JP2005031355A - Developing roller and developing device equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developing roller constituted such that the triboelectrification performance with respect to a toner is enhanced and the friction coefficient with respect to a toner supply roller is reduced, and also, the soil of the photoreceptor drum is prevented, and to provide a developing apparatus equipped with the developing roller. <P>SOLUTION: Additive for enhancing the electrification performance and also enhancing abrasion resistance is dissolved in processing solution containing isocyanate, and by immersing an elastic layer 11 formed on the surface of a conductive core bar 10 and mainly consisting of semiconductive urethane rubber in the surface processing solution, the surface layer 12 is formed on the elastic layer 11. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a developing roller that is used in an image forming apparatus of an electrophotographic apparatus such as a printer, a FAX, and a copying machine, and visualizes an electrostatic latent image with a non-magnetic one-component developer, and a developing device equipped with the developing roller.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, some image forming apparatuses such as printers, fax machines, and copiers use a developing device that visualizes an electrostatic latent image formed on a photosensitive drum with non-magnetic one-component toner.
[0003]
In the developing device, the toner charged in the toner container is conveyed to the developing roller by a stirrer, a toner supply roller or the like. The toner conveyed to the developing roller passes through a toner layer thickness regulating member that is in pressure contact with the outer peripheral surface of the developing roller and is carried on the surface of the developing roller in a thin layer, while being charged with frictional charging. In this way, the toner carried on the surface of the developing roller visualizes the electrostatic latent image formed and held on the photoreceptor using an electric field.
[0004]
The developing roller has a structure in which a semiconductive elastic layer is provided around the core metal, and examples of the rubber material forming the elastic layer include urethane, NBR, EPDM, and silicone rubber.
[0005]
An electroconductive filler such as carbon or conductive filler or an ionic conductive additive dispersed therein is also used. In addition, a material in which the surface of the elastic layer is coated with a semiconductive urethane paint mainly composed of urethane resin or polyurethane elastomer is also used (for example, see Patent Document 1).
[0006]
[Patent Document 1]
JP 05-158341 (page 2-3, FIG. 2)
[0007]
[Problems to be solved by the invention]
In the conventional developing roller, the toner is charged by friction between the developing roller and the toner, but there is a problem that fog is generated on the photosensitive drum due to insufficient charging.
[0008]
Furthermore, since the sponge-like toner supply roller provided in the developing device rotates while being pressed against the developing roller, and the coefficient of friction of the developing roller is large, the toner supply roller is damaged and worn out. There has also been a problem that the toner supply capability is reduced, and the problem of faint printing occurs.
[0009]
Further, when urethane rubber is used for the elastic layer, there is a problem that the photosensitive drum is contaminated because it contains a polyol that is easily compatible with the components of the photosensitive drum.
[0010]
SUMMARY OF THE INVENTION An object of the present invention is to provide a developing roller that increases the friction charging performance for toner, decreases the coefficient of friction for the toner supply roller, and prevents contamination of the photosensitive drum, and a developing device equipped with the developing roller.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, in the developing roller of the present invention, a processing solution containing isocyanate is added.
(1) Material having opposite polarity to toner charging polarity
(2) Charge control agent
(3) Silane coupling agent
(4) Silane
(5) Surfactant
Then, the elastic layer is immersed in a treatment solution in which at least one is dissolved as an additive to form a surface layer on the elastic layer.
[0012]
In order to achieve the same object, in the developing roller of the present invention, a processing solution containing isocyanate is added.
As the first additive
(1) Material having opposite polarity to toner charging polarity
(2) Charge control agent
(3) Silane coupling agent
(4) Silane
(5) Surfactant
Dissolve at least one from
As a second additive
(6) Resin containing silicone
(7) Resin containing fluorine
Then, the elastic layer is immersed in a treatment solution in which at least one of them is dissolved to form a surface layer on the elastic layer.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the element common to each drawing.
[0014]
FIG. 3 is a schematic configuration diagram of the image forming apparatus. In the image forming apparatus, a charging roller 2, a recording head 3, a developing device 4, and a transfer roller 5 are arranged around the photosensitive drum 1. The developing device 4 includes a developing roller 6 that is in contact with the surface of the photosensitive drum 1, and a toner layer thickness regulating member 7 and a toner supply roller 8 that are in pressure contact with the developing roller 6.
[0015]
For example, a predetermined negative voltage is applied to the charging roller 2 to uniformly charge the surface of the photosensitive drum 1 with negative charges. The recording head 3 exposes the surface of the photosensitive drum 1 uniformly charged with a negative charge based on the print data, and records an electrostatic latent image.
[0016]
In the developing device 4, the toner is supplied from the toner supply roller 8 to the developing roller 6 by the potential difference applied to the toner supply roller 8 and the developing roller 6 and the mechanical conveyance force by the sponge cell of the toner supply roller 8. As the developing roller 6 rotates, the toner is rubbed by the toner layer thickness regulating member 7 and is frictionally charged to a predetermined negative polarity, and the electrostatic latent image is visualized by the thinned toner.
[0017]
A predetermined positive voltage is applied to the transfer roller 5 to transfer the toner image on the photoreceptor 1 onto the printing paper 9. Thereafter, the toner image is fused and fixed onto the printing paper 9 by passing through a heating and fixing device (not shown).
[0018]
FIG. 1 is an explanatory view showing a configuration of a developing roller according to the embodiment, and FIG. 2 is a cross-sectional view taken along the line AA of the developing roller shown in FIG. In the developing roller 6, a semiconductive urethane elastic layer 11 is formed on the surface of a conductive metal core 10. Further, an additive for improving charging performance and reducing a friction coefficient is added to a processing solution containing isocyanate. A surface layer 12 cured by heat treatment is formed on the surface of the urethane elastic layer 11.
[0019]
Conductive metal core 10 is a conductive metal such as iron, aluminum or SUS brass, a conductive tree in which carbon black or metal powder is blended with a thermosetting resin, or an insulator surface of a thermoplastic resin or a thermosetting resin. And the like, which are made into a conductor by metal plating, and may be appropriately selected in consideration of workability and economy.
[0020]
The urethane elastic layer 11 formed on the surface of the core metal 10 may be any known one that is used as a developing roller. The preferred method for producing the semiconductive urethane elastic layer here is one in which a compound imparting conductivity is present during the production process of a widely known urethane rubber or urethane elastomer. For example, it can be obtained by subjecting a compound imparting electrical conductivity, an isocyanate compound, and a polyol to a heat reaction in the presence of other auxiliary agents as necessary.
[0021]
Alkali metal salts are preferred as the compound imparting conductivity, and the amount added is 0.001 to 3 parts by weight with respect to 100 parts by weight of the urethane elastic layer. Moreover, as another electrically conductive agent, you may use together 1 type (s) or 2 or more types among electroconductive carbon black, electroconductive zinc white, and electroconductive titanium oxide. The addition amount is 1 to 30 parts by weight.
[0022]
Examples of the isocyanate compound include diphenylmethane diisocyanate, tolylene diisocyanate, naphthalene diisocyanate, tolidine diisocyanate, paraphenylene diisocyanate, isophorone diisocyanate, isophorodiisocyanate, or a prepolymer or modification thereof.
[0023]
Examples of the polyol include polyester polyol, polyether polyol, polyester polycarbonate polyol, and the like. These isocyanate compounds or polyols may be used alone or in combination of two or more.
[0024]
Examples of the auxiliary agent include a chain extender and a crosslinking agent. Specific examples include glycols, hexanetriol, trimethylolpropane, and amines.
[0025]
Moreover, the urethane elastic layer 11 of the present invention can be formed from a mixture containing a compound having a siloxane bond. As used herein, the mixture is commonly used for producing the urethane elastic layer 11.
[0026]
The compound having a siloxane bond means a compound having a dimethylsiloxane bond or an organic compound such as a compound in which a methyl group is partially substituted with a phenyl group. For example, an isocyanate compound containing a dimethylsiloxane bond or a dimethylsiloxane bond is included. Examples include polyols. Specifically, product names SF8427 and SF8428 manufactured by Toray Dow Corning can be exemplified.
[0027]
After sufficiently mixing these compounds with a known mixing apparatus, the urethane elastic layer 11 can be formed on the surface of the cored bar 10 using a known molding method. In the present invention, the urethane elastic layer 11 is formed on the surface of the conductive core 10 by using a known one-shot method or prepolymer method. The hardness of the urethane elastic layer 11 is 65 ° (JISA) or less, preferably 25 ° to 55 ° (JISA) or less. If the hardness exceeds 65 ° (JISA), there is a disadvantage that surface polishing for obtaining a uniform contact surface with the photosensitive drum 1 becomes difficult, which is not preferable.
[0028]
The surface layer 12 is formed on the surface of the urethane elastic layer 11 obtained by such a method. The surface layer 12 is formed by dissolving an additive for improving charging performance or an additive for reducing a friction coefficient in a treatment solution containing isocyanate, immersing or applying the urethane elastic layer 11 and then heating the surface layer 12. Is done.
[0029]
That is, by heating, the organic solvent in the surface treatment solution volatilizes, and the isocyanate constituting the urethane elastic layer 11 reacts with the isocyanate in the surface treatment solution containing the additive to form a cross-linking bond to form the surface layer 12. To do.
[0030]
Since the surface layer 12 contains an additive in the isocyanate, the charging performance of the developing roller 6 can be improved or the friction coefficient can be reduced according to the additive.
[0031]
In the case of immersing the urethane elastic layer 11 in the surface treatment solution containing the additive, more specific treatment conditions will be described. The treatment temperature is set to 10 ° C. to 40 ° C., particularly 15 ° C. to 25 ° C. Is preferred. The immersion time depends on the viscosity of the treatment liquid, but is within 10 minutes, preferably within 5 minutes, and more preferably from 0.5 minutes to 3 minutes. Outside this time range, the surface layer 12 is still sticky, or the surface layer 12 is liable to crack and does not provide an excellent effect.
[0032]
Treatment solutions containing isocyanate include those in which an isocyanate compound is dissolved in an organic solvent, those in which an isocyanate compound and a polyol are dissolved in an organic solvent, and auxiliary agents that are commonly used in polyurethane formation reactions. And the like.
[0033]
The isocyanate compound may be any known compound, but can be selected from, for example, the aforementioned isocyanate compounds. The polyol may be any polyol as long as it can react with the above-described isocyanate compound to form a urethane compound. For example, the polyol can be selected from the above-mentioned polyols.
[0034]
As the organic solvent, an aprotic polar solvent is preferable, and ethyl acetate, dimethylformamide or a mixture thereof is particularly preferable. It is effective to adjust the amount of the organic solvent so that the viscosity of the surface treatment solution is 10 to 500 CP (centipoise).
[0035]
Additives that improve charging performance include acrylic-containing resins, charge control agents, silane coupling agents, silanes, and surfactants.
[0036]
Acrylic resin is a general term for resins mainly composed of esters of acrylic acid or methacrylic acid. The toner is charged by the frictional force between the toner and the developing roller surface by the toner layer thickness regulating member 7 and the toner supply roller 8. If the toner is to be negatively charged, a material on the plus side of the triboelectric charge train may be selected.
[0037]
Acrylic resin is the most positive resin material in the triboelectric train. However, when it is used for the surface layer, it is hard and easily cracked. Therefore, it is suitable to use a silicone-acrylic resin that is mixed with a silicone resin that is flexible and on the positive side of the triboelectric charge train. Furthermore, urethane / acrylic resin, which is a mixture of acrylic and urethane resin, may be used.
[0038]
Therefore, the addition of an acrylic resin or the addition of an acrylic / silicone resin is effective in improving the charging performance.
[0039]
When the charge control agent rubs, it has the same effect as an acrylic resin. Therefore, a positively chargeable charge control agent selected from nigrosine-based azine compounds and quaternary ammonium salts is finely pulverized and used. Therefore, the addition of a charge control agent, in particular, the addition of a positively chargeable charge control agent, is effective in improving the charging performance.
[0040]
A silane coupling agent is an organosilicon monomer having two different reactive groups in the molecule. One of the two reactive groups is a reactive group (such as a methoxy group, an ethoxy group, or a silanol group) that chemically bonds with inorganic substances (glass, metal, cinnabar, etc.). Another group is a reactive group (amino group, vinyl group, epoxy group, methacrylate group, mercapto group, etc.) that chemically bonds with organic materials (various synthetic resins). Here, for example, in the case of a silane coupling agent having an amino group, one reactive group reacts with Si or OH group on the surface of the added silicone resin, and other groups exist as unreacted groups. To do.
[0041]
When this unreacted amino group contacts or rubs with the toner, it supplies electrons to the toner to improve the charging performance of the toner. Among these, the amino group has the highest ability to donate electrons. Therefore, even when the silane coupling agent is added, the addition of the silane coupling agent having an amino group has an effect of improving the charging performance.
[0042]
Silane is an organosilicon compound monomer and the structure of a typical compound is RaSiX4-a (a = 0-3, R = -H, -CH₃  , -C₆H₆  , CnH_{2n + 1}Organic groups such as X = -Cl, -OCH₃  , -OC₂H₅It reacts with compounds having active hydrogen, such as water, alcohol, and amine.
[0043]
The surfactant has a structure in which a hydrophilic group and a lipophilic group are bonded, and is classified into an anion, a cation, a non-ion, and a zwitterion depending on the electrical properties of the hydrophilic group in the solution. Surfactants having anions donate electrons when rubbing to improve the chargeability of the developer. In addition, since the surfactant having amphoteric ions has both anions and cations, it partially donates electrons.
[0044]
Therefore, the addition of a surfactant, especially the addition of a surfactant having an anion or amphoteric ion, has the effect of improving the charging performance.
[0045]
It is preferable that the urethane elastic layer 11 has a high hardness surface by the formed surface layer 12. For example, when the hardness is 70 ° (JISA) or more, the prevention of photoconductor contamination becomes even more effective. It is preferable that the solution penetrates to about 1 mm from the surface by this surface treatment.
[0046]
Next, additives for reducing the coefficient of friction will be described. In general, a resin having a small coefficient of friction has a good water repellency or a material having a low surface tension, and a typical one is a silicone resin or a fluororesin.
[0047]
Next, although each embodiment shown in FIGS. 4 to 6 will be described in detail, it goes without saying that the present invention is not limited to this embodiment. The developing roller 6 used in each of the examples was prepared by adding 5 parts by weight of carbon black to 100 parts by weight of Kurapol P-2010 (manufactured by Kuraray Co., Ltd.), stirring the mixture, adjusting the temperature to 100 ° C., and then coronate C-HX (Japan). 20 parts by weight of polyurethane (made by Polyurethane Co., Ltd.) was added and stirred, and the mixture was poured into a mold preheated to 120 ° C. in which a core metal 10 (outer diameter 12 mm, length 270 mm) was previously placed, and at 130 ° C. Heated for 60 minutes in the urethane elastic layer 11 of the roller obtained under the same conditions (with the surface treatment solution kept at 20 ° C., immersed in the above-mentioned roller for a predetermined time and then heated in an oven kept at 120 ° C. for 20 minutes. The surface layer 12 is formed.
[0048]
The surface treatment solution uses MR400 (manufactured by Nippon Polyurethane Co., Ltd.) as the isocyanate compound and ethyl acetate as the organic solvent.
[0049]
In addition, the measurement of fog is described. The fog measurement is measured as follows in order to quantify the reversely charged toner adhering to the photosensitive drum 1. Utilizing the fact that the reflectivity decreases when there is a large amount of reversely charged toner adhering to the photosensitive drum 1, the power supply of the printer in an unprinted state is momentarily cut off, and the photosensitive drum 1 and the transfer roller 5 are placed on the photosensitive drum at the contact portion. Apply a highly transparent tape.
[0050]
Thereby, the reversely charged toner adhering to the photosensitive drum is transferred to the transparent tape. This tape is pasted on unused printing paper. The paper to be pasted is preferably a paper with high reflectivity. On the other hand, an unused transparent tape is stuck on the same printing paper.
[0051]
The measuring instrument for measuring the reflectance used was Minolta. Place the print paper with the transparent tape with the reversely charged toner on it and the print paper with the unused transparent tape on the paper with a reflectivity of 95% or more or a flat table. Measure the value.
[0052]
Fog value = K (%)-X (%) ... (1)
Here, K is the reflectance of the unused transparent tape, and X is the reflectance of the transparent tape to which the reversely charged toner is transferred.
[0053]
In addition, the measurement of blur will be described. Scratch means that when a character, a bold character, or a full surface printing is performed, a part of the character is not printed and white is removed.
[0054]
Example 1
The surface treatment solution was prepared by dissolving 100 parts by weight of MR400 (manufactured by Nippon Polyurethane Co., Ltd.) and 15 parts by weight of a silicone acrylic copolymer resin (manufactured by Toagosei Co., Ltd., Aron GS-30) in 900 parts by weight of ethyl acetate. Get dispersed.
[0055]
Comparative example
For comparison, as a surface treatment solution, 100 parts by weight of MR400 (manufactured by Nippon Polyurethane) is dissolved and dispersed in 900 parts by weight of ethyl acetate to obtain a surface treatment solution having no additive.
[0056]
Example 2
The surface treatment solution consists of 100 parts by weight of MR400 (manufactured by Nippon Polyurethane Co., Ltd.) and a nigrosine-based azine compound (BONTRON N-01: manufactured by Orient Chemical Co., Ltd.) having an average particle size of 10 to 15 μm to increase the specific surface area as an additive. And 5 parts by weight of the charge control agent obtained by pulverizing the powder into fine powder particles having a particle size of 1 μm or less are dissolved and dispersed in 900 parts by weight of ethyl acetate.
[0057]
Example 3
The surface treatment solution consists of 100 parts by weight of MR400 (manufactured by Nippon Polyurethane Co., Ltd.) and 15 parts by weight of a silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., N-β (aminoethyl) γ-aminepropyltriethoxysilane, KBM603). Are dissolved and dispersed in 900 parts by weight of ethyl acetate.
[0058]
Example 4
The surface treatment solution is obtained by dissolving and dispersing 100 parts by weight of MR400 (manufactured by Nippon Polyurethane Co., Ltd.) and 5 parts by weight of chlorosilane (manufactured by Shin-Etsu Chemical Co., Ltd., trimethylchlorosilane, KA31) in 900 parts by weight of ethyl acetate.
[0059]
Example 5
The surface treatment solution was composed of 100 parts by weight of MR400 (manufactured by Nippon Polyurethane Co., Ltd.) and 5 parts by weight of an anionic surfactant (manufactured by Lion, alkyl ether sulfate ester, Sannol LMT-1430) as an additive, 900 parts by weight of ethyl acetate. It is obtained by dissolving and dispersing in the part.
[0060]
Example 6
The surface treatment solution is obtained by dissolving and dispersing 100 parts by weight of MR400 (manufactured by Nippon Polyurethane Co., Ltd.) and 15 parts by weight of powdered silicone resin (X40-2134, manufactured by Shin-Etsu Chemical Co., Ltd.) in 900 parts by weight of ethyl acetate. obtain.
[0061]
Example 7
The surface treatment solution is obtained by dissolving and dispersing 100 parts by weight of MR400 (manufactured by Nippon Polyurethane Co., Ltd.) and 5 parts by weight of a fluororesin (manufactured by Dainippon Ink, Inc., TR-230K) in 900 parts by weight of ethyl acetate. .
[0062]
Example 8
The surface treatment solution consists of 100 parts by weight of MR400 (manufactured by Nippon Polyurethane Co., Ltd.), 15 parts by weight of silicone acrylic copolymer resin (manufactured by Toagosei Co., Ltd., Aron GS-30), and a powdered silicone resin (Shin-Etsu Chemical Co., Ltd.). And X40-2134), 15 parts by weight, obtained by dissolving and dispersing in 900 parts by weight of ethyl acetate.
[0063]
Example 9
The surface treatment solution consists of 100 parts by weight of MR400 (manufactured by Nippon Polyurethane Co., Ltd.) and a nigrosine-based azine compound (BONTRON N-01: manufactured by Orient Chemical Co., Ltd.) having an average particle size of 10 to 15 μm to increase the specific surface area as an additive. ) Is dissolved and dispersed in 900 parts by weight of ethyl acetate and 5 parts by weight of a charge control agent obtained by pulverizing the powder into 1 μm or less fine particles and 15 parts by weight of a powdery silicone resin (X40-2134, manufactured by Shin-Etsu Chemical Co., Ltd.). Let me get it.
[0064]
Example 10
The surface treatment solution consists of 100 parts by weight of MR400 (manufactured by Nippon Polyurethane Co., Ltd.) and 15 parts by weight of silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., N-β (aminoethyl) γ-aminepropyltriethoxysilane, KBM603) as an additive. And 15 parts by weight of powdered silicone resin (X40-2134, manufactured by Shin-Etsu Chemical Co., Ltd.) are dissolved and dispersed in 900 parts by weight of ethyl acetate.
[0065]
Example 11
The surface treatment solution consists of 100 parts by weight of MR400 (manufactured by Nippon Polyurethane Co., Ltd.), 5 parts by weight of chlorosilane (manufactured by Shin-Etsu Chemical Co., Ltd., trimethylchlorosilane, KA31) and powdered silicone resin (manufactured by Shin-Etsu Chemical Co., X40-2134). 15 parts by weight is obtained by dissolving and dispersing in 900 parts by weight of ethyl acetate.
[0066]
Example 12
The surface treatment solution consists of 100 parts by weight of MR400 (manufactured by Nippon Polyurethane Co., Ltd.), 5 parts by weight of an anionic surfactant (manufactured by Lion Corporation, alkyl ether sulfate ester salt, Sannol LMT-1430) and powdered silicone resin (Shin-Etsu). It is obtained by dissolving and dispersing 15 parts by weight of X40-2134) made by Kagaku Co. in 900 parts by weight of ethyl acetate.
[0067]
Example 13
The surface treatment solution consists of 100 parts by weight of MR400 (manufactured by Nippon Polyurethane Co., Ltd.), 15 parts by weight of silicone acrylic copolymer resin (manufactured by Toagosei Co., Ltd., Aron GS-30) and fluororesin (manufactured by Dainippon Ink, TR-230K) is obtained by dissolving and dispersing 5 parts by weight in 900 parts by weight of ethyl acetate.
[0068]
Example 14
The surface treatment solution consists of 100 parts by weight of MR400 (manufactured by Nippon Polyurethane Co., Ltd.), 15 parts by weight of silicone acrylic copolymer resin (manufactured by Toagosei Co., Ltd., Aron GS-30), and silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd.). N-β (aminoethyl) γ-aminepropyltriethoxysilane, KBM603) and 15 parts by weight of powdered silicone resin (Shin-Etsu Chemical Co., Ltd., X40-2134) are dissolved and dispersed in 900 parts by weight of ethyl acetate. Get.
[0069]
Example 15
The surface treatment solution consists of 100 parts by weight of MR400 (manufactured by Nippon Polyurethane Co., Ltd.), 15 parts by weight of silicone acrylic copolymer resin (manufactured by Toagosei Co., Ltd., Aron GS-30), and silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd.). , N-β (aminoethyl) γ-aminepropyltriethoxysilane, KBM603), 15 parts by weight, anionic surfactant (manufactured by Lion, alkyl ether sulfate ester, Sannol LMT-1430), 5 parts by weight, and powdered silicone It is obtained by dissolving and dispersing 15 parts by weight of a resin (manufactured by Shin-Etsu Chemical Co., Ltd., X40-2134) in 900 parts by weight of ethyl acetate.
[0070]
Example 16
The surface treatment solution consists of 100 parts by weight of MR400 (manufactured by Nippon Polyurethane Co., Ltd.), 15 parts by weight of silicone acrylic copolymer resin (manufactured by Toagosei Co., Ltd., Aron GS-30), and silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd.). , N-β (aminoethyl) γ-aminepropyltriethoxysilane, KBM603) 15 parts by weight, anionic surfactant (manufactured by Lion, alkyl ether sulfate ester, Sannol LMT-1430) 5 parts by weight, large specific surface area 5 parts by weight of a charge control agent obtained by pulverizing a nigrosine-based azine compound (BONTRON N-01: manufactured by Orient Chemical Co., Ltd.) having an average particle diameter of 10 to 15 μm into fine powder particles having a particle diameter of 1 μm or less, and 900 parts by weight of ethyl acetate with 15 parts by weight of powdered silicone resin (X40-2134, manufactured by Shin-Etsu Chemical Co., Ltd.) It is obtained by dissolving and dispersing in an amount of part.
[0071]
Comparison between Example and Comparative Example
The effects will be described sequentially from the first embodiment. The developing roller 1 is incorporated in the developing device 4 shown in FIG. 3 and compared with the case where the developing roller of the comparative example is used. As for fog characteristics, the comparative example is improved to 10% while the embodiment 1 is improved to 2%.
[0072]
In the comparative example, the friction coefficient is 50 degrees as measured by the method shown in Measurement 1, and the friction coefficient is considerably large. In the life test, blurring occurs after printing 10K sheets.
Example 1 is improved to 25 degrees, and in the life test, the number of occurrences of scraping is improved to 15K.
[0073]
Similarly, as shown in Examples 2 to 5, the additive for the purpose of improving fog is improved from 1% to 3% so that there is no problem. The coefficient of friction is improved from 25 degrees to 30 degrees, and the number of printed sheets on which blurring occurs is improved from 13K to 15K sheets.
[0074]
In Examples 6 to 7, the additive for improving the fog was not added and only the additive for improving the coefficient of friction was added. Therefore, the fog was not sufficiently satisfactory at 4% to 5%, but the coefficient of friction was 15%. It has become smaller and does not cause blurring up to 20K sheets which is the lifetime.
[0075]
In Examples 8 to 13, since an additive for improving fog and an additive for reducing the coefficient of friction are added, the fog is sufficiently satisfactory at 1% to 2%. Further, the friction coefficient is as small as 10 degrees to 13 degrees, and no blur is generated until 20K printing which is the life.
[0076]
In Examples 14 to 16, since two or more additives for improving fogging are added, the fogging level is sufficiently satisfactory at 1%. There was no problem of using two or more additives together. The friction coefficient is as small as 12 degrees to 13 degrees, and no blurring occurs until 20K printing, which is the lifetime.
[0077]
As described above, as shown in FIGS. 4 to 6, the additive added for the purpose of improving the fog is improved to the level of 1% to 3% where the fog is not caused by improving the charging property of the developing roller 6. Yes. A silane coupling agent having an amino group is particularly excellent, and the vinyl group, epoxy group, methacryl group, and mercapto group are deteriorated in this order.
[0078]
Scratch does not occur up to 13K-15K printing, but it is not sufficient. However, by adding an additive that reduces the friction coefficient, it is possible to obtain the developing roller 6 that does not cause any blurring until the printing of 20K sheets, which is the lifetime.
[0079]
【The invention's effect】
Since the present invention is configured as described above, the following effects can be obtained.
[0080]
It is formed by dissolving an additive for improving charging performance in a treatment solution containing isocyanate, and immersing an elastic layer mainly composed of semiconductive urethane rubber on the surface of the conductive core metal in the surface treatment solution. By providing the surface layer on the elastic layer, the charging performance between the developing roller and the toner is improved, and the toner charge amount is increased, so that the fog phenomenon during printing can be prevented.
[0081]
In addition, additives that improve charging performance and improve wear resistance are dissolved in the treatment solution containing isocyanate, and the surface treatment solution is mainly composed of semiconductive urethane rubber on the surface of the conductive metal core. By providing the elastic layer with a surface layer formed by immersing the configured elastic layer, the charging performance between the developing roller and the toner is improved, the toner charge amount is increased, and the toner supply roller is developed. Since the wear resistance of the roller is improved and the toner supply capability from the toner supply roller to the developing roller is improved, the fogging phenomenon and the blurring phenomenon during printing can be prevented.
[0082]
Further, by providing a surface layer mainly composed of isocyanate on an elastic layer mainly composed of urethane rubber, contact between the polyol contained in the urethane rubber and the photosensitive drum can be reduced, so that contamination of the photosensitive drum can be prevented.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram illustrating a configuration of a developing roller according to an embodiment.
FIG. 2 is a cross-sectional view of the developing roller shown in FIG.
FIG. 3 is a schematic configuration diagram of an image forming apparatus.
FIG. 4 is an explanatory view (1) showing an embodiment of the present invention.
FIG. 5 is an explanatory view (2) showing an embodiment of the present invention.
FIG. 6 is an explanatory view (3) showing an embodiment of the present invention.
[Explanation of symbols]
6 Development roller
11 Urethane elastic layer
12 Surface layer

Claims (10)

In the developing roller in which an elastic layer mainly composed of semiconductive urethane rubber is formed on the surface of the conductive metal core,
In the treatment solution containing isocyanate, (1) a material having a polarity opposite to that of the toner, (2) a charge control agent, (3) a silane coupling agent, (4) silane, and (5) a surfactant as an additive. Dissolve,
A developing roller, wherein the elastic layer is immersed in the processing solution to form a surface layer on the elastic layer. In the developing roller in which an elastic layer mainly composed of semiconductive urethane rubber is formed on the surface of the conductive metal core,
As a first additive to a treatment solution containing isocyanate, (1) a material having a polarity opposite to the toner charging polarity, (2) a charge control agent, (3) a silane coupling agent, (4) silane, and (5) a surfactant. Dissolve one,
(6) a resin containing silicone as a second additive, (7) dissolving at least one from a resin containing fluorine,
A developing roller, wherein the elastic layer is immersed in the processing solution to form a surface layer on the elastic layer. 3. The developing roller according to claim 1, wherein the resin containing a material having a polarity opposite to the toner charging polarity is a compound with a silicone resin, and is added in an amount of 5 to 50% by weight ratio after curing. . The developing roller according to claim 1, wherein the charge control agent contains a charge control agent for positive charge. The developing roller according to claim 1, wherein the silane coupling agent contains an amino group. The developing roller according to claim 1, wherein the silane contains chlorosilane having a chlorine group as a hydrolysis group. The developing roller according to claim 1, wherein the surfactant further contains an anionic or amphoteric surfactant as a classification of the surfactant. The developing roller according to claim 1, wherein a silicone resin having a large molecular weight is added to the processing solvent, and the silicone resin is deposited on the surface of the elastic layer after the solvent is heat-treated. The developing roller according to claim 1, wherein a fluororesin having a large molecular weight is added to the processing solvent, and the fluororesin is deposited on the surface of the elastic layer after the solvent is heat-treated. A developing device comprising the developing roller according to claim 1 or 2, and a non-magnetic one-component negatively charged developer.

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