JP3780203B2 - Method for producing toner particles - Google Patents

Description

【０１４６】
なお、カブリの判断基準は以下の通り。
Ａ：非常に良好（１．５％未満）
Ｂ：良好（１．５％以上乃至２．５％未満）
Ｃ：普通（２．５％以上乃至４．０％未満）
Ｄ：悪い（４％以上）
【０１４７】
[実施例２]
予備的加熱処理までは、実施例１と同様にして得られたトナー粒子を、図２と同様の態様をした減圧加熱処理装置を用いて処理を行った。
【０１４８】
減圧加熱処理条件は、温度が５０℃、エンタルピーが約２５００ｋＪ／ｋｇ（乾き空気）、水分含有率６０％の高湿空気を投入すること以外は、実施例１と同様の条件下で減圧加熱処理を行った。
【０１４９】
処理終了の時点で、含水率は０．１９％であり、ヘッドスペース法で得られた、トルエン換算の有機揮発成分総量は３０５ｐｐｍであった。
【０１５０】
また、得られたトナー粒子は、凝集した粒子も無く、流動性に非常に優れたものであった。
【０１５１】
この得られたトナー粒子を、実施例１と同様の操作を行ないトナーを作製し、同様の評価を行ったところ非常に良好な結果が得られた。評価結果を表１に示す。
【０１５２】
[実施例３]
予備的加熱処理までは、実施例１と同様にして得られたトナー粒子を、図２と同様の態様をした減圧加熱処理装置を用いて処理を行った。
【０１５３】
減圧加熱処理条件は、温度が５０℃の過熱水蒸気を投入すること以外は、実施例１と同様の条件下で減圧加熱処理を行った。
【０１５４】
処理終了の時点で、含水率は０．１７％であり、ヘッドスペース法で得られた、トルエン換算の有機揮発成分総量は１７０ｐｐｍであった。
【０１５５】
また、得られたトナー粒子は、凝集した粒子も無く、流動性に非常に優れたものであった。
【０１５６】
この得られたトナー粒子を、実施例１と同様の操作を行ないトナーを作製し、同様の評価を行ったところ非常に良好な結果が得られた。評価結果を表１に示す。
【０１５７】
[実施例４]
予備的加熱処理後の含水率が２．９％のトナー粒子を減圧加熱処理に用いること以外は、実施例３と同様の条件下で減圧加熱処理を行った。
【０１５８】
処理終了の時点で、含水率は０．１８％であり、ヘッドスペース法で得られた、トルエン換算の有機揮発成分総量は２５０ｐｐｍであった。
【０１５９】
また、得られたトナー粒子は、凝集した粒子も無く、流動性に非常に優れたものであった。この得られたトナー粒子を、実施例１と同様の操作を行ないトナーを作製し、同様の評価を行ったところ非常に良好な結果が得られた。評価結果を表１に示す。
【０１６０】
[実施例５]
予備的加熱処理までは、実施例１と同様にして得られたトナー粒子を、図２と同様の態様をした減圧加熱処理装置を用いて処理を行った。
【０１６１】
減圧加熱処理条件は、過熱水蒸気の供給流量が０．５ｍ³／（ｈｒ・ｋｇ（トナー粒子））、処理時減圧度が５ｋＰａであること以外は、実施例３と同様の条件下にて減圧加熱処理を行った。
【０１６２】
処理終了の時点で、含水率は０．３１％であり、ヘッドスペース法で得られた、トルエン換算の有機揮発成分総量は３００ｐｐｍであった。
【０１６３】
また、得られたトナー粒子は、凝集した粒子も無く、流動性に非常に優れたものであった。この得られたトナー粒子を、実施例１と同様の操作を行ないトナーを作製し、同様の評価を行ったところ良好な結果が得られた。評価結果を表１に示す。
【０１６４】
[実施例６]
予備的加熱処理までは、実施例１と同様にして得られたトナー粒子を、図２と同様の態様をした減圧加熱処理装置を用いて処理を行った。
【０１６５】
減圧加熱処理条件は、過熱水蒸気の供給流量が０．０１ｍ³／（ｈｒ・ｋｇ（トナー粒子））、処理時減圧度が２．５ｋＰａであること以外は、実施例３と同様の条件下にて減圧加熱処理を行った。
【０１６６】
処理終了の時点で、含水率は０．２％であり、ヘッドスペース法で得られた、トルエン換算の有機揮発成分総量は４００ｐｐｍであった。
【０１６７】
また、得られたトナー粒子は、凝集した粒子も無く、流動性に非常に優れたものであった。この得られたトナー粒子を、実施例１と同様の操作を行ないトナーを作製し、同様の評価を行ったところ、特にカブリに若干の悪化が見られたが実用上問題ないレベルであった。評価結果を表１に示す。
【０１６８】
[実施例７]
予備的加熱処理までは、実施例１と同様にして得られたトナー粒子を、図２と同様の態様をした減圧加熱処理装置を用いて処理を行った。
【０１６９】
減圧加熱処理条件は、処理時の減圧度を４．２ｋＰａにして、温度約３０℃の飽和水蒸気を減圧加熱処理装置に投入すること以外は、実施例１と同様の条件下にて減圧加熱処理を行った。処理終了の時点で、含水率は０．３５％であり、ヘッドスペース法で得られた、トルエン換算の有機揮発成分総量は３６０ｐｐｍであった。
【０１７０】
また、得られたトナー粒子は、凝集した粒子も無く、流動性に非常に優れたものであった。この得られたトナー粒子を、実施例１と同様の操作を行ないトナーを作製し、同様の評価を行ったところ良好な結果が得られた。評価結果を表１に示す。
【０１７１】
[実施例８]
予備的加熱処理までは、実施例１と同様にして得られたトナー粒子を、図２と同様の態様をした減圧加熱処理装置を用いて処理を行った。
【０１７２】
減圧加熱処理条件は、トナー質量Ｂ：４５ｋｇ、撹拌部材最大径における周速Ａ：１．８８４ｍ／ｓ、Ａ／³√Ｂ：０．５３ｍ／（ｓ・³√ｋｇ）であること以外は、実施例１と同様の条件下にて減圧加熱処理を行った。処理終了の時点で、含水率は０．１６％であり、ヘッドスペース法で得られた、トルエン換算の有機揮発成分総量は１５０ｐｐｍであった。
【０１７３】
また、得られたトナー粒子は、熱的に凝集したと予測されるものが若干見受けられた。この得られたトナー粒子を、実施例１と同様の操作を行ないトナーを作製し、同様の評価を行ったところ特にカブリに若干の悪化が見られたが、実用上問題ないレベルであった。
【０１７４】
評価結果を表１に示す。
【０１７５】
[実施例９]
予備的加熱処理までは、実施例１と同様にして得られたトナー粒子を、図２と同様の態様をした減圧加熱処理装置を用いて処理を行った。
【０１７６】
減圧加熱処理条件は、トナー質量Ｂ：４５ｋｇ、撹拌部材最大径における周速Ａ：０．０６ｍ／ｓ、Ａ／³√Ｂ：０．０１８ｍ／（ｓ・³√ｋｇ）であること以外は、実施例１と同様の条件下にて減圧加熱処理を行った。処理終了の時点で、含水率は０．２０％であり、ヘッドスペース法で得られた、トルエン換算の有機揮発成分総量は２６０ｐｐｍであった。
【０１７７】
また、得られたトナー粒子は、真空に起因して圧密・凝集したと予測されるトナー粒子が若干見受けられた。この得られたトナー粒子を、実施例１と同様の操作を行ないトナーを作製し、同様の評価を行ったところ特にカブリの若干の悪化が見られたが、実用上問題ないレベルであった。評価結果を表１に示す。
【０１７８】
[比較例１]
予備的加熱処理までは、実施例１と同様にして得られたトナー粒子を、図２と同様の態様をした減圧加熱処理装置を用いて処理を行った。
【０１７９】
減圧加熱処理条件は、３０℃／８０％ＲＨの空気を減圧及び４５℃に加熱した、エンタルピーが約１００ｋＪ／ｋｇ（乾き空気）、水分含有量約５％の低湿空気を減圧加熱処理装置に投入すること以外は、実施例３と同様の条件下にて減圧加熱処理を行った。処理終了の時点で、含水率は０．１９％であり、ヘッドスペース法で得られた、トルエン換算の有機揮発成分総量は５１５ｐｐｍであった。
【０１８０】
また、得られたトナー粒子は、凝集した粒子も無く、流動性に非常に優れたものであった。また、実施例３と同様の減圧度を保つ為には、実施例３で使用した真空ポンプより容量の大きなものが必要であった。この得られたトナー粒子を、実施例１と同様の操作を行ないトナーを作製し、同様の評価を行ったところ画像濃度の低下及びカブリの悪化が見られた。
【０１８１】
[比較例２]
予備的加熱処理までは、実施例１と同様にして得られたトナー粒子を、図２と同様の態様をした減圧加熱処理装置を用いて処理を行った。
【０１８２】
減圧加熱処理は、温度６５℃の過熱水蒸気を減圧加熱処理装置に投入すること以外は、実施例３と同様の条件下にて減圧加熱処理を行った。処理終了の時点で、含水率は０．１４％であり、ヘッドスペース法で得られた、トルエン換算の有機揮発成分総量は１５０ｐｐｍであった。
【０１８３】
また、得られたトナー粒子は、凝集したトナー粒子が多数混在していた。この得られたトナー粒子を、実施例１と同様の操作を行ないトナーを作製し、同様の評価を行ったところ画像濃度の低下及びカブリの悪化が見られた。評価結果を表１に示す。
【０１８４】
[比較例３]
予備的加熱処理までは、実施例１と同様にして得られたトナー粒子を、図２と同様の態様をした減圧加熱処理装置を用いて処理を行った。
【０１８５】
減圧加熱処理条件は、トナー質量Ｂ：４５ｋｇ、撹拌部材最大径における周速Ａ：０．０３１ｍ／ｓ、Ａ／³√Ｂ：０．００８８ｍ／（ｓ・³√ｋｇ）であること以外は、実施例３と同様の条件下にて減圧加熱処理を行った。処理終了の時点で、含水率は０．２％であり、ヘッドスペース法で得られた、トルエン換算の有機揮発成分総量は２００ｐｐｍであった。
【０１８６】
また、得られたトナー粒子は、真空に起因して圧密・凝集したと予測されるトナー粒子が多数混在していた。更に、凝集したトナー粒子の有機揮発成分を測定したところ３２０ｐｐｍであった。
【０１８７】
この得られたトナー粒子を、実施例１と同様の操作を行ないトナーを作製し、同様の評価を行ったところ画像濃度の低下及びカブリの低下が見られた。評価結果を表１に示す。
【０１８８】
[比較例４]
予備的加熱処理までは、実施例１と同様にして得られたトナー粒子を、図２と同様の態様をした減圧加熱処理装置を用いて処理を行った。
【０１８９】
減圧加熱処理条件は、トナー質量Ｂ：４５ｋｇ、撹拌部材最大径における周速Ａ：２．３９ｍ／ｓ、Ａ／³√Ｂ：０．６７ｍ／（ｓ・³√ｋｇ）であること以外は、実施例３と同様の条件下にて減圧加熱処理を行った。処理終了の時点で、含水率は０．１５％であり、ヘッドスペース法で得られた、トルエン換算の有機揮発成分総量は１５０ｐｐｍであった。
【０１９０】
また、得られたトナー粒子は、熱的に凝集したと予測されるトナー粒子が多数混在していた。
【０１９１】
この得られたトナー粒子を、実施例１と同様の操作を行ないトナーを作製し、同様の評価を行ったところ画像濃度の低下及びカブリの低下が見られた。評価結果を表１に示す。
【０１９２】
【表１】

【０１９３】
【発明の効果】
本発明によれば、重合法によって得られたトナー粒子中に存在する全ての揮発成分を均一にしかも短時間で減少させると同時に、凝集・劣化の無いトナー粒子が得られるトナー粒子の製造方法が実現できる。
【０１９４】
また、本発明によれば、残留する揮発成分及び凝集・劣化したトナー粒子が原因となる画像欠陥の無い高画質の画像が得られるトナー粒子の製造方法が実現できる。
【０１９５】
加えて本発明によれば、該揮発成分を除去する為にかかるエネルギー及びコストを低減することが実現できる。
【図面の簡単な説明】
【図１】トナー粒子を熱気流中で粉粒状に分散させ、高速気流と並流に送りながら加熱処理する装置の一例を示す概略的図である。
【図２】注入媒体を投入しながら、減圧加熱処理を行う装置の一例を示す概略的図である。
【符号の説明】
１． 吐出ブロアー
２． 熱風発生器
３． 気流分散部
４． 気流抜き出し口
５． ループ型気流加熱管
６． 原料供給装置
７． サイクロン
８． 取り出し口
９． バッグフィルター
１０． 排気ブロアー
１１． 減圧加熱処理容器
１２． 駆動モーター
１３． 撹拌中心軸
１４． リボン翼
１７． 原料供給口
１８． バグフィルター
１９． コンデンサー
２０． ジャケット
２１． 温水タンク
２２． 減圧ポンプ
２３． 仕切板
２４． 濾布
２５． 逆洗用ノズル
２６． 注入媒体加熱器
２７． セパレーター
２８． 膨張タンク
２９． 分散盤
３６．注入媒体流量計[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing toner particles, and relates to an improvement in a technique for removing volatile components in toner particles obtained by a polymerization method.
[0002]
[Prior art]
As described in U.S. Pat. No. 2,297,691, etc., many methods are known for electrophotography, and many methods are generally known. Generally, photoconductive materials are used. To form an electric latent image on the photosensitive member by various means, then develop the latent image with toner, transfer the toner image onto a transfer material such as paper, if necessary, and then heat , Fixing by pressure or solvent vapor to obtain a copy. Various methods have been proposed in the past as a method for developing with toner or a method for fixing a toner image, and a method suitable for each image forming process is employed.
[0003]
Conventionally, as a toner used for these purposes, generally, a colorant such as a dye and a pigment is melt-mixed in a thermoplastic resin and uniformly dispersed, and then a toner having a desired particle size is produced by a fine pulverizer and a classifier. I have done it.
[0004]
While this method of manufacture can produce fairly good toners, it has certain limitations, i.e., limited choice of toner materials. For example, the resin colorant dispersion must be sufficiently brittle and capable of being finely pulverized with economically possible production equipment. However, if the resin colorant dispersion is made brittle to satisfy these requirements, the particle size range of the particles formed when actually pulverized at high speed tends to be widened. It is included in the problem. Further, such a highly brittle material is likely to be further pulverized or powdered when used for development in a copying machine or the like. Also, with this method, it is difficult to completely disperse solid fine particles such as a colorant in the resin, and depending on the degree of dispersion, the increase in fog, the decrease in image density, and the color mixing / transparency may be difficult. Care must be taken to disperse as this will cause defects. Further, exposure of the colorant to the fracture surface may cause a change in development characteristics.
[0005]
On the other hand, in order to overcome the problems of the toner by the pulverization method, various toners by various polymerization methods such as the toner by the suspension polymerization method described in Japanese Patent Publication Nos. 36-10231, 43-10799, and 51-14895 are disclosed. And manufacturing methods thereof. For example, in the suspension polymerization method, a monomer composition is obtained by uniformly dissolving or dispersing a polymerizable monomer, a colorant, a polymerization initiator and, if necessary, a crosslinking agent, a charge control agent, and other additives. After that, the monomer composition is dispersed in a continuous phase containing a dispersion stabilizer, for example, an aqueous phase by using a suitable stirrer, and at the same time, a polymerization reaction is performed to obtain toner particles having a desired particle size. obtain.
[0006]
Since this method does not include a pulverization process, the toner does not need to be brittle, a soft material can be used, and the classification process can be omitted, thereby saving energy and saving time. Cost reduction effects such as shortening and improving process yield are significant.
[0007]
In recent years, there has been a demand for multifunctional toners such as high image quality, full color, and energy saving in recent copying machines and printers. For example, the toner particles have a small particle size to cope with high-resolution, digital methods with a finer particle size, improved transparency of OHP images with full color, and low-temperature fixing with energy saving. There is a demand for the inclusion of a softening point substance and the formation of toner particles that are effective in improving the transfer efficiency to a transfer material. As a means for realizing these requirements, a toner by a polymerization method is exemplified.
[0008]
On the other hand, as for the polymerization method, including the polymerization method toner, the reaction form of the polymerization reaction system increases as the polymerization proceeds, and it becomes difficult to move radicals and polymerizable monomers. Many body components tend to remain. In particular, in the case of a suspension polymerization method toner, the polymerizable monomer system contains components such as dyes, pigments (particularly carbon black), charge control agents, and magnetic substances that may inhibit the polymerization reaction. Since it exists in a large amount other than the body, unreacted polymerizable monomers are likely to remain.
[0009]
Furthermore, when dyes, pigments, polymerization initiators, charge control agents, magnetic materials, and the like are used, by-products derived from these substances are also generated. In addition, with the increase in multifunction and variety of toners, these internal components are also diversified, so that various by-products may be generated. In some cases, the total amount of various by-products may exceed the amount of unreacted polymerizable monomer.
[0010]
If these toner particles contain many components that act as a solvent for the binder resin as well as the polymerizable monomer, the fluidity of the toner is lowered and the image quality is deteriorated, and the blocking resistance is lowered. . In addition to the performance directly related to the toner, especially when an organic semiconductor is used as the photoconductor, in addition to the phenomenon of toner fusion to the photoconductor drum, there is a phenomenon of deterioration of the photoconductor such as memory ghost and image blurring. May cause problems. In addition to the matters related to the performance of the product, there is a problem in that the polymerizable monomer component and other by-products volatilize and generate a bad odor during fixing.
[0011]
Furthermore, along with the downsizing and personalization of copiers, printers, etc., the restrictions on the device have increased, the burden on the above-mentioned problems has increased, and the concern for the environment has also increased, resulting from toner particles generated by fixing etc. Therefore, it is preferable to reduce the total amount of volatile components present in the toner particles to 500 ppm or less.
[0012]
As a method for reducing the total amount of volatile components in the toner particles to be even smaller, a highly volatile organic solvent that does not dissolve the toner binder resin but dissolves the polymerizable monomer and / or other by-products A method of washing with an acid or an alkali; a method in which a solvent component that does not dissolve a foaming agent or a polymer is placed in a polymer system, and the resulting toner particles are made porous to increase the volatilized area of volatile components inside; And a method of removing volatile components under dry conditions. However, since it is difficult to select a solvent such as elution of toner constituents due to a decrease in toner capsule properties, and the residual property of the solvent, The most preferable method is to reduce the total amount of other by-products, that is, volatile components.
[0013]
Generally, volatile components are removed from toner particles after solid-liquid separation of a suspension in which a polymerization reaction has been completed conventionally, using a vacuum dryer or the like.
[0014]
Japanese Patent Application Laid-Open No. 08-160662 proposes a method of vacuum drying toner particles. This drying method has an advantage of drying an object to be dried at a low temperature, but the inside of the apparatus is in a reduced pressure state. Since the gas phase stays and the power for diffusing volatile components is remarkably reduced, it takes a very long drying time to further remove the volatile components after evaporating and removing the moisture.
[0015]
Japanese Patent Application Laid-Open No. 10-207122 proposes a method of vacuum drying toner particles while injecting a gas.
[0016]
However, as described in the specification of the publication, when an inert gas or the like is used as the gas to be injected, the effect of the carrier gas works and the volatile matter does not stay as compared with the case where the gas is simply vacuum dried. Although the drying efficiency is improved, in a dry gas such as an inert gas, the amount of heat that the gas itself can have is very small, so heat is taken away from the heated toner particles, and the drying efficiency is lowered.
[0017]
For this reason, the drying time is extended and the thermal history applied to the toner particles is lengthened, so that the deformation of the particles and the fusion of the particles occur, resulting in lumps and deteriorated image characteristics.
[0018]
In addition, when the temperature of the gas to be injected is not controlled by heating or the like, the gas whose temperature has been lowered due to adiabatic expansion enters the gas feed path as it is, and heat is further removed from the toner particles, resulting in a drying efficiency. Will be further reduced.
[0019]
Furthermore, in the gas, the resistance due to diffusion that hinders evaporation is a major factor that determines the drying speed (although it is less than when no carrier gas is used). In order to improve this, for example, when the flow rate of the gas is increased, the capacity of the exhaust equipment (mainly vacuum pump) needs to be increased accordingly, resulting in a great production cost. This is even more true when it comes to mass production.
[0020]
Further, when the toner particles are dried in a vacuum state, the toner particle layer is compacted and aggregated due to the vacuum. For this reason, it has been conventionally made to overcome the force of the toner particle layer to be compacted and aggregated by using the stirring member, that is, to apply a force for unraveling the toner particle layer.
[0021]
However, if there is a portion where fluidization of the toner particle layer stays due to poor agitation, the portion is highly likely to be consolidated and aggregated. There was a problem of becoming. Therefore, it may be necessary to separately provide a step of crushing the toner particles that have been consolidated and aggregated after drying, which is disadvantageous in terms of cost.
[0022]
On the other hand, too much agitation causes thermal and mechanical damage to the toner particles, and there is a problem that toner particles that are also the cause of image degradation are generated.
[0023]
As described above, this drying method still has many problems in terms of efficiency, quality, and cost, and it has been a problem for many engineers to solve this problem.
[0024]
[Problems to be solved by the invention]
An object of the present invention is to provide a method for producing toner particles that solves the above-described problems.
[0025]
Specifically, the object of the present invention is to uniformly reduce all the volatile components present in the toner particles obtained by the polymerization method in a short time, and at the same time, consolidate and aggregate and / or thermally and mechanically deteriorate. It is an object of the present invention to provide a method for producing toner particles in which toner particles that have not been obtained are obtained.
[0026]
Another object of the present invention is to provide a method for producing toner particles that can provide a high-quality image free from image defects caused by residual volatile components and compacted / aggregated toner particles.
[0027]
In addition, an object of the present invention is to reduce the energy and cost required to remove the volatile components.
[0028]
[Means for solving the problems]
  According to the present invention, toner particles produced in an aqueous dispersion medium are washed and dehydrated, and the resulting wet toner particles are supplied to a container, and saturated water vapor at a temperature lower than the glass transition temperature Tg of the toner particles. The heating temperature of the toner particles by the headspace method is performed by performing a reduced pressure heat treatment while introducing an injection medium selected from the group consisting of superheated steam or high humidity air having an enthalpy of 2500 kJ / kg (dry air) or more into the container. In the analysis of organic volatile components at 150 ° C, the total amount of organic volatile components in terms of toluene based on the toner particle mass is 500 ppm or less.And the container has a stirring means, and the stirring means is performed by using a stirring member provided in the container, and the peripheral speed at the maximum diameter of the stirring member is A (m / s), the container When the mass of toner particles inside is B (kg),
    0.01 (m / (s · ^Three √kg)) ≦ A / ^Three √B ≦ 0.6 (m / (s · ^Three √kg))
Process under conditions that satisfy the relationshipThe present invention relates to a method for producing toner particles.
[0029]
DETAILED DESCRIPTION OF THE INVENTION
As a result of intensive studies, the present inventors have supplied colored polymer particles to a container capable of reducing pressure and heating, and (i) saturated steam, (ii) superheated steam, (iii) enthalpy 2500 kJ / kg (dry air) It has been found that the total amount of volatile components can be reduced in a short time by performing a heat treatment under reduced pressure while introducing an injection medium that is one of the above humid air.
[0030]
Further, when the container includes a stirring member, when the peripheral speed at the maximum diameter of the stirring member is A (m / s) and the mass of toner particles in the container is B (kg),
0.01 (m / (s ·^Three√kg)) ≦ A /^Three√B ≦ 0.6 (m / (s ·^Three√kg))
It has been found that by performing the treatment under conditions satisfying the above relationship, it is possible to provide toner particles having excellent fluidity without compaction and aggregation.
[0031]
Furthermore, it has been found that the use of the heat treatment method according to the present invention can reduce power during processing, that is, reduce energy and cost.
[0032]
The present invention is advantageous in that water vapor has a relatively small resistance due to diffusion, which particularly hinders evaporation of volatile components present in the toner particles, and has a large amount of heat that can be held compared to dry gas, and is also heat efficient. By paying attention to and using the two points, it is possible to reduce the volatile matter from the toner particles in a very short time.
[0033]
Further, since a condensable gas such as water vapor (or high-humidity air in which water vapor occupies most) can be recovered as a liquid by the condensing device, an exhaust device for forming a reduced pressure state is provided. When the dry gas is used as the carrier gas, the entire amount needs to be exhausted, whereas when water vapor is used, only the amount that cannot be recovered by the condensing device may be exhausted.
[0034]
Therefore, the capacity of the exhaust device can be small, and the merit is great compared to the case of using dry gas in terms of energy and cost. In particular, the larger the scale of the heat treatment apparatus, the greater the merit.
[0035]
Further, the present invention prevents the toner particles from being consolidated and agglomerated due to the vacuum by operating the ratio of the peripheral speed of the stirring member to the toner mass under a predetermined condition, and further deteriorates the toner particles due to excessive stirring. In this state, the drying can be performed in a state with very high fluidity.
[0036]
In the drying using the vacuum drying used in the conventional method for producing the polymerized toner, as described above, the gas phase stays and the ability to diffuse the volatile matter is significantly reduced. Later, in order to further remove the unreacted polymerizable monomer, there was a problem that a very long drying time was required.
[0037]
Further, in the method of vacuum drying while injecting a gas (Japanese Patent Laid-Open No. 10-207122), as described above, in the case of a gas having a small amount of heat such as an inert gas, the toner particles are preheated. When the above-mentioned gas is not temperature-controlled by heating or the like, it takes heat, and when the temperature of the gas is not controlled by heating or the like, the airflow whose temperature has been reduced by adiabatic expansion enters the gas feeding path as it is. As described in the example, as shown in the fact that there is a large difference between the heating temperature and the product temperature of the toner particles, the toner particles are further deprived of heat and the drying efficiency is further reduced. . For this reason, the drying time is extended and the heat history applied to the toner becomes longer, so that the deformation of the particles and the fusion of the particles occur, resulting in the occurrence of lumps and the deterioration of the image characteristics. It was happening.
[0038]
Furthermore, since the above-mentioned gas is a non-condensable gas, it is necessary to exhaust the supplied amount as it is, and the capacity of the exhaust equipment (mainly the decompression pump) for maintaining the decompression becomes very large. There was a problem such as high costs.
[0039]
Hereinafter, the present invention will be described in more detail.
[0040]
The injection medium in the present invention is in a depressurized state in the course of being put into a container in which the reduced pressure heat treatment is performed. Strictly speaking, when the injection medium is put into the reduced pressure heat treatment apparatus, the operation decompression degree (heat treatment container Saturated steam, superheated steam, or high-humidity air that has been depressurized to the degree of depressurization within), and the injection medium temperature described in the specification is also in this state.
[0041]
In order to prevent condensation, the degree of vacuum used in the present invention is preferably 40 kPa from the viewpoint of obtaining a large temperature difference ΔT between the temperature of the injected injection medium and the boiling point (= saturation temperature). In order to improve the drying efficiency as the degree of vacuum increases, it is more preferably 20 kPa or less, further 15 kPa or less, and particularly preferably 10 kPa or less.
[0042]
Further, “saturated steam” and “superheated steam” used in the present invention are present only in water vapor, and “saturated steam” is steam that is substantially maintained at a saturation temperature corresponding to the degree of reduced pressure during operation. “Superheated steam” is steam that has been heated to a saturation temperature or higher. Further, “highly humid air” is mostly occupied by water vapor, but it contains some air (may be an inert gas such as nitrogen).
[0043]
Compared to the dry gas that is almost free of water vapor, which is generally used as a carrier gas, these are mostly water vapor, so they retain a large amount of heat, that is, they have a high enthalpy and differ greatly in properties. .
[0044]
The enthalpy used in the present invention is the total amount of heat of 1 kg of dry air per 1 kg of dry air and water vapor [kg] contained therein, and the unit is represented by “kJ / kg (dry air)”. It is.
[0045]
Furthermore, the high-humidity air used in the present invention has a very large enthalpy because most of the high-humidity air is occupied by water vapor, unlike a gas that hardly contains water vapor.
[0046]
In the present invention, there are no particular limitations because there are various methods for deriving the enthalpy of high-humidity air.
[0047]
The “supplied heat amount” of the injection medium used in the present invention is a flow rate fed into the apparatus per unit time and per kg of toner particles, and the unit is “m^Three/ (Hr · kg (toner particles)) ”.
[0048]
In the present invention, in order to reduce image quality deterioration due to organic volatile components, and to cope with the above-mentioned restrictions on apparatus associated with downsizing and personalization of copying machines, printers, etc., the headspace method In the analysis of organic volatile components at a toner particle heating temperature of 150 ° C., the total amount of organic volatile components in terms of toluene based on the toner particle mass is preferably 500 ppm or less, more preferably 400 ppm or less, particularly 300 ppm or less. Is preferred.
[0049]
Next, the “moisture content” used in the present invention refers to the mass-based moisture content, that is, the ratio of the moisture mass to the total mass (the sum of the dry toner mass and the moisture mass), and is determined by a heat loss method at 105 ° C. It was.
[0050]
The temperature of the injection medium in the present invention is preferably less than the glass transition temperature Tg of the toner particles.
[0051]
When the water vapor is higher than the glass transition temperature Tg of the toner particles, the toner particles are thermally deteriorated, resulting in problems such as fusing and damaging of the particles.
[0052]
In addition, when the steam introduced is brought into contact with an unheated part in the apparatus, the temperature drops, and when it falls to the boiling point (= saturation temperature) corresponding to the degree of decompression during operation, dew condensation occurs, resulting in Drying efficiency may be reduced. In order to prevent this, it is preferable to take a large temperature difference ΔT between the temperature of the injected injection medium and the boiling point (= saturation temperature) (however, the apparatus / toner particles are sufficiently heated, which may cause a temperature drop). If the water vapor temperature is low, saturated water vapor corresponding to the degree of decompression may be used.) When the water vapor temperature is low, in order to obtain ΔT, a considerably high vacuum is required, and the exhaust equipment and the like are loaded. The temperature is preferably 30 ° C. or higher. In addition, when the water vapor is higher than the glass transition temperature Tg of the toner particles, the toner particles are thermally deteriorated, resulting in problems such as fusing and damaging of the particles.
[0053]
The enthalpy of the high humidity air used in the present invention is 2500 kJ / kg (dry air) or more, preferably 6500 kJ / kg (dry air) or more, and the enthalpy is less than 2500 kJ / kg (dry air). In the case of water vapor, since the amount of heat that can be held is small, heat is taken away from the preheated toner particles, and the drying efficiency is lowered. As such high-humidity air having a high enthalpy, it is preferable to use air having a moisture content of 50% or more because it becomes easy to obtain a high-humidity air having a high enthalpy. % Or more, and particularly preferably 80% or more.
[0054]
The flow rate of the injection medium in the present invention is 0.01 to 0.5 m.^Three/ (Hr · kg (toner particles)), preferably 0.03 to 0.27 m^Three/ (Hr · kg (toner particles)) is preferable. Within this range, basically, the drying efficiency increases as the injection medium supply flow rate increases. Injection medium supply flow rate is 0.01m^ThreeWhen the injection medium is smaller than / (hr · kg (toner particles)), the amount of heat to be supplied generally decreases even with an injection medium having a large amount of heat, and the drying efficiency is lowered. On the other hand, the injection medium supply flow rate is 0.5 m.^Three/ (Hr · kg (toner particles)), a large amount of water vapor flow is required, and thus the degree of vacuum is often lowered. For this reason, the saturation temperature and the vapor temperature ΔT corresponding to the operating pressure reduction degree. There is a high possibility that condensation will occur.
[0055]
In the present invention, when the stirring member is provided in the container, when the peripheral speed at the maximum diameter of the stirring member is A (m / s) and the mass of the toner particles in the container is B (kg),
0.01 (m / (s ·^Three√kg)) ≦ A /^Three√B ≦ 0.6 (m / (s ·^Three√kg))
Preferably,
0.04 (m / (s ·^Three√kg)) ≦ A /^Three√B ≦ 0.5 (m / (s ·^Three√kg))
It is preferable to perform processing under conditions that satisfy the above relationship. This represents the ratio of the peripheral speed of the stirring member to the cube root mass. The mass root is attached to the mass because the mass increases in proportion to the scale, but the circumferential speed follows it. Therefore, the meaning of the correction to eliminate the difference due to the scale as much as possible is included.
[0056]
When stirring is performed within this range, the toner particle layer can be made to uniformly flow without causing toner deterioration and compaction / aggregation due to vacuum.
[0057]
A /^Three√B is 0.6 m / (s ·^ThreeIf the condition is larger than √kg), excessive shearing takes place due to stirring, so that the temperature of the toner particles suddenly increases with time, causing thermal damage. Furthermore, since the toner particles are mechanically loaded, there is a high possibility that the toner particles are deformed.
[0058]
On the other hand, A /^Three√B is 0.01 m / (s ·^ThreeIf the condition is smaller than (√kg), it is insufficient to prevent the above-described consolidation and aggregation due to the vacuum. Further, uniform stirring of the entire toner particle layer becomes difficult, and a portion where the toner layer stays is generated, and aggregation / drying unevenness only in that portion occurs.
[0059]
Further, the mixing state of the toner particle layer depends on the shape of the stirring member, but the ratio A / of the peripheral speed at the maximum diameter of the stirring member to the mass of the third root toner particles of the present invention^ThreeBy performing √B within the above range, the ability to dry under vacuum with excellent fluidity can be applied to various shapes of stirring members.
[0060]
Although the shape of the stirring member applicable to this invention is not specifically limited, It is preferable to use the ribbon-shaped stirring member shown in FIG.
[0061]
In addition, the present invention ultimately reduces the total amount of volatile components including the polymerizable monomer composition and volatile by-products, but if the toner particles contain a lot of moisture, the moisture is present on the particle surface. Therefore, the volatile components can be reduced only after moisture is removed. Therefore, in order to further improve the volatile component removal efficiency, it is preferable to remove moisture in advance.
[0062]
Specifically, the water content of the toner particles is preferably 3.0% or less, more preferably 1.0% or less. As a preliminary heat treatment, for example, the toner particles are dispersed in a high-speed hot air stream. At the same time, there is a method in which heat treatment is performed preliminarily while being sent in parallel flow. It is preferable that the toner particles having the above water content be preliminarily used by using this heat treatment apparatus capable of continuously supplying the toner particles in a high-speed hot air stream, and the toner whose temperature has been increased by the preliminary heat treatment It is more preferable to perform the heat treatment under reduced pressure while maintaining the temperature of the particles.
[0063]
As a result, a process governed by the amount of heat given from the heat transfer surface in the reduced-pressure heat treatment is completed in advance both when removing moisture that requires a large amount of latent heat of evaporation and when raising the temperature of a material that requires a large amount of sensible heat. By reducing the difference between the product temperature and the product temperature (with less heat transfer), not only can the processing time be shortened, but it is also placed in a device typified by a vacuum heat treatment device with a heat transfer surface. The disadvantage is that the ratio of the heat transfer area to the sample becomes smaller as the scale becomes larger, that is, the drying time required for the small scale is longer than that for the large scale. Further, it is possible to provide toner particles with less deterioration.
[0064]
As an apparatus for performing heat treatment instantaneously while being sent in parallel flow in a high-speed hot air flow, used as a preliminary heat treatment device of the present invention, for example, has a loop type air flow heating tube 5 as shown in FIG. Although heat processing apparatus etc. are mentioned, it does not restrict | limit in particular.
[0065]
In the preliminary heat treatment apparatus shown in FIG. 1, first, air supplied from the discharge blower 1 is compressed air heated to a predetermined temperature in the hot air generator 2 and discharged at supersonic speed in the airflow dispersion unit 3 to supply raw materials. The processed material supplied from the apparatus 6 is dispersed and processed instantaneously (0.5 to several tens of seconds) in the loop type airflow heating tube 5. By setting the air flow outlet 4 inside the loop type air flow heating tube 5, the coagulated particles are separated from the agglomerated particles and classified by the Coanda effect. The classified particles are separated from the air flow by the cyclone 7 and discharged from the take-out port 8. The air flow can be discharged out of the system from the exhaust blower 10 via the bag filter 9.
[0066]
Further, coarse particles in the particles coming out of the pipe 5 are separately classified by a classifier and returned to the raw material supply device 6, and only particles in a certain particle size range are supplied to the cyclone 7 to obtain desired toner particles. Classification and heat treatment can also be performed continuously.
[0067]
In addition to the loop type described above, the pipe type of the airflow heat treatment apparatus is a straight pipe type, with the inner cylinder enlarged to increase the residence time, and the particles are swirled and deposited at the bottom of the horizontal pipe. Although various types of heat treatment tubes such as a type for preventing airflow can be used, an airflow heat treatment apparatus having a loop-type airflow heating tube 5 as shown in FIG. 1 is most preferable.
[0068]
In the present invention, it is preferable to use compressed air heated to 40 to 150 ° C., preferably 60 to 120 ° C., for the heat treatment with a hot air stream. When the heating temperature is lower than 40 ° C., the drying efficiency is lowered. When the heating temperature is higher than 150 ° C., the toner is fused, which is not preferable.
[0069]
Specific examples include a flash jet dryer (manufactured by Seishin Enterprise) and a flash dryer (manufactured by Hosokawa Micron).
[0070]
In the present invention, as a device capable of reducing the pressure and heating and reducing the total amount of volatile components to 500 ppm or less while maintaining high fluidity without deterioration of toner particles, and a device that requires a stirring member, FIG. 2 is a schematic side view. A reduced-pressure heat treatment apparatus having a mode as shown is preferably used.
[0071]
Hereinafter, the reduced pressure heat treatment apparatus of the embodiment shown in FIG. 2 will be described in detail.
[0072]
In the reduced pressure heat treatment system shown in FIG. 2, the toner particles are supplied into the inverted conical reduced pressure heat treatment container 11 to perform the reduced pressure heat treatment. A stirring center shaft 13 that can be driven by the drive motor 12 extends in the container center longitudinal axis in the container, and a ribbon blade 14 having a single spiral structure is provided around the stirring center shaft 13.
[0073]
By rotating the ribbon blade 14, stirring and dispersion can be repeatedly applied while lifting the toner particles from below to above, so that the raw materials in the container can be efficiently stirred and mixed throughout.
[0074]
Further, as shown in FIG. 2, a bag filter 18 and then a condenser 19 are connected to the upper portion of the container, a raw material supply port 17 for supplying toner particles, and an exhaust path for reducing the pressure in the container. ing.
[0075]
Further, as shown in FIG. 2, a jacket 20 is provided around the above-described reduced-pressure heat treatment container 11 so that the temperature in the container can be appropriately controlled and heat treatment can be performed at a desired temperature. Has been. For this reason, a gap is formed between the outer wall of the container and the inner wall of the jacket 20, and hot water or steam / cooling water produced in the hot water tank 21 can be passed through the gap. At the same time, a discharge path for hot water, steam and cooling water is also provided.
[0076]
Further, pressure reduction in the container is performed by exhausting water vapor in the container from the exhaust port through the bag filter 18 and the condenser 19 by the decompression pump 22. As shown in FIG. 2, the bag filter 18 is partitioned into upper and lower chambers by a partition plate 23. A cylindrical filter cloth 24 is suspended below the partition plate, and an exhaust path connected to the condenser 19 is provided above the partition plate, and backwashing is performed at a position above the center of the filter cloth 24. A nozzle 25 is disposed. The backwash nozzle 25 is for intermittently jetting nitrogen, air, or the above injection medium (preferably heated nitrogen and air and the above injection medium) to wash the filter cloth 24 by back pressure.
[0077]
The supply source of the water vapor into the container is not particularly limited, but in general, it is often supplied from a boiler generator and passes through the injection medium flow meter 36 and heated by the injection medium heater 26. (If necessary, saturated water can be removed by the separator 27), and the pressure is reduced to near the operating pressure reduction level by the expansion tank 28. On the other hand, from the lower part of the apparatus, a disperser 29 for uniformly dispersing the injection medium is provided. And uniformly supplied into the apparatus. It is possible to prevent toner particles from blocking at the lower part of the apparatus.
[0078]
The injection medium supplied into the reduced pressure heat treatment container becomes vapor mixed with volatile components from the toner particles, passes through the bag filter 18, is condensed and recovered by the next condenser 19, and the vapor that could not be condensed is decompressed. It is discharged out of the system through the pump 22.
[0079]
In a state in which the water content of the toner particles is substantially removed, the volatile components generated from the toner particles are very small, so that most of the toner particles are controlled by the supplied injection medium. As a result, most of the condensable injection medium is recovered as water by the condenser 19, so that the capacity of the decompression pump 22 is small as described above.
[0080]
Specific examples of the reduced pressure heat treatment apparatus preferably used in the present invention include a double cone mixer (manufactured by Tokuju Seisakusho Co., Ltd.), a nauter mixer (manufactured by Hosokawa Micron Co., Ltd.), and a ribocorn. Examples include a mixer (manufactured by Okawara Seisakusho), a PV mixer (manufactured by Shinko Pantech Co., Ltd.), a vacuum stirring and drying device Inox system (manufactured by Paulek), and an SV mixer (manufactured by Shinko Pantech Co., Ltd.).
[0081]
The toner according to the present invention has a finer particle diameter, more specifically a weight average particle diameter measured by a Coulter counter of 4 to 4 in order to faithfully reproduce finer latent image dots for higher image quality. Number variation coefficient expressed by the following equation at 10 μm
Number variation coefficient = Sn / D1 × 100
(However, Sn is the standard deviation of the number distribution, D1 is the number average particle diameter)
However, less than 35% toner is most preferred.
[0082]
When the toner is less than 4 μm, a large amount of untransferred toner is generated on the photosensitive member or the intermediate transfer member due to poor transfer efficiency, which causes undesirable unevenness of the image due to fogging or transfer failure.
[0083]
In addition, when the mass average diameter of the toner exceeds 10 μm, fusion to the member is likely to occur. In addition, when the number variation coefficient of the toner exceeds 35, the tendency further increases and becomes a problem.
[0084]
The amount of the organic volatile component of the toner of the present invention is quantified using a headspace method. In the headspace method, the toner is sealed in a sealed container and heated at a constant temperature for a certain time to equilibrate between the sample and the gas phase, and then the gas in the gas phase in the sealed container is injected into the gas chromatograph. Quantify volatile components. At this time, an organic volatile component is detected using FID as a detector of the gas chromatograph. Conventionally, as a method for analyzing a volatile component in a toner, a method in which a toner is dissolved in a solvent and injected into a gas chromatograph and quantified is known. However, in this method, the peak of the volatile component is buried in the solvent peak. It is not suitable as a method for quantifying organic volatile components of toner.
[0085]
The toner of the present invention contains at least a resin and a colorant, but may contain a release agent, a charge control agent, or the like, which is a fixability improving agent, if necessary. Further, an external additive composed of inorganic fine particles or organic fine particles may be added to the toner particles containing the resin and the colorant as main components.
[0086]
In the toner of the present invention, a monomer is emulsion-polymerized in a suspension polymerization method or a liquid obtained by adding an emulsion of necessary additives to produce fine polymer particles. It can manufacture by the method of adding an agent etc. and making it associate. A method of preparing by mixing with a dispersion liquid such as a release agent or a colorant necessary for the composition of the toner at the time of association, or a toner component such as a release agent or a colorant is dispersed in the monomer And a method of emulsion polymerization. Here, the association means that a plurality of resin particles and colorant particles are fused.
[0087]
In addition, the aqueous medium as used in the field of this invention shows what contained 50 mass% or more of water at least.
[0088]
Although it does not specifically limit as a manufacturing method of a suspension polymerization method, The following manufacturing methods can be raised.
[0089]
That is, various constituent materials such as a colorant and, if necessary, a release agent, a charge control agent, and a polymerization initiator are added to the polymerizable monomer, and then a homogenizer, a sand mill, a sand grinder, an ultrasonic disperser, etc. Various constituent materials are dissolved or dispersed in the polymerizable monomer. The polymerizable monomer in which these various constituent materials are dissolved or dispersed is dispersed in oil droplets having a desired size as a toner in an aqueous medium containing a dispersion stabilizer using a homomixer or a homogenizer. Then, it transfers to the reaction apparatus which has a stirring mechanism, and a polymerization reaction is advanced by heating. After completion of the reaction, the dispersion stabilizer is removed, filtered, washed, and dried to prepare the toner of the present invention.
[0090]
Further, as a method for producing the toner of the present invention, a method of preparing by fusing resin particles in an aqueous medium can also be mentioned. The method is not particularly limited, and examples thereof include methods disclosed in JP-A-5-265252, JP-A-6-329947, and JP-A-9-15904. That is, a method of associating a plurality of fine particles composed of resin particles and colorants or the like, or a resin, a colorant and the like, particularly after dispersing them in an aqueous medium using an emulsifier, By adding a flocculant of a coagulation concentration or higher and salting out, at the same time, heat fusion at a temperature higher than the glass transition temperature of the formed polymer itself, and heating and drying the particles in a fluid state in a water-containing state, the present invention. The toner can be formed. Here, an organic solvent that is infinitely soluble in water may be added simultaneously with the flocculant.
[0091]
In the present invention, a so-called seed polymerization method in which a monomer is further adsorbed to the obtained polymer particles and then polymerized using a polymerization initiator can be suitably used in the present invention.
[0092]
Examples of the polymerizable monomer that can be used in the polymerized toner include styrene monomers such as styrene, o (m-, p-)-methylstyrene, m (p-)-ethylstyrene; methyl (meth) acrylate. , Ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, behenyl (meth) acrylate, (Meth) acrylate monomers such as 2-ethylhexyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate; butadiene, isoprene, cyclohexene, (meth) acrylonitrile, acrylic Vinyl monomers such as acid amides are preferably used. Moreover, it may be preferably used in combination of two or more as required.
[0093]
In the present invention, it is particularly preferable to add a polar resin in addition to the outer shell resin in order to encapsulate the low softening point substance in the outer shell resin. As the polar resin used in the present invention, a copolymer of styrene and (meth) acrylic acid, a maleic acid copolymer, a saturated polyester resin, and an epoxy resin are preferably used. The polar resin is particularly preferably one containing no unsaturated group capable of reacting with the outer shell resin or the monomer. In the case of containing a polar resin having an unsaturated group, a cross-linking reaction occurs with the monomer forming the outer shell resin layer, and as a full color toner, it becomes extremely high molecular weight, which is disadvantageous for the color mixture of four color toners, which is not preferable. .
[0094]
The low softening point substance used in the present invention is preferably a compound having a main maximum peak value measured in accordance with ASTM D3418-8 of 40 to 90 ° C. When the maximum peak is less than 40 ° C., the self-aggregation force of the low softening point substance becomes weak, and as a result, the high temperature offset resistance becomes weak, which is not preferable for a full color toner. On the other hand, when the maximum peak exceeds 90 ° C., the fixing temperature becomes high, and it becomes difficult to appropriately smooth the surface of the fixed image, which is not preferable from the viewpoint of mixing properties. Furthermore, in the case of obtaining a toner by direct polymerization, granulation and polymerization are carried out in an aqueous system, so if the temperature of the maximum peak value is high, a low softening point substance mainly precipitates during granulation and inhibits the suspension system. Therefore, it is not preferable. Specifically, paraffin wax, polyolefin wax, Fischer rope fish wax, amide wax, higher fatty acid, ester wax and derivatives thereof, or graft / block compounds thereof can be used.
[0095]
As the colorant used in the present invention, a black colorant that is toned in black using carbon black, a magnetic material, and the following yellow / magenta / cyan colorant is used.
[0096]
As the yellow colorant, compounds typified by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds are used. Specifically, C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 109, 110, 111, 128, 129, 147, 168, etc. are preferably used.
[0097]
As the magenta colorant, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds are used. Specifically, C.I. I. Pigment Red 2, 3, 5, 6, 7, 23, 48: 2, 48: 3, 48: 4, 57: 1, 81: 1, 122, 144, 146, 166, 169, 177, 184, 185, 202, 206, 220, 221, 254 are particularly preferred.
[0098]
As the cyan colorant, copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds, and the like can be used. Specifically, C.I. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62, 66 and the like can be used particularly preferably.
[0099]
These colorants can be used alone or in combination and further in the form of a solid solution. The colorant of the present invention is selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP transparency, and dispersibility in the toner. The colorant is added in an amount of 1 to 20 parts by mass with respect to 100 parts by mass of the resin.
[0100]
When a magnetic material is used as the black colorant, 40 to 150 parts by mass are added to 100 parts by mass of the resin, unlike other colorants.
[0101]
The magnetic material used in the toner of the present invention may contain elements such as phosphorus, cobalt, nickel, copper, magnesium, manganese, aluminum, and silicon. In addition, the magnetic substance is composed mainly of iron oxide such as triiron tetroxide and γ-iron oxide, and these are used alone or in combination of two or more. These magnetic materials preferably have a BET specific surface area by nitrogen adsorption method of 2 to 30 m.²/ G, especially 3 to 28m²/ G and a Mohs hardness of 5-7 are preferred.
[0102]
The shape of the magnetic body includes a polyhedron, an octahedron, a hexahedron, a sphere, a needle, a scale, and the like, but a polyhedron, an octahedron, a hexahedron, a sphere, and the like having low anisotropy increase the image density. Is preferable. The shape of such a magnetic material can be confirmed by SEM or the like. The volume average particle size of the magnetic material is preferably 0.05 to 0.4 μm, more preferably 0.1 to 0.3 μm. When the volume average diameter is less than 0.05 μm, the decrease in blackness becomes remarkable, the coloring power becomes insufficient as a colorant for black and white toner, and the cohesion between magnetic materials becomes strong, so that the dispersibility is high. Getting worse. In addition, the uniformity treatment of the magnetic surface becomes very difficult. On the other hand, when the volume average diameter exceeds 0.4 μm, the coloring power becomes insufficient as in the case of a general colorant. In addition, particularly when used as a colorant for small-diameter toner, it is probabilistically difficult to uniformly disperse magnetic particles in individual toner particles, and the dispersibility tends to deteriorate.
[0103]
In the magnetic material used in the magnetic toner of the present invention, when the particle surface is hydrophobized, the surface of the magnetic material is hydrolyzed in the aqueous medium while dispersing the magnetic material particles so as to have a primary particle size. It is highly preferred to use a method of treatment. This hydrophobic treatment method is less likely to cause coalescence between the magnetic particles than the treatment in the gas phase, and the repulsive action between the magnetic particles due to the hydrophobic treatment works, so that the magnetic material is almost in the state of primary particles. Surface treated.
[0104]
The method of treating the surface of the magnetic material while hydrolyzing the coupling agent in an aqueous medium does not require the use of a coupling agent that generates a gas, such as chlorosilanes and silazanes, and further, In the phase, magnetic particles can be easily combined with each other, and a highly viscous coupling agent that has been difficult to be processed can be used, so that the hydrophobizing effect is great.
[0105]
Examples of the coupling agent that can be used in the surface treatment of the magnetic material according to the present invention include a silane coupling agent and a titanium coupling agent. More preferably used is a silane coupling agent having a general formula
Rm SiYn
[Wherein, R represents an alkoxy group, m represents an integer of 1 to 3, Y represents a hydrocarbon group such as an alkyl group, a vinyl group, a glycidoxy group, or a methacryl group, and n represents an integer of 1 to 3. Show. ]. For example, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (βmethoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyl Diethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxy Silane, diphenyldimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, n-butyltrimethoxysilane, isobutyl Le trimethoxysilane, trimethyl methoxysilane, hydroxypropyl Ritori silane, n- hexadecyl trimethoxy silane, can be mentioned n- octadecyl trimethoxysilane.
[0106]
Among them, it is preferable to use a silane coupling agent having a double bond to improve the dispersibility of the magnetic substance, such as phenyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethyl. Methoxysilane is more preferred. This is thought to be due to the better compatibility between the magnetic substance and the polymerizable monomer, particularly when the suspension polymerization is performed with a coupling agent having a double bond. The dispersibility of the magnetic material is good.
[0107]
As the charge control agent used in the present invention, known ones can be used. However, a charge control agent that is colorless, has a high toner charging speed, and can stably maintain a constant charge amount is preferable. Further, when the direct polymerization method is used in the present invention, a charge control agent having no polymerization inhibition and no solubilized product in an aqueous system is particularly preferable. Specific examples of the negative compounds include salicylic acid, naphthoic acid, dicarboxylic acid metal compounds, sulfonic acid, polymer compounds having carboxylic acid in the side chain, boron compounds, urea compounds, silicon compounds, calixarene, and the like. As a positive system, a quaternary ammonium salt, a polymer compound having the quaternary ammonium salt in the side chain, a guanidine compound, an imidazole compound, and the like are preferably used. The charge control agent is preferably 0.5 to 10 parts by mass with respect to 100 parts by mass of the resin. However, in the present invention, it is not essential to add a charge control agent. When a two-component development method is used, frictional charging with a carrier is used, and even when a non-magnetic one-component blade coating development method is used, the blade It is not always necessary to include a charge control agent in the toner by actively utilizing frictional charging with the member or the sleeve member.
[0108]
Examples of the polymerization initiator that can be used in the polymerized toner according to the present invention include 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1 ′. -Azo or diazo polymerization initiators such as azobis (cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile; benzoyl peroxide; Peroxide polymerization initiators such as methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide are used. The addition amount of the polymerization initiator varies depending on the target degree of polymerization, but generally 0.5 to 20% by mass is added to the monomer. The kind of the polymerization initiator varies slightly depending on the polymerization method, but can be used alone or in combination with reference to the 10-hour half-life temperature.
[0109]
In order to control the degree of polymerization, a known crosslinking agent, chain transfer agent, polymerization inhibitor and the like can be further added and used.
[0110]
In the polymerized toner according to the present invention, particularly when using suspension polymerization using a dispersant, the dispersant used is an inorganic compound such as tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate. , Magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, alumina and the like. As organic compounds, polyvinyl alcohol, gelatin, methylcellulose, methylhydroxypropylcellulose, ethylcellulose, sodium salt of carboxymethylcellulose, polyacrylic acid and its salts, starch and the like can be dispersed in an aqueous phase. These stabilizers are preferably used in an amount of 0.2 to 20 parts by mass with respect to 100 parts by mass of the polymerizable monomer.
[0111]
Among these stabilizers, when an inorganic compound is used, a commercially available one may be used as it is, but in order to obtain fine particles, the inorganic compound may be produced in a dispersion medium. For example, in the case of tricalcium phosphate, a sodium phosphate aqueous solution and a calcium chloride aqueous solution may be mixed under high stirring.
[0112]
Moreover, you may use 0.001-0.1 mass part surfactant for fine dispersion | distribution of these stabilizers. This is to promote the desired action of the above dispersion stabilizer, and specific examples thereof include sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, lauric acid. Examples thereof include sodium, potassium stearate, calcium oleate and the like.
[0113]
In the toner manufacturing method of the present invention, the toner can be specifically manufactured by the following manufacturing method.
[0114]
That is, a release agent composed of a low softening point substance, a colorant, a charge control agent, a polymerization initiator and other additives are added to the polymerizable monomer, and the mixture is uniformly dissolved or dispersed by a homogenizer, an ultrasonic disperser or the like. The monomer system is dispersed in an aqueous phase containing a dispersion stabilizer by a usual stirrer or CLEARMIX, homomixer, homogenizer or the like. Preferably, granulation is performed by adjusting the stirring speed and time so that the monomer droplets have a desired toner particle size. Thereafter, stirring may be performed to such an extent that the particle state is maintained and the sedimentation of the particles is prevented by the action of the dispersion stabilizer. The polymerization is preferably carried out at a polymerization temperature of 40 ° C. or higher, generally 50 to 90 ° C. In addition, the temperature may be raised in the latter half of the polymerization reaction, and in order to remove unreacted polymerizable monomers and by-products that cause odor during toner fixing, the latter half of the reaction, or the completion of the reaction. A part of the aqueous medium may be distilled off later. After completion of the reaction, the produced toner particles are recovered by washing and filtration and dried by the drying method of the present invention. In the suspension polymerization method, it is usually preferable to use 300 to 3000 parts by mass of water as a dispersion medium with respect to 100 parts by mass of the monomer system.
[0115]
In the present invention, the Tg of the toner particles obtained in this way is adjusted to be 40 to 75 ° C. When the temperature is lower than 40 ° C., there are problems in terms of storage stability of the toner and durability of the developer. On the other hand, when the temperature exceeds 75 ° C., the fixing point is increased. Insufficient color mixing results in poor color reproducibility, and further reduces the transparency of the OHP image, which is undesirable from the standpoint of high image quality.
[0116]
Further, the production method in the present invention can be applied not only to toner but also to a binder resin for toner. The wet binder resin obtained by various polymerization methods, like the toner particles obtained by the polymerization method, requires a step of removing moisture, residual polymerizable monomer and other volatile components. As the volatile matter removing step, the above-described reduced pressure heat treatment can be used.
[0117]
Examples of the binder resin for toner used in the present invention include vinyl resins, polyester resins or copolymers of vinyl monomers and polyester monomers, but are not particularly limited.
[0118]
Below, the measuring method of each physical-property value used by this invention is described.
[0119]
1. Measuring method of toner particle Tg:
In this invention, it measured with the following method using the differential thermal analysis measuring device (DSC measuring device) and DSC-7 (made by Perkin-Elmer). First, a measurement sample is precisely weighed in an amount of 5 to 20 mg, preferably 10 mg. And this is put into an aluminum pan, and an empty aluminum pan is used as a reference, and the temperature rising rate is 10 ° C./min. Measure at room temperature and humidity. As a result, in this temperature rising process, before the endothermic peak of the main peak in the temperature range of 40 to 100 ° C. and after it has come out, the intersection point of the midpoint of the baseline and the differential heat curve is represented in the present invention. The glass transition temperature Tg.
[0120]
2. Method for measuring moisture content:
The moisture content of the toner of the present invention was measured by a heat loss method at 105 ° C. with a MA40 electronic moisture meter (manufactured by Sartorius).
[0121]
3. Method for measuring the total amount of volatile components:
The amount of organic volatile components in the toner by the headspace method may be measured as follows.
[0122]
In a headspace vial (volume: 22 ml), 300 mg of toner is precisely weighed and sealed with a crimper and a special septum coated with fluororesin using a crimper. This vial is set in a headspace sampler and analyzed under the following conditions. And the total area value of the peak of the obtained GC chart is calculated by data processing. At this time, an empty vial in which no toner is sealed is simultaneously measured as a blank, and the blank value such as an organic volatile component volatilized from the septum is subtracted from the toner measurement data. The amount of organic volatile component in terms of toluene based on the toner mass is prepared by preparing several points (for example, 0.1 μl, 0.5 μl, 1.0 μl) in which only toluene is precisely weighed in a vial. After measuring under the following analysis conditions before making measurements, a calibration curve was created from the amount of toluene charged and the toluene area value, and the area value of the organic volatile component of the toner was calculated based on this calibration curve. Can be converted to the mass of toluene based on the above.
[0123]
<Measurement device>
Headspace sampler: HEWLETT PACKARD 7694
Oven temperature: 150 ° C
Sample heating time: 60 minutes
Sample loop (Ni): 1ml
Loop temperature: 170 ° C
Transfer line temperature: 190 ° C
Pressurization time: 0.50 minutes
LOOP FILL TIME: 0.01 min
LOOP EQ TIME: 0.06 minutes
INJECT TIME: 1.00 minutes
GC cycle time: 80 minutes
Carrier gas: He
GC: HEWLETT PACKARD 6890GC (detector: FID)
Column: HP-1 (inner diameter 0.25 μm × 30 m), carrier gas: He
Oven: 35 ° C: hold for 20 minutes, heat up to 300 ° C at 20 ° C / minute, hold for 20 minutes
INJ: 300 ° C
DET: 320 ° C
Splitless, constant pressure (20 psi) mode
[0124]
【Example】
Hereinafter, the present invention will be described specifically by way of examples.
[0125]
[Example 1]
A surface-treated magnetic material was produced by the following method.
[0126]
In ferrous sulfate aqueous solution, l. 0 to 1.1 equivalent of caustic soda solution, 0.95 mass% sodium hexametaphosphate in terms of phosphorus element with respect to iron element, 0.95 mass% sodium silicate in terms of silicon element with respect to iron element, and An aqueous solution containing ferrous iron was prepared.
[0127]
While maintaining the pH of the aqueous solution at around 13, air was blown and an oxidation reaction was performed at 80 to 90 ° C. to obtain a slurry solution of magnetic particles. After washing and filtering, this hydrous slurry liquid was once taken out. At this time, a small amount of water-containing sample was collected and the water content was measured. Next, this water-containing sample was re-dispersed in another aqueous medium without drying, and then the pH of the re-dispersed liquid was adjusted to about 6, and the n-hexyltrimethoxysilane coupling agent was magnetically stirred with sufficient stirring. 1.9 parts by mass with respect to 100 parts by mass of iron oxide, 1.1 parts by mass of γ-methacryloxypropyltrimethoxysilane coupling agent (the amount of magnetic particles was calculated as a value obtained by subtracting the water content from the water sample) Then, a coupling process was performed. The produced hydrophobic magnetic particles are washed, filtered, and dried by a conventional method, and the obtained particles are sufficiently pulverized to have a number average particle diameter of 0.13 μm and a number average variation coefficient of 8 surface treated magnetic body. Got.
[0128]
0.1M-Na in 720 parts by mass of ion-exchanged water_ThreePO_FourAfter 450 parts by mass of aqueous solution and 16 parts by mass of 1N hydrochloric acid were added and heated to 60 ° C., 1.0M-CaCl₂Add 67.7 parts by weight of aqueous solution and add Ca._Three(PO_Four)₂An aqueous medium containing was obtained.
[0129]
on the other hand,
・ Styrene 78 parts by mass
・ 22 parts by mass of n-butyl acrylate
・ Saturated polyester resin 1 part by mass
・ Divinylbenzene 0.20 parts by mass
-Negative charge control agent (monoazo dye-based Fe compound) 1 part by mass
・ 85 parts by mass of the surface-treated magnetic material
The above formulation was uniformly dispersed and mixed using a homogenizer.
[0130]
This monomer composition was heated to 60 ° C., and 7 parts by mass of ester wax (72 ° C. maximum value of endothermic peak in DSC) was added, mixed and dissolved therein, and polymerization initiator t-butylperoxy 2- 4 parts by mass of ethyl hexanoate was dissolved.
[0131]
The polymerizable monomer system is charged into the aqueous medium, and 60 ° C., N₂In an atmosphere, the mixture was stirred for 15 minutes at 10,000 rpm with a TK homomixer (Special Machine Industries Co., Ltd.) and granulated. Thereafter, the mixture was reacted at 80 ° C. for 8 hours while stirring with a paddle stirring blade. After completion of the reaction, the suspension was cooled, hydrochloric acid was added to dissolve the dispersant at a pH of 2 or lower, filtered and washed to obtain wet toner particles having a water content of 22% and a mass average particle size of 7.2 μm.
[0132]
The obtained toner particles were subjected to preliminary heat treatment under the following conditions using an apparatus in the same manner as in FIG. 1 having a pipe diameter of 0.1016 m of the airflow heat treatment section.
[0133]
Blowing temperature: 90 ° C
Blowing air volume: 10m^Three/ Min
Raw material supply amount: 50 kg / hr
[0134]
The water content after the treatment was 0.20%, and the glass transition temperature of the toner particles was measured at this time, and it was 58 ° C.
[0135]
Volatile components were removed from the toner particles under the following conditions using a reduced-pressure heat treatment apparatus having a capacity of 100 L as shown in FIG.
Heating temperature: 50 ° C
Decompression degree during processing: 3 kPa
Toner mass B: 45 kg
Stirring member maximum diameter: 0.6m
Peripheral speed A at the maximum diameter of the stirring member: 0.785 m / s
A /^Three√B: 0.22 m / (s ·^Three√kg)
High humidity air with a temperature of 50 ° C., enthalpy of about 14000 kJ / kg (dry air) and a moisture content of about 90%, the supply amount is 0.13 m^Three/ (Hr · kg (toner particles)).
[0136]
Under the above conditions, a heat treatment under reduced pressure was performed for 3 hours.
[0137]
At the end of the treatment, the water content was 0.17%, and the total amount of organic volatile components in terms of toluene obtained by the headspace method was 200 ppm.
[0138]
Further, the obtained toner particles had no agglomerated particles and were extremely excellent in fluidity.
[0139]
100 parts by mass of the obtained toner particles and silica having a primary particle size of 12 nm were treated with hexamethyldisilazane and then treated with silicone oil, and the BET value after treatment was 120 m.²1.0 part by mass of / g hydrophobic silica fine powder was mixed with a Henschel mixer (Mitsui Miike Chemical Co., Ltd.) to obtain a toner.
[0140]
Using this toner, evaluation was carried out using a modified LBP-1760 machine manufactured by Canon as an image forming apparatus.
[0141]
First, 100 g of the obtained toner is filled in a cartridge, and the toner amount on paper is 0.8 mg / cm at high temperature and high humidity (30 ° C., 80% RH).²And a solid black image having an image density of 1.42 was obtained. Then, after performing idle rotation for 2 hours as an acceleration test of toner deterioration, an image print test of 1000 sheets was performed with an image pattern consisting only of horizontal lines with a printing rate of 2%. As a result, the obtained toner was able to obtain a very good image free from fogging on the non-image area after 1000 images were printed. The evaluation results are shown in Table 1.
[0142]
The evaluation items described in the examples of the present invention and the comparative examples and the judgment criteria thereof will be described.
[0143]
<Image density>
The image density formed a solid image portion, and this solid image was measured with a Macbeth reflection densitometer (manufactured by Macbeth).
[0144]
<Fog>
The fog was measured using a REFECTMETER MODEL TC-6DS manufactured by Tokyo Denshoku. The filter used was a green filter, and fog was calculated from the following formula.
[0145]
[Expression 1]

[0146]
The criteria for fogging are as follows.
A: Very good (less than 1.5%)
B: Good (1.5% or more to less than 2.5%)
C: Normal (2.5% or more to less than 4.0%)
D: Poor (4% or more)
[0147]
[Example 2]
Until the preliminary heat treatment, the toner particles obtained in the same manner as in Example 1 were treated using a reduced-pressure heat treatment apparatus having the same mode as in FIG.
[0148]
The reduced pressure heat treatment conditions were the same as in Example 1 except that high humidity air with a temperature of 50 ° C., an enthalpy of about 2500 kJ / kg (dry air), and a moisture content of 60% was introduced. Went.
[0149]
At the end of the treatment, the water content was 0.19%, and the total amount of organic volatile components in terms of toluene obtained by the headspace method was 305 ppm.
[0150]
Further, the obtained toner particles had no agglomerated particles and were extremely excellent in fluidity.
[0151]
The obtained toner particles were subjected to the same operation as in Example 1 to produce a toner, and the same evaluation was performed. As a result, very good results were obtained. The evaluation results are shown in Table 1.
[0152]
[Example 3]
Until the preliminary heat treatment, the toner particles obtained in the same manner as in Example 1 were treated using a reduced-pressure heat treatment apparatus having the same mode as in FIG.
[0153]
The reduced-pressure heat treatment was performed under the same conditions as in Example 1 except that superheated steam having a temperature of 50 ° C. was added.
[0154]
At the end of the treatment, the water content was 0.17%, and the total amount of organic volatile components in terms of toluene obtained by the headspace method was 170 ppm.
[0155]
Further, the obtained toner particles had no agglomerated particles and were extremely excellent in fluidity.
[0156]
The obtained toner particles were subjected to the same operation as in Example 1 to produce a toner, and the same evaluation was performed. As a result, very good results were obtained. The evaluation results are shown in Table 1.
[0157]
[Example 4]
The reduced pressure heat treatment was performed under the same conditions as in Example 3 except that toner particles having a water content of 2.9% after the preliminary heat treatment were used for the reduced pressure heat treatment.
[0158]
At the end of the treatment, the water content was 0.18%, and the total amount of organic volatile components in terms of toluene obtained by the headspace method was 250 ppm.
[0159]
Further, the obtained toner particles had no agglomerated particles and were extremely excellent in fluidity. The obtained toner particles were subjected to the same operation as in Example 1 to produce a toner, and the same evaluation was performed. As a result, very good results were obtained. The evaluation results are shown in Table 1.
[0160]
[Example 5]
Until the preliminary heat treatment, the toner particles obtained in the same manner as in Example 1 were treated using a reduced-pressure heat treatment apparatus having the same mode as in FIG.
[0161]
Under reduced pressure heat treatment conditions, the superheated steam supply flow rate is 0.5 m.^Three/ (Hr · kg (toner particles)), The heat treatment under reduced pressure was performed under the same conditions as in Example 3 except that the degree of vacuum during the treatment was 5 kPa.
[0162]
At the end of the treatment, the water content was 0.31%, and the total amount of organic volatile components in terms of toluene obtained by the headspace method was 300 ppm.
[0163]
Further, the obtained toner particles had no agglomerated particles and were extremely excellent in fluidity. The toner particles thus obtained were subjected to the same operation as in Example 1 to produce a toner, and the same evaluation was performed. As a result, good results were obtained. The evaluation results are shown in Table 1.
[0164]
[Example 6]
Until the preliminary heat treatment, the toner particles obtained in the same manner as in Example 1 were treated using a reduced-pressure heat treatment apparatus having the same mode as in FIG.
[0165]
Under reduced pressure heat treatment conditions, the supply flow rate of superheated steam is 0.01m^Three/ (Hr · kg (toner particles)), a heat treatment under reduced pressure was performed under the same conditions as in Example 3 except that the degree of vacuum during the treatment was 2.5 kPa.
[0166]
At the end of the treatment, the water content was 0.2%, and the total amount of organic volatile components in terms of toluene obtained by the headspace method was 400 ppm.
[0167]
Further, the obtained toner particles had no agglomerated particles and were extremely excellent in fluidity. The toner particles thus obtained were subjected to the same operation as in Example 1 to produce a toner, and the same evaluation was performed. In particular, although fog was slightly deteriorated, it was at a level where there was no practical problem. The evaluation results are shown in Table 1.
[0168]
[Example 7]
Until the preliminary heat treatment, the toner particles obtained in the same manner as in Example 1 were treated using a reduced-pressure heat treatment apparatus having the same mode as in FIG.
[0169]
The reduced-pressure heat treatment conditions were the same as in Example 1 except that the degree of reduced pressure during treatment was 4.2 kPa and saturated steam at a temperature of about 30 ° C. was introduced into the reduced-pressure heat treatment apparatus. Went. At the end of the treatment, the water content was 0.35%, and the total amount of organic volatile components in terms of toluene obtained by the headspace method was 360 ppm.
[0170]
Further, the obtained toner particles had no agglomerated particles and were extremely excellent in fluidity. The toner particles thus obtained were subjected to the same operation as in Example 1 to produce a toner, and the same evaluation was performed. As a result, good results were obtained. The evaluation results are shown in Table 1.
[0171]
[Example 8]
Until the preliminary heat treatment, the toner particles obtained in the same manner as in Example 1 were treated using a reduced-pressure heat treatment apparatus having the same mode as in FIG.
[0172]
The heat treatment conditions under reduced pressure are as follows: toner mass B: 45 kg, peripheral speed A: 1.84 m / s at the maximum diameter of the stirring member, A /^Three√B: 0.53 m / (s ·^ThreeThe heat treatment under reduced pressure was performed under the same conditions as in Example 1 except that √kg). At the end of the treatment, the water content was 0.16%, and the total amount of organic volatile components in terms of toluene obtained by the headspace method was 150 ppm.
[0173]
Some of the toner particles obtained were expected to be thermally aggregated. The toner particles thus obtained were subjected to the same operation as in Example 1 to prepare a toner, and the same evaluation was performed. In particular, although fog was slightly deteriorated, it was at a level of no practical problem.
[0174]
The evaluation results are shown in Table 1.
[0175]
[Example 9]
Until the preliminary heat treatment, the toner particles obtained in the same manner as in Example 1 were treated using a reduced-pressure heat treatment apparatus having the same mode as in FIG.
[0176]
The heat treatment conditions under reduced pressure are as follows: toner mass B: 45 kg, peripheral speed A at the maximum diameter of the stirring member A: 0.06 m / s, A /^Three√B: 0.018 m / (s ·^ThreeThe heat treatment under reduced pressure was performed under the same conditions as in Example 1 except that √kg). At the end of the treatment, the water content was 0.20%, and the total amount of organic volatile components in terms of toluene obtained by the headspace method was 260 ppm.
[0177]
Further, in the obtained toner particles, some toner particles predicted to be consolidated and aggregated due to vacuum were observed. The toner particles thus obtained were subjected to the same operation as in Example 1 to prepare a toner and subjected to the same evaluation. In particular, although slight deterioration of fog was observed, it was at a level causing no practical problem. The evaluation results are shown in Table 1.
[0178]
[Comparative Example 1]
Until the preliminary heat treatment, the toner particles obtained in the same manner as in Example 1 were treated using a reduced-pressure heat treatment apparatus having the same mode as in FIG.
[0179]
The reduced pressure heat treatment conditions were as follows: 30 ° C / 80% RH air was heated to 45 ° C under reduced pressure, and low humidity air with an enthalpy of about 100 kJ / kg (dry air) and a moisture content of about 5% was put into the reduced pressure heat treatment apparatus. A heat treatment under reduced pressure was performed under the same conditions as in Example 3 except that. At the end of the treatment, the water content was 0.19%, and the total amount of organic volatile components in terms of toluene obtained by the headspace method was 515 ppm.
[0180]
Further, the obtained toner particles had no agglomerated particles and were extremely excellent in fluidity. Further, in order to maintain the same degree of decompression as in Example 3, a larger capacity than the vacuum pump used in Example 3 was necessary. The obtained toner particles were subjected to the same operation as in Example 1 to produce a toner, and the same evaluation was performed. As a result, a decrease in image density and a deterioration in fog were observed.
[0181]
[Comparative Example 2]
Until the preliminary heat treatment, the toner particles obtained in the same manner as in Example 1 were treated using a reduced-pressure heat treatment apparatus having the same mode as in FIG.
[0182]
The reduced-pressure heat treatment was performed under the same conditions as in Example 3 except that superheated steam having a temperature of 65 ° C. was charged into the reduced-pressure heat treatment apparatus. At the end of the treatment, the water content was 0.14%, and the total amount of organic volatile components in terms of toluene obtained by the headspace method was 150 ppm.
[0183]
In addition, the obtained toner particles had many agglomerated toner particles mixed therein. The obtained toner particles were subjected to the same operation as in Example 1 to produce a toner, and the same evaluation was performed. As a result, a decrease in image density and a deterioration in fog were observed. The evaluation results are shown in Table 1.
[0184]
[Comparative Example 3]
Until the preliminary heat treatment, the toner particles obtained in the same manner as in Example 1 were treated using a reduced-pressure heat treatment apparatus having the same mode as in FIG.
[0185]
The heat treatment conditions under reduced pressure are as follows: toner mass B: 45 kg, peripheral speed A at the maximum diameter of the stirring member A: 0.031 m / s, A /^Three√B: 0.0088 m / (s ·^ThreeA vacuum heat treatment was performed under the same conditions as in Example 3 except that √kg). At the end of the treatment, the water content was 0.2%, and the total amount of organic volatile components in terms of toluene obtained by the headspace method was 200 ppm.
[0186]
In addition, the obtained toner particles were mixed with a lot of toner particles predicted to be consolidated and aggregated due to vacuum. Further, the organic volatile component of the aggregated toner particles was measured and found to be 320 ppm.
[0187]
The obtained toner particles were subjected to the same operation as in Example 1 to produce a toner, and the same evaluation was performed. As a result, a decrease in image density and a decrease in fogging were observed. The evaluation results are shown in Table 1.
[0188]
[Comparative Example 4]
Until the preliminary heat treatment, the toner particles obtained in the same manner as in Example 1 were treated using a reduced-pressure heat treatment apparatus having the same mode as in FIG.
[0189]
The heat treatment conditions under reduced pressure are as follows: toner mass B: 45 kg, peripheral speed A: 2.39 m / s at the maximum diameter of the stirring member, A /^Three√B: 0.67 m / (s ·^ThreeA vacuum heat treatment was performed under the same conditions as in Example 3 except that √kg). At the end of the treatment, the water content was 0.15%, and the total amount of organic volatile components in terms of toluene obtained by the headspace method was 150 ppm.
[0190]
In addition, the obtained toner particles were mixed with a large number of toner particles predicted to be thermally aggregated.
[0191]
The obtained toner particles were subjected to the same operation as in Example 1 to produce a toner, and the same evaluation was performed. As a result, a decrease in image density and a decrease in fogging were observed. The evaluation results are shown in Table 1.
[0192]
[Table 1]

[0193]
【The invention's effect】
According to the present invention, there is provided a method for producing toner particles in which all volatile components present in the toner particles obtained by the polymerization method are uniformly reduced in a short time, and at the same time, toner particles free from aggregation and deterioration can be obtained. realizable.
[0194]
In addition, according to the present invention, it is possible to realize a toner particle manufacturing method capable of obtaining a high-quality image free from image defects caused by residual volatile components and aggregated / deteriorated toner particles.
[0195]
In addition, according to the present invention, it is possible to reduce the energy and cost required for removing the volatile components.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing an example of an apparatus that disperses toner particles in a granular form in a hot air stream and heat-treats the toner particles while sending them in parallel with a high-speed air stream.
FIG. 2 is a schematic diagram showing an example of an apparatus that performs a heat treatment under reduced pressure while introducing an injection medium.
[Explanation of symbols]
1. Discharge blower
2. Hot air generator
3. Airflow dispersion part
4). Air outlet
5). Loop type air heating tube
6). Raw material supply equipment
7). Cyclone
8). Outlet
9. Bag filter
10. Exhaust blower
11. Vacuum heat treatment container
12 Drive motor
13. Stirring center axis
14 Ribbon wings
17. Raw material supply port
18. Bug filter
19. condenser
20. Jacket
21. Hot water tank
22. Decompression pump
23. Divider
24. Filter cloth
25. Backwash nozzle
26. Injection medium heater
27. separator
28. Expansion tank
29. Dispersion board
36. Injection medium flow meter

Claims (19)

Toner particles produced in the aqueous dispersion medium are washed and dehydrated, and the resulting wet toner particles are supplied to a container, saturated water vapor, superheated water vapor at a temperature lower than the glass transition temperature Tg of the toner particles, Alternatively, an organic medium at a toner particle heating temperature of 150 ° C. by the headspace method is obtained by performing a reduced pressure heat treatment while introducing an injection medium selected from the group consisting of high humidity air of enthalpy 2500 kJ / kg (dry air) or more into the container. In the volatile component analysis, the total amount of organic volatile components in terms of toluene based on the mass of the toner particles is set to 500 ppm or less , the container has a stirring means, and the stirring means is provided in the container. When the peripheral speed at the maximum diameter of the stirring member is A (m / s) and the mass of the toner particles in the container is B (kg),
^{0.01 (m / (s · 3} √kg)) ≦ A / 3 √B ≦ 0.6 (m / (s · 3 √kg))
A method for producing toner particles, wherein the treatment is carried out under conditions satisfying the relationship :   The method for producing toner particles according to claim 1, wherein the high-humidity air has a moisture content of 50% or more.   The method for producing toner particles according to claim 1, wherein the high-humidity air has a moisture content of 60% or more.   2. The method for producing toner particles according to claim 1, wherein the enthalpy of the high humidity air is 6500 kJ / kg (dry air) or more.   2. The method for producing toner particles according to claim 1, wherein high-humidity air has a water content of 50% or more and an enthalpy of 6500 kJ / kg (dry air) or more.   2. The method for producing toner particles according to claim 1, wherein the high humidity air has a water content of 60% or more and an enthalpy of 6500 kJ / kg (dry air) or more.   2. The method for producing toner particles according to claim 1, wherein the high humidity air has a water content of 80% or more and an enthalpy of 6500 kJ / kg (dry air) or more. When the stirring means is performed using a stirring member provided in the container, the peripheral speed at the maximum diameter of the stirring member is A (m / s), and the mass of the toner particles in the container is B (kg) ,
^{0.04 (m / (s · 3} √kg)) ≦ A / 3 √B ≦ 0.5 (m / (s · 3 √kg))
Method for producing toner particles according to any one of claims 1 to 7, characterized in that the process under the conditions satisfying the relationship. Supply flow rate of the injection ^{medium, 0.01~0.5m 3 / (hr · kg} ( toner particles)) The method of producing toner particles according to any one of claims 1 to 8, characterized in that a. Supply flow rate of the injection ^{medium, 0.03~0.27m 3 / (hr · kg} ( toner particles)) The method of producing toner particles according to any one of claims 1 to 8, characterized in that a. Method for producing toner particles according to any one of claims 1 to 10, characterized in that the organic volatile components the total amount of the toluene conversion below 400 ppm. Method for producing toner particles according to any one of claims 1 to 10, characterized in that the organic volatile components the total amount of the toluene converted to 300ppm or less. Before heating under reduced pressure, by performing preliminary heat treatment, the water content of the toner particles to be supplied to the reduced pressure heat treatment, any one of claims 1 to 12, characterized in that 3.0% or less 2. A method for producing toner particles according to 1. The water content of the toner particles to be supplied to the reduced pressure heat treatment method of the toner particles according to any one of claims 1 to 13, characterized in that 1.0% or less. The preliminary heat treatment is a method in which wet toner particles are dispersed in a high-speed hot air stream and simultaneously heated while being sent simultaneously. The wet toner particles are continuously supplied into the high-speed hot air stream. the method of the toner particles according to any one of claims 1 to 14, characterized in that can be processed. 16. The method for producing toner particles according to claim 1, wherein the polymerization initiator used for the polymerization in the aqueous medium is a peroxide polymerization initiator. Polymerizable monomer composition, method for producing toner particles according to any one of claims 1 to 16, characterized in that it contains at least a polymerizable monomer and a colorant and a magnetic material. The method for producing toner particles according to claim 17 , wherein the magnetic material is hydrophobized with a coupling agent. The method for producing toner particles according to claim 17 or 18 , wherein the magnetic substance in the magnetic toner is treated with a silane coupling agent having a double bond.

Images