JP2990005B2 - Developing roller and developing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to 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, the present invention relates to a developing roller having excellent stain resistance and capable of reliably obtaining a good image even during 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, or an electrostatic recording apparatus, 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 supplied to the photosensitive drum. As a developing method for visualizing a latent image by attaching a developer, a pressure developing method is known (US Pat. No. 3,152,352).
012 and 3731146), according to this method,
Since no magnetic material is required, the apparatus can be simplified and downsized easily, and the toner can be easily colored.

In this pressure development method, a developing roller carrying a toner (a non-magnetic one-component developer) is brought into contact with a latent image holding member such as a photosensitive drum holding an electrostatic latent image, and the toner is developed. Is developed by adhering to the latent image of the latent image holding member. Therefore, it is necessary to form the developing roller with an elastic material having conductivity.

That is, in the pressure development method, as shown in FIG. 2, for example, a toner coating roller 4 for supplying toner and a photosensitive drum 5 holding an electrostatic latent image are used. The developing roller 1 is disposed in contact with the photosensitive drum 5 between the developing roller 1, the developing roller 1, the photosensitive drum 5 and the toner coating roller 4 in the figure. By rotating in the direction of the arrow, the toner 6 is supplied to the surface of the developing roller 1 by the toner coating roller 4, and the toner is formed into a uniform thin layer by the layering blade 7. In this state, the developing roller 1 rotates while being in contact with the photosensitive drum 5,
The toner formed in a thin layer adheres to the latent image on the photosensitive drum 5 from the developing roller 1 to visualize the latent image. In the figure, reference numeral 8 denotes a transfer unit which transfers a toner image to a recording medium such as paper.
Is a cleaning part, and its cleaning blade 1
0 removes toner remaining on the surface of the photosensitive drum 5 after transfer.

In this case, the developing roller 1 is connected to the photosensitive drum 5
It is necessary to rotate while securely maintaining a state in which it is in close contact with the shaft. Therefore, as shown in FIG.
The elastic layer 3 is made of an elastic material having conductivity by adding a conductive agent to elastic rubber such as NBR or EPDM or urethane foam.

[0006]

However, the conventional developing roller composed of a single-layer elastic body has the following disadvantages due to the characteristics of the elastic layer. 1 . When the elastic layer is formed of an elastic rubber such as silicone rubber, NBR, EPDM, etc., low elasticity is required to obtain good adhesion.
If the temperature increases, contamination of the photosensitive drum may occur. 2 . When the elastic layer is formed with a general urethane-based elastomer, a developing roller with less contamination on the photosensitive drum can be obtained.
Is insufficient in charge-up characteristics, and problems such as fogging due to poor charging of toner, poor cleaning due to selective development, and decrease in print density are liable to occur, and the print quality is significantly reduced by long-term continuous printing.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has a low hardness and good adhesion, does not cause inconvenience such as contaminating a photoreceptor and the like, and has a low temperature and a low humidity to a high temperature and a high humidity. Provided is a developing roller and a developing device using the developing roller, which can provide a high-quality image without uneven density or fog in a wide environment and which does not cause deterioration of the image even when used for a long time. The purpose is to do.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, have developed a developing roller having a conductive elastic layer formed on the outer periphery of a good conductive shaft. Wherein the elastic layer is formed of a polyurethane resin having a water absorption of 3% or less and has a resistivity of 10 ⁴ to
By adjusting the hardness to 10 ¹⁰ ΩCm and the hardness to 55 ^° or less on a JIS-A scale, a non-magnetic one-component developer is carried on the surface of the developing roller to form a thin layer of the developer. Is brought into contact with a latent image holding member such as a photoreceptor to develop an electrostatic latent image on the latent image holding member. It has been found that a high-quality image free from uneven density and fogging can be obtained under a wide range of environmental conditions without inconvenience such as contamination, and that the image quality does not deteriorate even after long-term use.

Furthermore, the conventional single-layer roller has a water absorption of 3%.
% Of a polyurethane-based resin outer skin layer (skin layer), it was found that a developing roller having the same excellent performance as described above could be obtained, and the present invention was completed.

Therefore, the present invention provides (1) an elastic layer having conductivity on the outer periphery of a good conductive shaft,
A non-magnetic one-component developer is carried on the surface of the elastic layer to form a thin layer of the developer, and in this state, the electrostatic latent image is brought into contact with a latent image holding member holding the surface, and In a developing roller for adhering the developer to the electrostatic latent image on the surface of the latent image holding member and visualizing the electrostatic latent image, the elastic layer is made of a polyurethane resin, and has a resistivity of 10 ⁴ to 10. ^A developing roller having a hardness of ¹⁰ ΩCm, a hardness of 55 ° or less on a JIS-A scale and a water absorption of 3% or less of the elastic layer.
La.

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. A developing device for contacting the latent image holding member holding the electrostatic latent image on the surface thereof and attaching the developer from the thin layer to the electrostatic latent image on the surface of the latent image holding member to visualize the electrostatic latent image; In the above roller, the elastic layer is formed by forming a skin layer made of a polyurethane resin on the outer periphery of a base roller made of a conductive resin.
A developing roller, wherein the polyurethane resin forming the skin layer has a water absorption of 3% or less.

A roller-shaped or drum-shaped 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, in contact with the surface of the latent image holding member; The non-magnetic one-component developer is transferred to the electrostatic latent image on the surface of the latent image holding member by being rotated in conjunction with the rotation of the latent image holding member.
And a developing roller for visualizing the electrostatic latent image by adhering a developing roller, wherein the developing roller according to claim 1 is used as the developing roller. Provide equipment.

Hereinafter, the present invention will be described in more detail.
As shown in FIG. 1, the developing roller according to the first aspect of the present invention is formed by forming a conductive elastic layer 3 on the outer periphery of a good conductive shaft 2.

As the shaft 2, any shaft having good and good conductivity can be used. However, usually, a shaft made of a metallic solid body or a metal hollow inside is used. A metallic shaft such as a flexible cylinder is used.
Next, the elastic layer formed on the outer periphery of the shaft 2 is made of a polyurethane resin having a water absorption of 3% or less and having a conductive additive. In this case, the polyurethane resin is manufactured by various methods. Either one may be used, for example, a method in which carbon black is compounded in a polyurethane prepolymer and crosslinked and cured, a conductive material is compounded in a polyol, and this polyol is mixed with a polyisocyanate by a one-shot method. It can be obtained by a reaction method or the like.

[0015] The polyol used in the present invention is a polyether.
Any of terpolyols, polyester polyols, preferably polyolefin polyols, such as polybutadiene polyols and polyisoprene polyols, in which the reaction product with a polyisocyanate has a water absorption of 3%. One or a combination of two or more polyols can be selected.

The water absorption referred to herein is JIS-K7209.
(1984) This is the water absorption defined by the "Testing Methods for Water Absorption and Boiling Water Absorption of Plastics", and the measuring method followed the method A described in JIS-K7209. That is, it weighed conditioned specimens as M _1, a test piece was dipped 24 ± 1 hour placed in a vessel containing the specimen in water kept at a temperature of 23 ± 2 ° C. It was taken out, weighed and defined as M _2, and the water absorption was calculated according to the following equation. Absorption rate _{= (M 2 -M 1) /} M 1 × 100 (%)

When the elastic layer is formed of a polyurethane elastomer using a general polyol, the rising characteristics of the toner on the roller are sufficient particularly under high temperature and high humidity (33 ° C., 85% RH). Instead, image fogging occurs due to poor charging of the toner. The water absorption of these elastic layers was determined to be 3% or more. On the other hand, as a result of intensive studies, it was found that the water absorption of the elastic layer was suppressed to 3% or less by the selection of the polyol, so that the toner on the roller under high temperature and high humidity was obtained.
And the fog caused by poor charging of the toner could be reduced. More preferably, it has been found that by selecting a polyol so that the water absorption of the elastic layer is suppressed to 2% or less, fogging due to poor charging of the toner can be eliminated even under high temperature and high humidity.

The polyisocyanate is not particularly limited, but a polyisocyanate having a bent molecular structure is preferably used, and a polyisocyanate represented by the following general formula (Chemical Formula 1) is particularly preferable. Used for Such a polyisocyanate can prevent crystallization of the polyurethane chain, so that the hardness can be easily reduced, and the entanglement of the molecular chain can be easily formed. In other words, a pseudo-crosslinked structure can be obtained, so that the demolding is easy. .

[0019]

Embedded image (Wherein, R represents a carbon-carbon bond or an alkylene group ^;
Represents hydrogen or an alkyl group. )

[0020] Such polyisocyanates - specifically as preparative, 2, 4-toluene diisocyanate - DOO, 2, 6-
Toluene diisocyanate - DOO, mixtures thereof, m- tetramethyl xylylene diisocyanate - DOO, m- xylylene diisocyanate - DOO, m- phenylene diisocyanate - DOO and the like.

The conductivity-imparting substance is not particularly limited, but may be an electron-conductivity-imparting substance such as carbon black, graphite, metal filler or metal oxide, metal perchlorate, or an interface. An ionic conductivity-imparting substance such as an activator or a combination thereof can be used. The addition amount of these conductivity-imparting substances can be adjusted so that the resistance value of the elastic layer becomes a desired value.

The resistance value of the elastic layer 3 thus obtained is 10 ⁴ to 10 ¹⁰ Ωcm, particularly 10 ⁶ to 10 ⁹ Ω.
If it is less than 10 ⁴ , the charge may leak to the photosensitive drum or the like, or the developing roller itself may be broken by the voltage. On the other hand, if it exceeds 10 ¹⁰ Ωcm, fogging may occur. It will be easier.

The hardness of the developing roller formed by the elastic layer obtained in this manner is JIS-A scale.
The angle is 55 ^° or less, preferably 50 ^° or less. In this case, if the angle exceeds 55 ^° , the contact area with the photosensitive drum or the like becomes small, so that good development may not be performed. For this reason, the developing roller may be deformed or eccentric due to a problem of dimensional accuracy at the time of molding or compression set. Occurs, image density unevenness occurs.

Furthermore, as a result of repeated studies, even when a resin having a water absorption of 3% or more is used as the elastic layer, a skin layer made of a polyurethane resin is formed on the outer periphery of the roller and the water absorption of the urethane resin is obtained. It has been found that the same effect can be obtained by controlling the water absorption of the elastic body itself by controlling the water absorption of the elastic body to 3% or less, preferably 2% or less. The thickness of the skin layer is not particularly limited, but is preferably 10 μm or more. It is technically difficult to uniformly form a skin layer having a thickness of 10 μm or less on the outer periphery of the roller. If a hole is formed in the skin layer, such a portion causes image defects such as fogging.

The developing roller of the present invention can be incorporated in an ordinary developing device using a non-magnetic one-component developer. Specifically, as shown in FIG. 2, a toner for supplying toner is used. The developing roller 1 of the present invention is disposed between the coating roller 4 and the photosensitive drum 5 holding the electrostatic latent image in a state of being in contact with the photosensitive drum 5, and the toner coating roller 4 is provided. To supply the toner 6 to the developing roller 1 and to form a uniform thin layer by the layering plate 7. Further, the toner is supplied to the photosensitive drum 5 from the thin layer. The latent image can be visualized by attaching toner to the electrostatic latent image. Note that FIG.
Is described in the prior art, and the description is omitted.

Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

[0027]

Example 1 Polybutadiene-based polyol (R15HT, manufactured by Idemitsu Petrochemical Co., Ltd.) having a molecular weight of 1200 and having an allyl-type primary hydroxyl group at the end of polybutadiene
00 parts of a silicone surfactant (L52, manufactured by Nippon Yunika)
0) 1 part, 0.2 part of dibutyltin dilaurate (Neostan U-100, manufactured by Nitto Kasei Co., Ltd.) and 5.5 parts of acetylene black (Denka Black, manufactured by Denka Co., Ltd.) were added, and a stirrer was used. A polyol composition in which acetylene black was uniformly dispersed was prepared. After stirring the polyol composition under reduced pressure to remove bubbles, TDI-80 (Sumitomo Bayer Urethane Co., Ltd., Sumidur T-80) was added.
17.1 parts were added, mixed with stirring, poured into a mold heated to 110 ° C., and cured for 2 hours to form an elastic layer on the outer periphery of the metal shaft to obtain a roller having the structure shown in FIG. Was. The surface of the obtained roller was polished to make the surface JIS-B-0601.
The developing roller was obtained by adjusting the 10-point average roughness to 7 μmRz by the method.

[0028]

Example 2 Modified polytetramethylene ether glycol (PTG) having primary hydroxyl groups at both ends (L-2000, molecular weight 2000, manufactured by Hodogaya Chemical Industry Co., Ltd.) 10
0 part is a silicone surfactant (L52, manufactured by Nippon Yunika)
0) 1 part, 0.2 parts of dibutyltin dilaurate (Neostan U-100, manufactured by Nitto Kasei Co., Ltd.) and 4.0 parts of acetylene black (Denka Black, manufactured by Denka Corporation) were added. A polyol composition in which acetylene black was uniformly dispersed was prepared using a stirring mixer. After stirring the polyol composition under reduced pressure to remove bubbles, TDI-80 (Sumitomo Bayer Urethane Co., Ltd., Sumidur T-80) was used.
Was added to 9.1 parts, stirred and mixed, poured into a mold heated to 110 ° C., cured for 2 hours to form an elastic layer on the outer periphery of the metal shaft, and a roller having a structure shown in FIG. 1 was obtained. Obtained. The surface of the obtained roller was polished to make the surface JIS-B-0601.
The developing roller was obtained by adjusting the 10-point average roughness to 7 μmRz by the method.

[0029]

Example 3 Polyisoprene-based polyolefin-based polyol having hydroxyl groups at both terminals and having primary hydroxyl groups at both terminals
(Epole: molecular weight 250, manufactured by Idemitsu Petrochemical Co., Ltd.)
0) 100 parts, 1 part of a silicone surfactant (L520, manufactured by Nippon Yunika Co., Ltd.), 0.2 parts of dibutyltin dilaurate (Neostan U-100, manufactured by Nitto Kasei Co., Ltd.), acetylene black (manufactured by Denka Corporation) , Denka Black) 3.
0 parts were added, and a polyol composition in which acetylene black was uniformly dispersed was prepared using a stirring mixer. After stirring the polyol composition under reduced pressure to remove bubbles, TDI-
80 (Sumitomo Bayer Urethane Co., Ltd., Sumidur T-80) was added and stirred and mixed, then poured into a mold heated to 110 ° C., cured for 2 hours, and elasticized on the outer periphery of the metal shaft. The layer was formed to obtain a roller having the structure shown in FIG. The surface of the obtained roller is polished and the surface is JIS-B
A 10-point average roughness was adjusted to 7 μm Rz by a −0601 method to obtain a developing roller.

[0030]

Comparative Example 1 100 parts of polyetherpolyol (manufactured by Asahi Glass Co., Ltd., Exenol 828) having a molecular weight of 5,000 by adding polypropylene oxide and ethylene oxide to glycerin, and a silicon surfactant (manufactured by Nippon Yunika) , L520) 1 part, dibutyltin dilaurate (Neostan U-100, manufactured by Nitto Kasei Corporation) 0.2
And 3.0 parts of acetylene black (manufactured by Denka Corporation, Denka Black) were added, and a polyol composition in which acetylene black was uniformly dispersed was prepared using a stirring mixer.
After stirring the polyol composition under reduced pressure to remove bubbles,
5.5 parts of TDI-80 (manufactured by Sumitomo Bayer Urethane Co., Ltd., Sumidur T-80) is added, and the mixture is stirred and mixed.
Cast into a mold heated to ℃ and cured for 2 hours to form an elastic layer on the outer periphery of the metal shaft to obtain a structure having the structure shown in FIG.
Got LA. The surface of the obtained roller is polished to make the surface JI.
A 10-point average roughness was adjusted to 7 μmRz by the SB-0601 method to obtain a developing roller.

[0031]

Comparative Example 2 Polyetherpolyol having a molecular weight of 3000 by adding polypropylene oxide to glycerin
(Bowanol 302, manufactured by Dow Chemical Japan Co., Ltd.)
2J) 100 parts, 1 part of a silicon surfactant (L520, manufactured by Nippon Yunika), 0.2 parts of dibutyltin dilaurate (Nitto Kasei, Neostan U-100), and acetylene black (Denka) , Denka Black) 3.
0 parts were added, and a polyol composition in which acetylene black was uniformly dispersed was prepared using a stirring mixer. After stirring the polyol composition under reduced pressure to remove bubbles, TDI-
9.1 parts of Sumitomo Bayer Urethane Co., Ltd. (Sumitomo Bayer Urethane Co., Ltd.) was added, stirred and mixed, poured into a mold heated to 110 ° C., cured for 2 hours, and elastic layer was formed on the outer periphery of the metal shaft. Was formed to obtain a roller having the structure shown in FIG. The surface of the obtained roller is polished and the surface is JIS-B
A 10-point average roughness was adjusted to 7 μm Rz by a −0601 method to obtain a developing roller.

[0032]

Example 4 Polybutadiene-based polyol having an allyl-type primary hydroxyl group at the terminal of polybutadiene and having a molecular weight of 1200 (manufactured by Idemitsu Petrochemical Co., Ltd., R15HT) and TDI-80 (manufactured by Sumitomo Bayer Urethane Co., Ltd.). Polyetherpolyol (Made by Asahi Glass Co., Ltd., Exeno-) having a molecular weight of 5,000 by adding propylene oxide and ethylene oxide to 50 parts of a prepolymer having an NCO% of 7% and glycerin prepared by Sumidur T-80).
828) and 50 parts of a prepolymer having an NCO% of 7% prepared by TDI-80 were stirred and mixed to obtain an isocyanate composition. Then, 7.15 parts of 1,4 butanediol, 1 part of a silicon surfactant (L520, manufactured by Nippon Yunika Co., Ltd.), and 0.2 parts of dibutyltin dilaurate (Neostan U-100, manufactured by Nitto Kasei Co., Ltd.) , 3.5 parts of acetylene black (manufactured by Denka Corporation, Denka Black) were stirred and mixed.
It was poured into a mold heated to 0 ° C. and cured for 2 hours to form an elastic layer on the outer periphery of the metal shaft to obtain a roller having the structure shown in FIG. The surface of the obtained roller is polished to make the surface J
According to IS-B-0601 method, 10-point average roughness 7 μm Rz
And a developing roller was obtained.

[0033]

Example 5 A complex compound of sodium perchlorate and 2 (2methoxyethoxy) ethanol (Akishima Chemical Industry Co., Ltd., MP100) was used as an ion conductivity-imparting substance instead of acetylene black as an electron conductivity-imparting substance. A developing roller was prepared in the same manner as in Example 4 except that 2 parts of) were added.

[0034]

Example 6 Polybutadiene-based polyol (R45HT, manufactured by Idemitsu Petrochemical Co., Ltd.) having a molecular weight of 2,800 and having allyl-type primary hydroxyl group at the terminal of polybutadiene and TDI-80 (manufactured by Sumitomo Bayer Urethane Co., Ltd.). Sumidur T-80), NCO% of 7% prepolymer 100 parts, 1,4 butanediol 7.15 parts,
Silicon surfactant (L520, manufactured by Nippon Yunika) 1
Part, dibutyltin dilaurate (manufactured by Nitto Kasei Co., Ltd.
0.2 parts of Neostan U-100) and 4.0 parts of acetylene black (Denka Black, Denka Black) were stirred and mixed, then poured into a mold heated to 110 ° C., cured for 2 hours, and then cured around the outer periphery of the metal shaft. Then, a roller having the structure shown in FIG. 1 was obtained by forming an elastic layer. The surface of the obtained roller was polished, and the surface was polished to a 10-point average roughness of 7 according to JIS-B-0601.
It was adjusted to μmRz to obtain a developing roller.

[0035]

Comparative Example 3 Polyetherpolyol (Exenol 828, manufactured by Asahi Glass Co., Ltd.) having a molecular weight of 5,000 by adding polypropylene oxide and ethylene oxide to glycerin and TDI-80 (manufactured by Sumitomo Bayer Urethane Co., Ltd.). -TCO-80)
Is 100% of 7% prepolymer, 1,4 butane di-
7.15 parts, silicon surfactant (manufactured by Nippon Yunika,
L520) 1 part, dibutyltin dilaurate (Nitto Kasei Co., Ltd., Neostan U-100) 0.2 part, and acetylene black (Denka Corporation, Denka Black) 3.0 parts were stirred and mixed. It was poured into a heated mold and cured for 2 hours to form an elastic layer on the outer periphery of the metal shaft to obtain a roller having the structure shown in FIG. The surface of the obtained roller was polished, and the surface was adjusted to a 10-point average roughness of 7 μmRz by JIS-B-0601 to obtain a developing roller.

[0036]

Comparative Example 4 Polybutadiene-based polyol (R15HT, manufactured by Idemitsu Petrochemical Co., Ltd.) having a molecular weight of 1200 and having an allyl-type primary hydroxyl group at the terminal of polybutadiene and TDI-80 (manufactured by Sumitomo Bayer Urethane Co., Ltd.) A polyether polyol (Asahi Glass Co., Ltd., Exeno Corporation) made by adding 15 parts of a prepolymer having an NCO% of 7% and glycerin to propylene oxide and ethylene oxide and having a molecular weight of 5000.
828) and TDI-80 (Sumitomo Bayer Urethane Co., Ltd., Sumidur T-80) prepared by mixing and stirring 85 parts of a prepolymer having an NCO% of 7%.
7.15 parts of 1,4 butanediol, 1 part of a silicone surfactant (L520, manufactured by Nippon Unica Ltd.), and 0 parts of dibutyltin dilaurate (Neostan U-100, manufactured by Nitto Kasei Co., Ltd.) .2 parts, 3.5 parts of acetylene black (manufactured by Denka Corporation, Denka Black) were added, and after stirring and mixing,
It was poured into a mold heated to 110 ° C. and cured for 2 hours to form an elastic layer on the outer periphery of the metal shaft to obtain a roller having the structure shown in FIG. The surface of the obtained roller was polished, and the surface was polished according to JIS-B-0601 method.
The developing roller was adjusted to Rz.

[0037]

Example 7 A polybutadiene-based polyol having a molecular weight of 1200 and having an allyl-type primary hydroxyl group at the terminal of polybutadiene (Idemitsu Petrochemical Co., Ltd.) was formed on the surface of a roller similar to that prepared in Comparative Example 4. R15HT) and TD
I-80 (Sumitomo Bayer Urethane Co., Ltd., Sumidur T-80), 100 parts of a prepolymer having an NCO% of 7%, 7.15 parts of 1,4 butanediol, and a silicon surfactant (Japan One part of L520 manufactured by Unica and 0.1 part of dibutyltin dilaurate (Neostan U-100 manufactured by Nitto Kasei Co., Ltd.) were stirred and mixed, coated, and coated with a developing roller having a coat thickness of 80 μm. -I got la.

[0038]

Example 8 A polybutadiene-based polyol having a molecular weight of 1200 and having an allyl-type primary hydroxyl group at the terminal of polybutadiene (Idemitsu Petrochemical Co., Ltd.) was formed on the surface of a roller similar to that prepared in Comparative Example 4. R15HT) and TD
A polypolymer having a molecular weight of 5,000 by adding propylene oxide and ethylene oxide to glycerin, and 50 parts of a prepolymer having an NCO% of 7%, which was prepared using I-80 (Sumitomo Bayer Urethane Co., Ltd., Sumidur T-80). -NCO% prepared with terpoliol (Exasol 828, manufactured by Asahi Glass Co., Ltd.) and TDI-80 (Sumijur T-80, manufactured by Sumitomo Bayer Urethane Co., Ltd.) is 7%.
% Prepolymer was stirred and mixed with 7.15 parts of 1,4 butanediol, 1 part of a silicon surfactant (L520, manufactured by Nippon Yunika Co., Ltd.), and 1 part of dibutyltin dilaurate ( 0.1 part of Neostan U-100 manufactured by Nitto Kasei Co., Ltd. was stirred and mixed, followed by coating to obtain a developing roller having a coat thickness of 20 μm.

[0039]

Example 9 A polybutadiene-based polyol having a molecular weight of 1200 and having an allyl-type primary hydroxyl group at the terminal of polybutadiene (Idemitsu Petrochemical Co., Ltd.) was formed on the surface of a roller similar to that prepared in Comparative Example 4. R15HT) and TD
A polypolymer having a molecular weight of 5,000 by adding propylene oxide and ethylene oxide to glycerin, and 50 parts of a prepolymer having an NCO% of 7%, which was prepared using I-80 (Sumitomo Bayer Urethane Co., Ltd., Sumidur T-80). -NCO% prepared with terpoliol (Exasol 828, manufactured by Asahi Glass Co., Ltd.) and TDI-80 (Sumijur T-80, manufactured by Sumitomo Bayer Urethane Co., Ltd.) is 7%.
% Prepolymer was stirred and mixed with 7.15 parts of 1,4 butanediol, 1 part of a silicon surfactant (L520, manufactured by Nippon Yunika Co., Ltd.), and 1 part of dibutyltin dilaurate ( 0.1 part of Neostan U-100 manufactured by Nitto Kasei Co., Ltd. was stirred and mixed, followed by coating to obtain a developing roller having a coat thickness of 85 μm.

[0040]

Example 10 A polybutadiene-based polyol having a molecular weight of 1200 and having an allyl-type primary hydroxyl group at the terminal of polybutadiene (Idemitsu Petrochemical Co., Ltd.) was formed on the surface of a roller similar to that prepared in Comparative Example 4. Company made, R15HT) and T
DI-80 (Sumitomo Bayer Urethane Co., Ltd., Sumidur T-80), a prepolymer having an NCO% of 7% and 50 parts of a prepolymer having a molecular weight of 5000 by adding propylene oxide and ethylene oxide to glycerin. -Terpoliol (Exeno, manufactured by Asahi Glass Co., Ltd.)
828) and TDI-80 (Sumitomo Bayer Urethane Co., Ltd., Sumidur T-80) prepared by stirring and mixing 50 parts of a prepolymer having an NCO% of 7%.
And 3.5 parts of acetylene black, 7.15 parts of 1,4 butanediol, 1 part of a silicon surfactant (L520, manufactured by Nippon Unica), dibutyltin dilaurate (manufactured by Nitto Kasei Co., Ltd.) , Neostan U-100) 0.1
The resulting mixture was coated by stirring to obtain a developing roller having a coat thickness of 200 μm.

[0041]

Comparative Example 5 Polypropylene having a molecular weight of 5,000 was obtained by adding propylene oxide and ethylene oxide to glycerin on the surface of a roller similar to that prepared in Comparative Example 4.
Terpoliol (Exenol 82 manufactured by Asahi Glass Co., Ltd.)
8) and TDI-80 (Sumitomo Bayer Urethane Co., Ltd., Sumidur T-80) made NCO% 7%
In 100 parts of the prepolymer, 1,4 butanediol 7.
15 parts, silicon surfactant (L52, manufactured by Nippon Yunika)
0) 1 part and 0.1 part of dibutyltin dilaurate (Neostan U-100, manufactured by Nitto Kasei Co., Ltd.) were stirred and mixed, and then coated to obtain a developing roller having a coat thickness of 60 μm. Was.

[0042]

Comparative Example 6 Polyetherpolyol having a molecular weight of 3,000 by adding polypropylene oxide to glycerin.
(Bowanol 302, manufactured by Dow Chemical Japan Co., Ltd.)
2J) and TDI-80 (Sumitomo Bayer Urethane Co., Ltd., Sumidur T-80) have an NCO% of 7%.
In 100 parts of the prepolymer, 1,4 butanediol 7.
15 parts, silicon surfactant (L52, manufactured by Nippon Yunika)
0) 1 part and 0.1 part of dibutyltin dilaurate (Neostan U-100, manufactured by Nitto Kasei Co., Ltd.) were stirred and mixed, and then coated to obtain a developing roller having a coat thickness of 50 μm. Was.

With respect to the developing rollers obtained in Examples 1 to 10 and Comparative Examples 1 to 6, the following characteristic tests were performed. The results are shown in Tables 1 to 3.

[0044]

[Table 1]

[Table 2]

[Table 3]

(1) Volume resistance A sheet-like sample prepared under the same conditions as each roller was measured using a resistivity meter Hiresta (manufactured by Mitsubishi Yuka).
The measurement was performed by applying a voltage of 100V. (2) Surface roughness For each roller, use a surface roughness meter Handy Surf E-30
It was measured using a type A (manufactured by Tokyo Seimitsu Co., Ltd.). (3) Image test Each roller was installed as a developing roller in the developing unit shown in FIG. 2 and was subjected to normal temperature and normal humidity (23 ° C., 55% RH) and high temperature and high humidity conditions (33 ° C., 85%). % RH), reversal development,
Images were taken out while rotating at a peripheral speed of a linear speed of 60 mm / sec, and the occurrence of fog and toner dust was evaluated at the initial stage. At the same time, the toner filming state on the roller surface after 5000 prints was also observed.

As is evident from the results of Tables 1 to 3, the present invention reduces the amount of charge of the non-magnetic one-component developer and eliminates fogging even in a high-temperature and high-humidity environment where image quality is liable to deteriorate. It is possible to obtain a developing roller which can obtain a high-quality image and does not cause deterioration in image quality even when used for a long time.

[0047]

As described above, the developing roller of the present invention can be used.
According to (a), even in a high-temperature and high-humidity environment where the charge amount of the non-magnetic one-component developer is reduced and image quality is liable to be deteriorated, a clear, high-quality image without fogging can be obtained. It is possible to obtain a developing roller and a developing device that do not cause deterioration in image quality.

[Brief description of the 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.

[Description of Signs] 1 Development Roller 2 Shaft 3 Elastic Body 4 Toner Coating Roller 5 Photosensitive Drum (Latent Image Holder) 6 Toner (Non-magnetic One-Component Developer) 7 Layered Blade 8 Transfer Section 9 Cleaning part 10 Cleaning blade

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-1-124881 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) G03G 15/08-15/09

Claims (2)

(57) [Claims] An elastic layer having conductivity is formed on the outer periphery of a good conductive shaft. A non-magnetic one-component developer is carried on the surface of the elastic layer to form a thin layer of the developer. In this state, the developer contacts the latent image holding member holding the electrostatic latent image on the surface, and causes the developer to adhere to the electrostatic latent image on the surface of the latent image holding member from the thin layer, thereby visualizing the electrostatic latent image. In the developing roller,
The elastic layer is made of a polyurethane resin containing a conductive additive, and has a resistivity of 10 ⁴ to 10 ¹⁰ ΩCm and a hardness of J
A developing roller characterized by having an IS-A scale of 55 ° or less and a water absorption of the elastic layer of 3% or less. 2. A roller-shaped or drum-shaped latent image holding member for holding an electrostatic latent image on a surface thereof, and a non-magnetic one-component developer carried on an outer peripheral surface thereof. The non-magnetic one-component developer adheres to the electrostatic latent image on the surface of the latent image holding member by rotating in contact with the rotating movement of the latent image holding member, thereby forming the electrostatic latent image. 2. A developing device comprising a developing roller for visualizing, wherein the developing roller according to claim 1 is used as said developing roller.