JPH01210963A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To inhibit lowering of a dark part potential at high temp. and under high humidity of an electrophotographic sensitive body, and elevation of a light part potential thereof due to continuous use at low temp. and low humidity by incorporating a specified polymer into an undercoating layer. CONSTITUTION:An undercoating layer contg. a polymer consisting of a unit component expressed by formula I as polymeric component is formed between an electroconductive substrate and a photosensitive layer. In formula I, each R1-R4 is an 1-4C alkyl; each R5 and R6 is a 1-10C alkylene; 2-18C aralkylene, xylylene, etc.; X is an anion. The undercoating layer may be constituted singly of an above described polymer (e.g., polymer constituted of the unit expressed by formula II), or of plural components including other polymer (e.g., alcohol-soluble copolymeric polyamide), or additive. The undercoating layer may be formed by coating by a desired process on the substrate.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to an electrophotographic photoreceptor, and more specifically, an electrophotographic photoreceptor in which an undercoat layer having functions as an adhesive layer and a barrier layer is provided on a conductive support. Regarding photographic photoreceptors.

[Prior Art] Generally, a curl-type electrophotographic photoreceptor is
In order to form images with constant image density and no background smearing when exposure is repeated, the stability of the dark area potential and the bright area potential is important.

For this reason, it has been proposed to provide a layer functioning as a barrier layer between the photosensitive layer and the conductive layer. In addition, a layered structure in which the photosensitive layer is functionally separated into a charge generation layer and a charge transport layer has been proposed, but generally the charge generation layer is provided as an extremely thin layer 1, for example, about 0.51 L, on the conductive layer. Because of this, there may be slight defects, dirt, or
Deposits or scratches cause the charge generation layer to have an uneven thickness.

If the thickness of the charge generation layer is non-uniform, uneven sensitivity will occur in the photoreceptor, so it is required that the thickness of the charge generation layer be made as uniform as possible.

For this reason, it has been proposed to provide an undercoat layer between the charge generation layer and the conductive layer, which functions as a barrier layer and an adhesive layer.

Until now, the layers provided between the photosensitive layer and the conductive layer have been polyurethane, polyamide, polyester, polyvinyl alcohol, epoxy resin, and casein.

It is known to use methyl cellulose, nitrocellulose, phenol resin, or the quaternary ammonium salt type polymer conductive material described in Japanese Patent Publication No. 56-44431.

In photoreceptors using these layers as undercoat layers, the potential tends to change due to the influence of the temperature and humidity environment, and when the barrier function deteriorates under high temperature and high humidity, the dark area potential decreases due to carrier injection from the support side, causing copying problems. There was a drawback that the density of the image was reduced.

Furthermore, when such a photoreceptor is used in an electrophotographic printer that performs reversal development, there is a problem in that images tend to become foggy under high temperature and high humidity conditions.

Furthermore, photoreceptors using conventional materials as undercoat layers tend to cause an increase in bright area potential and fluctuations in dark area potential when used repeatedly, especially in low temperature and low humidity environments where the resistance of the undercoat layer becomes high. However, since charges remain in the undercoat layer, the bright area potential increases significantly, and when used continuously, it is difficult to obtain copies with a constant image quality.

[Problems to be Solved by the Invention] An object of the present invention is to provide an electrophotographic photoreceptor that can obtain a stable dark area potential against changes in temperature and humidity environment, and also to maintain a bright area potential even when used with edge reversal. An object of the present invention is to provide an electrophotographic photoreceptor in which an increase in potential and a fluctuation in dark area potential are suppressed.

[Means for Solving the Problems, Effects] The present invention provides an electrophotographic photoreceptor having an undercoat layer between a conductive support and a photosensitive layer, in which the undercoat layer has a unit component represented by the following general formula as a polymeric component. It is composed of an electrophotographic photoreceptor characterized by containing a polymer.

In the formula, RL, R2, R3oJ: (/R+ tt represents an alkyl group at carbons v11 to 4, and does not necessarily prevent them from being the same.

R5 and R6 are selected from an alkyl group having 61 to 10 carbon atoms, an arylalkylene group having 2 to 18 carbon atoms, a xylylene group, a cyclohexyl group, or a combination of these groups, and are not necessarily the same.

X represents an anion.

As anions, halogen ions (Fe, e□
θ C1, Br, I, etc.), but alkyl sulfate anions (CR3
S 04o, C2R5S 04°nato), through-S
O, 3, etc.), 7 anion θ of organic acid as acid anion
e(CH3Coo
, C5HBCOO, etc.), 11 acid-free y2, ton (NO
3, CfLO+e)lx, etc.

The undercoating calendar in the present invention may be composed of a single polymer (hereinafter referred to as a polycationic polymer) having the unit component represented by the above general formula as a polymerization component, or it may be composed of multiple components including other resins and additives. may be configured.

Typical specific examples of unit components of the polycationic polymer used in the present invention are listed below.

However, anions will be omitted and will be specifically described in Examples below.

Exemplary component (1) Exemplary component (2) Exemplary component (3)
) Exemplary component (4) Exemplary component (5)
Exemplary component (6) Exemplary component (7) Exemplary component (
8) Exemplary ingredient (9) Exemplary ingredient (10) Exemplary ingredient (11) Exemplary ingredient (12) Exemplary ingredient (13)
Exemplary ingredient (14) Exemplary ingredient (15) Exemplary ingredient (16) Exemplary ingredient (17) Exemplary ingredient (1)
8) Exemplary component (19) Exemplary component (20) Exemplary component (21) Exemplary component (
22) Exemplary component (23) Exemplary component (24) CH3C)+3 Exemplary component (25) Exemplary component (26) Exemplary component (27) Exemplary component (28) Next, polycation contained in the undercoat layer used in the present invention The method for producing the polymer will be explained.

The above polycationic polymer is synthesized by a Menschudkin reaction between a tertiary diamine and a dihalogen compound.

Therefore, the above polycationic polymer can be obtained by using a reactant containing an alkylene group, arylalkylene group, xylylene group and cyclohexyl group in a tertiary diamine or dihalogen compound. The polycationic polymer obtained in this way is easily soluble in alcohols such as methanol and ethanol, and solvents such as water.
Used alone or in combination with other polymers or additives as an undercoat layer.

The undercoat layer in the present invention has a thickness of 0.1 to og
, particularly preferably 0.5 to 5.0 μm, and is applied by a coating method such as a dip coating method, a spray coating method, or a roll coating method.

In the electrophotographic photoreceptor of the present invention, the photosensitive layer may be of a single-layer type or may be of a laminated structure type in which the functions are separated into a charge generation layer and a charge transport layer.

The charge generation layer is made of azo pigments such as Sudan Red, Guianpuru, and Jenas Green B, Algol Yellow,
Quinone pigments such as pyrenequinone and indanthrene brilliant violet RRP, quinocyanine pigments, perylene pigments, and indigo.

Indigo pigments such as thioindigo, bisbenzimidazole pigments such as India First Orange Toner, phthalocyanine pigments such as copper phthalocyanine, and charge generating substances such as quinacridone pigments are combined with polyvinyl butyral, polystyrene, polyvinyl chloride, polyvinyl acetate, acrylic resin, and polyvinylpyrrolidone. It can be formed by dispersing it in a binder resin such as , methyl cellulose, or hydroxypropyl methyl cellulose, and coating this dispersion on the above-mentioned undercoat layer. The thickness of such a charge generation layer is suitably 5 mm or less, preferably 0.01 to 2 mm.

The charge transport layer contains a polycyclic aromatic compound such as anthracene, pyrene, phenanthrene, coronene, or indole, carbazole, oxazole, inoxazole, thiazole, imidazole, pyrazole, etc. in the main chain or side chain.
Oxadiazole.

It is formed using a coating liquid in which a charge-transporting substance such as a nitrogen-containing cyclic compound such as pyrazoline, thiadiazole, or doriapool, a hydrazone compound, or a styryl compound is dissolved in a resin that has film-forming properties.

This is because the charge transporting substance generally has a low molecular weight and has poor film-forming properties by itself.

Examples of such resins include polyester, polysulfone, polycarbonate, polymethacrylic acid ester,
Examples include polystyrene.

The thickness of the charge transport layer is 5 to 40 mm, preferably 10 to 25 mm.
μ.

In addition to the above, examples of the photosensitive layer used in the present invention include poly-N-
Examples include an organic photoconductive polymer layer such as vinyl carbazole or polyvinylanthracene, a selenium vapor deposited layer, a selenium-tellurium vapor deposited layer, or an amorphous silicone layer.

The conductive support used in the present invention may be any material as long as it has a conductive layer, and specifically, examples include aluminum, copper, vanadium, molybdenum, chromium, nickel, titanium, zinc, indium, and brass. etc. molded into a drum or sheet shape, metal foil such as aluminum or copper laminated onto plastic film, aluminum, indium oxide, tin oxide, etc. deposited on plastic film, metal powder, carbon black, iodide, etc. Examples include plastic films and paper whose surfaces are coated with a conductive material such as copper or a polymer electrolyte together with a suitable binder resin and subjected to conductive treatment.

The electrophotographic photoreceptor of the present invention can be used not only for electrophotographic copying machines, but also for laser printers, CRT printers,
It can be used in electrophotographic plate making systems, etc.

[Example] Example 1 Polymer made from the above-mentioned exemplary component (5) (anion is Bre)
10 parts of the solution was dissolved in a mixed solvent of 60 parts of methanol and 30 parts of Improper Tool to prepare a paint for underpants.

The above undercoating paint was applied by dip coating onto a 60φ aluminum cylinder as a conductive support, and heated at 100″C for 30°C.
It was dried for a minute to form a subbing layer with a film thickness of 1 and 0 liters.

Next, add 10 parts of a disazo pigment having the following structural formula.

6 parts of cellulose acetate butyrate resin (average molecular weight: 21,000) and 60 parts of cyclohexanone were dispersed for 20 hours in a sand mill apparatus using 1φ glass beads. 7,100 parts of methyl ethyl keto was added to this dispersion, which was dip coated onto the undercoat layer and dried at 100° C. for 10 minutes to form a charge generation layer with a coating weight of 0.1 g/m''.

Next, 15 parts of p-diethylaminobenzaldehyde-N-α-naphthyl-N-phenylhydrazone and styrene-methyl methacrylate copolymer (styrene/methyl methacrylate = 8/2, average molecular weight 35,000) were dissolved in toluene at 80 fA. .

This solution was applied by dip coating onto the charge generation layer to give 51 oo'c.
The charge transport layer was dried with hot air for 1 hour to form a charge transport layer having a thickness of 19 IL.

The electrophotographic photoreceptor thus prepared was attached to a Canon ■ electrophotographic copying machine PC-24 at room temperature (21°C).
C160%RH) and high temperature and high humidity (33°C185%
When the electrophotographic properties were evaluated using RH), good images were obtained with no fluctuation in dark area potential even under high temperature and high humidity conditions. The results will be described later.

Comparative Example 1 5 parts of a polymer with the following structural formula was used as a paint for an undercoat layer.
- Using a paint solution dissolved in 95 parts of lube.

Otherwise, an electrophotographic photoreceptor was prepared in the same manner as in Example 1, and P
When evaluated by Mr. J, under high temperature and high humidity conditions, the dark area potential decreased due to increased carrier injection from the conductive support, resulting in a decrease in image density. Show the results.

At 21°C, 60% RH r VO-V Example 1 750 Comparative Example 1 740 At 33°C, 85% RH) VD -■ Example 1 740 Good Comparative Example 1 630 Low concentration Example 2 16) Polymer (anion is I)
A coating material for an undercoat layer was prepared in the same manner as in Example 1, and the paint was coated on an aluminum cylinder with a thickness of 1.2 PL.
A subbing layer was formed.

Next, 10 parts of a disazo pigment with the following structural formula, 5 parts of methyl methacrylate resin (average molecular weight 24,000), and 50 parts of cyclohexanone were dispersed for 20 hours in a sand mill using lφ glass beads, and then 80 parts of 2-methyl ethyl ketone were dispersed. A paint is prepared by adding 0.
A charge generation layer was formed with a coating weight of 15 g/m2.

Next, a charge transport layer was provided in the same manner as in Example 1 to prepare an electrophotographic photoreceptor.

The electrophotographic photoreceptor produced in this way was transferred to a Canon laser beam printer LBP-CX under normal temperature and humidity (20°C, 155% R, H) and under high temperature and high humidity (
When the electrophotographic properties were evaluated at 32° C. (180% RH), good images with no black spots or fog were obtained even under high temperature and high humidity conditions. The results will be described later.

Comparative Example 2 Polymer CH3N'C with the following structural formula was used as an undercoat S layer phase paint.
Hs (n = 50) A paint prepared by dissolving 6 parts of H3 in 94 parts of methanol was used.

An electrophotographic photoreceptor was prepared in the same manner as in Example 2, and evaluated in the same manner. It was found that under high temperature and high humidity, the dark area potential decreased due to carrier injection from the conductive support, and black spots appeared on the image. A type of fogging occurred. Show the results.

20°C, 55% R1 (VD-v Example 2 760 Comparative Example 2 770 32°C, 80% RH, vD-v Example 2 750 Good Comparative Example 2 680 Black spot fogging Example 3 Polymer (anion is Brθ
) was dissolved in 90 parts of methanol to prepare a paint for the undercoat layer, and the above paint for the undercoat layer was dip-coated onto a 30φ aluminum cylinder as a conductive support.
It was dried at ℃ for 15 minutes to form a subbing layer having a thickness of 1.2 tiles.

Next, 10 parts of a disazo pigment with the following structural formula, 6 parts of butyral resin (butyralization degree 69%, average molecular weight [19,000]), and 60 parts of cyclohexanone were dispersed for 4 hours in a sand mill device using 0.7φ glass beads. Thereafter, 120 parts of tetrahydrofuran was added to prepare a dispersion liquid, which was dip coated onto the above-mentioned undercoat layer to form a charge generation layer with a coating weight of 0.12 g/m<2>.

Next, 8 parts of the same hydrazone compound as in Example 1 and 10 parts of styrene-methyl methacrylate copolymer (styrene/methyl methacrylate = 8/2, average molecular weight 34,000) were dissolved in 70 parts of monochlorobenzene, and this solution was applied onto the above charge generation layer by dip coating, and dried at 120° C. for 60 minutes to provide a charge transport layer with a thickness of 21 μm to prepare an electrophotographic photoreceptor.

The thus prepared electrophotographic photoreceptor was attached to a Canon electrophotographic copying machine FC-5 under low temperature and low humidity (10°C,
When 1,000 images were continuously produced at 10% RH), very stable images were obtained without any rise in bright area potential. The results will be described later.

Comparative Example 3 An electrophotographic photoreceptor was prepared in the same manner as in Example 3 except that a polymer u3 having the following structural formula was used as a coating material for the undercoat layer, and evaluated in the same manner.

The results will be described later.

Example 4 An electrophotographic photoreceptor was prepared in the same manner as in Example 3 except that 5 parts of the polymer (anion is Br0) of the above-mentioned exemplary component (25) dissolved in 80 parts of methanol was used as a paint for the undercoat layer. was created and evaluated in the same way. The results will be described later.

Example 5 A paint for the undercoat layer in which 1 part of the polymer (anion is CH3SO4'') of the above-mentioned exemplified component (4) and 7 parts of alcohol-soluble copolymerized nylon (average molecular weight 29,000) were dissolved in 100 parts of methanol. An electrophotographic photoreceptor was prepared in the same manner as in Example 3, using the same method as in Example 3, and evaluated in the same manner.The results are shown below.

Example 3 Vo 700 710V L
190 200 Example 4VD 710 710VL
180 190 Example 5 Vo 720 710VL
190 190 Comparative Example 3 Vo 690 660VL
180 320 (Vo: dark area potential vL = light area potential) [Effects of the invention] The electrophotographic photoreceptor of the present invention has high temperature resistance by containing a polymer having a specific unit component as a polymerization component in the undercoat layer. Deterioration of barrier function under high humidity, almost no increase in resistance under low temperature and low humidity, and decrease in dark area potential under high temperature and high humidity, which was a problem with conventional electrophotographic photoreceptors with an undercoat layer, and low temperature and low humidity. It is an electrophotographic photoreceptor with excellent environmental stability, with a marked improvement in the increase in bright area potential due to continuous use.

Claims (1)

[Scope of Claims] 1. An electrophotographic photoreceptor having an undercoat layer between a conductive support and a photosensitive layer, wherein the undercoat layer contains a polymer having a unit component represented by the following general formula as a polymerization component. An electrophotographic photoreceptor characterized by: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ In the formula, R_1, R_2, R_3 and R_4 have 1 carbon number.
-4 alkyl groups, and there is no preclude that they are the same. R_5 and R_6 are selected from an alkyl group having 1 to 10 carbon atoms, an arylalkylene group having 2 to 18 carbon atoms, a xylylene group, a cyclohexyl group, or a combination of these groups, and are not necessarily the same. X represents an anion.