JP2002148866A - Electrostatic charge image developing toner and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide electrostatic charge image developing toners consisting of a polyester resin of spherical to approximately spherical shapes which enable a so-called oil-less system to make fixation possible without using an offset preventive liquid as a heat roller fixing system and make it possible to obtain developed images of excellent quality and a method of manufacturing for the same. SOLUTION: The electrostatic charge image developing toners contain at least a binder resin and coloring agents. The binder resin is a polyester resin. The outflow initiation temperature Tfb by a fixed load extrusion capillary type rheometer of the toners is >=90 deg.C, <=120 deg.C; temp. T1/2 is over 120 deg.C and <=160 deg.C; the outflow end temperature Tend is >=130 deg.C and <=170 deg.C and the toners are the spherical to approximately spherical shapes of >=0.97 in the average circularity defined by the equation: the average circularity = (the circumferential length of the circle of the same area as a particle projection area)/(the circumferential length of a particle projection image). The toner having such characteristics are adequately manufactured by adding an alcoholic solvent to the toners and effecting a phase inversion with a low share of 0.2 to 5 m/s.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner for developing an electrostatic image, which is suitably used for an electrophotographic copying machine, a printer, a facsimile and the like, and is also used for a toner jet printer and the like.

[0002]

2. Description of the Related Art In recent years, in electrophotographic copiers, printers, and fax machines, toners have been used to further improve the quality of printed images or to reduce machine cost, downsizing, power saving, and resource saving. The following needs are increasing. (1) Toner size reduction and spheroidization for improving the resolution and gradation of printed images, thinning the toner layer, reducing the amount of waste toner, and reducing the toner consumption per page. (2) Lowering the fixing temperature to reduce power consumption (3) Oil-less fixing for simplification of machines, etc. (4) Improvement of hue, transparency and gloss in full-color images (5) Human health Reduction of VOC (volatile organic compound) at the time of fixing which may adversely affect the image quality.

[0003] It is basically possible to reduce the particle size of the powder toner by a pulverization method which has been used for a long time.
As the particle size decreases, the ratio of a release agent such as a colorant or wax exposed on the surface of the toner particles increases, so that charge control becomes difficult. Due to the irregular shape of the toner particles, powder fluidity deteriorates. In addition, problems such as an increase in the energy cost required for the production occur, and it is practically difficult to sufficiently satisfy the above-mentioned needs with the irregular toner by the pulverization method.

[0004] From such a background, development of spherical toners by a polymerization method or an emulsification dispersion method has hitherto been actively carried out. Regarding the toner by the polymerization method, various methods are known, among them, a monomer, a polymerization initiator, a colorant, a charge control agent and the like are uniformly dissolved and dispersed, and the
A suspension polymerization method is widely used, in which an oil droplet is formed by adding to an aqueous medium containing a dispersion stabilizer while stirring to form an oil droplet, and then the polymerization reaction is performed by heating to obtain toner particles. According to the polymerization method, although there is no problem in reducing the particle size and spheroidization of the toner particles, since the main component of the binder resin is limited to a vinyl polymer that can be radically polymerized, it is suitable for color toners and the like. Toner particles made of a polyester resin or an epoxy resin cannot be produced by a suspension polymerization method. Further, in the polymerization method, there is a problem that it is difficult to reduce VOC (volatile organic compound composed of an unreacted monomer or the like), and improvement thereof is desired.

On the other hand, a method for producing a toner by the emulsification dispersion method is as follows.
JP-A-5-66600 and JP-A-8-21655
As disclosed in Japanese Unexamined Patent Application Publication No. H10-163, a method in which a mixture of a binder resin and a colorant and the like is mixed with an aqueous medium and emulsified to obtain toner particles. In addition to being able to easily cope with diameter and spheroidization, the range of choice of the type of binder resin is wider than in the polymerization method.
It has the advantages that the OC can be easily reduced and the concentration of the colorant and the like can be arbitrarily changed from a low concentration to a high concentration.

[0006] As a binder resin for a toner having a relatively low fixing temperature and which tends to be sharply melted at the time of fixing to make the image surface smooth, a polyester resin is preferable to a styrene-acrylic resin. It is well known that a polyester resin having excellent flexibility is preferable. However, as described above, the polymerization method cannot produce toner particles containing a polyester resin as a main component of the binder resin. Therefore, in recent years, attention has been focused on producing a spherical to substantially spherical small particle size toner using a polyester resin as a binder resin by an emulsification dispersion method.

However, in the spherical toner obtained by the emulsification dispersion method, the lowering of the fixing temperature and the widening of the anti-offset temperature range are not always sufficiently realized, so that the toner is prevented from adhering to the fixing drum at the time of fixing. An application process such as silicone oil is performed. If these spherical toners can be further improved in terms of thermal characteristics, an oil-less toner having high offset resistance can be realized while utilizing its high image quality.

As a method for producing a toner using a polyester resin as a binder resin by an emulsification dispersion method, JP-A-9-311502, JP-A-5-66600, JP-A-8-21655, and JP-A-6-212655 332
Although Japanese Patent Application Laid-Open No. 224, Japanese Patent Application Laid-Open No. 6-332225, and Japanese Patent Application Laid-Open No. 10-319639 are disclosed, they cannot solve all problems to be solved by the present invention.

Japanese Patent Application Laid-Open No. 5-66600 discloses that a mixture comprising a binder resin, a colorant and an organic solvent is given a self-water dispersibility by neutralizing the binder resin, thereby allowing the mixture to be dispersed in an aqueous medium. It is a method of dispersing. However, this technique mainly uses a styrene acrylic resin as a binder resin, and is not necessarily suitable for low-temperature fixing and color toner. Further, it does not mention the composition of a binder resin in a toner using a polyester resin that enables low-temperature fixing and oil-less fixing.

JP-A-6-332224, JP-A-6-322224
-332225 discloses a polyester resin, a colorant,
In this method, a mixture comprising an organic solvent and a specific dispersion stabilizer is dispersed in an aqueous medium. In this technique, since the polyester resin itself does not have self-water dispersibility, dispersion in an aqueous medium is based on the action of only a dispersion stabilizer. In such a method of dispersing using a dispersion stabilizer, dispersion is difficult at low shear, and high shear dispersion is required using a homomixer or the like. As a result, the generation of coarse particles and fine particles tends to increase, and the classification loss tends to increase. In addition, there is no mention of compositions that can solve low-temperature fixing and oil-less fixing. In addition, those containing a high molecular weight component or a tetrahydrofuran-insoluble component have a wide particle size distribution, and there is a limit in production.

Japanese Patent Application Laid-Open No. 9-311502 discloses a method in which a mixture comprising a polyester resin and a colorant is mechanically dispersed in an aqueous medium by reducing the viscosity by heating and melting without using a solvent. In this method, there is a limit that can be used for the molecular weight of the resin, and those having a high molecular weight component are
Molecular chain scission occurs and the hot offset temperature cannot be increased. As a result, a satisfactory fixing width in the oilless fixing system, which is a problem to be solved by the present invention, cannot be achieved.

Japanese Patent Application Laid-Open No. Hei 8-21655 discloses a mixture comprising a polyester resin, a colorant and an organic solvent.
This is a method of imparting self-water dispersibility by neutralizing a polyester resin and dispersing it in an aqueous medium. This technique can be used for a color toner, and a spherical toner having a small particle diameter can be obtained, so that a part of the problem of the present invention can be solved. However, there is no mention of a composition that can achieve a good fixing width in low-temperature fixing or an oilless fixing system.

That is, the polyester resin toner by the emulsification dispersion method which has been conventionally used uses a binder resin mainly composed of a linear resin having a relatively low molecular weight. The application of an anti-offset liquid such as silicone oil is indispensable and does not result in oilless fixing. In addition, in such a fixing system, in addition to the problem of maintenance, since silicone oil or the like is transferred to a printing paper or an OHP sheet, there is a problem that writing after printing is hindered or the oil becomes sticky. . There is also a problem that the peel strength is not always sufficient depending on the use. In addition, there is a problem that the emulsification loss is large and the classification loss is large due to insufficient particle size distribution.

[0014]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a heat roller fixing system which enables a good fixing width without using an offset preventing liquid. It is an object of the present invention to provide a spherical to substantially spherical toner for developing an electrostatic charge image made of a polyester resin, which enables a so-called oil-less system and can obtain a developed image of excellent quality. Another object of the present invention is to provide an image forming method using an electrostatic image developing toner which solves the above problems. Still another object of the present invention is to provide a method for producing a toner for developing an electrostatic image which solves the above-mentioned problems.

[0015]

The present inventors have focused on the flow tester value of the toner, that is, the outflow start temperature Tfb, T1 / 2 temperature, and outflow end temperature Tend by the constant load extrusion type capillary rheometer, and have conducted intensive studies. As a result, it has been found that by setting these in a specific range, it is possible to obtain good fixing start temperature and hot offset resistance temperature in the oilless fixing system, and completed the present invention.

That is, in the toner for developing an electrostatic charge image of the present invention, the toner for developing an electrostatic charge image containing at least a binder resin and a colorant, wherein the binder resin is a polyester resin, Outflow starting temperature Tfb by constant load extrusion type capillary rheometer is 90 ° C or higher, 120
℃ or less, T1 / 2 temperature exceeds 120 ℃, 160 ℃ or less,
The outflow end temperature Tend is 130 ° C. or more and 170 ° C. or less, and the following equation: average circularity = (perimeter of a circle having the same area as the particle projected area) /
The average circularity defined by (perimeter of particle projection image) is 0.97 or more spherical to substantially spherical.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The electrostatic image developing toner of the present invention contains at least a binder and a colorant, and the binder resin is a polyester resin. The polyester resin used as the binder resin is synthesized by dehydrating and condensing a polybasic acid and a polyhydric alcohol.

Examples of the polybasic acid include aromatic carboxylic acids such as terephthalic acid, isophthalic acid, phthalic anhydride, trimellitic anhydride, pyromellitic acid, and naphthalenedicarboxylic acid; maleic anhydride, fumaric acid, succinic acid, Aliphatic carboxylic acids such as alkenylsuccinic anhydride and adipic acid; alicyclic carboxylic acids such as cyclohexanedicarboxylic acid; These polybasic acids can be used alone or in combination of two or more. Among these polybasic acids, it is preferable to use aromatic carboxylic acids.

Examples of the polyhydric alcohol include aliphatic diols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, glycerin, trimethylolpropane, and pentaerythritol; cyclohexanediol And alicyclic diols such as cyclohexanedimethanol and hydrogenated bisphenol A; and aromatic diols such as ethylene oxide adduct of bisphenol A and propylene oxide adduct of bisphenol A. These polyhydric alcohols can be used alone or in combination of two or more. Among these polyhydric alcohols, aromatic diols and alicyclic diols are preferable, and aromatic diols are more preferable.

In addition, a monocarboxylic acid and / or a monoalcohol is further added to a polyester resin obtained by polycondensation of a polyvalent carboxylic acid and a polyhydric alcohol.
The hydroxyl value and / or carboxyl group at the polymerization end can be esterified to adjust the acid value of the polyester resin. Examples of the monocarboxylic acid used for such a purpose include acetic acid, acetic anhydride, benzoic acid, trichloroacetic acid, trifluoroacetic acid, and propionic anhydride. Further, as the monoalcohol, for example, methanol, ethanol, propanol, octanol,
Examples include 2-ethylhexanol, trifluoroethanol, trichloroethanol, hexafluoroisopropanol, and phenol.

The polyester resin can be produced by subjecting the above-mentioned polyhydric alcohol and polycarboxylic acid to a condensation reaction according to a conventional method. For example, the polyhydric alcohol and the polyhydric carboxylic acid are blended in a thermometer, a stirrer, a reaction vessel equipped with a falling condenser, and heated at 150 to 250 ° C. in the presence of an inert gas such as nitrogen. By continuously removing low-molecular compounds produced as by-products from the reaction system, stopping the reaction when a predetermined physical property value is reached, and cooling,
The desired reactant can be obtained.

The synthesis of such a polyester resin can be carried out by adding a catalyst. Examples of the esterification catalyst used include organic metals such as dibutyltin dilaurate and dibutyltin oxide, and metal alkoxides such as tetrabutyl titanate. When the carboxylic acid component used is a lower alkyl ester, a transesterification catalyst can be used. Examples of the transesterification catalyst include metal acetates such as zinc acetate, lead acetate and magnesium acetate; metal oxides such as zinc oxide and antimony oxide; and metal alkoxides such as tetrabutyl titanate. The addition amount of the catalyst is preferably in the range of 0.01 to 1% by weight based on the total amount of the raw materials.

In such a polycondensation reaction, in particular, in order to produce a crosslinked polyester resin, a polybasic acid having three or more carboxyl groups in one molecule or an anhydride thereof, and / or one molecule A polyhydric alcohol having three or more hydroxyl groups therein may be used as an essential synthesis raw material.

The toner for developing an electrostatic image of the present invention comprising the polyester resin thus obtained as a binder resin,
The flow tester value is in the following range. That is, as a flow tester value of the electrostatic image developing toner,
Outflow starting temperature Tfb by constant load extrusion type capillary rheometer is in the range of 90 ° C. or more and 120 ° C. or less, T1 / 2 temperature is more than 120 ° C. and 160 ° C. or less, and outflow end temperature Tend is 130 ° C. or more and 170 ° C. ℃ or below.
By having such a flow tester value, the toner for developing an electrostatic image of the present invention has good fixability.

Outflow start temperature Tfb, T1 / 2 temperature, outflow end temperature Tend by constant load extrusion type capillary rheometer
Is a flow tester CFT-50 manufactured by Shimadzu Corporation in the present invention.
It is determined using 0. This flow tester is shown in FIG.
As shown in (a), a cylinder 2 having a nozzle 1 having a nozzle diameter D of 1.0 mmΦ and a nozzle length (depth) L of 1.0 mm is charged with toner 3 (weight 1.5 g). Stroke S of load surface 4 (subsidence value of load surface 4) when a load of 30 kg per unit area (cm ² ) is applied from the opposite side and heated at a rate of 6 ° C./min.
Is obtained by measuring That is, the relationship between the temperature and the stroke S is determined as shown in FIG. 1B, and when the flow of the toner 3 from the nozzle 1 starts, the stroke S sharply increases and the curve rises. Let the temperature be Tfb and the toner 3 from nozzle 1
Tend is the temperature when the outflow of the water is almost finished and the curve is bent
And Then, the stroke Sfb at the time of Tfb and Tend
The temperature at S1 / 2, which is an intermediate value with the stroke Send at the time, is defined as T1 / 2 temperature.

In the measurement by the temperature raising method using this apparatus, the test is performed while raising the temperature at a constant rate with the passage of the test time, and the sample is transferred from the solid region to the transition region, through the rubbery elastic region, to the flow region. The process leading up to this can be measured continuously. With this device, the shear rate and the viscosity at each temperature in the flow region can be easily measured.

The outflow start temperature Tfb is an index of the sharp melt property and low-temperature fixability of the toner. If the temperature is too high, the low-temperature fixability deteriorates, and cold offset easily occurs. Further, if the temperature is too low, the storage stability decreases, and hot offset easily occurs. Therefore, the outflow starting temperature Tfb of the toner for developing an electrostatic image of the present invention is preferably from 90 ° C. to 115 ° C., and more preferably from 90 to 110 ° C.

The melting temperature T1 / 2 and the outflow end temperature Tend according to the 1/2 method are indicators of hot offset resistance. If both are too high, the solution viscosity increases, so that the particle formation time is reduced. Deteriorates the particle size distribution. In addition, if both are too low in temperature, offset tends to occur and the practicability is reduced. Therefore, the melting temperature T1 / 2 by the 1/2 method is preferably higher than 120 ° C. and 155 ° C. or lower, more preferably 130 to 150 ° C., and the outflow end temperature Tend is preferably 130 ° C. or higher and 165 ° C. or lower. It is more preferable that the temperature is not lower than 160 ° C and not higher than 160 ° C. Tf
By setting b, T1 / 2 and Tend within the above ranges, fixing can be performed in a wide temperature range.

Further, the toner for developing an electrostatic image of the present invention comprises:
The following formula, average circularity = (perimeter of a circle having the same area as the particle projected area) /
The average circularity defined by (peripheral length of particle projection image) is 0.97 or more, preferably 0.98 or more, from spherical to substantially spherical. By having such a spherical shape to a substantially spherical shape, the toner for developing an electrostatic image of the present invention can ensure good powder fluidity even if the particle diameter is reduced, and ensure good transfer efficiency. This makes it possible to form excellent image quality (resolution, gradation). If the average degree of circularity is smaller than 0.97, that is, if the shape approaches a spherical shape to an irregular shape, the transfer efficiency decreases, which is not preferable. The average circularity can also be obtained by taking an SEM (scanning electron microscope) photograph of the toner particles, measuring and calculating the same, but a flow-type particle image analyzer manufactured by Toa Medical Electronics Co., Ltd. Since it can be easily obtained by using FPIP-1000, in the present invention, it was measured by this apparatus.

In such an electrostatic image developing toner, the binder resin described above contains a crosslinked polyester resin, and the binder resin has a tetrahydrofuran-insoluble content of 0.2 to 20% by weight in the toner. , More preferably in the range of 0.5 to 10% by weight, more preferably 0.1 to 10% by weight.
Good hot offset resistance is ensured by using a polyester resin having a tetrahydrofuran-insoluble content of 0.2 to 20% by weight as the binder resin in the toner as described above. Is preferred. 0.
If the amount is less than 2% by weight, the effect of improving hot offset resistance is insufficient, which is not preferable. If the content is more than 20% by weight, the solution viscosity becomes too high, the particle size distribution at the time of particle formation deteriorates, and the fixing start temperature becomes high, and the fixing property is unbalanced. Where,
Regarding the tetrahydrofuran insoluble content of the binder resin in the toner, 1 g of the toner was precisely weighed, and 40 m of tetrahydrofuran was measured.
and 2 g of radiolite (# 700 manufactured by Showa Chemical Co., Ltd.) is spread evenly on a funnel (diameter 40 mm) on which Kiriyama filter paper (No. 3) is placed, and the cake is filtered. Place on a petri dish, then dry at 140 ° C. for 1 hour, and measure the dry weight. Then, a value obtained by dividing the amount of the residual resin in the dry weight by the amount of the first toner sample is calculated as a percentage, and this value is defined as the insoluble content. However, the toner contains additives such as pigments, waxes, and external additives. However, considering the content of these additives and whether they are soluble or insoluble in THF, the THF insoluble content of the binder resin is considered. Is calculated.

It is more preferable that the binder resin contains a linear polyester resin. That is,
In the electrostatic image developing toner of the present invention, the binder resin may be composed of one kind of polyester resin,
In general, it is preferable to use a blend of a high-molecular-weight, high-viscosity crosslinked polyester resin (cross-linked polyester resin) and a low-molecular-weight, low-viscosity linear polyester resin in the production of the resin. It is practical and preferable to obtain good fixing start temperature and hot offset resistance. Here, the crosslinked polyester resin indicates a resin having a component insoluble in tetrahydrofuran, and the linear polyester resin indicates a resin soluble in tetrahydrofuran containing no crosslinker component.

In the present invention, when a mixture of a linear polyester resin and a crosslinked polyester resin is used as the binder resin, the linear polyester resin (A) and the crosslinked polyester resin (B ) Is more preferably used as a mixture. That is, a straight-chain polyester resin (A) having a T1 / 2 temperature of 80 ° C or more and 120 ° C or less and a glass transition temperature Tg of 40 ° C or more and 75 ° C or less measured by a constant load extrusion type capillary rheometer. The crosslinked polyester resin (B) has a T1 / 2 temperature of 120 using a constant load extrusion type capillary rheometer.
° C and 210 ° C or lower, and having a glass transition temperature Tg of 40 ° C or higher and 75 ° C or lower, and further, these linear polyester resin (A) and crosslinked polyester resin (B)
And (A) / (B) = 20/80 to 80/20, and the T1 / 2 temperature is set to T1 / 2 (A) and T1 / 2, respectively.
In the case of (B), those having a relationship of 20 ° C. <T1 / 2 (B) −T1 / 2 (A) ≦ 120 ° C. are preferably used.

Considering each temperature characteristic by a constant load extrusion type thin tube rheometer, the melting temperature T1 / 2 (A) of the resin (A) by the 1/2 method is to provide sharp meltability and low-temperature fixability. T1 / 2 (A)
Is preferably in the range of 80 to 115 ° C., and 90 to 115 ° C.
The temperature is more preferably in the range of 110 ° C.

The resin (A) defined by these properties
Has a low softening temperature.In the fixing process using a heat roll, even if the applied heat energy is reduced by lowering the temperature of the heat roll or increasing the process speed, it sufficiently melts and achieves cold offset resistance and low-temperature fixability. Demonstrates excellent performance.

The melting temperature T1 / of the resin (B) by the 1/2 method
If both 2 (B) and the end-of-flow temperature Tend (B) are too low, hot offset is likely to occur, and if too high, the particle size distribution during particle formation deteriorates and productivity decreases. Therefore, T1 / 2 (B) is 125 ° C. to 2 ° C.
The temperature is preferably 10 ° C, more preferably 130 ° C to 200 ° C.

Resin (B) defined by these properties
Has a strong rubber elasticity and a high melt viscosity, so the internal cohesive force of the melted toner layer is maintained even during heating and melting in the fixing process, hot offset hardly occurs, and its toughness after fixing Demonstrates excellent friction resistance.

By blending the resin (A) and the resin (B) in a well-balanced manner, it is possible to provide a toner that sufficiently satisfies the anti-offset performance and the low-temperature fixing performance in a wide temperature range.

Weight ratio of resin (A) to resin (B) (A) /
If (B) is too small, it affects the fixability. If (B) is too large, it affects the anti-offset property, so it is preferably 20/80 to 80/20.
The ratio is more preferably 30/70 to 70/30.

The melting temperatures of the resin (A) and the resin (B) according to the を method are T1 / 2 (A) and T1 / 2 (B), respectively.
In this case, T1 / 2 (A) <T1 / 2 (B) may be sufficient, but in particular, from the viewpoint of achieving a balance between low-temperature fixability and offset resistance, and from the difference in viscosity between resins. In order to make it easy to mix uniformly without causing
The range of (B) -T1 / 2 (A) is preferably from 20 to 120C, more preferably from 30 to 110C.

Here, the T1 / 2 temperature measured by the constant load extrusion type capillary rheometer should be measured for the resin instead of the toner in the same manner as described above with reference to FIGS. 1 (a) and 1 (b). Is a value obtained by In the present invention, the glass transition temperature Tg is a value obtained by using a differential scanning calorimeter DSC-50 manufactured by Shimadzu Corporation at a heating rate of 10 ° C. per minute by a second run method.

The linear polyester resin (A) and the crosslinked polyester resin (B) both preferably have a glass transition temperature Tg of 40 ° C. or more and 75 ° C. or less, because the glass transition temperature Tg is preferably If it is lower than 40 ° C.,
The resulting toner tends to cause blocking (a phenomenon in which toner particles aggregate and clump) during storage or in a developing machine. On the other hand, when the glass transition temperature exceeds 75 ° C., the fixing temperature of the toner decreases. This is because they tend to be higher. As described above, as the polyester resin serving as the binder resin, the linear polyester resin (A) having the above relationship is used.
By using the crosslinked polyester resin (B), the obtained toner has better fixability, which is preferable.

Further, the toner of the present invention and the polyester resin used as the binder resin have a T1 / 2 temperature of T1 / 2 measured by a constant load extrusion type capillary rheometer, respectively.
(Toner) and T1 / 2 (resin), it is preferable that the relationship of T1 / 2 (toner) ≧ T1 / 2 (resin) is satisfied. The resulting toner has better fixability.

That is, as described later, the dispersion of the pigment which is a component of the toner is performed by dispersing and dispersing a polyester resin in a solvent and then kneading with a ball mill or the like to obtain a binder resin (polyester). The resin does not undergo molecular cleavage, so that the binder resin does not change in molecular weight or the like. Therefore, by using a mixture containing binder resin, pigment, wax and organic solvent obtained by such wet dispersion, the relationship of T1 / 2 (toner) ≧ T1 / 2 (resin) is obtained as described above. It becomes. On the other hand, in the case of the toner obtained by the pulverization method, the properties of the binder resin change due to the cutting of the polymer chains during melt kneading and the like.
(Toner) <T1 / 2 (resin). Thus, in order to have oil-less fixing property and to obtain good low-temperature fixing property and hot offset resistance, as in the present invention, T1 / 2
The relationship of (toner) ≧ T1 / 2 (resin) is important for balancing low-temperature fixability and hot offset resistance, and also simplicity in resin synthesis (a high-viscosity resin is used because polymer chains are not cut). It is preferable from the viewpoint of no need to synthesize).

The binder resin composed of a polyester resin has a weight average molecular weight of 30,000 or more, preferably 37,000 or more, as determined by gel permeation chromatography (GPC) using a tetrahydrofuran (THF) -soluble component. 000 or more, weight-average molecular weight Mw / number-average molecular weight Mn is 12 or more, preferably 15 or more, and the area ratio of components having a molecular weight of 600,000 or more is 0.5% or more of the whole;
Preferably, the area ratio of the component having a molecular weight of 0.7% or more and a molecular weight of 10,000 or less satisfies all the conditions of 20 to 80%, and preferably 30 to 70%, in order to obtain good fixability.

In the toner of the present invention, the high molecular weight component having a molecular weight of 600,000 or more has a function of ensuring hot offset resistance. A toner using a binder resin containing a high molecular weight component having a molecular weight of 600,000 or more is suitable as a toner used in an oilless fixing type fixing device. On the other hand, a low molecular weight component having a molecular weight of 10,000 or less is effective for lowering the melt viscosity of the toner, exhibiting a sharp melt property, and lowering the fixing start temperature. The toner of the present invention preferably contains a resin component having a molecular weight of 10,000 or less. In order to obtain good fixing properties such as low-temperature fixing and hot offset resistance in the oilless fixing method, it is preferable that the binder resin has such a broad molecular weight distribution. In addition, in the granulation of toner particles by the emulsification dispersion method, it is preferable to include a low molecular weight component from the viewpoint of lowering the viscosity of the resin solution.

Here, the molecular weight of the THF-soluble matter in the binder resin was determined by filtering the THF-soluble matter through a 0.2 μm filter, and then using GPC HLC-8120 manufactured by Tosoh, and a column “TSKgel SuperHM-M manufactured by Tosoh”. (15c
m), using a THF solvent (flow rate 0.6 ml / mi).
n, at a temperature of 40 ° C.), and the molecular weight was calculated by using a molecular weight calibration curve prepared with a monodisperse polystyrene standard sample.

The molecular weights of the tetrahydrofuran-insoluble component and the tetrahydrofuran-soluble component in the specific ranges described above in the present invention are those of the polyester resin in the toner, and are the raw materials of the polyester resin used in the production of the toner. Does not have. That is, when the characteristics of the resin that affects the fixing property are defined, the characteristics of the binder resin in the toner are important.

The acid value of the polyester resin (1 g of resin)
(The number of mg of KOH required to neutralize the toner) is such that the molecular weight distribution as described above is easily obtained, the granulation of toner particles is easily ensured by the emulsification dispersion method, and the environmental stability of the obtained toner ( Stability of charging when temperature and humidity change), it is easy to maintain good
A range of ３０30 mg KOH / g is preferred. As described above, the acid value of the polyester resin is determined by adding the monocarboxylic acid and / or the monoalcohol to the polyester resin obtained by condensation polymerization of the polyvalent carboxylic acid and the polyhydric alcohol. It can be adjusted by controlling the carboxyl group at the terminal of the polyester by the mixing ratio and the reaction rate of the polybasic acid and the polyhydric alcohol. Alternatively, a polyester having a carboxyl group in the main chain can be formed by using trimellitic anhydride as the polybasic acid component.

The toner for developing an electrostatic image of the present invention includes:
It is preferable to contain a release agent. In this case, examples of the release agent include hydrocarbon waxes such as polypropylene wax, polyethylene wax and Fischer-Tropsch wax, synthetic ester waxes, carnauba wax and rice wax. A wax selected from the group of ester waxes is used. Among them, natural ester waxes such as carnauba wax and rice wax, and synthetic ester waxes such as WEP-5 (manufactured by NOF CORPORATION) obtained from a polyhydric alcohol and a long-chain monocarboxylic acid are preferred.

The melting point of the wax used is not particularly limited, but is preferably 150 ° C. from the viewpoint of offset resistance.
The temperature is preferably in the range of 50 to 120 ° C. from the viewpoint of low-temperature fixability and storage stability. As such a wax, a solid wax may be used as it is, or may be used in an emulsified state. The wax is preferably dispersed in the toner particles, and is preferably dispersed to an average of 3 μm or less, preferably to an average of about 1 μm or less. The content of the wax is preferably in the range of 1 to 40% by weight based on the toner. If the amount is less than 1% by weight, the releasability tends to be insufficient, and if it exceeds 40% by weight, the wax tends to be exposed on the surface of the toner particles, and the chargeability and the storage stability tend to decrease.

The toner of the present invention preferably contains a positively chargeable charge control agent. The positively chargeable charge control agent is not particularly limited, and a known and commonly used nigrosine dye, a quaternary ammonium compound, an onium compound, a triphenylmethane compound and the like can be used for toner. In addition, compounds containing a basic group such as an amino group, an imino group, or an N-hetero ring, such as a styrene acrylic resin containing a tertiary amino group, also have an effect as a positively chargeable charge controlling agent. The control agent can be used alone or in combination with the positively chargeable charge control agent. Depending on the application, a small amount of a negative charge control agent such as an azo dye metal complex or a salicylic acid derivative metal complex salt may be used in combination with these positively chargeable charge control agents.

The content of the positively chargeable charge control agent in the toner of the present invention is preferably 0.01 to 10% by weight. In particular, it is preferably 0.1 to 6% by weight. Further, in the case of a production method in which a positive charge control agent is contained in the toner and a part thereof is exposed on the surface of the toner, the above content is necessary. When a means for fixing the positively chargeable charge control agent is employed, the amount of the positively chargeable charge control agent added to the toner surface can be reduced. In this case, the addition amount is preferably 0.01 to 1% by weight. Especially 0.01 to 0.5
Preferably, it is weight%. Since a desired appropriate charge can be obtained with a small amount of the charge control agent, it is more preferable to fix the positive charge control agent on the surface of the toner particles.

The colorant used in the toner for developing an electrostatic image of the present invention is not particularly limited, and a known and commonly used colorant is used, and a pigment is particularly preferably used. Examples of the black pigment include carbon black, cyanine black, aniline black, ferrite, and magnetite. In addition, a mixture of the following chromatic pigments so as to be black can also be used.

Examples of the yellow pigment include, for example, graphite, zinc yellow, cadmium yellow, yellow iron oxide, loess, titanium yellow, naphthol yellow S, Hansa yellow 10G, Hansa yellow 5G, Hansa yellow G, Hansa yellow GR, Hansa yellow. A, Hansa Yellow RN, Hansa Yellow R, Pigment Yellow L, Benzidine Yellow, Benzidine Yellow G, Benzidine Yellow GR,
Permanent Yellow NCG, Vulcan First Yellow 5G, Vulcan First Yellow R, Quinoline Yellow Lake, Anslagen Yellow 6GL, Permanent Yellow FGL, Permanent Yellow H10G,
Permanent yellow HR, anthrapyrimidine yellow, other isoindolinone yellow, chromophtal yellow, novo palm yellow H2G, condensed azo yellow, nickel azo yellow, copper azomethine yellow and the like.

As the red pigment, for example, red lead, molybdenum orange, permanent orange GTR, pyrazolone orange, vulcan orange, indaslen brilliant orange RK, indaslen brilliant orange GK, benzidine orange G, permanent red 4R, permanent red BL , Permanent red F
5RK, Risor Red, Pyrazolone Red, Watching Red, Lake Red C, Lake Red D, Brilliant Carmine 6B, Brilliant Carmine 3B, Rhodamine Lake B, Alizarin Lake, Permanent Carmine FBB, Verinone Orange, Isoindolinone Orange, Ansuanthrone Orange Pyranthrone orange, quinacridone red, quinacridone magenta, quinacridone scarlet, perylene red and the like.

Examples of the blue pigment include cobalt blue, cerulean blue, alkali blue lake, peacock blue lake, fanatone blue 6G, Victoria blue lake, metal-free phthalocyanine blue, copper phthalocyanine blue, fast sky blue, and induslen blue RS. , Indaslen Blue BC, Indico and the like. The amount of these colorants used is
The range of 1 to 50 parts by weight per 0 parts by weight is preferable, and
A range of 15 parts by weight is particularly preferred.

In order to maintain good triboelectric charging performance even when the particle size of the toner is reduced, it is necessary to prevent the colorant or the like from being exposed on the surface of the toner particle, that is, the colorant or the like is included in the toner particle. It is effective to adopt a toner structure having a low toner density. The deterioration of the chargeability due to the reduction in the particle size of the toner is also caused by the fact that a part of the contained colorant and other additives (such as wax) is exposed on the surface of the toner particles.
That is, even if the content (% by weight) of the colorant or the like is the same, the surface area of the toner particles increases due to the reduction in the particle size, and the ratio of the colorant or wax exposed on the surface of the toner particles increases. As a result, the composition of the toner particle surface changes greatly, and the triboelectric charging performance of the toner particles changes greatly, making it difficult to obtain an appropriate charging property.

The toner of the present invention desirably contains a colorant, wax, and the like in the binder resin, and a good printed image can be obtained by having such a structure. Whether the colorant, the wax, or the like is not exposed on the surface of the toner particles can be easily determined by, for example, observing the cross section of the particles with a TEM (transmission electron microscope). More specifically, a section obtained by embedding the toner particles in a resin and cutting with a microtome is dyed with ruthenium oxide or the like, if necessary, and observed with a TEM. Can be confirmed.

The toner for developing an electrostatic image of the present invention is prepared by mixing a mixture containing at least a binder resin comprising a carboxyl group-containing polyester resin, a colorant and a release agent with an aqueous solution in the presence of a base. By mixing and emulsifying with a medium, at least a colorant and a release agent are formed into colored particles (I) encapsulated in a binder resin, and then the colored particles (I) are separated from the liquid medium and dried. It is suitably manufactured by a manufacturing method. In this case, a mixture comprising a binder resin, a colorant, and a release agent can be manufactured by a known and commonly used method.For example, first, these raw material powders are mixed,
Then, it is preferable to produce by a method of sufficiently melting and kneading using any of a twin-screw extruder, a kneader, a two-roll, or the like. In such a melt-kneading step, a high molecular weight component of the binder resin may be cut off. Therefore, as in the case of the toner of the present invention, it is necessary to manufacture a toner composed of a binder resin having a flow tester value in a specific range. It is preferable to select a raw material resin to be used by predicting a change in molecular weight during kneading of the binder resin in advance. Further, as a method of mixing and kneading the kneaded material thus produced with an aqueous medium and emulsifying, for example, a method of emulsifying the kneaded material in an aqueous medium by adding high-speed stirring conditions in the presence of a base. Can be used.
In particular, when this step is used, it is preferable that the binder resin is softened and produced under a high temperature and a high pressure in which the boiling of the aqueous medium can be suppressed. Further, the toner for developing an electrostatic image of the present invention is obtained by mixing a binder resin, a colorant, and a release agent with an organic solvent, and further kneading and dispersing the mixture in a wet method to obtain the mixture. Can also be manufactured. In this case, the colorant and the release agent may be separately kneaded and dispersed by a wet method.

Specifically, a binder resin is dissolved in an organic solvent, a colorant and a release agent are added thereto, and a general mixer such as a despa (dispersion stirrer), a ball mill, a bead mill, a sand mill, a continuous bead mill or the like is used. By dispersing using a disperser, a resin solution in which a colorant and a release agent are finely dispersed in an organic solvent is produced, and then mixed with an aqueous medium in the presence of a basic neutralizing agent This is a method for producing an aqueous medium (suspension) of the colored particles (I) by emulsifying and further removing the organic solvent under reduced pressure. Thereafter, the colored particles (I) are separated from the aqueous medium and dried to obtain a toner. According to this production method, since the polymer component (gel component) is not cut, it is preferable to the above-mentioned method in which a high shear is added to the resin. The polyester resin used for producing the toner for developing an electrostatic image of the present invention is a polyester resin containing a carboxyl group.

The polyester resin containing a carboxyl group which is an acidic group becomes self-water dispersible by neutralizing the acidic group. The resin having self-water dispersibility increases hydrophilicity when the acidic group becomes an anionic type, and is dispersed in an aqueous medium (water or a liquid medium containing water as a main component).

The base used to neutralize the acidic group (carboxyl group) is not particularly limited, and may be, for example, an inorganic base such as sodium hydroxide, potassium hydroxide or ammonia, or an organic base such as diethylamine, triethylamine or isopropylamine. A base is used.

Examples of the organic solvent for dissolving or dispersing the binder resin, the colorant, and the wax (release agent) include hydrocarbons such as pentane, hexane, heptane, benzene, toluene, xylene, cyclohexane, and petroleum ether. Halogenated hydrocarbons such as methylene chloride, chloroform, dichloroethane, dichloroethylene, trichloroethane, trichloroethylene, and carbon tetrachloride; ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; esters such as ethyl acetate and butyl acetate. Used. These solvents are
They can be used alone or in combination of two or more. The organic solvent is preferably one that dissolves the binder resin, has a relatively low toxicity, and has a low boiling point that is easy to remove the solvent in the subsequent step. As such a solvent, methyl ethyl ketone is most preferred.

The method of neutralizing an acidic group (carboxyl group) of a polyester resin with a base is as follows: (1) A binder resin having a previously neutralized acidic group is used to contain a colorant, a wax and an organic solvent. Or (2) a method of preparing a mixture containing a binder resin having an acidic group, a colorant, a wax, and an organic solvent, and then neutralizing the mixture with a base.

The method of emulsifying the polyester resin after neutralizing the acidic groups with a base is as follows: (3) a method of emulsifying the mixture by adding the mixture to an aqueous medium; or (4) adding an aqueous medium to the mixture. Method. The above (2)
The combination of (4) and (4) is preferable because the particle size distribution is improved.

In addition, there is a method in which a basic neutralizing agent is mixed in an aqueous medium, but from the viewpoint of particle size distribution, a neutralization and emulsification method using the above combination is preferable.

In the production method of the present invention, a mixture containing at least a binder resin comprising a carboxyl group-containing polyester resin, a colorant, and a release agent is mixed with an aqueous medium in the presence of a base. When emulsification is performed, it is preferable to add a phase inversion accelerator. The phase inversion accelerator referred to here has a different function from the emulsifier and dispersion stabilizer described in the section of the prior art. That is, the emulsifier described in the section of the prior art,
The dispersion stabilizer has a function of adsorbing on the particle surface and having a function of stably dispersing the formed particles in an aqueous medium without fusing or agglomerating each other. On the other hand, the phase inversion accelerator used in the production method of the present invention refers to one having a phase inversion promoting function. That is, in the step of adding an aqueous medium (water or a liquid medium containing water as a main component) to a mixture of a binder resin, a colorant, and the like and an organic solvent, water is gradually added to the organic continuous phase of the mixture. Then, a discontinuous phase of Water in Oil is generated, and the phase is changed to a discontinuous phase of Oil in Water by further adding water, and the mixture is formed into particles (droplets) in an aqueous medium.
As a suspension is formed. At this time, Water i
A substance having a function of smoothly promoting the phase transition from a discontinuous phase of n Oil to a discontinuous phase of Oil in Water is referred to as a phase inversion promoter. As mentioned earlier,
In the production method of the present invention, particles composed of a self-water-dispersible resin obtained by neutralizing the resin are formed by phase inversion.
The particles do not require so-called emulsifiers and dispersion stabilizers because the neutralized functional groups in the resin are present on the particle surface and can be stably present in the aqueous medium. Since the binder resin used in the present invention has self-water dispersibility by neutralization, it can be dispersed in an aqueous medium without using a phase inversion accelerator. However, in a binder resin made of a polyester resin satisfying the requirements of the toner of the present invention, by using a phase inversion accelerator, it is possible to produce a suitable powder toner having an average particle size, and a particle size distribution. It will be easier. For example, when methyl ethyl ketone is used as a solvent and water is dropped under low shear stirring, fine particles of about 1 μm are dispersed in water, or the viscosity increases during the phase inversion process when trying to increase the particle diameter. Occurs, and the phenomenon that phase inversion does not occur occurs. When dispersed and associated with a high shear by using a homomixer based on the technology of JP-A-10-319639, a sphere having a spherical shape and an average particle size usable for a toner is obtained, as described in the section of the prior art. This is not preferable because fine particles and coarse particles are generated.

By adding the phase inversion accelerator used in the production method of the present invention, a resin satisfying the object of the present invention can be used, and further, by stirring with a low shear, a spherical and suitable average particle diameter for the toner can be obtained. Thus, a powder toner having a sharp particle size distribution and having a small number of fine particles and a small classification loss can be produced.

The following can be used as the phase inversion accelerator in the present invention. Alcohol solvent Metal salt compound

Examples of the alcohol solvent include methanol, ethanol, isopropanol, n-propanol, isobutanol, n-butanol, t-butanol and sec.
-Butanol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monoethyl ether and the like can be used. Of course, other materials can be used. Among them, preferred are isopropanol, which is dissolved in water and has a low boiling point,
n-Propanol is preferred. The amount of the alcohol solvent used is generally 10 to 50 per 100 parts by weight of the resin solids.
It is on the order of parts by weight, but of course is not limited to this amount.

As the metal salt compound, known and commonly used ones can be used, but a divalent or higher valent metal salt which is soluble in water is preferred. For example, barium chloride, calcium chloride, cuprous chloride, cupric chloride, ferrous chloride, ferric chloride and the like can be mentioned. The amount of the metal salt compound used is the resin solid content 1
The amount is generally about 0.01 to 3 parts by weight per 00 parts by weight, but is not limited to this amount, of course.

The method for emulsifying and dispersing a mixture comprising a binder resin, a colorant, an organic solvent, a basic neutralizing agent, and a phase inversion promoter in an aqueous medium is not limited to a special method. .

In the production method of the present invention, a homomixer (Tokusai Kika Kogyo Co., Ltd.), a slasher (Mitsui Mining Co., Ltd.), a Cavitron (Eurotech Co., Ltd.), a microfluidizer (Mizuho Kogyo Co., Ltd.), a Menton-Gaulin homogenizer ( High shear emulsifying and dispersing machines such as Gallin), Nanomizer (Nanomizer Co., Ltd.), and Static Mixer (Noritake Company) can be used.

However, for example, Japanese Patent Application Laid-Open No. 9-114
Agitator, anchor wing, as disclosed in 135,
Using a turbine blade, a Faudler blade, a full zone blade, a max blend blade, a half moon blade, etc., the stirring blade has a low peripheral speed of 0.2 to 5 m / s, more preferably 0.5 to 4 m / s. A method of dropping water while stirring is preferable.

By performing emulsification and dispersion under such a low shear, the generation of fine powder can be suppressed, and a more preferable uniform particle size distribution can be realized. Further, the low molecular weight component of the polyester resin is not concentrated on the fine powder, so that the molecular weight distribution of the toner particles is not unbalanced and the low temperature fixability of the toner is not deteriorated.

The toner for developing an electrostatic image in the present invention can be made a positively chargeable toner by using a positively chargeable charge control agent. As a method of producing a positively chargeable toner, for example, a mixture containing a polyester resin, a colorant, and a positively chargeable charge control agent as essential components, in the presence of a basic neutralizing agent, is mixed with an aqueous medium and emulsified. There is a method of separating the particles obtained from the liquid medium and drying. Or
A mixture of a positively chargeable charge control agent and a resin that becomes self-water dispersible and / or water-soluble by neutralization in the presence of a neutralizing agent,
A suspension of the fine particles (II) obtained by emulsification in an aqueous medium is produced, and then the suspension of the fine particles (II) and the suspension of the colored particles (I) produced in another step are mixed. And
Further, a compound having a polarity opposite to that of the neutralizing agent is added to form fine particles (III) in which fine particles (II) are deposited on the surface of the colored fine particles (I). And dried and dried.

A mixture comprising a resin which becomes self-water dispersible and / or water-soluble by neutralization and a positively chargeable charge controlling agent is mixed with an aqueous medium in the presence of a neutralizing agent and emulsified. The resin used in the step of obtaining the suspension of the fine particles (II) containing the chargeable charge control agent is not particularly limited as long as it is a resin containing an acidic group or a basic group.

Examples of the functional group which can be converted into a hydrophilic group by neutralization include, for example, an acidic group such as a carboxyl group, a phosphoric acid group, a sulfonic acid group, and a sulfuric acid group. Further, as the basic group, primary, secondary,
There are a tertiary amino group and a quaternary ammonium group, among which a tertiary amino group is preferable. Examples of the resin containing these functional groups include a styrene resin, a (meth) acrylic resin, a polyester resin, a polyurethane resin, and an epoxy resin. Resins are particularly preferably used.

The neutralizing agent for these acidic groups is not particularly restricted but includes, for example, inorganic bases such as sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide, sodium carbonate, ammonia, and diethylamine, triethylamine. And organic bases such as isopropylamine. Examples of the basic neutralizing agent which is a compound having the opposite polarity to the acidic neutralizing agent include, for example, hydrochloric acid, sulfuric acid, inorganic acids such as phosphoric acid, oxalic acid, formic acid, acetic acid, succinic acid,
Organic acids such as p-toluenesulfonic acid are exemplified.

In this case, it is preferable that the fine particles (II) containing the positively chargeable charge control agent have a smaller average particle diameter than the colored particles (I). The average particle size of the fine particles (II) is 0.1 to 1
μm is preferred. The content of the charge control agent in the fine particles (II) is preferably about 2 to 50% by weight, and 3 to 20% by weight.
% Is more preferred.

A suspension of the fine particles (II) is added to the suspension of the colored particles (I), and the resulting mixture is uniformly mixed.
The amount of the fine particles (II) added to the colored particles (I) in the step of precipitating the fine particles (II) on the surface of
A range of 10% by weight is preferable, and a range of 0.5 to 5% by weight is particularly preferable. In order to deposit the fine particles (II) comprising the carboxyl group-containing resin and the positively chargeable charge control agent on the surface of the colored particles (I), a suspension in which the colored particles (I) and the fine particles (II) are mixed is stirred. It is preferable to add an acid aqueous solution having a polarity opposite to that of the production process of the fine particles (II).
At this time, in order to precipitate uniformly, it is more preferable to add a small amount of an inorganic salt such as calcium chloride and use both acid precipitation and salt precipitation.

The colored particles obtained by the above process and having the positively chargeable charge controlling agent fixed on the particle surface are dried and then heated (40 to 80 ° C., depending on the Tg of the resin) under a heat, such as a Henschel mixer. Is more firmly fixed by being mixed and stirred by the mixing stirrer.

It is preferable that the organic solvent is first removed from the dispersion liquid of the spherical to substantially spherical colored resin particles obtained by emulsification by means such as distillation. Next, the aqueous dispersion is subjected to solid-liquid separation by means such as filtration, and the particles are dried to obtain toner particles. It is preferable that the colored resin particles obtained using the emulsifier and the dispersion stabilizer are more thoroughly washed.

The dispersion liquid of spherical to substantially spherical colored resin particles obtained by such emulsification may be prepared, for example, by removing hydrochloric acid, sulfuric acid, phosphoric acid, acetic acid, or the like after removing the organic solvent.
With an acid such as oxalic acid, a reverse neutralization treatment is performed to return the neutralized acidic groups and hydrophilic groups on the particle surface to the original functional groups, thereby further reducing the hydrophilicity of the particles themselves, and then removing water. It is preferable to filter and dry.

As the drying method, any of the well-known and commonly used methods can be adopted. For example, a method of drying under normal pressure or reduced pressure at a temperature at which the toner particles do not fuse or agglomerate, a method of freeze drying, And the like. Further, a method of simultaneously separating and drying the toner particles from the aqueous medium by using a spray drier or the like may also be used. In particular, a method of agitating and drying the powder under reduced pressure while heating at a temperature at which the toner particles do not thermally fuse or agglomerate, or a flash jet drier that instantaneously dries using a heated drying air flow (Seishin Enterprise) Is more efficient and preferable.

If it is necessary to classify the formed toner particles to remove the coarse particles and fine particles in order to adjust the particle size distribution, a general air-flow type commercially available for toner or the like is used after drying. It can be performed by a known and commonly used method using a classifier. Further, at the stage when the toner particles are dispersed in the solvent, a method of classifying a water slurry of the toner particles using a centrifugal separator by utilizing a difference in sedimentation depending on the particle diameter may be used. The removal of the coarse particles can be performed by filtering the water slurry of the toner particles with a filter, a wet vibration sieve, or the like. Regarding the particle size distribution of the toner of the present invention, a good image can be obtained with a 50% volume particle size / 50% number particle size of 1.35 or less, more preferably 1.25 or less, as measured by a Coulter Multisizer. Easy and preferred.

As the toner for developing an electrostatic image of the present invention,
The volume average particle diameter is preferably in the range of 1 to 13 μm from the viewpoint of the obtained image quality and the like, preferably 3 to 10 μm.
A thickness of about μm is more preferable because it is easy to obtain matching with a current machine. For color toner,
The volume average particle size is preferably about 3 to 8 μm. When the volume average particle diameter is small, not only the resolution and the gradation are improved, but also the effect that the thickness of the toner layer for forming the print image is reduced and the toner consumption per page is reduced is preferable.

The dried powder toner particles can be used as a developer as it is, but a known external additive such as inorganic oxide fine particles or organic polymer fine particles is added to the surface of the toner particles. It is preferable to improve the properties such as fluidity and chargeability by adding the compound. Examples of such external additives include silica, titanium oxide, aluminum oxide,
And vinyl (co) polymers. When these external additives are used, the amount of addition is 0.0
A range of 5 to 5% by weight is preferred.

The toner of the present invention can be used as a one-component developer or a two-component developer mixed with a carrier for developing an electrostatic latent image by electrophotography. The type of carrier is not particularly limited, and known and commonly used iron powders, ferrites, magnetites, and the like and carriers coated with a resin therefrom are used.

Further, the toner of the present invention has a function of adjusting the toner passing amount and the like of a frictionally charged powder toner using a non-magnetic one-component developing device having a developer carrying roll and a layer regulating member. The method can also be suitably used for a so-called toner jet printer, which is a method of forming an image by directly spraying the paper on the back electrode through a hole in a flexible printed circuit board having electrodes around it. The toner of the present invention is excellent in fixability and color characteristics, and is spherical, so that the control of the toner flight in the toner jet method becomes easier as compared with the irregular toner.

[0091]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples. In addition,
In Examples and Comparative Examples, parts are parts by weight and water is deionized water unless otherwise specified.

(Synthesis Example of Polyester Resin) Trimellitic anhydride (TMA) as polycarboxylic acid and terephthalic acid (TPA) and isophthalic acid (IP as dicarboxylic acid)
A), polyoxypropylene (2.4) -2,2-bis (4-hydroxyphenyl) as an aromatic diol
Propane (BPA-PO), polyoxyethylene (2.
4) Using 2,2-bis (4-hydroxyphenyl) propane (BPA-EO) and ethylene glycol (EG) as an aliphatic diol at the respective molar composition ratios shown in Table 1,
As a polymerization catalyst, tetrabutyl titanate was charged into a separable fresco at 0.3% by weight based on the total amount of monomers, and a thermometer, a stir bar, a condenser, and a nitrogen inlet tube were attached to the upper part of the flask, and an atmospheric pressure nitrogen gas was supplied in an electric heating mantle heater. After reacting at 220 ° C. for 15 hours under an air stream, the pressure was sequentially reduced, and the reaction was continued at 10 mmHg. The reaction is ASTM
-Pursuit was performed by the softening point according to E28-517, and when the softening point reached a predetermined temperature, the vacuum was stopped to terminate the reaction. Tables 1 and 2 show the composition and physical property values (characteristic values) of the synthesized resin. Table 1 shows a linear polyester resin, and Table 2 shows a crosslinked polyester resin.

[0093]

[Table 1]

[0094]

[Table 2]

In Tables 1 and 2, "T1 / 2 temperature" means the flow tester CFT-500 manufactured by Shimadzu Corporation as described above.
Is a value measured with a nozzle diameter of 1.0 mmΦ × 1.0 mm, a load of 10 kg per unit area (cm 2), and a heating rate of 6 ° C. per minute. The glass transition temperature “Tg” is a differential scanning calorimeter DSC-5 manufactured by Shimadzu Corporation.
0 is a value measured at a heating rate of 10 ° C. per minute by the second run method. Except that the load was set to 30 kg, the measured values of the flow tester measured under the above conditions were similarly described.

(Preparation Example of Release Agent and Release Agent Dispersion) 105 parts of release agent, 45 parts of polyester resin (R1 in Table 1) and 280 parts of methyl ethyl ketone were charged into a ball mill, stirred for 18 hours, and then taken out. With a solids content of 20
It was adjusted to% by weight to obtain a fine dispersion of the release agent (W1 to W4). Table 3 shows properties and the like of the obtained release agent dispersion.

[0097]

[Table 3]

The release agents shown in Table 3 are as follows. PP: "Viscol 660P" (polypropylene wax manufactured by Sanyo Chemical) PE: "LICOWAX PE-130PDR" (polyethylene wax manufactured by Clariant) FT-100: "LUVAX-1211" (Fischer-Tropsch wax manufactured by Nippon Seiro) Synthetic ester: "WEP" -5 "(Synthetic ester wax made by NOF Corporation)

(Preparation Example of Colorant Dispersion) Methyl ethyl ketone was charged into a ball mill so that the content of the colorant, the resin and the solid content was 35 to 50%, stirred for 18 to 36 hours, and then taken out. The content was adjusted to 20% by weight to obtain colorant dispersions (P1 to P4). Table 4 shows the properties of the obtained colorant dispersion.

[0100]

[Table 4]

The coloring agents shown in Table 4 are as follows. Carbon: "ELFTEX-8" (manufactured by Cabot Corporation) Cyan: Fast Gen Blue TGR (manufactured by Dainippon Ink and Chemicals, Inc.) Yellow: Shimla First Yellow 8GR (manufactured by Dainippon Ink and Chemicals, Inc.) Magenta: Fast Gen Super Magenta R ( Dainippon Ink and Chemicals, Inc.)

(Preparation of wet kneading mill base) The above colorant dispersion, resin and methyl ethyl ketone were mixed with a disper, and the solid content was adjusted to 55% to obtain a mill base (MB).
1 to MB13). Table 5 shows the composition of the prepared mill base.

[0103]

[Table 5]

(Preparation of Melt Kneading Mill Base) After premixing a resin, a colorant, and a release agent, kneading was performed with a biaxial kneading extruder, and then the kneaded product was dissolved and dispersed in methyl ethyl ketone using a disper. 55 solids content
% To prepare a mill base. The color pigment used was a master batch formed by two rolls. Table 6 shows the composition of the prepared mill base.

[0105]

[Table 6]

The releasing agents and coloring agents shown in Table 6 are as follows. Carnauba: "Carnauba wax 1" (imported by Kato Yoko) Carbon: "ELFTEX-8" (manufactured by Cabot) Cyan: First Gen Blue TGR (manufactured by Dainippon Ink and Chemicals, Inc.)

(Example 1) MB2 shown in Table 5
5.5 parts, 115 parts of W4 shown in Table 3, 57.5 parts of methyl ethyl ketone, 29.0 parts of isopropyl alcohol as a phase inversion accelerator, 2 parts of 1N aqueous ammonia solution
5.8 parts were charged in a cylindrical container and stirred well. Subsequently, 230 parts of water was added, the liquid temperature was adjusted to 30 ° C., and 44 parts of water was added dropwise with stirring to perform phase inversion emulsification. The peripheral speed at this time was 1.05 m / s. After stirring for 30 minutes, the rotation was reduced and 400 parts of water were added. Here, when the water slurry of the particles was observed with an optical microscope, no aggregate of the release agent was observed, and no release agent flowing out was observed. When the particle size distribution was measured with a Coulter counter, Dv / Dn was 1.32, and no generation of coarse particles was observed.

Then, the solvent was removed by distillation under reduced pressure, and the residue was washed with filtered water. Subsequently, the obtained wet cake was re-dispersed in water, a 1N hydrochloric acid aqueous solution was added until the pH of the dispersion became about 4, and the filtration and water washing were repeated. The wet cake thus obtained was freeze-dried and then classified using an airflow classifier to obtain toner particles having a volume average particle size of 7.4 μm and an average circularity of 0.983.

The obtained toner particles were embedded in a resin, cut with a microtome, and the cross section stained with ruthenate tetroxide was observed with a TEM (transmission electron microscope). A state of being included and being substantially uniformly dispersed in the particles was observed. Thereafter, using a Henschel mixer, 1.5 parts of hydrophobic silica and 0.5 parts of titanium oxide were externally added to 100 parts of the obtained toner particles to obtain a powder toner (toner for developing an electrostatic image). .

(Example 2) MB2 shown in Table 5 was converted to 54
5.5 parts, 115 parts of W4 shown in Table 3, 57.5 parts of methyl ethyl ketone, 28.0 parts of isopropyl alcohol as a phase inversion promoter, 2 parts of 1N aqueous ammonia solution
6.5 parts were charged into a cylindrical container and stirred well. Subsequently, 230 parts of water was added, the liquid temperature was adjusted to 30 ° C., and 44 parts of water was added dropwise with stirring to perform phase inversion emulsification. The peripheral speed at this time was 1.05 m / s. After stirring for 30 minutes, the rotation was reduced and 400 parts of water were added. Here, when the water slurry of the particles was observed with an optical microscope, no aggregate of the release agent was observed, and no release agent flowing out was observed. When the particle size distribution was measured with a Coulter counter, Dv / Dn was 1.35, and no generation of coarse particles was observed.

Then, the solvent was removed by distillation under reduced pressure, and the residue was washed with filtered water. Subsequently, the obtained wet cake was re-dispersed in water, a 1N hydrochloric acid aqueous solution was added until the pH of the dispersion became about 4, and the filtration and water washing were repeated. The wet cake thus obtained was freeze-dried and classified using an airflow classifier to obtain toner particles having a volume average particle size of 5.2 μm and an average circularity of 0.981.

The obtained toner particles were embedded in a resin, cut with a microtome, and the cross section stained with ruthenate tetroxide was observed with a TEM (transmission electron microscope). A state of being included and being substantially uniformly dispersed in the particles was observed. Then, using a Henschel mixer, 2 parts of hydrophobic silica and 1 part of titanium oxide were externally added to 100 parts of the obtained toner particles to obtain a powder toner (toner for developing an electrostatic image).

(Comparative Example 1) Resin R4 shown in Table 2 was replaced with 5
1.0 part, 34.0 parts of resin R1 shown in Table 1, 5 parts of synthetic ester "WEP-5" as a release agent, 10 parts of carbon black "ELFTEX-8" as a coloring agent, biaxial kneading The mixture was kneaded with an extruder, and further crushed and classified to obtain a powder toner having a volume average particle size of 5.4 μm (Comparative Example 1-
1) and a powder toner having a volume average particle size of 7.8 μm (Comparative Example 1-2). The obtained powder toner was subjected to TEM (transmission electron microscope) in the same manner as in Examples 1 and 2 above.
As a result, it was observed that a part of the pigment and wax were exposed on the surface of the toner particles.

(Other Examples and Comparative Examples) The other Examples and Comparative Examples are basically manufactured in the same manner as in Example 1, and methyl ethyl ketone to be added, isopropyl alcohol, etc. By appropriately adjusting the amount of solvent, the amount of dropped water, and the amount of base,
Each powder toner was obtained. Tables 7 and 8 show the measured MB (mill base) and used release agent, and the measured values such as the average circularity of the powder toners of the respective Examples and Comparative Examples.

[0115]

[Table 7]

[0116]

[Table 8]

Further, the powder toners of the examples and comparative examples were
The glass transition temperature Tg, the outflow start temperature Tfb, T1 / 2 temperature, outflow end temperature Tend, THF insoluble matter, and fixing temperature width measured by a constant load extrusion type capillary rheometer were measured, and the obtained results are shown in Table 9. Show. Further, it is determined whether or not each example and comparative example have a relationship of T1 / 2 (toner) ≧ T1 / 2 (resin), and the results are also shown in Table 9. (Table 9
In the figure, T1 / 2 (T) ≧ T1 / 2 (R) is shown.)

The glass transition temperature, Tg, was increased by 10 ° C./min by the second run method using a differential scanning calorimeter DSC-50 manufactured by Shimadzu Corporation in the same manner as in Tables 1 and 2 above. Measured at speed. The outflow start temperature Tfb, T1 / 2 temperature, and outflow end temperature Tend are shown in FIG.
As described in (a) and (b), the measurement was performed using a flow tester CFT-500 manufactured by Shimadzu Corporation. The load at the time of measurement was measured at 10 kg and 30 kg.

The fixing temperature range was determined by a fixing property test shown below, and was indicated by a range between the upper limit value and the lower limit value.

(Fixing property test) Using the powder toners of Examples and Comparative Examples, a printing paper was produced at a speed of 90 mm / sec.
The image is fixed through a heat roll (oil-less type) of Ricoh Imagio DA-250, a cellophane (registered trademark) is attached to the image after fixing, and the ID (image density) after peeling is 90% or more of the original ID. The surface temperature of the heat roll when no offset is observed
And

[0121]

[Table 9]

From the results shown in Table 9, it was confirmed that the fixing device according to the embodiment of the present invention had good fixing start temperature and hot offset resistance temperature, and had a wide fixing temperature range.

Further, the powder toners of Examples and Comparative Examples were
THF solubles in toner: Table 10 shows the results of GPC measurement. The GPC measurement was carried out in the same manner as the molecular weight measurement of the binder resin composed of the polyester resin described above by gel permeation chromatography (GPC).

[0124]

[Table 10]

(Image Deposition Test) Further, with respect to the powder toners of the respective Examples and Comparative Examples, images were output using a commercially available non-magnetic one-component developing type printer, and fog, resolution, and gradation were evaluated. , OHP permeability and transfer efficiency were evaluated. Table 11 shows the obtained evaluation results.

[0126]

[Table 11]

The fog, resolution, and gradation were evaluated by visual inspection of the image using a test pattern. In the evaluation results, “○” was slightly better than the standard, and “◎” was better.

The transfer efficiency was represented by a value obtained by the following transfer efficiency measuring method. (Transfer efficiency measuring method) Using a commercially available printer / copier, develop a solid image (100 mm long x 20 mm wide)
When the solid image on the photoreceptor has passed through the transfer portion by 50%, the printer / copier is stopped. Thereafter, the untransferred image (solid) and the transferred image on the photoreceptor were completely peeled off with a tape (30 mm × 20 mm), and the toner amount of the untransferred image and the toner amount after transfer were measured. The transfer efficiency (%) is calculated from the following equation. Transfer efficiency = 100− (toner amount after transfer / toner amount of untransferred image × 100)

Further, the OHP permeability was evaluated by the following OHP clearness evaluation method. (Method of Evaluating OHP Sharpness) An unfixed image was formed on a OHP sheet using a color toner, and the unfixed image was fixed using a separately prepared fixing tester. The fixing was performed by passing through a heat roll (oil-less type) of Ricoh Imagio DA-250 at a heat roll temperature of 160 ° C. and a speed of 90 mm / sec. On the OHP sheet created by the above procedure,
An OHP sheet printed in black was placed, projected on a screen with an overhead projector, and the sharpness of characters was visually evaluated. In the evaluation results, those in which the characters were clearly visible were represented by "O", and those in which the characters were blurred were represented by "X".

From the results shown in Table 11, it was confirmed that the example of the present invention was excellent in fog, resolution, gradation, and transfer efficiency. In addition, it was confirmed that in all the examples in which OHP permeability was evaluated, characters were clearly visible.

[0131] The powdery toner of the example was prepared by using a silicon-coated ferrite carrier (particle size: 80 µm),
Mixing was performed so that the toner concentration became 3% by weight, and an image forming test was performed using a two-component developing system copying machine. As a result, good images were obtained in each case. The toners of the examples and the comparative examples were subjected to a heat blocking test at 50 ° C. for 3 days. As a result, no aggregation was observed in all the toners.

(Example 16) (Synthesis example of styrene methacrylic resin) 200 parts of methyl ethyl ketone was put in a reaction vessel and heated to 80 ° C. Then, 23 parts of acrylic acid and 180 parts of styrene
, A mixture of 54 parts of methyl methacrylate, 43 parts of 2-ethylhexyl acrylate, and 2.2 parts of "Perbutyl O" (manufactured by Nippon Oil & Fats Co., Ltd.) were dropped over 2 hours under a nitrogen atmosphere. . After completion of the dropwise addition, 0.6 parts of perbutyl O was added to the reaction solution every 4 hours, and the reaction was continued at 80 ° C. for 24 hours to obtain a resin. Physical properties of this resin were a non-crosslinked resin having an acid value of 60, Tg of 70 ° C. and a weight average molecular weight of 50,000.

(Example of Preparation of Fine Particles Containing Positively Chargeable Charge Control Agent) 90 parts of the above styrene methacrylic resin was added to MEK.
(Methyl ethyl ketone) 122 parts, THF (tetrahydrofuran) 111 parts is added, further, 1N sodium hydroxide aqueous solution 102 parts and Bontron N-07 (Orient Chemical) 10 parts are added and mixed with a homomixer. With stirring, 2160 parts of water was added at a stretch to granulate submicron fine particles (II) containing a positively chargeable charge control agent. Next, MEK and THF were distilled off under reduced pressure to obtain an aqueous dispersion of fine particles (II) (solid content: 5% by weight).

(Example of Adjustment of Positively Charged Toner) The fine particles obtained above were added to 500 parts (solid content content: 100 parts) of the aqueous dispersion of the colored particles (I) after solvent removal obtained in Example 1. (II)
20 parts of water dispersion and 1% by weight calcium chloride aqueous solution 1
Add 4.4 parts and mix thoroughly, then stir with stirring.
An aqueous solution of N hydrochloric acid was added dropwise to adjust the pH to 2.5, and the fine particles (I
I) was precipitated on the surface of the colored particles (I). After repeated filtration and washing, the wet cake was freeze-dried. This dried powder was stirred and mixed using a Henschel mixer under a heating condition of 70 ° C. to obtain fine particles (I
I) was sufficiently fixed and stabilized. Subsequently, the particles were classified by an airflow classifier to obtain toner particles having a volume average particle diameter of 7.3 μm and an average circularity of 0.982.

The toner particles were embedded in a resin, cut with a microtome, and stained with ruthenate tetroxide.
When observed with a transmission electron microscope, it was found that the pigment and the wax were included in the binder resin and dispersed almost uniformly in the particles.

Silica HVK21 was added to 100 parts of the toner particles.
50 parts (Clariant) was externally added using a Henschel mixer to obtain a positively chargeable powder toner.

(Toner Physical Properties of Positively Charged Toner)
g is 60 ° C, Tfb under a load of 10 kg is 117 ° C, T1
/ 2 is 149 ° C, Tend is 158 ° C, Tfb under a 30 kg load is 104 ° C, T1 / 2 is 136 ° C, Tend is 145 ° C, THF insoluble content is 3.6%, T1 / 2 (T) ≧
T1 / 2 (R).

(Image Deposition Test of Positively Charged Toner) A developer obtained by mixing 3 parts of positively charged powder toner and 100 parts of a silicon resin-coated ferrite carrier (average particle size: 80 μm) was mixed with a commercially available copying machine. An image was formed using (Sharp Z-52) and evaluated for fog, resolution, gradation, and image density. As a result, a good image was obtained.

(Fixability Test and Result of Positively Charged Toner) The unfixed printing paper obtained by the above copying machine was passed through a heat roll (oilless type) of Ricoh Imagio DA-250 at a speed of 90 mm / sec. The surface temperature range of the heat roll when the ID (image density) after peeling is 90% or more of the original ID and no occurrence of offset is observed. Was determined as the “fixing temperature range”, and the fixing width was 116 to 210 ° C.

[0140]

As described above, the toner for developing an electrostatic image of the present invention is a spherical or substantially spherical toner having a polyester resin as a binder resin, and the flow tester value of the toner falls within a specific range. Therefore, the oil-less fixing heat roll has good fixing start temperature and hot offset resistance. In addition, due to the spherical and small particle size, powder fluidity, transfer efficiency,
The resolution and the gradation are excellent, so that a developed image of excellent quality can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining how to obtain a flow tester value, wherein FIG. 1 (a) is a side sectional view showing an outline of a measuring device,
(B) is a graph for explaining a method of obtaining each flow tester value from a measured value.

Claims (23)

[Claims] 1. An electrostatic image developing toner containing at least a binder resin and a colorant, wherein the binder resin is a polyester resin, and the toner starts to flow out by a constant load extrusion type capillary rheometer. When the temperature Tfb is 90 ° C or higher and 120 ° C or lower, the T1 / 2 temperature exceeds 120 ° C,
0 ° C or lower, outflow end temperature Tend is 130 ° C or higher, 170
° C or less and the following formula: Average circularity = (perimeter of a circle having the same area as the projected area of the particle) /
(Embodiment of Particle Projection Image) A toner for developing an electrostatic charge image, wherein the average circularity defined by the following formula is from 0.97 or more to a sphere to a substantially sphere. 2. The toner according to claim 1, wherein the binder resin contains a crosslinked polyester resin, and the tetrahydrofuran-insoluble content of the binder resin in the toner ranges from 0.2 to 20% by weight. Charge image developing toner. 3. The toner according to claim 2, wherein the binder resin further contains a linear polyester resin. 4. The method according to claim 1, wherein the binder resin has a T1 / 2 temperature of 80 ° C. or more measured by (A) a constant load extrusion type capillary rheometer.
0 ° C. or less, and the glass transition temperature Tg is 40 ° C. or more, 7
A linear polyester resin having a temperature of 5 ° C. or less, and (B) a T1 / 2 temperature of 12 with a constant load extrusion type capillary rheometer.
0 ° C. or higher and 210 ° C. or lower, and the glass transition temperature Tg
Is a mixture of a crosslinked polyester resin having a temperature of 40 ° C. or more and 75 ° C. or less, wherein the weight ratio of the resin (A) and the resin (B) is (A) / (B) = 20/80 to 80/20. When the T1 / 2 temperature is T1 / 2 (A) and T1 / 2 (B), respectively, the relationship of 20 ° C <T1 / 2 (B) −T1 / 2 (A) ≦ 120 ° C is satisfied. The toner for developing an electrostatic charge image according to claim 1. 5. The T1 / 2 temperatures of a toner and a polyester resin used as a binder resin measured by a constant load extrusion type capillary rheometer are T1 / 2 (toner) and T1 / T1, respectively.
2. The electrostatic image developing toner according to claim 1, wherein, when 2 (resin), T1 / 2 (toner) .gtoreq.T1 / 2 (resin). 6. A gel permeation chromatography measurement of a tetrahydrofuran-soluble component of a binder resin in a toner has a weight average molecular weight of 30,000 or more, a weight average molecular weight / number average molecular weight of 12 or more, and a molecular weight of 60 or more.
The area ratio of 10,000 or more is 0.5% or more, and the molecular weight is 1
The area ratio of not more than 10,000 is in the range of 20 to 80%.
6. The electrostatic image developing toner according to 2, 3, 4 or 5. 7. The binder resin according to claim 1, wherein the binder resin contains a carboxyl group, and the acid value of the binder resin is in the range of 1 to 30 KOH mg / g. The toner for developing an electrostatic image according to the above. 8. A part of the carboxyl group in the binder resin is
8. The toner for developing an electrostatic image according to claim 1, wherein the toner is a carboxylate neutralized with a base. 9. The electrostatic image developing toner according to claim 1, further comprising a release agent. 10. The toner according to claim 9, wherein the release agent is a synthetic ester wax and / or a natural ester wax. 11. The method according to claim 1, further comprising a positively chargeable charge control agent.
11. The toner for developing an electrostatic image according to 8, 9, or 10. 12. The method of claim 1, 2, 3, 4, 5, 6, 7,
An image forming method using the toner described in 8, 9, 10 or 11. 13. The image forming method according to claim 12, wherein an offset preventing liquid is not used for the fixing heat roll. 14. A mixture containing a polyester resin containing a carboxyl group, a colorant, and a release agent, is mixed with an aqueous medium in the presence of a base and emulsified (a step of emulsification). A method for producing a toner for developing an electrostatic image, comprising a step of producing a suspension of particles (I), and then separating the colored particles (I) from the aqueous medium and drying. The resin is (A)
T1 / 2 temperature of 80 ° C or more and 120 ° C or less by constant load extrusion type capillary rheometer, glass transition temperature T
a linear polyester resin having a g of 40 ° C. or more and 75 ° C. or less, (B) a T1 / 2 temperature measured by a constant load extrusion type capillary rheometer exceeding 120 ° C. and 210 ° C. or less;
It is a mixture of a crosslinked polyester resin having a glass transition temperature Tg of 40 ° C. or more and 75 ° C. or less, wherein the weight ratio of the resin (A) and the resin (B) is (A) / (B) = 20/80 to 80/20, where T1 / 2 temperatures are T1 / 2 (A) and T1 / 2 (B), respectively, and the relationship of 20 ° C <T1 / 2 (B) −T1 / 2 (A) ≦ 120 ° C The method for producing a toner for developing electrostatic images according to claim 1, wherein: 15. A mixture in which a carboxyl group-containing polyester resin, a colorant, and a release agent in the mixture are previously dissolved or dispersed in an organic solvent,
15. The method for producing a toner for developing an electrostatic charge image according to claim 14, wherein in the emulsification step, the colored particles (I) are produced by further adding a phase inversion accelerator. 16. The method for producing a toner for developing an electrostatic image according to claim 15, wherein the phase inversion accelerator is an alcohol solvent. 17. The method for producing a toner for developing an electrostatic image according to claim 15, wherein the stirring in the emulsifying step is performed by a stirring blade at a peripheral speed of 0.2 to 5 m / s. 18. The method according to claim 17, wherein the stirring blade is a max blend blade or a full zone blade. 19. The method for producing a toner for developing an electrostatic image according to claim 14, wherein the acid value of the carboxyl group-containing polyester resin is 1 to 30 KOH mg / g. 20. The method for producing a toner for developing an electrostatic image according to claim 14, wherein the release agent is a synthetic ester wax and / or a natural ester wax. 21. The method according to claim 14, wherein the mixture further contains a positively chargeable charge control agent. 22. A suspension of the colored particles (I) is mixed with a mixture of a positively chargeable charge control agent and a resin which becomes self-water dispersible and / or water-soluble by neutralization in the presence of a neutralizing agent. , A suspension of fine particles (II) obtained by emulsification in an aqueous medium is added, and then a compound having a polarity opposite to that of the neutralizing agent is added to the surface of the colored fine particles (I). The method for producing a toner for developing an electrostatic charge image according to claim 14, wherein the fine particles (III) on which the fine particles (III) are precipitated are separated, and then the fine particles (III) are separated from the aqueous medium and dried. 23. The colorant and the release agent used in the emulsification step in producing the suspension of the colored particles (I), which are kneaded and dispersed in advance by a wet method. 23. The method for producing a toner for developing electrostatic images according to any one of claims 15 to 22.