JP2007156082A - Method for evaluating toner for electrostatic image development and toner for electrostatic image development - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To evaluate and select toner particles excellent in fluidity and to enable excellent image quality formation with good dot reproducibility. <P>SOLUTION: A method for evaluating a toner is used which comprises: (1) a process of attaching one toner particle containing at least a resin and a pigment to a tip region of a probe 4 of AFM; (2) a process of measuring a first force (A) acting on the probe 4 when the tip region of the probe 4 is brought close to a surface of a toner powder phase 2 comprising the above toner particle until the single toner particle 3 on the probe 4 is brought into contact with a single toner particle present on the surface of the toner powder phase 2; (3) a process of measuring a second force (B) acting on the probe 4 when the probe 4 is separated from the surface of the toner powder phase; and (4) a process of calculating the difference between the first force (A) and the second force (B) to obtain an interparticle force between the single toner particle on the probe 4 and the single toner particle on the toner powder phase 2, wherein an average of such interparticle forces is used as an index of toner evaluation and variation in the measurements of such interparticle forces is further used as an index of toner evaluation to evaluate the toner. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electrostatic charge developing toner evaluation method and an electrostatic charge developing toner evaluated thereby.

Conventionally, as a technique for improving the image quality of electrophotography, the surface roughness of the latent image carrier is measured with an atomic force microscope (AFM), and the surface roughness of the latent image carrier and the wear rate are defined. (For example, refer patent document 1).
There has also been proposed a technique for performing electrical characteristics of an endless belt using SPM and defining a value of a total surface current amount of 25 μm × 25 μm when 100 V is applied (see, for example, Patent Document 2).

Furthermore, there is also a proposal for a technique in which SiO ₂ and PMMA true spherical particles are attached to the tip of an AFM cantilever to measure the adhesion between a glass substrate and an organic polymer flat plate (for example, non-patent) Reference 1).

JP 2004-109492 A JP 2004-94178 A Konica Minolta Technology Report Vol.1 (2004) p.19-22

By the way, with respect to the image quality of various image forming apparatuses such as copiers and printers, there is an increasing demand for higher image quality, and recently it has been very important to improve the reproducibility of fine dots. .
The dot reproducibility is affected by the fluidity in addition to the charge amount of toner and developer, and it has become necessary to stably supply a uniform toner layer or developer layer to the fine latent image portion. Yes.
Further, as the image quality increases, the toner is required to have a smaller particle size and higher functionality. For this reason, the fine structure of the toner is complicated, and precise control at the time of production is required.
In particular, the fluidity of the toner has an important influence on various image qualities in addition to the dot reproducibility, and can be said to be an important issue.
In addition, when the toner production method is changed from the pulverization method to the polymerization method, the production conditions have a large influence on the flow characteristics, and it is necessary to control and evaluate fine production compared to the pulverization method. It has become.

  Therefore, in the present invention, for the purpose of obtaining toner particles having stable fluidity, a toner evaluation method is provided, and further, a toner satisfying this evaluation standard is provided. The purpose was to enable the formation of high image quality.

In the present invention, (1) a step of attaching one toner particle containing at least a resin and a pigment to the tip region of the AFM probe; (2) the probe on the surface of the toner powder phase composed of the toner particle. When a single toner particle of the probe is brought into contact with a single toner particle on the surface of the toner powder phase, a first force (A) acting on the probe is applied. A step of measuring, (3) a step of measuring a second force (B) acting on the probe when the probe is separated from the surface of the toner powder phase, and (4) the first The difference between the second force (B) and the force (A) is calculated to determine the interparticle force between the single toner particle of the probe and the single toner particle of the toner powder phase. And the interparticle force obtained above or the average of interparticle force when the process is performed a plurality of times. The provides a method of evaluating the toner used as an indicator of the toner evaluation.
Preferably, the variation in the measured value of the interparticle force when the process is performed a plurality of times at different measurement locations is used as an index for toner evaluation.

In the invention of claim 3, wherein the toner particles powder phase, the electrostatic charge developing toner evaluation method according to claim 1, characterized in that a state of being compressed at a pressure of 100~900kg / cm ² provide.

  According to a fourth aspect of the present invention, after the probe having one toner particle attached is brought close to the toner particle powder phase from a distance of 500 to 2000 nm and pressed once onto one particle on the surface of the toner particle powder phase. 2. The electrostatic charge developing toner evaluation method according to claim 1, wherein the probe is pulled apart.

  According to a fifth aspect of the present invention, the piezo scanning speed when one toner particle attached to the tip region of the probe approaches one particle of the compressed toner particle powder phase is 0.16 Hz to 4.4. The toner evaluation method for electrostatic charge development according to claim 1, wherein the toner is set to 0 Hz.

According to a sixth aspect of the present invention, there is provided an electrostatic charge developing toner obtained by using the toner evaluation method according to the first aspect, wherein the toner particle powder phase is 100 when the toner is evaluated. The surface of the toner particle powder phase is brought into a compressed state at a pressure of ˜900 kg / cm ² , and the probe with one toner particle attached is brought close to the toner particle powder phase from a distance of 500 to 2000 nm. After pressing once on one particle, the probe is pulled away, and one toner particle attached to the tip region of the probe is brought close to one particle of the compressed toner particle powder phase. The average value of the force between the toner particles is 1 to 60 nN when the force between the toner particles is repeatedly measured 10 to 50 times under the condition that the scanning speed of the piezo is 0.16 Hz to 4.0 Hz. Is To provide a toner for charge development.

  According to a seventh aspect of the present invention, the variation σn-1 of measured values when the force between the toner particles is measured a plurality of times at different locations is 0.1 to 10 nN. An electrostatic charge developing toner is provided.

  The invention according to claim 8 provides the toner for developing electrostatic charge according to claim 6 or 7, wherein the toner particles containing at least the resin and the pigment have an average circularity of 0.9 to 0.99. .

  According to a ninth aspect of the invention, there is provided the electrostatic charge developing toner according to any one of the sixth to eighth aspects, wherein the toner particles containing at least the resin and the pigment are produced by a polymerization method. provide.

  According to a tenth aspect of the present invention, in any one of the sixth to ninth aspects, an additive comprising an inorganic fine powder having an average particle size of 10 to 200 nm is adhered or fixed to the surface of the toner particles containing at least the resin and the pigment. An electrostatic charge developing toner according to claim 1 is provided.

  In invention of Claim 11, the additive which consists of said inorganic fine powder consists of inorganic fine powder with an average particle diameter of 10-100 nm and inorganic fine powder with an average particle diameter of 100-200 nm. A toner for developing electrostatic charge is provided.

  In the invention of claim 12, an additive comprising a charge control agent having an average particle size of 10 to 200 nm is adhered or fixed to the surface of the toner particles containing at least the resin and the pigment. 11. The electrostatic charge developing toner according to any one of 11 above.

  According to a thirteenth aspect of the present invention, there is provided the electrostatic charge developing toner according to any one of the sixth to twelfth aspects, wherein the toner particles containing at least the resin and the pigment contain a charge control agent. To do.

  According to a fourteenth aspect of the present invention, there is provided the electrostatic charge developing toner according to any one of the sixth to thirteenth aspects, wherein a release agent is contained in the toner particles containing at least the resin and the pigment. To do.

  The electrostatic charge development according to any one of claims 6 to 14, wherein the toner particles containing at least the resin and the pigment contain a dispersant for the release agent. Toner is provided.

In invention of Claim 16, at least 1 type of the said resin is crystalline polyester represented by following General formula (1), It is described in any one of Claims 6 thru | or 15 characterized by the above-mentioned. Toner for electrostatic charge development.
[—O—CO—CR ₁ ═CR ₂ —CO—O— (CH ₂ ) _n —] _m (1)
However, n and m are the number of repeating units. R ₁ and R ₂ are hydrocarbon groups.

  According to a seventeenth aspect of the present invention, there is provided the electrostatic charge developing toner according to any one of the sixth to sixteenth aspects, wherein the toner and the pigment are prepared using a kneaded composition in advance.

  The invention according to claim 18 provides the electrostatic charge developing toner according to any one of claims 6 to 17 having an average particle diameter of 4 to 8 μm.

  According to a nineteenth aspect of the present invention, there is provided a developing method in which the electrostatic charge developing toner according to any one of the sixth to eighteenth aspects is used as a one-component developer to perform contact development or non-contact development.

  According to a twentieth aspect of the present invention, there is provided the developing method according to the nineteenth aspect, wherein an image forming apparatus including at least a photosensitive member, a doctor roller and / or a supply roller is used.

  According to a twenty-first aspect of the present invention, a two-component developer is formed using the electrostatic charge developing toner according to any one of the fifth to seventeenth aspects and a carrier having a particle diameter of 20 to 70 μm, and contact development or non-contact A development method for performing development is provided.

  The invention according to claim 22 provides the developing method according to any one of claims 19 to 21, wherein an AC bias voltage component is applied.

  According to a twenty-third aspect of the present invention, there is provided a toner cartridge in which the electrostatic charge developing toner according to any one of the sixth to eighteenth aspects is stored.

  According to a twenty-fourth aspect of the present invention, there is provided a process cartridge in which the electrostatic charge developing toner according to any one of the sixth to eighteenth aspects is stored.

  According to the invention of claim 25, there is provided a method for producing a toner for developing electrostatic charge, wherein the toner is evaluated by the toner evaluating method for electrostatic charge development according to claim 1 during or after the production process.

  According to a twenty-sixth aspect of the present invention, there is provided a probe having a toner powder phase compacted on a substrate stage, and a probe with a single toner particle so as to face the surface of the toner powder phase, The toner powder phase and the toner particles of the probe can be operated to approach or separate using a piezo scanner, and a laser emission source for irradiating the back side of the probe with laser light; And a detector for detecting a change in the reflected light of the laser beam, and irradiating a laser beam L emitted from a laser emission source on the back side of the probe to detect a force change generated in the probe. There is provided an electrostatic charge developing toner evaluation device which detects a change in reflected light by a detection unit.

  According to the present invention, the fluidity of the toner in the development area can be reliably improved, and thereby the dot reproducibility is remarkably improved and the image quality can be improved.

  Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to the following examples.

  The present invention includes (1) a step of attaching one toner particle containing at least a resin and a pigment to a tip region of an AFM probe, and (2) the surface of the toner powder phase composed of the toner particle on the surface of the probe. A first force (A) acting on the probe is measured when a single toner particle of the probe is brought into contact with a single toner particle on the surface of the toner powder phase with the tip region approached. (3) a step of measuring a second force (B) acting on the probe when the probe is separated from the surface of the toner powder phase; and (4) the first force. Calculating a difference between the second force (B) with respect to (A) and obtaining an interparticle force between a single toner particle of the probe and a single toner particle of the toner powder phase. And the average value of interparticle forces determined above as an index for toner evaluation, more preferably, Toner evaluation method using variation in inter-particle force when changing the measurement location multiple times as an index for toner evaluation, and toner for developing electrostatic charge selected using this evaluation method The present invention relates to a developing method using the electrostatic charge developing toner, various cartridges to be accommodated, a manufacturing method of the toner, and an electrostatic charge developing toner evaluation apparatus for performing the above evaluation.

There is an AFM (Atomic Force Microscope) method as a method of scanning a probe having a tip of about 10 nmφ to detect an atomic force acting between the probe and atoms on the sample surface and measuring the sample surface shape and the like.
This method has very high resolution and can measure the uneven shape in the Z direction with respect to the scanning direction (X direction) of the probe.

In the present invention, one toner particle is adhered to the tip of the probe or its peripheral portion (referred to as the tip region), and one particle on the surface of the toner powder phase in which the toner particles attached to the probe are consolidated. Was pressed once, and then scanned to separate, and the force change at that time was measured.
As a result, the force characteristics shown in FIG. 1 were obtained, and the interparticle force between the toner particles was obtained from the difference between the characteristics when the probe was brought close and the characteristics when the probe was pulled away.

A schematic configuration diagram of the AFM apparatus is shown in FIG.
A compacted toner powder phase 2 is provided on the substrate stage 1.
Subsequently, the probe 4 with one toner particle 3 is brought close to or separated from one particle on the surface of the toner powder phase 2 using the piezo scanner 5.
Specifically, (1) one toner particle containing at least a resin and a pigment is attached to the tip region of the probe 4 of the AFM, and (2) the probe is placed on the surface of the toner powder phase 2 composed of the toner particles. When a single toner particle 3 of the probe is brought into contact with a single toner particle on the surface of the toner powder phase 2 by bringing the tip region of the needle 4 close to the first region, the first particle that acts on the probe 4 A force (A) is measured; (3) a second force (B) acting on the probe 4 when the probe 4 is separated from the surface of the toner powder phase 2 is measured; ) The difference between the first force (A) and the second force (B) is calculated, and a single toner particle of the probe 4 and a single toner particle of the toner powder phase 2 are calculated. Find the interparticle force between.
The force change generated in the probe 4 is detected by the detection unit 8 via the mirror 7 as a change in the reflected light by irradiating the back side of the probe 4 with the laser light L emitted from the laser emission source 6. Can be measured.
At the time of measurement, it is necessary to detect all the forces acting on the single toner particle 3 attached to the tip region of the probe 4 with high accuracy. The single toner particle 3 attached to the tip region of the probe 4 is The distance when approaching one particle on the surface of the toner powder phase 2 composed of the same toner particles is important.

In the case of toner particles, since they are easily affected by frictional charging or the like, measurement from a considerably distant position is required, and from one toner particle 3 attached to the tip or the periphery of the probe 4 to the toner particle powder phase 2 The preferred distance when approaching one particle on the surface of was 500 to 2000 nm. The probe 4 to which one toner particle 3 is adhered from the distance of 500 to 2000 nm is brought close to the toner particle powder phase 2 and pressed once to one particle on the surface, and then the probe 4 is operated to be separated. Measured.
When this distance is shorter than 500 nm, the probe 4 cannot be separated from the surface of the toner particle powder phase 2, which is inappropriate for measurement.
When this distance is longer than 2000 nm, the measurement accuracy is deteriorated, and it is difficult to accurately measure the difference between the characteristics when the probe 4 approaches and the characteristics when the probe 4 is pulled apart. It is not preferable.
The constituent material of the probe 4 is preferably made of Si ₃ N ₄ , Si single crystal or the like.

The toner particle powder phase 2 is in a state compressed at a pressure of 100 to 900 kg / cm ² . It is assumed that the probe 4 to which one toner particle is adhered is fixed so as not to move even if it contacts.
However, if the compression pressure is less than 100 kg / cm ² , toner particles that are not sufficiently fixed partially exist and become unsuitable for measurement.
On the other hand, when the compression pressure exceeds 900 kg / cm ² , the toner particles are deformed, and the toner particle structure is collapsed to form a surface state in which the particles are arranged. Thus, the surface state becomes a flat surface, which is different from the state of toner particles and toner particles, and is not suitable for the measurement of interparticle force.
The toner particle powder phase compressed at a pressure of 100 to 900 kg / cm ² is used for measurement in a flat plate size of 10 mm × 10 mm × 5 mmt or less.
At the time of measurement, the compressed toner particle powder phase 2 is fixed to a sample stage of the AFM apparatus and measured.
At that time, the compressed toner particle powder phase 2 is brought into close contact with the surface of the sample table and fixed so as to be as horizontal as possible.
Further, a toner particle powder phase 2 in which one particle is randomly arranged and fixed on an adhesive layer on the surface of a flat substrate such as glass is used, and one toner particle 3 is adhered to the toner particle. Measurement may be performed by contacting the probe 4.
However, in this case, it is difficult to adjust the position so that the toner particles 3 at the tip of the probe 4 are brought into contact with one toner particle on the substrate side.

The scanning speed of the piezo when one toner particle 3 attached to the tip or the periphery of the probe 4 approaches one particle on the surface of the compressed toner particle powder phase 2 is 0.16 Hz to 4.0 Hz. Is optimal.
When the piezo scan speed is less than 0.16 Hz, the piezo operates slowly, so that it is strongly influenced by the adsorption state on the surface of the toner particles, resulting in a large variation and not suitable as a measurement condition.
When the piezo scanning speed exceeds 4.0 Hz, the piezo operates fast, so that the operation of pressing and separating toner particles is not sufficient, and the probe 4 to which one toner particle is attached is attached to the toner powder phase 2. The interparticle force between the toner particles, which is obtained by the difference in force between when the particles are brought close to one particle and when they are separated from each other, tends to be small, and is not suitable as a measurement condition.

A method of attaching one toner particle 3 to the tip of the AFM probe 4 will be described.
While observing the magnified image using an optical microscope, (1) the probe 4 is brought close to the wire coated with the adhesive and brought into contact, and the adhesive is attached to the tip of the probe 4 (2) the adhesive on the tip The probe 4 to which the toner is attached is brought close to a wire or a bar with sparsely attached toner particles, and only one toner particle is attached to the tip of the probe 4. (3) One toner particle is attached Each method is performed by the procedure of drying the probe 4 at room temperature for 24 hours or more.
Since the adhesive accurately measures the force between particles, a curable adhesive is suitable.
Further, a two-component mixed type capable of adjusting the curing time is suitable. Examples of the two-component mixed cured resin adhesive include EP-330 (manufactured by Cemedine).

The measurement of the force between toner particles using AFM is repeated 10 to 50 times, and the average value is used for evaluation.
The repetition is not repeated at the same place, but is preferably performed while changing the place (for example, while moving about 50 nm). At that time, it is also very important to evaluate the distribution of interparticle forces.
It is better that the number of repetitions is large, but if it is too large, it takes a measurement time and an analysis time.

The interparticle force of the toner particles changes depending on the toner particle surface state and the toner particle shape.
When the toner particle surface force is obtained when the toner particle surface has fine irregularities and the surface without fine irregularities, the interparticle force is as follows. Was confirmed to be small.
This is because the distance between the toner particles is increased due to the unevenness on the surface of the toner particles, or the contact area between the toner particles is reduced, and the interaction between the particles is reduced.
For fine uneven surface: Interparticle force 22nN
In the case of a smooth surface: interparticle force of 98 nN

The optimum region of the force between toner particles was determined from the relationship between toner fluidity and image quality.
As a result, it was confirmed that when the force between the toner particles is large, the fluidity of the toner deteriorates and the fine image reproducibility deteriorates.
On the other hand, it was confirmed that when the force between the toner particles is small, the fluidity of the toner is improved and the reproducibility of fine image quality is improved.
Specifically, the force between the toner particles was repeatedly measured 10 to 50 times by AFM, and when the average value was 1 to 60 nN, the fluidity of the toner was good and the reproducibility of fine image quality was improved.
When the average value of the force between toner particles is less than 1 nN, problems such as scattering during toner conveyance are not suitable, and when the average value of the force between particles is more than 60 nN, the toner fluidity is poor. Therefore, it was confirmed that it was not suitable because it could not achieve high image quality.
Further, in this case, the distribution of the force between the toner particles affects the fluidity and image quality of the toner, and the toner fluidity is improved when the variation σn-1 in the interparticle force is 0.1 to 10. The dot reproducibility that expresses image quality has improved. It is very difficult to make the toner particle by making the interparticle force variation σn-1 smaller than 0.1. When the interparticle force variation σn-1 is larger than 10, the toner fluidity is reduced. Decreases and the dot reproducibility deteriorates.

The shape of the toner particles also affects the interparticle force. The shape close to a sphere is suitable for measurement with small variations in measurement.
The shape of the toner is measured by circularity. Specifically, it can be measured using a flow type particle image analyzer (FPIA-2000; manufactured by Sysmex Corporation).
When the average circularity was 0.90 to 0.99, the fluidity of the toner was improved and high image quality was achieved. Further, in this condition range, since one toner particle adheres to the tip of the probe, no matter which part of the particle is attached to the tip of the probe 4, the toner particle powder in which the particle surface having substantially the same shape is compressed. Since it comes into contact with one particle on the surface of the body phase 2, the measurement variation of the interparticle force is also reduced. When the average circularity is smaller than 0.90, the difference in the interparticle force increases, each time the probe 4 with the toner contact surface is made with the contact surface of the particles. Further, the addition process of the fine particles is influenced by the shape of the powder (matrix) before adding the fine particles, but the average circularity of the powder (matrix) before adding the fine particles is 0.9 to 0.99. When it is close to a certain sphere, the effect of adding fine particles is excellent, and high image quality with excellent dot reproducibility can be realized.

The surface state of the toner particles can be controlled by the type of fine particles of the additive, the particle size, the mixing conditions when added, and the fixing injection conditions.
As fine particles to be added, inorganic fine powder is optimal, and the average particle size is preferably a small particle size of 10 to 200 nm. When the particle size of the inorganic fine particles to be added is smaller than 10 nm, only small irregularities can be formed, and the effect of addition cannot be obtained sufficiently.
When the particle size is larger than 200 nm, a frictional component is generated between the particles, which is an inappropriate factor for inhibiting fluidity.
Further, a mixed additive comprising at least an inorganic fine powder having an average particle diameter of 10 to 100 nm and an inorganic fine powder having an average particle diameter of 100 to 200 nm may be adhered or fixed to the surface of the toner.
The following materials can be applied to the inorganic fine powder as the additive.
For example, oxides such as Si, Ti, Al, Mg, Ca, Sr, Ba, In, Ga, Ni, Mn, W, Fe, Co, Zn, Cr, Mo, Cu, Ag, V, and Zr, and complex oxidation Things. Of these, fine particles of silicon dioxide (silica), titanium dioxide (titania), and alumina are preferred. Further, those subjected to surface modification treatment with a hydrophobizing agent or the like are also suitable. Typical examples of the hydrophobizing agent include the following.
Dimethyldichlorosilane, trimethylchlorosilane, methyltrichlorosilane, allyldimethyldichlorosilane, allylphenyldichlorosilane, benzyldimethylchlorosilane, bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, p-chloroethyltrichlorosilane, Chloromethyldimethylchlorosilane, chloromethyltrichlorosilane, hexaphenyldisilazane, hexatolyldisilazane, etc.
The amount of the inorganic fine powder added is preferably in the range of 0.1 to 5% by weight with respect to the toner.
If it is less than 0.1% by weight, the effect of improving the toner fluidity is poor, and if it exceeds 5% by weight, problems such as toner scattering between fine wires, contamination in the machine, scratches and abrasion of the photoreceptor tend to occur. There is.

In addition, a charge control agent may be attached or fixed to at least the surface of the powder made of resin or pigment so that the powder surface has irregularities.
The average particle diameter is preferably 10 to 200 nm. If it is less than 10 nm, it becomes difficult to create irregularities, and if the particle size is larger than 200 nm, friction is caused between the particles, which is inappropriate.
Examples of the charge control agent include nigrosine and quaternary ammonium salts, triphenylmethane dyes, imidazole metal complexes and salts, salicylic acid metal complexes and salts, organic boron salts, calixarene compounds, and the like. These may be used alone or in combination of two or more.
Regarding the mixing or fixing injection conditions at the time of addition, the state of the toner particle surface can be controlled mainly by the mixing rotation speed. That is, the mixing rotation speed can control the force for attaching the fine powder to the powder surface. The mixing rotation speed is optimally 1000 rpm to 6000 rpm. When the mixing rotation speed is lower than 1000 rpm, the fine powder adheres to the surface of the powder (matrix) with very weak force, the surface shape becomes unstable, the toner is scattered, and the machine is contaminated. Etc. are likely to occur. On the other hand, if the mixing rotational speed is higher than 6000 rpm, the added fine powder bites into the surface of the powder (base material) before being added, and the unevenness of the surface is smoothed to reduce the unevenness and flow. On the other hand, the sex gets worse.
These mixing conditions differ depending on the type of the mixer. In particular, in the case of a mixer that can be injected, the energy that acts between the powder (base) and the fine powder before the fine powder is added is likely to be applied, so finely adjust the optimum conditions. There is a need.

In order to obtain a structure having an optimal surface state, a structure having periodicity is required.
In this way, the uniformity of the surface state of the particles can be maintained, the same contact state can be realized at any part of the particle surface, and stable fluidity can be realized.
FIG. 3 shows a model diagram.
For example, as shown in FIG. 3 (a), it cannot be realized when it is completely adhered to the surface of the single layer powder. That is, it becomes a coating state with fine particles, and a cycle with fine fine powder cannot be realized.
Further, for example, as shown in FIG. 3D, when less than one layer is formed on the surface of the powder (matrix), a portion having a period and a portion having no period are formed by fine fine powder, and an optimum structure is obtained.
In order to realize this structure, the fine powder is not more than one layer on the surface of the powder (matrix) and is not an integer layer, but 0.2 layers ≦ fine powder layers ≦ as shown in FIGS. This can be realized by using 0.8 layer.
However, if the layer is 0.1 layer or 0.9 layer, a fine cycle cannot be provided. That is, in order to realize a structure having a small period, it is necessary to satisfy the condition of 0.2 layer ≦ fine powder layer ≦ 0.8 layer.
In other words, a small period is given due to the fine powder accumulation structure on the surface of the powder (base material) before the fine powder is added.
Therefore, the amount of fine powder satisfying the condition of 0.2 layer ≦ fine powder layer ≦ 0.8 layer is charged, and the mixture is mixed under such a mixing condition that the deposited structure of the fine powder is smoothed and not averaged. Is preferred.
In addition, it is inappropriate to set the mixing conditions such that the fine powder is not uniformly covered on the surface of the powder (matrix) (= mixing conditions that are covered unevenly) because the mixing conditions are insufficient. That is, it is necessary to carry out the mixing under the optimum mixing condition of 1000 rpm to 6000 rpm.
Further, if the fine powder layer is one or more layers, the fine powder layer is partially peeled off, which causes a scattering phenomenon and the like, which is not preferable because the stability is lowered.

The toner having the above structure preferably has a weight average particle diameter of 4 to 8 μm, and more preferably 5 to 7 μm, in order to realize a high-quality image.
If the weight average particle diameter is less than 4 μm, problems such as contamination in the machine due to toner scattering during long-term use, image density reduction in a low-humidity environment, poor photoconductor cleaning, etc. are likely to occur, and there is concern about the effect on the human body Is done.
On the other hand, if the weight average particle diameter exceeds 8 μm, the resolution of fine spots of 100 μm or less becomes insufficient, and the image quality deteriorates due to many scattering to non-image portions.

  The developer to which the toner of the present invention is applied needs to have an average particle diameter of the carrier of 20 to 70 μm in order to realize a high quality image. When the average particle diameter of the carrier is in the range of 20 to 70 μm, the charge amount of the toner can be made more uniform when the toner concentration in the developing machine is in the range of 2 to 10% by weight. When it is smaller than 20 μm, carrier particles are likely to adhere to the photoreceptor, and the stirring efficiency with the toner is deteriorated, so that it is difficult to obtain a uniform charge amount of the toner. On the other hand, when the average particle diameter of the carrier exceeds 70 μm, fine image reproducibility deteriorates and high image quality cannot be obtained.

Next, the toner and developer will be described in detail.
Examples of applicable resins include polystyrene resin, epoxy resin, polyester resin, polyamide resin, styrene acrylic resin, styrene methacrylate resin, polyurethane resin, vinyl resin, polyolefin resin, styrene butadiene resin, phenol resin, polyethylene resin, silicon resin, butyral Resins, terpene resins, polyol resins and the like can be mentioned.

  Specifically, as the vinyl resin, for example, styrene such as polystyrene, poly-p-chlorostyrene, polyvinyltoluene, and the like, a homopolymer of a substituted product thereof, a styrene-p-chlorostyrene copolymer, and a styrene-propylene copolymer. Styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer Polymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene -Vinyl methyl ether copolymer, styrene- Nyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-maleic Examples thereof include styrene copolymers such as acid ester copolymers, polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, and polyvinyl acetate.

As the polyester resin, a dihydric alcohol as shown in the following group A and a dibasic acid salt as shown in the group B can be applied. An acid may be added as a third component.
Group A: ethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4 butanediol, neopentyl glycol, 1,4 butenediol, 1,4-bis (hydroxymethyl) cyclohexane Bisphenol A, hydrogenated bisphenol A, polyoxyethylenated bisphenol A, polyoxypropylene (2,2) -2,2′-bis (4-hydroxyphenyl) propane, polyoxypropylene (3,3) -2, 2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2,0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2,0) -2,2′-bis (4 -Hydroxyphenyl) propane and the like.
Group B: maleic acid, fumaric acid, mesaconic acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, sebacic acid, malonic acid, linolenic acid, or These acid anhydrides or esters of lower alcohols.
Group C: Trivalent or higher alcohols such as glycerin, trimethylolpropane and pentaerythritol, and trivalent or higher carboxylic acids such as trimellitic acid and pyromellitic acid.

  As the polyol resin, an alkylene oxide adduct of an epoxy resin and a dihydric phenol, or a compound having one active hydrogen in the molecule that reacts with the glycidyl ether and the epoxy group, and an active hydrogen that reacts with the epoxy resin in the molecule. Examples include those obtained by reacting two or more compounds.

Examples of the applicable resin include crystalline polyester.
This is an aliphatic polyester having crystallinity, having a sharp molecular weight distribution, and increasing the absolute amount of its low molecular weight as much as possible.
This resin undergoes a crystal transition at the glass transition temperature (Tg), and at the same time, the melt viscosity suddenly decreases from the solid state and exhibits a fixing function to paper. By using this crystalline polyester resin, low-temperature fixing can be achieved without excessively reducing the Tg and molecular weight of the resin. Therefore, a decrease in storage stability accompanying a decrease in Tg is avoided.
In addition, it is possible to avoid excessively high gloss and offset resistance deterioration due to low molecular weight.
As described above, the low temperature fixability of the toner can be improved by applying the crystalline polyester resin.

In the toner of the present invention, in order to exhibit low-temperature fixability and obtain good hot offset resistance, the content of the crystalline polyester is 1 to 50 with respect to the total amount of the resin and the release agent in the toner. The content is preferably 2% by weight and the release agent content is preferably 2-15% by weight.
It was confirmed that when the content of the crystalline polyester is less than 1% by weight, there is no effect on the low-temperature fixability, and when it exceeds 50% by weight, the hot offset property is deteriorated.
Further, if the release agent content is less than 2% by weight, a sufficient effect on the offset resistance cannot be obtained, and if it exceeds 20% by weight, it is confirmed that the toner fluidity is lowered. It was.

As the polyester resin and polyol resin, any of those applied to known color toners can be used.
Polyester resins and polyol resins are superior in that they have better low-temperature fixability and relatively better heat-resistant storage stability than conventionally applied styrene-acrylic resins.
However, polyester resins and polyol resins have the disadvantage that the dispersibility of the release agent is poor compared to styrene-acrylic resins. If the dispersibility is poor, the crushing stress tends to concentrate at the interface between the resin and the wax at the time of crushing, so it is easy to crush at the interface between the resin and the release agent. The release agent is exposed to the toner, and the fluidity of the toner is deteriorated.

The molecular structure of the crystalline polyester resin is not limited, but from the viewpoint of the crystallinity and softening point of the polyester resin, a diol compound having 2 to 6 carbon atoms, particularly 1,4-butanediol and 1,6-hexanediol. And an aliphatic polyester represented by the following formula (1) synthesized using an alcohol component containing these derivatives and maleic acid, fumaric acid, succinic acid, and an acid component containing these derivatives. It is preferable to have.
[—O—CO—CR ₁ ═CR ₂ —CO—O— (CH ₂ ) _n —] _m (1)
(Here, n and m are the number of repeating units. R ₁ and R ₂ are hydrocarbon groups.)
From the viewpoint of the crystallinity and softening point of the polyester resin, a trivalent or higher polyhydric alcohol such as glycerin is added to the alcohol component to synthesize a non-linear polyester, and the trimellitic anhydride is added to the acid component. The polycondensation may be carried out by adding a trivalent or higher polyvalent carboxylic acid such as
The glass transition temperature (Tg) of the crystalline polyester resin is desirably low so long as the heat resistant storage stability does not deteriorate, and is preferably in the range of 80 to 130 ° C.
When the glass transition temperature (Tg) is 80 ° C. or lower, the heat-resistant storage stability deteriorates, and blocking tends to occur at the temperature inside the developing device. It becomes impossible.
The glass transition temperature (Tg) of the crystalline polyester resin is the endothermic peak temperature at the time of 2nd temperature increase by DSC.

The following can be applied as the pigment.
Examples of black pigments include azine dyes such as carbon black, oil furnace black, channel black, lamp black, acetylene black, and aniline black, metal salt azo dyes, metal oxides, and composite metal oxides.
Examples of yellow pigments include cadmium yellow, mineral fast yellow, nickel titanium yellow, navel yellow, naphthol yellow S, hansa yellow G, hansa yellow 10G, benzidine yellow GR, quinoline yellow lake, permanent yellow NCG, and tartrazine lake. .
Examples of the orange pigment include molybdenum orange, permanent orange GTR, pyrazolone orange, Vulcan orange, indanthrene brilliant orange RK, benzidine orange G, and indanthrene brilliant orange GK.
Examples of red pigments include Bengala, Cadmium Red, Permanent Red 4R, Resol Red, Pyrazolone Red, Watching Red Calcium Salt, Lake Red D, Brilliant Carmine 6B, Eosin Lake, Rhodamine Lake B, Alizarin Lake, Brilliant Carmine 3B.
Examples of purple pigments include fast violet B and methyl violet lake.
Examples of blue pigments include cobalt blue, alkali blue, Victoria blue lake, phthalocyanine blue, metal-free phthalocyanine blue, phthalocyanine blue partially chlorinated, first sky blue, and indanthrene blue BC.
Examples of green pigments include chrome green, chromium oxide, pigment green B, and malachite green lake.
The said pigment may be applied only by 1 type, or may combine 2 or more types.
In particular, in color toners, it is essential to uniformly disperse a good pigment. Instead of putting the pigment directly into a large amount of resin, a master batch in which the pigment is once dispersed at a high concentration is prepared and diluted. The method of throwing in the form is used. In this case, a solvent is generally used to assist dispersibility, but it is preferable to disperse using water in consideration of the influence on the environment.
When water is used, temperature control is important so that residual moisture in the masterbatch does not become a problem.

The toner is preferably blended (internally added) with the charge control agent inside the toner particles, but may be mixed (externally added) with the toner particles.
The charge control agent makes it possible to control the optimum charge amount according to the development system, and in particular, it is possible to further stabilize the balance between the particle size distribution and the charge amount.
As a toner for controlling the toner to be positively charged, nigrosine, a quaternary ammonium salt, a triphenylmethane dye, an imidazole metal complex and salts can be used alone or in combination of two or more.
Also, salicylic acid metal complexes, salts, organic boron salts, calixarene compounds, and the like can be applied to control the toner to be negatively charged.

In addition, a release agent is preferably added to the toner of the present invention in order to prevent an offset during fixing.
Release agents include natural waxes such as candelilla wax, carnauba wax, rice wax, montan wax and derivatives thereof, paraffin wax and derivatives thereof, polyolefin wax and derivatives thereof, sazol wax, low molecular weight polyethylene, and low molecular weight polypropylene. And alkyl phosphate esters. The melting point of these release agents is preferably 65 to 90 ° C. When the temperature is lower than this range, blocking during storage of the toner is likely to occur, and when the temperature is higher than this range, an offset is likely to occur in a region where the fixing roller temperature is low.
A dispersant may be added to improve the dispersibility of the release agent or the like.
As the dispersant, styrene acrylic resin, polyethylene resin, polystyrene resin, epoxy resin, polyester resin, polyamide resin, styrene methacrylate resin, polyurethane resin, vinyl resin, polyolefin resin, styrene butadiene resin, phenol resin, butyral resin, terpene resin, There is a polyol resin or the like, and a mixture of two or more of these resins may be used. The amount of the dispersant added is suitably 10 parts or less with respect to 100 parts of the resin. Even if it exceeds 10 parts, the effect of acidity of WAX is not observed, and conversely, the fixing property and the image reproducibility are deteriorated.

Next, a method for producing the electrostatic charge developing toner of the present invention will be described.
Conventionally known pulverization methods and polymerization methods (suspension polymerization, emulsion polymerization dispersion polymerization, emulsion aggregation, emulsion association, etc.) can be applied, but are not limited thereto.
Specifically, as an example of applying the pulverization method, first, the above-described resin, pigment or dye as a colorant, charge control agent, release agent, other additives, etc. are sufficiently mixed by a mixer such as a Henschel mixer. After that, the components are well kneaded using a thermal kneader such as a batch type two roll, a Banbury mixer, a continuous twin screw extruder, a continuous single screw kneader, etc., and after rolling and cooling, cutting is performed. . The toner kneaded product after cutting is crushed, coarsely pulverized using a hammer mill, etc., and further pulverized by a fine pulverizer or mechanical pulverizer using a jet stream, and a classifier or Coanda effect using a swirling airflow Is classified to a predetermined particle size by a classifier using Thereafter, an additive composed of inorganic fine particles or the like is adhered or fixed to the particle surface by a mixer under the optimum mixing conditions.
After the above mixing step, in order to evaluate whether or not a predetermined interparticle force is obtained, as shown in FIG. 2, the toner particles 3 adhered to the tip or the periphery of the probe 4 are compressed. Evaluation is performed by the method of the present invention using the toner particle powder phase 2 thus prepared.
As a result of the toner evaluation, when the predetermined standard is satisfied, it passes through a sieve of 250 mesh or more in an air sieving process to remove coarse particles and agglomerated particles, and then the sample is subjected to a filling process to thereby obtain the present invention. The toner for electrostatic charge development is obtained.

The evaluation method of the present invention using AFM is excellent in that high-accuracy measurement can be performed, distribution can be evaluated, and measurement without individual differences is possible.
Therefore, evaluation and measurement in a production line are possible, and an evaluation point can be set between each process in the production process, and quality evaluation in the middle of the process can be performed.

For example, as shown in FIG. 4, after passing the toner and additive mixing process by the mixer 20, the sample extraction unit 21 is provided in the middle of conveying the powder sample to the next process, and the shutter is released at a predetermined timing. A sample is collected by opening and closing 22 and transported to a predetermined measuring section (not shown). The tip of the measurement unit is assumed to be a container 24 made of SUS or the like, and the evaluation method of the present invention is applied here.
Alternatively, the container 24 can be transported to the interparticle force evaluation apparatus 10 shown in FIG. 2 applied to the present invention, and the present invention can be evaluated here.
As a result of the evaluation, if the numerical value is outside the predetermined setting range, the sample is not sent to the filling process and is transported to the reprocessing process.
Such a mechanism can be applied to any of the inspection after the pulverization / classification process, which is the process before the mixing process, the inspection after the air sieving process after the mixing process, and the inspection before filling.

As a method for producing the toner of the present invention, methods other than the pulverization method described above can also be applied.
For example, as an example of the polymerization method, toner particles are obtained by suspending and polymerizing a monomer composition in which a colorant, a charge control agent, and the like are added to a monomer in an aqueous medium.
The granulation method is not particularly limited.
For example, at least a polyester-based prepolymer containing an isocyanate group is dissolved in an organic solvent, a pigment-based colorant is dispersed, and a release agent is dissolved or dispersed to obtain an oily dispersion, which is dispersed in an aqueous medium. In the presence of inorganic fine particles and / or polymer fine particles, the prepolymer is reacted with a polyamine and / or a monoamine having an active hydrogen-containing group in the dispersion to obtain a urea-modified polyester resin having a urea group. It is formed by removing the liquid medium contained therein from the dispersion containing this urea-modified polyester resin.
In the urea-modified polyester resin, the Tg is 40 to 65 ° C, preferably 45 to 60 ° C. The number average molecular weight Mn is 2500 to 50000, preferably 2500 to 30000. The weight average molecular weight Mw is 10,000 to 500,000, preferably 30,000 to 100,000.
This toner contains, as a binder resin, a urea-modified polyester resin having a urea bond that has been increased in molecular weight by the reaction between the prepolymer and the amine. The colorant is highly dispersed in the binder resin.

  The obtained toner powder after drying is air-classified, and an additive composed of inorganic fine particles and the like is adhered or fixed to the particle surface by a mixer under the optimum mixing conditions. Alternatively, the charge control agent may be applied to the surface of the toner powder after drying and fixedly injected. Further, thereafter, an additive composed of inorganic fine particles or the like may be adhered or fixed to the particle surface. By placing the charge control agent on the surface, the charge amount of the toner can be easily controlled.

Specific means for mixing and fixing and injecting are as follows: a method of applying an impact force to the powder mixture with blades rotating at high speed; For example, a method of causing the particles to collide with a suitable collision plate.
As equipment, Ong mill (manufactured by Hosokawa Micron Co., Ltd.), I-type mill (manufactured by Nippon Pneumatic Co., Ltd.) has been modified to reduce the pulverization air pressure, hybridization system (manufactured by Nara Machinery Co., Ltd.), kryptron A system (manufactured by Kawasaki Heavy Industries Ltd.), automatic mortar, etc. can be applied.

After this mixing step, the interparticle force of the toner particles is evaluated by applying the method of the present invention in order to evaluate whether or not a predetermined particle structure is obtained.
As a result of the evaluation, if the numerical value is within a predetermined set range, it is transported to the wind sieving process, passed through a sieve of 250 mesh or more, and after removing coarse particles and aggregated particles, the sample is filled. It is conveyed to the process, and the final toner is obtained.
In addition, the evaluation of the present invention using the AFM method is the inspection after the granulation, the inspection after the air classification, the inspection after the processing of the charge control agent, the inspection after the mixing step of the additive, the wind sieve after the mixing step. It can be applied to both post-process inspection and pre-filling inspection.

The toner of the present invention can be used as a one-component developer used in a contact or non-contact development system.
A known method can be applied to either the contact or non-contact development method. For example, there are a contact development method using an aluminum sleeve, a contact development method using a conductive rubber belt, and a non-contact development method using a development sleeve in which a conductive resin layer containing carbon black or the like is formed on the surface of an aluminum base tube. .
In addition, this toner is excellent in fluidity when developing using an AC bias voltage component during development, so that it vibrates faithfully according to the electric field, and can faithfully develop fine latent images, and dot reproducibility. Development is possible.
Further, in the one-component development method, the present toner is used in a development method in which a roller-shaped blade for uniformizing the toner layer is provided at the outlet of the toner supply unit.

Further, the present invention can be applied to a developing method using the image forming apparatus having the structure shown in FIG.
In the system using the image forming apparatus 30 having the structure shown in FIG. 5, the toner supplied from the toner supply hopper 31 is stirred by the stirring blade 32 and then sent to the developing roller 34 through the supply roller 33. A predetermined image is formed on the image carrier 35.
In this method, not only filming on the photosensitive member 36 but also filming on the doctor roller 37 and the supply roller 33 occurs. For this reason, the toner layer cannot be formed uniformly, the toner charge becomes non-uniform, and the toner charge amount becomes small. For this reason, poor development occurs.
However, when the toner obtained by applying the toner evaluation method of the present invention is used, the occurrence of filming on the doctor roller 37 and the supply roller 33 is suppressed, stable development can be formed, and the system has excellent durability characteristics. It becomes.

Since the toner obtained by applying the toner evaluation method of the present invention is excellent in fluidity, the toner can be stored in a cartridge container, and the apparatus is configured to convey toner from the cartridge container to the developing unit. Also suitable for.
Examples of the cartridge container include a toner cartridge that fills toner, and a process cartridge that includes at least a photosensitive member and a developing unit, and that fills a toner storage portion of the developing unit. An image is formed by mounting the cartridge in the image forming apparatus.
FIG. 6 shows a schematic configuration diagram of an example of a process cartridge.
The process cartridge 90 includes at least the photosensitive member 60 and the developing device 50, and includes a toner cartridge 56 that fills the toner container of the developing device with toner.
The process cartridge 90 is mounted on a predetermined image forming apparatus, and image formation is performed.

Further, when the magnetic toner is used, magnetic particles may be internally added to the toner particles.
Examples of the magnetic material include ferromagnetic materials such as ferrite, magnetite, iron, nickel, cobalt, and alloys thereof.
The average particle size of the magnetic material is preferably 0.1 to 1 μm.
The content of the magnetic material is preferably 10 to 70 parts by weight with respect to 100 parts by weight of the toner.

The toner of the present invention can also be applied as a two-component developer.
As the carrier used in the two-component developer, known ones can be used. For example, magnetic particles such as iron powder, ferrite powder, nickel powder, and magnetite powder, or the surface of these magnetic particles are made of a fluororesin or vinyl resin. Examples thereof include those treated with a resin, a silicon-based resin, or the like, or magnetic particle-dispersed resin particles in which magnetic particles are dispersed in the resin. The average particle size of these magnetic carriers is preferably 20 to 70 μm. Preferably 25-65 micrometers is good.
The carrier surface is preferably coated with a predetermined material. Examples of the coating material include amino resins such as urea-formaldehyde resin, melamine resin, benzoguanamine resin, urea resin, polyamide resin, and epoxy resin.
Polyvinyl and polyvinylidene resins such as acrylic resins, polymethyl methacrylate resins, polyacrylonitrile resins, polyvinyl acetate resins, polyvinyl alcohol resins, polyvinyl butyral resins, polystyrene resins and styrene acrylic copolymer resins, Halogenated olefin resins such as vinyl, polyester resins such as polyethylene terephthalate resin and polybutylene terephthalate resin, polycarbonate resins, polyethylene resins, polyvinyl fluoride resins, polyvinylidene fluoride resins, polytrifluoroethylene resins, polyhexafluoro Propylene resin, copolymer of vinylidene fluoride and acrylic monomer, copolymer of vinylidene fluoride and vinyl fluoride, tetrafluoroethylene and vinylidene fluoride and non- Fluoro such as terpolymers of monomers including, and silicone resins.

Moreover, you may contain electrically conductive powder etc. in coating resin as needed. As the conductive powder, metal powder, carbon black, titanium oxide, tin oxide, zinc oxide and the like can be applied. These conductive fine particles preferably have an average particle diameter of 1 μm or less. This is because it becomes difficult to control the electric resistance when the average particle diameter is larger than 1 μm.
Furthermore, it is preferable to add inorganic fine powder as a fluidity improver.

  Further, other additives such as Teflon (registered trademark) powder, zinc stearate powder, and polyvinylidene fluoride powder may be added to the toner of the present invention and the developer using the toner within a range that does not substantially adversely affect the toner. A small amount of a lubricant powder such as cerium oxide powder, silicon carbide powder, strontium titanate powder, or a conductivity imparting agent such as carbon black powder, zinc oxide powder or tin oxide powder is used as a developing improver. You can also.

  The toner evaluation method according to the present invention can also be applied to a toner prepared by a polymerization method, a spray drying method, or the like prepared without using a kneading step or a pulverizing step, and a capsule toner.

  Hereinafter, although the specific Example of this invention is given and demonstrated, this invention is not limited to the example shown below.

In the following, the toner is prepared by changing the mixing conditions, and the interparticle force of the toner particles is adhered to the tip or the periphery of the probe to produce a compressed toner particle powder phase. And evaluated.
The toner particle powder phase was prepared at a compression pressure of 320 kg / cm ² , and the AFM measurement was performed under the following conditions to determine the average value of the interparticle force and the variation σn−1.
-Probe scanning distance: 1000 nm
-Piezo scan speed: 2.0Hz
・ Number of measurements: 30 times

Also, the dot reproducibility was evaluated on a five-point scale (rank 1: bad → rank 5: good) as the roughness of the image.
Furthermore, a running durability test of 20,000 sheets was performed using a copying machine using OPC, and problems with toner transportability such as blocking at the developing unit were evaluated. The case where there was no defect was evaluated as ◯, and the case where there was a defect was evaluated as x.
As for the fluidity of the toner, the space ratio was measured in a compacted state using a conical rotor evaluation apparatus, and then the torque and load values were measured when the conical rotor entered 20 mm from the surface of the toner powder phase. The evaluation conditions for the conical rotor were as follows.
-Space ratio of toner phase: 0.53
・ Vertical angle of conical rotor: 60 °
・ Rotation speed of conical rotor: 1rpm
・ Invasion speed of conical rotor: 5 mm / min

Further, the circularity of the powder (matrix) before being treated with the additive was measured as an average circularity by a flow type particle image analyzer FPIA-1000 (manufactured by Toa Medical Electronics Co., Ltd.).
In addition, all the parts in the following mixing | blending are a weight part.

[Example 1]
Resin Polyester resin: 100 parts
(Polyester synthesized from terephthalic acid and succinic acid derivative of propylene oxide adduct of bisphenol A)
Colorant Copper phthalocyanine blue pigment (CI pigment blue 15: 3): 3.5 parts
(Lionol Blue FG-7351; manufactured by Toyo Ink Co.)
Charge control agent Zinc salicylate: 5 parts
(Bontron E84, Orient Chemistry)
Mold release agent Low molecular weight polyethylene: 5 parts

The raw materials were sufficiently mixed with a mixer, and then melt-kneaded using a twin screw extruder at a barrel temperature of 100 ° C. and a kneader rotation speed of 120 rpm.
The kneaded product was rolled and cooled, coarsely pulverized with a cutter mill, pulverized with a fine pulverizer using a jet stream, and then classified into a particle size distribution with an average particle size of 6 μm using a swirling air classifier.
Further, an additive was mixed with 100 parts of the base coloring particles under the following mixing conditions to prepare a toner.
Additives Silica fine powder: 1.0 part
(R972; manufactured by Nippon Aerosil Co., Ltd.)
Mixing rotation speed: 1600rpm
Mixing time: 150 sec
Blender: θ Composer

After the toner was prepared as described above, the interparticle force was measured by the evaluation method of the present invention, and the toner fluidity was measured by the conical rotor method. The measurement results are shown in Table 1 below.
The toner obtained by the above production method and the carrier were mixed at a ratio of 2.5 parts with respect to 97.5 parts of the carrier to prepare a two-component developer.
This two-component developer was set in a copying machine in which the latent image carrier is an OPC drum photoreceptor and the cleaning method is blade cleaning, and an image evaluation experiment and a running experiment were performed.
The image evaluation results and the running evaluation results are shown in Table 1 below.

[Example 2]
Kneading, pulverization, and classification were performed using the same raw materials and production method as in Example 1 above, and the particles were classified into a particle size distribution with an average particle size of 6 μm.
Further, an additive was mixed with 100 parts of the base coloring particles under the following mixing conditions to prepare a toner.
Additives Silica fine powder: 1.5 parts
(R972; manufactured by Nippon Aerosil Co., Ltd.)
Mixing rotation speed: 1600rpm
Mixing time: 150 sec
Blender: θ Composer

After the toner was prepared as described above, the interparticle force was measured by the evaluation method of the present invention, and the toner fluidity was measured by the conical rotor method. The measurement results are shown in Table 1 below.
The toner prepared by the above method and the carrier were mixed at a ratio of 2.5 parts of toner to 97.5 parts of carrier to prepare a two-component developer.
This two-component developer was set in a copying machine in which the latent image carrier is an OPC drum photoreceptor and the cleaning method is blade cleaning, and an image evaluation experiment and a running experiment were performed.
The image evaluation results and the running evaluation results are shown in Table 1 below.

Example 3
Kneading, pulverization, and classification were performed using the same raw materials and production methods as in Example 1 above, and the particles were classified into a particle size distribution having an average particle size of 6.1 μm.
Further, an additive was mixed with 100 parts of the base coloring particles under the following mixing conditions to prepare a toner.
Additives Silica fine powder: 2.0 parts
(R972; manufactured by Nippon Aerosil Co., Ltd.)
Mixing rotation speed: 1600rpm
Mixing time: 150 sec
Blender: θ Composer

After the toner was prepared as described above, the interparticle force was measured by the evaluation method of the present invention, and the toner fluidity was measured by the conical rotor method. The measurement results are shown in Table 1 below.
The toner prepared by the above method and the carrier were mixed at a ratio of 2.5 parts of toner to 97.5 parts of carrier to prepare a two-component developer.
This two-component developer was set in a copying machine in which the latent image carrier is an OPC drum photoreceptor and the cleaning method is blade cleaning, and an image evaluation experiment and a running experiment were performed.
The image evaluation results and the running evaluation results are shown in Table 1 below.

Example 4
Kneading, pulverization, and classification were performed using the same raw materials and production methods as in Example 1 above, and the particles were classified into a particle size distribution with an average particle size of 6.0 μm.
Further, an additive was mixed with 100 parts of the base coloring particles under the following mixing conditions to prepare a toner.
Additives Silica fine powder: 2.5 parts
(R972; manufactured by Nippon Aerosil Co., Ltd.)
Mixing rotation speed: 1600rpm
Mixing time: 150 sec
Blender: θ Composer

After the toner was prepared as described above, the interparticle force was measured by the evaluation method of the present invention, and the toner fluidity was measured by the conical rotor method. The measurement results are shown in Table 1 below.
The toner prepared by the above method and the carrier were mixed at a ratio of 2.5 parts of toner to 97.5 parts of carrier to prepare a two-component developer.
This two-component developer was set in a copying machine in which the latent image carrier is an OPC drum photoreceptor and the cleaning method is blade cleaning, and an image evaluation experiment and a running experiment were performed.
The image evaluation results and the running evaluation results are shown in Table 1 below.

Example 5
Kneading, pulverization, and classification were performed using the same raw materials and production methods as in Example 1 above, and the particles were classified into a particle size distribution with an average particle size of 6.0 μm.
Further, an additive was mixed with 100 parts of the base coloring particles under the following mixing conditions to prepare a toner.
Additives Silica fine powder: 3.0 parts
(R972; manufactured by Nippon Aerosil Co., Ltd.)
Mixing rotation speed: 1600rpm
Mixing time: 150 sec
Blender: θ Composer

After the toner was prepared as described above, the interparticle force was measured by the evaluation method of the present invention, and the toner fluidity was measured by the conical rotor method. The measurement results are shown in Table 1 below.
The toner prepared by the above method and the carrier were mixed at a ratio of 2.5 parts of toner to 97.5 parts of carrier to prepare a two-component developer.
This two-component developer was set in a copying machine in which the latent image carrier is an OPC drum photoreceptor and the cleaning method is blade cleaning, and an image evaluation experiment and a running experiment were performed.
The image evaluation results and the running evaluation results are shown in Table 1 below.

Example 6
(Toner binder synthesis)
In a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen introduction tube, 724 parts of a 2-mole adduct of bisphenol A ethylene oxide, 276 parts of isophthalic acid, and 2 parts of dibutyltin oxide were placed at 230 ° C. at normal pressure. The reaction was carried out for 8 hours under the above conditions, and the reaction was further carried out at a reduced pressure of 10 to 15 mmHg for 5 hours, followed by cooling to 160 ° C., and 32 parts of phthalic anhydride was added thereto and reacted for 2 hours.
Next, the mixture was cooled to 80 ° C. and reacted with 188 parts of isophorone diisocyanate in ethyl acetate for 2 hours to obtain an isocyanate-containing prepolymer (1).
Next, 267 parts of the prepolymer (1) and 14 parts of isophoronediamine were reacted at 50 ° C. for 2 hours to obtain a urea-modified polyester (1) having a weight average molecular weight of 64,000.
In the same manner as above, 724 parts of bisphenol A ethylene oxide 2 mol adduct, 276 parts of terephthalic acid, polycondensation under conditions of 230 ° C. under normal pressure for 8 hours, and then reacted for 5 hours under reduced pressure of 10-15 mmHg. Unmodified polyester A having a peak molecular weight of 5000 was obtained.
200 parts of the urea-modified polyester (1), 800 parts of the unmodified polyester A, and 2000 parts of an ethyl acetate / MEK (1/1) mixed solvent are dissolved and mixed, and acetic acid in the toner binder (1) is mixed. An ethyl / MEK solution was obtained. Part of the mixture was dried under reduced pressure to isolate toner binder (1). As a result of analysis, the glass transition temperature Tg was 62 ° C.

(Production of toner)
Toner binder (1) in ethyl acetate / MEK solution: 240 parts Pentaerythritol tetrabehenate (melt viscosity 25 cps): 20 parts Copper phthalocyanine blue pigment (CI pigment blue 15: 3): 4 parts (Lionol Blue FG-7351; Toyo (Ink)
The above raw materials were stirred in a beaker at 12000 rpm with a TK homomixer at 60 ° C., and uniformly dissolved and dispersed to prepare a toner material solution.

Ion-exchanged water: 706 parts Hydroxyapatite 10% suspension: 294 parts (Nippon Chemical Industry Co., Ltd. Superite 10)
Sodium dodecylbenzenesulfonate: 0.2 part The above materials were uniformly dissolved in a beaker. Thereafter, the temperature was raised to 60 ° C., and the toner material solution was added and stirred for 10 minutes while stirring at 12000 rpm with a TK homomixer.
Next, this mixed solution is transferred to a flask equipped with a stir bar and a thermometer, heated to 30 ° C., the solvent is removed under reduced pressure, filtered, washed, dried, air classified, and toner particles. Got.
The volume average particle diameter was 6.3 μm.
To 100 parts of the toner particles, an additive was mixed under the following mixing conditions to obtain a toner.
Additives Silica fine powder: 1.0 part
(R972; manufactured by Nippon Aerosil Co., Ltd.)
Titanium oxide fine powder: 0.3 parts
(MT-150A; manufactured by Teika)
Mixing rotation speed: 1800 rpm
Mixing time: 150 sec
Mixer: Q mixer

After the toner was prepared as described above, the interparticle force was measured by the evaluation method of the present invention, and the toner fluidity was measured by the conical rotor method. The measurement results are shown in Table 1 below.
The toner obtained by the production method described above and the carrier were mixed in a ratio of 2.5 parts of toner to 97.5 parts of carrier to produce a two-component developer.
This two-component developer was set in a copying machine in which the latent image carrier is an OPC drum photoreceptor and the cleaning method is blade cleaning, and an image evaluation experiment and a running experiment were performed.
The image evaluation results and the running evaluation results are shown in Table 1 below.

Example 7
Powders were produced and classified using the same raw materials and production methods as in Example 6 above, and classified into a particle size distribution with an average particle size of 6.3 μm.
Further, an additive was mixed with 100 parts of the base coloring particles under the following mixing conditions to prepare a toner.
Additives Silica fine powder: 1.5 parts (R972; manufactured by Nippon Aerosil Co., Ltd.)
Titanium oxide fine powder: 0.3 part (MT-150A; manufactured by Teica)
Mixing rotation speed: 1800 rpm
Mixing time: 150 sec
Mixer: Q mixer

After the toner was prepared as described above, the interparticle force was measured by the evaluation method of the present invention, and the toner fluidity was measured by the conical rotor method. The measurement results are shown in Table 1 below.
The toner obtained by the above-described production method and the carrier were mixed at a ratio of 2.5 parts of toner to 97.5 parts of carrier to produce a two-component developer.
This two-component developer was set in a copying machine in which the latent image carrier is an OPC drum photoreceptor and the cleaning method is blade cleaning, and an image evaluation experiment and a running experiment were performed.
The image evaluation results and the running evaluation results are shown in Table 1 below.

Example 8
Powders were produced and classified using the same raw materials and production methods as in Example 6 above, and classified into a particle size distribution with an average particle size of 6.3 μm.
Further, an additive was mixed with 100 parts of the base coloring particles under the following mixing conditions to prepare a toner.
Additives Silica fine powder: 2.0 parts (R972; manufactured by Nippon Aerosil Co., Ltd.)
Titanium oxide fine powder: 0.3 part (MT-150A; manufactured by Teica)
Mixing rotation speed: 1800 rpm
Mixing time: 150 sec
Mixer: Q mixer

After the toner was prepared as described above, the interparticle force was measured by the evaluation method of the present invention, and the toner fluidity was measured by the conical rotor method. The measurement results are shown in Table 1 below.
The toner obtained by the above-described production method and the carrier were mixed at a ratio of 2.5 parts of toner to 97.5 parts of carrier to produce a two-component developer.
This two-component developer was set in a copying machine in which the latent image carrier is an OPC drum photoreceptor and the cleaning method is blade cleaning, and an image evaluation experiment and a running experiment were performed.
The image evaluation results and the running evaluation results are shown in Table 1 below.

Example 9
Resin Polyester resin: 100 parts
(Polyester synthesized from terephthalic acid and succinic acid derivative of propylene oxide adduct of bisphenol A)
Colorant Magenta pigment (CI pigmentlet 122): 3.5 parts
(HostapermPink E; manufactured by Clariant)
Charge control agent Zinc salicylate: 5 parts
(Bontron E84; manufactured by Orient Chemical)
The raw materials were sufficiently mixed with a mixer, and then melt kneaded with a twin screw extruder at a barrel temperature of 100 ° C. and a kneader rotation speed of 110 rpm.
This kneaded product was rolled and cooled, coarsely pulverized by a cutter mill, pulverized by a fine pulverizer using a jet stream, and then classified into a particle size distribution having an average particle size of 6.7 μm using a swirling air classifier.
Further, an additive was mixed with 100 parts of the base coloring particles under the following mixing conditions to prepare a toner.
Additives Silica fine powder: 1.0 part (R972; manufactured by Nippon Aerosil Co., Ltd.)
Titanium oxide fine powder: 0.3 part (MT-150A; manufactured by Teica)
Mixing rotation speed: 1800 rpm
Mixing time: 150 sec
Mixer: Q mixer

After the toner was prepared as described above, the interparticle force was measured by the evaluation method of the present invention, and the toner fluidity was measured by the conical rotor method. The measurement results are shown in Table 1 below.
The toner obtained by the above-described production method was set in a copier in which the latent image carrier is an OPC drum photoreceptor and the cleaning method is blade cleaning, and an image evaluation experiment and a running experiment were performed. The image evaluation results and the running evaluation results are shown in Table 1 below.

Example 10
Powders were produced and classified using the same raw materials and production methods as in Example 9, and classified into a particle size distribution with an average particle size of 6.7 μm.
Further, an additive was mixed with 100 parts of the base colored particles under the following mixing conditions to prepare a toner.
Additives Silica fine powder: 1.5 parts (R972; manufactured by Nippon Aerosil Co., Ltd.)
Titanium oxide fine powder: 0.3 part (MT-150A; manufactured by Teica)
Mixing rotation speed: 1800 rpm
Mixing time: 150 sec
Mixer: Q mixer

After the toner was prepared as described above, the interparticle force was measured by the evaluation method of the present invention, and the toner fluidity was measured by the conical rotor method. The measurement results are shown in Table 1 below.
The toner obtained by the above-described production method was set in a copier in which the latent image carrier is an OPC drum photoreceptor and the cleaning method is blade cleaning, and an image evaluation experiment and a running experiment were performed. The image evaluation results and the running evaluation results are shown in Table 1 below.

Example 11
Powders were produced and classified using the same raw materials and production methods as in Example 9, and classified into a particle size distribution with an average particle size of 6.7 μm.
Further, an additive was mixed with 100 parts of the base coloring particles under the following mixing conditions to prepare a toner.
Additives Silica fine powder: 2.0 parts (R972; manufactured by Nippon Aerosil Co., Ltd.)
Titanium oxide fine powder: 0.3 part (MT-150A; manufactured by Teica)
Mixing rotation speed: 1800 rpm
Mixing time: 150 sec
Mixer: Q mixer

After the toner was prepared as described above, the interparticle force was measured by the evaluation method of the present invention, and the toner fluidity was measured by the conical rotor method. The measurement results are shown in Table 1 below.
The toner obtained by the above-described production method was set in a copier in which the latent image carrier is an OPC drum photoreceptor and the cleaning method is blade cleaning, and an image evaluation experiment and a running experiment were performed. The image evaluation results and the running evaluation results are shown in Table 1 below.

[Comparative Example 1]
Kneading, pulverization, and classification were performed using the same raw materials and production methods as in Example 1 above, and the particles were classified into a particle size distribution with an average particle size of 6.0 μm.
Further, an additive was mixed with 100 parts of the base coloring particles under the following mixing conditions to prepare a toner.
Additives Silica fine powder: 0.1 parts
(R972; manufactured by Nippon Aerosil Co., Ltd.)
Mixing rotation speed: 800rpm
Mixing time: 120 sec
Mixer: Super mixer

After the toner was prepared as described above, the interparticle force was measured by the evaluation method of the present invention, and the toner fluidity was measured by the conical rotor method. The measurement results are shown in Table 1 below.
The toner obtained by the above-described production method and the carrier were mixed at a ratio of 2.5 parts of toner to 97.5 parts of carrier to produce a two-component developer.
This two-component developer was set in a copying machine in which the latent image carrier is an OPC drum photoreceptor and the cleaning method is blade cleaning, and an image evaluation experiment and a running experiment were performed. The image evaluation results and the running evaluation results are shown in Table 1 below.

[Comparative Example 2]
Kneading, pulverization, and classification were carried out using the same raw materials and production methods as in Example 9 above, and the particles were classified into a particle size distribution with an average particle size of 6.7 μm.
Further, an additive was mixed with 100 parts of the base coloring particles under the following mixing conditions to prepare a toner.
Additives Silica fine powder: 0.1 parts
(R972; manufactured by Nippon Aerosil Co., Ltd.)
Titanium oxide fine powder: 0.3 parts
(MT-150A; manufactured by Teika)
Mixing rotation speed: 800rpm
Mixing time: 150 sec
Mixer: Super mixer

After the toner was prepared as described above, the interparticle force was measured by the evaluation method of the present invention, and the toner fluidity was measured by the conical rotor method. The measurement results are shown in Table 1 below.
The toner obtained by the above-described production method was set in a copying machine in which the latent image carrier is an OPC drum photoreceptor and the cleaning method is blade cleaning, and an image evaluation experiment and a running experiment were performed. The image evaluation results and the running evaluation results are shown in Table 1 below.

  FIG. 7 shows the evaluation of toner inter-particle force and dot reproducibility (5-level evaluation of 1 to 5. 1 is bad and 5 is good).

  According to these, in the examples in which the measured average value of the force between the toner particles is 1 to 60 nN, all of the toners have good fluidity, and good evaluation of dot reproducibility is obtained, which is clear and clear. Image formation was possible. Further, even when a large number of sheets were run, the toner transportability was sufficiently good in practice.

On the other hand, in Comparative Examples 1 and 2 in which the measured average value of the force between the toner particles exceeds 60 nN and the value of the variation σ1-1 exceeds 10 (nN), the toner is inferior in fluidity. Good evaluation of reproducibility could not be obtained, and the image clarity and sharpness were inferior to the toners of the examples.
In addition, when a large number of sheets were run, good toner transportability could not be obtained.

The change in force is shown when scanning is performed such that the toner particles are once pressed against the surface of the compacted toner powder phase and then separated. The schematic block diagram of an interparticle force measuring apparatus is shown. It is a figure for demonstrating the arrangement | sequence of a toner particle suitable for the evaluation method of this invention. 1 is a schematic configuration diagram of an example of a toner manufacturing apparatus to which the method of the present invention is applied. 1 is a schematic configuration diagram of an example of an image forming apparatus suitable for a toner obtained by the present invention. The schematic block diagram of an example of a process cartridge is shown. The relationship between interparticle force and dot reproducibility is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate stage 2 Consolidated toner powder phase 3 Toner particle 4 Probe 5 Piezo scanner 6 Laser emission source 7 Mirror 8 Detector 10 Interparticle force evaluation device 20 Mixer 21 Extraction unit 22 Shutter 24 Container 30 Image forming device 31 Toner supply hopper 32 Stirrer blade 33 Supply roller 34 Developing roller 35 Image forming device 36 Photoconductor 37 Doctor roller 50 Developing device 56 Toner cartridge 60 Photoconductor 90 Process cartridge

Claims (26)

(1) A step of attaching one toner particle containing at least a resin and a pigment to the tip region of the AFM probe;
(2) The tip region of the probe is brought close to the surface of the toner powder phase composed of the toner particles, and the single toner particle of the probe is changed to a single toner particle on the surface of the toner powder phase. Measuring a first force (A) acting on the probe when contacted;
(3) a step of measuring a second force (B) acting on the probe when the probe is separated from the surface of the toner powder phase; and (4) the first force (A). Calculating a difference between the second force (B) with respect to the particle and determining an interparticle force between a single toner particle of the probe and a single toner particle of the toner powder phase;
And an average value of the interparticle force when the step is performed a plurality of times is used as an index for toner evaluation.   The variation in the measured value of the interparticle force when the steps (1) to (4) are performed a plurality of times at different measurement locations is used as an index for toner evaluation. Toner evaluation method. ^2. The toner evaluation method for electrostatic charge development according to claim 1, wherein the toner particle powder phase is compressed at a pressure of 100 to 900 kg / cm < ² >.   The probe with one toner particle attached is brought close to the toner particle powder phase from a distance of 500 to 2000 nm, and once pressed against one particle on the surface of the toner particle powder phase, the probe is pulled away. The toner evaluation method for electrostatic charge development according to claim 1, wherein:   A piezo scan speed when bringing one toner particle adhered to the tip region of the probe closer to one particle of a compressed toner particle powder phase is 0.16 Hz to 4.0 Hz. The toner evaluation method for electrostatic charge development according to claim 1. An electrostatic charge developing toner obtained by using the toner evaluation method according to claim 1,
In the evaluation of the toner, the toner particle powder phase is compressed at a pressure of 100 to 900 kg / cm ² .
The probe with one toner particle attached is brought close to the toner particle powder phase from a distance of 500 to 2000 nm, and once pressed against one particle on the surface of the toner particle powder phase, the probe is pulled away. To do,
And the piezo scan speed when bringing one toner particle adhered to the tip region of the probe closer to one particle of the compressed toner particle powder phase is 0.16 Hz to 4.0 Hz,
The toner for electrostatic charge development, wherein the average value of the force between the toner particles is 1 to 60 nN when the force between the toner particles is repeatedly measured 10 to 50 times.   The variation σn-1 of the measured value of the toner particle force when the toner particle force is measured 10 to 50 times at different measurement locations is 0.1 to 10 nN. The toner for developing electrostatic charge according to 1.   8. The electrostatic charge developing toner according to claim 6, wherein the toner particles containing at least a resin and a pigment have an average circularity of 0.9 to 0.99.   The electrostatic charge developing toner according to claim 6, wherein the toner particles containing at least a resin and a pigment are produced by a polymerization method.   10. The additive according to claim 6, wherein an additive made of an inorganic fine powder having an average particle size of 10 to 200 nm is attached or fixed to the surface of the toner particles containing at least a resin and a pigment. Toner for electrostatic charge development.   11. The electrostatic charge developing toner according to claim 10, wherein the additive comprising the inorganic fine powder comprises an inorganic fine powder having an average particle diameter of 10 to 100 nm and an inorganic fine powder having an average particle diameter of 100 to 200 nm. .   12. The additive comprising a charge control agent having an average particle diameter of 10 to 200 nm is attached or fixed to the surface of the toner particles containing at least a resin and a pigment. 12. Toner for electrostatic charge development.   The electrostatic charge developing toner according to claim 6, wherein the toner particles containing at least a resin and a pigment contain a charge control agent.   14. The electrostatic charge developing toner according to claim 6, wherein a release agent is contained in the toner particles containing at least a resin and a pigment.   The toner for electrostatic charge development according to any one of claims 6 to 14, wherein the toner particles containing at least a resin and a pigment contain a dispersant for the release agent. The toner for electrostatic charge development according to any one of claims 6 to 15, wherein at least one of the resins is a crystalline polyester represented by the following general formula (1).
[—O—CO—CR ₁ ═CR ₂ —CO—O— (CH ₂ ) _n —] _m (1)
(N and m are the number of repeating units. R ₁ and R ₂ are hydrocarbon groups.)   17. The electrostatic charge developing toner according to claim 6, wherein the toner and the pigment are prepared using a composition in which the resin and the pigment are previously kneaded.   The electrostatic charge developing toner according to any one of claims 6 to 17, wherein an average particle diameter is 4 to 8 µm.   A developing method, wherein the electrostatic charge developing toner according to any one of claims 6 to 18 is used as a one-component developer, and contact development or non-contact development is performed.   20. The developing method according to claim 19, wherein an image forming apparatus including at least a photosensitive member, a doctor roller and / or a supply roller is used.   A development characterized by carrying out contact development or non-contact development using a toner for electrostatic charge development according to any one of claims 6 to 18 and a carrier having a particle diameter of 20 to 70 μm as a two-component developer. Method.   The developing method according to claim 19, wherein an AC bias voltage component is applied.   A toner cartridge in which the electrostatic charge developing toner according to any one of claims 6 to 18 is stored.   19. A process cartridge in which the electrostatic charge developing toner according to claim 6 is contained.   A method for producing an electrostatic charge developing toner, comprising performing toner evaluation by the electrostatic charge developing toner evaluation method according to claim 1 during or after the production process. Having a compacted toner powder phase on the substrate stage;
Having a probe with a single toner particle facing the surface of the toner powder phase;
The toner powder phase and the toner particles of the probe can be operated to approach or separate using a piezo scanner,
A laser emission source for irradiating the back side of the probe with laser light;
A detection unit for detecting a change in reflected light of the laser beam;
An electrostatic charge characterized in that a change in force generated in the probe is detected by the detector as a change in reflected light by irradiating the back side of the probe with laser light L emitted from a laser emission source. Developing toner evaluation device.