JPH08101580A - Developing roller and developing device - Google Patents

Abstract

PURPOSE: To prevent a failure such as the contamination of a photoreceptor, to obtain a high-quality image without uneven density and surface fogging and to prevent image quality from being deteriorated even in long-term use. CONSTITUTION: This developing roller 1 is constituted by forming an elastic layer 3 having conductivity on the outer periphery of a good conductive shaft 2, and it visualizes an electrostatic latent image by carrying non-magnetic one- component developer on the surface of the elastic layer 3, forming the thin layer of the developer, and coming in contact with a latent image holding body holding the electrostatic latent image on its surface in such a state. The elastic layer 3 has a resin component which is non-contaminative to the latent image holding body and does not contain conductive powder on its surface. Besides, it satisfies relation being log (R2 /R1 )<=3 when it is assumed that the roller resistance in the case the layer 3 does not have the resin component is R1 and the roller resistance in the case it has the resin component is R2 .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing roller and a developing roller for visualizing an electrostatic latent image with a non-magnetic one-component developer in an electrophotographic apparatus such as a copying machine or a printer or an electrostatic recording apparatus. More specifically, it relates to a developing device used, and more particularly to a developing roller which is excellent in stain resistance and can surely obtain a good image even in long-term use, and a developing device using the roller.

[0002]

2. Description of the Related Art Conventionally, in an electrophotographic apparatus such as a copying machine or a printer, an electrostatic recording apparatus, etc., a non-magnetic one-component developer is supplied to a photosensitive drum holding a latent image, and the latent image on the photosensitive drum is exposed to the latent image. A pressure developing method is known as a developing method for visualizing a latent image by attaching a developer (US Pat. No. 3,152,311).
No. 012, No. 3731146, etc.), according to this method, the magnetic material is unnecessary, so that the apparatus can be easily simplified and downsized, and the toner can be easily colored.

In this pressure developing method, a developing roller carrying a toner (non-magnetic one-component developer) is brought into contact with a latent image holding member such as a photosensitive drum which holds an electrostatic latent image, and the toner is transferred to the latent image. Development is carried out by adhering the latent image on the holding member. Therefore, it is necessary to form the developing roller with an elastic body having conductivity.

That is, in this pressure developing method, as shown in FIG. 2, for example, between the toner coating roller 4 for supplying toner and the photosensitive drum 5 holding the electrostatic latent image, The developing roller 1 is disposed in contact with the photosensitive drum 5 and slightly separated from the toner applying roller 4,
By rotating the developing roller 1, the photosensitive drum 5, and the toner applying roller 4 in the directions of the arrows in the drawing,
The toner 6 is supplied to the surface of the developing roller 1 by the toner applying roller 4, the toner is adjusted to a uniform thin layer by the stratifying blade 7, and the developing roller 1 rotates while contacting the photosensitive drum 5 in this state. As a result, the toner formed in a thin layer adheres to the latent image on the photosensitive drum 5 from the developing roller 1 so that the latent image becomes visible. In the figure, reference numeral 8 denotes a transfer section, which is adapted to transfer a toner image onto a recording medium such as paper, and 9 denotes a cleaning section, which is cleaned by a cleaning blade 10 on the surface of the photosensitive drum 5 after transfer. It is designed to remove the residual toner.

In this case, the developing roller 1 is the photosensitive drum 5
It is necessary to rotate while firmly maintaining the state of being in close contact with, and as shown in FIG. 1, silicone rubber is attached to the outer periphery of the shaft 2 made of a metal or other good conductive material.
It has a structure in which an elastic layer 3 made of an elastic body to which conductivity is imparted is formed by blending a conductive agent into elastic rubber such as NBR or EPDM or urethane foam.

[0006]

However, the above-mentioned conventional developing roller has the following drawbacks due to the characteristics of its elastic layer. 1. When the elastic layer is formed of an elastic rubber such as silicone rubber, NBR or EPDM, if the hardness is lowered to obtain good adhesion, the photosensitive drum may be contaminated. 2. When the elastic layer is formed from a sponge such as urethane foam, if the toner enters the elastic layer and is used for a long period of time, the roller may become hard due to clogging of the toner, or the toner may be improperly charged, resulting in poor image quality. May decrease. The above tendency is true not only in the case of the sponge body but also in the case of a roller having a surface to which toner is easily attached. 3. Generally, when the developing roller is composed of a single layer, the surface friction coefficient is so large that a large load is applied between the developing blade and the photoconductor, which causes image defects due to uneven toner conveyance or jitter during driving. Easy to bring.

[0007] Generally, a developing roller composed of a single elastic layer does not have sufficient charge rise characteristics of toner on the roller, and problems such as poor cleaning due to fog selective development due to poor charging of toner and reduction in print density occur. Easy,
The printing quality is significantly deteriorated by long-term continuous printing. This phenomenon is particularly remarkable in a high temperature and high humidity environment.

The present invention has been made in view of the above circumstances, has low hardness and good adhesion, does not cause inconvenience such as contaminating a photosensitive member, and has no uneven density or background fog. An object of the present invention is to provide a developing roller that can obtain a high-quality image and that does not cause deterioration in image quality even after long-term use, and a developing device using the developing roller.

[0009]

Means for Solving the Problems The present inventor has made earnest studies to achieve the above object, and as a result, the surface of the elastic layer is non-contaminating to the latent image holding member and electrically conductive. Of a resin component containing no conductive powder, in which case the roller resistance when the resin component is not present on the surface is R
_1. When the roller resistance when the resin component is present on the surface is R ₂ , the resin component is attached so as to give a relationship of log (R ₂ / R ₁ ) ≦ 3. It was found that a developing roller with low friction can be effectively prevented, and contamination of the body) can be effectively prevented.

In this case, as a means for giving the above resin component to the surface, a resin solution having a resin component concentration of 9% by weight or less such as a soluble nylon, an acrylic resin, a urethane-modified acrylic resin, a polycarbonate, a fluororesin, etc. It has been found that surface treatment with is effective.
Further, 1 to 100 parts by weight of a friction-reducing agent selected from a silicone resin, a fluorine-based surfactant, a silicone-based surfactant, a silicon-based coupling agent, and silica powder is added to 100 parts by weight of the above resin component. Was found to be effective.

That is, contamination of the photoreceptor tends to occur in a state where there is no developer between the surface of the developing roller and the surface of the photoreceptor, that is, in an initial state before use. To be effective, and in particular, soluble nylon, urethane-modified acrylic resin, polycarbonate,
The surface treatment with the fluororesin solution is effective in blocking contaminants from the elastic layer, and further, by containing the friction-reducing agent, the driving property of the roller and the toner transporting property can be improved, and moreover, it is possible to improve the roller surface. The inventors have found that the charge amount of the developer is made appropriate, a high-quality image without density unevenness or background fog can be obtained, and the image quality is not deteriorated even in long-term use, and the present invention is made. It has come.

Therefore, according to the present invention, a conductive elastic layer is formed on the outer periphery of a good conductive shaft, and a non-magnetic one-component developer is carried on the surface of the elastic layer to form a thin layer of the developer. In the developing roller which forms the electrostatic latent image on the surface of the developing roller by contacting the latent image holding member, the elastic layer is formed on the surface of the developing roller to the latent image holding member. R _{1 is} a roller resistance when it has a resin component that is non-contaminating and does not contain conductive powder, and does not have this resin component, and R ₂ is a roller resistance when it has this resin component. At this time, there is provided a developing roller characterized by satisfying a relationship of log (R ₂ / R ₁ ) ≦ 3.

Further, according to the present invention, the latent image holding member holding the electrostatic latent image on the surface and the non-magnetic one-component developer carried on the outer peripheral surface are brought into contact with the surface of the latent image holding member to rotate. As a result, in the developing device, the non-magnetic one-component developer is attached to the electrostatic latent image on the surface of the latent image carrier to visualize the electrostatic latent image. A developing device using a developing roller is provided.

The present invention will be described in more detail below.
In the developing roller of the present invention, as shown in FIG. 1, an elastic layer 3 having conductivity is formed on the outer circumference of a good conductive shaft 2. In the present invention, this elastic layer is formed on the surface thereof. The roller resistance is R ₁ when it has a resin component which is non-contaminating to the latent image carrier and does not contain conductive powder, and when it does not have this resin component, the roller when it has this resin component. When the resistance is R ₂ , it is configured so as to satisfy the relationship of log (R ₂ / R ₁ ) ≦ 3.

Here, as the shaft 2, any one can be used as long as it has good conductivity, but usually, a cored bar made of a metallic solid body or the inside is hollowed out. A metal shaft such as a metal cylinder is used.

Next, the elastic layer formed on the outer periphery of the shaft 2 uses an elastomer or foam material such as polyurethane or EPDM as a base material, and conductive powder such as carbon black, metal or metal oxide powder, or the like. By mixing an ionic conductive material such as sodium perchlorate, the conductivity is optimized according to the application to a medium resistance region 10 ³ to 1 1.
It is preferably adjusted to 0 ¹⁰ Ωcm, particularly 10 ⁴ to 10 ⁸ Ωcm.

In this case, the base material is polyurethane, natural rubber, butyl rubber, nitrile rubber, polyisoprene rubber,
Examples thereof include polybutadiene rubber, silicone rubber, styrene-butadiene rubber, ethylene-propylene rubber, chloroprene rubber, acrylic rubber, and mixtures thereof, with polyurethane and EPDM being particularly preferred.

First, regarding polyurethane, polyurethane elastomers and foam materials may be any of those produced by various methods. For example, a method in which carbon black is blended in a polyurethane prepolymer and the prepolymer is subjected to a crosslinking reaction. It can be obtained by a method such as a method in which a conductive material is blended and this polyol is reacted with a polyisocyanate by a one-shot method.

The urethane used as the base material of the conductive material layer is, as a polyhydroxyl compound, a polyol used in the production of general flexible polyurethane foam or urethane elastomer, for example, a polyether polyol having a polyhydroxyl group at the end, In addition to polyester polyols and polyether polyols which are copolymers of both, polyol polyols such as polybutadiene polyols and polyisoprene polyols, so-called polymer polyols obtained by polymerizing ethylenically unsaturated monomers in polyols, etc. General polyols of can be used. Further, as the polyisocyanate compound, similarly, polyisocyanate used in the production of general flexible polyurethane foams and urethane elastomers, that is, tridiisocyanate (TDI),
Crude TDI, 4,4-diphenylmethane diisocyanate (MDI), crude MDI, C2-C18 aliphatic polyisocyanate, C4-C15 cycloaliphatic polyisocyanate and mixtures and modified products of these polyisocyanates, for example, partial A prepolymer or the like obtained by reacting with polyols is used.

On the other hand, EPDM is a terpolymer composed of ethylene, propylene and a third component in this case, and the third component is not particularly limited, but dicyclopentadiene, ethylidene norbornene may be used. , 1,4-hexadiene and the like are preferably used. Further, the ratio of ethylene, propylene and the third component is
Although not particularly limited, the ethylene content is 5
~ 95 wt%, propylene content 5-95 wt%,
The content of the third component is preferably 0 to 50 in terms of iodine value. It should be noted that two or more kinds of EPDM having different iodine values can be mixed and used. Silicone rubber, silicone-modified EPDM, or both may be blended with the EPDM. In this case, the mixing amount of silicone rubber and silicone-modified EPDM is E
It can be 5 to 80 parts by weight with respect to 100 parts by weight of PDM. The silicone-modified EPDM refers to a hybrid rubber in which the bonding force between both EPDM and silicone polymers is increased through a silanol compound or siloxane.

Furthermore, a crosslinking agent and a vulcanizing agent may be added to crosslink the elastic layer to form a rubber-like substance. In this case, a vulcanization aid, a vulcanization accelerator, a vulcanization acceleration aid, a vulcanization retarder, etc. can be used in both cases of organic peroxide crosslinking and sulfur crosslinking. Furthermore, in addition to the above, peptizers, foaming agents, plasticizers, softening agents, tackifiers, anti-tacking agents, separating agents, release agents, extenders, and coloring agents that are commonly used as compounding agents for rubber. Etc. can be added.

The elastic layer mainly composed of polyurethane or EPDM is charged with various charged materials such as nigrosine, triaminophenylmethane and cationic dye for the purpose of controlling the amount of toner charge on the surface when used as a developing member. A fine powder such as a control agent, silicone resin, silicone rubber, or nylon can be added. in this case,
The amount of these additives added is the above-mentioned polyurethane or EPD.
It is preferable that the charge control agent is 1 to 5 parts by weight and the fine powder is 1 to 10 parts by weight with respect to 100 parts by weight of M.

Examples of the conductive material include conductive carbon such as Ketjen Black EC and acetylene black, SAF, ISAF, HAF, and FE.
Carbon for rubber such as F, GPF, SRF, FT, MT,
Metals and metal oxides such as color (ink) carbon, pyrolytic carbon, natural graphite, artificial graphite, antimony-doped tin oxide, titanium oxide, zinc oxide, nickel, copper, silver and germanium that have been subjected to oxidation treatment. ,
Examples thereof include conductive polymers such as polyaniline, polypyrrole, and polyacetylene. Among them, carbon black is inexpensive and whose conductivity can be easily controlled with a small amount. Normally, 0.5 to 5 per 100 parts by weight of urethane
It is preferably used in an amount of 0 parts by weight, particularly in the range of 1 to 30 parts by weight.

Examples of ion conductive substances include sodium perchlorate, lithium perchlorate, calcium perchlorate,
Inorganic ionic conductive materials such as lithium chloride and organic ionic conductive materials such as modified aliphatic dimethylammonium ethosulfate, stearyl ammonium acetate, lauryl ammonium acetate, octadecyltrimethylammonium perchlorate, tetrabutylammonium borate, etc. Is exemplified.

In the present invention, although the elastic layer 3 is not particularly limited, the resistance of the elastic layer 3 is 10 ³ to 10 ¹⁰ Ωcm, particularly 10 ⁴ to 1, depending on the blending of the carbon black.
It is preferable that the 0 ⁸ [Omega] cm. Resistance value is 10 ³ Ωcm
If it is less than the range, the charge may leak to the photosensitive drum or the like, or the developing roller itself may be destroyed by the voltage. On the other hand, if it exceeds 10 ¹⁰ Ωcm, the fog tends to occur.

The hardness of the elastic layer 3 is not particularly limited, but is preferably 60 ° or less, particularly 25 to 55 ° on the JIS-A scale. In this case, if the hardness exceeds 60 °, the contact area with the photosensitive drum and the like may be reduced, and good development may not be performed. On the contrary, if the hardness is too low, the compression set becomes large, and for some reason When the roller is deformed or eccentric, uneven density of the image occurs. For this reason, even when the hardness of the elastic layer is set to a low hardness, it is preferable that the compression set be as small as possible, specifically, 20% or less.

The surface roughness of the elastic layer 3, that is, the surface roughness of the developing roller of the present invention is not particularly limited, but JIS 10-point average roughness is 15 μm R _z or less, particularly 1
It is preferably set to 10 μmR _z . Surface roughness is 15
When it exceeds 15 μmR _z , the layer thickness of the toner layer of the non-magnetic one-component developer (toner) and the uniformity of charging may be impaired, but when it is 15 μmR _z or less, the adhesion of the toner can be improved. In addition, it is possible to more reliably prevent image deterioration due to wear of the roller during long-term use.

As described above, in the developing roller of the present invention, the elastic layer has on its surface a resin component which is non-staining to the latent image holding member and contains no conductive powder. When the roller resistance in the case of not having a resin component is R ₁ and the roller resistance in the case of having this resin component is R ₂ , it is configured to satisfy the relationship of log (R ₂ / R ₁ ) ≦ 3. , Log (R ₂
/ R ₁ ) ≦ 3, more preferably log (R ₂ / R ₁ ) ≦ 2
By doing so, the object of the present invention can be achieved.

In this case, as a means for applying such a resin component to the surface of the elastic layer, a method of effectively treating the surface of the elastic layer with a resin solution is effectively employed. The concentration of the resin component in the resin solution is not particularly limited as long as the relationship of log (R ₂ / R ₁ ) ≦ 3 is satisfied, but the resin component concentration is 9% by weight or less, more preferably 5% by weight. The following is preferable. Various kinds of resins are selected, but soluble nylon, urethane-modified acrylic resin, acrylic resin, polycarbonate, and fluororesin are preferable, and one of these can be used alone or two or more can be used in combination.

Here, the soluble nylon refers to a polymer which is soluble in a common organic solvent by copolymerizing a different polyamide unit with ordinary nylon 6, nylon 66, or the like, or chemically modifying an amide group. Nylon.

Many copolymerized nylons are made alcohol-soluble by terpolymerization, for example, 6/66/1.
2, 6/66/610/12, 6/610/11/12
Examples include nylon.

Examples of the modified nylon include N-methoxymethylated nylon and N-ethoxyethylated nylon in which the hydrogen atom of an amide group is substituted with an alkoxyl group.

The urethane-modified acrylic resin is a resin in which a urethane component is introduced into the acrylic resin to impart flexibility and flexibility.

As a method of modifying the acrylic resin with the urethane component, it is effective to chemically bond the urethane resin and the acrylic resin component from the viewpoints of compatibility, liquid stability, film flexibility and the like. . Specifically, the reaction of a polymer having a hydroxyl group introduced into an acrylic polymer with β-hydroxyethyl methacrylate and the like and a urethane prepolymer having an isocyanate group at the molecular end, or at the molecular end as described below (one end or both ends). It is synthesized by reacting an acrylic component having a hydroxyl group at the end) with a urethane prepolymer (A: acrylic acid, acrylic acid ester monomer or oligomer). In the polymer obtained in this manner, the urethane chain and the acrylic chain may be bonded to each other in a block type or in a graft type.

[0035]

Embedded image

The urethane-modified acrylic resin used in the present invention is not limited to the one obtained by the above-mentioned method. In addition, a method in which diisocyanate is added to an acrylic diol mixed system, a terminal isocyanate polyester as an acrylic monomer, It can also be obtained by adding polyether or the like and polymerizing the urethane acrylate. In addition, the acrylic resin component used for the synthesis includes a glass transition temperature T as a polymer.
g is preferably from room temperature to about 110 ° C.
-In addition to hydroxyethyl methacrylate, those containing, for example, ethyl methacrylate, isobutyl methacrylate, glycidyl methacrylate and the like are used. At this time, the composition of the acrylic component in the urethane-modified acrylic resin is 5 to 90% by weight, particularly 20 to 80% by weight.
Is preferable, and particularly preferably 50 to 70% by weight.

The acrylic resin component may contain another monomer such as styrene in addition to the acrylic monomer.

Further, from the viewpoint of improving the adhesion to the photoreceptor,
A silicone component may be contained in the urethane-modified acrylic resin. Specifically, for example, a method of synthesizing by reacting a urethane prepolymer and an acrylic component using a polyol containing a silicone chain as a raw material can be considered. In this case, the composition of the silicone component in the urethane prepolymer is 2 to 80% by weight, particularly 5 to 50%.
It is preferably in the weight%. Further, the composition of the silicone component in the urethane-modified acrylic resin after the reaction is preferably 1 to 50% by weight, particularly preferably 3 to 30% by weight.

The polycarbonate used in the present invention includes bisphenol A type represented by the following general formula (1), and polymers containing the structures represented by the following general formulas (2) and (3) as repeating units. It is preferably used. Although the degree of polymerization is not particularly limited, it is generally 10 to 1000, preferably about 50 to 200.

[0040]

[Chemical 2](However, in the formulas (2) and (3), R ₁, R₂, R₃, R _FourIs
A hydrogen atom or a substituted or unsubstituted carbon number of 1 to 10
Monovalent hydrocarbon group (aliphatic group, carbocyclic group or aromatic group)
Indicates R _Five, R₆, R₇, R ₈, R ₉, R_Ten, R ₁₁, R₁₂
Is a hydrogen atom, a halogen atom, or substituted or unsubstituted
Represents a monovalent aliphatic group or a carbocyclic group having 1 to 10 carbon atoms
And Z is a substituted or unsubstituted carbon ring having 1 to 10 carbon atoms.
Or a group of atoms necessary for forming a heterocyclic ring. Also,
In the formulas (2) and (3), m is an integer of 0 to 10, n is 0 or
Is 1, and p of A and B is an integer of 1 to 10. )

Here, these polycarbonates are easily synthesized, for example, by reacting a diol compound represented by the following formula (4) with phosgene in a methylene chloride solution in the presence of an alkali.

[0042]

Embedded image

The structure of the polycarbonate used in the present invention is not limited to those described above, but may be a copolymer of these or a copolymer with another aliphatic or aromatic diol compound. .

Examples of the acrylic resin include polyacrylate, polymethyl methacrylate, polymethyl ethacrylate, those obtained by substituting their side chain terminals with a hydroxyalkyl group and the like, and copolymers thereof.

The fluororesin used in the present invention includes
Polytetrafluoroethylene, polyvinylidene fluoride,
A common fluorine-containing polymer such as ethylene tetrafluoride-propylene hexafluoride copolymer is used, and a solvent-soluble fluororesin is particularly preferably used. Solvent-soluble fluororesins include vinylidene fluoride copolymers such as ternary copolymers of CH ₂ CF ₂ , C ₂ F ₄ and C ₃ F ₆ , C ₂ F ₄ , C ₂
Fluoroolefins such as F ₃ Cl and vinyl ethers,
Various copolymers such as copolymers of hydrocarbon olefins such as vinyl esters and vinyl silanes, copolymers of fluoroacrylates and acrylates, and polymers of diepoxy compounds substituted by perfluoroalkyl groups are used. Can be

These resins may be used alone as the resin component of the present invention, or may be used as a mixture with other resins.

Among these, soluble nylon and fluororesin are particularly preferably used from the viewpoint of reducing contamination and further reducing toner adhesion.

By the above surface treatment with the resin, low friction of the roller surface is achieved to some extent, but various additives can be used for further reduction of friction. As a result of earnest studies, the present inventor has found that silicone resin, silicone resin powder, fluorine-based and silicone-based additives are used as additives capable of reducing friction without contamination of the photoreceptor and deterioration of surface treatment uniformity. It has been found that surfactants, silicon-based coupling agents and silica powder are effective.

As the solvent-soluble silicone resin, for example, methylsilicone, methylphenylsilicone, modified products thereof, silicone epoxy block copolymers and the like are used.

Examples of the silicone resin powder include fine powder of methylsilicone or methylphenylsilicone polymer, and the average particle diameter is 0.1 to 100 μm.
Are used.

The fluorinated surfactants are ionic ones in which alkyl fluoride and carboxylic acid, carboxylate, sulfonate and the like are bonded, alkyl fluoride and alcohol,
Examples thereof include nonionic ones to which ether or the like is bound, and polymer-based ones such as polymers and copolymers containing alkyl fluoride in the side chain and main chain.

Examples of the silicone-based surfactant include high molecular weight compounds such as a conjugate of a general silicone such as siloxane oxyethylene with a hydrophilic and lipophilic segment, and a copolymer of a methyl silicone and an acrylic segment. Things.

As the silicon-based coupling agent, not only a usual silane coupling agent but also an amino group at the terminal,
Included are silanes into which an isocyanate group, vinyl group, etc. have been introduced.

These may be used alone or in combination of two or more. The fluororesin also acts effectively as a friction reducing agent. The friction reducing agent is used in an amount of 1 to 100 parts by weight, preferably 10 to 75 parts by weight, based on 100 parts by weight of the resin component.

If necessary, the treatment liquid may contain the above-mentioned ion conductive substance. The compounding amount of the ion conductive material is preferably 0.001 to 1 part by weight with respect to 100 parts by weight of the resin component.

As the surface treatment, after preparing a treatment solution,
It can be performed by a spray method, a roll coater method, a dipping method, or the like. For example, surface treatment by dipping is usually performed at room temperature for 5 seconds to 5
Immersion for 10 minutes to 1 minute,
A drying method can be employed. When the spray method is adopted, the concentration of the resin in the treatment liquid can be set higher than that of the dipping method. For example, a resin whose concentration is adjusted to 10 to 30% can be used.
If the resin component can be applied to the surface of the elastic layer so that (R ₂ / R ₁ ) ≦ 3, the object of the present invention can be achieved.

The solvent for preparing the resin solution may be any solvent as long as it dissolves the above resin. Usually, lower solvents such as methanol, ethanol and isopropanol, and ketones such as acetone, methyl ethyl ketone and cyclohexanone are used. , Toluene, xylene and the like are preferably used.

In this case, it is considered that a uniform coating layer is not formed by the above resins on the surface of the developing roller subjected to the above surface treatment, and that the elastic layer is polished in some places. This means that the SEM
It can be easily determined by observing with a roller, and also in the measurement of roller resistance, if a uniform film is originally formed on the elastic layer, the roller resistance should rise sharply in proportion to the treated resin concentration. However, when the roller treated with the resin concentration of the present invention is treated with, for example, copolymerized nylon, the resistance gradually increases up to a concentration of 6 to 7% by weight, and then rapidly increases as shown in FIG. It is expected from the fact that the tendency to

Therefore, as described above, in the surface treatment of the present invention, when the surface is usually treated on a smooth surface, unlike the case where a uniform coating layer of several microns is formed, the surface of the elastic layer is irregularly formed. A resin is attached to the surface to improve the surface characteristics while maintaining the roughness of the elastic layer.

The developing roller of the present invention can be incorporated in an ordinary developing device using a non-magnetic monochromatic developer, and specifically, as shown in FIG. 2, a toner applying roller for supplying toner. 4 and the photosensitive drum 5 holding the electrostatic latent image, the developing roller 1 of the present invention is disposed in contact with the photosensitive drum 5, and the toner 6 is supplied to the developing roller 1 by the toner applying roller 4. Then, this is made into a uniform thin layer by the layering blade 7, toner is further supplied from this thin layer to the photosensitive drum 5, and toner is attached to the electrostatic latent image of the photosensitive drum 5 to visualize the latent image. You can Note that FIG.
Since details of the above have been described in the related art, the description thereof will be omitted.

[0061]

EXAMPLES The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples. In the following example, the surface treatment was performed by immersing the surface in the treatment liquid for 30 seconds at room temperature.

Example 1 A molecular weight of 500 was obtained by adding propylene oxide and ethylene oxide to glycerin.
100 parts of polyether polyol (Exenol 828 of Asahi Glass Co., Ltd.) with 0 (OH value 33) (parts by weight,
The same shall apply hereinafter), 1.0 part of 1,4-butanediol, a silicone surfactant (manufactured by Nippon Unica Ltd., L-520).
5 parts, 0.5 part of nickel acetylacetonate, 0.01 part of dibutyltin dilaurate and 2.0 parts of acetylene black (manufactured by Denka Co., pH 6.9) are added, and the mixture is preliminarily mixed using a mixer and then painted. Acetylene black was uniformly dispersed by kneading with a roll to prepare a polyol composition.

After degassing by stirring this polyol composition under reduced pressure, 17.5 parts of urethane-modified MDI (Sumijour PF manufactured by Sumitomo Bayer Urethane Co., Ltd.) was added to obtain 2
Stir for 1 minute and then cast into a mold heated to 110 ° C,
After curing for 2 hours, an elastic layer was formed on the outer circumference of the metallic shaft to obtain a roller having the structure shown in FIG. The surface of the obtained roller is ground to a JIS 10-point average roughness of 7 μmR.
_After adjusting to _z , a developing roller was prepared.

Next, the developing roller was filled with 3% by weight of soluble nylon (CM8000, manufactured by Toray) in methanol.
Immerse in the dissolved solution, pull it up, dry it,
Surface treatment was performed.

Example 2 3.32 parts of acetylene black was mixed with 100 parts of polyisoprene polyol having a molecular weight of 2500 (OH value = 47.1) and stirred for 30 minutes. Thereafter, 13.33 parts of Glue MDI (NCO% = 31.7) and 0.001 part of dibutyltin dilaurate were added and stirred for 3 minutes. Next, a shaft was arranged, and this reaction mixture was poured into a mold heated to 90 ° C. in advance, and a curing reaction was performed at 90 ° C. for 12 hours to obtain a roller.

The surface of the obtained roller is ground to JIS 10
The developing roller was prepared by adjusting the point average roughness to 7 μmR _z .

Next, the developing roller was mixed with toluene in a solvent-soluble fluororesin (Belflon 1000, manufactured by NOF CORPORATION).
Was immersed in a solution in which 5% by weight was dissolved, pulled up and dried to perform a surface treatment.

Example 3 Instead of the soluble nylon solution, polymethylmethacrylate (Dianal LR177,
The same operation as in Example 1 was performed except that the surface treatment was performed using a 3% by weight toluene / methyl ethyl ketone solution (manufactured by Mitsubishi Rayon Co., Ltd.).

[Example 4] ISAF carbon 25 to 100 parts of EPDM (EP33, manufactured by Japan Synthetic Rubber Co., Ltd.)
Part, 5 parts of zinc oxide, 1 part of stearic acid, and 1 part of dicumyl peroxide were mixed by a roll mill, and the mixture was wound around the outer circumference of a metal shaft and 100 kg / cm ² of a mold preheated to 150 ° C. The roller having the structure shown in FIG. 1 was molded by pressure for 30 minutes, and the surface thereof was polished, and then the JIS 10-point average roughness was set to 7 μm.

Next, the developing roller was immersed in a solution of polycarbonate (Z200, manufactured by Mitsubishi Gas Chemical Co., Inc.) in toluene at a concentration of 3% by weight, which was pulled up, dried and surface-treated. .

[Example 5] In Example 1, 50 parts of a solvent-soluble fluororesin (Nippon Oil & Fats, Belflon) was added to 100 parts of the soluble nylon in the soluble nylon solution, and the same surface treatment was carried out. .

[Example 6] In Example 1, 200 parts of silicone resin fine particles (Toshiba Silicon, Tospearl 240) were added to 100 parts of soluble nylon, and the same surface treatment was carried out.

Example 7 In Example 1, 5 parts by weight of a silicone-based surfactant (Modiper FS710, manufactured by NOF CORPORATION) was added to 100 parts of soluble nylon,
Surface treatment was performed similarly.

[Example 8] In Example 1, 10 parts of positively charged silica H2050EP (manufactured by Hexas Japan) was added to 100 parts of soluble nylon, and the same surface treatment was carried out.

Example 9 A developing roller was obtained in the same manner as in Example 3 except that 50 parts of silicone rubber (EH5250U, manufactured by Japan Synthetic Rubber Co., Ltd.) was added to 100 parts of EPDM. Next, the developing roller was filled with 3% by weight of a urethane-modified acrylic resin (EAU8B, manufactured by Asia Industrial Co., Ltd.) in toluene / methyl ethyl ketone / isopropyl alcohol.
It was immersed in a solution in which the concentration and sodium perchlorate were dissolved at a concentration of 0.3% by weight, pulled up, dried and subjected to a surface treatment.

Comparative Example 1 In Example 1, the developing roller before forming the surface coating layer was used as an evaluation sample.

Comparative Example 2 In Example 1, a 12 wt% methanol solution of soluble nylon was used to form a coating layer of about 10 μm on the surface.

[Comparative Example 3] In Example 1, 2% by weight of polyvinyl chloride (S-REC E, manufactured by Sekisui Chemical Co., Ltd.)
Surface treatment was performed using the solution.

The following characteristic tests were conducted on the developing rollers obtained in the above Examples and Comparative Examples. The results are shown in Table 1. (1) Roller resistance Each roller was pressed against a copper plate with a load of 500 g on both ends, and a resistance meter R8340A (manufactured by Advantest) was used to measure 100
The measurement was performed by applying a voltage of V. (2) Surface roughness For each roller, a surface roughness meter Handy Surf E-30
It was measured using A type (manufactured by Tokyo Seimitsu Co., Ltd.). (3) Contamination of photosensitive drum Each roller is manufactured by NEC, printer PC-PR1000E.
Press on both sides of the photosensitive drum for / 4 with a load of 500 g on both ends, and
After standing at 5 ° C. and 85% RH for 5 days, the contamination of the surface of the photosensitive drum and the image by the actual machine were visually confirmed. (4) Toner charge amount Each roller is installed as a developing roller in the developing unit shown in FIG. 2 and rotated at a peripheral speed of 50 mm / sec to form a uniform thin toner layer on the surface of the developing roller. The layer was sucked with air and introduced into a Faraday gauge, and the charge amount was measured. (5) Image Output Using the developing unit shown in FIG. 2 with each roller as a developing roller and a non-magnetic component toner having an average particle size of 7 μm, an image is output by reversal development while rotating at a peripheral speed of 60 mm / sec. The image quality (sharpness, density uniformity), fogging, and toner dust generation at the initial stage and after 2000 prints were evaluated. The results are shown in Table 1.

Further, in Example 1, the roller resistance was measured when the resin concentration was variously changed. The results are shown in Fig. 3.

[0081]

[Table 1]

[0082]

According to the developing roller of the present invention, it is possible to obtain a high-quality image without causing the inconvenience of contaminating the photosensitive member and the like and without causing the uneven density and the background fog, and in the long-term use. Does not cause deterioration of image quality.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an example of a developing roller of the present invention.

FIG. 2 is a schematic sectional view showing an example of the developing device of the present invention.

FIG. 3 is a graph showing a relationship between a resin concentration by a surface treatment and a roller resistance.

[Explanation of symbols]

 1 Developing Roller 2 Shaft 3 Elastic Body 4 Toner Applying Roller 5 Photosensitive Drum (Latent Image Holding Body) 6 Toner (Non-magnetic One-Component Developer) 7 Layering Blade 8 Transfer Section 9 Cleaning Section 10 Cleaning Blade

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Taro Miyamoto 3-5-5-610 Ogawahigashi-cho, Kodaira-shi, Tokyo (72) Inventor Manabu Yakushiji 3-5-5-612 Ogawa-higashi-cho, Kodaira-shi, Tokyo (72) Inventor Takahiro Kawagoe 1302-57 Aobadai, Tokorozawa, Saitama Prefecture

Claims (7)

[Claims] 1. An elastic layer having conductivity is formed on the outer periphery of a good conductive shaft, and a non-magnetic one-component developer is carried on the surface of the elastic layer to form a thin layer of the developer. In a developing roller for contacting a latent image holding member having an electrostatic latent image on its surface to visualize the electrostatic latent image, the elastic layer has a non-staining property on the surface of the latent image holding member. And has a resin component containing no conductive powder, and R _{1 is} the roller resistance when this resin component is not contained,
A developing roller characterized by satisfying a relationship of log (R ₂ / R ₁ ) ≦ 3, where R ₂ is a roller resistance when the resin component is included. 2. The developing roller according to claim 1, wherein the resin component is one or more selected from soluble nylon, acrylic resin, urethane-modified acrylic resin, polycarbonate and fluororesin. 3. A friction reducing agent selected from a silicone resin, a fluorine-based surfactant, a silicone-based surfactant, a silicon-based coupling agent, and silica powder is added to the resin component with respect to 100 parts by weight of the resin component. The developing roller according to claim 1 or 2, wherein 1 to 100 parts by weight is blended. 4. The developing roller according to claim 1, wherein an ionic conductive substance is added to the resin component. 5. The developing roller according to claim 1, wherein the elastic layer is surface-treated by immersing the surface of the elastic layer in a resin solution having a concentration of the resin component of 9% by weight or less. .. 6. The developing roller according to claim 1, wherein the elastic layer is mainly made of polyurethane elastomer or EPDM. 7. A latent image holding member for holding an electrostatic latent image on the surface thereof, and a non-magnetic one-component developer carried on the outer peripheral surface thereof are brought into contact with the surface of the latent image holding member and rotated, thereby A developing device, comprising: a developing roller for adhering a non-magnetic one-component developer to an electrostatic latent image on the surface of a latent image carrier to visualize the electrostatic latent image, wherein the developing roller is the developing roller. A developing device using the developing roller according to any one of 1.