JPH086307A - Electrophotographic carrier, manufacture thereof, and electrophotographic electrification imparting member - Google Patents

Electrophotographic carrier, manufacture thereof, and electrophotographic electrification imparting member

Info

Publication number
JPH086307A
JPH086307A JP6134235A JP13423594A JPH086307A JP H086307 A JPH086307 A JP H086307A JP 6134235 A JP6134235 A JP 6134235A JP 13423594 A JP13423594 A JP 13423594A JP H086307 A JPH086307 A JP H086307A
Authority
JP
Japan
Prior art keywords
resin
carrier
electrophotographic
manufacture
parts
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP6134235A
Other languages
Japanese (ja)
Inventor
Ikutaro Nagatsuka
育太郎 長束
Manabu Serizawa
学 芹澤
Sakon Takahashi
左近 高橋
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Fujifilm Business Innovation Corp
Original Assignee
Fuji Xerox Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Fuji Xerox Co Ltd filed Critical Fuji Xerox Co Ltd
Priority to JP6134235A priority Critical patent/JPH086307A/en
Publication of JPH086307A publication Critical patent/JPH086307A/en
Pending legal-status Critical Current

Links

Landscapes

  • Magnetic Brush Developing In Electrophotography (AREA)
  • Dry Development In Electrophotography (AREA)
  • Developing Agents For Electrophotography (AREA)

Abstract

PURPOSE:To manufacture an electrophotographic carrier improving the electrification maintenance property, environmental stability, and image quality maintenance property, capable of obtaining the excellent image quality having no density irregularity on an image and no blot on a background, and uniformly and efficiently applied on the surface of a core material and manufacture an electrification imparting member. CONSTITUTION:This coating layer is a thermosetting resin constituted of a condensate made of a guanamine resin of 40wt.% or above, e.g. guanamines, formaldehyde, and alcohols, and the second resin having the functional group capable of being reacted and cross-linked with the guanamine resin. The coating layer is baked, heated to the hardening temperature or above, and hardened on a core material to manufacture an electrophotographic carrier. The core material is coated with a coating resin to manufacture an electrophotographic electrification imparting member.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明は、電子写真法、静電記録
法等により形成される静電荷像を二成分現像剤で現像す
るときに用いる電子写真用キャリア及びその製造方法並
びに電子写真用帯電付与部材に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic carrier used for developing an electrostatic charge image formed by an electrophotographic method, an electrostatic recording method or the like with a two-component developer, a method for producing the same and an electrophotographic carrier. The present invention relates to a charging member.

【0002】[0002]

【従来の技術】電子写真法など静電荷像を経て画像情報
を可視化する方法は、現在様々な分野で利用されてい
る。電子写真法では、帯電、露光工程で感光体上に静電
潜像を形成し、トナーを含む現像剤で静電潜像を現像
し、転写、定着工程を経て可視化される。ここで用いる
現像剤は、トナーとキャリアからなる二成分現像剤と、
磁性トナーなどのように単独で用いる一成分現像剤があ
るが、二成分現像剤は、キャリアが現像剤の攪拌、搬
送、帯電などの機能を分担し、現像剤として機能分離が
なされているため、制御性がよいなどの理由で現在広く
用いられている。特に、樹脂被覆キャリアを用いる現像
剤は、帯電制御性が優れ、環境依存性並びに経時安定性
の改善が比較的容易である。また、現像方法としては、
古くはカスケード法などが用いられてきたが、現在は現
像剤搬送担体として磁気ロールを用いる磁気ブラシ法が
主流である。
2. Description of the Related Art A method of visualizing image information through an electrostatic charge image such as an electrophotographic method is currently used in various fields. In the electrophotographic method, an electrostatic latent image is formed on a photoconductor in the charging and exposing steps, the electrostatic latent image is developed with a developer containing toner, and the image is visualized through transfer and fixing steps. The developer used here is a two-component developer consisting of toner and carrier,
There is a one-component developer that can be used alone, such as magnetic toner, but in a two-component developer, the carrier shares functions such as stirring, carrying, and charging of the developer, and the functions are separated as the developer. Currently, it is widely used because of its good controllability. In particular, a developer using a resin-coated carrier has excellent charge controllability, and it is relatively easy to improve environmental dependency and temporal stability. As a developing method,
Although the cascade method and the like have been used for a long time, the magnetic brush method using a magnetic roll as a developer carrying carrier is now the mainstream.

【0003】二成分現像剤を用いる磁気ブラシ法には、
現像剤の帯電劣化による画像濃度の低下、著しい背景部
汚れの発生、画像へのキャリアの付着による画像の荒
れ、キャリアの消費、及び、画像濃度ムラの発生などの
問題がある。現像剤の帯電劣化は、キャリアコート層へ
のトナー成分の固着又はコートの剥がれなどにより発生
し易く、また、コート層が不均一になると、湿度、温度
などの環境変動時、トナー追加時及び高トナー濃度時に
背景部汚れ等を発生する傾向がある。
In the magnetic brush method using a two-component developer,
There are problems such as a reduction in image density due to charge deterioration of the developer, occurrence of remarkable background stain, image roughness due to carrier adhesion to the image, carrier consumption, and image density unevenness. The charge deterioration of the developer is apt to occur due to the adhesion of the toner component to the carrier coat layer or the peeling of the coat. When the toner concentration is high, background stains tend to occur.

【0004】これらの帯電劣化を防止するため、被覆樹
脂の硬度を挙げて剥がれ難くしたり、被覆樹脂の表面エ
ネルギーを下げることにより、キャリアコート層へのト
ナー成分の固着を防止したり、これらの方法を併用して
帯電劣化を防止する努力がなされてきた。
In order to prevent these charge deteriorations, the hardness of the coating resin should be raised to prevent peeling, or the surface energy of the coating resin should be lowered to prevent the toner components from sticking to the carrier coat layer. Efforts have been made to prevent charging deterioration by combining the methods.

【0005】例えば、芯物質への接着性及び被覆強度を
高め、キャリアの流動性、耐湿性、トナーとの分離性を
改善する目的で、未反応のヒドロキシル基を有する熱可
塑性樹脂とアルコキシ化メラミン樹脂とを硬化させた樹
脂成分で芯物質を被覆したキャリア(特開昭62─26
2057号公報参照)、耐久性、耐環境性を改善する目
的で、アクリル樹脂とメラミン樹脂を架橋した樹脂で芯
物質を被覆したキャリア(特開平2─79862号公報
参照)、耐久性、耐熱性及び耐環境性を改善する目的
で、メラミンホルムアルデヒド樹脂組成物で架橋したア
クリル樹脂で芯物質を被覆したキャリア(特開平5─2
16281号公報参照)などが提案されているが、メラ
ミン樹脂を含有するキャリアは高温高湿時の帯電低下が
大きいという問題があった。
For example, a thermoplastic resin having an unreacted hydroxyl group and an alkoxylated melamine are used for the purpose of enhancing adhesion to a core substance and coating strength, and improving fluidity of carrier, moisture resistance and separability from toner. A carrier in which a core substance is coated with a resin component obtained by curing a resin (JP-A-62-26).
2057), a carrier in which a core substance is coated with a resin obtained by crosslinking an acrylic resin and a melamine resin for the purpose of improving durability and environment resistance (see JP-A-2-79862), durability and heat resistance. And a carrier in which a core substance is coated with an acrylic resin cross-linked with a melamine-formaldehyde resin composition for the purpose of improving environmental resistance (JP-A-5-252).
However, there is a problem that a carrier containing a melamine resin causes a large decrease in charge at high temperature and high humidity.

【0006】また、摩擦帯電電荷の付与能力を改善する
目的で、グアナミン、グアナミン誘導体又はグアナミン
系縮合物を、被覆樹脂100重量部に対して0.1〜2
0重量部含有する被覆樹脂で芯物質を被覆するキャリア
が提案された(特開昭60─201360号公報参照)
が、長期にわたって充分な帯電量を維持することができ
なかった。
For the purpose of improving the triboelectric charge imparting ability, 0.1 to 2 parts of guanamine, a guanamine derivative or a guanamine-based condensate are added to 100 parts by weight of the coating resin.
A carrier in which a core substance is coated with a coating resin containing 0 part by weight has been proposed (see Japanese Patent Laid-Open No. 60-201360).
However, it was not possible to maintain a sufficient charge amount for a long period of time.

【0007】他方、芯物質表面に均一で堅固な被膜を形
成するコーティング方法として、被覆樹脂と芯物質を乾
燥状態で混合した後、被覆樹脂を溶融して被膜を形成す
る方法が提案されているが、最近における画質向上のた
めのトナー粒子の小径化、トナー材料の低融点化などを
考慮すると、上記の方法も必ずしも充分な効果を有して
いるとは直ちに言えない。
On the other hand, as a coating method for forming a uniform and firm coating on the surface of the core substance, a method has been proposed in which the coating resin and the core substance are mixed in a dry state and then the coating resin is melted to form a coating. However, in view of the recent decrease in the diameter of toner particles for improving the image quality and the lowering of the melting point of toner materials, it cannot be immediately said that the above method also has a sufficient effect.

【0008】[0008]

【発明が解決しようとする課題】そこで、本発明は、上
記の欠点を解消し、以下の特徴を備えた電子写真用キャ
リア及びその製造方法、並びに電子写真用帯電付与部材
を提供しようとするものである。 (1) 環境変動などによる帯電性変化に対する画質維持性
を改善すること。 (2) トナー追加時の背景部汚れを改善するとともに、現
像剤、帯電付与部材の寿命を延長すること。 (3) キャリア付着を防止して安定した高い画質を確保す
るとともに、キャリアの消費を抑制すること。 (4) 長期間使用しても、被覆層が剥がれないこと。 (5) 黒ベタ及び細線再現性に優れた画質を提供できる静
電荷像現像用正帯電キャリア及び正帯電付与部材を提供
すること。 (6) 上記キャリアを効率的に製造する方法を提供するこ
と。
SUMMARY OF THE INVENTION Therefore, the present invention is intended to solve the above-mentioned drawbacks and provide an electrophotographic carrier and a method for producing the same, and an electrophotographic charge imparting member having the following features. Is. (1) To improve the image maintainability against changes in charging property due to environmental changes. (2) To improve the background stain when adding toner and extend the life of the developer and the charging member. (3) To prevent the carrier from adhering to ensure stable and high image quality and to suppress the consumption of the carrier. (4) The coating layer should not peel off even after long-term use. (5) To provide a positive charge carrier and a positive charge imparting member for developing an electrostatic charge image, which can provide image quality excellent in solid black and fine line reproducibility. (6) To provide a method for efficiently manufacturing the carrier.

【0009】[0009]

【課題を解決するための手段】本発明者等は、グアナミ
ン樹脂と、この樹脂と加熱硬化可能な第2の樹脂とを含
有する被覆樹脂を鋭意検討した結果、上記の課題を解決
することができる電子写真用キャリア及びその製造方
法、並びに電子写真用帯電付与部材を完成するに至っ
た。具体的な態様は以下のとおりである。
Means for Solving the Problems The inventors of the present invention have diligently studied a coating resin containing a guanamine resin and a second resin capable of being heat-cured, and as a result, the above-mentioned problems can be solved. The electrophotographic carrier, the manufacturing method thereof, and the electrophotographic charge imparting member that can be completed have been completed. The specific mode is as follows.

【0010】(1) 芯物質上に被覆層を設けた電子写真用
キャリアにおいて、該被覆層が40重量%以上のグアナ
ミン樹脂と、該グアナミン樹脂と反応架橋できる官能基
を有する第2の樹脂からなる熱硬化樹脂で構成したこと
を特徴とする電子写真用キャリア。
(1) In an electrophotographic carrier having a core material provided with a coating layer, the coating layer comprises 40% by weight or more of a guanamine resin and a second resin having a functional group capable of reacting with the guanamine resin. A carrier for electrophotography, which is made of a thermosetting resin.

【0011】(2) グアナミン樹脂が、グアナミン類、ホ
ルムアルデヒド及びアルコール類からなる共縮合物であ
ることを特徴とする上記(2) 記載の電子写真用キャリ
ア。
(2) The electrophotographic carrier according to (2) above, wherein the guanamine resin is a cocondensation product of guanamines, formaldehyde and alcohols.

【0012】(3) グアナミン樹脂が、ベンゾグアナミン
樹脂であることを特徴とする上記(2) 記載の電子写真用
キャリア。
(3) The electrophotographic carrier according to (2) above, wherein the guanamine resin is a benzoguanamine resin.

【0013】(4) 第2の樹脂が、アクリル樹脂、ポリエ
ステル樹脂、アルキッド樹脂のうちの少なくとも1種か
らなることをを特徴とする上記(1) 〜(3) のいずれか1
項に記載の電子写真用キャリア。
(4) Any one of the above (1) to (3), characterized in that the second resin comprises at least one of acrylic resin, polyester resin and alkyd resin.
The electrophotographic carrier according to the item.

【0014】(5) 表面エネルギーを低減するための樹脂
を被覆樹脂に添加したことを特徴とする上記(1) 〜(4)
のいづれか1項に記載の電子写真用キャリア。
(5) The above (1) to (4), wherein a resin for reducing the surface energy is added to the coating resin.
The electrophotographic carrier according to any one of items 1.

【0015】(6) 帯電量を調整するための樹脂を被覆樹
脂に添加したことを特徴とする上記(1) 〜(5) のいづれ
か1項に記載の電子写真用キャリア。
(6) The electrophotographic carrier according to any one of the above (1) to (5), characterized in that a resin for adjusting the charge amount is added to the coating resin.

【0016】(7) 上記(1) 〜(6) 項のいづれか1項に記
載の樹脂と芯物質とを、樹脂の硬化温度より低い温度で
加熱混合して被覆層を形成した後、該被覆層を焼き付け
硬化温度以上に加熱して硬化することを特徴とする電子
写真用キャリアの製造方法。
(7) The resin according to any one of the above items (1) to (6) and the core substance are heated and mixed at a temperature lower than the curing temperature of the resin to form a coating layer, and then the coating layer is formed. A method for producing an electrophotographic carrier, which comprises heating the layer to a temperature higher than a baking temperature to cure the layer.

【0017】(8) 上記(1) 〜(6) 項のいづれか1項に記
載の被覆樹脂で芯物質を被覆したことを特徴とする電子
写真用帯電付与部材。
(8) A charge imparting member for electrophotography, comprising a core substance coated with the coating resin according to any one of the above items (1) to (6).

【0018】なお、上記(1) 〜(6) 記載のキャリアは静
電荷像現像用正帯電キャリアに、また、静電荷像現像用
正帯電付与部材に適したものである。
The carriers described in the above items (1) to (6) are suitable for a positively charged carrier for developing an electrostatic image and a positive charging member for developing an electrostatic image.

【0019】[0019]

【作用】本発明は、上記のグアナミン樹脂を被覆樹脂に
用いることにより、帯電維持性、環境安定性、画質維持
性を大幅に向上させることができ、画像への濃度ムラや
背景部汚れのない優れた画質の提供を可能にし、該樹脂
を芯物質表面に均一にかつ効率的に被覆するキャリアの
製造方法の提供を可能にした。
According to the present invention, by using the above-mentioned guanamine resin as the coating resin, the charge maintaining property, the environmental stability and the image quality maintaining property can be greatly improved, and the image is free from uneven density and background stains. An excellent image quality can be provided, and a method for manufacturing a carrier that uniformly and efficiently coats the resin on the surface of the core substance can be provided.

【0020】本発明に用いるグアナミン樹脂としては、
グアナミン類とホルムアルデヒドとアルコール類との共
縮合物を挙げることができる。分子内に含有されるグア
ナミン類としては、アセトグアナミン、ベンゾグアナミ
ン、シクロヘキシルグアナミン、シクロテトラオキサス
ピロウンデカン(CTU)グアナミンなどを挙げること
ができるが、帯電の環境安定性、維持性の面でベンゾグ
アナミンが最適である。
The guanamine resin used in the present invention includes:
Mention may be made of co-condensates of guanamines, formaldehyde and alcohols. Examples of guanamines contained in the molecule include acetoguanamine, benzoguanamine, cyclohexylguanamine, and cyclotetraoxaspiroundecane (CTU) guanamine, but benzoguanamine is most suitable in terms of environmental stability and sustainability of charging. Is.

【0021】グアナミン樹脂の含有量は、全被覆樹脂量
に対して40重量%以上、好ましくは45重量%以上、
より好ましくは50重量%以上で、かつ、95重量%以
下、好ましくは90重量%以下の範囲が適当である。4
0重量%未満では、長期にわたり充分な帯電制御能力を
発揮することができず、また、95重量%を越えると、
焼き付け硬化しても充分な被膜強度を得ることができな
い。
The content of guanamine resin is 40% by weight or more, preferably 45% by weight or more, based on the total amount of coating resin,
It is more preferably 50% by weight or more and 95% by weight or less, preferably 90% by weight or less. Four
If it is less than 0% by weight, sufficient charge control ability cannot be exhibited for a long time, and if it exceeds 95% by weight,
Sufficient film strength cannot be obtained even by baking and curing.

【0022】本発明で用いる、グアナミン樹脂と加熱硬
化可能な第2の樹脂としては、グアナミン樹脂と反応架
橋できる官能基を有するものであれば特に限定されない
が、アクリル樹脂、ポリエステル樹脂、アルキッド樹脂
が、帯電制御性、被膜形成の点で特に好適である。
The second resin which can be heat-cured with the guanamine resin used in the present invention is not particularly limited as long as it has a functional group capable of reacting with the guanamine resin and cross-links, but an acrylic resin, a polyester resin and an alkyd resin can be used. It is particularly preferable in terms of charge controllability and film formation.

【0023】本発明で使用する被覆樹脂としては、表面
エネルギー低減や帯電量の調整等の目的で、さらに、第
3の樹脂を混合使用することができる。第3の樹脂とし
てはフッ化ビニリデン、テトラフロロエチレン、ヘキサ
フルオロプロピレン、モノクロロトリフロロエチレン、
モノクロロエチレン、トリフロロエチレン、パーフロロ
アルキルアクリレートなどのフッ素含有モノマーの重合
体;スチレン、クロルスチレン、メチルスチレン等のス
チレン類;メチルメタクリレート、メチルアクリレー
ト、プロピルアクリレート、ラウリルアクリレート、メ
タクリル酸、アクリル酸、ブチルメタクリレート、ブチ
ルアクリレート、2-エチルヘキシルアクリレート、エチ
ルメタクリレート等のα−メチレン脂肪族モノカルボン
酸類;ジメチルアミノエチルメタクリレートなどの含窒
素脂肪族モノカルボン酸類;アクリロニトリル、メタク
リロニトリル等のニトリル類;2-ビニルピリジン、4-ビ
ニルピリジン等のビニルピリジン類;ビニルエーテル
類;ビニルケトン類:エチレン、プロピレン、ブタジエ
ン等のオレフィン類;メチルシリコン、メチルフェニル
シリコン等のシリコン類などの単独重合体、又は共重合
体を使用することができる。また、ビスフェノール、グ
リコール等を含むポリエステル類も使用することができ
る。
As the coating resin used in the present invention, a third resin may be mixed and used for the purpose of reducing the surface energy and adjusting the charge amount. As the third resin, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, monochlorotrifluoroethylene,
Polymers of fluorine-containing monomers such as monochloroethylene, trifluoroethylene and perfluoroalkyl acrylate; styrenes such as styrene, chlorostyrene and methylstyrene; methyl methacrylate, methyl acrylate, propyl acrylate, lauryl acrylate, methacrylic acid, acrylic acid, Α-methylene aliphatic monocarboxylic acids such as butyl methacrylate, butyl acrylate, 2-ethylhexyl acrylate, and ethyl methacrylate; nitrogen-containing aliphatic monocarboxylic acids such as dimethylaminoethyl methacrylate; nitriles such as acrylonitrile and methacrylonitrile; 2- Vinyl pyridines such as vinyl pyridine and 4-vinyl pyridine; vinyl ethers; vinyl ketones: olefins such as ethylene, propylene and butadiene; Rushirikon can be used homopolymers or copolymers such as silicone such as methyl phenyl silicone. Further, polyesters containing bisphenol, glycol and the like can also be used.

【0024】磁性芯物質としては、通常のフェライト粒
子、造粒マグネタイトなどほぼ球形の形状を有し、表面
性の制御可能な粒子を使用することができ、表面性の制
御手段としては、原料粒子径と焼成条件がある。核体粒
子の粒径は通常20〜120μmの範囲のものが使用さ
れる。
As the magnetic core substance, particles having a substantially spherical shape such as ordinary ferrite particles and granulated magnetite and having a controllable surface property can be used. As the surface property control means, raw material particles can be used. There are diameters and firing conditions. The particle size of the core particles is usually in the range of 20 to 120 μm.

【0025】被覆樹脂の配合量は、キャリアに対して総
量で0.1〜10重量%、好ましくは1.0〜7重量
%、より好ましくは1.5〜6重量%の範囲が、画質維
持性、2次障害の回避、及び、帯電性を確保する点で適
している。また、帯電付与部材については、金属スリー
ブやブレード表面に対し、上記の被覆樹脂を被覆するこ
とができる。
The total amount of the coating resin is 0.1 to 10% by weight, preferably 1.0 to 7% by weight, and more preferably 1.5 to 6% by weight, based on the carrier. It is suitable from the standpoint of ensuring the charging property, secondary obstacle, and ensuring the charging property. Further, in the charging member, the surface of the metal sleeve or the blade can be coated with the above coating resin.

【0026】本発明のキャリアの製造方法は、被覆樹脂
と核体粒子を溶剤を用いずに、硬化温度以下の温度で加
熱混合して被覆層を形成した後、被覆樹脂の焼き付け硬
化温度以上の温度に加熱して被覆樹脂を硬化し、核体粒
子を被覆する。製造装置としては、加熱型ニーダー、加
熱型ヘンシェルミキサー、UMミキサー、プラネタリー
ミキサーなどを使用することができる。
In the method for producing a carrier of the present invention, the coating resin and the core particles are heated and mixed at a temperature not higher than the curing temperature without using a solvent to form a coating layer, and then the baking temperature of the coating resin is higher than the curing temperature. It is heated to a temperature to cure the coating resin and coat the core particles. As a manufacturing device, a heating type kneader, a heating type Henschel mixer, a UM mixer, a planetary mixer, or the like can be used.

【0027】被覆樹脂の添加は、常温で芯物質と混合し
た後、溶融開始点以上の温度に加熱するか、芯物質のみ
を融点以上の温度に加熱した状態で添加することも可能
である。上記の方法で被覆された粒子は、そのままキャ
リアとして使用できるが、さらに、他の樹脂を溶融被覆
したり、溶剤に溶解した他の樹脂を溶液コート法で被覆
して複層キャリアとして用いることも可能である。
The coating resin may be added to the core material after being mixed with the core material at room temperature and then heated to a temperature above the melting start point, or only the core material may be heated to a temperature above the melting point. The particles coated by the above method can be used as a carrier as they are, but further, they may be melt-coated with another resin or may be used as a multi-layer carrier by coating another resin dissolved in a solvent by a solution coating method. It is possible.

【0028】本発明のキャリアは、トナーと混合して二
成分現像剤として用いられる。トナーは結着樹脂中に着
色剤を分散させたものである。トナーに使用する結着樹
脂としては、スチレン、パラクロロスチレン、α−メチ
ルスチレン等のスチレン類;(メタ)アクリル酸メチ
ル、(メタ)アクリル酸エチル、(メタ)アクリル酸n
−プロピル、(メタ)アクリル酸ラウリル、(メタ)ア
クリル酸2-エチルヘキシル等のα−メチレン脂肪族モノ
カルボン酸エステル類;(メタ)アクリロニトリル等の
ビニルニトリル類;2-ビニルピリジン、4-ビニルピリジ
ン等のビニルピリジン類;ビニルメチルエーテル、ビニ
ルイソブチルエーテル等のビニルエーテル類;ビニルメ
チルケトン、ビニルエチルケトン、ビニルイソプロペニ
ルケトン等のビニルケトン類:エチレン、プロピレン、
イソプレン、ブタジエン等の不飽和炭化水素類及びその
ハロゲン化物、クロロプレン等のハロゲン系不飽和炭化
水素類などの単量体による重合体、又は、これらの単量
体を2種以上組み合わせて得られる共重合体、さらに
は、これらの混合物、また、ロジン変性フェノールホル
マリン樹脂、エポキシ樹脂、ポリエステル樹脂、ポリウ
レタン樹脂、ポリアミド樹脂、セルロース樹脂、ポリエ
ーテル樹脂等の非ビニル縮合系樹脂、又は、これらと上
記のビニル系樹脂との混合物を挙げることができる。
The carrier of the present invention is mixed with a toner and used as a two-component developer. The toner is obtained by dispersing a colorant in a binder resin. Examples of the binder resin used in the toner include styrenes such as styrene, parachlorostyrene, and α-methylstyrene; methyl (meth) acrylate, ethyl (meth) acrylate, n (meth) acrylate.
-Propyl, α-methylene aliphatic monocarboxylic acid esters such as lauryl (meth) acrylate and 2-ethylhexyl (meth) acrylate; Vinyl nitriles such as (meth) acrylonitrile; 2-vinylpyridine, 4-vinylpyridine Vinyl pyridines such as vinyl methyl ether, vinyl isobutyl ether and other vinyl ethers; vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketone and other vinyl ketones: ethylene, propylene,
Polymers of monomers such as unsaturated hydrocarbons such as isoprene and butadiene and their halides, halogenated unsaturated hydrocarbons such as chloroprene, or copolymers obtained by combining two or more of these monomers Polymers, further mixtures thereof, non-vinyl condensation resins such as rosin-modified phenol formalin resin, epoxy resin, polyester resin, polyurethane resin, polyamide resin, cellulose resin, polyether resin, or these and the above A mixture with a vinyl resin can be mentioned.

【0029】トナーに用いる着色剤としては、カーボン
ブラック、ニグロシン染料、アニリンブルー、カルコオ
イルブルー、クロムイエロー、ウルトラマリンブルー、
メチレンブルー、ローズベンガル、フタロシアニンブル
ー又はこれらの混合物を挙げることができる。
As the colorant used for the toner, carbon black, nigrosine dye, aniline blue, chalco oil blue, chrome yellow, ultramarine blue,
Mention may be made of methylene blue, rose bengal, phthalocyanine blue or mixtures thereof.

【0030】着色剤以外のトナー成分としては、電荷制
御剤、オフセット防止剤、流動性向上剤などがあり、ま
た、必要に応じて磁性体微粉末を含有してもよい。ま
た、シリカ、チタニア、アルミナ等の流動化剤やポリス
チレン微粒子、ポリメチルメタクリレート微粒子、ポリ
フッ化ビニリデン微粒子等のクリーニング助剤又は転写
助剤等の外添剤を用いることができる。特に、一次平均
粒径が5〜30nmの疎水性シリカが好ましく用いられ
る。また、内添剤として、サリチル酸金属塩、含金属ア
ゾ化合物、ニグロシン、第四級アンモニウム塩等の電荷
制御剤、及び、低分子量ポリプロピレン、低分子量ポリ
エチレン、ワックス等のオフセット防止剤など公知の他
の成分を添加することができる。好ましくは重量平均分
子量が500〜5000の低分子量ポリプロピレンが好
ましい。トナーの粒径は、小径の方が高画質であり、5
〜12μm、好ましくは5〜10μm程度が良好であ
る。
As the toner component other than the colorant, there are a charge control agent, an anti-offset agent, a fluidity improver and the like, and a magnetic fine powder may be contained if necessary. Further, a fluidizing agent such as silica, titania, or alumina, or an external additive such as a cleaning aid or a transfer aid such as polystyrene fine particles, polymethylmethacrylate fine particles, or polyvinylidene fluoride fine particles can be used. In particular, hydrophobic silica having a primary average particle size of 5 to 30 nm is preferably used. As internal additives, charge control agents such as salicylic acid metal salts, metal-containing azo compounds, nigrosine, and quaternary ammonium salts, and other known offset preventing agents such as low molecular weight polypropylene, low molecular weight polyethylene, and wax are known. Ingredients can be added. A low molecular weight polypropylene having a weight average molecular weight of 500 to 5000 is preferable. The smaller the toner particle size, the higher the image quality.
.About.12 .mu.m, preferably about 5 to 10 .mu.m is good.

【0031】[0031]

【実施例】以下、本発明を実施例により説明するが、こ
れにより本発明が限定されるものではない。なお、実施
例において「部」は重量部を意味する。 〔実施例1〕 Cu−Znフェライト(パウダーテック社製、平均粒径50μm)1000部 ベンゾグアナミン・n−ブチルアルコール・ホルムアルデヒド共縮合体 (共縮合比1:1:3) 16部 アクリル樹脂(三井東圧社製、アルマテックス748−5M、固形分55%) 7.3部 上記材料を加熱ヒーターを備えた1L小型ニーダー中
で、90℃で30分間混合した後、熱媒温度を250℃
に上昇させて40分間攪拌混練し、次いでヒーターを切
り、攪拌しながら50分間冷却した。その後、105μ
mの篩で篩分してキャリアを得た。
EXAMPLES The present invention will now be described by way of examples, which should not be construed as limiting the invention. In the examples, “part” means part by weight. [Example 1] Cu-Zn ferrite (manufactured by Powdertec Co., average particle size 50 µm) 1000 parts Benzoguanamine / n-butyl alcohol / formaldehyde cocondensate (cocondensation ratio 1: 1: 3) 16 parts Acrylic resin (Mitsui Higashi) Manufactured by Tatsusha, Almatex 748-5M, solid content 55%) 7.3 parts In a 1 L small kneader equipped with a heater, the above materials were mixed at 90 ° C for 30 minutes, and then the heat medium temperature was 250 ° C.
To 40 ° C., the mixture was stirred and kneaded for 40 minutes, then the heater was turned off, and the mixture was cooled for 50 minutes while stirring. Then 105μ
The carrier was obtained by sieving with a m sieve.

【0032】〔実施例2〕Cu−Znフェライト(パウ
ダーテック社製、平均粒径50μm)1000部を加熱
ヒーターを備えた1L小型ニーダー中で、熱媒温度を1
00℃に上昇させて加熱攪拌しながら、ベンゾグアナミ
ン・n−ブチルアルコール・ホルムアルデヒド共縮合体
(共縮合比1:1:3)16部及びポリエステル樹脂
(三井東圧社製、アルマテックスP646、固形分60
%)6.7部を添加して40分間攪拌混練した後、熱媒
温度を250℃に上昇させて40分間攪拌混練し、次い
で、ヒーターを切り、攪拌をしながら50分間冷却し
た。その後、105μmの篩で篩分してキャリアを得
た。
Example 2 1000 parts of Cu—Zn ferrite (manufactured by Powdertec Co., average particle size: 50 μm) was heated at a heating medium temperature of 1 in a 1 L small kneader equipped with a heater.
16 parts of benzoguanamine / n-butyl alcohol / formaldehyde co-condensate (co-condensation ratio 1: 1: 3) and polyester resin (Mitsui Toatsu Co., Ltd., Almatex P646, solid content) while raising to 00 ° C. and stirring with heating. 60
%) Was added and the mixture was stirred and kneaded for 40 minutes, then the heating medium temperature was raised to 250 ° C. and the mixture was stirred and kneaded for 40 minutes, and then the heater was turned off and the mixture was cooled for 50 minutes while stirring. Then, it was sieved with a 105 μm sieve to obtain a carrier.

【0033】〔実施例3〕 Cu−Znフェライト(パウダーテック社製、平均粒径50μm)1000部 ベンゾグアナミン・n−ブチルアルコール・ホルムアルデヒド共縮合体 (共縮合比1:1:3) 16部 アクリル樹脂(三井東圧社製、アルマテックス748−5M、固形分55%) 7.3部 MMA・パーフロロオクチルメタクリレート共重合体(共重合比8:2)5部 上記材料を用い、実施例1と同様にしてキャリアを得
た。
[Example 3] Cu-Zn ferrite (manufactured by Powdertec Co., average particle size 50 µm) 1000 parts Benzoguanamine / n-butyl alcohol / formaldehyde cocondensate (cocondensation ratio 1: 1: 3) 16 parts Acrylic resin (Mitsui Toatsu Co., Ltd., Almatex 748-5M, solid content 55%) 7.3 parts MMA / perfluorooctyl methacrylate copolymer (copolymerization ratio 8: 2) 5 parts Using the above materials, Example 1 and I got a carrier in the same way.

【0034】〔実施例4〕 Cu−Znフェライト(パウダーテック社製、平均粒径50μm)1000部 ベンゾグアナミン・n−ブチルアルコール・ホルムアルデヒド共縮合体 (共縮合比1:1:3) 9部 アクリル樹脂(三井東圧社製、アルマテックス748−5M、固形分55%) 20部 上記材料を用い、実施例1と同様の処理を行ってキャリ
アを得た。
[Example 4] Cu-Zn ferrite (manufactured by Powdertec Co., average particle size: 50 µm) 1000 parts Benzoguanamine / n-butyl alcohol / formaldehyde cocondensate (cocondensation ratio 1: 1: 3) 9 parts Acrylic resin (Mitsui Toatsu Co., Ltd., Almatex 748-5M, solid content 55%) 20 parts Using the above materials, the same treatment as in Example 1 was performed to obtain a carrier.

【0035】〔比較例1〕Cu−Znフェライト(パウ
ダーテック社製、平均粒径50μm)1000部及びア
クリル樹脂(三井東圧社製、アルマテックス748−5
M、固形分55%)36.4部を用い、実施例1と同様
にしてキャリアを得た。
[Comparative Example 1] 1000 parts of Cu-Zn ferrite (manufactured by Powdertec Co., average particle size: 50 μm) and acrylic resin (manufactured by Mitsui Toatsu Co., Almatex 748-5)
M, solid content 55%) 36.4 parts were used to obtain a carrier in the same manner as in Example 1.

【0036】〔比較例2〕Cu−Znフェライト(パウ
ダーテック社製、平均粒径50μm)1000部及びポ
リエステル樹脂(三井東圧社製、アルマテックスP64
6、固形分60%)33.3部を用い、実施例2と同様
にして共重合体を得た。
[Comparative Example 2] 1000 parts of Cu-Zn ferrite (manufactured by Powdertec Co., average particle size: 50 μm) and polyester resin (manufactured by Mitsui Toatsu Co., Almatex P64)
6, solid content 60%) was used to obtain a copolymer in the same manner as in Example 2.

【0037】〔比較例3〕 アクリル樹脂(三井東圧社製、アルマテックス748−5M、固形分55%) 11.1部 メラミン樹脂(三井東圧社製、ユーバン20SE60、固形分55%) 2.9部 ベンゾグアナミン・n−ブチルアルコール・ホルムアルデヒド共縮合体 (共縮合比1:1:3) 1.3部 エポキシ樹脂(シエル化学社製、エピコート1004) 0.87部 上記材料をキシレン・メタノール(7:3)混合溶媒5
00部に溶解分散させた。次いで、上記溶液と、Cu−
Znフェライト(パウダーテック社製、平均粒径50μ
m)1000部を、減圧装置と加熱ヒーターを備えた1
L小型ニーダー中で、熱媒温度を120℃に上昇させて
加熱減圧攪拌しながら、溶剤を除去してキャリアを得
た。
Comparative Example 3 Acrylic resin (manufactured by Mitsui Toatsu, Almatex 748-5M, solid content 55%) 11.1 parts Melamine resin (manufactured by Mitsui Toatsu, Uban 20SE60, solid content 55%) 2 .9 parts Benzoguanamine / n-butyl alcohol / formaldehyde co-condensate (co-condensation ratio 1: 1: 3) 1.3 parts Epoxy resin (Ciel Chemical Co., Epicoat 1004) 0.87 parts The above materials are xylene / methanol ( 7: 3) Mixed solvent 5
It was dissolved and dispersed in 00 parts. Then, the above solution and Cu-
Zn ferrite (manufactured by Powder Tech Co., average particle size 50μ)
m) 1000 parts, 1 equipped with a decompression device and a heater
In a small L-kneader, the temperature of the heating medium was raised to 120 ° C., and the solvent was removed while stirring under heating and reduced pressure to obtain a carrier.

【0038】〔比較例4〕 Cu−Znフェライト(パウダーテック社製、平均粒径50μm)1000部 ベンゾグアナミン・n−ブチルアルコール・ホルムアルデヒド共縮合体 (共縮合比1:1:3) 4部 アクリル樹脂(三井東圧社製、アルマテックス748−5M、固形分55%) 29.1部 上記材料を実施例1と同様の処理を行ってキャリアを得
た。
Comparative Example 4 Cu-Zn ferrite (manufactured by Powdertec Co., average particle size 50 μm) 1000 parts Benzoguanamine / n-butyl alcohol / formaldehyde cocondensate (cocondensation ratio 1: 1: 3) 4 parts Acrylic resin (Manufactured by Mitsui Toatsu Co., Ltd., Almatex 748-5M, solid content 55%) 29.1 parts The same materials as those in Example 1 were processed to obtain a carrier.

【0039】〔トナー製造例1〕 結着樹脂(スチレン−n−ブチルメタクリレート、共重合比70:30) 87部 カーボンブラック(キャボット社製、BPL) 8部 帯電制御剤(保土谷化学社製、TRH) 1部 ポリプロピレンワックス(三洋化成社製、660P) 4部 上記材料を用いて混練粉砕法で平均粒径7.5μmのト
ナー粒子を得た。そして、上記トナー粒子100部及び
コロイダルシリカ(日本アエロジル社製、R972)1
部をヘンシェルミキサーで混合して評価用トナーを得
た。
[Toner Production Example 1] Binder resin (styrene-n-butyl methacrylate, copolymerization ratio 70:30) 87 parts Carbon black (manufactured by Cabot Co., BPL) 8 parts Charge control agent (manufactured by Hodogaya Chemical Co., Ltd., TRH) 1 part Polypropylene wax (manufactured by Sanyo Kasei Co., 660P) 4 parts Toner particles having an average particle size of 7.5 μm were obtained by a kneading and pulverizing method using the above materials. Then, 100 parts of the toner particles and colloidal silica (R972 manufactured by Nippon Aerosil Co., Ltd.) 1
Parts were mixed with a Henschel mixer to obtain a toner for evaluation.

【0040】(評価)実施例1〜4及び比較例1〜4で
得たキャリアは、トナー濃度5%となるようにトナー製
造例1で得たトナーと混合して評価用現像剤を作製し
た。これらの現像剤について、富士ゼロックス社製50
39改造機を用いて画質評価試験を行い、かつ、キャリ
アのコート状態を電子顕微鏡で観察して結果を表1に示
した。表1から明らかなように、実施例の現像剤は、比
較例に比べてソリッド部濃度、背景部汚れ、コート状態
がいずれも良好であり、帯電安定性に優れていることが
分かる。
(Evaluation) The carriers obtained in Examples 1 to 4 and Comparative Examples 1 to 4 were mixed with the toner obtained in Toner Production Example 1 so as to have a toner concentration of 5% to prepare a developer for evaluation. . About these developers, 50 manufactured by Fuji Xerox Co., Ltd.
An image quality evaluation test was conducted using a No. 39 remodeling machine, and the coated state of the carrier was observed with an electron microscope. The results are shown in Table 1. As is clear from Table 1, the developer of the example is superior in the solid portion density, the background portion stain, and the coated state as compared with the comparative example, and it is understood that the developer has excellent charge stability.

【0041】[0041]

【表1】 [Table 1]

【0042】〔実施例5〕富士ゼロックス社製レーザー
プリンター4105用現像ロールスリーブ(ステンレス
製)表面に、ベンゾグアナミン・n−ブチルアルコール
・ホルムアルデヒド共縮合体(共縮合比1:1:3)と
アクリル樹脂(三井東圧社製、アルマテックス748−
5M、固形分55%)を固形分重量比率で8:2になる
ように混合し、キシレン・メタノール(7/3)混合溶
媒に溶解した状態でディッピングにより、スリーブ上に
50g/m2 のコート層を形成した。その後このスリー
ブを加熱チャンバー中で250℃、30分間加熱硬化し
て帯電付与スリーブを得た。
[Example 5] A benzoguanamine / n-butyl alcohol / formaldehyde cocondensate (cocondensation ratio 1: 1: 3) and an acrylic resin were formed on the surface of a developing roll sleeve (stainless steel) for a laser printer 4105 manufactured by Fuji Xerox Co., Ltd. (Mitsui Toatsu Co., Ltd., Almatex 748-
5M, solid content 55%) was mixed so as to have a solid content weight ratio of 8: 2, and was dissolved in a mixed solvent of xylene / methanol (7/3) by dipping to coat 50 g / m 2 on the sleeve. Layers were formed. Thereafter, this sleeve was heated and cured at 250 ° C. for 30 minutes in a heating chamber to obtain a charging sleeve.

【0043】〔比較例5〕富士ゼロックス社製レーザー
プリンター4105用現像ロールスリーブ(ステンレス
製)をそのまま使用した。
Comparative Example 5 A developing roll sleeve (made of stainless steel) for a laser printer 4105 manufactured by Fuji Xerox Co., Ltd. was used as it was.

【0044】(トナーの製造例2) 結着樹脂(スチレン−n−ブチルメタクリレート、共重合比70:30) 44部 マグネタイト粉(戸田工業社製、EPT−1000) 50部 帯電制御剤(保土谷化学社製、TRH) 2部 ポリプロピレンワックス(三洋化成社製、660P) 4部 上記材料を用いて混練粉砕法で平均粒径9.0μmのト
ナー粒子を得た。そして、上記トナー粒子100部及び
コロイダルシリカ(日本アエロジル社製R972)0.
8部をヘンシェルミキサーで混合して評価用トナーを得
た。
(Production Example 2 of toner) Binder resin (styrene-n-butyl methacrylate, copolymerization ratio 70:30) 44 parts Magnetite powder (EPT-1000 manufactured by Toda Kogyo Co., Ltd.) 50 parts Charge control agent (Hodogaya) 2 parts polypropylene wax (660P, manufactured by Sanyo Kasei Co., Ltd.) 4 parts manufactured by Kagaku Co., Ltd. Toner particles having an average particle size of 9.0 μm were obtained by a kneading and pulverizing method using the above materials. Then, 100 parts of the toner particles and colloidal silica (R972 manufactured by Nippon Aerosil Co., Ltd.)
Toner for evaluation was obtained by mixing 8 parts by a Henschel mixer.

【0045】(評価)実施例4及び比較例4で得たスリ
ーブを富士ゼロックス社製レーザープリンター4105
に装着し、トナー製造例2のトナーを用いて画質評価試
験を行い、結果を表2に示した。表2から明らかなよう
に、実施例4のスリーブは、比較例4に比べて画質安定
性が優れていることが分かる。
(Evaluation) The sleeves obtained in Example 4 and Comparative Example 4 were used as laser printers 4105 manufactured by Fuji Xerox Co., Ltd.
The image quality evaluation test was performed using the toner of Toner Production Example 2 and the results are shown in Table 2. As is clear from Table 2, the sleeve of Example 4 is superior in image quality stability to Comparative Example 4.

【0046】[0046]

【表2】 [Table 2]

【0047】[0047]

【発明の効果】本発明は、上記の構成を採用することに
より、キャリア並びに帯電付与部材の帯電維持性、環境
安定性、画質維持性を大幅に向上させることができ、画
像の濃度ムラや背景部汚れのない良好な画質を得ること
ができるようになった。また、グアナミン樹脂を含有す
る被覆樹脂を芯物質表面に均一にかつ効率的に被覆する
ことができるようになった。
According to the present invention, by adopting the above-mentioned constitution, it is possible to greatly improve the charge maintaining property, the environmental stability and the image quality maintaining property of the carrier and the charge imparting member. It has become possible to obtain good image quality without stains on the parts. Further, it has become possible to uniformly and efficiently coat the surface of the core material with the coating resin containing the guanamine resin.

Claims (3)

【特許請求の範囲】[Claims] 【請求項1】 芯物質上に被覆層を設けた電子写真用キ
ャリアにおいて、該被覆層が40重量%以上のグアナミ
ン樹脂と、該グアナミン樹脂と反応架橋できる官能基を
有する第2の樹脂からなる熱硬化樹脂で構成したことを
特徴とする電子写真用キャリア。
1. An electrophotographic carrier having a coating layer provided on a core material, the coating layer comprising 40% by weight or more of a guanamine resin and a second resin having a functional group capable of reacting with the guanamine resin. An electrophotographic carrier comprising a thermosetting resin.
【請求項2】 請求項1記載の樹脂と、芯物質とを樹脂
の硬化温度より低い温度で加熱混合して被覆層を形成し
た後、該被覆層を焼き付け硬化温度以上に加熱して硬化
することを特徴とする電子写真用キャリアの製造方法。
2. The resin according to claim 1 and a core substance are heated and mixed at a temperature lower than the curing temperature of the resin to form a coating layer, and then the coating layer is heated to a temperature higher than the curing temperature for curing. A method for manufacturing a carrier for electrophotography, comprising:
【請求項3】 請求項1記載の被覆樹脂で芯物質を被覆
したことを特徴とする電子写真用帯電付与部材。
3. A charging member for electrophotography, comprising a core material coated with the coating resin according to claim 1.
JP6134235A 1994-06-16 1994-06-16 Electrophotographic carrier, manufacture thereof, and electrophotographic electrification imparting member Pending JPH086307A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP6134235A JPH086307A (en) 1994-06-16 1994-06-16 Electrophotographic carrier, manufacture thereof, and electrophotographic electrification imparting member

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP6134235A JPH086307A (en) 1994-06-16 1994-06-16 Electrophotographic carrier, manufacture thereof, and electrophotographic electrification imparting member

Publications (1)

Publication Number Publication Date
JPH086307A true JPH086307A (en) 1996-01-12

Family

ID=15123589

Family Applications (1)

Application Number Title Priority Date Filing Date
JP6134235A Pending JPH086307A (en) 1994-06-16 1994-06-16 Electrophotographic carrier, manufacture thereof, and electrophotographic electrification imparting member

Country Status (1)

Country Link
JP (1) JPH086307A (en)

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US4766851A (en) * 1985-05-23 1988-08-30 Kraftwerk Union Aktiengesellschaft Combustion chamber for a fluidized-bed furnace
US6500595B1 (en) 1999-10-20 2002-12-31 Ricoh Company, Ltd. Carrier for electrophotographic developer, method for manufacturing the carrier, and coating liquid for the method
JP2004212653A (en) * 2002-12-27 2004-07-29 Ricoh Co Ltd Two-component developer
US6904244B2 (en) 2001-11-26 2005-06-07 Ricoh Company, Ltd Developing device for suppressing variations in bulk density of developer, and an image forming apparatus including the developing device
US7020421B2 (en) 2002-12-27 2006-03-28 Ricoh Company, Ltd. Magnetic carrier, two-component developer, development method, development device and image forming apparatus of electrophotography
US7226713B2 (en) 2003-01-31 2007-06-05 Ricoh Company, Ltd. Carrier, developer including the carrier and image forming apparatus using the developer
US7381513B2 (en) 2004-07-29 2008-06-03 Ricoh Company, Ltd. Carrier, developer, image forming method and process cartridge for electrostatic image development
US7384719B2 (en) 2004-03-02 2008-06-10 Ricoh Company Ltd. Carrier, developer including the carrier, and image forming apparatus using the developer
EP1965261A2 (en) 2007-03-02 2008-09-03 Ricoh Company, Ltd. Toner for developing electrostatic image, method for producing the toner, image forming method, image forming apparatus and process cartridge using the toner
US7527908B2 (en) 2005-04-06 2009-05-05 Ricoh Company, Ltd. Carrier, developer, developer container, image forming method and process cartridge
US7553598B2 (en) 2005-03-18 2009-06-30 Ricoh Company, Limited Electrophotographic carrier, developer, developer container, process cartridge, image forming apparatus and image forming method
EP2090934A1 (en) 2008-02-13 2009-08-19 Ricoh Company, Ltd. Carrier, two-component developer containing carrier and toner, and image forming method
US7592116B2 (en) 2004-11-12 2009-09-22 Ricoh Company, Ltd. Indium-containing carrier for electrophotography, developer using the same, and developer container
US8026032B2 (en) 2006-10-20 2011-09-27 Ricoh Company, Ltd. Carrier, supplemental developer, developer in image developer, developer feeding apparatus, image forming apparatus and process cartridge
US8086143B2 (en) 2007-09-13 2011-12-27 Ricoh Company, Limited Image forming apparatus for use with carrier including a core and cover layer
US8213833B2 (en) 2007-01-15 2012-07-03 Ricoh Company, Ltd. Image forming apparatus, process cartridge, image forming method and developer for electrophotography
US8247150B2 (en) 2008-09-17 2012-08-21 Ricoh Company, Ltd. Carrier for developing electrostatic latent image, two-component developer, supplemental developer, process cartridge, and image forming method
US8247149B2 (en) 2007-12-03 2012-08-21 Ricoh Company, Ltd. Electrophotographic developer carrier, electrophotographic developer, image forming method, process cartridge and image forming apparatus
US8263302B2 (en) 2008-09-11 2012-09-11 Ricoh Company, Ltd. Carrier for electrophotography and two-component developer
US8512929B2 (en) 2009-09-14 2013-08-20 Ricoh Company, Ltd. Latent electrostatic image developing carrier, two-component developer and image forming method
US10025214B2 (en) 2015-12-28 2018-07-17 Ricoh Company, Ltd. Carrier, developing agent, image forming apparatus, image forming method, replenishment toner, and process cartridge
US10444651B2 (en) 2017-03-17 2019-10-15 Ricoh Company, Ltd. Carrier, developer, supplemental developer, image forming apparatus, image forming method, and process cartridge
WO2021094957A1 (en) 2019-11-15 2021-05-20 Ricoh Company, Ltd. Carrier for forming electrophotographic image, developer for forming electrophotographic image, electrophotographic image forming method, electrophotographic image forming apparatus, and process cartridge
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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4766851A (en) * 1985-05-23 1988-08-30 Kraftwerk Union Aktiengesellschaft Combustion chamber for a fluidized-bed furnace
US6500595B1 (en) 1999-10-20 2002-12-31 Ricoh Company, Ltd. Carrier for electrophotographic developer, method for manufacturing the carrier, and coating liquid for the method
US6904244B2 (en) 2001-11-26 2005-06-07 Ricoh Company, Ltd Developing device for suppressing variations in bulk density of developer, and an image forming apparatus including the developing device
US7003235B2 (en) 2001-11-26 2006-02-21 Ricoh Company, Ltd. Developing device for suppressing variations in bulk density of developer, and an image forming apparatus including the developing device
US7474867B2 (en) 2002-12-27 2009-01-06 Ricoh Company, Ltd. Magnetic carrier, two-component developer, development method, development device and image forming apparatus of electrophotography
JP2004212653A (en) * 2002-12-27 2004-07-29 Ricoh Co Ltd Two-component developer
US7020421B2 (en) 2002-12-27 2006-03-28 Ricoh Company, Ltd. Magnetic carrier, two-component developer, development method, development device and image forming apparatus of electrophotography
US7226713B2 (en) 2003-01-31 2007-06-05 Ricoh Company, Ltd. Carrier, developer including the carrier and image forming apparatus using the developer
US7272347B2 (en) 2003-01-31 2007-09-18 Ricoh Company, Ltd. Carrier, developer including the carrier, and image forming apparatus using the developer
US7384719B2 (en) 2004-03-02 2008-06-10 Ricoh Company Ltd. Carrier, developer including the carrier, and image forming apparatus using the developer
US7381513B2 (en) 2004-07-29 2008-06-03 Ricoh Company, Ltd. Carrier, developer, image forming method and process cartridge for electrostatic image development
US7592116B2 (en) 2004-11-12 2009-09-22 Ricoh Company, Ltd. Indium-containing carrier for electrophotography, developer using the same, and developer container
US7553598B2 (en) 2005-03-18 2009-06-30 Ricoh Company, Limited Electrophotographic carrier, developer, developer container, process cartridge, image forming apparatus and image forming method
US7527908B2 (en) 2005-04-06 2009-05-05 Ricoh Company, Ltd. Carrier, developer, developer container, image forming method and process cartridge
US8026032B2 (en) 2006-10-20 2011-09-27 Ricoh Company, Ltd. Carrier, supplemental developer, developer in image developer, developer feeding apparatus, image forming apparatus and process cartridge
US8213833B2 (en) 2007-01-15 2012-07-03 Ricoh Company, Ltd. Image forming apparatus, process cartridge, image forming method and developer for electrophotography
EP1965261A2 (en) 2007-03-02 2008-09-03 Ricoh Company, Ltd. Toner for developing electrostatic image, method for producing the toner, image forming method, image forming apparatus and process cartridge using the toner
US8086143B2 (en) 2007-09-13 2011-12-27 Ricoh Company, Limited Image forming apparatus for use with carrier including a core and cover layer
US8247149B2 (en) 2007-12-03 2012-08-21 Ricoh Company, Ltd. Electrophotographic developer carrier, electrophotographic developer, image forming method, process cartridge and image forming apparatus
EP2090934A1 (en) 2008-02-13 2009-08-19 Ricoh Company, Ltd. Carrier, two-component developer containing carrier and toner, and image forming method
US8263302B2 (en) 2008-09-11 2012-09-11 Ricoh Company, Ltd. Carrier for electrophotography and two-component developer
US8247150B2 (en) 2008-09-17 2012-08-21 Ricoh Company, Ltd. Carrier for developing electrostatic latent image, two-component developer, supplemental developer, process cartridge, and image forming method
US8512929B2 (en) 2009-09-14 2013-08-20 Ricoh Company, Ltd. Latent electrostatic image developing carrier, two-component developer and image forming method
US10025214B2 (en) 2015-12-28 2018-07-17 Ricoh Company, Ltd. Carrier, developing agent, image forming apparatus, image forming method, replenishment toner, and process cartridge
US10444651B2 (en) 2017-03-17 2019-10-15 Ricoh Company, Ltd. Carrier, developer, supplemental developer, image forming apparatus, image forming method, and process cartridge
US11106150B2 (en) 2018-11-22 2021-08-31 Ricoh Company, Ltd. Carrier, developer, method, and apparatus for forming electrophotographic image, and process cartridge
WO2021094957A1 (en) 2019-11-15 2021-05-20 Ricoh Company, Ltd. Carrier for forming electrophotographic image, developer for forming electrophotographic image, electrophotographic image forming method, electrophotographic image forming apparatus, and process cartridge

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