JPH11174872A - Transfer member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide such a transfer member that melt sticking of toner to an image carrying body, accumulation of the toner on the transfer member and cleaning property are improved. SOLUTION: Relating to this transfer member 10 which transfer a toner image formed on a photoreceptor to the body to be transferred by bringing the transfer member into contact with the body to be electrified and applying voltage between the member and the body to be transferred, the transfer member 10 has a conductive elastic layer 14 containing nonocrosslinked acryl resin particles 16 formed on a supporting body 12. It is preferable that particles 16 has 0.1 to 30 μm particle size and has positive or negative electrification property.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer member, and more particularly to a transfer member for transferring a toner image formed on a photoreceptor to a transfer target such as plain paper by applying a voltage.

[0002]

2. Description of the Related Art Conventionally, in an electrophotographic system of a printer such as a copying machine, first, the surface of a photoconductor is uniformly charged, and a latent image is formed on the photoconductor by receiving an image from an optical system. In general, an image forming method is used in which the toner is developed according to the following formula, and the formed toner image is transferred onto a sheet.

[0003] As the transfer method for transferring a toner image has been adopted various ones, for example, in the corotron discharge system it is necessary to apply a 5~10KV voltage as high as ozone, NO _x, etc. sulfide Of harmful substances,
There is an environmental problem.

In recent years, a contact transfer method has been developed which uses a conductive rubber roller in which conductive particles such as carbon or an electrolyte such as an alkali metal salt or a quaternary ammonium salt are dispersed. It is possible to solve various problems so far with less generation of ozone.

However, the conductive rubber roller tends to electrostatically attract the oppositely charged particles of the toner, and the roller directly contacts the photoreceptor at rest and between the sheets to be transferred. As a result, the residual toner of poor cleaning, adhered or fused toner, etc. remaining on the photoreceptor easily adheres to the transfer roll, causing problems such as a decrease in transfer characteristics, an increase in resistance, and a decrease in paper transportability. Was revealed.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and in addition to saving labor, accumulating discharge products due to generation of ozone, fusing toner to an image bearing member, and preventing toner accumulation on a transfer member. It is another object of the present invention to provide a transfer member having improved cleaning properties.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, have found that the conductive layer has a particle size of 0.3.
By dispersing the particles of 1 to 30 μm, it was found that the electrostatic adhesion and accumulation of the toner to the transfer member, the decrease in the paper transportability were reduced, and a transfer member with a small resistance reduction was obtained, and the present invention was completed. .

That is, the transfer member of the present invention is brought into contact with the member to be charged, and by applying a voltage between the member and the member to be transferred,
A transfer member for transferring a toner image formed on a photoreceptor to a transfer-receiving member, wherein the transfer member has a conductive elastic layer on which a particle made of a non-crosslinked type acrylic resin is arranged on a support. It is characterized by.

Here, the particle size of the particles is 0.1 to 30 μm.
m, and preferably has a positive charging property or a negative charging property by being charged by a surface treatment or the like.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

[0011] The transfer member of the present invention is provided with a conductive elastic layer (hereinafter referred to as a conductive layer) on a support.
In the conductive layer, particles made of a non-crosslinked type acrylic resin are dispersed and arranged.

The above-mentioned particles are particles of a non-crosslinking type acrylic resin having a reverse charge in accordance with the charging property of the toner. By dispersing into layers,
When the matrix is a foam, or when the matrix is a foam, the toner is effectively prevented from adhering and accumulating on the surface of the foam inside the roll of the matrix material such as an elastomer constituting the conductive layer.

This acrylic resin must be of an uncrosslinked type. In other words, the uncrosslinked acrylic resin is excellent in compatibility with various elastomers constituting the matrix, does not suffer from deterioration of permanent set, is excellent in dispersibility in liquid, miraple type resin, elastomer, etc., from the surface etc. Because of the excellent processability, the above-mentioned excellent properties can be exhibited even by adding a small amount.

The acrylic resin in the present invention includes those obtained by polymerizing acrylic acid and its derivatives.
Polyacrylic acid, polyacrylic acid ester, polymethacrylic acid, polymethacrylic acid ester, polyacrylamide, polyacrylonitrile and the like, but processability,
From the viewpoint of the effect, an uncrosslinked type of polymethacrylic acid or polymethacrylic acid ester is preferable.

Preferred physical properties of the uncrosslinked acrylic resin include that it is insoluble in polyol and the extraction amount with acetone is 5% or more. Due to this physical property, there is no reactivity with the isocyanate component, it is uniformly dispersed in an elastomer such as urethane, and is not agglomerated on the foam surface. It can be used for rubber tubes and the like, and exhibits the same performance for millable rubber.

The acrylic resin particles suitably used in the present invention are, for example, acrylic fine particles MP-2 manufactured by Soken Chemical Co., Ltd.
It is also available as commercial products such as 701, MP-1000 and MP-1400.

On the other hand, even if the same acrylic resin is used, as described in Japanese Patent Application Laid-Open No. Hei 7-152222, crosslinked acrylic particles have poor dispersibility in a resin having low compatibility, so that the chargeability due to uneven distribution is reduced. There is concern about the impact and partial reduction of the effect.

The particle size of the particles is 0.1 to 30 μm.
It is preferred that If the particle size exceeds 30 μm, problems such as abrasion of the photoreceptor, deterioration of the toner fusing characteristics, and generation of reverse charge due to triboelectric charging of the photoreceptor occur. Cannot be uniformly dispersed, and none of them can exhibit the effects of the present invention.

For example, Japanese Patent Application Laid-Open No. 7-15222 mentioned above
The particle size of the particles contained in the charging member described in Japanese Patent Publication No. 2 is
Although the particle size is 35 to 100 μm, since the particles to be blended are larger than the particles of the toner, the chargeability may be changed. Since it has a low amount and a large amount of addition, problems such as workability occur.

The amount of the particles to be added to the conductive layer is not particularly limited and can be appropriately selected according to the purpose. Generally, the amount of the elastomer or polymer forming the conductive layer such as a foamed elastic body or a surface elastic body is generally used. The amount is preferably 3 to 50 parts by weight, more preferably 5 to 30 parts by weight, based on 100 parts by weight of such a matrix component. If the amount is more than 50 parts by weight, problems such as workability and problems such as deterioration of surface cleaning properties may occur. If the amount is less than 3 parts by weight, the effect of preventing adhesion of the toner is reduced.

Further, the particles used in the present invention are preferably chargeable particles having either positive (+) chargeability or negative (-) chargeability, from the viewpoint of the effect of preventing electrostatic adhesion of the toner. In particular, those having the opposite chargeability to the chargeability of the toner used are preferable from the viewpoint of the effect. It is possible to suppress adverse effects due to toner adhesion to the inner surface of the foam or the surface of the elastic body, and maintain stable transfer performance.

Next, another configuration of the transfer member of the present invention will be described. FIG. 1 is a schematic sectional view showing one embodiment of the transfer member of the present invention, and FIG. 2 is a schematic perspective view thereof. A transfer roller 10 serving as a transfer member forms a conductive elastic layer 14 made conductive by dispersing a quaternary ammonium salt in urethane foam serving as a matrix around a stainless steel (SUS) core 12 serving as a support. It becomes. In the conductive elastic layer 14, particles 16 made of an acrylic resin
Are distributed.

The conductive layer of the present invention needs to contain conductive powder, and a polymer material is used as a substrate material for forming the conductive layer. This conductive elastic layer may be a foam or a solid layer containing no air bubbles, and a polymer material that can be used as a matrix constituting this layer does not impair the function as a conductive layer. There is no particular limitation as long as it is a known polymer compound, that is, a resin, a plastic, an elastomer, a rubber, and the like, which can be appropriately selected depending on the purpose. Examples thereof include natural rubber and isoprene rubber. , SBR, BUR, butyl rubber, ethylene propylene rubber, ethylene propylene terpolymer, chloroprene rubber, chlorosulfonated polyethylene, chlorinated polyethylene, NBR, urethane rubber, syndiotactic 1,2-polybutadiene, epichlorohydrin rubber, acrylic rubber, silicone rubber,
Fluorine rubber, polysulfide rubber, polynorbornene rubber, hydrogenated nitrile rubber, thermoplastic elastomer (polystyrene, polyolefin, polyvinyl chloride, polyurethane, polyamide, polyester, fluororesin), phenolic resin, epoxy resin , Polyester resin, polyester polyurethane resin, vinyl acetate resin,
Polyvinylidene chloride, ionomer resin, polyether urethane resin, polyvinyl butyral resin, polyamide resin and the like can be mentioned.

The rubber material, elastomer, and resin used for the conductive layer are not limited to those described above. In particular, a liquid polymer material that can be centrifugally molded, cast, and press-molded, or a suitable organic material. A polymer material dissolved in a solvent is preferred.

When the conductive layer of the present invention is a foamed layer,
Preferable examples of the matrix include a polyurethane foam, a silicone resin foam, and a liquid polybutadiene rubber foam.

Examples of the polyether polyol monomer of the polyol component of the polyurethane foam include polyoxyalkylene glycols such as polyoxypropylene glycol, polyoxyethylene glycol, polyoxybutylene glycol, and polyoxytetramethylene glycol, and polyoxypropylene. Polyoxyalkylene triols such as triol, polyoxypropylene polyoxyethylene triol, polyoxybrylene triol, etc., polyoxypropylene polyols and polyoxypropylene poly with ethylenediamine, pentaerythritol, sorbitol, sucrose, starch, etc. as initiators Poly (oxyalkylene) polyols such as oxyethylene polyol are exemplified. Examples of the polyester polyol compound monomer of the polyol component include polycarbonate polyol, polycaprolactone ester polyol, and glycol 1 such as ethylene glycol, diethylene glycol, 1,5-pentanediol, 1,3-hexanediol, and neopentyl glycol.
A mixture of two or more species or two to six carbon atoms such as adipic acid
And polyester polyols obtained by reacting the above with a dicarboxylic acid, but the polyol component is not limited to the above.

As the isocyanate component of the polyurethane foam, aromatic isocyanates such as tolylene diisocyanate (TDI), meta-xylene diisocyanate, diphenylmethane diisoanate (MDI), polymethylene polyphenyl diisocyanate, and fatty acids such as hexamethylene diisocyanate. Group isocyanates, prepolymer-modified isocyanates, and blocked isocyanates obtained by blocking these isocyanate compounds with phenol, aromatic secondary amines, tertiary alcohols, amides, lactams, heterocyclic compounds, sulfites, and the like.
Adjusted to 80 to 1.20, preferably 0.98 to 1.0
9 and the like.

It is particularly preferable to use a urethane foam as a matrix of the foam. By using a urethane foam, a stable foaming state can be maintained, and as a result, image uniformity can be obtained. By using a foaming method using water as a foaming agent or a mechanical foaming method using a mixture of nitrogen, air, or the like, heat generation can be suppressed, foam breakage and open cell formation can be reduced, distortion can be reduced, and further lower hardness can be obtained. Foaming hardness (Asker C hardness) is 3 to 60 degrees, and more preferably 5 to 20
It is preferable to set the temperature. In addition, the urethane foam has a small permanent set, has little dent, distortion, deformation and the like due to repeated use, has stable dimensional accuracy, and can reduce the frequency of replacement of the transfer member.

In order to impart conductivity to the conductive layer, a conductive powder such as carbon black or an ionic conductive agent such as an alkali metal or an organic electrolyte is added. The conductive powder can be appropriately selected from those used as electron conductors. Examples of preferable electron conductors include conductive carbon black, conductive metal oxide, graphite, and metal (copper). , Al, Ni, silver, etc.)
And conductive polymers (polyaniline, polypyrrole, polythiophene, polyacene, polyazulene, polydiphenylbenzidine, polyvinylcarbazole, poly-3-alkylthiophene, and the like).

Examples of the ionic conductive agent include metal salts and quaternary ammonium salts. As a metal salt, I
Group II and Group II metal salts are preferable, and salts of Li, Na, and K are preferable. Anions constituting the metal salt include halogen (F, Cl, Br, I), thiocyanate ion, perchlorate ion, and trifluorofluoride. Methanesulfonate ion, fluoroborate ion, phosphate ion and the like.

Examples of the quaternary ammonium salts include ammonium such as carboxylic acid (adipic acid, phthalic acid, azelaic acid, etc.), phosphoric acid, boric acid, sulfonic acid (aryl sulfonic acid, etc.), borofluoric acid, perchloric acid, etc. Salts.

The amount of the conductive powder in the conductive layer is 1 to 200% by weight, preferably 3 to 100% by weight, based on the solid content of the polymer material as the matrix.
The resistance can be adjusted to Ωcm.

The preferred amount of the ionic conductive agent is as follows:
0.001 to 10% by weight, more preferably 0.003 to 2% by weight, based on the solid content of the polymer material;
The resistance adjustment of logΩcm is possible. Also, if the resistance is 10
When adjusting to ³ to 10 ⁶ Ω · cm, it is possible to further add a resistance control agent and to use carbon black or the like in combination.

The conductive layer of the transfer member is 0.5 mm to 100 m
m, 5 to 10 m by adjusting the injection amount of polyurethane
m is preferable.

In the transfer member of the present invention, it is preferable to provide a conductive release layer on the conductive layer from the viewpoints of preventing toner from adhering to the surface and improving the transportability of the transfer object.

As the conductive release layer, it is preferable to use a conductive paint containing fine powder of, for example, tetrafluoroethylene resin (PTFE), which gives release properties. In particular, when a transfer member having a conductive release layer containing a fine powder such as PVdF, PTFE, or Teflon is used for at least the outermost surface layer, higher secondary transfer efficiency can be obtained. This is presumably because the surface energy of the transfer member is reduced and the releasability of the toner is improved when the outermost surface layer contains PTFE fine powder.

As the high release resin used for the conductive release layer on the surface, a silicone resin, a fluorine resin, a fluorosilicone resin, an ethylene-vinyl acetate copolymer, a polyacetal resin, a polyphenylene sulfide resin, or the like is used. Can be. Further, the fine powder of the high release resin may be mixed and dispersed in another thermosetting resin (urethane resin, polyester resin, epoxy resin, etc.) and used as the high release resin.

As the conductive powder added for imparting conductivity, ketjen black, acetylene black, zinc oxide, antimony-doped tin oxide, titanium oxide, carbon fiber and the like are used. When these resistance control agents (conductive powders) are added to the coating for forming the conductive release layer, they are added in an amount of 1 to 200% by weight, preferably 3 to 100% by weight, based on the resin solid content of the coating. The resistance is adjusted to 10 logΩcm. This conductive release layer has a thickness of 1 to 100 μm.
m, preferably 20 to 40 μm.

The volume resistance of the transfer member of the present invention is 10 ⁴ -1.
0 ¹³ Ω · cm, particularly 10 ⁶ to 10
It is preferably ¹⁰ Ω · cm. Further, at least the volume resistivity of the surface layer is preferably in these ranges.

The support on which these layers are formed is not particularly limited, and any general-purpose transfer member support can be used. The support may be flat or cylindrical depending on the shape of the transfer member. In a continuous image forming apparatus, the transfer member is generally in the form of a roll. As the material, for example, as the cylindrical metal support, a metal or alloy such as aluminum, iron, copper, and stainless steel, a conductive resin in which conductive carbon black, metal oxide particles, and the like are dispersed can be used.

The transfer member of the present invention can be manufactured by a conventional method. That is, for example, after coating or casting a polymer matrix material containing a conductive substance and acrylic resin particles on a metal support, cured to form a conductive layer, and then, if desired, a conductive release layer. It can be manufactured by a forming method or the like. It is desirable that the conductive release layer can be formed to a desired film thickness by crosshead molding using tubing or the like, spraying, surface coating using a dispenser, or the like, dip coating, or the like.

The transfer member of the present invention can be described for an image forming apparatus as described below. FIG. 3 is a schematic diagram of an image forming apparatus 20 using the transfer member 10 of the present invention. The image forming apparatus 20 charges the OPC photosensitive drum 22 with a primary charging roller 24 as a charging device,
A latent image is formed by performing image exposure using a laser beam 26, and a toner image is formed by a developing device 29 having a developing roller 28. The toner image on the surface of the photoreceptor 22 is conveyed to a transfer position, and a voltage is applied to the transfer target (plain paper) 30 by a fixing roller 10 as a fixing member, so that the toner image is transferred to the plain paper 30. The image is fixed and formed. The untransferred toner is OP (not shown).
Removed by C cleaner.

By incorporating the charging member 10 of the present invention into such an image forming apparatus 20, it is possible to effectively prevent the toner from being fused to the image carrier by the function of the charging member. Deterioration of transfer characteristics due to reduction in toner adhesion, increase in resistance over time, and prevention of electrostatic adhesion of the oppositely charged toner to the inside of the foam are prevented, and the maintainability of the paper transportability is improved. For this reason, the transfer member of the present invention can be widely used for electrophotography and electrostatic processes of copying machines, printers and the like.

[0044]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, “parts” in the examples means “parts by weight”. (Embodiment 1) FIG. 2 is a schematic sectional view showing the structure of the transfer roller of this embodiment. The transfer roller 10 has a conductive elastic layer 1 made conductive by dispersing a quaternary ammonium salt as a conductive substance in a urethane foam as a matrix around a stainless steel (SUS) core 12 as a support.
4 is formed.

A stainless steel support was used as a core material, and 100 parts of a liquid polyurethane prepolymer (Takenate L1290 manufactured by Takeda Pharmaceutical Co., Ltd.) was mixed with 2 parts of carbon black (Ketjen Black, manufactured by Mitsubishi Chemical Corporation) and particle size. 0.4
μm uncrosslinked acrylic fine particles (MP-2701,
10 parts (positive chargeability, manufactured by Soken Chemical Co., Ltd.) are added during the kneading and compounding step, and the mixture is cast around the core material 12 and heated (130 ° C. × 3).
0 minutes), and simultaneously solidified at the time of vulcanization and foaming, thereby forming a conductive layer having a thickness of 3 mm on the support to obtain a transfer roller (transfer member). (Example 2) Instead of acrylic fine particles (MP-2701, positively chargeable, manufactured by Soken Chemical Co., Ltd.), non-crosslinked type acrylic fine particles (MP-1000, negatively charged, 0.4 μm in diameter) were used as the acrylic resin particles to be blended. A transfer member was obtained in the same manner as in Example 1 except for using Soken Chemical Co., Ltd.). (Example 3) Using a stainless steel support as a core material, 100 parts of ethylene propylene rubber (Mirable EPDM33, manufactured by Nippon Synthetic Rubber Co., Ltd.) and 35 parts of carbon black (Furness Black FW-200, manufactured by Degussa) and particle size 1.
5 μm uncrosslinked acrylic fine particles (MP-140
(0, negatively chargeable, manufactured by Soken Chemical Co., Ltd.), 10 parts were added during the kneading and compounding step, and the mixture was poured around the core material 12 and heated (130 ° C.).
× 30 minutes) and simultaneously solidified at the time of vulcanization and foaming, thereby forming a conductive layer having a thickness of 3 mm on the support to obtain a transfer roller.

(Comparative Example 1) As the resin particles to be blended, instead of acrylic fine particles (MP-2701, manufactured by Soken Chemical), crosslinked acrylic particles (MR-
A transfer member was obtained in the same manner as in Example 1 except that 60G, negative chargeability, manufactured by Soken Chemical Co., Ltd. was used. (Comparative Example 2) As the resin particles to be blended, instead of acrylic fine particles (MP-2701, positive chargeability, manufactured by Soken Chemical),
Spherical type silicone particles having a particle size of 13 μm (KMP5
98, negative charging property, manufactured by Shin-Etsu Chemical Co., Ltd.), and a transfer member was obtained in the same manner as in Example 1.

The transfer members thus obtained in Examples and Comparative Examples were incorporated in the image forming apparatus shown in FIG. 3, and a magnetic two-component developer (particle size: 12 μm, negative chargeability, manufactured by Kao Corporation) was used as toner. After continuously forming an image at 300 kpv (print volume) under the conditions of 22 ° C. and 55% RH, the transfer member was taken out, and the state of toner adhered to the surface was visually observed. Was evaluated.

Δ: No toner adhered Δ: A small amount of toner adhered (no practical problem) ×: Toner adhered (practical problem) The results are shown in Table 1 below.

[0049]

[Table 1]

As is clear from Table 1, in the transfer member of the present invention, there is no adhesion of the toner to the transfer roller, and the prevention of the adhesion of the toner and the fusion of the toner from the transfer roller to the photosensitive member are effective. Was found to be prevented. On the other hand, it was found that a transfer member containing cross-linkable acrylic resin particles or silicone particles could not achieve the toner adhesion preventing effect.

[0051]

According to the transfer member of the present invention, fusion of toner to the image carrier and accumulation of toner in the transfer member are effectively prevented, and a transfer member having improved cleaning performance is obtained.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an image forming apparatus using a transfer member of the present invention.

FIG. 2 is a schematic sectional view showing a transfer member used in the embodiment of the present invention.

FIG. 3 is a schematic perspective view showing a transfer member used in the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Transfer member (transfer roller) 12 Metal support 14 Conductive layer 16 Acrylic resin particle 20 Image forming apparatus 22 OPC photosensitive drum. 24 Primary Charger 26 Laser Beam (Image Exposure) 28 Developing Roller 29 Developing Device 30 Transferred Object (Plain Paper)

Claims (3)

[Claims] 1. A transfer member for transferring a toner image formed on a photosensitive member to a transfer member by applying a voltage between the transfer member and the transfer member by bringing the transfer member into contact with the transfer member. The transfer member has a conductive elastic layer on which particles made of a non-crosslinked type acrylic resin are arranged on a support. 2. The transfer member according to claim 1, wherein said particles have a particle size of 0.1 to 30 μm. 3. The transfer member according to claim 1, wherein the particles have a positive charging property or a negative charging property.