JP2005025050A - Method for manufacturing polyester for toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for efficiently manufacturing polyester having excellent dispersion property with wax and favorable durability. <P>SOLUTION: The method for manufacturing polyester for toner containing wax includes a process of adding wax in the middle of the condensation polymerization reaction of the source monomer and carrying out the condensation polymerization reaction at ≥150°C and <220°C in the presence of the wax. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００９】
（式中、Ｒは炭素数２又は３のアルキレン基、ｘ及びｙは正の数を示し、ｘとｙの和は１〜１６、好ましくは１．５〜５．０である）
で表されるビスフェノールＡのアルキレンオキサイド付加物等の芳香族ジオール、エチレングリコール、１，２ −プロピレングリコール、１，４ −ブタンジオール、ネオペンチルグリコール、ポリエチレングリコール、ポリプロピレングリコール等の脂肪族ジオール、水素添加ビスフェノールＡ等の脂環式ジオール等が挙げられる。これらの中では、耐久性、帯電性及び着色剤の分散性の観点から、芳香族ジオールが好ましい。
【００１０】
芳香族ジオールの含有量は、２価のアルコール成分中、５０〜１００モル％が好ましく、８０〜１００モル％がより好ましく、１００モル％が特に好ましい。
【００１１】
３価以上の多価アルコールとしては、例えばソルビトール、ペンタエリスリトール、グリセリン、トリメチロールプロパン等が挙げられる。
【００１２】
また、２価のカルボン酸化合物としては、フタル酸、イソフタル酸、テレフタル酸等の芳香族ジカルボン酸；シュウ酸、マロン酸、マレイン酸、フマル酸、シトラコン酸、イタコン酸、グルタコン酸、コハク酸、アジピン酸、ドデセニルコハク酸、オクチルコハク酸等の炭素数１〜２０のアルキル基又は炭素数２〜２０のアルケニル基で置換されたコハク酸等の脂肪族ジカルボン酸；それらの酸の無水物及びそれらの酸のアルキル（炭素数１〜３）エステル等が挙げられる。これらの中では、耐久性、帯電性及び着色剤の分散性の観点から、芳香族ジカルボン酸化合物が好ましい。
【００１３】
芳香族ジカルボン酸化合物の含有量は、２価のカルボン酸成分中、５０〜１００モル％が好ましく、８０〜１００モル％がより好ましく、１００モル％が特に好ましい。
【００１４】
３価以上の多価カルボン酸化合物としては、例えば１，２，４−ベンゼントリカルボン酸（トリメリット酸）、２，５，７−ナフタレントリカルボン酸、ピロメリット酸及びこれらの酸無水物、低級アルキル（炭素数１〜３）エステル等が挙げられる。
【００１５】
３価以上の単量体、即ち３価以上の多価アルコール及び多価カルボン酸化合物、好ましくは３価以上の多価カルボン酸化合物の含有量は、耐久性の観点から、各成分中、１〜４０モル％が好ましく、１０〜３０モル％がより好ましい。
【００１６】
さらに、分子量調整等の観点から、１価のアルコールや１価のカルボン酸化合物を、本発明の効果を損なわない範囲で適宜使用してもよい。
【００１７】
ワックスとしては、ポリプロピレンワックス、ポリエチレンワックス、ポリプロピレンポリエチレン共重合体ワックス等のポリオレフィンワックス、カルナウバワックス、はぜろう、密ろう、鯨ろう、モンタンワックス等のエステル系ワックス、脂肪酸アミドワックス等のアミド系ワックス等が挙げられ、これらのなかでは、耐オフセット性及び耐久性の観点から、ポリオレフィンワックスが好ましく、その配合量は、ワックスの総量中、５０重量％以上が好ましく、８０〜１００重量％がより好ましく、１００重量％が特に好ましい。
【００１８】
ワックスの融点は、耐オフセット性及び耐久性の観点から、７５〜１４０℃が好ましく、１００〜１４０℃がより好ましい。
【００１９】
ワックスの配合量は、原料モノマーの総量１００重量部に対して、０．１〜５重量部が好ましく、０．５〜３重量部がより好ましい。
【００２０】
本発明のポリエステルの製造において、アルコール成分とカルボン酸成分からなる原料モノマーは、不活性ガス雰囲気中、要すればエステル化触媒の存在下で、１５０〜２８０℃で縮重合させることができるが、本発明では、原料モノマーの縮重合反応の途中でワックスを添加し、ワックスの存在下、１５０℃以上、２２０℃未満、好ましくは１８０℃以上、２２０℃未満、より好ましくは２００〜２１５℃で、好ましくは０．５〜１０時間、より好ましくは０．５〜５時間縮重合反応を行う工程を有する点に大きな特徴を有する。ワックス存在時の縮重合反応を、１５０℃以上、２２０℃未満の低温で行うことにより、ワックスの劣化、グラフト／エステル交換反応、ワックスの昇華・飛散等を抑制することができ、さらに、樹脂粘度の上昇によるワックス分散性の向上効果が得られる。
【００２１】
ワックスを反応系に添加する時期は特に限定されないが、最初に用いた原料モノマーの反応率が５０％以上、より好ましくは８０％以上、特に好ましくは９０％以上の時点が好ましい。特に、原料モノマーとして、芳香族ジオール及び芳香族ジカルボン酸化合物からなる群より選ばれた少なくとも１種を使用する場合には、それらの反応性の低い原料モノマーを２２０〜２８０℃の高温で上記反応率に達するまで反応させた後に、ワックスを添加することが好ましく、反応温度はワックスを添加する前に下げておくのがより好ましい。
【００２２】
なお、フマル酸等の脂肪族の原料モノマーや、３価以上の多価アルコール、多価カルボン酸化合物等の３価以上の単量体も、１５０℃以上、２２０未満で縮重合させるのが好ましい。特に、３価以上の単量体を使用する場合は、反応制御の観点から、３価以上の単量体を縮重合反応の途中で、好ましくはワックスと同じ時期、即ちワックスと前後して、好ましくは前後３０分以内、より好ましくは前後１０分以内、又はワックスと同時に、反応系に添加し、１５０℃以上、２２０℃未満で縮重合させるのが好ましく、これにより、安定的によりシャープな分子量分布のポリエステルを得ることができる。
【００２３】
なお、本発明の効果が損なわれない範囲であれば、ワックスの一部を、重合反応当初に原料モノマーに添加しても、重合反応後に添加し溶融混練してもよいが、ワックスの５０重量％以上、より好ましくは８０〜１００重量％、更には１００重量％を反応途中で添加するのが好ましい。なお、反応途中でのワックス添加は連続的又は断続的に添加してもよいが一括添加が好ましい。また、ワックス添加後の反応温度も、実質的に１５０℃以上、２２０℃未満であればよく、本発明の効果が損なわれない範囲であれば、ワックス添加後に２２０℃よりも高い温度に短時間上昇させてもよいが、１５０℃以上、２２０℃未満の温度を維持するのが好ましい。
【００２４】
本発明により得られるワックスを含有したポリエステルの軟化点は、１００〜１６０℃が好ましく、１３０〜１５５℃がより好ましい。また、ガラス転移点は、５５〜８５℃が好ましく、６５〜８０℃がより好ましい。
【００２５】
また、本発明により得られるポリエステルにおけるワックスの分散径は、大きすぎると該樹脂と着色剤等を溶融混練してもワックスの分散径が適度にならず、粉砕する際にワックス界面で粉砕されて、ワックスがトナー表面に露出し、トナーが融着しやすくなる。かかる観点から、ワックスの平均分散径は、１０μｍ以下が好ましく、３μｍ以下がより好ましい。ワックスの分散径は、ワックスの添加時期の他、原料モノマー、ワックスの種類、原料モノマーを重合させる際の攪拌強度や重合後の冷却速度等によっても調整することができる。
【００２６】
ワックスが小粒径で、かつ均一に分散した本発明により得られるポリエステルを結着樹脂としてトナーの製造に用いることにより、ワックスの分散径はさらに小粒径化し、耐久性に優れたトナーを得ることができる。従って、本発明により得られるポリエステルは、特に高い耐久性が要求される二成分現像用トナーの結着樹脂として好適に用いることができる。
【００２７】
トナーの製造方法は、混練粉砕法、転相乳化法、重合法等の従来より公知のいずれの方法であってもよいが、例えば、混練粉砕法による粉砕トナーの場合、本発明により得られたポリエステルを含む結着樹脂、着色剤、荷電制御剤等をヘンシェルミキサー等の混合機で均一に混合した後、密閉式ニーダー又は１軸もしくは２軸の押出機、オープンロール型混練機等で溶融混練し、冷却、粉砕、分級して製造することができる。
【００２８】
【実施例】
〔樹脂の軟化点（Ｔｍ）〕
高化式フローテスター（（株）島津製作所製、ＣＦＴ−５００）を用い、１ｇの試料を昇温速度６℃／分で加熱しながら、プランジャーにより１．９６ＭＰａの荷重を与え、直径１ｍｍ、長さ１ｍｍのノズルを押し出すようにし、これによりフローテスターのプランジャー降下量（流れ値）―温度曲線を描き、そのＳ字曲線の高さをｈとするときｈ／２に対応する温度（樹脂の半分が流出した温度）を軟化点とする。
【００２９】
〔樹脂のガラス転移点（Ｔｇ）及びワックスの融点〕
示差走査熱量計（セイコー電子工業社製、ＤＳＣ２１０）を用いて２００℃まで昇温し、その温度から降温速度１０℃／分で０℃まで冷却したサンプルを昇温速度１０℃／分で測定し、サンプルとしてワックスを使用した場合は、最大ピーク温度を融点とする。また、サンプルとして樹脂を使用した場合は、最大ピーク温度以下のベースラインの延長線とピークの立ち上がり部分から、ピークの頂点まで最大傾斜を示す接線との交点の温度をガラス転移点とする。
【００３０】
実施例１
表１に示す使用量のアルコール成分、無水トリメリット酸を除くカルボン酸成分及びジブチルスズオキサイドを５リットル容の四つ口フラスコに入れ、窒素雰囲気下、２３０℃で反応率が９０％に達するまで反応させた後、８．３ｋＰａにて１時間反応させた。その後、２１０℃まで冷却し、無水トリメリット酸、次いでその１分後にポリエチレンワックス（Ｃ１０５、シューマンサゾール社製、融点：１１６℃）を投入し、１時間常圧で反応させた後、２００ｋＰａにて所望の軟化点まで反応させて、ポリエステルを得た。なお、本発明において反応率とは、反応水量（ｍｏｌ）／理論生成水量（ｍｏｌ）×１００の値をいう。
【００３１】
実施例２
表１に示す使用量のアルコール成分、無水トリメリット酸及びフマル酸を除くカルボン酸成分、及びジブチルスズオキサイドを５リットル容の四つ口フラスコに入れ、窒素雰囲気下、２３０℃で反応率が９０％に達するまで反応させた後、８．３ｋＰａにて１時間反応させた。その後、１８０℃まで冷却、フマル酸及びハイドロキノンを添加し、３時間かけて２１０℃まで昇温し、８．３ｋＰａにて１時間反応させた。この後、無水トリメリット酸、次いでその１分後にポリプロピレンワックス（ＮＰ０５６、三井化学社製、融点：１２８℃）を投入し、１時間常圧で反応させた後、２００ｋＰａにて所望の軟化点まで反応させて、ポリエステルを得た。
【００３２】
実施例３
表１に示すアルコール成分及びカルボン酸成分を用い、ポリエチレンワックスとともに、ポリプロピレンワックス（ＮＰ０５６、三井化学社製、融点：１２８℃）を使用した以外は、実施例１と同様にして、ポリエステルを得た。
【００３３】
実施例４
ポリエチレンワックスの代わりに、カルナウバワックス（カルナバワックス１号 パウダー、加藤洋行社輸入、融点：８４℃）を使用した以外は、実施例１と同様にして、ポリエステルを得た。
【００３４】
実施例５
表１に示すアルコール成分及びカルボン酸成分を用いた以外は、実施例１と同様にして、ポリエステルを得た。
【００３５】
比較例１
ワックスをＢＰＡ−ＰＯ等ともに、初期の段階で用いる以外は、実施例１と同様にして、ポリエステルを得た。
【００３６】
比較例２
ワックスを使用しなかった以外は、実施例１と同様にして、ポリエステルを得た。
【００３７】
【表１】

【００３８】
試験例１
各実施例及び比較例において、ポリエステルを製造し、反応容器から取り出した後、反応容器に装備していた脱水管に付着したワックスの昇華物の程度を目視にて観察し、以下の評価基準により、製造性を評価した。結果を表２に示す。
【００３９】
〔評価基準〕
○：脱水管にワックスの昇華物付着せず
×：脱水管にワックスの昇華物付着
【００４０】
試験例２
５０ｍｌ容のサンプル管に、ポリエステル０．５ｇとテトラヒドロフラン２０ｍｌを加え、ボールミル荷台に載せ、１時間攪拌して十分に樹脂を溶解させて、サンプル溶液を調製した。このサンプル溶液をワックスが測定可能な濃度になるまで希釈し、島津レーザー回折式粒度分布測定装置「ＳＡＬＤ−２０００Ｊ」（（株）島津製作所製）を用いて、ワックス粒子の分散径を測定してその平均値を求め、以下の評価基準に従って、ワックスの分散性を評価した。結果を表２に示す。
【００４１】
なお、溶液中に不溶分が確認された場合は１Ｎの水酸化カリウム（ＫＯＨ）水溶液を滴下し、超音波照射を樹脂不溶分が無くなるまで繰り返し行い、測定を行った。
【００４２】
〔評価基準〕
◎：３μｍ未満
○：３μｍ以上、１０μｍ未満
×：１０μｍ以上
【００４３】
試験例３
各実施例及び比較例について、ポリエステル１００重量部、カーボンブラック「ＭＯＧＵＬ−Ｌ」（キャボット社製）４重量部及び負帯電性電荷制御剤「ボントロン Ｓ−３４」（オリエント化学工業社製）１重量部、さらに比較例２のみポリエチレンワックス（Ｃ１０５、シューマンサゾール社製、融点：１１６℃）１重量部をヘンシェルミキサーで十分混合した後、ロール内加熱温度１００℃の同方向回転二軸押出機を用いて溶融混練し、得られた混練物を冷却、粗粉砕した後、ジェットミルにて粉砕し、分級して、体積平均粒径８．０μｍの粉体を得た。
【００４４】
得られた粉体１００重量部に、外添剤として疎水性シリカ「ＴＳ−５３０」（キャボット社製、平均粒子径：８ｎｍ）０．１重量部を添加し、ヘンシェルミキサーで混合することにより、粉体に表面処理を施してトナーを得た。
【００４５】
トナー３重量部と平均粒子径９０μｍのシリコーンコートフェライトキャリア（関東電化工業社製）９７重量部とを混合して得られた現像剤を、「プリテール５５０」（リコー社製）に実装し、印字率５％の画像を１０時間連続印刷した後、現像剤を取り出した。かかる現像剤を目開きが３２μｍの篩を用いてトナー粒子を吸引した。残存したキャリアの炭素量を炭素分析装置「ＥＭＩＡ−１１０」（堀場製作所製）を用いて測定し、あらかじめトナーと混合する前に測定しておいたキャリアの炭素量との差を求め、以下の評価基準に従って耐久性を評価した。結果を表２に示す。すなわち、炭素量の差が大きいほど、キャリアに多量のトナーが付着しており、トナーの耐久性が低いものと判断できる。
【００４６】
〔評価基準〕
◎：０．０５未満
○：０．０５以上、０．１未満
△：０．１以上、０．２未満
×：０．２以上
【００４７】
【表２】

【００４８】
以上の結果から、比較例１、２と対比して、実施例１〜５では、ワックスの分散性に優れたポリエステルを効率よく製造することができ、かかるポリエステルを結着樹脂として用いることにより、耐久性に優れたトナーが得られることが分かる。
【００４９】
【発明の効果】
本発明により、ワックスの分散性に優れ、良好な耐久性を有するポリエステルを、効率よく製造することができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a polyester for toner suitable as a binder resin for toner used for developing a latent image formed in electrophotography, electrostatic recording, electrostatic printing, and the like.
[0002]
[Prior art]
Based on recent energy saving measures, a toner having a wide offset resistance region containing a wax that can be applied to a small-sized copying machine that does not include a silicone oil coating apparatus has been studied. However, polyester, which is a binder resin with excellent low-temperature fixability, is inherently low in compatibility with wax and it is difficult to disperse the wax uniformly and stably in the resin, so that the toner adheres to the carrier or the like. However, it has a drawback that durability is easily lowered. Therefore, in order to improve the compatibility with the wax, there is known a method for increasing the dispersibility of the wax by adding the wax in the presence of the wax, particularly in the early stage of the condensation polymerization reaction, and performing the polymerization reaction (patent) Although some effects are obtained, further improvement in performance is desired.
[0003]
[Patent Document 1]
JP-A-10-87839 (Claim 1)
[Patent Document 2]
JP 2000-1532 A (Claim 1)
[Patent Document 3]
Japanese Patent Laying-Open No. 2003-137991 (Claim 1)
[0004]
[Problems to be solved by the invention]
An object of the present invention is to provide a method capable of efficiently producing a polyester having excellent wax dispersibility and good durability.
[0005]
[Means for Solving the Problems]
The present invention relates to a method for producing a polyester for toner containing a wax, in which wax is added during the condensation polymerization reaction of raw material monomers, and the condensation polymerization reaction is performed at 150 ° C. or more and less than 220 ° C. in the presence of the wax. The present invention relates to a method for producing a polyester for toner having a process.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
As a raw material monomer for polyester, an alcohol component made of alcohol and a carboxylic acid component made of carboxylic acid compound are used.
[0007]
Examples of the divalent alcohol include polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane and polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane. Formula (I):
[0008]
[Chemical 1]

[0009]
(Wherein R is an alkylene group having 2 or 3 carbon atoms, x and y are positive numbers, and the sum of x and y is 1 to 16, preferably 1.5 to 5.0)
Aromatic diols such as alkylene oxide adducts of bisphenol A represented by the formula: Aliphatic diols such as ethylene glycol, 1,2-propylene glycol, 1,4-butanediol, neopentyl glycol, polyethylene glycol, polypropylene glycol, hydrogen Examples include alicyclic diols such as added bisphenol A. Among these, aromatic diols are preferable from the viewpoints of durability, chargeability, and dispersibility of the colorant.
[0010]
The content of the aromatic diol is preferably 50 to 100 mol%, more preferably 80 to 100 mol%, and particularly preferably 100 mol% in the divalent alcohol component.
[0011]
Examples of the trihydric or higher polyhydric alcohol include sorbitol, pentaerythritol, glycerin, trimethylolpropane and the like.
[0012]
Divalent carboxylic acid compounds include aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, and terephthalic acid; oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, Aliphatic dicarboxylic acids such as succinic acid substituted with alkyl groups having 1 to 20 carbon atoms or alkenyl groups having 2 to 20 carbon atoms such as adipic acid, dodecenyl succinic acid, octyl succinic acid; anhydrides of these acids and their Alkyl (C1-C3) ester of an acid etc. are mentioned. Among these, aromatic dicarboxylic acid compounds are preferable from the viewpoints of durability, chargeability, and dispersibility of the colorant.
[0013]
The content of the aromatic dicarboxylic acid compound is preferably 50 to 100 mol%, more preferably 80 to 100 mol%, and particularly preferably 100 mol% in the divalent carboxylic acid component.
[0014]
Examples of the trivalent or higher polyvalent carboxylic acid compound include 1,2,4-benzenetricarboxylic acid (trimellitic acid), 2,5,7-naphthalenetricarboxylic acid, pyromellitic acid and acid anhydrides thereof, and lower alkyl. (C1-C3) ester etc. are mentioned.
[0015]
From the viewpoint of durability, the content of the trivalent or higher monomer, that is, the trivalent or higher polyhydric alcohol and the polyvalent carboxylic acid compound, preferably the trivalent or higher polyvalent carboxylic acid compound is 1 in each component. -40 mol% is preferable and 10-30 mol% is more preferable.
[0016]
Furthermore, from the viewpoint of molecular weight adjustment and the like, a monovalent alcohol or a monovalent carboxylic acid compound may be appropriately used as long as the effects of the present invention are not impaired.
[0017]
As waxes, polyolefin waxes such as polypropylene wax, polyethylene wax, and polypropylene polyethylene copolymer wax, carnauba wax, ester waxes such as haze wax, beeswax, whale wax, and montan wax, and amides such as fatty acid amide waxes Among these, polyolefin wax is preferable from the viewpoint of offset resistance and durability, and the blending amount is preferably 50% by weight or more, more preferably 80 to 100% by weight in the total amount of wax. 100% by weight is preferred and particularly preferred.
[0018]
The melting point of the wax is preferably 75 to 140 ° C, more preferably 100 to 140 ° C, from the viewpoint of offset resistance and durability.
[0019]
The blending amount of the wax is preferably 0.1 to 5 parts by weight, and more preferably 0.5 to 3 parts by weight with respect to 100 parts by weight of the total amount of raw material monomers.
[0020]
In the production of the polyester of the present invention, the raw material monomer comprising an alcohol component and a carboxylic acid component can be polycondensed at 150 to 280 ° C. in an inert gas atmosphere, if necessary, in the presence of an esterification catalyst. In the present invention, a wax is added during the condensation polymerization reaction of the raw material monomer, and in the presence of the wax, 150 ° C. or more and less than 220 ° C., preferably 180 ° C. or more and less than 220 ° C., more preferably 200 to 215 ° C., It has a great feature in that it has a step of performing a polycondensation reaction preferably for 0.5 to 10 hours, more preferably for 0.5 to 5 hours. By conducting the condensation polymerization reaction in the presence of the wax at a low temperature of 150 ° C. or higher and lower than 220 ° C., the deterioration of the wax, the graft / transesterification reaction, the sublimation and scattering of the wax can be suppressed, and the resin viscosity The effect of improving the wax dispersibility due to the increase in the viscosity is obtained.
[0021]
The timing of adding the wax to the reaction system is not particularly limited, but it is preferable that the reaction rate of the raw material monomer used first is 50% or more, more preferably 80% or more, particularly preferably 90% or more. In particular, when at least one selected from the group consisting of an aromatic diol and an aromatic dicarboxylic acid compound is used as a raw material monomer, the above reactive raw material monomers are reacted at a high temperature of 220 to 280 ° C. It is preferable to add the wax after the reaction is allowed to reach the rate, and it is more preferable to lower the reaction temperature before adding the wax.
[0022]
In addition, it is preferable to carry out polycondensation at 150 ° C. or more and less than 220 for aliphatic raw material monomers such as fumaric acid and trivalent or higher monomers such as trivalent or higher polyhydric alcohols and polyvalent carboxylic acid compounds. . In particular, when using a monomer having a valence of 3 or more, from the viewpoint of reaction control, the monomer having a valence of 3 or more is preferably in the middle of the condensation polymerization reaction, preferably at the same time as the wax, that is, before and after the wax. Preferably, it is added within 30 minutes before and after, more preferably within 10 minutes before and after, or simultaneously with the wax, and it is preferably added to the reaction system and subjected to polycondensation at 150 ° C. or more and less than 220 ° C., whereby a stable and sharper molecular weight. A distribution of polyesters can be obtained.
[0023]
As long as the effect of the present invention is not impaired, a part of the wax may be added to the raw material monomer at the beginning of the polymerization reaction or may be added after the polymerization reaction and melt-kneaded. % Or more, preferably 80 to 100% by weight, and more preferably 100% by weight is added during the reaction. In addition, wax addition during the reaction may be added continuously or intermittently, but batch addition is preferable. Further, the reaction temperature after the addition of the wax may be substantially 150 ° C. or higher and lower than 220 ° C. If the effect of the present invention is not impaired, the reaction temperature after the addition of the wax is briefly increased to a temperature higher than 220 ° C. Although it may be increased, it is preferable to maintain a temperature of 150 ° C. or higher and lower than 220 ° C.
[0024]
100-160 degreeC is preferable and the softening point of polyester containing the wax obtained by this invention has more preferable 130-155 degreeC. Moreover, 55-85 degreeC is preferable and, as for a glass transition point, 65-80 degreeC is more preferable.
[0025]
In addition, if the dispersion diameter of the wax in the polyester obtained by the present invention is too large, the dispersion diameter of the wax is not appropriate even when the resin and the colorant are melt-kneaded, and the dispersion is performed at the wax interface when pulverizing. The wax is exposed on the toner surface and the toner is easily fused. From this viewpoint, the average dispersion diameter of the wax is preferably 10 μm or less, and more preferably 3 μm or less. The dispersion diameter of the wax can be adjusted by the addition timing of the wax, the raw material monomer, the kind of the wax, the stirring strength when polymerizing the raw material monomer, the cooling rate after polymerization, and the like.
[0026]
By using the polyester obtained according to the present invention in which the wax has a small particle diameter and is uniformly dispersed as a binder resin in the production of the toner, the dispersion diameter of the wax is further reduced to obtain a toner having excellent durability. be able to. Therefore, the polyester obtained by the present invention can be suitably used as a binder resin for a two-component developing toner that requires particularly high durability.
[0027]
The toner production method may be any conventionally known method such as a kneading and pulverizing method, a phase inversion emulsification method, and a polymerization method. For example, in the case of a pulverized toner by a kneading and pulverizing method, the toner was obtained according to the present invention. A binder resin containing polyester, a colorant, a charge control agent, etc. are uniformly mixed with a mixer such as a Henschel mixer, and then melt-kneaded with a closed kneader, a single or twin screw extruder, an open roll kneader or the like. Then, it can be manufactured by cooling, pulverizing and classifying.
[0028]
【Example】
[Softening point of resin (Tm)]
Using a Koka type flow tester (manufactured by Shimadzu Corporation, CFT-500), a 1 g sample was heated at a heating rate of 6 ° C./min, a load of 1.96 MPa was applied by a plunger, a diameter of 1 mm, A nozzle with a length of 1 mm is pushed out, and this draws a plunger drop amount (flow value) -temperature curve of the flow tester. When the height of the S-shaped curve is h, the temperature corresponding to h / 2 (resin The temperature at which half of the effluent flowed out) is taken as the softening point.
[0029]
[Glass transition point (Tg) of resin and melting point of wax]
Using a differential scanning calorimeter (DSC210, manufactured by Seiko Denshi Kogyo Co., Ltd.), the sample was heated to 200 ° C. and cooled to 0 ° C. at a rate of temperature decrease of 10 ° C./min. When a wax is used as a sample, the maximum peak temperature is taken as the melting point. When a resin is used as a sample, the glass transition point is defined as the temperature at the intersection of the base line extension below the maximum peak temperature and the tangent showing the maximum slope from the peak rising portion to the peak apex.
[0030]
Example 1
The amount of the alcohol component shown in Table 1, the carboxylic acid component excluding trimellitic anhydride, and dibutyltin oxide are placed in a 5-liter four-necked flask and reacted in a nitrogen atmosphere at 230 ° C. until the reaction rate reaches 90%. Then, the mixture was reacted at 8.3 kPa for 1 hour. Thereafter, the mixture was cooled to 210 ° C., trimellitic anhydride, and then polyethylene wax (C105, manufactured by Schumannsazole, melting point: 116 ° C.) was added after 1 minute, and the mixture was reacted at normal pressure for 1 hour. The polyester was obtained by reacting to the desired softening point. In the present invention, the reaction rate means a value of reaction water amount (mol) / theoretical water generation amount (mol) × 100.
[0031]
Example 2
The amount of the alcohol component shown in Table 1, the carboxylic acid component excluding trimellitic anhydride and fumaric acid, and dibutyltin oxide are placed in a 5-liter four-necked flask and the reaction rate is 90% at 230 ° C. in a nitrogen atmosphere. Then, the reaction was continued at 8.3 kPa for 1 hour. Then, it cooled to 180 degreeC, the fumaric acid and the hydroquinone were added, it heated up to 210 degreeC over 3 hours, and was made to react at 8.3 kPa for 1 hour. Thereafter, trimellitic anhydride, and then a polypropylene wax (NP056, manufactured by Mitsui Chemicals, melting point: 128 ° C.) after 1 minute are added and reacted at normal pressure for 1 hour, and then to a desired softening point at 200 kPa. Reaction was performed to obtain a polyester.
[0032]
Example 3
A polyester was obtained in the same manner as in Example 1 except that the alcohol component and the carboxylic acid component shown in Table 1 were used, and a polypropylene wax (NP056, manufactured by Mitsui Chemicals, melting point: 128 ° C.) was used together with the polyethylene wax. .
[0033]
Example 4
A polyester was obtained in the same manner as in Example 1 except that carnauba wax (carnauba wax No. 1 powder, imported by Kato Yoko Co., Ltd., melting point: 84 ° C.) was used instead of polyethylene wax.
[0034]
Example 5
A polyester was obtained in the same manner as in Example 1 except that the alcohol component and the carboxylic acid component shown in Table 1 were used.
[0035]
Comparative Example 1
A polyester was obtained in the same manner as in Example 1 except that wax was used at the initial stage together with BPA-PO and the like.
[0036]
Comparative Example 2
A polyester was obtained in the same manner as in Example 1 except that no wax was used.
[0037]
[Table 1]

[0038]
Test example 1
In each Example and Comparative Example, after producing polyester and taking it out from the reaction vessel, the degree of wax sublimation adhered to the dehydration tube equipped in the reaction vessel was visually observed, and the following evaluation criteria were used. The manufacturability was evaluated. The results are shown in Table 2.
[0039]
〔Evaluation criteria〕
○: Wax sublimate does not adhere to dehydration tube ×: Wax sublimate adheres to dehydration tube
Test example 2
A sample solution was prepared by adding 0.5 g of polyester and 20 ml of tetrahydrofuran to a 50 ml sample tube, placing the solution on a ball mill carrier, and stirring for 1 hour to sufficiently dissolve the resin. This sample solution is diluted until the wax has a measurable concentration, and the dispersion diameter of the wax particles is measured using a Shimadzu laser diffraction particle size distribution analyzer “SALD-2000J” (manufactured by Shimadzu Corporation). The average value was obtained and the dispersibility of the wax was evaluated according to the following evaluation criteria. The results are shown in Table 2.
[0041]
In addition, when insoluble matter was confirmed in the solution, 1N potassium hydroxide (KOH) aqueous solution was dropped, and ultrasonic irradiation was repeated until the resin insoluble matter disappeared, and measurement was performed.
[0042]
〔Evaluation criteria〕
A: Less than 3 μm B: 3 μm or more, less than 10 μm X: 10 μm or more
Test example 3
For each example and comparative example, 100 parts by weight of polyester, 4 parts by weight of carbon black “MOGUL-L” (manufactured by Cabot), and 1 weight of negative charge control agent “Bontron S-34” (manufactured by Orient Chemical Industries) 1 part by weight of polyethylene wax (C105, manufactured by Schumann Sazol, melting point: 116 ° C.) only in Comparative Example 2 was sufficiently mixed with a Henschel mixer, and then a co-rotating twin-screw extruder with a heating temperature of 100 ° C. in the roll was used. The resulting kneaded product was cooled and coarsely pulverized, and then pulverized and classified by a jet mill to obtain a powder having a volume average particle size of 8.0 μm.
[0044]
By adding 0.1 part by weight of hydrophobic silica “TS-530” (Cabot Corporation, average particle size: 8 nm) as an external additive to 100 parts by weight of the obtained powder, and mixing with a Henschel mixer, The powder was surface treated to obtain a toner.
[0045]
A developer obtained by mixing 3 parts by weight of toner and 97 parts by weight of a silicone-coated ferrite carrier (manufactured by Kanto Denka Kogyo Co., Ltd.) having an average particle size of 90 μm is mounted on “Pretail 550” (manufactured by Ricoh) and printed. After continuously printing an image with a rate of 5% for 10 hours, the developer was taken out. Toner particles were sucked from the developer using a sieve having an opening of 32 μm. The carbon content of the remaining carrier was measured using a carbon analyzer “EMIA-110” (manufactured by HORIBA, Ltd.), and the difference from the carbon content of the carrier measured before mixing with the toner was determined. Durability was evaluated according to the evaluation criteria. The results are shown in Table 2. In other words, it can be determined that the greater the difference in the amount of carbon, the more toner adheres to the carrier and the lower the durability of the toner.
[0046]
〔Evaluation criteria〕
◎: Less than 0.05 ○: 0.05 or more, less than 0.1 Δ: 0.1 or more, less than 0.2 ×: 0.2 or more
[Table 2]

[0048]
From the above results, in comparison with Comparative Examples 1 and 2, in Examples 1 to 5, it is possible to efficiently produce polyester excellent in wax dispersibility, and by using such polyester as a binder resin, It can be seen that a toner having excellent durability can be obtained.
[0049]
【The invention's effect】
According to the present invention, it is possible to efficiently produce a polyester having excellent wax dispersibility and good durability.

Claims (5)

A method for producing a polyester for toner containing a wax, comprising: adding a wax in the middle of a condensation polymerization reaction of a raw material monomer, and performing a condensation polymerization reaction at 150 ° C. or more and less than 220 ° C. in the presence of the wax Of polyester for use. The manufacturing method of Claim 1 which adds a wax after the process of polycondensing the raw material monomer containing at least 1 sort (s) chosen from the group which consists of an aromatic diol and an aromatic dicarboxylic acid compound at 220-280 degreeC. The production method according to claim 1 or 2, wherein a trivalent or higher monomer is added in the middle of the condensation polymerization reaction of the raw material monomer, and is subjected to condensation polymerization at 150 ° C or higher and lower than 220 ° C. The method according to any one of claims 1 to 3, wherein the wax is a polyolefin wax. The production method according to any one of claims 1 to 4, wherein the compounding amount of the wax is 0.1 to 5 parts by weight with respect to 100 parts by weight of the total amount of raw material monomers.