JP3044405B2 - Non-magnetic one-component development method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-magnetic one-component developing method among electrostatic image developing methods used for electrophotography and the like.

[0002]

2. Description of the Related Art Conventionally, electrophotography has been disclosed in U.S. Pat. No. 2,297,691, Japanese Patent Publication No. 42-23910.
Many methods are known as described in Japanese Patent Publication No. JP-A-Heisei, 43-24878 and Japanese Patent Publication No. 43-24748. Generally, a photoconductive substance is used to form an electric latent image on a photoreceptor by various means. Forming and then developing the latent image with toner,
After transferring the toner image to a transfer material such as paper as necessary,
The copy is obtained by fixing by heating, pressure, heating or pressurizing, or solvent vapor, and the remaining toner not transferred onto the photoreceptor is cleaned by various methods, and the above steps are repeated.

As a method for developing an electrostatic latent image in these processes, a two-component developing method using a mixture of a toner and a carrier and a one-component developing method using only a magnetic toner are generally used. In view of the fact that the two-component developing method uses a carrier and requires a so-called ATR mechanism for adjusting the mixing ratio of the carrier and the toner, it is difficult to reduce the size and weight, and the cost increases. On the other hand, the one-component developing method has a drawback that it is difficult to cope with a color toner because a magnetic toner is used.

On the other hand, JP-A-58-116559, JP-A-60-120368, and
The non-magnetic one-component developing method disclosed in Japanese Patent No. 271371 has attracted attention as a developing method for solving the above-mentioned problems. In the non-magnetic one-component developing method, a developer is coated on a developer carrier using a blade or the like. Since the developer is charged by friction with the blade or the surface of the developer carrier, the material of the blade is preferably one which is easily charged to the opposite polarity to the developer. JP-A-61-250666, JP-A-62-24285, JP-A-62-20317
No. 7, JP-A-63-81376, JP-A-63-81376
JP-A-250662 proposes to add a charge control component having a polarity opposite to that of the toner to the blade. Although the initial charging characteristics are significantly improved by these means,
When a toner to which silica is added is used, there has been a problem that the charge amount of the toner is reduced due to long-term use, resulting in a decrease in density and fogging. The cause of these image degradations is that silica added to the toner over a long period of time gradually adheres to the blade and contaminates the surface, and the ability to impart charge to the toner decreases. That is, there is a disadvantage that the blade material which is easily charged to the opposite polarity to the toner also has a large adhesion to silica at the same time.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a developing method which solves the above problems. That is, an object of the present invention is to prevent the silica fine powder from adhering to the developer coating blade, maintain the toner charge amount unchanged from the initial state even in long-term use, and stably produce an image without a decrease in density or fog. The aim is to provide a development method which can be obtained.

[0006]

According to the present invention, a non-magnetic one-component developer is supplied to a developing device in which a developer application blade is pressed against a developer carrier which is arranged opposite to a latent image holding member. Applying the non-magnetic one-component developer onto the developer carrier by the developer application blade, and applying the latent image to the non-magnetic one-component developer applied on the developer carrier. In a non-magnetic one-component developing method for developing an electrostatic latent image held on a holding member, the non-magnetic one-component developer has a non-magnetic toner and silica fine powder, and the silica fine powder is The surface is treated with at least one treatment agent selected from the group consisting of an organosilicon compound and a titanium coupling agent, and the same silica fine powder as the silica fine powder is dispersed in the developer coating blade. Features that A non-magnetic one-component developing method of relating.

The details will be described below. As the blade material used in the present invention, silicon rubber, polyurethane, fluorine rubber, polychlorobutadiene rubber, styrene butadiene rubber, nylon, and the like are preferable, and in particular, silicon rubber is used for positively charging the toner, and negatively charged. For this reason, nylon is preferred.

As the blade, a material obtained by press-molding the above-described material into a sheet may be used as it is, or the molded sheet may be adhered to the surface of a metal blade and used.
Further, the surface of a metal blade, a rubber blade or the like may be coated with the above-mentioned blade material and used.

The same silica fine powder as that added to the toner is dispersed in the blade material. The blade substrate has a polarity opposite to that of the developer as described above, and electrical adhesion of the silica fine powder added to the toner is inevitable because a material as far as possible from the charging series is used, but the material added to the toner By dispersing the same silica fine powder on the blade so that the silica fine powder is exposed on the blade surface, electrical adhesion of the silica fine powder can be prevented without lowering the charging characteristics. When a different kind of silica fine powder from that added to the toner is used, the above-mentioned effects cannot be obtained because a difference occurs in the charging characteristics of the two kinds of silica fine powder.

[0010] As the silica fine powder used here,
Although common wet and dry silicas can be used, those obtained by subjecting a dry silica to a surface treatment are preferable in consideration of the developing characteristics and environmental stability of the toner.

Examples of the treating agent include silicone oil, amino-modified silicone oil, amino-modified silicone varnish, and a silane coupling agent represented by the following formula: R _m SiY _n (R:
An alkoxy group or a chlorine atom, Y: an amino group, a vinyl group,
A hydrocarbon group containing at least one or more of a glycidoxy group, a mercapto group, a methacryl group, and a ureido group, m and n are integers of 1 to 3), hexamethyldisilazane, trimethylchlorosilane, trimethylethoxysilane, Dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyldichlorosilane, benzyldimethylchlorosilane, bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, p-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane , Triorganosilyl mercaptan, triorganosilyl acrylate, hexamethyldicycloxane, 1,3-divinyltetramethyldisiloxane, 1,3-diphenyltetramethyldisiloxane, and 1 molecule equivalent Organosilicon compounds such as dimethylpolysiloxane having 2 to 12 siloxane units, each having a hydroxyl group bonded to one Si at the terminal unit, isopropyltriisostearoyl titanate, isopropylitri (N, N Titanium coupling agents such as -dimethyl-ethylamino) titanate and dianthranylethylene titanate; and one or a mixture of two or more of these. In particular, when a positively chargeable developer is used, treatment with an amino-modified silicone oil and an aminosilane coupling agent is preferable, and when a negatively chargeable developer is used, hexamethyldisilazane is preferable.

When the silica fine powder surface-treated with these treating agents is dispersed in the blade material, it is preferably mixed with 5 to 60 parts by weight, more preferably 10 to 50 parts by weight, per 100 parts by weight of the blade material. It is.

As the binder resin for the toner used in the present invention, various resin materials conventionally known as toner binder resins for electrophotography are used. For example, styrene such as styrene, methyl styrene, chlorostyrene, and vinyl toluene and its substituted products; acrylates such as methyl acrylate, ethyl acrylate, n-butyl acrylate, and t-butyl acrylate; methyl methacrylate, methacrylic Methacrylates such as ethyl acrylate, n-butyl methacrylate, t-butyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate; acrylonitrile; vinyl ethers such as vinyl methyl ether and vinyl ethyl ether; maleic acid, maleic ester And olefins such as ethylene, propylene and butadiene, and diolefins. Monomers of these monomers, copolymers of two or more monomers, and polyesters, polyurethanes, polyamides, epoxy resins, polyamides, terpene resins, phenol resins, and the like can be used alone or in combination. .

The coloring agents used in the toner include known dyes and pigments such as carbon black, aniline black, acetylene black, phthalocyanine blue, indanthrene blue, permanent red, lake red, rhodamine lake, Hansa yellow, and naphthol yellow. Azo dyes, anthraquinone dyes, xanthene dyes, methine dyes and the like, and it is preferable to add 0.1 to 20 parts by weight to 100 parts by weight of the resin.

As the release agent, paraffin wax, low molecular weight polyethylene wax, low molecular weight polypropylene wax, carnauba wax and the like are used in an amount of 0.1 to 20 parts by weight based on 100 parts by weight of the resin.

As the charge control agent, a conventionally known positive or negative charge control agent is used. Nigrosine, quaternary ammonium salt,
Examples include fatty acid metal salts and amino group-containing vinyl polymers. In addition, salicylic acid,
Naphthoic acid, metal complexes of dicarboxylic acids and the like. These charge control agents are used in an amount of 0.1 to 1 based on 100 parts by weight of the resin.
0 parts by weight are used.

The toner of the present invention may optionally contain additives other than the silica fine powder. Lubricants such as Teflon, zinc stearate, polyvinylidene fluoride, abrasives such as cerium oxide, silicon carbide and strontium titanate, fluidity imparting agents such as aluminum oxide and titanium oxide, carbon black, zinc oxide, antimony oxide, and oxide A conductivity-imparting agent such as tin can be used within a range that does not cause blade contamination.

In order to prepare the toner for developing an electrostatic image according to the present invention, the resin composition and the charge control agent according to the present invention,
A pigment or dye as a colorant is thoroughly mixed with a ball mill or other mixer, and then heated, rolled, kneaded,
Using a hot kneader such as an extruder, melt or knead to disperse or disperse the pigments or dyes in the resins to make them compatible with each other.
~ 20 µm of toner can be obtained.

Next, an example of the developing device used in the present invention will be described, but the present invention is not necessarily limited thereto.
In FIG. 1, reference numeral 1 denotes a latent image holding member, and a latent image is formed by electrophotographic processing means or electrostatic recording means (not shown). Reference numeral 2 denotes a developer carrier, which is made of a non-magnetic sleeve made of aluminum or stainless steel. As the developer carrying member, a rough tube of aluminum or stainless steel may be used as it is, but preferably the surface is uniformly roughened by spraying glass beads or the like, or the surface is mirror-finished or coated with a resin or the like. Is good. Developer 6 is hopper 3
And supplied onto the developer carrier by the supply roller 4. The supply roller is made of a foam material such as a polyurethane foam,
It rotates in a forward or reverse direction at a relative speed other than 0, and strips off the developed developer (undeveloped developer) on the developer carrying member together with the supply of the developer. The developer supplied onto the development carrier is uniformly and thinly applied by the developer application blade 5. The contact pressure between the developer coating blade and the developer carrier is 3 to 250 g / cm, preferably 10 to 120 g / cm, as a linear pressure in the sleeve generatrix direction.
cm is effective. If the contact pressure is less than 3 g / cm, it becomes difficult to apply the toner uniformly, and the charge amount distribution of the toner becomes broad, causing fogging and scattering. On the other hand, when the contact pressure exceeds 250 g / cm, a large pressure is applied to the developer, and the developer is deteriorated. Further, a large torque is required to drive the developer carrier, which is not preferable.

[0020]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which do not limit the present invention in any way. The parts in the following formulations are parts by weight.

Example 1 Styrene-butyl acrylate copolymer 100 parts (St: BA = 70: 30) Carbon black 4 parts Nigrosine 2 parts Low molecular weight polypropylene 4 parts After the above materials were premixed with a Henschel mixer, 130
The mixture was melted and kneaded by a biaxial kneading extruder heated to 0 ° C., cooled, pulverized by an air-flow type pulverizer, and classified by an air classifier to obtain a black fine powder having a weight average particle size of 8.5 μm. AEROSIL 130 (manufactured by Nippon Aerosil Co., Ltd.)
Then, 1.8 parts of silica treated with 13 parts of amino-modified silicone oil was externally added to obtain a developer.

Next, silicon rubber in which 30 parts of the above silica was dispersed was molded into a 1.2 mm-thick sheet and cut to form a developer coating blade.

The above-mentioned developer is used in a Canon copier NP-12.
The evaluation was performed using a copying machine in which 15 developing devices were modified as shown in FIG. 1 (the developer coating blade 5 was as described above). No image deterioration such as a decrease in density or fogging was observed even after running through 10,000 sheets. The blade was removed and its surface was observed, but no adhesion of silica or the like was observed.

Example 2 Styrene-2-ethylhexyl acrylate 100 parts (St: 2EHA = 80: 20) Monoazo pigment 5 parts Quaternary ammonium salt 2 parts Low molecular weight polypropylene 4 parts In the same manner as in Example 1 using the above materials Weight average particle size 1
2.3 μm red fine powder was obtained. Add silica fine powder A
EROSIL 200 (manufactured by Nippon Aerosil Co., Ltd.) was treated with 20 parts of dibutylaminopropyltrimethoxysilane, 2.0 parts of silica and 0.3 parts of polyvinylidene fluoride fine particles.
Externally added developer was obtained. Next, a urethane rubber in which 40 parts of the above silica was dispersed was molded into a 1.5 mm-thick sheet and cut to obtain a developer coating blade.

The above-mentioned developer was evaluated by using a copying machine in which the developing device of a Canon copier FC-5 was modified as shown in FIG. 1 (the developer coating blade was as described above). 500
No image deterioration such as a decrease in density and fog was observed even after 0 sheets passed. When the blade was removed and its surface was observed, no adhesion of silica or the like was observed.

Example 3 Polyester resin 100 parts Carbon black 4 parts Salicylic acid metal complex 1 part Low molecular weight polypropylene 5 parts Weight average of 11.
A black fine powder of 5 μm was obtained. AER with silica fine powder
OSIL 200 (manufactured by Nippon Aerosil Co., Ltd.) was externally added with 1.5 parts of silica treated with 20 parts of hexamethylene disilazane and 10 parts of silicone oil to obtain a developer.

Next, a urethane rubber sheet cut to a thickness of 1.0 mm was coated with a nylon in which 20 parts of the above silica was dispersed to prepare a developer coating blade.

The above-mentioned developer was evaluated using a printer in which the developing device of a Canon laser beam printer LBP-8II was modified as shown in FIG. 1 (the developer coating blade was as described above). No image deterioration such as a decrease in density or fog was observed even after 8,000 sheets were passed. When the blade was removed and its surface was observed, no adhesion of silica or the like was observed.

Comparative Example 1 The same evaluation as in Example 1 was performed using the developer used in Example 1 and a developer coating blade of silicon rubber in which silica was not dispersed. After about 1000 sheets of paper passed, fogging occurred frequently and was not practical. Also, a large amount of silica externally added to the toner adhered to the blade.

Comparative Example 2 Evaluation was made in the same manner as in Example 2 using the developer used in Example 2 and the urethane rubber developer coating blade in which silica used in Example 1 was dispersed. After about 2,000 sheets passed, the image density was remarkably reduced, and the image was not practically used. Also, a large amount of silica externally added to the toner adhered to the blade.

[0031]

According to the present invention, in a non-magnetic one-component developing method, by using a developer coating blade in which the same silica as the silica added to the developer is dispersed, the silica is applied to the developer coating blade. Adhesion can be prevented, and an image free from density reduction and fog can be stably obtained.

[Brief description of the drawings]

FIG. 1 shows an example of a developing device used for a non-magnetic one-component developing method.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 latent image holder 2 developer carrier 3 hopper 4 supply roller 5 developer coating blade 6 developer

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masaji Fujiwara 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Shinji Doi 3-30-2 Shimomaruko, Ota-ku, Tokyo (56) References JP-A-63-81376 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 15/08 504 G03G 15/08 501 G03G 9/08 G03G 15/09 101

Claims (3)

(57) [Claims] A developing device in which a developer application blade is pressed against a developer carrying member disposed to face the latent image holding member;
A non-magnetic one-component developer was applied to, developer coating blade
The non-magnetic one-component developer on the developer carrier
And applying the non-magnetic material applied on the developer carrier.
It is held on the latent image holding member by a component developer.
In the non-magnetic one-component developing method for developing an electrostatic latent image , the non-magnetic one-component developer includes a non-magnetic toner and a silica fine powder.
And the silica fine powder is an organosilicon compound.
Selected from the group consisting of
Are surface treated by one or more processing agents, during developer coating blade, a non-magnetic one-component developing method in which the silica fine powder and the same fine silica powder is characterized that you have been dispersed. 2. The method according to claim 1, wherein the organosilicon compound is silicon oil.
Amino-modified silicone oil, amino-modified silicone oil
Varnish, R _m SiY _n The silane coupling agent represented by
Wherein R represents an alkoxy group or a chlorine atom, and Y represents amino
Group, vinyl group, glycidoxy group, mercapto group,
At least one or two or more of a luyl group and a ureido group.
M and n represent an integer of 1 to 3
), Hexamethyldisilazane, trimethylchlorosila
, Trimethylethoxysilane, dimethyldichlorosila
, Methyltrichlorosilane, allyldimethylchlorosi
Orchid, allylphenyldichlorosilane, benzyldimethy
Chlorosilane, bromomethyldimethylchlorosilane,
α-chloroethyltrichlorosilane, p-chloroethyl
Trichlorosilane, chloromethyldimethylchlorosila
, Triorganosilyl mercaptan, triorganosin
Ryl acrylate, hexamethyldicycloxane, 1,
3-divinyltetramethyldisiloxane, 1,3-diph
Phenyltetramethyldisiloxane, or 2 per molecule
Having 12 to 12 siloxane units, and
Each containing a hydroxyl group bonded to one Si at each position
2. The method according to claim 1, wherein
Non-magnetic one-component developing method described above. 3. The titanium coupling agent is isopropyl
Rutriisostearoyl titanate, isopropyl tri
(N, N-dimethyl-ethylamino) titanate, or
Is a dianthranyl ethylene titanate.
Claims to be collected 2. The non-magnetic one-component developing method according to 1.