JPH06266144A - Fine powder for surface coating of photosensitive body or cleaning member and image forming method using the same - Google Patents

Abstract

PURPOSE:To provide the fine powder for surface coating for a photosensitive body or cleaning member which can remove residual toners from the surface of the photosensitive body or the surface of a charge applying member, etc., without damaging the surface of the photosensitive body or without generating filmy phenomenon, etc., in a cleaning stage. CONSTITUTION:The fine powder for surface coating of the photosensitive body or the cleaning member is constituted of silicone resin particulates having an amino group or ammonium group. This fine powder for surface coating is supplied to the surface of the photosensitive body outside the developing region in the image forming method having a developing stage for developing the electrostatic latent image on the photosensitive body, a transfer stage for transferring the formed toner image on a transfer material and the cleaning stage for removing the toners remaining on the photosensitive body. The supply of the powder to the surface of the photosensitive body may be executed by direct dusting with a pouch or by coating the cleaning member.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fine powder for surface coating of an electrophotographic photoreceptor or a cleaning member and an image forming method using the same.

[0002]

2. Description of the Related Art In electrophotography, an electrostatic latent image formed on a photoconductor or the like is developed with a developer, toner on the photoconductor is transferred to a transfer material such as paper or sheet, and then heat, The toner is fixed by using a solvent, pressure or the like to obtain a permanent image. At that time, the toner remaining on the photoconductor is cleaned by a cleaning member. Therefore, electrophotography is
In order to complete a system with stable repeatability, it is necessary for each process to function perfectly during copying. In particular, in the cleaning step of the above steps, since the photoconductor and the cleaning member, etc. are in direct contact,
In some cases, scratches on the surface of the photoconductor or damage such as abrasion may be caused, and on the other hand, image defects due to poor cleaning may occur. Therefore, high cleaning performance is required in the cleaning process.

Conventionally, it has been proposed to add various additives to the toner as auxiliary agents in order to improve the fluidity, durability or cleaning property. However, for example, fine powders of inorganic compounds such as silica, titania, and alumina (JP-A-59-226355 and JP-A-61-2).
3160, JP-A-63-118757, JP-A-2-1870, JP-A-2-90175, etc.), the fluidity is remarkably improved but the hardness is high. There are problems that the surface of the photoconductor is likely to be dented or scratched, and that toner is likely to adhere to the scratched portion.

In recent years, the use of recycled paper has increased to save resources, but generally, recycled paper has a problem that a large amount of paper dust is generated. Paper dust and the like enter between the photoconductor and the blade. Induces cleaning failure such as black streaks. In order to solve these problems, a fatty acid metal salt as an additive to the toner (JP-A-54-16219 and JP-A-60-60).
198556), polyolefin (JP-A-61-161).
The external addition of 231562 and Japanese Patent Application Laid-Open No. 61-231563) has been studied. In each of the fatty acid metal salts and polyolefins disclosed in the above publications, the particle size of the additive is as large as 3 to 20 μm,
In order to efficiently bring out the effect, a considerable amount of addition is required. Furthermore, although these additives (lubricants) are initially effective, film formation as a lubricant is not uniform due to the filming unique to the additives, which causes white spots and image blurring in images. There's a problem.

On the other hand, the coating of the surface of the photoconductor with a resin fine powder of a homopolymer or a copolymer of acrylic acid ester monomer, methacrylic acid ester monomer, styrene-based monomer, etc. (Japanese Patent Publication No. 2-3188) is examined. Has been done. However, recently, the copying speed tends to be higher, and the stress (load, speed) applied to the photoconductor at the time of cleaning is also increased accordingly.
The resin fine powder is deformed by the stress during cleaning and causes problems such as filming. Further, there is a problem in that the polarity of the photoconductor that can be used is limited due to the charging polarity of the resin itself.

Further, in order to reduce the stress at the time of cleaning, a method of externally adding silicone resin fine particles to the toner has been reported (JP-A-64-49052, JP-A-1-106073, JP-A-1-106073). 1-293
354, JP-A-2-55367, etc.).

However, the addition of silicone resin fine particles to the toner is a very effective means for improving the cleaning property, but in general, since the silicone resin has an extremely strong negative polarity, various problems occur. . For example,
When the silicone resin fine particles are added to the positively chargeable toner, the strong negative polarity of the silicone resin hinders the positive chargeability of the toner and causes defects such as fog on the copy image. Also, when added to the negatively chargeable toner,
In the two-component developer, the silicone resin fine particles are electrostatically attracted to the carrier in the one-component developer and to the charging member to cause adhesion, fusion, etc., which causes the reverse charging capability, thereby lowering the toner charge. Therefore, there is a problem that image quality defects such as fogging occur.

[0008]

SUMMARY OF THE INVENTION The present invention has been made for the purpose of overcoming the above-mentioned problems of the prior art. That is, an object of the present invention is to remove residual toner without damaging the surface of the photoreceptor in the cleaning step and without causing the filming phenomenon or the like on the surface of the photoreceptor or the surface of the charging member. Another object is to provide a fine powder for coating the surface of the cleaning member. Another object of the present invention is to provide an image forming method using the fine powder for surface coating.

[0009]

Means for Solving the Problems As a result of various studies, the inventors of the present invention have achieved the above object by using a silicone resin having an amino group or an ammonium group as a fine powder for coating a surface of a photoreceptor or a cleaning member. They have found what can be achieved and have completed the present invention. That is, the fine powder for surface coating of the photoconductor or the cleaning member according to the present invention is characterized by comprising silicone resin fine particles having an amino group or an ammonium group. The image forming method of the present invention includes a developing step of developing an electrostatic latent image on a photoconductor, a transfer step of transferring the formed toner image onto a transfer material, and a cleaning step of removing toner remaining on the photoconductor. And the above-mentioned fine powder for surface coating is supplied to the surface of the photoconductor outside the developing area.

The present invention will be described in detail below. The fine powder for coating the surface of the photosensitive member or the cleaning member in the present invention is composed of silicone resin fine particles which have an amino group or an ammonium group and are appropriately charged. In the present invention, the silicone resin having an amino group or an ammonium group (hereinafter referred to as “amino group-containing silicone resin”) fine powder has a spherical shape and an average primary particle diameter of 0.05 to 3.0 μm. Those are preferable.

In the present invention, various amino group-containing silicone resins can be used. As the silicone resin used for having an amino group or an ammonium group, various commercially available silicone resins for modification can be used. By polycondensing polysiloxane obtained by cohydrolyzing organosilanes. Obtainable. For example, a silicone resin having a methyl group and a phenyl group can be obtained by cohydrolysis and polycondensation of dimethyldichlorosilane and phenyltrimethylsilane.

Any known method may be used as a method for providing these silicone resins with an amino group or an ammonium group. For example, a method of adding an alkoxy group- or hydroxyl group-containing amino-modified siloxane oligomer, for example, a siloxane oligomer obtained by hydrolysis of aminoalkylmethyldimethoxysilane to the above silicone resin and reacting with the hydroxyl group of the silicone resin,
Alternatively, a method called a cold blending method in which the amino group-containing siloxane is simply mixed with a silicone resin can be adopted. Further, an organosilane having an amino group can be used together during the synthesis of the silicone resin.

As the amino group introduced into the silicone resin or the siloxane oligomer, --NH ₂ ,> NH,
A group such as —NHR, —N (R) ₂ , —NHOH,> NOH (in the formula, R represents an alkyl group, a substituted alkyl group or an aryl group), or an ammonium group shown on the next page. Is, for example, an aminopropyl group, N- (β
-Aminoethyl) iminopropyl group, aminophenoxymethyl group or ammonium salt thereof and the like are linked to the polysiloxane skeleton.

[Chemical 1]

The image forming method of the present invention, in which the fine powder for surface coating comprising the above-mentioned amino group-containing silicone resin of the present invention is used, is a development step of developing an electrostatic latent image on a photoreceptor.
It has a transfer step of transferring the formed toner image to a transfer material, and a cleaning step of removing the toner remaining on the photoconductor.

The photoconductors used in the above-mentioned image forming method of the present invention include Se-based photoconductors, organic photoconductors, amorphous silicon photoconductors, and those having a coating layer provided on the surface thereof, if necessary. Any known material can be used. In the developing step, any known one such as a one-component developing machine and a two-component developing machine can be used. The toner used is not limited to a two-component toner containing a binder resin and a colorant as essential components, a magnetic one-component toner containing a magnetic material, or a capsule toner, but its average particle size is not limited. Is 30 μm or less, particularly 3 to 20 μm
It is preferable to set in the range of. Further, when the toner is used as a two-component developer, the carrier used is not particularly limited as long as it is a known carrier, and iron powder type carrier, ferrite type carrier, surface coated ferrite type carrier, magnetic powder dispersion A mold carrier or the like can be used. Further, in the clining step, a blade cleaning method by pressure bonding of a blade, a fur brush cleaning method, or any other known method may be adopted.

In the image forming method of the present invention, the surface coating fine powder of the present invention may be supplied to the surface of the photoreceptor outside the developing area. Various methods are used to supply the surface coating fine powder to the surface of the photoreceptor outside the developing area. For example, the surface coating fine powder may be directly supplied to the surface of the photosensitive layer from the outside of the image forming apparatus. For example,
It is sufficient to put fine cleaning powder in a small sack pouch and dust it directly onto the surface of the photoreceptor. As a result, the surface of the photoconductor is coated with the fine powder for surface coating.

Further, the cleaning member may be dusted by the pouch. That is, as the cleaning member in the cleaning step, when one or both of the brush and the blade is used, dusting may be performed using the above pouch on at least one of the brush and the blade, thereby, During cleaning, fine powder for surface coating is supplied to the surface of the photoconductor to coat the surface of the photosensitive layer. Further, in front of the cleaning member provided in the image forming apparatus, a web or sponge roll to which the fine powder for surface coating is attached is disposed,
Fine particles for surface coating may be supplied to the surface of the photoreceptor during cleaning.

[0018]

EXAMPLES The present invention will be specifically described below with reference to examples. In addition, in an Example, "part" means a "weight part." (Preparation example of developer) Preparation of toner Styrene-butyl acrylate copolymer (80/20) 100 parts Carbon black (R330; Cabot Corp.) 10 parts Low molecular weight polypropylene (Viscor 660P; Sanyo Chemical Co., Ltd.) 5 parts Charge control agent (P-51; manufactured by Orient Chemical Industry Co., Ltd.) 2 parts The above components are melt-kneaded in a Banbury mixer, cooled, finely pulverized by a jet mill, and classified by a classifier to obtain toner particles having an average particle diameter of 11 μm. Obtained. To 100 parts of this toner, 2 parts of titanium dioxide fine powder having an average primary particle diameter of 0.05 μm was added and dispersed and mixed by a Henschel mixer to obtain a toner. Preparation of carrier Styrene-butyl acrylate copolymer (70/30) 100 parts Magnetite (EPT-1000; manufactured by Toda Kogyo Co., Ltd.) 200 parts Polyvinylidene fluoride (KYNAR; manufactured by Penn Walt) 5 parts Pressure kneader for the above components Melt kneading with, further pulverizing and classifying using a turbo mill and a classifier to obtain an average particle size of 5
A carrier of 0 μm was obtained. Preparation of Developer A two-component developer was prepared by mixing 5 parts of the toner and 95 parts of the carrier.

Example 1 (Amino group-containing silicone resin fine particles used) Water 18
After stirring and mixing 00 g and 90 g of methyltrimethoxysilane for 30 minutes in a flask at 5 ° C. or lower, 39.2 g of ammonia water having a concentration of 30% was added and mixed for 10 minutes with stirring. Furthermore, while maintaining the temperature, 245.1 g of methyltrimethoxysilane was gradually added over 1 hour,
Mixture 3 of methyltrimethoxysilane and N- (β-aminoethyl) γ-aminopropyltrimethoxysilane 3
6 g (mixing ratio 35: 1) was gradually added over 10 minutes.
After the addition was completed, the mixture was stirred for 2 hours, then heated to 60 to 65 ° C. and stirred for 30 minutes to obtain a product. The product was filtered under pressure, and the residue was dried with a hot air dryer to give an average particle size of 0.3.
Amino group-containing silicone resin fine particles having a size of μm were obtained. (Image forming method) Dusting is performed on the surface of the photoreceptor of a modified Vivace 800 (manufactured by Fuji Xerox Co., Ltd.) using a pouch (a sack made of sack cloth) containing the above-mentioned amino group-containing silicone resin fine particles, and the surface of the photoreceptor is amino-coated. The group-containing silicone resin fine particles were adhered and coated. Then, according to an electrophotographic method, an electrostatic latent image is formed by a conventional method, then a toner image is formed using the above developer, and the image is formed by transferring the toner image onto copy paper. The amount of wear and the image quality defect of the image were evaluated. The results are shown in Table 1.

Example 2 A copying test was conducted in the same manner as in Example 1 except that the aminoalkyl group-containing silicone resin fine particles of Example 1 were attached to a cleaning brush instead of being attached to the surface of the photoconductor. The results are shown in Table 1.

Example 3 A copying test was conducted in the same manner as in Example 1 except that the aminoalkyl group-containing silicone resin fine particles of Example 1 were attached to a cleaning blade instead of being attached to the surface of the photoreceptor. The results are shown in Table 1.

Example 4 A copying test was conducted in the same manner as in Example 1 except that the aminoalkyl group-containing silicone resin fine particles of Example 1 were attached to a cleaning brush and a cleaning blade instead of being attached to the surface of the photoconductor. It was The results are shown in Table 1.

Example 5 The amino group-containing silicone resin fine particles of Example 1 were adhered to the cleaning brush and cleaning blade of a modified Vise 800 (manufactured by Fuji Xerox Co., Ltd.),
Further, a copying test was carried out in the same manner as in Example 1 except that the pouch containing the amino group-containing silicone resin fine particles was used to perform dusting so that the particles were also attached to the photoconductor. The results are shown in Table 1.

Comparative Example 1 A copying test was conducted in the same manner as in Example 1 except that the amino group-containing silicone resin fine particles were not attached to the surface of the photoconductor. The results are shown in Table 1. Comparative Example 2 A copying test was conducted in the same manner as in Example 1 except that the methyl methacrylate-styrene copolymer (50:50) fine particles having an average primary particle diameter of 0.5 μm were attached to the cleaning brush and the cleaning blade. . The results are shown in Table 1.

Comparative Example 3 A copying test was conducted in the same manner as in Example 4 except that polyvinylidene fluoride fine particles having an average primary particle diameter of 0.3 μm (KYNAR; manufactured by Penn Walt) were attached to the cleaning brush and the cleaning blade. It was The results are shown in Table 1. Comparative Example 4 Amorphous silica fine particles having an average primary particle diameter of 16 nm (R972;
A copying test was conducted in the same manner as in Example 4 except that the (Japan Aerosil Co., Ltd.) was attached. The results are shown in Table 1.

The test method and evaluation criteria in the above copy test are as follows. (1) Cleaning Performance A black belt having a width of 5 cm was subjected to blade cleaning in a 999-sheet mode × 3 times in a non-transferred state. This evaluation is a stress test. G1 to G3 cause no problem during normal copying, and G4 to G5 cause cleaning failure during normal copying. G1: The toner on the surface of the photoconductor could be cleaned without any problem. G2: When the number of sheets was 2500 or more, some cleaning failure occurred. G3: A cleaning failure occurred on 1500 to 2499 sheets. G4: A cleaning failure occurred on 500 to 1499 sheets. G5: A cleaning failure occurred on 499 sheets or less. (2) Abrasion amount of the photoconductor After taking 100,000 copies, the abrasion amount of the photoconductor was measured. (3) Image Quality Defects 100,000 copies were taken, and the image quality of the copies and defects on the surface of the photoconductor were observed. No problem: Image quality defects and scratches on the surface of the photoconductor were not observed between 100,000 copies and after 100,000 copies (black spots, black streaks, fog, etc.). * 1: About 800 copies produced black streaks due to cleaning and black spots due to photoconductor scratches. * 2: Black streaks occurred due to filming after copying about 1000 sheets. * 3: Black streaks due to cleaning and black spots due to photoconductor scratches occurred after copying about 200 sheets.

[0027]

[Table 1]

[0028]

Since the fine powder for surface coating of the photoreceptor or cleaning member of the present invention is a silicone resin having an amino group or an ammonium group, it is appropriately charge-controlled, and therefore the silicone resin main body It does not cause troubles caused by its extremely strong negative polarity, adhesion and fusion to a carrier or a charge-imparting member, fog on a copy image, and the like, and does not damage the photoreceptor surface in the cleaning step, and Photoconductor surface,
Alternatively, it does not cause the filming phenomenon on the surface of the charging member, etc., and exhibits an excellent effect of removing the residual toner.
Therefore, according to the image forming method of the present invention, it is possible to obtain a copy image with good image quality for a long period of time.

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[Procedure amendment]

[Submission date] March 24, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction content]

As the amino group introduced into the silicone resin or the siloxane oligomer, --NH ₂ ,> NH,
Examples include groups such as —NHR ¹ , —N (R ¹ ) ₂ , —NHOH, and> NOH (in the formula, R ¹ represents an alkyl group, a substituted alkyl group or an aryl group), or an ammonium group shown below. , They are, for example, aminopropyl groups, N
It is linked to the polysiloxane skeleton in the form of a-(β-aminoethyl) iminopropyl group, an aminophenoxymethyl group or its ammonium salt.

[Chemical 1]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yusuke Ishihara 1600 Takematsu, Minamiashigara City, Kanagawa Prefecture Fuji Xerox Co., Ltd.

Claims (3)

[Claims] 1. A fine powder for surface coating of a photoreceptor or a cleaning member, comprising fine silicone resin particles having an amino group or an ammonium group. 2. A developing step of developing an electrostatic latent image on a photoreceptor, a transferring step of transferring the formed toner image to a transfer material,
An image forming method comprising a cleaning step for removing toner remaining on a photoconductor, wherein the surface-coating fine powder according to claim 1 is supplied to the surface of the photoconductor outside the developing region. 3. In the cleaning step, a brush and / or a blade are used as a cleaning member,
The image forming method according to claim 2, wherein the fine powder for surface coating according to claim 1 is attached to at least one of the brush and the blade.