JP2004226493A - Toner and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner and a method for manufacturing the same in which discharge of a colorant into a water layer and flocculation are suppressed and by which a toner having a uniform colorant content is efficiently and stably obtained. <P>SOLUTION: The method for manufacturing a toner comprises a process of obtaining a mixture by mixing a colorant with a synthetic resin, wherein the number of gram equivalents of acidic or basic dissociating groups per unit weight of the colorant is smaller than the number of gram equivalents of acidic or basic dissociating groups per unit weight of the synthetic resin, a process of neutralizing the mixture obtained by the above process, a process of forming colorant-containing synthetic resin particles by inverse emulsification of the mixture neutralized by the above process by adding water to the neutralized mixture, and a process of separating the particles formed by the above process from the water and drying these. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０１０３】
画像サンプルの評価は、以下のようにして行なった。
画像サンプルの光学濃度は、「Ｘ−Ｒｉｔｅ９３８分光測色濃度計」（日本平版印刷機材社製）により測定し、光学濃度が１．５以上あれば、良好と判断した。
画像サンプルの白地カブリは、黒トナーの場合は、Ａ４サイズの前記専用紙の白度を、予め「白度計」（日本電色工業社製）にて測定し、その値を第１測定値とする。次に、直径５５ｍｍの白円を含む原稿を用いて、３枚複写し、得られたコピーサンプルの白部を前記白度計にて測定し、この値を第２測定値とする。第１測定値から第２測定値を差し引いた値をカブリの値とし、その値が２．０以下であれば、良好と判断した。カラートナーの場合は、目視にて、判断を行った。
【０１０４】
画像サンプルの顔料分散性は、トナー付着量１．７ｍｇ／ｃｍ^２ になるようにＯＨＰシート上に画像を作製し、「ＨＡＺＥメーター」（日本電色工業株式会社製、ｍｏｄｅｌＮＤＨ２０００）を用いて、ＨＡＺＥ値（曇度）を測定し、これを指標とした。ＨＡＺＥ値は小さい程、透過性がよいことを示しており、２０以下の場合は良好である、１５以下は極めて透明性が高く、顔料分散性も良好であると判断した。ＨＡＺＥ値が２５を超えると、カラートナーとしての実用性に欠ける。
【０１０５】
転写率は所定チャートにて複写したサンプルの紙面上のトナー重量Ｍｐと感光体上に残存したトナー重量Ｍｄから計算し、８５％以上の場合、合格と判断した。
転写率は、次式により求める。
転写率＝（１００ ×Ｍｐ）／（Ｍｄ＋Ｍｐ）
【０１０６】
上述した評価基準に基づき評価を行なった結果、表１に示したように、実施例１乃至３は合格であり、比較例１乃至３は不合格であることが判った。
以上のように、本発明に係るトナーの製造方法によれば、高精細画像に使用し得る小粒径で粒子径分布が狭く、しかも、転写性、流動性及び帯電環境安定性に優れた静電荷現像用トナーを簡便なるプロセスによって製造することができる。
そして、トナー内に着色剤が均一に分散しているので、トナーの着色剤含有量が高い場合においても、カブリや画像濃度ムラがなく、画像形成時のトナーの消費量が少なくてすむ。また、製造工程において、合成樹脂本来の定着性を損ねることもない。
【０１０７】
【発明の効果】
以上、詳述したように、本発明による場合は、単位重量当たりの酸性解離基又は塩基性解離基のグラム当量数が、合成樹脂の単位重量当たりの酸性解離基又は塩基性解離基のグラム当量数より少ない着色剤を合成樹脂に混合するので、転相乳化時に着色剤の方が合成樹脂より親水性が低く、着色剤が水層に排出されて凝集することが抑制され、安定的に、均一に着色剤が合成樹脂に内包されたトナーが得られる。
トナーの着色剤含有量が安定して、均一であるので、このトナーを用いて画像を形成した場合、良好な画像が得られる。また、トナー内に着色剤が均一に分散しているので、トナーの着色剤含有量が高い場合においても、カブリや画像濃度ムラがなく、画像形成時のトナーの消費量が少なくてすむ。
【０１０８】
そして、本発明による場合は、高精細画像に使用し得る小粒径で粒子径分布が狭く、しかも、転写性、流動性及び帯電環境安定性に優れた静電荷現像用トナーを簡便なるプロセスによって製造することができる。
また、製造工程において、合成樹脂本来の定着性を損ねることがない。
【０１０９】
また、本発明による場合は、合成樹脂を溶剤に溶解して得られた溶液に、着色剤を混合させて混合物を得るので、合成樹脂と着色剤とを溶融混練により混合させることなく、容易に混合させることができる。
【０１１０】
そして、本発明による場合は、合成樹脂を溶解する第１有機溶剤と、該第１有機溶剤より親水性が高い第２有機溶剤との混合物を溶剤として用いるので、転相乳化工程時に転相がし易くなり、得られるトナーの形態及び粒度分布が良好になる。
【０１１１】
さらに、本発明による場合は、第１有機溶剤の重量％を第２有機溶剤の重量％より大きくするので、さらに転相乳化工程時に転相がし易くなり、得られるトナーの形態及び粒度分布が良好になる。
【０１１２】
また、本発明による場合は、合成樹脂の粒子を生成した後に、中和された酸性解離基又は塩基性解離基を逆中和する過程を有するので、乾燥工程で粒子が凝集し、融着するのが防止されるとともに、空気中の水分の影響を受けることなく、良好な帯電性を有するトナーが得られる。
【０１１３】
そして、本発明による場合は、ポリエステル系の合成樹脂を少なくとも含む合成樹脂を用いるので、粉体流動性及び定着性等のバランスが良いトナーを容易に得ることができ、カラートナーにも適用可能であるトナーを得ることができる。
【０１１４】
さらに、本発明による場合は、カルボキシル基及びスルホン酸基の１又は複数を含む合成樹脂を用いるので、中和されやすく、合成樹脂の親水性が高くなり、合成樹脂と着色剤との混合物が容易に転相乳化されて、トナーが生成される。
【０１１５】
また、本発明による場合は、アンモニウム基を含む合成樹脂を用いるので、中和されやすく、合成樹脂の親水性が高くなり、合成樹脂と着色剤との混合物が容易に転相乳化されて、トナーが生成される。
【０１１６】
そして、本発明による場合は、ブラック、シアン、イエロー及びマゼンタの１又は複数の色材を含む着色剤を用いるので、黒又はカラーの画像を良好に形成することができるトナーが得られる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a toner for developing an electrostatic latent image, which contains a binding synthetic resin and a colorant and is used for image formation by electrophotography or the like, and a method for producing the same.
[0002]
[Prior art]
As the electrostatic charge image developer, a two-component developer containing toner and carrier particles and a one-component developer containing magnetic toner or non-magnetic toner are known.
The toner production method is roughly divided into a dry method and a wet method. As the dry method, a pulverization method in which a synthetic resin for binding and a colorant are kneaded, pulverized and classified, and a wet method are used. A polymerization method for obtaining a toner by including a colorant or the like during polymerization of a synthetic resin to be worn is known.
[0003]
In addition, there is a phase inversion emulsification method described in Patent Document 1 as a wet method. This is done by dissolving a self-water-dispersible synthetic resin and a coloring agent in an organic solvent and dispersing them, adding a neutralizing agent that neutralizes the dissociating groups of the synthetic resin, and adding water while stirring. In this method, droplets of a synthetic resin containing a colorant and the like are phase-inverted and emulsified to produce fine particles, which are dried to obtain a toner. Since this method includes a step of producing a toner in an aqueous solution, the colorant is required to be incorporated into the synthetic resin after phase inversion.
[0004]
[Patent Document 1]
Japanese Patent No. 3063269
[0005]
[Problems to be solved by the invention]
However, when toner is produced by the phase inversion emulsification method described above, a toner containing a colorant cannot be produced depending on the combination of the synthetic resin and the colorant, and a desired amount of colorant is encapsulated in the synthetic resin particles. There were problems such as difficulty.
When water is allowed to act in the phase inversion emulsification step, the colorant that is in a dispersed state in the organic layer aggregates, or a huge aggregate is generated near the surface of the toner, so that the colorant is uniformly applied to the toner. It is confirmed that the image forming property is deteriorated when the colorant content is different between toners or the colorant content is reduced.
[0006]
In order to efficiently and uniformly encapsulate the colorant in the binder synthetic resin, it is necessary to prevent the colorant from being discharged into the aqueous layer in the phase inversion emulsification step.
The present invention has been made in view of such circumstances, and the number of gram equivalents of acidic dissociable groups or basic dissociable groups per unit weight is the grams of acidic dissociable groups or basic dissociable groups per unit weight of the synthetic resin. By using less colorants than the number of equivalents, the colorant has lower hydrophilicity than the synthetic resin during phase inversion emulsification, and the colorant is prevented from being aggregated by being discharged into the aqueous layer. An object of the present invention is to provide a toner that is high and uniform and a method for producing the same.
[0007]
In addition, the present invention provides a mixture obtained by dissolving a synthetic resin in a solvent to obtain a mixture, thereby easily mixing the synthetic resin and the colorant without melting and kneading. It is an object of the present invention to provide a toner manufacturing method that can be used.
[0008]
In the present invention, the solvent is a mixture of the first organic solvent that dissolves the synthetic resin and the second organic solvent that is more hydrophilic than the first organic solvent, so that the phase inversion is performed during the phase inversion emulsification step. It is an object of the present invention to provide a method for producing a toner that is easy to form and has a good shape and particle size distribution of the obtained toner.
[0009]
Furthermore, according to the present invention, by making the weight percentage of the first organic solvent larger than the weight percentage of the second organic solvent, the phase inversion is facilitated during the phase inversion emulsification step, and the resulting toner has a good morphology and particle size distribution An object of the present invention is to provide a method for producing a toner.
[0010]
In addition, the present invention has a process of reversely neutralizing the neutralized acidic dissociation group or basic dissociation group after generating the synthetic resin particles, so that the particles are aggregated and fused in the drying step. It is an object of the present invention to provide a toner manufacturing method capable of preventing toner and obtaining a toner having good chargeability without being affected by moisture in the air.
[0011]
The present invention can easily obtain a toner having a good balance of powder fluidity and fixability by using a synthetic resin containing at least a polyester-based synthetic resin, and can also be applied to a color toner. It is an object of the present invention to provide a toner manufacturing method capable of obtaining a toner.
[0012]
Furthermore, in the present invention, by using a synthetic resin containing one or both of a carboxyl group and a sulfonic acid group, it is easily neutralized, the hydrophilicity of the synthetic resin is increased, and a mixture of the synthetic resin and the colorant is easily obtained. An object of the present invention is to provide a method for producing a toner to be phase-emulsified.
[0013]
In addition, the present invention provides a toner in which a synthetic resin containing an ammonium group is easily neutralized, the hydrophilicity of the synthetic resin is increased, and the mixture of the synthetic resin and the colorant is easily phase-inverted and emulsified. It aims to provide a method.
[0014]
The present invention also relates to a method for producing a toner by which a toner capable of satisfactorily forming a black or color image is obtained by using a colorant containing one or more coloring materials of black, cyan, yellow and magenta. The purpose is to provide.
[0015]
[Means for Solving the Problems]
The toner of the present invention essentially comprises a synthetic resin having acidic dissociable groups and a colorant having a number of gram equivalents of acidic dissociable groups per unit weight less than the number of gram equivalents of acidic dissociable groups per unit weight of the synthetic resin. The mixture as a component is neutralized, water is added to the neutralized mixture, phase inversion emulsification is performed to produce particles of the synthetic resin containing the colorant, and then the particles are separated from water and dried. It is characterized by letting it be.
[0016]
In the present invention, the number of gram equivalents of acidic dissociation groups per unit weight of the colorant is less than that of the synthetic resin, and the colorant is synthesized when the mixture containing the synthetic resin and the colorant as essential components is neutralized. Since the hydrophilicity is lower than that of the resin, when the neutralized mixture is subjected to phase inversion emulsification, the colorant is prevented from being discharged into the aqueous layer and agglomerating, and the colorant is stably and uniformly encapsulated in the synthetic resin. Toner is obtained.
Therefore, since the colorant content of the toner is stable, high and uniform, a good image can be obtained when an image is formed using this toner.
[0017]
The toner of the present invention is a colorant in which the number of gram equivalents of basic dissociation groups per unit weight of the synthetic resin having a basic dissociation group is less than the number of gram equivalents of basic dissociation groups per unit weight of the synthetic resin. After neutralizing the mixture containing the essential components, water is added to the neutralized mixture, and phase inversion emulsification is performed to produce particles of the synthetic resin containing the colorant, and then the particles are separated from the water. And dried.
[0018]
In the present invention, the number of gram equivalents of the basic dissociation group per unit weight of the colorant is less than that of the synthetic resin, and when the mixture containing the synthetic resin and the colorant as an essential component is neutralized, the colorant is better. Since the hydrophilicity is lower than that of synthetic resins, when phase-inversion emulsification of the neutralized mixture, the colorant is prevented from being discharged into the aqueous layer and agglomerated, and the colorant is included in the synthetic resin stably and uniformly. The obtained toner is obtained.
Therefore, since the colorant content of the toner is stable, high and uniform, a good image can be obtained when an image is formed using this toner.
[0019]
The toner production method of the present invention includes a synthetic resin having an acid dissociable group and a colorant having a number of gram equivalents of acid dissociable groups per unit weight less than the number of gram equivalents of acid dissociable groups per unit weight of the synthetic resin. A mixing process for obtaining a mixture comprising the essential components, a process for neutralizing the mixture obtained by the process, phase-emulsifying by adding water to the mixture neutralized by the process, The method includes a process of generating encapsulated synthetic resin particles, and a process of separating the particles generated by the process from water and drying.
[0020]
In the present invention, the number of gram equivalents of the acid dissociable group of the colorant is less than the number of gram equivalents of the acid dissociable group of the synthetic resin, and when neutralized, the colorant is less hydrophilic than the synthetic resin. When the phase inversion emulsification is performed, the colorant is prevented from being discharged into the aqueous layer and aggregating.
Therefore, a toner having an efficient, stable, high and uniform colorant content can be produced. When an image is formed using this toner, a good image can be obtained.
[0021]
In the method for producing the toner of the present invention, the number of gram equivalents of the basic dissociation group per unit weight of the synthetic resin and the number of gram equivalents of the basic dissociation group per unit weight of the synthetic resin having the basic dissociation group A mixing process for obtaining a mixture containing a small amount of a colorant as an essential component, a process for neutralizing the mixture obtained by the process, phase-inversion emulsification by adding water to the mixture neutralized by the process, and the colorant Characterized in that it comprises a step of producing particles of the synthetic resin encapsulating and a step of separating the particles produced by the step from water and drying.
[0022]
In the present invention, the gram equivalent number of the basic dissociation group of the colorant is less than the gram equivalent number of the basic dissociation group of the synthetic resin, and when neutralized, the colorant is less hydrophilic than the synthetic resin. When the mixture is subjected to phase inversion emulsification, the colorant is prevented from being discharged into the aqueous layer and agglomerating.
Therefore, a toner having an efficient, stable, high and uniform colorant content can be produced. When an image is formed using this toner, a good image can be obtained.
[0023]
The method for producing a toner of the present invention includes a synthetic resin in which some or all of the acidic dissociable groups are neutralized, and the number of gram equivalents of acidic dissociable groups per unit weight is determined by the acidic dissociation per unit weight of the synthetic resin. A mixing process for obtaining a mixture containing a coloring agent less than the number of gram equivalents of the group as an essential component, and adding the water to the mixture obtained by the process for phase inversion emulsification, and the synthetic resin containing the coloring agent And a process of separating the particles generated by the process from water and drying.
[0024]
In the present invention, the number of gram equivalents of the acid dissociation group of the colorant is less than the number of gram equivalents of the acid dissociation group of the synthetic resin, and the acid dissociation group of the synthetic resin is neutralized. The hydrophilicity is lower, and when the mixture is phase-inverted and emulsified, the colorant is prevented from being discharged into the aqueous layer and agglomerating.
Therefore, it is possible to produce a toner having an efficient, stable, high and uniform colorant content.
[0025]
The method for producing the toner of the present invention comprises a synthetic resin in which a part or all of the basic dissociating groups are neutralized, and the number of gram equivalents of the basic dissociating groups per unit weight is determined by A mixing process for obtaining a mixture containing an essential component with a colorant having a gram equivalent number less than the number of gram-dissociating groups, and phase-inversion emulsification by adding water to the mixture obtained by the process, and the colorant is included in the mixture It has the process of producing | generating the particle | grains of a synthetic resin, and the process of isolate | separating the particle | grains produced | generated by this process from water, and drying.
[0026]
In the present invention, the number of gram equivalents of the basic dissociation group of the colorant is less than the number of gram equivalents of the basic dissociation group of the synthetic resin, and the basic dissociation group of the synthetic resin is neutralized. However, the hydrophilicity is lower than that of the synthetic resin, and when the mixture is phase-inverted and emulsified, the colorant is prevented from being discharged into the aqueous layer and aggregating.
Therefore, it is possible to produce a toner having an efficient, stable, high and uniform colorant content.
[0027]
The toner manufacturing method of the present invention is characterized in that the mixing step is a step of mixing a colorant with a solution obtained by dissolving a synthetic resin in a solvent to obtain a mixture.
[0028]
In the present invention, the synthetic resin and the colorant can be easily mixed without being mixed by melt kneading.
[0029]
In the method for producing a toner of the present invention, the solvent is a mixture of a first organic solvent that dissolves the synthetic resin and a second organic solvent that is more hydrophilic than the first organic solvent.
In the present invention, phase inversion is facilitated during the phase inversion emulsification step, and the resulting toner has a good morphology and particle size distribution.
[0030]
The toner manufacturing method of the present invention is characterized in that the first organic solvent has a larger weight percentage of the first organic solvent and the second organic solvent.
In the present invention, phase inversion is facilitated during the phase inversion emulsification step, and the resulting toner has a good morphology and particle size distribution.
[0031]
The toner production method of the present invention is characterized by having a step of reverse neutralizing the neutralized acidic dissociation group or basic dissociation group after producing the synthetic resin particles.
In the present invention, the particles are prevented from aggregating and fusing in the drying step, and a toner having good chargeability can be obtained without being affected by moisture in the air.
[0032]
The method for producing a toner of the present invention is characterized in that the synthetic resin includes at least a polyester-based synthetic resin.
In the present invention, it is possible to easily obtain a toner having a good balance of powder fluidity and fixing property. The obtained toner can be fixed at a low temperature by taking advantage of sharp melt properties, and is excellent in transparency and secondary color reproducibility, so that a toner applicable to color toner can be obtained.
[0033]
The method for producing a toner of the present invention is characterized in that the synthetic resin contains one or both of a carboxyl group and a sulfonic acid group.
In the present invention, the resin is easily neutralized, the hydrophilicity of the synthetic resin is increased, and the mixture of the synthetic resin and the colorant is easily phase-inverted and emulsified.
[0034]
The method for producing a toner of the present invention is characterized in that the synthetic resin contains an ammonium group.
In the present invention, the resin is easily neutralized, the hydrophilicity of the synthetic resin is increased, and the mixture of the synthetic resin and the colorant is easily phase-inverted and emulsified.
[0035]
The toner manufacturing method of the present invention is characterized in that the colorant includes one or a plurality of color materials of black, cyan, yellow, and magenta.
In the present invention, a toner capable of satisfactorily forming a black or color image is obtained.
[0036]
DETAILED DESCRIPTION OF THE INVENTION
The synthetic resin applied to the toner of the present invention has a hydrophilic acidic dissociation group or basic dissociation group in the molecular chain, and when the dissociation group is acidic, a basic neutralizing agent is used. Is a synthetic resin that exhibits self-water dispersibility by neutralizing with an acidic neutralizing agent so that the dissociation group forms a salt, thereby improving hydrophilicity.
Moreover, the dissociation group may be partially or wholly neutralized from the beginning, and a synthetic resin that can be dispersed in water without passing through a neutralization step may be used.
[0037]
The degree of hydrophilicity improved by neutralizing the acidic dissociating group or basic dissociating group must be such that the synthetic resin itself can be dispersed in water. By mixing the self-water-dispersible synthetic resin thus obtained with water, phase inversion emulsification occurs, and particles are generated in water.
For example, in a self-dispersible polyester-based synthetic resin, in water, a hydrophilic dissociation group appears on the surface of the synthetic resin particle, and the particle is stabilized in such a form as to enclose a hydrophobic portion.
[0038]
The effect of the self-water dispersibility is the same when neutralizing dissociative groups in the synthetic resin with a neutralizing agent and when using a synthetic resin having a salt structure neutralized from the beginning.
[0039]
Examples of the neutralizing agent include ammonia, sodium hydroxide, potassium hydroxide, triethylamine and the like when the synthetic resin has an acidic dissociation group, and examples of the neutralizing agent include hydrochloric acid and acetic acid when the synthetic resin has a basic dissociation group. Etc. These neutralizing agents neutralize a predetermined amount of hydrophilic dissociation groups in the synthetic resin.
[0040]
The hydrophilicity of the self-water dispersible synthetic resin can be adjusted by the number of gram equivalents of the hydrophilic dissociating group in the synthetic resin and the neutralization rate thereof, thereby controlling the size of the particles when dispersed. .
The number of gram equivalents of the hydrophilic dissociation group (acid dissociation group or basic dissociation group) possessed by the synthetic resin is not particularly limited, but is preferably 10 mg equivalent to 1000 mg equivalent per 100 g of the synthetic resin solid content.
Furthermore, the number of gram equivalents of neutralizing acidic dissociable groups or basic dissociating groups required for the synthetic resin to exhibit self-water dispersibility depends on the molecular structure, molecular weight, etc. of the synthetic resin itself. Since the hydrophilicity is different, it differs depending on the synthetic resin, but is usually 1 mg equivalent to 500 mg equivalent to 100 g of the synthetic resin solid content.
[0041]
The glass transition temperature of the self-water dispersible synthetic resin is preferably 30 to 100 ° C., and the synthetic resin having a weight average molecular weight of 5,000 to 500,000 is preferably used.
[0042]
Specific examples of the synthetic resin that becomes self-dispersible by neutralization include, for example, polyester synthetic resins, polyurethane synthetic resins, epoxy synthetic resins, styrene-acrylic synthetic resins, and the like. Among these, a polyester synthetic resin that is easy to obtain a balance of powder fluidity and fixing property as a toner is preferable. Moreover, you may use the synthetic resin which grafted both taking advantage of both the polyester synthetic resin and the styrene-acrylic copolymer. By using a polyester synthetic resin, low-temperature fixing utilizing sharp melt properties is possible, and transparency and secondary color reproducibility are excellent, so that it can also be applied to color toners.
[0043]
A known colorant can be used as the colorant applied to the toner of the present invention, but there is no particular limitation as long as it is a dye or pigment conventionally used as a toner material. Such organic or inorganic dyes and pigments can be used.
[0044]
That is, examples of the black colorant include carbon black, copper oxide, manganese dioxide, aniline black, activated carbon, nonmagnetic ferrite, magnetic ferrite, and magnetite.
Yellow colorants include chrome yellow, zinc yellow, cadmium yellow, yellow iron oxide, mineral fast yellow, nickel titanium yellow, navel yellow, naphthol yellow S, Hansa Yellow G, Hansa Yellow 10G, Benzidine Yellow G, Benzidine Yellow GR Quinoline yellow lake, permanent yellow NCG, tartrazine lake, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 13, C.I. I. Pigment yellow 14, C.I. I. Pigment yellow 15, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 93, C.I. I. Pigment yellow 94, C.I. I. And compounds such as CI Pigment Yellow 138.
[0045]
Examples of the orange colorant include red yellow lead, molybdenum orange, permanent orange GTR, pyrazolone orange, Vulcan orange, Indanthrene Brilliant Orange RK, Benzidine Orange G, Indanthrene Brilliant Orange GK, C.I. I. Pigment orange 31, C.I. I. And compounds such as CI Pigment Orange 43.
Red colorants include bengara, cadmium red, red lead, mercury sulfide, cadmium, permanent red 4R, risor red, pyrazolone red, watching red, calcium salt, lake red C, lake red D, brilliant carmine 6B, eosin Lake, Rhodamine Lake B, Alizarin Lake, Brilliant Carmine 3B, C.I. I. Pigment red 2, C.I. I. Pigment red 3, C.I. I. Pigment red 5, C.I. I. Pigment red 6, C.I. I. Pigment red 7, C.I. I. Pigment red 15, C.I. I. Pigment red 16, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 53: 1, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 123, C.I. I. Pigment red 139, C.I. I. Pigment red 144, C.I. I. Pigment red 149, C.I. I. Pigment red 166, C.I. I. Pigment red 177, C.I. I. Pigment red 178, C.I. I. And compounds such as CI Pigment Red 222.
[0046]
Examples of purple colorants include compounds such as manganese purple, fast violet B, and methyl violet lake.
Blue colorants include bitumen, cobalt blue, alkali blue lake, Victoria blue lake, phthalocyanine blue, metal free phthalocyanine blue, phthalocyanine blue partially chlorinated, first sky blue, induslen blue BC, C.I. I. Pigment blue 15, C.I. I. Pigment blue 15: 2, C.I. I. Pigment blue 15: 3, C.I. I. Pigment blue 16, C.I. I. And compounds such as CI Pigment Blue 60.
[0047]
Examples of green colorants include chromium green, chromium oxide, pigment green B, micalite green lake, final yellow green G, C.I. I. And compounds such as CI Pigment Green 7.
Examples of the white colorant include compounds such as zinc white, titanium oxide, antimony white, and zinc sulfide.
[0048]
However, when the colorant shows stronger acidity or stronger basicity than a synthetic resin that exhibits self-water dispersibility by neutralization, it was in a dispersed state in the organic layer when water was allowed to act in the phase inversion emulsification step. The colorant aggregates, generating huge aggregates near the surface of the toner, adversely affecting the dispersion state of the colorant in the toner, and the colorant is not taken into the synthetic resin uniformly. The amount may be different or the colorant content may be reduced. It has been confirmed that variations in the colorant content of individual toners due to deterioration in the dispersion state of the colorant cause a decrease in image quality.
[0049]
Therefore, the colorant is more acidic or more unit weight than the number of grams or the number of gram equivalents of basic dissociation groups of the self-water-dispersible synthetic resin or the synthetic resin that becomes a self-water-dispersible synthetic resin by neutralization. Select those with a low number of gram equivalents of basic dissociation groups.
Specifically, when the synthetic resin used is acidic (in the case of a synthetic resin that has an acid dissociable group in an unneutralized state and becomes self-water-dispersible by neutralization with a base), On the other hand, if the synthetic resin used is basic (having a basic dissociation group in an unneutralized state and neutralizing with acid, it becomes self-water-dispersible. In the case of a synthetic resin), it is important to use a colorant having a weaker basicity than this, and after neutralization, the colorant is less hydrophilic than the synthetic resin. During the emulsification step, the colorant is prevented from being discharged into the aqueous layer and agglomerating, and the problem of a decrease in the colorant content and nonuniformity of the toner can be solved.
[0050]
In addition, as a method for quantitatively measuring the acid basicity of the surface of the colorant, potentiometric titration is used. This makes it possible to grasp the amount of dissociative groups that show acidity or basicity on the surface of the colorant, and by controlling the acidity and basicity of the colorant, it has the same colorant content for each production. Toner can be produced.
[0051]
Among the colorants that can be used in the present invention, the basic colorant having a base amount greater than the acid amount is, for example, a pH> 7, preferably 8 or more, while the acid amount is greater than the base amount. For example, those having pH <7, preferably 6 or less are used. Some colorants are surface-treated and surface polarity is changed, and it is convenient to use them after confirming the acid amount and base amount of the colorant before use. At this time, the number of gram equivalents of acidic dissociation groups or basic dissociation groups per unit weight is set so that the colorant is smaller than the synthetic resin.
[0052]
The colorant is not necessarily a single component, and in some cases, a plurality of components may be used. In this case as well, the number of gram equivalents of acidic or basic dissociation groups per unit weight of all components of the colorant is the unit of the synthetic resin. What is necessary is just to make it lower than the gram equivalent number of the acidic or basic dissociation group per weight.
[0053]
The particle diameter of the colorant can be selected as appropriate, but generally, the colorant having an average primary particle diameter of 10 to 100 nm is used. However, since the number of dissociating groups appearing on the surface changes as the particle size changes, and the acid basicity of the colorant changes, the particle size corresponding to the desired acid basicity is selected.
[0054]
Next, polyester synthetic resin will be described in detail as an example.
The polyester-based synthetic resin that can be applied to the toner of the present invention and becomes self-dispersible by neutralization is an emulsifier or dispersion stabilizer due to the action of a dissociating group present in the synthetic resin molecule and having increased hydrophilicity by neutralization. It is possible to form stable particles in water without substantially using.
[0055]
Self-water dispersible polyester-based synthetic resins, that is, polyester-based synthetic resins that exhibit self-water dispersibility by neutralization can be synthesized and used by known synthesis methods. For example, a polyester synthetic resin that becomes a self-water dispersible synthetic resin having a carboxyl group as a hydrophilic group is synthesized by a normal polycondensation reaction.
That is, the polybasic acid and polyhydric alcohol as raw materials are subjected to dehydration condensation in the presence of a catalyst in the presence or absence of a solvent. A part of the polybasic acid may be subjected to demethanol polycondensation by using the methyl esterified product.
[0056]
Examples of the polybasic acid used include terephthalic acid, isophthalic acid, phthalic anhydride, trimellitic anhydride, pyromellitic acid, naphthalenedicarboxylic acid and other aromatic carboxylic acids, maleic anhydride, fumaric acid, succinic acid, alkenyl anhydride Examples thereof include aliphatic carboxylic acids such as succinic acid and adipic acid.
Examples of the polyhydric alcohol used include aliphatic polyhydric alcohols such as ethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, and glycerin, cyclohexanediol, cyclohexanedimethanol, hydrogenated bisphenol A, and the like. And aromatic diols such as alicyclic polyhydric alcohols, ethylene oxide adducts of bisphenol A, propylene oxide adducts of bisphenol A, and the like.
[0057]
For example, the content of the terminal carboxyl group can be controlled by the blending ratio and reaction rate of the polybasic acid, which is a raw material of the polyester, and the polyhydric alcohol. Alternatively, a carboxyl group can be easily introduced into the main chain by using trimellitic anhydride.
The polycondensation reaction is terminated when the acid value and the softening point reach predetermined values, and an intended polyester-based synthetic resin that exhibits self-water dispersibility can be obtained.
[0058]
The polyester synthetic resin system has been described above, but urethane synthetic resins, epoxy synthetic resins, acrylic synthetic resins, and the like can be used instead of polyester synthetic resins.
[0059]
When the synthetic resin is a urethane-based synthetic resin, for example, a diol containing an acidic dissociation group or basic dissociation group such as dimethylolpropionic acid or N-methyldiethanolamine, a polyether polyol such as polyethylene glycol, a polyester polyol, Acid dissociation group or basic dissociation by a known method such as addition polymerization with polyisocyanate such as tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate as part of various polyol components such as acrylic polyol and polybutadiene polyol A group-containing urethane synthetic resin is obtained.
[0060]
When the synthetic resin is an epoxy-based synthetic resin, for example, by adding or polymerizing a polyvalent carboxylic acid such as adipic acid or trimellitic anhydride to the base epoxy synthetic resin, or dibutylamine, ethylenediamine Etc. are added or subjected to addition polymerization to obtain an acidic synthetic group-containing or basic dissociable group-containing epoxy synthetic resin.
[0061]
When the synthetic resin is an acrylic synthetic resin, for example, an acrylic polymerizable monomer having an acidic dissociating group or a basic dissociating group and a polymerizable monomer other than the polymerizable monomer having a hydrophilic group are used. A product obtained by radical polymerization of a monomer in the presence of a radical initiator can be used. The polymerization reaction for obtaining it can be appropriately selected from solution polymerization, suspension and emulsion polymerization.
[0062]
The synthetic resin that becomes self-dispersible by neutralization or the self-water-dispersible synthetic resin used may be a single synthetic resin or a mixture of a plurality of resins having different molecular weights and monomer compositions.
Examples of the dissociation group of the self-water dispersible synthetic resin of the present invention include those containing at least one of a carboxyl group, a sulfonic acid group, a sulfuric acid group, an amino group, a quaternary ammonium base, and a sulfonium group.
[0063]
In the present invention, the acid value and hydroxyl value of the synthetic resin are determined, for example, by the following method. The basic operation conforms to Japanese Industrial Standard J1S K 0070, but the reagents used, their types, instruments, etc. are not limited to these.
First, measurement of the acid value of the synthetic resin will be described.
The equipment and instruments used are flasks, burettes, water baths or heaters.
Reagent is 0.1 kmol / m ³ Hydrochloric acid, 0.1 kmol / m ³ Potassium hydroxide ethanol solution (standard is 0.1 kmol / m ³ Take 25 ml of hydrochloric acid into an Erlenmeyer flask using a whole pipette, add phenolphthalein solution, 0.1 kmol / m ³ Titrate with potassium hydroxide ethanol solution, and determine the factor from the amount required for neutralization. ), Phenolphthalein solution, solvent (diethyl ether and ethanol mixed at a volume ratio of 1: 1 or 2: 1. These are added just a few drops of phenolphthalein solution as an indicator just before use, and 0.1 kmol / m ³ Neutralize with potassium hydroxide ethanol solution. ).
[0064]
The acid value of the synthetic resin is measured as follows.
(1) A synthetic resin is precisely weighed in a flask.
(2) Add a few drops of phenolphthalein solution as a solvent and indicator, and shake well until the synthetic resin is completely dissolved in a water bath.
(3) 0.1 kmol / m ³ Titrate with potassium hydroxide ethanol solution, and the end point is when the red color of the indicator no longer disappears.
[0065]
The acid value is calculated according to the following formula.
A = 5.611 × B × f / S
However, A: Acid value (mgKOH / g)
B: 0.1 kmol / m used for titration ³ Amount of potassium hydroxide ethanol solution (ml)
f: 0.1 kmol / m ³ Factor of potassium hydroxide ethanol solution
S: Mass of synthetic resin (g)
5.611: Formula weight of potassium hydroxide 56.11 × 1/10
[0066]
The hydroxyl value of the synthetic resin is measured as follows.
The equipment and instruments used are graduated cylinders, pipettes, flasks and oil baths.
The reagents used are acetylating reagents (for example, acetic anhydride in a flask, pyridine added, and thoroughly shaken), phenolphthalein solution, 0.5 kmol / m. ³ It is a potassium hydroxide ethanol solution.
[0067]
The measurement is performed as follows.
(1) A synthetic resin is precisely weighed in a predetermined amount of flask, and an acetylating reagent is added thereto using a pipette.
(2) The flask is heated by immersing it in an oil bath having a temperature of 95-100 ° C.
(3) After 1 hour, the flask is removed from the oil bath, allowed to cool, water is added and shaken to decompose acetic anhydride.
(4) Further, in order to complete the decomposition, the flask is heated again in an oil bath for 10 minutes, allowed to cool, and then the flask wall is washed with ethanol.
(5) Add a few drops of phenolphthalein solution as an indicator, 0.5 kmol / m ³ Titrate with potassium hydroxide ethanol solution, and the end point is when the light red color of the indicator no longer disappears.
(6) In the blank test, (1) to (5) are performed without adding a synthetic resin.
(7) If the sample is difficult to dissolve, add a small amount of pyridine, or add another solvent such as xylene, toluene, or THF to dissolve it.
[0068]
The hydroxyl value is calculated according to the following formula.
A = [{(BC) × 28.05 × f} / S] + D
However, A: hydroxyl value (mgKOH / g)
B: 0.5 kmol / m used for blank test ³ Amount of potassium hydroxide ethanol solution (ml)
C: 0.5 kmol / m used for titration ³ Amount of potassium hydroxide ethanol solution (ml)
f: 0.5 kmol / m ³ Factor of potassium hydroxide ethanol solution
S: Mass of synthetic resin (g)
D: Acid value
28.05: Formula weight of potassium hydroxide 56.11 × 1/2
[0069]
The number of gram equivalents of dissociated groups per unit weight of the synthetic resin described in this specification can be determined from the acid value and hydroxyl value obtained by using the above potentiometric titration. For example, the gram equivalent number of acidic dissociation groups contained per gram of synthetic resin is the acid value [KOH (mg) used for neutralization] / (1000 × KOH formula amount).
In addition, the solvent for obtaining the number of gram equivalents of the acidic dissociation group and basic dissociation group of the synthetic resin is changed to a solvent that can be dissolved depending on the type of the synthetic resin, and the base and acid of the neutralizing agent are not particularly limited, and are commercially available. Appropriate products can be used.
[0070]
The number of gram equivalents of acidic dissociable groups or basic dissociable groups per unit weight of the colorant can be determined by neutralizing with a base or acid by titration.
For example, the gram equivalent number of all acidic dissociable groups of carbon black can be determined as the amount reacted with a base such as NaOH or KOH.
The method for obtaining the total acidic dissociation group is as follows.
A predetermined amount of carbon black is weighed, a known amount of NaOH aqueous solution is put in a flask, nitrogen is allowed to flow through the flask, and the reaction is performed while stirring with a stirrer. The reaction product is filtered using a membrane filter to obtain a filtrate.
[0071]
The filtrate is taken and titrated with an automatic neutralization titrator using a known concentration of hydrochloric acid to determine the NaOH concentration of the filtrate.
Thereby, the gram equivalent number of all acidic dissociable groups contained in the unit weight of carbon black can be obtained by the following equation.
Gram equivalent number of total acidic dissociable groups / g = (NaOH aqueous solution concentration (N) × NaOH aqueous solution amount (ml) −hydrochloric acid concentration (N) × hydrochloric acid amount (ml)) ÷ (1000 × carbon black weight (g))
[0072]
Further, the gram equivalent number of all basic dissociation groups of carbon black can be determined as the amount reacted with an acid such as hydrochloric acid.
The method for determining the number of gram equivalents of all basic dissociation groups is as follows.
A predetermined amount of carbon black is taken, a known amount of hydrochloric acid is put in a flask, nitrogen is passed through the flask, and the mixture is reacted while stirring with a stirrer. The reaction product is filtered using a membrane filter to obtain a filtrate.
[0073]
The filtrate is taken and titrated with an automatic neutralization titrator using a known concentration of NaOH, KOH or the like to determine the hydrochloric acid concentration of the filtrate.
As a result, the number of gram equivalents of all basic dissociation groups contained in the unit weight of carbon black can be obtained by the following equation.
Gram equivalent number of all basic dissociable groups / g = (hydrochloric acid concentration (N) × hydrochloric acid amount (mL) −NaOH concentration (N) × NaOH amount (ml)) ÷ (1000 × carbon black weight (g))
[0074]
The acid dissociation group of the colorant, the solvent for determining the number of gram equivalents of the basic dissociation group, the base of the neutralizing agent, and the acid are not particularly limited, and any commercially available product can be used. In order to compare the acidic dissociation group and the basic dissociation group of the resin, it is preferable to use the same resin as the synthetic resin.
[0075]
In the present invention, an organic solvent is used as a solvent for dissolving the self-water dispersible synthetic resin.
Any known organic solvent can be used. One kind may be used alone, or two or more kinds may be used.
This is not the case when a solid melt mainly composed of a self-water dispersible synthetic resin and a neutralizing agent are used and neutralized in an aqueous solution and emulsified by phase inversion without using an organic solvent.
[0076]
As the organic solvent, from the viewpoint of ease of phase inversion during phase inversion emulsification, the form (state) of the toner obtained and the good particle size distribution, an organic solvent that dissolves the synthetic resin, and a hydrophilic property from this solvent, It is preferable to use a mixture with an organic solvent (hereinafter referred to as a co-solvent) having a high surface tension reducing property.
[0077]
As the organic solvent, any organic solvent capable of dissolving the self-water dispersible synthetic resin can be used. Preferably, a so-called low boiling point solvent such as methyl ethyl ketone or ethyl acetate, which can be easily removed from the solvent, is preferable. It is also possible to mix two or more solvents.
[0078]
As the co-solvent, for example, an organic solvent that is water-soluble, such as acetone, butanol, isopropyl alcohol, hexanediol, tetrahydrofuran, dimethylformamide, butyl cellosolve, or the like, or has high hydrophilicity and high surface tension reducing ability can be used. A mixture of these two or more solvents may be used.
[0079]
The use of a co-solvent makes it possible to reliably cause phase inversion during phase inversion emulsification, to make the phase inversion proceed smoothly with an extremely low share, and to prevent the generation of irregularly shaped particles. It has an effect of facilitating toner generation, such as easy control of diameter and particle size distribution.
Due to the action of the cosolvent, the hydrophilicity of the self-water dispersible synthetic resin does not need to be increased as the cosolvent is not used, and phase inversion emulsification can be performed in a lower hydrophilic region. This is presumed to be because the mixture with higher hydrophilicity increases the generation of submicron-class fine particles containing a colorant.
[0080]
In the present invention, the weight ratio of the solvent and the cosolvent varies depending on various conditions such as the composition and molecular weight of the synthetic resin to be used, the type of the solvent and the cosolvent, and the temperature at the time of phase inversion. )> Adjusted under the condition of co-solvent (S2).
[0081]
In the present invention, the emulsifier used for phase inversion emulsification is not particularly limited, and any emulsifier and disperser that are generally commercially available can be used. For example, “Ultra Turrax” (manufactured by IKA), “Polytron homogenizer” (manufactured by Kinematica), “TK Autohomomixer” (manufactured by Tokushu Kika Kogyo Co., Ltd.), “National Cooking Mixer” (Matsushita Electric Industrial Co., Ltd.) Etc.) etc., "Ebara Milder" (Ebara Manufacturing Co., Ltd.), "TK Pipeline Homomixer", "TK Homomic Line Flow", "Fill Mix" (above, special machine) Chemical Industry Co., Ltd.), "Colloid Mill" (manufactured by Shinko Pantech Co., Ltd.), "Slasher", "Trigonal Wet and Fine Crusher" (Mitsui Miike Chemical Co., Ltd.), "Cabitron" (Eurotech) ), "Fine Flow Mill" (manufactured by Taiheiyo Kiko Co., Ltd.) and other continuous emulsifiers, "Clearmix" (Mtechnics), "Fillmix" Mechanization Industry Co., Ltd.) and the like of the batch, or continuous dual emulsifier and the like, but is not limited thereto.
[0082]
Examples of other components (additive components) that can be used in the present invention include various auxiliary agents such as charge control agents and mold release agents, and depending on the purpose of use and use conditions, You can select and use.
[0083]
Next, the manufacturing method of this invention is demonstrated below.
First, in the first step, a self-water-dispersible synthetic resin obtained by neutralizing a synthetic resin that becomes self-water-dispersible by neutralization with a neutralizing agent, an organic solvent that dissolves the synthetic resin, and a coloring agent If necessary, a mixture in which other additives are uniformly mixed is prepared.
In the case of a synthetic resin that has an acidic dissociable group and the acidic dissociable group is neutralized with a base to form a self-water dispersible synthetic resin, the number of gram equivalents of the acidic dissociable group per unit weight is the unit of the synthetic resin. Mix with less than a gram equivalent of acid dissociable groups per weight. In the case of a synthetic resin that has a basic dissociation group and this basic dissociation group is neutralized with an acid group to form a self-water dispersible synthetic resin, the number of gram equivalents of the basic dissociation group per unit weight is Less than the gram equivalent of basic dissociation groups per unit weight of the synthetic resin is mixed with a colorant.
[0084]
The colorant is mixed by a known dispersing means such as a dispersing machine.
When obtaining a mixture using an organic solvent, a synthetic resin and an organic solvent are mixed, and a colorant is dispersed by a disperser or the like.
When a mixture is obtained by melt kneading without using an organic solvent, a colorant is further dispersed in the synthetic resin using a kneader.
The synthetic resin is neutralized by a necessary amount with a neutralizing agent before adding water in the next step. In the case of a synthetic resin in which the acidic dissociation group or the basic dissociation group has already been neutralized and has self-water dispersibility, it is not necessary to neutralize in this step.
[0085]
In the second step, the mixture obtained in the previous step is phase-inverted and emulsified to produce self-water dispersible synthetic resin particles encapsulating a colorant.
By adding water to a mixture of a self-dispersing synthetic resin, in which some or all of the dissociating groups have been neutralized, dissolved in an organic solvent, and phase inversion emulsification, the synthetic resin is stably dispersed in water. To do. The liquid temperature for phase inversion emulsification is preferably about 10 to 40 ° C. However, since the particle size varies depending on the liquid temperature, it is necessary to maintain a constant temperature. As water to be used, ion-exchanged water or distilled water is preferable.
If necessary for phase inversion emulsification, a neutralizing agent may be added to water.
[0086]
Further, if necessary, an emulsifier and a dispersion stabilizer may be used in combination.
Examples of the emulsifier include anionic surfactants such as sodium dodecylbenzenesulfonate, sodium lauryl sulfate, sodium dodecyldiphenyl oxide disulfonate, and nonionic surfactants such as polyoxyethylene lauryl ether and polyoxyethylene ninylphenol ether. Can be mentioned.
As the dispersion stabilizer, a water-soluble polymer compound is used, and examples thereof include polyvinyl alcohol, polyvinyl pyrrolidone, hydroxyethyl cellulose, carboxymethyl cellulose, and cellulose gum.
In the case of a production method in which a synthetic resin is not dissolved in an organic solvent and mixed with a colorant by melt kneading, the same production process can be applied.
[0087]
In the third step, after phase inversion emulsification, the particles are recovered from the water in which the generated particles are dispersed. In this step, a solvent removal treatment for removing the organic solvent from the toner and water is performed.
Next, it processes using the neutralizing agent of the reverse polarity to the above-mentioned neutralizing agent which neutralized the synthetic resin. That is, the self-water dispersible synthetic resin constituting the toner uses an acid when the acidic dissociation group is neutralized, and uses a base when the basic dissociation group is neutralized. The original dissociated group is restored. When this treatment is not performed, the toner is easily affected by moisture in the air, resulting in a defect in the chargeability of the toner.
All of the above-described processes are not necessarily performed, and can be selected according to circumstances.
[0088]
Finally, particles are collected from the water by filtration, etc., and if necessary, washed to remove water-soluble components such as ions, impurities such as submicron fine particles, which affect the chargeability of the toner, and dried to a powder. A toner is obtained. The drying method may be any known drying method, and examples thereof include a freeze drying method and an airflow drying method.
The obtained toner can be added with silica or the like, or various surface modifications can be performed. Moreover, wax, a charge control agent, etc. can also be added in the above-mentioned manufacturing process.
[0089]
【Example】
EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.
[0090]
The potentiometric titration of the number of gram equivalents of acidic dissociation groups and basic dissociation groups of the synthetic resin used in Examples or Comparative Examples is performed as follows.
The measurement of the number of gram equivalents of acidic dissociation groups was carried out by dissolving 1 g of synthetic resin in 100 ml of a solution in which methyl ethyl ketone (hereinafter referred to as MEK) and methanol were mixed at a ratio of 4: 1, and 0.01 N potassium methoxide solution (Wako Pure Chemical Industries, Ltd.). 0.1N potassium methoxide for pharmaceutical non-aqueous titration, benzene / methanol solution is prepared by diluting with a solution in which MEK and methanol are mixed at a ratio of 4: 1. From the amount of potassium butoxide solution required for neutralization, the number of gram equivalents of acidic dissociation groups possessed by the synthetic resin is determined.
Measurement of the number of gram equivalents of the basic dissociation group is performed by dissolving 1 g of synthetic resin in 100 ml of MEK and titrating with 0.01 N perchloric acid MEK solution. From the amount of the perchloric acid MEK solution required for neutralization, the number of gram equivalents of the basic dissociation group possessed by the synthetic resin is determined.
[0091]
The potentiometric titration of the number of gram equivalents of acidic dissociation groups and basic dissociation groups of the colorant used in Examples or Comparative Examples is performed as follows.
When obtaining the number of gram equivalents of the basic dissociation group, first, 2 g of pigment as a colorant and 30 ml of 0.01N perchloric acid MEK solution are placed in a flask and sealed, and then ultrasonically dispersed in an ultrasonic cleaner for 1 hour. To do. From this dispersion, 10 ml of the supernatant obtained by centrifuging the pigment was diluted with 100 ml of MEK, and then 0.01N tetrabutylammonium hydroxide (hereinafter referred to as TBAH) solution (TBAH 30% methanol solution for non-water titration manufactured by Tokyo Chemical Industry Co., Ltd.). Is diluted with MEK) and back titrated. Thereby, the amount of perchloric acid consumed by the basic dissociation group on the surface of the colorant is determined, and the number of grams equivalent of the basic dissociation group per unit weight of the colorant is determined.
[0092]
When determining the number of gram equivalents of acidic dissociable groups, 2 g of pigment and 30 ml of TBAH / MEK solution are placed in a flask, and 10 ml of the supernatant obtained by performing the same operation as described above is titrated with a 0.01 N perchloric acid MEK solution. . Thereby, the amount of TBAH consumed by the acid dissociable groups on the colorant surface is determined, and the number of gram equivalents of acid dissociable groups per unit weight of the colorant is determined.
[0093]
Hereinafter, examples and comparative examples will be described.
[Example 1]
After 170 parts by weight of MEK was added to 170 parts by weight of a polyester synthetic resin (acid value: 14 mg · KOH / g) and dissolved well, the amount of acidic dissociable groups / the amount of basic dissociated groups = 0.138 mg equivalent (mol) / g / Add 20 parts by weight of 0.013 mg equivalent / g of carbon black and 10 parts by weight of wax, put into “Fillmix 56 (made by Tokushu Kika Kogyo)”, disperse for 5 minutes at 40 m / s, and finish dispersion Thereafter, the solid content was adjusted to 50% with MEK to obtain a synthetic resin solution mixture. 2 parts by weight of 1N ammonia water was added to 200 parts by weight of this synthetic resin solution mixture, the rotation speed of the homogenizer was set to 5000 RPM, and 100 parts of deionized water was added dropwise to carry out phase inversion emulsification. Next, MEK was removed by distillation under reduced pressure, washed with filtered water, and then dried to obtain a toner containing a colorant.
[0094]
[Example 2]
A toner was obtained in the same manner as in Example 1 except that a modified polyether polyol synthetic resin (acid value: 14 mg · KOH / g) was used instead of the polyester synthetic resin of Example 1.
[0095]
Example 3
The same procedure as in Example 1 except that instead of the carbon black of Example 1, an acidic dissociable group amount / basic dissociable group amount = 0.004 mg equivalent / g / 0.004 mg equivalent / g phthalocyanine pigment was used. And a toner was obtained.
[0096]
[Comparative Example 1]
The same procedure as in Example 1 except that instead of the carbon black of Example 1, carbon dissociation of acidic dissociation group amount / basic dissociation group amount = 0.382 mg equivalent / g / 0.016 mg equivalent / g was used. And a toner was obtained.
[0097]
[Comparative Example 2]
Instead of the carbon black of Example 2, the amount of acidic dissociable groups / the amount of basic dissociable groups = 0.382 mg equivalent / g / 0.016 mg equivalent / g of carbon black was used. And a toner was obtained.
[0098]
[Comparative Example 3]
Instead of the phthalocyanine pigment of Example 3, the same amount of acidic dissociable group / basic dissociable group = 0.350 mg equivalent / g / 0.010 mg equivalent / g of phthalocyanine pigment was used, except that a phthalocyanine pigment was used. And a toner was obtained.
[0099]
The evaluation of the toner in each example and comparative example was performed as follows.
The particle size and particle size distribution of the obtained toner were measured using “Coulter Multisizer II” (manufactured by Coulter).
The average circularity of the obtained toner was measured using “Flow type particle image analyzer FPIA-2000” (manufactured by Toa Medical Electronics Co., Ltd.). The average circularity is defined by (perimeter of a circle having the same projection area as the particle image) / (perimeter of the particle projection image) in the particle image detected by this measuring apparatus. Takes a value.
[0100]
The dispersion average particle diameter of the colorant in the toner is calculated by observing a cross section of the toner with a transmission electron microscope, sampling 50 colorant fine particles enlarged at a magnification of 10,000 times, and averaging the 50 particles. did.
[0101]
For each of the above Examples and Comparative Examples, the obtained toner and a ferrite core carrier having an average particle diameter of 60 μm were adjusted and mixed so that the toner concentration was 5% by weight to prepare a two-component developer.
Using this developer, using “AR-C150” (manufactured by Sharp Corporation), the toner adhesion amount is 0.8 mg / cm on “full-color exclusive paper” (manufactured by Sharp Corporation, product number: PP106A4C). ² An image sample was prepared using an external fixing machine.
Table 1 shows the result of evaluation of each image sample.
[0102]
[Table 1]

[0103]
The evaluation of the image sample was performed as follows.
The optical density of the image sample was measured with an “X-Rite 938 spectrocolorimetric densitometer” (manufactured by Nippon Planographic Printing Equipment Co., Ltd.).
When the white background fog of the image sample is black toner, the whiteness of the A4 size special paper is measured in advance with a “whiteness meter” (manufactured by Nippon Denshoku Industries Co., Ltd.), and the measured value is the first measured value. And Next, using a manuscript including a white circle with a diameter of 55 mm, three copies are made, and the white portion of the obtained copy sample is measured with the whiteness meter, and this value is set as the second measurement value. A value obtained by subtracting the second measurement value from the first measurement value is defined as a fogging value. In the case of color toner, the determination was made visually.
[0104]
The pigment dispersibility of the image sample is 1.7 mg / cm of toner adhesion amount. ² An image was prepared on the OHP sheet so that the HAZE value (cloudiness) was measured using a “HAZE meter” (manufactured by Nippon Denshoku Industries Co., Ltd., model NDH2000), and this was used as an index. The smaller the HAZE value, the better the transparency. It was judged that the transparency was good when 20 or less, the transparency was very high when 15 or less, and the pigment dispersibility was also good. When the HAZE value exceeds 25, practicality as a color toner is lacking.
[0105]
The transfer rate was calculated from the toner weight Mp on the paper surface of the sample copied on the predetermined chart and the toner weight Md remaining on the photoconductor.
The transfer rate is obtained by the following equation.
Transfer rate = (100 × Mp) / (Md + Mp)
[0106]
As a result of evaluation based on the evaluation criteria described above, as shown in Table 1, it was found that Examples 1 to 3 were acceptable and Comparative Examples 1 to 3 were unacceptable.
As described above, according to the toner manufacturing method of the present invention, the particle size distribution is narrow with a small particle size that can be used for a high-definition image, and the static property is excellent in transferability, fluidity, and charging environment stability. The toner for charge development can be produced by a simple process.
Further, since the colorant is uniformly dispersed in the toner, even when the toner has a high colorant content, there is no fogging or uneven image density, and the amount of toner consumed during image formation can be reduced. Further, the original fixing property of the synthetic resin is not impaired in the manufacturing process.
[0107]
【The invention's effect】
As described above in detail, in the case of the present invention, the number of gram equivalents of acidic dissociation groups or basic dissociation groups per unit weight is the gram equivalent of acidic dissociation groups or basic dissociation groups per unit weight of the synthetic resin. Since fewer colorants are mixed into the synthetic resin, the colorant is less hydrophilic than the synthetic resin during phase inversion emulsification, and the colorant is prevented from being discharged into the aqueous layer and agglomerating, stably. A toner in which a colorant is uniformly encapsulated in a synthetic resin is obtained.
Since the colorant content of the toner is stable and uniform, a good image can be obtained when an image is formed using this toner. In addition, since the colorant is uniformly dispersed in the toner, even when the toner has a high colorant content, there is no fogging or uneven image density, and the amount of toner consumed during image formation can be reduced.
[0108]
According to the present invention, a toner for developing an electrostatic charge having a small particle size and a narrow particle size distribution that can be used for a high-definition image and having excellent transferability, fluidity, and charging environment stability is obtained by a simple process. Can be manufactured.
Further, the original fixing property of the synthetic resin is not impaired in the manufacturing process.
[0109]
In the case of the present invention, the colorant is mixed with the solution obtained by dissolving the synthetic resin in the solvent to obtain a mixture. Therefore, the synthetic resin and the colorant can be easily mixed without being mixed by melt kneading. Can be mixed.
[0110]
In the case of the present invention, since the mixture of the first organic solvent that dissolves the synthetic resin and the second organic solvent having higher hydrophilicity than the first organic solvent is used as the solvent, the phase inversion is performed during the phase inversion emulsification step. The shape and particle size distribution of the resulting toner are improved.
[0111]
Furthermore, in the case of the present invention, since the weight percentage of the first organic solvent is larger than the weight percentage of the second organic solvent, phase inversion is facilitated during the phase inversion emulsification step, and the resulting toner has a morphology and particle size distribution. Become good.
[0112]
In addition, in the case of the present invention, after the synthetic resin particles are generated, the neutralized acid dissociation group or basic dissociation group is reversely neutralized, so that the particles are aggregated and fused in the drying step. Thus, a toner having good chargeability can be obtained without being affected by moisture in the air.
[0113]
In the case of the present invention, since a synthetic resin containing at least a polyester-based synthetic resin is used, a toner having a good balance of powder fluidity and fixing property can be easily obtained, and can be applied to a color toner. A certain toner can be obtained.
[0114]
Furthermore, in the case of the present invention, since a synthetic resin containing one or more of a carboxyl group and a sulfonic acid group is used, it is easily neutralized, the hydrophilicity of the synthetic resin is increased, and a mixture of the synthetic resin and the colorant is easy. The toner is produced by phase inversion emulsification.
[0115]
Further, in the case of the present invention, since a synthetic resin containing an ammonium group is used, the toner is easily neutralized, the hydrophilicity of the synthetic resin is increased, and the mixture of the synthetic resin and the colorant is easily phase-inverted and emulsified. Is generated.
[0116]
In the case of the present invention, a colorant containing one or more color materials of black, cyan, yellow, and magenta is used, so that a toner capable of satisfactorily forming a black or color image is obtained.

Claims (14)

A mixture comprising, as essential components, a synthetic resin having an acidic dissociable group and a colorant having a gram equivalent number of acidic dissociable groups per unit weight less than the gram equivalent number of acidic dissociable groups per unit weight of the synthetic resin. Water is added to the hydrated and neutralized mixture, and phase-inversion emulsification is performed to produce particles of the synthetic resin containing the colorant, and then the particles are separated from water and dried. Toner. An essential component is a synthetic resin having a basic dissociation group and a colorant having a gram equivalent number of basic dissociation groups per unit weight less than the gram equivalent number of basic dissociation groups per unit weight of the synthetic resin. The mixture is neutralized, water is added to the neutralized mixture, phase inversion emulsification is performed to produce particles of the synthetic resin containing the colorant, and then the particles are separated from water and dried. Toner characterized by the above. A mixture containing, as essential components, a synthetic resin having an acidic dissociable group and a colorant having a gram equivalent number of acidic dissociable groups per unit weight less than the gram equivalent number of acidic dissociable groups per unit weight of the synthetic resin is obtained. Mixing process,
Neutralizing the mixture obtained by the process;
Adding water to the mixture neutralized by the process to phase-emulsify and producing the synthetic resin particles encapsulating the colorant;
And a step of separating the particles produced by the process from water and drying. An essential component is a synthetic resin having a basic dissociation group and a colorant having a number of gram equivalents of basic dissociation groups per unit weight less than the number of gram equivalents of basic dissociation groups per unit weight of the synthetic resin. A mixing process to obtain a mixture;
Neutralizing the mixture obtained by the process;
Adding water to the mixture neutralized by the process to phase-emulsify and producing the synthetic resin particles encapsulating the colorant;
And a step of separating the particles produced by the process from water and drying. A synthetic resin in which part or all of the acidic dissociable groups have been neutralized, and a colorant having a number of gram equivalents of acidic dissociable groups per unit weight less than the number of gram equivalents of acidic dissociable groups per unit weight of the synthetic resin A mixing process for obtaining a mixture comprising
Adding water to the mixture obtained by the process to phase-emulsify and producing particles of the synthetic resin including the colorant;
And a step of separating the particles produced by the process from water and drying. The number of grams equivalent of the basic dissociation group per unit weight of the synthetic resin and the number of grams equivalent of the basic dissociation group per unit weight of the synthetic resin in which some or all of the basic dissociation groups are neutralized A mixing process to obtain a mixture containing a small amount of colorant as an essential component;
Adding water to the mixture obtained by the process to phase-emulsify and producing particles of the synthetic resin including the colorant;
And a step of separating the particles produced by the process from water and drying. 7. The toner manufacturing method according to claim 3, wherein the mixing step is a step of mixing a colorant with a solution obtained by dissolving a synthetic resin in a solvent to obtain a mixture. The toner manufacturing method according to claim 7, wherein the solvent is a mixture of a first organic solvent that dissolves the synthetic resin and a second organic solvent that is more hydrophilic than the first organic solvent. The toner manufacturing method according to claim 8, wherein the first organic solvent has a larger weight percentage of the first organic solvent and the second organic solvent. 10. The toner manufacturing method according to claim 3, further comprising a step of reverse neutralizing the neutralized acidic dissociation group or basic dissociation group after the synthetic resin particles are generated. The toner production method according to claim 3, wherein the synthetic resin includes at least a polyester-based synthetic resin. The method for producing a toner according to claim 3, wherein the synthetic resin contains one or both of a carboxyl group and a sulfonic acid group. The method for producing a toner according to claim 4, wherein the synthetic resin contains an ammonium group. The method for producing a toner according to claim 3, wherein the colorant includes one or a plurality of color materials of black, cyan, yellow, and magenta.