No. 1, JP-A-59-136742, JP-A-5
Publication No. 9-38753, Japanese Unexamined Patent Publication No. 59-28161, etc. are known.

Organic plasma polymerized films can be prepared from all kinds of organic compound gases such as ethylene gas, benzene, and aromatic silanes (e.g., Ni, T, Be1l).
), M, 5hen, et al., Journal of Applied Polymer Science (Journa
l of Applied Polymer 5cie
nce), Vol. 17, pp. 885-892 (1973)
etc.), but organic plasma polymerized films produced by conventional methods are used only for the above-mentioned applications with insulating properties. Therefore, these films were considered to be insulating films having an electrical resistance of about <10'' ΩCZ like ordinary polyethylene films, or at least were used with the understanding that they were such films.

The technique described in Japanese Patent Application Laid-Open No. 60-61761 discloses a photoreceptor coated with a diamond-like carbon insulating film having a thickness of 500 to 2 μm as a surface protective layer.

This carbon thin film has a-9i photocorona discharge resistance and l
l! This is to improve the loss strength. The polymer membrane is very thin, and charges move through the membrane through the tunnel effect, so the membrane itself does not require charge transport ability. Furthermore, there is no mention of the carrier transport properties of organic plasma polymerized films;
It does not solve the above-mentioned essential problems of the a-9i.

JP-A No. 59-214859 discloses a technique in which an organic hydrocarbon monomer such as ethylene or acetylene is coated as an overcoat layer with a thickness of about 5 μm by plasma polymerization. A-9i Improves peeling, durability, pinholes, and production efficiency. There is no description whatsoever regarding the carrier transport properties of organic plasma polymerized films, and it does not solve the above-mentioned essential problems of a-Si.

JP-A No. 51-46130 discloses that N-vinylcarbazole is coated on the surface with a thickness of 3 μm to 0.0 μm by glow discharge.
A photoreceptor on which an organic plasma polymerized film of 0.01 μm is formed is disclosed. The purpose of this technology is to make it possible to use a poly-N-vinylcarbazole photoreceptor, which could only be used with positive charging, with bipolar charging. This film is 0.001
It is very thin at ~3 μm and is used as an overcoat.

It is thought that the polymer membrane is very thin and does not require charge transport ability. Furthermore, there is no description whatsoever regarding the carrier transportability of the polymeric membrane, and it does not solve the above-mentioned essential problems of a-9i.

JP-A No. 50-20728 discloses a sensitizing layer on a substrate,
A technique has been disclosed in which a number of conductive electrical insulators are sequentially laminated and a glow discharge polymer film with a thickness of 0.1 to 1 μm is formed on top of the film. It is intended to protect the surface and is used as an overcoat.

Polymerized membranes are very thin and do not require charge transport capabilities.

Furthermore, there is no description whatsoever regarding the carrier transport properties of the polymeric membrane, and it does not solve the above-mentioned essential problems of a-Si.

JP-A-60-63541 discloses a photoreceptor using a diamond-like organic plasma polymerized film of 200 to 2 μm as an a-Si undercoat layer.
The purpose of this organic plasma polymerized film is to improve the adhesion between the substrate and a-St.

Polymerized membranes can be very thin, charges move through the membrane by tunneling, and the membrane itself does not require charge transport capabilities. Further, there is no description whatsoever regarding the carrier transport properties of the G-machine plasma polymerized film, and there is no solution to the above-mentioned essential problems of a-8i.

JP-A-59-28161 discloses a photoreceptor in which an organic plasma polymerized film and a-3i are sequentially formed on a substrate. The organic plasma polymerized film is an undercoat layer that takes advantage of its insulating properties and functions as a blocking layer, adhesive layer, or peel prevention layer. Polymerized membranes can be very thin, charges move through the membrane by tunneling, and the membrane itself does not require charge transport capabilities. Further, there is no description whatsoever regarding the carrier transport properties of the organic plasma polymerized film, and it does not solve the above-mentioned essential problems of a-St.

JP-A No. 59-38753 discloses that 10 to 100
Form an organic plasma polymerized thin film on top of the a-9i
Techniques for depositing layers are disclosed. The organic plasma polymerized film is an undercoat layer that takes advantage of its insulating properties, and functions as a blocking layer or a peel-preventing layer. Polymerized membranes can be very thin, charges move through the membrane by tunneling, and the membrane itself does not require charge transport capabilities. Further, there is no description whatsoever regarding the carrier transport properties of plasma polymerized membranes, and the above-mentioned essential problems of a-Si are not solved.

Japanese Patent Application Laid-open No. 59-136742 discloses that about 5μ
A semiconductor device is disclosed in which an organic plasma polymerized film and a silicon film of m are sequentially formed. However, although the purpose of this organic plasma polymerized film is to prevent the diffusion of aluminum, which is a substrate, into the a-5i, there is no description of its preparation method, film quality, etc. Furthermore, there is no description whatsoever regarding the carrier transport properties of organic plasma polymerized films, and a-9
It does not solve the above-mentioned essential problem of i.

Problems to be Solved by the Invention As mentioned above, organic polymer films conventionally used in photoreceptors have been used as undercoat layers or overcoat layers, but these do not require a carrier transport function. It is a membrane, and some polymeric membranes are used based on the judgment that they are insulating. Therefore, its thickness is at most 5μ
It is used only as an extremely thin film, about the size of a shoulder, and the carriers pass through the film through the tunnel effect, or if a tunnel effect cannot be expected, the film is thin enough that there is no problem with the residual potential in practical use. only used.

While considering the application of organic polymer films to photoreceptors, we found that organic polymer films, which were originally thought to be insulating, decreased electrical resistance by increasing the content of methyl groups. It was discovered that the material began to exhibit charge transport properties.

By utilizing this new knowledge, the present invention solves all the problems of conventional a-Si photoreceptors, such as problems in the film thickness of a-9i, manufacturing time, manufacturing cost, etc. It is an object of the present invention to provide a photoreceptor using an organic polymer film, particularly an organic plasma polymer film, which has completely different purposes and characteristics from conventional ones, and a method for manufacturing the same.

In other words, the present invention provides a function-separated photoreceptor having a charge generation layer (3) and a charge transport layer (2).
A hydrocarbon plasma polymerized film is provided as a plasma polymerized film, and the infrared absorption spectrum of the polymerized film is 1460 to 1470 C due to methyl groups <-CH5-) and methylene groups (-CH,-).
The peak absorption coefficient α near JI-' and 1 due to the methyl group
The ratio of the peak absorption coefficient α around 380 cN-' to α1/
The present invention relates to an electrophotographic photoreceptor characterized in that α is 0.5 to 5.0.

The photoreceptor of the present invention is composed of at least a charge generation layer and a charge transport layer.

The photoreceptor of the present invention is characterized in that a hydrocarbon polymer film is provided as a charge transport layer, and the methyl and methylene groups formed in the polymer film have an infrared absorption spectrum of 1460 to 1470 CI- 1380cx- due to the peak absorption coefficient α near 1 and the methyl group
'Peak absorption coefficient α near ! The ratio α1/α2 is 0.5
(Hereinafter, the polymer film of the present invention will be referred to as an a-C film).

In the present invention, the absorption coefficient of the infrared absorption spectrum is calculated from the transmittance and film thickness using the following formula [r] [where α represents the absorption coefficient, d represents the film thickness, and T/T o represents the transmittance. ] It is expressed as .

The a-C film of the present invention has an infrared absorption spectrum with a peak absorption coefficient α around 1460 to 1470 cm due to methyl groups and methylene groups, and a peak absorption coefficient α around 1380 cm due to methyl groups.
The ratio αl/α to the peak absorption coefficient α near -' is 0.
5 to 5. It is suitable when it is more preferably 0.7 to 3.5, especially 0.9 to 2.5, and if it is larger than 5.0, suitable transport properties cannot be obtained and it cannot be used as an electrophotographic photoreceptor. , if it is smaller than 0.5, the charging ability will be lowered, the film quality will be deteriorated, and the film formability will be lowered.

In general, the peak absorption coefficient derived from methyl groups and methylene groups follows formula [I], and only when the value of α1/α is smaller than 5°0 does the resistivity become less than about IQIIΩCX, and the carrier mobility becomes 10-' cx”V・sec or more.

The a-C film of the present invention contains various groups derived from carbon atoms, such as methyl groups, methylene groups, or methine groups, or carbon atoms with various bonding modes, such as single bonds, double bonds, triple bonds, etc. exists, but according to the formula [+] α
In the present invention, it is important that the value of 1/α2 is 0.5 to 5.0.

The thickness of the a-C layer is suitably 5 to 50 .mu.m, particularly 7 to 20 .mu.m; if it is thinner than 5 .mu.m, the surface potential is low and sufficient density of the copied image cannot be obtained. If it is thicker than 50 μm, it is not preferable in terms of productivity. This a-C layer has excellent light transmittance, relatively high dark resistance, and is rich in charge transport properties, and transports carriers without causing charge traps even when the film thickness is 5 μm or more as described above.

The plasma polymerized layer of the present invention may be used as an overcoat layer with charge transport properties. It goes without saying that even when the plasma polymerized layer of the present invention is simply used as an overcoat layer, good durability can be obtained without increasing the residual potential.

Hydrocarbons are used as the organic gas for forming the a-C layer.

The phase state of the hydrocarbon does not necessarily have to be a gas phase at room temperature and normal pressure, but it can be melted by heating or reduced pressure, etc.
As long as it can be vaporized through evaporation, sublimation, etc., it can be used in either a liquid phase or a solid phase.

As the hydrocarbon, for example, methane series hydrocarbons, ethylene series hydrocarbons, acetylene series hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, etc. may be used.

Examples of methane series hydrocarbons include methane, ethane,
Propane, butane, pentane, hexane, heptane, octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, pentadecane, hexadecane,
Normal paraffins such as heptadecane, octadecane, nonadecane, eicosane, heneicosane, tocosane, tricosane, tetracosane, pentacosane, hexacosane, heptacosane, octacosane, nonacosane, triacontane, todoriaconcune, pentatriacontane, isobutane, isopentane, neopentane, isohexane, neo hexane, 2゜3-dimethylbutane,
2-Methylhexane, 3-ethylpentane, 2.2-dimethylpentane, 2゜4-dimethylbencune, 3.3-
trimethylpentane, tributane, 2-methylhebutane,
3-methylhebutane, 2,2-dimethylhexane, 2,
2゜5-dimethylhexane, 2,2.3-trimethylpentane, 2,2.4-trimethylpentane, 2.3゜3
Isoparaffins such as -trimethylpentane, 2,3,4-trimethylpentane, isonanone, etc. are used.

Examples of ethylene series hydrocarbons include ethylene, propylene, isobutylene, l-butene, 2-butene, l-
Pentene, 2-pentene, 2-methyl-1-butene, 3
-Methyl-■-butene, 2-methyl-2-butene, 1-
hexene, tetramethylethylene, 1-heptene, 1-
Olefins such as octene, ■-nonene, 1-decene, olefins such as allene, methylalene, butadiene, pentadiene, hexadiene, cyclopentanoene, etc., and triolefins such as ocimene, alloonemene, myrcene, hexatriene, etc. , etc. are used.

Examples of acetylene series hydrocarbons include acetylene,
Methylacetylene, 1-butyne, 2-butyne, l-pentyne, l-hexyne, l-heptyne, 1-octyne, l
-Nonin! -decine, etc. are used.

Examples of alicyclic hydrocarbons include cyclopropane, cyclobutane, cyclopencune, cyclohexane, cyclohebutane, cyclooctane, cyclononane, cyclodecane, cycloundecane, cyclododecane, cyclotridecane, cyclotetradecane, cyclopentadecane, cyclohexadecane, and the like. and cycloolefins such as cyclopropene, cyclobutene, cyclopentene, cyclohexane, cycloheptene, cyclooctene, cyclononene, cyclodecene, and limonene, tervirune, phelandrene, sylvestrene, thuene, carene, pinene, bornylene, camphen, and fenchen. , cycloundecane, tricyclene, bisabolene, zingiberene, curcumene, humulene, kajinensesesquivenichen, selinene, caryophyllene, santarene, cedrene, campholene, phylloclatene, bodocarbrene, mirene, and other terpenes, steroids, and the like are used.

Examples of aromatic hydrocarbons include benzene, toluene, xylene, hemimelithene, pseudocumene, mesitylene, prenitene, isodurene, durene, pentamethylbenzene, hexamethylbenzene, ethylbenzene,
Propylbenzene, cumene, styrene, biphenyl, terphenyl, diphenylmethane, triphenylmethane,
Dibenzyl, stilbene, indene, naphthalene, tetralin, anthracene, phenanthrene, etc. are used.

As carrier gas, Hl, Ar, Ne, He
etc. are appropriate.

In the present invention, it is most preferable to form the a-C organic polymer film through a plasma state such as direct current, high frequency, or microwave plasma method, or through an ion state such as ionization vapor deposition or ion beam vapor deposition. Alternatively, it may be formed from neutral particles using a vacuum evaporation method, a sputtering method, or a combination thereof.

What is important in this case is to form the organic polymer film so that the infrared absorption peak ratio α1/α2 based on methyl groups and methylene groups is 0.5 to 5.0 as described above.

Further, it is preferable that the charge generation layer is formed by the same method as the a-C film, as this leads to reductions in manufacturing equipment costs and process labor.

The charge generation layer of the photoreceptor of the present invention is not particularly limited, and may be an amorphous silicon (a-3i) film (with various different elements such as H, C, OlS, N, P, B, halogen, Ge, etc. to change the characteristics). or may have a multilayer structure), Se film, 5e-As film, 5e-Te film,
CdS film, copper phthalonoanine, inorganic substances such as zinc oxide and/or bisazo pigments, triarylmethane dyes, thiazine dyes, oxanone dyes, xanthine dyes, anine dyes, styryl dyes, pyrylium dyes, azo Resin films containing organic substances such as pigments, quinacridone pigments, indigo pigments, perylene pigments, polycyclic quinone pigments, bisbenzimidazole pigments, induthrone pigments, squarylium pigments, phthalocyanine pigments, etc. Illustrated.

In addition, any material that absorbs light and generates charge carriers with extremely high efficiency can be used.

The charge generation layer may be provided at any position on the photoreceptor, for example, the top layer, the bottom layer, or the middle layer. The film thickness depends on the type of material, especially its spectral absorption characteristics, exposure light source, purpose, etc., but it is generally 90% for 550no+ light.
It is set so that absorption of % or more can be obtained. In the case of a-9i, it is 0.1 to 3 μm.

In the present invention, heteroatoms other than carbon or hydrogen may be mixed in order to adjust the charging characteristics of the a-C charge transport layer. For example, in order to further improve the hole transport properties, atoms of Group I of the periodic table or halogen atoms may be mixed. In order to further improve the electron transport properties, atoms of Group I of the periodic table or alkali metal atoms may be mixed. When a-C1li is used as an overcoat layer or an undercoat layer, these atoms may be added so as to reverse bias the charge polarity in order to prevent charge injection from the surface or substrate. In order to further improve the transport properties of both positive and negative carriers, Si
, Ge, Sn, alkaline earth metals, chalcogen atoms, and various metals may be mixed.

A plurality of these atoms may be used, or they may be mixed only at specific positions in the charge transport layer depending on the purpose, or they may have a concentration distribution, etc., but in any case, the important thing is , the ratio α1/α of infrared absorption peaks based on methyl groups and methylene groups in the polymer film is 0.5 to 5 as described above.
．． It is to form it so that it becomes 0.

1 to 12 are schematic cross-sectional views showing one embodiment of the photoreceptor of the present invention. In the figure, (1) indicates a substrate, (2) an a-C charge transport layer as a charge transport layer, and (3) a charge generation layer. In the photoreceptor of the embodiment shown in FIG. 1, when the photoreceptor is charged, for example, ten times and then imaged, charge carriers are generated in the charge generation layer (3) and electrons neutralize the surface charges.

On the other hand, holes are transported to the substrate (1) side, guaranteed by the excellent charge transport properties of the a-C1X charge transport layer (2). In the present invention, when this electrification is performed, the aCiiC charge transport layer table 1A
It may be adjusted to P type by containing group elements. In this way,
Holes can move more easily to the substrate side, improving sensitivity, and injection of electrons from the substrate can be reliably prevented. It is preferable to use an N-type charge generation layer (3), for example,
a-9i is suitable because it is itself a weak N type. Of course, Group VA elements of the periodic table may be included. This is effective in preventing surface charge injection and electron movement.

Used for P-type adjustment [as a group IA element, BS
Examples include AQ, Ga, In, etc., but B is particularly preferred. It is preferable to mix a VA group element, such as phosphorus, into the a-Si2[i charge generation layer to make the surface layer a relatively stronger N type. In this case, the polarity of the a-C charge transport layer is adjusted to P type. When the photoreceptor shown in FIG. 1 is used with one charge, contrary to the above, the a-CM charge transport layer 2) may be adjusted to N type by containing phosphorus, and the charge generation layer (3) may be used as the a-CM charge transport layer 2). When using B, B may be contained.

The photoreceptor shown in Figure 2 is an example in which the a-C charge transport layer (2) is used as the uppermost layer. Charge generation layer (3
), it may be relatively N-type to facilitate the movement of electrons. - When used for charging, B or the like may be contained and adjusted in the opposite manner.

The photoreceptor shown in FIG. 3 is an example in which the a-C charge transport layer (2) is used above and below the charge generation layer (3). When used with ten charges, the upper a-C charge transport layer ( 2) is a charge generation layer (3)
It is preferable that the lower a-C charge transport layer (2) is adjusted to be P-type in order to facilitate electron hyperactivity by making it more N-type.

The photoreceptors shown in FIGS. 4 to 6 are examples of the photoreceptors shown in FIGS. 1 to 3 in which a surface protective layer with a thickness of 0.01 to 5 μm is further provided as an overcoat layer (4).
This is intended to protect the charge generation layer (3) or the a-C charge transport layer (2) and improve the initial surface potential. For the surface protective layer, a known substance may be used, and the aC charge transport layer of the present invention may be used. This protective layer (4) may also be doped with Group 1 I[A and Group VA elements, if necessary.

The photoreceptors shown in FIGS. 7 to 9 are examples in which an a-C charge transport layer used as a charge transport layer is used as an undercoat layer (5) on a substrate (1) as a barrier layer or an adhesive layer. Of course, other known materials may be used for the undercoat layer. The barrier layer has a rectifying function of effectively blocking charge injection from the substrate (+) and transporting the charge generated in the charge generation layer (3) to the substrate side. In this sense, it is preferable that the barrier layer contains a Group IIA element when charged, and a Group VA element when charged.

Further, the thickness of the barrier layer is preferably 0.01 to 5 μm. Furthermore, the photoreceptor shown in FIGS. 7 to 9 may be provided with an overcoat layer (4) shown in FIGS. 11 to 6 on the substrate (
Figures 1O to 12).

In order to mix the mA group element into the a-C charge transport layer, a suitable gaseous compound containing these elements may be formed in an ionized state or a plasma state together with a hydrocarbon gas to form a film. In addition, the formed a-C charge transport layer was
It may be doped by exposing it to a compound gas containing a group element.

B-containing compounds that can be used in the present invention include B (QC
,H3),,B t He,B(4,,BBrs,BP
.

etc. are exemplified.

Compounds containing A4 include Ak(Of-C3H9)s,
(CHs)sAJ! s(CtH6)sAflll(i-
CtHs)tA, Alcl, etc. are exemplified.

As a compound containing Ga, Ga(Ot-CsHt)3
, (CH3)1Ga-(CyHs)iGa, GaC15
, G aB ra, etc.

A compound containing In is In(Ot-cs H?
)3, (CtHs)all, etc.

(2) The amount of the group A element introduced is 20,000 atm, ppm or less, more preferably 3 to 1,000 atm, ppm, based on the sum of the introduced atomic weight and the carbon atomic weight.

VA group elements used for polarity adjustment include PlAs,
Although Sb is included, P is particularly preferred. This VA group element is also I
It can be introduced into the a-C charge transport layer in the same manner as Group IIA elements.

Compounds containing group VA elements that can be used in the present invention include the following.

Examples of compounds containing P include P O(OCHJ3, (C,
1 (,), P, PH3, poc, etc.; As a compound containing As, As Hi, ASC+! 3.AsBr1 etc.
Sb(OCxHs)3, Sb as a compound containing sb
Examples include C-5.5bHa.

The amount of the VA group element introduced is about 20,000 atm, ppm or less, more preferably about 1 to IOOatm, ppm, based on the sum of the introduced atomic weight and the carbon atomic weight.

Further, other elements may be introduced into the charge generation layer of the photoreceptor of the present invention to adjust its characteristics.

As an example of a different element that may be contained in the charge transport layer (2), Si, Ge and/or Sn may be added at l Oatomic% (hereinafter referred to as atm
By avoiding mixing these elements in the following amounts (denoted as , %), charge injection from the charge generation layer becomes easy,
Effects such as a reduction in residual potential, an increase in sensitivity, and a reduction in memory can be obtained. Furthermore, the adhesion to the AL substrate, the charge generation layer, etc. is improved.

In order to introduce these elements, a method similar to that described in the introduction of group I[[A elements may be employed.

For Si introduction, SiH4,5ttHs, (CtHs)*
S 1H1SiF 5iHtC 1, SiC 5
i(OCI-[z)-1S! (OCzH5)a, S
t(OC5H7)i, etc., to introduce Ge)
I 4, ce CZ a, Ge(OCtH4
) 4% Ge(CtHs)a etc., and for Sn introduction (CH3)4S nl(C2HS)4S n1S
nCC10 may be used.

It is also possible to adjust the band gap by adding Si or Ge to the charge transport layer to reduce the interface barrier with the charge generation layer. In FIG. 1, polyfi(>t.

By unevenly distributing the Ge-added portion (%) on the substrate side, the reflection of excess light is prevented, and interference fringes and
It is also possible to prevent the occurrence of blur. Also, St%Ge
By adding , a hard film with wear resistance and water repellency can be formed.

Nitrogen, oxygen, sulfur and/or various metals may be further mixed into the a-C charge transport layer of the photoreceptor of the present invention, or a portion of hydrogen may be replaced with halogen or alkali metal.

Generally, the nitrogen sources are N,,NH,,N,O,N01N
o,,C,H3NH,,HCN, (CHa)sN.

CH3N II * or the like is used, and by mixing it, the interface barrier with the charge generation layer can be reduced.

As an oxygen source, 01.01, N, O, No, CO, C
Examples include O,, CHa, COCH3, CH, CHO, etc., and by mixing these, the charging ability is improved.

In addition, in the case of plasma CVD method, introducing oxygen (0) has the side effect of increasing the film formation speed. As a sulfur tIt source, CS, (CtHs)tS, HvS
.

Examples include SF, SO7, etc. Mixing sulfur is effective in absorbing light and preventing interference. Additionally, the introduction of sulfur (S) has the secondary effect of increasing the film formation speed.

Examples of metals that can be mixed include the following (2 and below are examples of gases that can be mixed and used).
OCtHS)+, Ca: Ca(OCtHS)3, F
e: Pa(Of-CiH7)*, (CtHs)tFe
, Fe(CO)2, [-1f: Hf(Oi-CaH
2) i, K: KOi-CaH7, Li: Li(
Oi-CsHt), La: La (Oi-CxH3
) Mg: Mg(OCtHs)t, (CzHs)t
Mg-Na: Na(Of-CaH2), Nb: N
b(OCtHs)s, Sr: 5r(OCHs)*, T
l: T t(O1-CsHJasT t(OCaHJ
ITI CL, T e : Hs T es (C
Hs)tTe, Se:H*Se, Ta: Ta(
OCtHs)s, V: VO(OC*Hs)s, Y:
Y(Oj-CaH2)*, Zn: Zn(OCtHs)
t, (CHs)tZJ (CtH+t)sZns Z
r: Zr(Of-CsHt)a, Cd: (CHs
)*Cd, Co: Cow(CO)s, Cr:
Cr(Co)s, Mn: Mn(CO)+o, Mo:
Mo(Co),, Mob,, MoCe6, W: w
(co)a, WF6, WCl, .

In addition, by replacing some of the hydrogen in the a-C charge transport layer with halogen or alkali metal, water repellency, abrasion resistance, and light transmission properties are improved.
F, etc. are formed, and the refractive index n becomes small (1,39
), the anti-reflection effect appears.

Further, when the a-C charge transport layer obtained according to the present invention is post-treated with argon and then brought into contact with the atmosphere, carbonyl groups are introduced and the surface is activated, and -CF', - is CF
becomes.

Carbon and halogen sources include C* Hs Cl, C
1H, +4, CH, C4, CH, Elr%C0CfL2
, CCi, t F t, CHC Katsu F! ,CF,,Cs
Examples include F s, H(4, C1, , F3, etc.).

Examples of carbon and alkali metal sources include lithium ternary butyralate, potassium acrylate, and the like.

The photoreceptor of the present invention has a charge generation layer and a charge transport layer. Therefore, at least two steps are required to manufacture it. When using, for example, an a-5i layer formed using a glow discharge decomposition device as the charge generation layer, it is possible to perform plasma polymerization using the same vacuum device, so that the a-C charge transport layer and the surface It is particularly preferable to form the protective layer, barrier layer, etc. by plasma polymerization.

The charge transport layer of the electrophotographic photoreceptor according to the present invention includes, for example,
Molecules in the gas phase are decomposed by discharge under reduced pressure, and active neutral species or charged electrodes contained in the generated plasma atmosphere are diffused onto the substrate, induced by electric force, magnetic force, etc., and regenerated on the substrate. It is preferably produced from a so-called plasma polymerization reaction, in which it is deposited as a solid phase by a bonding reaction.

FIGS. 13 and 14 show a capacitively coupled plasma CVD apparatus which is a photoreceptor manufacturing apparatus according to the present invention. FIG. 13 shows a parallel plate plasma CVD apparatus, and FIG. 14 shows a cylindrical plasma CVD apparatus.

First, explanation will be given using FIG. 13.

In FIG. 13, (701) to (706) are the first to sixth tanks in which the raw material compound and carrier gas, which are in a gaseous state at room temperature, are sealed, and each tank is a first to sixth tank.
It is connected to moderation valves (707) to (712) and first to sixth flow rate controllers (713) to (718). H, He, Ar, etc. are used as the carrier gas.

In the figure, (719) to (721) are first to third containers filled with raw material compounds that are in a liquid or solid phase at room temperature, and each container is connected to a first to third heater (721) for vaporization.
22) to (724), and each container is further connected to seventh to ninth control valves (725) to (727) and seventh to ninth flow rate controllers (728) to (730). has been done.

These gases are mixed in a mixer (731) and then sent into a reaction chamber (733) via a main pipe (732).

The pipes along the way can be heated by appropriately placed pipe heaters (734) so that the gas, which is the vaporized raw material compound that is in a liquid or solid state at room temperature, does not condense on the way. .

Inside the reaction chamber, there is a ground electrode (735) and a power application electrode (73).
6) are installed facing each other, and each electrode is connected to an electrode heater (7).
37) allows for heating.

The power application electrode is connected to a high frequency power source (739) and a low frequency power matching device (73!l) via a high frequency power matching device (73!l).
A low frequency power source (741) is connected through a low-frequency power source (741) and a DC power source (743) is connected through a low-pass filter (742), and power with different frequencies can be applied by a connection selection switch (744).

The pressure inside the reaction chamber can be adjusted by a pressure control valve (745), and the pressure inside the reaction chamber can be reduced by using a diffusion pump (747) and an oil rotary pump (748) through an exhaust system selection valve (746).
), or by a cooling exclusion device (749), mechanical booster pump (750), or oil rotary pump.

The exhaust gas is further rendered safe and harmless by an appropriate exclusion device (753) before being exhausted into the atmosphere.

These exhaust system pipings are also heated by appropriately placed piping heaters to prevent the vaporized gas from the raw material compounds, which are in a liquid or solid phase at room temperature, from condensing on the way.
It is said that heating is possible.

For the same reason, the reaction chamber can also be heated by a reaction chamber heater (751), and a conductive substrate (
752) is installed.

In FIG. 13, the conductive substrate (752) is the ground electrode (752).
35), but when power is applied 1! pole (7
36), or may be arranged on both sides.

The apparatus shown in FIG. 14 is basically the same as the apparatus shown in FIG. 13, and the shape inside the reaction chamber (733) is
52) is changed in accordance with the fact that it is cylindrical. The substrate also serves as a ground electrode (735'), and both the power application electrode (736) and electrode heater (737) have a cylindrical shape.

In the above configuration, the reaction chamber includes a diffusion pump (747)
The pressure is reduced to about 10-4 to 10-1 in advance, and the degree of vacuum is checked and the gas adsorbed inside the device is desorbed.

At the same time, the electrode heater (,737)
36) and a conductive substrate fixedly arranged on the electrode (75)
2) is heated to a predetermined temperature.

Next, the raw material gas is transferred from the first to sixth tanks (701) to (706) and the first to third containers (719) to (721) to the first to ninth flow rate controllers (713) to (718),
(728) to (730) are used to introduce the reaction volume (733) into the reaction chamber (733) while maintaining a constant flow rate.
3) Maintain a constant reduced pressure inside.

After the gas flow rate has stabilized, press the connection selection switch (744)
For example, a high frequency power source (739) is selected, and high frequency power is applied to the power application electrode (736).

A discharge starts between both electrodes, and as time passes, the substrate (752
) a solid-phase a-C film is formed on the top.

This charge transport layer is the above-mentioned α1/α produced by the present invention.
2 ratio is 0.5 to 5.0. This α
The 1/α2 ratio can be controlled by manufacturing conditions, such as electric power, power supply frequency, electrode spacing, pressure, substrate temperature, source gas, gas concentration, gas flow rate, etc. For example, by increasing the electric power, it is possible to reduce the loss of Medyl groups and increase the value of α1/α, the ratio. Similar control can be achieved by narrowing the electrode spacing, increasing the substrate temperature, increasing the pressure, decreasing the molecular weight of the source gas, increasing the gas flow rate, etc. Further, opening of the frame can also be controlled by superimposing a bias voltage of 50 V to IKV from a DC power source (743). Of course, the opposite effect can be obtained by reversing the direction of control. A plurality of these control methods may be appropriately adopted for the purpose of imparting additional properties such as hardness and translucency to the charge transport layer, or for the purpose of ensuring manufacturing stability. .

The present invention will be explained below with reference to Examples.

Example 1 (1) (Formation of a-C layer) In the glow discharge decomposition apparatus shown in FIG. And open the 2nd F4 regulating valves (707) and (708), and open the 1st tank (701).
H4 gas is supplied from the second tank (702) to the mass flow controller (
713) and (714). Then, adjust the scale of each mass flow controller, and C! The flow rate of H4 was set to 30 sec+a and the Hz was set to 40 sec, and it flowed into the reaction chamber (733). After each flow rate became stable, the internal pressure of the reaction chamber (733) decreased to 0.
I adjusted 'J61 so that Torr. On the other hand, as a conductive substrate (752), use an aluminum slope of 3 x 50 x 50 mm, heat it in advance to 250 ° C, and use a high frequency power source (752) with the flow rate of each gas stabilized and the internal pressure stabilized.
39) and apply 100 wa to the power application electrode (736).
tts power (frequency 13.56 Ml1z) was applied for about 4 hours to perform plasma polymerization to form a conductive group 11iE (7
52) A charge transport layer with a thickness of about 7 μm was formed on top.

FIG. 15 shows a spectrum chart obtained by measuring the a-C film obtained as described above using a Fourier transform infrared absorption spectrometer (manufactured by Perkin-Nilmer). The measurement was performed by placing the a-C film on KBr and measuring at a resolution of 2 cm-'. 1st
In Figure 5, a is for the 1380cm- section and b is for the 1460cx- section.
' is the transmittance peak. From formula [1], the infrared absorption peak ratio α, (1460)/αt(+380) of the a-C film is 1
．． It was 41.

(■) (Formation of charge generation layer) The application of power from the high frequency power source (739) was temporarily stopped, and the inside of the reaction chamber was evacuated.

Open the fourth and second regulating valves (710) and (708), and output Si H4 gas from the fourth tank (704) and H gas from the second tank (702) to the output pressure gauge tK.
g/c into the mass flow controllers (716) and (714). Adjust the scale of each mass flow controller to set the SiH flow rate to 90 sec + m.
, The flow rate of Ht was set at 210 sec, and was allowed to flow into the reaction chamber.

After each flow rate became stable, the internal pressure of the reaction chamber (733) was adjusted to 1.0 Torr.

When the gas flow rate is stable and the internal pressure is stable, turn on the high frequency power supply (
739) and apply 150W to the power application electrode (736).
electric power (frequency: 13.56 MHz) was applied to generate glow discharge. This glow discharge was performed for 40 minutes to form a 1 μm thick a-8i:H charge generation layer.

The obtained photoreceptor had an initial surface potential (Vo) = -600vo
Half-exposure "l/2" at lt is 0.2512ux・s
It was ec. Furthermore, when an image was formed and transferred onto this photoreceptor, a clear image was obtained.

Table 1 shows the film forming conditions and the characteristics of the photoreceptor obtained. In the table, Vo is the initial surface potential, E l/2 is the half-decreased exposure amount, and V
r is the residual potential, and Dcots is the ratio of dark decay in 5 seconds from the initial charging potential.

In addition, in the evaluation of repeated stability, ◎ indicates that the initial electrostatic properties hardly changed after 10,000 times of charging and exposure. % environment, clear images were obtained.

Cold Storm Carp 121L According to Example 1, a photoreceptor having the structure shown in FIG. 1 was obtained under the conditions shown in Tables 2 to 17. The characteristics of the obtained photoreceptors are also shown in Tables 2 to 17.

Table 1 (Example 1) Table 2 (Example 2) Table 3 (Example 3) Table 4 (Example 4) Table 5 (Example 5) *1 Heated to 50℃ using a heater Table 6 (Example 6) Table 7 (Example 7) *1 Sensitivity was slightly lower than in Examples 1 to 6.

Table 8 (Example 8) *1 Compared to Examples 1 to 6, the charging ability was lower in relation to the film thickness.

Table 9 (Example 9) *1 Straight-chain hexane: Heated to about 70°C with a heater.

*2 Compared to Examples 1 to 8, the charging ability per unit film thickness was lower.

Table 10 (Example 10) *1 Sensitivity was lower than in Examples 1 to 8.

Table 11 (Example 11) *' 1,3-butadiene (the same applies hereinafter) Table 12
(Example 12) Table 13 (Example 13) Table 14 (Example + 4) Table 15 (Example 15) Table 16 (Example 16) Table 17 (Example! 7) Example! 8 In this example, a laminate type photoreceptor having an overcoat layer as shown in FIG. 4 was prepared using an aluminum dam plate of 3 x 50 x 50 mm.

Note that the charge transport layer and overcoat layer were produced under the conditions shown in Table 18. As the charge generation layer, monochloroaluminum monochlorophthalonoanine (AQCi!P
c(CQ)) according to the conventional vacuum evaporation method at a boat temperature of 4.
Under conditions of 80°C and a pressure of 5 x 10-'Torr, 1
Vapor deposition was performed for 0 minutes to form a film with a thickness of 1000 mm.

Table 18 (Example + 8) Example 19 In this example, a 3x50xb aluminum plate was used to produce a laminated type photoreceptor having an undercoat layer as shown in FIG. 8.

Note that the undercoat layer and charge transport layer were produced under the conditions shown in Table 19. The charge generation layer was provided in the same manner as in Example 18.

Table 19 (Example 19) Comparative Example 1 The step (formation of IXa-0 layer) in Example 1 was omitted, and a-9i:I- with a film thickness of 6 μm was prepared under the same conditions as step (■).
One layer was formed to obtain an a-Si:H photoreceptor.

The obtained photoreceptor had an initial surface potential (Vo) of -100μ and a half-exposure "El/2" of 0.7 1ux-sec, and did not exhibit sufficient charging ability with ten polarity, and good image formation could not be performed. There wasn't.

It was understood that the charge transport layer according to the present invention significantly contributes to improving charging ability and has suitable transport properties.

Comparative Example 2 Instead of the charge transport layer according to the invention prepared in step (1) of Example 1, α, (1460)/α, (+380)
A polyethylene film having a ratio of 7.06 was prepared by a conventional method of organic polymerization, and step (n) was performed thereon. The obtained laminated film differs from the present invention only in the infrared absorption peak ratio. Although the charging ability is the same as in Example 1, the sensitivity is a −
With a slight potential attenuation due to the Si layer,
This did not reach the half-reduced value. The superiority of the charge transport layer of the present invention was recognized.

Comparative Examples 3 and 4 According to Example 1, photoreceptors having the configuration shown in FIG. 1 were obtained under the conditions shown in Table 20 (Comparative Example 3) and Table 21 (Comparative Example 4). However, as the charge transport layer, α1/α of a-C@,
is a value outside the scope of the present invention. The characteristics of the obtained photoreceptor are also shown in Table 20 and Table 21.

Table 20 (, Comparative Example 3) Table 21 (Comparative example 4) *1 Heated to approximately 50°C using a heater.

*2 Partial peeling occurred.

Effects of the Invention The photoreceptor having the organic plasma polymerized film according to the present invention in its charge transport layer has excellent charge transport properties and charging ability, can obtain a sufficient surface potential even with a thin film thickness, and can produce good images. can do. According to the present invention, the charge generation layer has a-5
When using i, it is possible to obtain a thin film photoreceptor, which could not be achieved with the conventional a-1i photoreceptor.

In the photoreceptor of the present invention, the raw materials thereof are inexpensive, each necessary layer can be formed in the same tank, and the film thickness may be thin, so that the manufacturing cost is low and the manufacturing time is short. The organic plasma polymerized film according to the present invention is difficult to form pinholes even when formed into a thin film, and can be formed homogeneously, so that it can be easily made into a thin film. Furthermore, corona resistance, acid resistance,
It also has excellent moisture resistance, heat resistance, and rigidity, so when used as a surface protective layer, it improves the durability of the photoreceptor.

[Brief explanation of drawings]

1 to 12 show schematic cross-sectional views of the photoreceptor of the present invention. FIG. 13 and FIG. 14 are diagrams showing an example of an apparatus for manufacturing a photoreceptor. FIG. 15 is a diagram showing an infrared absorption spectrum of the a-C film. The symbols in the figure are as follows. (1)...Substrate (2)...Charge transport layer (a
-C layer) (3)...Charge generation Ji! (4)...
Overcoat layer (5)... Undercoat layer (701) to (706)... Tank (707) to (712) and (725) to (727).
...Control valves (7H) to (718) and (728) to (7
30)...Flow rate controller (mass flow controller)
(719) ~ (721) ... Container (722) ~ (72
4)... Heater (731)... Mixer (73
2) Main pipe (733) Reaction chamber (734
)...Pipe heater (735)...Ground electrode (7
38)...Power application electrode (737)...Power heater ('738)...High frequency power matching device (739)...
・High frequency power supply (740)...Low frequency power matching box (741)...Low frequency type 11 (742)...Low pass filter (743)...DC power supply (744)
)...Connection selection switch (745)...Pressure control valve (746)...Exhaust system selection valve (747)...Diffusion pump (74g)...Oil rotary pump (749)...Cooling exclusion device ( 75G)...Mechanical booster pump (751)
... Reaction heater (752) ... Conductive substrate (75
3)... Excluded device patent applicant Representative of Minolta Camera Co., Ltd. Patent attorney Aobai Ao and two others III
Figure 2 Figure 3 Figure 4 Figure 5
fs6 drawing drawing 7 drawing 8 drawing 9 drawing 10! ! i! I Fig. 11 Fig. 12
Figure @15 Figure +600 1200 Number of trenches (cm”)

Claims (1)

[Claims] 1. In a functionally separated photoreceptor having a charge generation layer (3) and a charge transport layer (2), a hydrocarbon plasma polymerized film is provided as the charge transport layer (2), and the infrared absorption spectrum of the polymerized film is Methyl (-CH_3) group and methylene (-C
1460 to 1470 cm^-^ depending on the H_2-) group
138 due to peak absorption coefficient α_1 near 1 and methyl group
Ratio α_ to peak absorption coefficient α_2 near 0cm^-^1
A photoreceptor characterized in that 1/α_2 is 0.5 to 5.0.