JPH03243970A - Developing device - Google Patents

Abstract

PURPOSE:To make the electrostatic charge performance and the separation performance of toner excellent and to prevent an after image from being produced even when a developing device is repeatedly used for a long time by making the constitution of a toner carrier multiple layers and containing surfactant in at least one among the inner layers. CONSTITUTION:The toner 2 and the toner carrier 5 are electrostatically coupled by triboelectrification. However, counter charge is left in the carrier 5 after the toner 2 is moved to a photosensitive body and the after image is produced. In order to quickly leak such counter charge and to improve the electrostatic charge performance, the carrying performance and the separation performance of the toner, the toner carrier 5 whose structure is specified is used. That means, the layer 23 containing the surfactant is provided just above a developing counter electrode and the polymer layer 22 is provided on it, besides. Thus, an excellent image without the after image whose residual electric charge is extremely small and which shows the stable electrostatic charge performance is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a developing device for electrophotography, and more particularly to a developing device for electrostatic latent images using a one-component toner.

[Conventional technology]

Conventionally, as a method for developing an electrostatic latent image using a non-magnetic component toner, the toner on a toner carrier (i.e., a developing roller) is made into a thin layer using a blade-like or roll-like member, and this is used to form an electrostatic latent image. A method is known in which the image is developed by contacting it on a holder (i.e., a photoreceptor) holding the image. In this method, the toner carrier repeats the following cycles: ■ Toner replenishment ■ Toner charging ■ Toner thin layer formation ■ Toner transport ■ Development ■ Residual charge removal.
When the toner carrier is cycled and enters the next cycle, a counter charge occurs on the toner carrier due to frictional charging with the toner, and the charge distributed from the photoreceptor remains on its surface or inside, so repeated use may cause the charging characteristics of the toner to deteriorate. There have been disadvantages such as deterioration of development characteristics and the occurrence of so-called afterimage development.

For this reason, various methods of neutralizing the toner carrier have been studied, and for example, a method has been proposed in which a low resistance body such as a metal brush or a conductive sponge is brought into contact with the surface of the toner carrier.

However, the method using a metal brush may cause streaks to appear on the image due to uneven contact with the surface of the toner carrier, and the method using a conductive sponge eliminates the afterimage. The effect was not sufficient. Furthermore,
Since these methods contact the toner carrier through a thin toner layer, they have the disadvantage that the static elimination effect is extremely poor. In addition, various attempts have been made to improve the static elimination effect, such as examining the material and density of the brush and the number of sponge rolls installed, but it has not been possible to completely eliminate the afterimage.

On the other hand, improvements from the developing system side have led to the development of toner carriers that are very easy to initialize, in other words, there is no residual charge.

For such a toner carrier, for example, an elastic material with a medium volume resistance (hereinafter referred to as medium resistance) of 10'-1011 Ω·Cm is used as the conductive base of the first coating layer, and a second coating layer is formed on the elastic material. As an example, there is a toner carrier coated with a semiconductive material made of flexible synthetic resin and conductive particles. However, the materials used in this product are acrylonitrile butadiene rubber, epichlorohydrin rubber, chloroprene rubber,
Since it is made of urethane rubber, it is difficult to make a uniform and stable product, and the electrical properties are particularly poor in environmental resistance (heat and humidity), which has the disadvantage that the development characteristics change depending on the environmental conditions. .

In addition, a toner carrier has been proposed in which a conductive elastic body having a volume resistivity of 106Ω・0 m or less is used, a resin or rubber layer in the medium to high resistance range is laminated thereon, and then an electrode layer is sequentially laminated thereon. . This product has the advantage that environmental resistance can be significantly improved by using resin or rubber (for example, silicone type, fluorine type polymer) with excellent heat resistance and moisture resistance in each layer.

However, since this toner carrier uses a medium-to-high resistance resin as a coating layer, residual charges generated by the frictional charging process with the toner remain and accumulate, which significantly affects the toner charging performance and development characteristics in the next process. influence,
It has the disadvantage of producing an afterimage. In addition, attempts have been made to promote charge leakage by dispersing conductive particles in the electrode layer of the developing roller to lower the resistance, but if the surface layer is made conductive enough to leak charge, Decreased charge amount and toner transportability 0 Excessive concentration and decreased resolution due to increased electric field strength with the holder due to lower resistance of the surface layer Problems such as deterioration, occurrence of toner filming, and deterioration of abrasion resistance occur, and the current situation is that a toner carrier that is satisfactory in all aspects has not been developed.

The inventors of the present invention have made extensive studies to solve the above-mentioned problems, and have found that a single-layer toner carrier in which a resin layer containing a surfactant is first provided is effective.

However, since the surface layer of such a toner carrier is a layer containing a surfactant, depending on the type of surfactant,
The problem is that the toner's charge level decreases and filming occurs, which limits its range of use.
Furthermore, a single layer has the problem of high cost due to the use of a large amount of expensive surfactant.

[Problem to be solved by the invention]

The present invention has been made in view of the actual state of the prior art described above, and has excellent toner charging properties and mold releasability, does not produce afterimages even after repeated use over a long period of time, has excellent durability, and has low It is an object of the present invention to provide a developing device using a toner carrier that can be reduced in size and cost.

(Means for Solving the Problems) In order to achieve the above object, the inventors of the present invention have made intensive studies and found that 1. The toner carrier has a multilayer structure and at least one of the inner layers contains a surfactant. They have found that this is effective and have completed the present invention.

That is, according to the present invention, a supply roller supplies toner to a toner carrier carrying toner on its surface, a regulating member forms a uniform thin layer, and the electrostatic latent image is developed on a holder holding the toner. A developing device is provided in which the toner carrier has a multilayer structure, and at least one of the inner layers is a layer containing a surfactant.

The developing device of the present invention will be explained 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 (developing roller), 6 is a toner thin layer blade, and 7 is a photoreceptor.

In FIG. 1, a toner container 1 contains a non-magnetic monocomponent toner 2. As shown in FIG. This toner 2 is conveyed by an agitator 3 to a toner storage section formed by a supply roller 4 and a toner carrier 5, and is carried on the surface of the toner carrier 5. Furthermore, a uniform thin layer is formed by the toner thin layer blade 6, and the toner is triboelectrically charged to a predetermined polarity. The thin toner layer is transported to a development area where the photoconductor 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 photoconductor 7, forming the latent image. is visualized. In the above process, the toner 2 and the toner carrier 5 are electrostatically bonded by frictional charging, but after the toner 2 moves to the photoreceptor 7, a counter charge is generated in the toner carrier 5. The residual image remains behind, causing so-called afterimage development.

The present invention uses a toner carrier having a specific structure as described above in order to quickly leak such countercharge and improve toner charging properties, transport properties, mold release properties, etc.

Namely, the present inventors found that by providing a layer containing a surfactant directly above the developing counter electrode and further providing a polymer layer thereon, a sufficient afterimage prevention effect can be obtained, and the material for the uppermost layer is selected. By the way.

It has been found that the toner can have excellent charging properties and toner release properties. in this regard.

As a result of further research, the present inventors found that when the resin layer of the toner carrier has a multilayer structure and at least one of the inner layers of the resin layer is a layer containing a surfactant, the toner It has been found that it has excellent charging properties, transportability, and mold release properties, as well as excellent afterimage prevention effects.

That is, the developing device of the present invention is characterized in that a toner carrier having a multi-layered structure and at least one layer constituting the inner layer is a layer containing a surfactant.

In the present invention, the layer containing a surfactant may be provided in at least one of the inner layers, but preferably two layers, and more preferably all of the inner layers are layers containing a surfactant.

The present invention can be applied not only to a toner carrier for non-magnetic component development as described above, but also to a toner carrier for magnetic component development. Furthermore, the shape is not limited to a roll shape, but can also be applied to a belt shape.

Further, the electrostatic latent image holder is not limited to a photoconductor, and any member capable of holding an electrostatic latent image may be used.

2 to 4 show representative examples of toner carriers used in the present invention, in which 25, 35, 46 are core metals; 24, 34, 4
5 is a conductive elastic layer, 23, 32.42 is surfactant content, 22, 33.43 is a polymer layer, 21, 31.41
is the electrode layer.

The toner carrier shown in FIG. 2 has a conductive elastic layer 2 on a core bar 25.
4. It has a structure in which a surfactant-containing layer 23, a polymer layer 22, and an electrode layer 21 are sequentially laminated. The one in Figure 3 is
In FIG. 2, the lamination order of the surfactant-containing layer and the polymer layer is reversed.

The toner carrier shown in FIG. 4 has two surfactant-containing layers.1. A conductive elastic layer 45 is formed on the core bar 46 . Surfactant-containing layer 44. It has a structure in which a polymer layer 43, a surfactant content 42, and an electrode layer 41 are sequentially laminated.

The core bar is made of a conventionally known material, such as a metal material such as stainless steel, aluminum, or iron.

The conductive elastic layer is provided because elasticity of the toner carrier is required in contact development with a photoreceptor drum as in the developing device shown in FIG. 1 used in the present invention. In the case of development, etc., this layer may be omitted. This layer has a resistance of 10"Ω to function as a counter electrode.
- It is desirable to use a conductive elastic body having a volume resistivity of cm or less.

In this case, a polar rubber such as styrene-butadiene rubber, epichlorohydrin rubber, acrylic rubber, or chloroprene rubber, or a high-resistance rubber such as silicone rubber, EPDM, or fluororubber, in which low-resistance particles such as carbon are dispersed, is used. Particularly preferred is silicone rubber, which can be made to have a low grade without using a plasticizer or the like. These materials can be obtained by ordinary molding means such as press molding, injection molding, extrusion molding, etc., and can be further formed into a predetermined shape by polishing. The thickness of this conductive elastic layer is preferably 11 or more in order to exhibit a sufficient elastic effect.

The polymer layer is made of alkyd resin, chlorinated polyether, epoxy resin, fluororesin, phenolic resin, polyamide, polycarbonate, polyethylene, methacrylic resin,
Resins such as polypropylene, polystyrene, polyurethane, polyvinyl chloride, polyvinylidene chloride, silicone,
It is formed from rubber such as butadiene rubber, styrene-butadiene rubber, ethylene propylene rubber, chloroprene rubber, chlorinated polyethylene, epichlorohydrin rubber, nitrile rubber, acrylic rubber, silicone rubber, fluorine rubber, etc., but from the viewpoint of heat resistance and moisture resistance. Look at silicone resin,
Preferably, a fluororesin is used.

The thickness of this polymer layer can be arbitrarily determined by considering electrical properties such as volume resistance and dielectric constant, but it is usually 50 mm or more.
It is 2■. To create this layer, any suitable method such as spray coating, dipping, steam vulcanization, extrusion vulcanization, etc. may be employed as appropriate.

Furthermore, the same materials and construction methods as those for the above polymer can be used for the surfactant-containing layer and the electrode layer. The surfactant-containing layer is
The polymer layer is usually obtained by incorporating a surfactant into the polymer layer, but it does not necessarily have to be incorporated into the resin or rubber, and may be applied by dissolving it in a solvent such as alcohol, water, MEK, toluene, or xylene. The thickness is
0.1 to 50 paffi is preferred.

As a surfactant, it is nonionic and cationic.

Both anionic and amphoteric compounds can be used. in particular,
Nonionic ones include ether compounds, amide condensates, etc., and cationic ones include aliphatic amine salts and their quaternary ammonium salts, aromatic quaternary ammonium salts, heterocyclic quaternary ammonium salts, etc. Anionic ones include alkyl carboxylates, N-acylamino acid salts, alkyl ether carboxylates, acylated peptides, alkyl sulfonates, alkylbenzene and alkylnaphthalene sulfonates, sulfosuccinates, α-
Olefin sulfonate, N-7 silsulfonate, alkyl sulfate, alkyl ether sulfuric acid solution, alkyl allyl ether sulfate, alkylaminide sulfate, alkyl phosphate, alkyl ether phosphate, alkyl allyl ether phosphate Examples of amphoteric substances include carboxybetaine, sulfobetaine, and aminocarboxylic acid salts, but when a fluorine-based surfactant is included.

In the present invention, it is particularly desirable to use a fluorine-based surfactant because a toner carrier with particularly excellent environmental resistance can be obtained. Both can be used,
Specifically, there are the following.

Nonionic ones include, for example, perfluoroalkyl-based lipophilic group-containing oligomers, perfluoroalkyl-based hydrophilic group-containing oligomers, perfluoroalkyl ethylene oxide adducts, and cationic ones include perfluoroalkyl-containing oligomers. Quaternary ammonium salts, etc. are anionic, such as sulfonic acids containing perfluoroalkyl, monovalent metal salts of carboxylic acids, phosphoric acid esters, etc., and amphoteric ones, such as betaine containing perfluoroalkyl. can be mentioned.

Further, these surfactants can be appropriately selected from the viewpoint of compatibility with the resin or rubber used. It is also possible to use a nonionic surfactant and an ionic surfactant in combination.

When the surfactant is included in the polymer layer, it is preferably 0.1 to 50 parts by weight based on 100 parts by weight of the resin solid content. More preferably, it is 0.5 to 20 parts by weight. 0
．． If the amount is less than 1 part by weight, the effect will not be sufficiently expressed.

An afterimage occurs. On the other hand, if it exceeds 50 parts by weight, the wear resistance
Deterioration of environmental resistance and toner transportability occur.

The uppermost electrode layer is made by adding conductive particles or conductive particles whose surfaces are coated with a resin to the same resin or rubber material as described above. These are added to the extent that they do not impair the releasability, chargeability, etc. of the toner, and the amount added is preferably 100 parts by weight or less per 100 parts by weight of the resin or rubber material. When the amount is 100 parts by weight or more, it becomes difficult to maintain surface properties.

Furthermore, inorganic fillers, crosslinking agents, heat stabilizers, processing aids, and the like can be added to the toner carrier used in the present invention for various purposes. Inorganic fillers include diatomaceous earth 1 quartz powder, iron oxide, zinc oxide, titanium oxide, calcium oxide,
Magnesium oxide.

Powders such as talc, aluminum silicate, and aluminum oxide, fibers such as potassium titanate, asbestos, glass, and carbon, and powders such as Teflon and boron nitride are used.

Further, the toner may be either positively chargeable or negatively chargeable, and conventionally known toners can be used. Specific examples of such toner include fine particles containing a coloring agent in a binder resin such as styrene-〇-butyl methacrylate or epoxy resin, and if necessary, a charge control agent such as glosine dye or basic toner. (dye, etc.), a fluidizing agent such as silica, an abrasive agent such as silicon carbide, and a lubricant such as a fatty acid metal salt.

〔Example〕

The present invention will be explained in detail below using Examples and Comparative Examples.

Example 1 Conductive primer (manufactured by Toray Silicone Co., Ltd.: DY39)
-011) on the core bar (8 layers φ) coated with the following conductive elastic layer forming components: 170°C/10 minutes, 1
20kg/cm2, secondary addition: 200℃/4 hours press molding to form a conductive elastic layer with a wall thickness of 6@layers (volume resistivity = 1.5X 10'Ω'cm, rubber hardness (JISA)
): 28 degrees) was formed.

[Conductive elastic layer forming components] Methyl vinyl polysiloxane 100 parts by weight Carbon (Ketchen Black EC) 5 parts by weight Quartz
20 parts by weight After kneading the above mixture with two rolls, a crosslinking agent (2,
4-dimethyl-2,4-di-tert-butyl peroxyhexane: manufactured by Toray Silicone: RC-4) 1.
Added 5 parts by weight.

Next, after cleaning the surface of the conductive elastic layer with trichlene, a titanate coupling agent (manufactured by Matsumoto Pharmaceutical Co., Ltd.: TA
-25) 1% xylene solution was applied, and after drying for 30 minutes, the following surfactant-containing layer forming component was spray applied,
Cured at 100°C for 71 hours.

Then, it is polished to a film thickness of 10. A surfactant-containing layer was formed.

[Surfactant-containing layer] Coronate EH (50% xylene solution) 20 parts by weight ME
400 parts by weight of K Next, the following polymer layer forming components were spray coated thereon and cured at 100° C. for 1 hour.

A resin layer having a thickness of 50 IJs was formed by polishing.

[Polymer layer forming components] Coronate EH (50% xylene solution) 20 parts by weight Toluene 200 parts by weight Xylene 200 parts by weight Next,
Spray coat the following electrode layer forming components on top of it,
After curing at 0° C. for 71 hours, it was polished to form a 10-electrode layer to produce a toner carrier as shown in FIG. 2.

[Electrode layer forming component] Coronate EH (50% xylene solution) 20 parts by weight Fx
126G (acrylic aluminum paste: manufactured by Toyo Aluminum Co., Ltd.) 5 parts by weight toluene
200 parts by weight xylene
200 parts by weight Example 2 The conductive elastic layer, polymer layer, surfactant-containing layer, and electrode layer in Example 1 were laminated in this order by the same means, and the third
A toner carrier as shown in the figure was prepared.

Example 3 In the same manner as in Example 1, a conductive elastic layer, a surfactant-containing layer, a polymer layer, a surfactant-containing layer, and an electrode layer were laminated in this order to produce a toner carrier as shown in FIG. 4. did.

Comparative Example 1 A toner carrier was produced in the same manner as in Example 1 except that the surfactant-containing layer was not provided.

Each of the rollers obtained in Examples 1 to 3 and Comparative Example 1 above was evaluated as follows.

■ In the developing device shown in Figure 1, l! The chargeability of the toner on the image roller after one rotation and after 10 rotations was measured by a blow-off method.

1. Afterimage was evaluated using a pattern image using the same toner and developing device as above 6. In other words, after solid black development, halftone dots were developed, and the image density of the halftone dots corresponding to the position of the black solid. (IDL)
and the halftone image density (I
DH) (IDL/IDH) was measured using a Macbeth densitometer. The ratio was measured at two locations on the left and right.

The following toner, toner thin layer blade, replenishment roller, and photoreceptor were used.

(Toner used): Particle size 12 - Styrene acrylic resin 100 parts by weight carbon
10 parts by weight Chromium-containing monoazo dye 2 parts by weight [Toner thin layer blade] Silicone rubber (1 ma + thickness) [Toner supply roller] Conductive urethane sponge [Photoreceptor] PC Table 1 Figure 4 shows typical examples used in the present invention FIG. 3 is a schematic cross-sectional view of a toner carrier.

Claims (3)

[Claims] (1) In a developing device that supplies toner to a toner carrier carrying toner on its surface using a replenishment roller, forms a uniform thin layer using a regulating member, and develops the toner onto a holder that holds an electrostatic latent image. A developing device characterized in that the carrier has a multilayer structure, and at least one of the inner layers is a layer containing a surfactant. (2) The developing device according to claim (1), wherein the surfactant is an ionic surfactant. (3) Claim (1) or (2) characterized in that the ionic surfactant is a fluorine-based ionic surfactant.
).