JPH11344856A - Contact member, developer carrier and developing equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the situations such that developer adheres to various contact members and characteristic of the contact member is lowered by providing a coating layer, using emulsion particles on the surface of the contact member coming in contact with the developer. SOLUTION: What is constituted by providing a conductive elastic roller 41b on the outer periphery of a rotary shaft 41a made of metal is used as a developer carrier 41 holding the developer 4a on its surface and carrying it to a developing area facing opposite an image carrier 1 in this developing device 4 developing an electrostatic latent image formed on the image carrier 1. The coating layer 41c using the emulsion particles and having elongation of 300 to 1,000% and rubber hardness of 15 to 50 deg. is provided on the outer peripheral surface of the roller 41b. By rotating the carrier 41, the developer 4a supplied to the surface is carried by the carrier 41. Then, a regulating member 42 provided in the device 4 is made to press-contact with the surface of the carrier 41 so a to regulate the quantity of the developer 4a carried to a developing area by the carrier 41.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine or a printer, and various kinds of contact members which come into contact with a developer, and the developer held on its surface and conveyed to a development area facing an image carrier. More specifically, the present invention relates to a developing device used to develop a latent image formed on a developer carrier and an image carrier, and more particularly, to a developing area in which the developer is held on the surface of the developer carrier to face the image carrier. When the regulating member is pressed against the surface of the developer carrying member to regulate the amount of the developer carried to the developing area, the developer is cracked and the surface of the developer carrying member and the regulating member are conveyed. It is characterized in that it can easily be prevented from adhering to the surface.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine or a printer, the surface of an image carrier 1 is charged by a charging device such as a charging roller 2 as shown in FIG. The surface of the image carrier 1 is exposed by the exposure device 3 in accordance with image information to form an electrostatic latent image on the surface of the image carrier 1, and the image carrier having the electrostatic latent image thus formed A developer 4a is supplied from the developing device 4 to the surface of the body 1 to form a toner image on the surface of the image carrier 1, and this toner image is recorded on a recording medium (not shown) by a transfer device using a transfer roller 5 or the like. ), The toner remaining on the surface of the image carrier 1 after the transfer is removed from the surface of the image carrier 1 by the cleaning blade 61 of the cleaning device 6, and such an operation is repeated to form an image. I was

A developing device 4 for supplying a developer 4a to the surface of the image carrier 1 on which an electrostatic latent image is formed as described above uses a developer 4a containing a carrier and a toner.
In addition to the developing device of the component developing system, a developing device of a one-component developing system using a developer 4a without using a carrier has been known.

In this one-component developing system, as shown in FIG. 1, a developer 4a is held on the surface of a developer carrier 41 and transported to a development area facing the image carrier 1. On the way, a regulating member 42 having spring elasticity or rubber elasticity is brought into pressure contact with the surface of the developer carrier 41, and the amount of the developer 4 a held on the surface of the developer carrier 41 is regulated by the regulating member 42. At the same time, a developer in which the developer 4a is frictionally charged has been generally used.

However, when an image is formed as described above, the developer 4a adheres to the charging roller 2, the transfer roller 5, the cleaning blade 61, etc., which come into contact with the developer 4a, thereby causing the charging roller 2, the transfer roller 5 and the cleaning blade 61 have problems.

In particular, as in the above-described one-component developing type developing apparatus, a regulating member 42 is pressed against the surface of the developer carrier 41 so as to regulate the amount of the developer 4a conveyed to the developing area. In this case, a large load is applied to the developer 4 a by the pressing force of the regulating member 42, whereby the developer 4 a on the surface of the developer carrier 41 is cracked and fine powder is generated. And regulating member 42
However, there is a problem that density unevenness or the like occurs in an image formed by fusing to the surface of the image.

Therefore, conventionally, in order to prevent the developer 4a from being cracked by the pressure contact of the regulating member 42 as described above, the regulating member 4
A method of reducing the pressure applied to the developer 4a by reducing the pressing force of No. 2 has been considered.

However, when the pressing force of the regulating member 42 is reduced in this manner, it becomes difficult to regulate the amount of the developer 4a conveyed to the image carrier 1 by the developer carrier 41 to an appropriate amount. And the developer 4a cannot be sufficiently triboelectrically charged.

In recent years, Japanese Patent Application Laid-Open No. 3-249
As disclosed in Japanese Patent Application Laid-Open Nos. 675-675 and 9-292754, it has been proposed to provide a coating layer using a urethane resin or the like on the surface of a developer carrying member.

However, these coating layers are for the purpose of improving light resistance and environmental resistance, and cannot sufficiently prevent the developer from adhering to the surface of the developer carrier.
In addition, when providing a coating layer as described above, generally, a resin is dissolved in an organic solvent and applied.
There were problems such as the type of resin used being limited, making it difficult to provide a coating layer having appropriate characteristics.

[0011]

SUMMARY OF THE INVENTION According to the present invention, in an image forming apparatus such as a copying machine or a printer, the developer adheres to various contact members that come into contact with the developer, and the characteristics of these contact members are reduced. It is an object to prevent such a situation.

In particular, according to the present invention, in the developing device in which the regulating member is pressed against the surface of the developer carrying member to regulate the amount of the developer conveyed to the developing area as described above, It suppresses the generation of fine powder due to the cracking of the developer due to the pressure contact, and prevents the fine powder of the developer from fusing to the surface of the developer carrying member and the like, thereby preventing density unevenness and the like from being generated in the formed image. The amount of the developer conveyed to the developing area is appropriately regulated by the regulating member, so that the developer is appropriately frictionally charged by the regulating member, and a good image having a sufficient image density is stably formed. It is an object of the present invention to be able to obtain it.

[0013]

According to a first aspect of the present invention, there is provided a contact member for contacting a developer with a coating layer using emulsion particles on a surface thereof in order to solve the above-mentioned problems. Is provided.

When the coating layer using the emulsion particles is provided on the surface of the contact member that comes into contact with the developer, the coating layer prevents the developer from adhering to the surface of the contact member. Thus, it is possible to prevent the characteristics of the contact member from being deteriorated due to the adhesion of the developer.

Further, when the coating layer is provided using emulsion particles, it is not necessary to dissolve the resin in an organic solvent, and a coating layer having various characteristics can be easily formed using various emulsion particles. In addition, the problem due to the evaporation of the organic solvent is eliminated.

According to the second aspect of the present invention, there is provided a developer carrying member for solving the above problems.
In a developer carrier that holds the developer on the surface and transports the developer to a development area facing the image carrier, a coating layer using emulsion particles is provided on the surface of the developer carrier.

When the coating layer using the emulsion particles is provided on the surface of the developer carrying member in this manner, the coating layer prevents the developer from adhering to the surface of the developer carrying member. .

Further, when the coating layer using the emulsion particles is provided on the surface of the developer carrier, the elongation is 300-1000% and the rubber hardness is 15-1000.
It is preferable to provide a coating layer within a range of 50 degrees. Here, the above rubber hardness and elongation are measured according to JIS K6301.
Is a value measured according to

A developer carrier holding the developer on the surface and transporting the developer to a development area opposed to the image carrier is brought into pressure contact with the surface of the developer carrier. In a developing device having a regulating member that regulates the amount of the developer conveyed to the developing region, when a developer carrier having a coating layer using emulsion particles on the surface is used as described above, the developer is Adhesion to the surface of the developer carrier is suppressed.

Further, as set forth in claim 3, the surface of the developer carrying member has an elongation of 300 to 1000% and a rubber hardness of 1%.
By providing the coating layer in the range of 5 to 50 degrees, the load applied to the developer is greatly reduced by deforming the surface of the developer carrying member without reducing the pressing force of the regulating member. Become like

For this reason, the regulating member is pressed against the surface of the developer carrying member with an appropriate pressing force so that the amount of the developer conveyed by the developer carrying member to the developing area facing the image carrying member is adjusted to an appropriate amount. In addition to being regulated, the developer is appropriately triboelectrically charged, and the cracking of the developer due to the pressure contact of the regulating member is suppressed, and the fine powder of the developer is fused to the surface of the developer carrying member. It is possible to prevent density unevenness or the like from occurring in an image formed by the above method.

[0022]

Embodiments of the present invention will be specifically described below with reference to the accompanying drawings.

In this embodiment, as shown in FIG. 2, in a developing device 4 for developing an electrostatic latent image formed on the image carrier 1, the developer 4a is
And a conductive elastic roller 41b provided around the outer periphery of a metal rotary shaft 41a. The elastic roller 41b
Elongation of 300 to 1 using emulsion particles on the outer peripheral surface of
The coating layer 41c has a rubber hardness of 000% and a range of 15 to 50 degrees.

Here, in the developing device 4 of this embodiment, the developer carrier 41 is provided so as to face the image carrier 1, the developer 4a is accommodated in the developing device 4, and the agitator 43 is installed in the developing device 4. The developer 4 a is supplied to the surface of the developer carrier 41 by rotating the agitator 43.

Then, the developer carrier 41 is rotated, the developer 4a supplied to the surface thereof is transported by the developer carrier 41, and the developer 4a is transported to the development area. Then, a regulating member 42 provided in the developing device 4 is pressed against the surface of the developer carrier 41, and the amount of the developer 4 a conveyed to the developing area by the developer carrier 41 is regulated by the regulating member 42. At the same time, the developer 4a on the surface of the developer carrier 41 is frictionally charged.

Next, the developer 4a triboelectrically charged as described above is conveyed to the developing area facing the image carrier 1 by the developer carrier 41, and a power source (not shown) is supplied to the developer carrier 41. ), The developing bias voltage is applied to the developer 4a held on the surface of the developer carrier 41.
Is supplied to the electrostatic latent image formed on the image carrier 1 to perform development.

When the development is performed in this manner, the regulating member 42 is pressed against the surface of the developer carrying member 41 as described above to regulate the amount of the developer 4a conveyed to the developing area. 4a is reduced and the developer carrier 4
Adhering of the developer 4a to the control member 1 and the regulating member 42 is suppressed, and a good image with less density unevenness and fog can be stably obtained.

Here, in the developer carrier 41, the elastic material constituting the elastic roller 41b is, for example, polystyrene, polyolefin, polyurethane, polyester, polyvinyl chloride, polybutadiene, or polyamide. Various thermoplastic elastomers and the like can be used, and natural rubber, cis-polyisoprene, styrene-butadiene rubber, cis-polybutadiene, chloroprene rubber, butyl rubber, nitrile rubber, ethylene propylene rubber, acrylic rubber, Vulcanized rubber such as urethane rubber and silicone rubber can also be used.

Further, in order to impart conductivity to the elastic roller 41b, for example, carbon black such as Ketjen black, acetylene black, and furnace black, and a conductivity imparting agent such as fine particles of a metal oxide are mixed. The elastic roller 41b has a volume resistivity value of 1
× 10 ³ to 1 × 10 ⁸ Ω · cm, preferably 1 × 10
It should be in the range of ⁴ to 1 × 10 ⁶ Ω · cm.

Further, when the coating layer 41c is provided on the surface of the elastic roller 41b using the emulsion particles as described above, as the thickness of the coating layer 41c increases, the volume resistivity value of the coating layer 41c increases. When the thickness of the coating layer 41c is reduced while developing characteristics are reduced, it becomes difficult to form the coating layer 41c uniformly, so that the thickness of the coating layer 41c is preferably in the range of 5 to 50 μm. Is in the range of 15 to 40 μm.

The coating layer 41 having such a thickness is formed.
In providing c, the emulsion particles have a particle size of 0.01 to 10 μm, preferably 0.05 to 10 μm.
The thing of 8.0 μm is used. Here, as a material used for the emulsion particles, for example, styrene-butadiene-based, acrylonitrile-butadiene-based,
Various materials such as vinyl chloride, vinyl acetate, polystyrene, acrylic acid, urethane, benzoguanamine, melamine, and olefin can be used.
Further, such emulsion particles may be used alone or in combination of two or more. The particle size of the particles is
Laser Diffraction Particle Size Analyzer (Horiba, Ltd .: LA-
500).

If the surface roughness of the coating layer 41c provided on the surface of the elastic roller 41b is small, a sufficient amount of the developer 4a cannot be transported, and density unevenness may occur in the formed image. On the other hand, when the surface roughness of the coating layer 41c is large, an excessive developer 4a is transported to generate a poorly charged developer 4a, and fogging is likely to occur in a formed image. Therefore, it is preferable that the surface roughness of the coating layer 41c be in the range of 1 to 8 μm.
The value of the surface roughness is a ten-point average roughness Rz based on JIS B0601.

On the other hand, as the above-mentioned developer 4a, a known developer generally used conventionally can be used. In general, a colorant, a charge control agent, a release agent, etc. are contained in a binder resin. The used toner is used, and if necessary, a fluidizing agent and the like are added.

The developer 4a can be produced by a known method generally used in the art. For example, a pulverization method, an emulsion polymerization method, a suspension polymerization method, or the like can be used. it can.

On the other hand, if the particle size of the developer 4a is too small, the fluidity of the developer 4a deteriorates, and poor cleaning or the like easily occurs. On the other hand, if the particle size of the developer 4a is too large, the reproducibility of a halftone image deteriorates. Therefore, a developer having a volume average particle size of 5 to 12 μm, preferably 6 to 10 μm is used. When the amount of the developer 4a having a volume average particle diameter of 3 μm or less increases, such a small-diameter developer 4a is fused to the developer carrier 41, and the charge of the developer 4a becomes non-uniform. In order to easily cause fogging, density unevenness, and the like in an image to be formed, a developer in which the number of developers 4a having a particle diameter of 3 μm or less is 20% by number or less is used.

Here, as the binder resin used for the developer 4a, a conventionally known binder resin can be used, for example, a polyester resin, a styrene resin, a styrene-acryl copolymer resin, an epoxy resin, or the like. Resins, synthetic terpene resins, synthetic rosin ester resins and the like can be used alone or as a mixture of two or more.

The binder resin has a number average molecular weight (Mn) of 1000 to 1500 as measured by gel permeation chromatography (GPC).
0, preferably in the range 3000-12000,
Softening point Tm measured by Koka type flow tester
Has a glass transition point Tg of 50 ° C to 75 ° C, preferably 55 ° C to 70 ° C, as measured by a differential scanning calorimeter (DSC). It is preferable to use those in the range.

As the above-mentioned coloring agent, known coloring agents generally used can be used. For example, carbon black, aniline black, activated carbon,
Magnetite, benzidine yellow, permanent yellow, naphthol yellow, phthalocyanine blue, fast sky blue, ultramarine blue, rose bengal, lake red, quinacridone, and the like can be used. It is preferable to use it in a proportion by weight.

As the charge control agent, well-known charge control agents which have been generally used can be used. Examples thereof include monoazo metal complexes, aromatic hydroxycarboxylic acid-based metal complexes, and aromatic dicarboxylic acid-based metal complexes. An organic metal complex such as a metal complex or a chelate compound can be used, and it is generally preferable to use 1 to 8 parts by weight based on 100 parts by weight of the binder resin.

As the above-mentioned release agent, known ones generally used conventionally can be used. For example, low molecular weight polyethylene, low molecular weight polypropylene, oxidized low molecular weight polyethylene, oxidized low molecular weight polypropylene , Microcrystalline wax, paraffin wax, carnauba wax, sasol wax or the like can be used alone or in combination of two or more kinds. Generally, 1 to 8 parts by weight based on 100 parts by weight of the binder resin. Preferably, it is used.

Also, as the above-mentioned fluidizing agent, a known one generally used conventionally can be used.
For example, inorganic fine particles such as silica, titanium oxide, and aluminum oxide, and fine resin particles such as acrylic resin, styrene resin, silicon resin, and fluororesin can be used.
In particular, it is preferable to use one that has been made hydrophobic with a silane coupling agent, a titanium coupling agent, silicon oil, or the like. Then, such a fluidizing agent is added to the developer 100 described above.
0.1 to 3 parts by weight based on parts by weight.

Next, in the developing device 4 of the above embodiment, an experiment was conducted in which the type of the coating layer 41c on the surface of the developer carrier 41 was changed, and the coating layer 41c on the surface of the developer carrier 41 In the developing device 4 of the embodiment that satisfies the conditions of the present invention, cracks and the like of the developer 4a are reduced, and filming of the developer 4a on the developer carrier 41 and adhesion of the developer 4a to the regulating member 42 are suppressed. It will be clarified by giving a comparative example that a good image having a sufficient image density can be obtained with less occurrence of density unevenness.

(Embodiment 1) In this embodiment 1, in the developing device 4 shown in FIG.
As No. 1, the one manufactured as follows was used.

In the first embodiment, the developer carrier 4
1, a conductive coating layer is provided on the surface of the metal rotating shaft 41a using Bunny Height C-9T (trade name) manufactured by Nippon Graphite Co., Ltd., and the elastic roller 41 is formed on the conductive coating layer.
b was formed.

In forming the elastic roller 41b, 100 parts by weight of unvulcanized rubber composed of ethylene-propylene-diene-methylene rubber (EPDM), 7 parts by weight of Ketjen black, a kind of carbon black, 3 parts by weight of sulfur as a vulcanizing agent and 0.5 parts by weight of cyclohexyl / benzothiazylsulfenamide as a vulcanization accelerator, and these were added to one part by three rolls.
After kneading and dispersing at 40 ° C., this is coated on a conductive coating layer provided on the surface of the rotating shaft 41a, and vulcanized at 150 ° C. for 30 minutes in a dryer, and then cooled. The surface was polished to form the elastic roller 41b. The elastic roller 41b had a rubber hardness of 46 degrees and an elongation of 670%.

Then, a coating layer 41c using emulsion particles is provided on the surface of the elastic roller 41b.

Here, when providing the coating layer 41c using the emulsion particles, 15 parts by weight of 1,2-butadiene (manufactured by Nippon Synthetic Rubber Co., Ltd .: JSR, SIS-5000P) is dissolved in 85 parts by weight of toluene as a solvent. Was. on the other hand,
In a 5 liter beaker, 3 liters of ion-exchanged water, 0.5 part by weight of dispersant sodium dodecylbenzenesulfonate, and 1 part of polyvinyl alcohol having an average polymerization degree of 500 are added.
Parts by weight and a stirrer (Toki Kika Co., Ltd .: T
While stirring at 6000 rpm using a K homomixer), the solution in which 1,2-butadiene was dissolved was charged into the beaker, and the mixture was stirred for 15 minutes.
The temperature was raised to 55 to 60 ° C. while stirring at m to remove the solvent toluene, thereby obtaining an emulsion solution in which 1,2-butadiene emulsion particles having a particle size of 6.8 μm were dispersed.

A commercially available emulsion solution in which acrylonitrile-butadiene-based emulsion particles having a particle size of 0.2 μm are dispersed with respect to 30 parts by weight of the above emulsion solution (Nipol 15 manufactured by Zeon Corporation).
20) and 50 parts by weight of a commercially available emulsion solution (HUX-395, manufactured by Nippon Shokubai Co., Ltd.) in which urethane emulsion particles having a particle size of 2.0 μm are dispersed.

Then, a rubber-based conductive adhesive (Dotite RA-3 manufactured by Fujikura Kasei Co., Ltd.) having a volume specific resistance of 1 Ω · cm is applied to the surface of the elastic roller 41b, and the surface is coated as described above. A mixture obtained by mixing three types of emulsion solutions is applied, and this is heat-treated and cured. As shown in Table 1 below, the rubber hardness is 39 degrees, the elongation is 780%,
Surface roughness Rz is 5.5 μm and volume resistivity is 7.3 ×
A coating layer 41c of 10 ⁵ Ω · cm was formed.

(Embodiment 2) In Embodiment 2, only the coating layer 41c formed on the surface of the elastic roller 41b is changed from the case of Embodiment 1 described above.

Here, in the second embodiment, when forming the coating layer 41c on the surface of the elastic roller 41b,
Styrene-butadiene elastomer (Aron Kasei Co., Ltd .:
AR-S-3948A) 13 parts by weight of toluene 8 as a solvent
It was dissolved in 7 parts by weight. Meanwhile, 3 in a 5 liter beaker
1 liter of ion-exchanged water and 0.5 part by weight of sodium dodecylbenzenesulfonate as a dispersant, and an average degree of polymerization of 50
Of styrene-butadiene elastomer was dissolved in this beaker while stirring at 8000 rpm using a stirrer (manufactured by Tokushu Kika Kogyo Co., Ltd .: TK homomixer). After the solution was added and stirred for 15 minutes, the temperature was raised to 55 to 60 ° C. while stirring at 200 rpm to remove the solvent toluene, and styrene-butadiene emulsion particles having a particle size of 4.2 μm were dispersed. The obtained emulsion solution was obtained.

Then, 75 parts by weight of a commercially available emulsion solution (HUX-575, manufactured by Nippon Shokubai Co., Ltd.) in which urethane emulsion particles having a particle size of 2.2 μm are dispersed with respect to 20 parts by weight of the above emulsion solution. 5 parts by weight of commercially available cross-linked polymethyl methacrylate particles (manufactured by Nippon Shokubai Co., Ltd .: MA-1004) having a particle size of 4.3 μm were mixed at a ratio of 5 parts by weight. In the same manner as in Example 1, the rubber-based conductive adhesive is applied to the surface of the elastic roller 41b, which is applied with heat, cured by heat treatment, and has a rubber hardness of 48 degrees as shown in Table 1 below. , Elongation is 480%, and surface roughness Rz is 3.
A coating layer 41c having a thickness of 8 μm and a volume resistivity of 1.2 × 10 ⁶ Ω · cm was formed.

(Embodiment 3) In Embodiment 3 as well, in Embodiment 3, only the coating layer 41c formed on the surface of the elastic roller 41b is changed.

Here, in the third embodiment, when forming the coating layer 41c on the surface of the elastic roller 41b,
1,2-butadiene (manufactured by Nippon Synthetic Rubber Co., Ltd .: TR-282)
7) 10 parts by weight are dissolved in 90 parts by weight of toluene as a solvent, and thereafter, emulsion particles of 1,2-butadiene having a particle size of 3.9 μm are dispersed in the same manner as in Example 1 above. The obtained emulsion solution was obtained.

Then, a commercially available emulsion solution (HUX-290H, manufactured by Asahi Denka Kogyo Co., Ltd.) in which urethane emulsion particles having a particle size of 2.0 μm are dispersed with respect to 50 parts by weight of the above emulsion solution. 50 parts by weight, and 10 parts of commercially available crosslinked melamine resin particles (S-12, manufactured by Nippon Shokubai Co., Ltd.) having a particle size of 3.1 μm were added to the emulsion solution thus mixed.
% By weight, and this emulsion solution is applied to the surface of the elastic roller 41b to which the rubber-based conductive adhesive has been applied in the same manner as in Example 1 above, and this is cured by heat treatment. As shown in Table 1 below, the rubber hardness was 4
The coating layer 41c was formed three times, with an elongation of 630%, a surface roughness Rz of 2.6 μm, and a volume resistivity of 8.7 × 10 ⁴ Ω · cm.

Comparative Example 1 In Comparative Example 1, only the coating layer 41c formed on the surface of the elastic roller 41b was changed from that in Example 1 described above.

Here, in Comparative Example 1, when forming the coating layer 41c on the surface of the elastic roller 41b,
1,2-butadiene (JSRRB8 manufactured by Nippon Synthetic Rubber Co., Ltd.)
05) 4 parts by weight of toluene 90 parts by weight, ethyl acetate 6
The resin was dissolved in a solvent in a weight part ratio, and this solution was applied to the surface of the elastic roller 41b to which the rubber-based conductive adhesive was applied in the same manner as in Example 1 above, and this was heat-treated. As shown in Table 1 below, the rubber hardness was 65 degrees, the elongation was 830%, and the surface roughness Rz was 0.7 μm.
m, a coating layer 41c having a volume resistivity value of 6.4 × 10 ¹⁵ Ω · cm was formed.

Comparative Example 2 In Comparative Example 2, only the coating layer 41c formed on the surface of the elastic roller 41b was changed from that of Example 1 described above.

Here, in Comparative Example 2, when forming the coating layer 41c on the surface of the elastic roller 41b,
1,2-butadiene (JSRRB8 manufactured by Nippon Synthetic Rubber Co., Ltd.)
05) 4 parts by weight of toluene 90 parts by weight, ethyl acetate 6
Dissolved in a solvent in a proportion of parts by weight, and in this solution, commercially available crosslinked polymethyl methacrylate particles having a particle size of 12 μm (Nippon Shokubai Co., Ltd .: Eposter MA-1013) were dispersed in a proportion of 7% by weight. This solution was used in Example 1 above.
Is applied to the surface of the elastic roller 41b to which the rubber-based conductive adhesive is applied in the same manner as in the case of above, and this is cured by heat treatment. As shown in Table 1 below, the rubber hardness is 67 degrees and the elongation is The coating layer 41c having a thickness of 810%, a surface roughness Rz of 6.7 μm, and a volume resistivity of 8.7 × 10 ¹⁵ Ω · cm was formed. When the coating layer 41c is formed in this manner, a part of the crosslinked polymethyl methacrylate particles swells, the viscosity of the solution in which 1,2-butadiene is dissolved increases, and the surface of the elastic roller 41b is increased. When coating was performed, coating unevenness occurred, and the coating layer 41c having a uniform thickness could not be formed.

Comparative Example 3 In Comparative Example 3, only the coating layer 41c formed on the surface of the elastic roller 41b was changed from that in Example 1 described above.

Here, in Comparative Example 3, when forming the coating layer 41c on the surface of the elastic roller 41b,
Styrene-butadiene elastomer (Aron Kasei Co., Ltd .:
AR-S-3948A) and a styrene-butadiene elastomer (AR-S-394, manufactured by Aron Kasei Co., Ltd.).
8C) at a ratio of 3 parts by weight, and these are dissolved in a solvent having a ratio of 70 parts by weight of toluene and 20 parts by weight of ethyl acetate. Commercially available silica (Ube Nitto Kasei Kogyo Co., Ltd.) having a particle size of 5 μm in this solution Co., Ltd .: High Pressica UF) is dispersed at a ratio of 5% by weight, and this solution is applied to the surface of the elastic roller 41b to which the rubber-based conductive adhesive has been applied in the same manner as in Example 1 above. This was cured by heat treatment, and as shown in Table 1 below, the rubber hardness was 46 degrees, the elongation was 620%, the surface roughness Rz was 3.6 μm, and the volume resistivity was 2.1 × 10 ¹⁶ Ω · cm of the coating layer 41c was formed.

[0062]

[Table 1]

Then, the above Examples 1 to 3 and Comparative Example 1
Each developer carrier 41 manufactured as shown in FIGS.
While used in the above-described developing device 4 shown in FIG. 2, a toner manufactured as described below was used as the developer 4a.

Here, in manufacturing the toner,
A 5-liter four-necked flask was equipped with a reflux condenser, a water separator, a nitrogen gas inlet tube, a stirrer, and a thermometer. The flask was set in a heating mantle, and 2 mol of bisphenol A ethylene oxide was placed in the flask. 1300 g of adduct, 120 g of diethylene glycol,
1150 g of isophthalic acid was added, nitrogen was introduced into the flask, and dehydration polycondensation was performed at 230 ° C. with stirring.
When the acid value or the hydroxyl value reaches a predetermined value, the inside of the flask is gradually evacuated to 240 ° C. and 5 mm
The reaction was performed at Hg for 1 hour to obtain a polyester resin. The polyester resin had an acid value of 40 KOHmg /
g, hydroxyl value is 8 KOH mg / g, number average molecular weight Mn is 3200, glass transition point Tg is 64 ° C., and softening point Tm is 1.
07 ° C.

Next, 100 parts by weight of the above polyester resin, 3.5 parts by weight of a phthalocyanine pigment as a colorant, and a charge control agent (Bontron E- manufactured by Orient Chemical Co., Ltd.)
81) and 1.0 part by weight of carnauba wax (manufactured by Kato Yoko Co., Ltd.), and these were mixed with a Henschel mixer at a rotation speed of 2800 rpm for 3 minutes. The mixture was cooled and coarsely pulverized.

Then, the coarsely crushed material is finely pulverized by the above-mentioned kryptron crusher (KTM-1 manufactured by Kawasaki Heavy Industries, Ltd.), and the finely crushed material is classified by an elbow jet (manufactured by Matsuzaka Trading Co., Ltd.). The volume average particle size is 9.0 μm,
8.3% by number of particles having a particle size of 3 μm or less were obtained.
Then, hydrophobic silica (Cabotil TS-500, manufactured by Cabot Corporation) was added to the toner particles at a ratio of 0.8% by weight, and the mixture was mixed with a Henschel mixer at a rotation speed of 2500 rpm for 90 seconds to obtain a negatively chargeable toner. Was obtained.

Then, the above-mentioned toner is used in each of the developing devices 4 using the above-mentioned developer carrying members 41, and the regulating member 42 is applied to the surface of each developer carrying member 41 at a linear pressure of 7 g / mm. The temperature is regulated by pressing at 15 ° C and humidity is 3
0% low temperature / low humidity environment (L / L) and temperature 35
In a high-temperature and high-humidity environment (H / H) at 80 ° C. and a humidity of 80%, a printing durability test of 10,000 sheets was performed at a system speed of 160 mm / s, and the toner fixing state to the regulating member 42 and the developer carrier 41 were measured. The evaluation of the filming state of the toner, the image density of the formed image and the density unevenness was performed, and the results are shown in Table 2 below.

Here, the toner adhesion to the regulating member 42 was evaluated by visual observation. A: good when there was no toner adhesion, ト ナ ー: when slight toner adhesion was observed but there was no practical problem, The case where the above problem occurs is indicated by x.

The filming of the toner on the developer carrying member 41 was also evaluated by visual observation. 場合: good without filming, Δ: slight filming but no practical problem, filming: Are marked by x when there are many practical problems.

Regarding the evaluation of the image density, the reflection density (ID) of the image formed by the Sakura densitometer (trade name) was measured. Δ, I in the case of 2 or more and less than 1.4
The case where D was less than 1.2 was indicated by x.

Regarding the density unevenness, the formed image was evaluated by visual observation, and the case where a good image was obtained without the occurrence of the density unevenness was evaluated as “good”. Δ, a case where the density unevenness was serious and caused a problem was indicated by x.

[0072]

[Table 2]

As a result, each of Examples 1 to 3 in which the coating layer 41c having an elongation of 300 to 1000% and a rubber hardness of 15 to 50 degrees was provided on the surface of the developer carrier 41 using emulsion particles. In the developing device, the developer carrier 41
When the amount of the toner supplied to the surface of the toner cartridge is regulated by the regulating member 42, cracking of the toner and the like is suppressed, and the toner adheres to the surface of the regulating member 42, and the toner adheres to the surface of the developer carrier 41. In addition to suppressing the occurrence of filming, a good image having a sufficient image density and having less density unevenness can be stably obtained.

On the other hand, when the coating layer 41c having a rubber hardness higher than 50 degrees is provided on the surface of the developer carrier 41 irrespective of the emulsion particles as in the developing devices of Comparative Examples 1 and 2, When the amount of toner supplied to the surface of the developer carrying member 41 is regulated by the regulating member 42, a large amount of toner cracks occur, and the toner adheres to the surface of the regulating member 42 or the surface of the developer carrying member 41 In addition, filming due to toner occurred, and the image density of the formed image decreased, and the occurrence of density unevenness increased.

Further, as in the developing device of Comparative Example 3, when the coating layer 41c having an elongation of 300 to 1000% and a rubber hardness of 15 to 50 degrees is provided on the surface of the developer carrier 41. Also, the properties of the coating layer 41c are deteriorated due to evaporation of the organic solvent used when the coating layer 41c is provided, and the developer carrying member is lower than in the case of Examples 1 to 3 in which the coating layer 41c is provided by emulsion particles. 41, the occurrence of filming of the toner on the surface increased.

In the above embodiments and examples, the case where the coating layer 41c made of emulsion particles is provided on the surface of the developer carrier 41 has been described.
As shown in (2), when the regulating member 42 regulates the amount of the developer 4a supplied to the surface of the developer carrying member 41, a coating layer 42a made of emulsion particles is provided on the surface which is brought into pressure contact with the surface of the developer carrying member 41. Further, the adhesion of the developer 4a to the regulating member 42 is further suppressed.

Further, in the image forming apparatus shown in FIG. 1, the charging roller 2 and the transfer roller 5
When a coating layer made of emulsion particles is provided on the surface of the cleaning blade 61, the adhesion of the developer 4a to these is also suppressed.

[0078]

As described above in detail, in the contact member according to the first aspect of the present invention, a coating layer using emulsion particles is provided on the surface in contact with the developer. Is suppressed from adhering to the surface of the contact member, and deterioration of the characteristics of the contact member due to the adhesion of the developer is suppressed.

Further, as in the case of the developer carrying member according to the second aspect of the present invention, the emulsion particles are used on the surface of the developer carrying member which holds the developer on the surface and conveys the developer to a developing area opposed to the image carrying member. When the amount of the developer conveyed to the developing area by the developer carrier is regulated by the regulating member, the adhesion of the developer to the surface of the developer carrier is suppressed. Became.

Further, when the coating layer using the emulsion particles is provided on the surface of the developer carrier, the elongation is 300 to 1000% and the rubber hardness is 15%.
When a coating layer having a range of 〜50 degrees was provided, the load applied to the developer due to deformation of the coating layer was greatly reduced.

As a result, in the developing device using such a developer carrying member, the amount of the developer conveyed by the developer carrying member can be appropriately regulated by the regulating member, and sufficient frictional charging can be achieved. At the same time, it is suppressed that the developer is cracked and fused to the surface of the developer carrying member and the regulating member, so that a good image having sufficient image density and no unevenness in density can be stably obtained. became.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of an image forming apparatus.

FIG. 2 is a schematic explanatory view of a developing device according to the embodiment of the present invention.

FIG. 3 is a partial explanatory view showing a state in which a coating layer is formed on a surface of a regulating member in the embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 image carrier 2 charging roller 4 developing device 4 a developer 5 transfer roller 6 cleaning device 41 developer carrier 41 c coating layer of developer carrier 42 regulating member 42 a covering layer of regulating member 61 cleaning blade

Continuation of the front page (72) Inventor Ichiro Izumi 2-3-13 Azuchicho, Chuo-ku, Osaka City Inside Osaka International Building Minolta Co., Ltd. (72) Inventor Ryuji Inoue 2-3-1, Azuchicho, Chuo-ku, Osaka-shi Inside Osaka International Building Minolta Co., Ltd. (72) Inventor Eiji Gyutoku 2-3-1-13 Azuchicho, Chuo-ku, Osaka City Inside Osaka International Building Minolta Co., Ltd.

Claims (4)

[Claims] 1. A contact member contacting a developer, wherein a coating layer is provided on the surface of the contact member using emulsion particles. 2. A developer carrier for holding a developer on a surface thereof and transporting the developer to a developing area facing the image carrier, wherein a coating layer is provided on the surface of the developer carrier using emulsion particles. Characteristic developer carrier. 3. The developer carrier according to claim 2, wherein the coating layer has an elongation of 300 to 1000% and a rubber hardness of 15 to 50 degrees. . 4. A developer carrier that holds the developer on the surface and transports the developer to a development area facing the image carrier, and a developer carrier that is brought into pressure contact with the surface of the developer carrier and transported to the development area. A developing device having a regulating member for regulating the amount, wherein the developer carrier according to claim 2 or 3 is used.