JPH03129368A - Developing device - Google Patents

Abstract

PURPOSE:To prevent occurrence of an afterimage and to improve electric chargeability and releasability of a toner and abrasion resistance of a toner carrying body by forming a layer containing an ionic surfactant on the toner carrying body. CONSTITUTION:The resin layer 21 containing the surfactant is formed on the toner carrying body, and as the surfactant, all of nonioic, cationic, anionic, and amphoteric surfactants can be used, and as the anionic surfactant, ester compounds, ether-ester compounds, ether compounds, and amido condensates, derived from fatty acids and the like are enumerated, thus permitting the obtained developing device to be superior in chargeability and releasability of the toner, to prevent occurrence of an afterimage even at the time of repeated uses for a long time, to be enhanced in durability, and to be reduced in the cost and the size of the device.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrostatic latent image developing device using a -component toner.

[Prior Art] 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-shaped or roll-shaped member, and then A method is known in which the electrostatic latent image is brought into contact with a holder (i.e., a photoreceptor) holding an electrostatic latent image for development. In this method, the developing roller repeats the following cycles: ■ Replenishing toner ■ Charging the toner ■ Forming a thin layer of toner ■ Transporting the toner ■ Developing ■ Eliminating residual charges. When the developing roller enters the cycle, a counter charge occurs due to frictional charging with the toner, and the distributed charge from the photoreceptor remains on its surface or inside, so the charging characteristics and development characteristics of the toner deteriorate with repeated use. However, there was a problem that so-called afterimage development occurred.

For this reason, various methods of neutralizing the developing roller have been studied, and for example, a method has been proposed in which a low-resistance member 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 layer of toner, 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, as a result of these improvements from the developing system side, developing rollers that are very easy to initialize, in other words, no charge remains, have been developed.

For such a developing roller, for example, an elastic material with a medium volume resistivity (hereinafter referred to as medium resistance) of tOS to IQIIΩ·elN is used as the conductive base of the first coating layer, and a conductive substrate is used as the second coating layer thereon. There is a developing roller coated with a semiconductive material made of flexible synthetic resin and conductive particles. However, since the materials used for this product are acrylonitrile butadiene rubber, epichlorohydrin rubber, chloroprene rubber, urethane rubber, etc., it is difficult to make a uniform and stable product, and it is particularly difficult to make a uniform and stable product with environmental resistance such as electrical properties (heat, etc.). It has the disadvantage that the development characteristics change depending on the environmental conditions.

On the other hand, a developing roller has been proposed in which a conductive elastic body having a volume resistivity of 106 Ω·C11 or less is used, a resin or rubber layer in the medium to high resistance range is sequentially laminated thereon, and then an electrode layer is laminated thereon. This product has the advantage that environmental resistance can be significantly improved by using resin or rubber (eg, silicone type, fluorine type polymer) with excellent heat resistance and moisture resistance in each layer.

However, this developing roller has a medium resistance as a coating layer.
Since a high-resistance resin is used, residual charges generated by the frictional charging process with the toner remain and accumulate, which greatly affects toner chargeability and development characteristics in the next step, resulting in 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. Obi 1! Decreased amount and toner transportability■ Excessive concentration and decreased resolution due to increased electric field strength with the holder due to lower resistance of the surface layer■ Decreased M-type property of the surface layer for toner due to the addition of a large amount of conductive particles Problems such as occurrence of toner filming and reduction in abrasion resistance occur, and the current situation is that 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 actual state of the prior art, and the toner has excellent chargeability and releasability, and does not cause afterimages even after repeated use over a long period of time. It is an object of the present invention to provide a toner carrier that has excellent durability, is low cost, and can be downsized, and a developing device using the toner carrier.

[Means for Solving the Problems] As a result of intensive studies to solve the above-mentioned problems, the present inventors found that it is effective to provide a resin layer containing a surfactant on a toner carrier, This led to the present invention.

That is, the present invention provides at least an electrostatic latent image holder that holds an electrostatic latent image, a toner carrier that makes the latent image visible on the holder, and a thin layer of toner that is formed on the toner carrier. The developing device includes a regulating member in which a resin layer containing a surfactant is provided on the toner carrier.

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 such as a developing roller, 6 is a toner thin layer blade as a regulating member, and 7 is a photoreceptor, for example. It is a drum-like electrostatic latent image holder.

In FIG. 1, a non-magnetic monocomponent toner 2 is contained in a toner container l. 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 B, and the toner is triboelectrically charged to a predetermined polarity. The thin toner layer is carried to a development area where the holder 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 holder 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 holder 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.

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

FIG. 2 shows a toner carrier used in the present invention.

It has a structure in which a conductive elastic layer 22 and a resin layer 21 are sequentially provided on a core bar 23.

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

The conductive elastic layer 22 is provided because elasticity of the developing roller is required in contact development with a photoreceptor drum as in the developing device shown in FIG. 1 used in the present invention. In this case, this layer may be omitted. In order for this layer to function as a counter electrode, it is desirable to use a conductive elastic material having a volume resistivity of 1O12Ω.8 m 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 suitably 1 mm or more 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 formed from resins such as silicone, rubbers such as butadiene rubber, styrene-butadiene rubber, ethylene propylene rubber, chlorobrene rubber, chlorinated polyethylene, epichlorohydrin rubber, nitrile rubber, acrylic rubber, silicone rubber, fluorine rubber, etc., but has heat resistance, From the viewpoint of moisture resistance, it is preferable to use silicone resins and fluororesins.

The thickness of this resin layer 21 can be arbitrarily determined by considering electrical properties such as volume resistance and dielectric constant, but is usually 50 μm to 2 as. To create this layer, spray application,
An appropriate method such as dipping, steam vulcanization, or extrusion vulcanization may be employed as appropriate.

The present invention is achieved by incorporating a surfactant into this layer, and any of nonionic, cationic, anionic, and amphoteric surfactants can be used. Specifically, nonionic compounds include ester compounds such as fatty acids, ether ester compounds, 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
-acyl amino acid salt, alkyl ether carboxylate,
Acylated peptides, alkyl sulfonates, alkylbenzene and alkylnaphthalene sulfonates, fluphosuccinates, α-olefin sulfonates, N-acylsulfonates, alkyl sulfates, alkyl ether sulfates, alkyl allyl ether sulfates, Alkylamide sulfates, alkyl phosphates, alkyl ether phosphates, alkyl allyl ether phosphates, etc., and amphoteric ones include carboxybetaine, sulfobetaine, aminocarboxylate, and the like.

In the present invention, it is preferable to include a fluorine-based surfactant as the above-mentioned surfactant because it has excellent environmental resistance. Any of nonionic, cationic, anionic, and amphoteric fluorine-based surfactants can be used, and specific examples include the following.

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

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

The amount of this surfactant mixed is 10% of the solid content of the binder resin.
It is preferably 0.1 to 50 parts by weight relative to 0 parts by weight. More preferably, it is 0.5 to 20 parts by weight. If the amount is less than 0.1 part by weight, the effect will not be sufficiently exhibited and an afterimage will occur. On the other hand, if it exceeds 50 parts by weight, abrasion resistance, environmental resistance, and toner transportability may deteriorate.

Furthermore, inorganic fillers, crosslinking agents, heat stabilizers, processing aids, etc. can be added to the developing roller used in the present invention for various purposes. Inorganic fillers include diatomaceous earth, quartz powder, iron oxide, zinc oxide, titanium oxide, calcium oxide, magnesium oxide, talc, aluminum silicate, aluminum oxide powder, potassium titanate, asbestos,
Fibers such as 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, for example, styrene-
Fine particles containing a coloring agent in a binder resin such as n-butyl methacrylate or epoxy resin, and if necessary, a charge control agent such as glosine dye or basic dye), a fluidizing agent such as silica, and silicon carbide. Examples include those to which abrasives such as, lubricants such as fatty acid metal salts, etc. are added.

[Examples] Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

Example 1 Conductive brimer (manufactured by Toray Silicone Co., Ltd.: DY39)
-O1l) was coated with the following conductive elastic layer forming components on the core metal (Biiφ): 170°C/10 minutes, 1
20kg/cm2, secondary flow rate: 6m thick conductive elastic layer press-molded under conditions of 200°C for 74 hours (volume resistivity: 1.5X 105Ω・C-, rubber hardness (
JIS^): 28 degrees) was formed.

[Conductive elastic layer forming component] Methyl vinyl polysiloxane 100 parts by weight carbon (
Ketchen Black EC) 5 parts by weight Quartz 20 parts by weight The above mixture was kneaded with two rolls, and then a crosslinking agent (2,4-dimethyl-2°4-di-tert-butylperoxyhexane) was added to 100 parts by weight of the mixture. : Manufactured by Toray Silicone Co., Ltd.: R
C-4) Added 1.5 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.: T
A-25) Kei% xylene solution was applied, and after drying for 30 minutes, the following resin layer forming components were spray coated,
The resin was cured at 150° C. for 1 hour, and then polished to form a resin layer with a thickness of 50 μm, thereby producing a developing roller.

[Resin layer forming components] Fluorine copolymer resin (solid content 50%) (Nilumiflon 801C manufactured by Asahi Glass Company) 100 parts by weight Coronate EH (50% xylene solution) 20 parts by weight M E K 400 parts by weight fluorine cation surfactant (CI FI7S02 NH (C3H!)N” (
CH3) 31-) 5 parts by weight fFlj 2 In place of the fluorine-based cationic surfactant used in Example 1, a fluorine-based anionic surfactant (C7F Is C0
The procedure was the same as in Example 1 except that 0Na) was used.

Example 3 Instead of the fluorine-based cationic surfactant used in Example 1, a fluorine-based amphoteric surfactant [CI F17SO2N
H(C2H4)N” (CH3) 2tC2H+(0
The procedure was the same as in Example 1 except that 0″″] was used.

Example 4 Implementation f! In place of the fluorine-based cationic surfactant in II 1, a hydrocarbon-based cationic surfactant [Cl2
HzsSO2NH(C3Hs)N” (CH3)
The procedure was the same except that 3 I-1 was used.

Example 5 A hydrocarbon-based anionic surfactant (Cy Hl5COONa) was used instead of the fluorine-based surfactant in Example 1.
The same procedure was used except that .

Example 6 The same procedure as in Example 1 was carried out except that a hydrocarbon-based amphoteric surfactant (C14H2, CHOO-) was used instead of the fluorine-based surfactant. , N(CH3) Comparative Example 1 The same procedure as in Example 1 was used except that the surfactant was not used.

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

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

Fluorine copolymer resin (solid content 50%) (manufactured by Asahi Glass Company: Lumiflon 801C) 100 parts by weight Carbon black (Black Bar L: manufactured by Cabot Corporation) 40 parts by weight Toluene 50 parts by weight Xylene
A carbon masterbatch was prepared by dispersing 50 parts by weight of the above mixture in a ball mill for 72 hours.

Comparative Example 3 The carbon black masterbatch in Comparative Example 2 was
The same procedure was used except that the amount was changed from 5 parts by weight to 50 parts by weight.

The developing rollers of Examples and Comparative Examples obtained as described above were used as the developing rollers shown in FIG. 10℃24% for each item
, 22° C. 50%, and 30”080%. The results are shown in Table 1. The evaluation method was as follows.

[Charge amount of toner] The charge amount in the developing device shown in FIG. 1 was measured by the blow-off method using the accompanying type toner described below.

(Toner used) Two particle size 12! r-■ Styrene acrylic resin 100 parts by weight carbon
10 parts by weight chromium-containing monoazo dye
2 parts by weight [Toner releasability] Using the above toner and developing device, the state of the toner on the surface of the developing roller after running idly for 72 hours was evaluated according to the following criteria.

Rank A: Toner on the roller surface can be easily wiped off with a cloth.

Rank B: A slight amount of toner remains after wiping.

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

Rank D=Toner in a molten state is strongly adhered to the roller surface.

[Abrasion of developing roller]

Using the same toner and developing device as above, the amount of wear after running idle for 20 hours was measured by measuring the diameter of the developing roller. The diameter of the roller was measured using a laser micro gauge (DT-4002A; Iwatsu Electronics).

[Evaluation of afterimage property] Afterimage was evaluated based on a pattern image using the same toner and developing device as above. That is, after solid black development, halftone dots are developed, and the image density (IDL) of the halftone dots corresponding to the position of the black solid is determined.
and the halftone image density (I
Do) and the ratio (r DL / r DH) was measured using a Macbeth densitometer. The ratio was measured at two locations on the left and right.

[Evaluation of image unevenness] Take one point during one rotation of the black solid developing roller, and then measure each I with a Macbeth densitometer for a total of 5 points for up to 5 rotations.
Measured D and found armor with ID10DX100.

OD: Original density of solid black portion ID: Copy density of solid black portion Note that the following were used as the toner thin layer blade, replenishment roller, and photoreceptor.

[Toner thin layer blade silicone rubber (II 1m thick) [Toner replenishment roller] Conductive urethane sponge [Photoreceptor] P C [Effects of the invention] As explained above, the resin containing an ionic surfactant according to the present invention By providing the layer on the toner carrier, it is possible to prevent afterimages, and at the same time, good results are obtained in terms of toner charge amount, toner releasability, and abrasion resistance of the toner carrier.

[Brief explanation of the drawing]

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

Claims (3)

[Claims] (1) An electrostatic latent image holder that holds at least an electrostatic latent image;
In a developing device comprising a toner carrier for making a latent image visible on the holder, and a regulating member for forming a thin layer of toner on the toner carrier, a resin layer containing a surfactant on the toner carrier. A developing device characterized by being provided with. (2) The developing device according to claim (1), wherein the surfactant is an ionic surfactant. (3) The developing device according to claim 1 or 2, wherein the surfactant is a fluorine-based ionic surfactant.