JP3878468B2 - Dry electrophotographic toner - Google Patents

Description

【００４０】
上記合成例１で得られたポリオール樹脂１、および合成例２〜合成例４で得られたポリエステル樹脂１〜ポリエステル樹脂３の軟化点、ガラス転移点（Ｔｇ）、分子量（数平均分子量（Ｍｎ））、分子量分布（Ｍｗ／Ｍｎ）、エポキシ当量、酸価を下記評価方法により測定した。結果を表２に示す。
【００４１】
評価方法
−軟化点の測定−
軟化点を測定する装置として、メトラ社の全自動滴点装置ＦＰ５／ＦＰ５３を使用し、以下の手順で測定した。
（１）粉砕試料を溶融つぼに入れて２０分放置した後、試料カップ（滴下口径６．３５ｍｍ）のカップのふちまで試料を注ぎ込み、常温になるまで冷却してカートリッジにセットする。
（２）ＦＰ−５コントロールユニットに所定の昇温速度（１℃／ｍｉｎ）、測定開始温度（予期軟化温度の１５℃以下に設定する）をセットする。
（３）ＦＰ−５３加熱炉にカートリッジを装着し、３０秒放置後、スタートレバーを押し下げ、測定を開始する（以降の測定は自動的に行なわれる）。
（４）測定が終了したら、カートリッジをはずす。
（６）軟化点（℃）は、以下のように計算する。
ＦＰ−５の結果表示パネルＡの値＋補正値
なお、得られた結果に上記の補正値を加えれば、デュラン水銀法の結果と対応する。また、結果表示パネルＡの値と測定開始温度（パネルＢ、Ｃの値）の差が１５℃以上でない時は試験をやり直す。
−Ｔｇの測定−
Ｔｇを測定する装置として、セイコー電子製ＤＳＣ−２００を使用し、以下の手順で測定した。
（１）試料を粉砕し、重量１０±１ｍｇをアルミ製試料容器に計り取り、その上からアルミ蓋をクリンプする。
（２）窒素雰囲気中でＤＳＣ法によりガラス転移点（Ｔｇ）を測定する。
分析条件：
試料を、室温から昇温速度２０℃／ｍｉｎで１５０℃まで加熱した後、１５０℃で１０ｍｉｎ間放置、降温速度５０℃／ｍｉｎで０℃まで試料を冷却して１０ｍｉｎ放置後、窒素雰囲気（２０ｃｃ／ｍｉｎ）で再度１５０℃まで昇温速度２０℃／ｍｉｎで加熱してＤＳＣ測定を行う。Ｔｇは、解析ソフト〔Ｔｇジョブ〕を用いてピーク立ち上がり温度を読み取る。
−分子量の測定−
分子量はＧＰＣ法により、次の条件で測定した。
４０℃の恒温槽中でカラムを安定させ、溶離液としてクロロホルムを毎分１ｍｌの流速で流し、試料濃度０．０５〜０．５重量％に調整した試料のクロロホルム溶液を１００μｌ注入して測定を行う。試料の分子量は、あらかじめ作成した検量線に基づき、リテンションタイムにより決定した分子量分布から算出した。このときの検量線は、数種類の単分散ポリエチレンを標準試料として作成したものである。なお、分析カラムにはＧＭＨＬＸ＋Ｇ３０００ＨＬＸ（東ソー（株）製）を用いた。
−エポキシ当量の測定−
エポキシ当量はＪＩＳ Ｋ ７２３６の４．２に示される指示薬滴定法によって測定した。
−酸価の測定−
酸価はＪＩＳ Ｋ ００７０に規定される方法によって測定した。
【００４２】
【表２】

【００４３】
実施例１
（各カラートナーの処方）
前記合成例１で得られたポリオール樹脂１、および合成例２で得られたポリエステル樹脂１と着色剤、離型剤、帯電防止剤（ＣＣＡ）などを配合して下記イエロートナー、マゼンタトナー、シアントナー、ブラックトナーを処方した。
イエロートナー処方：
ポリオール樹脂１ ５０部
ポリエステル樹脂１ ５０部
カルナウバワックス（エステルワックス、融点：約８２℃） ３部
黄色顔料（クラリアント社製Ｔｏｎｅｒ Ｙｅｌｌｏｗ ＨＧ） ６部
ＣＣＡ（オリエント化学工業社製Ｅ−８４） ２部
マゼンタトナー処方：
ポリオール樹脂１ ５０部
ポリエステル樹脂１ ５０部
カルナウバワックス ３部
赤色顔料（東洋インキ製造社製リオノゲンマゼンタＲ） ５部
ＣＣＡ（オリエント化学工業社製Ｅ−８４） ２部
シアントナー処方：
ポリオール樹脂１ ５０部
ポリエステル樹脂１ ５０部
カルナウバワックス ３部
青色顔料（東洋インキ製造社製リオノールブルーＦＧ−７３５１）４部
ＣＣＡ（オリエント化学工業社製Ｅ−８４） ２部
ブラックトナー処方：
ポリオール樹脂１ ５０部
ポリエステル樹脂１ ５０部
カルナウバワックス ３部
黒色顔料（カーボンブラック；三菱化学社製＃４４） ６部
ＣＣＡ（オリエント化学工業社製Ｅ−８４） ２部
【００４４】
（各色現像剤の作製）
上記各カラートナー処方の混合物を熱ロールミルで溶融混練し、冷却後、ハンマーミルで粗粉砕後、エアージェット粉砕機で微粉砕し、得られた微粉末を分級して平均粒径約７μｍのトナーをそれぞれ得た。
次に、得られた各カラートナーそれぞれの１００部に対し、疎水性シリカＨＤＫ２０００Ｈ（クラリアントジャパン社製）０．７部を混合して一成分系現像剤を作製した。得られた各色一成分系現像剤を下記により評価した。
【００４５】
実施例２
実施例１と同様にポリオール樹脂１とポリエステル樹脂１とをバインダー樹脂成分として用いて、下記に示す各カラートナーを処方し、実施例１と全く同様にして、これらの混合物から平均粒径約７μｍのトナーを分級により得た。
（各カラートナーの処方）
イエロートナー処方：
ポリオール樹脂１ ２０部
ポリエステル樹脂１ ８０部
黄色顔料（東洋インキ製造社製リオノールイエローＦＧＮ−Ｔ） ５部
ＣＣＡ（オリエント化学工業社製Ｅ−８４） １部
マゼンタトナー処方：
ポリオール樹脂１ ２０部
ポリエステル樹脂１ ８０部
赤色顔料（東洋インキ製造社製リオノゲンマゼンタＲ） ５部
ＣＣＡ（オリエント化学工業社製Ｅ−８４） １部
シアントナー処方：
ポリオール樹脂１ ２０部
ポリエステル樹脂１ ８０部
青色顔料（東洋インキ製造社製リオノールブルーＦＧ−７３５１）３部
ＣＣＡ（オリエント化学工業社製Ｅ−８４） １部
ブラックトナー処方：
ポリオール樹脂１ ２０部
ポリエステル樹脂１ ８０部
黒色顔料（カーボンブラック） ４．５部
ＣＣＡ（オリエント化学工業社製Ｅ−８４） １部
【００４６】
（各色現像剤の作製）
上記で得られたカラートナー１００部に対し、Ｒ９７２（日本アエロジル社製）０．５部とＳＴＴ−３０Ａ（チタン工業社製）０．３部を混合した。次いで各カラートナー５部を平均径５０μｍの球状フェライトにシリコン樹脂をコートしたキャリア９５部と混合して各色の二成分系現像剤を得た。得られた各色二成分系現像剤を下記により評価した。
【００４７】
実施例３
実施例２において、ポリオール樹脂１を８０部、ポリエステル樹脂１を２０部に替えたほかは実施例２と全く同様にして各カラートナーを処方した。得られた各カラートナーを実施例２と同様の手順でキャリアと混合調製し、各色の二成分系現像剤を得た。得られた各色二成分系現像剤を下記により評価した
【００４８】
実施例４
実施例１において、ポリエステル樹脂１をポリエステル樹脂２（Ｍｎ：３４００、Ｍｗ／Ｍｎ：７．５、Ｔｇ：６１℃、軟化点：１２２℃、酸価：４）に替えたほかは実施例１と全く同様にして各カラートナーを処方した。この各カラートナーを実施例１と同様の手順で疎水性シリカＨＤＫ２０００Ｈ（クラリアントジャパン製）と混合して一成分系現像剤を得た。得られた各色一成分系現像剤を下記により評価した。
【００４９】
実施例５
実施例１において、ポリエステル樹脂１をポリエステル樹脂３（Ｍｎ：３７００、Ｍｗ／Ｍｎ：５．５、Ｔｇ：５９℃、軟化点：１２０℃、酸価：０．２）に替えたほかは実施例１と全く同様にして各カラートナーを処方した。この各カラートナーを実施例１と同様の手順で疎水性シリカＨＤＫ２０００Ｈ（クラリアントジャパン製）と混合して一成分系現像剤を得た。得られた各色一成分系現像剤を下記により評価した。
【００５０】
比較例１
実施例１において、ポリオール樹脂１を１００部に、ポリエステル樹脂１を０部に替えたほかは実施例１と全く同様にして各カラートナーを処方した。この各カラートナーを実施例１と同様の手順で疎水性シリカＨＤＫ２０００Ｈ（クラリアントジャパン製）と混合して一成分系現像剤を得た。得られた各色一成分系現像剤を下記により評価した。
【００５１】
比較例２
実施例１において、ポリオール樹脂１を０部に、ポリエステル樹脂１を１００部に替えたほかは実施例１と全く同様にして各カラートナーを処方した。この各カラートナーを実施例１と同様の手順で疎水性シリカＨＤＫ２０００Ｈ（クラリアントジャパン製）と混合して一成分系現像剤を得た。得られた各色一成分系現像剤を下記により評価した。
【００５２】
評価１（一成分系現像剤の評価）
実施例１、４、５および比較例１、２の各現像剤をそれぞれ、図１に示す現像部を有し、φ３０ｍｍのＰＦＡコートシリコンローラー(設定温度１６０℃)の定着部を有する実験機（一成分現像装置）に入れ、７５ｍｍ／ｓのプロセス速度でＡ４サイズの２５％画像面積率の原稿を９９枚連続印字し、それぞれの画像を下記評価項目（「地かぶり」、「画像ぼそつき」、「凝集体」、「塩ビ付着」、「環境変動」）、および評価ランクにより評価した。評価結果を表３に示す。
【００５３】
評価２（二成分系現像剤の評価）
実施例２、３の各現像剤をそれぞれ、Ｉｍａｇｉｏ Ｃｏｌｏｒ ４０５０（二成分現像装置）に入れ、単色カラーにてＡ４サイズの２５％画像面積率の原稿を２５０枚連続で印字し、それぞれの画像を下記評価項目（「地かぶり」、「画像ぼそつき」、「凝集体」、「塩ビ付着」、「環境変動」）および評価ランクにより評価した。評価結果を表３に示す。
【００５４】
＜評価項目＞
地かぶり：連続複写時の地肌部分の汚れを評価
画像ぼそつき：ハーフトーン部の均一性を評価
凝集体：トナーを５０℃にて４８時間保管した後の凝集度合いを評価
塩ビ付着：一定条件でが像を５０℃８時間放置した後の塩ビ（塩化ビニル）に対する融着性を評価
環境変動：３０℃／８０％の環境での画像濃度の変化を評価
＜評価ランク＞
◎：全く問題なし
○：問題なし
△：若干問題あるが許容レベル
×：問題あり
【００５５】
【表３】

【００５６】
表３から明らかなように、本発明のポリオール樹脂とポリエステル樹脂とを配合してバインダー樹脂とした乾式写真用トナーは、一成分系現像剤の場合でも、二成分系現像剤とした場合にも、地かぶりや画像ぼそつきが無く、凝集体の発生も見られず、また塩ビ付着も無く、環境変動に対して安定した特性を示し、総じてバランスのとれた特性を呈している。これに対して比較例のポリオール樹脂のみをバインダー樹脂とした場合には、画像ぼそつきに問題を生じたり、あるいはポリエステル樹脂のみをバインダー樹脂とした場合には、塩ビ付着を生じたり、環境変動を生ずるなどの問題が発生する。
【００５７】
【発明の効果】
本発明の乾式電子写真用トナーを用いることにより、地汚れ画像がなく十分な画像濃度を有する鮮明な画像を得ることができる。更に、適正かつ均一な光沢を有する画像が得られるとともに、ハーフトーン部で画像ムラのない画像を得ることができる。また、長期間にわたってトナーボトルや現像器内で凝集物が生ぜず、それにより凝集物が存在する部分の画像が白く抜ける現象が発生しない。更に、複写画像が塩ビマット等に付着することがない。しかも、製造時にバインダ樹脂の副反応によるゲル化が生じず安定しており、感作性による作業者の健康や安全性に影響を与えないトナーを得ることができる。
【図面の簡単な説明】
【図１】本発明における実施例の一成分系現像剤の評価に用いる一成分現像装置を示す概略構成図である。
【符号の説明】
１ トナータンク
２ トナー担持体
３ トナー層厚規制部材
４ トナー供給部材
５ 感光体
６ 撹拌羽根
７ トナー
８ 現像間隔[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a dry electrophotographic toner.
More specifically, the present invention relates to a toner suitable for a full-color image forming apparatus of a one-component developing system or a two-component developing system using a small developing device with a small amount of developer.
[0002]
[Prior art]
In dry electrophotography, an electrostatic latent image is formed on a photoreceptor, developed with dry toner, the toner image is transferred onto a copy sheet, and then thermally fixed (usually using a heat roller) to obtain a copy.
In particular, in order to obtain a full-color image, image gloss and good color development are required. Therefore, polyester resins as shown in JP-A-61-7844 and polyol resins as shown in JP-A-7-77832 are often used. Has been. However, when the former polyester resin is used, agglomerates are likely to occur in the toner bottle or the developing device, and a phenomenon that the image of the part where the agglomerates are present may appear white, or the obtained image may be converted into PVC mat (chloride chloride). If it is in contact with a vinyl mat) or the like, the problem that the image sticks or the image becomes sticky is likely to occur. Further, when the acid value of the polyester resin is high, the charge becomes high, but environmental fluctuations easily occur and the characteristics are deteriorated. On the other hand, when the latter polyol resin is used, especially when a full-color image forming apparatus of a one-component developing system or a two-component developing system using a small developing device with a small amount of developer is used, the ground due to the charging characteristics is used. In some cases, a dirty image is generated or the image density is low.
[0003]
[Problems to be solved by the invention]
The present invention has been made in view of the above problems. For example, the following is used in an image forming apparatus of a one-component development system or a two-component development system using a small developing device with a small amount of developer. An object is to provide a toner having characteristics.
First, to provide a toner capable of obtaining a clear image having a sufficient image density without a background image.
Second, to provide a toner capable of obtaining an image having a proper and uniform gloss;
Third, to provide a toner capable of obtaining an image having no image blur, particularly in a halftone portion,
Fourth, to provide a toner in which aggregates do not occur in a toner bottle or a developing device, and a phenomenon in which an image of a portion where aggregates are present does not occur white,
Fifth, providing toner that does not adhere to PVC mats, etc.
It is in. It is another object of the present invention to provide a toner with good manufacturability. Here, good manufacturability means that there is no possibility that a problem that a target product cannot be obtained due to, for example, a side reaction during production. Also, it means that sensitization does not affect the health and safety of workers.
[0004]
[Means for Solving the Problems]
The present invention relates to a dry electrophotographic toner comprising at least a colorant and a binder resin.
(I) a polyol resin obtained by reacting the following reaction components (a), (b), and (c):
(A): Epoxy resin
(B): Divalent phenol
(C): Low molecular weight polyester polymer which is a reaction product of an alkylene oxide adduct of dihydric phenol and a polycarboxylic acid
(II) By using a binder resin composed of an alkylene oxide adduct of at least a dihydric phenol or a polyester resin obtained by reacting a glycidyl ether thereof with a polyvalent carboxylic acid, the image is whitened or adhered to a PVC mat. A dry process that prevents blemishes and maintains image density when using a one-component development system or a two-component development system that uses a small amount of developer, and that gives a glossy image without blurring. This makes it possible to provide toner for electrophotography.
In particular, by setting the blending ratio of the polyol resin and the polyester resin (polyol resin / polyester resin (weight ratio)) to 20/80 to 80/20, there is no environmental fluctuation and adhesion to PVC mat and the like is prevented. The image quality can be improved in a full-color image forming apparatus of a one-component development method or a two-component development method using a small developing device with a small amount of developer.
Further, by using a binder resin in which the epoxy value of the polyol resin is 20,000 or more, a dry electrophotographic toner having excellent sensitization and manufacturing stability can be obtained. Furthermore, by setting the acid value of the polyester resin in the binder resin to 5 or less, particularly 1 or less, a dry electrophotographic toner having excellent charge amount stability at high humidity can be obtained.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below. However, the present invention is not limited to the embodiment.
The polyol resin in the present invention refers to a polyol resin having a molecular structure derived from an epoxy resin raw material which is a reaction component, but having a molecular structure in which terminal epoxy groups are consumed by the reaction. Further, glossiness can be obtained by incorporating a low molecular polyester polymer, which is a reaction product of an alkylene oxide adduct of a dihydric phenol and a polyvalent carboxylic acid, into the main chain of the polyol resin by reaction. The gloss is equivalent to that of a resin having a polyoxyalkylene moiety in the main skeleton, and the compatibility with the polyester resin, which is one component of the binder resin, is improved, and it is homogeneous and stable for high-quality dry electrophotography. It is possible to increase toner productivity.
[0006]
In addition, when the polyol part of the present invention is synthesized, if the polyol part is constituted by using at least two kinds of bisphenol A type epoxy resins having different number average molecular weights, an appropriate molecular weight distribution can be obtained and a clear color image can be obtained. It becomes possible. In this case, the number average molecular weight of the low molecular weight component epoxy resin is preferably 360 to 2,000, and the number average molecular weight of the high molecular weight component epoxy resin is preferably 3,000 to 10,000. The molecular weight distribution is expressed by the ratio (Mw / Mn) of the number average molecular weight (Mn) to the volume average molecular weight (Mw). In the case of a glossy color toner, Mw / Mn is preferably 3 to 8, and this value is It can be controlled by adjusting the ratio of the low molecular weight component epoxy resin and the high molecular weight component epoxy resin used.
[0007]
On the other hand, the low molecular weight polyester polymer can be synthesized, for example, by a condensation reaction of an alkylene oxide adduct of bisphenol A and a polyvalent carboxylic acid, and preferably has a number average molecular weight of 500 to 2,000.
[0008]
The polyol resin of the present invention comprises a low-molecular polyester polymer that is a reaction product of the above-mentioned epoxy resin, an alkylene oxide adduct of a dihydric phenol and a polyvalent carboxylic acid, and a dihydric phenol as a reaction composition. It can be obtained by adding an alkylene oxide adduct of a dihydric phenol, a monohydric phenol compound, a carboxylic acid compound or the like and polymerizing it in a xylene solvent in the presence of a lithium chloride catalyst, and having an arbitrary molecular weight. Can do.
[0009]
The following materials are mentioned as a compound which comprises the polyol resin of this invention.
Examples of the epoxy resin (a) used in the production of the polyol resin include those obtained by condensation reaction of bisphenol A or bisphenol with epichlorohydrin. Examples of the dihydric phenol (b) include bisphenols such as bisphenol A and bisphenol F.
[0010]
On the other hand, the dihydric phenol alkylene oxide adduct used for the synthesis of the low molecular weight polyester polymer (c), which is a reaction product of the dihydric phenol alkylene oxide adduct and the polyvalent carboxylic acid, is as follows. Is exemplified.
For example, the reaction product of alkylene oxide which consists of ethylene oxide, propylene oxide, butylene oxide, and these mixtures etc., and bisphenol compounds, such as bisphenol A and bisphenol F, is mentioned.
[0011]
Moreover, the following are illustrated as polyvalent carboxylic acid used for the synthesis | combination of a low molecular polyester polymer.
Specific examples of divalent carboxylic acids include aliphatic dicarboxylic acids and derivatives thereof (maleic acid, fumaric acid, succinic acid, adipic acid, sebacic acid, malonic acid, azelaic acid, mesaconic acid, citraconic acid, glutaconic acid, octyl succinic acid. Acid, decyl succinic acid, dodecyl succinic acid, tetradecyl succinic acid, hexadecyl succinic acid, octadecyl succinic acid, isooctadecyl succinic acid, hexenyl succinic acid, octenyl succinic acid, decenyl succinic acid, dodecenyl succinic acid, tetrapropenyl succinic acid, tetradecenyl succinic acid Succinic acid, hexadecenyl succinic acid, isooctadecenyl succinic acid, octadecenyl succinic acid, nonenyl succinic acid, etc.) and alicyclic dicarboxylic acids (cyclohexanedicarboxylic acid, methylmedicic acid, etc.), aromatic dicarboxylic acids ( Phthalic acid, Sofutaru acid, terephthalic acid, toluene dicarboxylic acid, naphthalene and di-carboxylic acid) as well as these divalent anhydrides of carboxylic acids or lower alkyl (methyl, butyl, etc.) ester.
Examples of trivalent or tetravalent carboxylic acids include trimellitic acid, pyromellitic acid, 1,2,4-cyclohexanetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalene. There are tricarboxylic acids, 1,2,5-hexanetricarboxylic acid, 1,2,7,8-octanetetracarboxylic acid and acid anhydrides thereof. These can be used alone or in combination.
[0012]
The softening point of the polyol resin is preferably in the range of 100 to 130 ° C. If the temperature is lower than 100 ° C., agglomerates are likely to be generated in the toner bottle or the developing device, and there is a tendency that an image of the agglomerated portion is whitened when the agglomerates are developed and transferred. On the other hand, when the temperature exceeds 130 ° C., there is a tendency that sufficient fixing properties are difficult to obtain.
[0013]
Furthermore, if necessary, an alkylene oxide adduct of a dihydric phenol can be added as a reaction component of the polyol resin of the present invention. Examples of such compounds include reaction products of alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide and mixtures thereof and bisphenol compounds such as bisphenol A and bisphenol F.
[0014]
Also, if the polyol resin has an epoxy value of 20,000 or more, so-called resin having as little epoxy group as possible is excellent in terms of sensitization and production stability.
[0015]
In consideration of chemical stability and environmental stability as a dry electrophotographic toner as described above, the terminal epoxy group of the polyol resin can be capped if necessary, but in this case, it can be reacted with the epoxy group. A compound having one active hydrogen in the molecule, for example, a monohydric phenol compound or a carboxylic acid compound can be mentioned.
Examples of the monohydric phenol compound include phenol, cresol, isopropylphenol, amylphenol, nonylphenol, dodecylphenol, xylenol, p-cumylphenol and the like. Examples of the carboxylic acids include aromatic carboxylic acids such as benzoic acid, and aliphatic carboxylic acids such as stearic acid.
Using these monovalent compounds, the polyol resin in which the terminal epoxy group is capped by reacting in the presence of a lithium chloride catalyst in a solvent such as xylene, as described above, as the reaction component of the polyol resin. Is obtained.
[0016]
The polyester resin which is one component of the binder resin of the present invention can be synthesized by reacting an alkylene oxide adduct of dihydric phenol or a glycidyl ether thereof with a polyvalent carboxylic acid.
[0017]
The following materials are mentioned as a compound used for the synthesis | combination of a polyester resin.
Examples of the dihydric phenol alkylene oxide adducts or glycidyl ethers thereof include reaction products of alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, and mixtures thereof with bisphenol compounds such as bisphenol A and bisphenol F. .
[0018]
Moreover, the following are illustrated as polyvalent carboxylic acid.
Specific examples of divalent carboxylic acids include aliphatic dicarboxylic acids and derivatives thereof (maleic acid, fumaric acid, succinic acid, adipic acid, sebacic acid, malonic acid, azelaic acid, mesaconic acid, citraconic acid, glutaconic acid, octyl succinic acid. Acid, decyl succinic acid, dodecyl succinic acid, tetradecyl succinic acid, hexadecyl succinic acid, octadecyl succinic acid, isooctadecyl succinic acid, hexenyl succinic acid, octenyl succinic acid, decenyl succinic acid, dodecenyl succinic acid, tetrapropenyl succinic acid, tetradecenyl succinic acid Succinic acid, hexadecenyl succinic acid, isooctadecenyl succinic acid, octadecenyl succinic acid, nonenyl succinic acid, etc.) and alicyclic dicarboxylic acids (cyclohexane dicarboxylic acid, methyl nadic acid etc.), aromatic dicarboxylic acids (Phthalic acid, Sofutaru acid, terephthalic acid, toluene dicarboxylic acid, naphthalene and di-carboxylic acid) as well as these divalent anhydrides of carboxylic acids or lower alkyl (methyl, butyl, etc.) ester.
Examples of trivalent or tetravalent carboxylic acids include trimellitic acid, pyromellitic acid, 1,2,4-cyclohexanetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalene. There are tricarboxylic acids, 1,2,5-hexanetricarboxylic acid, 1,2,7,8-octanetetracarboxylic acid and acid anhydrides thereof. These can be used alone or in combination.
[0019]
The softening point of the polyester resin used in the present invention is preferably in the range of 110 ° C to 130 ° C. Further, as mentioned above, the acid value is preferably 5 or less, and more preferably 1 or less. When the acid value is high, the stability tends to be lacking, such as a decrease in charge amount at high humidity.
[0020]
The polyester resin of the present invention can carry out, for example, an esterification reaction or a transesterification reaction by charging the alkylene oxide adduct of dihydric phenol or its glycidyl ether and a polyvalent carboxylic acid compound into a reaction kettle and heating to increase the temperature. Can do. At this time, if necessary, an esterification catalyst or a transesterification catalyst used in a normal esterification reaction or transesterification reaction such as sulfuric acid, titanium butoxide, dibutyltin oxide, and manganese acetate can be used. Next, it is preferable to carry out the polymerization while removing water or alcohol produced by the reaction according to a conventional method and further distilling and removing the diol component under reduced pressure. In the polymerization, generally known polymerization catalysts such as titanium butoxide, dibutyltin oxide, tin acetate, zinc acetate, tin disulfide, antimony trioxide, germanium dioxide and the like can be used.
[0021]
The Tg of the obtained polyester resin is preferably 50 ° C to 75 ° C, more preferably 55 ° C to 70 ° C. When the Tg is low, aggregates are likely to be generated in the toner bottle or the developing device, and when the aggregates are developed and transferred, there is a tendency that an image of the aggregate portion is whitened. Conversely, when Tg is high, there is a tendency that sufficient image gloss is difficult to obtain.
[0022]
Here, the blending ratio (polyol resin / polyester resin (weight ratio)) of the polyol resin and the polyester resin as the binder resin is preferably 20/80 to 80/20 as described above. If it is less than 20/80, the characteristics are likely to deteriorate due to environmental fluctuations, which is not preferable, and a phenomenon such as adhesion to a PVC mat or the like is observed. If the ratio is larger than 80/20, there is a problem that improvement in image quality is not observed in a full-color image forming apparatus of a one-component development system or a two-component development system using a small developing device with a small amount of developer.
[0023]
Next, other materials used for the dry toner of the present invention will be described.
In the present invention, a so-called release agent that imparts releasability to the toner may be used. The softening point of the release agent used is preferably 70 to 100 ° C. When the softening point is lower than 70 ° C., there is a problem in storage stability. Conversely, when the softening point is higher than 100 ° C., not only fixing is insufficient, but the color image is poor such as low gloss. It is easy.
[0024]
Specific release agents include synthetic waxes such as low molecular weight polyethylene and polypropylene, copolymers thereof, candelilla wax, carnauba wax, rice wax, wood wax, jojoba wax and other plant waxes, beeswax, Examples thereof include animal waxes such as lanolin and whale wax, mineral waxes such as montan wax and ozokerite, and fat waxes such as hardened castor oil, hydroxystearic acid, fatty acid amide, and phenol fatty acid ester.
[0025]
From the viewpoint of the chemical structure of the wax, hydrocarbon waxes, ester waxes, amide waxes and the like are known. In the present invention, ester waxes are used for storage stability, image quality, and fixing. It is preferable to evaluate from the viewpoint of temperature range and the like.
[0026]
The amount of the release agent is preferably 1 to 6 parts by weight with respect to 100 parts by weight of the binder resin. If the amount is more than 6 parts by weight, problems such as storage stability may occur, the image surface may be rough, and gloss may be lowered. Further, even if the amount is less than 1 part by weight, the color image tends to be poor because the image surface is rough and gloss is low.
[0027]
As the colorant, all known dyes and pigments can be used. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ocher, Yellow lead, Titanium yellow, Polyazo yellow, Oil yellow, Hansa yellow (GR, A, RN, R), Pigment yellow L, Benzidine yellow (G, GR), Permanent yellow (NCG), Vulcan fast yellow (5G, R) ), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Red Dan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R, Para Red, Phi Se Red, Parachlor Ortonito Aniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmin Min BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX, Permanent Red F5R , Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo red B, thioindigo maroon, oil red, quinacridone red, pyrazolone red Polyazo Red, Chrome Vermillion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal Free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), indigo, ultramarine blue, bitumen, anthraquinone blue, fast violet B, methyl violet lake, cobalt purple, manganese purple, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium oxide, pyridian, emerald green, pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Green Lake, Lid Russian Nine Green, Anthraquinone Green, Titanium Oxide, Zinc Hana, Litobon and mixtures thereof.
The amount of the colorant used is generally preferably 0.1 to 50 parts by weight with respect to 100 parts by weight of the binder resin.
[0028]
The dry electrophotographic toner of the present invention may contain a charge control agent as required. Any known charge control agent can be used. For example, nigrosine dyes, triphenylmethane dyes, chromium-containing complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (fluorine-modified 4 Secondary ammonium salts or compounds, tungsten simple substances or compounds, fluorine activators, salicylic acid metal salts, and metal salts of salicylic acid derivatives.
[0029]
Other additives include, for example, silica fine particles, fatty acid metal salts (such as zinc stearate and aluminum stearate), metal oxides (such as titanium oxide, aluminum oxide, tin oxide, and antimony oxide), and fluoropolymers. Also good. In particular, hydrophobized silica, titania, and alumina fine particles are suitable.
[0030]
Silica fine particles include HDK-H-2000, HDK-H-2000 / 4, HDK-H-2050EP, HDK-H-1303VP (manufactured by Clariant) and R972, R974, RX200, RY200, R202, R805, R812. (Nippon Aerosil Co., Ltd.)
[0031]
Further, as titania fine particles, P-25 (manufactured by Nippon Aerosil Co., Ltd.), STT-30, STT-65C-S (manufactured by Titanium Industry Co., Ltd.), TAF-140 (manufactured by Fuji Titanium Industry Co., Ltd.), MT-150W, MT -500B, MT-600B (manufactured by Teika).
In particular, as hydrophobized titanium oxide fine particles, anatase-type or rutile-type crystalline or non-crystalline can be used, and T-805 (manufactured by Nippon Aerosil Co., Ltd.) or rutile-type MT- 100S, MT-100T, MT-150A, MT-150AFM, MT-150AI (manufactured by Teica), STT-30A, STT-65S-S (manufactured by Titanium Industry), TAF-500T, TAF-1500T (and above) Fuji Titanium Industrial Co., Ltd.), MT-100S, MT-100T (manufactured by Teika), IT-S (Ishihara Sangyo Co., Ltd.), and the like.
[0032]
In order to obtain hydrophobized silica fine particles, titania fine particles, and alumina fine particles, hydrophilic fine particles must be treated with a silane coupling agent such as methyltrimethoxysilane, methyltriethoxysilane, or octyltrimethoxysilane. Can do. Further, fatty acid metal salts (zinc stearate, aluminum stearate, etc.), metal oxides (alumina, tin oxide, antimony oxide, etc.), fluoropolymers, etc. may be contained together as additives.
[0033]
The dry electrophotographic toner of the present invention composed of the above materials may be used alone as a one-component developer, or may be used as a two-component developer together with the carrier described below.
When used as a two-component developer, iron powder, ferrite, glass beads and the like are used as the carrier used in the toner, as is conventionally known. These carriers may be those coated with a resin. The resin used in this case may be a known resin, and examples thereof include acrylic resin, polyfluorinated carbon, polyvinyl chloride, polyvinylidene chloride, phenol resin, polyvinyl acetal, and silicone resin. The mixing ratio of the toner and the carrier is generally about 2.5 to 8.0 parts by weight of the toner with respect to 100 parts by weight of the carrier.
[0034]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the examples. In addition, all the parts in an Example show a weight part.
[0035]
Synthesis example 1 (Synthesis example of polyol resin 1)
Stirrer, thermometer, N ₂ Into a separable flask with an inlet and a cooling tube, 300 g of low molecular weight bisphenol A / epichlorohydrin type epoxy resin (EPOMIKR-140 manufactured by Mitsui Chemicals, number average molecular weight: about 360), high molecular weight bisphenol A / epichlorohydrin type epoxy resin (Mitsui Chemicals) EPOMIK R-309, number average molecular weight: about 2900) 150 g, bisphenol A type propylene oxide adduct 230 g, bisphenol A 240 g, p-cumylphenol 90 g, low molecular weight polyester polymer (bisphenol A type propylene oxide adduct and anhydrous 50 g of phthalic acid condensate, number average molecular weight of about 1500), and 200 g of xylene were added. N ₂ The temperature was raised to 70-100 ° C. in an atmosphere, 0.183 g of lithium chloride was added, the temperature was further raised to 160 ° C., xylene was distilled off under reduced pressure, and polymerization was performed at a reaction temperature of 180 ° C. for 6-9 hours. A polyol resin 1 was obtained.
[0036]
Synthesis Example 2 (Synthesis example of polyester resin 1)
The raw materials of the acid component and the alcohol component shown in the polyester resin composition 1 of Table 1 below are placed in a 1 L four-necked round bottom flask equipped with a thermometer, a stirrer, a condenser and a nitrogen gas introduction tube according to the blending amount. This flask was set in a mantle heater. Next, nitrogen gas is introduced from the nitrogen gas introduction tube, and the temperature is raised in a state where the inside of the flask is kept in an inert atmosphere. Next, 0.05 g of dibutyltin oxide is added and the temperature is kept at 200 ° C. for reaction. A polyester resin 1 was obtained.
[0037]
Synthesis Example 3 (Synthesis example of polyester resin 2)
According to the blending amount, raw materials of the acid component and the alcohol component shown in the polyester resin composition 2 in Table 1 below are put into a 1 L four-necked round bottom flask equipped with a thermometer, a stirrer, a condenser and a nitrogen gas introduction tube. This flask was set in a mantle heater. Next, nitrogen gas is introduced from the nitrogen gas introduction tube, and the temperature is raised in a state where the inside of the flask is maintained in an inert atmosphere. Next, 0.05 g of dibutyltin oxide is added, and the temperature is kept at 210 ° C. for reaction. A polyester resin 2 was obtained.
[0038]
Synthesis Example 4 (Synthesis example of polyester resin 3)
The raw materials of the acid component and the alcohol component shown in the polyester resin composition 3 of Table 1 below are put in a 1 L four-necked round bottom flask equipped with a thermometer, a stirrer, a condenser and a nitrogen gas introduction tube according to the blending amount. This flask was set in a mantle heater. Next, nitrogen gas is introduced from the nitrogen gas introduction tube, and the temperature is raised in a state where the inside of the flask is maintained in an inert atmosphere. Next, 0.05 g of dibutyltin oxide is added, and the temperature is kept at 210 ° C. for reaction. A polyester resin 3 was obtained.
[0039]
[Table 1]

[0040]
Softening point, glass transition point (Tg), molecular weight (number average molecular weight (Mn)) of polyol resin 1 obtained in Synthesis Example 1 and polyester resin 1 to polyester resin 3 obtained in Synthesis Examples 2 to 4 ), Molecular weight distribution (Mw / Mn), epoxy equivalent, and acid value were measured by the following evaluation methods. The results are shown in Table 2.
[0041]
Evaluation methods
-Measurement of softening point-
As a device for measuring the softening point, a fully automatic drip point device FP5 / FP53 manufactured by Metra Corporation was used, and the measurement was performed according to the following procedure.
(1) Place the ground sample in a melting pot and leave it for 20 minutes, then pour the sample into the cup edge of the sample cup (droplet diameter 6.35 mm), cool to room temperature, and set it in the cartridge.
(2) A predetermined temperature increase rate (1 ° C./min) and a measurement start temperature (set to an expected softening temperature of 15 ° C. or lower) are set in the FP-5 control unit.
(3) Mount the cartridge in the FP-53 heating furnace, leave it for 30 seconds, and then depress the start lever to start the measurement (the following measurements are performed automatically).
(4) When the measurement is completed, remove the cartridge.
(6) The softening point (° C.) is calculated as follows.
FP-5 result display panel A value + correction value
In addition, if said correction value is added to the obtained result, it corresponds to the result of the Duran mercury method. When the difference between the value of the result display panel A and the measurement start temperature (values of the panels B and C) is not 15 ° C. or more, the test is repeated.
-Measurement of Tg-
As a device for measuring Tg, Seiko DSC-200 was used, and the measurement was performed according to the following procedure.
(1) Crush the sample, weigh 10 ± 1 mg into an aluminum sample container, and crimp the aluminum lid from above.
(2) The glass transition point (Tg) is measured by DSC method in a nitrogen atmosphere.
Analysis conditions:
The sample was heated from room temperature to 150 ° C. at a heating rate of 20 ° C./min, then left at 150 ° C. for 10 min, cooled to 0 ° C. at a cooling rate of 50 ° C./min and left for 10 min, and then a nitrogen atmosphere (20 cc / Min), and DSC measurement is performed by heating again to 150 ° C. at a heating rate of 20 ° C./min. Tg reads the peak rise temperature using analysis software [Tg job].
-Measurement of molecular weight-
The molecular weight was measured by the GPC method under the following conditions.
The column was stabilized in a constant temperature bath of 40 ° C., chloroform was flowed as an eluent at a flow rate of 1 ml / min, and 100 μl of a sample chloroform solution adjusted to a sample concentration of 0.05 to 0.5% by weight was injected for measurement. Do. The molecular weight of the sample was calculated from the molecular weight distribution determined by the retention time based on a calibration curve prepared in advance. The calibration curve at this time was prepared using several types of monodisperse polyethylene as standard samples. In addition, GMHLX + G3000HLX (manufactured by Tosoh Corporation) was used as an analytical column.
-Measurement of epoxy equivalent-
The epoxy equivalent was measured by an indicator titration method shown in 4.2 of JIS K 7236.
-Measurement of acid value-
The acid value was measured by the method defined in JIS K 0070.
[0042]
[Table 2]

[0043]
Example 1
(Prescription of each color toner)
The following yellow toner, magenta toner, cyan are prepared by blending the polyol resin 1 obtained in Synthesis Example 1 and the polyester resin 1 obtained in Synthesis Example 2 with a colorant, a release agent, an antistatic agent (CCA) and the like. Toner and black toner were formulated.
Yellow toner prescription:
50 parts of polyol resin 1
50 parts of polyester resin 1
Carnauba wax (ester wax, melting point: about 82 ° C) 3 parts
6 parts of yellow pigment (Toner Yellow HG manufactured by Clariant)
CCA (Orient Chemical Industries E-84) 2 parts
Magenta toner prescription:
50 parts of polyol resin 1
50 parts of polyester resin 1
Carnauba wax 3 parts
5 parts of red pigment (Rionogen Magenta R manufactured by Toyo Ink Co., Ltd.)
CCA (Orient Chemical Industries E-84) 2 parts
Cyan toner prescription:
50 parts of polyol resin 1
50 parts of polyester resin 1
Carnauba wax 3 parts
4 parts of blue pigment (Lionol Blue FG-7351 manufactured by Toyo Ink Manufacturing Co., Ltd.)
CCA (Orient Chemical Industries E-84) 2 parts
Black toner prescription:
50 parts of polyol resin 1
50 parts of polyester resin 1
Carnauba wax 3 parts
Black pigment (carbon black; Mitsubishi Chemical # 44) 6 parts
CCA (Orient Chemical Industries E-84) 2 parts
[0044]
(Preparation of each color developer)
A mixture of the above color toner formulations is melt-kneaded with a hot roll mill, cooled, coarsely pulverized with a hammer mill, and then finely pulverized with an air jet pulverizer. Respectively.
Next, 0.7 parts of hydrophobic silica HDK2000H (manufactured by Clariant Japan) was mixed with 100 parts of each of the obtained color toners to prepare a one-component developer. Each color one-component developer thus obtained was evaluated as follows.
[0045]
Example 2
Each color toner shown below was formulated using polyol resin 1 and polyester resin 1 as binder resin components in the same manner as in Example 1, and an average particle size of about 7 μm was obtained from these mixtures in exactly the same manner as in Example 1. Toner was obtained by classification.
(Prescription of each color toner)
Yellow toner prescription:
20 parts of polyol resin 1
80 parts of polyester resin 1
5 parts of yellow pigment (Lionol Yellow FGN-T manufactured by Toyo Ink Co., Ltd.)
CCA (Orient Chemical Industries E-84) 1 part
Magenta toner prescription:
20 parts of polyol resin 1
80 parts of polyester resin 1
5 parts of red pigment (Rionogen Magenta R manufactured by Toyo Ink Co., Ltd.)
CCA (Orient Chemical Industries E-84) 1 part
Cyan toner prescription:
20 parts of polyol resin 1
80 parts of polyester resin 1
3 parts of blue pigment (Lionol Blue FG-7351, manufactured by Toyo Ink Co., Ltd.)
CCA (Orient Chemical Industries E-84) 1 part
Black toner prescription:
20 parts of polyol resin 1
80 parts of polyester resin 1
Black pigment (carbon black) 4.5 parts
CCA (Orient Chemical Industries E-84) 1 part
[0046]
(Preparation of each color developer)
To 100 parts of the color toner obtained above, 0.5 part of R972 (manufactured by Nippon Aerosil Co., Ltd.) and 0.3 part of STT-30A (manufactured by Titanium Industry Co., Ltd.) were mixed. Subsequently, 5 parts of each color toner was mixed with 95 parts of a carrier in which spherical ferrite having an average diameter of 50 μm and silicon resin was coated to obtain a two-component developer of each color. Each color two-component developer thus obtained was evaluated as follows.
[0047]
Example 3
In Example 2, each color toner was formulated in exactly the same manner as in Example 2, except that 80 parts of polyol resin 1 and 20 parts of polyester resin 1 were replaced. Each color toner obtained was mixed and prepared with a carrier in the same procedure as in Example 2 to obtain a two-component developer of each color. Each color two-component developer obtained was evaluated as follows.
[0048]
Example 4
Example 1 is the same as Example 1 except that polyester resin 1 is replaced with polyester resin 2 (Mn: 3400, Mw / Mn: 7.5, Tg: 61 ° C., softening point: 122 ° C., acid value: 4). Each color toner was formulated in exactly the same way. Each color toner was mixed with hydrophobic silica HDK2000H (manufactured by Clariant Japan) in the same procedure as in Example 1 to obtain a one-component developer. Each color one-component developer thus obtained was evaluated as follows.
[0049]
Example 5
Example 1 except that polyester resin 1 was replaced with polyester resin 3 (Mn: 3700, Mw / Mn: 5.5, Tg: 59 ° C., softening point: 120 ° C., acid value: 0.2) in Example 1. Each color toner was formulated exactly as in 1. Each color toner was mixed with hydrophobic silica HDK2000H (manufactured by Clariant Japan) in the same procedure as in Example 1 to obtain a one-component developer. Each color one-component developer thus obtained was evaluated as follows.
[0050]
Comparative Example 1
Each color toner was formulated in exactly the same manner as in Example 1, except that 100 parts of the polyol resin 1 and 0 parts of the polyester resin 1 were replaced in Example 1. Each color toner was mixed with hydrophobic silica HDK2000H (manufactured by Clariant Japan) in the same procedure as in Example 1 to obtain a one-component developer. Each color one-component developer thus obtained was evaluated as follows.
[0051]
Comparative Example 2
In Example 1, each color toner was formulated in exactly the same manner as in Example 1 except that the polyol resin 1 was changed to 0 part and the polyester resin 1 was changed to 100 parts. Each color toner was mixed with hydrophobic silica HDK2000H (manufactured by Clariant Japan) in the same procedure as in Example 1 to obtain a one-component developer. Each color one-component developer thus obtained was evaluated as follows.
[0052]
Evaluation 1 (Evaluation of one-component developer)
Each of the developers in Examples 1, 4, 5 and Comparative Examples 1 and 2 was an experimental machine having a developing part shown in FIG. 1 and a fixing part of a PFA-coated silicon roller (set temperature 160 ° C.) of φ30 mm ( 99 sheets of A4 size 25% image area ratio at a process speed of 75 mm / s, and 99 sheets of originals were printed continuously. Each image was evaluated according to the following evaluation items ("ground fog", "image blurring"). ”,“ Aggregate ”,“ vinyl chloride adhesion ”,“ environmental change ”), and evaluation rank. The evaluation results are shown in Table 3.
[0053]
Evaluation 2 (Evaluation of two-component developer)
Each developer of Examples 2 and 3 was put in an Image Color 4050 (two-component developing device), and 250 sheets of A4 size 25% image area ratio originals were printed continuously in a single color, and each image was printed. The evaluation was performed based on the following evaluation items (“ground fog”, “image blurring”, “aggregate”, “vinyl chloride adhesion”, “environmental fluctuation”) and evaluation rank. The evaluation results are shown in Table 3.
[0054]
<Evaluation items>
Ground fogging: Evaluates dirt on the background during continuous copying
Image blurring: Evaluate the uniformity of the halftone part
Aggregate: Evaluates the degree of aggregation after storing the toner at 50 ° C. for 48 hours.
PVC adhesion: Evaluates the fusing property to PVC (vinyl chloride) after leaving the image at 50 ° C for 8 hours under certain conditions.
Environmental fluctuation: Evaluate changes in image density in an environment of 30 ° C / 80%
<Evaluation rank>
A: No problem at all
Y: No problem
Δ: Slightly problematic but acceptable level
×: There is a problem
[0055]
[Table 3]

[0056]
As is apparent from Table 3, the dry photographic toner prepared by blending the polyol resin and the polyester resin of the present invention into a binder resin can be used as a one-component developer or a two-component developer. There is no ground fogging or image blurring, no agglomeration is observed, there is no adhesion of vinyl chloride, it exhibits stable characteristics against environmental fluctuations, and generally exhibits balanced characteristics. On the other hand, when only the polyol resin of the comparative example is used as the binder resin, there is a problem in image blurring, or when only the polyester resin is used as the binder resin, vinyl chloride adheres to the environment. Problems occur.
[0057]
【The invention's effect】
By using the dry electrophotographic toner of the present invention, it is possible to obtain a clear image without a background image and having a sufficient image density. Furthermore, an image having an appropriate and uniform gloss can be obtained, and an image having no image unevenness can be obtained in the halftone portion. Further, no agglomerates are generated in the toner bottle or the developing device for a long period of time, and as a result, a phenomenon in which the image of the part where the agglomerates exists is not generated white. Further, the copy image does not adhere to the PVC mat or the like. Moreover, it is stable without producing gelation due to side reaction of the binder resin during production, and a toner that does not affect the health and safety of workers due to sensitization can be obtained.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing a one-component developing device used for evaluation of a one-component developer according to an embodiment of the present invention.
[Explanation of symbols]
1 Toner tank
2 Toner carrier
3 Toner layer thickness regulating member
4 Toner supply member
5 Photoconductor
6 Stirrer blade
7 Toner
8 Development interval

Claims (8)

In a dry electrophotographic toner comprising at least a colorant and a binder resin, the binder resin is:
(I) a polyol resin obtained by reacting the following reaction components (a), (b), and (c):
(A): epoxy resin (b): divalent phenol (c): low molecular weight polyester polymer (II) which is a reaction product of an alkylene oxide adduct of divalent phenol and a polyvalent carboxylic acid A dry electrophotographic toner comprising an alkylene oxide adduct or a polyester resin obtained by reacting a glycidyl ether thereof with a polyvalent carboxylic acid. 2. The dry electrophotographic toner according to claim 1, wherein an alkylene oxide adduct of dihydric phenol is added as a reaction component of the polyol resin. 3. The dry electrophotographic toner according to claim 1, wherein a compound having one active hydrogen in a molecule that reacts with an epoxy group is added as a reaction component of the polyol resin. 4. The dry electrophotographic toner according to claim 3, wherein the compound having one active hydrogen that reacts with the epoxy group in the molecule is a monohydric phenol compound. The ratio of the polyol resin to the polyester resin (polyol resin / polyester resin (weight ratio)) is 20/80 to 80/20, for dry electrophotography according to any one of claims 1 to 4. toner. 6. The dry electrophotographic toner according to claim 1, wherein in the reaction composition of the polyol resin, (a) is at least two bisphenol type epoxy resins having different number average molecular weights. The dry electrophotographic toner according to claim 1, wherein an epoxy equivalent of the polyol resin is 20,000 or more. The dry electrophotographic toner according to claim 1, wherein the polyester resin has an acid value of 5 or less.

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