JPH03279982A - Developing device - Google Patents

Abstract

PURPOSE:To make improvement in image characteristics by incorporating a silicone oil having an amino group in the molecular side chain having a specific constitutional unit into at least the surface of constituting members. CONSTITUTION:The silicone oil bonded with the amino group in the molecular side chain contg. the constituting unit expressed by formula I is incorporated into the surface of at least any of a developing roller, regulating member and developer supplying means which impart friction charges onto a developer. In the formula I, R1 denotes a hydrogen atom, alkyl group, aryl group, alkoxy group; R2 denotes an alkylene group, phenylene group; R3, R4 denote a hydrogen atom, alkyl group, arylene group. The impartation of the effective charges necessary for development to the developer is possible in this way and sharp line images and uniform solid images are prepd. and surely outputted. In addition, the life of the developing device is prolonged.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Field of Application) The present invention is an electrophotographic apparatus in which an electrostatic latent image formed on an electrostatic latent image carrier is developed using a non-magnetic component. The present invention relates to a developing device suitable for visualizing an image using an agent.

(Prior Art) A developing device that visualizes an electrostatic latent image formed on an electrostatic latent image holder using a non-magnetic component developer is shown in FIG. 1 in cross section. A developing device configured and operated as follows is known. That is, a non-magnetic component developer 2 placed in a developer (toner) container 1 is conveyed to a developing roller 5 by an agitator 3, a developer supply roller 4, and the like. The developer 2 conveyed to the developing roller 5 is
By passing through the region of the developer layer thickness regulating member 6 whose end is disposed close to the outer circumferential surface of the developing roller 5, the developer is held in a thin layer on the surface of the developing roller 5, while being provided with a required charge. Ru. The electrostatic latent image formed on the latent image carrier 7 is developed by the developer carried on the surface of the developing roller 5 using an electric field, and the electrostatic charge recorded on the latent image carrier 7 is This is a non-magnetic component developing device that visualizes digital information.

Incidentally, the developing roller 5 usually has a structure shown in perspective with a portion cut away in FIG. 2.

That is, when at least the outer peripheral surface contains a binder selected from resins such as polyurethane resins, or elastomers such as polyurethane elastomers, and conductive carbon, the resistance value is lo lfiΩ [hereinafter preferably the resistance value is 10'Ω].・Conductive layer 5a below the mark
6301 according to the Moon S standard on the inside of this conductive layer 5a.
The elastic body layer 5b is made of oil-resistant rubber and has a hardness of 40 degrees or less, preferably 35 degrees or less, as measured by a type A hardness tester.

In addition, in FIG. 2, 5C is a metal roller base,
Further, as the oil-resistant rubber forming the elastic layer 5b, EPDM, urethane, silicone, chloroprene, N
Examples include BR, and a system in which a conductive filler is dispersed in these to make them conductive may also be used. Furthermore, the conductive material used for forming the conductive layer 5a may be a solvent-soluble binder such as a commercially available conductive urethane paint or a conductive acrylic paint in which a conductive filler is dispersed; Conductive resin etc. are used.

(Problem 2fi to be solved by the invention) However, the following problems are recognized in the above-mentioned developing device. That is, it is desirable that at least the surface of the developing roller 5 used in the developing device is positively chargeable in order to apply a necessary negative charge to the developer 2 through friction. However, regarding the coating film of these conductive paints constituting the conductive layer 5a of the developing roller 5,
When measuring electrostatic chargeability, many of them have almost no charging ability even if they have the same polarity as the developer or the opposite polarity. For this reason, it is not possible to consciously apply an appropriate amount of charge to the developer, which tends to cause developer layer defects such as developer spillage and non-uniformity of the adhering and carrying developer layer, as well as poor transport.
There are many cases where it is not possible to obtain images that are sufficient for practical use.

In the above development process, a negatively charged developer is used, and members that apply a triboelectric charge to the developer, such as a developing roller, a developer layer thickness regulating member, and an intermediate roller, are positively charged. Improvement measures are also known that focus on the ability to impart sufficient charge to the developer. For example, at least the surface of the developing roller may contain an electron-donating dye (e.g., azine-based nigrosine, nigrosine bases, nigrosine rust conductor, organic quaternary ammonium salts such as benzomethyl-hexyldecyl ammonium chloride, etc.).
Attempts have been made to add charge control agents. However, because these charge control agents are insoluble or poorly soluble in solvents for boat fishing, they are difficult to disperse in organic paints, making it difficult to express their functions, and it is necessary to increase the amount added. There are drawbacks.

Although adding and blending an acrylic resin or styrene resin that is soluble in an organic solvent is one way of improving the composition, it is necessary to add and blend a large amount to obtain the desired effect. However, adding a large amount of acrylic resin or styrene resin impairs the elasticity of the developing roller 5, and thus cannot be put to practical use.

The present invention has been made in order to solve the above-mentioned problems, and is a developing device configured to constantly and reliably apply the required amount of charge to the developer carried and conveyed on the developing roller. The purpose is to provide.

[Structure of the Invention] (Means for Solving the Problems) The present invention supplies a developer to an elastic developing roller, forms a thin layer of the developer on the outer circumferential surface of the developing roller using a regulating member, and also controls the electric charge. and a mechanism for bringing this thin layer of developer close to or in contact with an electrostatic latent image carrier to cause the developer to adhere to the electrostatic latent image held on the electrostatic latent image carrier and develop it into a visible image. In the developing device equipped with a mechanism for applying a triboelectric charge to the developer, at least one surface of the developing roller regulating member and the developer supplying means is provided with the following formula] % formula % (wherein R1 is a hydrogen atom , alkyl group, aryl group, alkoxy u, R2 is alkylene group, phenylene group, R3
, R4 is a hydrogen atom, an alkyl group, or an arylene group.

However, the alkyl group, aryl group, alkylene group, and phenylene group may be amine-modified, and may have a substituent such as halogen as long as it does not affect chargeability. ) It is characterized by containing a silicone oil in which an amino group is bonded to the molecular side chain containing the structural unit shown in the following.

Therefore, in the above-mentioned development process, the present invention requires that a negatively charged developer is used, and that members that impart a triboelectric charge to the developer, such as the developing roller, developer layer thickness regulating member, and intermediate roller, are positively charged. This was made with the focus on the fact that sufficient charge can be imparted to the developer by doing so.

The member that imparts a triboelectric charge to the developer included in the developing device according to the present invention, that is, the developing roller, the developer thin layer regulating member, the developer supply means, etc., has an amine group in the side chain used to positively charge the member. Silicone oil is not only easy to handle because it is easily soluble in solvents, but also has excellent dispersibility and compatibility with paints because it is resin-based, so it has the advantage of being effective even when added in small amounts.

For example, when a developer layer thickness regulating member made of silicone rubber contains silicone oil having an amine group in its side chain, the desired effect can be obtained with a small amount of addition because of its excellent compatibility with the main binder. .

By the way, the silicone oil having an amine group in its side chain is generally commercially available as an amino-modified silicone oil, and is represented by the following structural formula, for example.

Examples of amino-modified silicone oils having such a molecular structure include TSF-4700 and TSF-470.
1. TSF-4720 (all product names, manufactured by Toshiba Silicone Corporation), KP-369, KF-383, Kl'-3
93, KP-857, KF-859, KF-860, K
P-861, KF-862, KF-8 (i4, KF-8
05 (all product names, manufactured by Shin-Etsu Chemical Co., Ltd.), X-22-
3680, X-22-3800, X-22-380IC
,X-22-3810B (1' deviation is also the product name,
・Manufactured by Dow Corning Silicone Co.), etc.
These may be used in a mixed system of two or more types.

In the present invention, silicone oil having an amino group in the side chain is added to the surface of the developing roller or the developer layer thickness regulating member in an amount of 0.01 to 40 wt%, preferably 0.1 to 10 wt% based on the constituent materials. By containing it, the surface triboelectric charging property of a developing roller or the like is improved.

Here, if the amount of silicone oil having an amino group in the side chain added is less than 0.01 vt%, the triboelectric charging property of the surface will not be improved, and if it exceeds 40 vt%, the mechanical Strength decreases.

In the present invention, for example, when applying a conductive paint to a developing roller, an appropriate amount of the silicone oil is dissolved in advance in a diluted solution of the conductive paint, and mixed and dispersed with the conductive paint body. It is applied to the developing roller using dipping or spray roller methods, dried, and then incorporated into the developing device. The thickness of the conductive layer coated here is in the range of 1μ to 300μ, preferably 30μ to
It is 120 μm. In addition, when improving the surface triboelectric charging property of the developer layer thickness regulating member, for example, when silicone rubber is used as the developer layer thickness regulating member, the silicone oil is added from 0.01w% to 40vt% with respect to the silicone rubber. , preferably 0.1 vt% to 10 vL%, is dispersed and contained in a mixer such as a kneader, and then vulcanized and molded to be incorporated into a developing device as a developer layer thickness regulating member.

In the developing device having the above configuration, a known non-magnetic component developer (toner) consisting of a binder resin, a coloring material, a charge control agent, a wax, an anti-caking agent, etc. is used.

For example, as the binder resin, polystyrene, polyP
- Homopolymers of styrene and its substituted products such as chlorostyrene and polyvinyltoluene, such as styrene-P-vinyltoluene copolymer, styrene-propylene copolymer, styrene-vinyltoluene cofff polymer, styrene-
Vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-acrylic acid copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer , styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-octyl methacrylate copolymer, styrene-α chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, Styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-acrylonitrile-indene copolymer, styrene-isoprene copolymer, Styrenic copolymers such as styrene-maleic acid copolymers and styrene-maleic acid ester copolymers, polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, polyurethane, polyamide, Epoxy resins, polyvinyl butyral, polyacrylic acid resins, rosins, modified rosins, terpene resins, phenolic resins, aliphatic or alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffins, paraffin waxes, etc. alone or in mixtures. Can be mentioned.

In addition, carbon black is used as a coloring agent and a charge control agent.
Various dyes and pigments are used, offset inhibitors include low molecular weight polyethylene and polypropylene, and anti-caking agents include hydrophobic silica, metal oxides, PMMA, etc.
Spherical resin particles such as Teflon and styrene are used.

In the above, application to a -component development method has been described, but the present invention can also be applied to a developing roller, a developer layer thickness regulating member, etc. in a two-component development method, a magnetic toner development method, a liquid development method, and the like.

(Function) By containing the silicone oil on at least the surface of the member that imparts the required triboelectric charge to the developer (toner), such as the developing roller and the developer layer thickness regulating member, an effective charge necessary for development is created. can be applied to the developer, and not only can sharp line images and uniform solid images be prepared and reliably output, but also the life of the developing device can be extended.

In order to confirm the effect of this silicone oil having an amino group in its side chain, the amount of charge was measured using an electrostatic coating surface analyzer (manufactured by Toshiba Chemical Co., Ltd.) schematically shown in FIG.

The principle of this electrostatic coating surface analysis device is that a metal plate coated with a sample is fixed on an inclined plate 16, iron powder is dropped onto this metal plate, the iron powder rolls down, and the metal plate coated with the sample is The frictional charge generated between the
I? 1 and is used as the amount of charge.

Measurement conditions were 25℃, 85% I? The environment was set to 11, using spherical iron, and the amount of pouring was 1.30 per time.
g.

The sink time is 5 seconds, the slope is 60 degrees, 71? + When 1 fixed point and 5 samples were determined, the material to which the silicone oil was not added had a HX of 10'C or less, whereas the material to which the silicone oil of the present invention was added had a HX of 10'C or more. It can be seen that the binding properties are clearly improved.

In addition, in FIG. 3, 15 is a reference iron powder input port, 17 is a falling iron powder, 18 is a receiving plate, 19 is an insulating plate, and 21 is a meter connection terminal.

(Example) Next, the present invention will be explained in detail.

Example 1 [100 parts by weight of polyurethane conductive paint Subalex manufactured by Miractran, and tetrahydrofuran TIIF
Methyl ethyl ketone MEK (1:l) mixed solvent 10
0 parts by weight of amino-edible silicone oil TSP-470
A solution in which 5 parts by weight of 0 (manufactured by Toshiba Silicone Co., Ltd.) was dissolved was mixed and dispersed. This mixed dispersion liquid is transferred to the developing roller (
After coating the surface of the urethane rubber (urethane rubber) by a dipping method, it was dried in a dryer for 20 minutes to prepare a developing roller.

The surface resistance of the developing roller thus obtained was 1×105Ω・
1, and the coating film thickness formed was 95 μl.

The developing roller constructed as described above was substituted for the developing roller 5 of the developing device whose essential structure is shown in FIG.

The developer 2 has a volume average particle diameter of lOμ- and is composed of 92 parts by weight of a polyester resin, 4 parts by weight of carbon, 2 parts by weight of low molecular weight polypropylene, 2 parts by weight of a metal-containing dye, and 0.5 parts by weight of silica as an external additive. Using a negatively charged developer, the rotation of the latent image carrier (OPC) 7 was set at a surface speed of 50 mm/sec, and the surface potential was uniformly charged to -500 V by the corona discharge from the charger 9, and as the exposure device 8. After recording image information with a laser, the developing roller 5 rotated at a surface speed of +00-m for 7 seconds and applied with -200V was pressed against the latent image carrier (photoreceptor) 7 to perform the required development. . This developed powder image was transferred to a recording paper using a 6 kV DC corona discharge in a transfer device 11, and then thermally fixed.

The image after the transfer was a clear line image, a uniform solid image, and a high density (1.4 on Macbeth densitometer) without fogging. Furthermore, the images after the life test of 50,000 sheets were clear images with no deterioration and maintaining the initial state. Furthermore, extremely good images were obtained even under hot and humid conditions of 30° C. and 80% R11.

Example 2 Amino-modified silicone oil TSP-472 was added to 100 parts by weight of electrovac, a conductive paint manufactured by Taitika T Co., Ltd., 5 parts by weight of isocyanate, and 100 parts by weight of toluene.
A solvent in which 5 parts by weight of 0 (manufactured by Toshiba Silicone Co., Ltd.) was dissolved was mixed and dispersed. This mixed dispersion was applied to the surface of a developing roller (urethane rubber) by a dipping method, and then dried for 20 minutes in a dryer to produce a developing roller. The surface resistance of the developing roller thus obtained was 2.4×10'Ω·mark, and the thickness of the formed coating film was togμ■.

The developing roller constructed as described above was replaced with the developing roller 5 of the developing device whose essential structure is shown in FIG.

As developer 2, 92 parts by weight of polyester resin, 4 parts by weight of carbon, 2 parts by weight of low molecular weight polypropylene,
A non-magnetic component developer (with a volume average particle diameter of lOμ) consisting of 2 parts by weight of a metal-containing dye and 0.5 parts by weight of silica as an external additive.
The rotation of the latent image carrier (OPC) 7 is set at a surface speed of 50/sec using a negative charger (negative charger) 2, and the surface potential is uniformly charged to -500 V by corona discharge from the charger 9. After recording image information with a laser, the surface speed is 100 m/
A developing roller 5 rotated in seconds and applied with 200 V was pressed against the latent image carrier (photoreceptor) 7 to perform the required development.

The developed powder was transferred to recording paper using a 6 kV DC corona discharge in the transfer device 11, and then thermally fixed.

The image after the transfer was a clear line image, a uniform solid image, and a high density (1.41 as measured by Macbeth densitometer) without fogging. Furthermore, the images after the life test of 50,000 sheets were clear images with no deterioration and maintaining the initial state. Furthermore, extremely good images were obtained even under high temperature and high humidity conditions of 30° C. and 80% R11.

Comparative Example 1 100 parts by weight of polyurethane conductive paint SPAREX manufactured by Nippon Miractran Co., Ltd. was added to THP: M)? ) [(1: 1
The mixture was diluted and dispersed with 100 parts by weight of a mixed solvent, applied to the surface of a developing roller (urethane rubber) by a dipping method, and then dried in a dryer for 20 minutes to produce a developing roller.

The surface resistance of the developing roller thus obtained was 3. IX 10
'Ω・country, and the coating film thickness formed was 105 μm.

Using the developing roller 5 configured as described above, a developing device having the same configuration as the developing device whose main part configuration is shown in FIG.
Image printing was performed under the following conditions.

As a developer, 92 parts by weight of polyester resin, 4ffiffi parts of carbon, 2 parts by weight of low molecular weight polypropylene, 1 part of metal-containing dye 21iIj, and 0.5r external additive silica.
Using a non-magnetic component developer (negative band N) 2 with a volume average particle diameter of 10 μ■ consisting of 1 part of f1j, latent image carrier (OPC)
The rotation of 7 was set at a surface speed of 50 mm/sec, and the surface potential was uniformly charged to -500 V by corona discharge from the charger 9.
After recording image information with a laser as an exposure device 8, a developing roller 5 rotated at a surface speed of lOO/sec and to which -200 is applied is pressed against a latent image carrier (photoreceptor) 7.
Necessary development was performed. This developed powder image was transferred to a recording paper using a direct current corona discharge of 8 kV in a transfer device 11, and then thermally fixed.

In the image after the transfer, although the line image was clear, the solid image was an image exhibiting non-uniform conveyance defects.

Example 3 Amino-modified silicone oil TSP-4720 (manufactured by Toshiba Silicone Co., Ltd.) 5 parts by weight of silicone rubber
0 parts by weight and 150 parts by weight of aerosilic silica were added and kneaded in a kneader for 20 minutes at 120°C, then 10 parts by weight of benzoyl peroxide was added and the mixture was kneaded at 150°C.
It was vulcanized for 20 minutes at 200°C for 4 hours. This was molded into a metal jig to constitute a developer layer thickness regulating member.

The developer layer thickness regulating member configured above was replaced with the developer layer thickness regulating member 6 of the developing device whose main part configuration is shown in FIG. I made an image.

The developer 2 is a negative material with a volume average particle diameter of lOμ-, which is composed of 92 parts by weight of a polyester resin, 4 parts by weight of carbon, 2 parts by weight of low molecular weight polypropylene, 2 parts by weight of a metal-containing dye, and 0.5 parts by weight of silica as an external additive. Using a charged developer, the rotation of the latent image carrier (OPC) 7 is set at a surface speed of 50 fins/sec, and the surface potential is uniformly set to -5 by corona discharge from the charger 9.
After being charged to 00V and recording image information with a laser as the exposure device 8, the developing roller 5 rotated at a surface speed of 1G (1+n/sec) and applied with -200V is transferred to the latent image carrier (
It was pressed against photoreceptor) 7 and the required development was performed. This developed powder image was transferred to a recording paper using a 6 kV DC corona discharge in a transfer device 11, and then thermally fixed.

The image after the transfer was a clear line image, a uniform solid image, and a high density (1.42 as measured by Macbeth densitometer). Furthermore, the image after the life test of 50,000 sheets was a clear image with no deterioration, maintaining the initial state. moreover,
Very good images were obtained even under the high temperature and high humidity conditions of 30° C. and 80% R1.

Comparative Example 2 A developer layer thickness regulating member was produced in the same manner as in Example 3, except that the silicone rubber did not contain the di-amino edible silicone oil.

Using the above-mentioned developer layer thickness regulating member, a prototype developing device having the same structure as that shown in FIG. 1 above was constructed, and images were produced under the following conditions.

As developer 2, 92 parts by weight of polyester resin, 4 parts by weight of carbon, 1 part by weight of low molecular weight polypropylene 21f,
Using a negatively charged developer with a volume average particle diameter of 10μ, consisting of 2 parts by weight of a metal-containing dye and 0.5 parts by weight of silica as an external additive, the latent image carrier (OPC) 7 was rotated at a surface speed of 50/sec. The corona discharge from the charger 9 uniformly increases the surface potential to -5.
After being charged to 00V and recording image information with a laser as an exposure device 8, a developing roller 5 rotated at a surface speed of 100III/sec and applied with -200V is pressed against a latent image carrier (photoreceptor) 7. , the necessary development was performed. This developed powder image was transferred to a recording paper using a 6 kV DC corona discharge in a transfer device 11, and then thermally fixed.

In the image after the transfer, although the line image was clear, the solid image was an image with non-uniform conveyance defects.

In addition, although the structure in which the above-mentioned amino-modified silicone oil is contained in either the developing roller or the developer layer thickness regulating member is shown above, it is also possible to have a structure in which both of them contain the amino-modified silicone oil. In short, at least one of the constituent members that plays the role of imparting the required triboelectric charge to the developer used may contain the silicone oil having an amino group in the side chain according to the present invention. For example, a developer supply roller may be used.

Further, the region containing the silicone oil having an amino group in the side chain may be only the surface portion that participates in imparting a triboelectric charge.

[Effects of the Invention] As explained above, at least the surface of the constituent member that plays the role of imparting a triboelectric charge to the developer is provided with a structural unit represented by the following formula (hereinafter blank) 1-0-2. Containing silicone oil that has amino groups in its molecular side chains improves image characteristics, making it easy to always produce clear line images, uniform solid images, and high-density fog-free images. It became possible to obtain. Moreover, it can be said that it brings about many practical advantages, such as being able to maintain the above-mentioned required functions for a long period of time, and being able to cope with changes in the properties of the developer due to the environment.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing the main part of the developing device, Figure 2 is a partially cutaway perspective view showing the configuration of the developing roller, and Figure 3 is the principle of an electrostatic coating surface analysis device for measuring charge m. It is a diagram. 1...Developer container 2...Developer 3...Stirrer 4...Developer supply Roller 5a...
Developing roller 5b... Conductive layer 6... Elastic layer 7... Latent image holder 8...・Exposure unit 9...Charger 0...Cleaning unit...
...Transfer device 2...Recovery blade 3...
...Protection resistor 4...DC power supply

Claims (1)

[Scope of Claims] A developer supply means for supplying developer to the outer peripheral surface of the developing roller, a regulating member forming a developer layer whose end portion is supplied close to the outer peripheral surface of the developing roller, and the thin layer. a developing device comprising an electrostatic latent image holder that develops an electrostatic latent image held in close proximity to or in contact with a converted developer layer into a visible image, a developing roller that applies a triboelectric charge to the developer; , the surface of at least one of the regulating member and the developer supplying means has the following formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, R_1 is a hydrogen atom, an alkyl group, an aryl group,
Alkoxy group, R_2 is alkylene group, phenylene group,
R_3 and R_4 are a hydrogen atom, an alkyl group, or an arylene group. However, the alkyl group, aryl group, alkylene group, and phenylene group may be amine-modified, and may have a substituent such as halogen as long as it does not affect chargeability. ) A developing device characterized by containing silicone oil in which an amino group is bonded to a molecular side chain containing a structural unit represented by: