JPS61205950A - Image preserving material - Google Patents

Abstract

PURPOSE:To enhance cleanability of a surface layer and to reduce friction resistance and mechanical damage by forming the surface layer of an image preserving material for bearing an electrostatic latent image or a toner image incorporating an F-contg. silane coupling agent. CONSTITUTION:The surface layer is obtained by applying a coating material contg. as an additive for enhancing lubricity of the surface layer an F-contg. silane coupling agent, and above all ones having perfluoroalkyl groups, such as a compd. of the formula shown here, can obtain the highest mold releasability and water repellency and cleanability. Since at the time of drying the coating film a solvent of the coating film begins to evaporate from the surface and said agent is allowed to migrate toward the surface in accordance with the movement of the solvents, the content of the agent is increased in the surface of the coating film, and accordingly, the effect of the modification of the surface can be exhibited.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image holding member for holding an electrostatic image or a toner image.

[Conventional technology]

Electrostatic or toner images are formed by various electrophotographic processes. Image holding members that hold formed images include image holding members that have a photoconductive layer and are called electrophotographic photoreceptors, and image holding members that do not have a photoconductive layer.

Electrophotographic photoreceptors have various configurations depending on the type and location of the electrophotographic process to which they are applied. Typical photoreceptors used in electrophotography include photoreceptors in which a photoconductive layer is formed on a support, and photoreceptors in which a photoconductive layer and its insulating layer are laminated as an image holding layer. It is used.

The electrophotographic photoreceptor is subjected to a predetermined electrophotographic process to form an electrostatic image, which is developed and visualized.

Incidentally, the surface layer of such an image holding member is subjected to various treatments in an electrophotographic process, such as charging, exposure, development,
Subjected to electromechanical processing such as transfer and cleaning.

Therefore, since the photoreceptor is used repeatedly, the surface layer of K must be highly durable against these treatments. In particular, durability against surface damage caused by cleaning is an important item. On the other hand, in addition to the residual toner after transfer, paper dust from the transfer paper and various products caused by ozone generated by corona charging adhere to the surface layer.
If sufficient IJ is not performed, cleaning failure, toner adhesion to the surface layer, and a decrease in surface resistance may occur. Therefore, a surface layer of the image holding member with good cleaning properties is necessary in order to satisfy the repeated durability.

[Problem that the invention seeks to solve]

Therefore, an object of the present invention is to provide an image holding member having a surface layer with excellent surface lubricity and mold releasability1, and as a result, improved cleaning performance. Furthermore, it is an object of the present invention to provide an image holding member in which the frictional resistance of the surface layer is reduced and mechanical damage is reduced.

[Means for Solving the Problems] In order to achieve the object of the present invention, it is preferable to use an additive that improves the lubricity of the surface layer. It is characterized by being contained in the fc surface layer.

The fluorine-containing silane coupling agent is represented by the general formula % (X is a divalent bonding group). As R, for example, the general formula CnH2n+1-mFm (in the formula, n represents an integer of 1 or more, m represents an integer of 1 or more and 2n+1 or less)
Examples include fluorinated alkyl groups represented by

Among these, a silane coupling agent having a perfluoroalkyl group (CnF2n-11) where m=2n+1 has better mold releasability and water repellency than a partially fluorinated alkyl group where 1≦m×2n+1 has better mold releasability and water repellency. It is possible to improve the cleaning properties as described above.

Examples of perfluoroalkylsilane coupling agents include cap, 7ctt2cH2si(ocH3)3, C
6F 17CONH8i (OCHs) s, C6F
15cH2cH2si (OCH5)5, C6F 15
CONH8l(OCHg)3, and the like. In addition to this, Cl0F218i (OCH3)! ,C1
3F 17CH2CH2S i (OCH2CH20C
H5) 3 etc. can also be used.

The surface layer of the image holding member according to the present invention contains the above-mentioned material.

It is formed by applying a layer-forming paint containing a coupling agent. Apply this paint and let it dry
-The solvent in the coating film begins to volatilize from the surface, and as the solvent moves, the fluorine-containing silane coupling agent moves to the surface, so its concentration on the coating film surface is high, thus achieving the effect of surface modification. .

When the surface layer is an insulating layer, this modifier is added to the resin solution in which the insulating layer is to be formed. As the resin, polyvinyl chloride, polyvinyl acetate, copolymers thereof, polystyrene, polyacrylic acid esters, copolymers thereof, 4? Thermoplastic resins such as listerene-acrylonitrile, polyarylate, polysulfone, and polycargonate, and curable resins such as epoxy, urethane, and unsaturated acrylates are used. To these? Dispersions of various powders such as vinylidene litzide, polyethylene, polypropylene, fluororesin, cerium oxide, titanium oxide, aluminum oxide, silicon carbide, and calcium carbonate are also used.

When there is a photoconductive layer under the insulation layer, the photoconductive layer may be CdS, ZnO1Ss, So-Te.
, amorphous silicon, etc. are used.

When the surface layer is a photosensitive layer, a fluorine-containing 7-rank cutting agent is added to the coating material in which the photosensitive layer is to be formed. Materials for forming the photosensitive layer include CdS, ZnO, and S.
e, 5e-To, amorphous silicon, phthalocyanine, oxa-cyazole, ? Examples include ribinylcarpasol, which can be made into a paint together with a binder resin if necessary.

In addition, when using organic photoconductive materials, an effective method for improving properties is to combine a charge generation layer that generates charge carriers upon exposure to light and a charge transport layer that has the ability to move the generated charge carriers. Functions may be separated.

The charge generation layer may contain azo pigments such as Sudan Red and Diane Blue, disazo pigments, quinone pigments such as Algol Yellow, pyrenequinone, and anthantrone, quinocyanine pigments, perylene pigments, i/-)go pigments such as indigo and thioindigo, and Indofast. bisbenzimidazole pigments such as orenzo toner, phthalocyanine pigments such as copper phthalocyanine, aluminum phthalocyanine,
Charge-generating substances such as quinacridone pigments, biryllium salts, and azulenium salts are dispersed in binder resins such as esters, polyvinyl acetate, acrylic resins, polyvinyl butyral, polyvinylpyrrolidone, methylcellulose, hydroxyglopyl methylcellulose, and cellulose esters. It is formed by

Alternatively, it can also be formed by vapor deposition or the like.

The thickness of the charge generation layer is approximately 0.05 to 0.2 μm.

In addition, the charge transport layer has a polycyclic aromatic structure in the main chain or side chain, or indole, carbazole, oxazole, inoxazole, thiazole, imidazole, pyrazole, oxadiazole, pyrazoline, thiadiazole,
It is formed by dissolving a charge-transporting substance such as a compound having a nitrogen-containing cyclic structure such as triazole, a hydrazone compound, or a stilbene compound in a resin having film-forming properties as required. This is because when the charge transporting substance is a low molecular weight substance, it has poor film-forming properties by itself. Such resins include various polycargonates, polyarylates, polystyrenes, polymethacrylates, styrene-methyl methacrylate copolymers, polyesters, styrene-acrylonitrile copolymers, polysulfones, and the like.

The thickness of the charge transport layer is 5 to 20 microns. The fluorine-containing silane coupling agent is used in the charge transport layer when the charge transport layer is formed on the charge generation layer, and in the charge generation layer when the charge generation layer is formed on the charge transport layer. added to.

In any of the above cases, the addition lid is 0 per paint solids.
．． 0.01 to 5% by weight, particularly 0.1 to 2% by weight is suitable. If the amount is too large, the surface becomes brittle and the electrical resistance is decreased, causing problems; if the amount is too small, it is difficult to obtain the effect of surface modification.

〔effect〕

Since the surface layer of the image holding member according to the present invention contains the fluorine-containing silane coupling agent, the cleaning properties thereof are improved. Furthermore, due to the reactivity of the silane coupling agent with the resin or dispersion in the image holding member, there is no tendency for it to separate from the surface, and the durability is improved compared to those using oil or the like.

Example 1 After thoroughly stirring 100 parts of Cd5 powder (parts by weight, same hereinafter) and 12 parts of vinyl chloride-vinyl acetate copolymer resin as a binder in methyl ethyl ketone (MEK) solvent,
Mix well with a μgap roll mill and have a viscosity of 600.
A cP photoconductive paint was prepared. Using this, 80φX
It was applied to a 330m At cylinder using the dipping method and heated to 80℃5.
The photoconductive layer was dried for 40 minutes to form a 40 micron thick photoconductive layer. Next, an n-hexane solution of butyl rubber (trade name Nisu 365, manufactured by Nippon Gosei Rubber Co., Ltd.) was applied on top of this by dipping, and the mixture was heated at 80°C for 50 minutes.
It was allowed to dry for a minute to form a 10 micron thick layer. This is to prevent the subsequent application of an insulating layer from being affected by the photoconductive layer.

On the other hand, 100 parts of AS resin (trade name: Sunrex-C1 manufactured by Mitsubishi Monsanto Chemical) was dissolved in 300 parts of MEK and 200 parts of cyclohexanone. To this, 50 parts of polytetrafluoroethylene (PTFE) (trade name: /'Bron L-2, manufactured by Daikin Industries), 5 parts of polyvinyl butyral resin (trade name: S-LEC BM-2, manufactured by Building Block Chemical Co., Ltd.)
1 part was added, mixed well, and further processed in a sand mill for 1 hour to disperse the PTFE powder in the fat.

This was coated onto the cylinder by a dipping method to a thickness of 12 μm to form an insulating layer. When the thus produced electrophotographic photoreceptor was attached to a copying machine and the image was viewed, it was found to be very good. This copying machine has negative +6 kV corona charging, secondary AC corona charging, simultaneous image exposure, full-surface light irradiation, dry toner development, toner image transfer to plain paper, and urethane rubber blade (2 pieces thick, 30° angle). °, pressure 1011w/c
Cleaning was carried out smoothly. Further, even after a durability test of 50,000 sheets, there was no decrease in cleaning performance and no deterioration in image quality.

However, if 1 part of a silica/coupling agent having a structure of C8F', 7CONH-8i (OCH3)3 is added to the AS resin liquid after dispersing the PTFE powder, and the other parts are manufactured in the same manner, the same durability is obtained. When tested, there was no deterioration in image quality even after 80,000 copies.

Example 2 Copolymerized nylon (product name: CM 8000. East side table)
5 parts, 8 nylon (part name: EF30T, manufactured by Teikoku Kagaku)
5 parts were dissolved in 40 parts of methanol and 40 parts of butanol.

Immerse this liquid in an At cylinder of t-60φ x 300mm.
The coating was coated by the method and dried at 80° C. for 10 minutes to form an undercoat layer with a thickness of 10 μm.

Next, 10 parts of a bisazo pigment having the following structural formula, 8 parts of polyvinyl butyral resin (trade name: Eslec BxL, manufactured by Sekisui Chemical Co., Ltd.), and 60 parts of cyclohexanone were dispersed for 20 hours using a sand mill device using 1φ glass beads. . 100 parts of methyl ethyl ketone was added to this dispersion, which was applied onto the undercoat layer by dip coating, and dried at 100° C. for 5 minutes to form a charge generation layer having a thickness of 0.15 μm.

Next, hydrazone compound 9 having the following structure and 10 parts of AS resin (trade name: Sunrex C2 manufactured by Mitsubishi Monsando Kasei) were dissolved in 70 parts of monochlorobenzene.

This was coated on the charge generation layer and dried with hot air at 100° C. for 1 hour to form a charge transport layer with a thickness of 16 μm.

Adhesion was examined from above the charge transport layer using the crosshatch method, and it was found to be 100/100 with no peeling.

-5,6K
V corona charging, image exposure, dry toner development, toner transfer to plain paper, IJ using a urethane rubber blade (hardness 70°, pressure 5 gw□, angle 20° to photoreceptor)
The electrophotographic characteristics were evaluated by attaching it to an electrophotographic copying machine having a printing process.

Evaluation of electrophotographic characteristics is based on initial potential (Vo) and sensitivity,
The actual electric potential and sensitivity were measured after repeated use 3000 times. Sensitivity is 1/1 the potential when dark decayed for 5 seconds after 6 kV corona charging.
Exposure required to attenuate to 0 El/1G lux・sec)
It was evaluated by measuring. These results are the first
Shown in the table.

Table 1 ■ -6809,8-65010,6 On the other hand, when forming the charge transport layer, 0.1 part of a silane cagging agent with a structure of C9F17CH2CH2Si(OCH5)3 was added, and the other results were produced in the same manner. are shown in Table 2.

As shown in Table 2-6809, 7-68010, and 2-66010, the durability was improved by about 1000 cycles compared to the one without additives.

Claims (4)

[Claims] (1) An image holding member that holds an electrostatic image or a toner image, the surface layer of which contains a fluorine-containing silane coupling agent. (2) The image holding member according to claim 1, wherein the fluorine-containing silane coupling agent is a perfluoroalkylsilane coupling agent. (3) The image holding member according to claim 1, wherein the surface layer is formed on the photoconductive layer. (4) The image holding member according to claim 1, wherein the surface layer is a charge transporting layer containing a charge transporting substance and a resin.