JPH0359566A - Developer and image forming method - Google Patents

Abstract

PURPOSE:To prevent the sticking of a developer to the surfaces of an elastic blade and a image carrying member by the strong pushing of both or the film- like contamination thereof by incorporating a toner and fine powder treated with a silicone oil or silicone varnish into the developer. CONSTITUTION:The fine powder treated with the silicone oil or silicone varnish is incorporated into the developer in the case of using a developing device intended to form a thin developer layer by the elastic blade 9 onto the developer carrying member 6 which carries and transports the developer in a developer container 2 from the container 2 to the developing area facing the image carrying member 3. The sticking of the developer to the elastic blade 9 and the developer carrying member 6 by the strong pushing of both and the film-like contamination thereof are prevented and the lubrication between both is rather accelerated to lower the driving torque of the developer carrying member, by which the inversion and peeling of the elastic blade are prevented and the failure of the driving gear of the developer carrying member is prevented. The good image formation is thus executed.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an image forming method for forming a latent image on an image carrier and making the latent image visible in a developing device, and a developer used therefor. In particular, a thin layer of developer is formed using an elastic blade on a developer carrier that supports and transports the developer in the developer container from the developer container to the development area facing the image carrier. The present invention relates to an image forming method using a developing device and a developer used therein.

[Prior Art] Conventionally, in image forming apparatuses in which a latent image is formed on an image carrier using an electrophotographic method or an electrostatic recording method, and the latent image is visualized by a developing device, various developing devices have been used. Proposed. An example thereof is illustrated in FIG.

Referring to FIG. 6, the developing device 1 generally includes a developer container 2 for storing developer, and a developing area facing the image carrier 3 from which the developer in the developer container 2 is transferred. 4, and a developer carrier 6 that carries and conveys the developer to the developer. The developer carrier may have any structure, but is usually composed of a developing sleeve 8 having a built-in magnet 7.

Further, the developing device includes a developer carrying member 6 carrying the developer and developing area 4 .
A developer regulating member 9 is provided to regulate the developer conveyed to the developer to a predetermined thickness and form a thin developer layer on the developer carrier 6.
It is equipped with Configuring the developer in a layered manner on the developer carrier 6 in this way is an extremely important technique for ensuring the uniformity of solid images, especially in -component developing devices, and it is an extremely important technique for ensuring uniformity of solid images. Various proposals have been made above.

Conventionally, the developer regulating member 9 is often a rigid blade disposed at a distance am from the developer carrier 6, but recently, the developer regulating member 9 is a rigid blade disposed a distance am from the developer carrier 6. In place of a rigid blade, an elastic blade made of an elastic material is used, as shown in the figure, because it exhibits outstanding stability against changes in external environmental conditions when applying a triboelectric charge to a surface. 9 was proposed and has come to be used frequently (Japanese Patent Application Laid-Open No. 1983-1997, filed by the present applicant).
Please refer to Publication No. 43038 and Japanese Patent Application Laid-Open No. 58-116559. ).

The elastic blade 9 is made of urethane rubber, silicone rubber A, N
It is composed of known elastic plates such as rubber elastic bodies such as BR, metal elastic bodies such as phosphor bronze and stainless steel plates, and resin elastic bodies such as polyethylene terephthalate and high-density polyethylene. The developer container 2 is fixed to the developer container 2 by the blade support member 10 .

In a developing device using such an elastic blade 9, the pressing force between the elastic blade 9 and the developer carrier 6 is closely related to the image density. As long as the applied amount of the agent is not less than 0.9 mg/cm2, the higher the pressing force, the higher the image density. Therefore, the elastic blade 9 tends to be pressed more strongly against the developer carrier 6.

As a result, as the developer carrier 6 is repeatedly rotated to perform a developing operation, the developer may be pressed and adhere to the surface of the developer carrier 6 or the surface of the elastic blade 9, or become contaminated in the form of a film. If this problem becomes worse, the torque of the developer carrier may be so large that the image carrier and developer carrier may become separated from each other, or the developer carrier may not rotate and gear teeth may skip. In some cases, the drive gear may also be damaged.

[Problem B to be Solved by the Invention] Therefore, an object of the present invention is to provide an image forming method using a developing device that uses an elastic blade to apply a developer onto a developer carrier. Even with strong pressure from the body, the elastic blade does not stick to the surfaces of the two or cause film-like contamination. Rather, it promotes lubrication between the two and reduces the driving torque of the developer carrier, allowing the elastic blade to reverse its rotation. It is an object of the present invention to provide a developer and an image forming method that can prevent peeling, prevent damage to a developer carrier drive gear, and perform good image formation.

[Means and effects for solving the problem] The above object has an image carrier for carrying a latent image and a developing device for developing the latent image on the image carrier, according to the present invention. The developing device includes a developer container for storing developer, and a developer carrier for carrying and transporting the developer in the developer container from the developer container to a developing area facing an image carrier. and an elastic blade for regulating the developer carried and conveyed on the developer carrier to a predetermined thickness and forming a thin layer of developer on the developer carrier. This is achieved by a developer used in an image forming method, which is characterized by containing a toner and a fine powder treated with silicone oil or silicone varnish, and the image forming method.

The image forming apparatus according to the image forming method of the present invention will be explained in more detail below with reference to the drawings.

1 and 2 show an embodiment of an image forming apparatus according to the present invention. In this embodiment, the image carrier 3 is a drum-shaped photoreceptor or a dielectric material, and a latent image is formed thereon by an image forming process well known to those skilled in the art. The latent image is made into a visible image by a developing device, and then the visible image is transferred to a transfer material such as paper and made into a permanent image by a fixing device. Such latent image forming means, transfer means, fixing means, etc. disposed around the image carrier are well known to those skilled in the art as described above, and therefore are omitted in FIG. 1, and only the developing device is shown. has been done.

The developing device IA according to the present invention has a configuration similar to that of a commonly used developing device, and includes a developer container 2 for storing developer, and a developer container 2 for removing the developer from the developer container. A developer carrier 6 carries and transports the developer to the developing area 4 facing the image carrier 3, and the developer carried by the developer carrier and transported to the developing area 4 is regulated to a predetermined thickness and developed. It has an elastic blade 9 for forming a thin layer of developer on the developer carrier.

The developer carrier 6 may have any structure, but usually,
It consists of a non-magnetic developing sleeve 8 with a built-in magnet 7. The developing sleeve 8 of the developer carrier 6 can be a cylindrical rotating body as shown in the figure, but it can also be shaped like a circulating belt. Its material is generally aluminum.

SUS or the like is used, but the material is not particularly limited thereto.

The elastic blade 9 may be made of a known elastic plate such as a rubber elastic body such as urethane rubber, silicone rubber, or NBR, a metal elastic body such as phosphor bronze or a stainless steel plate, or a resin elastic body such as polyethylene terephthalate or high-density polyethylene. The blade support member 10 is made of a rigid body such as iron, and is fixed to the developer container 2 by a blade support member 10 made of a rigid body such as iron. In this embodiment, it is preferable that the elastic blade 9 is brought into contact with the developer carrier 6 in the forward direction relative to the rotating direction of the developer carrier 6 with a linear pressure of 5 to gag/cm.

FIG. 3 shows another embodiment of the invention. Also in FIG. 3, the various image forming means disposed around the image carrier 3 are omitted, and only the developing device IB is illustrated.

The basic structure of the developing device IB is the same as that of the developing device IA of the first embodiment described with reference to FIG. 1, but in this embodiment, the developing device is unitized and made into a disposable type. In a developing device having such a configuration, when the developing device is not in use, the developer is stored in a container in order to prevent the developer from leaking from the developing device and to facilitate transportation and storage of the image forming device or the developing device. A sealing member 15, such as a vinyl sheet, fixed to the developer container 2 with an adhesive or the like.
When the developing device with such a configuration is installed in an image forming apparatus, a user can press the sealing member 15 on the side of the paper shown in FIG. 3, for example. The developer I3 is removed by pulling it out in the vertical direction, and the developer I3 is supplied onto the developer carrier 6, making it possible to form an image.

Further, as shown in FIG. 4, it is also possible to adopt a configuration such as a developing device 1c in which the elastic blade 9 is brought into contact with the counter in one direction with respect to the rotating direction of the developer carrier 6.

FIG. 5 shows another embodiment of the image forming apparatus according to the present invention. According to this embodiment, an image forming unit, a so-called cartridge 18, which integrates a developing device 1D, which is the center of image formation, a drum-shaped image carrier (photosensitive drum) 3, a cleaner 16, and a charger 17, is used. An electrophotographic image forming apparatus is provided.

In this apparatus, the developing device 1 in the cartridge 18 is
When the developer 13 of D runs out, it is replaced with a new cartridge.

According to this embodiment, the developing device 1D uses a one-component developer as the developer 13, and a predetermined electric field is formed between the photoreceptor drum 3 and the developer carrier 6, thereby making the developing operation suitable. The distance between the drum 3 and the developer carrier 6 is very important. In this example, 3
It is centered at 00gm and measured and adjusted so that the error is ±30pm.

Next, the developer according to the present invention will be explained.

The developer of the present invention contains fine powder treated with silicone oil or silicone varnish, and preferably has a form in which the fine powder is dispersed on the surface of the developer.

The developer according to the present invention has the above configuration, so that
The pressing force between the developer carrier and the elastic blade also prevents adhesion to the surfaces of the two and film-like contamination, making it possible to always form good images. That is, the developer according to the present invention is a developer that matches extremely well with the image forming apparatus according to the present invention and allows the image forming apparatus to be fully utilized, and the developer according to the present invention and the image forming apparatus are compatible. By using this method, an image forming method that provides good images was established.

The present inventors believe that the reason for this is that the fine particles present on the surface of the developer serve as a lubricant between the developer and the device components, but it is particularly important to treat the fine particles with silicone oil or silicone varnish. It is presumed that this may also soften the impact of contact between fine particles and device members.

The particle size of the fine powder used in the present invention is 0.001 to 2μ
It is preferably in the range of 0.005 to 0.2μ, especially
is preferred. The material of the fine powder used in the present invention is preferably an inorganic compound. For example, silicic acid, alumina, titanium oxide, etc.
Metal oxides of Group 3 and Group 4 are preferred.

Particularly preferred is silicic acid fine powder, and as silicic acid fine powder,
Both the so-called dry process or fumed silica produced by vapor phase oxidation of a silicon halide compound, and the so-called wet process silica produced from water glass etc. can be used; There are few silanol groups in NatO, SOs''-
It is preferable to use dry silica which does not leave manufacturing residues such as silica.

In addition, in the manufacturing process of dry silica, for example,
It is also possible to obtain a composite fine powder of silica and other metal oxides by using other metal halide compounds such as aluminum chloride or titanium chloride together with a silicon halide compound, and these are also included.

In the silicone oil treatment of fine powder used in the present invention, by applying silicone oil to the surface of the fine powder, the silanol groups can be completely covered and hidden.
Moisture resistance is dramatically improved.

The silicone oil or silicone varnish solid content used in the present invention is generally represented by the following formula: R: R': R'': C, -C, alkyl group alkyl, halogen-modified alkyl.

Silicone oil modified groups such as phenyl and modified phenyl C3 to C3 alkyl or alkoxy groups Examples include dimethyl silicone oil, alkyl modified silicone oil, α-methylstyrene modified silicone oil, chlorphenyl silicone oil, fluorine modified silicone oil, etc. It will be done. The silicone oil preferably has a viscosity of about 50 to 1000 centistokes at 25°C. Silicone oil with a molecular weight that is too low may generate volatile matter when subjected to heat treatment, etc., and a silicone oil with a molecular weight that is too high may have too high a viscosity, making it difficult to perform treatment operations.

Known techniques can be used for the silicone oil treatment; for example, fine powder and silicone oil may be directly mixed using a mixer such as a Henschel mixer, or silicone oil may be sprayed onto the base fine powder using RJJI. Also good. Alternatively, it may be prepared by mixing the varnish with the base fine powder and then removing the solvent.

Further, it is more preferable that the fine powder used in the present invention is first treated with a silane coupling agent and then treated with silicone oil or silicone varnish.

In general, with silicone oil treatment alone, a large amount of silicone oil is needed to cover the surface of the fine powder, making it easy for fine powder aggregates to form during the treatment, and when applied to a developer, the fluidity of the developer may deteriorate. , it is necessary to be very careful about the silicone oil treatment process. Therefore, in order to remove the agglomerates of fine powder while maintaining good moisture resistance, it is better to treat the fine powder with a silane coupling agent and then with silicone oil to fully demonstrate the treatment effect of silicone oil. That's what it means.

The silane coupling agent used in the present invention is represented by the general formula % R: alkoxy group or chlorine atom m: an integer of 1 to 3 and an integer of 3 to 1, typically dimethyldichlorosilane. , trimethylchlorosilane, allyldimethylchlorosilane, hexamethyldisilazane, allyl phenyldichlorosilane, benzyldimethylchlorosilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, divinylchlorosilane, Examples include dimethylvinylchlorosilane.

The above fine powder is treated with a silane coupling agent by a dry process in which the fine powder is made into a cloud shape by stirring or the like and reacted with a vaporized silane coupling agent, or by dispersing the fine powder in a solvent and dropping the silane coupling agent. The treatment can be carried out by a generally known method such as a wet reaction method.

The silane coupling agent is used for 100 parts by weight of fine powder.
It is preferable to use 1 to 50 parts by weight, more preferably 5 to 40 parts by weight.

The processing amount of silicone oil or silicone varnish solid content in the present invention is preferably 1 to 35 parts by weight, more preferably 2 to 30 parts by weight, based on 100 parts by weight of the fine powder. The reason for limiting the above processing amount is that if the silicone oil processing amount is too small, the result will be the same as silane coupling agent treatment alone, and the moisture resistance will not improve and the fine powder will absorb moisture under high humidity, resulting in high quality copies. Images cannot be obtained. Furthermore, if too much silicone oil is processed, the above-mentioned fine powder aggregates are likely to form, and free silicone oil is also formed, so it is difficult to improve the fluidity when applied to a developer. There are disadvantages such as not being able to do so. The amount of these treated fine powders to be applied to the developer is 0.01 to 20 parts by weight, more preferably 0.1 to 3 parts by weight, per 100 parts by weight of the developer (toner).

As the binder resin of the toner according to the present invention, monopolymers of styrene and its substituted products such as polystyrene and polyvinyltoluene; styrene-propylene copolymers, styrene-propylene copolymers, etc.
Vinyltoluene copolymer.

Styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-dimethylamino acrylate Ethyl copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-methyl methacrylate copolymer.

Styrene-dimethylaminoethyl methacrylate copolymer, styrene-vinyl methyl ether copolymer, styrene-vinylethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer Styrenic copolymers such as , styrene-maleic acid copolymer, styrene-maleic acid ester copolymer: polymethyl methacrylate, polybutyl methacrylate, polyvinyl acetate, polyethylene, polypropylene, polyvinyl butyral, polyacrylic acid resin, rosin , modified rosin.

Terpene resin, phenolic resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, paraffin wax,
Carnauba wax and the like can be used alone or in combination.

Further, as coloring materials that can be added to the toner according to the present invention, conventionally known carbon black, copper phthalocyanine,
Iron black etc. can be used.

Further, in the present invention, as the magnetic fine particles contained in the magnetic toner that brings about a more remarkable effect in the magnetic toner containing a magnetic substance, a substance that is magnetized by being placed in a magnetic field is used, such as iron, cobalt, nickel, etc. ferromagnetic metal powder, or magnetite, γ-Fe203. Alloys and compounds such as ferrite can be used.

These magnetic fine particles preferably have a BET specific surface area of 1 to 2 om2/g, particularly 2.5 to 12 m' by nitrogen adsorption method.
/g, and preferably a magnetic powder having a Mohs hardness of 5 to 7.

The content of this magnetic powder is preferably 70% by weight of 1ON based on the weight of the toner.

Further, the toner of the present invention may contain a charge control agent if necessary, such as metal complex salts of monoazo dyes, salicylic acid,
A negative charge control agent such as a metal complex salt of alkyl salicylic acid, dialkyl salicylic acid or naphthoic acid is used. Furthermore, the magnetic toner according to the present invention has a volume resistivity of 1010Ω.
-cm or more, especially 10''Ω・cm or more is preferable in terms of triboelectric charge and electrostatic transferability.The volume resistivity referred to here is determined by molding the toner at a pressure of 100 kg/cm',
An electric field of 100 V/cm is applied to this, and it is defined as a value converted from the current value after 1 minute has passed after application.

The developer of the present invention may further include other additives, such as Teflon, lubricants such as zinc stearate, fixing aids (such as low molecular weight polyethylene), or conductivity imparting agents, as long as they do not have a substantial adverse effect. Alternatively, a metal oxide such as tin oxide may be added.

In producing the toner of the present invention, the constituent materials are thoroughly kneaded using a thermal kneader such as a hot roll, kneader, or extruder, and then mechanically crushed or classified, or the materials are mixed in a binder resin solution. A method of producing a toner by dispersing and then spray drying, or a polymerization method of obtaining a toner by mixing a specified material with a monomer to constitute a binder resin to form an emulsified suspension and then polymerizing the resulting toner. , each method can be applied.

[Example] Specific examples will be described below, but the present invention is not restricted in any way by the following examples.

Incidentally, the number of parts in the examples indicates parts by weight.

After mixing the above materials, they were kneaded for 20 minutes in a two-roll mill heated to 150°C. After cooling the mixed material, it is coarsely pulverized, pulverized using a pulverizer using a jet stream, and further classified using a wind classifier to obtain black fine powder (magnetic toner) with a volume average particle diameter of 11°8 μm. Obtained.

Next, 100 parts of silicic acid fine powder Aerosil #200 (manufactured by Nippon Aerosil Co., Ltd.) with a specific surface area of 200 m27 g was treated with 20 parts of hexamethyldisilazane (HMDS).
Silicic acid treated with 10 parts of dimethyl silicone oil KF-96100cS (manufactured by Shin-Etsu Chemical Co., Ltd.) diluted with a solvent, dried and then heated at 250°C, treated with hexamethyldisilazane, and then treated with dimethyl silicone oil. A fine powder was obtained, and 0.7 parts of silica was externally added to 100 parts of the above-mentioned magnetic black fine powder to obtain a magnetic toner (developer) with external addition of silica.

Next, the developing device of a commercially available copier Fl Knee 5 (manufactured by Canon) was modified as shown in Figure 5, and the contact pressure of the urethane rubber elastic blade to the developer carrier (developing sleeve) was increased to 28.
g/cm.

A reverse electrostatic latent image was formed with primary charging at -600 V, a gap of 15 g (300 μm) was set in a non-contact manner between the photosensitive drum and the developer layer on the developing sleeve (with magnet included), and AC bias (f = 1) ( a800Hz, V, p= 1.20
0 V) and DC bias (Voc=-390V
) was applied to the developing sleeve, and the transfer potential was reversed in polarity to form an image.

As a result, even after producing 3,000 images, no toner sticking or film formation due to toner components was observed on either the elastic blade surface or the developing sleeve surface, and good images continued to be produced.

Similar experiments were conducted under high temperature and high humidity conditions of 32.5℃ and 85% RH, and under low temperature and low humidity conditions of 15℃ and 10%RH.
The results were equally good.

Furthermore, no problem occurred even when images were continued to be produced up to 5,000 sheets while replenishing toner.

Example 2 100 parts of silicic acid fine powder Aerosil #200 was treated with 20 parts of dimethyl silicone oil KF-960 diluted with a solvent, dried and then heat treated at about 280°C to obtain treated silica.

The treated silica was added to magnetic black fine powder to make a magnetic toner in the same manner as in Example 1, and an image production test similar to that in Example 1 was conducted. The results were obtained.

Furthermore, when I continued to produce images up to 5,000 sheets while replenishing l. It was of a good level.

Aerosil #, a silicic acid fine powder with a specific surface fi of 130 m and 27 g
130 (Nippon Aerosil Co., Ltd.) was treated with 3 parts of dimethyl silicone oil KF-963 in the same manner as in Example 2,
Similarly, it was added to magnetic black fine powder to obtain a magnetic toner.

When this toner was subjected to an image printing test in the same manner as in Example 1, good results were obtained under all environmental conditions up to 3,000 sheets.

Furthermore, when I continued to print images up to S, 000 sheets without replenishing the toner, slight scratches were seen on the surface of the elastic blade after 4,500 sheets under low temperature and low humidity conditions, but no defects appeared on the images. It was in good condition.

The same process as in Example 2 was carried out except that the amount of F-96 was changed to 32 parts in 104 Ni dimethyl silicone oil, and the same image output test was conducted.
Good results were obtained under all environmental conditions.

Furthermore, when we continued to print images up to 5,000 sheets while replenishing toner, under high temperature and high humidity conditions, film-like contamination was observed on the surface of the developing sleeve after 3,500 sheets, and after 4,500 sheets, a slight amount of image However, it was determined that there was no problem in practical use, although it appeared as a white spot-like defect.

Silicic acid fine powder Aerosil # with specific surface area: +oom”/g
300 (Shiraki Aerosil Co., Ltd.) 100 parts was treated in the same manner as in Example 2 with 25 parts of fluorine-modified silicone oil (200C5) to obtain a magnetic toner.

Further, the developing device of the modified copying machine used in Example 1 was further modified to the one shown in FIG. 4, and the contact pressure of the silicone rubber elastic blade to the developing sleeve was set to 35 g/cm.

When the above-mentioned toner was put into the above-mentioned modified copying machine and the same image output test as in Example 1 was conducted, the results up to 5,000 sheets were at the same level as in Example 2.

[Effects of the Invention] As explained above, by using the developer according to the present invention in an image forming method using a developing device that applies a developer onto a developer carrier using an elastic blade, Even with strong pressure between the developer carrier and the developer carrier, it does not stick to the surfaces of the two or cause film-like contamination, but rather promotes lubrication between the two and reduces the driving torque of the developer carrier. It has become possible to prevent the elastic blade from reversing or peeling off, and also to prevent damage to the developer carrier drive gear, thereby making it possible to form good images.

[Brief explanation of drawings]

FIG. S1 is a schematic sectional view of an embodiment of an image forming apparatus according to the present invention. FIG. 2 is a sectional view showing the relationship between the elastic blade and the developer carrier in the developing device. Figures 'fJ3 to 5 are schematic cross-sectional views of other embodiments of the image type warning device according to the present invention. FIG. 6 is a schematic cross-sectional view of a conventional image forming apparatus. 2: Developer container 3: Image carrier 6: Developer carrier 9: Elastic blade 14: Friction reducer

Claims (2)

[Claims] (1) (a) An image carrier for carrying a latent image, and (b)
A developer container for accommodating developer, a developer carrier that supports and transports the developer in the developer container from the developer container to a development area facing an image carrier, and the developer carrier. and an elastic blade for regulating the developer carried and conveyed by the image carrier to a predetermined thickness and forming a thin layer of developer on the developer carrier, for developing the latent image on the image carrier. A developer applied to an image forming method using an image forming apparatus equipped with a developing device, characterized in that the developer contains toner and fine powder treated with silicone oil or silicone varnish. agent. (2) (a) an image carrier for carrying a latent image, and (b)
A developer container for accommodating developer, a developer carrier that supports and transports the developer in the developer container from the developer container to a development area facing an image carrier, and the developer carrier. and an elastic blade for regulating the developer carried and conveyed by the image carrier to a predetermined thickness and forming a thin layer of developer on the developer carrier, for developing the latent image on the image carrier. An image forming method using an image forming apparatus equipped with a developing device, characterized in that a developer containing toner and fine powder treated with silicone oil or silicone varnish is used as the developer. Method.