JP2003098818A - Developer carrier and developing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developer carrier for attaining low harding of elastic layer and effectively preventing contamination of other members adhered thereto. SOLUTION: The developer carrier for dispersing an absorbent of 0.4 m<2> /g or greater for the specific surface in an elastic body, constituting an elastic layer 8 at a ratio of 0.5-100 pts.wt. to 100 pts.wt. of a polymeric substance component forming the elastic body is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic or electrostatic recording type image forming apparatus such as a copying machine, a facsimile or a printer, which carries a developer on a surface thereof and conveys the developer, thereby forming a photosensitive drum or the like. The present invention relates to a developer carrier for supplying a developer to a latent image carrier to develop an electrostatic latent image on the latent image carrier, and a developing device using the developer carrier.

[0002]

2. Description of the Related Art Conventionally, in an electrophotographic image forming apparatus such as a copying machine or a printer, a developer is supplied to a latent image holding member such as a photosensitive drum that holds an electrostatic latent image, and the latent image holding member is used. A pressure developing method is known as a developing method in which an image is attached and visualized.

In this pressure developing method, for example, as shown in FIG. 2, the developer 3 is supplied to the developer carrier 2 by the blade-shaped or roll-shaped (roll-shaped in the figure) developer supply body 1. The developer carrier 2 is carried on the surface of the developer carrier 2 and conveyed by the rotation of the developer carrier 2,
Is regulated to a thin layer having an appropriate thickness when passing between the developer amount regulating blade 4 arranged in pressure contact with the developer amount regulating blade 4 and at the same time charged to a proper potential by friction with the developer amount regulating blade 4. , Is supplied to the latent image holding member 5 arranged in contact with the developer carrying member 2 and adheres to the electrostatic latent image formed on the surface of the latent image holding member 5 to form an electrostatic latent image. It is what is visualized (developed). Incidentally, reference numeral 6 in FIG. 2 denotes a developer sealing material arranged along the end portion of the developer carrier 2, and the developer sealing material 6 prevents the developer 3 from leaking. There is.

In recent years, in electrophotographic type or electrostatic recording type image forming apparatuses such as copiers, facsimiles, printers, etc., the developer is made into fine particles for the purpose of colorization and improvement of image quality. Along with the lowering of the melting point of the developer for power saving, the developer on the developer carrying member 2 is contacted with the developer amount regulating blade 4 and the developer supplying member 1 at the contact surface. The problem of taking damage is getting serious. Therefore, in order to reduce the damage of the developer, it is required to reduce the hardness of the developer carrier 2.

Generally, in the developer carrying member 2, at least one elastic layer made of resin, rubber, elastomer or the like is formed on the outer periphery of a core material made of metal such as phosphor bronze, stainless steel, aluminum or iron. It is configured as
As a main material for forming the elastic layer, a diene rubber,
Rubber materials such as urethane rubber, EPDM, and silicone rubber, and urethane elastomers obtained by curing a polyol compound with a polyisocyanate compound are used.

However, when a developer bearing member is manufactured by forming an elastic layer having a low hardness with the above materials, there arises a problem that the contact portion such as the latent image holding member is contaminated.
This is because in order to achieve low hardness in the above materials, a method of introducing a low molecular weight component or reducing the reaction points of the cured product is adopted, which does not contribute to the reaction that is increased when the cured product is formed. Unreacted components and low-molecular-weight components contained in the material itself bleed out to the area where they are in close contact with the latent image carrier and cause contamination.

The present invention has been made in view of the above circumstances, and in an electrophotographic or electrostatic recording type image forming apparatus, the developer supplied from a developer supply member is carried on the surface and conveyed, By supplying a developer to the electrostatic latent image formed on the image carrier, the hardness of the elastic layer of the developer carrier for developing the electrostatic latent image can be reduced and the developer can be adhered to it. It is an object of the present invention to provide a technique capable of effectively preventing contamination of members.

[0008]

Means for Solving the Problems and Modes for Carrying Out the Invention As a result of earnest studies for achieving the above-mentioned object, the present inventor found that at least one elastic layer was formed on the outer periphery of a core body to form a developer. When obtaining a carrier, it was found that an adsorbent that adsorbs contaminants is dispersed in the elastic layer to prevent bleed-out of contaminants from the elastic layer, and as a result of further studies, the above adsorption The specific surface area of the agent is 0.4 m ² / g or more, and the amount of the adsorbent compounded is in the range of 0.5 to 100 parts by weight with respect to 100 parts by weight of the polymeric substance component forming the elastic layer. , The contaminants in the elastic layer can be adsorbed well and the bleed-out of the contaminants can be effectively prevented, and the contamination of other members in the close contact part can be prevented as much as possible, and the problem of contamination with low hardness can be solved. We found that a developer carrier that does not occur can be obtained. One in which the present invention has been completed.

Therefore, according to the present invention, a developer is carried on the surface to form a thin layer of the developer, which is conveyed and supplied to the electrostatic latent image formed on the surface of the latent image carrier, In a developer carrier for developing the electrostatic latent image, at least one elastic layer is provided on the outer periphery of a core body, and the elastic body constituting the elastic layer has a specific surface area of 0.4 m ² / g. The amount of the above adsorbent is 0.5 with respect to 100 parts by weight of the polymeric substance component forming the elastic body.
Disclosed is a developer carrying member characterized by being dispersed in an amount of 100 to 100 parts by weight, and a developing device comprising the developer carrying member.

The present invention will be described in more detail below.
The developer carrying member of the present invention is one in which at least one elastic layer in which an adsorbent is dispersed is formed on the outer periphery of a core, and for example, as shown in FIG. An example is a roller-shaped development carrier in which the elastic layer 8 in which is dispersed is formed.

The core body 7 is not particularly limited and may be a solid or hollow core body made of various metals or resins. Examples of the metal include iron, copper, nickel silver, stainless steel, phosphor bronze and the like. The resin is exemplified by polyethylene, polyamide, polyacetal, polycarbonate, polyethylene terephthalate, polyimide, polyamide imide, polyester, phenol resin, melamine resin, silicone resin, epoxy resin, acrylic resin, methacrylic resin, urea resin and the like. A resin is exemplified.

As the main material for forming the elastic body 8, isoprene rubber, butadiene rubber, styrene / butadiene rubber, acrylonitrile / butadiene com, chloroprene rubber, ethylene / propylene rubber, ethylene / propylene terpolymer, butyl rubber, acrylic resin. Rubber materials such as rubber, chlorosulfonated polyethylene, silicone rubber, fluororubber, polyether rubber, epichlorohydrin rubber, urethane rubber, and polyurethane elastomer materials obtained by curing polyol compounds with a polyisocyanate compound, polyurethane, silicone , Polystyrene / polybutadiene block polymer (S
BS), styrene ethylene butylene styrene block copolymer (SEBS), styrene ethylene propylene styrene block copolymer (SEPS), polyolefin,
Examples thereof include thermoplastic elastomers such as polyethylene, chlorinated polyethylene, ethylene / vinyl acetate copolymer, and mixtures thereof. Among them, in order to reduce the hardness of the elastic layer as much as possible, organic rubber materials such as diene rubber, urethane rubber, EPDM and silicone rubber, or elastomer materials such as urethane, SBS, SEBS and SEPS are preferably used. Among them, silicone rubber is more preferably used because it can easily form an elastic body having a low hardness and a low compression set.

If desired, known additives may be added to these elastic bodies. For example, fillers such as carbon, plasticizers such as various oils, and additives such as charge control agents may be used for the purpose of the present invention. An appropriate amount can be added if necessary within the range not deviating from the above.

The elastic layer 8 may be composed of a single layer or a plurality of layers of two or more layers. Further, a part or the whole of the elastic layer 8 in the thickness direction may be a foam, and by providing the foam layer in this way, the polymer material itself which is a constituent material of the elastic layer 8 has a significantly low hardness. It is also possible to eliminate the need to reduce the hardness, or to eliminate the need to reduce the hardness of the polymer material, it is possible to effectively reduce the generation of unreacted components and low molecular weight components that occur with the reduction in hardness, Contamination can be prevented more effectively.

The developer carrying member of the present invention is prepared by mixing and dispersing an adsorbent in the elastic body forming the elastic layer 8, and the unreacted component and the low content in the low hardness material forming the elastic layer 8 are reduced. By adsorbing pollutants having a molecular weight to this adsorbent, bleed-out of these pollutants is prevented as much as possible.

This adsorbent has a specific surface area of 0.4 m ² / g
The above is used, preferably 1 m ² / g or more, more preferably 5 m ² / g or more. As the adsorbent, any adsorbent may be used as long as it satisfies the specific surface area, and is not particularly limited, and examples thereof include various activated carbons, zeolites, acid clay, silica, silica gel, silica-alumina gel. , Alumina, magnesia, oxides of Mg, Al or Si, silicates, carbonates, and the like, and one or more of these may be used in combination. The amount of the adsorbent compounded and dispersed is 0.5 to 100 parts by weight, preferably 2 to 100 parts by weight of the polymeric material forming the elastic layer 8.
˜80 parts by weight, more preferably 5 to 50 parts by weight.

Here, the specific surface area of the adsorbent is 0.4 m.
If it is less than ² / g, a large amount of adsorbent exceeding 100 parts by weight is required to secure a necessary amount of adsorption sites for contaminants existing on the surface of the adsorbent, and the physical properties of the elastic body forming the elastic layer 8 are required. It will cause a change. Specifically, even if the elastic layer 8 is formed of a low-hardness material, the hardness becomes high due to the addition of a large amount of an adsorbent, or the compression set deteriorates, so that the developer amount control member or the latent image holding member is formed. Due to the long-term pressure contact, the developer bearing member is deformed, resulting in inconvenience such as image failure. On the other hand, the admixture dispersion amount of the adsorbent is 0.
If the amount is less than 5 parts by weight, the total amount of adsorption sites is insufficient to sufficiently adsorb the contaminants, and the latent image holding member or the like is contaminated, and the object of the present invention cannot be achieved.

The elastic layer 8 is shown as an example of one layer in FIG. 1, but it is also possible to form a plurality of layers. In this case, the adsorbent is dispersed in at least one elastic body constituting the elastic layer. If you have.

In addition, a conductive agent may be added to the elastic layer 8 as needed to impart conductivity or adjust conductivity. As the conductive agent, tetraethylammonium, tetrabutylammonium, lauryltrimethylammonium, stearyltrimethylammonium, octadecyltrimethylammonium, dodecyltrimethylammonium, hexadecyltrimethylammonium,
Perchlorates such as benzyltrimethylammonium and modified fatty acid dimethylethylammonium, chlorates, hydrochlorides, bromates, iodates, borofluorides, sulfates, ethylsulfates, carboxylates, sulfonic acids Ammonium salts such as salts; lithium, sodium, calcium,
Perchlorates, chlorates, hydrochlorides, bromates, iodates, borofluorides, trifluoromethylsulfates of alkali metals or alkaline earth metals such as magnesium,
Ion conductive agents such as sulfonates; conductive carbon such as Ketjen black and acetylene black; SAF,
ISAF, HAF, FEF, GPF, SRF, FT, M
Carbon for rubber such as T; carbon for ink subjected to oxidation treatment, pyrolytic carbon, graphite; conductive metal oxide such as tin oxide, titanium oxide and zinc oxide; electronic conductive agent such as metal such as nickel and copper For example, conductive carbon, carbon for rubber, and carbon for ink are preferably used.

The amount of the conductive agent blended is appropriately selected according to the type of the conductive agent and is not particularly limited,
Usually, it is preferably 0.01 to 50 parts by weight, particularly 1 to 30 parts by weight, relative to 100 parts by weight of the above-mentioned polymer substance, which is the main material of the elastic layer 8, whereby the electric resistance of the elastic layer 8 is 10 parts by weight. ² to 10 ¹¹ Ω · cm, especially 10 ⁴ to 10 ⁹ Ω
-It is preferable to adjust to about cm.

In addition to the above-mentioned adsorbent and conductive agent, known fillers, vulcanizing agents, and other additives may be added to the elastic layer 8 if necessary, within the scope of the present invention. It may be added appropriately.

The hardness of the elastic layer 8 is not particularly limited, but is 20 to 85, particularly 4 as measured by an Asker C hardness meter.
0 to 75 is preferable, and the developer carrying member of the present invention ensures a good developing operation without causing a problem of contamination due to the action of the adsorbent even when set to such a low hardness. It is something you can do.

The elastic layer 8 can be formed by any known method without particular limitation. Generally, it is applied, integrally molded, extruded, or previously formed into a cylindrical shape and cut into a suitable size. A method of inserting the core body 7 into the elastic body and adhering it is adopted. An adhesive layer may be provided between the core body 7 and the elastic layer 8 if necessary.

The developer carrier of the present invention is, as described above,
The elastic layer 8 in which an adsorbent is dispersed is formed on the outer periphery of the core body 7. As shown by the one-dot chain line in FIG. 1, the adhesion resistance is improved and the charging property is optimized on the elastic layer 8. The coating layer 9 can be formed as necessary for the purpose of reducing the friction coefficient.

As the material for forming this coating layer, polyester resin, polyether resin, fluororesin, epoxy resin, amino resin, polyamide resin, acrylic resin,
Examples thereof include acrylic urethane resin, urethane resin, alkyd resin, phenol resin, melamine resin, urea resin, silicone resin, polyvinyl butyral resin, and mixtures thereof.

If necessary, a filler such as carbon, a plasticizer such as oil, an additive such as a charge control agent may be appropriately added to the coating layer 9 within a range not departing from the object of the present invention. Absent. The method for forming the coating layer 9 on the elastic layer 8 is not particularly limited, and for example, coating, in-mold coating method, or a method of coating by shrinking a shrink tube previously formed in a cylindrical shape by overheat shrinkage is appropriately selected. To be done. An adhesive layer may be provided between the elastic layer 8 and the coating layer 9 if necessary.

The developer carrying member of the present invention is for supplying a developer to a latent image holding member to develop an electrostatic latent image on the latent image holding member in an electrophotographic apparatus or an electrostatic recording apparatus. Yes,
For example, in the developing device having the mechanism shown in FIG.
Is used as. Since the developing device in FIG. 2 has been described above, its details are omitted.

The developer carrier of the present invention is shown in FIGS.
The present invention is not limited to the roller-shaped member as shown in (1), but may have an appropriate form depending on the structure of the developing device used. Also, the developing device of the present invention,
The present invention is not limited to the one shown in FIG. 2 above, and is provided with a developer carrier that carries a developer on the surface to form a thin layer of the developer, and conveys the developer to supply it to the latent image carrier. If,
Its structure may be different from that of the developing device of FIG.

[0029]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. Example 1 An organic rubber material having the following composition (1) was mixed with a kneader, molded with a mold, cured by heating, and then demolded and polished to form an elastic layer on the outer periphery of a cylindrical core, Figure 1
A developer carrier having the structure shown in was obtained. However, the coating layer 9 indicated by the alternate long and short dash line in FIG. 2 was not formed. Alumina used as an adsorbent (manufactured by Sumitomo Chemical Co., Ltd .: “AL
The specific surface area of M43 ") was 1.2 m ² / g. Further, the surface hardness of the obtained developer bearing member was 68 ° with an Asker C hardness meter. Blend (1) Polybutadiene rubber (JSR: “BR18”) 75.0 g Liquid polyisoprene (Kuraray: “LIR30”) 25.0 g Conductive carbon black (Lion: “Ketjen EC600JD”) 3.2 g Zinc oxide (manufactured by Huxui Tech: "Zinc Hua No. 1") 1.0 g Alumina (manufactured by Sumitomo Chemical Co., Ltd .: "ALM43") 20.0 g Stearic acid (manufactured by Miyoshi Yushi Co., Ltd.) 1.0 g Vulcanizing agent (Nippon Yushi Co., Ltd.) Product: "Perhexa 3M-40") 1.5 g

The obtained developer bearing member was installed in a developing device similar to that shown in FIG. 2 and left under high temperature and high humidity (50 ° C., 90%) for 7 days. No pollution was found in the. On the other hand, when the developing device was attached to the image forming apparatus and a printing test was conducted, a good image was obtained. Further, a developer carrying member prepared in the same manner as described above was incorporated into a developing device, allowed to stand for 4 weeks in a state of being in pressure contact with the latent image holding member, and a printing test was carried out. As a result, a good image was obtained.

[Comparative Example 1] The amount of the cross-linking agent (Nippon Yushi Co., Ltd .: "Perhexa 3M-40") was increased to 2.0 g without adding the adsorbent alumina (Sumitomo Chemical Co., Ltd .: "ALM43"). A developer carrying member was obtained in the same manner as in Example 1 except that the organic rubber material having the same composition as the above-mentioned formulation (1) was used except for the above.
The surface hardness of the obtained developer carrying member was 68 ° by an Asker C hardness meter.

The developer carrier thus obtained was used in Example 1.
When the same test was performed, a clear contamination was found on the contact surface with the latent image holder in the storage test under high temperature and high humidity, and in the printing test, the image was found at the position corresponding to the contact part. A defect has occurred.

[Comparative Example 2] The adsorbent alumina was changed to "AS-10" manufactured by Showa Denko KK, and the compounding amount was 40.0.
A developer carrying member was obtained in the same manner as in Example 1 except that the organic rubber material having the same composition as the above-mentioned formulation (1) was used except that the amount was changed to g. The specific surface area of the alumina added as an adsorbent,
It was 0.3 m ² / g. The surface hardness of the obtained developer bearing member was 68 ° with an Asker C hardness meter.

The developer carrier thus obtained was used in Example 1.
When the same test was performed, a clear contamination was found on the contact surface with the latent image holder in the storage test under high temperature and high humidity, and in the printing test, the image was found at the position corresponding to the contact part. A defect has occurred.

[Comparative Example 3] The adsorbent alumina (Showa Denko KK: "AS-10") was added to 120.0 g, and the cross-linking agent (NOF CORPORATION: "Perhexa 3M-40") was added to 0.
An organic rubber material having the same composition as the organic rubber material used in Comparative Example 2 was used except that the amount was reduced to 8 g, and a developer carrying member was obtained in the same manner as in Example 1. The surface hardness of the obtained developer carrying member was 70 ° on an Asker C hardness meter.

The developer carrier thus obtained was used in Example 1.
When a test similar to the above was performed, no contamination was found on the contact surface with the latent image holding member in the standing test under high temperature and high humidity, and a good image was obtained in the printing test. However, in the printing test after leaving the latent image carrier in pressure contact for 4 weeks, the residual strain of the developer carrier was found at the position corresponding to the contact portion between the developer image carrier and the latent image carrier. The cause is a defective image.

[Comparative Example 4] The alumina of the adsorbent was changed to "AL-43-L" manufactured by Showa Denko KK, and the compounding amount was adjusted to 0.
The above formulation (1) used in Example 1 except that the amount was reduced to 3 g.
A developer carrying member was obtained in the same manner as in Example 1, using an organic rubber material having the same composition as in (1). The specific surface area of the alumina added as the adsorbent was 3.2 m ² / g. Also,
The surface hardness of the obtained developer carrying member was 68 ° by an Asker C hardness meter.

The developer carrier thus obtained was used in Example 1.
When the same test was performed, a clear contamination was found on the contact surface with the latent image holder in the storage test under high temperature and high humidity, and in the printing test, the image was found at the position corresponding to the contact part. A defect has occurred.

Example 2 A liquid silicone rubber raw material having the following composition (2) was mixed, cast into a mold, molded and heat-cured, and then demolded and polished to form a cylindrical core outer periphery. An elastic layer was formed to obtain a developer carrier having the structure shown in FIG. However, the coating layer 9 indicated by the alternate long and short dash line in FIG. 2 was not formed. Further, the specific surface area of alumina (Sumitomo Chemical Co., Ltd .: "ALM43") used as an adsorbent is 1.2 m.
It was ² / g. Further, the surface hardness of the obtained developer bearing member was 70 ° with an Asker C hardness meter. Formulation (2) Liquid silicone (Toray Dow Corning: “DY35-4046A”) 50.0 g Liquid silicone (Toray Dow Corning: “DY35-4046B”) 50.0 g Alumina (Sumitomo Chemical Co., Ltd.) Made: "ALM43") 20.0 g

The developer carrier thus obtained was used in Example 1.
When a test similar to the above was performed, no contamination was found on the contact surface with the latent image holding member in the standing test under high temperature and high humidity, and a good image was obtained in the printing test. Further, a good image was obtained in the printing test after leaving the latent image carrier in pressure contact for 4 weeks.

[Comparative Example 5] A liquid silicone rubber raw material having the same composition as that of the above-mentioned formulation (2) was used, except that alumina as an adsorbent ("ALM43" manufactured by Sumitomo Chemical Co., Ltd.) was not used. Similarly, a developer carrying member was obtained. The surface hardness of the obtained developer bearing member is 68 by an Asker C hardness meter.
It was °.

The developer carrier thus obtained was used in Example 1.
When the same test was performed, a clear contamination was found on the contact surface with the latent image holder in the storage test under high temperature and high humidity, and in the printing test, the image was found at the position corresponding to the contact part. A defect has occurred.

[0043]

As described above, when the developer carrying member of the present invention is used in an electrophotographic type or electrostatic recording type image forming apparatus, it is used for colorizing the image forming apparatus and improving the image quality. Despite the fine particles of the developer or the low melting point of the developer to save power, the hardness is low enough not to break or stick the developer when it is used, and bleed-out of contaminants accompanying the low hardness Therefore, a good image can be reliably obtained without contaminating the latent image holding member or the developer supply member.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an example of a developer carrying member according to the present invention.

FIG. 2 is a schematic view showing an example of a developing device.

[Explanation of symbols]

1 Developer supply member 2 Developer support 3 developer 4 Developer amount control blade 5 Latent image holder 6 Developer sealant 7 core 8 elastic layer 9 coating layer

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B01J 20/10 B01J 20/10 A D 20/12 20/12 C 20/16 20/16 20/20 20 / 20 F F16C 13/00 F16C 13/00 B F term (reference) 2H077 AC04 AD06 AD13 AD17 FA12 FA22 FA26 FA27 3J103 AA02 AA13 AA14 AA23 BA41 GA02 GA58 GA60 HA03 HA12 HA20 HA53 4G066 AA05B AA16B AA20B30AA22B10A30B AA22B10A30B AA22B10A30A10A30A10A30A30A

Claims (6)

[Claims] 1. A developer is carried on the surface to form a thin layer of the developer, which is conveyed to be supplied to the electrostatic latent image formed on the surface of the latent image holding member to obtain the electrostatic latent image. In a developer carrying member for developing the toner, at least one elastic layer is provided on the outer periphery of the core, and the elastic body constituting the elastic layer has a specific surface area of 0.
4. A developer carrier, wherein 4 m ² / g or more of an adsorbent is dispersed in a proportion of 0.5 to 100 parts by weight with respect to 100 parts by weight of a polymeric substance component forming the elastic body. 2. The developer carrier according to claim 1, wherein the polymer substance forming the elastic body is an organic rubber material. 3. The developer carrying member according to claim 1, wherein the polymer substance forming the elastic body is a silicone rubber material. 4. The adsorbent is selected from oxides, silicates or carbonates of Mg, Al or Si; silicate activated carbon; zeolite; acid clay; silica; silica gel; silica-alumina gel; alumina; magnesia 1 The developer carrying member according to claim 1, wherein the developer carrying member is one kind or two or more kinds. 5. The developer carrying member according to claim 1, wherein a part or all of the elastic body layer along the thickness direction is formed of a foam. 6. A developing device comprising the developer carrying member according to claim 1. Description: