JP2004294737A - Toner and method for manufacturing toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner having satisfactory durability and exhibiting excellent fixability (fixing strength) in a wide temperature range, and to provide a method for manufacturing a toner by which the above toner can be manufactured. <P>SOLUTION: The toner consists of materials including a block polyester mainly made up of a block copolymer, an amorphous polyester having lower crystallinity than the block polyester, and a colorant. The block polyester has crystalline blocks prepared by condensing alcohol and carboxylic acid components, and amorphous blocks having lower crystallinity than the crystalline blocks. The toner has a first region mainly made up of the block polyester and a second region mainly made up of the amorphous polyester in toner particles, wherein a concentration of the colorant in the first region is higher than that in the second region. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０２７２】
【表２】

【０２７３】
［３］評価
以上のようにして得られた各トナーについて、定着良好域、現像耐久性、保存性、帯電特性、転写効率、透明性の評価を行った。
［３．１］定着良好域
まず、前述した図７〜図１４、図１７に示すような定着装置を作製した。この定着装置では、トナーがニップ部を通過するのに要する時間Δｔを０．０５秒に設定した。この定着装置を用いて図５、図６に示すような画像形成装置（カラープリンタ）を作製した。この画像形成装置を用いて、未定着の画像サンプルを採取し、当該画像形成装置の定着装置で、以下のような試験を実施した。なお、採取するサンプルのベタは付着量を０．４０〜０．５０ｍｇ／ｃｍ^２に調整した。
【０２７４】
画像形成装置を構成する定着装置の定着ローラの表面温度を所定温度に設定した状態で、未定着のトナー像が転写された用紙（セイコーエプソン社製、上質普通紙）を、定着装置の内部に導入することにより、トナー像を用紙に定着させ、定着後におけるオフセットの発生の有無を目視で確認した。
同様に、定着ローラの表面の設定温度を１００〜２５０℃の範囲で順次変更していき、各温度でのオフセットの発生の有無を確認し、オフセットが発生しなかった温度範囲を、「定着良好域」として求め、以下の３段階の基準に従い評価した。
◎：定着良好域の幅が６０℃以上である。
○：定着良好域の幅が３５℃以上６０℃未満である。
×：定着良好域の幅が３５℃未満である。
【０２７５】
［３．２］現像耐久性
前記［３．１］で用いた画像形成装置の現像装置にトナーを３０ｇセットした後、無補給でエージングを行い、現像ローラへのフィルミングが発生するまでの時間を測定し、以下の３段階の基準に従い評価した。
◎：エージング開始後、１２０分以上経過しても、フィルミングの発生は認められなかった。
○：エージング開始後、６０〜１２０分でフィルミングが発生。
×：エージング開始後、６０分未満でフィルミングが発生。
【０２７６】
［３．３］保存性
各実施例および各比較例のトナーを、それぞれ１０ｇずつサンプル瓶に入れ、５０℃の恒温槽内に４８時間放置した後、固まり（凝集）の有無を目視で確認し、以下の３段階の基準に従い評価した。
◎：固まり（凝集）の存在が全く認められなかった。
○：小さい固まり（凝集）がわずかに認められた。
×：固まり（凝集）がはっきりと認められた。
【０２７７】
［３．４］帯電特性
前記［３．１］で用いた画像形成装置において、印字途中で画像形成装置を停止させ、カートリッジを取り外し、粉黛帯電量分布測定装置（ホソカワミクロン社製、Ｅ−ｓｐａｒｔ ａｎａｌｙｚｅｒ）を用いて、帯電量分布を測定し、その結果から、帯電量および逆帯電量としてプラス帯電量を求めた。
【０２７８】
帯電量については、初期帯電量と、１０００枚印字後（１Ｋ後）の帯電量について求めた。
１０００枚印字後（１Ｋ後）の帯電量については、以下の４段階の基準に従い評価した。
◎：初期帯電量からの変化量（絶対値）が０．５μＣ／ｇ未満。
○：初期帯電量からの変化量（絶対値）が０．５μＣ／ｇ以上１μＣ／ｇ未満。
△：初期帯電量からの変化量（絶対値）が１μＣ／ｇ以上３μＣ／ｇ未満。
×：初期帯電量からの変化量（絶対値）が３μＣ／ｇ以上。
また、逆帯電性のトナーについては、全トナー量に対する存在比率を求め、逆帯電性のトナーの存在比率が３ｗｔ％未満の場合は○、逆帯電性のトナーの存在比率が３ｗｔ％以上の場合は×とした。
【０２７９】
［３．５］転写効率
前記［３．１］で用いた画像形成装置を用いて、以下のように評価した。
感光体（像担持体）への現像工程直後（転写前）の感光体上のトナーと、転写後（印刷後）の感光体上のトナーとを、別々のテープを用いて採取し、それぞれの重量を測定した。転写前の感光体上のトナー重量をＷ_ｂ［ｇ］、転写後の感光体上のトナー重量をＷ_ａ［ｇ］としたとき、（Ｗ_ｂ−Ｗ_ａ）×１００／Ｗ_ｂとして求められる値を、転写効率とした。
【０２８０】
［３．６］透明性
まず、微量のトナーを２枚のスライドガラス間に挿し込み、ホットプレート上で溶融させ、その後、徐冷した。トナーを構成する樹脂が完全に固化するまで放置し、その後、ＨＡＺＥメーター（日本電色工業社製、ＭＯＤＥＬ１００１ＤＰ）でＨＡＺＥ値を測定し、ＨＡＺＥ値が５０未満のものを○、ＨＡＺＥ値が５０以上のものを×として、評価した。ＨＡＺＥ値は、拡散透過率を全透過率で除した値であり、トナー中の各成分の分散性が良い程、この値は小さくなる。
これらの結果を表３にまとめて示した。
【０２８１】
【表３】

【０２８２】
表３から明らかなように、本発明のトナーは、いずれも、現像耐久性に優れ、幅広い温度領域で、優れた定着性を発揮するものであった。また、本発明のトナーは、保存性にも優れていた。特に本発明のトナーでは、帯電特性、転写効率、透明性を保持しつつ、優れた現像耐久性、定着性、保存性を発揮するものであった。特に、ブロックポリエステル、非晶性ポリエステルの組成が好ましく、かつ、第１の領域の平均粒径が最適な大きさである実施例１、２、４、７のトナーでは、特に優れた結果が得られた。
【０２８３】
これに対して、比較例のトナーでは、十分な特性が得られなかった。
特に、ブロックポリエステルを含まない比較例１のトナーでは、機械的ストレスに弱く、現像耐久性、保存性が特に劣っていた。
また、非晶性ポリエステルを含まない比較例２のトナーは、定着強度が弱く、定着性に劣っていた。また、比較例２のトナーは、透明性にも劣っていた。
【０２８４】
また、ブロックポリエステルを用いず、非晶性ポリエステルと、結晶性の高いポリエステルＤとを併用した比較例３、４のトナーは、樹脂同士の親和性（ブロックポリエステルと結晶性ポリエステルとの親和性）に劣り、トナー粒子中においてマクロ相分離が発生しており、定着性と耐久性が特に劣っていた。
また、第２の領域に着色剤が偏在している比較例４では、定着性が特に劣っており、定着良好域が狭かった。
【０２８５】
また、着色剤を含まない比較例５、６のトナーでは、比較的優れた定着性を有していたが、いずれも、実施例１〜９のトナーに比べると劣っていた。このことから、本発明のように、主としてブロックポリエステルで構成された第１の領域に、着色剤を偏在させることにより、（ブロックポリエステルと非晶性ポリエステルとの配合比等に関わらず、）トナーの定着性を向上させる（定着良好域の拡大、定着強度の増強）効果が得られることがわかる。
【０２８６】
また、前記各トナーについて、上記の定着装置のニップ部を通過させ、トナー粒子の前記ニップ部の通過時間Δｔ［秒］における、緩和弾性率Ｇ（ｔ）の変化量を測定したところ、実施例１〜９の各トナーでは、緩和弾性率Ｇ（ｔ）の変化量は、いずれも１００［Ｐａ］以下であった。なお、トナー粒子が通過する際における、ニップ部の温度は、１８０℃であった。
【０２８７】
また、着色剤として、シアン顔料（Ｐ．Ｒ．１５：３）に代わり、キナクリドン（Ｐ．Ｒ．１２２）、ピグメントレッド５７：１、Ｃ．Ｉ．ピグメントイエロー９３、カーボンブラックを用いた以外は、前記各実施例および前記各比較例と同様にして、トナーを作製し、これらの各トナーについても前記と同様の評価を行った。その結果、前記各実施例および前記各比較例と同様の結果が得られた。
【図面の簡単な説明】
【図１】本発明のトナーの製造方法の第１実施形態で用いる混練機、冷却機の構成の一例を模式的に示す縦断面図である。
【図２】ブロックポリエステルについて示差走査熱量分析を行ったときに得られる、ブロックポリエステルの融点付近での示差走査熱量分析曲線のモデル図である。
【図３】軟化点解析用フローチャートである。
【図４】トナー中に含まれるトナー粒子から遊離したルチルアナターゼ型の酸化チタンの量を測定する方法を説明するための図である。
【図５】本発明の画像形成装置（本発明のトナーが好適に適用される画像形成装置）の好適な実施形態を示す全体構成図である。
【図６】図５の画像形成装置が有する現像装置の断面図である。
【図７】図５の画像形成装置に用いられる本発明の定着装置の詳細構造を示し、一部破断面を示す斜視図である。
【図８】図７の定着装置の要部断面図である。
【図９】図７の定着装置を構成する剥離部材の斜視図である。
【図１０】図７の定着装置を構成する剥離部材の取付状態を示す側面図である。
【図１１】図７の定着装置を上面から見た正面図である。
【図１２】定着ニップ部の出口における接線に対する、剥離部材の配置角度を説明するための模式図である。
【図１３】定着ローラ、加圧ローラの形状と、定着ニップ部の形状を模式的に示す図である。
【図１４】図１３（ａ）のＸ−Ｘ線における断面図である。
【図１５】定着ローラ、加圧ローラの形状と、定着ニップ部の形状を模式的に示す図である。
【図１６】図１５（ａ）のＹ−Ｙ線における断面図である。
【図１７】定着ローラと、剥離部材とのギャップを説明するための断面図である。
【図１８】本発明のトナーの製造方法の第２実施形態で用いる混練機、冷却機の構成の一例を模式的に示す縦断面図である。
【符号の説明】
１、１’……混練機 １２……プロセス部 １２１……バレル １２２、１２３……スクリュー １２４……固定部材 １３……ヘッド部 １３１……内部空間 １３２……押出口 １３３……横断面積漸減部 １４……フィーダー ２……第１の混練部 ２１……フィーダー ２２……プロセス部 ２２１……バレル２２２、２２３……スクリュー ３……第２の混練部 ３１……フィーダー ３２……プロセス部 ３２１……バレル ３２２、３２３……スクリュー ３２４……固定部材 ４……接続部 ５……ヘッド部 ５１……内部空間 ５２……押出口 ５３……横断面積漸減部 ６……冷却機 ６１、６２、６３、６４……ロール ６１１、６２１、６３１、６４１……回転軸 ６５、６６……ベルト ６７……排出部 ７……第１の原料 ８……第１の混練物 ９……第２の原料 １０……第２の混練物 １０００……画像形成装置 ２０……装置本体 ３０……像担持体 ４０……帯電装置 ５０……露光装置 ６０……ロータリー現像装置 ６００……支持フレーム ６０１……ハウジング ６０３……供給ローラ ６０４……現像ローラ ６０５……規制ブレード ６０５ａ……板状部材 ６０５ｂ……弾性部材 ６０Ｙ……イエロー用現像装置 ６０Ｍ……マゼンタ用現像装置 ６０Ｃ……シアン用現像装置 ６０Ｋ……ブラック用現像装置 ７０……中間転写装置 ９０……駆動ローラ １００……従動ローラ １１０……中間転写ベルト １２０……一次転写ローラ １３０……転写ベルトクリーナ １４０……二次転写ローラ １５０……給紙カセット １６０……ピックアップローラ１７０……記録媒体搬送路 １９０……定着装置 ２００……排紙トレイ ２１０……定着ローラ（加熱定着部材） ２１０ａ……熱源 ２１０ｂ……筒体 ２１０ｃ……弾性層 ２１０ｄ……回転軸 ２２０……加圧ローラ（加圧部材）２２０ｂ……筒体 ２２０ｃ……弾性層 ２２０ｄ……回転軸 ２３０……両面印刷用搬送路 ２４０……ハウジング ２５０……軸受 ２６０……加圧レバー ２７０……加圧スプリング ２８０……駆動ギヤ ２９０……支持軸 ３００……支持軸 ３１０……剥離部材 ３１０ａ……剥離部 ３１０ｂ……折曲部３１０ｃ……支持片 ３１０ｄ……嵌合穴 ３１０ｅ……ガイド部 ３１０ｆ……先端部 ３２０……剥離部材 ３２０ａ……剥離部 ３２０ｅ……ガイド部３３０……スプリング ３４０……定着ニップ部（ニップ部） ３４１……ニップ出口 ５００……記録媒体 Ｔ……トナー Ｓ……接線 Ｇ１……ギャップＧ２……ギャップ[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a toner and a method for producing the toner.
[0002]
[Prior art]
As the electrophotographic method, many methods are known. In general, a step (exposure step) of forming an electric latent image on a photoconductor by various means using a photoconductive substance, and A developing step of developing the latent image using toner, a transfer step of transferring the toner image to a transfer material (recording medium) such as paper, and a fixing step of fixing the toner image by heating using a fixing roller or the like. have.
[0003]
The toner used in the electrophotography as described above is usually composed of a material containing a resin (hereinafter, also simply referred to as “resin”) as a main component and a colorant.
[0004]
As a resin constituting the toner, a polyester resin is widely used. The polyester resin has a characteristic that characteristics such as elasticity and chargeability of the finally obtained toner are easily controlled.
[0005]
In such a toner, an aromatic diol such as bisphenol A has been generally used as a diol component constituting the polyester resin (for example, see Patent Document 1).
[0006]
However, polyesters composed of such a diol component have a relatively large coefficient of friction and are susceptible to mechanical stress. The problem may occur.
[0007]
Further, a toner using a polyester composed of an aliphatic diol without using an aromatic diol such as bisphenol A is also known (for example, see Patent Document 2). The polyester resin used as the polyester resin was a polyester block copolymer having a block formed by condensing an aliphatic diol and a carboxylic acid and a polyester block formed by condensing an alicyclic diol and a carboxylic acid in the molecule. Things. However, such a toner has a problem that a temperature region in which a sufficient fixing property (fixing strength) can be secured becomes narrow.
[0008]
[Patent Document 1]
JP-A-57-109825 (page 1, lines 1-27)
[Patent Document 2]
JP 2001-324832 A (page 2, lines 1 to 13)
[0009]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a toner having sufficient durability and exhibiting excellent fixability (fixing strength) in a wide temperature range, and a method for producing a toner capable of producing the toner. Is to provide.
[0010]
[Means for Solving the Problems]
Such an object is achieved by the present invention described below.
The toner of the present invention is a toner composed of a material containing a polyester resin and a colorant,
The polyester-based resin includes a block polyester mainly composed of a block copolymer and an amorphous polyester having a lower crystallinity than the block polyester,
The block polyester has a crystalline block formed by condensing an alcohol component and a carboxylic acid component, and an amorphous block having a lower crystallinity than the crystalline block.
In the toner particles, a first region mainly composed of the block polyester, and a second region mainly composed of the amorphous polyester,
The concentration of the colorant in the first region is higher than the concentration of the colorant in the second region.
This makes it possible to provide a toner having sufficient durability and exhibiting excellent fixability (fixing strength) in a wide temperature range.
[0011]
In the toner of the present invention, the concentration of the colorant in the first area is C ₁ [Vol%], the concentration of the colorant in the second region is represented by C ₂ [Vol%], 0.1 ≦ C ₂ / C ₁ It is preferable to satisfy the relationship of ≦ 1.
As a result, it is possible to further improve the fixing property (enlarge the fixing good temperature region and improve the fixing strength) while sufficiently securing the durability of the toner.
[0012]
In the toner of the present invention, it is preferable that, in the toner particles, the first region is finely dispersed to have an average particle diameter of 2 μm or less.
As a result, it is possible to further improve the fixing property (enlarge the fixing good temperature region and improve the fixing strength) while sufficiently securing the durability of the toner.
In the toner of the present invention, the toner preferably has a crystal mainly formed by the crystalline block.
As a result, the stability of the shape of the finally obtained toner is improved, and the toner exhibits particularly excellent stability (durability) against mechanical stress.
[0013]
In the toner of the present invention, the average length of the crystals is preferably 10 to 500 nm.
Thereby, the stability of the shape of the finally obtained toner is further improved, and the toner exhibits particularly excellent stability (durability) against mechanical stress.
In the toner of the present invention, the melting point of the block polyester is preferably higher than the softening point of the amorphous polyester.
As a result, the stability of the shape of the finally obtained toner is improved, and the toner exhibits particularly excellent stability (durability) against mechanical stress. In the case of performing the thermal sphering process, the thermal sphering process can be performed efficiently, and the circularity of the finally obtained toner (toner particles) is relatively high. be able to.
[0014]
In the toner of the present invention, it is preferable that 50 mol% or more of the monomer component constituting the amorphous polyester is the same as the monomer component constituting the amorphous block of the block polyester.
Thereby, the affinity between the amorphous polyester and the block polyester can be made particularly excellent, and the occurrence of macro phase separation in the toner particles can be more effectively prevented.
[0015]
In the toner of the present invention, the compounding ratio of the block polyester to the amorphous polyester is preferably 5:95 to 45:55 by weight.
As a result, it is possible to further improve the fixing property (enlarge the fixing good temperature region and improve the fixing strength) while sufficiently securing the durability of the toner.
In the toner of the present invention, the content of the crystalline block in the block polyester is preferably 5 to 60% by weight.
As a result, the durability of the toner can be made particularly excellent while securing sufficient fixability in a wide temperature range.
[0016]
In the toner of the present invention, it is preferable that 80 mol% or more of the alcohol component constituting the crystalline block of the block polyester is an aliphatic diol.
Thereby, the crystallinity of the block polyester (crystalline block) can be made particularly high, and the durability of the toner can be made particularly excellent.
[0017]
In the toner of the present invention, the crystalline block of the block polyester has a linear molecular structure having 3 to 7 carbon atoms and has a hydroxyl group at both ends as an alcohol component. Is preferred.
As a result, the crystallinity of the block polyester (crystalline block) is improved, and the coefficient of friction is reduced. Therefore, the toner is resistant to mechanical stress, and is particularly excellent in durability and storage stability.
[0018]
In the toner of the present invention, it is preferable that 50 mol% or more of the carboxylic acid component constituting the crystalline block of the block polyester has a terephthalic acid skeleton.
Thereby, the balance of various properties required for the toner is particularly excellent.
[0019]
In the toner of the present invention, it is preferable that at least a part of the alcohol component constituting the amorphous block of the block polyester is an aliphatic diol.
As a result, a toner suitable for forming a fixed image having more excellent toughness (more excellent bending resistance) can be obtained.
[0020]
In the toner of the present invention, it is preferable that at least a part of the alcohol component constituting the amorphous block of the block polyester has a branched chain.
Thereby, the crystallinity of the amorphous block can be reduced, and the transparency of the toner can be further improved.
[0021]
In the toner of the present invention, the melting point of the block polyester is preferably 190 ° C. or higher.
Thereby, the durability of the toner can be made particularly excellent.
In the toner of the present invention, the block polyester preferably has a heat of fusion of 5 mJ / mg or more when the endothermic peak of the melting point is measured by differential scanning calorimetry.
Thereby, the durability of the toner can be made particularly excellent.
[0022]
In the toner of the present invention, the weight average molecular weight Mw of the block polyester is 1 × 10 ⁴ ~ 3 × 10 ⁵ It is preferable that
Thereby, the durability of the toner can be made particularly excellent while sufficiently maintaining the affinity (wetting property) for the recording medium (transfer material).
In the toner of the present invention, the block polyester is preferably a linear polymer.
Thereby, the releasability of the toner can be improved, and the transfer efficiency can be made particularly excellent.
[0023]
In the toner of the present invention, the softening point of the block polyester is preferably 90 to 160 ° C.
Thereby, the durability of the toner can be made particularly excellent while sufficiently maintaining the affinity (wetting property) for the recording medium (transfer material).
In the toner of the present invention, it is preferable that 80 mol% or more of the carboxylic acid component constituting the amorphous polyester has a terephthalic acid skeleton.
Thereby, the balance of various properties required for the toner is particularly excellent.
[0024]
In the toner of the present invention, the weight average molecular weight Mw of the amorphous polyester is 5 × 10 ³ ~ 4 × 10 ⁴ It is preferable that
Thereby, the durability of the toner can be made particularly excellent while sufficiently maintaining the affinity (wetting property) for the recording medium (transfer material).
In the toner of the present invention, the amorphous polyester is preferably a linear polymer.
Thereby, the releasability of the toner can be improved, and the transfer efficiency can be made particularly excellent.
[0025]
In the toner of the present invention, the softening point of the amorphous polyester is preferably 90 to 160 ° C.
Thereby, the durability of the toner can be made particularly excellent while sufficiently maintaining the affinity (wetting property) for the recording medium (transfer material).
In the toner of the present invention, the content of the polyester resin in the toner is preferably 50 to 98 wt%.
As a result, it is possible to improve both the fixability in a wide temperature range and the durability of the toner while sufficiently exhibiting the functions of the components other than the polyester resin such as the colorant.
[0026]
In the toner of the present invention, the average circularity R represented by the following formula (I) is preferably 0.91 to 0.98.
R = L ₀ / L ₁ ... (I)
(However, in the formula, L ₁ [Μm] is the perimeter of the projected image of the toner particles to be measured, L ₀ [Μm] represents the circumference of a perfect circle having an area equal to the area of the projected image of the toner particles to be measured. )
This makes it possible to make the developability, transfer efficiency, mechanical strength, and the like on the photoreceptor particularly excellent while sufficiently maintaining the cleaning property (easiness of removal) from the photoreceptor.
[0027]
The toner of the present invention preferably contains an external additive.
This makes it possible to make the charging characteristics and the releasability of the toner particularly excellent.
In the toner of the present invention, the average particle size of the toner is preferably 3 to 12 μm.
This makes it possible to sufficiently prevent the occurrence of fusion or the like between the toner particles and to make the resolution of an image obtained by using the toner particularly excellent.
[0028]
In the toner of the present invention, a fixing roller,
A pressure roller pressed against the fixing roller,
It is preferable that the fixing device is used in a fixing device having a separation member for separating the recording medium that has passed through a fixing nip formed at a contact portion between the fixing roller and the pressure roller from the fixing roller.
This makes it possible to reliably fix the recording medium to the recording medium and to prevent the occurrence of streaks and disturbances in the image.
[0029]
In the toner of the present invention, it is preferable that the fixing device has a recording medium feeding speed of 0.05 to 1.0 m / sec.
This makes it possible to more reliably prevent the occurrence of streaks and disturbances in the image.
In the toner of the present invention, it is preferable that the peeling member is a plate-shaped member having a predetermined length in an axial direction of the fixing roller and / or the pressure roller.
Thereby, the recording medium can be efficiently separated from the fixing roller and the pressure roller.
[0030]
In the toner according to the aspect of the invention, it is preferable that in the fixing device, the peeling member is disposed downstream of the fixing nip in the recording medium conveyance direction.
Thereby, the recording medium can be efficiently separated from the fixing roller and the pressure roller.
In the toner according to the aspect of the invention, it is preferable that the peeling member is disposed near the fixing roller and / or the pressure roller.
Thereby, the recording medium can be efficiently separated from the fixing roller and the pressure roller.
[0031]
In the toner according to the aspect of the invention, it is preferable that the fixing device is configured such that the fixing roller and the pressure roller are disposed in a substantially horizontal state.
As a result, it is possible to prevent the occurrence of streaks or disturbances in the image, and to improve the releasability of the recording medium.
In the toner according to the aspect of the invention, it is preferable that the fixing device is provided with the release member such that a gap between the fixing roller and the release member is substantially constant during operation.
As a result, a decrease in the releasability of the recording medium can be prevented.
[0032]
In the toner according to the aspect of the invention, it is preferable that the peeling member is disposed along an axial direction of the fixing roller, and has a shape that conforms to a shape of an outlet of the fixing nip portion.
Thereby, the recording medium can be efficiently separated from the fixing roller and the pressure roller.
[0033]
In the toner of the present invention, the arrangement angle θ of the peeling member with respect to the tangent line of the exit of the fixing nip portion. _A Is preferably −5 to + 20 ° when the fixing roll side has a positive angle and the pressure roll side has a negative angle.
As a result, it is possible to prevent the occurrence of streaks or disturbances in the image, and to improve the releasability of the recording medium.
[0034]
In the toner according to the aspect of the invention, the fixing device extends in the axial direction of the fixing roller and the pressure roller, and is located downstream of the fixing nip portion in the recording medium conveyance direction and close to the fixing roller and the pressure roller. The fixing device is provided with the peeling member, and the positioning of the peeling member on the fixing roller side is performed on the fixing roller surface, and the positioning of the peeling member on the pressure roller side is performed on the bearing surface of the pressure roller. It is preferable to do it.
Thereby, the releasability of the recording medium from the fixing roller and the pressure roller can be improved.
[0035]
In the toner of the present invention, it is preferable that the fixing device has a configuration in which the axial length of the pressure roller is shorter than that of the fixing roller, and the bearing is provided in an empty space.
Thereby, the releasability of the recording medium from the fixing roller and the pressure roller can be improved.
[0036]
In the toner of the present invention, in the fixing device, the gap G2 [μm] between the fixing roller and the peeling member near the axial end of the fixing roller is near the axial center of the fixing roller. Preferably, the gap is larger than the gap G1 [μm] between the fixing roller and the peeling member.
Thereby, gap management can be easily performed while maintaining the releasability of the recording medium.
[0037]
The method for producing a toner of the present invention is a method for producing a toner composed of a material containing a polyester resin and a colorant,
The polyester-based resin includes a block polyester mainly composed of a block copolymer and an amorphous polyester having a lower crystallinity than the block polyester,
The block polyester has a crystalline block formed by condensing an alcohol component and a carboxylic acid component, and an amorphous block having a lower crystallinity than the crystalline block.
A first kneading step of producing a first kneaded material containing the block polyester and the colorant;
At least a second kneading step of kneading a material containing the first kneaded material and the amorphous polyester to produce a second kneaded material is provided.
This makes it possible to provide a toner having sufficient durability and exhibiting excellent fixability (fixing strength) in a wide temperature range.
[0038]
The method for producing a toner of the present invention is a method for producing a toner composed of a material containing a polyester resin and a colorant,
The polyester-based resin includes a block polyester mainly composed of a block copolymer and an amorphous polyester having a lower crystallinity than the block polyester,
The block polyester has a crystalline block formed by condensing an alcohol component and a carboxylic acid component, and an amorphous block having a lower crystallinity than the crystalline block.
A first kneading step of producing a first kneaded material containing the block polyester and the colorant;
At least a second kneading step of kneading a material containing the first kneaded material and the amorphous polyester to produce a second kneaded material,
Forming a first region mainly composed of the block polyester and a second region mainly composed of the amorphous polyester;
The method is characterized in that a toner is manufactured in which the concentration of the colorant in the first region is higher than the concentration of the colorant in the first region.
This makes it possible to provide a toner having sufficient durability and exhibiting excellent fixability (fixing strength) in a wide temperature range.
[0039]
In the method for producing a toner of the present invention, the material temperature in the first kneading step is preferably from 120 to 260 ° C.
This makes it possible to obtain a first kneaded product in which the components are uniformly mixed, while sufficiently preventing the material from being thermally decomposed or oxidized.
In the toner manufacturing method of the present invention, the material temperature during the second kneading step is preferably 80 to 260 ° C.
As a result, the first region mainly composed of the block polyester and the second region mainly composed of the amorphous polyester can be sufficiently uniformly finely dispersed (microphase separation), and the function of the toner can be improved. Can be made particularly excellent.
[0040]
In the method for producing a toner according to the present invention, it is preferable that the first kneading step and the second kneading step are continuously performed.
Thereby, the manufacturing process can be simplified, and the productivity of the toner is improved. In addition, deterioration of the constituent components of the toner can be more effectively prevented, and the reliability of the toner is further improved.
[0041]
In the method for producing a toner according to the present invention, a two-stage barrel-type kneader having a first kneading section for performing the first kneading step and a second kneading section for performing the second kneading step is used. Is preferred.
Thereby, the manufacturing process can be simplified, and the productivity of the toner is improved. In addition, deterioration of the constituent components of the toner can be more effectively prevented, and the reliability of the toner is further improved.
[0042]
In the method for producing a toner according to the present invention, the softening point of the amorphous polyester is set to T. _1/2 (A) [° C.], melting point T of the block polyester _m (B) [° C.], the material temperature in the second kneading step is set to T _K2 [° C], T _m (B)> T _K2 > T _1/2 It is preferable to satisfy the relationship (A).
Thereby, the first region mainly composed of the block polyester and the second region mainly composed of the amorphous polyester can be phase-separated (micro-separated) to an appropriate size, and The colorant contained in the first kneaded material can be effectively prevented from migrating into the second region. As a result, the obtained toner can have particularly excellent fixability and durability in a wide temperature range.
[0043]
In the method for producing a toner of the present invention, a step of pulverizing and classifying the second kneaded material to obtain a toner production powder;
A heat sphering step of heating the toner production powder to form a sphere.
This makes it possible to minimize the variation in the particle size among the toner particles, and to easily and reliably control the circularity of the toner particles to a value within a suitable range.
In the method for producing a toner of the present invention, the temperature of the atmosphere during the thermal sphering step is preferably from 210 to 320 ° C.
This makes it possible to easily and reliably control the circularity of the toner particles to a value in a suitable range while suitably preventing thermal decomposition and oxidative deterioration of the constituent components.
[0044]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the toner and the method for producing the toner of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a longitudinal sectional view schematically showing an example of the configuration of a kneader and a cooler used in the first embodiment of the toner production method of the present invention, and FIG. 2 shows a differential scanning calorimetric analysis of a block polyester. FIG. 3 is a model diagram of a differential scanning calorimetry curve obtained around the melting point of the block polyester, FIG. 3 is a flowchart for softening point analysis, and FIG. 4 is an oxidation of rutile-anatase type liberated from toner particles contained in the toner. It is a figure for explaining the method of measuring the amount of titanium. Hereinafter, in FIG. 1, the left side will be referred to as a “base end” and the right side will be referred to as a “distal end”.
[0045]
[Constituent materials]
First, the constituent materials of the toner of the present invention will be described. The toner of the present invention contains at least a polyester resin as a resin component (hereinafter, also simply referred to as “resin”) and a colorant.
Hereinafter, each component contained in the toner of the present invention will be described.
[0046]
1. Resin (binder resin)
In the present invention, the resin (binder resin) is mainly composed of a polyester resin. The content of the polyester resin in the resin is preferably at least 50 wt%, more preferably at least 80 wt%.
The polyester resin contains at least a block polyester as described below and an amorphous polyester. As described above, the present invention is characterized in that a block polyester and an amorphous polyester are used in combination.
[0047]
1-1. Block polyester
The block polyester is composed of a block copolymer having a crystalline block formed by condensing an alcohol component and a carboxylic acid component, and an amorphous block having lower crystallinity than the crystalline block.
(1) Crystalline block
The crystalline block has higher crystallinity than the amorphous block or the amorphous polyester. That is, the molecular arrangement structure is stronger and more stable than the amorphous block or the amorphous polyester. For this reason, the crystalline block contributes to improving the strength of the whole toner. As a result, the finally obtained toner is resistant to mechanical stress, and has excellent durability and storage stability.
Incidentally, a resin having high crystallinity generally has a so-called sharp melt property as compared with a resin having low crystallinity. That is, when a resin having high crystallinity is measured for an endothermic peak at a melting point by differential scanning calorimetry (DSC), it has a property that an endothermic peak appears as a sharper shape than a resin having low crystallinity. I have.
[0048]
On the other hand, the crystalline block has high crystallinity as described above. Therefore, the crystalline block has a function of imparting a sharp melt property to the block polyester. For this reason, the toner of the present invention has excellent shape stability (durability) even at a relatively high temperature (temperature near the melting point of the block polyester) at which the amorphous polyester described later is sufficiently softened. Can be held. Therefore, the toner of the present invention can exhibit sufficient fixability (fixing strength) in a wide temperature range.
Further, since such a crystalline block is contained in the block polyester, in the present invention, the thermal sphering treatment described later can be performed efficiently (in a short time), and easily and finally The circularity of the obtained toner particles can be made relatively high.
[0049]
Hereinafter, components constituting the crystalline block will be described.
As the alcohol component constituting the crystalline block, an alcohol component having two or more hydroxyl groups can be used, and among them, an alcohol component having two hydroxyl groups is preferable. Examples of such an alcohol component having two hydroxyl groups include an aromatic diol having an aromatic ring structure and an aliphatic diol having no aromatic ring structure. As the aromatic diol, for example, bisphenol A, an alkylene oxide adduct of bisphenol A (for example, polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (3.3) ) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2.0) -polyoxyethylene ( 2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane, and the like. Is, for example, ethylene glycol, 1,3-propanediol, 1,2-propylene glycol, 1,3- Propylene glycol, 1,4-butanediol, diethylene glycol, 1,5-pentanediol, 1,6-hexanediol, dipropylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-butane Diol, 2,3-butanediol, neopentyl glycol (2,2-dimethylpropane-1,3-diol), 1,2-hexanediol, 2,5-hexanediol, 2-methyl-2,4-pentane Diol, 3-methyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, 2-butyl-2-ethyl-1,3-propanediol, 2,4-diethyl-1,5-pentane Diol, polyethylene glycol, polypropylene glycol, polytetramethylene Chain diols such as recall, 2,2-bis (4-hydroxycyclohexyl) propane, an alkylene oxide adduct of 2,2-bis (4-hydroxycyclohexyl) propane, 1,4-cyclohexanediol, 1,4 And cyclic diols such as cyclohexanedimethanol, hydrogenated bisphenol A, and alkylene oxide adducts of hydrogenated bisphenol A.
[0050]
The alcohol component having three or more hydroxyl groups includes sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4- Butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethyl Benzene and the like can be mentioned.
[0051]
As described above, the alcohol component constituting the crystalline block is not particularly limited, but at least a part thereof is preferably an aliphatic diol, more preferably 80 mol% or more of which is an aliphatic diol, and 90 mol% or more thereof. More preferably, at least% is an aliphatic diol. Thereby, the crystallinity of the block polyester (crystalline block) can be made particularly high, and the above-mentioned effects become more remarkable.
[0052]
The alcohol component constituting the crystalline block has a linear molecular structure having 3 to 7 carbon atoms and has hydroxyl groups at both ends (general formula: HO- (CH ₂ ) _n It is preferable to include a diol represented by -OH (where n = 3 to 7). When such an alcohol component is contained, the crystallinity is improved and the coefficient of friction is reduced, so that the composition is resistant to mechanical stress and particularly excellent in durability and storage stability. Such diols include, for example, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol and the like, and among them, 1,4-butanediol Is preferred. By including 1,4-butanediol, the above-mentioned effects become particularly remarkable.
[0053]
When 1,4-butanediol is contained as an alcohol component constituting the crystalline block, it is more preferable that 50 mol% or more of the alcohol component constituting the crystalline block is 1,4-butanediol, and 80 mol% or more of the alcohol component constitutes the crystalline block. More preferably, it is 1,4-butanediol. As a result, the above-mentioned effects become more remarkable.
[0054]
As the carboxylic acid component constituting the crystalline block, a divalent or higher carboxylic acid or a derivative thereof (eg, acid anhydride, lower alkyl ester, etc.) can be used, and a divalent carboxylic acid or a derivative thereof, etc. It is preferable to use Examples of such a divalent carboxylic acid component include o-phthalic acid (phthalic acid), terephthalic acid, isophthalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, octylsuccinic acid, cyclohexanedicarboxylic acid, and fumaric acid. Acids, maleic acid, itaconic acid and derivatives thereof (for example, anhydrides, lower alkyl esters, etc.).
[0055]
Examples of the trivalent or higher carboxylic acid component include trimellitic acid, pyromellitic acid and derivatives thereof (for example, anhydrides and lower alkyl esters).
As described above, the carboxylic acid component constituting the crystalline block is not particularly limited, but it is preferable that at least a part thereof has a terephthalic acid skeleton, and at least 50 mol% of the carboxylic acid component has a terephthalic acid skeleton. It is more preferable that 80 mol% or more of the compound has a terephthalic acid skeleton. As a result, the finally obtained toner has a particularly excellent balance of various properties required for the toner. However, the "carboxylic acid component" here refers to a carboxylic acid component when it is made into a block polyester, and when adjusting the block polyester (forming a crystalline block), the carboxylic acid component itself or Derivatives such as acid anhydrides and lower alkyl esters can be used.
[0056]
The content of the crystalline block in the block polyester is not particularly limited, but is preferably 5 to 60 mol%, and more preferably 10 to 40 mol%. If the content of the crystalline block is less than the lower limit, the effect of having the crystalline block as described above may not be sufficiently exhibited depending on the content of the block polyester and the like. On the other hand, when the content of the crystalline block exceeds the upper limit, the content of the amorphous block relatively decreases, so that the affinity between the block polyester and the amorphous polyester described below decreases, and The first region may be coarse.
The crystalline block may include components other than the alcohol component and the carboxylic acid component as described above.
[0057]
(2) Amorphous block
The amorphous block has lower crystallinity than the above-described crystalline block. Further, the amorphous polyester described later also has lower crystallinity than the crystalline block. That is, the amorphous block has lower crystallinity than the crystalline block, similarly to the amorphous polyester described later.
[0058]
By the way, in a blended resin, generally, resins having greatly different crystallinities have low affinity, and phase separation (particularly, macrophase separation) is easily performed. Resins having small crystallinity differences have high affinity and are easily mixed with each other. . On the other hand, as described above, the block polyester used in the present invention has a crystalline block and an amorphous block. That is, the block polyester has an amorphous block having a high affinity with the amorphous polyester and a crystalline block having a low affinity. For this reason, in the present invention, while the block polyester and the amorphous polyester are sufficiently uniformly mixed, an appropriate phase separation (microphase separation) is likely to occur. Thereby, it is possible to effectively prevent macro phase separation (for example, phase separation such that the average particle diameter of each phase becomes 1 μm or more) in the toner particles, and the advantage of the block polyester is obtained. And the advantages of the amorphous polyester can be sufficiently and stably exhibited.
[0059]
Hereinafter, components constituting the amorphous block will be described.
As the alcohol component constituting the amorphous block, an alcohol component having two or more hydroxyl groups can be used, and among them, an alcohol component having two hydroxyl groups is preferable. Examples of such an alcohol component having two hydroxyl groups include an aromatic diol having an aromatic ring structure and an aliphatic diol having no aromatic ring structure. As the aromatic diol, for example, bisphenol A, an alkylene oxide adduct of bisphenol A (for example, polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (3.3) ) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2.0) -polyoxyethylene ( 2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane, and the like. Is, for example, ethylene glycol, 1,3-propanediol, 1,2-propylene glycol, 1,3- Propylene glycol, 1,4-butanediol, diethylene glycol, 1,5-pentanediol, 1,6-hexanediol, dipropylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-butane Diol, 2,3-butanediol, neopentyl glycol (2,2-dimethylpropane-1,3-diol), 1,2-hexanediol, 2,5-hexanediol, 2-methyl-2,4-pentane Diol, 3-methyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, 2-butyl-2-ethyl-1,3-propanediol, 2,4-diethyl-1,5-pentane Diol, polyethylene glycol, polypropylene glycol, polytetramethylene Chain diols such as recall, 2,2-bis (4-hydroxycyclohexyl) propane, an alkylene oxide adduct of 2,2-bis (4-hydroxycyclohexyl) propane, 1,4-cyclohexanediol, 1,4 And cyclic diols such as cyclohexanedimethanol, hydrogenated bisphenol A, and alkylene oxide adducts of hydrogenated bisphenol A.
[0060]
The alcohol component having three or more hydroxyl groups includes sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4- Butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethyl Benzene and the like can be mentioned.
[0061]
As described above, the alcohol component constituting the amorphous block is not particularly limited, but at least a part thereof is preferably an aliphatic diol, and more preferably 50 mol% or more is an aliphatic diol. As a result, an effect of obtaining a fixed image having more excellent toughness (excellent bending resistance) can be obtained.
Further, the alcohol component constituting the amorphous block preferably has at least a part thereof having a branched chain (side chain), and more preferably has at least 30 mol% of a branched chain. This has the effect of suppressing regular arrangement, lowering crystallinity, and improving transparency.
[0062]
As the carboxylic acid component constituting the amorphous block, a divalent or higher carboxylic acid or a derivative thereof (eg, an acid anhydride, a lower alkyl ester, etc.) can be used, but a divalent carboxylic acid or a derivative thereof can be used. And the like are preferably used. Examples of such a divalent carboxylic acid component include o-phthalic acid (phthalic acid), terephthalic acid, isophthalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, octylsuccinic acid, cyclohexanedicarboxylic acid, and fumaric acid. Acids, maleic acid, itaconic acid and derivatives thereof (for example, anhydrides, lower alkyl esters, etc.).
[0063]
Examples of the trivalent or higher carboxylic acid component include trimellitic acid, pyromellitic acid and derivatives thereof (for example, anhydrides and lower alkyl esters).
As described above, the carboxylic acid component constituting the amorphous block is not particularly limited, but it is preferable that at least a part thereof has a terephthalic acid skeleton, and at least 80 mol% of the carboxylic acid component has a terephthalic acid skeleton. More preferably, there is. As a result, the finally obtained toner has a particularly excellent balance of various properties required for the toner. However, the “carboxylic acid component” here refers to a carboxylic acid component when it is made into a block polyester, and when adjusting the block polyester (forming an amorphous block), the carboxylic acid component itself or And derivatives thereof such as acid anhydrides and lower alkyl esters.
[0064]
The amorphous block may contain components other than the above-mentioned alcohol component and carboxylic acid component.
The average molecular weight (weight average molecular weight) Mw of the block polyester having a crystalline block and an amorphous block as described above is not particularly limited, but is 1 × 10 ⁴ ~ 3 × 10 ⁵ And preferably 1.2 × 10 ⁴ ~ 1.5 × 10 ⁵ Is more preferable. If the average molecular weight Mw is less than the lower limit, the mechanical strength of the finally obtained toner may be reduced, and sufficient durability (storability) may not be obtained. On the other hand, when the average molecular weight Mw is too small, cohesive failure tends to occur during fixing of the toner, and the offset resistance tends to decrease. On the other hand, when the average molecular weight Mw exceeds the above upper limit, the grain boundary is likely to be broken at the time of fixing the toner, the wettability to a transfer material (recording medium) such as paper is reduced, and the amount of heat required for fixing is increased.
[0065]
Glass transition point T of block polyester _g Although it is not particularly limited, it is preferably 50 to 75 ° C, more preferably 55 to 70 ° C. When the glass transition point is less than the lower limit, the storage stability (heat resistance) of the toner is reduced, and depending on the use environment, fusion between toner particles may occur. On the other hand, when the glass transition point exceeds the upper limit, the low-temperature fixability and the transparency are reduced. On the other hand, if the glass transition point is too high, the effect may not be sufficiently exhibited when performing a thermal sphering treatment as described later. The glass transition point can be measured according to JIS K7121.
[0066]
Softening point T of block polyester _1/2 Although it is not particularly limited, it is preferably from 90 to 160 ° C, and more preferably from 100 to 150 ° C. If the softening point is less than the lower limit, the storability of the toner may decrease, and sufficient durability may not be obtained. On the other hand, if the softening point is too low, cohesive failure tends to occur when fixing the toner, and the offset resistance tends to decrease. On the other hand, when the softening point exceeds the above upper limit, grain boundary destruction is likely to occur at the time of fixing the toner, the wettability to a transfer material (recording medium) such as paper is reduced, and the amount of heat required for fixing is increased. The softening point T _1/2 For example, using a flow tester, a sample amount: 1 g, a die hole diameter: 1 mm, a die length: 1 mm, a load: 20 kgf, a preheating time: 300 seconds, a measurement starting temperature: 50 ° C., and a heating rate: 5 ° C./min. Can be obtained as a temperature at a point on the flow curve corresponding to h / 2 in the analysis flowchart as shown in FIG.
[0067]
Melting point T of block polyester _m (The center value T of the peak when the endothermic peak of the melting point is measured by differential scanning calorimetry described later. _mp ) Is not particularly limited, but is preferably 190 ° C or higher, more preferably 190 to 230 ° C. If the melting point is lower than 190 ° C., there is a possibility that effects such as improvement in offset resistance may not be sufficiently obtained. On the other hand, if the melting point is too high, the material temperature must be set to a relatively high temperature in a kneading step described later. As a result, the transesterification reaction of the resin material is likely to proceed, and it may be difficult to sufficiently reflect the resin design on the finally obtained toner. The melting point can be determined, for example, by measuring an endothermic peak by differential scanning calorimetry (DSC).
[0068]
When the finally obtained toner is used in a fixing device having a fixing roller as described later, the melting point of the block polyester (when the endothermic peak of the melting point is measured by differential scanning calorimetry described later) The center value T of the peak _mp ) To T _m (B) [° C.], the standard set temperature of the surface of the fixing roller is T _fix [° C], T _fix ≤T _m (B) ≦ (T _fix +100), and (T _fix +10) ≦ T _m (B) ≦ (T _fix +70) is more preferably satisfied. By using a block polyester having a melting point in such a range, it is possible to effectively prevent toner from adhering to a fixing roller of a fixing device described later. Further, since the block polyester has a property of easily forming crystals of an appropriate size as described later, stability and durability can be maintained even after the toner is fixed on the recording medium. In particular, in the present invention, since the block polyester is used in combination with the amorphous polyester described below, even if a block polyester having a melting point in the above-described temperature range is included, the amorphous polyester described below is fixed during fixing. It can be sufficiently softened. For this reason, the fixability (fixing strength) of the toner to the recording medium can be sufficiently increased, and the low-temperature fixability of the toner also becomes excellent. In addition, since the block polyester easily forms a crystal having high hardness, the toner also has excellent stability after fixing.
[0069]
Further, the melting point of the block polyester is preferably higher than the softening point of the amorphous polyester described later. As a result, the stability of the shape of the finally obtained toner is improved, and the toner exhibits particularly excellent stability (durability) against mechanical stress. Further, when the melting point of the block polyester is higher than the softening point of the amorphous polyester described later, for example, when performing the thermal sphering treatment described later, the block polyester ensures the shape stability of the powder for toner production to some extent. In addition, the amorphous polyester can be sufficiently softened. As a result, the thermal sphering process can be performed efficiently, and the circularity of the finally obtained toner (toner particles) can be relatively easily increased.
[0070]
By the way, as described above, since the block polyester used in the present invention has a crystalline block with high crystallinity, it is compared with a resin material having relatively low crystallinity (for example, an amorphous polyester described later). And has a so-called sharp melt property.
As an index representing the crystallinity, for example, the center value of the peak when the endothermic peak of the melting point is measured by differential scanning calorimetry (DSC) is T. _mp [° C], the shoulder peak value is T _ms When [° C.], ΔT = T _mp -T _ms (See FIG. 2). The smaller the ΔT value, the higher the crystallinity.
The ΔT value of the block polyester is preferably at most 50 ° C, more preferably at most 20 ° C. T _mp [° C], T _ms Although the measurement conditions of [° C.] are not particularly limited, for example, after the temperature of a block polyester to be a sample is increased to 200 ° C. at a rate of temperature increase of 10 ° C./min, and further decreased at a rate of temperature decrease of 10 ° C./min. The temperature can be measured by raising the temperature at a rate of 10 ° C./min.
[0071]
Further, the block polyester has higher crystallinity than the amorphous polyester described below. Accordingly, the ΔT value of the amorphous polyester is ΔT _A [° C], the ΔT value of the block polyester is ΔT _B When [° C], ΔT _A > ΔT _B Satisfy the relationship. In particular, in the present invention, ΔT _A −ΔT _B > 10 is preferably satisfied. _A −ΔT _B More preferably, the relationship of> 30 is satisfied. By satisfying such a relationship, the above-described effects become more remarkable. However, when the crystallinity of the amorphous polyester is particularly low, T _mp Or T _ms May be difficult to measure (discriminating). In such a case, ΔT _A Is ∞ [° C].
[0072]
The block polyester has a heat of fusion E obtained when the endothermic peak of the melting point is measured by differential scanning calorimetry. _f Is preferably 5 mJ / mg or more, and more preferably 15 mJ / mg or more. Heat of fusion E _f Is less than 5 mJ / mg, the above-mentioned effect due to having a crystalline block may not be sufficiently exerted. However, the heat of fusion does not include the calorific value of the endothermic peak at the glass transition point (see FIG. 2). The conditions for measuring the endothermic peak of the melting point are not particularly limited. For example, the temperature of a block polyester to be a sample was increased to 200 ° C. at a rate of 10 ° C./min, and further decreased at a rate of 10 ° C./min. Thereafter, a value measured when the temperature is raised at a temperature rising rate of 10 ° C./min can be determined as the heat of fusion.
[0073]
The block polyester is preferably a linear polymer (a polymer having no cross-linked structure). Linear polymers have a lower coefficient of friction than cross-linked polymers. Thereby, particularly excellent releasability is obtained, and the transfer efficiency of the toner is further improved.
The block polyester may have a block other than the above-described crystalline block and amorphous block.
[0074]
1-2. Amorphous polyester
Amorphous polyester has lower crystallinity than the above-mentioned block polyester.
Amorphous polyester is a main component of the second region described in detail below.
Amorphous polyesters mainly include the pulverizability of a kneaded material during toner production, toner fixability (particularly low-temperature fixability), transparency, mechanical properties (eg, elasticity, mechanical strength, etc.), and chargeability. It is a component that contributes to improving functions such as moisture resistance. In other words, if the amorphous polyester as described in detail below is not contained in the toner, it will be difficult to sufficiently exhibit the characteristics required for the toner as described above.
[0075]
Hereinafter, components constituting the amorphous polyester will be described.
As the alcohol component constituting the amorphous polyester, those having two or more hydroxyl groups can be used, and among them, the alcohol component having two hydroxyl groups is preferable. Examples of such an alcohol component having two hydroxyl groups include an aromatic diol having an aromatic ring structure and an aliphatic diol having no aromatic ring structure. As the aromatic diol, for example, bisphenol A, an alkylene oxide adduct of bisphenol A (for example, polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (3.3) ) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2.0) -polyoxyethylene ( 2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane, and the like. Is, for example, ethylene glycol, 1,3-propanediol, 1,2-propylene glycol, 1,3- Propylene glycol, 1,4-butanediol, diethylene glycol, 1,5-pentanediol, 1,6-hexanediol, dipropylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-butane Diol, 2,3-butanediol, neopentyl glycol (2,2-dimethylpropane-1,3-diol), 1,2-hexanediol, 2,5-hexanediol, 2-methyl-2,4-pentane Diol, 3-methyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, 2-butyl-2-ethyl-1,3-propanediol, 2,4-diethyl-1,5-pentane Diol, polyethylene glycol, polypropylene glycol, polytetramethylene Chain diols such as recall, 2,2-bis (4-hydroxycyclohexyl) propane, an alkylene oxide adduct of 2,2-bis (4-hydroxycyclohexyl) propane, 1,4-cyclohexanediol, 1,4 And cyclic diols such as cyclohexanedimethanol, hydrogenated bisphenol A, and alkylene oxide adducts of hydrogenated bisphenol A.
[0076]
The alcohol component having three or more hydroxyl groups includes sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4- Butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethyl Benzene and the like can be mentioned.
[0077]
As the carboxylic acid component constituting the amorphous polyester, a divalent or higher carboxylic acid or a derivative thereof (eg, acid anhydride, lower alkyl ester, etc.) can be used, but a divalent carboxylic acid or a derivative thereof can be used. And the like are preferably used. Examples of such a divalent carboxylic acid component include o-phthalic acid (phthalic acid), terephthalic acid, isophthalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, octylsuccinic acid, cyclohexanedicarboxylic acid, and fumaric acid. Acids, maleic acid, itaconic acid and derivatives thereof (for example, anhydrides, lower alkyl esters, etc.).
[0078]
Examples of the trivalent or higher carboxylic acid component include trimellitic acid, pyromellitic acid and derivatives thereof (for example, anhydrides and lower alkyl esters).
As described above, the carboxylic acid component constituting the amorphous polyester is not particularly limited, but it is preferable that at least a part thereof has a terephthalic acid skeleton, and at least 80 mol% of the carboxylic acid component has a terephthalic acid skeleton. More preferably, 90 mol% or more thereof has a terephthalic acid skeleton. As a result, the finally obtained toner has a particularly excellent balance of various properties required for the toner. However, the "carboxylic acid component" here refers to a carboxylic acid component when it is an amorphous polyester, and when adjusting the amorphous polyester, the carboxylic acid component itself or its acid anhydride is used. And derivatives such as lower alkyl esters.
[0079]
In addition, it is preferable that 50 mol% or more (more preferably, 80 mol% or more) of the monomer component constituting the amorphous polyester is the same as the monomer component constituting the above-described amorphous block. That is, the amorphous polyester is preferably composed of the same monomer components as the amorphous block. Thereby, the affinity between the amorphous polyester and the block polyester becomes particularly excellent, and the occurrence of macro phase separation in the toner particles (toner mother particles) can be more effectively prevented. However, the “monomer component” here does not indicate a monomer used for producing an amorphous polyester or a block polyester, but indicates a monomer component contained in the amorphous polyester or the block polyester.
[0080]
The amorphous polyester may include components other than the alcohol component and the carboxylic acid component as described above.
The average molecular weight (weight average molecular weight) Mw of the amorphous polyester is not particularly limited. ³ ~ 4 × 10 ⁴ And preferably 8 × 10 ³ ~ 2.5 × 10 ⁴ Is more preferable. If the average molecular weight Mw is less than the lower limit, the mechanical strength of the finally obtained toner may be reduced, and sufficient durability (storability) may not be obtained. On the other hand, when the average molecular weight Mw is too small, cohesive failure tends to occur during fixing of the toner, and the offset resistance tends to decrease. On the other hand, when the average molecular weight Mw exceeds the above upper limit, the grain boundary is likely to be broken at the time of fixing the toner, the wettability to a transfer material (recording medium) such as paper is reduced, and the amount of heat required for fixing is increased.
[0081]
Glass transition point T of amorphous polyester _g Although it is not particularly limited, it is preferably 50 to 75 ° C, more preferably 55 to 70 ° C. When the glass transition point is less than the lower limit, the storage stability (heat resistance) of the toner is reduced, and depending on the use environment, fusion between toner particles may occur. On the other hand, when the glass transition point exceeds the upper limit, the low-temperature fixability and the transparency are reduced. On the other hand, if the glass transition point is too high, the effect may not be sufficiently exhibited when performing a thermal sphering treatment as described later. The glass transition point can be measured according to JIS K7121.
[0082]
Softening point T of amorphous polyester _1/2 Although it is not particularly limited, it is preferably from 90 to 160 ° C, more preferably from 100 to 150 ° C, even more preferably from 100 to 130 ° C. If the softening point is less than the lower limit, the storability of the toner may decrease, and sufficient durability may not be obtained. On the other hand, if the softening point is too low, cohesive failure tends to occur when fixing the toner, and the offset resistance tends to decrease. On the other hand, when the softening point exceeds the above upper limit, grain boundary destruction is likely to occur at the time of fixing the toner, the wettability to a transfer material (recording medium) such as paper is reduced, and the amount of heat required for fixing is increased.
[0083]
Further, the softening point of the amorphous polyester is defined as T _1/2 (A) [° C.] _m (B), T _m (B)> (T _1/2 (A) +60) is preferably satisfied, and (T) _1/2 (A) +60) <T _m (B) <(T _1/2 It is more preferable to satisfy the relationship of (A) +150). By satisfying such a relationship, for example, at a relatively high temperature, the amorphous polyester can be sufficiently softened while the block polyester secures the shape stability of the toner particles to some extent. As a result, the fixing property in a wide temperature range (particularly, the fixing property in a low temperature range) can be improved while sufficiently securing the stability of the shape of the toner. Further, by satisfying the above-described relationship, for example, the thermal sphering process described later can be performed more efficiently, and the circularity of the obtained toner (particles) can be further improved. Further, by satisfying the above relationship, the toner can exhibit excellent fixability in a wider temperature range.
[0084]
The softening point T _1/2 For example, using a flow tester, a sample amount: 1 g, a die hole diameter: 1 mm, a die length: 1 mm, a load: 20 kgf, a preheating time: 300 seconds, a measurement starting temperature: 50 ° C., and a heating rate: 5 ° C./min. Can be obtained as a temperature at a point on the flow curve corresponding to h / 2 in the analysis flowchart as shown in FIG.
The amorphous polyester is preferably a linear polymer (a polymer having no cross-linked structure). Linear polymers have a lower coefficient of friction than cross-linked polymers. Thereby, particularly excellent releasability is obtained, and the transfer efficiency of the toner is further improved.
[0085]
As described above, the present invention is characterized in that a block polyester and an amorphous polyester are used in combination. As described above, by using the block polyester and the amorphous polyester in combination, it is possible to achieve both the features of the block polyester and the features of the amorphous polyester as described above. As a result, the finally obtained toner has sufficient durability and can exhibit excellent fixability (fixing strength) in a wide temperature range. Further, during the production of the toner, the pulverizability of the obtained kneaded material is improved, and the productivity of the toner is improved.
[0086]
The synergistic effect as described above cannot be obtained when only one of the block polyester and the amorphous polyester is used.
That is, when only the block polyester is used (when the amorphous polyester is not contained in the toner), the fixing property of the toner (particularly, the fixing property in a low temperature region) is reduced. When only the block polyester is used (when the amorphous polyester is not contained in the toner), for example, it becomes difficult to sufficiently lower the viscosity of the toner particles when fixing the toner. Fixability to the medium (fixing strength) is reduced. Further, when only the block polyester is used (when the amorphous polyester is not contained in the toner), the functions such as the transparency of the toner are deteriorated, and each component constituting the toner (for example, as described later) Dispersibility of various colorants, waxes, antistatic agents, etc.) and the pulverizability of the kneaded material during the production of the toner are also reduced.
[0087]
When only amorphous polyester is used (when no block polyester is contained in the toner), the finally obtained toner is weak in mechanical stress and has sufficient durability and storage stability. I can't. Further, when only amorphous polyester is used (when no block polyester is contained in the toner), a sharp melt property cannot be obtained, so that sufficient fixability (fixing strength) can be obtained in a wide temperature range (particularly a high temperature range). ), It becomes difficult to perform efficiently when, for example, a thermal sphering process as described later is performed, and the circularity of the finally obtained toner particles is adjusted to an appropriate value. It becomes difficult.
[0088]
By the way, a polyester having high crystallinity (hereinafter, referred to as “crystalline polyester”) generally has a stable molecular arrangement structure, so that even if it is not a block polyester as described above, the strength as a toner is improved. It is possible to make it resistant to mechanical stress. However, crystalline polyesters other than the above-described block polyester have poor affinity for the amorphous polyester, and when used in combination with the amorphous polyester, macro phase separation easily occurs. Therefore, when the crystalline polyester other than the block polyester and the amorphous polyester are used in combination without using the block polyester, the synergistic effect of using the block polyester and the amorphous polyester as described above is used. No effect.
[0089]
The mixing ratio between the block polyester and the amorphous polyester is preferably from 5:95 to 45:55 by weight, more preferably from 10:90 to 30:70. If the blending ratio of the block polyester is too low, it may be difficult to sufficiently improve the offset resistance of the toner. On the other hand, if the compounding ratio of the amorphous polyester is too low, sufficient low-temperature fixability and transparency may not be obtained. On the other hand, if the blending ratio of the block polyester is too low, it becomes difficult to efficiently distribute the colorant in the first region described later, and the effect of the present invention may not be sufficiently exerted. If the compounding ratio of the amorphous polyester is too low, the kneaded material (second kneaded material 10) is efficiently pulverized to a uniform size in a pulverizing step of a toner manufacturing method described later. It will be difficult to do.
[0090]
The content of the polyester resin in the toner is not particularly limited, but is preferably from 50 to 98 wt%, more preferably from 85 to 97 wt%. When the content of the polyester resin is less than the lower limit, the functions (and the synergistic effect thereof) of the block polyester and the amorphous polyester described above may not be sufficiently exhibited in the finally obtained toner. There is. On the other hand, when the content of the polyester-based resin exceeds the upper limit, the content of components other than the resin such as the colorant is relatively reduced, and it is difficult to sufficiently exhibit toner characteristics such as color development. .
[0091]
Further, the resin (binder resin) may include a component (third resin component) other than the above-described block polyester and amorphous polyester.
As the resin component (third resin component) other than the block polyester and the amorphous polyester, for example, polystyrene, poly-α-methylstyrene, chloropolystyrene, styrene-chlorostyrene copolymer, styrene-propylene copolymer, Styrene-butadiene copolymer, styrene-vinyl chloride copolymer, styrene-vinyl acetate copolymer, styrene-maleic acid copolymer, styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene Styrene-based resins such as acrylate-methacrylate copolymer, styrene-α-methyl methacrylate copolymer, styrene-acrylonitrile-acrylate copolymer, and styrene-vinyl methyl ether copolymer; Or containing a styrene substituent Homopolymer or copolymer, polyester resin (different from the above-mentioned block polyester and amorphous polyester), epoxy resin, urethane-modified epoxy resin, silicone-modified epoxy resin, vinyl chloride resin, rosin-modified maleic resin, Phenyl resin, polyethylene, polypropylene, ionomer resin, polyurethane resin, silicone resin, ketone resin, ethylene-ethyl acrylate copolymer, xylene resin, polyvinyl butyral resin, terpene resin, phenol resin, aliphatic or alicyclic hydrocarbon resin, etc. And these may be used alone or in combination of two or more.
[0092]
The content of the resin in the toner is not particularly limited, but is preferably from 50 to 98 wt%, and more preferably from 85 to 97 wt%. When the content of the resin is less than the lower limit, the function (for example, good fixability in a wide temperature range) of the resin may not be sufficiently exhibited in the finally obtained toner. On the other hand, when the content of the resin exceeds the above upper limit, the content of components other than the resin such as the colorant relatively decreases, and it is difficult to sufficiently exhibit the toner characteristics such as color development.
[0093]
2. Colorant
As the colorant, for example, a pigment, a dye, or the like can be used.
As will be described later in detail, the toner of the present invention has a first region (phase) mainly composed of block polyester and a second region (phase) mainly composed of amorphous polyester. The colorant concentration in the first region is higher than the colorant concentration in the second region. For this reason, it is preferable to use a coloring agent having excellent affinity with the block polyester.
[0094]
Examples of such pigments and dyes include carbon black, spirit black, lamp black (CI No. 77266), magnetite, titanium black, graphite, cadmium yellow, mineral fast yellow, navel yellow, and naphthol yellow S , Hansa Yellow G, Permanent Yellow NCG, Chrome Yellow, Benzidine Yellow, Quinoline Yellow, Tartrazine Lake, Red Mouth Lead, Molybdenum Orange, Permanent Orange GTR, Pyrazolone Orange, Benzidine Orange G, Cadmium Red, Permanent Red 4R, Watching Red Calcium salt, eosin lake, brilliant carmine 3B, manganese purple, fast violet B, methyl violet lake, navy blue, cobalt blue, aluminum Ribble Lake, Victoria Blue Lake, First Sky Blue, Indanthrene Blue BC, Ultramarine, Aniline Blue, Phthalocyanine Blue, Calco Oil Blue, Chrome Green, Chromium Oxide, Pigment Green B, Malachite Green Lake, Phthalocyanine Green, Final Yellow Green G, Rhodamine 6G, quinacridone, rose bengal (CI No. 45432), C.I. I. Direct Red 1, C.I. I. Direct Red 4, C.I. I. Acid Red 1, C.I. I. Basic Red 1, C.I. I. Modant Red 30, C.I. I. Pigment Red 48: 1, C.I. I. Pigment Red 57: 1, C.I. I. Pigment Red 122, C.I. I. Pigment Red 184, C.I. I. Direct Blue 1, C.I. I. Direct Blue 2, C.I. I. Acid Blue 9, C.I. I. Acid Blue 15, C.I. I. Basic Blue 3, C.I. I. Basic Blue 5, C.I. I. Modant Blue 7, C.I. I. Pigment Blue 15: 1, C.I. I. Pigment Blue 15: 3, C.I. I. Pigment Blue 5: 1, C.I. I. Direct Green 6, C.I. I. Basic Green 4, C.I. I. Basic Green 6, C.I. I. Pigment Yellow 17, C.I. I. Pigment Yellow 93, C.I. I. Pigment Yellow 97, C.I. I. Pigment Yellow 12, C.I. I. Pigment yellow 180, C.I. I. Pigment Yellow 162, nigrosine dye (CI No. 50415B), metal complex dye, silica, aluminum oxide, magnetite, maghemite, various ferrites, cupric oxide, nickel oxide, zinc oxide, zirconium oxide, titanium oxide, Examples thereof include metal oxides such as magnesium oxide, and magnetic materials including magnetic metals such as Fe, Co, and Ni, and one or more of these can be used in combination.
[0095]
The content of the colorant in the toner is not particularly limited, but is preferably 1 to 10% by weight, and more preferably 3 to 8% by weight. When the content of the colorant is less than the lower limit, it may be difficult to form a visible image having a sufficient density depending on the type of the colorant. On the other hand, when the content of the coloring agent exceeds the upper limit, the content of the resin relatively decreases, and the fixability to a transfer material (recording medium) such as paper at a required color density decreases.
[0096]
The size of the colorant particles is not particularly limited, but the length (average length in the longitudinal direction) is preferably from 10 to 200 nm, and more preferably from 20 to 100 nm. When the size of the colorant particles is in such a range, it is possible to appropriately refine crystals mainly composed of crystalline blocks as described later.
[0097]
3. wax
Further, wax may be contained in the toner as necessary.
By including the wax, for example, the releasability of the toner particles can be improved.
Examples of the wax include ozokerite, celsin, paraffin wax, microwax, microcrystalline wax, petrolatum, hydrocarbon wax such as Fischer-Tropsch wax, carnauba wax, rice wax, methyl laurate, methyl myristate, palmitic acid Methyl, methyl stearate, butyl stearate, candelilla wax, cotton wax, wood wax, beeswax, lanolin, montan wax, ester wax such as fatty acid ester, polyethylene wax, polypropylene wax, oxidized polyethylene wax, oxidized polypropylene wax Amide wax such as olefin wax such as 12-hydroxystearic amide, stearic amide and phthalic anhydride; lauro , Ketone waxes such as stearone, ether waxes, and the like, can be used singly or in combination of two or more of them.
[0098]
Among the above-mentioned materials, particularly when an ester wax (for example, carnauba wax or rice wax) is used, the following effects can be obtained.
The ester wax has an ester structure in the molecule similarly to the polyester resin described above, and is excellent in compatibility with the polyester resin. For this reason, generation and coarsening of free wax in the finally obtained toner particles can be prevented (fine dispersion and microphase separation of the wax in the toner can be easily achieved). As a result, the finally obtained toner has particularly excellent releasability from the fixing roller.
[0099]
Examples of the low-melting polyester (hereinafter, also referred to as “low-melting polyester”) used as the wax include, for example, a melting point T _m Is preferably about 70 to 90 ° C. Further, the weight average molecular weight Mw of the low melting point polyester is preferably about 3500 to 6500. The low-melting polyester is preferably a polymer of an aliphatic monomer. When the low-melting polyester satisfies such conditions (at least one, and preferably two or more), the compatibility with the polyester-based resin described above becomes particularly excellent, and the release of the toner is performed. Properties can be made particularly excellent.
[0100]
Melting point T of wax _m Although it does not specifically limit, It is preferable that it is 30-160 degreeC, and it is more preferable that it is 50-100 degreeC. Note that, for example, by differential scanning calorimetry (DSC), the temperature was raised to 200 ° C. at a rate of 10 ° C./min, and further decreased at a rate of 10 ° C./min. The melting point T _m And the heat of fusion.
[0101]
Further, for example, in addition to the above-described wax, a low-melting polyester (hereinafter, also referred to as “low-melting polyester”) can be used as a component capable of imparting a wax effect. The low melting point is, for example, a melting point T _m Is preferably about 70 to 90 ° C. Further, the weight average molecular weight Mw of the low melting point polyester is preferably about 3500 to 6500. The low-melting polyester is preferably a polymer of an aliphatic monomer. When the low-melting polyester satisfies such conditions (at least one, and preferably two or more), the compatibility with the polyester resin described above becomes particularly excellent, and the durability of the toner is improved. Can be provided without releasing the toner. Further, since the melting point is relatively low, low-temperature fixability can be improved.
[0102]
4. Other ingredients
Further, components other than the resin, the colorant, and the wax may be contained in the toner. Examples of such a component include a charge control agent, a dispersant, and a magnetic powder.
Examples of the charge control agent include a metal salt of benzoic acid, a metal salt of salicylic acid, a metal salt of alkyl salicylic acid, a metal salt of catechol, a metal-containing bisazo dye, a nigrosine dye, a tetraphenylborate derivative, a quaternary ammonium salt, Examples thereof include an alkylpyridinium salt, a chlorinated polyester, and nitrophenic acid.
[0103]
Examples of the dispersant include metal soaps, inorganic metal salts, organic metal salts, and polyethylene glycol.
Examples of the metal soap include metal tristearate (eg, aluminum salt), metal distearate (eg, aluminum salt, barium salt), and metal stearate (eg, calcium salt, lead salt, zinc salt, etc.). ), Metal linolenate (eg, cobalt salt, manganese salt, lead salt, zinc salt, etc.), metal octanoate (eg, aluminum salt, calcium salt, cobalt salt, etc.), metal oleate (eg, calcium salt) , Cobalt salts, etc.), metal palmitates (e.g., zinc salts, etc.), metal naphthenates (e.g., calcium salts, cobalt salts, manganese salts, lead salts, zinc salts, etc.), metal resinate salts (e.g., calcium Salt, cobalt salt, manganese lead salt, zinc salt and the like).
[0104]
Examples of the inorganic metal salt and the organic metal salt include, as a cationic component, a cation of an element selected from the group consisting of metals of Groups IA, IIA, and IIIA of the periodic table; Examples of the sexual component include salts containing an anion selected from the group consisting of halogen, carbonate, acetate, sulfate, borate, nitrate, and phosphate.
Examples of the magnetic powder include magnetite, maghemite, various ferrites, cupric oxide, nickel oxide, zinc oxide, zirconium oxide, titanium oxide, metal oxides such as magnesium oxide, and Fe, Co, and Ni. Examples thereof include those made of a magnetic material including a magnetic metal.
As the additive, for example, zinc stearate, zinc oxide, cerium oxide, or the like may be used in addition to the above-described materials.
[0105]
Further, the toner of the present invention may be a toner to which an external additive is added.
Examples of the external additive include metals such as titanium oxide, silica (positive charge silica, negative charge silica, etc.), aluminum oxide, strontium titanate, cerium oxide, magnesium oxide, chromium oxide, zinc oxide, alumina, magnetite and the like. Oxides, nitrides such as silicon nitride, carbides such as silicon carbide, fine particles made of inorganic materials such as calcium sulfate, calcium carbonate, and metal salts such as aliphatic metal salts, acrylic resin, fluorine resin, polystyrene resin, polyester Examples thereof include those made of organic materials such as resins and aliphatic metal salts (for example, magnesium stearate).
[0106]
Among the above external additives, examples of titanium oxide that can be used as an external additive include rutile-type titanium oxide, anatase-type titanium oxide, and rutile-anatase-type titanium oxide.
The rutile-anatase type titanium oxide has rutile-type titanium oxide (titanium dioxide) and anatase-type titanium oxide (titanium dioxide) in the same particle. That is, the rutile-anatase type titanium oxide has a mixed crystal type titanium oxide (titanium dioxide) of a rutile type crystal and an anatase type crystal.
[0107]
Rutile-type titanium oxide generally has a property of easily forming a spindle-shaped crystal. Moreover, anatase type titanium oxide has a property that it easily precipitates fine crystals and has an excellent affinity with a silane coupling agent used for a hydrophobic treatment or the like.
And, since rutile-anatase type titanium oxide has a mixed crystal type titanium oxide of rutile type crystal and anatase type crystal, advantages of rutile type titanium oxide and advantages of anatase type titanium oxide It has both. That is, in rutile-anatase type titanium oxide, fine anatase-type crystals are mixed between the rutile-type crystals (inside the rutile-type crystal), and as a whole, have a substantially spindle shape, so that the toner It becomes difficult to be buried in the mother particles, and since the rutile-anatase type titanium oxide as a whole has an excellent affinity with a silane coupling agent, etc., it is uniform on the surface of the rutile-anatase type titanium oxide powder. A stable hydrophobic film (silane coupling film) is easily formed. Therefore, the toner obtained by containing the rutile-anatase type titanium oxide has a uniform charge distribution (sharp charge distribution of toner particles), stable charge characteristics, environmental characteristics (especially moisture resistance), and fluidity. It is excellent in properties, anti-caking properties and the like.
[0108]
In particular, the rutile-anatase type titanium oxide exerts the following synergistic effects when used in combination with the polyester resin as described above.
That is, as described above, in the present invention, since the polyester-based resin contains a block polyester having a crystalline block with high crystallinity, the toner particles have a predetermined size mainly formed by the crystalline block in the toner particles. It may have a crystal. By having such crystals, the rutile-anatase type titanium oxide is less likely to be buried in the base particles of the toner. That is, by containing a hard component such as the crystal, the rutile-anatase type titanium oxide is securely carried (attached) to the vicinity of the surface of the toner base particles. Thereby, the function of the rutile-anatase type titanium oxide (particularly, effects such as excellent fluidity and chargeability) can be sufficiently exhibited. As described above, when used in combination with the above-described polyester-based resin, the function of the rutile-anatase type titanium oxide can be sufficiently exhibited, so that the amount of the external additive used can be suppressed. As a result, it is possible to effectively prevent inconveniences caused by adding a large amount of the external additive (for example, a decrease in fixability to a transfer material (recording medium) such as paper).
[0109]
The ratio of rutile-type titanium oxide to anatase-type titanium oxide in rutile-anatase-type titanium oxide is not particularly limited, but is preferably 5:95 to 95: 5 by weight, and 50:50. More preferably, it is 90:10. By using such rutile-anatase-type titanium oxide, the effect of using the above-described rutile-anatase-type titanium oxide becomes more remarkable.
[0110]
Further, it is preferable that the rutile-anatase type titanium oxide absorbs light in a wavelength region of 300 to 350 nm. As a result, the toner is particularly excellent in light fastness (in particular, light fastness after fixing to a recording medium).
Although the shape of the rutile-anatase type titanium oxide used in the present invention is not particularly limited, it is generally a spindle shape.
[0111]
When the rutile anatase type titanium oxide has a substantially spindle shape, the average major axis diameter is preferably from 10 to 100 nm, more preferably from 20 to 50 nm. When the average major axis diameter is in such a range, the rutile-anatase type titanium oxide can sufficiently exhibit the above-described function, and is hardly buried in the base particles of the toner, and It is difficult to release. As a result, the stability of the toner against mechanical stress is further improved.
[0112]
The content of rutile-anatase type titanium oxide in the toner is not particularly limited, but is preferably 0.1 to 2.0% by weight, and more preferably 0.5 to 1.0% by weight. If the content of rutile anatase type titanium oxide is less than the lower limit, the effect of using rutile anatase type titanium oxide as described above may not be sufficiently exerted. On the other hand, when the content of the rutile-anatase type titanium oxide exceeds the above upper limit, the fixability of the toner tends to decrease.
[0113]
Such rutile-anatase-type titanium oxide may be prepared by any method, and for example, can be obtained by calcining anatase-type titanium oxide. By using such a method, the ratio of rutile-type titanium oxide to anatase-type titanium oxide in rutile-anatase-type titanium oxide can be relatively easily and reliably controlled. When rutile-anatase type titanium oxide is obtained by such a method, the firing temperature is preferably about 700 to 1000 ° C. By setting the firing temperature to a value in such a range, it is possible to more easily and reliably control the abundance ratio of rutile-type titanium oxide and anatase-type titanium oxide in rutile-anatase-type titanium oxide. Become.
[0114]
The rutile-anatase type titanium oxide is preferably subjected to a hydrophobic treatment. By performing the hydrophobizing treatment, an effect is obtained that charging is not greatly affected by humidity. As the hydrophobizing treatment, for example, HMDS, a silane coupling agent (for example, one having a functional group such as an amino group), a titanate coupling agent, a fluorine-containing silane coupling agent, a silicone oil, or the like is used. Surface treatment of powder (particles) of rutile-anatase type titanium oxide.
[0115]
Further, among the external additives described above, examples of the silica that can be used as the external additive include positively chargeable silica and negatively chargeable silica. Positively chargeable silica can be obtained, for example, by subjecting negatively chargeable silica to a surface treatment with a silane coupling agent having a functional group such as an amino group.
When negatively chargeable silica is used as the external additive, the charge amount (absolute value) of the toner particles can be increased. As a result, a stable negatively charged toner can be obtained, and the effect that toner control of the image forming apparatus becomes easy can be obtained.
[0116]
In addition, when negatively chargeable silica is used in combination with the above-mentioned rutile-anatase type titanium oxide, particularly excellent effects are obtained. That is, by using negatively chargeable silica and rutile anatase type titanium oxide in combination, the fluidity and environmental characteristics (particularly, moisture resistance) of the toner can be further improved, and more stable triboelectric chargeability can be exhibited. , So-called fogging can be more effectively prevented. Further, by using a combination of negatively chargeable silica and rutile anatase type titanium oxide, the obtained toner can have a large charge amount (absolute value) and a sharper charge distribution.
[0117]
The average major axis diameter of the substantially spindle-shaped rutile-anatase type titanium oxide is D ₁ [Nm], and the average particle diameter of the negatively chargeable silica is D ₂ [Nm], 0.2 ≦ D ₁ / D ₂ It is preferable to satisfy the relationship of ≦ 15, and 0.4 ≦ D ₁ / D ₂ It is more preferable to satisfy the relationship of ≦ 5. By satisfying such a relationship, the effect of using the negatively chargeable silica and the rutile anatase type titanium oxide together becomes more remarkable. In this specification, the “average particle size” refers to a volume-based average particle size.
[0118]
When positively chargeable silica is used as the external additive, for example, the positively chargeable silica can function as a microcarrier, and the chargeability of the toner particles themselves can be further improved. In particular, by using the positively chargeable silica and the above-described rutile-anatase type titanium oxide in combination, the obtained toner can have a large charge amount (absolute value) and a sharper charge distribution. .
[0119]
When it contains positively chargeable silica, its average particle size is preferably from 30 to 100 nm, more preferably from 40 to 50 nm. When the average particle diameter of the positively chargeable silica is in such a range, the above-described effect becomes more remarkable.
As the external additive, HMDS, a silane-based coupling agent (for example, one having a functional group such as an amino group), a titanate-based coupling agent on the surface of the fine particles composed of the above-described materials may be used. Alternatively, a material that has been surface-treated with a fluorine-containing silane coupling agent, silicone oil, or the like may be used.
[0120]
[toner]
Next, the toner of the present invention composed of the above materials will be described.
As described above, the toner of the present invention contains at least a block polyester, an amorphous polyester, and a colorant.
By the way, attempts to manufacture a toner using a binder resin containing two or more different resin components (resin components having different softening points) have been conventionally made. However, such a conventional toner has sufficient low-temperature fixability even when a resin component having a relatively low softening point (a low softening point resin) is contained in addition to a resin component having a relatively high softening point. In some cases, it could not be obtained. In such a case, if the content of the low softening point resin is increased in order to improve the fixability at a low temperature, there is a problem that sufficient durability as a toner cannot be obtained. That is, it has been difficult for the conventional toner to achieve both sufficient durability and excellent fixability (fixing strength) in a wide temperature range.
[0121]
Accordingly, the present inventor has conducted intensive studies, and as a result, used the above-described block polyester and an amorphous polyester in combination, and further included a first polyester mainly composed of the block polyester in the toner (toner particles). Region and a second region mainly composed of amorphous polyester, and the concentration (content) of the colorant in the first region and the concentration (content) of the colorant in the second region The present invention has been found to provide a toner having sufficient durability and exhibiting excellent fixability (fixing strength) in a wide temperature range by satisfying a predetermined relationship with the present invention. Reached. That is, the present invention is characterized in that the concentration of the colorant in the first region is higher than the concentration of the colorant in the second region.
[0122]
Further, as described above, since the block polyester has a crystalline block with high crystallinity, the toner (toner particles) of the present invention usually contains crystals mainly composed of crystalline blocks. . The presence of such crystals makes the toner particularly excellent in durability (shape stability). As will be described in detail below, such crystals preferably have an appropriate size. That is, if the crystal size is too large, the first region and the second region, which will be described later, are likely to undergo macrophase separation, and the functions of the block polyester and the amorphous polyester (and the synergistic effect thereof) It is difficult to exert the effect sufficiently. It is generally known that crystal growth is hindered by the presence of impurities (particularly, the presence of solid impurities). On the other hand, the present invention is characterized in that the concentration (content) of the colorant in the second region is higher than the concentration (content) of the colorant in the second region, as described above. By satisfying such a relationship, excessive growth of crystals in the first region can be effectively prevented and suppressed due to the presence of the colorant as an impurity, and the crystal was miniaturized to an appropriate size. Crystals can be formed uniformly (variation in the size of each crystal is small).
[0123]
Further, by satisfying the above relationship, the content of the colorant in the second region (a region mainly composed of amorphous polyester) can be reduced. As described above, the amorphous polyester that mainly constitutes the second region generally has a lower softening point than the block polyester, and softens in preference to the block polyester during fixing of the toner. , Which greatly contributes to the fixability of the toner (especially, the fixability at a low temperature). As described above, if the concentration of the colorant in the second region is low, the environment at a relatively high temperature Even below, the colorant can be effectively prevented from seeping out of the toner particles (first region). As a result, it is possible to effectively prevent so-called streaks from occurring in an image formed using the toner, and to effectively prevent stains from adhering to components of an image forming apparatus such as a photoconductor. Can be prevented. Further, by lowering the content of the colorant in the second region, the function of the amorphous polyester can be sufficiently exhibited, and the fixability of the toner as a whole (especially, the fixability in a low temperature region). Can be made particularly good.
[0124]
As described above, the present invention uses a combination of a block polyester and an amorphous polyester, and furthermore, by unevenly distributing a colorant in a predetermined region, these act synergistically to provide sufficient durability as a whole toner. It is characterized in that it has excellent fixability (fixing strength) in a wide temperature range.
The concentration (content) of the colorant in the first region is C ₁ [Vol%], the concentration (content) of the colorant in the second region is represented by C ₂ [Vol%], 0.1 ≦ C ₂ / C ₁ It is preferable to satisfy the relationship of ≦ 1 and 0.1 ≦ C ₂ / C ₁ It is more preferable to satisfy the relationship of ≦ 0.5. By satisfying such a relationship, the above-described effects become more remarkable.
[0125]
In contrast, C ₂ / C ₁ Is less than the lower limit, the concentration of the colorant in the first region is relatively too high, and the above-described problem may occur. Further, if the concentration of the colorant in the first region is relatively low in order to avoid such a problem, the content of the colorant in the entire toner is reduced, and the function of the colorant as described above is reduced. May not be fully exhibited.
[0126]
Also, C ₂ / C ₁ Exceeds the upper limit, the concentration of the colorant in the second region becomes relatively too high, and the above-described effect may not be sufficiently obtained. Further, if the concentration of the colorant in the second region is relatively low in order to avoid such a problem, the content of the colorant in the entire toner is reduced, and the function of the colorant as described above is reduced. May not be fully exhibited.
[0127]
Further, the first region is preferably present in a state of being finely dispersed in the toner particles. This makes it difficult for a difference in strength or chargeability to appear between the first region and the second region, further improving durability and charge stability. Specifically, the size (average particle size) of the first region is preferably finely dispersed to 2 μm or less, and more preferably 0.05 to 1 μm. As a result, the above-mentioned effects become more remarkable.
[0128]
The proportion of the colorant contained in the first region among all the colorants contained in the toner is preferably 95 vol% or less, and more preferably 90 vol% or less. By satisfying such a condition, the above-mentioned effects become more remarkable. On the other hand, when the concentration of the colorant in the first region exceeds the upper limit, the effect of the crystal refinement by the colorant is saturated, and it is difficult to achieve a further effect. If the concentration of the colorant in the region (1) becomes extremely high, the durability of the toner is reduced.
In addition, the proportion of the colorant contained in the second region among all the colorants contained in the toner is preferably 49 vol% or less, and more preferably 40 vol% or less. By satisfying such a condition, the above-mentioned effects become more remarkable.
[0129]
The toner (toner powder) of the present invention preferably has an average circularity R represented by the following formula (I) of 0.91 to 0.98, and more preferably 0.93 to 0.98. More preferred. When the average circularity R is less than 0.91, it is difficult to sufficiently reduce the difference in charging characteristics between the individual toner powders, and the developability on the photoconductor tends to decrease. On the other hand, if the average circularity R is too small, the adhesion (filming) of the toner on the photoreceptor is likely to occur, and the transfer efficiency of the toner may decrease. On the other hand, when the average circularity R exceeds 0.98, transfer efficiency and mechanical strength are increased, but there is a problem that granulation (joining of particles) is promoted to increase the average particle diameter. On the other hand, when the average circularity R exceeds 0.98, it becomes difficult to remove, for example, toner adhered to the photoreceptor or the like by cleaning.
R = L ₀ / L ₁ ... (I)
(However, in the formula, L ₁ [Μm] is the perimeter of the projected image of the toner particles to be measured, L ₀ [Μm] represents the circumference of a perfect circle (complete geometric circle) having an area equal to the area of the projected image of the toner particles to be measured. )
[0130]
The average particle size of the toner is preferably 3 to 12 μm, and more preferably 5 to 10 μm. When the average particle size of the toner is less than the lower limit, fusion and the like between toner particles easily occur. On the other hand, when the average particle size of the toner exceeds the upper limit, the resolution of the printed matter tends to decrease.
Further, the content of the polyester resin in the toner is preferably from 50 to 98% by weight, and more preferably from 85 to 97% by weight. When the content of the polyester resin is less than the lower limit, the effects of the present invention may not be sufficiently obtained. On the other hand, if the content of the polyester-based resin exceeds the above upper limit, the content of components such as a coloring agent may be relatively reduced, and it may be difficult to exhibit characteristics such as coloring properties.
[0131]
When wax is contained in the toner, the content thereof is not particularly limited, but is preferably 5% by weight or less, more preferably 3% by weight or less, and is preferably 0.5 to 3% by weight. More preferred. If the content of the wax is too large, the wax is liberated and coarsened, and the wax exudes to the toner surface.
[0132]
The acid value as a physical property of a toner is one of the factors that influence the environmental characteristics (particularly, moisture resistance) of the toner. The acid value of the toner is preferably 8 KOH mg / g or less, more preferably 1 KOH mg / g or less. When the acid value of the toner is 8 KOHmg / g or less, the environmental characteristics (particularly, moisture resistance) of the toner become particularly excellent.
Further, when the toner of the present invention is used in a fixing device having a nip portion as described later, the amount of change in the relaxation modulus G (t) in the passage time Δt [second] of the toner particles is: It is preferably at most 500 [Pa], more preferably at most 100 [Pa]. By satisfying such conditions, inconveniences such as offsets are less likely to occur.
[0133]
Further, when the toner of the present invention is used in a fixing device having a fixing nip portion as described later, the time required for toner particles to pass through the fixing nip portion is Δt [sec], and the toner particle is 0.01 sec. Is the initial relaxation modulus G (0.01), and the relaxation modulus at Δt seconds of the toner is G (Δt), G (0.01) / G (Δt) ≦ Preferably, the relationship of 10 is satisfied, more preferably, the relationship of 1 ≦ G (0.01) / G (Δt) ≦ 8 is satisfied, and 1 ≦ G (0.01) / G (Δt) ≦ 6. It is more preferable to satisfy the following relationship. By satisfying such a relationship, the tearing of the toner due to the decrease in the elastic modulus of the toner particles and the offset are less likely to occur. On the other hand, when G (0.01) / G (Δt) exceeds 10, toner tearing and offset tend to occur. The relaxation elastic modulus of the toner is determined by, for example, the composition of the constituent materials of the toner (for example, the molecular weight of block polyester or amorphous polyester, monomer component, randomness, the composition of wax and external additives, the content of each constituent component, etc. ), The concentration (content) of the colorant in the first region and the second region, the toner production conditions (for example, the raw material temperature in the kneading step, the kneading time, the cooling rate of the kneaded material in the cooling step, the heat The processing temperature in the sphering step).
[0134]
As described above, the toner of the present invention usually contains crystals mainly composed of crystalline blocks of block polyester.
Such crystals preferably have an average length (average length in the longitudinal direction) of 10 to 700 nm, more preferably 50 to 500 nm, and even more preferably 50 to 300 nm. When the length of the crystal satisfies such conditions, the stability of the toner shape is particularly excellent, and the stability (durability) is particularly excellent against mechanical stress. In particular, the external additive is more reliably held near the surface of the toner particles (toner base particles) (the external additives can be effectively prevented from being buried in the base particles). The particles are particularly excellent in stability in a developing device or the like, and hardly cause filming or the like.
[0135]
In particular, when the toner contains rutile anatase type titanium oxide, it is preferable that the following relationship be satisfied. That is, the average major axis diameter of the substantially spindle-shaped rutile anatase type titanium oxide is represented by D ₁ [Nm], and the average length of the crystal is L _C [Nm], 0.01 ≦ D ₁ / L _C It is preferable to satisfy the relationship of ≦ 2, and 0.02 ≦ D ₁ / L _C It is more preferable to satisfy the relationship of ≦ 1. By satisfying such a relationship, the rutile-anatase type titanium oxide is not easily buried in the base particles while sufficiently exhibiting the above-described effects. As a result, the toner retains the above-described functions sufficiently and has particularly excellent stability against mechanical stress.
[0136]
The average length of the crystal can be measured by a transmission electron microscope (TEM), small-angle X-ray scattering measurement, or the like.
Further, the toner of the present invention is preferably applied to a non-magnetic one-component toner. The non-magnetic one-component toner is generally applied to an image forming apparatus having a regulating blade as described below. Therefore, the toner of the present invention, which is resistant to mechanical stress, can exert the above-mentioned effects more remarkably when used as a non-magnetic one-component toner.
[0137]
The fixing device using the toner of the present invention is not particularly limited, but is preferably used for a contact-type fixing device as described below. As a result, both the advantages of high releasability from the fixing roller due to the block polyester crystal and the effect of improving the fixing property (fixing strength) due to the low-viscosity amorphous polyester are sufficiently exhibited, and a wide good fixing area is obtained. Secured.
[0138]
Next, a fixing device and an image forming apparatus to which the toner of the present invention is suitably applied will be described.
FIG. 5 is an overall configuration diagram showing a preferred embodiment of an image forming apparatus of the present invention (an image forming apparatus to which the toner of the present invention is suitably applied), and FIG. 6 is a developing device of the image forming apparatus of FIG. FIG. 7 is a perspective view showing a detailed structure of the fixing device of the present invention used in the image forming apparatus shown in FIG. 5, and is a partially broken cross-sectional view. FIG. 9 are perspective views of a peeling member constituting the fixing device of FIG. 7, FIG. 10 is a side view showing a mounting state of the peeling member constituting the fixing device of FIG. 7, and FIG. 11 is a fixing diagram of FIG. FIG. 12 is a schematic view for explaining an arrangement angle of a peeling member with respect to a tangent line at an exit of a fixing nip portion, and FIG. FIG. 14 is a view schematically showing the shape of the nip portion, and FIG. 15 is a view schematically showing the shape of the fixing roller and the pressure roller and the shape of the fixing nip, FIG. 16 is a cross-sectional view taken along line Y-Y of FIG. FIG. 4 is a cross-sectional view for explaining a gap between a fixing roller and a peeling member.
[0139]
An image carrier 30 composed of a photosensitive drum is provided in the apparatus main body 20 of the image forming apparatus 1000, and is driven to rotate in a direction indicated by an arrow by a driving unit (not shown). Around the image carrier 30, a charging device 40 for uniformly charging the image carrier (photoconductor) 30 along the rotation direction, and forms an electrostatic latent image on the image carrier 30. Device 50, a rotary developing device 60 for developing an electrostatic latent image, and an intermediate transfer device 70 for primarily transferring a single-color toner image formed on the image carrier 30.
[0140]
The rotary developing device 60 has a yellow developing device 60Y, a magenta developing device 60M, a cyan developing device 60C, and a black developing device 60K mounted on a support frame 600, and the support frame 600 is driven to rotate by a drive motor (not shown). It has a configuration. The plurality of developing devices 60Y, 60C, 60M, and 60K are selectively rotated so that the developing roller 604 of one developing device faces the image carrier 30 for each rotation of the image carrier 30. Have been. In each of the developing devices 60Y, 60C, 60M, and 60K, a toner storage unit that stores a toner of each color is formed.
The developing devices 60Y, 60C, 60M, and 60K all have the same structure. Therefore, although the structure of the developing device 60Y will be described here, the structures and functions of the developing devices 60C, 60M, and 60K are the same.
[0141]
As shown in FIG. 6, in the developing device 60Y, a supply roller 603 and a developing roller 604 are mounted on a housing 601 that accommodates the toner T therein, and when the developing device 60Y is positioned at the above-described developing position. The developing roller 604 functioning as a “toner carrier” is positioned in contact with the image carrier (photoconductor) 30 or at a predetermined gap, and these rollers 603 and 604 are provided on the main body side. It is configured to engage with a rotating drive unit (not shown) and rotate in a predetermined direction. The developing roller 604 is formed in a cylindrical shape from a metal or alloy such as copper, stainless steel, or aluminum so that a developing bias is applied.
[0142]
In the developing device 60Y, a regulating blade 605 for regulating the thickness of the toner layer formed on the surface of the developing roller 604 to a predetermined thickness is arranged. The regulating blade 605 includes a plate-like member 605a such as stainless steel or phosphor bronze, and an elastic member 605b such as a rubber or resin member attached to the tip of the plate-like member 605a. The rear end of the plate member 605a is fixed to the housing 601, and the elastic member 605b attached to the front end of the plate member 605a is connected to the rear end of the plate member 605a in the rotation direction D3 of the developing roller 604. It is arranged so as to be located on the upstream side.
[0143]
The intermediate transfer device 70 is provided so as to face the image carrier 30 on the back surface of the intermediate transfer belt 110, the intermediate transfer belt 110 driven by the two rollers in the direction indicated by the arrow, and the driven roller 90 and the driven roller 100. A primary transfer roller 120, a transfer belt cleaner 130 for removing residual toner on the intermediate transfer belt 110, and a four-color full-color image formed on the intermediate transfer belt 110 are disposed opposite to the drive roller 90, and the recording medium ( And a secondary transfer roller 140 for transferring the image onto paper.
[0144]
A paper feed cassette 150 is provided at the bottom of the apparatus main body 20. 200. Incidentally, reference numeral 230 denotes a conveyance path for double-sided printing.
The operation of the image forming apparatus 1000 having the above configuration will be described. When an image forming signal is input from a computer (not shown), the image carrier 30, the developing roller 604 of the developing device 60, and the intermediate transfer belt 110 are driven to rotate. First, the outer peripheral surface of the image carrier 30 is charged by the charging device 40. The outer peripheral surface of the uniformly charged and uniformly charged image carrier 30 is selectively exposed by the exposure device 50 in accordance with the image information of the first color (for example, yellow), and the yellow electrostatic latent image is formed. An image is formed.
[0145]
On the other hand, in the developing device 60Y, the two rollers 603 and 604 rotate while being in contact with each other, so that the yellow toner rubs against the surface of the developing roller 604 and a toner layer having a predetermined thickness is formed on the surface of the developing roller 604. . Then, the elastic member 605b of the regulating blade 605 elastically contacts the surface of the developing roller 604 to regulate the toner layer on the surface of the developing roller 604 to a predetermined thickness.
[0146]
At the latent image position formed on the image carrier 30, the yellow developing device 60 </ b> Y rotates and its developing roller 604 abuts, whereby the yellow electrostatic latent image toner image is formed on the image carrier 30. Then, the toner image formed on the image carrier 30 is transferred onto the intermediate transfer belt 110 by the primary transfer roller 120. At this time, the secondary transfer roller 140 is separated from the intermediate transfer belt 110.
[0147]
The above-described processing is repeated for the second, third, and fourth colors of the image forming signal, and the latent image formation, development, and transfer by one rotation of the image carrier 30 and the intermediate transfer belt 110 are repeated. Are transferred on the intermediate transfer belt 110 in a superimposed manner. Then, at the timing when this full-color image reaches the secondary transfer roller 140, the recording medium is supplied from the transport path 170 to the secondary transfer roller 140. At this time, the secondary transfer roller 140 is pressed against the intermediate transfer belt 110 and A secondary transfer voltage is applied, and the full-color toner image on the intermediate transfer belt 110 is transferred onto a recording medium. Then, the toner image transferred onto the recording medium is heated and pressed by the fixing device 190 and fixed. The toner remaining on the intermediate transfer belt 110 is removed by the transfer belt cleaner 130.
[0148]
In the case of double-sided printing, the recording medium that has exited the fixing device 190 is switched back so that the rear end thereof is at the front end, is supplied to the secondary transfer roller 140 via the double-sided printing conveyance path 230, and is The full-color toner image on the transfer belt 110 is transferred onto the recording medium, and is again heated and pressed by the fixing device 190 to be fixed.
In FIG. 5, the fixing device 190 according to the present invention includes a fixing roller 210 having a heat source and a pressing roller 220 pressed against the fixing roller 210. A line connecting the fixing roller 210 and the axis of the pressing roller 220 is a horizontal line. It is arranged to have an angle of θ. Note that 0 ° ≦ θ ≦ 30 °.
[0149]
Next, the fixing device 190 will be described in detail.
7 and 11, a fixing roller 210 is rotatably mounted in a housing 240, and a driving gear 280 is connected to one end of the fixing roller 210. A pressure roller 220 is rotatably mounted opposite to the fixing roller 210. The length of the pressure roller 220 in the axial direction is shorter than that of the fixing roller 210, and a bearing 250 is provided in the empty space, and both ends of the pressure roller 220 are supported by the bearings 250. A pressure lever 260 is rotatably provided on the bearing 250, and a pressure spring 270 is disposed between one end of the pressure lever 260 and the housing 240, whereby the pressure roller 220 and the fixing roller 210 are pressed. It is configured to be.
[0150]
8, a fixing roller 210 includes a metal cylinder 210b having a heat source 210a such as a halogen lamp therein, an elastic layer 210c made of silicon rubber or the like provided on the outer periphery of the cylinder 210b, and a surface of the elastic layer 210c. A surface layer (not shown) made of fluoro rubber and fluoro resin (for example, pertetrafluoroethylene (PTFE)), and a rotating shaft 210d fixed to the cylindrical body 210b.
[0151]
The pressure roller 220 has a metal cylindrical body 220b, a rotating shaft 220d fixed to the cylindrical body 220b, a bearing 250 for supporting the rotating shaft 220d, and a fixing roller 210 on the outer periphery of the cylindrical body 220b. It comprises an elastic layer 220c provided and a surface layer (not shown) made of fluoro rubber or fluoro resin coated on the surface of the elastic layer 220c. The thickness of the elastic layer 210c of the fixing roller 210 is extremely smaller than the thickness of the elastic layer 220c of the pressing roller 220, whereby a fixing nip portion (nip portion) 340 is formed such that the pressing roller 220 side is concavely concave. ing.
[0152]
As shown in FIGS. 7 and 8, support shafts 290 and 300 are provided on both side surfaces of the housing 240, and the peeling member 310 and the pressure roller 220 on the fixing roller 210 side are respectively provided on the support shafts 290 and 300. The peeling member 320 on the side is rotatably mounted. As a result, the peeling members 310 and 320 are disposed downstream of the fixing nip 340 in the recording medium transport direction in the axial direction of the fixing roller 210 and the pressure roller 220.
[0153]
As shown in FIGS. 9 and 10, the peeling member 310 on the fixing roller 210 side has a resin sheet or a metal sheet as a base material, and has a fluorine-based resin layer formed on the surface of the base material. The peeling member 310 includes a plate-like peeling portion (base material) 310a, a bent portion 310b bent in an L-shape behind the peeling portion 310a toward the fixing roller 210, and a lower portion at both ends of the peeling portion 310a. It comprises a support piece 310c bent in the direction, a fitting hole 310d formed in the support piece 310c, and a guide part 310e extending forward on both sides of the peeling part 310a.
[0154]
The peeling section 310a is disposed so as to be inclined toward the exit (nip exit 341) of the fixing nip section 340, and the tip of the peeling section 310a is in non-contact with and close to the fixing roller 210. The support shaft 290 described with reference to FIG. 8 is fitted into the fitting hole 310d of the support piece 310c. The guide portion 310e is urged against the housing 240 by the spring 330, whereby the front end of the guide portion 310e is in contact with the fixing roller 210. As a result, the gap between the front end of the peeling portion 310a and the surface of the fixing roller 210 is formed. The gap is kept constant at all times.
[0155]
The peeling member 320 on the pressure roller 220 side has the same shape as the peeling member on the fixing roller 210 side. However, as shown in FIGS. 7 and 8, the leading end of the peeling section 320a is larger than the leading end of the peeling section 310a. It is arranged on the downstream side in the medium transport direction. Further, the tip of the guide portion 320e is in contact with the peripheral surface of the bearing 250 of the pressure roller 220 at point P, whereby the gap between the tip of the peeling portion 320a and the surface of the pressure roller 220 is always constant. Is to be.
[0156]
In this embodiment, as shown in FIGS. 7 and 8, the peeling members 310 and 320 are disposed on the downstream side of the nip 340 in the recording medium conveyance direction in the axial direction of the fixing roller 210 and the pressure roller 220. The tip of the peeling member 310 on the side of the fixing roller 210 is disposed so as to be inclined toward the exit of the nip portion 340, and is in non-contact and close proximity to the fixing roller 210. The leading end of the peeling member 320 on the pressing roller 220 side is disposed downstream of the leading end of the peeling member 310 on the fixing roller 210 side in the recording medium transport direction.
[0157]
As shown in FIG. 10, the guide portion 310 e of the peeling member 310 on the fixing roller 210 side is urged against the housing 240 by a spring 330, whereby the tip of the guide portion 310 e is in contact with the fixing roller 210. As a result, the positioning is performed such that the gap between the tip of the peeling section 310a and the surface of the fixing roller 210 is always constant.
[0158]
The peeling member 320 on the pressure roller 220 side has the same shape as the peeling member on the fixing roller 210 side. As shown in FIGS. 7 and 8, the leading end of the peeling section 320a is larger than the leading end of the peeling section 310a. The guide 320e is disposed downstream in the transport direction, and the tip of the guide 320e is in contact with the surface of the bearing 250 of the pressure roller 220 at point P. Positioning is performed so that the gap between them is always constant. Therefore, as shown in FIG. 11, the axial length of the pressure roller 220 is shorter than that of the fixing roller 210, and a bearing 250 is provided in the empty space. Supported.
[0159]
In the case of double-sided printing, the recording medium printed on one side is peeled off by the peeling member 310 on the fixing roller 210 side, and then switched back so that the rear end of the recording medium becomes the front end, and passed through the conveyance path 230 for double-sided printing. The full-color toner image on the intermediate transfer belt 110 is supplied to the secondary transfer roller 140, and is transferred onto a recording medium. Then, the full-color toner image is again heated and pressed by the fixing roller 210 to be fixed. The resulting recording medium is peeled off by the peeling member 320 on the pressure roller 220 side.
[0160]
As described above, in the fixing device according to the present embodiment, the peeling member is disposed in the axial direction of the fixing roller and the pressure roller and downstream of the fixing nip in the recording medium conveyance direction in the vicinity of the fixing roller and the pressure roller. Since the positioning of the peeling member on the fixing roller side is performed on the surface of the fixing roller and the positioning of the peeling member on the pressing roller side is performed on the bearing surface of the pressing roller, recording from the fixing roller and the pressing roller is performed. The removability of the medium can be improved.
[0161]
Further, in the present embodiment, as shown in FIG. 12, a method is adopted in which the fixing roller 210 and the pressure roller 220 are arranged in a substantially horizontal state, and the recording medium 500 is discharged upward from the fixing nip portion 340. Is the arrangement angle θ of the peeling member 310 with respect to the tangent S of the nip exit 341 of the fixing nip portion 340. _A Is preferably set in the range of −5 to 25 °. The arrangement angle θ of the peeling member 310 with respect to the tangent S of the nip exit 341 of the fixing nip portion 340 _A Is set to a value in such a range, streaks are less likely to occur in the image, and the releasability is improved. Note that the arrangement angle θ _A Is "+" on the fixing roller 210 side and "-" on the pressure roller side.
[0162]
Further, the fixing roller 210 and the pressing roller 220 have, for example, substantially constant outer diameters in their respective axial directions (they may have a substantially cylindrical shape, but the outer diameters are small near both ends. It may have a so-called crown shape that is large near the center, or a so-called inverted crown shape in which the outer diameter dimension is large near both ends and small near the center.
[0163]
For example, when the fixing roller 210 and the pressure roller 220 have an inverted crown shape as shown in FIG. 13, the cross-sectional shape of the peeling member 310 is preferably as shown in FIG. When the fixing roller 210 and the pressing roller 220 have a crown shape as shown in FIG. 15, the cross-sectional shape of the peeling member 310 is preferably as shown in FIG.
[0164]
As described above, when the peeling member 310 disposed along the fixing roller 210 has a shape that follows the shape of the nip outlet 341 of the nip portion 340, the peeling member 310 side of the peeling member 310 at the time of peeling. The number of contact points between the side edge of the recording medium and the recording medium increases, and the adverse effects caused by concentration of the contact pressure between them, such as winding of the recording medium, disturbance in a formed image, and generation of streaks can be effectively reduced. Can be prevented and suppressed.
[0165]
As shown in FIG. 17, in the fixing device 190, the gap G2 [μm] between the fixing roller 210 and the peeling member 310 near the axial end of the fixing roller 210 is set at the center of the fixing roller 210 in the axial direction. It is preferable that the gap G1 [μm] between the fixing roller 210 and the peeling member 310 near the portion is larger than the gap G1 [μm]. By satisfying such a relationship, the following effects can be obtained.
[0166]
That is, since the gap between the peeling member 310 and the fixing roller 210 is small in the vicinity of the central portion in the length direction, the gap management can be simplified without greatly impairing the peeling property, and the manufacturing of the fixing device 190 is also possible. It will be easier. Further, even when foreign matter enters or paper jams occur, the peeling member 310 and the fixing roller 210 are hardly damaged by these, and the durability and reliability of the peeling member 310 and the fixing roller are improved. The durability and reliability of the apparatus 190 and the image forming apparatus 1000 are also improved. The relationship between G1 and G2 as described above may be determined by, for example, forming the peeling member 310 into an arcuate shape, forming the distal end portion 310f of the peeling member 310 into an arcuate shape, or forming the fixing roller 210 into a crown shape. Can be satisfied.
[0167]
In the fixing device as described above, the length of the fixing nip 340 is such that the time required for the toner particles to pass through the fixing nip 340 is 0.02 to 0.2 seconds. Is preferably, and more preferably 0.03 to 0.1 seconds. When the time required for the toner particles to pass through the fixing nip portion 340 is within such a range, the toner is heated to the melting temperature, and the toner is not excessively melted, and the releasability to the fixing roller is sufficiently high. Secured.
[0168]
The fixing device 190 is suitable for high-speed printing (high-speed fixing, high-speed image formation). Specifically, the fixing device 190 has a feeding speed (feeding speed) of the recording medium 500 of 0.05 to 1.0 m / sec. Preferably, it is 0.2 to 0.5 m / sec. As described above, according to the present invention, even when the toner is fixed on the recording medium 500 at a relatively high speed, it is possible to prevent the occurrence of streaks or disturbances in the image, and to prevent the recording medium 500 from being wound. Hardly causes peeling failure.
[0169]
Further, the temperature of the fixing nip 340 during operation is preferably from 100 to 220 ° C., and more preferably from 120 to 200 ° C. When the temperature of the fixing nip 340 is in such a range, it is possible to sufficiently prevent a decrease in toner fixing strength due to a temperature drop (temperature drop) during paper passage.
Further, the set fixing temperature (set temperature on the surface of the fixing roller 210) during operation is preferably 110 to 220 ° C, more preferably 130 to 200 ° C. When the set temperature of the fixing roller 210 is in such a range, it is possible to secure both the fixing strength of the toner and to shorten the warm-up time (warm-up time).
[0170]
The fixing device 190 described above is suitable for high-speed printing (high-speed fixing, high-speed image formation) as described above. However, in such a fixing device, the toner is in a high temperature state even when the recording medium on which the toner is fixed comes into contact with the peeling member. In this case, the fixed image may be disturbed or streaked. Further, if the fixed toner is brought into contact with the release member in a molten state (low viscosity state), it may be difficult to reliably release the recording medium.
[0171]
On the other hand, the above-described fixing device 190 can suitably apply the toner of the present invention. That is, since the toner of the present invention contains an amorphous polyester having a relatively low softening point, the toner of the present invention is reliably fixed to the recording medium when passing through the fixing nip portion 340, and the toner of the present invention is Contains a block polyester having a crystalline block, and the colorant is unevenly distributed in the first region mainly composed of the block polyester. For this reason, a crystal having high hardness and an appropriate size (refined) tends to precipitate inside the toner (inside the first region). The presence of such crystals makes it possible to prevent the melt viscosity of the toner from being lower than a predetermined value even at a relatively high temperature such as at the time of fixing. There will be hard sites. As a result, even when the fixed image of the toner comes into contact with the peeling member, the formed image is less likely to be disturbed or streaked. In particular, in the present invention, since the colorant is unevenly distributed in the first region, it is extremely unlikely that disturbance or streak occurs in such a formed image. Further, in the recording medium on which the toner of the present invention is fixed, peeling failure is particularly unlikely to occur, and the peeling member surely peels off from the fixing roller.
[0172]
[Method of Manufacturing Toner]
Next, a preferred embodiment of the method for producing a toner of the present invention will be described. FIG. 1 is a longitudinal sectional view schematically showing the configuration of a kneading machine and a cooling machine used in the first embodiment of the method for producing a toner of the present invention. Hereinafter, in FIG. 1, the left side will be described as a “base end” and the right side will be described as a “top end” (the same applies to FIG. 18 described later).
[0173]
<1A> First kneading process (first kneading process)
First, a first raw material 7 containing at least a block polyester and a colorant among the above materials is kneaded to obtain a first kneaded material 8 (first kneading step). It is preferable that the first raw material 7 to be subjected to the first kneading step is previously uniformly mixed by a mixer such as a Henschel mixer.
[0174]
The first kneading step (first kneading process) can be performed using a kneader 1 as shown in FIG.
The kneading machine 1 includes a process unit 12 for kneading the first raw material 7 while transporting the same, a head unit 13 for forming and extruding the first kneaded material 8 obtained by kneading into a predetermined cross-sectional shape, and a process unit 12. And a feeder 14 for supplying the first raw material 7 therein.
[0175]
The process section 12 has a barrel 121, screws 122 and 123 inserted in the barrel 121, and a fixing member 124 for fixing the head section 13 to the tip of the barrel 121.
In the process section 12, the screws 122 and 123 rotate, so that a shearing force is applied to the first raw material 7 supplied from the feeder 14, and the components constituting the first raw material 7 are sufficiently uniformly dispersed. A first kneaded material 8 is obtained.
[0176]
Raw material temperature T in the first kneading step _K1 Although it depends on the composition, softening point and the like of the first raw material 7, the temperature is preferably from 120 to 260 ° C, more preferably from 180 to 260 ° C. If the raw material temperature is lower than the lower limit, the viscosity of the first raw material 7 becomes too high, and it becomes difficult to knead the components so that the respective constituent components are sufficiently uniformly dispersed. On the other hand, when the raw material temperature exceeds the upper limit, thermal decomposition, oxidative deterioration, and the like of the material, aggregation, macro phase separation, and the like are likely to occur, and the function of the finally obtained toner may be reduced. .
[0177]
In the present embodiment, the first raw material 7 only needs to include at least the block polyester and the colorant, and may include components other than these. For example, the first raw material 7 may include, as a part of its constituent components, an amorphous polyester contained in a second raw material 9 described later.
[0178]
<1B> Extrusion process
The first kneaded material 8 obtained in the first kneading step is pushed out of the kneader 1 via the head 13 by the rotation of the screws 122 and 123.
The head unit 13 has an internal space 131 into which the first kneaded material 8 is sent from the process unit 12 and an extrusion port 132 from which the first kneaded material 8 is extruded.
[0179]
In the illustrated configuration, the internal space 131 has a cross-sectional area gradually decreasing portion 133 whose cross-sectional area gradually decreases toward the extrusion port 132.
By having such a cross-sectional area gradually decreasing portion 133, the extruded amount of the first kneaded material 8 extruded from the extrusion port 132 is stabilized, and the cooling rate of the first kneaded material 8 in the cooling step described later is stabilized. I do. As a result, the toner produced by using the toner has a small variation in characteristics among the toner particles, and has excellent characteristics as a whole.
[0180]
<1C> Cooling process
The first kneaded material 8 in a softened state extruded from the extrusion port 132 of the head portion 13 is cooled by the cooler 6 and solidified.
The cooler 6 has rolls 61, 62, 63, 64 and belts 65, 66.
[0181]
The belt 65 is wound around a roll 61 and a roll 62. Similarly, the belt 66 is wound around the roll 63 and the roll 64.
The rolls 61, 62, 63, and 64 rotate in directions indicated by e, f, g, and h in the figure, respectively, around the rotation shafts 611, 621, 631, and 641. Thereby, the first kneaded material 8 extruded from the extrusion port 132 of the kneader 1 is introduced between the belt 65 and the belt 66. The first kneaded material 8 introduced between the belt 65 and the belt 66 is cooled while being formed into a plate having a substantially uniform thickness. The cooled first kneaded material 8 is discharged from the discharge unit 67. The belts 65 and 66 are cooled by a method such as water cooling or air cooling. When such a belt-type cooler is used, the contact time between the kneaded material extruded from the kneader and the cooling body (belt) can be prolonged, and the cooling efficiency of the kneaded material is particularly excellent. It can be.
[0182]
<1D> Coarse crushing process
The first kneaded material 8 that has undergone the cooling step as described above is coarsely pulverized as necessary.
The method of coarse pulverization is not particularly limited, and can be performed using various pulverizing devices and crushing devices such as a ball mill, a vibration mill, a hammer mill, a pin mill, and a feather mill.
[0183]
By such a coarse pulverization process, the first kneaded material is generally coarsely pulverized to an extent that it passes through a mesh having an opening diameter of several mm. The pulverized first kneaded product preferably has an average particle size of 3 mm or less, more preferably 2 mm or less. When the average particle size of the first kneaded product has such a value, fine dispersion can be performed sufficiently uniformly in the second kneading step described later. As a result, the finally obtained toner has small variations in characteristics among the particles, and the reliability of the entire toner is improved.
[0184]
<1E> Second kneading process (second kneading process)
Next, the first kneaded material 8 obtained as described above and the second raw material 9 containing at least an amorphous polyester are kneaded to obtain a second kneaded material 10 (second kneading). Process). It is preferable that the first kneaded material 8 and the second raw material 9 to be subjected to the second kneading step are uniformly mixed in advance by a mixer such as a Henschel mixer.
[0185]
As described above, by performing the kneading process in two stages, the second kneaded material 10 (the same applies to a toner production powder described later) is provided inside the first kneaded material 10 with the first region mainly composed of block polyester. And a second region mainly composed of an amorphous polyester, wherein the concentration of the colorant in the first region is higher than the concentration of the colorant in the second region (where the colorant is (Area unevenly distributed in one region). Then, by using such a second kneaded material 10, the toner of the present invention, that is, the concentration of the colorant contained in the first region is higher than the concentration of the colorant contained in the second region. A high toner can be obtained easily and reliably.
[0186]
The second kneading step (second kneading process) can be performed using the kneading machine 1 as shown in FIG. 1, as in the first kneading step described above.
The first kneaded material 8 and the second raw material 9 stored in the feeder 14 are supplied into the processing unit 12. The first kneaded material 8 and the second raw material 9 supplied into the process unit 12 are kneaded by rotating the screws 122 and 123, and the second kneaded material 10 is obtained.
[0187]
Raw material temperature (temperature of first kneaded material 8 and second raw material 9) T in the second kneading step _K2 Although it depends on the composition, softening point, and the like of the first kneaded material 8 and the second raw material 9, it is preferably 80 to 260 ° C, more preferably 100 to 150 ° C. When the raw material temperature is lower than the lower limit, the viscosity of the raw materials (the first kneaded material 8 and the second raw material 9) becomes too high, and it becomes difficult to sufficiently uniformly finely disperse (microphase separation). . On the other hand, when the raw material temperature exceeds the upper limit, thermal decomposition of the material, occurrence of oxidative degradation, and the like, aggregation, macro phase separation, and the like are likely to occur, and the function of the finally obtained toner is sufficiently high. Can be difficult to do.
[0188]
Further, the softening point of the amorphous polyester is defined as T _1/2 (A) [° C.], melting point T of block polyester _m (B) [° C.], the material temperature (kneading temperature) in the second kneading step is set to T _K2 [° C], T _m (B)> T _K2 > T _1/2 It is preferable to satisfy the relationship (A). By satisfying such a relationship, the first region and the second region can be phase-separated (micro-separated) to an appropriate size, and the coloring contained in the first kneaded material 8 can be achieved. It is possible to effectively prevent the agent from migrating into the second region. As a result, in the obtained second kneaded material 10, the ratio of the content of the colorant contained in the first region to the content of the colorant contained in the second region can be particularly increased. . As a result, the above-described effects are more remarkable in the finally obtained toner.
In addition, in this embodiment, the 2nd raw material 9 should just contain an amorphous polyester at least, and may contain components other than these. For example, the second raw material 9 may include the block polyester contained in the first raw material 7 as a part of its constituent components.
[0189]
<1F> Extrusion process
The second kneaded material 10 obtained in the second kneading step is pushed out of the kneader 1 via the head 13 by the rotation of the screws 122 and 123.
In the illustrated configuration, the internal space 131 has a cross-sectional area gradually decreasing portion 133 whose cross-sectional area gradually decreases toward the extrusion port 132.
[0190]
By having such a cross-sectional area gradually decreasing portion 133, the extruded amount of the second kneaded material 10 extruded from the extrusion port 132 is stabilized, and the cooling rate of the second kneaded material 10 in the cooling step described later is stabilized. I do. As a result, the toner produced by using the toner has a small variation in characteristics among the toner particles, and has excellent characteristics as a whole.
[0191]
<1G> Cooling process
The softened second kneaded material 10 extruded from the extrusion port 132 of the head portion 13 is cooled by the cooler 6 and solidified.
The rolls 61, 62, 63, and 64 rotate around the rotation shafts 611, 621, 631, and 641 in directions indicated by e, f, g, and h in the drawing, respectively, so that the extrusion port 132 of the kneader 1 is rotated. The second kneaded material 10 extruded from is introduced between the belt 65 and the belt 66. The second kneaded material 10 introduced between the belt 65 and the belt 66 is cooled while being formed into a plate having a substantially uniform thickness. The cooled second kneaded material 10 is discharged from the discharge unit 67.
[0192]
By the way, in the second kneading step, since a shear force is applied to the raw material (the second kneaded material), macro phase separation or the like is sufficiently prevented, but the second kneading step after the second kneading step is completed. Since the kneaded material does not receive any shearing force, if left for a long period of time, there is a possibility that macro phase separation or the like may occur. Therefore, it is preferable to cool the second kneaded material obtained as described above as soon as possible. Specifically, the cooling rate of the second kneaded material (for example, the cooling rate when the second kneaded material is cooled to about 60 ° C.) is preferably −3 ° C./sec or more, More preferably, it is -100 ° C / sec. Also, the time required from the end of the second kneading step (when the shearing force is no longer applied) to the completion of the cooling step (for example, the time required to cool the temperature of the second kneaded substance to 60 ° C. or lower) ) Is preferably 20 seconds or less, more preferably 3 to 12 seconds.
[0193]
<1H> Granulation process
By granulating the second kneaded material 10 having undergone the cooling step as described above, a powder for producing a toner is obtained.
In the present embodiment, the granulating step has a pulverizing step and a thermal spheronizing step as described below. Note that the thermal spheroidizing step is not necessarily performed.
[0194]
(1) grinding process
First, the second kneaded material 10 having undergone the cooling step as described above is pulverized.
The method of pulverization is not particularly limited, and the pulverization can be performed using various types of pulverizers and crushers such as a ball mill, a vibration mill, a hammer mill, a jet mill, a pin mill, and a feather mill.
[0195]
The pulverizing step may be performed a plurality of times (for example, two steps of a coarse pulverizing step and a fine pulverizing step).
Further, after such a pulverizing step, if necessary, a treatment such as a classification treatment may be performed.
For the classification process, for example, a sieve, an airflow classifier, or the like can be used.
[0196]
Further, the obtained powder for toner production may be subjected to an external addition treatment for adding an external additive as a pretreatment of a heat sphering step described later. By performing such an external addition treatment as a pretreatment, the fluidity and dispersibility of the toner particles are improved, and fusion of the toner particles due to heat can be more reliably prevented and suppressed. Note that the external additive as described above can be used in the external addition process as such a pretreatment. Further, such an external addition process as a pretreatment can be suitably performed by using a Henschel mixer or the like, similarly to an external addition process as a post-process of the thermal sphering process as described later.
[0197]
(2) Thermal sphering process (thermal sphering process)
Next, the powder (powder for toner production) obtained in the above-mentioned pulverizing step is subjected to a thermal sphering treatment for spheroidizing by heating.
By performing such a thermal sphering treatment, relatively large irregularities on the surface of the toner production powder are removed, and the circularity is relatively high. As a result, the toner obtained finally has a small difference in charging characteristics between the individual toner powders, thereby improving the developability on the photoconductor and adhering the toner to the photoconductor (filming). ) Is more effectively prevented, and the transfer efficiency of the toner is further improved.
[0198]
In particular, in the present invention, since a block polyester having a crystalline block is contained (because the first region mainly composed of the block polyester is contained), the stability of the shape of the toner production powder during the thermal sphering treatment is reduced. The amorphous polyester can be sufficiently softened while securing a certain amount. Therefore, in the present invention, the thermal sphering treatment can be performed more efficiently than in the case where a raw material containing no block polyester is used, and the circularity of the finally obtained toner (toner particles) can be relatively easily determined. Can be relatively high. As a result, the effect of the above-described thermal sphering process can be more effectively exerted.
[0199]
Further, as described above, in the toner production powder, the colorant is unevenly distributed in the first region mainly composed of the block polyester. Therefore, in the present invention, when the above heat treatment (thermal sphering treatment) is performed, the colorant contained in the powder for toner production hardly seeps out, and the relatively circularity as described above is obtained. High toner particles can be obtained.
Further, the toner of the present invention that has been subjected to the thermal sphering treatment is particularly excellent in fixability at a relatively low temperature (low-temperature fixability). This is considered to be due to the following reasons.
[0200]
As described above, in the present invention, generally, T _1/2 (B)> T _1/2 Since the relationship of (A) is satisfied, the amorphous polyester is softened and melted in preference to the block polyester during the heat sphering treatment, and the viscosity is reduced. The amorphous polyester (the second region) whose viscosity has been reduced in this way is in a state of coating the surface of the block polyester (the first region) whose viscosity is maintained at a relatively high state. Therefore, the surface properties of the finally obtained toner largely reflect the characteristics of the amorphous polyester, and the toner has excellent low-temperature fixability.
[0201]
On the other hand, since the toner contains a block polyester having a relatively high softening point, the toner particles as a whole have sufficient shape stability (durability) and can be fixed in a high temperature region. It also has excellent properties.
The thermal sphering treatment can be performed by injecting the toner production powder obtained in the pulverizing step under a heated atmosphere using, for example, compressed air. The ambient temperature at this time is preferably from 210 to 320 ° C, more preferably from 230 to 300 ° C. If the ambient temperature is lower than the lower limit, it may be difficult to sufficiently increase the circularity. On the other hand, when the ambient temperature exceeds the upper limit, thermal decomposition, oxidative degradation, and the like of the material, aggregation, phase separation, and the like are likely to occur, and the function of the finally obtained toner may be reduced.
[0202]
Further, the melting point of the block polyester is set to T _m (B) [° C.], the softening point of the amorphous polyester is T _1/2 (A) When [° C.], the ambient temperature T during the thermal spheroidizing step _S [° C] is (T _1/2 (A) +120) ≦ T _S ≤ (T _m (B) +90), and (T _1/2 (A) +140) ≦ T _S ≤ (T _m It is more preferable to satisfy the relationship of (B) +70). Such an ambient temperature T _s By performing the thermal sphering process, the degree of circularity of the obtained toner particles is made relatively high while sufficiently preventing the occurrence of thermal decomposition, oxidative degradation, etc. of the material, aggregation, phase separation, etc. be able to.
[0203]
By performing such processing, the average circularity R of the finally obtained toner (toner powder) can be easily and reliably controlled to a value in the above-described range.
Further, after such a thermal sphering step, if necessary, a treatment such as a classification treatment may be performed.
Further, such a thermal sphering treatment may be performed in a liquid.
Note that the thermal sphering process does not necessarily have to be performed.
For the classification process, for example, a sieve, an airflow classifier, or the like can be used.
[0204]
<1I> External addition step (external addition processing)
Next, the external additive as described above is applied to the heat-spherized or non-spheroidized pulverized and classified toner-producing powder.
Such application of the external additive can be suitably performed, for example, by mixing the powder for toner production with the external additive using a Henschel mixer or the like.
[0205]
The toner powder thus obtained has a coverage of the external additive (a ratio of the surface area of the toner particles to the area covered by the external additive. (Calculated coverage when a sphere equivalent to a diameter is covered by six-way close packing) is preferably 100 to 300%, and more preferably 120 to 220%. If the coverage of the external additive is less than the lower limit, the effect of the external additive as described above may not be sufficiently exerted. On the other hand, when the coverage of the external additive exceeds the upper limit, the fixing property of the toner tends to decrease.
[0206]
Further, in the toner, the external additive may be substantially entirely attached to the toner particles (base particles), or may be partially released from the surface of the toner particles. Good. That is, the toner may contain an external additive released from the toner particles.
As described above, when the toner contains an external additive released from the mother particles (hereinafter, also referred to as a “free external additive”), such a free external additive is used, for example, in the opposite direction to the toner particles. It can function as a microcarrier charged to a polarity. When such a free external additive that functions as a microcarrier is included in the toner, the toner particles having the opposite charge during development or the like (the toner particles having the opposite polarity to the polarity that the toner particles should originally exhibit when charged) ) Can be effectively prevented and suppressed. As a result, the toner hardly causes inconveniences such as fog.
[0207]
The amount of the external additive released from the toner particles can be determined, for example, by referring to the “Transportation of New Hardening Method-Toner Analysis by Particle Analyzer-” (Suzuki, Japan) (in Japanese). Toshiyuki, Toshio Takahara, sponsored by the Society of Electrophotography, July 9-11, 1997). Hereinafter, an example of a method of measuring the amount of a free external additive by a particle analyzer (PT1000) when titanium oxide (of rutile anatase type) is used as the external additive will be described.
[0208]
This measurement method uses titanium oxide (TiO 2) on the surface of base particles made of resin (C). ₂ )), By introducing particles of toner T formed by adhering an external additive into plasma, thereby exciting the toner particles, obtaining an emission spectrum associated with the excitation, and measuring by performing elemental analysis. It is.
[0209]
First, an external additive (TiO 2) is added to the powder for toner production (mother powder). ₂ ) Is introduced into the plasma, the mother particles (C) and the external additive (TiO 2) ₂ ) Both emit light. At this time, the base particles (C) and the external additive (TiO 2) ₂ ) Are simultaneously introduced into the plasma, so that the base particles (C) and the external additive (TiO 2) ₂ ) And emit light simultaneously. Thus, the base particles (C) and the external additive (TiO 2) ₂ ) Simultaneously emit light, the mother particles (C) and the external additive (TiO 2) ₂ ) Is synchronized. In other words, the base particles (C) and the external additive (TiO 2) ₂ ) Is synchronized with the external additive (TiO 2). ₂ ) Indicates a state in which the particles adhere to the base particles (C).
[0210]
In addition, an external additive (TiO 2) ₂ ) Is not attached to the base particles (C) or an external additive (TiO) released from the base particles (C). ₂ ) Is introduced into the plasma, the mother particles (C) and the external additive (TiO 2) ₂ ) Emits light, but at this time, the base particles (C) and the external additive (TiO 2) ₂ ) Are introduced into the plasma at different times, so that the base particles (C) and the external additive (TiO 2) ₂ ) (E.g., when the base particles are introduced into the plasma before the external additive, the base particles emit light first, and then the external additive emits light after a delay).
[0211]
Thus, the base particles (C) and the external additive (TiO 2) ₂ ) Emit light at different times from each other, the base particles (C) and the external additive (TiO 2) ₂ ) Is not synchronized (that is, asynchronous). In other words, the base particles (C) and the external additive (TiO 2) ₂ ) Is asynchronous with the external additive (TiO 2). ₂ ) Indicates a state in which the particles do not adhere to the base particles (C).
[0212]
Further, in the emission spectrum obtained as described above, the height of the emission signal indicates the intensity of the emission, but the intensity of the emission is not included in the particle, rather than the size or shape of the particle. Are the elements (C, TiO ₂ ) Is proportional to the number of atoms. Therefore, in order to express the emission intensity of the element as the size of the particles, the base particles (C) and the external additive (TiO 2) are used. ₂ ) Is obtained, the base particles (C) and the external additive (TiO 2) ₂ ) Is assumed, and the particles of the true sphere at this time are called equivalent particles, and their particle diameters are called equivalent particle diameters. Since the external additive is very small, these particles cannot be detected one by one. Therefore, the detected emission signal of the external additive is added to be converted into one equivalent particle and analyzed.
[0213]
When the equivalent particle diameters of the equivalent particles obtained by the respective emission spectra of the base particles and the external additives are plotted for each particle of the toner, an equivalent particle size distribution diagram of the toner particles as shown in FIG. 4 is obtained. Can be
In FIG. 4, the horizontal axis represents the equivalent particle size of the base particles (C), and the vertical axis represents the external additive (TiO 2). ₂ ) Represents the equivalent particle size. The equivalent particles on the horizontal axis represent the external additive (TiO 2). ₂ ) Represents the non-synchronous parent particles (C) to which no particles are attached, and the equivalent particle on the vertical axis represents the asynchronous external additive (TiO 2) released from the parent particles (C). ₂ ). Equivalent particles not on the horizontal axis and the vertical axis represent external additives (TiO 2) added to the base particles (C). ₂ ) Indicates the synchronous toner to which the toner is attached. In this way, the external additive (TiO 2) for the base particles (C) of the toner ₂ ) Is analyzed.
[0214]
The amount of rutile-anatase-type titanium oxide released from the toner particles, which can be measured in this manner (the ratio of rutile-anatase-type titanium oxide contained in the toner, which is a free external additive) is , 0.1 to 5.0 wt%, more preferably 0.5 to 3.0 wt%. If the ratio of the free external additive is too small, the function as the microcarrier described above may not be sufficiently exhibited. On the other hand, when the ratio of the free external additive exceeds the upper limit, the free external additive adheres to the toner contact member and filming easily occurs.
[0215]
Next, a second embodiment of the method for producing a toner of the present invention will be described.
FIG. 18 is a longitudinal sectional view schematically showing the configuration of a kneader and a cooler used in the second embodiment of the method for producing a toner of the present invention. Hereinafter, the method of manufacturing the toner of the second embodiment will be described focusing on the differences from the first embodiment described above, and the description of the same items will be omitted.
The kneading machine 1 ′ used in the present embodiment includes a first kneading unit 2 that performs a first kneading process (a first kneading process) and a second kneading unit that performs a second kneading process (a second kneading process). It has a kneading section 3, a connecting section 4 for connecting the first kneading section 2 and the second kneading section 3, and a head section 5 for forming and extruding the second kneaded material 10 into a predetermined sectional shape. ing.
[0216]
<2A> First kneading process (first kneading process)
First, a first raw material 7 containing at least a block polyester and a colorant among the above materials is kneaded to obtain a first kneaded material (first kneading step). It is preferable that the first raw material 7 to be subjected to the first kneading step is previously uniformly mixed by a mixer such as a Henschel mixer.
[0219]
The first kneading step (first kneading process) is performed in the first kneading unit 2.
The first kneading unit 2 has a feeder 21 for storing the first raw material 7 and a process unit 22 for kneading while conveying the first raw material 7 supplied from the feeder 21. The process section 22 has a barrel 221 and screws 222 and 223 inserted in the barrel 221.
[0218]
In the process unit 22, as the screws 222 and 223 rotate, a shearing force is applied to the first raw material 7 supplied from the feeder 21, and the components constituting the first raw material 7 are sufficiently uniformly dispersed. A first kneaded material 8 is obtained.
The first kneaded material 8 obtained as described above is sent to the second kneading unit 3 via the connection unit 4 by the rotation of the screws 222 and 223.
[0219]
<2B> Second kneading step (second kneading process)
Next, the first kneaded material 8 obtained in the first kneading step and the second raw material 9 containing at least the amorphous polyester are kneaded (second kneading step).
The second kneading step (second kneading process) is performed in the second kneading unit 3.
[0220]
The second kneading unit 3 has a feeder 31 for storing the second raw material 9 and a process unit 32 for kneading the second raw material 9 supplied from the feeder 31 while transporting the second raw material 9. The process section 32 has a barrel 321, screws 322 and 323 inserted in the barrel 321, and a fixing member 324 for fixing the head section 5 to the tip of the barrel 321.
In the process unit 32, the first kneaded material 8 sent from the first kneading unit 2 via the connection unit 4 and the second raw material supplied from the feeder 31 are rotated by rotating the screws 322 and 323. 9 is kneaded to obtain a second kneaded material 10.
[0221]
<2C> Extrusion process
The second kneaded material 10 kneaded in the process unit 32 is pushed out of the kneader 1 via the head unit 5 by the rotation of the screws 322 and 323.
The head unit 5 has an internal space 51 into which the second kneaded material 10 is sent from the process unit 32 and an extrusion port 52 through which the second kneaded material 10 is extruded.
[0222]
In the illustrated configuration, the internal space 51 has a cross-sectional area gradually decreasing portion 53 whose cross-sectional area gradually decreases toward the extrusion port 52.
By having such a cross-sectional area gradually decreasing portion 53, the extruded amount of the second kneaded material 10 extruded from the extrusion port 52 is stabilized, and the cooling rate of the second kneaded material 10 in the cooling step described later is stabilized. I do. As a result, the toner produced by using the toner has a small variation in characteristics among the toner particles, and has excellent characteristics as a whole.
[0223]
<2D> Cooling process
The softened second kneaded material 10 extruded from the extrusion port 52 of the head portion 5 is cooled by the cooler 6 and solidified similarly to the first embodiment.
<2E> Granulation process
Same as the above step <1H>.
<2F> External addition process (external addition process)
Same as step <1I> described above.
[0224]
As described above, in the present embodiment, a kneader (a two-stage barrel-type kneader) having a first kneading unit and a second kneading unit is used. Thereby, the first kneading step and the second kneading step can be performed continuously, and the steps such as <1B> to <1D> described in the first embodiment can be omitted. it can.
Thereby, the productivity of the toner is improved.
[0225]
Further, by using a kneading machine as shown in FIG. 18, the temperature fluctuation of the raw material (particularly, the first raw material) used for producing the toner can be made relatively small, and the heat applied to the raw material used for producing the toner can be reduced. Reduce history. Further, the time during which the heated kneaded material comes into contact with air can be shortened. As a result, deterioration of the components of the toner can be more effectively prevented, and the reliability of the finally obtained toner is further improved.
[0226]
As described above, the toner and the method for producing the toner of the present invention have been described based on the preferred embodiments, but the present invention is not limited to these embodiments.
For example, the toner of the present invention is not limited to one manufactured by the method described above. For example, in the embodiment described above, the method of kneading the constituent materials of the toner in two steps of the first kneading step and the second kneading step has been described, but the kneading step is performed three or more times. It may be performed separately or only once.
[0227]
Further, different kneading apparatuses may be used in the first kneading step and the second kneading step, and kneading conditions such as the number of rotations of the screw may be different.
Further, in the above-described embodiment, a configuration in which a continuous twin screw extruder is used as the kneader has been described, but the kneader used for kneading the raw materials (first kneading and second kneading) is not limited thereto. Not done. For kneading the raw materials, for example, various kneaders such as a kneader or a batch type triaxial roll, a continuous biaxial roll, a wheel mixer, a blade type mixer, or the like can be used.
[0228]
Further, in the present invention, a wet method (for example, a flushing method) may be applied instead of the dry kneading method as described above.
In the above-described embodiment, the toner production powder obtained through the granulation process is described as being obtained by performing the external addition process. Powder (toner production powder) may be used as the toner as it is. Further, in the above-described embodiment, the heat sphering treatment is performed after the pulverizing step. However, such a heat sphering treatment may be omitted.
[0229]
Further, in the above-described embodiment, the powder for toner production (toner particles) is described as using a powder obtained by a pulverization method. However, a powder produced by another method such as a spray drying method, a polymerization method or the like is used. It may be.
In the above-described embodiment, the configuration in which the thermal sphering process is performed under dry conditions is described. However, the thermal sphering process may be performed under wet conditions, such as in a solution.
[0230]
In the illustrated configuration, a kneader having a configuration having two screws has been described, but the number of screws may be one, or three or more.
Further, in the above-described embodiment, a configuration using a belt-type cooling device has been described. However, for example, a roll-type (cooling roll-type) cooling device may be used. Further, the cooling of the kneaded material extruded from the extrusion port of the kneader is not limited to the one using the above-described cooler, and may be, for example, air cooling or the like.
[0231]
In the above-described embodiment, rutile-anatase-type titanium oxide is described as being added as an external additive.However, for example, by using rutile-anatase-type titanium oxide as one component of a raw material to be supplied to the kneading step, , May be included inside the toner.
In the above-described embodiment, ΔT obtained by measuring the endothermic peak of the melting point by differential scanning calorimetry (DSC) was described as an index indicating the crystallinity, but the index indicating the crystallinity is not limited to this. For example, as an index indicating the crystallinity, a crystallinity measured by a density method, an X-ray method, an infrared method, a nuclear magnetic resonance absorption method, or the like may be used.
[0232]
Further, the fixing device and the image forming apparatus to which the toner of the present invention is applied are not limited to those described in the above-described embodiments, and each unit constituting the fixing device and the image forming apparatus can exhibit the same function. It can be replaced with any configuration.
For example, in the above-described embodiment, a contact-type fixing device has been described. However, the present invention is not limited to such a contact-type fixing device, and may be applied to a non-contact-type fixing device. Good.
[0233]
【Example】
[1] Production of polyester
Prior to the production of the toner, the following three types of polyesters A, A ', B, C and D were produced.
[1.1] Production of polyester A (amorphous polyester)
First, a mixture of 36 mol parts of neopentyl glycol, 36 mol parts of ethylene glycol, 48 mol parts of 1,4-cyclohexanediol, 90 mol parts of dimethyl terephthalate, and 10 mol parts of phthalic anhydride was prepared.
[0234]
A reflux condenser, a distillation column, a water separator, a nitrogen gas inlet tube, a thermometer, and a stirrer were installed in a two-liter four-necked flask according to a conventional method, and a mixture of the diol component and the dicarboxylic acid component: 1000 g , An esterification condensation catalyst (titanium tetrabutoxide (PPB)): 1 g, and placed in the 2 liter four-necked flask. Thereafter, at a material temperature of 180 ° C., the esterification reaction was allowed to proceed while flowing out generated water and methanol from the distillation column. When water and methanol stopped flowing from the distillation column, the distillation column was removed from the 2-liter four-necked flask and connected to a vacuum pump. With the pressure in the system reduced to 5 mmHg or less, the temperature was set to 200 ° C., and the stirring was performed at 150 rpm, whereby the free diol generated in the condensation reaction was discharged out of the system, and the resulting reactant was obtained. Was designated as polyester A (PES-A).
[0235]
About the obtained polyester A, the measurement of the endothermic peak of the melting point by the differential scanning calorimeter was tried. As a result, a sharp peak that could be determined to be the absorption peak of the melting point could not be confirmed. Also, the softening point T of polyester A _1/2 Is 111 ° C., glass transition point T _g Is 60 ° C., the weight average molecular weight Mw is 1.3 × 10 ⁴ Met.
[0236]
[1.2] Production of polyester A '(amorphous polyester)
First, a mixture of neopentyl glycol: 96 mol parts, ethylene glycol: 12 mol parts, 1,4-cyclohexanediol: 12 mol parts, and dimethyl terephthalate: 100 mol parts was prepared.
A reflux condenser, a distillation column, a water separator, a nitrogen gas inlet tube, a thermometer, and a stirrer were installed in a two-liter four-necked flask according to a conventional method, and a mixture of the diol component and the dicarboxylic acid component: 1000 g , An esterification condensation catalyst (titanium tetrabutoxide (PPB)): 1 g, and placed in the 2 liter four-necked flask. Thereafter, at a material temperature of 180 ° C., the esterification reaction was allowed to proceed while flowing out generated water and methanol from the distillation column. When water and methanol stopped flowing from the distillation column, the distillation column was removed from the 2-liter four-necked flask and connected to a vacuum pump. With the pressure in the system reduced to 5 mmHg or less, the temperature was set to 200 ° C., and the stirring was performed at 150 rpm, whereby the free diol generated in the condensation reaction was discharged out of the system, and the resulting reactant was obtained. Was designated as polyester A ′ (PES-A ′).
[0237]
About the obtained polyester A ', the measurement of the endothermic peak of the melting point by the differential scanning calorimeter was tried. As a result, a sharp peak that could be determined to be the absorption peak of the melting point could not be confirmed. Also, the softening point T of the polyester A ' _1/2 Is 108 ° C., glass transition point T _g Is 58 ° C. and the weight average molecular weight Mw is 1.5 × 10 ⁴ Met.
[0238]
[1.3] Production of polyester B (block polyester)
A 2-liter four-necked flask was equipped with a reflux condenser, a distillation column, a water separator, a nitrogen gas inlet tube, a thermometer, and a stirrer according to a conventional method, and the polyester A obtained in the above [1.1]: 70 A mixture of a molar part and 1,4-butanediol as a diol component: 15 mol parts and dimethyl terephthalate as a dicarboxylic acid component: 15 mol parts: 1000 g, and an esterification condensation catalyst (titanium tetrabutoxide (PPB)): 1 g was placed in the 2 liter four-necked flask. Thereafter, the esterification reaction was allowed to proceed at a material temperature of 200 ° C. while the generated water and methanol were flowing out of the distillation column. When water and methanol stopped flowing from the distillation column, the distillation column was removed from the 2-liter four-necked flask and connected to a vacuum pump. With the pressure in the system reduced to 5 mmHg or less, the temperature was set to 220 ° C., and the number of rotations: 150 rpm, the free diol generated in the condensation reaction was discharged out of the system, and the resulting reactant was obtained. Was designated as polyester B (PES-B).
[0239]
The central value T of the endothermic peak of the melting point of polyester B measured by a differential scanning calorimeter. _mp Is 218 ° C., shoulder peak value T _ms Was 205 ° C. Further, the heat of fusion E of polyester B determined from the differential scanning calorimetry curve obtained by the measurement. _f Was 18 mJ / mg. Also, the softening point T of polyester B _1/2 Is 149 ° C., glass transition point T _g Is 64 ° C., the weight average molecular weight Mw is 2.8 × 10 ⁴ Met.
[0240]
[1.4] Production of Polyester C (Block Polyester)
A 2-liter four-necked flask was equipped with a reflux condenser, a distillation tower, a water separator, a nitrogen gas inlet tube, a thermometer, and a stirrer according to a conventional method, and the polyester A obtained in the above [1.1]: 90 A mixture of a mole part and 1,4-butanediol as a diol component: 5 mole parts and dimethyl terephthalate as a dicarboxylic acid component: 5 mole parts: 1000 g, and an esterification condensation catalyst (titanium tetrabutoxide (PPB)): 1 g was placed in the 2 liter four-necked flask. Thereafter, at a material temperature of 180 ° C., the esterification reaction was allowed to proceed while flowing out generated water and methanol from the distillation column. When water and methanol stopped flowing from the distillation column, the distillation column was removed from the 2-liter four-necked flask and connected to a vacuum pump. With the pressure in the system reduced to 5 mmHg or less, the temperature was set to 200 ° C., and the stirring was performed at 150 rpm, whereby the free diol generated in the condensation reaction was discharged out of the system, and the resulting reactant was obtained. Was designated as polyester C (PES-C).
[0241]
The center value T of the endothermic peak of the melting point of polyester C measured by a differential scanning calorimeter. _mp Is 195 ° C., shoulder peak value T _ms Was 182 ° C. Further, the heat of fusion E of polyester C determined from the differential scanning calorimetry curve obtained by the measurement. _f Was 8 mJ / mg. Also, the softening point T of polyester C _1/2 Is 120 ° C., glass transition point T _g Is 63 ° C., the weight average molecular weight Mw is 2.5 × 10 ⁴ Met.
[0242]
[1.5] Production of polyester D (polyester having high crystallinity, not block polyester)
A 2-liter four-necked flask was equipped with a reflux condenser, a distillation column, a water separator, a nitrogen gas inlet tube, a thermometer, and a stirrer according to a conventional method. 1,4-butanediol as a diol component: 50 mol parts 1000 g of a mixture of dimethyl terephthalate as a dicarboxylic acid component: 60 mol parts and 1 g of an esterification condensation catalyst (titanium tetrabutoxide (PPB)) were placed in the two-liter four-necked flask. Thereafter, the esterification reaction was allowed to proceed at a material temperature of 260 ° C. while flowing out generated water and methanol from the distillation column. When water and methanol stopped flowing from the distillation column, the distillation column was removed from the 2-liter four-necked flask and connected to a vacuum pump. With the pressure inside the system reduced to 5 mmHg or less, the temperature was set to 280 ° C., and the stirring was performed at 150 rpm to discharge the free diol generated in the condensation reaction out of the system. Was designated as polyester D (PES-D).
[0243]
The center value T of the endothermic peak of the melting point of polyester D measured by a differential scanning calorimeter. _mp Is 228 ° C., shoulder peak value T _ms Was 215 ° C. Further, the heat of fusion E of polyester D obtained from the differential scanning calorimetry curve obtained by the measurement was obtained. _f Was 35 mJ / mg. Also, the softening point T of polyester D _1/2 Is 180 ° C., glass transition point T _g Is 70 ° C. and the weight average molecular weight Mw is 2.0 × 10 ⁴ Met.
[0244]
The melting point, softening point, glass transition point, and weight average molecular weight of each of the above resin materials were measured as follows.
Melting point T _m Was measured as follows using a differential scanning calorimeter DSC (manufactured by Seiko Instruments Inc., Model DSC220). First, the temperature of the resin sample was increased to 200 ° C. at a rate of temperature increase of 10 ° C./min, and then decreased to 0 ° C. at a rate of temperature decrease of 10 ° C./min. Thereafter, the temperature was raised at a rate of temperature increase of 10 ° C./min. _m Asked.
[0245]
Softening point T _1/2 Was measured using a capillary tube rheometer (manufactured by Shimadzu Corporation, flow tester CFT-500). The sample was extruded under the following conditions: sample amount: 1 g, die hole diameter: 1 mm, die length: 1 mm, load: 20 kgf, preheating time: 300 seconds, measurement start temperature: 50 ° C., heating rate: 5 ° C./min, and outflow. The temperature (1/2 method temperature) at the time when the fluctuation width of the piston stroke between the start time and the outflow end time is 1/2 is set to the softening point T. _1/2 (See FIG. 3).
[0246]
Glass transition point T _g Was measured simultaneously with the measurement of the melting point using a differential scanning calorimeter DSC (manufactured by Seiko Instruments Inc., DSC220 type). The tangent line of the maximum differential value (maximum slope point of DSC data) between the two designated points of the baseline before and after the glass transition and the extension of the baseline before the glass transition during the 2nd run described in the method of measuring the melting point. The point of intersection with the line is the glass transition point T _g Asked.
[0247]
The measurement of the weight average molecular weight Mw was performed as follows using gel permeation chromatography GPC (manufactured by Tosoh Corporation, Model HLC-8220).
First, 1 g of a resin sample was dissolved in THF (tetrahydrofuran) to obtain 1 mL of a THF solution (including an insoluble content). This THF solution was poured into a sample bottle dedicated to centrifugation, centrifuged at 2,000 ppm for 5 minutes using a centrifuge, and filtered through the supernatant sample LCP13-LH (pore size: 0.5 μm). A filtrate was obtained.
The filtrate thus obtained is subjected to gel permeation chromatography GPC (manufactured by Tosoh Corporation) under the following conditions: column: TSKgel SuperHZ4000 + SuperHZ4000 (manufactured by Tosoh Corporation), flow rate: 0.5 mL / min, temperature: 25 ° C., solvent: THF. HLC-8220), and the weight average molecular weight Mw of the resin sample was determined based on the resulting chart. In addition, monodisperse polystyrene was used as a standard sample.
[0248]
[2] Production of toner
A toner was manufactured as follows.
(Example 1)
First, polyester B: 60 parts by weight as a block polyester and cyan pigment (PR: 15: 3): 40 parts by weight as a colorant were prepared.
These components were mixed using a 20 L Henschel mixer to obtain a first raw material.
[0249]
The first raw material thus obtained was kneaded using a kneader as shown in FIG. 1 to obtain a first kneaded product (first kneading step).
In the first kneading step, the barrel temperature T _K1 : 240 ° C, temperature in the head part: 240 ° C, screw rotation speed: 120 rpm, material (first raw material) supply speed: 10 kg / h.
The first kneaded product obtained in the first kneading step was extruded from an extrusion port of a head portion, cooled with a cooler, and coarsely pulverized with a feather mill to an average particle size of 1 to 2 mm (see FIG. 1). .
[0250]
Using a kneader as shown in FIG. 1, 10 parts by weight of the powdery first kneaded material obtained as described above was used as a second raw material (polyester A: 64 parts by weight as an amorphous polyester). , Polyester B: 22 parts by weight, a chromium salicylate complex (Bontron E-81): 1 part by weight as a charge controlling agent, and carnauba wax: 3 parts by weight as a wax) to obtain a second kneaded product. (Second kneading step).
[0251]
In the second kneading step, the barrel temperature T _K2 : 130 ° C, the temperature in the head part: 130 ° C, the screw rotation speed: 120 rpm, and the material (mixture of the first kneaded material and the second raw material) supply speed: 20 kg / h.
The second kneaded product obtained in the second kneading step was extruded from an extrusion port of the head portion and cooled by a cooler (see FIG. 1).
[0252]
The second kneaded product cooled as described above was roughly pulverized (average particle size: 1 mm or less) and then finely pulverized. A feather mill was used for coarse pulverization of the kneaded material, and a jet mill (manufactured by Hosokawa Micron, 200AFG) was used for fine pulverization. The fine pulverization was performed under the conditions of pulverizing air pressure: 500 kPa and rotor rotation speed: 7000 rpm.
The pulverized material thus obtained was classified using an airflow classifier (100 ATP, manufactured by Hosokawa Micron Corporation).
[0253]
The cooling rate of the second kneaded product was −7 ° C./sec. The time required from the end of the kneading step to the end of the cooling step was 10 seconds.
Thereafter, the classified pulverized product (toner production powder) was subjected to a thermal spheroidizing treatment. The heat sphering treatment was performed using a heat sphering apparatus (SFS3, manufactured by Nippon Pneumatic Co., Ltd.). The temperature of the atmosphere during the thermal sphering treatment was 270 ° C.
[0254]
Thereafter, an external additive was added to the powder subjected to the thermal sphering treatment to obtain a toner. The application of the external additive was performed by mixing 100 parts by weight of the powder subjected to the thermal spheroidization treatment and 2.5 parts by weight of the external additive using a 20 L Henschel mixer. As external additives, negatively chargeable small particle size silica (average particle size: 12 nm): 1 part by weight, negatively chargeable large particle size silica (average particle size: 40 nm): 0.5 part by weight, rutile anatase Mold titanium oxide (substantially spindle shape, average major axis diameter: 30 nm): 1 part by weight. As the negatively chargeable silica (negatively chargeable small particle size silica, negatively chargeable large particle size silica), those which had been subjected to surface treatment (hydrophobization treatment) with hexamethyldisilazane were used. Further, as the rutile anatase type titanium oxide, the ratio of the rutile type titanium oxide and the anatase type titanium oxide crystal structure is 90:10, and light in the wavelength region of 300 to 350 nm is absorbed. Was used.
However, in the production of the toner as described above, the rate of change of the weight average molecular weight of each resin material before and after the production is within ± 10%, and the variation of the melting point, softening point, and glass transition point is within ± 10 ° C. It was performed under such conditions.
[0255]
The average particle size of the finally obtained toner was 7.5 μm. The average circularity R of the obtained toner was 0.94. The acid value of the toner was 0.8 KOHmg / g. The average length of the crystals in the toner was 300 nm. Further, the coverage of the external additive in the obtained toner was 160%. The ratio (release rate) of the rutile-anatase type titanium oxide contained as a free external additive to the toner was 1.6 wt%.
[0256]
The circularity was measured in an aqueous dispersion using a flow-type particle image analyzer (FPIA-2000, manufactured by Sysmex Corporation). However, the circularity R is represented by the following formula (I).
R = L ₀ / L ₁ ... (I)
(However, in the formula, L ₁ [Μm] is the perimeter of the projected image of the toner particles to be measured, L ₀ [Μm] represents the circumference of a perfect circle having an area equal to the area of the projected image of the toner particles to be measured. )
The average length of the crystals in the toner was determined from the result of measurement with a transmission electron microscope (TEM).
[0257]
(Example 2)
A toner was manufactured in the same manner as in Example 1 except that polyester C was used as the block polyester and positively chargeable silica (average particle size: 40 nm): 1 part by weight was used as an external additive. The positively chargeable silica used was obtained by subjecting negatively chargeable silica to a surface treatment (hydrophobizing treatment) using a silane coupling agent (aminosilane) having an amino group.
[0258]
(Examples 3 and 4)
The composition of the raw material (first raw material) to be supplied to the first kneading step and the raw material (second raw material, first kneaded material) to be supplied to the second kneading step are as shown in Table 1; A toner was manufactured in the same manner as in Example 1 except that the types and amounts of the external additives used in Table 1 were as shown in Table 1. Also, in Example 3, the second kneading step was performed by changing the barrel internal temperature T _K2 : 150 ° C, the temperature in the head part: 150 ° C, the screw rotation speed: 120 rpm, and the supply rate of the material (mixture of the first kneaded material and the second raw material): 10 kg / h.
[0259]
(Examples 5 and 6)
Using polyester A ′ instead of polyester A, the composition of the raw material (first raw material) to be provided to the first kneading step and the raw material (second raw material, first kneaded product) to be provided to the second kneading step A toner was manufactured in the same manner as in Example 1 except that the external additives used in the external addition step were as shown in Table 1 and the types and amounts of the external additives were as shown in Table 1.
(Examples 7 to 9)
A kneader having a configuration as shown in FIG. 18 was used, and the first kneading step and the second kneading step were performed in the same manner as in Examples 1, 3, and 5 except that the kneading step was performed continuously. In each case, a toner was manufactured.
[0260]
(Comparative Example 1)
A toner was manufactured in the same manner as in Example 1 except that the polyester B contained in the first raw material was changed to polyester A contained in the second raw material.
(Comparative Example 2)
A toner was manufactured in the same manner as in Example 1 except that polyester A contained in the second raw material was changed to polyester B.
(Comparative Example 3)
A toner was manufactured in the same manner as in Example 1 except that polyester D was used in the first raw material instead of polyester B contained in the second raw material.
[0261]
(Comparative Example 4)
First, 60 parts by weight of polyester A and 40 parts by weight of a cyan pigment (PR: 15: 3) as a coloring agent were prepared.
These components were mixed using a 20 L Henschel mixer to obtain a first raw material.
[0262]
The first raw material thus obtained was kneaded using a kneader as shown in FIG. 1 to obtain a first kneaded product (first kneading step).
In the first kneading step, the barrel temperature T _K1 : 240 ° C, temperature in the head part: 240 ° C, screw rotation speed: 120 rpm, material (first raw material) supply speed: 10 kg / h.
[0263]
The first kneaded product obtained in the first kneading step was extruded from an extrusion port of a head portion, cooled with a cooler, and coarsely pulverized with a feather mill to an average particle size of 1 to 2 mm (see FIG. 1). .
Using a kneader as shown in FIG. 1, 10 parts by weight of the powdery first kneaded material obtained as described above was used as a second raw material (polyester A: 58 parts by weight, polyester D: 28 parts by weight). Parts by weight, and 1 part by weight of a chromium salicylate complex (Bontron E-81) as a charge controlling agent, and 3 parts by weight of carnauba wax as a wax to obtain a second kneaded product (second kneading). Process).
[0264]
In the second kneading step, the barrel temperature T _K2 : 130 ° C, the temperature in the head part: 130 ° C, the screw rotation speed: 120 rpm, and the material (mixture of the first kneaded material and the second raw material) supply speed: 20 kg / h.
The second kneaded product obtained in the second kneading step was extruded from an extrusion port of the head portion and cooled by a cooler (see FIG. 1).
[0265]
The cooling rate of the second kneaded product was −7 ° C./sec. The time required from the end of the kneading step to the end of the cooling step was 10 seconds.
Thereafter, the second kneaded product obtained as described above was subjected to each of the processes of pulverization, classification, heat spheroidization, and external addition in the same manner as in Example 1 to produce a toner.
[0266]
(Comparative Examples 5 and 6)
Toners (colorless toners) were produced in the same manner as in Examples 1 and 4, respectively, except that a material containing no coloring agent was used as the first raw material.
Table 1 shows the constituent components of the toners of the above Examples and Comparative Examples. The average particle diameter of the toner, the average circularity R, the acid value, the average length of the crystals in the toner, the coverage of the external additive, Table 2 summarizes the release rates of rutile anatase type titanium oxide. In the table, polyester A, polyester A ', polyester B, polyester C, and polyester D are represented by PES-A, PES-A', PES-B, PES-C, and PES-D, respectively.
[0267]
In addition, the toner of each example and each comparative example was observed using a transmission electron microscope (TEM). As a result, in the toners of the respective examples and the toners of Comparative Examples 5 and 6, the first region mainly composed of the block polyester and the second region mainly composed of the amorphous polyester were phase-separated ( In particular, it was confirmed that the toners of Examples 1 to 9 were present with microphase separation. Further, in the toners of Comparative Examples 3 and 4, it was confirmed that the region mainly composed of the crystalline polyester (polyester D) and the region mainly composed of the amorphous polyester were present with microphase separation. Was done. The average particle diameter of the first region in the toner particles measured by the above observation is in the range of 0.05 to 1.0 μm for each of the toners of Examples 1 to 9. Value. From the above observations, it was confirmed that the colorant was unevenly distributed mainly in the region (first region) mainly composed of the block polyester in the toners of Examples and Comparative Example 3. In the toner of Example 4, the colorant was unevenly distributed mainly in the region (second region) mainly composed of amorphous polyester. The length of the colorant (average length in the longitudinal direction) contained in the toner particles of each of the examples and the comparative examples 1 to 4 was 50 to 500 nm.
[0268]
Further, with respect to the toners of Examples and Comparative Examples 3 and 4, the toner particles were thinly sliced with a microtome, and the phase separation state between the first region and the second region was observed with a TEM (transmission electron microscope). did. Further, based on the size and number of the colorant observed by a TEM (transmission electron microscope), the concentration (C ₁ [Vol%] and C ₂ [Vol%]), and from these results, C ₁ / C ₂ Was determined. In Comparative Examples 3 and 4, the region mainly composed of polyester D was regarded as the first region.
[0269]
Further, for the toners of the respective examples and comparative examples, Δt = 0.05 [second], and the relaxation elastic modulus G of the toner at 0.01 second is defined as an initial relaxation elastic modulus G (0.01) [Pa]. Further, the ratio of G (0.01) [Pa] to G (Δt) [Pa], where G is the relaxation elasticity G (Δt) [Pa] at Δt seconds of the toner, G (0.01) / G (Δt) was determined as follows.
[0270]
First, about 1 g of the toner was sandwiched between parallel plates and melted by heating to adjust the height to 1.0 to 2.0 mm. The sample thus obtained was subjected to viscoelasticity measurement under the following measurement conditions in a stress relaxation measurement mode using an ARES viscoelasticity measurement device (manufactured by Rheometric Scientific F.E.).
・ Measurement temperature: 150 ° C,
・ Amount of applied strain: Maximum strain in the wire diameter region
・ Geometry: Parallel plate (25mm diameter)
Based on the above measurement, the initial relaxation modulus (relaxation modulus at 0.01 seconds): G (0.01) [Pa], and the relaxation modulus at Δt = 0.05 seconds: G (Δt) [ Pa] was determined. The values of G (0.01) / G (Δt) obtained from these results are also shown in Table 2.
[0271]
[Table 1]

[0272]
[Table 2]

[0273]
[3] Evaluation
With respect to each of the toners obtained as described above, a good fixing area, development durability, storability, charging characteristics, transfer efficiency, and transparency were evaluated.
[3.1] Good fixing area
First, a fixing device as shown in FIGS. 7 to 14 and 17 described above was manufactured. In this fixing device, the time Δt required for the toner to pass through the nip is set to 0.05 seconds. Using this fixing device, an image forming apparatus (color printer) as shown in FIGS. Using this image forming apparatus, an unfixed image sample was collected, and the following test was performed with the fixing apparatus of the image forming apparatus. In addition, the solid of the sample to be collected has an attached amount of 0.40 to 0.50 mg / cm. ² Was adjusted to
[0274]
With the surface temperature of the fixing roller of the fixing device constituting the image forming apparatus set at a predetermined temperature, the paper (high quality plain paper manufactured by Seiko Epson Corporation) onto which the unfixed toner image has been transferred is placed inside the fixing device. By introducing the toner image, the toner image was fixed on the paper, and the occurrence of offset after the fixing was visually confirmed.
Similarly, the set temperature of the surface of the fixing roller is sequentially changed within the range of 100 to 250 ° C., and it is checked whether or not an offset has occurred at each temperature. And evaluated according to the following three-level criteria.
A: The width of the good fixing area is 60 ° C. or more.
：: The width of the good fixing area is 35 ° C. or more and less than 60 ° C.
X: The width of the good fixing area is less than 35 ° C.
[0275]
[3.2] Development durability
After setting 30 g of toner in the developing device of the image forming apparatus used in [3.1], aging is performed without replenishment, and the time until filming occurs on the developing roller is measured. The evaluation was performed according to the following criteria.
A: No filming was observed even after 120 minutes or more had elapsed after the start of aging.
：: Filming occurred 60 to 120 minutes after the start of aging.
×: Filming occurred within 60 minutes after the start of aging.
[0276]
[3.3] Storage
10 g of each of the toners of Examples and Comparative Examples was placed in a sample bottle and left in a constant temperature bath at 50 ° C. for 48 hours. Then, the presence or absence of agglomeration (aggregation) was visually checked. It evaluated according to.
：: Existence of agglomeration (aggregation) was not recognized at all.
：: Small lump (aggregation) was slightly observed.
X: Lump (aggregation) was clearly recognized.
[0277]
[3.4] Charging characteristics
In the image forming apparatus used in [3.1], the image forming apparatus is stopped during printing, the cartridge is removed, and the charge amount is measured using a powder charge distribution measuring device (E-spart analyzer, manufactured by Hosokawa Micron Corporation). The distribution was measured, and from the results, a positive charge amount was obtained as a charge amount and a reverse charge amount.
[0278]
Regarding the charge amount, the initial charge amount and the charge amount after printing 1000 sheets (after 1K) were obtained.
The charge amount after printing 1000 sheets (after 1K) was evaluated according to the following four-step criteria.
A: The amount of change (absolute value) from the initial charge amount is less than 0.5 μC / g.
：: The change amount (absolute value) from the initial charge amount is 0.5 μC / g or more and less than 1 μC / g.
Δ: The amount of change (absolute value) from the initial charge amount is 1 μC / g or more and less than 3 μC / g.
X: The change amount (absolute value) from the initial charge amount is 3 μC / g or more.
In addition, for the reversely chargeable toner, the abundance ratio with respect to the total amount of the toner is obtained. When the abundance ratio of the reversely chargeable toner is less than 3 wt%, ○ is indicated, Is x.
[0279]
[3.5] Transfer efficiency
The following evaluation was performed using the image forming apparatus used in [3.1].
The toner on the photoconductor immediately after the development process on the photoconductor (image carrier) (before transfer) and the toner on the photoconductor after transfer (after printing) are collected using separate tapes. The weight was measured. The toner weight on the photoreceptor before transfer is W _b [G], the toner weight on the photoreceptor after the transfer is W _a [G], (W _b -W _a ) × 100 / W _b Was determined as the transfer efficiency.
[0280]
[3.6] Transparency
First, a small amount of toner was inserted between two slide glasses, melted on a hot plate, and then gradually cooled. The resin constituting the toner was allowed to stand until it was completely solidified. Then, the HAZE value was measured with a HAZE meter (Model 1001DP, manufactured by Nippon Denshoku Industries Co., Ltd.). Was evaluated as x, and evaluated. The HAZE value is a value obtained by dividing the diffuse transmittance by the total transmittance. The better the dispersibility of each component in the toner, the smaller the value.
The results are summarized in Table 3.
[0281]
[Table 3]

[0282]
As is evident from Table 3, all of the toners of the present invention were excellent in development durability and exhibited excellent fixability in a wide temperature range. Further, the toner of the present invention was excellent in storage stability. In particular, the toner of the present invention exhibited excellent development durability, fixability, and storage stability while maintaining charging characteristics, transfer efficiency, and transparency. In particular, in the toners of Examples 1, 2, 4, and 7 in which the composition of the block polyester and the amorphous polyester is preferable and the average particle size of the first region is the optimum size, particularly excellent results are obtained. Was done.
[0283]
On the other hand, in the toner of the comparative example, sufficient characteristics were not obtained.
In particular, the toner of Comparative Example 1 containing no block polyester was weak in mechanical stress, and was particularly inferior in development durability and storage stability.
Further, the toner of Comparative Example 2 containing no amorphous polyester had low fixing strength and poor fixability. Further, the toner of Comparative Example 2 was inferior in transparency.
[0284]
Further, the toners of Comparative Examples 3 and 4, in which an amorphous polyester and a highly crystalline polyester D were used together without using a block polyester, had an affinity between resins (an affinity between a block polyester and a crystalline polyester). , Macro phase separation occurred in the toner particles, and fixability and durability were particularly poor.
In Comparative Example 4, in which the colorant was unevenly distributed in the second region, the fixability was particularly poor, and the good fixing region was narrow.
[0285]
Further, the toners of Comparative Examples 5 and 6, which did not contain a colorant, had relatively excellent fixing properties, but all were inferior to the toners of Examples 1 to 9. From this, as in the present invention, the colorant is unevenly distributed in the first region mainly composed of the block polyester, so that the toner (regardless of the mixing ratio of the block polyester and the amorphous polyester, etc.) It can be seen that the effect of improving the fixability (enlargement of a good fixing area and enhancement of fixing strength) can be obtained.
[0286]
Further, for each of the toners, the amount of change in the relaxation modulus G (t) during the passage time Δt [sec] of the toner particles through the nip portion of the fixing device was measured. In each of the toners 1 to 9, the amount of change in the relaxation modulus G (t) was 100 [Pa] or less. The temperature at the nip portion when the toner particles passed was 180 ° C.
[0287]
In addition, quinacridone (PR.122), Pigment Red 57: 1, C.I. I. Pigments Yellow 93 and carbon black were used, and toners were prepared in the same manner as in the above Examples and Comparative Examples, and the same evaluations were performed on these toners. As a result, the same results as those of the above examples and comparative examples were obtained.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view schematically illustrating an example of a configuration of a kneader and a cooler used in a first embodiment of a toner manufacturing method of the present invention.
FIG. 2 is a model diagram of a differential scanning calorimetry curve near the melting point of the block polyester obtained when differential scanning calorimetry is performed on the block polyester.
FIG. 3 is a flowchart for softening point analysis.
FIG. 4 is a diagram for explaining a method for measuring the amount of rutile-anatase type titanium oxide released from toner particles contained in the toner.
FIG. 5 is an overall configuration diagram showing a preferred embodiment of an image forming apparatus of the present invention (an image forming apparatus to which the toner of the present invention is suitably applied).
6 is a sectional view of a developing device included in the image forming apparatus of FIG.
FIG. 7 is a perspective view showing a detailed structure of a fixing device of the present invention used in the image forming apparatus of FIG.
FIG. 8 is a sectional view of a main part of the fixing device of FIG. 7;
FIG. 9 is a perspective view of a peeling member constituting the fixing device of FIG. 7;
FIG. 10 is a side view showing an attached state of a peeling member constituting the fixing device of FIG. 7;
11 is a front view of the fixing device of FIG. 7 as viewed from above.
FIG. 12 is a schematic diagram for explaining an arrangement angle of a peeling member with respect to a tangent line at an exit of a fixing nip portion.
FIG. 13 is a diagram schematically illustrating shapes of a fixing roller and a pressure roller and a shape of a fixing nip portion.
FIG. 14 is a cross-sectional view taken along line XX of FIG.
FIG. 15 is a diagram schematically illustrating shapes of a fixing roller and a pressure roller and a shape of a fixing nip portion.
FIG. 16 is a cross-sectional view taken along line YY of FIG.
FIG. 17 is a cross-sectional view illustrating a gap between a fixing roller and a peeling member.
FIG. 18 is a longitudinal sectional view schematically illustrating an example of a configuration of a kneading machine and a cooling machine used in a second embodiment of the toner manufacturing method of the present invention.
[Explanation of symbols]
1, 1 'Kneader 12 Process part 121 Barrel 122, 123 Screw 124 Fixing member 13 Head part 131 Internal space 132 Extrusion port 133 Cross sectional area gradually decreasing part 14 feeder 2 first kneading unit 21 feeder 22 process unit 221 barrels 222 and 223 screw 3 second kneading unit 31 feeder 32 process unit 321 ... Barrels 322, 323 ... Screws 324 ... Fixing members 4 ... Connection parts 5 ... Head parts 51 ... Internal space 52 ... Extrusion ports 53 ... Cross-sectional area gradually decreasing parts 6 ... , 64 rolls 611, 621, 631, 641 rotating shafts 65, 66 belt 67 discharge unit 7 first raw material 8 first kneaded material 9 second Material 10 Second kneaded material 1000 Image forming apparatus 20 Apparatus main body 30 Image carrier 40 Charging device 50 Exposure device 60 Rotary developing device 600 Support frame 601 Housing 603 Supply roller 604 Developing roller 605 Regulator blade 605a Plate member 605b Elastic member 60Y Yellow developing device 60M Magenta developing device 60C Cyan developing device 60K Developing device for black 70 Intermediate transfer device 90 Driving roller 100 Driven roller 110 Intermediate transfer belt 120 Primary transfer roller 130 Transfer belt cleaner 140 Secondary transfer roller 150 Supply Paper cassette 160 Pickup roller 170 Recording medium transport path 190 Fixing device 200 ... Discharge tray 210... Fixing roller (heat fixing member) 210 a... Heat source 210 b... Cylinder 210 c... Elastic layer 210 d. 220c elastic layer 220d rotary shaft 230 double-sided printing conveyance path 240 housing 250 bearing 260 pressurizing lever 270 pressurizing spring 280 drive gear 290 supporting shaft 300 ... Support shaft 310... Peeling member 310a... Peeling part 310b... Bending part 310c... Supporting piece 310d. 320e Guide part 330 Spring 340 Fixing nip part (nip part) 341 Nip outlet 500 Recording medium T Toner S ... tangential G1 ...... gap G2 ...... gap

Claims (48)

A toner comprising a polyester resin and a material containing a colorant,
The polyester-based resin includes a block polyester mainly composed of a block copolymer and an amorphous polyester having a lower crystallinity than the block polyester,
The block polyester has a crystalline block formed by condensing an alcohol component and a carboxylic acid component, and an amorphous block having a lower crystallinity than the crystalline block.
In the toner particles, a first region mainly composed of the block polyester, and a second region mainly composed of the amorphous polyester,
The toner according to claim 1, wherein a concentration of the colorant in the first region is higher than a concentration of the colorant in the second region. When the concentration of the colorant in the first region is C ₁ [vol%] and the concentration of the colorant in the second region is C ₂ [vol%], 0.1 ≦ C ₂ / The toner according to claim 1, wherein a relationship of C ₁ ≦ 1 is satisfied. 3. The toner according to claim 1, wherein in the toner particles, the first region is finely dispersed to have an average particle diameter of 2 μm or less. 4. The toner according to claim 1, wherein the toner mainly has crystals formed by the crystalline blocks. The toner according to claim 4, wherein the average length of the crystals is 10 to 500 nm. The toner according to claim 1, wherein a melting point of the block polyester is higher than a softening point of the amorphous polyester. The toner according to any one of claims 1 to 6, wherein the monomer component constituting the amorphous polyester has the same content as 50% by mol or more of the monomer component constituting the amorphous block of the block polyester. The toner according to claim 1, wherein a mixing ratio of the block polyester to the amorphous polyester is 5:95 to 45:55 by weight. 9. The toner according to claim 1, wherein the content of the crystalline block in the block polyester is 5 to 60 wt%. The toner according to any one of claims 1 to 9, wherein at least 80 mol% of the alcohol component constituting the crystalline block of the block polyester is an aliphatic diol. The crystalline block of the block polyester has a linear molecular structure having 3 to 7 carbon atoms, and contains a hydroxyl group at both ends thereof as an alcohol component. The toner according to any one of the above. The toner according to claim 1, wherein the carboxylic acid component constituting the crystalline block of the block polyester has a terephthalic acid skeleton in an amount of 50 mol% or more. 13. The toner according to claim 1, wherein at least a part of an alcohol component constituting the amorphous block of the block polyester is an aliphatic diol. 14. The toner according to claim 1, wherein at least a part of the alcohol component constituting the amorphous block of the block polyester has a branched chain. The toner according to claim 1, wherein the melting point of the block polyester is 190 ° C. or higher. The toner according to any one of claims 1 to 15, wherein the block polyester has a heat of fusion of 5 mJ / mg or more determined when an endothermic peak of a melting point is measured by differential scanning calorimetry. 17. The toner according to claim 1, wherein the block polyester has a weight average molecular weight Mw of 1 × 10 ^{4 to} 3 × 10 ⁵ . 18. The toner according to claim 1, wherein the block polyester is a linear polymer. The toner according to any one of claims 1 to 18, wherein the block polyester has a softening point of 90 to 160C. 20. The toner according to claim 1, wherein the carboxylic acid component constituting the amorphous polyester has a terephthalic acid skeleton in an amount of 80 mol% or more. The toner according to any one of claims 1 to 20, wherein the amorphous polyester has a weight average molecular weight Mw of 5 x 10 ³ to 4 x 10 ⁴ . 22. The toner according to claim 1, wherein the amorphous polyester is a linear polymer. The toner according to any one of claims 1 to 22, wherein the amorphous polyester has a softening point of 90 to 160C. 24. The toner according to claim 1, wherein the content of the polyester resin in the toner is 50 to 98 wt%. 25. The toner according to claim 1, wherein the average circularity R represented by the following formula (I) is 0.91 to 0.98.
R = L ₀ / L ₁ (I)
(Where L ₁ [μm] is the perimeter of the projected image of the toner particles to be measured, and L ₀ [μm] is the circumference of a perfect circle having an area equal to the area of the projected image of the toner particles to be measured. Length.) 26. The toner according to claim 1, further comprising an external additive. 27. The toner according to claim 1, wherein the toner has an average particle size of 3 to 12 [mu] m. A fixing roller,
A pressure roller pressed against the fixing roller,
28. The fixing device according to claim 1, which is used in a fixing device having a separating member for separating a recording medium that has passed through a fixing nip formed by a contact portion between the fixing roller and the pressure roller from the fixing roller. The toner according to any one of the above. 29. The toner according to claim 28, wherein the fixing device has a feeding speed of the recording medium of 0.05 to 1.0 m / sec. 30. The toner according to claim 28, wherein the peeling member is a plate-shaped member having a predetermined length in an axial direction of the fixing roller and / or the pressure roller. 31. The toner according to claim 28, wherein in the fixing device, the peeling member is disposed downstream of the fixing nip in the recording medium conveyance direction. 32. The toner according to claim 28, wherein the peeling member is disposed near the fixing roller and / or the pressure roller. 33. The toner according to claim 28, wherein the fixing device has the fixing roller and the pressure roller disposed substantially horizontally. The toner according to any one of claims 28 to 33, wherein the fixing device is provided with the release member such that a gap between the fixing roller and the release member is substantially constant during operation. . 35. The peeling member according to claim 28, wherein the peeling member is disposed along an axial direction of the fixing roller, and has a shape along a shape of an outlet of the fixing nip portion. Toner. Respect to the tangent of the exit of the fixing nip portion, the arrangement angle theta _A of the release member, the fixing roll side + angle, the pressure to the pressure roll side - when the angle is -5 to + 20 ° claims Item 34. The toner according to any one of Items 28 to 35. The fixing device extends in the axial direction of the fixing roller and the pressure roller, and is disposed downstream of the fixing nip in the recording medium conveyance direction and close to the fixing roller and the pressure roller. The apparatus according to claim 1, further comprising the peeling member, wherein the positioning of the peeling member on the fixing roller side is performed on the surface of the fixing roller, and the positioning of the peeling member on the pressure roller side is performed on a bearing surface of the pressure roller. 37. The toner according to any one of 28 to 36. 38. The toner according to claim 37, wherein in the fixing device, the axial length of the pressure roller is shorter than that of the fixing roller, and the bearing is provided in an empty space thereof. The fixing device may be configured such that a gap G2 [μm] between the fixing roller and the peeling member near an axial end of the fixing roller is close to an axial center of the fixing roller. The toner according to any one of claims 28 to 38, wherein the gap is larger than a gap G1 [μm] with a peeling member. A method for producing a toner composed of a material containing a polyester-based resin and a colorant,
The polyester-based resin includes a block polyester mainly composed of a block copolymer and an amorphous polyester having a lower crystallinity than the block polyester,
The block polyester has a crystalline block formed by condensing an alcohol component and a carboxylic acid component, and an amorphous block having a lower crystallinity than the crystalline block.
A first kneading step of producing a first kneaded material containing the block polyester and the colorant;
A method for producing a toner, comprising: a second kneading step of kneading at least a material containing the first kneaded material and the amorphous polyester to produce a second kneaded material. A method for producing a toner composed of a material containing a polyester-based resin and a colorant,
The polyester-based resin includes a block polyester mainly composed of a block copolymer and an amorphous polyester having a lower crystallinity than the block polyester,
The block polyester has a crystalline block formed by condensing an alcohol component and a carboxylic acid component, and an amorphous block having a lower crystallinity than the crystalline block.
A first kneading step of producing a first kneaded material containing the block polyester and the colorant;
At least a second kneading step of kneading a material containing the first kneaded material and the amorphous polyester to produce a second kneaded material,
Forming a first region mainly composed of the block polyester and a second region mainly composed of the amorphous polyester;
A method for producing a toner, comprising: producing a toner in which the concentration of the colorant in the first region is higher than the concentration of the colorant in the first region. 42. The method according to claim 40, wherein the material temperature in the first kneading step is 120 to 260 [deg.] C. 43. The method according to claim 40, wherein the material temperature during the second kneading step is 80 to 260 [deg.] C. The method for producing a toner according to any one of claims 40 to 43, wherein the first kneading step and the second kneading step are continuously performed. 45. A two-stage barrel-type kneader having a first kneading section for performing the first kneading step and a second kneading section for performing the second kneading step is used. The method for producing the toner described in the above. The softening point of the amorphous polyester is T _1/2 (A) [° C.], the melting point of the block polyester T _m (B) [° C.], and the material temperature in the second kneading step is T _K2 [° C.]. The method for producing a toner according to any one of claims 40 to 45, wherein a relationship of _Tm (B)> _TK2 > T1 _{/ 2} (A) is satisfied. Pulverizing and classifying the second kneaded product to obtain a toner production powder;
The method for producing a toner according to any one of claims 40 to 46, further comprising heating the toner production powder to form a sphere. The method for producing a toner according to any one of claims 40 to 47, wherein the temperature of the atmosphere during the thermal sphering step is 210 to 320 ° C.

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