JP4907385B2 - Toner for electrostatic latent image development - Google Patents

Description

The present invention, concerning a copier, a printer, an electrostatic latent image developing toner used in an image forming such as a facsimile.

  In recent years, the development of electrophotography has been remarkable and widely used in image forming units such as copying machines, printers, and facsimiles. The reason for this is that high-quality images can be formed at high speed, and analog images as well as color images and digital images can be formed, and the degree of completeness is high and the stability and durability of performance are high. However, the demand for higher image quality for this method is strong, and further improvement is required. As the countermeasure, the most effective measure is to make the toner used as small as possible and to narrow the particle size distribution as much as possible.

On the other hand, in recent years, from the viewpoint of environmental impact, there has been an increasing demand for multifunctional toners that contain release agents, such as oilless toners, even at lower temperature fixing and higher speed printing, and the toner resin composition is rubbery. The condensate of the toner is an indispensable condition, so that the viscosity of the toner melt is 1 × 10 ⁵ Pa.s. Increasing viscosity, such as s or more. As a result, in the fixing process, it is desired to develop a toner that pays attention to rheological characteristics during heating, such as gelation and aggregation of the toner. In addition, quantification of rheological properties during heating has been an issue.

  Regarding the quantification of rheological properties, for example, the capillary rheometer described in Patent Document 1 was devised for the purpose of measuring the viscosity of resins, raw rubber, foods, etc., but is a thermoplastic resin used for electrostatic toners for electrostatic charge. Rheological characteristics of electrostatic toners for kneading and mixing, or a so-called outflow start temperature and softening point, and a capillary rheometer is used.

Patent Documents 2 to 6 disclose toners for developing electrostatic latent images focusing on rheology.
Patent Document 2 describes the content of obtaining the viscosity of a sample from the amount of piston movement in the cylinder and the time required for the capillary rheometer, but there is no description about the viscosity loss (pressure loss) of the measurement sample. The shape of the end is a plane. In addition, there is no description regarding a toner having a high viscosity and a high pressure loss when melted, for example, a toner using a polyester resin.

  Patent Documents 3 to 5 disclose toners characterized by viscosity characteristics measured using a capillary rheometer, but are characterized by specific conditions such as viscosity at a specific temperature and outflow start temperature. It can be said that the toner is not sufficient to express the toner characteristics, not the viscosity characteristics derived from temperature changes. There is no description about viscosity loss (pressure loss) in the measuring means.

  Regarding Patent Document 6, the viscosity characteristics as a toner are indicated by a T1 / 2 temperature characteristic using a constant load extrusion type capillary rheometer. However, since the shape of the end of the cylinder is a flat surface, the viscosity is inside the cylinder. Since a loss (pressure loss) occurs, an accurate value cannot be ensured, and in the measurement, the upper limit is 140 to 230 ° C. and the value is 200 ° C. or more, and the content is up to the decomposition point region of the thermoplastic resin.

  According to the description in the above-mentioned patent documents, the toner has a melt viscosity having a planar shape with a flow angle of 180 ° of the cylinder end shape of the capillary rheometer.

  However, as described above, from the viewpoint of environmental load, in the case of lower temperature fixing and higher speed printing, there is an increasing demand for lower temperature fixing and higher speed printing, and as the melt viscosity of toner powder increases, the viscosity becomes higher. Since the loss (pressure loss) increases, a means for suppressing and minimizing the pressure loss is required.

  In addition, the above-described toner for developing an electrostatic latent image having a high viscosity is generally constituted by dispersing a dye or pigment for coloring in a binder resin. Even if the particles are crushed, they tend to re-aggregate and become coarse to secondary particles. In addition, metal chelate pigments are often used as color toner colorants. In metal chelate pigments, dyes that act as ligands are coordinated by surrounding metal in bidentate, tridentate, and tetradentate, and pigmentation proceeds. However, although the light fastness increases, there is a problem that the color of the pigment becomes cloudy due to the broad light absorption. Further, the metal chelate pigment has a problem (hot offset phenomenon) that the toner adheres to the surface of the rotary heating member of the fixing device at the time of heat fixing and contaminates the rotary heating member.

  As prior art for such a problem, the inventions disclosed in Patent Documents 7 to 10 are known. For example, in Patent Document 7, by using a naphthol pigment mixed with a coupler having an acidic group or a base when performing salt milling, a fine pigment that is not easily affected by heat during salt milling can be generated. It is described.

  Further, Patent Document 8 describes that even when naphthol AS dye is used as a colorant for a polymerized toner, it is possible to provide a toner that does not change in color during heat fixing.

  Further, Patent Document 9 describes that in a toner using a pigment based colorant, the dispersibility of the pigment can be improved without using a low boiling point organic solvent.

  Furthermore, Patent Document 10 describes the state of dispersion of the colorant in the toner particles by allowing a specific metal phthalocyanine and a specific polymer ligand capable of coordinating with the metal phthalocyanine to coexist in the toner. It is described that a significantly improved toner can be obtained.

Japanese Patent Publication No. 5-87778 Japanese Patent Laid-Open No. 10-186716 JP 11-38669 A JP 2000-39794 A JP 2003-98738 A JP 2002-196538 A Japanese Patent No. 3550969 JP 2002-99116 A JP 2003-98747 A JP 2004-295117 A

  When adopting a capillary type rheometer, there are the above-mentioned problems, and there is a problem in the evaluation means for increasing the viscosity when a condensate having rubber elasticity is blended. In particular, a resin (polymer chain) kneaded with a plurality of resins In the evaluation in the viscosity range where the polymer chains are oriented from the high melt viscosity range in the temperature range in which the particles are associated, a big problem arises.

  More specifically, after focusing on the end shape of the cylinder of the capillary rheometer and melting by heat reception, the uniformity of the kneaded product was examined. As a result, the flow angle of the end shape of the cylinder (the details of the flow angle will be described later) ) Has a problem that the effluent measured at 180 ° (planar shape) flows out in a pulsating manner and a uniform outflow cannot be obtained.

In addition, as a result of studying the rheology during resin heating when dealing with toners for low-temperature fixing and high-speed fixing, the viscosity is increased particularly when a condensate having rubber elasticity is blended, and 10 × 10 ⁶ Pa · s to 20 ×. It was found that the melt viscosity in the 10 ⁶ Pa · s region is deeply related to the offset property of high-speed printing. In addition, when a rubber elastic component is mixed with a thermoplastic resin, the melt viscosity particularly increases, and the resin component that flows out pulsates, making it impossible to accurately handle displacement and melt viscosity.

  While investigating the cause of these phenomena and observing the outflow trajectory of the reservoir, it was found that there was outflow retention at both ends of the shape of the cylinder end. However, the end shape inside the cylinder has a flow angle of 180 ° and a flat shape is the cause of stagnation, and the melt viscosity in the outflow start region of the kneaded melt becomes a high viscosity region. ) Occurs and the pressure loss increases depending on the melt viscosity. Therefore, in order to measure the melt viscosity of the kneaded melt of the electrostatic latent image developing toner and obtain the rheological characteristics during heating, there is a means for suppressing and minimizing the pressure loss inside the cylinder. is necessary.

  On the other hand, with respect to the electrostatic latent image developing toner, viscosity characteristics control that focuses on rheological characteristics such as gelation and agglomeration of the toner during heating is not performed. However, it cannot be said that the low-temperature fixing property and the prevention of contamination (offset resistance) of the rotary heating member are sufficiently achieved, and it has not sufficiently met the recent demand for low-temperature fixing and high-speed printing.

That is, the present invention has been made in view of the above circumstances, and has the following object (I), preferably further object (II).
(I) To provide a toner for developing an electrostatic latent image suitable for a high-speed copying system having excellent low-temperature fixability and offset resistance.
(II) In the measurement using a capillary type rheometer, the electrostatic latent image developing toner having a high viscosity of 10 × 10 ⁵ Pa · s or more can be evaluated with high accuracy. To provide a method for evaluating the melt viscosity characteristics of a toner for developing an electrostatic latent image.

As a result of intensive studies, the inventors of the present invention have developed at least a binder resin, a colorant, a charge control agent, a release agent, and a dispersion auxiliary agent, and electrostatic latent image development obtained by a kneading pulverization method. In the toner for use in combination with a specific compound as the dispersion aid, the toner for developing an electrostatic latent image has a melt viscosity characteristic from an outflow start temperature to an outflow end temperature measured by a capillary rheometer, The following formula (1) is satisfied,
Y = aX ² −bX + c (1)
The capillary type rheometer includes a heating device, a cylinder that holds the electrostatic latent image developing toner, and a piston that presses the electrostatic latent image developing toner held by the cylinder, It has pores through which the electrostatic latent image developing toner melted in the piston pressing direction flows out, and the cylinder end having the pores has an angle of 30 ° to 85 ° with respect to the outflow direction. It has been found that the above-mentioned problems can be solved by being characterized by the shape, and the present invention has been completed.
(However, in Formula (1), X represents measurement temperature (degreeC), Y represents a viscosity (Pa * s), a is 100-900, b is 1 * 10 < ⁴ > -2 * 10 < ⁵ >, c is 2 *. 10 ^{6 to} 2 × 10 ^7. )

That is, an electrostatic latent image developing toner over according to the present invention specifically has the technical features described in the following (1) to (5).
(1) In an electrostatic latent image developing toner obtained by a kneading and pulverizing method, including at least a binder resin, a colorant, a charge control agent, a release agent, and a dispersion aid. The toner has a melt viscosity characteristic from the outflow start temperature to the outflow end temperature measured by a capillary rheometer satisfying the following formula (1),
Y = aX ² −bX + c (1)
The capillary type rheometer includes a heating device, a cylinder that holds the electrostatic latent image developing toner, and a piston that presses the electrostatic latent image developing toner held by the cylinder, It has pores through which the electrostatic latent image developing toner melted in the piston pressing direction flows out, and the cylinder end having the pores has an angle of 30 ° to 85 ° with respect to the outflow direction. Ri shape der, said dispersing aid is a toner for electrostatic latent image development which is a compound represented by the following general formula (1).
(However, in Formula (1), X represents measurement temperature (degreeC), Y represents a viscosity (Pa * s), a is 100-900, b is 1 * 10 < ⁴ > -2 * 10 < ⁵ >, c is 2 *. 10 ^{6 to} 2 × 10 ^7. )

（Ｒ１およびＲ２は炭素数１〜５のアルキル基、アルコキシ基から選ばれる１であり、Ｒ３は水素、フェニル基から選ばれる１である。） Compound (1)

(R1 and R2 are 1 selected from an alkyl group having 1 to 5 carbon atoms and an alkoxy group, and R3 is 1 selected from hydrogen and a phenyl group.)

(2) The electrostatic latent image developing toner according to (1) above, wherein the compounding amount of the compound (1) is in the range of 5 to 20 wt% with respect to the colorant.
(3) The electrostatic latent image developing toner according to (1) or (2), wherein the binder resin is a polyester resin.
(4) The electrostatic latent image developing toner according to any one of (1) to (3) above, wherein the volume average particle diameter is 5 μm to 15 μm.
(5) The electrostatic latent image developing toner according to any one of (1) to (4) above, further comprising an external additive.

According to the present invention, Ru can provide suitable toner for developing an electrostatic latent image on the high-speed copying method superior in low temperature fixing property and offset resistance.

Hereinafter, the electrostatic latent image developing toner of the present invention will be described in detail.
In the present embodiment, in the toner obtained by the melt-kneading pulverization method, it is possible to provide a toner that has excellent dispersibility of the colorant and that can obtain a high-quality image, and to improve the offset quality of the copy in low-temperature fixing and high-speed printing. It is possible to provide an excellent toner for developing an electrostatic latent image. Further, regarding the measurement in which a capillary rheometer is conventionally used for measuring the melt viscosity of a kneaded product for an electrophotographic toner, 1 × 10 ⁵ Pa · s. It is an object of the present invention to provide a method capable of accurately evaluating the above-mentioned high-viscosity kneaded product and resin component.

  For this purpose, in this embodiment, a toner raw material mixture having at least a binder resin, a colorant, and a charge control agent is heated and kneaded, and the obtained kneaded product is cooled and then made into fine particles. Applied to a toner for developing an electrostatic latent image, in which the toner resin component contains a condensate having rubber properties, and particularly a dealcoholized condensate of a polyester resin, preferably having a molecular weight of 60,000 to 100,000. This is a toner containing 5 wt% to 20 wt% with respect to other resin components, and is a value obtained by evaluating toner thermal characteristics from rheological characteristics such as melt viscosity characteristics.

After the toner is molded to a predetermined pressure density and heated at elevated temperature, the toner component melts and flows out of the capillary tube. More specifically, the cylinder end of the capillary tube rheometer is focused on. As a result of examining the uniformity evaluation of the kneaded material after melting by heat reception, the core of the effluent flowed out pulsatingly and uniformly when the flow angle of the end shape of the cylinder was measured in a flat shape of 180 ° I found outflow could not be obtained. That is, when the flow angle is 180 ° and the planar shape is found, stagnant portions are generated at both ends of the syringe. This phenomenon has a high melt viscosity of 1 × 10 ⁵ Pa · s to 1 × 10 ⁷ Pa · s or higher. As the viscosity increases, it is understood that the order of melt viscosity may change compared to the conventional measurement method.

That is, in the above-described means for determining the temperature gradient and the melt viscosity of the toner with the rheometer, a viscosity-temperature curve in which the pickup temperature interval is set to 1 ° C. is drawn, and the melt viscosity characteristic of the toner is a quadratic expression (Y = aX ² −bX + c (Y Is a toner for electrostatic charge development obtained from a kneading and pulverizing method applied to: Viscosity, X: Measurement temperature), and a value of a is 100 to 300, and b value is in the range of 1 × 10 ^{4 to} 20 × 10 ^4. An electrostatic toner for developing an electrostatic latent image having a melt viscosity characteristic that falls within a range of 2 × 10 ^{6 to} 20 × 10 ⁶ .

The a value is more preferably 300 to 800, the b value is more preferably 1 × 10 ⁴ to 10 × 10 ⁴ , and the c value is 4 × 10 ^{6 to} 11 × 10 ^6. Further preferred.

When the melt viscosity characteristic rises from the above-mentioned value, the cold offset that is the fixing quality is hindered, and particularly when the melt viscosity characteristic is lowered, the hot offset property of the high-speed fixing quality is hindered. There is a problem in fixing quality when 100 or more sheets are continuously printed. Specifically, if the value of a is 100 or less, it is not suitable for high-speed copying, and the same thing can be said if the b value is 1 × 10 ⁴ or less, and if the C value is 2 × 10 ⁶ or less. The quality of the hot offset property is impaired, which is not preferable. These viscosity characteristics are influenced by the kneading quality, and if the mechanical shearing force is insufficient, the viscosity characteristics vary and a value approximated to an accurate quadratic expression cannot be obtained.

  These toners having the above-mentioned quadratic approximate viscosity characteristics are mainly composed of a thermoplastic resin, and in particular, a polyester resin kneaded product easily enters this range, and in particular, a mixture in which a condensate having rubber elasticity is kneaded. Is preferred.

  In order to satisfy the viscosity characteristics of the toner for developing an electrostatic latent image of the present invention, it is preferable to use resins having different molecular weights in combination, and kneading is carried out with a mechanical shearing force. It is anticipated that a viscosity decrease will occur, i.e. such viscosity properties are obtained by molecular chain association and orientation.

  According to the present invention, the amount of displacement of the sample is recorded from the temperature at which the thermoplastic resin of the toner component melts and flows out as a result of the temperature rise until the viscosity further decreases due to the temperature rise and finishes flowing out, from the point of displacement to the end point of outflow. The temperature at which the amount of displacement of the resin becomes 1/2 is generally referred to as the softening temperature of the resin, but it is measured with a capillary rheometer having a flow angle of 90 ° to 170 ° according to the present invention. Is also possible.

  Accordingly, the same measurement and evaluation can be performed for the handling of the softening temperature and the like, and if the toner powder is uniformly kneaded, there is no problem such as pulsation and smooth outflow is possible.

  By evaluating the kneaded product with a capillary rheometer having a flow angle in the outflow in such a cylinder, for example, when there is a mixture of components that cause instability in the kneading uniformity, the melt from the start of the outflow From the cold offset, a phenomenon in which the outflow of the material is unstable and the outflow is observed in spite of the kneaded material with stable material and kneading state is observed. Furthermore, considering the thermal characteristics that satisfy the hot offset property, the temperature gradient of the fixing part is determined from the melt viscosity characteristics of the toner, so evaluation with reduced viscosity loss (pressure loss) is possible, and reliable fixing quality is expected. it can. Furthermore, by using a specific naphthol AS azo compound in combination with a colorant, a toner having extremely high dispersibility of the colorant could be obtained. Naphthol AS has been used as a colorant so far, but the inventor is not aware of any example of melt-kneading using a colorant and a specific naphthol AS azo compound as in this embodiment.

The raw materials used for the electrostatic latent image developing toner of this embodiment will be described below.
The compound (1) represented by the following general formula used in this embodiment is a compound belonging to the naphthol AS type of an azo pigment, and has a structure in which a morpholine ring is substituted at the p-position of the azo group. This compound has sharper light absorption than the alkyl-substituted product of Patent Document 7 described above, and has a cyan color in which λMAX (wavelength of maximum peak value) is shifted to the longer wavelength side.

（Ｒ１およびＲ２は炭素数１〜５のアルキル基、アルコキシ基から選ばれる１であり、Ｒ３は水素、フェニル基から選ばれる１である。） Compound (1)

(R1 and R2 are 1 selected from an alkyl group having 1 to 5 carbon atoms and an alkoxy group, and R3 is 1 selected from hydrogen and a phenyl group.)

  In the present invention, a toner raw material mixture containing at least a binder resin, a colorant, and a charge control agent is heated and kneaded, and the obtained kneaded product is cooled and then finely divided to obtain an electrostatic latent image developing toner. Thus, with respect to the resin component used for achieving low-temperature fixing and high-speed fixing quality, which is the subject of the present invention, a porester resin is preferable, and the content of the polyester resin is not particularly limited. % By weight or more is preferable, and 80% by weight or more is preferable.

  The polyester may be either a crystalline polyester or an amorphous polyester. However, when the crystalline polyester is melted with an increase in temperature, a rapid viscosity drop occurs, so that a rubber elastic component is used in combination. These compositions have a problem in compatibility between resins, and a mechanical shearing force is required more in the kneading process than in ordinary resins.

  The present invention is applied to a toner resin component containing a condensate having rubber properties, particularly a dealcoholized condensate of a polyester resin, preferably a component having a molecular weight of 60,000 to 100,000, and 5 wt.% Relative to other resin components. % To 20 wt%, and the same kind and a plurality of polyester resin components can be used.

In the heat-melt kneading, by mixing and kneading a plurality of resin types, the thermorheological properties of individual resins that match the toner can be obtained.
Therefore, it becomes an indispensable characteristic for the thermal characteristics of the fixing portion in the image forming process using the electrostatic latent image developing toner, and the intended melt viscosity characteristic can be obtained in balance with the mechanical shearing force in the kneading described above.

  In order to disperse and mix components such as pigments, polarity control agents, and mold release agents in the above-mentioned resins, compatibility and affinity between the materials influences. For example, the influence of functional groups on pigment dispersion In some cases, the efficiency is increased by introducing a third substance having similar properties to both materials.

  In the present invention, it is understood that the dispersibility of pigments such as phthalocyanine and / or metal phthalocyanine and carbon black becomes extremely high when such a naphthol AS-based azo pigment coexists. These comparison results and the like will be described with reference to specific data in the examples and comparative examples described later. However, in order to achieve mixing and kneading of the solid phase and the melt phase, the homogeneity of the kneaded material due to the melt viscosity characteristic is an evaluation means. A case occurs.

  That is, the measured value of the capillary rheometer when the kneading component is insufficient is a pulsating value, and even in the case of high viscosity, the resin outflow is a measured value that lacks reproducibility.

The cylinder end shape in the capillary rheometer described above was able to suppress pressure loss in the region where the melt viscosity was high by adjusting the flow angle in the range of 90 ° to 170 °. This angle is the viscosity of the toner melt. Is 1 × 10 ⁵ Pa · s or more and can be applied to the range where the viscosity is increased, and the viscosity range is 1 × 10 ⁷ Pa · s at the maximum.

  The naphthol AS azo dye of the present invention can be synthesized through a coupling reaction from a diazonium salt in an organic solvent. Examples of such an organic solvent include methylene chloride, chloroform, ethyl acetate, methyl acetate, carbon tetrachloride, cyclohexane, dioxane, hexane, toluene and the like. The branched chain aliphatic hydrocarbon type is an isoparaffin type hydrocarbon, and includes Isopar G, H, K, L, M, V and the like. Particularly desirable as normal paraffin hydrocarbons are Norpearl 12, Norpar 13, Norpar 15 (made by Exxon), etc., but in some cases, it is also preferable to mix alcohol solvents (methyl alcohol, ethyl alcohol, isopropyl alcohol, etc.). . In particular, in the synthesis of the naphthol AS azo dye used in the present embodiment, it is preferable to use a nonpolar organic solvent as the organic solvent because it is advantageous for extraction of the obtained pigment.

Examples of the diazonium salt include p-morpholino-2,5-butoxybenzenediazonium tetrafluoride, p-morpholino-2,5-ethoxybenzenediazonium tetrafluoride, p-morpholino-2,5-propoxybenzenediazonium tetrafluoride, p -Morpholino-2,5-isopropoxybenzenediazonium tetrafluoride, p-morpholino-2,5-t-butoxybenzenediazonium tetrafluoride and the like.
Examples of the coupler component include naphthol AS and naphthol AS-SW.

  The above components are dissolved in the above-mentioned organic solvent in an equimolar amount to a coupler component in an amount of about 1.3 mol, and the temperature of the solvent is kept at about 20 ° C. while the alcohol amine is added dropwise. As the coupling reaction proceeds, the color of the solution changes to blue, and an azo dye is produced. After adding to about 10% alcohol aqueous solution and filtering, the azo dye of this embodiment can be obtained. When the elemental analysis of CHN is carried out and the purity becomes 98% or more, the compound of this embodiment is obtained. In some cases, it is possible to verify the carboamide group and the stretching vibration wavelength of the alkoxy group by infrared spectroscopic analysis.

A synthesis example is shown below.
p-morpholino-2,5-butoxybenzenediazonium 1/2 Zinc chloride (0.1 mol) is dissolved in 1 L of 0.2% citric acid solution and stirred while 0.1 mol of commercially available hydrofluoric acid is added dropwise. To do. The liquid temperature is kept at 20 ° C. The decomposition product and the like are removed, and a yellow precipitate is formed. This is filtered and dried. A three-necked flask that dissolves 0.11 mol of commercially available naphthol AS in 1.4-dioxane and dissolves the diazonium salt in place of the double salt described above (light length: 300 nm to 420 nm) uses a shaded color. Next, when 5 ml of alcoholamine is dropped and the solution is stirred, the coupling reaction proceeds and a blue pigment is precipitated. After filtration, it is filtered and dried while partially washing with an aqueous solution. Recrystallization with ethanol solvent, analysis of CHN element, and purity of 99% or more (ie, 1- (p-morpholino-2,5-butoxyazobenzene) -2-hydroxynaphthalene-3-phenylnaphthamide The structural formula is a theoretical value, and the purity obtained by calculation from the value of the elemental analysis CHN, for example, from the numerical value of carbon number) is not a problem.
In this way, a coloring aid 1- (p-morpholino-2,5-butoxyazobenzene) -2-hydroxynaphthalene-3-phenylnaphthamide was obtained.

Further, the following compound (coloring aid or dispersion aid) was synthesized using the diazonium compound and coupler compound described above.
1- (p-morpholino-2,5-dibutoxyazobenzene) -2-hydroxynaphthalene-3-phenylnaphthamide, 1- (p-morpholino-2,5-diethoxyazobenzene) -2-hydroxynaphthalene-3- Phenylnaphthamide, 1- (p-morpholino-2,5-diisopropoxyazobenzene) -2-hydroxynaphthalene-3-phenylnaphthamide, 1- (p-morpholino-2,5-dimethoxyazobenzene) -2-hydroxy Naphthalene-3-phenylnaphthamide, 1- (p-morpholino-2,5-dibutoxyazobenzene) -2-hydroxynaphthalene-3-carboxamide.

  The naphthol AS-based azo dye of the present embodiment obtained as described above is allowed to coexist with 5 wt% to 20 wt% of the colorant such as phthalocyanine and / or metal phthalocyanine dye or carbon black, thereby suppressing reaggregation of the colorant. The

Next, the binder resin will be described.
As the binder resin in the present embodiment, a polyester resin is mainly used, and a plurality of resins of the same kind having different degrees of polymerization are used. In some cases, a styrene- (meth) acrylate copolymer resin or the like is used. Also used.

  When using a polyester resin, a dicarboxylic acid and a diol, and further, if necessary, a trivalent or higher monomer (polyhydric carboxylic acid and polyhydric alcohol component) are added, followed by dehydration condensation (dehydration (or dehydration (or dehydration)). Dealcoholization) and polycondensation).

  Examples of the dicarboxylic acid include phthalic anhydride, terephthalic acid, isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, adipic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, citraconic acid, hexahydrophthalic anhydride, and tetrahydrophthalic anhydride. Examples thereof include dicarboxylic acids such as acid, cyclohexanedicarboxylic acid, succinic anhydride, succinic acid, malonic acid, glutaric acid, azelaic acid and sebacic acid, or derivatives or ester compounds thereof.

  Examples of the diol include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, butanediol, pentanediol, hexanediol, cyclohexanedimethanol, bisphenol A polyethylene oxide addition alcohol, polyoxyethylene- (2.0) -2,2-bis (4-hydroxyphenyl) propane and derivatives thereof, polyoxypropylene- (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene- ( 2.2) -polyoxyethylene- (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene- (6) -2,2-bis (4-hydroxyphenyl) propane, poly Oxypropylene- (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene- (2.4) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene- ( 3.3) -2,2-bis (4-hydroxyphenyl) propane and derivatives thereof, polyethylene glycol, polypropylene glycol, ethylene oxide-propylene oxide random copolymer diol, ethylene oxide-propylene oxide block copolymer diol, ethylene Examples include oxide-tetrahydrofuran copolymer diol, polycaprolactone diol, and the like.

  Examples of the trivalent or higher polyvalent monomer include trifunctional or higher polyvalent carboxylic acids such as trimellitic acid, trimellitic anhydride, pyromellitic anhydride, pyromellitic anhydride, and pyromellitic anhydride, or derivatives thereof. Or esterified product thereof (acid component), or sorbitol, 1,2,3,6-hexanetetraol, 1,4-sorbitan, pentaerythritol, 1,2,4-butanetriol, 1,2, 5-pentanetriol, glycerin, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trimethylolbenzene (above, alcohol component), etc. There is.

  The polyester resin that can be used in the present embodiment can be obtained by performing a dehydration condensation reaction or a transesterification reaction using the above raw material components in the presence of a catalyst. The reaction temperature and reaction time at this time are not particularly limited, but are usually 150 to 300 ° C. and 2 to 24 hours.

  As a catalyst for performing the above reaction, for example, zinc oxide, stannous oxide, tetrabutyl titanate, monobutyltin oxide, dibutyltin oxide, dibutyltin dilaurate, paratoluenesulfonic acid, and the like can be used as appropriate.

  For example, as an example of production of polyester, polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane and polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) ) Equal amount of propane, 1.5 times the amount of terephthalic acid, and 0.15% of dibutyltin oxide were placed in a four-necked flask equipped with a nitrogen inlet tube, a dehydrating tube, a stirrer and a thermocouple. The polyester resin can be synthesized by stirring at 220 ° C. and reacting until the softening point measured in accordance with ASTM D36-86 reaches 140 ° C.

  The condensed polyester resin used in this embodiment may have an appropriate glass transition point as a toner, and a glass transition temperature (Tg) of 40 ° C. or higher is preferable. Among them, Tg is 50 to 85 ° C. More preferred is 60 to 85 ° C. Further, the acid value is preferably 30 or less, more preferably in the range of 20 to 30, and if the acid value is too high, the charge amount is lowered and the desired charge amount cannot be obtained.

  In addition, as a styrene monomer used in a monofunctional styrene- (meth) acrylate copolymer resin with a styrene- (meth) acrylate copolymer resin that may be used in this embodiment, For example, there are styrene, α-methyl styrene, vinyl toluene, p-sulfone styrene, dimethylaminomethyl styrene and the like.

  Monofunctional (meth) acrylic acid ester monomers include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl ( Alkyl (meth) acrylates such as meth) acrylate, tertiary butyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate; cyclohexyl (meth) acrylate Alicyclic (meth) acrylates such as: aromatic (meth) acrylates such as benzyl (meth) acrylate; hydroxyl-containing (meth) acrylates such as hydroxyethyl (meth) acrylate; (meth) acrylates Phosphoric acid group-containing (meth) acrylates such as acryloxyethyl phosphate; halogen atoms such as 2-chloroethyl (meth) acrylate, 2-hydroxy3-chloropropyl (meth) acrylate, and 2,3-dibromopropyl (meth) acrylate (Meth) acrylate; epoxy group-containing (meth) acrylate such as glycidyl (meth) acrylate; ether group-containing (meth) acrylate such as 2-methoxyethyl (meth) acrylate and 2-ethoxyethyl (meth) acrylate; dimethylaminoethyl (Meth) acrylate, basic nitrogen atom such as diethylaminoethyl (meth) acrylate or amide group-containing (meth) acrylate;

  Moreover, the monofunctional unsaturated compound copolymerizable with these can also be used as needed. For example, a carboxyl group-containing vinyl monomer such as (meth) acrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid; a sulfo group-containing vinyl monomer such as sulfoethylacrylamide; a nitrile group-containing vinyl monomer such as (meth) acrylonitrile; Ketone group-containing vinyl monomers such as vinyl methyl ketone and vinyl isopropenyl ketone; basic such as N-vinyl imidazole, 1-vinyl pyrrole, 2-vinyl quinoline, 4-vinyl pyridine, N-vinyl 2-pyrrolidone, N-vinyl piperidone Nitrogen atom or amide group-containing vinyl monomers can be used.

  When a styrene- (meth) acrylic acid ester copolymer is used as a binder resin, a normal polymerization method can be adopted as a production method thereof, such as solution polymerization, suspension polymerization, bulk polymerization, etc. The method of performing a polymerization reaction in presence is mentioned.

  Examples of the polymerization catalyst include 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile), Examples thereof include benzoyl peroxide, dibutyl peroxide, butyl peroxybenzoate, and the amount used is preferably 0.1 to 10.0% by weight of the vinyl monomer component.

  A resin having a high melting temperature in the styrene (meth) acrylic resin is desirably used in combination with the above monofunctional monomer and the above crosslinking agent. The second resin having a melting temperature lower than that of the resin is preferably produced using the above monofunctional monomer, but it may be produced by appropriately adding a bifunctional or higher polyvalent monomer as necessary. You can also.

  The copolymer resin of styrene- (meth) acrylic acid ester used in this embodiment may have an appropriate glass transition point as a toner, and the glass transition temperature (Tg) is preferably 40 ° C. or higher. Among them, those having a Tg of 45 to 85 ° C are more preferable, and 50 to 80 ° C is particularly desirable. The acid value is preferably 30 or less, more preferably 15 or less, and particularly preferably 10 or less. If the acid value is too high, the charge amount is lowered and the desired charge amount cannot be obtained.

  In addition, the binder resin used in the toner of the exemplary embodiment can be used by adding a wax as a release agent to the resin in part or in whole. The amount used is preferably 3% by weight or more, particularly preferably about 10% by weight of the total resin.

  There is no particular limitation on the means for internally adding the wax to the resin, but the temperature is higher than the temperature at which the wax melts, and the normal conditions under which the monomer for producing the resin reacts, for example, the heating conditions of 120 ° C. to 250 ° C. Below, a wax-added resin can be obtained by adding a predetermined amount of wax and proceeding the polymerization reaction of the monomer. Further, the timing of adding the predetermined amount of wax may be in the initial stage of the polymerization reaction of the resin, may be in the middle thereof, or may be immediately before the polymerization reaction is completed and the resin is removed from the reaction vessel. . In addition, when adding a wax after completion | finish of superposition | polymerization, it is necessary to take out resin, after fully stirring so that the added wax may disperse | distribute uniformly in resin.

  Next, examples of the colorant that can be used in the present embodiment include phthalocyanine and / or metal phthalocyanine, as well as known ones. Carbon blacks such as furnace black, channel black, acetylene black, thermal black, lamp black, etc. classified by the production method are used as black colorants, and phthalocyanine C.I. I. Pigment Blue 15-3, Indanthrone C.I. I. Pigment Blue 60 and the like are quinacridone C.I. I. Pigment Red 122, an azo-based C.I. I. Pigment Red 22, C.I. I. Pigment Red 48: 1, C.I. I. Pigment Red 48: 3, C.I. I. Pigment Red 57: 1 and the like are azo-based C.I. I. Pigment Yellow 12, C.I. I. Pigment Yellow 13, C.I. I. Pigment Yellow 14, C.I. I. Pigment Yellow 17, C.I. I. Pigment Yellow 97, C.I. I. Pigment Yellow 155, an isoindolinone-based C.I. I. Pigment Yellow 110, a benzimidazolone-based C.I. I. Pigment Yellow 151, C.I. I. Pigment Yellow 154, C.I. I. Pigment Yellow 180, and the like. The content of the colorant is in the range of 1 to 20 parts by weight. These colorants can be used alone or in combination of two or more.

  In the toner of the present exemplary embodiment, a charge control agent is used in addition to the binder resin, the colorant, and the color auxiliary agent.

  The positive charge control agent is not particularly limited as long as it is a compound that imparts positive chargeability to the toner. However, triphenylmethane dyes, nigrosine dyes, quaternary ammonium salts, quaternary ammonium groups and / or It is preferably a resin containing an amino group. These compounds can be used alone or in combination with two or more charge control agents. Examples of the positive charge control agent include the following products, but are not limited to those exemplified.

  Examples of the triphenylmethane dye include “OIL BLUE” (Orient Chemical Co., Ltd.) and “Copy Blue PR” (Clariant Co., Ltd.). Examples of nigrosine dyes include “NIGROSINE BASE EX”, “OIL BLACK BS”, “BONTORON N-01”, “BONTORON N-04”, “BONTORON N-07”, “BONTORON N-21” (oriental chemistry (above) Etc.). As quaternary ammonium salt compounds, “BONTORON P-51” (Orient Chemical Co., Ltd.), “TP-302”, “TP-610”, “TP-415” (above Hodogaya Chemical Co., Ltd.), “ COPY CHARGE PSY "(Clariant Corporation) and the like. Examples of the resin containing a quaternary ammonium group and / or an amino group include “FCA-201-PS” (Fujikura Kasei Co., Ltd.).

  The negatively chargeable charge control agent used in the exemplary embodiment is not particularly limited as long as it is a compound that imparts a negative chargeability to the toner. However, an azo metal complex (salt), a salicylic acid metal complex (salt) Benzyl acid metal complex (salt), tetraphenyl metal complex (salt), calixarene type phenol condensate, cyclic polysaccharide, and resin charge control agent are preferred.

  Examples of the salicylic acid-based metal complex include “BONTORON E-81”, “BONTORON E-84”, “BONTORON E-88” (above Orient Chemical Co., Ltd.) and the like. Examples of the benzyl acid metal complex include “LR-147” (Nippon Carlit Co., Ltd.). Examples of the tetraphenyl-based metal complex include “COPY CHARGENX” (Clariant). Examples of the calixarene-type compound include “BONTORON E-89” and “BONTORON F-21” (Orient Chemical Co., Ltd.). Examples of the cyclic polysaccharide include “COPY CHARGE NCA” (Clariant Co., Ltd.). Examples of the resin charge control agent include “FCA-1001-NS” (Fujikura Kasei Co., Ltd.), “COPY LEVEL NCS” (Clariant Co., Ltd.), and the like.

  The content of the charge control agent is preferably 0.1 to 10 parts by weight, more preferably 0.3 to 8 parts by weight per 100 parts by weight of the binder resin. More preferably, it is 0.5 to 6 parts by weight.

  As the release agent, known polypropylene wax, polyethylene wax, modified polyolefin wax, higher fatty acid ester, Fischer-Tropsch wax, graft polymerization wax, higher aliphatic alcohol, amide wax, natural wax, etc. can be used. A release agent containing a higher fatty acid ester compound and / or an aliphatic alcohol compound as a main component is preferable because of good dispersibility in the polyester resin and good release properties and sliding properties. When the higher fatty acid ester wax and / or aliphatic alcohol is added to the toner, better hot offset resistance and fixing strength can be obtained as compared with the same amount of polyolefin wax such as polypropylene wax and polyethylene wax.

  Among the waxes composed mainly of higher fatty acid ester compounds, natural waxes include carnauba wax, montan wax, candelilla wax, rice wax, ibota wax, etc., and these waxes are refined and pulverized in the resin. The dispersion in is further improved. Examples of the synthetic ester wax include higher fatty acid esters such as pentaerythritol. Examples of the higher fatty acid ester include “WEP-5”, “WEP-6” (Nippon Yushi Co., Ltd.) and the like. Examples of the release agent mainly composed of an aliphatic alcohol compound include those mainly composed of a higher alcohol obtained by an oxidation reaction of paraffin, olefin and the like.

  For example, “Unilin 425”, “Unilin 550” (above Petrolite Co., Ltd.), “NPS-9210”, “Parakol 5070” (above Nippon Seiwa Co., Ltd.) )) And the like.

  Among mold release agents mainly composed of higher fatty acid ester compounds or aliphatic alcohol compounds, those having a melting point in the range of 65 ° C. to 130 ° C. are particularly preferable because they contribute greatly to offset resistance.

  The release agent may be used alone or in combination, and good fixing offset performance can be obtained by containing 0.3 to 15 parts by weight, preferably 1 to 5 parts by weight with respect to the binder resin. When the amount is less than 0.3 part by weight, the offset resistance is impaired. When the amount is more than 15 parts by weight, the fluidity of the toner is deteriorated.

  The toner according to the exemplary embodiment includes the binder resin, the colorant, the release agent, and the charge control agent as described above, and may further include other additives. For example, a lubricant such as metal soap or zinc stearate can be used, and cerium oxide, silicon carbide, or the like can be used as an abrasive.

  Prior to melt-kneading the above toner materials, they are uniformly mixed in advance by a Henschel mixer or the like. The mixing conditions are not particularly limited, but may be mixed so as to obtain desired uniformity. For example, the mixing time can be changed, the temperature at the time of mixing can be changed, the number of rotations of stirring can be changed, and the shape and combination of the stirring blades can be changed. In addition, various raw materials may be added in order to perform multistage mixing. The coloring agent, coloring auxiliary agent and / or charge control agent used here may be a flashing treatment or a master batch previously melt-kneaded with the resin at a high concentration so as to be uniformly dispersed in the resin.

  The above mixture is mixed by a kneading means such as a two-roll, a three-roll, a pressure kneader, or a twin screw extruder. At this time, the colorant or the like may be uniformly dispersed in the resin, and the melt-kneading conditions are not particularly limited, but are usually 80 to 200 ° C. for 30 seconds to 2 hours. The kneaded product is usually cooled by a cooling belt, a roller, or the like. Since the dispersion state of the release agent changes depending on the cooling condition, the cooling condition can be set so as to obtain a desired dispersion state.

  If necessary, rough pulverization is performed for the purpose of reducing the load and improving the pulverization efficiency in the fine pulverization step. The apparatus and conditions used for coarse pulverization are not particularly limited, but it is general to coarsely pulverize to a particle size of 3 mm mesh pass or less with a rotoplex or a pulverizer.

  Next, a method of finely pulverizing with a mechanical pulverizer such as a turbo mill or a kryptron, an air pulverizer such as a spiral jet mill, a counter jet mill or a collision plate jet mill, and classifying with a wind classifier or the like can be mentioned. The pulverization and classification devices and conditions may be selected and set so as to obtain a desired particle size, particle size distribution, and particle shape. The volume average particle diameter of the particles constituting the toner is not particularly limited, but is usually adjusted to 5 to 15 μm.

  The kneaded alloy can be measured according to the evaluation method of the present invention for the purpose of evaluating the kneaded product of the toner powder after the pulverization and classification treatment obtained above. Further, the toner powder after the external additive is attached can be similarly evaluated.

In the evaluation method of the present invention, a predetermined toner is molded into a pressure density of 0.5 g / ml to 0.7 g / ml by being attached to a flow tester manufactured by Shimadzu Corporation, and injected into a syringe under pressure of 10 kgf / cm ² . The sample was inserted into the cylinder shape of the present invention under the condition of a die hole of 1.0 mm under the condition of a heating rate of 3 ° C./min under load, and the viscosity characteristics from the start of the outflow to the end of the outflow were obtained. Viscosity on the Y axis Plotting the melt viscosity on the coordinate of the temperature on the X axis at 1 ° C each, uniform kneading quality from the melt viscosity curve, that is, alloy state of the same resin, dispersibility of the pigment, dispersibility of the release agent A simple evaluation becomes possible by comparing the content and the like with the viscosity characteristics of a standard sample prepared in advance.

The evaluation method of the present invention will be described in detail with reference to FIG.
FIG. 1 is a capillary rheometer that is preferably used in the method for evaluating the melt viscosity characteristic of the toner for developing an electrostatic latent image according to the present invention.
The capillary type rheometer holds a sample 1 inside a cylinder constituted by a cylinder member 2 provided with a heater 3 and a die body 4, and the sample 1 is pressed by a piston 6 that presses in a pressing direction a. A die body 4 having a die thickness 1a has a die hole 4a which is a fine hole, and the sample 1 heated and melted by a cylinder or the like is discharged. The die body 4 is fixed to a cylinder or the like by a die presser 5.

FIG. 2 shows a sample measuring section of a capillary rheometer that is preferably used in the method for evaluating the melt viscosity characteristic of the toner for developing an electrostatic latent image according to the present invention.
The cylinder member 2 is preferably configured such that the angle θ / 2 from the vertical point corresponding to the pressing direction a in FIG. 1 to the wall surface of the cylinder end located in the downward direction in the drawing is 30 ° to 85 °. In the present specification, θ is defined as a flow angle.

  Usually, an external additive is mixed with the toner thus obtained using a mixer such as a Henschel mixer.

  In the present exemplary embodiment, various additives (referred to as external additives) can be used for toner surface modification such as improvement of toner fluidity and charging characteristics. Examples of external additives that can be used in the present embodiment include inorganic fine powders such as silicon dioxide, titanium oxide, and alumina, and those obtained by surface treatment with a hydrophobizing agent such as silicone oil, resin fine powders, and the like. It is done.

  Among these, those suitably used as an external additive include those obtained by surface-treating inorganic fine powder of silicon dioxide with various polyorganosiloxanes, silane coupling agents, and the like (preferably silica subjected to hydrophobic treatment).

  Specifically, there are those marketed under the following trade names. AEROSIL; R972, R974, R202, R805, R812, RX200, RY200, R809, RX50, RA200HS, RA200H [Japan Aerosil Co., Ltd.] WACKER; HDK H2000, H2050, H3050, HVK2150 [Wacker Chemicals Co., Ltd.], Nippon; SS-10, SS-15, SS-20, SS-50, SS-60, SS-100, SS-50B, SS-50F, SS-10F, SS-40, SS-70, SS-72F, [Japan Silica Industry Co., Ltd.], CABOSIL; TS-500, TS-530, TS-610, TS-720, TG-308F, TG-709F, TG-810G, TG-811F, TG820F [Cabot Specialty Chemicals Ink), etc. It can gel.

  Further, the titanium oxide may be a hydrophilic grade or a hydrophobic grade that is surface-treated with octylsilane or the like. For example, there are those marketed under the following trade names. Titanium oxide T805 [Degussa Co., Ltd.], titanium oxide P25 [Nippon Aerosil Co., Ltd.] and the like. Examples of alumina include aluminum oxide C [Degussa Co., Ltd.].

  The particle diameter of these external additives is preferably 1/3 or less of the diameter of the toner, and particularly preferably 1/10 or less. These external additives may be used in combination of two or more of different average particle sizes. The proportion of silica used is usually 0.05 to 5% by weight, preferably 0.1 to 3% by weight, based on the toner.

  When the toner of this embodiment is used in the two-component development method, a carrier as shown below can be used. Iron powder, magnetite, ferrite, etc. used in the usual two-component development system can be used as the carrier core agent, but above all, the true specific gravity is low, the resistance is high, the environment is stable, and it is easy to make it spherical, so it has fluidity. Good ferrite or magnetite is preferably used. The shape of the core agent can be used without any problem, such as a spherical shape or an irregular shape. The average particle diameter is generally 10 to 500 μm, but 30 to 80 μm is preferable for printing a high-resolution image at high speed.

  Examples of coating resins for coating these core agents include polyethylene, polypropylene, polystyrene, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl carbazole, polyvinyl ether polyvinyl ketone, vinyl chloride / vinyl acetate. Copolymers, styrene / acrylic copolymers, straight silicone resins composed of organosiloxane bonds or modified products thereof, fluorine resins, (meth) acrylic resins, polyesters, polyurethanes, polycarbonates, phenol resins, amino resins, melamine resins, benzoguanamine resins Urea resin, amide resin, epoxy resin, acrylic polyol resin and the like can be used. Among these, silicone resin, fluororesin, and (meth) acrylic resin are particularly excellent in charging stability and coating strength, and can be used more suitably. That is, the resin-coated carrier used in the present embodiment is a resin-coated magnetic carrier that uses ferrite or magnetite as a core agent and is coated with one or more kinds of resins selected from silicone resins, fluororesins, and (meth) acrylic resins. Preferably there is.

  In addition, as a non-magnetic one-component developing method, the non-magnetic toner conveyed by the toner carrier is frictionally charged by the layer thickness regulating member and the layer thickness is regulated to reduce the thickness on the toner carrier. In general, the electrostatic latent image is developed in such a manner that the electrostatic latent image bearing member is opposed to or not in contact with the electrostatic latent image carrier.

Next, an image forming method in which the toner of this embodiment is preferably used will be described.
The image forming method used in the present embodiment includes a charging process in which a voltage is applied to a charging member from the outside to charge the electrostatic latent image carrier, and a latent image forming an electrostatic latent image on the charged electrostatic latent image carrier. An image forming step, a developing step of developing the electrostatic latent image with the toner of the present embodiment to form a toner image on the electrostatic latent image carrier, and a toner image on the electrostatic latent image carrier being an intermediate transfer member Image formation comprising: a transfer process for transferring onto or without a recording medium, and a fixing process for fixing a toner image on the recording material by heating and pressing by a heating and pressing means to form a fixed image on the recording material Is the method.

  The heating and pressing means in the fixing step includes a rotary heating member having at least a heating body and a rotary pressure member that forms a nip by mutual pressure contact with the rotary heating member. The toner image on the recording material is heated by the rotating heating member and the rotating pressure member while the recording material is nipped and conveyed by the nip portion with or without the application of the offset prevention liquid on the contact surface with the toner image. Pressure.

  The rotary heating member is for applying heat for fixing the toner image on the recording material, and is used for a heat roller type heating and pressurizing unit to heat the toner image. The rotary pressing member forms a nip by mutual pressure contact with the rotary heating member, and heats the toner image on the recording material while sandwiching the recording material at the nip portion. It is a roller to pressurize.

  According to the toner for developing an electrostatic latent image of the present embodiment, a colorant and a specific compound classified into the naphthol AS represented by the general formula (1) are used together as a color aid in the heat-kneaded toner. Therefore, the dispersibility of the pigment is extremely good, the image density is high, a high-quality image without image fogging or white spot is obtained, the fixing part is not contaminated in heat fixing, and the color tone before and after fixing is stable. High-quality images can be obtained.

  Further, according to the toner for developing an electrostatic latent image of the present embodiment, since a polyester resin is used as the binder resin, the dispersion miscibility with the colorant and the color auxiliary agent is high, and the spectral absorption characteristic of the colorant after fixing is high. In addition to not affecting the image quality, there was no contamination during fixing.

  Further, according to the toner for developing an electrostatic latent image of this embodiment, since at least one of phthalocyanine or metal phthalocyanine or carbon black is used as a colorant, the dispersion miscibility is high, and the colorant spectrum after fixing is high. Does not affect the absorption characteristics.

  Further, according to the electrostatic latent image developing toner of the present embodiment, since the toner is mixed with an external additive and used, not only the fluidity is improved, but also the effect of suppressing deterioration of the toner with time is obtained.

  Further, according to the image forming method using the toner for developing an electrostatic latent image of the present embodiment, since the toner is used, the heating member is not contaminated and heat fixing is performed, and a high-quality image is formed. be able to.

Hereinafter, the present embodiment will be described more specifically with reference to examples and comparative examples, but the present embodiment is not limited to the following examples and comparative examples . In addition, the following Example 4 is a reference example.
In the following , parts represent parts by weight.

The polyester resin (C) used in the examples is a condensate obtained by alcohol dehydration [Example 1].
<Toner matrix prescription>
Polyester resin (A) (weight average molecular weight 2,000, Tg (glass transition temperature) 62 ° C., acid value 25 mg KOH / g) 45 parts Polyester resin (B) (weight average molecular weight 15,500, Tg 50 ° C., acid value 15 parts KOH / g) 30 parts polyester resin (C) (weight average molecular weight 65,500, Tg 63 ° C., acid value 5 mg KOH / g) 13 parts 1- (p-morpholino-2,5-dibutoxyazobenzene) -2- Hydroxynaphthalene-3-phenylnaphthamide (dispersing aid) 3 parts Carbon black (# 44: Mitsubishi Kasei Co., Ltd.) 7 parts Charge control agent (salicylic acid metal complex (Orient Chemical)) 2 parts

The above material mixture was charged into a kneader, heated to 150 ° C., and sequentially charged in a predetermined cutout amount to obtain a colored resin.
At this time, the first kneading zone temperature was set at 110 ° C., the second kneading zone at 90 ° C., the third and fourth kneading zone temperatures at 100 ° C., and the fifth kneading zone at 90 ° C.
From the above conditions, a toner kneaded product was produced at a rate of 150 kg per hour.

This kneaded product was pulverized and classified with a commercially available jet pulverizer, and measured with a Coulter Multisizer (manufactured by Coulter Inc.) to obtain a toner base having a volume average particle diameter of 8.5 μm.
To 100 parts of this toner base, 0.5 part of silicon dioxide (R-972: manufactured by Nippon Aerosil Co., Ltd.) was mixed using a Henschel mixer to obtain the toner of Example 1.

[Example 2]
<Toner matrix prescription>
Polyester resin (A) (weight average molecular weight 2,000, Tg 62 ° C., acid value 25 mgKOH / g) 35 parts Polyester resin (B) (weight average molecular weight 15,500, Tg 50 ° C., acid value 15 mg KOH / g) 33 parts Polyester resin (D) (weight average molecular weight 65,500, Tg 50 ° C., acid value 5 mg KOH / g) 15 parts 1- (p-morpholino-2,5-dibutoxyazobenzene) -2-hydroxynaphthalene-3-phenyl 3 parts of naphthamide (dispersion aid), charge control agent (salicylic acid metal complex (made by Orient Chemical)) 2 parts, copper phthalocyanine pigment metal complex type dye (made by Dainichi Seika) 7 parts, polyethylene oxide 5 parts

The toner mixture material mixture was kneaded with a kneader in the same manner as in Example 1.
The kneaded product was pulverized with a jet pulverizer and then classified to obtain a toner base having a volume average particle size of 8.5 μm. To 100 parts of this toner base, 0.5 part of silicon dioxide (R-972: manufactured by Nippon Aerosil Co., Ltd.) was mixed with a Henschel mixer to obtain the toner of Example 2.

[Example 3]
A toner of Example 3 was obtained in the same manner as in Example 2 except that the same amount of carnauba wax was used instead of the oxidized polyethylene wax in the formulation of Example 2.

[Example 4]
<Toner matrix prescription>
Polyester resin (A) (weight average molecular weight 2,000, Tg 62 ° C., acid value 25 mgKOH / g) 45 parts Polyester resin (B) (weight average molecular weight 15,500, Tg 50 ° C., acid value 15 mg KOH / g) 43 parts Polyester resin (D) (weight average molecular weight 65,500, Tg 50 ° C., acid value 5 mg KOH / g) 3 parts I. Pigment Red 3 and CI Pigment Red 6 53: 1 7 parts Charge control agent (salicylic acid metal complex (made by Orient Chemical)) 2 parts

The material mixture of the toner formulation was kneaded with a kneader in the same manner as in Example 1.
This kneaded product was pulverized by a jet pulverizer and then classified to obtain a toner base having a volume average particle size of 8.5 μm. To 100 parts of this toner base, 0.5 part of silicon dioxide (R-972: manufactured by Nippon Aerosil Co., Ltd.) was mixed with a Henschel mixer to obtain the toner of Example 4.

[Example 5]
<Toner matrix prescription>
Polyester resin (E) (weight average molecular weight 15,000, Tg 59 ° C., acid value 25 mgKOH / g) 40 parts Polyester resin (F) (weight average molecular weight 4,500, Tg 49 ° C., acid value 5 mg KOH / g) 28 parts・ Polyester resin (D) (weight average molecular weight 65,500, Tg 50 ° C., acid value 5 mg KOH / g) 14.7 parts ・ Carnauba wax 60%, rice wax 40% mixed product 5 parts ・ 1- (p-morpholino- 2,5-dibutoxyazobenzene) -2-hydroxynaphthalene-3-phenylnaphthamide (dispersing aid) 0.3 part C.I. I. Pigment Yellow 180 10 parts ・ Charge Control Agent (Salicylic acid metal complex (Orient Chemical Co., Ltd.)) 2 parts

The toner mixture material mixture was kneaded with a kneader in the same manner as in Example 1.
The kneaded product was pulverized with a jet pulverizer and then classified to obtain a toner base having a volume average particle size of 8.5 μm. To 100 parts of this toner base, 0.5 part of silicon dioxide (R-972: manufactured by Nippon Aerosil Co., Ltd.) was mixed with a Henschel mixer to obtain the toner of Example 5.

[Example 6]
<Toner matrix prescription>
Polyester resin (G) (weight average molecular weight 21,000, Tg 63 ° C., acid value 5 mgKOH / g) 40 parts Polyester resin (F) (weight average molecular weight 4,500, Tg 49 ° C., acid value 5 mg KOH / g) 33 parts・ Polyester resin (D) (weight average molecular weight 65,500, Tg 50 ° C., acid value 5 mg KOH / g) 10 parts ・ Carnauba wax 60%, rice wax 40% mixed product 4.7 parts ・ 1- (p-morpholino- 2,5-dibutoxyazobenzene) -2-hydroxynaphthalene-3-phenylnaphthamide (dispersion aid) 0.3 part carbon black (# 44: manufactured by Mitsubishi Kasei) 10 parts charge control agent (salicylic acid metal complex) (Orient Chemical Co., Ltd.)) 2 parts

The toner mixture material mixture was kneaded with a kneader in the same manner as in Example 1.
This kneaded product was pulverized by a jet pulverizer and then classified to obtain a toner base having a volume average particle size of 8.5 μm. To 100 parts of this toner base, 0.5 part of silicon dioxide (R-972: manufactured by Nippon Aerosil Co., Ltd.) was mixed with a Henschel mixer to obtain the toner of Example 6.

[Example 7]
<Toner matrix prescription>
Polyester resin (G) (weight average molecular weight 21,000, Tg 63 ° C., acid value 5 mg KO
H / g) 40 parts polyester resin (F) (weight average molecular weight 4,500, Tg 49 ° C., acid value 5 mg KOH
/ G) 33 parts ・ Polyester resin (H) (weight average molecular weight 66,000 Tg 55 ° C., acid value 5 mgKOH / g) 10 parts ・ Carnauba wax 60%, rice wax 40% mixed product 4.7 parts ・ 1- ( p-morpholino-2,5-dibutoxyazobenzene) -2-hydroxynaphthalene-3-phenylnaphthamide (dispersion aid) 0.3 parts carbon black (# 44: manufactured by Mitsubishi Kasei) 10 parts charge control agent (Salicylic acid metal complex (Orient Chemical)) 2 parts

The toner mixture material mixture was kneaded with a kneader in the same manner as in Example 1.
This kneaded product was pulverized by a jet pulverizer and then classified to obtain a toner base having a volume average particle size of 8.5 μm. To 100 parts of this toner base, 0.5 part of silicon dioxide (R-972: manufactured by Nippon Aerosil Co., Ltd.) was mixed with a Henschel mixer to obtain the toner of Example 7.

[Example 8]
The toner formulation was Example 7 and the mixture was kneaded with a kneader in the same manner as in Example 7, but the kneading conditions were twice as long as in Example 7.
This kneaded product was pulverized by a jet pulverizer and then classified to obtain a toner base having a volume average particle size of 8.5 μm. To 100 parts of this toner base, 0.5 part of silicon dioxide (R-972: manufactured by Nippon Aerosil Co., Ltd.) was mixed with a Henschel mixer to obtain the toner of Example 8.

[Comparative Example 1]
<Toner matrix prescription>
・ Polyester resin (H) (weight average molecular weight 8,500, Tg 55 ° C., acid value 20 mgKOH / g) 42 parts ・ Polyester resin (I) (weight average molecular weight 8,000, Tg 63 ° C., acid value 15 mg KOH / g) 41 parts・ Low molecular weight polyethylene wax (Biscol 550P: Sanyo Kasei Co., Ltd.) 5 parts ・ Carbon black (# 44: Mitsubishi Kasei Co., Ltd.) 10 parts ・ Charge control agent (Saltylic acid metal complex (Orient Chemical Co., Ltd.)) 2 parts

A mixture of the toner formulation materials was kneaded in a kneader in the same manner as in Example 1.
The kneaded product was pulverized with a jet pulverizer and then classified to obtain a toner base material having a volume average diameter of 8.5 μm. To 100 parts of this toner base, 0.5 part of silicon dioxide (R-972: manufactured by Nippon Aerosil Co., Ltd.) was mixed with a Henschel mixer to obtain a toner of Comparative Example 1.

[Comparative Example 2]
The mixture was kneaded in the same manner as in Example 2 except that the dispersion aid used in Example 2 was not used, and then pulverized with a jet mill pulverizer and classified with a classifier to obtain a volume average particle size of 8.5 μm. A toner was obtained. To 100 parts of this toner base, 0.5 part of silicon dioxide (R-972: manufactured by Nippon Aerosil Co., Ltd.) was mixed with a Henschel mixer to obtain a toner of Comparative Example 2.

[Comparative Example 3]
A blue toner base material having a volume average particle size of 8.5 μm was obtained by kneading, pulverizing, and classifying in the same manner as in Example 3 except that the dispersing aid used in Example 3 was not used. To 100 parts of this toner base, 0.5 part of silicon dioxide (R-972: manufactured by Nippon Aerosil Co., Ltd.) was mixed with a Henschel mixer to obtain a toner of Comparative Example 3.

  As described above, the eight types of toners obtained in the examples and the three types of toners obtained in the comparative examples were carried out according to the following evaluation methods, and the results are shown in Table 1.

(Evaluation Method of Melt Viscosity Characteristics of Toner Powder According to the Present Invention)
The melt viscosity of the toner in the present invention is attached to, for example, a commercially available flow tester CFT-500C (manufactured by Shimadzu Corporation). In this case, the measurement conditions were: extrusion pressure: 1.96 MPa, temperature increase rate: 3 ° C./min, die diameter: 1.0 mm, die length: 1.0 mm, and the sample was measured at the measurement part flow angle of 120 ° in FIG. It can be mounted and measured using products.

In addition, melt viscosity (eta) is calculated | required by the following formula.
Melt viscosity η = τ / γ = πD4 × P / 128 × L × Q
Where, P: extrusion pressure (Pa), Q = X / 10 × A / t
D: Die diameter (mm)
L: Die length (mm)
t: Measurement time (s)
X: Movement amount of piston with respect to measurement time t (mm)
A: Cross-sectional area of the piston (mm ² )
Sample preparation: Toner powder is molded to a pressure density of 0.642 g / ml and weighed in the range of 1.000 to 1.030.
The load can be selected depending on the melt viscosity of the toner powder, and for a product exceeding 1 × 10 ⁴ Pa · s, 10 kg / cm ² or more is desirable. The temperature rise start temperature may be from 40 ° C. or 50 ° C. Then, the temperature is raised to the temperature at which the outflow ends and the melt viscosity is calculated from the outflow amount.
In the present invention, the pick-up temperature is 1 ° C., the melt viscosity η is calculated from the outflow start temperature, the viscosity until the end of the outflow is plotted as Y: melt viscosity, and X: temperature at the time of temperature rise. = AX ² -bX + c.

  Here, the pick-up temperature refers to a specified value of the temperature interval in the melt viscosity measurement method in the case of performing control for measuring the viscosity when the temperature rise from the temperature at the previous measurement becomes a specified value. .

(Measurement of volume average particle diameter)
The volume average particle diameter of the toner is measured with a Coulter Counter TA-IIC or Coulter Multisizer (manufactured by Coulter Inc.). In the present embodiment, a Coulter Multisizer is used, and an interface (manufactured by Nikkaki Co., Ltd.) that outputs a particle size distribution and a personal computer are connected to use. The aperture used in the Coulter Multisizer was 100 μm, and the volume distribution of toner of 2 μm or more and less than 60 μm was measured to calculate the particle size distribution and average particle size.

Measurement condition (1) Aperture: 100 μm
(2) Sample preparation method: Electrolyte [ISOTON] Coulter Counter TA-IIC Coulter Multisizer (manufactured by Coulter), an appropriate amount of 50 to 100 ml of surfactant (neutral detergent) was added and stirred, and measurement sample 10 was added thereto. Add ~ 20 mg. This system was prepared by dispersing for 1 minute using an ultrasonic disperser.

  Each toner was mixed with a ferrite carrier having a volume average particle diameter of 50 μm coated with a silicone resin to prepare a developer having a toner concentration of 6%.

  Using the developer prepared here, evaluation of toner quality, image quality, and fixing quality by heating and pressing means was performed using a digital color printer IPSIO CX8200. Each evaluation item, evaluation contents and evaluation criteria are shown below. The fixing temperature was controlled by the surface temperature of the upper roll and was set to a set temperature of 175 ° C.

(Toner coloring power)
A solid image was prepared so that the toner amount on the transfer paper was 0.95 to 1.05 mg / cm ² and the gloss of the image surface after heat and pressure fixing was 20 to 30, and the reflection density of the obtained image was adjusted. Measurement was carried out by X-Rite 508. The obtained measured values were evaluated according to the following evaluation criteria.
A: 1.20 or more B: 1.05 or more and less than 1.20 C: 0.90 or more and less than 1.05 D: Less than 0.90

(Image density)
A square solid image having a side of 5 mm was printed out on a recording paper (transfer paper) (62 g / m ² ), and the reflection density of the printed out image was measured by “Macbeth reflection densitometer RD918” (manufactured by Macbeth). The obtained measured values were evaluated according to the following evaluation criteria.
A: 1.40 or more B: 1.35 or more and less than 1.40 C: 1.00 or more and less than 1.35 D: less than 1.00

(Image fog)
When a solid white image is formed, the toner existing on the photosensitive drum is removed by taping with Mylar tape during the transition from the development step to the transfer step, and the reflection density of the toner stuck on the paper is measured by X-Rite. Measured with 508 manufactured. Evaluation was performed according to the following evaluation criteria using a numerical value obtained by subtracting the reflection density when the Mylar tape was directly applied to paper from the obtained reflection density. The smaller the numerical value, the more image fog is suppressed.
A: Less than 0.03 B: 0.03 or more and less than 0.07 C: 0.07 or more and less than 1.00 D: 1.00 or more

(Dot reproducibility)
Although the electric field is easily closed and difficult to reproduce due to the latent image electric field, an image of an isolated dot pattern with a small diameter (40 μm) is printed on an A4 size general high-quality paper with an area of 100 × 100 mm. Evaluation was performed according to the evaluation criteria.
A: 2 or less defects in 100 B: 3 to 5 defects in 100 C: 6 to 10 defects in 100 D: 11 or more defects in 100

(Image is missing)
An image in which a circular image (diameter 20 mm) was arranged at five locations was printed out, and the occurrence of a white spot of 100 μm or more generated on the image was measured and evaluated according to the following evaluation criteria.
A: Not generated B: Image blank is 5 or less C: Image blank is 6 to 10 D: Image blank is 11 or more

(Image vertical stripe)
A halftone image was printed out, and the number of vertical stripe-shaped image density unevenness generated on the image was measured and evaluated according to the following evaluation criteria.
A: Not generated B: One minor vertical image streak C: Two to four minor vertical image stripes D: Five or more minor vertical image stripes

(Surface contamination of rotating heating member)
After completion of the 7000 printout test for an image pattern with an image area ratio of 50, the appearance of the residual toner adhering to the surface of the rotary heating member and the influence on the printout image were visually evaluated according to the following evaluation criteria.
A: No toner adherence B: Contamination of the rotating heating member with paper dust and toner adhering to the end of the rotating heating member were observed, but the influence on the fixed image was slight. C: Paper dust Although there is slight toner contamination on the back surface of the printout image due to contamination of the rotary heating member due to the toner and toner adhering to the end of the rotary heating member, there is almost no effect on the fixed image. D: Toner Effect on fixing image due to fixing and wrapping of printout image during printout test

(Fixed tone stability)
This evaluation measures the change in color after fixing from the color before fixing held by the toner itself. A Macbeth color eye 7000 was used, and the light source was ASTM-D65, the observation field of view was 2 °, and the SCE mode was used.

  The change in color was evaluated based on the fluctuation range before and after fixing b *. If this fluctuation range is large, a desired color cannot be obtained, and color matching is displaced. Practically, the fluctuation range needs to be less than 2.0, preferably less than 1.0. The above b * represents the b value of Lab.

The above evaluation results are shown in Table 1.

From Table 1, it can be seen that the toners of the examples have good toner quality, image quality, and fixing quality.
On the other hand, the toner of the comparative example which does not include the coloring auxiliary material according to the present embodiment has image fogging and dot reproducibility is not good. Further, it can be seen that the fixing portion is contaminated and the variation range of the color tone before and after fixing is large.

3 to 10 show the melt viscosity characteristics of Examples 1 to 8, and FIGS. 11 to 13 show the melt viscosity characteristics of Comparative Examples 1 to 3, respectively.
Table 2 shows constants a, b, and c of the melt viscosity characteristic approximate quadratic expressions of the examples and comparative examples.

  The difference in the level of the melt viscosity property between the toner obtained in the example and the toner obtained in the comparative example is due to the influence of the PET resin condensate used for the toner component. The uniform kneading quality of pigments is expected to be excellent due to the influence of the compound.

  In this example and the comparative example, the cylinder end shape described in the evaluation method of the present invention was adopted with a flow angle of 120 °, but the measurement value was not disabled and there was no significant fluctuation.

As described above, the toner of the present embodiment is a toner that is close to uniform dispersion although the melt viscosity characteristic is higher than that of the conventional toner. In addition, as an evaluation technique, the end flow angle of the cylinder of a commercially available thin tube rheometer is made sharper than the current one to increase the measurement accuracy such as pulsation, and the high viscosity region (10 × 10 ⁶ pa · s) with poor measurement accuracy. The viscosity characteristics of can be measured.

In addition, a compound having hydroxy naphthalene having a similar skeleton to the pigment compound is a toner having a more uniform dispersibility by helping to disperse the naphthol pigment, the outflow start temperature also improves rheological properties such as melt viscosity properties. It is clear from that. As in the present embodiment, in the toner containing the naphthol pigment with improved rheological properties, the base resin is made more uniform than the conventional toner, and the specific melt viscosity property is reduced although the outflow start temperature is lowered. Y = aX ² −bX + c A toner selected from a range represented by the quadratic approximation is excellent in rheological characteristics that can be fixed at low temperature and can be printed at high speed by using a toner. It is.

  The naphthol compound, which is achieved by using a toner having a specific viscosity range used in the toner of the present embodiment and improves the dispersibility of the pigment, deteriorates the image quality as shown in Table 1 above. It can be seen that the fixing quality is also excellent. That is, it can be said that the toner of the present embodiment prevents thermal deterioration in the fixing process and maintains the image quality at the same level as the toner image before fixing. Even if some residual toner is generated after fixing, the residual toner is excellent in cleaning property because it is resistant to thermal degradation. From this point, it can be said that the toner of the present embodiment is excellent in maintainability.

It is the schematic which shows the structure of the capillary type rheometer used for the evaluation method of the melt viscosity characteristic of the toner for electrostatic latent image development concerning this invention. It is this schematic diagram which shows the structure of the flow angle of 120 degrees of the cylinder end part used for the capillary type rheometer of this embodiment. The melt viscosity characteristic of the electrostatic latent image developing toner of Example 1 is shown. The melt viscosity characteristic of the electrostatic latent image developing toner of Example 2 is shown. The melt viscosity characteristic of the electrostatic latent image developing toner of Example 3 is shown. The melt viscosity characteristic of the electrostatic latent image developing toner of Example 4 is shown. The melt viscosity characteristic of the electrostatic latent image developing toner of Example 5 is shown. The melt viscosity characteristic of the electrostatic latent image developing toner of Example 6 is shown. The melt viscosity characteristic of the electrostatic latent image developing toner of Example 7 is shown. The melt viscosity characteristic of the electrostatic latent image developing toner of Example 8 is shown. The melt viscosity characteristic of the electrostatic latent image developing toner of Comparative Example 1 is shown. The melt viscosity characteristic of the electrostatic latent image developing toner of Comparative Example 2 is shown. The melt viscosity characteristic of the electrostatic latent image developing toner of Comparative Example 3 is shown.

Explanation of symbols

1 Sample 2 Cylinder member 3 Heater 4 Die body 4a Die hole diameter (pore)
5 Die holder 6 Piston

Claims (5)

In the toner for developing an electrostatic latent image, which contains at least a binder resin, a colorant, a charge control agent, a release agent, and a dispersion aid, and is obtained by a kneading pulverization method.
The electrostatic latent image developing toner has a melt viscosity characteristic from the outflow start temperature to the outflow end temperature measured by a capillary rheometer, satisfying the following formula (1):
Y = aX ² −bX + c (1)
The capillary tube rheometer includes a heating device, a cylinder that holds the electrostatic latent image developing toner, and a piston that presses the electrostatic latent image developing toner held in the cylinder,
The cylinder has pores through which the electrostatic latent image developing toner melted in the piston pressing direction flows.
Cylinder end having a pore is Ri shape der having an angle of 30 ° to 85 ° relative to the outflow direction,
An electrostatic latent image developing toner, wherein the dispersion aid is a compound (1) represented by the following general formula:
(However, in Formula (1), X represents measurement temperature (degreeC), Y represents a viscosity (Pa * s), a is 100-900, b is 1 * 10 < ⁴ > -2 * 10 < ⁵ >, c is 2 *. 10 ^{6 to} 2 × 10 ^7. )
Compound (1)

(R1 and R2 are 1 selected from an alkyl group having 1 to 4 carbon atoms and an alkoxy group, and R3 is 1 selected from hydrogen and a phenyl group.) 2. The electrostatic latent image developing toner according to claim 1, wherein the compounding amount of the compound (1) is in the range of 5 to 20 wt% with respect to the colorant . The electrostatic latent image developing toner according to claim 1, wherein the binder resin is a polyester resin. The electrostatic latent image developing toner according to claim 1, wherein the electrostatic latent image developing toner has a volume average particle diameter of 5 μm to 15 μm. The electrostatic latent image developing toner according to claim 1, further comprising an external additive.

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