JPH037948A - Electrostatic charge image developing toner - Google Patents
Electrostatic charge image developing tonerInfo
- Publication number
- JPH037948A JPH037948A JP1142833A JP14283389A JPH037948A JP H037948 A JPH037948 A JP H037948A JP 1142833 A JP1142833 A JP 1142833A JP 14283389 A JP14283389 A JP 14283389A JP H037948 A JPH037948 A JP H037948A
- Authority
- JP
- Japan
- Prior art keywords
- toner
- resin
- quaternary ammonium
- ammonium salt
- alkyl
- 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.)
- Granted
Links
- 229920005989 resin Polymers 0.000 claims abstract description 16
- 239000011347 resin Substances 0.000 claims abstract description 16
- 150000003242 quaternary ammonium salts Chemical class 0.000 claims abstract description 11
- 125000000217 alkyl group Chemical group 0.000 claims abstract description 10
- 239000003086 colorant Substances 0.000 claims abstract description 6
- 125000001797 benzyl group Chemical group [H]C1=C([H])C([H])=C(C([H])=C1[H])C([H])([H])* 0.000 claims abstract description 3
- 125000004432 carbon atom Chemical group C* 0.000 claims description 6
- 239000000126 substance Substances 0.000 claims description 3
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 abstract description 8
- 230000006866 deterioration Effects 0.000 abstract description 4
- 238000004898 kneading Methods 0.000 abstract description 3
- 238000010298 pulverizing process Methods 0.000 abstract description 3
- 239000006229 carbon black Substances 0.000 abstract description 2
- 238000001816 cooling Methods 0.000 abstract description 2
- 229920000728 polyester Polymers 0.000 abstract description 2
- 239000000975 dye Substances 0.000 description 8
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 5
- 239000003795 chemical substances by application Substances 0.000 description 5
- 150000001875 compounds Chemical class 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- 239000002245 particle Substances 0.000 description 4
- 239000000203 mixture Substances 0.000 description 3
- 108091008695 photoreceptors Proteins 0.000 description 3
- 229920001225 polyester resin Polymers 0.000 description 3
- 239000004645 polyester resin Substances 0.000 description 3
- CJPQIRJHIZUAQP-MRXNPFEDSA-N benalaxyl-M Chemical compound CC=1C=CC=C(C)C=1N([C@H](C)C(=O)OC)C(=O)CC1=CC=CC=C1 CJPQIRJHIZUAQP-MRXNPFEDSA-N 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000002349 favourable effect Effects 0.000 description 2
- SZVJSHCCFOBDDC-UHFFFAOYSA-N iron(II,III) oxide Inorganic materials O=[Fe]O[Fe]O[Fe]=O SZVJSHCCFOBDDC-UHFFFAOYSA-N 0.000 description 2
- 239000000377 silicon dioxide Substances 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 229910000859 α-Fe Inorganic materials 0.000 description 2
- 229910002012 Aerosil® Inorganic materials 0.000 description 1
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 125000003277 amino group Chemical group 0.000 description 1
- 239000000969 carrier Substances 0.000 description 1
- 229920006026 co-polymeric resin Polymers 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 239000003822 epoxy resin Substances 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- LNEPOXFFQSENCJ-UHFFFAOYSA-N haloperidol Chemical compound C1CC(O)(C=2C=CC(Cl)=CC=2)CCN1CCCC(=O)C1=CC=C(F)C=C1 LNEPOXFFQSENCJ-UHFFFAOYSA-N 0.000 description 1
- 239000006247 magnetic powder Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 229920000768 polyamine Polymers 0.000 description 1
- 229920000647 polyepoxide Polymers 0.000 description 1
- 229920000098 polyolefin Polymers 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 229920002050 silicone resin Polymers 0.000 description 1
- 229920001909 styrene-acrylic polymer Polymers 0.000 description 1
Landscapes
- Developing Agents For Electrophotography (AREA)
Abstract
Description
【発明の詳細な説明】
〈従来の技術〉
電子複写機等で使用される現像剤は、その現像工程にお
いて、例えば静電荷像が形成されている感光体等の像担
持体に一旦付着せしめられ、次に転写工程において感光
体から転写紙に転写された後、定着工程においてコピー
紙面に定着される。[Detailed Description of the Invention] <Prior Art> In the development process, a developer used in an electronic copying machine or the like is once attached to an image bearing member such as a photoreceptor on which an electrostatic image is formed. Next, in a transfer step, the image is transferred from the photoreceptor to a transfer paper, and then, in a fixing step, it is fixed on the copy paper surface.
その際、潜像保持面上に形成される静電荷像を現像する
ための現像剤として、キャリアーとトナーとから成る二
成分系現像剤およびキャリアーを必要としない一成分系
現像剤（磁性トナー）が知られている。At that time, the developer for developing the electrostatic charge image formed on the latent image holding surface is a two-component developer consisting of a carrier and toner, and a one-component developer (magnetic toner) that does not require a carrier. It has been known.
そして、従来より現像剤に帯電性を付与するものとして
ニグロシン系染料、４級アンモニウム塩等の帯電制御剤
やキャリアのコーティング割等が知られていた。Conventionally, charge control agents such as nigrosine dyes and quaternary ammonium salts, carrier coatings, etc. have been known to impart chargeability to the developer.
〈発明が解決しようとする課題〉
しかしながら、これら従来の帯電性付与剤は、帯電性付
与効果は必ずしも満足できるものではなく、適度な帯電
性を環境等によらず安定的に示し、且つその帯電の経時
変化が好ましい形態を示すトナーを得るのは難しく、高
温高温下、又は連続複写時にカプリ等、画像汚れが発生
し、或は安定したコピー濃度が得られない点が問題とな
っていた。<Problems to be Solved by the Invention> However, these conventional chargeability imparting agents do not necessarily have a satisfactory chargeability imparting effect, and are capable of stably exhibiting appropriate chargeability irrespective of the environment and the like. It is difficult to obtain a toner that exhibits a favorable change over time, and there have been problems in that image stains such as capri occur under high temperatures or during continuous copying, or that stable copy density cannot be obtained.
本発明者等はかかる課題を解決すべく鋭意検討した結果
、特定の構造式で示される４級アンモニウム塩とニグロ
シン系染料を併用することにより、好ましい帯電特性を
示し、画質に優れたトナーが得られることを見出し、本
発明に到達した。As a result of intensive studies to solve these problems, the present inventors have found that by using a quaternary ammonium salt represented by a specific structural formula and a nigrosine dye in combination, a toner with favorable charging characteristics and excellent image quality can be obtained. The present invention was achieved based on the discovery that
即ち、本発明の目的は、画質の経時劣化および環境によ
る劣化の少ない、帯電特性に優れた静電荷像現像用トナ
ーを提供することにある。That is, an object of the present invention is to provide a toner for developing electrostatic images with excellent charging characteristics and less deterioration of image quality over time and environment.
く課題を解決する為の手段〉
しかして、かかる本発明の目的は、少くとも樹脂、着色
剤、ニグロシン系染料および下記一般式（Ｉ・）で表さ
れる４級アンモニウム塩を含有することを特徴とする静
電荷像現像用トナーにより容易に達成される。Means for Solving the Problems> However, the object of the present invention is to provide a method containing at least a resin, a colorant, a nigrosine dye, and a quaternary ammonium salt represented by the following general formula (I). This can be easily achieved using the characteristic electrostatic image developing toner.
（式中、Ｒ１は炭素数１〜８のアルキル基を表し、Ｒ２
およびＲ３はそれぞれ炭素数１〜８のアルキル基を表し
、Ｒ４は炭素数１〜８のアルキル基またはベンジル基を
表す。）
（作 用）
以下、本発明の詳細な説明する。(In the formula, R1 represents an alkyl group having 1 to 8 carbon atoms, and R2
and R3 each represent an alkyl group having 1 to 8 carbon atoms, and R4 represents an alkyl group having 1 to 8 carbon atoms or a benzyl group. ) (Function) The present invention will be explained in detail below.
本発明に用いられる４級アンモニウム塩は前記一般式（
１）で表される通りの４級アンモニウム塩とナフトール
スルホン酸の造塩化合物であって、具体的には例えば下
記の化合物が挙げられる。The quaternary ammonium salt used in the present invention has the general formula (
Salt-forming compounds of a quaternary ammonium salt and naphtholsulfonic acid as represented by 1) include, for example, the following compounds.
一方ニグロシン系染料としては、公知の種りのものが使
用可能で、例えば、オリエント化学■製ボントロンＮシ
リーズ、オリエント スピリットブラックＡＢ、オリエ
ント スピリット ブラックＳＢ、ソルベントブラック
＃５、ソルベントブラック＃７、住友化学■製スピリッ
トブラックＮα８５０、スピリットブラックＮα９００
等が挙げられる。On the other hand, as the nigrosine dye, known types can be used, such as Orient Chemical's Bontron N series, Orient Spirit Black AB, Orient Spirit Black SB, Solvent Black #5, Solvent Black #7, Sumitomo Chemical ■Spirit Black Nα850, Spirit Black Nα900
etc.
本発明に、使用し得る樹脂成分としては、静電荷像現像
用トナーに適した公知の種々のものが使用できる。例え
ば、スチレン系樹脂、スチレンアクリル系共重合樹脂、
ポリエステル系樹脂、エポキシ系樹脂及びこれらの混合
樹脂、また、これらのアルキル側鎖にアミノ基を有する
もの等があるが、中でもスチレン系又はポリエステル系
の樹脂が好ましい。As the resin component that can be used in the present invention, various known resin components suitable for toners for developing electrostatic images can be used. For example, styrene resin, styrene acrylic copolymer resin,
There are polyester resins, epoxy resins, mixed resins thereof, and resins having amino groups in their alkyl side chains, among which styrene or polyester resins are preferred.
トナー中の一般式（Ｉ）で表される化合物の含有量は、
樹脂１００重量部に対して０．５〜５重量部、ニグロシ
ン系染料は０．０１〜５重量部とし、両者の合計が５，
５部以下とするのが好ましい。The content of the compound represented by general formula (I) in the toner is:
0.5 to 5 parts by weight for 100 parts by weight of resin, 0.01 to 5 parts by weight for nigrosine dye, and the total of both is 5,
The amount is preferably 5 parts or less.
本発明で用いる着色剤としては、従来から黒色トナーに
用いられているものであれば特に制限されるものではな
く、カーボンブラック等を使用する。The colorant used in the present invention is not particularly limited as long as it has been conventionally used in black toners, and carbon black or the like may be used.
着色剤の含有率は、樹脂１００重量部に対して３〜２０
重量部とするのが好ましい。The content of the colorant is 3 to 20 parts by weight per 100 parts by weight of the resin.
Preferably, it is expressed in parts by weight.
更に、本発明のトナーには、一般式（１）で表される化
合物およびニグロシン系染料とは別に、公知のものを含
めて他の帯電制御剤、即ち、例えばポリアミン樹脂等を
含有せしめてもよい。Furthermore, the toner of the present invention may contain other charge control agents, including known ones, such as polyamine resins, in addition to the compound represented by formula (1) and the nigrosine dye. good.
その他、本発明のトナー構成成分として、定着性や流動
性を向上させるため、低分子量オレフィン重合体や微粉
末シリカ等の添加剤を含有せしめてもよい。In addition, additives such as a low molecular weight olefin polymer and finely powdered silica may be included as the toner constituent components of the present invention in order to improve fixing properties and fluidity.
トナーの製造法としては、上記の各成分をニーダ−等で
混練し冷却後、粉砕し分級すればよいヶ又、本発明のト
ナーは二成分系現像剤の他に、カプセル化トナーや重合
トナー及びマグネタイト含有トナー等のいわゆる一成分
系現像剤（Ｉ性トナー）にも適用することができる。The toner can be produced by kneading the above-mentioned components in a kneader or the like, cooling, pulverizing, and classifying.The toner of the present invention can be used in addition to two-component developers, encapsulated toners, and polymerized toners. It can also be applied to so-called one-component developers (I-type toners) such as magnetite-containing toners.
トナーの平均粒径は５〜２０ａｍが好適である。The average particle size of the toner is preferably 5 to 20 am.
本発明のトナーと混合して現像剤を形成するキャリアー
としては、特に制限はないが１０〜２００μｍの平均粒
径を有するフェライトが好ましい。The carrier to be mixed with the toner of the present invention to form a developer is not particularly limited, but ferrite having an average particle size of 10 to 200 μm is preferable.
又、マグネタイト系のキャリアーや鉄粉も使用すること
ができる。この場合、連続使用時の耐久性向上の目的で
フッ素系樹脂等をコーティングしたいわゆるコーティン
グキャリアーも使用することができる。このほか樹脂中
に磁性粉を練りこんだ樹脂キャリアーを用いることもで
きる。これらキャリアーは、トナー１重量部に対して、
５〜１００重量部使用することが好ましい。Furthermore, a magnetite carrier and iron powder can also be used. In this case, a so-called coated carrier coated with a fluororesin or the like can also be used for the purpose of improving durability during continuous use. In addition, a resin carrier in which magnetic powder is kneaded into resin can also be used. These carriers are based on 1 part by weight of toner.
It is preferable to use 5 to 100 parts by weight.
〈実施例〉
以下、実施例により本発明を更に詳細に説明するが本発
明はその要旨を超えない限り以下の実施例によりなんら
制限されるものではない。<Examples> Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited in any way by the following Examples unless the gist thereof is exceeded.
なお、下記実施例中単に「部」とあるのはいずれも「重
量部」を意味するものとする。In addition, in the following examples, the term "parts" simply means "parts by weight."
（実施例１）
＃４０（三菱化成■裂）
・４級アンモニウム塩帯電制御剤 ３部Ｐ−５１（
オリエント化学■製）
を配合、混練、粉砕し分級して平均粒径１１μｍの黒色
トナーを得た。この黒色トナー１００部に対してシリカ
粉末（日本アエロジル■製Ｒ−９７２）０．２１をヘン
シェルミキサーにて外添処理した。得られたトナー４部
と平均粒径約１００ｔ！ｍのシリコーン系樹脂で被覆さ
れたフェライトキャリアー１００部とを混合、攪拌し、
現像剤を作製した。(Example 1) #40 (Mitsubishi Kasei ■) ・Quaternary ammonium salt charge control agent 3 parts P-51 (
A black toner with an average particle size of 11 μm was obtained by blending, kneading, pulverizing, and classifying (manufactured by Orient Kagaku ■). To 100 parts of this black toner, 0.21 parts of silica powder (R-972 manufactured by Nippon Aerosil ■) was externally added using a Henschel mixer. The resulting toner was 4 parts and the average particle size was about 100 tons! m and 100 parts of ferrite carrier coated with silicone resin, mixed and stirred,
A developer was prepared.
次に、この現像剤について、有機光導電体を感光体とす
る複写機を用いて４０〜４５℃７８５〜９０％の高温／
高湿条件下で１０００００枚の実写テストを実施した。Next, this developer is processed at a high temperature of 40-45°C, 785-90% using a copying machine using an organic photoconductor as a photoreceptor.
A 100,000-shot photo test was conducted under high humidity conditions.
又、実写テストに使用した補給用トナーは、上記現像剤
に用いられたトナーと同一組成物のトナーである。Furthermore, the replenishment toner used in the actual photographing test had the same composition as the toner used in the developer described above.
実写テストの結果、ｔｏｏｏｏｏ枚後の実写も、コピー
の白地部の汚れであるカプリの増加がなく、又コピー黒
地部の均−性及び濃度も高く高温高湿度下の厳しい環境
下でも耐久性に優れたトナー及び現像剤であった。As a result of the live copy test, even after too many copies, there was no increase in capri, which is the stain on the white background of the copy, and the black background of the copy was highly uniform and dense, making it durable even in harsh environments of high temperature and high humidity. It was an excellent toner and developer.
（実施例２〜５）
用いるニグロシン系染料および４級アンモニウム塩並び
にその使用料を下記表の通りとした以外は実施例１と全
く同様にしたところ、１０００００枚実写テスト後もカ
ブリや画像濃度低下のない現像剤が得られた。(Examples 2 to 5) The same procedure as in Example 1 was performed except that the nigrosine dye, quaternary ammonium salt, and usage amount were as shown in the table below, and even after the 100,000-sheet live-action test, there was no fogging or decrease in image density. A developer free of
表
（実施例６）
スチレン系樹脂のかわりにポリエステル樹脂（日本合成
化学工業■製 ニチゴーポリエスターＨＰ−３１３）を
使用した以外は実施例１と全く同様にしたところ、１ｏ
ｏｏｏｏ枚実写テスト後もカブリや画像濃度低下のない
現像剤が得られた。Table (Example 6) The same procedure as in Example 1 was performed except that a polyester resin (Nichigo Polyester HP-313 manufactured by Nippon Gosei Kagaku Kogyo ■) was used instead of the styrene resin.
A developer was obtained that did not cause fogging or decrease in image density even after the oooo-sheet photocopying test.
（比較例−１）
実施例−１で使用したニグロシン系染料Ｎ−０４を使用
しなかった以外は、実施例１と全く同一組成で１０００
００枚の実写テストを実施した結果、カブリが増加する
等使用上問題があった。(Comparative Example-1) The composition was exactly the same as in Example 1 except that the nigrosine dye N-04 used in Example-1 was not used.
As a result of conducting a live-action test on 00 sheets, there were problems in use, such as increased fogging.
（比較例−２）
実施例−１で使用した第４級アンモニウム塩帯電制御剤
を使用しなかった以外は、実施例１と同一組成で１００
０００枚の実写テストを実施した結果、カブリが増加す
る等使用上問題があった。(Comparative Example-2) Same composition as Example 1 except that the quaternary ammonium salt charge control agent used in Example-1 was not used.
As a result of conducting a live-action test of 1,000 sheets, there were problems in use, such as an increase in fog.
〈発明の効果〉
本発明の静電荷像現像用トナーは常に適度で且つ安定し
た帯電性を示す等帯電性能が良好で、従来問題となって
いた高温高湿下或は連続複写時のコピー汚れや画像濃度
の低下が少ない等使用条件に係わらず良好な画像を与え
、多大な工業的利益を提供するものである。<Effects of the Invention> The toner for developing electrostatic images of the present invention has good charging performance such as constant and stable charging performance, and eliminates copy stains that have been a problem in the past under high temperature and high humidity conditions or during continuous copying. It provides a good image regardless of the conditions of use, such as low deterioration in image density and small decrease in image density, and provides great industrial benefits.
Claims (1)
下記一般式（ I ）で表される４級アンモニウム塩を含
有することを特徴とする静電荷像現像用トナー。 ▲数式、化学式、表等があります▼・・・（ I ） （式中、Ｒ＾１は炭素数１〜８のアルキル基を表し、Ｒ
＾２およびＲ＾３はそれぞれ炭素数１〜８のアルキル基
を表し、Ｒ＾４は炭素数１〜８のアルキル基またはベン
ジル基を表す。）(1) A toner for developing electrostatic images characterized by containing at least a resin, a colorant, a nigrosine dye, and a quaternary ammonium salt represented by the following general formula (I). ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(I) (In the formula, R^1 represents an alkyl group having 1 to 8 carbon atoms, and R
^2 and R^3 each represent an alkyl group having 1 to 8 carbon atoms, and R^4 represents an alkyl group having 1 to 8 carbon atoms or a benzyl group. )
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1142833A JP3004282B2 (en) | 1989-06-05 | 1989-06-05 | Electrostatic image developer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1142833A JP3004282B2 (en) | 1989-06-05 | 1989-06-05 | Electrostatic image developer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH037948A true JPH037948A (en) | 1991-01-16 |
| JP3004282B2 JP3004282B2 (en) | 2000-01-31 |
Family
ID=15324678
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1142833A Expired - Lifetime JP3004282B2 (en) | 1989-06-05 | 1989-06-05 | Electrostatic image developer |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3004282B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6238836B1 (en) | 1998-09-25 | 2001-05-29 | Dainippon Ink Chemicals, Inc. | Toner composition and developer for electrostatic image development |
| US6335139B1 (en) | 1999-11-22 | 2002-01-01 | Dainippon Ink And Chemicals, Inc. | Toner for electrostatic image development and image forming method employing the same |
| JP2005173025A (en) * | 2003-12-09 | 2005-06-30 | Kao Corp | Positive charge type toner |
-
1989
- 1989-06-05 JP JP1142833A patent/JP3004282B2/en not_active Expired - Lifetime
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6238836B1 (en) | 1998-09-25 | 2001-05-29 | Dainippon Ink Chemicals, Inc. | Toner composition and developer for electrostatic image development |
| US6335139B1 (en) | 1999-11-22 | 2002-01-01 | Dainippon Ink And Chemicals, Inc. | Toner for electrostatic image development and image forming method employing the same |
| JP2005173025A (en) * | 2003-12-09 | 2005-06-30 | Kao Corp | Positive charge type toner |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3004282B2 (en) | 2000-01-31 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JPH037948A (en) | Electrostatic charge image developing toner | |
| JPH0429157A (en) | Electrostatic charge image developing toner | |
| JPH04328758A (en) | Developer for developing electrostatic charge image | |
| JP2794797B2 (en) | Developer for developing electrostatic images | |
| JP2830082B2 (en) | Developer for developing electrostatic images | |
| JP2833011B2 (en) | Toner for developing electrostatic images | |
| JPH0352857B2 (en) | ||
| JPS6333755A (en) | Developer for electrophotography | |
| JP2532058B2 (en) | Toner for electrostatic charge development | |
| JPH03236064A (en) | Positively charged toner for developing electrostatic charge image | |
| JP3136792B2 (en) | Toner for developing electrostatic images | |
| JPH03217855A (en) | Toner for developing electrostatic charge image | |
| JP2969720B2 (en) | Toner for developing electrostatic images | |
| JP2969719B2 (en) | Toner for developing electrostatic images | |
| JP4135048B2 (en) | Charge adjusting agent and negatively chargeable toner for developing electrostatic image using the same | |
| JPH02238463A (en) | Electrostatic charge image developing toner | |
| JPH03217851A (en) | Toner for developing electrostatic charge image | |
| JPH04347864A (en) | Electrostatic charge image developing toner | |
| JPH03217853A (en) | Toner for developing electrostatic charge image | |
| JPH02219065A (en) | Developer for electrostatic photography | |
| JPH0154696B2 (en) | ||
| US5275902A (en) | Developer composition for electrophotography | |
| JPH04121754A (en) | Electrostatic charge developing toner | |
| JP3409097B2 (en) | Method for producing negatively chargeable toner for developing electrostatic images and electrostatic image developer using the toner | |
| JP2946523B2 (en) | Two-component positively charged developer |