JP3065323B2 - Developing device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic latent image developing device using a one-component toner.

[Prior Art] Conventionally, as a method of developing an electrostatic latent image using a non-magnetic one-component toner, a toner on a toner carrier (that is, a developing roller) is thinned by a blade-shaped or roll-shaped member, There is known a method in which a photoconductor is brought into contact with a holding member (that is, a photoconductor) holding an electrostatic latent image and developed. In this method, the developing roller repeats a cycle such as charge removal of the charge remaining in the transfer development of the thin layer forming toner of the charged toner of the toner replenishing toner.However, when the developing roller performs one cycle and enters the next cycle, The developing roller generates a counter charge due to frictional charging with the toner, and the distributed charge from the photoreceptor remains on the surface or inside thereof, so that repeated use deteriorates the charging characteristics and developing characteristics of the toner. There was a disadvantage that it occurred.

For this reason, conventionally, various methods of removing the charge of the developing roller have been studied. For example, a method of contacting the surface of the toner carrier with a low-resistance element such as a metal brush or a conductive sponge has been proposed.

However, the method using a metal brush may cause streaks to appear on an image because the contact with the surface of the toner carrier is not uniform, and the method using a conductive sponge causes the afterimage to disappear. The effect was not enough. Further, these methods have a drawback that the static elimination effect is extremely poor since they are methods in which a toner carrier is contacted via a thin toner layer. In addition, various attempts have been made to improve the static elimination effect, for example, by examining the material and density of the brush and the number of sponge rolls to be installed. However, no attempt has been made to completely eliminate the afterimage. On the other hand, due to the improvement from the afterimage system side, a developing roller that is very easily initialized, in other words, a developing roller in which no charge remains, has been developed.

As such a developing roller, for example, first, an elastic material having a medium volume resistance (hereinafter, referred to as medium resistance) of 10 ⁵ to 10 ¹¹ Ω · cm is used as a conductive substrate of the coating layer, As a coating layer, there is a developing roller coated with a semiconductive body composed of a flexible synthetic resin and conductive particles. However, this material uses acrylonitrile butadiene rubber,
Since it is epichlorohydrin rubber, chloroprene rubber, urethane rubber, etc., it is difficult to produce a uniform and stable product. Especially, the environmental resistance (heat and humidity) of electric characteristics is inferior. It has the disadvantage of changing.

On the other hand, a developing roller has been proposed in which a conductive elastic body having a volume resistance of 10 ⁶ Ωcm or less is used, and a resin or rubber layer in a medium resistance-high resistance region is laminated thereon, and an electrode layer is sequentially laminated thereon. I have. This has the advantage that environmental resistance can be significantly improved by using a resin or rubber (for example, a silicone-based or fluorine-based polymer) having excellent heat and moisture resistance for each layer.

However, since the developing roller uses a medium-resistance to high-resistance resin as a coating layer, the charge generated by the friction charging process with the toner remains and accumulates, and greatly affects the toner charging property and the developing characteristics in the next process. give,
It has the disadvantage of producing an afterimage. Attempts have also been made to promote charge leakage by dispersing conductive particles in the electrode layer of the developing roller and lowering the resistance. However, when the surface layer is provided with sufficient conductivity to leak charges, Decrease in charge amount and toner transportability Excessive concentration and decrease in resolution due to increase in electric field strength with the holder due to lower resistance of the surface layer. At present, a developing roller that is satisfactory in all aspects has not been developed.

[Problems to be Solved by the Invention] The present invention has been made in view of the above-mentioned circumstances of the related art, and has an excellent chargeability and releasability of a toner, and may cause an afterimage even after repeated use for a long time. It is an object of the present invention to provide a toner carrier which has no durability, is durable, can be reduced in size at low cost, and a developing device using the toner carrier.

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that it is effective to provide a resin layer containing a surfactant on a toner carrier, The present invention has been reached.

That is, the present invention provides an electrostatic latent image holder for holding at least an electrostatic latent image, a toner carrier for visualizing a latent image on the holder, and forming a thin layer of toner on the toner carrier. A one-component developing device comprising a regulating member, wherein the toner carrier is provided with a resin layer containing a surfactant (however, excluding a quinolinium salt; the same applies hereinafter).

The developing device of the present invention will be described with reference to FIG. In FIG. 1, 1 is a container, 2 is a toner, 3 is an agitator 4
Is a supply roller, 5 is a toner carrier such as a developing roller, 6 is a thin toner layer blade as a regulating member, and 7 is an electrostatic latent image holder such as a photosensitive drum.

In FIG. 1, a non-magnetic one-component toner 2 is contained in a toner container 1. The toner 2 is conveyed by the agitator 3 to a toner storage section formed by the supply roller 4 and the toner carrier 5, and is carried on the surface of the toner carrier 5. Further, the toner thin layer blade 6 forms a uniform thin layer and is triboelectrically charged to a predetermined polarity. The thin toner layer is transported to a developing area where the holding member 7 holding the electrostatic latent image and the toner carrier 5 are in contact with each other, where the toner is electrostatically transferred from the toner carrier to the holding member 7, The image is visualized. In the above process, the toner 2 and the toner carrier 5 are electrostatically coupled by frictional charging. After the toner 2 moves to the holder 7, a counter charge is stored in the toner carrier 5. Residual, so-called afterimage development occurs.

In the present invention, the toner carrier having the specific structure as described above is used in order to quickly leak such a counter charge and to improve the chargeability, transportability, and releasability of the toner.

The present invention can be applied not only to the non-magnetic-component developing toner carrier as described above, but also to a magnetic-component developing developing roller. Further, the shape is not limited to the shape of a roller but may be, for example, a shape of a belt. Further, the electrostatic latent image holding member is not limited to the photoreceptor, but may be any member that can hold the electrostatic latent image.

FIG. 2 shows the toner carrier used in the present invention. Core metal 23
It has a configuration in which a conductive elastic layer 22 and a resin layer 21 are sequentially provided thereon.

The core bar 23 is formed of a conventionally known material, for example, a metal material such as stainless steel, aluminum, and iron.

The conductive elastic layer 22 is provided because the elasticity of the developing roller is required in contact development with a photosensitive drum such as the developing device of FIG. 1 used in the present invention. In this case, this layer may not be provided. For this layer to function as a counter electrode, it is desirable to use a conductive elastic body having a volume resistivity of 10 ¹² Ω · cm or less.

In this case, styrene-butadiene rubber, epichlorohydrin rubber, acrylic rubber, polar rubber such as chloroprene rubber or silicone rubber, EPDM, a dispersion of low-resistance particles such as carbon in high-resistance rubber such as fluoro rubber is used, Silicone rubber, which can be reduced in height without using a plasticizer or the like, is particularly preferably used. These materials can be obtained by ordinary molding means such as press molding, injection molding, extrusion molding, and the like, and can be formed into a predetermined shape by polishing. The thickness of the conductive elastic layer is suitably at least 1 mm in order to exhibit a sufficient elastic effect.

The resin layer 21 is made of alkyd resin, chlorinated polyether, chlorinated polyethylene, epoxy resin, fluororesin, phenol resin, polyamide, polycarbonate, polyethylene, methacrylic resin, polypropylene, polystyrene,
Polyurethane, polyvinyl chloride, polyvinylidene chloride,
It is made of resin such as silicone, butadiene rubber, styrene butadiene rubber, ethylene propylene rubber, chloroprene rubber, chlorinated polyethylene, epichlorohydrin rubber, nitrile rubber, acrylic rubber, silicone rubber, fluorine rubber, and other rubbers. From the viewpoint of properties, use of a silicone resin or a fluorine resin is preferred. The thickness of the resin layer 21 can be arbitrarily determined by considering electrical characteristics such as volume resistance and dielectric constant.
~ 2mm. In order to form this layer, an appropriate method such as spray coating, dipping, steam vulcanization, or extrusion vulcanization may be appropriately employed.

The present invention is achieved by incorporating a surfactant into this layer, and the surfactant may be any of nonionic, cationic, anionic and amphibian. Specifically, nonionic compounds include ester compounds such as fatty acids, ether ester compounds, ether compounds, amide condensates, and cationic compounds include aliphatic amine salts and quaternary ammonium salts thereof. ,
Examples of anionic compounds such as aromatic quaternary ammonium salts and heterocyclic quaternary ammonium salts include alkyl carboxylate, N-acyl amino acid salt, alkyl ether carboxylate, acylated peptide, alkyl sulfonate, alkyl benzene, and the like. Alkyl naphthalene sulfonate, fursuccinate, α-olefin sulfonate, N-acyl sulfonate, alkyl sulfate, alkyl ether sulfate, alkyl allyl ether sulfate, alkyl amide sulfate, alkyl phosphate, alkyl ether Phosphates, alkyl allyl ether phosphates and the like, amphibious ones include carboxybetaine, sulfobetaine, aminocarboxylate and the like.

In the present invention, particularly when a fluorine-based surfactant is contained as the above-mentioned surfactant, environmental resistance is excellent and it is preferable. This fluorine-based surfactant can be any of nonionic, cationic, anionic and amphoteric, and specific examples include the following.

Nonionic ones include perfluoroalkyl group lipophilic group-containing oligomers, perfluoroalkyl group hydrophilic group-containing oligomers, perfluoroalkyl ethylene oxide adducts, and the like. Examples of anionic compounds such as quaternary ammonium salts include perfluoroalkyl-containing sulfonic acids and carboxylic acid monovalent metal salts and phosphate esters, and examples of amphoteric compounds include perfluoroalkyl-containing betaines. .

These can be appropriately selected from the viewpoint of compatibility with the resin or rubber used. Further, it can be used in combination with a nonionic surfactant.

The mixing amount of this surfactant is 10% of the solid content of the binder resin.
0.1 to 50 parts by weight with respect to 0 parts by weight is preferred. More preferably, it is 0.5 to 20 parts by weight. When the amount is less than 0.1 parts by weight, the effect is not sufficiently exhibited and an afterimage is generated. Conversely, if the amount exceeds 50 parts by weight, the abrasion resistance, the environmental resistance deteriorates, and the toner transportability deteriorates.

Further, an inorganic filler, a crosslinking agent, a heat stabilizer, a processing aid and the like can be added to the developing roller used in the present invention for various purposes. As inorganic fillers, diatomaceous earth, quartz powder, iron oxide, zinc oxide, titanium oxide, calcium oxide,
Powders such as magnesium oxide, talc, aluminum silicate, and aluminum oxide, potassium titanate, asbestos, glass, fibers such as carbon, and powders such as Teflon and boron nitride are used.

The toner may be either positively chargeable or negatively chargeable, and conventionally known toners can be used. Specific examples of such a toner include, for example, fine particles containing a colorant in a binder resin such as styrene-n-butyl methacrylate or an epoxy resin, and, if necessary, a charge control agent (a nigrosine dye, a basic Dyes), fluidizers such as silica, abrasives such as silicon carbide, and lubricants such as fatty acid metal salts.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

Example 1 A conductive primer (DY39-0 manufactured by Toray Silicone Co., Ltd.)
11) On the core metal (6 mmφ) coated with, the following conductive elastic layer forming components: primary flow: 170 ° C / 10 minutes, 120 kg / cm ² , secondary flow: 200 ° C / 4 hours Press-formed underneath, conductive elastic layer with a thickness of 6 mm (volume resistivity: 1.5 × 10 ⁵ Ω · cm, rubber hardness (J
ISA): 28 °).

[Conductive Elastic Layer Forming Component] Methyl vinyl polysiloxane 100 parts by weight Carbon (Ketjen Black EC) 5 parts by weight Quartz 20 parts by weight After kneading the above mixture with two rolls, 100 parts by weight of the mixture was mixed with a crosslinking agent (2 1,4-dimethyl-2,4-di-tert-butylperoxyhexane: 1.5 parts by weight, manufactured by Toray Silicone Co., Ltd .: RC-4).

Next, after the surface of the conductive elastic layer is washed with tricrene, a titanate-based coupling agent (TA: manufactured by Matsumoto Pharmaceutical Co., Ltd .: TA)
-25), and dried for 30 minutes. Then, the following resin layer forming components are spray-coated at 150 ° C /
The resin was cured under the condition of 1 hour, and then polished to form a resin layer having a thickness of 50 μm, thereby forming a developing roller.

[Resin layer forming component] Fluorine copolymer resin (solid content 50%) (Asahi Glass Co., Ltd.)
Company: Lumiflon 601C) 100 parts by weight Coronate EH (50% xylene solution) 20 parts by weight MEK 400 parts by weight Fluorinated cationic surfactant (C ₈ F ₁₇ SO ₂ NH (C ₃ H ₆ )
^{_{N + (CH 3) 3 I}} -) except for using a fluorine-based anionic surfactant (C ₇ F ₁₅ COONa) is in place in a fluorine-based cationic surface active agent used in 5 parts by weight EXAMPLE 2 Example 1, Same as Example 1.

Example 3 Instead of the fluorinated cationic surfactant used in Example 1, a fluorinated amphoteric surfactant [C ₈ F ₁₇ SO ₂ NH (C ₃ H ₆ )] was used.
N ⁺ (CH ₃ ) ₂ .C ₂ H ₄ COO ⁻ ] was used in the same manner as in Example 1.

Example 4 Instead of the fluorinated cationic surfactant in Example 1, a hydrocarbon-based cationic surfactant [C ₁₂ H ₂₅ SO ₂ NH
^{_{(C 3 H 6) N +}} (CH 3) 3 I -] and the other is the same used.

Example 5 The procedure was the same as in Example 1 except that a hydrocarbon-based anionic surfactant (C ₇ H ₁₅ COONa) was used instead of the fluorine-based surfactant.

Example 6 A hydrocarbon-based amphoteric surfactant in place of the fluorine-based surfactant in Example 1 Were the same except for using.

Comparative Example 1 Example 1 was the same except that no surfactant was used.

Comparative Example 2 The procedure was the same as in Example 1, except that the following was used instead of the surfactant.

Carbon black master batch 15 parts by weight The carbon master batch was prepared as follows.

Fluorine-based copolymer resin (solid content 50%) (Asahi Glass Co., Ltd.)
Company: Lumiflon 601C) 100 parts by weight Carbon black (Black Pearl L: manufactured by Cabot) 40 parts by weight Toluene 50 parts by weight Xylene 50 parts by weight The above mixture was dispersed in a ball mill for 72 hours to prepare a carbon master batch.

Comparative Example 3 The carbon black masterbatch in Comparative Example 2 was used.
Except that the amount was changed from 15 parts by weight to 50 parts by weight, the conditions were the same.

Each of the developing rollers of the example and the comparative example obtained as described above was used as the developing roller in FIG. 1, and each of the toner charge amount, the toner releasing property, the developing roller wear property, the afterimage property, and the image unevenness was measured. For each item, 10 ℃ 24%,
The evaluation was performed under each environment of 20 ° C 50% and 30 ° C 80%. Table 1 shows the results. The evaluation method was as follows.

[Charge Amount of Toner] The charge amount in the developing device shown in FIG. 1 was measured by a blow-off method using the following charged toner.

(Toner used): Particle size: 12 μm Styrene acrylic resin: 100 parts by weight Carbon: 10 parts by weight Chromium-containing monoazo dye: 2 parts by weight [Release property of toner] Using the above toner and developing device, developing after idling for 72 hours. The toner condition on the roller surface was evaluated according to the following criteria.

Rank A: The toner on the roller surface can be easily wiped off with a cloth or the like.

Rank B: Slight toner remains after wiping.

Rank C: The toner cannot be completely wiped off and a thin film of the toner remains.

Rank D: The toner in the molten state is strongly fixed to the roller surface.

[Abrasion of Developing Roller] Using the same toner and developing device as described above, the amount of abrasion after idling for 20 hours was measured by measuring the diameter of the developing roller. The diameter of the roller was measured with a laser micro gauge (DT-4002A; Iwatsu Electronics).

[Evaluation of Afterimage Property] An afterimage was evaluated by a pattern image using the same toner and developing device as described above. That is, after black solid development, halftone dots are developed, and the image density (ID _L ) of halftone dots corresponding to the positions of black solids
Halftone dot density (ID
_H )) (ID _L / ID _H ) was measured with a Macbeth densitometer. The ratio was measured at two places on the left and right.

[Evaluation of Image Unevenness] One point in one rotation of the solid black developing roller was taken, and 5 points were added.
For a total of 5 points up to the rotation, Macbeth densitometer
The ID was measured, and the value of ID / OD × 100 was determined.

OD: Original density of solid black part ID: Copy density of solid black part The following were used as the thin toner layer blade, the supply roller and the photoconductor.

[Thin toner layer blade] Silicone rubber (1mm thick) [Toner supply roller] Conductive urethane sponge [Photoconductor] OPC [Effects of the Invention] As described above, by providing a resin layer containing an ionic surfactant on a toner carrier according to the present invention, it is possible to prevent an afterimage, and at the same time, to improve the toner charge amount, Good results are also obtained for the toner releasability and the abrasion resistance of the toner carrier.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a developing device of the present invention, and FIG. 2 is a diagram for explaining a configuration of a toner carrier used in the present invention.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-58-156974 (JP, A) JP-A-53-107337 (JP, A) JP-A-61-258268 (JP, A) 93952 (JP, U)

Claims (3)

(57) [Claims] 1. An electrostatic latent image holder for holding at least an electrostatic latent image, a toner carrier for visualizing the latent image on the holder,
And a one-component developing device comprising a regulating member for forming a thin layer of toner on the toner carrier, wherein the toner carrier is provided with a resin layer containing a surfactant (excluding a quinolinium salt). Characterized one-component developing device. 2. The one-component developing apparatus according to claim 1, wherein said surfactant is an ionic surfactant. 3. The one-component developing apparatus according to claim 1, wherein the surfactant is a fluorinated ionic surfactant.