JP2006078918A - Electrophotographic carrier, developer, developer container, image forming method and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a carrier for a two-component developer having high durability even when combined with a toner containing a release agent. <P>SOLUTION: In the carrier with a coating film comprising at least a binder resin and particles, a particle diameter (D) of the particles and a film thickness (h) of the binder resin satisfy 1<[D/h]<10 and the particles have been surface-treated with one or more organometallic compounds represented by formula (1), wherein M denotes SiR<SP>3</SP>, TiR<SP>3</SP>or Al; R denotes H or a 1-6C alkyl; R<SP>1</SP>and R<SP>2</SP>each independently denote a 1-6C alkyl; and R<SP>3</SP>denotes an optionally alkoxy-substituted alkyl or alkoxy having 1-6 carbons in total. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a carrier, a developer, a developer container, an image forming method, and an image forming apparatus used for developing an electrostatic image in electrophotography, electrostatic recording, electrostatic printing, and the like.

  In general, in image forming methods such as electrophotography and electrostatic photography, development obtained by stirring and mixing a toner and a carrier in order to develop an electrostatic latent image formed on a latent image carrier. Agent is used. This developer is required to be a suitably charged mixture. Generally, as a method for developing an electrostatic latent image, a method using a two-component developer obtained by mixing a toner and a carrier and a method using a one-component developer containing no carrier are known. . The former developing method using a two-component developer can provide a relatively stable and good image, but has a drawback that carrier deterioration and fluctuation in the mixing ratio of the toner and the carrier are likely to occur. On the other hand, the latter one-component developer does not have the disadvantages of the former, but has the disadvantage that the chargeability is difficult to stabilize.

  Also, when developing electrostatic latent images repeatedly using a two-component developer, the toner in the developer is consumed and the toner density fluctuates, so it is necessary to obtain a stable image during printing. Therefore, it is necessary to replenish the toner and suppress this fluctuation. In general, as a method for controlling the toner replenishment amount, a copying machine is provided with a permeability detection sensor, a fluidity detection sensor, an image density detection sensor, a bulk density detection sensor, etc., but an image density detection sensor is used. Is the mainstream. This sensor is a method of controlling a toner replenishment amount by developing a fixed image pattern on a latent image carrier and detecting an image density from reflected light.

The granular carrier used in such a two-component development method is to prevent the carrier coating film from being scraped and peeled off, to prevent toner filming on the carrier surface, to form a uniform carrier surface, to prevent surface oxidation, and to be moisture sensitive. It is usually hardened by coating it with an appropriate resin material for the purpose of preventing deterioration, extending the life of the developer, protecting the photoconductor from scratches or abrasion, controlling the charge polarity, or adjusting the charge amount. A high-strength coating layer is provided. For example, a coating layer coated with a specific resin material (see, for example, Patent Document 1), and various additives added to the coating layer (for example, patents) References 2 to 8), those using additives attached to the carrier surface (see, for example, Patent Document 9), and further containing conductive particles larger than the coating film thickness in the coating film Those using those obtained (e.g., see Patent Document 10) have been disclosed.
Patent Document 11 describes the use of a benzoguanamine-n-butyl alcohol-formaldehyde copolymer as a main component for a carrier coating material, and Patent Document 12 describes a carrier coating of a cross-linked product of a melamine resin and an acrylic resin. The use as a material is described.

However, the durability is still insufficient, and there are problems such as spent toner on the carrier surface, destabilization of the charge amount, and resistance reduction due to scraping of the coating resin. However, as the number of copies increases, the image quality of the copied image decreases, so improvement is necessary. Therefore, Patent Document 13 describes that the relationship between the particle diameter and the binder resin film thickness is defined and the specific resistance of the particles is defined, and it is reported that these problems can be solved thereby. Yes. Certainly, the effect is remarkable as compared with the conventional ones, but the demand for the durability of the recent developer is further increased, and further improvement is desired. Further, it has been clarified that the combination of the toner containing the release agent and the carrier proposed in Patent Document 13 cannot provide the same effect as the toner containing no release agent. A commercially available digital full-color copying machine described in Patent Document 13 uses a developer composed of toner and developer that does not contain a release agent.
In recent years, both copying machines and printers have many demands for space saving, and in response to this demand, measures are taken to reduce the fixing portion by omitting the fixing oil or by applying a small amount. In this case, since the toner has a toner configuration including a release agent, there is a great demand for a carrier having high durability even in combination with the toner including the release agent.

JP 58-108548 A JP 54-1555048 A JP 57-40267 A JP 58-108549 A JP 59-166968 A Japanese Patent Publication No. 1-19584 Japanese Examined Patent Publication No. 3-628 JP-A-6-202381 JP-A-5-273789 JP-A-9-160304 JP-A-8-6307 Japanese Patent No. 2683624 JP-A-2001-188388

  The first object of the present invention has been made in view of the above circumstances, and is to provide a more highly durable two-component developer carrier. A second object is to provide a two-component developer carrier that is highly durable even in combination with a toner containing a release agent.

  According to the present invention, the above-mentioned problem is as follows: (1) In a carrier having a coat film composed of at least a binder resin and particles, the particle diameter (D) of the particles and the film thickness (h) of the binder resin are 1 < [D / h] <10, and the particles are surface-treated with one or more organometallic compounds represented by the following general formula (1);

（式中、Ｍは、ＳｉＲ^３、ＴｉＲ^３、Ａｌを示し、Ｒは水素原子又は炭素数１〜６のアルキル基を示し、Ｒ^１及びＲ^２は、各々独立して炭素数１〜６のアルキル基を示し、Ｒ^３は、アルコキシ基で置換されていてもよい全炭素数１〜６のアルキル基又は、アルコキシ基を示す）」、
（２）「少なくとも結着樹脂と粒子からなるコート膜を有するキャリアにおいて、該粒子の粒子径（Ｄ）と該結着樹脂の膜厚（ｈ）が１＜［Ｄ／ｈ］＜１０であり、該コート膜が下記一般式（１）で表わされる有機金属化合物の単独或いは２種以上を含有することを特徴とする電子写真用キャリア；

(In the formula, M represents SiR ³ , TiR ³ , and Al, R represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R ¹ and R ² each independently represent 1 to 6 carbon atoms. Represents an alkyl group, and R ³ represents an alkyl group having 1 to 6 carbon atoms which may be substituted with an alkoxy group or an alkoxy group).
(2) “In a carrier having a coating film composed of at least a binder resin and particles, the particle diameter (D) of the particles and the film thickness (h) of the binder resin are 1 <[D / h] <10. An electrophotographic carrier characterized in that the coating film contains one or more organometallic compounds represented by the following general formula (1);

（式中、Ｍは、ＳｉＲ^３、ＴｉＲ^３、Ａｌを示し、Ｒは水素原子又は炭素数１〜６のアルキル基を示し、Ｒ^１及びＲ^２は、各々独立して炭素数１〜６のアルキル基を示し、Ｒ^３は、アルコキシ基で置換されていてもよい全炭素数１〜６のアルキル基又は、アルコキシ基を示す）」、
（３）「少なくとも結着樹脂と粒子からなるコート膜を有するキャリアにおいて、該粒子の粒子径（Ｄ）と該結着樹脂の膜厚（ｈ）が１＜［Ｄ／ｈ］＜１０であり、該粒子が下記一般式（１）で表わされる有機金属化合物の単独或いは２種以上で表面処理されており、コート膜が一般式（１）で表わされる有機金属化合物の単独或いは２種以上を含有することを特徴とする電子写真用キャリア；

(In the formula, M represents SiR ³ , TiR ³ , and Al, R represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R ¹ and R ² each independently represent 1 to 6 carbon atoms. Represents an alkyl group, and R ³ represents an alkyl group having 1 to 6 carbon atoms which may be substituted with an alkoxy group or an alkoxy group).
(3) “In a carrier having a coating film composed of at least a binder resin and particles, the particle diameter (D) of the particles and the film thickness (h) of the binder resin are 1 <[D / h] <10. The particles are surface-treated with one or more organometallic compounds represented by the following general formula (1), and the coating film contains one or more organometallic compounds represented by the general formula (1). An electrophotographic carrier comprising:

（式中、Ｍは、ＳｉＲ^３、ＴｉＲ^３、Ａｌを示し、Ｒは水素原子又は炭素数１〜６のアルキル基を示し、Ｒ^１及びＲ^２は、各々独立して炭素数１〜６のアルキル基を示し、Ｒ^３は、アルコキシ基で置換されていてもよい全炭素数１〜６のアルキル基又は、アルコキシ基を示す）」、
（４）「前記粒子の固有抵抗が１０^１２（Ω・ｃｍ）以上であることを特徴とする前記第（１）項乃至第（３）項のいずれかに記載の電子写真用キャリア」、（５）「前記粒子がアルミナまたは／及びシリカであることを特徴とする前記第（１）項乃至第（４）項のいずれかに記載の電子写真用キャリア」、（６）「前記粒子の含有量が前記コート膜の組成成分の４０〜９５ｗｔ％であることを特徴とする前記第（１）項乃至第（５）項のいずれかに記載の電子写真用キャリア」、（７）「前記結着樹脂の膜厚が０．０５μｍ〜１．００μｍであることを特徴とする前記第（１）項乃至第（６）項のいずれかに記載の電子写真用キャリア」、（８）「前記結着樹脂が、少なくともアクリル樹脂とアミノ樹脂を架橋反応させた樹脂または／及びシリコーン樹脂を含有したものであることを特徴とする前記第（１）項乃至第（７）項のいずれかに記載の電子写真用キャリア」、（９）「前記結着樹脂のＴｇが２０〜１００℃であることを特徴とする前記第（１）項乃至第（８）項のいずれかに記載の電子写真用キャリア、（１０）「前記一般式（１）で示される有機金属化合物が、下記一般式（２）で示されるシロキサン化合物であることを特徴とする前記第（１）項乃至第（９）項のいずれかに記載の電子写真用キャリア；

(In the formula, M represents SiR ³ , TiR ³ , and Al, R represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R ¹ and R ² each independently represent 1 to 6 carbon atoms. Represents an alkyl group, and R ³ represents an alkyl group having 1 to 6 carbon atoms which may be substituted with an alkoxy group or an alkoxy group).
(4) “The electrophotographic carrier according to any one of (1) to (3) above, wherein the specific resistance of the particles is 10 ¹² (Ω · cm) or more”, ( 5) “The electrophotographic carrier according to any one of (1) to (4) above, wherein the particles are alumina and / or silica”, (6) “Contains the particles” The electrophotographic carrier according to any one of (1) to (5) above, wherein the amount is 40 to 95 wt% of the composition component of the coating film ”, (7) The electrophotographic carrier according to any one of (1) to (6), wherein the film thickness of the resin is 0.05 μm to 1.00 μm. The resin is a resin obtained by crosslinking at least an acrylic resin and an amino resin or / and The electrophotographic carrier according to any one of (1) to (7), wherein the binder resin contains a corn resin, (9) “Tg of the binder resin is 20 to 20”. The carrier for electrophotography according to any one of the items (1) to (8), wherein the organometallic compound represented by the general formula (1) is 100 ° C. The carrier for electrophotography according to any one of (1) to (9), wherein the carrier is a siloxane compound represented by the following general formula (2):

（式中、Ｒ^４及びＲ^５は、それぞれ独立して、メチル基又はエチル基を示す。Ｒ^６はメチル基、エチル基、メトキシ基及びエトキシ基よりなる群より選ばれた１種の基を示す）」によって解決される。
また、上記課題は、本発明の（１１）「少なくとも、結着樹脂と顔料とからなるトナーと前記第（１）項乃至第（１０）項のいずれかに記載の電子写真用キャリアとからなることを特徴とする電子写真用現像剤」、（１２）「前記トナーが離型剤を含むことを特徴とする前記第（１１）項に記載の電子写真用現像剤」によって解決される。
また、上記課題は、本発明の（１３）「前記第（１１）項又は第（１２）項に記載の電子写真用現像剤を用いることを特徴とする画像形成方法」、（１４）「前記第（１１）項又は第（１２）項に記載の電子写真用現像剤を用いることを特徴とする多色画像形成方法」によって解決される。
また、上記課題は、本発明の（１５）「前記第（１１）項又は第（１２）項に記載の電子写真用現像剤を収納したことを特徴とする現像剤容器」によって解決される。
また、上記課題は、本発明の（１６）「前記第（１５）項に記載の現像剤容器を搭載したことを特徴とする画像形成装置」によって解決される。
また、上記課題は、本発明の（１７）「感光体及び現像手段と、帯電手段、クリーニング手段より選ばれる少なくとも一つの手段とを一体に支持し、画像形成装置本体に着脱自在であるプロセスカートリッジにおいて、前記現像手段は、現像剤を保持し、該現像剤は、前記第（１１）項又は第（１２）項に記載の現像剤であることを特徴とするプロセスカートリッジ」によって解決される。
また、上記課題は、本発明の（１８）「前記第（１７）項に記載のプロセスカートリッジを複数並置した状態で用いる画像形成方法であって、それぞれのプロセスカートリッジに収納せる現像剤の色が異なるものであることを特徴とする多色画像形成方法」によって解決される。

(In the formula, R ⁴ and R ⁵ each independently represent a methyl group or an ethyl group. R ⁶ represents one group selected from the group consisting of a methyl group, an ethyl group, a methoxy group, and an ethoxy group. Is resolved)
In addition, the above-described problem is (11) of the present invention, “consisting of at least a toner composed of a binder resin and a pigment, and the electrophotographic carrier according to any one of the items (1) to (10). The electrophotographic developer ”, (12)“ The electrophotographic developer described in (11) above, wherein the toner contains a release agent ”.
In addition, the above-mentioned problems are solved by (13) “Image forming method using the electrophotographic developer according to (11) or (12)”, (14) “The above”. This is solved by a “multicolor image forming method using the electrophotographic developer according to item (11) or (12)”.
Further, the above-mentioned problems are solved by (15) “Developer container characterized in that the developer for electrophotography according to the above item (11) or (12)” is accommodated.
In addition, the above-described problems are solved by (16) “Image forming apparatus having the developer container described in (15)” mounted thereon.
Further, the above-mentioned problem is (17) “process cartridge which integrally supports at least one means selected from a photoconductor and a developing means and a charging means and a cleaning means and is detachable from an image forming apparatus main body. The developing means holds the developer, and the developer is the developer according to the item (11) or the item (12).
Further, the above-described problem is an image forming method used in a state where a plurality of process cartridges according to (18) “(17) of the present invention are juxtaposed, and the color of the developer stored in each process cartridge is different. It is solved by a “multicolor image forming method characterized by being different”.

  According to the present invention, it is possible to provide a carrier for two-component developer, a developer, an image forming method, a storage container, and an image forming apparatus that are more durable than conventional ones. Further, even in combination with a toner containing a release agent, a highly durable carrier for two-component developer, developer, image forming method, storage container, image forming apparatus, and process cartridge can be provided.

Hereinafter, the present invention will be described in more detail.
As a result of continuous studies to solve the above-described problems of the prior art, the present inventors have determined that the particle diameter (D) and the binder resin in a carrier having a coating film having at least a binder resin and particles. The film thickness (h) is 1 <[D / h] <10, and the particles are surface-treated with one or more organometallic compounds represented by the following general formula (1). Was found to be prominent.

（式中、Ｍは、ＳｉＲ^３、ＴｉＲ^３、Ａｌを示し、Ｒは水素原子又は炭素数１〜６のアルキル基を示し、Ｒ^１及びＲ^２は、各々独立して炭素数１〜６のアルキル基を示し、Ｒ^３は、アルコキシ基で置換されていてもよい全炭素数１〜６のアルキル基又は、アルコキシ基を示す）

(In the formula, M represents SiR ³ , TiR ³ , and Al, R represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R ¹ and R ² each independently represent 1 to 6 carbon atoms. Represents an alkyl group, and R ³ represents an alkyl group having 1 to 6 carbon atoms which may be substituted with an alkoxy group, or an alkoxy group)

  This is because the particles are more convex than the coating film, so the contact with the strong impact on the binder resin is reduced by the friction with the toner or the friction between the carriers by agitation to frictionally charge the developer. Thus, it is possible to prevent the toner from being spent on the carrier, and to prevent the binder resin from being scraped off, which is a charging generation point. However, the convex part, that is, the part of the particle relaxes the contact accompanied by a strong impact on the binder resin, so that the particle itself is always easily detached from the coating film. In order to cope with further high durability, the detachment of the particles must be suppressed. According to the present inventors, the particles can be surface-treated with the above general formula alone or in combination of two or more. Therefore, it is possible to suppress the detachment of the particles. This is because detachment of the particles is suppressed by increasing the adhesion between the particles and the binder resin in the coating film.

  In the case of a toner containing a release agent, the release of the particles is accelerated mainly by the release agent. However, the adhesion between the particles and the binder resin in the coating film has increased. The same effect as in the case of a toner containing a mold is obtained. Further, according to the present inventors, it has been revealed that there is a specific range for the [D / h]. When the [D / h] is 1 or less, since the particles are buried in the binder resin, the effect is remarkably lowered, which is not preferable. Conventionally, when [D / h] is 5 or more, a contact area between the particles and the binder resin is small, so that a sufficient restraining force cannot be obtained, and the particles are easily detached. When the particles are surface-treated with the organometallic compound represented by the general formula (1) alone or in combination of two or more, the adhesion with the binder resin is increased, and even when the particles are 5 or more and less than 10, It was possible to obtain a convex coating film without desorption.

  In the present invention, the “particles” constituting the carrier coat film together with the binder resin include metal powder, metal suboxide, metal oxide, metal hydroxide, inorganic salt, metal chelate compound and other organometallic compounds, carbon Various kinds of particles such as non-metallic element particles such as black, thermosetting resin particles, ceramic particles, and organic pigments may be mentioned, and a mixture of a plurality of these particles may be used. The primary particles have a volume average particle size of 0.2 nm to 200 nm (0.2 μm), preferably 0.3 nm to 150 nm, more preferably 0.3 nm to 120 nm.

Specific examples of R in the general formula (1) include a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a sec-butyl group, and a tert-butyl group. And n-hexyl group can be exemplified, and among these, a hydrogen atom is particularly preferable. R ¹ and R ² are linear or branched alkyl groups having 1 to 6 carbon atoms, and those having 1 to 4 carbon atoms are more preferable from the viewpoint of reactivity with metal oxide particles during surface treatment. A methyl group and an ethyl group are particularly preferable. M is SiR ³ , TiR ³ or Al, and R ³ is an alkyl group having 1 to 6 carbon atoms, an alkoxy group, an alkoxyalkyl group having 2 to 6 carbon atoms, or an alkoxyalkoxy group. Specifically, alkyl groups such as methyl group, ethyl group, n-propyl group, i-propyl group, butyl group, heptyl group and hexyl group; alkoxy groups such as methoxy group, ethoxy group, propoxy group and butoxy group; methoxy Examples thereof include alkoxyalkyl groups such as methyl group, methoxyethyl group, ethoxymethyl group and ethoxyethyl group; alkoxyalkoxy groups such as methoxymethoxy group, methoxyethoxy group, ethoxymethoxy group and ethoxyethoxy group. Of these, a methyl group, an ethyl group, a methoxy group, and an ethoxy group are particularly preferable.

  Of the organometallic compounds represented by the general formula (1), particularly preferred are organosilicon compounds represented by the following general formula (2).

（式中、Ｒ^４；Ｒ^５は各々独立してメチル基又はエチル基を表わし、Ｒ^６はメチル基、エチル基、メトキシ基及びエトキシ基から選ばれる１種の基を示す。）

(In the formula, R ^{4 and} R ⁵ each independently represents a methyl group or an ethyl group, and R ⁶ represents one group selected from a methyl group, an ethyl group, a methoxy group, and an ethoxy group.)

  The surface treatment of the metal oxide with the surface treatment agent can be performed by either a dry method or a wet method. In the case of the dry method, the base metal oxide is charged into a high-speed stirrer such as a Henschel mixer or a super mixer, and the above-mentioned surface treatment solution is dropped or sprayed on the high-speed stirrer while uniformly stirring. After that, it may be added by spraying, stirred uniformly and then dried. In the case of the wet method, the base titanium oxide and the surface treatment agent are added to the solvent, and after dispersion treatment with a bead mill such as a ball mill, a coball mill, a sand grind mill, or a pearl mill, the solvent may be evaporated. In both methods, it is preferable that baking be performed at a temperature of about 100 ° C. to 200 ° C. during or after the treatment to further strengthen the bond between the metal oxide and the surface treatment agent.

  The ratio of the organometallic compound to the particles in the present invention is influenced by the particle size of the particles and the kind of the organometallic compound, but is 0.01 to 100% by weight with respect to the total weight of the surface-treated particles. It is preferable that it is 3 to 50 weight% especially.

  In the present invention, if necessary, the conductive fine particles may be treated in the same manner as the aforementioned particles. This treatment stabilizes the dispersion state of the conductive fine particles in the coat film. In particular, in the case of colored conductive fine particles, it is possible to suppress color stains of the color developer.

  Examples of the conductive particles used in the present invention include metals, alloys thereof, metal oxides, metal and metal oxides deposited on the surfaces of plastic particles, and carbon black. Examples of metals and alloys include aluminum, zinc, copper, chromium, nickel, stainless steel, and silver, and alloys thereof. Examples of metal oxides include zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, and oxide. Examples thereof include bismuth, tin-doped indium oxide, antimony-doped tin oxide, and zirconium oxide. These can be used alone or in combination of two or more. When two or more types are used in combination, they may be simply mixed, or may be in the form of a solid solution or fusion. In the present invention, among the conductive particles as described above, it is particularly preferable to use a metal oxide in terms of transparency. Among these, tin oxide, indium oxide, indium oxide doped with tin, and tin oxide doped with antimony are more preferable.

Any carbon black that is commonly used for carriers or toners can be used. As the acidic catalyst, one having a catalytic action can be used. For example, it has a reactive group such as a fully alkylated type, a methylol group type, an imino group type, and a methylol / imino group type, but is not limited thereto.
Further, the organometallic compound was not only subjected to surface treatment on the particles, but the same effect was obtained when it was contained alone or in combination of two or more in the coating film.
In addition, when these particles were surface-treated and contained in the coat film, the effect was more prominent.
The content of these is desirably 0.01 to 50 parts by weight with respect to 100 parts by weight of the particles. More preferably, it is 0.05 to 40 parts by weight.
A preferable compound as the organometallic compound represented by the general formula (1) includes a compound represented by the formula (2), but is not limited thereto.

In addition, according to the present invention, it is effective that the specific resistance of the particles is 10 ¹² (Ω · cm) or more in order to suppress a decrease in charge amount during storage of the developer over a long period of time. This is because even if the particles are exposed to the surface while having contact with the core material, charge leakage can be suppressed, so that stable chargeability can be obtained. On the other hand, when the specific resistance of the particles is less than 10 ¹² (Ω · cm), charge leakage cannot be suppressed, so that stable chargeability cannot be obtained. In addition, as mentioned in the prior art, this is a technique similar to the present invention, which is different from the one in which conductive particles larger than the coating resin film thickness are contained in the coating film (see Patent Document 10). The invention is characterized in that the particles are not used as a resistance adjusting material as in the prior art, but are used as a protective material for the coating film resin and a surface shape adjusting material. Furthermore, the organometallic compound represented by the general formula (1) is essential for suppressing the detachment of the particles.

  Further, the effect is remarkable when the particles are alumina and the content thereof is in the range of 40 to 95 wt%, preferably 50 to 95 wt%, more preferably 70 to 90 wt% of the coating film composition component. Further, the effect is remarkable when the particles are silica and the content thereof is in the range of 40 to 95 wt%, preferably 50 to 95 wt%, more preferably 70 to 90 wt% of the coating film composition component. A mixture of alumina and silica may also be used. When the content of the particles is less than 40 wt%, since the proportion of the particles occupies less than the proportion of the binder resin on the surface of the carrier particles, the contact with strong impact on the binder resin is reduced. This is not preferable because sufficient durability cannot be obtained. On the other hand, when the amount is more than 95 wt%, the proportion of the particles is too much compared to the proportion of the binder resin on the carrier surface. Insufficient charging ability. In addition, since the amount of particles is too large compared to the amount of binder resin, the ability to hold particles by the binder resin becomes insufficient, and the particles are easily detached, which is not preferable because sufficient durability cannot be obtained. Further, Patent Document 10 similar to the present invention described above is different from the present invention in terms of the content range of particles, and the technique is "0.01 to 50% by weight of the coating resin", that is, the present invention. In terms of the content rate calculation method, it is “0.01 to 33.33 wt% of the coating film composition component”. In this case, the durability is improved as compared with the conventional case. Since the proportion of the particles occupies less than the proportion of the binder resin, the effect of relaxing contact with a strong impact on the binder resin is small, and sufficient durability cannot be obtained.

According to the present invention, the binder resin preferably contains a resin obtained by crosslinking an acrylic resin and an amino resin or / and a silicone resin.
As this amino resin, a conventionally known amino resin can be used. However, the use of guanamine or melamine remarkably improves the charge imparting ability.
Further, as the silicone resin, conventionally known silicone resins can be used.

  In addition to the resins listed here, resins generally used as carrier coating resins can be used, and of course, they may be used in combination with the above resins. For example, polystyrene resin, poly (meth) acrylic resin, polyolefin resin, polyamide resin, polycarbonate resin, polyether resin, polysulfinic acid resin, polyester resin, epoxy resin, polybutyral resin, urea Resins, urethane / urea resins, polyethylene resins, Teflon (registered trademark) resins, and other thermoplastic resins and thermosetting resins, and mixtures thereof, as well as copolymers, block polymers, and graft weights of these resins Examples include, but are not limited to, coalescence and polymer blends.

  According to the present invention, these resins should have a Tg of 20-100 ° C, preferably 25-80 ° C. When the Tg of the resin is within this range, the resin has an appropriate elasticity, and the friction between the toner and the carrier or the friction between the carriers in the stirring for frictionally charging the developer causes the resin to be bonded to the binder resin. In the case of contact with a strong impact, the impact can be absorbed and the coating film can be maintained without being damaged. Moreover, when Tg is less than 20 ° C., the binder resin blocks even at room temperature, which is not preferable because the storage stability is poor and it cannot be used practically. On the other hand, when Tg exceeds 100 ° C., the binder resin is hard and brittle, and the impact cannot be absorbed, and the binder resin is scraped from the brittleness and the particles can be retained. Therefore, it is not preferable because it is easily detached.

  The carrier core material is at least 20 μm (average particle size) from the viewpoint of preventing carrier adhesion (scattering) to the electrostatic latent image carrier, and prevents the generation of carrier streaks etc. From the standpoint of preventing the decrease, the one having a maximum of 100 μm is used. Specific materials that are known as two-component carriers for electrophotography, such as ferrite, magnetite, iron, nickel, etc., may be appropriately selected according to the use and purpose of use of the carrier.

  The carrier of the present invention is used as a two-component developer composed of toner, but the composed toner may be black toner or multicolor toner used in the multicolor image forming method.

The image forming apparatus of the present invention will be described below with reference to the drawings.
FIG. 1 shows an example of an image forming apparatus in which a container filled with a developer using the electrophotographic carrier of the present invention is mounted, and a developing section (within a main body of the image forming apparatus) 1), a developer storage container (2) filled with a developer using the electrophotographic carrier of the present invention replenished to the developing section (1), and a developer feed means (3) for connecting the two. FIG.

  In FIG. 1, the developing section (1) is a development filled with a developer using the electrophotographic carrier of the present invention containing a liquid two-component developer (D) formed by mixing a toner and a carrier. The developing roller (7) includes a housing (4), first and second stirring screws (5) and (6) for stirring and mixing the developer (D), and a developing roller (7). Is disposed to face the photosensitive member (8) of the latent image carrier. The photoconductor (8) is rotationally driven in the direction indicated by the arrow, and an electrostatic latent image is formed on the surface thereof. In the drawing, reference numeral (126) denotes a cap fitted on the connecting member (124) with or without the filter (125). Around the photosensitive member (8), other well-known units such as a charging unit, an exposure unit, a transfer unit, a charge removing unit, and a cleaning unit (not shown) are arranged.

  As the first and second agitating screws (5) and (6) rotate, the developer (D) in the developing housing (4) is agitated, and the toner is triboelectrically charged with opposite polarity to the carrier. . The developer (D) is supplied to the peripheral surface of the developing roller (7) that is rotationally driven in the direction of the arrow, and the supplied developer is carried on the peripheral surface of the developing roller (7). It is conveyed in the rotation direction by the rotation of 7). Next, the amount of the conveyed developer is regulated by the doctor blade (9), and the regulated developer is conveyed to the development area between the photosensitive member (8) and the developing roller (7), where The toner in the developer is electrostatically transferred to the electrostatic latent image on the surface of the photoreceptor, and the electrostatic latent image is visualized as a toner image.

Still another embodiment in which the image forming method of the present invention is carried out by another example of the image forming apparatus of the present invention (for example, the image forming apparatus shown in FIGS. 2 to 5) will be described with reference to FIG.
The image forming apparatus (100) of the example shown in FIG. 2 includes a photosensitive drum (10) as an electrostatic latent image carrier (hereinafter referred to as “photosensitive member 10”), a roller-shaped charging unit (20), and an exposure unit. (30), a developing means (40), an intermediate transfer member (50), a cleaning means (60) having a cleaning blade, and a static elimination lamp as a static elimination means (70).

  The intermediate transfer member (50) is an endless belt, and is designed to be movable in the direction of the arrow by three rollers (51) that are arranged on the inner side and stretch the belt. A part of the three rollers (51) also functions as a transfer bias roller capable of applying a predetermined transfer bias (primary transfer bias) to the intermediate transfer member (50). A cleaning means (90) having a cleaning blade is disposed in the vicinity of the intermediate transfer member (50), and a developed image (image-forming particle image) is transferred to a transfer paper (95) as a final transfer material. Transfer rollers as transfer means (80) to which a transfer bias for (secondary transfer) can be applied are arranged to face each other. Around the intermediate transfer member (50), there is a corona charger (58) for applying a charge to the image-forming particle image on the intermediate transfer member (50) in the rotational direction of the intermediate transfer member (50). It is arranged between the contact portion between the photoconductor (10) and the intermediate transfer member (50) and the contact portion between the intermediate transfer member (50) and the transfer paper (95).

  The developing means (40) includes a developing belt (41) as a developer carrier, a black developing means (unit) (45K) provided around the developing belt (41), a yellow developing means (unit) (45Y), It is composed of a magenta developing means (unit) (45M) and a cyan developing means (unit) (45C). The black developing means (45K) includes a developer accommodating portion (42K), a developer supply roller (43K), and a developing roller (44K). The yellow developing means (45Y) is provided with a developer accommodating portion ( 42Y), a developer supply roller (43Y), and a development roller (44Y). The magenta developing means (45M) includes a developer accommodating portion (42M), a developer supply roller (43M), and a development roller (44M). The cyan developing means (45C) includes a developer container (42C), a developer supply roller (43C), and a developing roller 44C. Further, the developing belt 41 is an endless belt, is rotatably stretched around a plurality of belt rollers, and a part thereof is in contact with the photoreceptor (10).

  In the image forming apparatus (100) shown in FIG. 2, for example, the charging means (20) charges the photosensitive drum 10 uniformly. The exposure means (30) exposes the photosensitive drum (10) imagewise to form an electrostatic latent image. The electrostatic latent image formed on the photosensitive drum (10) is developed by supplying image forming particles from the developing means (40) to form a visible image (image forming particle image). The visible image (image-forming particle image) is transferred (primary transfer) onto the intermediate transfer body (50) by the voltage applied from the roller (51), and further transferred onto the transfer paper (95) (secondary transfer). ) As a result, a transfer image is formed on the transfer paper (95). The residual image forming particles on the photoreceptor (10) are removed by the cleaning means (60), and the charge on the photoreceptor (10) is once removed by the charge eliminating means (charge eliminating lamp) (70).

  Another mode for carrying out the image forming method of the present invention by the image forming apparatus of the present invention will be described with reference to FIG. The image forming apparatus (100) shown in FIG. 3 does not include the developing belt (41) in the image forming apparatus (100) shown in FIG. 2, and a black developing means (developing unit) (developing unit) ( 45K), the yellow developing means (developing unit) (45Y), the magenta developing means (developing unit) (45M) and the cyan developing means (developing unit) (45C) are arranged directly opposite to each other, as shown in FIG. The image forming apparatus (100) shown in FIG. In FIG. 3, the same components as those in FIG. 2 are denoted by the same reference numerals.

Still another embodiment for carrying out the image forming method of the present invention by the image forming apparatus of the present invention will be described with reference to FIG. The tandem image forming apparatus (120) shown in FIG. 4 is a tandem color image forming apparatus. The tandem image forming apparatus (120) includes a copying apparatus main body (150), a paper feed table (200), a scanner (300), and an automatic document feeder (ADF) (400). The copying machine main body (150) is provided with an endless belt-like intermediate transfer member (50) at the center. The intermediate transfer member (50) is stretched around the support rollers (14), (15) and (16), and can rotate clockwise in FIG. An intermediate transfer body cleaning device (17) for removing residual image forming particles on the intermediate transfer body (50) is disposed in the vicinity of the support roller (15). The intermediate transfer member (50) stretched between the support roller (14) and the support roller (15) has four image forming units (18) of yellow, cyan, magenta, and black along the conveyance direction. A tandem developing means (120) arranged opposite to each other is arranged. An exposure means (21) is disposed in the vicinity of the tandem developing means (120). A secondary transfer unit (22) is disposed on the side of the intermediate transfer member (50) opposite to the side on which the tandem type developing unit (120) is disposed. In the secondary transfer means (22), a secondary transfer belt (24), which is an endless belt, is stretched between a pair of rollers (23), and a transfer sheet conveyed on the secondary transfer belt (24); The intermediate transfer member (50) can contact each other. A fixing means (25) is disposed in the vicinity of the secondary transfer means (22). The fixing means (25) includes a fixing belt (26) that is an endless belt, and a pressure roller (27) that is pressed against the fixing belt (26).
In the tandem image forming apparatus (120), a sheet reversal is performed in the vicinity of the secondary transfer unit (22) and the fixing unit (25) for reversing the transfer paper in order to form an image on both sides of the transfer paper. A device (28) is arranged.

  Next, full color image formation (color copying) using the tandem developing means (120) will be described. That is, first, a document is set on the document table (130) of the automatic document feeder (ADF) (400) or the automatic document feeder (400) is opened and the contact glass (32) of the scanner (300) is opened. A document is set on the document and the automatic document feeder (400) is closed.

  When a start switch (not shown) is pressed, when a document is set on the automatic document feeder (400), the document is transported and moved onto the contact glass (32). ) Immediately after the document is set on the scanner (300), the first traveling body (33) and the second traveling body (34) travel. At this time, light from the light source is irradiated by the first traveling body (33) and reflected light from the document surface is reflected by the mirror in the second traveling body (34), and is read through the imaging lens (35). The color original (color image) is read at (36), and is read as black, yellow, magenta and cyan image information.

  Each image information of black, yellow, magenta and cyan is stored in each image forming means (18) (black image forming means, yellow image forming means, magenta image forming means and cyan) in the tandem developing means (120). Image forming means), and image forming particle images of black, yellow, magenta and cyan are formed in each image forming means. That is, each image forming means (18) (black image forming means, yellow image forming means, magenta image forming means and cyan image forming means) in the tandem developing means (120) is partially enlarged in FIG. As shown in FIG. 5, which is a schematic diagram, the photoreceptor (10) (the photoreceptor for black (10K), the photoreceptor for yellow (10Y), the photoreceptor for magenta (10M), and the photoreceptor for cyan (10C), respectively. ), A charging means (59) for uniformly charging the photoconductor, and exposing the photoconductor to each color image corresponding image based on each color image information (L in FIG. 5). Exposure means for forming an electrostatic latent image corresponding to each color image on the surface, and each color developer (black developer, yellow developer, magenta developer and cyan developer) of the present invention on the electrostatic latent image. Use and develop each A developing means (61) for forming a toner image with a developer, a transfer charger (62) for transferring the developed toner image onto the intermediate transfer body (50), and a photoreceptor cleaning means (63). And a static eliminator (64), and each monochrome image (black image, yellow image, magenta image, and cyan image) can be formed based on the image information of each color. The black image, the yellow image, the magenta image, and the cyan image formed in this way are transferred onto the intermediate transfer member (50) that is rotationally moved by the support rollers (14), (15), and (16) in FIG. The black image formed on the black photoconductor (10K), the yellow image formed on the yellow photoconductor (10Y), the magenta image formed on the magenta photoconductor (10M), and the cyan photoconductor, respectively. The cyan image formed on the body (10C) is sequentially transferred (primary transfer). Then, the black image, the yellow image, the magenta image, and the cyan image are superimposed on the intermediate transfer member (50) to form a composite color image (color transfer image).

On the other hand, in the paper feed table (200), one of the paper feed rollers (142) is selectively rotated so that the sheet (recording paper) is fed from one of the paper feed cassettes (144) provided in the paper bank (143). ), Separated one by one by the separation roller (145), sent to the paper feed path (146), and conveyed by the conveyance roller (147) to the paper feed path (148) in the copier body (150). Guide and stop against the registration roller (49). Alternatively, the sheet feed roller (142) is rotated to feed out the sheets (recording paper) on the manual feed tray (54), separated one by one by the separation roller (52), and put into the manual feed path (53). Stop against the registration roller (49). The registration roller (49) is generally used while being grounded, but may be used in a state where a bias is applied to remove paper dust from the sheet.
Then, the registration roller (49) is rotated in synchronism with the synthesized color image (color transfer image) in which the respective toners are synthesized on the intermediate transfer member (50), and the intermediate transfer member (50) and the secondary transfer means ( 22), a sheet (recording paper) is sent to the sheet (recording paper), and the composite color image (color transfer image) is transferred (secondary transfer) onto the sheet (recording paper) by the secondary transfer means (22). A color image is transferred and formed on the sheet (recording paper). The residual toner on the intermediate transfer member (50) after the image transfer is cleaned by the intermediate transfer member cleaning device (17).

  The sheet (recording paper) on which the color image has been transferred is transported by the secondary transfer means (22) and sent to the fixing means (25). The fixing means (25) generates heat and pressure. The composite color image (color transfer image) is fixed on the sheet (recording paper). Thereafter, the sheet (recording paper) is switched by the switching claw (55) and discharged by the discharge roller (56) and stacked on the discharge tray (57), or switched by the switching claw (55) and the sheet is reversed. The image is reversed by the device (28) and guided again to the transfer position, and an image is recorded also on the back surface. Then, the image is discharged by the discharge roller (56) and stacked on the discharge tray (57).

  FIG. 6 specifically shows a schematic diagram of an image forming apparatus equipped with the process cartridge of the present invention.

The process cartridge of the present invention uses the developer of the present invention, and a photoreceptor and developing means,
And a process cartridge that integrally supports at least one unit selected from a charging unit and a cleaning unit and is detachable from the main body of the image forming apparatus.
FIG. 6 shows a schematic configuration of an image forming apparatus having the process cartridge of the present invention.
In the figure, (101) indicates the entire process cartridge, (10) indicates a photosensitive member, (20) indicates a charging unit, (40) indicates a developing unit, and (60) indicates a cleaning unit.
In the present invention, a plurality of components such as the photosensitive member (10), the charging unit (20), the developing unit (40), and the cleaning unit (60) are integrally combined as a process cartridge. The process cartridge is configured to be detachable from an image forming apparatus main body such as a copying machine or a printer.

  In the image forming apparatus having the process cartridge of the present invention, the photosensitive member is rotationally driven at a predetermined peripheral speed. In the rotation process, the photosensitive member is uniformly charged with a positive or negative predetermined potential on its peripheral surface by the charging unit, and then receives image exposure light from an image exposing unit such as slit exposure or laser beam scanning exposure. An electrostatic latent image is sequentially formed on the peripheral surface of the body, and the formed electrostatic latent image is then developed with toner by a developing unit, and the developed toner image is transferred between the photosensitive member and the transfer unit from the paper feeding unit. Then, the image is sequentially transferred to the transfer material fed in synchronization with the rotation of the photosensitive member by the transfer means. The transfer material that has received the image transfer is separated from the surface of the photosensitive member, introduced into the image fixing means, and fixed on the image, and printed out as a copy (copy). The surface of the photoconductor after the image transfer is cleaned by removing toner remaining after transfer by a cleaning unit, and after being further neutralized, it is repeatedly used for image formation.

EXAMPLES Next, although an Example and a comparative example are given and this invention is demonstrated further more concretely, this invention is not limited to these.
Toner production example 1
<Toner Production Example 1>
Black toner 1
Water 1200 parts Phthalocyanine green water-containing cake (solid content 30%) 200 parts Carbon black (MA60, manufactured by Mitsubishi Chemical Corporation) 540 parts is thoroughly stirred with a flasher. To this, 1200 parts of epoxy resin (Mn; 3500) was added, kneaded at 150 ° C. for 30 minutes, 1000 parts of xylene were added, kneaded for 1 hour, water and xylene were removed, rolled and cooled, pulverized with a pulverizer, master batch pigment Got.
Epoxy resin (Mn; 3500) 100 parts Master batch 5 parts Zinc salicylate derivative 4 parts (Bontron E84, Orient Chemical)
The above materials were mixed with a mixer and then melt-kneaded with a two-roll mill, and the kneaded product was rolled and cooled. Thereafter, pulverization and classification were performed to obtain a toner having a weight average particle diameter of 7.8 μm. Further, as in the case of the yellow toner 1, additives were added and mixed with a Henschel mixer to obtain a black toner 1.

<Toner Production Example 2>
Black toner 2
Except for adding 5 parts of carnauba wax to Toner Production Example 1, all were produced in the same manner as in Production Example 1.

<Surface treatment particle production example 1>
Alumina particles 1
100 parts by weight of alumina (0.3 μm, specific resistance 10 ¹⁴ Ω · cm) particles were added to a solution consisting of 10 parts by weight of methyldimethoxysilane (product of TOSHIBA Silicone Co., TSL8117) and 300 parts by weight of methanol, followed by stirring for 2 hours. After removing the solvent by filtration, drying was performed at 140 ° C. for 2 hours to obtain alumina particles 1 surface-treated with methyldimethoxysilane.

<Carrier production example 1>
Career 1
Acrylic resin solution (solid content 50% by weight) 80 parts Guanamin solution (solid content 77% by weight) 25 parts Alumina particles 1 230 parts Toluene 1300 parts Butyl cellosolve 1300 parts are dispersed with a homomixer for 10 minutes to prepare a coating film forming solution did. A sintered ferrite powder [Mn ferrite: average particle size: 35 μm (manufactured by Powdertech Co., Ltd.)] is used as a core material, and the above-mentioned coating film forming solution is spiral coater (Okada Seiko Co., Ltd.) so that the film thickness is 0.15 μm on the core material surface. Applied and dried. The obtained carrier was baked in an electric furnace at 300 ° C. for 2 hours. After cooling, the ferrite powder bulk was pulverized using a sieve having an opening of 100 μm, and carrier 1 was obtained. The measurement of the binder resin film thickness was performed by observing the cross section of the carrier with a transmission electron microscope so that the coating film covering the carrier surface could be observed.

<Carrier production example 2>
Career 2
Acrylic resin solution (solid content 50% by weight) 80 parts Guanamin solution (solid content 77% by weight) 25 parts Alumina particles (0.3 μm, specific resistance 10 ¹⁴ Ω · cm) 230 parts Methyldimethoxysilane (Toshiba Silicone Corporation product, TSL8117) ) 1 part Toluene 1300 parts Butyl cellosolve 1300 parts All were produced in the same manner as in Carrier Production Example 1 except that the above formulation was changed.

<Carrier Production Example 3>
Career 3
All were produced in the same manner as in Production Example 2 except that the alumina particles described in Carrier Production Example 2 were changed to the surface-treated alumina particles described in Carrier Production Example 1.

<Carrier Production Example 4>
Carrier 4
Acrylic resin solution (solid content 50% by weight) 80 parts Guanamin solution (solid content 77% by weight) 25 parts Alumina particles (0.3 μm, specific resistance 10 ¹⁴ Ω · cm) 230 parts Toluene 1300 parts Butyl cellosolve 1300 parts Except for the changes, all were manufactured in the same manner as in Carrier Production Example 1.

<Example 1>
The carrier 1 and the black toner 1 thus obtained were placed in a ball mill and mixed for 10 minutes so that the toner concentration would be 7% to obtain a developer. This developer and black toner 1 were set in a commercially available digital full-color copying machine (imageColor 2800 manufactured by Ricoh Co., Ltd.), and 1,000,000 sheets were evaluated for running. Table 2 shows the results of determining the charge reduction amount and resistance reduction amount of the carrier after the running.

  The amount of charge reduction referred to here is a general blow-off method [TB-: manufactured by Toshiba Chemical Co., Ltd.] by mixing a frictionally charged sample by mixing 7% by weight of toner with 95% by weight of the initial carrier. 200] is subtracted from the charge amount (Q2) measured by the same method as described above, from the carrier from which the toner in the developer after running has been removed by the blow-off device. The target value is 7.0 (μc / g) or less. Further, since the cause of the decrease in the charge amount is the toner spent on the carrier surface, the decrease in the charge amount can be suppressed by reducing the toner spent. The amount of decrease in resistance is a value obtained by converting an initial carrier into a resistance measurement parallel electrode: an electrode having a gap of 2 mm, applying a DC 200V, and measuring a resistance value after 30 seconds with a high resist meter into a volume resistivity ( R1) is the amount obtained by subtracting the value (R2) measured by the same method as the resistance measuring method from the carrier that can remove the toner in the developer after running by the blow-off device. The value is 2.0 [Log (Ω · cm)] or less. In addition, since the cause of the resistance reduction is scraping of the binder resin film of the carrier, the resistance reduction amount can be suppressed by reducing the film scraping.

<Example 2>
Evaluations were made in the same manner as in Example 1 except that the black toner 1 of Example 1 was changed to black toner 2. The evaluation results are shown in Table 2.

<Example 3>
Evaluations were made in the same manner as in Example 2 except that carrier 1 in Example 2 was changed to carrier 2. The evaluation results are shown in Table 2.

<Example 4>
Evaluations were made in the same manner as in Example 2 except that the carrier 1 in Example 2 was changed to the carrier 3. The evaluation results are shown in Table 2.

<Comparative Example 1>
Evaluations were made in the same manner as in Example 1 except that the carrier 1 in Example 1 was changed to the carrier 4. The evaluation results are shown in Table 2.

<Comparative example 2>
Evaluations were made in the same manner as in Example 1 except that the carrier 2 in Example 2 was changed to the carrier 4. The evaluation results are shown in Table 2.

  From the table, by using the carrier of the present invention, an effect more than doubled compared with the conventional durability was obtained. Further, in the combination with the toner containing the release agent, the effect of 6 times or more was obtained as compared with the conventional result.

FIG. 2 is a diagram illustrating a developer container filled with the electrophotographic developer of the present invention and an example of an image forming apparatus equipped with the container. It is the schematic which shows another example of the image forming apparatus which enforces the image forming method of this invention. It is the schematic which shows the further another example of the image forming apparatus which enforces the image forming method of this invention. It is the schematic which shows an example of the further another image forming apparatus (tandem type color image forming apparatus) for enforcing the image forming method of this invention. FIG. 5 is a partially enlarged schematic view of the image forming apparatus shown in FIG. 4. It is the schematic of the process cartridge of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Developing part 2 Developer storage container 3 Developer supply means 4 Developing housing 5 Stirring screw 6 Stirring screw 7 Developing roller 8 Photoconductor 9 Doctor blade 10 Photoconductor (photosensitive drum)
10K black photoconductor 10Y yellow photoconductor 10M magenta photoconductor 10C cyan photoconductor 14 support roller 15 support roller 16 support roller 17 intermediate transfer cleaning device 18 image forming means 20 roller charging means 21 exposure means 22 secondary transfer means 23 Roller 24 Secondary transfer belt 25 Fixing means 26 Fixing belt 27 Pressure belt 28 Sheet reversing device 30 Exposure means 32 Contact glass 33 First traveling body 34 Second traveling body 35 Imaging lens 36 Reading sensor 40 Developing means 41 Developing belt 42K developer container 42Y developer container 42M developer container 42C developer container 43K developer supply roller 43Y developer supply roller 43M developer supply roller 43C developer supply roller 44K developer roller 44Y developer roller 44M Developing roller 44C Developing roller 45K Black developing means (developing unit)
45Y yellow development means (development unit)
45M Magenta development means (development unit)
45C Cyan development means (development unit)
49 Registration roller 50 Intermediate transfer member 51 Roller 52 Separation roller 53 Manual feed path 54 Manual feed tray 55 Switching claw 56 Discharge roller 57 Discharge tray 58 Corona charger 59 Charging means 60 Cleaning means 61 Developing means 62 Transfer charger 63 Photoconductor cleaning Means 64 Static eliminator 70 Static elimination means (static elimination lamp)
80 Transfer roller 90 Cleaning means 95 Transfer paper 100 Image forming apparatus 101 Process cartridge 110 Belt type fixing device 120 Tandem type developing means 124 Connection member 125 Filter 126 Cap 130 Document table 142 Paper feed roller 143 Paper bank 144 Paper feed cassette 145 Separating roller 146 Feeding path 147 Conveying roller 148 Feeding path 150 Copier main body 200 Feeding table 300 Scanner 400 Automatic document feeder (ADF)

Claims (18)

In a carrier having a coat film composed of at least a binder resin and particles, the particle diameter (D) of the particles and the film thickness (h) of the binder resin are 1 <[D / h] <10, and the particles An electrophotographic carrier characterized in that it is surface-treated with one or more organometallic compounds represented by the following general formula (1).

(In the formula, M represents SiR ³ , TiR ³ , and Al, R represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R ¹ and R ² each independently represent 1 to 6 carbon atoms. Represents an alkyl group, and R ³ represents an alkyl group having 1 to 6 carbon atoms which may be substituted with an alkoxy group, or an alkoxy group) In a carrier having a coating film composed of at least a binder resin and particles, the particle diameter (D) of the particles and the film thickness (h) of the binder resin are 1 <[D / h] <10. Contains an organometallic compound represented by the following general formula (1) alone or in combination of two or more thereof.

(In the formula, M represents SiR ³ , TiR ³ , and Al, R represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R ¹ and R ² each independently represent 1 to 6 carbon atoms. Represents an alkyl group, and R ³ represents an alkyl group having 1 to 6 carbon atoms which may be substituted with an alkoxy group, or an alkoxy group) In a carrier having a coat film composed of at least a binder resin and particles, the particle diameter (D) of the particles and the film thickness (h) of the binder resin are 1 <[D / h] <10, and the particles It is surface-treated with one or more organometallic compounds represented by the following general formula (1), and the coating film contains one or more organometallic compounds represented by the general formula (1). A characteristic carrier for electrophotography.

(In the formula, M represents SiR ³ , TiR ³ , and Al, R represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R ¹ and R ² each independently represent 1 to 6 carbon atoms. Represents an alkyl group, and R ³ represents an alkyl group having 1 to 6 carbon atoms which may be substituted with an alkoxy group, or an alkoxy group) The carrier for electrophotography according to any one of claims 1 to 3, wherein the specific resistance of the particles is 10 ¹² (Ω · cm) or more. The electrophotographic carrier according to claim 1, wherein the particles are alumina and / or silica. The electrophotographic carrier according to claim 1, wherein the content of the particles is 40 to 95 wt% of the composition component of the coat film. The electrophotographic carrier according to claim 1, wherein the binder resin has a thickness of 0.05 μm to 1.00 μm. The electrophotographic carrier according to any one of claims 1 to 7, wherein the binder resin contains at least a resin obtained by cross-linking an acrylic resin and an amino resin or / and a silicone resin. The carrier for electrophotography according to any one of claims 1 to 8, wherein Tg of the binder resin is 20 to 100 ° C. The electrophotographic carrier according to claim 1, wherein the organometallic compound represented by the general formula (1) is a siloxane compound represented by the following general formula (2).

(In the formula, R ⁴ and R ⁵ each independently represent a methyl group or an ethyl group. R ⁶ represents one group selected from the group consisting of a methyl group, an ethyl group, a methoxy group, and an ethoxy group. Show) An electrophotographic developer comprising at least a toner comprising a binder resin and a pigment and the electrophotographic carrier according to claim 1. 12. The electrophotographic developer according to claim 11, wherein the toner contains a release agent. 13. An image forming method using the electrophotographic developer according to claim 11 or 12. A multicolor image forming method using the electrophotographic developer according to claim 11. 13. A developer container containing the electrophotographic developer according to claim 11 or 12. An image forming apparatus comprising the developer container according to claim 15. In a process cartridge that integrally supports a photosensitive member and a developing unit, and at least one unit selected from a charging unit and a cleaning unit, and is detachable from the image forming apparatus main body, the developing unit holds a developer, The process cartridge according to claim 11 or 12, wherein the developer is the developer according to claim 11 or 12. An image forming method for use in a state where a plurality of process cartridges according to claim 17 are juxtaposed, wherein the developer colors stored in the respective process cartridges are different.

Images